JPS6232051A - Printing roller - Google Patents

Abstract

PURPOSE:To eliminate defective printing, by mounting a solenoid coil to the shaft core of a printing roller to be driven to the axial direction and mounting a magnetic body in the shaft core insert hole of the roller main body opposed to the solenoid coil so as to drive the roller main body to the axial direction corresponding to the change in a magnetic field. CONSTITUTION:A shaft core 32 is mounted and fixed to the main body of an offset printing press 11 and, when the magnetic field generated by the solenoid coil 33 takes positive and negative (+-) change, a roller main body 31 is driven to left and right axial directions by attractive and repulsive forces acting between the solenoid coil 33 and a ferrite permanent magnet 35 and the moving quantity and moving speed thereof is determined by the intensity of attractive and repulsive forces generated by the magnetic field in the distance range of the side end of the roller main body 31 and a slide bearing 38. Therefore, by controlling the intensity and positive and negative change of the magnetic field generated by the solenoid coil 33 and the cycle or speed of said change by a computer, the reciprocal driving cycle of an inking roller and a water rod roller can be made random.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to offset printing technology.

[Conventional technology]

In an off-cent printing press, when the inking roller and water rod roller that supply ink and water to the plate cylinder are swung left and right in the axial direction, a ghost image (the plate image of the part to be printed first becomes the print image of the part to be printed next) It has been found to be effective in eliminating a kind of printing defect (a kind of printing defect, which is a thin shadow that appears on printed matter by overlapping the image like an afterimage).

[Problem that the invention seeks to solve]

Conventionally, the reciprocating drive of this type of printing roller in the axial direction was performed using a cam or a link mechanism, which resulted in a complex device structure with a large number of parts, high manufacturing and repair costs, and inconvenience in handling. was also insufficient.

[Purpose of the invention]

Therefore, the first object of the present invention is to eliminate printing defects caused by ghosts.

A second object of the present invention is to simplify the structure of a device for reciprocating the printing roller in the axial direction, thereby making it easier to handle.

[Means for solving problems]

Intensive research for the above purpose revealed that when the inking roller that rotates and feeds the ink to the plate cylinder is driven back and forth in the axial direction, the surface of the inking roller is stroked from side to side, eliminating ink coating spots and ghosting. However, if the reciprocating drive cycle is made random, the viscosity of the ink will decrease, and the ink will exhibit thixotropic behavior with good kneading and printability. The present invention was completed based on the knowledge that if the particles were also made random, the unevenness of the water coating film on the plate surface would be eliminated and the ghost elimination effect would be further enhanced.

[Structure of the invention]

That is, the present invention supports a printing roller to be driven in the axial direction by inserting the shaft core into the shaft core insertion hole of the roller body so that the roller body can be slid in the axial direction and rotatable in the circumferential direction of the shaft core. Then, a solenoid coil (like an electromagnet, which changes the magnetic field by turning on and off electricity) is attached to the shaft core, and a magnetic material is placed inside the shaft core insertion hole of the roller body facing the installation position of the solenoid coil. The roller body is configured to be driven in the axial direction according to changes in the magnetic field of the solenoid coil, and this is attached to one or more inking rollers or water rod rollers of an offset printing machine. The gist of this is that

The circumferential surface of the roller body is Molton (
wI-like cloth), chrome plating, rubber, plastic, etc.
In addition, inking rollers are made of chrome plating, rubber,
It is constructed from appropriate materials such as vinyl chloride, ebonite, nylon, and other plastics.

As the magnetic material, a permanent magnet such as a ferromagnetic ferrite alloy such as iron, nickel, cobalt, etc. is used.

Hereinafter, the present invention will be described by way of examples with reference to the drawings. FIG. 1 shows a cross-sectional side view of the main parts of an off-cent printing press 11, 12 is an inking roller, 13 is a water rod roller, 14 is a plate cylinder, 15 is a blanket cylinder, 16 is an impression cylinder, 17 is a printing paper, and 18 is a printed product.

The ink is kneaded from the ink fountain 19 by several ink buffing rollers 20 and transferred from the inking roller 12 to the plate cylinder 14. The arrow of each roller in the figure indicates the direction of rotation.

The plate cylinder 14 has a water source 2 on the front side of the inking roller 12.
1, water is applied via a water rod roller 13.

As the inking roller 12 and the water rod roller 13, the printing roller according to the present invention shown in FIG. 2 is used.

The peripheral surface of the cola body 31 is coated with soft vinyl chloride on the inking roller 12 and with Molton on the water rod roller 13, respectively.

32 is made of a steel pipe for the shaft core, a solenoid coil 33 is fitted and connected near the end, and an inner race 34 is fitted and attached near the end.

The roller body 31 is made of a steel pipe that is thicker than the shaft core 32.
A cylindrical ferrite permanent magnet 35 is inserted and attached to the cylinder inner wall of the roller body facing the solenoid coil 33 of the shaft core 32 to be fitted, and the inner race 3 of the shaft core 32
A stroke bearing 36 is mounted on the cylinder inner wall of the roller body facing the roller body 4, and is rotatably supported on the shaft core 32 by the inner race 34 and the stroke bearing 36 so as to be rotatable and slidable in the axial direction.

