JP6248966B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an ink jet image forming apparatus that cleans a conveying belt with a cleaning roller.

  2. Description of the Related Art Conventionally, an ink jet image forming apparatus includes a paper transport unit that transports paper under a recording head that ejects ink to paper based on image data information. The paper transport unit is configured by winding an endless transport belt around various rollers such as a driving roller, a driven roller, and a tension roller.

  In such an ink jet image forming apparatus, paper jam occurs in the paper transport unit or a torn paper is transported, so that ink from the recording head is not properly ejected onto the paper. It may adhere to the conveyor belt and stain the conveyor belt. The ink adhering to the transport belt will contaminate the next transported paper, and hinder the normal printing state.

  Further, in the inkjet storage device of Patent Document 1, in order to clean unnecessary ink on the conveyance belt of the cleaning device, the wiper is pressed against the conveyance belt and moved, and the ink on the conveyance belt is scraped with the wiper. It is configured to drop and collect in the ink receiver. However, such a cleaning device cannot remove ink adhering to the inside of the conveyor belt.

  Further, in the image forming apparatus of Patent Document 2, a suction hole is provided in the conveyance support member (platen), and a suction fan sucks the recording medium through the suction hole. However, when such a suction hole is provided in the transport belt of the paper transport unit, ink adheres to the inside of the transport belt through the suction hole. In addition, there is a possibility that problems such as slip may occur between the driving roller that drives the conveying belt by the ink between the inner surface of the conveying belt and the conveying belt.

  By the way, there is an ink jet image forming apparatus in which a paper transport unit including a transport belt is movable between a printing position (paper transport position) and a retracted position (cleaning position). When the paper transport unit is disposed at the retracted position, the transport belt is sandwiched between the cleaning roller on the outer side of the transport belt and the opposing roller on the inner side, and the transport belt is driven to remove ink on the transport belt. .

Japanese Patent Laid-Open No. 03-227648 JP 2010-280149 A

  The paper transport unit that holds the transport belt between the cleaning roller and the counter roller as described above is suspended from the apparatus main body by, for example, a wire and the print position and the retraction position are controlled by controlling the suspension length. However, it has the following problems.

  First, the paper transport unit is positioned (fixed) with respect to the apparatus main body at the printing position, but is not fixed with respect to the apparatus main body at the retracted position, and exists only with its own weight while being suspended by a wire or the like. Yes. For this reason, when the cleaning roller comes into contact with the transport belt, the paper transport unit is repelled and lifted by the tension of the transport belt, and a desired pressure from the cleaning roller cannot be applied to the transport belt.

  Further, since the cleaning roller comes into contact with the conveyance belt in the vicinity of one end of the sheet conveyance unit, the sheet conveyance unit is lifted by a rotation operation with the other end as a rotation center. For this reason, as the paper transport unit moves up, the contact position between the cleaning roller and the transport belt shifts. As a result, even if the paper transport unit moves to the retracted position, it faces the cleaning roller. There is a concern that the roller may deviate from the normal position where it faces.

  In view of the above circumstances, an object of the present invention is to pinch a conveyance belt between a cleaning roller and a counter roller at a desired pressure and position.

  An image forming apparatus according to the present invention includes an image forming unit that forms an image on a sheet, a conveying belt that conveys the sheet, and a face that contacts the conveying belt from the inside, and is disposed below the image forming unit. A paper transport unit including a roller, an elevating device that moves the paper transport unit up and down between a printing position and a retracted position, and is disposed closer to the retracted position than the paper transport unit. A cleaning unit including a movable cleaning roller, and the cleaning unit further includes a first engaging portion and a first position restricting portion that moves together with the cleaning roller, and the paper transport unit. Is further provided with a second engagement portion provided at a position corresponding to the first engagement portion, and a second engagement portion provided at a position corresponding to the first position restriction portion. And the first engaging portion and the second engaging portion are engaged with each other when the paper transport unit is moved to the retracted position by the elevating device, so that the paper transport is performed. The first position restricting portion and the second position restricting portion are engaged with each other when the cleaning roller moves in a direction approaching the transport belt. The cleaning roller is positioned at a position facing the opposing roller with the conveyor belt interposed therebetween.

