JPH0439003Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a plate vise device that is installed on the plate cylinder of a printing press and fixes the grip side and bottom side of the plate that is wound around the cylinder circumferential surface. be.

[Conventional technology]

Various printing machines are equipped with a plate cylinder on the circumference of which a printing plate is mounted, and in the case of a sheet-fed printing press, for example, in addition to the plate cylinder, a blanket cylinder and an impression cylinder are provided. The image transferred from the surface of the printing plate to the blanket surface of the blanket cylinder is transferred and printed on paper that is conveyed while being applied with printing pressure between the blanket cylinder and the impression cylinder. In the case of a multicolor printing press, this operation is repeated for each color.

In this way, a large printing pressure is applied to the paper each time it is printed, so it gradually stretches, and in the case of offset printing, the paper is stretched due to the use of dampening water to form the image. Since the tendency is large, the patterns of each printing unit of each color do not overlap in the same place, so-called register accuracy may not match, and the clarity and color tone reproducibility of printing may deteriorate.

Conventionally, so-called fan-out adjustment has been carried out by stretching a plate attached to the circumferential surface of a plate cylinder in the axial direction of the cylinder in accordance with the amount of elongation of the paper.

[Problem that the invention attempts to solve]

However, in conventional fan-out adjustment, the plate vise, which fixes the butt side of the plate attached to the circumferential surface of the plate cylinder, is divided in the cylinder axis direction and moved in the direction away from each other to stretch the plate. Not only does it spread only near the plate vise and there is no adjustment to account for the elongation of the paper,
If the plate is stretched too much, cracks tend to form in the plate, so in order to avoid this, the amount of adjustment is often insufficient, and high registration accuracy cannot be expected.

[Means for solving problems]

In order to solve such problems, in the present invention, the gripper side plate vise extending in the cylinder axis direction is divided in the cylinder axis direction, and these plate vises that are in contact with each other are connected to each other at one end in the cylinder circumferential direction of the divided part. Pivotally attached so that it can rotate freely, and adjust the rotation around the pivot joint so that the anti-vises are in the shape of a letter to each other and the shape of a letter opposite to each other on the opposite side of the pivot point in the circumferential direction of the split part. A screw member was provided.

[Effect]

After wrapping the plate around the circumferential surface of the plate cylinder and holding both ends of the plate in the grip side plate vise and the bottom side plate vise to fix it, turn the screw member provided at the split part of the grip side plate vise. When the machine is operated dynamically, both of the divided plate vises turn into a shape that is opposite to each other, and the plate becomes fan-shaped as a whole, with the grip side expanding or contracting more than the bottom side. Corresponds to elongation.

〔Example〕

1 to 6 show an embodiment of the plate vise device for a printing press according to the present invention, FIG. 1a is a partially cutaway plan view of the gripper side plate vise, and FIG. A of a
A front view as seen, Figure 2 is a plan view showing both plate vises adjusted to an inverted shape, and Figure 3 is a plan view showing both plate vises adjusted to an inverted shape. ,
Figure 4 is a plan view of the plate made with the adjustments shown in Figure 2, Figure 5 is a plan view of the plate made with the adjustments shown in Figure 3, and Figure 6 is a plan view of the plate made with the adjustments shown in Figure 3.
The figure is a plan view of paper shown to explain the elongation of paper in a four-color printing press. In the figure, a plate vise 1 on the grip side extending in the cylinder axis direction and a plate vise 1 on the rear side (not shown) are installed in parallel in the outer peripheral notch of the plate cylinder. A plate 2 formed into a rectangular shape is wrapped around the circumferential surface of the plate cylinder, and fixed at both ends by a plate vise 1 on the grip side and a plate vise on the bottom side.

The plate vise 1 on the gripping side is divided into a plate vise 1a and a plate vise 1b which extend in the cylinder axis direction and are arranged in parallel.
Both of the divided plate vises 1a and 1b are rotatably attached to a pivot shaft 3 provided at one end of the divided portion in the circumferential direction. A screw member 4 for adjusting the rotation of both plate vises 1a and 1b about the pivot shaft 3 is provided on the opposite side of the split portion to the pivot attachment portion. This screw member 4 includes a rotatable adjustment screw 6 which is inserted into a hole in the end face of the plate vise 1a and whose movement in the axial direction is regulated by a collar 5. A screw shaft 9 whose movement in the axial direction is restricted by collars 7 and 8 is rotatably supported in a hole in the end face of the notch provided on the side. As shown in FIG. 1b, the collar 7 also serves as a rotation stopper, and restricts the rotation of the screw shaft 9 by coming into contact with the bottom surface of the notch. This screw shaft 9 is screwed into the screw hole of the adjustment screw 6, and its rotation is restricted.
By rotating the adjusting screw 6 against the
Both plate vises 1a, 1b are configured to rotate so that they are turned inward or opposite to each other. Note that a scale and a pointer are provided between the adjusting screw 6 and the plate vise 1a to indicate the amount of rotation of the adjusting screw 6.

