JP5124830B2 - Stencil printing machine - Google Patents

Description

  The present invention relates to a stencil printing apparatus capable of performing double-sided printing on the front and back surfaces of a sheet, and more specifically, a master as a stencil sheet in which a first image and a second image are made side by side within the length of one plate. The present invention relates to a stencil printing apparatus that performs printing by winding paper around the outer peripheral surface of a printing drum and automatically re-feeding under a single printing drum configuration.

  A heat-sensitive digital stencil printing apparatus is known, in which a perforated master is wound on a rotatable plate cylinder having a structure in which a mesh screen made of resin or metal mesh is wound around a porous support cylinder. Then, ink is supplied from the ink supply member provided inside the plate cylinder, the ink is oozed out from the plate cylinder opening part and the master punching part, and the paper is continuously pressed to the plate cylinder side by a press roller or the like. And printing.

The stencil master used here has a laminate structure in which a thermoplastic resin film and a Japanese paper fiber or synthetic fiber of a porous support, or a mixture of Japanese paper and synthetic fiber are bonded together. The master wound around the plate cylinder is brought into contact with the heating element of the thermal head to form a perforated plate according to the original image, and the master perforated portion oozes ink passing through the plate cylinder opening. Printing on paper.
In JP-A-6-48014 (Patent Document 1), ink is extruded from a stencil printing base paper, transferred onto an ink receptor, and further transferred onto a printing medium to be printed. A stencil printing apparatus capable of transferring an appropriate amount of ink is disclosed.

  The opening portion of the porous cylindrical plate cylinder used in such a conventional stencil printing apparatus is set in accordance with the maximum paper to be printed. For example, when A3 paper is the maximum paper, the opening length is about 420 mm. In the case of small size paper, a printing cylinder is used, and there are a lot of blank parts that are not used for printing, and there is a disadvantage that the master is wasted together with ink that is attached to the master and discarded. . Japanese Patent Application Laid-Open No. 64-24783 (Japanese Patent No. 2625437) (Patent Document 2) discloses a pre-made heat-sensitive stencil sheet which is detected in accordance with the size of a sheet set in a paper feeding unit and drawn out according to the size. A stencil printing apparatus is disclosed in which the cutting length of the paper is changed and adjusted, thereby eliminating wasteful consumption of the base paper when forming a printed matter having a small size.

In time and, in order to reduce the consumption of the printing paper, duplex printing for printing on both sides of the printing paper has come to be performed. In such double-sided printing, in general, the printing sheets stacked on the sheet feeding unit are separated and fed one by one, and after printing on one side, the printed sheets discharged and stacked on the discharge tray are again printed. A method has been proposed in which the paper is turned upside down and fed, and the other side is printed. In this double-sided printing method, printing in the same process is performed twice, which increases the printing time and necessitates the work of neatly aligning printing paper that has already been printed on one side and setting it again in the paper feed unit. It was very troublesome to be.

Therefore, it is desired to propose a device that can print on both sides in one pass by printing with two plate cylinders facing each other. However, the size of the device is increased, and when printing on one side, the printing from one plate cylinder is required. In order to prevent ink transfer, there is a restriction such as winding a plate-free master. Under such conditions, the master is unnecessarily consumed and the operation is troublesome.
Therefore, a method has been attempted in which the plate cylinder surface is divided into two, and the printing is performed on both sides by reversing the paper with respect to the front and rear plate surfaces while the pressing means is continuously pressed against the plate cylinder.

  For example, in Japanese Patent Application Laid-Open No. 2003-200355 (Patent Document 3) and Japanese Patent Application Laid-Open No. 2006-48014 (Patent Document 4), the first image and the second image are printed within the length of one plate. A master that has been made in line in the paper transport direction is wound around the outer peripheral surface of the printing drum, and the printing paper that has been printed on the front surface is refeeded by the discharge direction switching means while controlling the pressing timing of the press roller against the printing drum. A double-sided printing apparatus has been proposed in which the paper is fed back by re-feeding along the peripheral surface of a press roller by a re-feeding means and discharged after finishing the back-side printing.

  Here, when a large number of double-sided prints are continuously printed, the double-sided printing mode is performed at a normal double-sided printing speed. That is, when normal multi-sheet continuous printing is performed in the double-sided printing mode at this double-sided printing speed, the first plate-making image is printed on the surface of the first sheet, and the surface-printed sheet is fed again by the switching member. The first plate-making image is printed on the surface of the second sheet after being guided to the sheet re-feed conveyance unit, and the first sheet having the surface printed is printed from the sheet re-feed conveyance unit of the sheet re-feed unit. The paper is re-supplied to the printing section, the second plate-making image is printed on the reverse side, the first printed sheet is printed on the paper discharge section by the switching means, and the second printed sheet is printed on the switching section. The double-sided printing mode of guiding to the sheet refeeding conveyance unit of the sheet feeding unit is repeated.

  When such a double-sided printing mode is repeatedly performed, the front end of the front surface printed paper conveyed by the refeeding conveyance unit in the refeeding unit is temporarily stopped before being transferred to the pressing unit. Thus, the surface-printed paper that is reversed and passed is held in a state in which the leading edge of the paper is temporarily stopped by the refeed stop means in order to align the resist and correct the skew. After that, the re-feed resist roller as the re-feed resist means provided without interfering with the stopper member as the re-feed stop means operates at a predetermined timing and the surface-printed paper is put on the rotating press roller. By abutting, it is sent to the printing unit while being reversed by the rotary conveying operation of the press roller, and duplex printing is performed.

JP-A-6-48014 JP-A 64-24783 JP 2003-200355 A JP 2006-48014 A

In time and, in the conventional double-sided printing apparatus of Patent Documents 3 and 4, repeat the two-sided printing mode in the normal duplex printing speed, in the final paper, when the surface already become the back surface of the surface printed last sheet In order to print the second plate-making image, the re-feed means hits the stopper-membered final paper that has reached the re-feed conveyance means, and the re-feed resist roller is pressed against the rotating press roller. Then, the front surface printed paper is brought into contact. As a result, the second side is continuously printed on the back side of the final sheet by being sent to the printing unit while being reversed by the rotary conveying operation of the press roller.
However, by continuously releasing the paper at high speed and performing suction conveyance in this way, at this time, the vibration due to switching of the pressing range of the press roller with a large load, speed fluctuation, etc. When the double-sided printing speed is maintained, there is a tendency that the variation in image position becomes large.

  Even when the duplex printing mode at the normal duplex printing speed is repeated, the present invention reduces the plate cylinder rotation speed when printing the second surface on the back surface of the final sheet, It is an object of the present invention to provide a stencil printing apparatus that can hold an image position deviation, in particular, a resist.

In order to achieve the above object, according to the first aspect of the present invention, the first image for front surface printing and the second image for back surface printing are approximately two front and rear surfaces within the length of one plate by the plate making means. The master made separately is wound around the outer peripheral surface of a porous cylindrical plate cylinder supported so as to be rotatable about its own central axis, and is relatively separated from the plate cylinder on which the master is wound. One-sided printing is performed by pressing a sheet against a first surface divided into two front and rear parts by a free pressing unit, and the sheet is reversed by a refeed unit disposed below the plate cylinder. In the stencil printing apparatus that presses the second side of the stencil and performs other side printing, the refeeding unit temporarily stops and holds the single-sided printed paper before refeeding the pressing unit. a paper conveying means, wherein the leading edge of the paper toward and away from the pressing means and nipped conveying the re-feeding Comprising a holding and conveying means for guiding the stage, single-sided printing above in parallel to the operation guides to the first surface to press one of the paper clamp the the paper on which the single-sided printing refeeding means Control means for controlling to perform double-sided printing at a predetermined printing speed by releasing the previous paper held by the holding and conveying means and pressing the reversed paper against the second surface to perform other side printing,
The control means releases and prints the final sheet after single-sided printing held by the holding and conveying means after the plate cylinder speed is reduced from the double-sided printing speed to a predetermined final speed. Stencil printing device.

  According to a second aspect of the present invention, in the stencil printing apparatus according to the first aspect, the control means controls the set final speed as a rotation speed at the time of the judgment process.

According to the first aspect of the present invention, in the printing of the second surface of the final sheet after the single-sided printing once nipped by the nipping and conveying means, the plate cylinder speed is switched from the normal duplex printing speed to the set final speed. Since the final sheet is released and printed after the single-sided printing by the nipping and conveying means after the same as the set final speed, the influence of vibration of the printing pressure of the press roller can be reduced, and the image position in the second side printing can be reduced. A printed matter from which variations such as the above are eliminated can be obtained. Further, after the printing is completed, the plate cylinder is decelerated and stopped at the home position, and it is usually completed. Therefore, even if the plate cylinder rotation decelerating area is put in the middle of printing the final sheet, it is particularly in every cycle. Printing time does not become long.
According to the second aspect of the present invention, in the conveyance printing on the second side, the speed of the plate cylinder is reliably switched from the normal duplex printing speed to the rotational speed at the judgment process which is the set final speed, and the judgment process. Since the final sheet after single-sided printing by the nipping and conveying means is released and printed after reaching the rotation speed at that time, a printed matter in which variations such as image positions are reliably eliminated in printing on the second side can be obtained. .

  FIG. 1 shows a stencil printing apparatus adopting an embodiment of the present invention. The stencil printing apparatus includes a printing unit 16, a plate making unit 15, a paper feeding unit 30, a plate discharging unit 17, a paper discharging unit 19, an image reading unit 18, a refeeding unit 45, a switching guide 46, and a control unit 110. Yes. Here, the refeeding means 45 includes a refeeding conveyance means 48 disposed below the plate cylinder 1, a press roller 21 that is a pressing means that can freely come into contact with and separate from the plate cylinder 1, and a pressing means 21 that approaches and separates And a nipping / conveying means 190 for guiding the leading end of the single-side printed paper 36a to the refeed / conveying means 48.

  The printing unit 16 disposed almost at the center of the apparatus main body 100 includes a plate cylinder 1 forming a printing drum and a press roller 21 as a pressing unit. The plate cylinder 1 is connected to a main motor 320 as a plate cylinder driving unit via a drive transmission unit such as a gear or a belt (not shown). It is rotationally driven (clockwise). The output shaft of the main motor 320 is provided with an optical rotary encoder (not shown) and a plate cylinder sensor (not shown) that generates a pulse by cooperating with the rotary encoder. As a result, the rotational speed (printing speed) of the plate cylinder 1 is controlled and the rotational position is determined.

  The plate cylinder 1 has a clamper 7 that can be freely opened and closed on its outer peripheral surface, and a divided pre-made master 8 (see FIG. 3) made by the plate making unit 15 is wound around the outer peripheral surface of the plate cylinder 1 at the time of duplex printing. Be dressed. The divided plate-making master 8 is formed with a first plate-making image (first surface 8A image) corresponding to the front surface image and a second plate-making image (second surface 8B image) corresponding to the back surface image. A plate making portion 8C is formed between 8A and the second surface 8B.

On the plate cylinder 1, the divided plate-making master 8 has a first plate-making image 8A in the front surface area e1 shown in FIG. 1, a second plate-making image 8B in the same back surface region e2, and a non-plate-making part 8C in the same intermediate region e3. Each is wound to correspond.
In FIG. 1, a plate making unit 15 for making a master 8 based on image information is disposed on the upper left side of the plate cylinder 1. In the plate making section 15, the master 8 is wound as a master roll 8a, and the roll core 8b is rotatably supported by holder means (not shown).

The master 8 is pressed against a platen roller 9 rotatably supported by a plate making side plate (not shown) by a thermal head 11 having innumerable heating elements. The platen roller 9 is driven to rotate clockwise by a stepping motor (not shown), so that the master 8 is fed out from the master roll 8a.
The thermal head 11 is urged toward the platen roller 9 by a material such as a spring portion (not shown). In the main scanning direction of the thermal head 11, a large number of heat generating elements (not shown) are disposed at portions that contact the platen roller 9 via the master 8. The thermal head 11 passes through an A / D conversion unit and an image signal processing unit, both not shown, and the heat generation based on a digital image signal processed and sent out by a plate making control device and a thermal head drive circuit (both not shown). By selectively heating the element, it has a well-known function as a plate making means for selectively heating, melting, punching and making the master 8.

