JP6224919B2 - Sheet processing device - Google Patents

Description

  The present invention relates to a sheet processing apparatus that performs processing on a sheet.

  2. Description of the Related Art Conventionally, there is a sheet-fed rotary printing press with a reversing mechanism having a sheet reversing mechanism for reversing and printing the back side after printing the front surface of a sheet (see, for example, Patent Document 1). This sheet-fed rotary printing press with a reversing mechanism includes a reversing unit capable of reversing sheets between adjacent printing units, and can perform single-sided printing and double-sided printing.

  In this sheet-fed rotary printing press with a reversing mechanism of Patent Document 1, the reversing unit includes a transfer cylinder (number 17 in FIG. 4 of Patent Document 1) and an impression cylinder (number 16 in FIG. 4 of Patent Document 1). When performing double-sided printing, the trailing edge of the sheet being conveyed with the leading edge of the sheet held by the transfer cylinder can be grasped by the impression cylinder, and the conveyance direction of the sheet can be changed and conveyed. It has become.

Japanese Patent Publication No. 03-080108

  However, in the sheet-fed rotary printing press with a reversing mechanism disclosed in Patent Document 1, the configuration for printing the front surface and the back surface is divided, and the entire apparatus has a configuration that includes a printing portion for the front surface and a printing portion for the back surface, respectively. There was a problem that it would increase in size.

  The present invention has been made to solve such a problem, and an object of the present invention is to propose a sheet processing apparatus having a smaller configuration than the conventional one.

In order to solve this problem, in the first aspect of the invention, a processing cylinder that holds and conveys one end of a sheet, and a process that performs processing including digital printing on the surface of the sheet that is conveyed by the processing cylinder. A supply unit that supplies a sheet to the processing cylinder, a downstream side in the sheet conveyance direction of the processing cylinder, and the processing unit. Provided on the downstream side in the sheet conveying direction of the sheet, the conveying cylinder that holds and conveys one end of the processed sheet on one surface, and the conveying cylinder that is provided on the downstream side in the sheet conveying direction of the conveying cylinder. A reversing cylinder that receives the other end of the sheet being conveyed by the cylinder and inverts and conveys the sheet; a downstream side of the reversing cylinder in the sheet conveying direction; and an upstream side of the feeding unit in the sheet conveying direction Establishment Is the transporting from the convertible cylinder receiving the other end of the sheet, to comprise a single transfer cylinder to pass to the processing drum so that the processing is performed on the other surface of the sheet by the processing unit To do.

  According to a second aspect of the present invention, the sheet processing apparatus includes a discharge device that receives and discharges a sheet processed by the processing unit from the conveyance cylinder, and the conveyance unit performs processing only on one side of the sheet. When the sheet processed on one side is discharged to the discharge device and processed on both sides of the sheet, the sheet processed on one side by the processing unit is transferred to the reversing cylinder and the transfer cylinder. Then, the sheet is selectively conveyed so that the sheet processed on the other side by the processing unit is discharged to the discharge device.

  According to a third aspect of the present invention, the conveying cylinder is in contact with the processing cylinder, the inversion cylinder is in contact with the conveying cylinder, and the transfer cylinder is in contact with the inversion cylinder and the processing cylinder. To do.

  In the invention according to claim 4, the reversing cylinder receives the other end of the sheet from the conveying cylinder and the other end of the sheet from the first holding apparatus. And a second holding device to be transferred.

  6. The invention according to claim 5, wherein the processing cylinder has a first holding claw device that holds one or the other end of the sheet, and the conveying cylinder has a second holding claw device that holds one end of the sheet. A first holding device that holds the other end of the sheet, and the other end of the sheet from the first holding device. And a third gripping device for transferring to the transfer cylinder, wherein the transfer cylinder transfers the other end of the sheet from the third gripping device. Have a device.

  According to the first aspect of the present invention, after one side of the sheet conveyed through the processing cylinder is processed by the processing unit, the sheet is returned to the processing cylinder again and the other side of the sheet is processed by the processing unit. Therefore, the processing for one surface and the other surface of the sheet can be executed by one processing cylinder and processing unit, and thus a sheet processing apparatus having a smaller configuration than the conventional one can be realized.

  According to the invention of claim 2, in addition to being able to execute both processing on one side of the sheet and processing on both sides of the sheet, processing is performed on one side of the sheet, and processing is performed on both sides of the sheet. In both cases, the processing cylinder, the conveyance cylinder, and the discharge device are used to discharge the sheet, so that the number of shared parts is increased and the configuration can be downsized as a whole.

  According to the invention of claim 3, the conveying cylinder is in contact with the processing cylinder, the inversion cylinder is in contact with the conveying cylinder, and the transfer cylinder is in contact with the inversion cylinder. In addition, the sheet can be delivered to the processing cylinder with a minimum number of cylinder configurations such as a conveyance cylinder, a reversing cylinder, and a transfer cylinder. In addition, since the transfer cylinder is composed of the minimum necessary number, the size of the reversing mechanism in which a sheet to be processed on both sides is reversed by the processing cylinder after one side is processed by the processing cylinder and then returned to the processing cylinder again is reduced. In addition, since the processed sheet is received from the processing cylinder to the transport cylinder and discharged from the discharge device, the sheet is discharged after being processed by the processing cylinder. It can be downsized.

  According to the fourth aspect of the present invention, the first holding device of the reversing cylinder receives the other end of the sheet from the conveyance cylinder, and the second holding device receives the other end of the sheet from the first holding apparatus. By passing it to the transfer cylinder, the front and back of the sheet can be reversed.

  According to the fifth aspect of the present invention, the sheet can be conveyed by holding and changing the processing cylinder, the conveying cylinder, the reversing cylinder and the transfer cylinder by the holding claw device, so that the registration accuracy of the sheet can be improved.

It is a side view which shows the whole structure of a digital printing apparatus. It is a side view which shows the conveyance process (1) of a sheet | seat. It is a side view which shows the conveyance process (2) of a sheet | seat. It is a side view which shows the conveyance process (3) of a sheet | seat. It is a side view which shows the conveyance process (4) of a sheet | seat. It is a side view which shows the conveyance process (5) of a sheet | seat. It is a side view which shows the conveyance process (6) of a sheet | seat. It is a side view which shows the conveyance process (7) of a sheet | seat. It is a side view which shows the conveyance process (8) of a sheet | seat. It is a side view which shows the conveyance process (9) of a sheet | seat. It is a side view which shows the conveyance process (10) of a sheet | seat. It is a side view which shows the conveyance process (11) of a sheet | seat. It is a block diagram which shows the circuit structure for controlling the rotational speed of an adsorption | suction cylinder according to sheet | seat size. It is a graph which shows the rotational speed control sequence of an adsorption cylinder. It is a block diagram which shows the circuit structure for controlling the rotational speed of a suction cylinder according to sheet size in other embodiment.

