Plate removal system and method as well as printer

Abstract

To provide a plate removal system and method with improved workability in printing plate removal work.SOLUTION: In a plate removal system, a plate cylinder is supported so as to be freely driven and rotatable by a drive device, a slit is provided, the slit being along an axial direction of an outer peripheral part of the plate cylinder and being inclined with respect to a tangential direction and a normal direction of an outer peripheral surface of the plate cylinder, a printing plate is wound around the outer peripheral surface of the plate cylinder, one end portion and the other end portion of the printing plate are inserted to and engaged with the slit, and an end portion of the printing plate is drawn through the slit and removed. The system includes: a holding device that holds the other end portion side of the printing plate; a movement device that moves the holding device along the normal direction; and a control device that outputs a command signal of moving the holding device by the movement device and rotating the plate cylinder by the drive device.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] SUMMARY The present disclosure relates to a plate removal system and method and a printing press. [Background technology]

[0002] A newspaper offset web press includes a paper feeder, a printing device, a web path device, and a folder. The printing device has multiple printing units, each of which prints on a corresponding web. Each printing unit includes an ink supply source, an ink supply device that supplies ink using multiple rollers, a plate cylinder on which a printing plate is mounted, and a blanket cylinder that transfers the ink (image) to the web.

[0003] In a printing unit, a worker loads and unloads a printing plate onto a plate cylinder. The plate cylinder has a slit along its outer periphery that runs along the axial direction. To load a printing plate, the worker inserts one end of the printing plate into the slit, then rotates the plate cylinder to wrap the printing plate around the outer periphery of the plate cylinder, and inserts the other end into the slit. To unload a printing plate, the worker removes the other end of the printing plate from the slit, rotates the plate cylinder to detach the printing plate from the outer periphery of the plate cylinder, and removes one end from the slit. Examples of such plate changing devices include those described in Patent Documents 1 and 2 listed below. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-84738 [Patent Document 2] Patent No. 5291172 Summary of the Invention [Problem to be solved by the invention]

[0005] Because printing plates are formed by bending aluminum along the circumferential surface of the plate cylinder, they are subject to circumferential warping forces. Furthermore, because the plate cylinder rotates at high speed in contact with the blanket cylinder and ink form roller, the plate requires sufficient holding force to resist combined forces such as centrifugal force, circumferential rotational resistance, and adhesive forces with the blanket cylinder and ink form roller. To generate plate holding force, the plate cylinder has a slit with an inclined surface for inserting the plate into the plate cylinder. The plate is inserted at one end and the other end into the slit, and is retained within the slit by frictional resistance due to contact between the one end and the other end of the plate and between the plate and the slit. Meanwhile, conventionally, when workers remove the other end of a printing plate from the slit in the plate cylinder, they remove the plate using a suction cup. However, for the reasons mentioned above, it is difficult to remove the plate from the plate cylinder by simply pulling the plate in the normal direction, requiring the operator's strength, skill, and familiarity. Furthermore, newspaper offset rotary presses can require plate changes of around 100 sheets per printing run, which poses the challenge of requiring a large number of operators and a large workload.

[0006] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a plate removal system and method, and a printing press, that improve the workability of plate removal work. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the plate removal system disclosed herein comprises a plate cylinder supported by a drive unit so as to be freely driven and rotatable, a slit is provided on the outer periphery of the plate cylinder along the axial direction and inclined relative to the tangential and normal directions of the outer periphery of the plate cylinder, a printing plate is wrapped around the outer periphery of the plate cylinder, one end and the other end of the printing plate are inserted into and engaged with the slit, and the end of the printing plate is removed by pulling it out from the slit, and comprises: a holding device that holds the other end side of the printing plate; a moving device that moves the holding device along the normal direction; and a control device that outputs a command signal to move the holding device with the moving device and rotate the plate cylinder with the drive unit.

[0008] In addition, the plate removal method disclosed herein includes a plate cylinder supported by a drive device so as to be freely rotatable, a slit is provided on the outer periphery of the plate cylinder along the axial direction and inclined relative to the tangential and normal directions of the outer periphery of the plate cylinder, a printing plate is wrapped around the outer periphery of the plate cylinder, one end and the other end of the printing plate are inserted into and engaged with the slit, and the end of the printing plate is removed by pulling it out of the slit, and includes the steps of advancing a holding device along the normal direction to approach the outer periphery of the plate cylinder and holding the other end side of the printing plate, retracting the holding device along the normal direction to move away from the outer periphery of the plate cylinder and moving the other end side of the held printing plate outside the plate cylinder, and rotating the plate cylinder in the direction in which the printing plate is removed.

[0009] The printing press of the present disclosure also includes an ink supply device that supplies ink, a plate cylinder from which ink is supplied from the ink supply device to a printing plate attached to its outer periphery, a blanket cylinder that transfers the ink image received from the plate cylinder to a web, and the plate removal system. [Effects of the Invention]

[0010] According to the plate removal system and method and printing press disclosed herein, it is possible to improve the workability of the printing plate removal operation. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a newspaper web offset printing press according to this embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the configuration of a printing unit in a newspaper offset web printing press. [Figure 3] FIG. 3 is a schematic side view showing the plate removing system of this embodiment. [Figure 4] FIG. 4 is a schematic front view showing the plate removal system. [Figure 5] FIG. 5 is a schematic diagram showing a modified example of the plate removal system. [Figure 6] FIG. 6 is a schematic diagram showing a modified example of the plate removal system in a retracted state. [Figure 7] FIG. 7 is a flowchart showing a plate removal method performed by the plate removal system. [Figure 8] FIG. 8 is an explanatory diagram for explaining a plate removing method using the plate removing system. [Figure 9] FIG. 9 is an explanatory diagram for explaining the plate removing operation. [Figure 10] FIG. 10 is an explanatory diagram for explaining the plate removing operation. [Figure 11] FIG. 11 is an explanatory diagram for explaining the plate removing operation. [Figure 12] FIG. 12 is an explanatory diagram for explaining the plate removing operation. [Figure 13] FIG. 13 is an explanatory diagram for explaining the plate removing operation. [Figure 14] FIG. 14 is an explanatory diagram for explaining the plate removing operation. [Figure 15] FIG. 15 is an explanatory diagram for explaining the plate removing operation. [Figure 16] FIG. 16 is a flowchart showing a modified example of the plate removing method by the plate removing system. [Figure 17] FIG. 17 is a time chart showing the plate removal method by the plate removal system. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that the present disclosure is not limited to these embodiments, and when there are multiple embodiments, the present disclosure also includes configurations that combine the embodiments. Furthermore, the components in the embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially identical, and those that are within the so-called equivalent range.