The platen roller 9 has both end portions of the platen roller shaft rotatably supported by the plate making side plate pair. The platen roller 9 is connected to a master transport motor 10 via a rotation transmission member (not shown) such as a timing belt and a gear, and is thereby driven to rotate clockwise. The master transport motor 10 is formed of a stepping motor, for example, and is driven to rotate clockwise to pull out the master 8 from the master roll 8a.
On the downstream side of the platen roller 9 in the master conveyance direction, a conveyance roller pair 13 is provided that is rotatably supported in a state where the plate-making side plates (not shown) are pressed against each other. The conveying roller pair 13 is set at a speed slightly higher than the peripheral speed of the platen roller 9, and applies an appropriate tension to the master 8 while sliding with the master 8.

A cutter 12 is provided on the upstream side of the conveying roller pair 13 to cut the master 8 that has been subjected to plate making to an appropriate length. The cutter 12 is a guillotine type composed of an upper blade 12a and a lower blade 12b. The cutter may be a rotary blade moving type or the like. A master guide plate 14 that is fixed between plate making side plates (not shown) and guides the tip of the master 8 is provided. These constitute the plate making section 15.
An image reading unit 18 is disposed on the upper part of the apparatus main body 100. The image reading unit 18 focuses a contact glass (not shown), a pressure plate (not shown) provided so as to be able to contact with and separate from the contact glass, a reflection mirror and a fluorescent lamp (not shown) that scan and read a document image, and a scanned image, respectively. The lens includes a lens (not shown), an image sensor (not shown) that processes a focused image, and the like. This image sensor performs photoelectric conversion corresponding to the received reflected light, and an image signal obtained thereby is input to the control means 110 via the A / D conversion unit.

A document vertical size detection sensor and a document horizontal size detection sensor are provided near the lower part of the contact glass, and detect the size of a document (not shown) placed on the contact glass. Collectively referred to as sensor 149.
In FIG. 2, the control target drive means of the image reading unit 18 is collectively referred to as a read drive means 128.
The control means (main controller of the double-sided printing apparatus) 110 that has received the image information of the document read by the image reading unit 18 drives the thermal head 11 of the plate making unit 15 based on this image information and energizes the heating elements. Heat-drilling plate making is performed. The control unit 110 is input with a command whether normal single-sided printing or double-sided printing is performed by the operator through the operation panel 350 in a timely manner.

The plate cylinder 1 has a configuration in which a plurality of layers of resin or metal mesh mesh screens are wound on the outer peripheral surface of a porous support cylindrical body, and is rotatably supported by an ink pipe 5 as a support shaft (not shown). It is fixed to the flange. The plate cylinder 1 is driven to rotate clockwise by a driving force transmitted from a driving source (not shown) by a driving transmission means (gear or the like) (not shown).
A side plate (not shown) fixed to the ink pipe 5 is provided inside the plate cylinder 1, and the ink roller 2 is rotatably supported by an ink roller shaft supported by the side plate. The ink roller 2 is rotationally driven in the same direction in synchronization with the plate cylinder 1 by drive transmission means (gear, belt, etc.) not shown. A doctor roller 3 is provided with a slight gap from the outer peripheral surface of the ink roller 2, and the ink in the ink reservoir 4 formed in the wedge-shaped space between the ink roller 2 and the doctor roller 3 by the doctor roller 3 is transferred to the ink roller 2. Is supplied to the outer surface of the film in a thin film.

The ink in the ink reservoir 4 is sucked from an ink pack or the like provided outside the plate cylinder 1 by an ink supply device (not shown) and supplied dropwise from a supply hole 5 a of the ink pipe 5.
The plate cylinder 1 has an opening 1a through which ink can pass and a non-opening 1b. On the surface of the non-opening portion 1b, a stage 6 made of a magnetic material is provided in a state parallel to the rotation center line of the plate cylinder 1. A clamper shaft 7a is rotatably supported in parallel with the stage 6, and the clamper 7 is integrally fixed to the clamper shaft 7a. The clamper 7 is opened and closed at a predetermined position by an opening / closing device (not shown).

  In FIG. 1, the end plate flange of the plate cylinder 1 on the back side of the paper surface and the main body frame side in the vicinity of the end plate flange, as shown in FIG. Components for providing start / trigger information to the sheet feeding motor 37 and the registration motor 41 shown in FIG. 1 are arranged. That is, on the outer wall of the end plate flange on the back side in the plate cylinder 1, the sheet feeding start light shielding plate 121 and the resist start light shielding plate 122 are spaced apart from each other on the same circumference of the plate cylinder 1. Each is attached to a predetermined position. On the other hand, a paper feeding registration sensor 120, which is an optical sensor, is attached to the main body frame side in the vicinity of the respective light shielding plates 121 and 122 so as to sandwich the light shielding plates 121 and 122.

  In the present embodiment, the home position (initial position) of the plate cylinder 1 is the tip of the divided plate-making master 8X or the plate-making master 8Y conveyed from the plate-making unit 15 with the clamper 7 positioned almost directly above. It is set to the same position as the plate feeding standby position, which is the position for receiving and holding. A light shielding plate for home position (not shown) for detecting the home position of the plate cylinder 1 is attached to a predetermined position on the outer wall of the end plate flange on the back side of the plate cylinder 1. A home position sensor (not shown), which is a transmissive optical sensor, is attached to the main body frame side in the vicinity of the home position light shielding plate so as to sandwich the home position light shielding plate. In FIG. 2, the plate cylinder sensor, the paper feed registration sensor, and the home position sensor are collectively referred to as a plate cylinder position detection sensor 29 as a plate cylinder position detection unit that detects the rotational position of the plate cylinder 1.

A press roller 21 is disposed below the plate cylinder 1 as a pressing means that can be moved toward and away from the plate cylinder 1.
As shown in FIGS. 5 and 6, the press roller 21 is pivotally supported by one end of a pair of front and rear arms 22. A pair of front and rear arms 22 (hereinafter simply referred to as an arm pair) is pivotally supported on an arm shaft 22a via a pin 21a. The arm shaft 22a is supported between a pair of housing side plates (not shown) fixed to the main body frame side 100 via a bearing (not shown) so as to be rotatable by a predetermined angle. A rotatable cam follower 241 is provided on the lower end side with respect to the arm shaft 22 a which is the other end of the arm pair 22. The cam follower 241 is urged so as to come into contact with a plurality of cams 243 rotatably supported on the apparatus main body (not shown) by a spring 242 or the like. The plurality of cams 243 rotate in synchronization with the plate cylinder 1 by a driving unit (not shown), and function to bring the press roller 21 into contact with the plate cylinder 1 at a predetermined position and separate them.

Here, a method is adopted in which the plurality of cams 243 are switched and the pressing range is switched as in the first surface 8A, the second surface 8B, and the whole as shown in FIG. The press roller 21 is rotationally driven in a direction opposite to the plate cylinder 1 at substantially the same peripheral speed as the plate cylinder 1.
A notch 22b that selectively engages with a locking claw 60a of a locking member 60 described later is formed at the lower end of the arm pair 22 shown in FIG.

  The press roller 21 is formed of, for example, nitrile rubber (NBR), which is an elastic body having oil resistance, and at least the outer peripheral surface of the rubber is a film having a fine uneven surface treatment, for example, For example, glass beads as glassy fine particles, which are the same as those used for preventing smearing of printed matter in an offset printing machine or the like, are uniformly coated or adhered. As a result, swelling and ink caused by contact with the outer peripheral surface of the plate cylinder 1 or the divided master-making master 8X or the master-making master 8Y or contact with the ink on the printed image surface side of the surface-printed paper 36a as will be described later. It is configured to minimize contamination.

  The press roller 21 receives the unprinted paper 36 or the like on the divided master-making master 8X or the master-making master 8Y on the plate cylinder 1 via the printing pressure range changing means 28, the locking means 64 and the arm pair 22 shown in FIG. It is configured to be displaceable between a printing position (shown in FIG. 6) for pressing the front surface printed paper 36a and a non-printing position including the initial position shown in FIGS. 1 and 5 away from the printing position.

In FIG. 5, reference numeral 54 denotes a press roller rotation driving unit as a pressing unit driving unit that rotationally drives the press roller 21. The press roller rotation drive means 54 is a press roller drive as a drive means for driving the press roller 21 to rotate in the direction opposite to the rotation direction of the plate cylinder 1 (counterclockwise) at substantially the same peripheral speed as that of the plate cylinder 1. The motor 55 and the driving force transmitting means for transmitting the rotational driving force of the press roller driving motor 55 to the press roller 21 are mainly configured. The press roller drive motor 55 is attached and fixed to the outer wall of the arm pair 22 on the back side in FIG.
As shown in FIG. 5, the driving force transmitting means includes a toothed driving pulley 56 fixed to the output shaft 55a of the press roller driving motor 55, and a press roller shaft 21a protruding further to the back side of the paper surface of the arm pair 22. And a toothed driven pulley 57 that is fixed to the drive pulley 56 and a toothed endless belt 58 that is stretched between the driving pulley 56 and the driven pulley 57.

  The press roller 21 is set in accordance with the timing at which the unprinted paper 36, the front-side printed paper 36a, or the single-side printed paper 36c is pressed against the divided master-making master 8X or the master-making master 8Y (see FIG. 3) on the plate cylinder 1. The press roller drive motor 55 is rotationally driven. The operation of the press roller drive motor 55 is controlled by the control means 110 shown in FIG. The rotational speed of the press roller drive motor 55 is controlled so that the peripheral speed of the press roller 21 is substantially the same as the peripheral speed of the plate cylinder 1. According to the example of the present embodiment, the press roller 21 is rotationally driven by the press roller drive motor 55 at a substantially same peripheral speed as the peripheral speed of the plate cylinder 1, so that a printed matter with no print image position deviation can be obtained.

As shown in FIGS. 5 and 6, in addition to the press roller 21 constituting the refeed unit 45, the refeed conveyance unit 48, and the refeed resist contact and separation shown only in FIG. Means 70, a stopper member 53, a roller guide plate 50, and the like are disposed.
The refeed unit 45 temporarily holds the surface-printed paper 36 a on which the printed image is formed by the printing unit 16 and conveys the paper 36 a toward the press roller 21 via the stopper member 53. In order to temporarily stop and position the re-feeding conveyance unit 48 that can be stopped and started, and the front end of the front-side printed paper 36 a conveyed by the re-feeding conveyance unit 48 before being transferred to the press roller 21. The stop member 53 as a refeed stop means and the stop state of the front end of the front surface printed paper 36a temporarily stopped by the stopper member 53 are released at a predetermined timing to release the front end of the front surface printed paper 36a. A refeeding registration roller 5 as a refeeding resisting means that is displaceable between a contact position where the press roller 21 is contacted and a non-contact position spaced apart from the contact position. And a re-feeding resist contacting / separating means 70 for displacing the re-feeding registration roller 51 between the contact position and the non-contact position, and provided on the right side of the press roller 21 close to the outer peripheral surface of the press roller 21. A roller guide plate 50 that guides the surface-printed paper 36a abutted on the outer peripheral surface of the press roller 21 by the re-feeding registration roller 51 to the nip portion 16a formed in the printing section 16, and the one-side printed paper 36a. It is mainly composed of nipping / conveying means 190 that guides the re-feeding / conveying means 48 while pinching the tip.

  As shown in FIGS. 1, 5, and 6, the refeed conveyance unit 48 extends below the reciprocating path of the movable guide 81 of the nipping conveyance unit 190 and near the left side of the refeed registration roller 51. Are arranged. As shown in FIGS. 5 and 6, the refeed conveyance means 48 includes a refeed housing 110 that rotatably supports the drive shaft 107a and the driven shaft 106a, and a drive provided integrally with the drive shaft 107a. A rear roller 107 serving as a roller, and a front roller 106 provided integrally with a driven shaft 106a disposed upstream of the drive shaft 107a in the paper conveyance direction X and in the vicinity of the refeeding registration roller 51. And a plurality of holes for air suction on the endless belt that holds and conveys the surface-printed paper 36 a that is wound and stretched between the rear 107 of the conveying roller and the front 106 of the conveying roller and is delivered from the movable guide 81. (Not shown) formed with a plurality of conveyor belts 108, and connected to the drive shaft 107a via a driving force transmission means such as a gear or a belt, and conveyed via the rotational drive of the rear 107 of the conveyor rollers. An upper surface side of the conveyor belt 108 by sucking air from a plurality of holes (not shown) through the surface-printed paper 36a delivered from the movable guide 81 and a belt drive motor 105 as belt drive means for rotating the belt 108. And a suction fan 109 for adsorbing and holding.