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

<Configuration of digital printing device>
As shown in FIG. 1, a digital printing apparatus 1 as a sheet processing apparatus includes a paper feeding device 2 as a supply unit, a digital printing unit 3 as a processing unit, and a discharge device 5.

  The paper feeding device 2 is provided with a stacking table 21 on which a plurality of sheets S1 are stacked, and a soccer device 23 that conveys the uppermost sheet S1 of the stacking table 21 to the feeder board FB. The soccer device 23 includes a first suction 23a and a second suction 23b, and the first suction 23a and the second suction 23b are connected to a negative pressure source via a valve.

  In the vicinity of the front end of the feeder board FB on the downstream side in the sheet conveying direction, the holding claw device (not shown) is supported by the frame 3a so as to be swingable and holds the front end (the end on the holding side) as one end of the sheet S1. A swing device 31 is provided. A paper feeding side transfer drum 32 is disposed opposite to the swing device 31, and the paper feeding side transfer drum 32 is rotatably supported by the frame 3a.

  The feeding side transfer cylinder 32 is provided with a holding claw device 32 a that holds the leading end of the sheet S <b> 1 that is delivered by the holding claw device of the swing device 31. The sheet feeding side transfer cylinder 32 is formed with one notch in which the gripping claw device 32a is disposed and one effective surface that supports the sheet S1, and the effective surface is the maximum size sheet S1, that is, sheet conveyance. The circumferential length is such that one sheet S1 having the longest direction length can be conveyed. This is called a 1x cylinder (single cylinder). In the digital printing unit 3, the swing device 31 and the sheet feeding side transfer cylinder 32 constitute an upstream sheet conveying device.

  A printing cylinder 33 as a processing cylinder is disposed in contact with the sheet feeding-side transfer cylinder 32 on the downstream side in the sheet conveying direction from the swing device 31, and the printing cylinder 33 is rotatably supported by the frame 3a. The printing cylinder 33 is a triple cylinder provided with printing cylinder holding claw devices 33a, 33b, and 33c as first holding claw devices that receive and hold the leading end of the sheet S1 from the holding claw device 32a of the feeding side transfer cylinder 32. The diameter is also three times as large as that of the feed-side transfer cylinder 32. Here, the printing cylinder holding claw devices 33a, 33b, and 33c that hold the sheet S1 are provided in a state in which the phases are shifted from each other by 120 degrees in the circumferential direction.

  An inkjet nozzle section 34 as a processing section is disposed opposite to the peripheral surface of the printing cylinder 33 on the downstream side in the sheet conveying direction from the portion where the printing cylinder 33 is in contact with the sheet feeding side transfer cylinder 32. A plurality of inkjet nozzle heads 34 a to 34 d in which inks of different colors are set are arranged in the inkjet nozzle portion 34 side by side along the circumferential surface of the printing cylinder 33, and each of them is a circumferential surface of the printing cylinder 33. Is oriented.

  The ink jet nozzle heads 34 a to 34 d are disposed in the vicinity of the printing cylinder 33 so that the gap between the inkjet nozzle heads 34 a to 34 d and the sheet S <b> 1 supported by the peripheral surface of the printing cylinder 33 is slightly spaced. The printing cylinder 33 and the inkjet nozzle unit 34 constitute a sheet printing apparatus.

  On the downstream side of the printing cylinder 33 with respect to the inkjet nozzle portion 34 in the sheet conveyance direction, an adsorption cylinder 35 as a conveyance cylinder is disposed in contact with the printing cylinder 33, and the adsorption cylinder 35 is rotatably supported by the frame 3a. . The suction cylinder 35 is a double cylinder having a diameter twice that of the supply side transfer cylinder 32, and two cutouts 35a and 35b are arranged at intervals of 180 degrees. Then, the notches 35a and 35b are sucked as a second gripping nail device that holds the leading end (the gripping side end) that is one end of the sheet S1 conveyed through the printing cylinder 33. A torso gripper device 42 is provided.

  Further, the rear end (butt side end portion) which is the other end portion of the sheet S <b> 1 is sucked into the suction cylinder 35 by the negative pressure from the negative pressure source, and the rear end of the sheet S <b> 1 is surrounded by the circumference of the suction cylinder 35. Two adsorbing devices 41 to be brought into close contact with the surface are arranged with an interval of 180 degrees.

  The suction device 41 can suck the trailing end of the sheet S1 when the length of the sheet S1 is the longest maximum size, and the minimum length of the sheet S1 is the shortest size of the sheet S1. In order to make it possible to suck the rear end of the sheet S <b> 1 in a certain case, the sheet S <b> 1 is formed with a certain length along the circumferential surface of the suction drum 35.

  A reversing cylinder 37 is disposed in contact with the suction cylinder 35 downstream of the contact point of the suction cylinder 35 with the printing cylinder 33 in the sheet conveying direction, and the reversing cylinder 37 is rotatably supported by the frame 3a. As shown in FIG. 5, the inversion cylinder 37 is provided with a notch 37 a, and the notch 37 a has a suction portion 43 as a first holding device, a second holding device, and a third holding claw device. An inversion body holding claw device 44 is provided. Here, a reversing device is constituted by the suction portion 43 and the reversing body holding claw device 44.

  The suction portion 43 includes a suction surface 43a having a plurality of suction holes at its tip and a base end portion 43c, and is supported so as to be swingable about the base end portion 43c. The first receiving position (FIG. 5) for receiving the rear end of the sheet S1 from the suction device 41 of the suction cylinder 35 in a state where the suction surface 43a faces the circumferential surface of the suction cylinder 35 by the movement, and the suction portion 43 The rear end of the sheet S1 adsorbed on the sheet is pulled into the inside of the notch 37a and is positioned at the first delivery position (FIG. 6) where the rear end of the sheet S1 is held and delivered to the inversion body holding claw device 44.

