JPH0822710B2 - Paper output device of printing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper discharge device incorporated in a printing device, and more particularly to a paper discharge device that conveys print paper from a printing unit to a paper discharge tray.

<< Prior Art >> Generally, a rotary printing apparatus has a plate cylinder on the outer peripheral surface of which a plate such as a stencil plate is mounted, and in contact with the plate in synchronization with the rotation of the plate cylinder A printed image is formed on the upper surface with printing ink. Conventionally, the discharge of a printing apparatus of this type, that is, the action of guiding the print sheet for which printing has been completed to the discharge tray is driven by the kinetic force applied to the print sheet by the rotation of the plate cylinder.

In most cases, the printing direction of the printing paper discharged from the printing section by the plate cylinder is substantially horizontal, and when the printing paper is discharged in a flat and natural state, the front side of the printing paper is self-weighted. Then, the printing paper is bent due to air resistance at that time, and the printing paper flies on the paper ejection tray in that state. In such a case, the ejected flight distance of the print sheets varies, and the print sheets cannot be regularly stacked on the eject tray. In addition, the front edge of the drooped printing paper will scrape the image surface of the printing paper that has been ejected onto the paper ejection tray first, so that the printed image will be destroyed and the printing paper will be contaminated. It will be.

When a new printing base paper is attached to the plate cylinder of the printing device and printing is started, it is necessary to perform low-speed printing for a while after the start of printing in order to adapt the printing ink to the new original plate. Since the discharging speed of discharging the printing paper is also slowed down, the leading end portion of the printing paper is liable to hang down, and the above-mentioned inconvenience becomes prominent.

In view of such a problem, the present applicant previously filed Japanese Patent Application No. 54-
No. 133801 (Japanese Patent Publication No. 58-46428) proposes a paper ejection guide device. The content of this is that the discharged printing paper is curved in a substantially U-shaped arc shape in a cross section orthogonal to the paper discharging direction in the paper discharging process so that the apparent rigidity of the printing paper along the paper discharging direction is increased. It is configured to cause the printing paper to fly to a position directly above the paper ejection tray without causing hang-up and to cause the printing paper to drop onto the paper ejection tray while maintaining a substantially horizontal posture. It is said that the printing paper can be ejected one after another onto the ejection tray without rubbing the printed image surface of the printing paper on the ejection tray.

Further, there is known a paper discharge device including a belt conveyor that conveys print paper from the printing unit toward the paper discharge tray. In this paper discharge device, the belt conveyor conveys the motive force for transporting the print paper from the printing section to the paper discharge tray. Therefore, the flying force of the print paper to the paper discharge tray is increased, and the paper discharge performance of the print paper is improved.

<< Problems to be Solved by the Invention >> In the paper discharge process, the printed paper discharged is curved in an arc shape of a substantially U shape when viewed in a cross section orthogonal to the paper discharge direction, and an apparent appearance along the paper discharge direction. Increasing the upper rigidity achieves the intended purpose of causing the printing paper to fly to a position directly above the output tray without causing sagging, but the printing speed, the type of printing paper, and the like. In some cases, the increase in apparent rigidity may be insufficient.

In order for the printing paper to fly vigorously onto the paper ejection tray without hanging down due to its own weight, it is important that the flying inertia applied to the printing paper when the trailing edge of the printing paper leaves the belt conveyor is large. Is.

However, the contact area between the print paper and the belt conveyor decreases as the print paper advances toward the discharge tray by the belt conveyor.Therefore, when the trailing edge of the print paper separates from the belt conveyor, it is applied to the print paper by the belt conveyor. The amount of transporting momentum to be carried out is reduced most, and along with this, the flying inertial force applied to the printing paper becomes small at a critical point, and there is a limit to the improvement of the discharging performance of the printing paper.

In view of the above problems, the present invention sufficiently and surely enhances the apparent rigidity regardless of the type of printing paper,
Also, when the trailing edge of the printing paper leaves the belt conveyor, it gives an accurate large flying inertia force to the printing paper, and the printing papers are stacked and ejected on the paper ejection tray surely in order to be ejected. The purpose is to provide a paper device.

