JPH046914Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a plate clamping device that automatically returns plate tension bolts in a printing press.

(Prior Art) A plate cylinder is provided with a plate clamping device for attaching a plate.

The preparation time required for each change in printing items greatly affects the operating rate of the printing machine. Particularly, the time for changing editions occupies a large part of the preparation time.

In particular, in machines that employ an automatic ink amount presetting system, color matching time and preparation time are shortened, so plate change time now accounts for more than half of the total preparation time. Various improvements have been made to plate changing devices in order to reduce plate changing time and improve machine availability. In particular, the number of man-hours involved in operating the plate tension bolts was the highest among plate changing operations, and there was a strong demand for improved operability.

Figures 3 and 4 are a cross-sectional view and a plan view of a plate tightening device equipped with a conventional plate tensioning bolt, and the plate tightening device is divided into a plate gripping side and a plate bottom side with the center line of the plate cylinder as the border. Each has a plate tension bolt 08.
are provided, and the number is usually 6 to 10 per plate cylinder.

A side plate tightening device 03r and a rear plate tightening device 0 are installed in the recess 02 formed in the longitudinal direction of the plate cylinder 01.
3e is stored. Version 04 has lower teeth 0 respectively.
5r, 05e and upper teeth 06r, 06e, and is held in the mouth by operating the gripping cams 07r, 07e. Next, the plate is stretched by turning the plate tensioning bolts 08 with a spanner. Furthermore, the registration bolts are used to make slight corrections in the registration of one to four colors.

Next, when removing the plate and retracting the plate tension bolt, it was necessary to turn the bolt head with a wrench or fingertips, but the plate tension bolt was
In the case of color machines, there were 24 to 40 machines, and it took a lot of time to operate them. If a mechanism for automatically returning the machine by omitting this process could be realized, it would be of great help in reducing the number of man-hours in print preparation work and improving the operating rate.

(Problems to be solved by the invention) As described above, the problem with conventional plate tightening devices is that a great deal of time and effort is wasted in screwing in plate tension bolts and retracting them during plate change operations. It had

This invention is a plate tightening device that aims to automate the bolt loosening process by utilizing the energy applied to a torsion spring inserted into a part of the plate tension bolt and the friction caused by the tip of the plate tension bolt coming into contact with the fixing member. It provides:

(Means for solving the problem) Therefore, the present invention is to screw a plate tensioning bolt into the lower gear body of the plate tightening device in a printing press, and to bring the tip of the plate tensioning bolt into contact with a fixing member, and to In a plate tightening device that moves the lower tooth main body by rotation of the plate tensioner and performs plate tightening, the lower tooth main body and the plate tightening bolt are each attached with both ends of a torsion spring that is inserted into a part of the bolt. , and use this as a means to solve problems.

(Function) The energy for the automatic return of the plate tension bolt is utilized by the torsional stress of the torsion spring that is twisted together when the bolt is screwed in. When the plate is removed after printing, that is, when the upper teeth are opened, the tension of the plate no longer acts on the plate tightening device. At this time, the energy applied to the torsion spring is released. In other words, when the tension of the plate no longer acts on the plate tightening device, no external force acts on the plate tensioning bolt, and the return stress of the torsion spring acts, automatically turning the plate tensioning bolt before operating the plate tensioning bolt. automatically return to the state of

(Example) Hereinafter, an example of the present invention will be specifically described with reference to the drawings.

1 and 2 show one embodiment of the present invention, with FIG. 1 being a front (cross-sectional) view and FIG. 2 being a side view of the same.

The main screw portion 8t of the plate tensioning bolt 8 is screwed into the upper teeth 5r from the outside of the grip side plate tightening device 3r, and comes into contact with the collar 8c and is stopped. Further, the tip of the plate tensioning bolt 8 is in contact with a fixing member (plate cylinder). Then, the torsion coil spring 11 is inserted into the stem 8s,
One end of the spring on both sides is fitted into a stopper hole 8h on the side surface of the stem 8s, and the other end is fitted into a stopper hole 12h provided in the stopper plate 12.
is fixed to the lower teeth 5r. A nut 13 is screwed into a set screw portion 8l at the outer protruding end of the plate tension bolt 8, and its side portion is fixed with a small screw 19.

A spanner hook 13s and a groove 13g are machined on the outer periphery of the nut 13, one end of a brake spring 14 formed in an annular shape is fitted into the groove 13g, and the other end of the brake spring 14 is an L-shaped brake lever. 1
It is supported by a pin 16 protruding from one end of 5. The center part of the brake lever 15 has lower teeth 5r.
It is pivotally supported on a support shaft 17 fixed to the support shaft 17, and is rotated by manual operation about the support shaft 17, and its movement is regulated at the position of a stopper pin 18. The brake spring 14 is extended at the position shown by the solid line in FIG. 2, and the annular portion applies the necessary frictional force against the groove 13g of the nut 13, and is released at the position shown by the dashed-dotted line when rotated counterclockwise. . The above brake device is generally indicated by an arrow 20.