  The reversing body gripping claw device 44 has a gripping claw 44a and a claw base 44b for holding the sheet S1, and the gripping claw 44a is located between the claw base 44b and the closed position where the sheet S1 is sandwiched and the claw base 44b. It is supported so as to be swingable between the open positions that are separated from each other.

  Further, the gripper claw 44a and the claw base 44b are supported so as to be swingable about the base end portion 44c. As shown in FIG. 6, the first claw 44a and the claw base 44b are swung. A second receiving position that receives the rear end of the sheet S1 facing the suction portion 43 positioned at the delivery position and sucked by the suction surface 43a of the suction portion 43 by the gripper 44a and the claw base 44b; The transfer cylinder 38 is positioned at a second transfer position where the rear end of the sheet S1 is held and transferred to the transfer cylinder holding claw device 38a.

One transfer cylinder 38 is located downstream of the reverse cylinder 37 in contact with the suction cylinder 35 in the sheet conveyance direction, and further upstream of the print cylinder 33 in contact with the supply transfer cylinder 32 in the sheet conveyance direction. The transfer cylinder 38 is rotatably supported by the frame 3 a while being in contact with the reversing cylinder 37 and the printing cylinder 33.

The transfer cylinder 38 receives the rear end of the sheet S1 from the reversing cylinder holding claw device 44 of the reversing cylinder 37 and delivers the rear end of the sheet S1 to the printing cylinder holding claw devices 33a, 33b, 33c. A transfer cylinder gripping claw device 38a as a fourth gripping claw device is provided.

  Here, the swing device 31, the paper feeding side transfer cylinder 32, the printing cylinder 33, the reversing cylinder 37, and the transfer cylinder 38 are connected to each other by gears and are driven by a main motor 55 (FIG. 13) described later. On the other hand, only the suction drum 35 is independent of the swing device 31, the feeding-side transfer drum 32, the printing drum 33, the reversing drum 37, and the transfer drum 38 by a suction drum drive motor 56 (FIG. 13) described later. It is driven alone.

  The path of the sheet S1 conveyed by the suction cylinder 35, the reversing cylinder 37, and the transfer cylinder 38 constitutes a sheet reversing path. The sheet reversing path is a path for receiving the sheet S1 from the printing cylinder 33, reversing the sheet S1 and returning it to the printing cylinder 33 in a state where the sheet S1 is reversed.

  By the way, a belt-conveyor-like delivery belt 36 that conveys the sheet S1 released from the suction cylinder 35 is disposed in the vicinity of the downstream side of the suction cylinder 35 in the sheet conveyance direction with respect to the contact point with the reverse cylinder 37, and the delivery is performed. On the downstream side of the belt 36 in the sheet conveying direction, a stacking table 45 (FIG. 1) for stacking sheets S1 is disposed.

  The delivery belt 36 and the stacking table 45 constitute the discharging device 5 that discharges the sheet S1, and the path of the sheet S1 discharged by the suction cylinder 35, the delivery belt 36, and the stacking table 45 constitutes a sheet discharging path. That is, the suction cylinder 35 constitutes a sheet conveyance path switching device that selectively switches the conveyance path of the sheet S1 between the sheet reversal path and the sheet discharge path.

<Circuit Configuration of Sheet Conveyance Control Device According to Sheet Size>
Next, as shown in FIG. 13, in the digital printing apparatus 1, when the sheet conveyance direction length of the sheet S <b> 1 is the longest maximum size or the shortest minimum size, sheet conveyance control according to the sheet size. A circuit configuration of the sheet conveyance control device 50 that performs the above will be described.

  The sheet conveyance control device 50 of the digital printing apparatus 1 includes a control unit 51 having a CPU (Central Processing Unit) configuration that performs overall control of the entire printing operation and the like. A single-sided / double-sided printing selection button 52 to be selected, a sheet size input unit 53 to which the sheet size of the sheet S1 is input, and a rotary encoder 54 as speed / phase detection means are connected, and a main motor 55 and suction cylinder drive motor 56 is connected.

<Printing operation of digital printing device>
The printing operation of the digital printing apparatus 1 configured as described above will be described separately when the single-sided printing mode is selected and when the double-sided printing mode is selected.

  When the single-sided printing mode is selected by the operator's operation of the single-sided / double-sided printing selection button 52, the control unit 51 drives the main motor 55 and the suction drum driving motor 56, thereby causing the swing device 31, the paper feeding side transfer cylinder to be driven. 32, the printing cylinder 33, the reversing cylinder 37 and the transfer cylinder 38 are rotated, and the suction cylinder 35 is rotated.

  At this time, the suction drum driving motor 56 is controlled by the control unit 51 so that the suction drum 35 is rotated in synchronization with the printing drum 33 based on the detection result of the rotary encoder 54. Accordingly, the phases of the suction cylinder holding claw device 42 of the suction cylinder 35 and the printing cylinder gripping claw devices 33 a to 33 c of the printing cylinder 33 coincide with each other, and the peripheral speed of the adsorption cylinder 35 matches the peripheral speed of the printing cylinder 33. . The reversing cylinder 37 and the transfer cylinder 38 are also rotated by the drive of the main motor 55.

  In this manner, the control unit 51 operates the valve of the soccer device 23 with the feeding side transfer cylinder 32, the printing cylinder 33, and the suction cylinder 35 being rotated in synchronization with each other. The second suction 23b sucks the sheet S1 on the loading table 21 and conveys it to the feeder board FB.

  The sheet S1 conveyed by the feeder board FB is conveyed to the feeding side transfer cylinder 32 by the holding claw device of the swing device 31 and is transferred from the holding claw device of the swing device 31 to the holding claw device 32a of the feeding side transfer cylinder 32. The tip of S1 is replaced.

  As shown in FIG. 2, the sheet S <b> 1 conveyed along with the rotation of the paper feeding side transfer cylinder 32 is fed from the gripping claw device 32 a of the paper feeding side transfer cylinder 32 to the printing cylinder 33 at the contact portion with the printing cylinder 33. After the leading end of the printing cylinder holding nail device 33a to 33c (in this case, the printing cylinder holding nail device 33a) is transferred, the printing cylinder 33 is conveyed along with the rotation of the printing cylinder 33.

