JP2019151455A - Conveyance device, drying device and image formation device - Google Patents

Abstract

To provide a conveyance device capable of maintaining a specified sheet interval, and to provide the conveyance device, a drying device and an image formation device capable of maintaining the specified sheet interval.SOLUTION: A conveyance device includes: a conveyance drum such as a delivery barrel 202 for conveying a sheet material such as a paper P; and a conveyance belt 325 for adsorbing and conveying the sheet material delivered from the conveyance drum. The conveyance belt 325 is provided with an abutment part such as an abutting protrusion 324 where a tip end of the sheet material abuts.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a conveyance device, a drying device, and an image forming apparatus.

  2. Description of the Related Art Conventionally, a conveyance device having a conveyance drum that conveys a sheet material and a conveyance belt that adsorbs and conveys the sheet material transferred from the conveyance drum is known.

  Japanese Patent Application Laid-Open No. H10-228667 describes a conveyance device that includes a conveyance belt that receives a sheet material having ink adhered to the surface from a conveyance drum and conveys the sheet material to an ink drying unit.

  However, when the sheet material is transferred from the conveyance drum to the conveyance belt, the sheet material slides on the conveyance belt in the sheet conveyance direction and is displaced from a predetermined position, and there is a possibility that the predetermined space between the sheets is not maintained.

  In order to solve the above-described problems, the present invention is a transport apparatus including a transport drum that transports a sheet material, and a transport belt that sucks and transports the sheet material transferred from the transport drum. The belt is provided with an abutting portion against which the leading end of the sheet material abuts.

  According to the present invention, it is possible to maintain a specified paper interval.

1 is a schematic diagram illustrating a schematic configuration of an ink jet recording apparatus according to an embodiment. The front view which shows the drying part in this embodiment. The perspective view which shows the conveyance belt in which the linear member is mesh shape. The figure which looked at the delivery cylinder on the one side of the axial direction. The figure seen from the arrow A direction of FIG. The figure which shows the state which the cam projection part of the cam follower contact | abutted to the cam surface. Diagram showing cam follower cam projection near the top of the cam surface The figure which shows a mode that plain paper is delivered from a delivery cylinder to a conveyance belt. The figure which shows a mode that cardboard is delivered from a delivery cylinder to a conveyance belt. The figure which shows a mode that it is delivered to the conveyance belt from the delivery cylinder in this embodiment. The figure shown about an example of butting protrusion. The perspective view which shows the positional relationship of abutment protrusion and the paper gripper of a delivery cylinder. The perspective view which shows a mode that the butting protrusion was attached to the conveyance belt by which the linear member is mesh shape. The figure shown about the example which provided 3 or more butting protrusions in the belt width direction. The figure shown about the example which lengthened the butting protrusion in the belt width direction. The figure explaining the drive control of a conveyance belt. The flowchart of drive control of a conveyance belt. The schematic perspective view of a suction mechanism. Sectional drawing which shows the internal structure of the chamber for suction in a 2nd suction part. The perspective view of a 1st suction part. Sectional drawing when cut | disconnecting along the paper conveyance direction of a 1st suction part. FIG. 6 is a cross-sectional view when the first suction unit is cut along a cross section orthogonal to the paper conveyance direction.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[Overall description]
FIG. 1 is a schematic diagram illustrating a schematic configuration of an ink jet recording apparatus according to the present embodiment.
The inkjet recording apparatus 1 according to the present embodiment mainly includes a paper feeding unit 100, an image forming unit 200, a drying unit 300, and a paper discharge unit 400. In the inkjet recording apparatus 1, an image is formed on the paper P, which is a recording material as a sheet material fed from the paper feeding unit 100, with ink that is an image forming liquid in the image forming unit 200. Then, after the ink attached on the paper is dried in the drying unit 300, the paper is discharged from the paper discharge unit 400.

[Paper Feeder]
The sheet feeding unit 100 mainly includes a sheet feeding tray 110 on which a plurality of sheets P are stacked, a feeding device 120 that separates and feeds sheets from the sheet feeding tray 110 one by one, and the sheets to the image forming unit 200. The registration roller pair 130 is fed in. As the feeding device 120, any feeding device such as a device using a roller or a roller or a device using air suction can be used. The sheet fed from the sheet feeding tray 110 by the feeding device 120 is fed to the image forming unit 200 by the registration roller pair 130 being driven at a predetermined timing after the leading edge reaches the registration roller pair 130. The In the present embodiment, the configuration of the paper feeding unit 100 is not limited as long as it feeds the paper P to the image forming unit 200.

[Image forming unit]
The image forming unit 200 mainly includes a receiving cylinder 201 that receives the fed paper P, a paper carrying drum 210 that carries the paper P conveyed by the receiving cylinder 201 on the outer peripheral surface, and a paper carrying drum 210. The ink ejection unit 220 ejects ink toward the paper P carried on the paper and the transfer cylinder 202 that delivers the paper P conveyed by the paper carrying drum 210 to the drying unit 300.

  The leading edge of the sheet P conveyed from the sheet feeding unit 100 to the image forming unit 200 is gripped by a sheet gripper provided on the surface of the receiving cylinder 201, and is conveyed as the surface of the receiving cylinder 201 moves. The paper conveyed by the receiving cylinder 201 is delivered to the paper carrying drum 210 at a position facing the paper carrying drum 210.

  A paper gripper is also provided on the surface of the paper carrying drum 210, and the leading edge of the paper is gripped by the paper gripper. In addition, a plurality of suction holes are dispersedly formed on the surface of the paper carrying drum 210, and a suction air flow toward the inside of the paper carrying drum 210 is generated in each suction hole by the suction device 211. The paper P delivered from the receiving cylinder 201 to the paper carrying drum 210 is gripped at the tip by the paper gripper, and is attracted to the surface of the paper carrying drum 210 by the suction airflow, and accompanying the surface movement of the paper carrying drum 210 Are transported.