The operation of the plate vise device configured as above will be explained. The plate 2 wrapped around the circumferential surface of the plate cylinder is held and fixed by a plate vise 1 on the grip side and a plate vise on the bottom side. If the test printing results in a pattern shift due to paper elongation, fan-out adjustment is performed prior to actual printing. As shown in FIG. 6, the paper 10 of the first color gradually expands due to the printing pressure as shown by numerals 10a, 10b, and 10c as the paper 10 of the first color becomes the second, third, and fourth colors. The amount of elongation is 1
It is approximately 2 mm and is exaggerated in the figure.
Therefore, when adjusting screw 6 whose axial movement is regulated by collar 5 is rotated, the screw shaft 9 is regulated from axial movement by collars 7 and 8, and rotation is regulated by collar 7. Therefore, the adjusting screw 6 and the screw shaft 9 move relative to each other in the axial direction due to the screw action of the screw shaft 9. When the screw shaft 9 moves in the direction in which it is screwed into the screw hole, the plate vise 1a and the plate vise 1b rotate about the pivot 3 so as to form a cross shape with each other, as shown in FIG. As a result, the grip side of plate 2 is pulled in the width direction, and the fourth
As shown by reference numeral 2a in the figure, the gripping side extends and the fourth
This corresponds to the elongation of the paper 10 shown in the figure. Furthermore, when the adjusting screw 6 is rotated in the opposite direction to move the screw shaft 9 in the direction in which it comes out of the screw hole, the plate vise 1a and the plate vise 1b move in opposite directions to each other, as shown in FIG. Since it rotates around the axis 3 so as to form a shape,
The gripping side of the plate 2 is compressed in the width direction, and the gripping side shrinks to correspond to the paper 10, as shown by reference numeral 2b in FIG.

In such fan-out adjustment, by rotating the plate vises 1a and 1b on the gripping side, the gripping end of the plate 2 expands and contracts in the width direction, and both edges of the plate 2 are pulled. The paper is ideally transformed into the same shape as the stretched paper. The plate 2 stretches naturally without being locally stretched or cracked, unlike the conventional method in which the bottom side of the plate 2 is stretched horizontally. Furthermore, if the number of times of printing by the printing unit and the amount of paper elongation depending on the paper quality are known empirically, appropriate registration can be achieved in a short time by adjusting the adjusting screw 6 by a predetermined amount while checking the scale.
In addition, plate 2 is generally made of aluminum, synthetic resin,
Since it is made of paper or the like, it easily changes due to external stress and has enough strength to withstand the amount of adjustment, which is usually 1 to 2 mm or less, without cracking.

[Effect of idea]

As is clear from the above explanation, according to the present invention, in the plate vise device of a printing press, the grip side plate vise extending in the cylinder axis direction is divided in the cylinder axis direction, and these mutually adjacent plate vises are divided into divided parts. are pivotally connected to each other at one end in the circumferential direction of the torso, and the pivot joints are attached to the sides of the split parts opposite to the pivot joints in the circumferential direction so that the anti-vises are in the shape of a letter to each other and the shape of a letter to be opposite to each other. By installing a screw member in the center that can be rotated, the plate naturally deforms to the same shape as the paper stretches, without causing cracks or local deformation when the screw member is rotated. Extremely high registration accuracy is obtained, improving printing quality, and if you know the amount of paper elongation empirically, you can correct it in advance, reducing registration time, improving work efficiency, and reducing paper waste. The amount of generation will decrease.

[Brief explanation of drawings]

1 to 6 show an embodiment of the plate vise device for a printing press according to the present invention, FIG. 1a is a partially cutaway plan view of the gripper side plate vise, and FIG. A of a
A front view as seen, Figure 2 is a plan view showing both plate vises adjusted to an inverted shape, and Figure 3 is a plan view showing both plate vises adjusted to an inverted shape. ,
Figure 4 is a plan view of the plate made with the adjustments shown in Figure 2, Figure 5 is a plan view of the plate made with the adjustments shown in Figure 3, and Figure 6 is a plan view of the plate made with the adjustments shown in Figure 3.
The figure is a plan view of paper shown to explain the elongation of paper in a four-color printing press. 1... Grip side plate vise, 1a, 1b... Divided plate vise, 2, 2a, 2b... plate, 3... Pivot, 4... Screw member, 5, 7, 8... Collar ,6
... Adjustment screw, 9 ... Screw shaft, 10, 10a, 1
0b, 10c...Paper.

Claims (1)

[Scope of utility model registration request] A gripping side plate vise extending in the cylinder axis direction is divided in the cylinder axis direction, and plate vises for connecting the parts to each other are rotatably connected to each other at one end in the cylinder circumferential direction of the divided part,
A screw member is provided on the side of the divided portion opposite to the pivot joint in the circumferential direction of the trunk, for adjusting the rotation of the plate vise around the pivot joint so that the plate vises are in the shape of the opposite direction. Features a printing press plate vise device.