[0013] <Newspaper offset web printing press> 1 is a schematic diagram showing the configuration of a newspaper offset web press according to this embodiment. The newspaper offset web press according to this embodiment is a 4x1 web press in which the size of the plate cylinder of the printing device is set to 4 page widths x 1 page circumference, but it may also be a 4x2 web press in which the size of the plate cylinder is set to 4 page widths x 2 page circumferences.

[0014] 1, the printing press of this embodiment is a newspaper offset web printing press P. The newspaper offset web printing press P includes a paper feeder R, an infeed device I, a printing device U, a web path device D, and a folder F.

[0015] The paper feed device R has a plurality of paper feed units R1 to R5 (five in this embodiment). The in-feed device I has a plurality of in-feed units I1 to I5 (five in this embodiment). The printing device U has a plurality of printing units U1 to U5 (five in this embodiment). The web path device D has one web path unit D1. The folding machine F has one folding unit F1.

[0016] In the paper feeder R, the paper feed units R1 to R5 have substantially the same configuration and each have a holding arm that holds three rolls of web (printing medium) W. By rotating the holding arm, the roll can be rotated to the paper feed position. In the in-feed device I, the in-feed units I1 to I5 have substantially the same configuration and adjust the tension of the web W fed into each printing unit U1 to U5 of the printing device U, thereby stably maintaining the tension of the web W traveling through the printing device U at an appropriate value. The tension of the web W from the paper feeder R to the in-feed device I is controlled by a brake device (not shown) provided in the paper feed units R1 to R5.

[0017] In the printing device U, printing units U1 to U5 are multi-color printing units capable of double-sided four-color printing. However, each printing unit U1 to U5 can be divided into upper and lower printing units U11 to U52 capable of double-sided two-color printing. The printing units U11 to U52 have almost the same configuration and include ink supply devices, plate cylinders, blanket cylinders, etc.

[0018] In the web path device D, a web path unit D1 is provided for the printing units U1 to U5. The web path unit D1 has a slitter that cuts the web W in the vertical direction (the transport direction of the web W) at the center of its width (longitudinal cutting), a turn bar that sets a transport path for the vertically cut web W, and a compensator that adjusts the position of a pattern in the vertical direction of the web W. Each web W that has been printed in the printing units U1 to U5 is cut vertically by the slitter in the web path unit D1, has its transport path changed by the turn bar, and has its pattern position adjusted by the compensator before being superimposed in a predetermined order.

[0019] In the folding machine F, the folding unit F1 vertically folds the webs W introduced from the web path unit D1, in which multiple webs W are stacked, cuts them horizontally to a predetermined length, folds them horizontally to form folded sheets, and discharges them as newspapers.

[0020] <Printing unit> 2 is a schematic diagram showing the configuration of the printing units in a newspaper web offset printing press. In the following, only printing unit U1 will be described, but the other printing units U2 to U5 have almost the same configuration.

[0021] As shown in Figure 2, the printing unit U1 is an H-shaped tower unit that enables four-color printing. The printing unit U1 transports the web W vertically from bottom to top. The printing unit U1 is configured with four stacks 21, 22, 23, and 24 arranged from bottom to top, corresponding to black, blue, red, and yellow. Each stack 21, 22, 23, and 24 has a roller arrangement that is symmetrical on the left and right.

[0022] The stacks 21, 22, 23, and 24 are arranged such that the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b are in contact with each other on the left and right sides of the transport path of the web W. The blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b are in contact with the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a, and 44b. The stacks 21, 22, 23, and 24 are provided with ink supply devices 51a, 51b, 52a, 52b, 53a, 53b, 54a, and 54b for the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a, and 44b. Further, the stacks 21, 22, 23, and 24 are provided with dampening units 61a, 61b, 62a, 62b, 63a, 63b, 64a, and 64b for the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a, and 44b.

[0023] <Plate removal system> Fig. 3 is a schematic side view of the plate removal system of this embodiment, and Fig. 4 is a schematic front view of the plate removal system. Below, the plate removal system applied to stack 21 of printing unit U1 will be described, but the other stacks 22, 23, and 24 have substantially the same configuration. Below, the plate removal system for the reverse side printing side of stack 21 will be described, but the plate removal system for the front side printing side also has substantially the same configuration.

[0024] As shown in Figures 3 and 4, stack 21 is located on the most upstream side in the transport direction of web W. Stack 21 includes blanket cylinder 31b, plate cylinder 41b, ink supply unit 51b, and dampening unit 61b. Ink supply unit 51b includes at least an ink reciprocating roller 71 and two ink form rollers 72. Dampening unit 61b includes at least a dampening roller 73. Note that the configuration, arrangement, and number of the various rollers are not limited to those described above and may be changed as necessary. A beam 74 is located on the ink reciprocating roller 71 side of plate cylinder 41b, and a cover 75 is attached to beam 74 to cover the ink form roller 72 from above.

[0025] FIG. 3 shows the blanket cylinder 31b and the ink form roller 72 in a throw-off state, separated from the plate cylinder 41b.