The refeed housing 110 has bearings (not shown) on both the upstream and downstream sides in the paper transport direction, and these bearings rotatably support the drive shaft 107a and the driven shaft 106a, respectively. Yes. Both ends of the drive shaft 107a penetrate both side surfaces of the refeed housing 110, and both ends of the penetrated drive shaft 107a can be rotated by a bearing member (not shown) provided on the main body frame. It is supported.
A drive gear (not shown) is attached to one end of the drive shaft 107a (the back side of the sheet of FIG. 5), and the drive shaft 107a is rotationally driven by a belt drive motor 105 connected via the drive gear. . The conveyance belt 108 is intermittently rotated clockwise at a specific timing according to the type of paper as will be described later by the operation of the belt drive motor 105 based on a command signal from the control unit 110 shown in FIG. . The belt drive motor 105 is composed of, for example, a stepping motor, and is fixed to the main body frame side. The driven shaft 106 a is configured such that both ends thereof do not penetrate both side surfaces of the refeed housing 110.

Pins 111 are protruded and fixed to the outer walls on both sides of the upstream end portion in the paper transport direction X in the paper refeeding housing 110, and each pin 111 is formed on each arm pair 22 (not shown). Each of the relief holes is loosely fitted. As a result, the re-feed housing 110 moves the drive shaft 107a along with the swinging of each arm pair 22 when the press roller 21 is brought into and out of contact with the plate cylinder 1 by the printing pressure range varying means 28 described later. The re-feed conveyance means 48 on the side where the pin 111 is arranged at the center can be swung.
The conveying roller rear 107 and the conveying roller front 106 are divided into skewers, are formed of, for example, a toothed roller, and are formed of a high friction material. The conveyor belt 108 is formed of, for example, a toothed belt, and a plurality of belts are wound and stretched between a conveyor roller rear 107 and a conveyor roller front 106 which are divided into skewers.

The suction fan 109 is driven by a fan so that the surface-printed paper 36 a delivered from the movable guide 81 is attracted to the upper surface side of the transport belt 108 by sucking air from a large number of holes (not shown) of the transport belt 108. Built-in motor. Hereinafter, the fan drive motor is simply referred to as “suction fan 109”.
The stopper member 53 temporarily stops the front end of the front surface printed paper 36a at a position where it can be delivered to the press roller 21, and also has a function of positioning the front end of the front surface printed paper 36a and correcting skew. The stopper member 53 is made of, for example, a sheet metal or an appropriate resin, has a substantially L-shaped cross section, and includes a stopper surface 53a for abutting and positioning the front end of the surface-printed paper 36a. The stopper member 53 has cutout openings at a plurality of locations so as not to come into contact with each other when the plurality of refeeding registration rollers 51 come into contact with the press roller 21. The base end (left end side in FIG. 2) of the stopper member 53 is fixed to the paper refeed housing 110, and thereby the stopper member 53 is oscillated and displaced together with the paper refeed conveyance means 48 and the press roller 21.

As shown in FIGS. 5 and 6, the lower surface of the stopper member 53 in the vicinity of the protruding end is re-supplied as a surface printed paper detection unit that detects that the front end of the surface printed paper 36 a is close to the stopper member 53. A paper sensor 52 is provided. The re-feed sensor 52 includes a reflective optical sensor and has a function of detecting the leading edge and the trailing edge of the front surface printed paper 36a (the left edge of the front surface printed paper 36a).
As shown in FIG. 7, the re-feed resist contact / separation means 70 mainly includes a support shaft 72, a pair of swing arms 71, a solenoid 73, and a tension spring 75. The re-feeding registration roller 51 has a roller shape, is a high friction material, and is an elastic body having oil resistance (ink corrosion resistance), for example, nitrile rubber (NBR). And is formed integrally. The re-feeding registration roller 51 is normally held in a state where it occupies a non-contact position on the lower side of the press roller 21 and the stopper member 53, and each swinging portion in which both end portions of the shaft 51a have a substantially square shape. The arm 71 is rotatably attached to one end. Each swing arm 71 has a bent portion fixed to a support shaft 72 supported rotatably between each arm pair 22. As a result, when the re-feeding registration roller 51 occupies the contact position, it receives the rotational force of the press roller 21 and rotates in the direction opposite to the rotation direction (counterclockwise) of the press roller 21 (clockwise).

  In FIG. 7, a plunger 74 of a solenoid 73 is attached to the other end of the swing arm 71 on the back side of the paper surface via a pin. The solenoid 73 is a pull type, and is attached and fixed to one arm pair 22 via a bracket which is a non-moving member (not shown). Further, the other end of the swing arm 71 is fixed to one arm pair 22, and a tension spring that urges the re-feeding registration roller 51 around the support shaft 72 to always occupy the non-contact position. The other end of 75 is attached. The solenoid 73 has a function as a refeed resist driving unit that displaces the refeed resist roller 51 so as to occupy the contact position at a predetermined timing. As described above, when the solenoid 73 is operated against the urging force of the tension spring 75 (ON operation), the outer sheet of the re-feeding registration roller 51 is pressed against the outer periphery of the press roller 13 with a predetermined pressing force. By contacting the surface and occupying the contact position, the surface-printed paper 36a is brought into contact with the outer peripheral surface of the press roller 21 for a predetermined time, and receives the rotational force of the press roller 21 in the clockwise direction opposite to the press roller 21. When the surface-printed paper 36a is assisted while being rotated and the operation of the solenoid 73 is released (OFF operation), the outer peripheral surface of the press roller 13 is separated from the outer peripheral surface by the urging force of the tension spring 75. Occupies a non-contact position.

The roller guide plate 50 has a function of guiding the surface-printed paper 36 a conveyed by the rotational force of the press roller 21 toward the plate cylinder 1 by abutting the outer peripheral surface of the press roller 21. The roller guide plate 50 is fixed between the pair of arms 22 with a predetermined gap from the outer peripheral surface of the press roller 21. The guide surface side of the roller guide plate 50 has a low friction coefficient and is smoothly coated with a film having ink repellency and oil resistance such as polytetrafluoroethylene resin.
A nipping / conveying means 190 for nipping the leading end of the one-side printed paper 36a approaching and separating from the pressing means 21 and leading to the refeeding / conveying means 48 is disposed below the paper discharge section 19 and above the refeeding / conveying means 48. Is done.

  As shown in FIGS. 6 and 7, the nipping / conveying means 190 has a leading end portion including the leading end of the front surface printed paper 36 a sent out from the nip portion 16 a at a moving position P 1 as a first position in the vicinity of the printing portion 16. The leading end of the front surface printed paper 36a is opened at the initial position P2 as a second position in the vicinity of the upstream side of the refeed conveyance means 48 that is nipped and lower than the movement position P1, and the holding position P before the initial position P2 is released. It has a function and configuration as a sheet clamping means that clamps and stops the front end of the front surface printed sheet 36a.

  The nipping and conveying unit 190 includes a nipping guide 81 and a moving unit 87 that drives the nipping guide 81 between the moving position P1 and the initial position P2.

  The sandwiching guide 81 is integrated with the sandwiching base 81f that sandwiches and places the leading end of the front surface printed paper 36a, and the downstream gripping base 81f in the paper traveling direction Xa of the front surface printed paper 36a fed from the nip 16a. A pair of end fences 81d having a paper contact surface 81e that contacts the front end of the surface-printed paper 36a formed on the front and back sides of the paper surface of the clamping table 81f and integrated in the reciprocating direction. Four projections 81c as guided portions formed on the front surface, clamp claws 81b as clamping members that can be opened and closed with respect to a clamping base 81f that grips and clamps the front end portion of the surface-printed paper 36a, and clamp claws 81b A clamp shaft 81a that can be pivoted (rotated by a predetermined angle) for mounting and fixing the base end of the clamp, and a clamp shaft 81a for supporting the clamp shaft 81a so as to be rotatable by a predetermined angle. A pair of bearing brackets 81g shown only in FIG. 8 that are integrally attached to both side ends of the holding base 81f, and a torsion coil spring (not shown) that urges the free end of the clamp claw 81b to press against the upper surface of the holding base 81f. 8 is mainly composed of a pair of upper and lower release levers 82 and a lower release lever 83 shown in FIG. 8 attached and fixed to the back side of the paper surface of the clamp shaft 81a.

The movable guide 81 is formed in a substantially L-shaped cross section by a clamping table 81f and an end fence 81d. The four protrusions 81c are loosely fitted into guide grooves 88 formed in the housing side plate pairs 130a and 130b (integrated with the apparatus main body 100) shown in FIG. The clamp claw 81b is inclined with an acute rising angle with respect to the paper traveling direction Xa (conveying direction) of the surface-printed paper 36a fed from the nip portion 16a, and its base end is attached and fixed to the clamp shaft 81a. The free end is formed into an acute angle. A mounting portion 84 shown in FIG. 8 is integrally provided at a lower portion of the clamping table 81f on the back side of the paper surface, and the mounting portion 84 is fixed to a timing belt 89 on the moving means 87 side.
The release lever 82 and the release lever lower 83 are formed of a plate-like member. Note that the protrusion 81c is not limited to being formed integrally with the holding base 81f, but may be formed of a roller that can roll on the inner wall of the guide groove 88 with little frictional resistance.

  As shown in FIG. 8, the moving means 87 constituting the main part of the nipping / conveying means 190 is disposed outside the casing side plate 130b on the back side of the paper, and is movable between the moving position P1 and the initial position P2. It has a function and configuration for reciprocating the guide 81. The moving means 87 is an arcuate guide formed so as to be inclined downward to the left so as to be substantially the same as the transport drop path in the paper traveling direction Xa of the surface-printed paper 36a and penetrate the housing side plate pair 130a, 130b. A groove 88, a toothed drive pulley 90 rotatably supported with a shaft 90a on a housing side plate 130b near the downstream end in the paper traveling direction Xa of the surface-printed paper 36a in the guide groove 88, and a guide groove A toothed driven pulley 91 having a shaft 91a rotatably supported by a housing side plate 130b in the vicinity of the upstream end in the paper traveling direction Xa of the surface-printed paper 36a in 88, a drive pulley 90 and a driven pulley 91; A timing belt 89 that is stretched between and stretched between the housing and the casing side plate 130b so as to abut against the timing belt 89 and apply tension thereto. A plurality of tension rollers 95 supported rotatably with a shaft, a drive gear 92 attached and fixed to the shaft 90a of the drive pulley 90, and a housing side plate 130b in the vicinity of the shaft 90a of the drive pulley 90 It is mainly composed of a drive motor 94 as a fixed forward / reverse drive means, and a motor gear 93 that is attached and fixed to the output shaft 94a of the drive motor 94 and meshes with the drive gear 92.

  The timing belt 89 is connected and fixed to the movable guide 81 via an attachment portion 84 formed integrally with the lower portion of the sandwiching table 81 f of the movable guide 81. The drive motor 94 is composed of a stepping motor, for example. As described above, the driving motor 94 is the driving means of the moving means 87, the guide groove 88 is the guiding means of the moving means 87, and the timing belt 89, the driving pulley 90, the driven pulley 91, the driving gear 92, and the motor gear 93 are the driving motor 94. The driving force transmitting means for transmitting the driving force to the movable guide 81 is provided.

  As described above, the movable guide 81 is moved in the vicinity of the printing unit 16 indicated by the solid line in FIG. FIG. 8 shows a holding position P ′ near the upstream side of the refeed conveyance means 48 that is lower than the movement position P1 and the front end of the surface-printed paper 36a being drawn, and then the front end of the paper 36a is opened. It reciprocates to selectively occupy an initial position (second position) P2 indicated by a two-dot chain line. In the vicinity of the drive pulley 90, a home position sensor 85 is provided for detecting when the movable guide 81 occupies the second position, which is the home position P2 (initial position P2).

  As shown in FIG. 8, when the movable guide 81 occupies the movement position P1 indicated by the solid line, the release cam 98 resists the biasing force of the torsion coil spring by abutting with the lower release lever 83 of the movable guide 81. Then, the clamp claw 81b is pivoted clockwise (rotated by a predetermined angle) via the release lever lower 83 and the clamp shaft 81a to be released once, and then the movable guide 81 moves from the movement position P1 toward the initial position P2. When starting, the contact state with the lower release lever 83 is released, and the clamping pawl 81b is swung counterclockwise by the biasing force of the torsion coil spring. It has a function to operate so as to be held. As shown in FIG. 8, when the movable guide 81 reaches the initial position P2 from the holding position P ′, the release pin 99 comes into contact with the release lever upper 82 of the movable guide 81, thereby attaching a torsion coil spring (not shown). The clamp claw 81b is swung clockwise through the release lever upper 82 and the clamp shaft 81a against the force to act to open the front end of the surface-printed paper 36a.

