JPH0344523Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an offset printing machine, and particularly to an offset printing machine having an automatic plate change device that automatically changes plates while rotating the plate cylinder.

[Prior Art] In conventional offset printing machines, plate cylinder change work is performed by stopping the rotation of the plate cylinder, and after the printed plate is removed, the next plate is attached. It was something to do.

[Problem that the invention attempts to solve]

Therefore, in conventional offset printing machines, when printing starts again after a plate change, the amount of ink applied to the plate becomes too large, resulting in an unstable state, or it is difficult to maintain a stable printing speed from a stopped state. Because the transport speed of the paper to be printed changes, the ink that adheres from the plate through the blanket cylinder becomes unstable, requiring adjustment and time to stabilize, and printing efficiency is extremely low. Not only is this bad for the printer, but it also results in a lot of time wasted if the printing press is stopped and then the plate is changed.

The present invention was developed in view of this point, and allows printing to be carried out continuously without interruption.
It is an object of the present invention to provide an offset printing press having an automatic plate change device that can perform plate change operations in parallel.

[Means for solving problems]

The present invention allows one of a plurality of blanket cylinders to come into contact with a rotatable plate cylinder and an impression cylinder of an offset printing press, and around the plate cylinder,
a plate supply unit for feeding a plate to insert the leading edge of the plate into an opening of the plate cylinder when the plate cylinder is rotating; A plate unloading section is installed to sequentially unload the plate from
The plate supply unit is configured to supply the next plate to the opening after the leading edge of the plate released from the opening is supported by the plate carrying unit, and the plate cylinder is always capable of printing. It supports the version in the state.

[Effect]

Even during the plate change operation, the plate is supported by the plate cylinder in a printable state, so it is possible to perform printing work while changing the plate, making it possible to perform continuous printing, and the printing machine Since there is no need to stop the ink supply, the amount of ink supplied from the inking roll and the transport speed of the paper to be printed can be kept stable, and extremely stable printing can be performed continuously. Further, among the plurality of blanket cylinders, those not in contact with the plate cylinder and the impression cylinder can be cleaned even during printing operations.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Here, FIG. 1 is a schematic side view of the entire apparatus with the plate cylinder in cross section, showing only one blanket cylinder for convenience and explaining the state during printing, and FIG. 2 is a rotary joint used in the air supply path. 3 is a schematic front view of the control pipe of the rotary joint, FIGS. 4a to 4f are operation explanatory diagrams of the plate change operation, and FIG.
FIG. 6 is a schematic side view showing the relationship between the blanket cylinder, plate cylinder, and impression cylinder.

In Fig. 1, a metal plate cylinder 2, which supports a plate 1 made of synthetic resin or paper on its circumferential surface, and a soft rubber blanket cylinder 3 are in contact with each other, and are rotated in opposite directions indicated by the arrows. Ru. Further, the blanket cylinder 3 is in contact with a metal impression cylinder 4, and is driven to rotate in opposite directions, which are the directions indicated by the arrows. printing is performed. At predetermined positions around the plate cylinder 2, there are respectively a plate supply section 6 for supplying the plate 1 to the plate cylinder 2, an ironing roll 7 for bringing the plate 1 into close contact with the circumferential surface of the plate cylinder 2, and a squeezing roll 7 for applying wet water to the plate surface. A plurality of inking rolls 9 are used to apply ink from the ink storage section to the plate surface, and the plate 1, which has been discharged from the plate cylinder 2 after printing has been completed, is conveyed to an appropriate location. A plate transport section 10 is provided for this purpose.