  The ink ejection unit 220 according to the present embodiment ejects four colors of ink of C (cyan), M (magenta), Y (yellow), and K (black), and forms an image. Liquid ejection heads 220C, 220M, 220Y, and 220K. The liquid discharge heads 220C, 220M, 220Y, and 220K are not limited in configuration as long as they discharge liquid, and any configuration can be adopted. If necessary, a liquid discharge head that discharges special inks such as white, gold, and silver may be provided, or a liquid discharge head that discharges liquid that does not constitute an image, such as a surface coating liquid, may be provided.

  The discharge operations of the liquid discharge heads 220C, 220M, 220Y, and 220K of the ink discharge unit 220 are controlled by drive signals corresponding to image information. When the paper P carried on the paper carrying drum 210 passes through the region facing the ink ejection unit 220, each color ink is ejected from the liquid ejection heads 220C, 220M, 220Y, and 220K, and an image corresponding to the image information is formed. It is formed. In the present embodiment, the image forming unit 200 is not limited in its configuration as long as it forms an image by adhering liquid onto the paper P.

[Dry section]
The drying unit 300 mainly includes a drying mechanism 301 for drying the ink adhered on the paper P in the image forming unit 200 and a transport mechanism 302 for transporting the paper P transported from the image forming unit 200. Has been. The paper P transported from the image forming unit 200 is received by the transport mechanism 302, transported so as to pass through the drying mechanism 301, and delivered to the paper discharge unit 400. When passing through the drying mechanism 301, the ink on the paper P is subjected to a drying process, whereby liquid components such as moisture in the ink are evaporated, the ink is fixed on the paper P, and the paper P is curled. It is suppressed.

[Output section]
The paper discharge unit 400 mainly includes a paper discharge tray 410 on which a plurality of sheets P are stacked. The sheets P conveyed from the drying unit 300 are sequentially stacked and held on the sheet discharge tray 410. In the present embodiment, the configuration of the paper discharge unit 400 is not limited as long as it discharges the paper P.

[Other functional parts]
The inkjet recording apparatus 1 according to the present embodiment includes the paper feeding unit 100, the image forming unit 200, the drying unit 300, and the paper discharge unit 400, but other functional units may be added as appropriate. For example, after a pre-processing unit that performs pre-processing of image formation is added between the paper feeding unit 100 and the image forming unit 200, or after post-processing of image formation is performed between the drying unit 300 and the paper discharge unit 400 A processing unit can be added.

  Examples of the pre-processing unit include a unit that performs a processing liquid application process that applies a processing liquid that reacts with ink and suppresses bleeding to the paper P. However, the content of the pre-processing is not particularly limited. . Further, as the post-processing unit, for example, a sheet reversal conveyance process for inverting the sheet on which the image is formed by the image forming unit 200 and sending the sheet to the image forming unit 200 again to form images on both sides of the sheet, There are no particular restrictions on the content of post-processing.

In this embodiment, the printing apparatus is described as an example of an inkjet recording apparatus. However, the “printing apparatus” includes a liquid discharge head that discharges liquid toward a surface to be dried of a sheet material, and is discharged. In addition, the liquid is not limited to visualizing significant images such as characters and figures, and includes, for example, a pattern that has no meaning in itself. The sheet material is not limited in material, and may be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramic, etc., as long as the liquid can be attached even temporarily, for example, It may be used for film products, cloth products for clothing, building materials such as wallpaper and flooring, and leather products. In addition, the “printing apparatus” can include means for feeding, transporting, and discharging a liquid to which a liquid can adhere, a pre-processing apparatus, a post-processing apparatus, and the like.
The “liquid” is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, and the viscosity is 30 mPa · s or less at room temperature, normal pressure, or by heating and cooling. Preferably there is. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, and the like, suspensions, emulsions, and the like, which can be used in applications such as ink jet inks and surface treatment liquids.
The “printing apparatus” includes an apparatus in which the liquid discharge head and the sheet material move relatively, but is not limited thereto. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like.

  The “liquid ejection head” is a functional component that ejects and ejects liquid from ejection holes (nozzles). As an energy generation source for discharging liquid, piezoelectric actuators (laminated piezoelectric elements and thin film piezoelectric elements), thermal actuators using electrothermal transducers such as heating resistors, electrostatic actuators composed of diaphragms and counter electrodes, etc. Although energy generation means can be used, the discharge energy generation means to be used is not limited.

  In addition, the inkjet recording apparatus 1 includes a reverse conveyance mechanism 500. When recording images on both sides of the paper, the paper that has passed through the drying mechanism 301 is transported to the reverse transport mechanism 500. The sheet conveyed to the reverse conveyance mechanism 500 is switched back and retransmitted to the registration roller pair 130. Then, after the leading edge of the paper in the conveyance direction reaches the registration roller pair 130, the registration roller pair is driven at a predetermined timing, so that it is retransmitted to the ink ejection unit 220, and an image is formed on the other surface of the paper. The

  In the present embodiment, when images are formed on both sides of a sheet by a predetermined number or more, images are formed on both sides of the sheet by interleaf conveyance control. In the interleaf conveyance control, images are continuously formed on one side of a sheet, these are conveyed to the reverse conveyance mechanism 500, the sheet on which the image is formed on one side is conveyed to the ink discharge unit 220, and the sheet feeding unit 100. The conveyance control alternately performs conveyance of the sheet from the ink to the ink discharge unit 220. By performing such control, it is possible to suppress a decrease in productivity when a predetermined number of images are performed on both sides of the sheet.

[Details of drying section]
Next, the detail of the drying part 300 in this embodiment is demonstrated.
FIG. 2 is a front view showing the drying unit 300 in the present embodiment.

  The drying mechanism 301 in the drying unit 300 of the present embodiment mainly includes a plurality of hot air blowers 301a that blow hot air toward the paper P that is transported by the transport mechanism 302, and air that is blown by the warm air blower 301a. The drying chamber 301b is formed by surrounding the region with a wall member. The drying chamber 301b is configured such that at least a part of the wall member is formed of a heat insulating material, and the internal temperature of the drying chamber 301b is not easily lowered. The plurality of hot air blowers 301a are arranged side by side in the paper transport direction. In the drying mechanism 301, the ink on the image surface of the paper P is dried by blowing warm air on the image surface of the paper P conveyed to the internal space of the drying chamber 301b.