  In this way, when the movable guide 81 occupies the movement position P1, it comes into contact with the release cam 98, so that the front end of the surface printed paper 36a is smoothly inserted into the open portion by the conveying force applied by the nip portion 16a. The Therefore, the front end of the surface-printed paper 36a can be securely clamped and clamped between the front end of the clamping claw 81b and the upper surface of the clamping base 81f without being affected by the strength of the paper.

  Furthermore, after the front surface printed paper 36a held by the clamp claw 81b is pulled to the holding position P ′, the movable guide 81 contacts the release pin 99 when it occupies the initial position P2, so that the clamp claw 81b By opening the front end and the upper surface of the clamping table 81f, the front end of the paper 36a falls on the transport belt 108 of the refeed transport device 48. The paper 36 a is temporarily sucked and held on the transport belt 108 by the suction force of the suction fan 109 operating at this time, and then transported by the rotational drive of the transport belt 108. Needless to say, the length of the transport belt 108 and the initial position P2 of the movable guide 81 are set to have optimum lengths depending on the length of the paper 36 used for duplex printing in the paper transport direction X.

In FIG. 2, the control target drive means of the refeed means 45 includes a press roller drive motor 55, a solenoid 73, a belt drive motor 105, a suction fan 109, a drive motor 94 for moving means, and the like. Various detection means of the refeed means 45 include a refeed sensor 52, a home position sensor 85, and the like.
Next, the configuration around the printing pressure range variable means 28 that determines the printing pressure range of the press roller 21 will be described. As shown in FIG. 3, a printing pressure range pattern I as a first printing pressure range pattern that applies printing pressure only to the surface area e1 corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1; A printing pressure range pattern II as a second printing pressure range pattern for applying a printing pressure only to the back surface area e2 corresponding to the back plate making image 8B in the divided plate-making master 8X on the plate cylinder 1, and on the plate cylinder 1 Three printing pressures with a printing pressure range pattern III as a third printing pressure range pattern that applies a printing pressure from the front surface area e1 to the back surface area e2 corresponding to the single-side plate-making image 8YA in the plate-making master 8Y. One of the range patterns can be selectively switched. A mechanism relating to the printing pressure range variable means 28 for selectively switching one of these three printing pressure range patterns is shown in FIGS. The printing pressure range varying means 28 also has a configuration / function for displacing the press roller 21 between the printing position and the non-printing position.

  The printing pressure range variable means 28 has the same configuration as that shown in FIGS. 2 to 4 of Japanese Patent Laid-Open No. 2003-200355. In the present embodiment, the arm shaft 22a, the arm pair 22, the pair of cam followers 241, the pair of printing springs 242, the printing pressure cam shaft 244, the pair of multistage cams 243, and the like are provided. The stepping motor 252 is shown only in the printing pressure range variable means 28 shown in FIG.

  As shown in FIG. 5 and FIG. 6, each component constituting the printing pressure range varying means 28 includes a pair of arms 22 to apply a uniform pressing force of the press roller 21 to the outer peripheral surface of the plate cylinder 1. In other words, they are arranged on the front side and the back side of the sheet of FIG. 5 and FIG. 6, respectively.

  As shown in FIGS. 5 and 6, a cam follower 241 is rotatably held on the inner wall of the arm pair 22 on which the press roller 21 is supported, on the outer wall on the inner side facing the central portion. Has been. The cam follower 241 is configured by a rolling bearing so that the cam follower 241 can contact the multistage cam 243 with reduced frictional resistance.

One end of a printing spring 242 (tensile spring) that urges the press roller 21 in a direction in which the press roller 21 is always pressed against the outer peripheral surface of the plate cylinder 1 is locked to the other end of the arm pair 22. The other end is locked to the housing side plate. The printing spring 242 oscillates and urges the other end of the arm pair 22 about the arm shaft 22a and urges the press roller 21 in a direction in which it presses against the outer peripheral surface of the plate cylinder 1. Yes. At the other end of the arm pair 22, a notch 22 b that can be engaged with the locking claw 60 a of the locking member 60 is integrally formed, and can be engaged with and disengaged from the locking member 60.
On the other hand, on each casing side plate in the vicinity of each cam follower 241, a printing cam shaft 244 to which a pair of multistage cams 243 rotating in synchronization with the rotation of the plate cylinder 1 is fixed is rotatably supported. The multistage cam 243 is composed of, for example, a plate cam in which a small diameter portion (concave portion) and a large diameter portion (convex portion) are formed.

  A belt pulley or gear (not shown) is fixed to the printing cam shaft 244, and is connected to the main motor 20 (shown in FIG. 2) via drive transmission means such as a belt and gear (not shown). As a result, the multistage cam 243 rotates in synchronization with the rotation of the plate cylinder 1. At this time, the cam follower 241 is urged by the printing pressure spring 242 so as to always come into contact with the multistage cam 243. Therefore, the cam driving means for rotationally driving the multistage cam 243 is mainly composed of the main motor 20.

  The multistage cam 243 has three cam plates 243A, 243B, and 243C, which are fixed to the printing cam shaft 244 at an appropriate interval. The cam plates 243A, 243B, and 243C are arranged in the order of the cam plate 243B, the cam plate 243A, and the cam plate 243C from the front side of the sheet of FIG. 5 and FIG. Each of the cam plates 243A, 243B, and 243C has a small-diameter portion (concave portion or base portion) that is a disc concentric with the cam shaft 244, and a large-diameter portion (convex portion) having the same protruding amount. In the multistage cam 243, the cam shaft 244 is transmitted with the rotational force from the main motor 20 in the same manner as the cam shaft (44) shown in FIG. It is driven to rotate around.

  The press roller 21 has a non-printing position shown in FIG. 2 in which the peripheral surface is separated from the outer peripheral surface of the plate cylinder 1 when any one of the large diameter portions of the cam plates 243A, 243B, 243C contacts the cam follower 241. 6 and 7 in which the peripheral surface is pressed against the outer peripheral surface of the plate cylinder 1 by the urging force of the printing pressure spring 242 when the contact between any large diameter portion and the cam follower 241 is released. Occupy position. Each of the cam plates 243A, 243B, and 243C is configured so that the small diameter portion (base portion) and the cam follower 241 do not come into contact with each other when the press roller 21 occupies the printing position.

  The shape of the large diameter portion of each cam plate 243A, 243B, 243C is such that the contact area between the press roller 21 and the plate cylinder 1 is the surface area e1, the intermediate area e3 and the back area e2 shown in FIG. The cam plate 243B has the same range as the surface region e1 (see the printing pressure range pattern I shown in FIG. 3) so that all the ranges are combined (see the printing pressure range pattern III shown in FIG. 3). The cam plate 243C is formed so as to be in the same range as the back surface region e2 (see the printing pressure range pattern II shown in FIG. 3).

As shown in FIGS. 5 and 6, the locking means 64 is for holding the press roller 21 in the non-printing position shown in FIGS. 1 and 5 except when paper is passed. The locking means 64 is mainly composed of a locking member 60, a support shaft 61, a solenoid 62, and a tension spring 63. The locking means 64 is disposed on the back side of the page.
The locking member 60 is swingably supported around a support shaft 61 implanted in the casing side plate on the back side of the paper surface, and is selectively connected to the notch 22b of the arm pair 22 at one end thereof. An engaging claw 60a is formed to engage the. At the other end of the locking member 60, one end of a tension spring 63 that urges the engaging claw 60a in a direction to always engage with the notch 22b of the arm pair 22 is locked. The other end of the tension spring 63 is locked to the housing side plate side on the back side of the drawing. Further, the plunger of the solenoid 62 fixed to the housing side plate on the back side of the drawing via a bracket (not shown) as a stationary member on the side opposite to the arrangement portion of the tension spring 63 at the other end of the locking member 60. 62a is connected via a pin. The solenoid 62 uses a pull type.

  As described above, when the solenoid 62 is energized and the solenoid 62 is turned on, the printing pressure range variable means 28 is operated, and the press roller 21 occupies the printing position through the operation described later. As a result, the press roller 21 continuously presses the paper 36 while rotating it on the divided master-making master 8X or the master-making master 8Y on the plate cylinder 1. When the energization of the solenoid 62 is cut off and the solenoid 62 is turned off, the printing pressure range variable means 28 is deactivated, and the press roller 21 is separated from the printing position through the operation described later. 5 occupies a non-printing position (initial position).

The solenoid 62 is on / off controlled by the control means 110 described later. By the on / off switching control of the solenoid 62 by the control means 110, the arm pair 22 is selectively switched between the state in which the arm pair 22 is held and the state in which the holding is released. As will be described later, the solenoid 62 is turned on when the cam follower 241 is in contact with the large diameter portion of the multistage cam 243 (see FIG. 5).
FIG. 3 shows the printing pressure range of the press roller 21 in an easily understandable manner. The divided plate-making master 8X wound around the opening portion 1a on the plate cylinder 1 (not shown in the figure) has an area portion of the front plate-making image 8A and an area portion of the back-side plate-making image 8B. Between them, an unfinished blank intermediate intermediate plate making area 8C is provided.

The printing pressure range pattern for normal printing including single-sided printing is as shown in III. That is, the printing pressure range pattern III is applied on one side of the prepressed master 8Y by applying a printing pressure from the region portion of the front plate making image 8A to the region portion of the back plate making image 8B through the intermediate non-plate making region 8C. The cam plate 243A is selected by the operation of the printing pressure range varying means 28 in response to a command from the control means 110 shown in FIG. 2 so that the paper 36 is continuously pressed against the plate-making image 8YA, and the cam plate 243A is selected. Is rotated so that the small diameter portion thereof faces the cam follower 241.
At the time of surface printing, the printing pressure range variable means 28 is operated by a command from the control means 110 so as to be printed corresponding to the area portion of the surface plate-making image 8A as shown in the printing pressure range pattern I. Thus, the cam plate 243B is selected, and the cam plate 243B is rotationally driven so that the small diameter portion of the cam plate 243B faces the cam follower 241 and then the printing pressure is released in the intermediate unmade region 8C.

At the time of printing on the back side, the printing pressure range pattern II is obtained, and the cam plate 243C is selected by the operation of the printing pressure range variable means 28 in response to a command from the control means 110, and the area portion of the first front plate-making image 8A is selected. Then, in order to release the printing pressure, the cam plate 243C is rotationally driven so that the large diameter portion of the cam plate 243C faces the cam follower 241 and then the small diameter portion of the cam plate 243C faces the cam follower 241.
According to the present embodiment, since the printing pressure range variable means 28 is provided, the printing pressure on range is optimally set, and the printing pressure is turned on when there is no sheet and the press roller 21 It is possible to prevent a problem that the printed image is transferred to the outer peripheral surface and is stained with ink.

  As shown in FIG. 1, the paper discharge unit 19 is provided so as to be close to the outer peripheral surface of the plate cylinder 1, and a peeling claw 170 that peels the single-side printed paper 36 c from the plate-making master 8 </ b> Y on the plate cylinder 1. A separation fan 171 for blowing air between the front end portion of the single-side printed paper 36c separated by the nail 170 and the plate cylinder 1 to assist the separation action by the separation nail 170, and separation by the separation nail 170 and the separation fan 171. The paper sheet is mainly composed of a paper discharge transport device 152 that transports one of the printed single-sided paper 36c and the double-sided printed paper 36b while sucking, and a paper discharge tray 172.

  The peeling claw 170 is provided in the vicinity of the downstream side of the nip portion 16 a formed when the press roller 21 is pressed against the outer peripheral surface of the plate cylinder 1. The peeling claw 170 is placed on the plate cylinder 1 in the vicinity of the outer peripheral surface of the plate cylinder 1 by a peeling claw displacing means (not shown) provided with a cam, a spring and the like that are driven to rotate in synchronization with the rotation of the plate cylinder 1. A separation position for forcibly separating the single-sided printed paper 36c from the pre-printed master 8Y, and a non-peeling position for avoiding contact with the clamper 7 arrangement portion protruding from the outer peripheral surface of the plate cylinder 1 apart from the separation position It is configured to be freely displaceable between. The peeling fan 171 has a built-in fan drive motor that rotationally drives the peeling fan.

  As shown in FIG. 1, the paper discharge conveyance device 152 is disposed below the peeling claw 170 and to the left of the switching guide 46, and after the paper discharge roller 154 as a driving roller and discharge as a driven roller. A paper roller front 156, a paper discharge belt 158 which is an endless belt, a suction fan 159, and the like are provided. A plurality of paper discharge roller rears 154 are attached to a drive shaft 154a rotatably supported by the casing side plate pair at a predetermined interval. A plurality of front discharge rollers 156 are also provided on the driven shaft 156a rotatably supported by the casing side plate pair at equal intervals with the rear 154 of each discharge roller. A paper discharge belt 158 is stretched around each paper discharge roller 154 and each paper discharge roller front 156 corresponding thereto. A drive gear (not shown) or a drive pulley (not shown) is attached to the drive shaft 154a (for example, the back side of the sheet of FIG. 1), and is stretched between a motor gear (not shown) that meshes with the drive gear or the drive pulley and a pulley (not shown). It is connected to a paper discharge belt drive motor 153 via a driving force transmission means such as a belt. As a result, the paper discharge belt 158 is rotationally driven by the paper discharge belt drive motor 153 in the direction of the arrow (counterclockwise) shown in FIG.

A suction fan 159 is disposed below the paper discharge belt 158. The suction fan 159 includes a fan drive motor that rotationally drives the suction fan. The paper discharge conveyance device 152 sucks either the single-side printed paper 36c or the double-side printed paper 36b on each paper discharge belt 158 by the suction force of the suction fan 159, and rotates the rear 154 after each paper discharge roller. 1 in the direction of the arrow.
In FIG. 2, the control target drive means of the paper discharge section 19 including the fan drive motor of the separation fan 171, the paper discharge belt drive motor 153, and the fan drive motor of the suction fan 159 in the paper discharge section 19 is generally the paper discharge drive means. 127.

  As shown in FIG. 1, the switching guide 46 includes a nip portion 16 a as a print image forming portion in the printing portion 16 formed by pressing the press roller 21 against the plate cylinder 1, a paper discharge conveyance device 152, and the like. Is disposed on the paper conveyance path between the two. The switching guide 46 is made of a plate material having substantially the same width as the plate cylinder 1 and the press roller 21, and its base end is fixed to a shaft 46 a that is rotatably supported by a casing side plate by a predetermined angle, and its free The end is swingable about the shaft 46a.

  The switching guide 46 has a free end portion formed in an acute cross section when a solenoid 47 as a switching drive means shown in FIGS. 2 and 5 operates against a biasing force of a tension spring as a biasing means (not shown). Are selectively positioned at a first displacement position indicated by a solid line and a second displacement position indicated by a two-dot chain line in FIG. The switching guide 46 is usually given a habit of swinging in an initial position shown in FIG. When the switching guide 46 occupies the initial position (first displacement position), the tip of the switching guide 46 is placed close to the outer peripheral surface of the press roller 21 and does not interfere with the clamper 7 on the plate cylinder 1. When the displacement position (see FIG. 6) is occupied, the tip is placed at a position close to the peripheral surface of the plate cylinder 1. The double-side printed paper 36b or the single-side printed paper 36c that has passed between the plate cylinder 1 and the press roller 21 is guided to the paper discharge unit 6 when the switching guide 46 occupies the first displacement position, The printed paper 36a is delivered to the movable guide 81 on the nipping and conveying means 190 side while being guided by the switching guide 46 when the switching guide 46 occupies the second displacement position.

  As shown in FIG. 1, the plate removal unit 17 includes an upper plate removal member 160, a lower plate removal member 161, a plate removal box 162, a compression plate 163, and the like. The upper plate removal member 160 rotationally drives the endless belt 166 wound around the drive roller 164 and the driven roller 165 in the clockwise direction of FIG. 1 by a plate discharge drive means 126 (see FIG. 2) including a plate discharge motor (not shown). The lower plate removal member 161 includes a driving roller 167, a driven roller 168, an endless belt 169, and the like. The driving roller 167 is rotationally driven in the clockwise direction in FIG. 1 by transmitting the driving force of a plate discharging motor that rotationally drives the driving roller 164 by a driving force transmitting means (not shown) such as a gear or a belt. As a result, the endless belt 169 moves in the direction of the arrow in FIG. Further, the lower plate discharging member 161 is movably provided by a moving unit (not shown) included in the plate discharging driving unit 126, and an endless belt 169 positioned on the outer peripheral surface of the driven roller 168 and the position shown in the figure is the plate cylinder 1. And a position that abuts on the outer peripheral surface.

The plate removal box 162 stores a used master therein and is detachably attached to the main body frame 130. The compression plate 163 is supported by the main body frame 130 so as to be movable up and down so that the used master carried by the upper plate removal member 160 and the lower plate removal member 161 is pushed into the plate release box 162. It is moved up and down by lifting means (not shown) including the lifting motor included.
In FIG. 2, the discharge target drive means 126 is collectively referred to as the control target drive means of the discharge plate section 17 including the discharge motor, the moving means, and the lifting motor of the discharge section 17.

  As shown in FIG. 1, the paper feed unit 30 takes a timing described later between the paper feed tray 35 that can stack and lift up the paper 36 and the outer peripheral surface of the plate cylinder 1 and the press roller 21. A pair of registration rollers 31 a and 31 b (hereinafter referred to as “registration roller pair 31”) that feeds the sheet 36, and contacts the sheet 36 on the sheet feeding tray 35 toward the nip portion of the pair of registration rollers 31. A paper feed roller 33 and a separating member 34 as paper feeding means for separating and transporting the paper 36 one by one, and a paper size detection sensor 117 as a paper size detection means for detecting the paper size of the paper 36 are provided. Yes.

  The paper feed tray 35 is provided with a drive device (not shown) including a paper feed tray lifting / lowering motor (not shown) as a lifting / lowering means (not shown) for moving the paper feeding tray 35 up and down. A state in which the upper layer contacts the paper feed roller 33 with a predetermined pressing force (a pressing force capable of transporting the paper 36), that is, a state in which the paper 36 contacts with a pressing force within a range in which the paper 36 can be transported in conjunction with increase / decrease of the paper 36. It is lifted while holding. The paper feed tray 35 has a structure in which many paper types and paper sizes can be used, and the paper stacking capacity thereof is, for example, a paper size A3 (horizontal placement: the user stands in front of the paper in FIG. And a structure suitable for a stencil printing apparatus that can stack 500 sheets or more of paper 36 of paper size A4.

  In the vicinity of the lower portion of the paper feed tray 35, paper length size detection sensors 117a, 117b, and 117c (both are made of a reflective optical sensor) for detecting the length of the fed paper 36 and the fed paper 36 In this figure, a paper width size detection sensor (not shown) for detecting the paper width on the front side and the back side of the paper surface is provided. The paper length and size detection sensors 117a, 117b, and 117c detect the size of the fed paper 36, and these are collectively referred to as the paper size detection sensor 117.

As shown in FIG. 1, the paper feed roller 33 is formed integrally with the paper feed roller shaft 33a, and one end of the paper feed roller shaft 33a is rotatably supported by a housing side plate (not shown). . The surface of the paper feed roller 33 is formed of at least a high friction resistance member such as rubber. A toothed paper feed roller pulley 39 is attached to one end of the paper feed roller shaft 33a. Between the paper feed roller shaft 33a and the paper feed roller pulley 39, a one-way clutch (not shown) for rotating the paper feed roller 33 so as to transport the paper 36 only in the paper transport direction X is disposed. Yes. The separation member 34 has a member called a separation pad that is made of rubber or resin having a high coefficient of friction with respect to the paper 36 and that can contact the paper feed roller 33. The separation pad is urged in a direction to be pressed against the paper feed roller 33 by a compression spring (not shown) as urging means.
Below the paper feed roller pulley 39, a paper feed motor 37 as a paper feed driving means for rotationally driving the paper feed roller 33 is fixed to the casing side plate. The paper feed motor 37 is composed of, for example, a stepping motor, and a rotational driving force is transmitted between the paper feed roller pulley 39 and the paper feed motor 37 via a one-way clutch.

  As shown in FIG. 1, the upper registration roller 31a is integrally formed with the registration roller shaft, and the lower registration roller 31b is integrally formed with the registration roller shaft 31c, and both ends of each registration roller shaft 31c are formed on the casing side plate. It is supported rotatably. A registration motor 41 is connected to one end of the lower registration roller shaft 31c as registration driving means for rotating the registration roller pair 31. The registration motor 41 is composed of, for example, a stepping motor. Thus, the rotational driving force is transmitted between the lower registration roller 31b and the registration motor 41.

In FIG. 1, in the paper conveyance path from between the plate cylinder 1 and the press roller 21 to the nip portion of the registration roller pair 31, paper detection for detecting the leading edge and the rear edge of the paper 36 fed from the registration roller pair 31. As a means, a paper detection sensor 32 is provided. The paper detection sensor 32 is a reflective optical sensor.
In FIG. 2, control target drive means of the paper feed unit 30 including the paper feed tray lifting / lowering motor, the paper feed motor 37, and the registration motor 41 of the paper feed unit 30 are collectively referred to as a paper feed drive unit 125.

  Next, a main control configuration of the stencil printing apparatus will be described with reference to FIG. In FIG. 2, the control means 110 has a function and configuration as means for controlling mainly a document reading operation, plate making / plate feeding operation, paper feeding operation and printing operation of the stencil printing apparatus. The control means 110 is a timer backed up by a CPU 101 (central processing unit), an I / O (input / output) port (not shown), a ROM 102 (read-only storage device), a RAM 103 (read / write storage device), a battery (not shown), and the like. And a microcomputer having a configuration in which they are connected by a signal bus (not shown).

  As shown in FIG. 1, the control means 110 is provided in a control board arrangement section in the main body frame 130. The CPU 101 of the control means 110 (hereinafter, sometimes simply referred to as “control means 110” for the sake of simplicity of explanation) detects various input signals from the operation panel 350 and detection from various sensors provided on the main body frame 130. Based on the signal and the operation program called from the ROM 102 and related data, the main motor 20 of the printing unit 16, the stepping motor 252 of the printing pressure range varying unit 28, the solenoid 62 of the locking unit 64, the plate making unit 15, and the paper feeding unit 30, the plate discharge unit 17, the paper discharge unit 19, the respective control target drive units provided in the image reading unit 18, the press roller drive motor 55 provided in the refeed unit 45, and the suction fan 109 of the refeed conveyance device 48. , Belt drive motor 105, solenoid 73, solenoid 47 of switching guide 46, and drive mode provided in moving means 87. It controls each operation or the like of the motor 94, and controls the overall operation of the stencil printing device. The control means 110 also determines the rotational position of the plate cylinder 1 and grasps the printing speed based on various plate cylinder position signals from the plate cylinder position detection sensor 29 generally shown in FIG. .

  The ROM 102 stores in advance an operation program for the entire stencil printing apparatus, necessary relation data, and the like, and this operation program is appropriately called by the CPU 101. The relational data includes relational data set for each printing speed with the stop timing of the belt drive motor 105 after the front end of the front surface printed paper 36a abuts against the stopper surface 53a. These relational data are, for example, a data table for changing the conveyance speed of the conveyance belt 108 determined in advance for each printing speed and set according to the paper type for each printing speed. The data is stored in advance in the ROM 102 as a data table for changing the stop timing of the belt drive motor 105 set according to the type. The RAM 103 has a function of temporarily storing calculation results of the CPU 101, a function of storing data signals and on / off signals set and input from various keys and various sensors on the operation panel 350 as needed.

The CPU 101 of the control means 110 recognizes and grasps the rotational speed of the plate cylinder 1 as needed based on various plate cylinder position signals from the plate cylinder position detection sensor 29, and also rotates the rotational position (rotation phase position) of the plate cylinder 1. Is recognized and grasped in real time.
The control unit 110 is a control unit that changes the plate cylinder rotation speed, the conveyance speed of the conveyance belt 108 of the refeed conveyance apparatus 48, and the rotation speed of the press roller in accordance with an input signal of the plate cylinder rotation speed from the operation panel 350. It has the function of.
In other words, the control means 110, for example, according to an input signal from the operation panel 350, for example, a preset high speed, for example, 120 sheets / minute, a medium speed, for example, 90 sheets / minute, a low speed, for example, 60 sheets / minute. It has a function of controlling the main motor 320 so as to change in accordance with the printing speed lower than the low speed, for example, 30 sheets / minute and the fine rotation used during maintenance.