  When the sheet S <b> 1 conveyed by the printing cylinder 33 passes between the printing cylinder 33 and the inkjet nozzle part 34, the sheet S <b> 1 is atomized from the inkjet nozzle heads 34 a to 34 d of the inkjet nozzle part 34 on the surface of the sheet S <b> 1. The digital printing process is performed by discharging the discharged ink.

  As shown in FIG. 3, when the printing cylinder holding claw device 33a of the printing cylinder 33 and the adsorption cylinder holding claw device 42 of the adsorption cylinder 35 face each other, the printing cylinder holding claw device 33a of the printing cylinder 33 is changed to the adsorption cylinder. The leading end of the sheet S1 is replaced by 35 suction cylinder holding claw devices 42.

  At the timing when the sheet S1 conveyed by the suction cylinder 35 faces the delivery belt 36, the suction cylinder holding claw device 42 is controlled by the control unit 51 so as to release the holding of the front end of the sheet S1, thereby the suction cylinder. The sheet S1 is placed on the delivery belt 36 from 35. The sheet S1 placed on the delivery belt 36 is conveyed along with the belt running of the delivery belt 36 and is discharged onto the stacking table 45.

  On the other hand, when performing double-sided printing on the sheet S1, the operator operates the single-sided / double-sided printing selection button 52 to select the double-sided printing mode, and the sheet conveyance direction length of the sheet S1 via the sheet size input unit 53 Enter the size.

  When performing duplex printing on the sheet S1, the control unit 51 controls the driving speed of the suction cylinder drive motor 56 based on the input sheet S1 length in the sheet conveyance direction. The case of the maximum size sheet that always rotates synchronously at the same peripheral speed as the cylinder 33 and the reversing cylinder 37 will be described. The case where the control unit 51 performs speed change control on the rotation speed of the suction drum drive motor 56 will be described later.

  First, the control unit 51 drives the main motor 55 and the suction drum drive motor 56 to rotate the swing device 31, the paper feed side transfer drum 32, the printing drum 33, the reversing drum 37, and the transfer drum 38, and the suction drum 35. Rotate.

  At this time, the control unit 51 controls the rotational speed of the suction cylinder 35 based on the detection result of the rotary encoder 54 as in the single-sided printing mode, and the sheet S1 input via the sheet size input unit 53. Based on the fact that the length in the sheet conveying direction is the maximum size, the suction cylinder 35 is controlled to rotate synchronously at the same peripheral speed from the printing cylinder 33 and the reverse cylinder 37 throughout. Accordingly, the phases of the printing cylinder holding claw devices 33 a to 33 c of the printing cylinder 33 and the suction cylinder holding claw device 42 of the suction cylinder 35 coincide with each other, and the maximum size held by the suction cylinder holding claw device 42 of the suction cylinder 35. The phases of the rear end of the sheet S1 and the suction portion 43 of the reversing drum 37 coincide.

  In this way, the control unit 51 operates the valve of the soccer device 23 in a state in which the feeding side transfer cylinder 32, the printing cylinder 33, the reversing cylinder 37, the transfer cylinder 38, and the suction cylinder 35 are rotated synchronously. The first suction 23a and the second suction 23b of the soccer device 23 suck the sheet S1 on the stacking base 21 and convey it to the feeder board FB.

  The sheet S1 conveyed by the feeder board FB is conveyed to the feeding side transfer cylinder 32 by the holding claw device of the swing device 31, and the leading end of the sheet S1 is replaced by the holding claw device 32a of the feeding side transfer cylinder 32. The

  As shown in FIG. 2, the sheet S <b> 1 conveyed along with the rotation of the paper feeding side transfer cylinder 32 is fed from the gripping claw device 32 a of the paper feeding side transfer cylinder 32 to the printing cylinder 33 at the contact portion with the printing cylinder 33. After the front end is replaced by any of the printing cylinder holding nail devices 33a to 33c, the printing cylinder 33 is conveyed along with the rotation of the printing cylinder 33.

  When the sheet S <b> 1 conveyed by the printing cylinder 33 passes between the printing cylinder 33 and the inkjet nozzle part 34, the sheet S <b> 1 is atomized from the inkjet nozzle heads 34 a to 34 d of the inkjet nozzle part 34 on the surface of the sheet S <b> 1. When the ink is discharged, digital printing is performed on the surface of the sheet S1 in the double-sided printing mode.

  As shown in FIG. 3, when the printing cylinder holding claw device 33a of the printing cylinder 33 and the adsorption cylinder holding claw device 42 of the adsorption cylinder 35 face each other, the printing cylinder holding claw device 33a of the printing cylinder 33 is changed to the adsorption cylinder. The leading end of the sheet S1 is replaced by 35 suction cylinder holding claw devices 42.

  Thereafter, as shown in FIG. 4, as the suction drum 35 rotates, the suction drum gripping claw device 42 transports the sheet S <b> 1 with its leading edge held. When the rear end of the sheet S1 and the suction device 41 face each other, the suction of the suction device 41 is started by the control unit 51, and the rear end of the sheet S1 is sucked and held by the suction device 41.

  In this state, the suction cylinder 35 is further rotated, and as shown in FIG. 5, the suction cylinder 35 is positioned at the first receiving position at the rear end of the sheet S1 wound around and closely attached to the circumferential surface of the suction cylinder 35 and the reverse cylinder 37. At the timing when the suction surface 43a of the suction portion 43 faces, the control portion 51 starts the suction of the rear end of the sheet S1 by the suction portion 43 of the reversing drum 37 and the sheet by the suction device 41 of the suction drum 35. The suction to the rear end of S1 is released, and the suction cylinder holding claw device 42 releases the holding of the sheet S1 to the front end. As a result, the rear end of the sheet S <b> 1 is transferred from the suction device 41 of the suction cylinder 35 to the suction portion 43 of the reversal cylinder 37.

  Subsequently, the suction portion 43 of the notch 37a in the reversing cylinder 37 rotates from the first receiving position shown in FIG. 5 toward the inside of the notch 37a (in the direction of arrow P) around the base end portion 43c. 6 is positioned at the first delivery position shown in FIG. 6, and the inversion body gripping claw device 44 of the notch 37a is directed from the second delivery position shown in FIG. 5 toward the inside of the notch 37a with the base end 44c as the center. It rotates (in the direction of arrow Q) and is positioned at the second receiving position shown in FIG. 6, and the suction surface 43a of the suction portion 43 and the gripping claws 44a and claw bases 44b of the inverted body gripping claw device 44 face each other.