  According to the present invention, it is possible to clean the conveyor belt by holding the conveyor belt between the cleaning roller and the counter roller at a desired pressure and position.

1 is a diagram illustrating an outline of a printer according to an embodiment of the present invention. FIG. 3 is a perspective view illustrating a paper transport unit of the printer according to the embodiment of the invention. FIG. 4 is a perspective view illustrating a pin to be locked and a guide portion of a paper transport unit and a periphery thereof in a printer according to an embodiment of the present invention. FIG. 2 is a perspective view illustrating a lifting device of a printer according to an embodiment of the present invention. It is sectional drawing which shows the raising / lowering apparatus of the printer which concerns on one Embodiment of this invention. FIG. 3 is a perspective view illustrating a cleaning unit of the printer according to the embodiment of the invention. FIG. 5 is a perspective view showing a lock member of the cleaning unit and its periphery in the printer according to the embodiment of the present invention. FIG. 3 is a perspective view showing guide pins of a cleaning unit and its periphery in a printer according to an embodiment of the present invention. FIG. 5 is a perspective view showing a support plate driving mechanism of the cleaning unit and its periphery in the printer according to the embodiment of the present invention. It is a top view which shows the support plate drive mechanism of the cleaning unit in the printer which concerns on one Embodiment of this invention, and its periphery. FIG. 3 is a perspective view showing a lock driving mechanism of the cleaning unit and its periphery in the printer according to the embodiment of the present invention. FIG. 5 is a perspective view showing a cam engaging portion and a cam engaged portion of a lock driving mechanism of a cleaning unit in a printer according to an embodiment of the present invention.

  First, an overall configuration of a color printer 1 (hereinafter, simply referred to as “printer 1”) as an ink jet image forming apparatus will be described with reference to FIG. Hereinafter, the front side in FIG. 1 is the front side (front side) of the printer 1.

  As shown in FIG. 1, the printer 1 includes a box-shaped printer main body 2. A paper feed cassette 3 for storing paper P is accommodated in a lower portion of the printer main body 2 so as to be drawn out.

  A conveyance path 4 for the paper P is formed on the right side of the printer body 2. A paper feed roller 5 is provided in the vicinity of the paper feed cassette 3 at the lower end of the transport path 4, and a transport roller 6 is provided to the right of the paper feed roller 5. A registration roller 7 is provided at the upper end of the conveyance path 4.

  A paper transport unit 8 is provided at the center of the printer body 2 so as to be lifted and lowered by a lifting device 10. The paper transport unit 8 includes a transport frame 11, a drive roller 12, a driven roller 13, a tension roller 14, a counter roller 15, an endless transport belt 16, and an intake portion 17. Each part of the paper transport unit 8 and the lifting device 10 will be described later.

  Further, four sets of recording heads 18 (18K, 18C, 18M, 18Y) are arranged in parallel at the center of the printer main body 2 above the paper transport unit 8. Each recording head 18 corresponds to each color of black (K), cyan (C), magenta (M), and yellow (Y) in order from the upstream side (right side in the present embodiment) in the conveyance direction of the paper P. . Hereinafter, the symbols “K”, “C”, “M”, and “Y” are omitted for the recording head 18, unless otherwise specified. Each recording head 18 is provided with a nozzle (not shown) so as to face the upper surface of the conveyance belt 16. Each recording head 18 is an image forming unit that forms an image on a sheet.

  Four ink containers 20 (20K, 20C, 20M, and 20Y) are arranged in parallel on the upper portion of the printer main body 2 so as to be detachable in the front-rear direction. The four ink containers 20 are provided for each ink color, and in order from the upstream side (the right side in the present embodiment) in the transport direction of the paper P, black (K), cyan (C), magenta (M), The ink of each color of yellow (Y) is accommodated. Hereinafter, the symbols “K”, “C”, “M”, and “Y” are omitted for the ink container 20 except when a color is specifically described.