On the other hand, the blanket cylinder 3, only one of which is shown for convenience, is provided with an automatic cleaning device for cleaning ink adhering to its peripheral surface. This automatic cleaning device includes a spray 11 that spouts cleaning liquid, a wiping roll 12 that wipes off ink, and a cover 13.
It consists of. If there is only one blanket cylinder 3, the cleaning work is usually done on each cylinder 2,
3 and 4 are separated in a non-contact state and the blanket cylinder 3 is rotated. However, if the printing paper is continuous paper 5, there is no problem even if this cleaning work is not performed. As shown in FIG. 6, the blanket cylinder of this embodiment actually consists of two blanket cylinders 40 and 41 equipped with an automatic cleaning device (not shown), which are alternately connected to the plate cylinder 2 and the impression cylinder. 4, printing is performed with the blanket cylinders in the facing state, the blanket cylinder 40 in FIG. 6, while cleaning work is performed on the blanket cylinder 41 in the non-facing state. ing. Blanket body 40, 41
For switching, for example, a switching device may be used that integrally reciprocates the blanket cylinders 40, 41 located at appropriate intervals in the horizontal direction.

As shown in FIG. 1, the plate supply unit 6 includes a pair of upper and lower delivery rolls 14 and 15 for feeding a new plate 1a to be supplied toward the plate cylinder 2, and a pair of upper and lower delivery rolls 14, 15 for feeding the new plate 1a
It consists of a front stopper 16 and a rear stopper 17 that can be raised and lowered to respectively lock the front and rear of the new plate 1a in order to regulate the supply of the new plate 1a.In this plate supply section 6, the new plate 1a is positioned in the width direction. Ru. The feed roll 14 is connected to the same rotational drive source as the plate cylinder 2, and is constantly driven to rotate, and is movable toward and away from the new plate 1a on the feed roll 15, during printing as shown in the figure. Although they are separated, when they come into contact, a force is applied to the new plate 1a in the direction of the plate cylinder 2. This movement of the feeding roll 14 toward and away from the old plate 1b (see Fig. 4), which has been removed from the plate cylinder 2, is carried out by an air cylinder and a cam (see Fig. 5), which are not shown, to the plate transport section (described later). Immediately after the leading end is supported, the new plate 1a is controlled so as to be inserted into the opening to be described later. Further, in the printing state shown in the drawing, each of the stoppers 16 and 17 are both in a locked state in which they are facing down.

The squeezing roll 7 is configured to be rotatable and capable of moving toward and away from the circumferential surface of the plate cylinder. The plate cylinder 2 is crimped by an air cylinder (see FIG. 5), which is not shown, just before the lower edge of the opening of the plate cylinder 2, which will be described later, is in the corresponding position, and the plate cylinder 2 is crimped at the rear of the plate 1. It is controlled so that it separates immediately after the end passes. That is, the ironing roll 7 presses the entire new plate 1 supported on the circumferential surface of the plate cylinder 2 to bring it into close contact with the circumferential surface, while contacting the plate 1 after ink has been applied. It is something that never happens. Therefore, since ink does not adhere to the ironing roll 7, the plate 1 to be pressed next is not stained.

The plate carrying out section 10 includes a carrying out belt 18 which is driven in circulation by an appropriate rotational drive system, and a carrying out belt 18 which is rotatably driven to guide the old plate 1b (see FIG. 4) discharged from the plate cylinder 2 onto the carrying out belt 18. It consists of a pair of upper and lower guide rolls 19 and 20. The rotational speed of each of the guide rolls 19 and 20 is set slightly higher than the rotational speed of the plate cylinder 2, and when the old plate 1b discharged from the plate cylinder 2 is drawn in, the speed difference mentioned above causes the rotation speed of the old plate 1b to be slightly higher than that of the plate cylinder 2. Constructed to absorb slack. Further, the guide rolls 19, 2
A well-known torque limiter mechanism is provided at a suitable location in the rotary drive system (not shown) of 0, and when a tension of a predetermined level or more is applied to the old plate 1b, this mechanism is activated to close the guide rolls 19, 20 and the plate. The rotation speeds of the cylinders 2 are the same, and the old plate 1b is always discharged from the plate cylinder 2 with constant tension.

Next, the configuration of the plate cylinder will be explained in detail based on FIG. 1 as well.