  At the same time, it has a function of controlling the belt drive motor 105 so that the conveyance speed of the conveyance belt 108 of the re-feed conveyance apparatus 48 changes according to the high speed, medium speed, low speed, printing speed lower than the low speed, and fine movement. Further, the belt drive is performed so that the conveyance stop timing of the conveyance belt 108 after the front-side printed sheet 36a comes into contact with the stopper surface 53a varies depending on the high speed, medium speed, low speed, lower printing speed than low speed, and fine movement. It has a function of controlling the motor 105. Further, it has a function of controlling the press roller driving motor 55 so that the rotation speed of the press roller can be switched according to the high speed, the medium speed, the low speed, the printing speed lower than the low speed, and the fine movement.

Based on the above-described configuration, the operation including the operation procedure of the double-sided stencil printing apparatus 300 in the present embodiment will be described with reference to FIGS.
First, “Operation Example 1” in which single-sided printing mode is set and single-sided printing is performed will be described. “Operation Example 1” is substantially the same as the operation of performing single-sided printing by a conventional stencil printing apparatus, and substantially the same as the operation of performing single-sided printing disclosed in Japanese Patent Laid-Open No. 2003-200355 (Patent Document 3). Since it is the same, it demonstrates easily. In the single-sided printing operation, the printing pressure range pattern III is used, and the cam plate 243A for normal printing is selected and used from among the components of the printing pressure range variable means 28. In “Operation Example 1”, in order to facilitate understanding of each operation, a master size of A3 is used, and a document size and a paper size of A3 are used.

The user places an A3 size document to be printed on the image reading unit 18, and then inputs a single-sided print command through the operation panel 350. Further, a plate making command is input.
When this is input to the control means 110, a series of operations from discharging to discharging are automatically performed. Prior to this, when the control unit 110 determines that the paper 36 is ready to be fed by detecting the on-state of a paper feed position detection sensor (not shown), the paper feed device 30 enters a paper feed standby state. .

First, in the plate removal unit 17, a plate removal operation for peeling the used master from the outer peripheral surface of the plate cylinder 1 is performed. When the start signal is input to the control means 110, the plate cylinder 1 rotates, and when the clamper 7 reaches a home position that is almost directly above, the operation of the main motor 20 is stopped and the plate cylinder 1 stops at the plate discharge position. To do.
Next, the plate discharge driving means 126 is operated, the endless belt 169 comes into contact with the used master, and then the main motor 20 is started, whereby the plate cylinder 1 is rotated by the rotation of the plate cylinder 1 and the movement of the endless belt 169. The used master scooped up from the outer peripheral surface is peeled off from the outer peripheral surface of the plate cylinder 1. The peeled used master is discarded in the discharge box 162 and then compressed by the compression plate 163.
Even after the master is peeled off, the plate cylinder 1 rotates and rotates to the plate feeding standby position where the clamper 7 is located almost directly above, and the clamper 7 is released to enter the plate feeding standby state.
In parallel with the plate removal operation, a document image reading operation is performed by the image reading unit 18, and an electric signal corresponding to the read document image is input to an A / D conversion unit (not shown) in the main body frame 130. It is transmitted to a thermal head drive circuit (not shown) via the control means 110.

  In parallel with the plate discharging operation and the image reading operation, the plate making unit 15 performs the plate making operation. That is, a digital image signal is transmitted to the thermal head 11 via the thermal head drive circuit. At this time, the thermal head 11, the platen roller 9, and the conveying roller pair 13 start rotating, and the thermoplastic resin film portion of the master 8 is selectively heated and punched according to the image information. Then, the tip of the master-making master 8Y is inserted into the expanded clamper 7, and when this is determined, the clamper 7 is closed, and the tip of the master-making master 8Y is placed between the stage 6 and the clamper 7. Adsorbed and pinched.

After clamping the front end portion of the master-making master 8Y, the master-making master 8Y is conveyed and wound on the plate cylinder 1 by the rotational drive of the main motor 20. When it is determined that the plate making to the master 8 and the conveyance of the set amount of the plate making master 8Y have been completed, the plate making master 8Y is cut, and the rotation driving of the master carrying motor 10 is stopped, thereby the plate feeding operation. Ends.
When the winding of the plate-making master 8Y around the plate cylinder 1 is completed, a paper feeding / printing process for printing is started.
The plate cylinder 1 rotates in the direction of the arrow at the printing speed, and the paper feed motor 37 is activated (rotation drive is started). When the sheet feeding motor 37 is driven to rotate, the uppermost sheet 36 on the sheet feeding tray 35 that is in contact with the sheet feeding roller 33 is moved to the nip portion of the registration roller pair 31 on the downstream side in the sheet conveying direction X. It is sent toward.

Next, the plate cylinder 1 further rotates in the direction of the arrow in FIG. 1, and the registration start light shielding plate 122 engages with the paper feed registration sensor 120, whereby a registration start signal is generated and the registration motor 41 is activated.
The registration motor 41 drives the registration roller pair 31, and the leading edge of the paper 36 that is in contact with the nip portion and stands by is sent out between the plate cylinder 1 and the press roller 21.

Next, when the leading edge of the paper 36 is detected by the paper detection sensor 32, this signal is input to the control means 110. Based on the detection signal of the leading end of the sheet 36 from the sheet detection sensor 32 and the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor 29, the control unit 110 instructs the solenoid 62 of the locking unit 64 to energize. When the solenoid 62 is turned on, the cam plate 243A of the printing pressure range varying means 28 is operated.
As the solenoid 62 is turned on, the arm 22 swings about the arm shaft 22a by the biasing force of the printing pressure spring 242. At the rotational position where the outer peripheral surface of the cam follower 241 faces the peripheral surface of the small-diameter portion of the cam plate 243A and is in a non-contact state, the arm pair 22 swings clockwise around the arm shaft 22a by the biasing force of the printing spring 242. To do.

As a result, the press roller 21 presses the sheet 36 against the pre-made master 8Y wound around the front surface area e1 or the back surface area e2 of the plate cylinder 1 to apply printing pressure. At the same time, the press roller drive motor 55 rotates the press roller 21 at a speed substantially equal to the peripheral speed of the plate cylinder 1, thereby bringing the master 8 </ b> Y into close contact with the outer peripheral surface of the plate cylinder 1 and performing the printing. Is called. In this printing, stencil printing is performed by the ink oozing from the opening portion of the opening portion 1a of the plate cylinder 1 to the punching portion of the master-making master 8Y and transferred to the surface of the paper 36.
In the single-sided printing mode, the refeed conveyance device 48 and the moving unit 87 remain in an inoperative state, and the movable guide 81 remains in the initial position P2.
After plate printing corresponding to this single-side plate-making image 8YA is performed, when the large-diameter portion peripheral surface of the cam plate 243A contacts the outer peripheral surface of the cam follower 241, the arm pair 22 rotates counterclockwise about the arm shaft 22a. The printing pressure application state by the press roller 21 is released.

The single-sided printed paper 36c that has been subjected to plate printing is reliably peeled off from the master-making master 8Y on the plate cylinder 1 by the air from the peeling claw 170 and the peeling fan 171 approaching the outer peripheral surface of the plate cylinder 1, and is discharged and conveyed. The paper is sent to the paper discharge belt 158 of the apparatus 152 and discharged to the paper discharge tray 172 with its both ends aligned by a pair of paper discharge side fences 172a and 172b.
On the other hand, at the time when the plate cylinder 1 makes approximately three-quarters of a turn from when the press roller 21 contacts the outer peripheral surface of the plate cylinder 1, and the locking claw 60a and the notch 22b of the printing pressure arm 22 can be locked. The energization of the solenoid 62 is cut off (off), and the notch 22b of the printing pressure arm 22 is locked to the locking claw 60a of the locking member 60. The plate cylinder 1 rotates again to the home position and stops, and after the plate making operation is finished, the stencil printing apparatus enters a print standby state.

  It is assumed that a trial printing command is input from the operation panel 350 after the stencil printing apparatus is in a print standby state. In this case, the plate cylinder 1 is driven to rotate at the set low printing speed, and one sheet of paper 36 is fed from the paper feeding unit 30. The fed paper 36 is temporarily stopped by the registration roller pair 31 and then fed at the same timing as that at the time of printing. The press roller 21 is pressed against the plate-making master 8Y on the outer peripheral surface of the plate cylinder 1. The single-sided printed paper 36c on which the printed image is formed is peeled off from the plate-making master 8Y on the plate cylinder 1 as described above, and the peeled single-sided printed paper 36c is discharged to the paper discharge tray 172.

  Along with the set printing speed, control target drive means such as various motors such as printing pressure range variable means 28, paper feed unit 30, paper discharge conveyance device 152, and various solenoids are driven at speeds and timings suitable for the print speed. Be controlled. The position or density of the image is confirmed by trial printing, and the number of prints and the print density are adjusted and input via the operation panel 350. When the print start key 175 is pressed, the paper 36 is continuously fed from the paper supply unit 30 and a printing operation is performed under the same conditions as the trial printing.

Next, “Operation Example 2” in which the duplex printing mode is set and duplex printing is performed will be described. In “Operation Example 2”, in order to facilitate understanding of each operation, a master size of A3 is used, and a document size and a paper size of A4 are used. Hereinafter, the difference from “Operation Example 1” will be mainly described.
After the user places the first A4 size original for surface printing on the image reading unit 18, the user receives a paper size detection signal from the paper size detection sensor 117 and the original size detection sensor as in the first operation example. Document size detection signals are sent from 149 to the control means 110, and the control means 110 that receives these signals compares the signals. In the present embodiment, since the maximum paper size that can be printed by the plate cylinder 1 during single-sided printing is A3 size, the paper size that can be used during double-sided printing is up to A4 portrait.

  As a result of comparing the document size and the paper size, if both sizes are the same, an image reading operation is immediately performed. Thereafter, when a plate making start command is input, a series of operations from discharging to discharging are automatically performed as in “Operation Example 1”. Similarly to “Operation Example 1”, when the control unit 110 determines that the uppermost sheet 36 of the sheet feeding tray 35 is ready to be fed, the sheet feeding unit 30 enters a sheet feeding standby state. . After the plate removal operation similar to Operation Example 1 is performed, the plate cylinder 1 from which all used masters have been peeled off from the outer peripheral surface is stopped at the plate feed standby position as in Operation Example 1, and is opened and closed (not shown) The clamper 7 is opened by the device.

  In part in parallel with this plate removal operation, the image reading unit 18 performs the reading operation of the first original image for front surface printing in the same manner as in Operation Example 1, and the image data signal passes through the plate making control device or the like. It is transmitted to the thermal head drive circuit. In part in parallel with the image reading operation, the plate making unit 15 performs plate making by the thermal head 11 as in the operation example 1, and the master 8 is pulled out from the master roll 8a by the rotation of the platen roller 9 and the conveying roller pair 13. While being transported in the master transport direction X1, the thermoplastic resin film portion of the master 8 is selectively heated and punched according to image information, and a surface plate-making image 8A for surface printing is formed in the first half of the master 8. (See the divided master-making master 8X shown in FIG. 3).

  When it is determined that the leading end of the divided master-making master 8X has been inserted into the expanded clamper 7 and the leading edge of the split master-making master 8X has reached between the stage 6 and the clamper 7, the clamper 7 is closed. Then, the tip of the divided master-making master 8X is sucked and sandwiched between the stage 6 and the clamper 7.

  After clamping the leading end of the divided plate-making master 8X, the divided plate-making master 8X is conveyed by the platen roller 9 and the conveying roller pair 13 and wound around the outer peripheral surface of the plate cylinder 1. When the controller 110 determines that the front plate making image 8A has been made by the number of steps of the master transport motor 10, the plate making for making the back side printing image 8B for back side printing in the next divided plate making master 8X. It will be in a standby state.

  Next, the user places the second A4 size original for back side printing on the image reading unit 18 again. Thereafter, it is assumed that a plate making start command is input to the control means 110 again. At this time, as in the case of the first document, the control unit 110 compares the document size and the paper size. In the image reading section 18, the reading operation of the second original image for back side printing is performed in the same manner as that for the first original, and the image data signal is transmitted to the thermal head driving circuit. In the plate making unit 15, plate making is performed by the thermal head 11 as in the case of the first document, and the platen roller 9 and the carry roller pair 13 are rotated by the master carrying motor 10 being rotated again. Then, the master 8 is pulled out from the master roll 8a, and selectively heated and punched according to the image information, so that the back side plate-making image 8B for back side printing is formed in the latter half of the master 8.