  Each ink container 20 is connected to each recording head 18 via a sub-container (not shown), and after the ink stored in each ink container 20 is once stored in the sub-container, each recording head 18. To be supplied. The sub-container is provided corresponding to each color of black (K), cyan (C), magenta (M), and yellow (Y), similarly to the recording head 18 and the ink container 20.

  Further, a cleaning unit 21 including a cleaning roller 22 is provided at the lower left side (retracted position side) of the paper transport unit 8 at the center of the printer main body 2. The cleaning unit 21 will be described later.

  A discharge mechanism 23 is provided on the left side of the printer body 2. The discharge mechanism 23 includes a drying device 24 provided on the upper left side of the paper transport unit 8, a discharge roller 25 provided on the left side of the drying device 24, and a printer provided below the discharge roller 25 via a discharge port 26. A paper discharge tray 27 protruding outside the main body 2 is provided.

  Next, an image forming operation of the printer 1 having such a configuration will be described.

  When the printer 1 receives image data from an external computer or the like, the paper P stored in the paper feed cassette 3 is sent out to the transport path 4 by the paper feed roller 5. The paper P sent out to the transport path 4 is transported to the downstream side of the transport path 4 by the transport roller 6, and sent out from the transport path 4 to the upper surface of the transport belt 16 by the registration roller 7.

  At this time, the air intake unit 17 is operated, and from the upper surface side of the transport belt 16 to the air intake unit 17 through the air intake hole (not illustrated) of the transport belt 16 and the opening (not illustrated) of the air intake unit 17. Air is aspirated. Then, the paper P sent out to the upper surface of the transport belt 16 is adsorbed on the upper surface of the transport belt 16 by the suction force of the intake portion 17.

  On the other hand, each recording head 18 is supplied with ink from each ink container 20. Each recording head 18 ejects ink to the paper P adsorbed on the conveyance belt 16 based on information of image data received from an external computer or the like. Thereby, a color ink image is formed on the surface of the paper P. The paper P on which the color ink image is formed is discharged on the discharge tray 27 from the discharge port 26 by the discharge roller 25 after the ink on the surface is dried by the drying device 24.

  Next, each part of the paper transport unit 8 will be described with reference to FIGS. First, as shown in FIG. 2, the transport frame 11 includes a bottom plate 30 and a pair of side plates 31 erected on the front and rear ends of the bottom plate 30. The bottom plate 30 is provided with a locked pin 32 (second engaging portion) at the left front portion and the left rear portion, respectively, and only the left rear locked pin 32 is shown in FIG. The pin 32 to be locked is provided at a position corresponding to a lock member 57 described later, and is formed in a columnar shape extending in the front-rear direction (a direction intersecting the bending direction of the tip of the lock member 57), for example. Each of the pair of side plates 31 is provided with a guide portion 33 (second position restricting portion) at the left front portion and the left rear portion, and only the left rear guide portion 33 is shown in FIG. The guide portion 33 is provided at a position corresponding to a guide pin 61 to be described later, and includes, for example, a rail portion 34 that is long in the left-right direction and a groove portion 35 that is provided at the right end of the rail portion 34 and that is open at the lower side. The inner side and the lower side in the front-rear direction are formed so as to open.

  The driving roller 12 is rotatably supported at the upper left corner of the transport frame 11, the driven roller 13 is rotatably supported at the upper right corner of the transport frame 11, and the tension roller 14 is disposed at the lower center of the transport frame 11. The counter roller 15 is rotatably supported by the lower left part of the conveyance frame 11 (see FIG. 1).

  The conveyor belt 16 is wound around the driving roller 12, the driven roller 13 and the tension roller 14. The conveyor belt 16 is provided with a number of intake holes (not shown). The contact between the conveyor belt 16 and the counter roller 15 occurs when the cleaning roller 22 of the cleaning unit 21 is pressed against the conveyor belt 16 when the conveyor belt 16 is cleaned, and the conveyor belt 16 bends inward. become.

  The intake portion 17 is disposed so as to be surrounded by the conveyance belt 16, and has an opening (not shown) on the upper side, and is configured to intake air from above the conveyance belt 16.

  Next, the lifting device 10 will be described with reference to FIGS. 4 and 5. The lifting device 10 is provided below each recording head 18 so that the paper transport unit 8 is moved up and down between a printing position (paper transport position) and a retracted position (cleaning position). As shown in FIGS. 4 and 5, the lifting device 10 includes a device main body frame 40, a unit placement portion 41, a wire 42, a hoisting shaft 43, a drive portion 44, and a wire support portion 45. ing.

  The apparatus main body frame 40 is a box-shaped housing that can store the paper transport unit 8 and has an upper side opened. Further, the apparatus main body frame 40 is provided with a plurality of main body side pulleys 46. The plurality of main body side pulleys 46 are, for example, at least four of the left front part, the left rear part, the right front part, and the right rear part of the apparatus main body frame 40. It is provided so that it can rotate about the front-rear direction as an axial direction.

  The unit mounting portion 41 is disposed below the plurality of main body side pulleys 46 and includes a bottom plate 47 and a plurality of side plates 48. On the bottom plate 47 of the unit mounting portion 41, the paper transport unit 8, particularly, the bottom plate 30 of the transport frame 11 is placed. The plurality of side plates 48 of the unit mounting portion 41 are erected on the left front portion, the left rear portion, the right front portion, and the right rear portion of the bottom plate 47, for example, and each of the plurality of side plates 48 has a mounting portion side pulley 49. Is provided to be rotatable about the front-rear direction as an axial direction.

  The hoisting shaft 43 is rotatably provided at the upper right side in the apparatus main body frame 40 with the front-rear direction as the axial direction. The drive unit 44 is, for example, a motor or the like, and is attached to the apparatus main body frame 40 so as to rotationally drive the hoisting shaft 43. The wire support portions 45 are provided in the left front portion and the left rear portion in the apparatus main body frame 40, respectively, and only the left rear wire support portion 45 is shown in FIGS.

  In the lifting device 10 as described above, the wires 42 are provided at the front and rear portions of the lifting device 10. One wire 42 is wound around a main body side pulley 46 at the left front portion and the right front portion of the apparatus main body frame 40 and a left front portion and a right front portion mounting portion side pulley 49 of the unit mounting portion 41. One end of the wire 42 is fixed to the front portion of the hoisting shaft 43, and the other end of the wire 42 is supported by the wire support portion 45 at the left front portion of the apparatus main body frame 40. The other wire 42 is wound around the main body side pulley 46 at the left rear portion and the right rear portion of the apparatus main body frame 40 and the mounting portion side pulley 49 at the left rear portion and the right rear portion of the unit mounting portion 41. One end of the wire 42 is fixed to the rear portion of the hoisting shaft 43, and the other end of the wire 42 is supported by a wire support portion 45 at the left rear portion of the apparatus main body frame 40.

  Next, the cleaning unit 21 will be described with reference to FIGS. As shown in FIG. 6, the cleaning unit 21 includes a cleaning roller 22, a unit main body frame 50, a pair of support plates 51, two lock members 52 (first engagement portions), and two guide pins 53 ( 1st position control part), the roller drive mechanism 54, the support plate drive mechanism 55, and the lock drive mechanism 56 are provided.

  The cleaning roller 22 is rotatably attached to the right side (one end side close to the paper transport unit 8) of the pair of support plates 51.

  The unit main body frame 50 includes a bottom plate 57 and a pair of attachment members 58 erected on the front and rear portions of the bottom plate 57. On the right side (one end side) of the bottom plate 57, a rod-like member 59 that is long in the front-rear direction is rotatably provided, and on the left side (other end side) of the bottom plate 57, the pair of attachment members 58 are provided. A rotation center shaft 60 is attached to each attachment member 58.