  Further, as the drying unit 300, a plurality of radiant heaters may be arranged to dry the ink on the image surface of the paper P by the radiant heat of the radiant heaters.

  The transport mechanism 302 of the present embodiment is mainly composed of a belt transport mechanism 320 and a suction mechanism 330. The belt transport mechanism 320 carries the paper P on the surface of the endless transport belt 325 spanned between the two support rollers 322 and 323, and transports the paper P as the transport belt 325 moves. The length of the conveyance belt 325 in the direction (width direction) orthogonal to the sheet conveyance direction is set to be equal to or greater than the width direction length of the sheet P to be conveyed.

  The conveyor belt 325 travels in the direction of the arrow in the drawing and moves on the surface when at least one of the two support rollers 322 and 323 is driven. The conveying belt 325 of the present embodiment is a suction belt having a ventilation structure in which a plurality of minute through holes (suction holes) are dispersed and opened on the surface thereof, and a belt portion (from the first support roller 322) that carries a sheet. A suction mechanism 330 is provided on the inner peripheral surface side of the belt portion that moves toward the second support roller 323.

  The conveying belt 325 that conveys the sheet material may be any structure that can be ventilated. For example, a conveying belt 325 in which linear members are meshed as shown in FIG. 3 may be used. It may be a porous member.

  The upstream portion of the conveyance belt 325 in the sheet conveyance direction is disposed so as to face the transfer drum 202 of the image forming unit 200. The sheet P conveyed by the transfer cylinder 202 is transferred to the conveyance belt 325 so that the back surface of the image surface thereof faces the surface of the conveyance belt 325, and is carried on the surface of the conveyance belt 325. The paper P carried on the surface of the transport belt 325 is transported to the second support roller 323 side as the transport belt 325 moves.

  The outer diameter of the paper carrying drum 210 is three times the outer diameter of the receiving drum 201 and the transfer drum 202, and the paper carrying drum 210 is a paper that includes the tip of the paper P at three locations on the circumference. A gripper 210a is provided. Further, paper grippers 201 a and 202 a are provided at one place on the circumference of the receiving cylinder 201 and the transfer cylinder 202.

  When the paper gripper 201a of the receiving cylinder 201 is located at a position facing the paper carrying drum 210, one of the paper grippers 210a provided at three locations in the circumferential direction of the paper carrying drum 210 is positioned so as to face the above. The rotational phase of the receiving cylinder 201 and the paper carrying drum 210 is adjusted. Similarly, when the paper gripper 202a of the transfer drum 202 is located at a position facing the paper carrying drum 210, one of the paper grippers 210a provided at three circumferential directions of the paper carrying drum 210 is opposed to the above. The rotational phase of the transfer drum 202 and the paper carrying drum 210 is adjusted so as to be positioned.

  A plurality of paper grippers 210a, 201a, and 202a provided on the paper carrying drum 210, the receiving cylinder 201, and the transfer cylinder 202 are provided at predetermined intervals in the rotation axis direction (paper width direction). Further, the paper gripper 210 a of the paper carrying drum 210 is provided at different positions in the rotational axis direction with respect to the paper grippers 201 a and 202 a of the receiving cylinder 201 and the transfer cylinder 202.

  At a position where the paper carrying drum 210 and the receiving cylinder 201 face each other, the paper gripper 210 a of the paper carrying drum 210 enters between the paper grippers 201 a of the receiving cylinder 201, and the paper of the paper carrying drum 210 from the paper gripper 201 a of the receiving cylinder 201. The gripping of the leading edge of the sheet to the gripper 210a is changed. As a result, the paper is delivered from the receiving cylinder 201 to the paper carrying drum 210.

  Similarly, the paper gripper 210 a of the paper carrying drum 210 enters between the paper gripper 202 a of the delivery drum 202 at the position where the paper carrying drum 210 and the transfer drum 202 face each other, and from the paper gripper 210 a of the paper carrying drum 210. The holding of the leading end of the sheet from the sheet gripper 202a of the transfer cylinder 202 is changed. As a result, the paper P is delivered from the paper carrying drum 210 to the delivery cylinder 202.

  When the paper gripper 202a of the transfer cylinder 202 reaches a position facing the conveyance belt 325 (hereinafter referred to as a belt facing position K), the gripping of the front end of the paper of the paper gripper 202a is released. As a result, the paper P is delivered from the delivery cylinder 202 to the transport belt 325 at the belt facing position K.

  A belt portion (a belt portion that moves from the first support roller 322 toward the second support roller 323) on the conveyance belt 325 is disposed so as to pass through the inside of the drying chamber 313 of the drying mechanism 301. Accordingly, the paper P carried on the surface of the transport belt 325 passes through the inside of the drying chamber 313 of the drying mechanism 301 as the transport belt 325 moves, and then leaves the surface of the transport belt 325 to guide the paper P. The paper is delivered to the paper discharge unit 400 via a plate, a conveyance roller, or the like.

  On the outer peripheral surface of the conveyance belt 325, abutting protrusions 324 with which the leading end of the paper P transferred from the transfer cylinder 202 to the conveyance belt 325 abuts are arranged at equal intervals in the conveyance direction of the conveyance belt 325. The interval between the abutting protrusions 324 is set to the sheet interval (the length in the sheet conveyance direction + the interval between sheets). Further, the circumferential length of the conveyor belt 325 is an integral multiple of the sheet interval.

  The suction mechanism 330 includes a first suction unit 340 provided in a region facing the transfer cylinder 202 on the upstream side in the paper transport direction with respect to the region facing the drying mechanism 301 of the transport belt 325, and the drying mechanism 301 of the transport belt 325. It has the 2nd suction part 350 provided in the field which counters.