  At this time, the plate cylinder 1 resumes rotating at the same peripheral speed as the master conveyance speed, so that the latter half of the divided plate-making master 8X is drawn out from the plate making unit 15 and wound around the outer peripheral surface of the plate cylinder 1. To go. When the controller 110 determines that the plate making of the last backside plate making image 8B in the divided plate making master 8X is completed by the number of steps of the master transport motor 10, the rear end portion of the divided plate making master 8X is cut and the platen is cut. The rotation of the roller 9 and the conveying roller pair 13 is stopped, and the divided plate-making master 8X for one plate cut by the rotation of the plate cylinder 1 is wound and fed to the plate cylinder 1.

  In the present embodiment, when the plate making of the front plate making image 8A in the divided plate making master 8X is completed, the plate making is made to be in a plate making standby state for making the back plate making image 8B for back printing in the next divided plate making master 8X. Although the unit 15 is temporarily stopped, it is desirable to do as follows. That is, when an ADF (not shown) is attached to the image reading unit 18, in addition to the automatic document feeding operation, the second document is scanned in advance, and image data relating to the read document image is stored and stored. For example, an image memory (not shown) such as a bitmap memory is provided, and the first and second image data are stored and stored in the image memory, and the plate making is continuously performed while sequentially calling the image data. Such a configuration is desirable from the viewpoint of shortening the plate making time.

  The printing operation is performed following the plate feeding operation. When the plate cylinder 1 stops at the home position, the control means 110 activates the printing pressure range variable means 28. In the following, when the printing corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 or the front surface printing in the regular double-sided printing operation is performed first, the mark shown in FIG. The printing pressure range variable means 28 is controlled so that the printing pressure ON timing by the press roller 21 in the pressure range pattern I is selected. That is, through a known detailed operation, the cam plate 243B is selected and the contour peripheral surface of the cam plate 243B comes into contact with the cam follower 241.

When the winding of the divided plate-making master 8X around the plate cylinder 1 is completed, the plate cylinder 1 starts to rotate in the direction of the arrow shown in FIG. 1 at a predetermined low printing speed (for example, 30 sheets / minute). Then, a paper feeding / printing process for printing is started.
As in the first operation example, first, the sheet feeding start light shielding plate 121 shown in FIG. 4 is engaged with the sheet feeding registration sensor 120, so that the sheet feeding motor 37 is activated and comes into contact with the sheet feeding roller 33. The uppermost first sheet 36 on the sheet feeding tray 35 is fed toward the nip portion of the registration roller pair 31.
Next, when the plate cylinder 1 further rotates in the direction of the arrow in FIG. 1 and the registration start light shielding plate 122 engages with the paper feeding registration sensor 120, the registration motor 41 is started in the same manner as in the first operation example. The sheet 36 is sent out between the plate cylinder 1 and the press roller 21 by the rotation of the registration roller pair 31.

  Next, based on the detection signal of the leading edge of the sheet 36 from the sheet detection sensor 32 and the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor 29, the control unit 110 turns on the solenoid 62 in the same manner as in the first operation example. The cam plate 243B of the printing pressure range varying means 28 is operated. The same detailed operation of the locking means 64 as in the operation example 1 is performed, the contour peripheral surface of the cam plate 243B contacts the outer peripheral surface of the cam follower 241, and the outer peripheral surface of the cam follower 241 is in contact with the peripheral surface of the small diameter portion of the cam plate 243B. At the rotational position of the cam plate 243B that is opposed and in a non-contact state, the arm pair 22 is swung clockwise by the urging force of the printing spring 242 about the arm shaft 22a.

  As a result, as shown in FIG. 3, the press roller 21 has a sheet 36 on the surface plate-making image 8A of the divided plate-making master 8X whose outer peripheral surface is wound on the surface region e1 of the plate cylinder 1 shown in FIG. Is displaced to a printing position where printing pressure is applied. At the same time, the press roller drive motor 55 rotates the press roller 21 at a speed substantially equal to the peripheral speed of the plate cylinder 1, so that the sheet 36 is formed on the surface plate-making image 8 A portion of the divided plate-making master 8 X on the plate cylinder 1. Is continuously pressed so that the surface plate-making image 8A of the divided plate-making master 8X is brought into close contact with the outer peripheral surface of the plate cylinder 1 and is filled with ink.

  In this way, after the plate printing corresponding to the surface plate-making image 8A on the divided plate-making master 8X on the plate cylinder 1 is performed, the large-diameter portion peripheral surface of the cam plate 243B and the cam follower 241 come into contact with each other, so The arm 22 is rotated counterclockwise about the arm shaft 22a, and the press roller 21 is held in the non-printing position. At this time, the solenoid 62 of the locking means 64 is already turned off by a command from the control means 110, so that the press roller 21 is returned to and held in the initial position state in which the non-printing position is occupied.

  In parallel with the printing operation, when the clamper 7 of the plate cylinder 1 passes over the press roller 21 occupying the non-printing position, the switching guide 46 is swung counterclockwise about the shaft 47a. Occupies the second displacement position and stops. At the same time, the drive motor 94 of the moving means 87 is activated, so that the movable guide 81 is also printed from the initial position (standby position) P2 by printing as shown in FIG. Is moved to the movement position P1 so as to be held. When the movable guide 81 occupies the movement position P1, as shown by the solid line in FIG. 8, the lower release lever 83 slides on the contour circumferential surface of the release cam 98, and the clamp pawl 81b swings clockwise. And it waits and stops in the state released from the contact state with the upper surface of the clamping base 81f.

  When the movable guide 81 occupies the movement position P1 and stops, as shown in FIG. 5, the front end of the front surface printed paper 36a occupies the second displacement position and stops at the switching guide 46 and the peeling fan 171. By the operation of, it is reliably peeled off from the divided plate-making master 8X on the plate cylinder 1. The front end portion of the peeled surface-printed paper 36a is guided by the inclined surface of the clamp claw 81b provided on the movable guide 81, and the gap portion between the upper surface of the clamping base 81f and the free end of the clamp claw 81b that is opened. And then abuts against the sheet abutting surface 81e of the end fence 81d to abut and align the tip. At this time, the drive motor 94 is activated so as to be approximately the same speed as the conveyance speed of the front surface printed paper 36a, and the movable guide 81 starts moving toward the initial position P2.

  At this time, when the lower release lever 83 is disengaged from the contour peripheral surface of the release cam 98, the front end portion of the surface-printed paper 36a is clamped and clamped between the free end of the clamp claw 81b and the upper surface of the clamping base 81f. . As described above, after the plate printing corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 is completed, the press roller 21 is returned to and held in the initial position that occupied the non-printing position. In a paper feed standby state for the next paper feed.

  On the other hand, the front-side printed paper 36a is conveyed toward the initial position P2 while being sandwiched between the movable guides 81. When the movable guide 81 reaches the holding position P2 ′, the movable guide 81 is temporarily stopped while holding the leading end of the double-side printed paper 36a, and then the release lever upper 82 is moved as shown by a two-dot chain line in FIG. By abutting with the release pin 99, the clamp pawl 81b is swung clockwise, so that the front end portion of the front surface printed paper 36a is released from the nipping state.

When the rear end of the front surface printed paper 36a passes the switching guide 46, the switching guide 46 returns to the first displacement position (initial position) and stops as shown by the solid line in FIG.
The front-side printed paper 36a whose leading end is released is temporarily sucked and held by the re-feed transport device 48 by suction from the non-printed image surface on the back surface of the transport belt 108 according to a command from the control unit 110. Next, the belt drive motor 105 transports the paper 36a at a transport speed corresponding to the printing speed, but is stopped by the stopper surface 53a immediately after that. As a result, the front end portion of the front surface printed paper 36a can be deflected and displaced by an appropriate amount by the energy when the front surface printed paper abuts against the stopper surface 53a.

  Next, based on the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor 29, the plate cylinder 1 performs printing on the back surface of the front surface printed paper 36a corresponding to the back plate making image 8B in the divided plate making master 8X. It is assumed that the control unit 110 determines that a possible rotational position has been reached. In response to this, the solenoid 73 is turned on and the re-feeding registration roller 51 is raised toward the outer peripheral surface of the press roller 21 to release the front end portion of the front surface printed paper 36a from the contact state with the stopper surface 53a. Then, it is pressed against the outer peripheral surface of the press roller 21, and at the same time, the press roller driving motor 55 is driven to rotate, whereby the press roller 21 is rotated counterclockwise. As a result, the surface-printed paper 36 a is pressed and held between the press roller 21 that rotates counterclockwise and the refeed resist roller 51 that rotates clockwise, while the rotational force of the press roller 21 causes the plate cylinder 1 to rotate. It is formed by the plate cylinder 1 and the press roller 21 being brought into pressure contact with each other at a speed substantially equal to the peripheral speed and guided by the roller guide plate 50 along the outer peripheral surface of the press roller 21. The paper is conveyed while being turned upside down toward the nip portion 16a.

  At this time, when performing printing corresponding to the back side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1 or back side printing in a regular double-sided printing operation described later, it is shown in FIG. The printing pressure range variable means 28 is controlled so that the printing pressure ON timing by the press roller 21 in the printing pressure range pattern II is selected, the cam plate 243C is selected, and the contour peripheral surface of the cam plate 243C comes into contact with the cam follower 241. .

  In parallel with this conveyance, when the small diameter portion of the cam plate 243C rotating in synchronization with the rotation of the plate cylinder 1 is brought into a non-contact state facing the cam follower 241, the outer periphery of the press roller 21 is shown in FIG. The back surface pre-printed image 8B of the divided pre-made master 8X shown in FIG. At this time, the nip portion 16a is formed by the urging force of the printing pressure spring 242, and double-sided printing for printing is performed.

  In this way, a plate on which double-sided printing has been performed in which ink is filled corresponding to the backside plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1 and a backside printed image is formed on the backside of the front surface printed paper 36a. The double-sided printed paper 36b for attachment is peeled off from the divided plate-making master 8X on the plate cylinder 1 by the air from the peeling claw 170 and the peeling fan 171 whose leading end approaches the outer peripheral surface of the plate cylinder 1. The double-sided printed paper 36 b is sent to the paper discharge conveyance device 152 and discharged to the paper discharge tray 172.

  On the other hand, when the press cylinder 21 makes approximately three-quarters of a turn from the time when the press roller 21 contacts the outer peripheral surface of the plate cylinder 1 and the cam follower 241 contacts the large diameter peripheral surface of the cam plate 243C, an example of operation is performed. 1, the press roller 21 is returned to and held in the non-printing position away from the outer peripheral surface of the plate cylinder 1, and the plate cylinder 1 rotates to the home position again and stops. After the attaching operation, the stencil printing apparatus enters a print standby state for the next regular duplex printing.

After the stencil printing apparatus is in a print standby state, the printing conditions are input by the operation panel 350, the position or density of the image is confirmed by trial printing, and the print start command is input after the number of prints is input. Then, the paper 36 is continuously fed from the paper supply unit 30 and a set number of double-sided printing operations are performed.
The printing operation (see FIG. 9A) at a set low speed (for example, 60 sheets / minute) is basically different from the printing operation described above as summarized below. Since the above operation can be easily understood and carried out by those skilled in the art from the double-sided printing operation disclosed in the above-described plate-making operation, the description thereof is simplified.
First, the stencil printing apparatus is configured, and the driving of each unit / apparatus for direct operations such as paper feeding, refeeding, front surface printing, back surface printing, and paper discharge corresponds to the set printing speed. Driven.

Next, as shown in FIG. 9A, when printing is performed on the second sheet corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1, and subsequently, reprinting is performed. When printing corresponding to the back side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1 is performed on the back side of the first front-side printed paper 36a reversely conveyed by the paper feeding means 45, the normal single-sided printing mode is used. Similarly, the printing pressure range variable means 28 controls so that the printing pressure ON timing by the press roller 21 in the printing pressure range pattern III shown in FIG. 3 (see the pressing roller pattern in FIG. 9A) is selected. Is done.
The detailed operation of the printing pressure range varying means 28 at this time is performed in the same manner as in the operation example 1 as described above, and as shown in FIG. 9A, in the divided plate-making master 8X on the plate cylinder 1. A second sheet of paper is pressed by the press roller 21 against the surface plate-making image 8A, and the press roller 21 continuously occupies the printing position in the divided plate-making master 8X on the plate cylinder 1. The back surface of the first front-side printed paper 36 a that is reversely conveyed by the re-feeding means 45 to the back-side plate-making image 8B is pressed by the press roller 21.