  At this time, the control unit 51 opens and closes the gripping claw 44a with respect to the claw base 44b, whereby the rear end of the sheet S1 is held and held by the gripping claw 44a and the claw base 44b. Since the suction of 43 is released, the rear end of the sheet S1 is delivered from the suction portion 43 to the reversing body holding claw device 44.

  As shown in FIG. 7, while the rear end of the sheet S1 is held by the reversing body holding claw device 44 of the notch 37a in the reversing body 37, the reversing body 37 is rotated in the arrow direction (sheet conveying direction). The reversing body holding claw device 44 is rotated in the direction opposite to the arrow Q direction around the base end portion 44c, so that the reversing body holding claw device 44 is positioned at the second delivery position.

  Thereafter, as the reversing cylinder 37 is rotated as shown in FIG. 8, the sheet S1 is conveyed while being gradually wound around the circumferential surface of the reversing cylinder 37 with the rear end of the sheet S1 held by the reversing cylinder holding claw device 44. The

  As shown in FIG. 9, when the reversing cylinder holding claw device 44 of the reversing cylinder 37 and the transferring cylinder holding claw device 38 a of the transfer cylinder 38 face each other, the reversing position is set at the second position of the reversing cylinder 37. The rear end of the sheet S1 is replaced by the transfer gripper claw device 38a of the transfer drum 38 from the transfer gripper device 44.

  As shown in FIG. 10, the transfer cylinder 38 rotates while holding the rear end of the sheet S1 by the transfer cylinder holding claw device 38a of the transfer cylinder 38, so that the sheet S1 is directed from the rear end side toward the printing cylinder 33. Are transported.

  As shown in FIG. 11, when the transfer cylinder holding claw device 38a of the transfer cylinder 38 and the printing cylinder holding claw device 33c of the printing cylinder 33 face each other, the trailing edge of the sheet S1 is transferred from the transfer cylinder 38 to the printing cylinder 33. It will be replaced. As a result, as shown in FIG. 12, the sheet S1 is returned again to the printing cylinder 33 in order to print the back surface of the sheet S1 with the sheet S1 turned upside down.

  Note that the sheet feeding device 2 intermittently supplies every other sheet S1 from the stacking base 21 to the feeder board FB in the double-sided printing mode in contrast to the supply of the sheet S1 in the single-sided printing mode. As a result, the printing cylinder 33 receives a new sheet S1 supplied from the paper feeding device 2 every other printing cylinder gripping device 33a to 33c. In other words, the printing cylinder 33 does not receive the new sheet S1. Every other gripper device 33a-33c is present. Here, at the timing when the transfer cylinder 38 faces the printing cylinder holding nail devices 33a to 33c that do not receive the new sheet S1, the rear end of the sheet S1 is transferred from the transfer cylinder holding nail device 38a to the printing cylinder holding nail devices 33a to 33c. Deliver. As a result, the front and back of the new sheet S1 transferred from the sheet feeding side transfer cylinder 32 and the front and back surfaces transferred from the transfer cylinder holding claw apparatus 38a of the transfer cylinder 38 to the printing cylinder holding nail apparatuses 33a to 33c of the printing cylinder 33. The inverted sheets S1 are alternately held and conveyed to the inkjet nozzle unit 34.

  At this time, the sheet S1 in the reverse state, which has been transferred from the transfer cylinder holding claw device 38a of the transfer cylinder 38, has a surface that has already been subjected to digital printing processing by the inkjet nozzle unit 34 (surface that has been subjected to digital printing processing). The sheet S1 is conveyed in a state where the rear end of the sheet S1 is exposed and the rear end of the sheet S1 is exposed and the rear end of the sheet S1 is held by the printing cylinder holding claw device 33c of the printing cylinder 33. Then, digital printing processing is performed on the back surface of the sheet S1 by the ink jet nozzle unit.

  Here, each of the inkjet nozzle heads 34 a to 34 d of the inkjet nozzle section 34 performs printing for the back side of the sheet S <b> 1 that has been transferred from the transfer cylinder 38, and transfers it from the feed-side transfer cylinder 32. Control is performed so as to perform printing for the front surface of the new sheet S1. As a result, the inkjet nozzle heads 34a to 34d alternately perform printing for the front surface and printing for the back surface corresponding to the new sheets S1 alternately held on the printing cylinder 33 and the sheet S1 in the reverse state. become.

  Thereafter, the sheet S1 that has been printed on the back side is discharged from the delivery belt 36 to the stack 45 via the suction cylinder 35, as in the single-sided printing mode.

<Rotational speed control of suction cylinder according to sheet length>
When the maximum size sheet S1 is used, the control unit 51 controls the suction cylinder drive motor 56 to rotate the suction cylinder 35 at a reference speed that is the same peripheral speed as the printing cylinder 33 and the reverse cylinder 37. Here, the reference speed is a rotational speed at which the suction cylinder 35 rotates at the same peripheral speed as that of the printing cylinder 33 and the reversing cylinder 37. When the suction cylinder 35 rotates at the reference speed, the printing cylinder 33 and It is rotating in a state where there is no peripheral speed difference from the reversing drum 37.

  Here, the control of the rotation speed of the suction drum 35 by the controller 51 will be described with reference to FIG. FIG. 14 shows the rotation speed of the suction cylinder 35 when the digital printing apparatus 1 is operated at a steady speed, that is, when the printing cylinder 33 and the reversing cylinder 37 of the digital printing apparatus 1 are rotating at a constant peripheral speed. In the figure, the horizontal axis indicates time t or the phase of the digital printing apparatus 1, and the vertical axis indicates the rotational speed v of the suction cylinder 35.

  In FIG. 14, t <b> 0 is a receiving time point when the leading end of the sheet S <b> 1 is transferred from the printing cylinder holding claw devices 33 a to 33 c of the printing cylinder 33 to the suction cylinder holding claw device 42 of the suction cylinder 35, and t <b> 1 is the rotational speed of the suction cylinder 35. At the time of the first adjustment start, t2 is the time when the first adjustment of the rotation speed of the suction cylinder 35 is completed, and t3 is received by changing the suction of the rear end of the sheet S1 from the suction device 41 of the suction cylinder 35 to the suction portion 43 of the reversing cylinder 37. At the time of delivery, t4 is the second adjustment start time of the rotation speed of the suction cylinder 35, t5 is the second adjustment end time of the rotation speed of the suction cylinder 35, and t6 is again from the printing cylinder holding nail devices 33a to 33c of the printing cylinder 33. This is the time when the suction cylinder holding claw device 42 of the suction cylinder 35 is replaced with the leading end of the sheet S1.

