JPH0337959Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatic plate surface dust removal device for a printing press, and more particularly to an automatic plate surface dust removal device for removing dust such as ink scum and paper dust adhering to the plate surface during offset printing.

Traditionally, in offset printing, ink scum, paper dust, etc. adhere to the plate surface during printing, resulting in pinhole-like white spots (called "hitskies") on the printed matter, so the operator has to stop the printing machine. Alternatively, although this is extremely dangerous, a rod-shaped dust remover with a rubber tip is brought into contact with the rotating plate to remove dust. However, this work reduces the operating efficiency and is also dangerous, so partially automated devices have been proposed.

In these conventional devices, when an operator discovers a white area on a printed matter, the operator identifies the location by corresponding to a number previously assigned in the width direction of the printing plate, and displays the corresponding location on the operation panel. A mechanism is adopted that automatically activates a dust removal device installed opposite the printing plate by pressing a button. and,
The dust removal device includes a dust removal head portion whose tip is made of a blade-like elastic material such as rubber and is brought into contact with the printing plate during dust removal, and a moving portion that moves the removal head to a predetermined position on the printing plate. However, this device has the following drawbacks and has not yet been put into practical use.

In other words, since dust removal from the printing plate is carried out by bringing a blade-shaped elastic material into contact with the printing plate, ink, etc. adheres to the tip of the blade, and after several dust removal operations, the ink accumulated on the blade tip adheres to the printing plate. If the plate surface is soiled and left for several hours, the ink will solidify and cause problems such as scratches, so the operator must clean it frequently. This cleaning work places a heavy burden on the workers. For this reason, it has been proposed to automatically clean the blade tip by spraying a cleaning agent from a spray nozzle on the tip of the blade when the dust removal device is on standby, but it is difficult to completely clean it and has not been a practical solution.

This idea was created in view of the above-mentioned problems.
The purpose is to provide a plate surface dust removal device for a printing press having a dust removal tool that does not require frequent cleaning and does not cause the above-mentioned problems even if ink is deposited on the tip during dust removal work.

According to the present invention, the dust removal head is formed of a disk-like member, and the disk-like member is rotated by small angles so that a part of the periphery of the disk-like member can be successively opposed to the plate surface. The above objective is thus achieved.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an offset rotary printing press, which, as is well known, has a plate cylinder 2;
A dampening water device 3 and an ink roller 4 are provided in contact with. The dust removal mechanism of the automatic plate surface dust removal device, which is a main part of the present invention, is provided, for example, under the dampening water device 3 and in contact with the plate cylinder 2, as shown by reference numeral 5 in the figure. A dust removal position input device for specifying the dust removal position to the dust removal mechanism 5 can be provided below the color booth 8 as shown by reference numeral 7.

Note that the dust removal mechanism 5 may be installed between the dampening water device 3 and the ink roller 4 instead of being provided on the front side of the dampening water device 3 in the rotational direction of the plate cylinder 2 (in the illustrated case). Further, the position input device 7 may be installed separately from the color booth 8 instead of being built into the color booth 8 as shown.

The garbage removal position input device 7 has the overall configuration as illustrated in FIG. It has a microcomputer that functions to move the dust removal head to a specified position and control the dust removal operation, which will be described later.

As shown in FIG.
It has a position input section 10, a display section 11, a memory 12, a motor controller 13, and the like. The dust removal position input data from the position input unit 10 is input to the central processing unit CPU via the interface I/F, where it is arithmetic processed and converted into position data.

This data is used when there are multiple dust removal parts.
It is also possible to sequentially store the information in the memory 12 so that the dust removal operation can be performed sequentially by specifying the positions continuously.

The position data is converted into data, for example, the number of pulses, for controlling the later-described drive motor of the dust removal mechanism 5 through arithmetic processing in the central processing unit CPU, and is sent to the motor controller 13 via the interface I/F. The motor controller controls the drive motor of the dust removal mechanism 5 based on this data.

The dust removal position input section of the dust removal position input device 7 is in the form of a support plate, as shown by reference numeral 15 in FIG. This position input section 15
The printed matter feeding device 19, which is provided on a pedestal 17 supported by When the printed matter 18 is placed on the position input section 15 as shown in the figure and the feeding device 19 is operated, the printed matter 18 is placed on the position input section 1.
The printed material 18 is sequentially fed to the destination on the surface of the printed material 5, and by stopping the feeding device 19, the printed material 18 can be stopped at any position in the front and back direction. The feeding device 19 can be operated by an operation button 20.

As shown in FIG. 4, the dust removal position input section 15 includes a printed circuit board 21, a pressurized conductive sheet 22,
It has a plate body constructed by sequentially laminating protective sheets 23 from bottom to top. As shown in FIG. 5, which shows the position input unit 15 upside down, the printed circuit board 21 has a comb-shaped circuit 25 to which the reference signal A is always inputted at a certain sampling period from the central processing unit CPU. is provided. On the other hand, a large number of position signal extraction circuits B1, ..., B whose ends are inserted between adjacent comb teeth 25a of this circuit 25
8... are provided. The spacing between the intricate circuits is, for example, about 2.5 mm.