The plate cylinder 2 is composed of a main body 2a and a lid 2b detachably fixed to the main body 2a by bolts or the like. Both these bodies 2a, 2b
A communication space 21 is formed in the plate cylinder 2, and an opening 22 thereof into which the plate 1 is inserted is opened on the circumferential surface of the plate cylinder 2 so as to extend in the axial direction at a predetermined angle with respect to the radial direction. The vertical distance between the openings 22 is larger than the thickness of the plate 1, but is set so narrow that it is impossible to insert a finger into the hole. A recess 23 formed by communicating with the opening 22 while blocking a part of the communication space 21 positions the plate 1 inserted through the opening 22 in the vertical direction at its rear end surface. It is.

A plurality of jet ports 24 are opened at a predetermined interval on the lower surface of the recess 23 (however, only one is shown),
Each spout 24 communicates with a flow path 25 that communicates with a blower device (not shown). The flow path 25
A rotary joint 26 shown in FIGS. 2 and 3 is provided at the connecting end of the plate cylinder 2 in the air supply path. And the rotary joint 26
A circular hole 28 is opened at an eccentric position at the end of the reverse plate cylinder 2 of the through hole in the rotary part 27 which is the connecting part to the plate cylinder 2. On the other hand, the rotary joint 26
A control tube 31 having a long hole 30 located on the movement path corresponding to the movement trajectory of the circular hole 28 is fixed to the through hole in the fixed part 29 at the abutting end with the rotation part 27. has been done. The supply of air to the flow path 25 is primarily controlled by a solenoid valve (not shown) (see FIG. 5), but the provision of the control pipe 31 improves its accuracy. and only while the solenoid valve is in the on state and the circular hole 28 corresponds to the elongated hole 30.
Air is supplied to the flow path 25. That is, the air is controlled to be ejected from the ejection ports 24 only within a certain range of rotational movement of the plate cylinder 2.

A plurality of suction ports 32 are opened at predetermined intervals on the upper surface of the recess 23 for temporarily supporting the tip of the plate 1 inserted through the opening 22 (however, only one is shown); Each intake port 32 communicates with a flow path 33 that communicates with a vacuum suction device (not shown). Although not shown, the flow path 33
Regarding the flow path 25, a similar electromagnetic valve and rotary joint are provided. (See FIG. 5) Also, the opening 22 on the circumferential surface of the lid 2b
A plurality of air intake ports 34 for sucking and supporting the rear end portion of the plate 1 are opened slightly above the plate 1 at predetermined intervals (however, only one air intake port 34 is shown).
It communicates with a flow path 35 that communicates with a vacuum suction device (not shown). Regarding the flow passage 35, although not shown, a solenoid valve for on/off control is provided. (See FIG. 5) As is clear from FIG. 1, the clamp claw 36 that clamps the tip of the plate 1 inserted into the plate cylinder 2 from the opening 22 is located in the communication space 21 and rotates around the rotation axis. A plurality of springs 37 are fixed at predetermined intervals, and each tip is brought into contact with the upper surface of the recess 23 by the urging force of a spring 38 disposed in the communication space 21, so that the tip of the plate 1 is clamped. It is configured. When the rotating shaft 37 is rotated to a predetermined state against the urging force, the clamp claw 36 releases the clamping operation.

Next, the version changing operation of this embodiment will be explained based on FIGS. 1, 4, and 5.

In the printing state shown in FIG. 1, when printing of a predetermined number of sheets is completed, a plate change command signal is issued from a counter (not shown).
When the plate cylinder 2 rotates and the opening 22 reaches a position slightly past the top, the proximity switch that has received the command signal detects this and issues a detection signal, causing the clamp claw operating cam and the feeder to move. While each of the roll operating cams is turned on, the air cylinder for the feeding roll and the air control solenoid valves associated with the flow passages 25 and 33 are turned on.