  As shown in FIGS. 8 to 10, each support plate 51 is rotatably attached to the rotation center shaft 60 on the left side (the other end side). A cam contact portion 61 having an upper surface as a contact surface (see FIGS. 9 and 10) and an urging member 62 such as a coil spring (see FIGS. 7 and 9) are provided below the support plate 51 on the rear side. ), Are provided. For example, the urging member 62 has an upper end supported by the support plate 51 and a lower portion supported by the bottom plate 57 of the unit main body frame 50, and urges the support plate 51 upward with respect to the unit main body frame 50.

  As shown in FIGS. 7, 8, and 11, each lock member 52 includes a claw-like claw portion 63 that extends to the right side (one end side) and has a tip bent downward. Each lock member 52 is attached to, for example, a rod-shaped member 59 provided in the unit main body frame 50, and rotates with the rotation of the rod-shaped member 59. In the present embodiment, the two lock members 52 are provided in the front and rear portions of the rod-shaped member 59, respectively, but may be configured to include one or three or more lock members 52. Further, an urging member 64 such as a torsion coil spring is attached to each lock member 52. Each urging member 64 is provided so as to urge each lock member 52 together with the rod-shaped member 59 in the clockwise direction when viewed from the front. When the urging force of each urging member 64 is not applied, each lock member 52 is in an engaged state in which the claw portion 63 is positioned on the right side (one end side), and each lock member 52 and the bar-shaped member 59 are urged. When the member 64 rotates counterclockwise against the urging force of the member 64, the claw portion 63 is in a disengaged state located on the left side (the other end side). Each lock member 52 is provided at a position corresponding to the locked pin 32 of the paper transport unit 8.

  As shown in FIGS. 6 and 8 to 10, each guide pin 53 is provided on the right side (one end side) of each support plate 51 and is formed in a cylindrical shape protruding outward in the front-rear direction. For example, the rear guide pin 53 is provided in one of a plurality of gears 66 of a roller driving mechanism 54 described later.

  As shown in FIGS. 8 to 10, the roller drive mechanism 54 includes a transmission coupling 65 and a plurality of gears 66. The transmission coupling 65 is formed in a columnar shape, and is rotatably attached to a mounting member 58 on the rear side of the unit main body frame 50, and a driving force from a driving unit (not shown) such as a motor is input. To rotate. The plurality of gears 66 are rotatably provided on the rear mounting member 58 and the rear support plate 51. For example, the plurality of gears 66 includes a gear 66 attached to the transmission coupling 65, a gear 66 attached to the rotation center shaft 60, and a gear 66 attached coaxially to the cleaning roller 22, and sequentially meshes with each other. Arranged. Accordingly, the roller driving mechanism 54 can transmit the rotation input from the transmission coupling 65 to the cleaning roller 22 via the plurality of gears 66 regardless of the rotation of the support plate 51.

  As shown in FIGS. 9 to 10, the support plate driving mechanism 55 includes a driving unit 67 such as a motor, a cam 68 having an elliptical cross section, and a plurality of gears 69. The cam 68 has a rotation shaft in the front-rear direction and is provided so as to be rotatable. For example, the plurality of gears 69 include a gear 69 attached to the drive unit 67 and a gear 69 attached coaxially to the cam 68, and are sequentially engaged with each other. Thereby, the support plate drive mechanism 55 can transmit the rotation from the drive unit 67 to the cam 68 via the plurality of gears 69, and the cam contact portion 61 of the support plate 51 can be moved according to the rotation of the cam 68. It can be pressed downward.