[0026] The plate cylinder 41b can be driven to rotate by a drive unit 81. The drive unit 81 has a so-called shaftless motor that drives only the plate cylinder 41b of the stack 21 of the printing unit U1. The drive unit 81 can rotate the plate cylinder 41b in a clockwise direction. The plate cylinder 41b can accommodate multiple (four in this embodiment) printing plates 91 arranged in the axial direction. The plate cylinder 41b has a slit 82 on its outer periphery. The slit 82 is formed along the axial direction on the outer periphery of the plate cylinder 41b. The slit 82 is also formed at a predetermined angle with respect to the tangential and normal directions of the outer periphery of the plate cylinder 41b.

[0027] The printing plate 91 has a leading edge end 92 at one end in the winding direction around the plate cylinder 41b, and a trailing edge end 93 at the other end in the winding direction around the plate cylinder 41b. The leading edge end 92 is bent at an acute angle relative to the printing plate 91, and the trailing edge end 93 is bent at an obtuse angle relative to the printing plate 91. The printing plate 91 is wrapped around the outer peripheral surface of the plate cylinder 41b, and the leading edge end 92 and the trailing edge end 93 are inserted into the slit 82 of the plate cylinder 41b to be fixed. That is, after the leading edge end 92 is inserted into the slit 82, the printing plate 91 is wrapped around the outer peripheral surface of the plate cylinder 41b, and the trailing edge end 93 is inserted into the slit 82 and locked.

[0028] On the other hand, when removing the printing plate 91 from the plate cylinder 41b, the trailing edge 93 is removed from the slit 82, the printing plate 91 is then removed from the outer peripheral surface of the plate cylinder 41b, and the leading edge 92 is then removed from the slit 82. The plate removal system 100 automatically performs the operation of removing the trailing edge 93 of the printing plate 91 from the slit 82 of the plate cylinder 41b.

[0029] The printing unit U1 (stack 21) has a plate removal system 100. The plate removal system 100 includes a holding device 101, a moving device 102, and a control device 103.

[0030] The holding device 101 is a suction device with suction cups. By pressing the suction cups against the surface of the printing plate 91, the printing plate 91 can be suction-held. Although not shown, the holding device 101 is provided with an air supply / exhaust device that supplies and / or exhausts air to the suction surface of the suction cup. When the suction cups are pressed against the surface of the printing plate 91, the suction force of the suction cups to the printing plate 91 can be increased by exhausting air from the suction surface of the suction cups to apply suction. Furthermore, by supplying air to the suction surface of the suction cups to reduce the suction force, the suction of the printing plate 91 by the suction cups can be released. Note that the holding device 101 is not limited to a suction device with suction cups, and may be, for example, a device that includes an adhesive member or the like.

[0031] The moving device 102 can move the holding device 101 in the normal direction to the outer peripheral surface of the plate cylinder 41b (in the radial direction of the plate cylinder 41b). That is, the moving device 102 can advance the holding device 101 so that it approaches the outer peripheral surface of the plate cylinder 41b, and can also retract the holding device 101 so that it moves away from the outer peripheral surface of the plate cylinder 41b. The moving device 102 is an actuator. The actuator is a fluid pressure cylinder mechanism that operates by supplying and discharging a fluid (e.g., air). However, the moving device (actuator) 102 is not limited to a fluid pressure cylinder mechanism, and may be configured, for example, by a motor, a screw shaft, etc. In the moving device 102, the holding device 101 is attached to the tip of a drive rod 102a.

[0032] The moving device 102 can move the holding device 101 along the normal direction to the plate cylinder 41b. However, the moving device 102 may also be capable of moving the holding device 101 along a direction inclined at a predetermined angle relative to the normal direction to the plate cylinder 41b. When the drive rod 102a moves forward, the moving device 102 moves the holding device 101 in a direction approaching the printing plate 91 (plate cylinder 41b) and presses the holding device 101 against the surface of the printing plate 91 to hold it. When the drive rod 102a moves backward, the moving device 102 moves the holding device 101 in a direction away from the printing plate 91 (plate cylinder 41b) and removes the trailing edge 93 of the printing plate 91 held by the holding device 101 from the slit 82.

[0033] A plurality of holding devices 101 and moving devices 102 are arranged at intervals in the axial direction of the plate cylinder 41b. The plurality of moving devices 102 are supported by a frame 76 arranged along the axial direction of the plate cylinder 41b. A plurality of printing plates 91 are mounted on the plate cylinder 41b in the axial direction. A plurality of holding devices 101 and moving devices 102 (three in this embodiment) are arranged for each printing plate 91 mounted on the plate cylinder 41b. The three holding devices 101 and moving devices 102 are arranged at equal intervals in the width direction of the printing plate 91 (axial direction of the plate cylinder 41b). In this case, it is preferable that the holding device 101 and moving device 102 arranged in the center be arranged opposite the register pin 41b1 that engages with the notch in the printing plate 91. The number of holding devices 101 and moving devices 102 is not limited to three, and may be two or less or four or more.

[0034] The control device 103 outputs a command signal to move the holding device 101 using the moving device 102 and to rotate the plate cylinder 41b using the driving device 81. The control device 103 is a controller, and is realized by, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit) executing various programs stored in a storage unit using RAM as a working area.

[0035] Specifically, the control device 103 outputs an advance command signal to cause the moving device 102 to move the holding device 101 forward, and after a predetermined time has elapsed, outputs a retreat command signal to cause the moving device 102 to move the holding device 101 backward. In response to the advance command signal, the moving device 102 advances the holding device 101 using the drive rod 102a, holding the trailing edge 93 of the printing plate 91. After the predetermined time has elapsed, the moving device 102 receives a retreat command signal to cause the drive rod 102a to retreat the holding device 101, and removes the trailing edge 93 of the held printing plate 91 from the slit 82.