4 is a view of the transfer drum 202 as viewed from one side in the axial direction, and FIG. 5 is a view as seen from the direction of arrow A in FIG. In FIG. 5, the flange member 202b of the transfer cylinder 202 is not shown.
As shown in FIG. 5, a cam 260 serving as a gripping release unit is attached to the side plate 200 a of the image forming unit 200. Cams for releasing the gripping of the paper gripper 202 a of the transfer drum 202 are provided at the belt facing position K and the facing position of the transfer drum 202 and the paper carrying drum 210.

  The plurality of paper grippers 202a are screwed to gripper mounting members 247 provided corresponding to the respective paper grippers 202a. Each gripper attaching member 247 is attached to the rotating shaft 242 so as to rotate integrally with the rotating shaft 242. Both sides of the rotating shaft 242 are rotatably supported by the flange mounting member 241. Cam followers 243 are attached to both ends of the rotary shaft 242 so as to rotate integrally with the rotary shaft 242.

  A torsion spring 244 is attached to the rotating shaft 242, and one end of the torsion spring is attached to a spring receiving member 245 fixed to the rotating shaft 242. The other end passes through the flange mounting member 241 and is attached to the spring receiving hole 243a of the cam follower 243 shown in FIG. 4. The cam follower 243 is attached to the center side of the transfer cylinder 202 as indicated by an arrow F in the figure. It is fast. Further, the cam follower 243 is provided with a cam projection 243 b that abuts on the cam surface 260 a of the cam 260.

Next, the release of the gripping of the paper gripper 202a at the belt facing position K will be described with reference to FIGS. FIG. 6 is a diagram showing a state where the cam projection 243b of the cam follower 243 is in contact with the cam surface 260a, and FIG. 7 is a diagram showing a state where the cam projection 243b of the cam follower 243 is near the top of the cam surface. FIG.
As shown in FIG. 6, when the sheet gripper 202a approaches the belt facing position due to the rotation of the transfer cylinder 202, the cam projection 243b of the cam follower 243 comes into contact with the cam surface 260a. The cam surface 260a is a convex curved surface in the rotation direction of the transfer cylinder. Accordingly, the cam projection 243b that is in contact with the cam surface 260a moves on the cam surface 260a as the transfer cylinder 202 rotates. The cam surface 260 is guided by the inclined portion, and the cam projection 243 b moves to the outside of the transfer cylinder 202 against the urging force of the torsion spring 244. As a result, the cam follower 243 rotates clockwise in the drawing together with the rotating shaft 242, and the paper gripper 202 a rotates in the clockwise direction in the drawing together with the gripper mounting member 247 attached to the rotating shaft 242. The holding is released. As described above, the leading edge of the sheet from which the gripping by the sheet gripper 202 a is released at the belt facing position K falls to the transport belt 325.

FIG. 8 is a diagram illustrating a state in which plain paper is transferred from the transfer cylinder 202 to the conveyance belt 325.
When the gripping of the leading edge of the sheet is released by the sheet gripper 202a in FIG. 8A, the leading edge of the sheet falls to the conveyance belt due to its own weight. When the leading edge of the sheet comes into contact with the conveyance belt, as shown in FIG. 8B, the leading edge of the sheet is attracted to the conveyance belt 325 by the suction force of the first suction unit 340, and the leading edge of the sheet is attracted to the conveyance belt 325. In addition, the boundary between the bent portion (portion away from the transfer cylinder 202) on the upstream side of the sheet conveyance with respect to the leading end portion of the sheet and the leading end portion of the sheet becomes a buckled shape. Then, after the leading end portion of the sheet is attracted to the conveyance belt 325, the leading end portion of the sheet is conveyed together with the conveyance belt 325.

FIG. 9 is a diagram illustrating a state in which thick paper is transferred from the transfer drum 202 to the conveyance belt 325.
When the gripping of the leading end of the sheet is released by the sheet gripper 202a in FIG. 9A, the leading end of the sheet falls to the transport belt due to its own weight. For thick paper, the stiffness of the paper is stronger than the suction force of the first suction unit 340, so that after the front end of the paper comes into contact with the transport belt, the front end portion of the paper does not stick to the transport belt and slides on the transport belt. Then, when the leading end side of the sheet approaches the conveying belt 325, the leading end portion of the sheet is attracted to the conveying belt, and the sheet is conveyed together with the conveying belt. As described above, a strong paper such as a thick paper slides on the transport belt after the front end of the paper comes into contact with the transport belt, so that it can be understood by comparing FIG. 8B and FIG. 9B. In this way, the position of the leading edge of the paper when using thick paper is positioned downstream of the leading edge of the paper when using plain paper, and the position relative to the specified position (the leading edge of the paper when using plain paper). Will shift.

  If such a positional shift occurs, the arrival timing of the reverse transport mechanism 500 and the paper discharge unit 400 to the branching unit is shifted, and the transport destination is transported to a transport destination that is different from the transport destination that should originally be transported. There is a risk that a conveyance failure may occur.

  Therefore, in this embodiment, the abutting protrusion 324 is provided on the conveyor belt 325.

FIG. 10 is a diagram illustrating a state of delivery from the delivery drum 202 to the conveyor belt 325 in the present embodiment.
As shown in FIG. 10A, the conveyance control is performed so that the abutting protrusion 324 comes in the vicinity of the downstream side with respect to the leading end of the paper dropped on the conveyance belt by its own weight. As a result, after the leading edge of the paper falls on the conveying belt due to its own weight, if the leading edge of the sheet slides on the conveying belt and moves in the conveying direction, the leading edge of the sheet abuts against the abutting protrusion 324 and the movement in the paper direction is restricted. Is done. Thereby, a strong paper such as a thick paper can be positioned at a predetermined position on the transport belt. As a result, it is possible to suppress the occurrence of problems such as a shift in the arrival timing of the reverse conveyance mechanism 500 and the paper discharge unit 400 to the branch portion.

  It should be noted that the gap between the leading edge of the paper dropped on the conveyance belt and the abutting protrusion 324 may be within a misalignment tolerance that does not cause conveyance failure.