<< Structure of the Invention >> In order to achieve the above-mentioned object, the present invention is a paper discharge device of a printing apparatus that conveys print paper from a printing unit to a paper discharge tray. A belt conveyer to convey, a side protrusion guide member and a center protrusion guide member respectively provided on both side portions and a center portion in the vicinity of a conveyance end portion of the printing paper by the belt conveyor, and provided at an arrangement position of the center protrusion guide member. And a sheet feeding roller which is brought into contact with the printing sheet on the outer peripheral surface thereof and is rotationally driven at a peripheral speed higher than the conveying rate of the printing sheet by the belt conveyor, and air opened to the conveying surface of the printing sheet by the belt conveyor. And a paper suction means for sucking the printing paper such that the printing paper is pressed against the belt conveyor including the suction port, and the air suction port is the bell. A side air suction port opened to the conveyance surface between the side protrusion guide member and the center protrusion guide member in the vicinity of the conveyance end portion of the print sheet by the conveyor, and the center protrusion guide member. A central air suction port opened on the upper surface, and the central air suction port is disposed closer to the terminal end side of the conveyance of printing paper by the belt conveyor than the side air suction port.

<< Operation of the Invention >> According to the above-described configuration, the printing paper is sucked by the air suction port (side portion) in the process of riding over the side protrusion guide members and the center protrusion guide members on both sides. It is sucked into the valley bottom between the side raised guide member and the central raised guide member. As a result, the printing paper is surely bent into a substantially W-shaped wavy shape, the apparent rigidity is surely increased, and the printing paper flies toward the discharge tray.

Further, since the paper delivery roller is rotating at a peripheral speed faster than the printing paper transport speed, the printing paper is accelerated by contact with the outer peripheral surface of the paper delivery roller when the trailing edge of the printing paper is separated from the belt conveyor, Increases flight inertia.

In this case, the printing paper is pressed against the outer peripheral surface of the paper delivery roller by air suction from the central air suction port,
Moreover, since the central air suction port is located closer to the end of the printing paper conveyance by the belt conveyor than the side air suction port, the printing paper is finally pressed only on the outer peripheral surface of the paper delivery roller by the central air suction port. As a result, the printing paper is effectively accelerated by the contact with the outer peripheral surface of the paper delivery roller.

<Example> Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 show an embodiment of a paper discharge device of a printing device according to the present invention.

In these figures, reference numeral 1 indicates a cylindrical plate cylinder of the printing apparatus. The cylindrical plate cylinder 1 has a porous structure that allows the passage of printing ink in the direction of the through wall, and the stencil sheet 2 is provided on the outer peripheral surface.
Is attached and attached, and is rotationally driven in the counterclockwise direction in FIG. 1 by a drive device (not shown) around its own central axis.

A press roller 3 is provided below the cylindrical plate cylinder 1. The press roller 3 is rotatably supported around a support shaft 4 and is selectively pressed toward the outer peripheral surface of the cylindrical plate cylinder 1 by a spring device (not shown). The printing paper P that is fed between and is pressed against the outer peripheral surface of the cylindrical plate cylinder 1.

A separation claw 5 is provided at a position close to the outer peripheral surface of the cylindrical plate cylinder 1 while being supported by a support shaft 6. This separation claw 5
Is very close to the outer peripheral surface of the cylindrical plate cylinder 1 at the pointed tip portion 5a, and the printing paper P stuck with the printing ink is hooked on the outer peripheral surface of the cylindrical plate cylinder 1 to make the cylindrical plate cylinder 1 It is peeled off from the cylindrical plate cylinder 1 with the rotation of.

In the figure, reference numeral 10 generally indicates a paper discharge device. The paper discharge device 10 has a suction box 11. The suction box 11 has a flat upper plate 12, and the upper plate 12 is orthogonal to the central axis of the cylindrical plate cylinder 1 due to the proximity of the cylindrical plate cylinder 1 and the press roller 3, that is, the proximity of the printing section. It extends in the direction away from the outer peripheral surface of the cylindrical plate cylinder 1 along the direction and is inclined downward and toward the paper discharge tray 7. That is, the suction box 11 is arranged between the printing unit and the paper discharge tray 7.