[0036] A hold detector 104 may be provided to detect the holding of the trailing edge 93 of the printing plate 91 by the holding device 101. The hold detector 104 preferably uses a position detector, a pressure detector, a camera, or the like. The control device 103 outputs a retreat command signal when a predetermined time has elapsed after outputting an advance command signal, but the hold detector 104 may also output a retreat command signal when it detects that the holding device 101 is holding the trailing edge 93. When the hold detector 104 detects that the holding device 101 is holding the trailing edge 93, it may sound an alarm (via a display, speaker, etc.).

[0037] Simultaneously with or after outputting the retraction command signal, the control device 103 outputs a rotation command signal to rotate the plate cylinder 41b by the drive device 81. Simultaneously with or after the movement device 102 retracts the holding device 101 by the drive rod 102a to remove the tail edge 93 from the slit 82, the drive device 81 rotates the plate cylinder 41b.

[0038] That is, the moving device 102 applies a first acting force to the trailing edge end 93 of the printing plate 91 held by the holding device 101 by moving the trailing edge end 93 of the printing plate 91 outward in the normal direction of the plate cylinder 41b. The drive device 81 also applies a second acting force to the trailing edge end 93 of the printing plate 91 by rotating the plate cylinder 41b clockwise in FIG. 3 to move the trailing edge end 93 of the printing plate 91 in the tangential direction. Then, the trailing edge end 93 of the printing plate 91 is smoothly removed from the slit 82 by the resultant force of the first acting force and the second acting force.

[0039] The control device 103 outputs a rotation command signal, and when the plate cylinder 41b rotates a predetermined angle, it outputs a stop command signal to stop the rotation of the plate cylinder 41b by the drive device 81, and simultaneously or after outputting the stop command signal, it outputs a hold release command signal to release the holding device 101 from holding the trailing edge 93 of the printing plate 91. Simultaneously with or after receiving the stop command signal, the drive device 81 stops the rotation of the plate cylinder 41b, the holding device 101 releases its hold on the trailing edge 93 of the printing plate 91. In this case, since the rotation speed of the plate cylinder 41b is set to a predetermined speed, the predetermined angle may be a predetermined time.

[0040] Before or after outputting an advance command signal that causes the moving device 102 to advance the holding device 101, the control device 103 outputs a holding command signal that causes the holding member to advance and hold the outer peripheral surface of the printing plate 91. Here, the holding member is, for example, the dampening roller 73, but a separate holding roller may also be provided.

[0041] As described above, a plurality of printing plates 91 are mounted on the plate cylinder 41b in the axial direction, and a plurality of holding devices 101 and moving devices 102 are arranged for each printing plate 91. The control device 103 outputs command signals to individually operate each moving device 102 provided for each printing plate 91. The control device 103 may also output command signals to simultaneously operate each moving device 102 provided for each printing plate 91.

[0042] The movement speed, operation stop timing, and operation time of the moving device 102, and the rotation speed, rotation stop timing, and rotation time of the plate cylinder 41b can be individually adjusted. That is, the movement speed, operation stop timing, and operation time of the moving device 102, and the rotation speed, rotation stop timing, and rotation time of the plate cylinder 41b can be adjusted according to the type (manufacturer, size, thickness, etc.) of the printing plate 91.

[0043] <Modification of plate removal system> FIG. 5 is a schematic diagram showing a modified example of the plate removing system, and FIG. 6 is a schematic diagram showing the modified example of the plate removing system in a retracted state.

[0044] As shown in Figures 5 and 6, the plate removal system 100 has a retraction device 110 that moves the holding device 101 between a holding position (state in Figure 5) facing the plate cylinder 41b (printing plate 91) and a retracted position (state in Figure 6) where the holding device 101 is retracted from the plate cylinder 41b (printing plate 91).

[0045] The moving device 102 has a holding device 101 attached to its tip. A support shaft 111 is fixed to the moving device 102, and the support shaft 111 is rotatably supported by the frame 76 (see FIG. 4). The support shaft 111 is parallel to the axial direction of the plate cylinder 41b. The swing cylinder 112 has a drive rod 112a, and its base end is rotatably supported by the frame 76 (see FIG. 4) by a support shaft 113. The support shaft 113 is parallel to the axial direction of the plate cylinder 41b. One end of the pivot link 114 is connected to the support shaft 111, and the other end is connected to the tip of the drive rod 112a by a connecting shaft 115.

[0046] As shown in Fig. 5, when the drive rod 112a of the swing cylinder 112 is retracted, the moving device 102 is positioned along the normal direction of the plate cylinder 41b, and the holding device 101 is positioned in a holding position facing the surface of the printing plate 91. When the drive rod 112a of the swing cylinder 112 is extended, the moving device 102 rotates counterclockwise in Fig. 5 around the support shaft 111, and as shown in Fig. 6, the moving device 102 is positioned inclined with respect to the normal direction of the plate cylinder 41b, and the holding device 101 is positioned in a retracted position where it is separated from the surface of the printing plate 91. The holding position is the operating position of the plate removal system 100, and the retracted position is the maintenance position of the plate removal system 100.

[0047] <How to remove the plate> Figure 7 is a flowchart showing the plate removal method using the plate removal system, Figure 8 is an explanatory diagram for explaining the plate removal method using the plate removal system, and Figures 9 to 15 are explanatory diagrams for explaining the plate removal operation.

[0048] As shown in FIG. 8 , in the unit on the reverse side of stack 21, blanket cylinder 31b and plate cylinder 41b are partially exposed, and ink form roller 72 is covered by cover 75. A printing plate 91 is mounted on the outer periphery of plate cylinder 41b. When removing the printing plate 91 from plate cylinder 41b, the trailing edge 93 (leading edge 92) of the printing plate 91 inserted into slit 82 of plate cylinder 41b must be positioned in a predetermined position. The position of trailing edge 93 (slit 82) when removing the printing plate 91 is a position that is easy for an operator to work in, for example, within working range θ where plate cylinder 41b is exposed. A holding device 101 and a moving device 102 are disposed above working range θ.

