JPS6372550A - Plate cylinder bearing support structure of printing press - Google Patents

Abstract

PURPOSE:To dispense with the adjustment work of an eccentric bearing heretofore required each time when the thickness of printing paper changes, by a method wherein a spring mechanism for imparting rotary power to the eccentric bearing in a direction allowing a plate cylinder and a blanket cylinder to aproach each other is provided and the eccentric bearing automatically rotates when the position of the blanket cylinder is adjusted with the variation of the thickness of printing paper to prevent the change in the bearer contact pressure of the plate cylinder and the blanket cylinder. CONSTITUTION:The contact surface 19 of an eccentric bearing 2 and a frame 4 is processed into a low friction state so as to be made freely slidable. A rod 9 is con nected to one point (a) of the eccentric bearing 2 and a stud 11 is screwed into the connection point (b) with the frame 4. A special nut 21 is screwed into the stud 11 and the rod 9 pierces through the center of said special nut 12. A compression spring 15 is provided between the nut 12 and the stud 11 through a spring guide 14 and the eccentric bearing 2 always receives revolving force by the spring force of the compression spring 15, and a plate cylinder 1 and a blanket cylinder 6 always hold a contact state through bearers 7, 8 by the revolution of the eccentric bearing 2 and the plate cylinder 1 follows the movement of the blanket cylinder 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a structure for adjusting bearer contact pressure between a plate cylinder and a blanket cylinder in an offset printing press.

[Prior art J In FIGS. 3 and 4, the printing image formed with ink on the printing plate on the surface of the printing cylinder 01fi is
In order to transfer correctly to the surface, cylinder f7 between the plate cylinder and blanket cylinder must be
41 It is necessary to always keep the distance constant and to match the circumferential speeds of each cylinder to the coin so as not to distort the transferred image.

To keep this in mind, generally the T-bearer is in contact between the plate cylinder and blanket cylinder,
It is operated by applying appropriate contact pressure between both bearers.

The fc stamp is correctly transferred to the rubber cylinder, (the jjj image is
The image is transferred onto the surface of the paper 018, which is attached to the surface of the impression cylinder 016, by the pressure between the rubber cylinder and the impression cylinder (referred to as pressure/rubber turning pressure).

There are various thicknesses of paper used for printing, and it is important to always compress the rubber 06a (called a blanket) by the same amount when printing on any paper thickness in order to obtain good printed matter.

Finally, when printing on thin paper and when printing on thick paper, it is necessary to change the total distance between the blanket cylinder 06 and impression cylinder 016 by the thickness of the paper. A common method for changing this distance is to fix the position of the impression cylinder 016 and move the blanket cylinder 06 closer to or farther from the impression cylinder 016. (Illustration omitted) Here, move the rubber cylinder 06 to the impression cylinder 0.
16 (using an eccentric mechanism for the blanket cylinder bearing), when the blanket cylinder 06 is brought closer to the impression cylinder 016, the distance between the blanket cylinder 06 and the plate cylinder 01 increases. On the contrary, rubber cylinder 0
6 closer to the impression cylinder 016, the distance between the blanket cylinder 06 and the plate cylinder 01 becomes shorter.

In the conventional method, when the distance between the impression cylinder 016 and the blanket cylinder 06 is changed, a device 03 configured with a turnbuckle is used to compensate for the change in the distance between the plate cylinder 016 and the blanket cylinder 06. I used it and adjusted it. 01 is the plate cylinder, 0 point is the center of the plate cylinder, 02 is the eccentric bearing, and its outer circumference is 0.
19 is slidably assembled into a hole in the frame 04.

In addition, the inner circumference 020 is connected to the plate cylinder 01 via a bearing 05.
It is connected to the shaft of.

A part of the eccentric bearing 02 is connected to the turnbuckle 03 at the 0 point.
is connected to. The turnbuckle 03 is connected to the frame 04 at the other end point 0. When the turnbuckle is turned, the eccentric bearing rotates around the point and moves in an arc with a radius of the eccentricity of the plate cylinder 01i. This positional movement causes the plate cylinder 01 to move closer to the blanket cylinder 06 and further away from the blanket cylinder 06. [Problems to be Solved by the Invention] The above-mentioned prior art has the following problems: (1) It is necessary to adjust the positional relationship between the plate cylinder and blanket cylinder (bearer contact pressure) using a turnbuckle each time the paper thickness used for printing changes. A large amount of time is lost for adjustment.

(2) If the distance between the plate cylinder and blanket cylinder changes by a few microns,
Bearer contact status is broken. P where the toe 9472 is far apart
On the other hand, if the pressure is too high, good prints cannot be obtained.

(3) It is impossible to accurately adjust the shear contact pressure using a turnbuckle, and the current position is roughly adjusted using a scale plate.

[Means for solving problems]

A bearer is provided for each of the plate cylinder and blanket cylinder.

An eccentric bearing is provided between the frame and the bearing that supports the plate cylinder.

A spring force is applied to the eccentric bearing in a direction in which the plate cylinder and blanket cylinder approach each other.

The spring force is adjustable.

[Effect]

When the distance between the impression cylinder and the blanket cylinder is changed, the distance between the blanket cylinder and the plate cylinder changes, and the contact pressure between them changes.

When the contact pressure between both bearers changes, the eccentric bearing rotates so that the bearer contact pressure becomes a predetermined pressure.

When the bearer contact pressure is greater than the predetermined pressure, the eccentric bearing rotates against the spring force, and when the bearer contact pressure is less than the predetermined pressure, the eccentric bearing rotates according to the spring force.

Therefore, even if the distance between the blanket cylinder and the plate cylinder changes, the contact pressure between them remains a predetermined pressure.

By adjusting the spring force, the contact pressure between the rubber cylinder and the plate cylinder can be adjusted.

〔Example〕

In Figure M1 and Figure 2, 1 is the plate cylinder, 6 is the blanket cylinder, 7 is the bearer of the plate cylinder 1, 8 is the bearer of the blanket cylinder 6, 5 is the bearing, 2 is the eccentric bearing, 4 is the fly, 4 is the eccentric The contact surface 19 between the bearing 2 and the frame 4 is processed to have low friction and is slidable. A rod 9 is connected to one point O of the eccentric bearing 2 via a pin 10t. On the other hand, a stud 11 is screwed into the connection point (3) with the frame 4. or,
A special nut 12 is screwed into this stud 11, and a rod 9 passes through the center of this special nut.

A nut 13 is screwed into the end of the rod 9.
A compression screw 15 is provided between the stud 911 and the stud 911 via a spring guide 14. Due to the spring force of this compression spring 15, the eccentric bearing 2 is constantly receiving a turning force, and due to this turning, the Q plate cylinder 1 is constantly kept in contact with the rubber cylinder 6 via the bearer 7.8. The plate cylinder 1 follows the movement of the cylinder 6.

Here, a gap force (adjustable) is provided between the special nut 12 and the rod 9, which causes the blanket cylinder 6 to be in a state called "blanket removal" (the blanket cylinder 6 is removed from both the impression cylinder 16 and the plate cylinder 1). When it is completely released (mechanism omitted), the hole serves as a stopper to prevent the eccentric bearing 2 from turning excessively.

In order to adjust the contact pressure of the bearer 7.8, the amount of compression of the spring 15 may be adjusted.

The plate cylinder 1 is in a state where the bearers are in contact with each other with appropriate pressure.
This is the optimum distance between the rubber cylinders 6.

Here, due to the difference in paper thickness, the blanket cylinder 6 is moved closer to the impression cylinder 16,
Even when the blanket cylinder 6 is moved away from the impression cylinder 16, the distance between the plate cylinder 1 and the blanket cylinder 6 is maintained due to the contact between the eccentric bearing 2 and the spring mechanisms 9 to 15 provided between the frame and the bearers 7 and 8. The distance and bearer contact pressure are always constant.

In the above embodiment, a compression spring is used as the spring mechanism, but the entire fluid pressure cylinder may be used.

〔Effect of the invention〕

(1) The adjustment work for eccentric bearings, which is required every time the paper thickness changes, is completely unnecessary.

(2) It has become possible to always maintain the bearer contact state in an optimal state.

It is now possible to automatically absorb changes in bearer contact pressure caused by changes in the thickness of the pick paper, bearer wear, bearing wear, etc.

[Brief explanation of the drawing]

FIG. 1 is a side view of an embodiment of a plate cylinder bearing support structure for a printing press according to the present invention, and FIG. 2 is a plan view of FIG. 1. FIG. 3 is a side view of the conventional structure, and FIG. 4 is a plan view of FIG. 3. 1... Plate cylinder 2... Eccentric bearing 6... Rubber cylinder 7.8... Bearer 9... Rod 15.
...Compression spring 16...Impression cylinder sub-agent Patent attorney Shige Okamoto Monju 2 people 1-Print cylinder 2-One-sided emotion 1 eye 3 receiver 6-Rubber cylinder 7.8--Bearer 9- Mouth・15-One-pressure spring 16-Impression cylinder

Claims (1)

[Claims] In an offset printing machine that employs a bearer contact between a plate cylinder and a blanket cylinder, an eccentric bearing that supports the plate cylinder, and a spring mechanism that applies a rotational force to the eccentric bearing in a direction in which the plate cylinder and blanket cylinder approach each other. and when the blanket cylinder position is adjusted due to changes in the thickness of printing paper, the eccentric bearing automatically rotates so that the bearer contact pressure between the plate cylinder and blanket cylinder does not change. Features a printing press plate cylinder bearing support structure.