Pulley shafts 16 and 18 are rotatably provided at the end of the suction box 11 on the side of the cylindrical plate cylinder 1 and the end on the side of the discharge tray 7, respectively, and three pulley shafts 16 and 18 are provided on each end. Pulley 1
5 and 17 are mounted axially spaced from each other.

Each of the three pairs of pulleys 15 and 17 is provided with three thread-shaped endless belts 19 spaced apart from each other in the axial direction and applied with a predetermined tension. It has been passed. The endless belt 19 is made of a material having a relatively high coefficient of friction such as rubber or a rubber-like material.

The upper span of the endless belt 19 is close to the upper plate 12 and
The lower span extends along 12 and passes through a tunnel portion 13 provided through the suction box 11.

A driving pulley 20 is attached to one end of the pulley shaft 16, and the driving pulley 20 is drivingly connected to an electric motor (not shown) by a driving endless belt 21.
As seen in the figure, the endless belt 19 is driven to rotate clockwise, and the endless belt 19 is driven to travel at a speed higher than the peripheral speed of the cylindrical plate cylinder 1.

By this traveling drive, the endless belt 19 conveys the printing paper P placed on the upper span from the printing unit to the paper ejection tray 7.

An air suction port 22 is formed at a portion near the plate cylinder side end of the upper plate 12 and at a portion corresponding to the upper span of each endless belt 19. As a result, each endless belt 19 runs on the air suction port 22 in the vicinity of the start end of the upper span.

A side air intake port 38 is formed near the end of the upper plate 12 on the side of the discharge tray and at a portion corresponding to the upper span of the endless belt 19 on both the left and right sides. As a result, the left and right endless belts 19 run on the side air intake port 38 near the end of the upper span.

The suction box 11 communicates with a fan chamber 25 of a fan housing 24 attached to the lower bottom portion of the suction box 11 through a communication hole 23 formed in the bottom plate 14. A centrifugal fan 27, which is rotationally driven by an electric motor 26, is attached to the fan chamber 25.

The centrifugal fan 27 sucks air from the communication port 23, discharges this air to the exhaust chamber 30 in the lower case 29 from the exhaust port 28 provided at the bottom of the fan housing 24, and the suction box 11
A negative pressure is generated inside. An air outlet 31 is provided on the lower bottom of the lower case 29, and the air outlet 31 has a filter.
32 is installed.

On the upper plate 12, of the three sets of endless belts 19, a central raised guide member 35 is attached at a position along the central endless belt 19. The central raised guide member 35 is a cylindrical plate cylinder 1.
It has an inclined upper surface 35a that is inclined upward with respect to the upper surface of the upper plate 12 as it goes from the side toward the sheet discharge tray 7.

A paper feed roller 37 is rotatably provided by a shaft 37c at an upper end portion of the central raised guide member 35 on the paper discharge tray 7 side, and an endless belt 19 at the center of an outer peripheral groove 37a of the paper feed roller 37 is stretched. Has been done. As a result, the central endless belt 19 runs along the inclined upper surface 35a of the central raised guide member 35.

The paper feed roller 37 is rotationally driven in the clockwise direction as seen in FIGS. 1 and 3 as the endless belt 19 runs. The paper feeding roller 37 is in contact with the printing paper in the paper discharging process at the outer peripheral surface 37b and is engaged with the endless belt 19 at the outer peripheral groove 37a. Therefore, the peripheral speed of the outer peripheral surface 37b is the printing paper by the endless belt 19. The peripheral speed is higher than the transport speed.

On the inclined upper surface 35a of the central raised guide member 35, a central air suction port 39 is opened at a position near the paper feeding roller 37. The central air intake port 39 communicates with the inside of the suction box 11 through a communication hole 40 provided in the upper plate 12. The central air suction port 39 is provided on the transport advance side of the side air suction port 38 (the transport end side of the print sheet P by the endless belt 19), that is, on the sheet discharge tray 7 side.