  The time point indicates time or the phase of the digital printing apparatus 1. When the time point is expressed in phase, the reception time point t6 and the reception time point t0 are in the same phase. Further, a section from the first adjustment start time t1 to the first adjustment end time t2 is defined as a first speed adjustment area, and a section from the second adjustment start time t4 to the second adjustment end time t5 is defined as a second speed adjustment area. .

  Here, in the case of the maximum size sheet (maximum paper) having the longest conveyance direction length of the sheet S1, when the digital printing apparatus 1 is operated at a steady speed, as shown by the thick line in FIG. The suction cylinder 35 is rotated at a constant rotation speed v0 without changing the rotation speed of the suction cylinder 35 from t0 to the receiving time t6. In other words, the suction cylinder 35 is rotated at the reference speed from start to finish.

  Since the suction cylinder 35 rotates at the same peripheral speed as the printing cylinder 33 and the reversing cylinder 37, the printing cylinder 33 and the reversing cylinder 37 rotate at a constant speed when the digital printing apparatus 1 is operated at a steady speed. However, when the digital printing apparatus 1 is not operated at a steady speed, for example, at the start of operation, at the end of operation, or at a low speed operation, the printing cylinder 33 and the reversing cylinder are rotated. It rotates synchronously at the same peripheral speed as the peripheral speed of 37.

  Thereby, at the receiving time t0, as shown in FIG. 3, the printing cylinder holding claw device 33a of the printing cylinder 33 and the suction cylinder holding claw device 42 of the suction cylinder 35 face each other, and the leading end of the maximum size sheet S1 is held. Be replaced.

  Thereafter, at the delivery time t3, as shown in FIG. 5, the rear end of the maximum size sheet S1 conveyed by the suction drum 35 rotated at a constant rotation speed v0 is the first suction portion 43 of the reversing drum 37. The sheet S <b> 1 is transferred from the suction cylinder 35 to the reversal cylinder 37 so as to face the suction portion 43 of the reversal cylinder 37 at a fixed period of time positioned at the receiving position.

  As described above, when the sheet S1 is a maximum size sheet, the suction cylinder 35 is simply controlled by the control unit 51 so as to rotate at the reference speed via the suction cylinder drive motor 56. Is transferred to the reversing cylinder 37, and the increase / decrease adjustment of the rotation speed of the suction cylinder 35 with respect to the reference speed is not performed.

  Next, the control in the case of the sheet S1 whose length in the sheet conveyance direction is not the maximum size will be described. Here, a case of the minimum size sheet S1 (minimum paper) having the shortest conveyance direction length that can be printed by the digital printing machine 1 will be described.

  As indicated by a broken line in FIG. 14, the control unit 51 rotates the suction cylinder 35 at the same reference speed (speed v0) as that of the maximum size sheet S1 at the receiving time t0, the delivery time t3, and the receiving time t6. However, in the first speed adjustment area, the speed is adjusted so as to gradually decelerate from the reference speed from the first adjustment start time t1 to return to the reference speed at the first adjustment end time t2, and then the second speed adjustment area , The rotational speed of the suction cylinder 35 is adjusted so as to gradually increase from the second adjustment start time t4 with respect to the reference speed and return to the reference speed at the second adjustment end time t5. Here, the control unit 51 sets the speed adjustment amount in the first speed adjustment region and the second speed adjustment region based on the sheet conveyance direction length of the sheet S1 input via the sheet size input unit 53. In the case of the minimum size sheet S1, the speed increase amount and the speed reduction amount are maximized.

  Note that the control unit 51 performs the period from the reception time t0 to the first adjustment start time t1, from the first adjustment end time t2 to the second adjustment start time t4, and from the second adjustment end time t5 to the reception time t6. The suction cylinder 35 is rotated at a reference speed (rotation speed v0). By controlling in this way, the suction cylinder 35 rotates at the same peripheral speed as the printing cylinder 33 and the reversing cylinder 37 at the receiving time t0 and the delivery time t3 to perform the receiving operation and the delivery operation. The sheet S1 can be reliably delivered between the printing cylinder 33 and the suction cylinder 35 and between the suction cylinder 35 and the reversal cylinder 37.

  When the suction of the rear end of the sheet S1 is performed from the suction cylinder 35 to the reversal cylinder 37, if the sheet S1 is the minimum size, the rotation speed of the suction cylinder 35 is rotated at a constant rotation speed v0 (reference speed). At the time point t3 when the suction device 41 of the suction cylinder 35 and the suction part 43 of the reversing cylinder 37 face each other, the rear end of the sheet S1 has already passed through the suction part 43. Since the suction cylinder 35 is decelerated with respect to the reference speed in the first speed adjustment region and the phase of the suction cylinder 35 is delayed with respect to the phase of the digital printing machine 1, the trailing end of the sheet S1 and the reversing cylinder at the delivery time t3. 37 adsorption parts 43 oppose.

  As a result, the rear end of the sheet S <b> 1 is transferred from the suction device 41 in the suction drum 35 to the suction portion 43 of the reversal drum 37. Note that the suction / adsorption release timing of the suction device 41 and suction portion 43 and the operation timing of the suction drum gripper device 42 when the sheet S1 is transferred from the suction drum 35 to the reversing drum 37 are the same as those of the maximum size sheet S1. Same as timing.

  When the trailing end of the sheet S1 of the minimum size is delivered from the suction cylinder 35 to the reversing cylinder 37 at the timing of delivery time t3, the suction cylinder 35 is rotated as it is at the rotation speed v0 (reference speed). At the timing when the 33 printing cylinder gripping devices 33a to 33c face the suction drum 35, the suction drum holding claw device 42 of the suction drum 35 has not yet reached the contact point with the printing drum 33. In the two-speed adjustment region, the suction cylinder 35 is increased from the rotational speed v0 (reference speed), and the phase of the suction cylinder 35 whose phase is delayed is advanced with respect to the phase of the digital printing machine 1. Therefore, the suction cylinder 35 is received at the receiving time t6. As shown in FIG. 3, the suction cylinder holding claw device 42 faces one of the printing cylinder holding claw devices 33 a to 33 c of the printing cylinder 33. As a result, the leading edge of the sheet S1 is replaced again from the printing cylinder holding claw devices 33a to 33c of the printing cylinder 33 to the suction cylinder holding claw device 42 of the adsorption cylinder 35.