When the plate cylinder 2 further rotates and the opening 22 reaches a position slightly past the bottom, the clamp claw 36 releases the clamp on the tip of the old plate 1b due to the action of the cam, and then each of the rotary joints 26 The holes 28 and 30 begin to correspond and the air flows through the flow path 25.
The ejection starts from each ejection port 24 through the ejection port 24. (4th
(See Figure a) As a result, the leading edge of the old plate 1b begins to separate from the plate cylinder 2, and the plate discharging operation is started. Then, air is continuously ejected from each ejection port 24 for a predetermined time defined by each of the holes 28 and 30, so that the tip of the old plate 1b is securely and
It is smoothly removed from the recess 23 of the plate cylinder 2.

The tip of the old plate 1b separated from the plate cylinder 2 is drawn into a pair of guide rolls 19 and 20, and the tip of the old plate 1b
are sequentially guided onto the delivery belt 18. on the other hand,
When the opening 22 reaches a position slightly in front of the standby position of the new plate 1a due to the rotation of the plate cylinder 2, each hole 28, 3
The corresponding state of 0 ends and the air jetting stops. When the opening 22 corresponds to the standby position of the new plate 1a, each stopper 16, 17 releases the locked state, the feed roll 14 comes into contact with the new plate 1a by the action of a cam, and the tip of the new plate 1a is brought into contact with the opening. 22
It is inserted into the recess 23 of the plate cylinder 2 and positioned by its rear end surface. Here, the flow path 33 communicates with a vacuum device by the action of a rotary joint (not shown), and the positioned tip of the new plate 1a is maintained in a positioned state by the air suction force acting on each intake port 32. . (See Fig. 4b) When the positioning is completed, the feed roll 14 separates from the new plate 1a, and the new plate 1a remains positioned by the above-mentioned air suction force, and the clamp claw 36 is displaced by the action of the cam. accurately clamped. After this clamping operation, the air suction force is stopped by the action of the rotary joint. (See Figure 4c) When the plate cylinder 2 rotates and the lower edge of the opening 22 reaches a position slightly in front of the corresponding position of the ironing roll 7, that is, immediately after the rear end of the old plate 1b has passed, the air cylinder opens. As a result, the ironing roll 7 is pressed against the plate cylinder 2. As a result, as the plate cylinder 2 rotates, the new plate 1a whose tip end is supported by the plate cylinder 2 is squeezed by the ironing roll 7 and is successively brought into close contact with the circumferential surface of the plate cylinder 2. (See FIG. 4d) When the plate cylinder 2 further rotates and the aforementioned proximity switch issues a second detection signal, the feed roll 14, the cam that controls the clamp claw 36, and the flow passages 25, 33, respectively. The air control solenoid valve is turned off and remains in the same state until a plate change command signal is issued. On the other hand, when the rear end of the old plate 1b passes slightly below, the vacuum suction force acting on the intake port 34 is released by the solenoid valve, and the old plate 1b completely separates from the plate cylinder 2. Until this state of separation was reached, the old version 1b
is always guided onto the delivery belt 18 while being applied with a constant tension by the pair of guide rolls 19, 20, so that it can be neatly transferred to the blanket cylinder 3 to the end without sagging. Therefore, printing on the continuous paper 5 can also be performed neatly.

When the old plate 1b has been discharged, the water roll 8 releases wet water, and the inking roll 9 removes ink.
A subsequent transfer to the blanket cylinder 3 is possible with the respective applied new printing plate 1a. Subsequently, after the rear end of the new plate 1a is brought into close contact with the plate cylinder 1 by the ironing roll 7, the intake port 34 is opened by the solenoid valve.
The vacuum suction force at is again applied to the rear end of the new plate 1a, so that the new plate 1a is completely supported in a cylindrical manner on the plate cylinder 2. On the other hand, the squeezing roll 7 is separated from the plate cylinder 2 immediately before the upper edge of the opening 22 reaches the corresponding position. (See FIG. 4e) Next, a new plate 1a to be supplied next is brought from a stacker (not shown), and is set in a predetermined standby state in preparation for a new plate change operation. (See Figure 4f and Figure 1) In this embodiment, as is clear from the above, since the ejection operation from the plate cylinder 2 is performed by air, the ejection operation can be controlled easily and reliably. Moreover, in addition to the simple structure, since the lid 2b can be removed, maintenance of each component in the plate cylinder 2, including the clamp claw 36, is extremely easy. Furthermore, although the plate 1 is easily damaged due to its material, since the blanket cylinder 3 that is in contact with it is made of soft rubber, there is no risk of damage during printing operations.