  As shown in FIG. 11, the lock drive mechanism 56 includes a drive unit 70 such as a motor, a drive cam 71, a driven cam 72, and a plurality of gears 73. As shown in FIGS. 12 (A) and 12 (B), the drive cam 71 is formed in a substantially cylindrical shape having a step on a part of the circumferential surface, and the circumferential direction (clockwise) from a position where the step is low to a high position. ), The diameter is gradually increased. A portion having a large diameter constituting the step of the drive cam 71 becomes a cam engagement portion 74. As shown in FIGS. 12A and 12B, the driven cam 72 is formed in a substantially cylindrical shape with a part of the peripheral surface protruding, and the protruding portion of the driven cam 72 becomes the cam engaged portion 75. The driven cam 72 is coaxially attached to a rod-like member 59 provided on the unit main body frame 50. The drive cam 71 and the driven cam 72 are arranged so that their peripheral surfaces face each other and the cam engaging portion 74 and the cam engaged portion 75 are engaged. For example, the plurality of gears 73 include a gear 73 attached to the drive unit 70 and a gear 73 attached coaxially to the drive cam 71, and are sequentially meshed. Thereby, the lock drive mechanism 56 can transmit the rotation from the drive unit 70 to the drive cam 71 via the plurality of gears 73. For example, when the drive cam 71 is rotated clockwise in front view, the lock drive mechanism 56 is driven. When the cam engaging portion 74 of the cam 71 is engaged with the cam engaged portion 75 of the driven cam 72, the driven cam 72 is rotated counterclockwise when viewed from the front, and accordingly, the rod-shaped member 59 is viewed when viewed from the front. The lock member 52 is disengaged by rotating counterclockwise.

  Next, the raising / lowering operation | movement by the raising / lowering apparatus 10 of the paper conveyance unit 8 in the printer 1 provided with the above structures is demonstrated.

  First, when the image forming operation as described above is performed in the printer 1, the lifting device 10 causes the driving unit 44 to rotate the hoisting shaft 43 to wind up the wire 42, whereby the hoisting shaft 43 to the wire support unit 45. The length of the wire 42 is shortened. At this time, the paper transport unit 8 suspended by the wire 42 is raised and positioned at the printing position as the suspension length becomes shorter. Thereby, the printer 1 can perform the image forming operation as described above by using the paper transport unit 8 arranged at the printing position.

  Next, when the cleaning operation of the conveyance belt 16 of the paper conveyance unit 8 is performed in the printer 1, the lifting device 10 causes the driving unit 44 to rotate the hoisting shaft 43 and feed the wire 42, thereby causing the lifting device 10 to move from the hoisting shaft 43. The length of the wire 42 up to the wire support 45 is increased. At this time, the sheet transport unit 8 suspended by the wire 42 is lowered and moved to the retracted position as the suspended length becomes longer. In the cleaning unit 21, in the support plate driving mechanism 55, the cam 68 presses the cam contact portion 61 of the support plate 51 downward, and the cleaning roller 22 rotates downward around the rotation center axis 60. It has become. In the lock drive mechanism 56, the cam engaging portion 74 of the drive cam 71 is engaged with the cam engaged portion 75 of the driven cam 72 (see FIG. 12A), and the lock member 52 is in the non-engaged state. It has become.

  When the paper transport unit 8 is disposed at the retracted position, the lock drive mechanism 56 of the cleaning unit 21 rotates the drive cam 71 counterclockwise by the drive unit 67 and the cam engagement unit 74 of the drive cam 71. The driven cam 72 is disengaged from the cam engaged portion 75 (see FIG. 12B). Thereby, each lock member 52 and the rod-shaped member 59 are rotated clockwise in front view by the urging force of each urging member 64 so that each lock member 52 is engaged. Then, the claw portion 63 of each lock member 52 covers the upper side of the locked pin 32. As a result, the locked pin 32 of the paper transport unit 8 and the lock member 52 of the cleaning unit 21 are engaged, and the paper transport unit 8 is locked to the cleaning unit 21 at the retracted position.