On both the left and right sides of the upper plate 12 in the vicinity of the end of the paper discharge tray 7, the side protrusion guide members 36 are provided outside the left and right endless belts 19, respectively.
Is attached. The side raised guide member 36 is an upper plate.
The upper surface of the upper plate 12 is inclined upwards with respect to the upper and lower sides of the upper plate 12 from the center side of the 12 to the left and right sides, and the upper surface of the upper plate 12 is extended from the side of the cylindrical plate cylinder 1 of the upper plate 12 toward the discharge tray 7. On the other hand, it has an inclined upper surface 36a inclined upward.

Due to the relative positional relationship between the endless belt 19 and the central raised guide member 35 and the side raised guide member 36, the side air suction port 38 is located between the side raised guide member and the central raised guide member 35. It means that it is open to the transport surface (the upper surface of the upper plate 12).

Next, the operation of the paper discharge device having the above-described configuration will be described.

As the cylindrical plate cylinder 1 rotates in the counterclockwise direction in FIG. 1, the printing paper P is sent between the cylindrical plate cylinder 1 and the press roller 3 and sandwiched between the two, and the cylindrical plate cylinder 1 The stencil sheet 2 attached to the outer peripheral surface of the stencil sheet is brought into contact with the stencil sheet 2, printing ink is applied to the upper surface of the stencil sheet 2 from the perforated image portion, and a printed image is formed on the upper surface.

The printing paper P sticks to the outer peripheral surface of the cylindrical plate cylinder 1 due to the viscosity of the printing ink. When the leading edge of the printing paper P contacts the tip portion 5a of the separation claw 5, the printing sheet P is separated as the cylindrical plate cylinder 1 rotates. It is peeled off from the outer peripheral surface of the cylindrical plate cylinder 1 by the peeling action of the claws 5, and its tip portion has its own weight and the air suction port 22.
Is sucked by the negative pressure generated in the vicinity of the air suction port 22 by sucking the outside air, falls on the upper plate 12 of the suction box 11, and is pressed on the upper span of the endless belt 19.

Since the printing paper P is pressed onto the upper span of the endless belt 19, the printing paper P is pulled away from the cylindrical plate cylinder 1 as the endless belt 19 travels and is pulled toward the paper ejection tray 7 while being pulled up. It is forcibly conveyed toward the discharge tray 7 at the top.

The printing paper P moves on the upper plate 12 toward the paper ejection tray 7 as the endless belt 19 travels, and at that time, the central portion along the paper ejection direction of the printing paper P is on the central raised guide member 35. It rides up and moves along the inclined upper surface 35a, and both left and right sides ride on the left and right side raised guide members 36 and the inclined upper surface 36
The paper P slides on a and moves at the same time, and at the same time, air is sucked by the side air inlets 38 on both sides so that the printing paper P is at the bottom of the valley between the central raised guide member 35 and the left and right side raised guide members 36. The upper plate 12 is sucked.

As a result, the printing paper P is surely curved into a substantially W-shaped wavy shape when viewed in a cross section orthogonal to the paper discharge direction as shown by the phantom line in FIG. Increases the rigidity of the hanging, making it stiff.

Therefore, even if the leading end of the printing paper P is projected from the upper plate 12 onto the paper discharge tray 7, it does not hang down.

Further, the printing paper P is subjected to air suction by the central air suction port 39 at the central portion and the endless belt 19 and the paper feeding roller.
It is pressed against the outer peripheral surface 37b of 37. As a result, the rear end side of the printing paper P approaches the position where the paper delivery roller 37 is arranged, and when the end of the conveyance by the endless belt 19 is approached, the paper delivery roller rotating at a peripheral speed faster than the conveyance speed of the printing paper by the endless belt 19. It is accelerated by the contact with the outer peripheral surface 37b of 37 and is blown toward the paper tray 7 side.

Since the central air suction port 39 is provided so as to be offset from the side air suction port 38 toward the paper ejection tray 7 side, the end side of the printing paper P is finally set by the central air suction port 39 of the paper feeding roller 37. Since it is pressed only on the outer peripheral surface and the contact pressure with the outer peripheral surface of the paper delivery roller 37 is increased, the printing paper is effectively accelerated by the paper delivery roller 37.

As a result, when the trailing edge of the printing paper P separates from the endless belt 19, a large flying inertia force is applied to the printing paper P, and the printing paper P has an apparent rigidity increase due to the substantially W-shaped wavy curve. Combined with the effect of the above, until it collides with the collision plate 8 provided at the front end of the paper ejection tray 7, it flies vigorously while maintaining a substantially horizontal state without causing sagging, and substantially on the paper ejection tray 7. Keep horizontal and fall.

By this action, the printing papers P are stacked orderly and regularly on the paper ejection tray 7 even when the papers have low rigidity including low speed printing, and the printing papers P are first placed on the paper ejection tray 7. The printed surface of the printing paper is discharged without being scratched.

<< Advantages of the Invention >> As is clear from the above description, the side portion of the printing paper is sucked by the side air suction port in the course of traveling on the side raised guide members on both sides and the central raised guide member. By being attracted to the bottom of the valley between the raised guide member and the central raised guide member, the printing paper surely bends into a substantially W-shaped wavy shape, so that the apparent rigidity is surely increased.
Since it flies toward the paper ejection tray, including during low-speed printing,
Further, even if the printing paper has a low rigidity, the printing paper can be reliably and neatly stacked and ejected on the paper ejection tray, and the paper ejection performance is improved.

In addition, the paper feed roller that rotates at a peripheral speed faster than the printing paper conveyance speed gives a large flying inertial force to the printing paper when the trailing edge of the printing paper leaves the belt conveyor, causing the printing paper to bend in a substantially W shape. Combined with the apparent rigidity improvement effect of
The sheets will be more reliably and neatly stacked and discharged,
The paper ejection performance is dramatically improved.

Also, since the central air suction port is located closer to the end of the printing paper conveyance by the belt conveyor than the side air suction port, the printing paper is finally pressed only on the outer peripheral surface of the paper delivery roller by the central air suction port. Therefore, the printing paper is effectively accelerated by the contact with the outer peripheral surface of the paper delivery roller.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a paper discharge device of a printing apparatus according to the present invention, and FIG. 2 is a front view of the paper discharge apparatus of the printing apparatus according to the present invention as seen from the side of a paper discharge tray. FIG. 1 is a partially cutaway perspective view of a paper discharge device of a printing apparatus according to the present invention. 1 …… Cylindrical plate cylinder 7 …… Paper ejection tray 10 …… Paper ejection guide 11 …… Suction box 12 …… Upper plate 15 …… Pulley 17 …… Pulley 19 …… Endless belt 22 …… Air inlet 35 …… Central raised guide member 36 …… Side raised guide member 37 …… Paper feed roller 38 …… Side air suction port 39 …… Central air suction port

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Koyama 2-20-15 Shimbashi, Minato-ku, Tokyo Inside Ideal Science Industry Co., Ltd. (56) References JP-A-50-88769 (JP, A) 56-80337 (JP, U) Jitsuko Sho 52-53766 (JP, Y2) Patent 132625 (JP, C2)

Claims (1)

[Claims] 1. A paper discharging device of a printing device for carrying printing paper from a printing unit to a paper ejection tray, and a belt conveyor for carrying the printing paper from the printing unit to the paper ejection tray; Side ridge guide members and center ridge guide members respectively provided on both sides and the center near the transport terminal end portion, and at the position where the center ridge guide member is arranged to contact the printing paper on the outer peripheral surface, The printing paper is pressed against the belt conveyor including a paper feeding roller that is driven to rotate at a peripheral speed faster than the printing paper transportation speed by the belt conveyor, and an air suction port opened to the printing paper transportation surface by the belt conveyor. And a sheet suction means for sucking the printing sheet, and the air suction port is in the vicinity of the end portion of the conveyance of the printing sheet by the belt conveyor. There is a side air suction port opened to the transport surface between the side raised guide member and the central raised guide member, and a central air suction port opened to the upper surface of the central raised guide member. A sheet discharging device of a printing apparatus, wherein the central air suction port is disposed closer to a terminal end side of the printing paper conveyed by the belt conveyor than the side air suction port.