  As described above, the control unit 51 receives the time t0 when the leading end of the sheet S1 having the minimum size is replaced, the time t3 when the rear end of the sheet S1 is transferred, and the time t6 when the leading end of the sheet S1 is replaced again. The rotation speed of the suction cylinder 35 is increased or decreased in the first speed adjustment area and the second speed adjustment area that do not affect the control, and the phase of the suction cylinder 35 with respect to the digital printing machine 1 is adjusted.

  As a result, the control unit 51 moves the leading end of the sheet S1 from the printing cylinder 33 to the adsorption cylinder 35 by increasing or decreasing the rotation speed of the adsorption cylinder 35 even if the sheet S1 has the shortest length in the sheet conveyance direction. The sheet S1 can be reliably replaced and received, and the rear end of the sheet S1 can be reliably transferred from the suction cylinder 35 to the reversal cylinder 37. Thereafter, the next new sheet is transferred from the printing cylinder 33 to the suction cylinder 35. The tip of S1 can be reliably replaced and received.

  As described above, the control unit 51 of the digital printing apparatus 1 sucks from the printing cylinder 33 by controlling the suction cylinder driving motor 56 to increase or decrease the rotation speed of the suction cylinder 35 regardless of the size of the sheet S1. The front end of the sheet S1 can be replaced with the cylinder 35, and the rear end of the sheet S1 can be reliably transferred from the suction cylinder 35 to the reversing cylinder 37, and mechanical adjustment associated with the change in the sheet size can be eliminated. As a result, the burden on the operator is reduced, and preparation work is eliminated, thereby improving productivity.

  Further, in the digital printing apparatus 1, the sheet S1 that has been printed on the front surface by the printing cylinder 33 is transferred again to the printing cylinder 33 through only the suction cylinder 35, the reversing cylinder 37, and the transfer cylinder 38, and the back surface printing is performed. Since digital printing processing on the front and back surfaces can be executed while reusing the cylinder 33, the size can be reduced as compared with the conventional case.

  Further, the digital printing apparatus 1 is constituted by the minimum number of cylinders in a state where the printing cylinder 33 and the suction cylinder 35 are in contact with each other and one transfer cylinder 38 is in contact with both the printing cylinder 33 and the reversing cylinder 37. Thus, the size can be further reduced as compared with the conventional case.

  Furthermore, in the digital printing apparatus 1, the printing cylinder 33, the suction cylinder 35, and the delivery belt 36 are used both when the digital printing process is performed on one side of the sheet S1 and when the digital printing process is performed on both sides of the sheet S1. Therefore, the number of shared parts in both the single-sided printing mode and the double-sided printing mode is increased, and the configuration can be downsized as a whole.

  In addition, when the digital printing apparatus 1 conveys the sheet S1 to the sheet feeding side transfer cylinder 32, the printing cylinder 33, the suction cylinder 35, the reversing cylinder 37, and the transfer cylinder 38, the digital printing apparatus 1 sequentially transfers the sheet S1 by holding and suction replacement. Therefore, it is possible to obtain high registration accuracy in the conveyance direction and width direction of the sheet S1 with respect to the front and back surfaces of the sheet S1, and to obtain high front and back registration accuracy, and to improve the printing quality for the sheet S1. .

<Other embodiments>
In the above-described embodiment, the case where the sheet size input unit 53 is provided as the configuration of the sheet conveyance control device 50 has been described. However, the present invention is not limited to this, and as illustrated in FIG. Instead of the input unit 53, a sheet size detection unit 59 composed of a photoelectric sensor or the like that detects the sheet conveyance direction length (actual size) of each sheet S 1 is provided in the vicinity of the printing cylinder 33 or in the paper feeding device 2. May be.

  In this case, the control unit 51 uses the sheet size detection unit 59 to detect the length (actual dimension) of each sheet S1 in the sheet conveyance direction. Then, the control unit 51 adjusts the rotation speed of the suction cylinder 35 by controlling the suction cylinder drive motor 55 based on the actual dimension measurement data of the actual sheet S1 detected by the sheet size detection unit 59. Accordingly, the sheet S1 of any size can be received by reliably replacing the leading end of the sheet S1 from the printing cylinder 33, and the trailing edge of the sheet S can be reliably transferred from the suction cylinder 35 to the reversing cylinder 37. It can be delivered after being absorbed.

  In the embodiment described above, as the drive control of the suction cylinder drive motor 56 based on the length of the sheet S1 in the sheet conveyance direction when performing double-sided printing on the sheet S1, the suction cylinder 35 is used for the maximum size sheet S1. In the above description, the suction cylinder 35 is rotated at the reference speed all the time, and the suction cylinder 35 is accelerated and decelerated for other sizes. However, the present invention is not limited to this, and the suction cylinder 35 is used for the minimum size sheet S1. The suction cylinder 35 may be rotated at a speed, and the suction cylinder 35 may be accelerated or decelerated at other sizes.

  In this case, both cylinders are arranged so that the phase of the rear end of the smallest sized sheet S1 on the adsorption cylinder 35 and the adsorption portion 43 of the reversing cylinder 37 when the adsorption cylinder 35 is rotated at the reference speed from start to finish. If the length of the sheet S1 input through the sheet size input unit 53 is not the minimum size, the suction cylinder 35 is increased with respect to the reference speed in the first speed adjustment area. Thus, the suction cylinder drive motor 56 is controlled so that the phase of the suction cylinder 35 is advanced with respect to the phase of the digital printing machine 1 and the suction cylinder 35 is decelerated with respect to the reference speed in the second speed adjustment region.

  Further, the length in the sheet conveyance direction of the reference sheet S1 may be a specific length that is neither the maximum size nor the minimum size. At this time, the suction cylinder 35 is rotated at the reference speed throughout the time when the sheet S1 is the reference size, and the rear end of the sheet on the suction cylinder 35 is opposed to the suction portion 43 of the reversal cylinder 37 when the sheets are other sizes. In addition, the rotation speed of the suction cylinder 35 in the first speed adjustment region and the second speed adjustment region is controlled so that the suction drum gripping device 42 of the suction drum 35 faces the printing drum gripping devices 33a to 33c of the printing drum 33. do it.