Note that the present invention is not limited to the above-described embodiment, and for example, the plate 1 can be
As a mechanism for temporarily supporting the tip of the plate 1 prior to supporting the tip, in addition to using vacuum suction force, a pair of rotationally driven rolls may be adopted, and in this case, the rolls can be rotated in forward and reverse directions. If this is done, the air ejection force for discharging the plate 1 becomes unnecessary. Further, the shape and size of the lid body 2b can be changed in various ways, and it is sufficient that the lid body 2b includes at least a part of the opening 22. Furthermore, the printing paper used may be supplied as a single piece of paper from a sheet feeding device or the like, instead of being supplied as a continuous paper.
In this case, when cleaning the blanket cylinders, the rotation of each cylinder may be maintained while the supply of paper may be stopped. Furthermore, it is not necessarily necessary to provide an automatic cleaning device for the blanket cylinder. In addition, the plate format is not limited to planography, but may also be letterpress or the like.

[Effects] As is clear from the above explanation, according to the present invention, when the plate cylinder is rotating, after the leading edge of the old plate falls off, the leading edge of the next new plate is inserted into the opening. , printing can be performed continuously without interruption, and plate changes can be performed in parallel, so there is no need to stop the printing machine, so the amount of ink supplied from the inking roll and the transfer of printing paper can be changed. In addition to being able to continuously perform extremely stable printing by keeping the speed stable, it is also possible to improve the efficiency of printing work.In addition, since multiple blanket cylinders are provided, any one of the blanket cylinders can be By enabling printing, it is possible to eliminate the occurrence of paper waste that occurs during the cleaning operation of the blanket cylinder.

[Brief explanation of drawings]

The figures show a preferred embodiment of the present invention, and FIG. 1 is a schematic side view of the entire apparatus with the plate cylinder in cross section, showing only one blanket cylinder for convenience and explaining the state during printing, and FIG. A schematic side sectional view of the rotary joint used in the air supply path, FIG. 3 is a schematic front view showing the control pipe, FIGS. 4 a to f are explanatory diagrams of the plate change operation, and FIG. The timing chart in FIG. 6 is a schematic side view showing the relationship between the blanket cylinder, plate cylinder, and impression cylinder. 1, 1a, 1b... plate, 2... plate cylinder, 3, 4
0,41... Blanket cylinder, 4... Impression cylinder, 6...
... Plate supply unit, 7... Ishigo roll, 10... Plate transport unit, 14, 15... Feeding roll, 22...
opening, 23... recess, 24... spout, 25,
33, 35... Distribution path, 32, 33... Intake port,
36...Clamp claw.

Claims (1)

[Scope of utility model registration request] A rotatable plate cylinder that supports a plate on its circumferential surface is opposed to a blanket cylinder that is rotatable in the opposite direction to the plate cylinder, and an impression cylinder that is rotatable in the opposite direction to the blanket cylinder is attached to the blanket cylinder. An offset printing machine that performs printing by passing printing paper between the impression cylinder and the blanket cylinder, which is provided with a plurality of blanket cylinders, and one of which is provided with a plurality of blanket cylinders.
The plate cylinder is configured such that it can come into contact with the plate cylinder and the impression cylinder, and the plate cylinder is provided with an opening through which the leading end of the plate is inserted. A plate feeding section for feeding a plate so as to insert the leading edge of the plate into an opening of the cylinder, and a plate transporting part for supporting the leading edge of the plate detached from the plate cylinder and sequentially transporting the plate from the plate cylinder. and the plate supply unit is configured to supply the next plate to the opening after the leading edge of the plate released from the opening is supported by the plate carrying unit. An offset printing machine with a plate change device.