Note that there is a gap between the solenoid coil 33 and the ferrite permanent magnet 35, and the rotation of the roller body 31 is not hindered.

37 is a ring-shaped adapter that prevents the bearing 36 from popping out.

A ring-shaped slide bearing 38 is installed near the end of the shaft core 32 slightly away from the side end of the roller body 31, thereby preventing the roller body 31 from being pulled out from the shaft core 32. Further, the solenoid coil 33 is controlled by a computer (not shown) via an electric wire 39 wired within the shaft core to generate a magnetic field.

[Function] The shaft core 32 is attached and fixed to the main body (frame) of the offset printing machine 11, and when the magnetic field generated by the solenoid coil 33 changes in the forward and reverse directions (+ and -), the solenoid coil 3
The roller body 31 is driven in the left-right axial direction by the repulsive force acting between the roller body 31 and the ferrite permanent magnet 35, and its movement amount and speed are such that a magnetic field is generated within the distance range between the side end of the roller body 31 and the slide bearing 38. It is determined by the strength of the repulsive force.

For this purpose, the strength and reverse (ten-) changes of the magnetic field generated by the solenoid coil 33, as well as the period and speed of the changes, are controlled by a computer, or the solenoid coil 33 is stopped, moved quickly, or moved slowly. By freely changing the amount and speed of movement of the roller body 31 in the axial direction, the reciprocating drive cycle of the inking roller and water rod roller can be made random.

The above shows the structure of the printing roller when the magnetic material 35 is a permanent magnet, but if the magnetic material 35 is made of iron, nickel, cobalt, etc. without residual magnetization (non-permanent magnet), a solenoid Coils 33 are attached to the left and right sides of the shaft core 32, and correspondingly magnetic materials 35 such as iron, nickel, cobalt, etc. are attached to the roller body 31.

Installed on the left and right, the left and right solenoid coils 33 (33'
), the magnetic field of
(35') The roller body 31 is reciprocated in the left-right axial direction by the suction force acting alternately between the rollers 35' and 35', and in this case also, the reciprocating drive cycle can be randomly controlled by a computer.

In addition, it is also possible to use a changeover switch, relay relay, etc. instead of a computer, so the solenoid coil 33
The use of a computer to control the magnetic field is not essential to the invention.

〔Effect of the invention〕

As described above, in the present invention, the drive device for the left and right sides of the printing roller that supplies ink and water to the plate cylinder is slidable in the axial direction by inserting the shaft core into the shaft core insertion hole of the roller body. A roller body is supported rotatably in the circumferential direction, a solenoid coil is mounted on the shaft core, a magnetic material is mounted inside the shaft core insertion hole of the roller body facing the mounting position of the solenoid coil, and the solenoid coil is The roller body is built into the printing roller so that it is driven in the axial direction in response to changes in the magnetic field, and since it has an extremely simple structure of a solenoid coil 33 and a magnetic body 35, it is compact and easy to manufacture. It is convenient and economical in terms of both repair and handling.

In addition, the reciprocating drive cycle of the printing roller in the left-right axis direction can be made random by changing the amount of movement and the speed of movement at any time, and in the case of an inking roller, the ink is thixotropic, which has good printability. In addition, if it is a water stick roller, it eliminates unevenness in the water film on the plate surface to be humidified and effectively eliminates water ghost.

In this way, the reciprocating drive cycle of the inking roller 12 and water rod roller 13 can be changed at any time by the computer, so while checking the printing quality of the printed matter 18, the viscosity of the ink, the degree of kneading, or the degree of humidification of the plate surface can be adjusted based on the temperature. The present invention is extremely convenient and can be used in the printing industry. It contributes a lot to this.

Note that even if measures are taken to strengthen the repulsive force, such as attaching coke to the magnetic body 35 in order to eliminate leakage of the magnetic field when implementing the present invention, such measures do not limit the technical scope of the present invention in any way. is not reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional side view of a main part of an offset printing machine, and FIG. 2 is a sectional front view of a printing roller according to an embodiment of the present invention. 11... Offset printing machine, 12... Inking roller, 13... Water bar roller, 14... Plate cylinder,
15...Blanket cylinder, 16...Impression cylinder, 17.
...Printing paper, 18...Printed matter, 19...
Ink pot, 20...kneading roller, 21...
・Mizumoto, 31...Roller body, 32...
・Axis core, 33-... Solenoid coil,
34... Inner race, 35... Magnetic body (magnet), 36... Stroke bearing, 37... Adapter, 38... Slide bearing, 39... Electric wire.

Claims (1)

[Claims] The shaft core 32 is inserted into the shaft core insertion hole of the roller body 31 to be slidable in the axial direction and rotatably supported in the circumferential direction of the shaft core 32, and the solenoid coil 33 is attached to the shaft core 32.
A magnetic body 35 is mounted inside the shaft core insertion hole of the roller body 31 facing the mounting position of the solenoid coil 33, and the roller body 31 is driven in the axial direction according to changes in the magnetic field of the solenoid coil 33. A printing roller characterized by: