JP2009126116A - Liquid suction device, maintenance recovery device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently exhibit a recovery function of a recording head by preventing ink from flowing from a suction cap into a flexible tube communicating with a discharge port in a period other than a sucking operation period and preventing the flexible tube from being clogged due to an increase in ink viscosity. <P>SOLUTION: In a non-active state where the ink droplets are not ejected from the recording head 34 and not sucked, the flow path of a suction pump 120 is opened while putting a cap 92a on the recording head 34, and the flow path of the flexible tube 119 communicating between the cap 92a and the suction pump 120 is closed by an eccentric cam 160, then, the ink is prevented from flowing from the cap 92a into the flexible tube 119, consequently, the flow path is prevented from being clogged due to the increase in liquid viscosity in the flexible tube 119. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid suction device and a maintenance / recovery device for a droplet discharge device, and an image forming apparatus using the same, and more particularly to prevention of clogging of a suction channel for a liquid having a high viscosity.

  In an ink jet recording apparatus that records an image by ejecting ink droplets from a recording head ink ejection port (nozzle) to a recording medium such as paper based on image information, the recording head is brought into an optimum state for ejecting ink droplets. In order to recover, the ink discharge port portion of the recording head is covered with a suction cap, and extraneous ink, foreign matter such as dust and bubbles in the recording head, particularly nozzle holes, are sucked and removed by a suction device. The sucked ink travels along the inner wall of the cap and is mostly discharged from a discharge port provided below the suction cap.

  Due to the recent increase in image quality and speed, the ink needs to be quickly dried and the ink viscosity tends to increase. For this reason, the ink adhering to the inner wall of the cap after the suction gradually gathers downward over time and flows into the flexible tube connected to the discharge port. If left in this state, moisture permeates from the surface of the flexible tube, and the moisture that has evaporated from the discharge port causes the ink flowing into the flexible tube to thicken and clog the flexible tube. Arise. When the flexible tube is clogged, the recovery function of the recording head cannot be performed, and the discharge function of the recording head cannot be recovered to an optimum state, which affects the image to be formed and causes a problem.

  For example, the ink suction device disclosed in Patent Document 1 uses a roller pump in which one or a plurality of rollers are rotatably provided at predetermined positions around a rotating plate, and partially crushes a flexible tube. The ink is sucked from the recording head by rubbing. In this method, since the flexible tube communicated with the discharge port is always crushed and closed by the roller pump, the ink can be prevented from flowing into the flexible tube after the suction. However, since the flexible tube is constantly squeezed by the roller pump, the flexible tube tends to crush, and its restoring force reduces the function of the suction performance, leading to variations in suction volume and recoverability. There is a problem that affects.

On the other hand, the ink suction device using the tube pump shown in Patent Document 2 or Patent Document 3 sequentially crushes the flexible tube by two rollers provided on the pump wheel only during the ink suction operation, and the recording head. Ink is sucked from the nozzle, and when it is not in the suction operation, the roller is slightly in contact with the flexible tube so that the flexible tube is not crushed to prevent a failure such as sticking of the flexible tube. ing. When ink with high ink viscosity is sucked with this ink suction device, it cannot prevent the ink from flowing from the suction cap into the flexible tube after suction, and if the flexible tube becomes clogged, the recording head recovers. Cannot be fulfilled.
JP 2002-200777 A JP 2001-138531 A JP 2003-205637 A

  Therefore, according to the present invention, the ink is prevented from flowing into the flexible tube communicating with the discharge port from the suction cap at a time other than the suction operation, thereby preventing the flexible tube from being clogged due to ink thickening. An object of the present invention is to provide a liquid suction device, a maintenance / recovery device, and an image forming apparatus of a droplet discharge device that can satisfactorily perform the recovery function of a recording head.

  The liquid suction device of the present invention includes a cap member that can be brought into contact with and separated from the droplet discharge device, a suction pump that generates negative pressure, and a flexible liquid transport that connects the cap member and the suction pump. A liquid suction device comprising a member, and having a flow channel opening and closing means for switching the flow channel of the flexible liquid transport member between an open state and a closed state, and when sucking liquid from the droplet discharge device, With the cap member capped in the droplet discharge device, the flow channel opening / closing means opens the flow channel of the flexible liquid transport member, and the droplet discharge device discharges the liquid and the liquid. In a non-operating state in which suction is not performed, the flow path of the suction pump is opened with the cap member capped on the droplet discharge device, and the flexible liquid transport member is Closed flow path Characterized in that it.

  The channel opening / closing means operates in conjunction with a cam mechanism that contacts and separates the cap member from the droplet discharge device.

  The channel opening / closing means may be an eccentric cam provided on a cam shaft that rotates a cam mechanism that contacts and separates the cap member from and to the droplet discharge device.

  Further, it is desirable to provide a swingable pressing plate between the flexible liquid transport member and the eccentric cam constituting the flow path opening / closing means.

  The flexible liquid transport member is made of silicone.

  The maintenance / recovery device according to the present invention includes the liquid suction device.

  The image forming apparatus according to the present invention includes a nozzle, a pressurized liquid chamber communicating with the nozzle, a diaphragm having at least one wall surface of the pressurized liquid chamber, having a resin layer, and the pressurizing of the diaphragm. A droplet discharge device having a piezoelectric element provided on the side opposite to the side on which the liquid chamber is formed, and the maintenance and recovery device are provided.

  The liquid suction device of the present invention opens the suction pump flow path with the cap member being capped on the droplet discharge device when the droplet discharge device does not discharge droplets and does not perform liquid suction. Since the flow path of the flexible liquid conveyance member that connects the cap member and the suction pump is closed by the flow path opening / closing means, the liquid enters the flexible liquid conveyance member from the cap member. It is possible to prevent the occurrence of clogging of the flow path due to liquid thickening in the flexible liquid transport member.

  Further, the channel opening / closing means is operated in conjunction with a cam mechanism for bringing the cap member into and out of contact with the droplet discharge device, thereby providing capping of the droplet discharge device by the cap member and flexibility by the channel opening / closing means. It is possible to open and close the flow path of the liquid transport member at a stable timing, and reliably prevent malfunction.

  Furthermore, the flow path opening / closing means is composed of an eccentric cam provided on the rotating camshaft for moving the cam mechanism for contacting and separating the cap member to and from the droplet discharge device, thereby enabling stable operation with a small number of parts. it can.

  Further, by providing a swingable pressing plate between the flexible liquid conveying member and the eccentric cam constituting the flow path opening / closing means, the liquid conveying member is closed to close the flow path of the liquid conveying member. When crushing, the pressure plate can be crushed without sliding on the surface of the liquid conveying member, improving the durability of the liquid conveying member and providing the surface of the liquid conveying member with wear resistance and flexibility Can be prevented from becoming harder, increasing the load for crushing the liquid conveying member, increasing the output of the motor that rotates the camshaft, and increasing power consumption.

  In addition, since it is possible to prevent flow path clogging due to liquid thickening in a flexible liquid conveying member, silicone having good rebound resilience (restorability) and compression set resistance as a material for the liquid conveying member Can be used, and the crushed portion of the liquid conveying member can be easily restored.

  The maintenance / recovery device having the liquid suction device of the present invention can stably maintain the droplet discharge performance of the droplet discharge device by the liquid suction device.

  The image forming apparatus according to the present invention includes a nozzle, a pressurized liquid chamber communicating with the nozzle, a diaphragm having at least one wall surface of the pressurized liquid chamber, having a resin layer, and the pressurizing of the diaphragm. By maintaining the droplet ejection performance of the droplet ejection device, which has a piezoelectric element on the opposite side of the side where the liquid chamber is formed, with the maintenance and recovery device, it is possible to stably form high-quality images. can do.

  1 and 2 show a configuration of an image forming apparatus according to the present invention, FIG. 1 is a perspective view of the image forming apparatus as viewed from the front side, and FIG. 2 is a schematic configuration diagram showing an overall configuration of a mechanism portion of the image forming apparatus. FIG. 3 is a plan view of the main part of the mechanism.

  As shown in FIG. 1, an image forming apparatus includes an apparatus main body 1, a paper feed tray 2 for loading a recording sheet attached to the apparatus main body 1, and an image recorded (formed) attached to the apparatus main body 1. And a paper discharge tray 3 for discharging and stocking the recorded paper. One end side of the front surface 4 of the apparatus main body 1 has a cartridge loading portion 6 that protrudes forward from the front surface 4 and is lower than the upper surface 5. On the upper surface of the cartridge loading portion 6, operation keys, indicators, etc. The operation unit 7 is arranged.

  The cartridge loading unit 6 includes a plurality of liquid cartridges 10k each containing liquid (ink) of different colors, for example, black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink. 10c, 10m, and 10y (referred to as the liquid cartridge 10 when colors are not distinguished) can be inserted and loaded from the front side of the apparatus main body 1 toward the rear side, and on the front side of the cartridge loading unit 6, A front cover (cartridge cover) 8 that is opened when the liquid cartridge 10 is attached or detached is provided to be openable and closable.

  As shown in FIG. 3, the mechanism of this image forming apparatus is configured to move the carriage 33 in the main scanning direction by a guide rod 31 and a stay 32 which are guide members horizontally mounted on the left and right side plates 21A and 21B constituting the frame 21. It is slidably held and moved and scanned in the direction of the arrow (carriage main scanning direction) in FIG. 3 by a main scanning motor (not shown). The carriage 33 is provided with a recording head 34 having a plurality of nozzle rows that discharge droplets of black (K), cyan (C), magenta (M), and yellow (Y), and a plurality of nozzles (discharge ports). ) Are arranged in a direction crossing the main scanning direction, and the droplet discharge direction is directed downward. The recording head 34 includes a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change due to liquid film boiling using an electrothermal transducer such as a heating resistor, a shape memory alloy actuator that uses a metal phase change due to a temperature change, An electrostatic actuator using an electrostatic force or the like provided as an energy generating means for discharging droplets can be used.

  The carriage 33 is equipped with sub-tanks 35k, 35c, 35m, and 35y for each color for supplying the recording liquids for the respective colors to the recording heads 34 (referred to as sub-tanks 35 when colors are not distinguished). The sub tank 35 is supplied with recording liquid from each color ink cartridge 10 mounted on the cartridge loading section 6 via the recording liquid supply tube 36 for each color. The cartridge loading unit 6 is provided with a supply pump unit 23 for feeding the recording liquid in the ink cartridge 10. Further, the recording liquid supply tube 36 from the ink cartridge loading section 6 to the sub tank 35 is fixed and held by the main body side holder 25 on the rear plate 21C constituting the frame 21 in the middle of turning. Further, it is fixed on the carriage 33 by the fixing rib 26.

  As shown in FIG. 2, one sheet of recording paper 42 is fed from the paper stacking unit 41 as a paper feeding unit for feeding the recording paper 42 stacked on the paper stacking unit (bottom plate) 41 of the paper feed tray 2. A half-moon roller (sheet feeding roller) 43 that separates and feeds the sheet and a separation pad 44 made of a material having a large friction coefficient are provided opposite to the sheet feeding roller 43. The separation pad 44 is urged toward the sheet feeding roller 43 side. Yes. A transport belt 51 for electrostatically attracting and transporting the recording paper 42 as a transport section for transporting the recording paper 42 fed from the paper feed section below the recording head 34, and a paper feed The counter roller 52 for transporting the recording paper 42 sent from the section via the guide 45 sandwiched between the transport belt 51 and the recording paper 42 sent substantially vertically upward is changed in direction by about 90 degrees to the transport belt. The conveyance guide 53 for making it follow on 51 and the front-end | tip pressurizing roller 55 urged | biased by the pressing member 54 at the conveyance belt 51 side are provided. In addition, a charging roller 56 that is a charging unit for charging the surface of the conveyance belt 51 is provided.

  The transport belt 51 is an endless belt, and is configured to be looped around the transport roller 57 and the tension roller 58 in the belt transport direction of FIG. The charging roller 56 is disposed so as to come into contact with the surface layer of the conveyor belt 51 and to be rotated by the rotation of the conveyor belt 51, and 2.5N is applied to both ends of the shaft as a pressing force. In addition, a guide member 61 is disposed on the back side of the conveyor belt 51 so as to correspond to a printing area by the recording head 54. The upper surface of the guide member 61 protrudes closer to the recording head 34 than the tangent line between the conveying roller 57 and the tension roller 58 that support the conveying belt 51. As a result, the conveyance belt 51 is pushed up and guided by the upper surface of the guide member 61 in the printing region, so that highly accurate flatness is maintained.

  Further, as a paper discharge unit for discharging the recording paper 42 recorded by the recording head 34, a separation claw 71 for separating the recording paper 42 from the conveying belt 51, a paper discharge roller 72, and a paper discharge roller 73, And a paper discharge tray 3 below the paper discharge roller 72. Here, the height from between the paper discharge roller 72 and the paper discharge roller 73 to the paper discharge tray 3 is increased to some extent in order to increase the amount that can be stored in the paper discharge tray 3.

  A double-sided paper feeding unit 81 is detachably attached to the back surface of the apparatus body 1. The double-sided paper feeding unit 81 takes in the recording paper 42 returned by the reverse rotation of the transport belt 51, reverses it, and feeds it again between the counter roller 52 and the transport belt 51. A manual paper feed unit 82 is provided on the upper surface of the duplex paper feed unit 81.

  Further, as shown in FIG. 3, a maintenance / recovery device 91 for maintaining and recovering the state of the nozzles of the recording head 34 is disposed in the non-printing area on one side of the carriage 33 in the scanning direction. The maintenance / recovery device 91 includes cap portions (hereinafter referred to as caps) 92a to 92d for capping each nozzle surface of the recording head 34, and a wiper blade 93 which is a blade member for wiping the nozzle surface. In addition, an empty discharge receiver 94 that receives liquid droplets for discharging a liquid droplet that does not contribute to recording in order to discharge the thickened recording liquid, and an empty discharge receiver 94 that are formed integrally with the empty discharge receiver 94, are formed on the wiper blade 93. A wiper cleaner 95 that is a cleaning member for removing the attached recording liquid, and a cleaner roller 96 that constitutes a cleaner unit that presses the wiper blade 93 against the wiper cleaner 95 when the wiper blade 93 is cleaned are provided.

  Further, as shown in FIG. 3, in the non-printing area on the other side in the scanning direction of the carriage 33, idle ejection for ejecting liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like is performed. An empty discharge receiver 98 for receiving droplets when performing the operation is disposed, and the empty discharge receiver 98 includes an opening 99 along the nozzle row direction of the recording head 34.

  In the image forming apparatus configured as described above, the recording sheets 42 are separated and fed one by one from the sheet feeding tray 2, and the sheet 42 fed substantially vertically upward is guided by the guide 45, and the conveying belt 51 and the counter It is sandwiched between the rollers 52 and conveyed, and further, the leading end is guided by the conveying guide 53 and pressed against the conveying belt 51 by the tip pressing roller 55, and the conveying direction is changed by approximately 90 degrees. At this time, a positive output and a negative output are alternately repeated from the high-voltage power supply to the charging roller 56 by a control circuit (not shown), that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 51 alternates, that is, In the sub-scanning direction, which is the circumferential direction, plus and minus are alternately charged in a band shape with a predetermined width. When the recording paper 42 is fed onto the conveyance belt 51 that is alternately charged with plus and minus, the recording paper 42 is electrostatically attracted to the conveyance belt 51, and the recording paper 42 is moved by the circular movement of the conveyance belt 51. It is conveyed in the sub-scanning direction. Therefore, by driving the recording head 34 according to the image signal while moving the carriage 33, ink droplets are ejected onto the stopped recording paper 42 to record one line, and the recording paper 42 is conveyed by a predetermined amount. After that, the next line is recorded. Upon receiving a recording end signal or a signal that the trailing edge of the recording paper 42 has reached the recording area, the recording operation is terminated and the recording paper 42 is discharged onto the paper discharge tray 3.

  During printing (recording) standby, the carriage 33 is moved to the maintenance / recovery device 91 side, the recording head 34 is capped by each cap 92, and the nozzles are kept in a wet state to prevent ejection failure due to ink drying. To do. In addition, the recording liquid is sucked from the nozzle in a state where the recording head 34 is capped by the cap 92 (referred to as nozzle suction or head suction), and a recovery operation is performed to discharge the thickened recording liquid and bubbles. In addition, an idle ejection operation for ejecting ink not related to recording is performed before the start of recording or during recording. As a result, the stable ejection performance of the recording head 34 is maintained.

  An outline of the configuration of the maintenance / recovery device 91 will be described with reference to FIGS. 4 is a plan view of a main part of the maintenance / recovery device 91, FIG. 5 is a schematic configuration diagram of the maintenance / recovery device 91, and FIG. 6 is a right side view of FIG.

  A frame (maintenance device frame) 111 of the maintenance / recovery device 91 includes two cap holders 112A and 112B which are cap holding mechanisms, a wiper blade 93 which is a wiping member including an elastic body as a cleaning means, and a carriage lock. 115 are held up and down (movable up and down). An empty discharge receiver 94 is disposed between the wiper blade 93 and the cap holder 112 </ b> A, and the wiper blade 93 is a cleaning member for the empty discharge receiver 94 from the outside of the frame 111 in order to clean the wiper blade 93. Cleaner means 118 including a cleaner roller 96, which is a cleaning member for pressing against the wiper cleaner 95 side, is held in a swingable manner.

  The cap holder 112A holds a cap 92a and a cap 92b for capping the nozzle surfaces of the two recording heads 34, and the cap holder 112B holds two caps 92c and a cap 92d. Here, a tubing pump (suction pump) 120 as a suction means is connected to the cap 92a held by the cap holder 112A closest to the printing area via a flexible tube 119, and the other caps 92b, 92c, 92d does not connect the suction pump 120. That is, only the cap 92a is a suction (recovery) and moisture retention cap (hereinafter simply referred to as a suction cap), and the other caps 92b, 92c, and 92d are all just moisture retention caps. Therefore, when performing the recovery operation of the recording head 34, the recording head 34 that performs the recovery operation is selectively moved to a position where it can be capped by the suction cap 92a.

  A cam shaft 121 rotatably supported by the frame 111 is disposed below the cap holders 112A and 112B. Cap cams 122A and 122B for raising and lowering the cap holders 112A and 112B are disposed on the cam shaft 121. A wiper cam 124 for raising and lowering the wiper blade 93, a carriage lock cam 125 for raising and lowering the carriage lock 115 via the carriage lock arm 117, and a droplet discharged in the idle discharge receiver 94. A roller 126 as a rotating body, which is an empty discharge landing member, and a cleaner cam 128 for swinging the wiper cleaner 118 are provided.

  Here, the cap 92 is moved up and down by the cap cams 122A and 122B. The wiper blade 93 is moved up and down by the wiper cam 124. When the wiper cleaner 118 is lowered, the wiper cleaner 118 advances, and the wiper blade 93 descends while being sandwiched between the cleaner roller 96 of the wiper cleaner 118 and the wiper cleaner 95 of the idle discharge receiver 94. Ink adhering to 93 is scraped off into the empty ejection receiver 94. The carriage lock 115 is urged upward (in the lock direction) by a compression spring (not shown), and is raised and lowered via a carriage lock arm 117 driven by a carriage lock cam 125.

  In order to rotationally drive the suction pump 120 and the camshaft 121, the rotation of the motor 131 is meshed with the motor gear 132 provided on the motor shaft 131a and the pump gear 133 provided on the pump shaft 120a of the suction pump 120 is further engaged. An intermediate gear 136 with a one-way clutch 137 is engaged with an intermediate gear 134 integral with 133 via an intermediate gear 135, and the intermediate gear 138 coaxial with the intermediate gear 136 is fixed to the camshaft 121 via the intermediate gear 139. The cam gear 140 is engaged. An intermediate gear 136 with a clutch 137 and an intermediate shaft 141 that is a rotation shaft of the intermediate gear 138 are rotatably held by the frame 111.

  Further, the cam shaft 121 is provided with a home position sensor cam 142 for detecting the home position. When the cap 92 comes to the lowermost end by a home position sensor (not shown) provided in the maintenance / recovery device 91, a home position lever is provided. (Not shown) is activated, and the sensor is opened to detect the home position of the motor 131 (other than the suction pump 120). Note that when the power is turned on, the position moves up and down (up and down) regardless of the position of the cap 92 (cap holder 112), the position is not detected until the movement starts, and the position is determined after detecting the home position of the cap 92 (on the way up). To the bottom end. Thereafter, the carriage moves left and right, returns to the cap position after position detection, and the recording head 34 is capped.

  FIG. 7 is a layout diagram illustrating a connection configuration of the suction cap 92a, the flexible tube 119, and the suction pump 120 of the maintenance / recovery device 91 when the recording head 34 is capped in a non-printing operation. As shown in FIG. 7, the suction pump 120 includes a pump wheel 161 rotated by a pump shaft 120a, a pair of guide grooves 162 formed with a gradient in the radial direction of the pump wheel 161, and along each guide groove 162. And a pump housing 164 that holds the flexible tube 119 in an arc shape along the roller 163. The suction cap 92 a caps the recording head 34 in a capping state during non-printing operation, and a flexible tube 119 connected between the suction cap 92 a and the suction pump 120 is formed integrally with the cam shaft 121. Alternatively, the flow path is closed (sealed) by an eccentric cam 160 formed of a separate member. At this time, the pump wheel 161 of the suction pump 120 rotates in the direction of arrow A, retracts the roller 162 to the retracted position inside the radial direction by the guide groove 162, and the flexible tube 119 held by the pump housing 164. The flow path is not sealed.

  As shown in the block diagram of FIG. 8, the eccentric cam 160 provided on the cam shaft 121 is configured so that the cam shaft 121 is rotated when the cap holders 112A and 112B are moved up and down in the C direction indicated by an arrow. When the recording head 34 is capped with the cap 92 by rotating the shaft 121 in the C direction, the flexible tube 119 is crushed by the rotation to close the flow paths of the suction cap 92a and the suction pump 120. Here, the flexible tube 119 is fixed to the housing 111 by the holding rib 165 so as not to move carelessly.

  Further, when performing an operation during printing, by rotating the cam shaft 121 and rotating the eccentric cam 160, the tip of the eccentric cam 160 is separated from the flexible tube 119, and the suction cap 92 a and the suction pump 120 are separated from each other. The flexible tube 119 connected between them is opened and the flow path is opened to communicate with the atmosphere. Thereafter, when the camshaft 121 is further rotated, the suction cap 92a can print away from the recording head. Further, at the time of maintenance in which it is necessary to suck ink from the recording head 34, the roller 163 is rotated by rotating the pump wheel 161 of the suction pump 120 in the B direction after the suction cap 92 a comes into contact with the recording head 34 and is sealed. It moves to the outer side in the radial direction along the guide groove 163 and rotates while crushing the flexible tube 119 in the suction pump 120. A suction force is generated by the volume change of the flexible tube 119 generated at this time. At this time, the eccentric cam 160 is separated from the flexible tube 119, and the flexible tube 119 connected between the suction cap 92 a and the suction pump 120 opens the flow path and sucks ink from the recording head 34.

  The timing for sealing the flow path of the flexible tube 119 with the eccentric cam 160 will be described with reference to the cam diagram of FIG. When printing is finished and the recording head 34 is moved to the capping state, the camshaft 121 is rotated with the cap 92 in the lowermost home position to raise the cap holders 112A and 112B. When rotated by the angle θ1, the recording head 34 is capped by the cap 92. Thereafter, when the cam shaft 121 rotates by an angle θ2 from the home position, the eccentric cam 160 crushes the flexible tube 119 to close the flow path of the suction cap 92a and the suction pump 120, and the flexible from the suction cap 92a. The ink is prevented from entering the sex tube 119. When the printing operation is started in this state, when the cam shaft 121 is rotated from the home position by an angle θ3, the eccentric cam 160 is separated from the flexible tube 119 and the flow path of the suction cap 92a and the suction pump 120 is opened. . When the cam shaft 121 further rotates and rotates from the home position by an angle θ4, the capping of the recording head 34 by the cap 92 is released. Further, when ink is sucked from the recording head 34, the cam shaft 121 is controlled to stop rotating when the rotation angle of the cam shaft 121 is between the angle θ1 and the angle θ2 or between the angle θ3 and the angle θ4. good.

  Thus, since the flow path of the flexible tube 119 connected between the suction cap 92a and the suction pump 120 is sealed in the non-printing operation (standby) state, the suction cap is attached to the flexible tube 119. Ink can be prevented from entering from 92a, and tube clogging due to thickening of ink in the flexible tube 119 can be prevented. Therefore, any of a pigment and a dye can be used as the color material of the ink, and a mixture of the pigment and the dye can also be used.

  Further, since the ink is prevented from entering the flexible tube 119 from the suction cap 92a in the non-printing operation state, as shown in the following table, it is easier to increase the viscosity of gas permeability than fluororesin or polyethylene resin. Although disadvantageous, the flexible tube 119 can be formed of a silicone material better than fluororesin or polyethylene resin in terms of rebound resilience (restorability) and resistance to compression set. Thus, by using a silicone material as the material of the flexible tube 119, the flexible tube 119 can be easily crushed by the eccentric cam 160, and when the eccentric cam 160 is separated from the flexible tube 119. The crushed portion of the flexible tube 119 can be easily restored.

  In addition, the flexible tube 119 that connects the suction cap 92a and the suction pump 120 is crushed and released using a part of the cam mechanism that raises and lowers the cap 92, thereby decentering the timing linked to the capping operation. It can be determined by the shape of the cam 160, and a stable operation can be performed with a simple configuration by preventing malfunction.

  Further, in order to minimize the load when the flexible tube 119 is crushed by the eccentric cam 160, as shown in FIG. 10, the thickness of the distal end portion 160a for crushing the flexible tube 119 of the eccentric cam 160 is set to the cam. It is desirable to make it thinner than the shaft 121 side.

  As shown in FIG. 11, a swing plate 170 is provided at an engaging portion of the flexible tube 119 with the eccentric cam 160, and the swing plate 170 is pressed against the flexible tube 119 by the eccentric cam 160 to be flexible. The sex tube 119 may be crushed. By providing the swing plate 170 in this way, when the flexible tube 119 is crushed, the flexible tube 119 can be crushed without sliding the swing plate 170 on the surface of the flexible tube 119. In addition to improving the durability of the flexible tube 119, the surface of the flexible tube 119 is made wear-resistant so that the flexibility is lowered and hardened, and the load for crushing the flexible tube 119 is increased. It is possible to prevent an increase in power consumption by increasing the output of the motor 131 that rotates and rotates the camshaft 121.

It is the perspective view which looked at the image forming apparatus of this invention from the front side. 1 is a schematic configuration diagram illustrating an overall configuration of a mechanism unit of an image forming apparatus according to the present invention. It is a principal part top view of the mechanism part of the image forming apparatus of this invention. 1 is a plan view of a main part showing a configuration of a maintenance / recovery device of an image forming apparatus. It is a schematic block diagram of a maintenance recovery apparatus. It is a side view which shows the structure of a maintenance recovery apparatus. It is a layout view showing a connection configuration of a suction nozzle, a flexible tube, and a suction pump. It is a fragmentary perspective view which shows arrangement | positioning of the eccentric cam with respect to a flexible tube. It is a cam diagram of the eccentric cam which shows the timing when crushing a flexible tube. It is a block diagram which shows the other structure of an eccentric cam. It is a block diagram which shows arrangement | positioning of the rocking | swiveling plate which crushes a flexible tube, and an eccentric cam.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Apparatus main body, 2; Paper feed tray, 3; Paper discharge tray, 6: Cartridge loading part,
7; operation unit, 10; liquid cartridge, 34; recording head, 91; maintenance and recovery device,
92; cap, 112; cap holder, 119; flexible tube,
121; camshaft; 120; suction pump; 160; eccentric cam;
161; pump wheel, 162; guide groove, 163; roller,
164; pump housing, 165; holding rib, 170; swing plate.

Claims (7)

A liquid suction device comprising: a cap member that can contact and separate from the droplet discharge device; a suction pump that generates negative pressure; and a flexible liquid transport member that connects between the cap member and the suction pump In
Flow path opening and closing means for switching the flow path of the flexible liquid transport member between an open state and a closed state;
When sucking the liquid from the droplet discharge device, the flow channel opening / closing means opens the flow path of the flexible liquid transport member with the cap member capped to the droplet discharge apparatus,
When the droplet discharge device does not discharge droplets and does not suck liquid, the suction pump channel is opened with the cap member capped in the droplet discharge device, and the channel A liquid suction apparatus characterized in that the flow path of the flexible liquid transport member is closed by an opening / closing means.   2. The liquid suction device according to claim 1, wherein the flow path opening / closing means operates in conjunction with a cam mechanism that contacts and separates the cap member from the droplet discharge device.   3. The liquid suction device according to claim 2, wherein the flow path opening / closing means is an eccentric cam provided on a cam shaft that rotates a cam mechanism that contacts and separates the cap member from the droplet discharge device.   4. The liquid suction device according to claim 3, wherein a swingable pressing plate is provided between the flexible liquid conveying member and an eccentric cam constituting the flow path opening / closing means.   5. The liquid suction device according to claim 1, wherein a material of the flexible liquid transport member is silicone.   A maintenance / recovery device comprising the liquid suction device according to claim 1. A nozzle, a pressurized liquid chamber communicating with the nozzle, a diaphragm having at least one wall surface of the pressurized liquid chamber and having a resin layer, and a side of the diaphragm on which the pressurized liquid chamber is formed; Is a droplet discharge device having a piezoelectric element provided on the opposite side;
An image forming apparatus comprising the maintenance / recovery device according to claim 6.

Images