FIG. 11 is a diagram illustrating an example of the abutting protrusion 324, and FIG. 12 is a perspective view illustrating a positional relationship between the abutting protrusion 324 and the paper gripper 202 a of the transfer cylinder 202.
As shown in FIG. 11, the abutting protrusion 324 is provided with two predetermined intervals in the width direction of the conveyor belt 325. Further, the abutting protrusion 324 is provided with a sheet interval (length in the sheet conveyance direction + interval between sheets) in the conveyance direction of the conveyance belt 325. Further, as shown in FIG. 11, the abutting protrusion 324 is provided so that the joint 325 a of the transport belt 325 is between the sheets. This is because the joint 325a portion of the conveying belt 325 does not act by the suction force of the suction mechanism 330, so that the paper cannot be sucked and held when the paper is placed on the joint 325a.

  Further, the abutting protrusion 324 is provided so as to be positioned between the paper grippers 202a of the transfer cylinder 202 as shown in FIG. Accordingly, it is possible to prevent the paper gripper 202a in the gripping release state from hitting the abutting protrusion 324 at the belt facing position K.

  Further, as shown in FIG. 13, the size of the abutting protrusion 324 (length in the conveyance direction × length in the width direction) is substantially the same as the mesh of the conveyance belt 325. Further, the abutting protrusion 324 is fixed to the conveyor belt 325 by sewing on a mesh-like wire of the conveyor belt 325.

  Due to a manufacturing error or the like, the timing at which the paper gripper 202a of the transfer drum 202 is released from the belt holding position K may be different in the paper width direction. As described above, when the timing for releasing the paper holding differs in the paper width direction, the timing at which the leading edge of the paper contacts the conveying belt differs in the paper width direction. As a result, the amount of slip on the conveyor belt differs between the one end side and the other end side in the sheet width direction, and there is a risk of sheet skew. In addition, when the sliding resistance of the transport belt is different in the paper width direction, there is a possibility that the skew of the paper skew occurs because the amount of paper slip on the transport belt differs in the width direction.

  When there is only one abutting protrusion 324 at the center in the conveyance belt width direction, it is not possible to restrict slippage on both sides of the sheet in the width direction. As a result, the position of the sheet in the conveyance direction can be regulated by the leading edge of the sheet abutting against the abutting protrusion 324, but there is a possibility that sheet skew may occur.

  However, by providing two abutting protrusions 324 with a predetermined interval in the width direction of the conveyor belt 325, the sliding on both sides in the sheet width direction can be well regulated by each abutting protrusion 324, and This is preferable because it can suppress misalignment and sheet skew.

  In addition, three or more abutting protrusions 324 may be provided in the conveying direction of the conveying belt, or the abutting protrusion 324 may be long in the conveying direction of the conveying belt 325 as shown in FIG. 14 and 15 can also satisfactorily suppress sheet skew and sheet misalignment.

  In order to prevent the leading edge of the paper from slipping when the leading edge of the paper abuts against the abutting protrusion 324 when the paper is transferred from the transfer drum 202 to the conveying belt 325, when the leading edge of the paper comes into contact with the conveying belt 325, the leading edge of the paper is pushed forward. It is necessary that the contact protrusion 324 come. For this reason, in the present embodiment, the driving of the conveying belt 325 is controlled as follows, and when the leading edge of the sheet comes into contact with the conveying belt 325, the abutting protrusion 324 comes to the front.

FIG. 16 is a diagram for describing drive control of the conveyor belt 325.
As shown in FIG. 16, the gripper sensor 13 that detects the paper gripper 202 a at a position facing the paper carrying drum 210 and the transfer drum 202, and the protrusion sensor that detects the abutting protrusion 324 at a predetermined position facing the conveyance belt 325. 12 are provided. The control unit 10 that controls the drive motor 11 that drives the transport belt 325 controls the drive motor 11 based on the detection results of the gripper sensor 13 and the protrusion sensor 12. In FIG. 16, the driving force of the driving motor 11 is input to the support roller 323, but the driving force of the driving motor 11 may be input to the support roller 322.

FIG. 17 is a flowchart of drive control of the conveyor belt 325.
First, when the gripper sensor 13 detects the paper gripper 202a (Yes in S1), the control unit 10 starts a timer and starts time measurement (S2). When the protrusion sensor 12 detects the abutting protrusion 324 (Yes in S3), the timer is stopped and the time measurement is ended (S4).

  Next, the control unit 10 calculates a difference value between the measurement time (the time from when the gripper sensor 13 detects the paper gripper 202a to when the protrusion sensor 12 detects the abutting protrusion 324) and the specified time. . The specified time is the time from when the leading edge of the paper is caught in the paper gripper 202a of the transfer cylinder 202 to the detection position of the protrusion sensor 12, and can be theoretically obtained as follows. That is, as shown in FIG. 16, the transport distance from the position of the gripper sensor 13 to the belt facing position K where the leading edge of the sheet is released is X1, the transport distance X2 from the belt facing position K to the protrusion sensor 12, and the transfer cylinder 202 The specified time T is T = X1 × V1 + X2 × V2, where V1 is the transport speed of the belt and V2 is the transport speed of the transport belt. In this embodiment, the conveyance speed V1 of the transfer cylinder 202 and the conveyance speed V2 of the conveyance belt are the same speed V0, and therefore T = (X1 + X2) × V0.

  When the measurement time is the specified time (difference value 0) (Yes in S5), when the leading edge of the sheet comes into contact with the conveying belt 325, the abutting protrusion 324 is positioned in front of it, and the processing is ended as it is.

  On the other hand, when the measurement time is shorter than the specified time (No in S5, Yes in S6), the belt speed is decreased for a predetermined time (S7), and longer than the specified time (No in S5, No in S6). Increases the belt speed for a predetermined time (S8). The above flow is repeated until the measurement time reaches a specified time (difference value 0). The ratio of changing the belt speed is obtained from the difference value between the measurement time and the specified time. On the other hand, the rate of change of the belt speed may be constant, and the predetermined time may be changed based on the difference value.

  The control flow shown in FIG. 17 may be performed at a timing such as when the power is turned on, for example. The circumferential length of the conveyor belt 325 is an integral multiple of the sheet interval (interval of the butting protrusions 32), and the conveyor belt rotates at a constant speed. Therefore, after controlling the abutting protrusion 324 to be in the belt facing position at a specified timing, the timing at which the abutting protrusion 324 is at the belt facing position is hardly shifted. As described above, the circumference of the conveyor belt 325 is set to an integral multiple of the sheet interval (interval of the butting protrusions 324), so that the conveyor belt 325 can be rotated at a constant speed after the control flow is executed. By control, the abutting protrusion 324 can be positioned at the belt facing position at a specified timing. Note that the control flow shown in FIG. 17 may always be performed to check whether the timing at which the abutting protrusion 324 comes to the belt facing position is deviated.

  Also, the circumference of the transport belt 325 that is replaced when the drying mechanism 301 is expanded is an integral multiple of the sheet interval. This is preferable because the abutting protrusion 324 can be positioned at the belt facing position at a specified timing by belt drive control similar to that before expansion.

FIG. 18 is a schematic perspective view of the suction mechanism 330.
The suction mechanism 330 includes a suction plate 361 that faces the inner peripheral surface of the belt portion that carries the paper in the transport belt 325. A plurality of suction ports 361 a are formed in the suction plate 361. Between the suction plate 361 and the conveyor belt 325, five belt support rods 349 as lower support members that are supported from the inner peripheral surface of the conveyor belt 325 are provided at predetermined intervals in the belt width direction. .

  These belt support rods 349 can suppress the conveyance belt 325 from being sucked by the suction port 361 a of the suction plate 361 and adsorbed to the suction plate 361. Thereby, it is possible to prevent the ventilation structure portion (portion where the suction port 361a of the suction plate 361 is not formed) between the transport belt 325 and the suction plate 361 from being blocked. Accordingly, it is possible to suppress a decrease in the suction airflow of the suction holes of the conveyance belt 325, and it is possible to favorably adsorb the sheet to the conveyance belt 325.

  An exhaust duct 341 of the first suction part 340 and a suction chamber 355 of the second suction part 350 are arranged on the opposite side of the suction plate 361 facing the conveying belt. A plurality of axial fans 342 are disposed in the exhaust duct 341 so as to face the suction plate 361.

  The second suction unit 350 includes a suction chamber 355 disposed in the belt inner space surrounded by the inner peripheral surface (back surface) of the transport belt 325, a decompression chamber 353 disposed outside the belt inner space, and a suction chamber 355. And a connection duct 354 as a connection passage for communicating the decompression chamber 353 and a suction duct 352 for connecting the decompression chamber 353 and the suction device 351.

FIG. 19 is a cross-sectional view showing the internal structure of the suction chamber 355 in the second suction part 350. FIG. 19 is a schematic diagram showing a cross section orthogonal to the paper transport direction.
The second suction unit 350 sucks the inside of the decompression chamber 353 through the suction duct 352 by the suction device 351, thereby bringing the inside of the decompression chamber 353 into a negative pressure state, and the negative pressure in the decompression chamber 353 causes the connection via the connection duct 354. Then, the inside of the suction chamber 355 is sucked. The inside of the suction chamber 355 is divided into an upper chamber part 341A and a lower chamber part 341B by a partition plate 356 in the vertical direction. The upper chamber portion 341A and the lower chamber portion 341B communicate with each other through a first communication port 356a and a second communication port 356b formed in the partition plate 356.

  The plurality of communication ports 356a and 356b are long through holes that are elongated along the paper conveyance direction, and open at positions facing the both end portions in the width direction of the paper P in this embodiment. In the present embodiment, an example in which the number of communication ports 356a and 356b is two will be described, but three or more may be used.

  In the present embodiment, when suction is performed by the suction device 351, the suction duct 352, the decompression chamber 353, the connection duct 354, and the lower chamber portion 355 </ b> B become negative pressure, and the plurality of communication ports 356 a and 356 b of the partition plate 356 include the upper chamber portion 355 </ b> A. A suction air flow that sucks in the air is generated. Thereby, the air (gas) in the upper chamber part 355A is sucked into the lower chamber part 355B, and the inside of the upper chamber part 355A is in a negative pressure state.

  When the upper chamber portion 355A is in a negative pressure state, a suction air flow that sucks air in the region 355A1 between the suction plate 361 and the conveyance belt 325 is generated in the suction port 361a of the suction plate 361. As a result, the region 355A1 between the suction plate 361 and the transport belt 325 is in a negative pressure state, the paper P on the transport belt 325 is sucked from the suction hole of the transport belt 325, and the paper P is adsorbed to the transport belt 325.

  In the present embodiment, in order to reduce the difference in suction capability between the first communication port 356a and the second communication port 356b, the lower chamber portion 341B is provided with a plurality of communication ports 356a and 356b. A partition member 357 for partitioning the suction channels toward the common connection duct 354 is provided. By providing such a partition member 357, it is possible to adjust the channel cross-sectional area (cross-sectional area orthogonal to the channel direction) of each partitioned suction channel. Specifically, for example, by adjusting the cross-sectional area of the suction channel of the second communication port 356b having a long suction channel length to be relatively large, the first communication port 356a and the second communication port 356b It is possible to reduce the difference in flow resistance between the first communication port 356a and the second communication port 356b.

  Further, in the present embodiment, as shown in FIG. 18, the connecting duct 354 opens into the suction chamber 355 over the conveyance direction range L where the plurality of communication ports 356a and 356b are opened. Thereby, the suction unevenness in the sheet conveyance direction can be reduced as compared with the case where the connection duct 354 is opened in the suction chamber 355 only in a part of the conveyance direction range L where the plurality of communication ports 356a and 356b are opened. it can. In particular, as in the present embodiment, the sheet conveyance direction range in which the connecting duct 354 opens into the suction chamber 355 and the conveyance direction range L in which the plurality of communication ports 356a and 356b are opened are set to substantially the same range. preferable.

Next, the first suction unit 340 of the suction mechanism 330 will be described.
20 is a perspective view of the first suction unit 340, FIG. 21 is a cross-sectional view when the first suction unit 340 is cut along the paper conveyance direction, and FIG. 22 shows the first suction unit 340. FIG. 6 is a cross-sectional view when cut along a cross section orthogonal to the paper transport direction.
The first suction part 340 is mainly composed of an exhaust duct 341 and a plurality of axial fans 342. As shown in FIG. 20, five axial fan groups in which five axial fans 342 are arranged in the width direction of the conveying belt 325 are arranged in the paper conveying direction. That is, a total of 25 axial fans are arranged side by side in the width direction of the transport belt 325 and in the paper transport direction.

  In the first suction unit 340, air is sucked from the suction port 361 a of the suction plate 361 to the exhaust duct 341 by a plurality of axial fans 342, so that the space between the suction plate 361 and the conveyor belt 325 is in a negative pressure state. To do. Accordingly, the sheet can be sucked from the suction hole of the transport belt 325 and the sheet can be sucked to the transport belt 325. The air sucked into the exhaust duct 341 from the suction port 361a is exhausted through the exhaust duct 341. Note that the exhaust duct 341 is not necessarily provided.

  In the first suction unit 340, the suction means (axial fan) is disposed in the inner space of the conveyor belt 325. Therefore, even if an inexpensive axial fan with low pressure loss and weak suction force is used, the first suction unit 340 is good. The paper can be adsorbed to the transport belt. Thereby, power consumption can be suppressed and it can comprise at low cost. If the suction structure at the position facing the drying mechanism 301 is the same as that of the first suction unit, the suction means such as the axial fan is damaged by the heat of the drying mechanism 301. Therefore, the suction means cannot be disposed in the internal space of the transport belt 325 at a location facing the drying mechanism 301. Therefore, for the second suction part 350 in the region facing the drying mechanism, a suction chamber as a negative pressure means is disposed in the inner space of the transport belt 325, and the suction means is disposed outside the inner space of the transport belt 325. A configuration is adopted in which air is sucked from the suction chamber to create a negative pressure so that the paper is adsorbed to the transport belt. Thereby, it is possible to prevent the suction device 351 as the suction means from being directly affected by the heat of the drying mechanism, and to prevent the suction device from being damaged by the heat of the drying mechanism.

  When the suction chamber is extended from the transfer cylinder 202 outside the area facing the drying mechanism to the transfer area where the paper is transferred, and the transfer area is also sucked by the suction device 351 of the second suction unit, The problem arises. That is, by extending the suction chamber to the delivery area, the volume of the suction chamber increases and the pressure loss increases. As a result, it is necessary to use a high-power suction device 351 as the suction device 351 in order to obtain a suction force that favorably attracts the paper to the transport belt. Thus, since the high-power suction device 351 is expensive and large, there is a problem that the cost of the device is increased and the size of the device is increased. In addition, the power consumption increases and the running cost also increases.

  Therefore, in the transfer area where the paper is transferred from the transfer cylinder 202, a suction means (axial fan) is disposed in the internal space of the transport belt, and air is sucked directly from the suction hole of the transport belt by the suction means. Therefore, it is possible to suppress an increase in the cost and size of the apparatus and an increase in running cost.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect 1)
A conveyance device having a conveyance drum such as a transfer drum 202 that conveys a sheet material such as paper, and a conveyance belt 325 that adsorbs and conveys the sheet material delivered from the conveyance drum. An abutment portion such as an abutment protrusion 324 against which the tip of the abutment abuts is provided.
According to this, at the time of delivering the sheet material from the conveyance drum to the conveyance belt, the sheet material can be positioned at a specified position by abutting the leading end of the sheet material against the abutting portion, and the specified gap between the sheets can be determined. Can be maintained.

(Aspect 2)
In the aspect 1, a plurality of abutting portions such as the abutting protrusion 324 are provided side by side in the width direction of the conveyance belt 325.
According to this, as described in the embodiment, it is possible to suppress paper skew and paper positional deviation.

(Aspect 3)
In the first or second aspect, the conveyance belt is arranged such that the abutting portion is positioned near the downstream side in the sheet material conveyance direction with respect to the leading end of the sheet material transferred from the conveyance drum such as the transfer drum 202 to the conveyance belt 325. Control means, such as the control part 10 which controls rotation of 325, was provided.
According to this, as described in the embodiment, the leading edge of the sheet material transferred from the conveying drum such as the transfer drum 202 to the conveying belt 325 slides on the conveying belt 325 in the sheet conveying direction. The front end is abutted against the abutting portion such as the abutting protrusion 324 to restrict the movement of the front end. As a result, the sheet can be positioned within an allowable range of misalignment that does not cause poor conveyance of the sheet material, and occurrence of poor conveyance due to misalignment can be suppressed.

(Aspect 4)
In the aspect 3, the belt length of the conveyance belt 325 is an integral multiple of the sheet material conveyance interval. As a result, after adjusting so that the abutting portion such as the abutting protrusion 324 is positioned immediately before the sheet material transferred from the conveying drum such as the transfer drum 202 to the conveying belt 325, the conveying belt is rotated at a constant speed. It is possible to position the abutting portion just before the sheet material transferred from the transfer drum such as the transfer drum 202 to the transfer belt 325. Accordingly, the abutting portion can be positioned immediately before the sheet material transferred from the transfer drum such as the transfer drum 202 to the transfer belt 325 with simple control.

(Aspect 5)
In modes 1 to 4, the conveyance belt 325 conveys a sheet material to a sheet material drying unit such as the drying mechanism 301, and the conveyance belt 325 is a mesh belt.
According to this, the sheet material can be favorably adsorbed to the conveyance belt, and stable sheet conveyance can be realized.

(Aspect 6)
In any one of the first to fifth aspects, the conveyance belt 325 conveys the sheet material to the sheet material drying unit, and is disposed in a transfer area where the sheet material is transferred from a transfer drum such as the transfer drum 202 of the transfer belt 325. The first suction unit such as a first suction unit 340 that sucks the sheet material on the conveyance belt from the ventilation portion of the conveyance belt 325 and adsorbs the sheet material to the conveyance belt, and the sheet material drying unit of the conveyance belt 325 is a sheet. And a second suction unit such as a second suction unit 350 that is disposed in a drying region for drying the material and sucks the sheet material on the conveyance belt from the ventilation unit to adsorb the sheet material to the conveyance belt.
According to this, as described in the embodiment, the second suction unit such as the second suction unit 350 can be a suction unit considering heat resistance, and the first suction unit such as the first suction unit 340 can be Therefore, it is possible to use an inexpensive suction means that does not take into consideration the property, and it is possible to achieve both the durability of the apparatus and the suppression of the cost increase of the apparatus.