  Further, in the above-described embodiment, the case where the suction portion 43 of the notch 37a in the reversing cylinder 37 is used to deliver the sheet S1 is described, but the present invention is not limited to this, and instead of the suction portion 43. A nail gripper device may be used. In this case, in the suction cylinder 35, a gripping claw device may be used instead of the suction device 41 of the gripper holding portion 35B.

  Further, in the above-described embodiment, the rear end of the maximum size sheet S1 can be adsorbed and the rear end of the minimum size sheet S1 can be adsorbed and formed along the peripheral surface of the adsorbing cylinder 35. However, the present invention is not limited to this, and an adsorber that is supported movably along the peripheral surface of the adsorption cylinder 35 and adsorbs the sheet S1 is described. You may make it provide. In this case, the suction unit is controlled to be positioned at a position facing the rear end of the sheet S1 according to the length of the sheet S1 in the sheet conveyance direction.

  Furthermore, in the above-described embodiment, regarding the reversing device, the sheet S <b> 1 from the suction drum 35 by the two cooperation of the suction portion 43 as the first holding device and the reverse drum gripping claw device 44 as the second holding device. The case where the rear end of the sheet S1 is received and the sheet S1 is turned upside down and then transferred to the transfer cylinder 38 has been described. However, the present invention is not limited to this, and one inversion cylinder holding claw device is moved to the notch 37a. The reverse body holding claw device receives the rear end of the sheet S1 from the suction cylinder 35, and then the reverse cylinder holding claw device reverses the front and back of the sheet S1 by swinging. The sheet S <b> 1 that has been turned upside down by the reversing cylinder gripping device may be transferred to the transfer cylinder 38.

  Further, in the above-described embodiment, the case where the printing cylinder 33 having a triple cylinder is used as the processing cylinder has been described. However, the present invention is not limited to this, and the double cylinder, the quadruple cylinder, and the six times cylinder. You may make it use the printing cylinder which consists of cylinders.

  Furthermore, in the above-described embodiment, a case is described in which the sheet processing apparatus of the present invention is applied to the digital printing apparatus 1 that performs digital printing processing on the sheet S1 by the inkjet nozzle section 34 as a processing section. However, the present invention is not limited to this, and a processing unit that performs various processes such as a toner process and other various processes, an offset printing process, an inspection process, a foil transfer process, and a stamping process on the sheet S1. May be applied to the sheet processing apparatus.

  DESCRIPTION OF SYMBOLS 1 ... Digital printing apparatus (sheet processing apparatus), 2 ... Paper feeding apparatus, 3 ... Digital printing unit, 5 ... Delivery belt (discharge apparatus), 21 ... Loading platform, 23 ... Soccer apparatus, 31 ... Swing apparatus, 32 ... Feeding Paper side transfer cylinder, 33 ... Printing cylinder (processing cylinder), 33a to 33c ... Printing cylinder holding nail device (first holding nail device), 34 ... Inkjet nozzle unit (processing unit), 35 ... Adsorption cylinder (conveying cylinder) , 36 ... delivery belt (discharge device), 37 ... reverse drum, 38 ... transfer drum, 38a ... transfer drum gripper device (fourth gripper device), 41 ... suction device, 42 ... suction drum gripper device (first) 2 holding claw device), 43 ... adsorption part (first holding device), 44 ... inverted body holding claw device (second holding device, third holding claw device), 45 ... loading platform (discharge device), 50 ... sheet conveyance control device, 51 ... control , 52 ... single-sided / double-sided printing selection buttons, 53 ... sheet size input unit, 54 ... rotary encoder, 55 ... main motor 56 ... suction cylinder drive motor 59 ... sheet size detection unit, FB ... feeder board, S1 ... sheet.

Claims (5)

A processing cylinder that holds and conveys one end of the sheet;
A sheet processing apparatus comprising: a processing unit that performs processing including digital printing on a surface of a sheet conveyed by the processing cylinder;
A supply unit that is provided upstream of the processing unit in the sheet conveying direction, and that supplies a sheet to the processing cylinder;
A conveying cylinder that is provided on the downstream side in the sheet conveying direction of the processing cylinder and on the downstream side in the sheet conveying direction of the processing unit, and holds and conveys one end of the processed sheet on one surface;
A reversing cylinder that is provided on the downstream side of the conveying cylinder in the sheet conveying direction, receives the other end of the sheet being conveyed by the conveying cylinder, and reverses and conveys the front and back of the sheet;
The sheet conveying direction of the downstream side of the convertible cylinder, and provided in the sheet conveyance direction upstream side of the supply unit, and conveyed from the convertible cylinder receiving the other end of the sheet, the other surface of the sheet by the processing unit A sheet processing apparatus , comprising : a transfer cylinder that is transferred to the processing cylinder so as to be processed. A discharge device that receives and discharges the sheet processed by the processing unit from the transport cylinder;
When the conveying cylinder performs processing only on one side of the sheet, the processing unit discharges the sheet processed on one side to the discharge device, and when processing on both sides of the sheet, the processing unit A sheet processed on one side is conveyed to the processing cylinder via the reversing cylinder and the transfer cylinder, and the sheet processed on the other side by the processing unit is discharged to the discharge device. The sheet processing apparatus according to claim 1, wherein the sheet is selectively conveyed. The transfer cylinder is in contact with the processing cylinder, the inversion cylinder is in contact with the transfer cylinder, and the transfer cylinder is in contact with the inversion cylinder and the processing cylinder. The sheet processing apparatus according to the description. The reversing cylinder has a first holding device that receives the other end of the sheet from the conveyance cylinder, and a second holding that receives the other end of the sheet from the first holding device and transfers it to the transfer cylinder. The sheet processing apparatus according to claim 2, further comprising: an apparatus. The processing cylinder has a first holding claw device that holds one or the other end of the sheet;
The conveying cylinder has a second gripping claw device that holds one end of the sheet, and a suction device that sucks the other end of the sheet,
The reversing cylinder has a first holding device that holds the other end of the sheet, and a third gripping device that receives the other end of the sheet from the first holding device and transfers it to the transfer cylinder. Have
The sheet processing apparatus according to claim 2, wherein the transfer cylinder includes a fourth gripping claw device that replaces the other end portion of the sheet from the third gripping device.

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