[0049] Furthermore, the ink form roller 72 and damper roller 73 are in an operating position where they are in contact with the plate cylinder 41b, as shown by the two-dot chain line in Figure 8, and when the plate is being removed, they are moved to a release position away from the plate cylinder 41b, as shown by the solid line in Figure 8. The damper roller 73 rotates in synchronization with the rotation of the plate cylinder 41b, but may also be in a free-rotating state. The plate cylinder 41b can be moved between the contact position and release position relative to the plate cylinder 41b by a device such as a cam mechanism.

[0050] As shown in Figures 7 and 9, in step S11, the control device 103 (see Figure 3) determines whether a printing plate removal signal has been input. The printing plate removal signal is a signal for automatically performing the removal work of the printing plate 91, and can be input by an operator using an operating device (not shown). If the control device 103 determines that a printing plate removal signal has not been input (No), it does not operate the plate removal system 100. On the other hand, if the control device 103 determines that a printing plate removal signal has been input (Yes), in step S12, it starts an automatic removal mode for automatically removing the printing plate 91 using the plate removal system 100.

[0051] When the automatic removal mode is initiated, as shown in FIGS. 7 and 10, in step S13, the control device 103 rotates the plate cylinder 41b clockwise using the drive device 81 (see FIG. 3) to position the trailing edge 93 (slit 82) of the printing plate 91 within the working range θ (see FIG. 8). In step S14, with the trailing edge 93 within the working range θ, the control device 103 outputs an advance command signal to actuate the moving device 102 to move the holding device 101 forward. In response to the advance command signal, the moving device 102 moves the holding device 101 forward and presses it against the trailing edge 93 of the printing plate 91. As shown in FIGS. 7 and 11, in step S15, suction force is applied to the suction cups of the holding device 101 (air is exhausted), allowing the holding device 101 to properly hold the trailing edge 93 of the printing plate 91.

[0052] As shown in FIGS. 7 and 12, in step S16, the control device 103 determines whether a predetermined time has elapsed since outputting the forward movement command signal. The predetermined time is the time it takes for the moving device 102 to move the holding device 101 forward and contact the printing plate 91, and is set in advance. If the control device 103 determines that the predetermined time has not elapsed since outputting the forward movement command signal (No), the control device 103 maintains this state. On the other hand, if the control device 103 determines that the predetermined time has elapsed since outputting the forward movement command signal (Yes), the control device 103 outputs a backward movement command signal in step S17 to operate the moving device 102 and move the holding device 101 backward. As shown in FIGS. 7 and 12, the moving device 102 then moves the holding device 101 backward in response to the backward movement command signal. At this time, the holding device 101 holds the trailing edge 93 of the printing plate 91, allowing the trailing edge 93 of the printing plate 91 to be removed from the slit 82. In this case, the control device 103 may output a reverse command signal based on the detection result of the holding detector 104.

[0053] 7 and 13, in step S18, the control device 103 outputs a rotation command signal to rotate the plate cylinder 41b using the drive device 81. In response to the rotation command signal, the drive device 81 rotates the plate cylinder 41b. The rotation direction of the plate cylinder 41b is clockwise in FIG. 13, which is the direction in which the printing plate 91 is separated from and removed from the plate cylinder 41b.

[0054] In the processing of steps S17 and S18, the moving device 102 moves the holding device 101 backward before the driving device 81 rotates the plate cylinder 41b, but the processing is not limited to this. For example, the moving device 102 may move the holding device 101 backward and the driving device 81 may rotate the plate cylinder 41b simultaneously. That is, the moving device 102 moves the holding device 101 backward and the driving device 81 rotates the plate cylinder 41b at the same time. Also, the driving device 81 may rotate the plate cylinder 41b while the moving device 102 moves the holding device 101 backward. That is, the driving device 81 rotates the plate cylinder 41b while the moving device 102 moves the holding device 101 backward.

[0055] 7 and 14, the plate cylinder 41b has an inclined slit 82, and the printing plate 91 has a trailing edge 93 bent at an obtuse angle to fit the slit 82. Therefore, when the trailing edge 93 of the printing plate 91 moves outward in the normal direction of the plate cylinder 41b, the plate cylinder 41b is rotated so that the trailing edge 93 moves along the inclined slit 82, allowing the trailing edge 93 to be smoothly removed from the slit 82.

[0056] In step S19, the control device 103 determines whether the plate cylinder 41b has rotated a predetermined angle since outputting the rotation command signal. The predetermined angle is the angle at which the trailing edge 93 of the printing plate 91 completely exits the slit 82 of the plate cylinder 41b, and is set in advance. The predetermined angle may also be a predetermined time. If the control device 103 determines that the plate cylinder 41b has not rotated the predetermined angle (No), the control device 103 continues to rotate the plate cylinder 41b. On the other hand, if the control device 103 determines that the plate cylinder 41b has rotated the predetermined angle (Yes), the control device 103 outputs a stop command signal to stop the drive device 81 from rotating the plate cylinder 41b in step S20. In response to the stop command signal, the drive device 81 stops the rotation of the plate cylinder 41b.

[0057] In step S21, the control device 103 outputs a hold release command signal to release the holding device 101 from holding the trailing edge 93 of the printing plate 91. The holding device 101 then releases its hold on the trailing edge 93 of the printing plate 91. That is, the suction force acting on the suction cups of the holding device 101 is released (air is supplied), thereby releasing the hold on the trailing edge 93 of the printing plate 91.

[0058] In the processing of steps S20 and S21, the drive device 81 stops the rotation of the plate cylinder 41b and then the holding device 101 releases the holding of the trailing edge 93 of the printing plate 91, but the processing is not limited to this. For example, the drive device 81 may stop the rotation of the plate cylinder 41b and the holding device 101 may release the holding of the trailing edge 93 of the printing plate 91 simultaneously.