As shown in FIG. 2, when the printing unit 18 is placed on the position input unit 15 and the white part is pressed with a pen-shaped presser, the pressed part of the pressurized conductive sheet 22 becomes conductive. Therefore, printed circuit board 2
1 adjacent circuits become conductive. For example, if the part indicated by P in FIG. 5 is pressed, an input signal will be obtained from the port of circuit B2. Afterwards,
The position in the left and right direction in FIG. 2 can be detected from the port number from which this signal was obtained and the pitch of the circuit conductors.

If signals are obtained from a plurality of ports, one piece of data on the dust removal position can be obtained by calculating the average value (intermediate position information) of the input data using a program as necessary.

Since the maximum size of printed matter is as large as A times (880 x 1250), if the existing color booth is used as a position input section, it will be necessary to remodel the color booth.
On the other hand, if a printed matter feeding device 19 is provided as shown in FIG. 2, the position input section 15 can be downsized in terms of its depth.

Next, details of the dust removal mechanism 5 will be explained with reference to FIG.

The dust removal mechanism 5 has a guide rail 27 provided along the entire length of the plate cylinder 2, and both ends of the guide rail 27 are supported by support members 28. Each of the supporting members 28 has one end supported by a member 29a connected to the other end of an air cylinder 29 fixed to a fixed frame 29b.
As the member 29a moves forward and backward with respect to the plate cylinder 2 by the air cylinder 29, the guide rail 27 also moves forward and backward in the same direction.

Reference numeral 30 denotes a dust removal head, which has a disk shape. The head 30 is preferably made of a resilient material, such as nitrile rubber (NBR). The removal head 30 has a rotating shaft 31 which is rotatably supported by a slide member 32 and connected to a stepping motor 33 by a timing belt or the like. The slide member 32 is movable along the guide rail 27 and is connected to a transmission member 36, such as a wire or timing belt, driven by a removal head movement motor 34 fixed to a support member 28 at one end of the guide rail. The transmission member 36 is connected to the pulley 3 at the other end of the guide rail.
It spans 7.

When the position of the dust removal portion of the printed matter is specified by pressing with the pusher in the dust removal position input section 10, the removal head moving motor 34 is operated under the control of the motor controller 13.
A slide member 32 supporting the dust removal head 30
is moved along the guide rail 27 and stopped at a designated position.

The guide rail 27 is then advanced by the cylinder towards the plate cylinder 2, so that part of the periphery of the dust removal head 30 is pressed against the surface of the plate cylinder 2. At this time, the plate cylinder 2 is rotating, so
Due to the relative movement of the plate cylinder 2 of the dust removal head 30,
Dust on the plate is removed.

After a certain contact time, the guide rail 27 is moved back from the printing plate by the cylinders on both sides, and the dirt removal head 30 is separated from the printing plate.

At the same time, the stepping motor 33 rotates the dust removal head 30 by a certain angle in preparation for the next removal operation. As the dust removal head 30 rotates, the peripheral edge of the removal head 30 to which dust has adhered due to dust removal is displaced to a position where it does not face the plate cylinder, so that the part of the removal head facing the plate cylinder is always free from ink and dirt. Keeps dust free.

Based on practical results, the rotation angle of the dust removal head 30 is preferably about 5 degrees, and the previous contact portion of the dust removal head with the plate cylinder may partially overlap with the next contact portion. Normally, about 70 consecutive dirt removals are possible with the same dirt removal head.
By doing this, the tip of the removal head, which conventionally had to be cleaned frequently, can be cleaned in one go.
You will only need to do it once a day. It also becomes possible to use the same removal head for one day, then replace it with another removal head, clean it outside the printing press, and reuse it.

As mentioned above, in the present invention, the dust removal head is shaped like a disk, and by rotating it little by little, a part of its periphery is brought into contact with the plate cylinder, so that ink and dust are always removed. The peripheral edge of the new disk, which is free from adhesion, can be brought into contact with the plate cylinder, making it possible to reliably remove dust without having to wash the head frequently.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the relationship between the plate dust removal device of the present invention and the printing machine, Fig. 2 is a perspective view of the dust removal position input device, Fig. 3 is a block diagram of the dust removal position input device, and Fig. 4 is FIG. 5 is a longitudinal cross-sectional view of the dust removal position input section, FIG. 5 is a rear view of the same principle, and FIG. 6 is a perspective view of the dust removal mechanism that forms the main part of the present invention. 2... Plate cylinder, 3... Dampening water device, 4... Ink roller, 5... Dust removal mechanism, 7... Dust removal position input device, 8... Color booth, 10... Dust removal position input unit, 12 ... Memory, 13 ... Motor controller, 15 ... Dust removal position input section, 18 ...
...Printed material, 19...Printed material feeder, 21...Printed circuit board, 22...Piezoelectric sheet, 23...
Protective sheet, 25... comb-shaped circuit, B1, B2,
...B8...Circuit conductor for position signal extraction, 27...
Guide rail, 30... Garbage removal head, 32...
...slide member, 33...stepping motor,
34... Dust removal head moving motor, 36... Transmission member.

Claims (1)

[Scope of claims for utility model registration] 1. A dust removal head that is freely displaceable along the plate cylinder;
In a plate surface dust removal device for a printing press having a device for moving the dust removal head forward and backward relative to the plate cylinder, the dust removal head is formed by a disk-shaped member provided so that a part of its periphery can come into contact with the plate cylinder surface, A printing plate dust removal device characterized by being provided with a device that rotates this disk-shaped member around its axis in small angle increments. 2. The printing plate dust removal device according to claim 1, wherein the dust removal head is formed of an elastic material.