  Thereafter, the support plate drive mechanism 55 of the cleaning unit 21 rotates the cam 68 by the drive unit 67, so that the pressing of the cam contact portion 61 of the support plate 51 by the cam 68 is released, and the support plate 51 is biased by the urging member 62. Is rotated upward around the rotation center axis 60. As the support plate 51 is rotated, the cleaning roller 22 is rotated upward around the rotation center axis 60 and approaches the conveying belt 16 of the sheet conveying unit 8. At this time, since the guide pins 53 of the pair of support plates 51 are guided by the rail portion 34 of the guide portion 33 of the conveyance frame 11 of the paper conveyance unit 8 and are fitted into the groove portion 35, the cleaning roller 22 moves the conveyance belt 16. It is disposed at a regular position facing the opposing roller 15 with the pinch in between.

  When the printer 1 shifts from the cleaning operation to the image forming operation, the support plate driving mechanism 55 of the cleaning unit 21 further rotates the cam 68 to rotate the support plate 51 around the rotation center axis 60 downward. As a result, the guide pin 53 is separated from the groove portion 35 and separated from the guide portion 33. Further, the lock driving mechanism 56 rotates the driving cam 71 in the clockwise direction to engage the cam engaging portion 74 of the driving cam 71 and the cam engaged portion 75 of the driven cam 72 (see FIG. 12A). When the driven cam 72 is rotated counterclockwise when viewed from the front, each lock member 52 and the rod-shaped member 59 are rotated counterclockwise when viewed from the front, and each lock member 52 is disengaged. Then, the claw portion 63 of the lock member 52 is separated from the upper side of the locked pin 32. Therefore, the paper transport unit 8 can move up without being restricted.

  In the present embodiment, as described above, the printer 1 includes the recording head 18 (image forming unit) that forms an image on a sheet, and the conveyance belt 16 that is disposed below the recording head 18 and conveys the sheet. A paper transport unit 8 having an opposing roller 15 that contacts the transport belt 16 from the inside, an elevating device 10 that raises and lowers the paper transport unit 8 between a printing position and a retracted position, and a retracted position more than the paper transport unit 8. And a cleaning unit 21 including a cleaning roller 22 that is disposed on the side and is movable with respect to the conveyor belt 16. The cleaning unit 21 further includes a lock member 52 (first engagement portion) and a guide pin 53 (first position restriction portion) that moves together with the cleaning roller 22. The paper transport unit 8 further includes a locked pin 32 (second engagement portion) provided at a position corresponding to the lock member 52 and a guide portion 33 (second position) provided at a position corresponding to the guide pin 53. Regulatory Department). The lock member 52 and the pin to be locked 32 are engaged with each other when the paper transport unit 8 is moved to the retracted position by the lifting device 10, and restricts the upward movement of the paper transport unit 8 relative to the cleaning unit 21. The guide pin 53 and the guide portion 33 are engaged with each other when the cleaning roller 22 moves in a direction approaching the conveyance belt 16, and the cleaning roller 22 is positioned at a position facing the opposing roller 15 with the conveyance belt 16 interposed therebetween. Positioning.

  Thus, when the paper transport unit 8 is lowered for the cleaning operation, the locked pin 32 of the paper transport unit 8 and the lock member 52 of the cleaning unit 21 are engaged, and therefore the transport belt 16 of the paper transport unit 8 is engaged. Even if the tension of the belt receives a repulsive force against the cleaning roller 22 of the cleaning unit 21, the transport belt 16 does not move away from the cleaning roller 22 and move upward. Therefore, a desired pressure from the cleaning roller 22 can be applied to the transport belt 16, and the ink on the transport belt 16 can be appropriately cleaned. Further, during the cleaning operation, the guide pin 53 of the cleaning unit 21 is guided to the guide portion 33 of the paper transport unit 8, so that the contact between the cleaning roller 22 and the transport belt 16 is repeated even when the paper transport unit 8 is repeatedly raised. The contact position is not displaced, and the cleaning roller 22 can be positioned at a normal position facing the opposing roller 15 with the conveying belt 16 in between. Accordingly, it is possible to sandwich the transport belt 16 between the cleaning roller 22 and the counter roller 15 at a desired pressure and position.