(Aspect 7)
In the aspect 6, the first suction unit such as the first suction unit 340 is configured by a blowing unit such as a plurality of axial fans 342 disposed to face the inner peripheral surface of the conveyance belt 325, and the second suction unit 350. The second suction means such as negative pressure means for setting the internal space of the conveyor belt 325 to a negative pressure state (in this embodiment, a suction chamber 355, a decompression chamber 353, a connecting duct 354, a suction duct 352, a suction device 351, etc. Consists of).
According to this, as explained in the embodiment, the first suction means such as the first suction unit 340 can obtain a good suction force with an inexpensive configuration. On the other hand, since the second suction means such as the second suction part 350 does not arrange the suction means on the inner peripheral surface of the conveyor belt 325, the second suction means is strong in heat resistance and is damaged by the heat of the sheet material drying part. Can be suppressed.

(Aspect 8)
In the drying apparatus such as the drying unit 300 including the conveyance apparatus and the drying mechanism 301 that dries the sheet material being conveyed by the conveyance apparatus, the conveyance apparatus according to any one of aspects 1 to 7 is used as the conveyance apparatus.
According to this, it is possible to convey between prescribed sheets without causing a positional deviation of the sheets.

(Aspect 9)
In an image forming apparatus such as the inkjet recording apparatus 1 that includes liquid discharge means such as liquid discharge heads 220C, 220M, 220Y, and 220K that discharge liquid onto a sheet material and a transfer device that transfers the sheet material, The conveyance device according to any one of aspects 1 to 7 was used.
According to this, it is possible to convey between prescribed sheets without causing a positional deviation of the sheets.

1: Inkjet recording apparatus 10: Control unit 11: Drive motor 12: Protrusion sensor 13: Gripper sensor 32: Abutting projection 200: Image forming unit 200a: Side plate 201: Receiving cylinder 201a: Paper gripper 202: Delivery cylinder 202a: Paper gripper 202b: flange member 210: paper carrying drum 210a: paper gripper 211: suction device 220: ink discharge unit 220C: liquid discharge head 220K: liquid discharge head 220M: liquid discharge head 220Y: liquid discharge head 241: flange mounting member 242: rotation Shaft 243: Cam follower 243a: Spring receiving hole 243b: Cam protrusion 244: Torsion spring 245: Spring receiving member 247: Gripper mounting member 260: Cam 260a: Cam surface 300: Drying section 301 Drying mechanism 301a: Hot air blower 301b: Drying chamber 302: Conveying mechanism 313: Drying chamber 320: Belt conveying mechanism 324: Butting protrusion 325: Conveying belt 325a: Joint 330: Suction mechanism 340: First suction part 341: Exhaust Duct 341A: Upper chamber portion 341B: Lower chamber portion 342: Axial fan 349: Belt support rod 350: Second suction portion 351: Suction device 352: Suction duct 353: Decompression chamber 354: Connection duct 355: Suction chamber 355A: Upper Chamber part 355B: Lower chamber part 356: Partition plate 356a: First communication port 356b: Second communication port 357: Partition member 361: Suction plate 361a: Suction port 400: Paper discharge unit 410: Paper discharge tray 500: Reverse conveyance mechanism

Japanese Patent No. 5980622

Claims (9)

A transport drum for transporting the sheet material;
A conveying device having a conveying belt that adsorbs and conveys the sheet material delivered from the conveying drum,
A conveying device, wherein an abutting portion that abuts the leading end of the sheet material against the conveying belt is provided. In the conveyance apparatus of Claim 1,
A conveying device, wherein a plurality of the abutting portions are provided side by side in the width direction of the conveying belt. In the conveyance apparatus of Claim 1 or 2,
Control means for controlling the rotation of the conveying belt is provided so that the abutting portion is positioned near the downstream side in the sheet material conveying direction with respect to the leading edge of the sheet material transferred from the conveying drum to the conveying belt. A conveying device characterized by that. In the conveyance apparatus of Claim 3,
The conveying apparatus characterized in that the length of the conveying belt is an integral multiple of the conveying interval of the sheet material. In the conveyance apparatus as described in any one of Claims 1 thru | or 4,
The conveyor belt conveys the sheet material to a sheet material drying unit,
The conveyance device, wherein the conveyance belt is a mesh belt. In the conveyance apparatus as described in any one of Claims 1 thru | or 5,
The conveyor belt conveys the sheet material to a sheet material drying unit,
First, the sheet material is disposed in a transfer area where the sheet material is transferred from the conveyance drum of the conveyance belt, and the sheet material on the conveyance belt is sucked from the ventilation portion of the conveyance belt to adsorb the sheet material to the conveyance belt. Suction means;
A sheet material drying unit of the conveyance belt is disposed in a drying region for drying the sheet material, and a second suction unit that sucks the sheet material on the conveyance belt from the ventilation unit and adsorbs the sheet material to the conveyance belt; A conveying device characterized by comprising. In the conveyance apparatus of Claim 6,
The first suction means is composed of a plurality of air blowing means arranged to face the inner peripheral surface of the conveyor belt,
The conveying device, wherein the second suction means is constituted by a negative pressure means for bringing the inner space of the conveyor belt into a negative pressure state. A transport device;
In a drying apparatus comprising a drying mechanism for drying the sheet material being conveyed by the conveying apparatus,
A drying apparatus using the conveyance apparatus according to claim 1 as the conveyance apparatus. Liquid ejection means for ejecting liquid to the sheet material;
In an image forming apparatus comprising a conveying device that conveys the sheet material,
An image forming apparatus using the transport device according to claim 1 as the transport device.