[0059] In step S22, the control device 103 outputs a rotation command signal to rotate the plate cylinder 41b by the drive device 81. In response to the rotation command signal, the drive device 81 rotates the plate cylinder 41b again. The rotation direction of the plate cylinder 41b is clockwise in FIG. 15, which is the direction in which the printing plate 91 is removed from the plate cylinder 41b.

[0060] In step S23, the control device 103 determines whether the plate cylinder 41b has rotated a predetermined angle since outputting the rotation command signal. The predetermined angle is the angle at which the printing plate 91 completely exits the ink form roller 72, and is set in advance. The predetermined angle may also be a predetermined time. If the control device 103 determines that the plate cylinder 41b has not rotated the predetermined angle (No), the control device 103 continues to rotate the plate cylinder 41b. On the other hand, if the control device 103 determines that the plate cylinder 41b has rotated the predetermined angle (Yes), the control device 103 outputs a stop command signal in step S24 to stop the drive device 81 from rotating the plate cylinder 41b. In response to the stop command signal, the drive device 81 stops the rotation of the plate cylinder 41b. Then, in step S25, the automatic release mode ends.

[0061] As shown in FIG. 16, in step S26, the operator removes the printing plate 91 from the plate cylinder 41b.

[0062] <Modification of plate removal method> 16 is a flowchart showing a modified example of the plate removal method using the plate removal system. Note that the processing from step S11 to step S26 is the same as in the above-described embodiment, with the addition of new steps S31 and S32, and duplicated processing will be omitted.

[0063] As shown by the two-dot chain line in FIG. 10, when the automatic removal mode is initiated, in step S13, the control device 103 rotates the plate cylinder 41b using the drive device 81 (see FIG. 3) to position the trailing edge 93 (slit 82) of the printing plate 91 within the working range θ (see FIG. 8). At this time, in step S31, the control device 103 outputs a holding command signal to move the dampening roller 73 to hold the outer peripheral surface of the printing plate 91. The dampening roller 73 then contacts the outer peripheral surface of the printing plate 91 mounted on the plate cylinder 41b and holds the printing plate 91. Therefore, during the processing from step S14 to step S23, the dampening roller 73 holds the printing plate 91, as shown by the two-dot chain line in FIGS. 11 to 15.

[0064] Then, in step S23, the control device 103 determines whether the plate cylinder 41b has rotated a predetermined angle since outputting the rotation command signal. If the control device 103 determines that the plate cylinder 41b has rotated a predetermined angle (Yes), it outputs a hold release command signal to move the dampening roller 73 and separate it from the outer peripheral surface of the printing plate 91. As a result, the dampening roller 73 separates from the outer peripheral surface of the printing plate 91 attached to the plate cylinder 41b, and releases its hold on the printing plate 91.

[0065] <Plate removal operation> FIG. 17 is a time chart showing the plate removal method by the plate removal system.

[0066] As shown in Figures 3 and 17, at time t1, the automatic removal mode for the printing plate 91 by the plate removal system 100 is started (ON). At time t2, the rotation of the drive device (shaftless motor) 81 is locked. At time t3, the moving device 102 advances the holding device 101, pressing it against and holding the trailing edge 93 of the printing plate 91. At time t4, the rotation of the drive device (shaftless motor) 81 is unlocked. In addition, the dampening roller 73 moves to contact the outer peripheral surface of the printing plate 91 attached to the plate cylinder 41b, thereby holding the printing plate 91. The dampening roller 73 may hold the printing plate 91 before the holding device 101 holds the trailing edge 93.

[0067] At time t5, the moving device 102 retracts the holding device 101, and the trailing edge 93 of the printing plate 91 is removed from the slit 82. Then, at time t6, the driving device 81 rotates the plate cylinder 41b. Note that the retraction of the holding device 101 by the moving device 102 and the rotation of the plate cylinder 41b by the driving device 81 may be performed simultaneously.

[0068] At time t7, the drive unit 81 stops the rotation of the plate cylinder 41b. Between times t8 and t9, the holding unit 101 releases the holding of the trailing edge 93 of the printing plate 91. At time t10, the drive unit 81 starts rotating the plate cylinder 41b again, and at time t11, the rotation of the plate cylinder 41b is stopped, ending the automatic release mode. Then, at time t12, the dampening roller 73 moves, releasing the holding of the printing plate 91.

[0069] [Effects of this embodiment] The plate removal system of the first embodiment is a plate removal system 100 in which a plate cylinder 41b is supported by a drive device 81 so as to be freely driven and rotatable, a slit 82 is provided on the outer periphery of the plate cylinder 41b along the axial direction and inclined relative to the tangential and normal directions of the outer periphery of the plate cylinder 41b, a printing plate 91 is wrapped around the outer periphery of the plate cylinder 41b, one end and the other end of the printing plate 91 are inserted into and engaged in the slit 82, and the end of the printing plate 91 is removed by pulling it out through the slit 82, and the plate removal system 100 comprises a holding device 101 that holds the other end side of the printing plate 91, a moving device 102 that moves the holding device 101 along the normal direction of the plate cylinder 41b, and a control device 103 that outputs a command signal to move the holding device 101 with the moving device 102 and rotate the plate cylinder 41b with the drive device 81.

[0070] In the plate removal system according to the first aspect, the control device 103 outputs a command signal to move the holding device 101 using the moving device 102 and to rotate the plate cylinder 41b using the driving device 81, thereby moving the other end of the printing plate 91 held by the holding device 101 outward in the normal direction and separating the other end of the printing plate 91 from the plate cylinder 41b in the circumferential direction. Therefore, even if the slit 82 is provided at an angle, the other end of the printing plate 91 can be smoothly removed from the slit 82, improving the workability of the printing plate removal operation.