The above is the configuration of the device according to this embodiment, and its operation will be explained next.

To apply tension to the plate using the plate tension bolt 8,
When applying a wrench to the nut 13 and screwing the plate tension bolt 8 into the upper teeth 5r, the tip of the plate tension bolt 8 is in contact with the fixing member (plate cylinder), and the bolt 8
cannot move forward, so the upper teeth 5r move backward, and therefore printing is performed. At the same time, the torsion spring 11 is also torsioned, and at the end of screwing in the plate tension bolt, this torsion stress reaches its maximum value and the torsion coil spring is in a biased state. This applied torsional stress is used for automatic return of the bolt. Next, when the plate tensioning bolt 8 is rotated in the opposite direction to loosen the plate tension, the collar 8c of the bolt 8 is in contact with the stepped part of the upper tooth 5r, and the bolt 8 cannot be moved backward. moves forward and loosens the tension. Then, if T is the return rotational force of the bolt due to the torsional stress applied to the torsion coil spring 11 at this time, and Tr is the rotational force that acts as a frictional force between the male and female threads that prevents this rotational force, then T≦ When Tr, the bolt remains stationary, and when T>Tr, the bolt automatically returns. While the return rotational force T of the bolt due to the torsional stress increases in proportion to the amount of deflection of the spring, that is, the amount of screwing of the bolt,
The frictional rotational force Tr is not necessarily proportional to the screwing amount of the bolt, and the rise of the curve is gradual at first, and increases suddenly at the end of the printing process.

That is, until the middle stage of printing, T>Tr and the bolt 8 is in an automatic return state, but at the end of printing, T>Tr and remains stationary. Therefore, until the middle stage of printing, if you take your hand off to change the spanner, the bolt will automatically return to its original position, so it is necessary to increase the frictional rotational force Tr.
For this purpose, the brake lever 15 is operated to apply the frictional force by the brake spring 14 to the plate tension bolt 8.

The operation when using this device is as follows.

(1) The plate 4 is sandwiched between the lower teeth 5r, 5e and the upper teeth (not shown), and held in the grip by operating a gripping cam (also not shown). Here, the upper teeth and the gripping cam have the same structure as the conventional one shown in FIG.

(2) Operate the brake lever 15 to rotate it to the position shown by the solid line in FIG. 2 to close (load) the brake spring 14, and tighten the plate tension bolt 8.

(3) Next, after correcting the register with the stencil bolt, operate the brake lever 15 and rotate it to the position shown by the dashed line in FIG. 2 to open the brake spring 14.

(4) Start printing.

(5) Printing completed.

(6) Loosen the grip cam.

(7) The tension in the plate 4 is released and it becomes free, and the plate tension bolt 8 automatically returns as the torsional stress is released.

Note that here, the bolt return rotational force T is obtained by calculation, and the frictional rotational force Tr is easily obtained by experiment. In addition, the brake device 20 of the stencil bolt 8 is not limited to this embodiment.
Appropriate known commercially available ones can be used, or the initial purpose can be achieved even if it is replaced with a ratchet or the like.

(Effects of the invention) As explained above in detail, according to the invention, the torsion spring, which is integrally torsioned when the plate tensioning bolt is screwed in, is torsioned internally at the same time as the tension of the plate is released when the plate is removed. The stress is released, a force is applied to untwist the bolt, and the bolt automatically returns to its original position. As described above, the present invention can automate the work of loosening the bolt by utilizing the energy applied to the torsion spring and the friction caused by the tip of the plate tensioning bolt contacting the fixing member, resulting in an extremely large labor-saving effect.

[Brief explanation of the drawing]

FIG. 1 is a partial front view of a plate tightening device showing one embodiment of the present invention, FIG. 2 is a side view of the same, and FIG.
The figure is a sectional view of a conventional plate clamping device, and FIG. 4 is a plan view thereof. Explanation of the main parts of the figure, 5r...lower tooth, 8...printing bolt, 11...torsion spring, 20...brake device.

Claims (1)

[Scope of utility model registration request] A plate tightening bolt is screwed into the lower gear body of a plate clamping device in a printing press, and the tip of the plate tension bolt is brought into contact with a fixing member, and the lower gear body is moved by rotation of the bolt to perform plate tightening. A plate tightening device, characterized in that both ends of a torsion spring, which is inserted into a part of the lower tooth main body and the plate tension bolt, are respectively attached.