Next, it is assumed that a command for rotating the plate cylinder 1 at a low speed (60 sheets / minute) and a print number command are input from a control panel (not shown). In this case, with respect to the set number N, double-sided printing on the sheet 36 up to the (N-1) th sheet is continuously reversed and conveyed on the first surface 8A and the second surface 8B, as described above. However, the printing operation is repeated as shown in FIG.
Printing proceeds and the final sheet (Nth sheet) is printed on the first surface 8A and reaches the movable guide 81 of the nipping and conveying means 190. Here, the final sheet (Nth sheet) is nipped by the movable guide 81 that has reached the first position P1, and is conveyed and held by this movable guide 81 to the holding position P2 ′. Next, when the rotation of the plate cylinder 1 proceeds and the movable guide 81 of the nipping and conveying means 190 also reaches the initial position P2 from the holding position P2 ′, the final sheet (Nth sheet) is released from the movable guide 81. Here, the final sheet (Nth sheet) is held and released until the plate cylinder 1 rotates and reaches the next rotation cycle. The released final sheet (Nth sheet) is sucked by the suction fan 109 of the refeed conveyance means 48 to the lower sheet discharge belt 108, and the lower sheet discharge belt 108 rotates clockwise to form the final sheet (Nth sheet). Is transported to a predetermined position where the end surface of the first end contacts the stopper portion 53a and stops. When it is determined that the plate cylinder 1 is rotated and the second surface 8B has reached the print-corresponding position, the paper feeding registration roller 51 is raised, and the final paper (Nth sheet) is clamped and brought into contact with the press roller 21. Then, the sheet 36 a on which the first surface (indicated as “A” in FIG. 9A) is printed is transmitted with driving force from the press roller 21, and the nip between the plate cylinder 1 and the press roller 21 along the roller guide plate 50. It is conveyed toward the part. At this time, the press roller 21 is also controlled to be pressed by the cam 243 at a position corresponding to only the second surface. The final sheet (Nth sheet) is pressed against the plate cylinder 1 by the press roller 21 to complete the printing of the second surface (denoted as B in FIG. 9A), and then the paper discharge claw 46 approaches and separates from the plate cylinder 1. Are peeled off from the plate cylinder 1 by the peeling fan 171, sucked and conveyed by the paper discharge belt 158, and discharged to the paper discharge tray 172 to complete printing.

As described above, when the rotational speed of the plate cylinder 1 is low (60 sheets / min), the printing of the second surface (indicated as B in FIG. 9A) is performed in the next rotation cycle of the plate cylinder 1. Done.
Next, it is assumed that a command for rotating the plate cylinder 1 at a high speed (120 sheets / minute) and a print number command are input from a control panel (not shown). In this case, as shown in FIG. 9C, for the set number N, duplex printing on the sheet 36 up to the (N-1) th sheet is performed on the first side as in the case of the low speed described above. As shown in FIG. 9C, the printing operation is repeatedly performed while A and the second surface B are continuously reversed and conveyed.

Printing proceeds and the final sheet (Nth sheet) is printed on the first surface 8A and reaches the movable guide 81 of the nipping and conveying means 190. Here, the final sheet (Nth sheet) is nipped by the movable guide 81 that has reached the first position P1, and is conveyed and held by this movable guide 81 to the holding position P2 ′. Here, the control means 110 issues a command to reduce the rotational speed of the plate cylinder 1 to a low speed (60 sheets / minute) which is a preset final speed Va set in advance. Accordingly, when the rotational speed of the plate cylinder 1 is controlled to be reduced and reaches a low speed (60 sheets / minute), the control means 110, which has detected this, holds the movable guide 81 of the nipping and conveying means 190 in the holding position. Switch from P2 'to the initial position P2. In response to this, the final sheet (Nth sheet) is released from the movable guide 81.
Here, the plate cylinder 1 is decelerated, and the final sheet (Nth sheet) is held and released until the rotation cycle reaches a low speed (60 sheets / min) which is the set final speed Va. .

  Thereafter, as in the case of the low speed described above, the released final sheet is sucked by the suction fan 109 to the lower sheet discharge belt 108, and the end surface of the final sheet (Nth sheet) comes into contact with the stopper portion 53a and stops. When it is determined that the rotation of the plate cylinder 1 continues and the print corresponding position of the second surface B is reached, the paper feed registration roller 51 is raised and the final sheet (Nth sheet) is held in contact with the press roller 21. Thus, the paper 36 a on which the first surface is printed is transmitted to the nip portion between the plate cylinder 1 and the press roller 21 by the driving force transmitted from the press roller 21. After the printing of the second surface B is completed, the final sheet (Nth sheet) is peeled off from the plate cylinder 1, sucked and conveyed to the discharge belt 158, and discharged to the discharge tray 172 to complete the printing.

  In addition, when the rotational speed of the plate cylinder 1 is medium speed (90 sheets / minute), as shown in FIG. 9B, compared with the case of high speed (120 sheets / minute), the final After the sheet (Nth sheet) is conveyed and held from the first position P1 to the holding position P2 ′, the deceleration time for decelerating to the low speed (60 sheets / min) that is the set final speed Va is relatively short. However, there is no difference in other control processes, and redundant explanation is eliminated.

And at the time, usually, in the double-sided printing, general printing speed is there is a variable-speed mode of about five steps at a speed of about 60 to 120 sheets / minute. In the present embodiment, a fine movement speed, a printing speed (30 sheets / minute), a low speed (60 sheets / minute), a medium speed (90 sheets / minute), and a high speed (120 sheets / minute) are employed. Here, in double-sided printing of a large number of sheets, there is a high frequency of adopting continuous printing at medium speed (90 sheets / minute) and high speed (120 sheets / minute). Under such circumstances, in the case of high-speed double-sided printing at a high speed, the final paper (Nth sheet) is nipped and conveyed prior to printing on the second side after printing on the first side in the final sheet (Nth sheet). Once sandwiched by 48, printing of the second surface is continued in the next rotation cycle. In normal double-sided printing, the printing roller ON timing is selected continuously through the first surface A and the second surface B in one rotation cycle along the printing pressure range pattern III shown in FIG. When the printing pressure on the second surface B of the final sheet (Nth sheet) is turned on, the printing pressure is turned on when it approaches the second surface B after passing through the first surface A.

  For this reason, in addition to the influence of vibration due to switching of the pressing range of the press roller having a large load, the holding conveyance means 48 performs suction conveyance etc. after releasing the paper at high speed, and subjected to speed fluctuation etc. In normal double-sided printing while maintaining medium speed and high speed, there has been a tendency for the image position of the final paper (Nth sheet) to vary greatly.

  On the other hand, since such a problem does not occur in double-sided printing at low speed, in the present invention, the set final speed is set to low speed (60 sheets / minute) here. In addition, in the printing of the second surface B of the final sheet (Nth sheet) after printing on one side (first surface A) once sandwiched by the sandwiching and conveying means 48, normal medium speed and high speed are maintained. The speed of the plate cylinder 1 is decelerated and switched from double-sided printing to a low speed (60 sheets / minute), which is the set final speed, and after the same speed as the set final speed, single-sided (first side A) printing by the nipping and conveying means 48 The subsequent final sheet (Nth sheet) is released and the second side B is printed. As a result, it is possible to obtain a printed matter in which variations such as image positions are eliminated in printing of the second surface 8B. Further, after the printing is completed, the plate cylinder 1 is decelerated and stopped at the home position, and it is usually completed. Therefore, the plate cylinder rotation deceleration area is put in the middle of printing the final sheet (Nth sheet). In particular, the printing time per cycle does not increase.

In the above-described preparative time, in the printing of the second surface B of one side of a large number of sheets of double-sided printing the final paper (first surface A) after printing (N th), the rotational speed of the plate cylinder 1 is at a set final speed When a certain low speed (60 sheets / min) is reached, the second side B is printed. However, where the set final speed may be any number of revolutions that can be reliably eliminate the variation of an image position in the printing of the second surface, is not limited to low speed described above, for example, during determine with step The rotation speed (30 sheets / min) may be set, and in this case, a printed matter in which variations such as the image position are eliminated in the printing of the second surface 8B can be obtained more reliably.

1 is a schematic front view of a stencil printing apparatus according to a first embodiment of the present invention. It is a block diagram which shows the control structure of the stencil printing apparatus of FIG. FIG. 3 is a diagram for developing and explaining three printing pressure range patterns applied corresponding to a divided master-making master on a plate cylinder used in the stencil printing apparatus of FIG. 1. FIG. 2 is a perspective view showing an arrangement example of a sheet feeding start light shielding plate and a resist start light shielding plate used in the stencil printing apparatus in FIG. 1 on an end plate of a plate cylinder. FIG. 2 is a partial cross-sectional front view illustrating an enlarged configuration and operation around a printing unit, a refeed unit, and a printing pressure range variable unit of the stencil printing apparatus in FIG. 1. FIG. 2 is a partial cross-sectional front view illustrating an enlarged configuration and a surface printing operation around a printing unit, a refeed unit, and a printing pressure range variable unit of the stencil printing apparatus in FIG. 1. FIG. 3 is a partial cross-sectional front view illustrating an enlarged double-sided printing operation in parallel with the configuration of the printing unit and the re-feeding unit of the stencil printing apparatus in FIG. It is a partial cross section front view of the clamping conveyance means of the stencil printing apparatus in FIG. FIG. 2 is a diagram for explaining a correlation between a printing pattern on the second surface of a final sheet, a rotation mode of a plate cylinder, and a printing pressure pattern of a press roller when performing duplex printing on a large number of sheets by the stencil printing apparatus in FIG. At low speed, (b) shows a pattern at medium speed, and (c) shows a pattern at high speed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plate cylinder 8 Master 8A The surface plate-making image as a 1st plate-making image 8B The back surface plate-making image as a 2nd plate-making image 8C Intermediate | middle non-plate-making area 8X The division plate-making master 8Y The plate-making master 8YA Single-side plate-making image 11 Thermal head 15 Plate-making Section 16 Printing section 16a Nip section 17 Plate discharging section 18 Image reading section 19 Paper discharge section 21 Press roller (pressing means)
28 Printing Pressure Range Variable Means 30 Paper Feed Unit 36 Paper (Example of Sheet-like Recording Medium)
45 Refeeding means 46 Switching guide (switching means)
48 Re-feed conveying means 51 Re-feed resist roller 52 Re-feed sensor (front printed paper detection means)
53 Stopper member (refeed stop means / refeed stop member)
53a Stopper surface 81 Movement guide (paper clamping means)
81b Clamp claw (clamping member)
87 Moving means 104 Refeeding conveyance device (refeeding conveyance means)
DESCRIPTION OF SYMBOLS 110 Control apparatus as a control means 190 Nipping conveyance means A 1st surface B 2nd surface X Paper conveyance direction X1 Master conveyance direction Y Paper width direction Va Set final speed

Claims (2)

A master made by making a first image for front side printing and a second image for back side printing into two front and rear sides within the length of one plate by the plate making means can be rotated around its own central axis. Is wound around the outer peripheral surface of the porous cylindrical plate cylinder supported by the sheet, and the sheet is placed on the first surface which is divided into two front and rear portions by a pressing means which is relatively movable with respect to the plate cylinder on which the master is wound. A stencil printing apparatus that performs single-sided printing by pressing and reversing the same sheet by a refeeding means disposed below the plate cylinder, and pressing the reversed sheet against the second surface of the plate cylinder In
The re-feeding means sandwiches the one-side printed paper temporarily stopped before re-feeding the paper to the pressing means, and the leading edge of the paper approaching and separating from the pressing means. comprising a holding and conveying means for guiding said refeeding means Te,
Has been clamped by the clamping transfer means is single-sided printing above in parallel to the operation guides the clamping to refeeding means the paper on which the single-sided printing by pressing the first sheet to the first surface Control means for controlling to perform double-sided printing at a predetermined printing speed by opening the previous paper and pressing the inverted paper against the second surface to perform other side printing;
The control means releases and prints the final sheet after single-sided printing held by the holding and conveying means after the plate cylinder speed is reduced from the double-sided printing speed to a predetermined final speed. Stencil printing device. In the stencil printing apparatus according to claim 1,
The stencil printing apparatus, wherein the control means controls the set final speed as a rotation speed at the time of the judgment process.

Images