  Further, in the present embodiment, the lock member 52 as the first engagement portion is formed to extend toward the paper transport unit 8 and the tip is bent downward, and the locked pin 32 as the second engagement portion. Is formed so as to extend in a direction intersecting the bending direction of the distal end of the lock member 52. As a result, the first engagement portion and the second engagement portion that restrict the upward movement of the sheet conveyance unit 8 relative to the cleaning unit 21 can be realized with a simple configuration.

  Furthermore, in this embodiment, the guide pin 53 as the first position restricting portion is formed so as to protrude on both sides from the cleaning roller 22, and the guide portion 33 as the second position restricting portion is located on both sides from the transport belt 16. The guide pins 53 are open so that the guide pins 53 can be fitted therein. Thereby, the 1st position control part and the 2nd position control part which position the cleaning roller 22 correctly with respect to the conveyance belt 16 and the opposing roller 15 are realizable with simple structure.

  In the present embodiment, an example in which the first engagement portion is configured by the lock member 52 including the claw portion 63 and the second engagement portion is configured by the locked pin 32 that the lock member 52 covers on the upper side has been described. The configuration of the first engaging portion and the second engaging portion is not limited to this as long as the upward movement of the conveyance belt 16 with respect to the cleaning roller 22 can be restricted.

  In the present embodiment, the first position restricting portion is configured by the guide pin 53 and the second position restricting portion is configured by the guide portion 33 that guides the guide pin 53. However, the cleaning roller 22 is conveyed. If it can position correctly with respect to the belt 16 and the opposing roller 15, the structure of a 1st position control part and a 2nd position control part will not be limited to this.

  In the present embodiment, the case where the configuration of the present invention is applied to the printer 1 has been described. However, in another different embodiment, any image forming apparatus that includes an image forming unit that forms an image on paper may be copied. It is also possible to apply the configuration of the present invention to other different image forming apparatuses such as a machine, a facsimile machine, and a multifunction machine.

1 Color printer (image forming device)
DESCRIPTION OF SYMBOLS 8 Paper conveyance unit 10 Lifting device 15 Opposed roller 16 Conveyance belt 18 Recording head 21 Cleaning unit 22 Cleaning roller 32 Pin to be locked (second engagement portion)
33 Guide part (second position restriction part)
52 Locking member (first engaging part)
53 Guide pin (first position restricting part)

Claims (3)

An image forming unit that forms an image on paper;
A paper transport unit that is disposed below the image forming unit and includes a transport belt that transports the paper and an opposing roller that contacts the transport belt from the inside;
A lifting device that lifts and lowers the paper transport unit between a printing position and a retracted position;
A cleaning unit that is disposed closer to the retracted position than the paper transport unit and includes a cleaning roller that is movable with respect to the transport belt,
The cleaning unit further includes a first engagement portion and a first position restriction portion that moves together with the cleaning roller,
The paper transport unit further includes a second engagement portion provided at a position corresponding to the first engagement portion, and a second position restriction portion provided at a position corresponding to the first position restriction portion. Prepared,
The first engaging portion and the second engaging portion are engaged with each other when the paper transport unit is moved to the retracted position by the lifting device, and the paper transport unit is located above the cleaning unit. Restricting movement,
The first position restricting portion and the second position restricting portion engage with each other when the cleaning roller moves in a direction approaching the transport belt, and face the opposing roller with the transport belt interposed therebetween. An image forming apparatus, wherein the cleaning roller is positioned at a position where the cleaning is performed. The first engagement portion is a lock member that extends toward the paper transport unit and has a tip bent downward.
The image forming apparatus according to claim 1, wherein the second engagement portion is a pin to be locked that extends in a direction intersecting a bending direction of a tip end of the first engagement portion. The first position restricting portion is a guide pin protruding on both sides of the cleaning roller,
The said 2nd position control part is a guide part which is arrange | positioned on both sides rather than the said conveyance belt, and the inner side and the lower side are open and can fit the said guide pin. Image forming apparatus.

Images