[0071] The plate removal system according to the second aspect is the plate removal system according to the first aspect, and further includes a control device 103 that outputs an advance command signal to cause the moving device 102 to advance the holding device 101 so as to approach the outer peripheral surface of the plate cylinder 41b, and outputs a retreat command signal to cause the moving device 102 to retreat the holding device 101 so as to move away from the outer peripheral surface of the plate cylinder 41b after a predetermined time has elapsed. This allows the other end of the printing plate 91 held by the holding device 101 to be removed from the slit 82.

[0072] The plate removal system according to the third aspect is the plate removal system according to the second aspect, and further includes the control device 103 outputting a rotation command signal to rotate the plate cylinder 41b by the drive device 81 at the same time as or after outputting the retraction command signal. This allows the other end of the printing plate 91 to be smoothly removed from the slit 82, even if the slit 82 is provided at an angle.

[0073] The plate removal system according to the fourth aspect is the plate removal system according to the third aspect, further comprising: a control device 103 that outputs a rotation command signal, and when the plate cylinder 41b rotates a predetermined angle, outputs a stop command signal to stop the rotation of the plate cylinder 41b by the drive device 81, and simultaneously with or after outputting the stop command signal, outputs a hold release command signal to release the hold of the other end of the printing plate 91 by the holding device 101. This allows the other end of the printing plate 91 that has been removed from the slit 82 to be released.

[0074] The plate removal system according to the fifth aspect is the plate removal system according to any one of the first to fourth aspects, and further, before or after outputting an advance command signal that causes the moving device 102 to advance the holding device 101 so as to approach the outer peripheral surface of the plate cylinder 41b, the control device 103 outputs a hold command signal that causes the dampening roller (holding member) 73 to advance so as to approach the outer peripheral surface of the plate cylinder 41b and hold the outer peripheral surface of the printing plate 91 on the plate cylinder 41b. This allows the printing plate 91 to be stably held when the other end of the printing plate 91 is removed from the slit 82.

[0075] The plate removal system according to the sixth aspect is the plate removal system according to any one of the first to fifth aspects, further comprising: the moving device 102 applies a first acting force to the other end of the printing plate 91 by moving the other end of the printing plate 91 held by the holding device 101 outward in the normal direction; the drive device 81 applies a second acting force to the other end of the printing plate 91 by rotating the plate cylinder 41b to move the other end of the printing plate 91 in the tangential direction; and the resultant force of the first acting force and the second acting force removes the other end of the printing plate 91 from the slit 82. This allows the other end of the printing plate 91 to be smoothly removed from the slit 82 even if the slit 82 is provided at an angle, improving the workability of the printing plate removal operation.

[0076] The plate removal system according to the seventh aspect is the plate removal system according to any one of the first to sixth aspects, and further includes a plurality of holding devices 101 arranged at intervals in the axial direction of the plate cylinder 41b. This allows the other end of the printing plate 91 to be held by the plurality of holding devices 101, thereby enabling the other end of the printing plate 91 to be stably held. In this case, one or more moving devices 102 are arranged for the plurality of holding devices 101.

[0077] The plate removal system according to the eighth aspect is the plate removal system according to any one of the first to seventh aspects, and furthermore, the plate cylinder 41b can be fitted with a plurality of printing plates 91 arranged in the axial direction, and the control device 103 outputs command signals to individually operate a plurality of moving devices 102 provided corresponding to the plurality of printing plates 91. This allows the plurality of printing plates 91 to be removed individually.

[0078] The plate removal system according to the ninth aspect is the plate removal system according to any one of the first to seventh aspects, and furthermore, the plate cylinder 41b can be fitted with a plurality of printing plates 91 arranged in the axial direction, and the control device 103 outputs command signals to simultaneously operate a plurality of moving devices 102 provided corresponding to the plurality of printing plates 91. This allows a plurality of printing plates 91 to be simultaneously removed, improving workability.

[0079] The plate removal system according to the tenth aspect is the plate removal system according to any one of the first to ninth aspects, and furthermore, the movement speed, operation stop timing, and operation time of the moving device 102, and the rotation speed, rotation stop timing, and rotation time of the plate cylinder 41b are individually adjustable. This makes it possible to accommodate different types of printing plates 91.

[0080] The plate removal system according to an eleventh aspect is the plate removal system according to any one of the first to tenth aspects, and further includes a retraction device 110 that moves the holding device 101 between a holding position facing the printing plate 91 and a retracted position where the holding device 101 is retracted from the printing plate. This allows smooth maintenance work on the plate cylinder 41b and the like without the holding device 101 getting in the way.

[0081] The plate removal system according to the twelfth aspect is the plate removal system according to any one of the first to eleventh aspects, and further includes a hold detector 104 that detects whether the holding device 101 is holding the other end of the printing plate 91, and the control device 103 controls the moving device 102 based on the detection result of the hold detector 104. This makes it possible to appropriately detect whether the holding device 101 is holding the other end of the printing plate 91.

[0082] The plate removal method according to the thirteenth aspect includes the steps of advancing the holding device 101 along the normal direction of the plate cylinder 41b so as to approach the outer peripheral surface of the plate cylinder 41b and hold the other end side of the printing plate 91, advancing the holding device 101 along the normal direction of the plate cylinder 41b so as to move away from the outer peripheral surface of the plate cylinder 41b and move the other end side of the held printing plate 91 outward from the plate cylinder 41b, and rotating the plate cylinder 41b in the direction in which the printing plate 91 is removed. This allows the other end side of the printing plate 91 to be smoothly removed from the slit 82 even if the slit 82 is provided at an angle, improving the workability of the printing plate removal operation.

[0083] The printing press according to the fourteenth aspect includes an ink supply device 51b that supplies ink, a plate cylinder 41b to which ink is supplied from the ink supply device 51b to a printing plate attached to the outer periphery thereof, a blanket cylinder 31b that transfers an ink image received from the plate cylinder 41b to a web W, and a plate removal system 100. Thus, by using the plate removal system 100, the other end of the printing plate 91 can be smoothly removed from the slit 82 even if the slit 82 is provided at an angle, thereby improving the workability of the printing plate removal operation.

[0084] In the above-described embodiment, the newspaper offset rotary press P is used as the printing press, but it may also be used as a commercial offset rotary press or an offset sheet-fed press. [Explanation of symbols]

[0085] 21, 22, 23, 24 stacks 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b Blanket body 41a,41b,42a,42b,43a,43b,44a,44b Plate cylinder 51a, 51b, 52a, 52b, 53a, 53b, 54a, 54b Ink supply device 61a,61b,62a,62b,63a,63b,64a,64b Moistening device 71 Ink reciprocating roller 72 Ink form roller 73 Swimsuit Roller 74 Beam 75 Cover 76 frames 81 Drive unit 82 Slit 91 Printing plate 92 Grip side end (one end) 93 End of the rear end of the jaw (other end) 100 Plate Removal System 101 Holding device 102 Mobile Device 103 Control device 104 Retention Detector 110 Evacuation Device 111 Support shaft 112 Swing Cylinder 113 Support shaft 114 Rotating link 115 Connecting shaft P Newspaper offset rotary printing press (printing press) R Paper feeder R1~R5 Paper feed units I Infeed device I1~I5 Infeed units U Printing device U1~U5, U11~U52 Printing units D Web Pass Device D1 Web Pass Unit F folding machine F1 folding unit

Claims

1. The plate cylinder is supported so as to be rotatable by a drive device, a slit extending along the axial direction of the outer peripheral surface of the plate cylinder and inclined with respect to the tangential direction and the normal direction of the outer peripheral surface of the plate cylinder; a printing plate is wound around the outer peripheral surface of the plate cylinder, and one end and the other end of the printing plate are inserted into the slit and locked; In a plate removal system in which an end portion of the printing plate is removed by pulling it out through the slit, a holding device that holds the other end side of the printing plate; a moving device that moves the holding device along the normal direction; a control device that outputs a command signal to move the holding device using the moving device and to rotate the plate cylinder using the driving device; A plate removal system comprising:

2. the control device outputs an advance command signal to cause the moving device to advance the holding device so as to approach the outer peripheral surface of the plate cylinder, and when a predetermined time has elapsed, outputs a retreat command signal to cause the moving device to retreat the holding device so as to move away from the outer peripheral surface of the plate cylinder. The plate removal system of claim 1 .

3. the control device outputs a rotation command signal to cause the drive device to rotate the plate cylinder simultaneously with or after outputting the retraction command signal; The plate removal system according to claim 2 .

4. the control device outputs the rotation command signal, and when the plate cylinder rotates by a predetermined angle, outputs a stop command signal to stop the rotation of the plate cylinder by the drive device, and simultaneously with or after outputting the stop command signal, outputs a hold release command signal to release the hold of the other end of the printing plate by the holding device. The plate removal system according to claim 3 .

5. the control device outputs a holding command signal to cause the holding member to advance so as to approach the outer peripheral surface of the plate cylinder by the moving device before or after outputting the forward movement command signal to cause the moving device to advance the holding device so as to approach the outer peripheral surface of the plate cylinder, thereby holding the outer peripheral surface of the printing plate on the plate cylinder. The plate removal system of claim 1 .

6. The moving device applies a first acting force to the other end side of the printing plate by moving the other end side of the printing plate held by the holding device outward in the normal direction, and the drive device applies a second acting force to the other end side of the printing plate by rotating the plate cylinder to move the other end side of the printing plate in the tangential direction, and the other end side of the printing plate is pulled out of the slit by the resultant force of the first acting force and the second acting force. The plate removal system of claim 1 .

7. a plurality of the holding devices are arranged at intervals in the axial direction of the plate cylinder; The plate removal system of claim 1 .

8. the plate cylinder is capable of mounting a plurality of the printing plates in a line in the axial direction, and the control device outputs command signals to the plurality of moving devices provided corresponding to the plurality of printing plates to individually operate them. The plate removal system of claim 1 .

9. the plate cylinder is capable of mounting a plurality of the printing plates in a line in the axial direction, and the control device outputs a command signal to simultaneously operate the plurality of moving devices provided corresponding to the plurality of printing plates. The plate removal system of claim 1 .

10. The moving speed, operation stop timing, and operation time of the moving device and the rotation speed, rotation stop timing, and rotation time of the plate cylinder are individually adjustable. The plate removal system of claim 1 .

11. a retracting device is provided that moves the holding device between a holdable position facing the printing plate and a retracted position retracted from the printing plate; The plate removal system of claim 1 .

12. a hold detector for detecting the holding of the other end of the printing plate by the holding device, and the control device controls the moving device based on the detection result of the hold detector. The plate removal system of claim 1 .

13. The plate cylinder is supported so as to be rotatable by a drive device, a slit extending along the axial direction of the outer peripheral surface of the plate cylinder and inclined with respect to the tangential direction and the normal direction of the outer peripheral surface of the plate cylinder; a printing plate is wound around the outer peripheral surface of the plate cylinder, and one end and the other end of the printing plate are inserted into the slit and locked; In the plate removal method, the end of the printing plate is removed by pulling it out through the slit, a step of advancing a holding device along the normal direction so as to approach the outer peripheral surface of the plate cylinder and holding the other end side of the printing plate; a step of retracting the holding device along the normal direction so as to be separated from the outer peripheral surface of the plate cylinder, thereby moving the other end side of the held printing plate to the outside of the plate cylinder; rotating the plate cylinder in a direction in which the printing plate is removed; A plate removal method having the above structure.

14. an ink supply device that supplies ink; a plate cylinder through which ink is supplied from the ink supply device to a printing plate attached to an outer periphery thereof; a blanket cylinder for transferring the ink image received from the plate cylinder to a web; A plate removal system according to claim 1; A printing press comprising:

Images