JPS6242873A - Plate cylinder for rotary mimeograph - Google Patents

Abstract

PURPOSE:To prevent the irregularity and non-uniformity of printing density, by providing an inking roller in the vicinity of the inner peripheral side of a cylinder and forming a gap capable of passing ink between the inking roller and the cylinder. CONSTITUTION:A predetermine ink gap 3 in a radius direction for flowing ink is provided between the outer peripheries of side cylinders 9a, 9b and an inner cylinder 4 and a porous reticulated body 1a formed by providing a large number of small through-holes to a metal net, a metal plate and a synthetic resin film by drilling is wound around and fixed to the side cylinders 9a, 9b so as to cover the gap 3 and a screen 1b made of silk, cotton or a synthetic resin is wound around the outer periphery of said reticulated body 1a to cover the same and an outer cylinder 1 is formed by both of them. An inking roller 6 is pivotally supported in an ink through 7 by the inking roller shaft 27 parallel to a plate cylinder shaft 2 and the outer peripheral side surface of the inking roller 6 revolves so as to hold a predetermined roller gap 5 capable of passing ink between the outer peripheral side surface of said roller 7 and the inner peripheral side surface of the reticulated body 1a. The inking roller 6 has a width almost equal to a printing width and, for example, the ink gap 3 and the roller gap 5 are pref. 0.5-1.5mm.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial field of application The present invention is directed to pasting base paper for plate making onto a cylindrical plate cylinder (~, ink leaching from inside the plate cylinder is passed through the plate making part of the base paper and applied to the surface of the plate cylinder). This relates to plate cylinders for rotary copying machines that print by fully feeding the printing paper between the plate cylinder and the impression cylinder, which rotate in close contact, and transferring the ink from the plate making unit onto the paper. .

(o) Prior art The conventional plate cylinder for a rotary copying machine consists of a hollow cylindrical body consisting only of an outer cylindrical portion. Either the cylindrical surface is completely leached naturally, or the inner cylinder has an inner cylinder with a predetermined radial gap between the outer cylinder and its inner circumferential surface, and the ink is rotated differentially to the outer cylinder. The ink inside the cylinder gradually flowed into the gap through a large number of small holes by centrifugal force, and the ink oozed out to the surface of the entire outer circle due to the pressure increase caused by differential rotation.

In the former, a small amount of ink is injected into a large-capacity cylindrical body and rotated, so the ink is constantly exposed to air and mixed, which tends to dry and deteriorate, making it impossible for it to seep out onto the normal surface. There was no means to cope with changes in the physical properties of the ink due to temperature changes, and for example, there was no means to compensate for the increase in the viscosity of the ink in cold weather, making it difficult to seep out to the outer periphery.

In the latter case, the inner and outer cylinders move differentially with each other, and the ink in the ink gap receives a shearing force, and the pressure increases, so the ink can be leached to the outer periphery without being affected by changes in the physical properties of the ink. If the ink deteriorates inside the inner cylinder, the small holes drilled on the outer periphery often get clogged, but due to the nature of ink being a viscous substance, once the ink is clogged, the ink no longer leaches out of the hole. Then, the liquid detours to the hole that is not clogged and leaches out. Naturally, depending on the location, the leaching liquid to the outer periphery becomes unrestricted or does not leak at all, making printing impossible. In such a case, it is difficult to disassemble and repair the plate cylinder filled with ink, and the entire plate cylinder must be replaced, which is a heavy economic burden.

In order to overcome this problem, a rotary copying machine plate cylinder in which an ink supply roller (inking roller) is housed inside a cylindrical body has been proposed (Japanese Patent Application Laid-Open No. 57-5].
No. 483).

This plate cylinder for a rotary copying machine has a rotating shaft, and a stencil paper is mounted on the outer circumferential surface of the cylinder, which is supported by the rotating shaft, extends concentrically around the rotating shaft, and is aligned with its own central axis by the rotating shaft. A porous cylindrical plate cylinder (cylindrical body) that is rotationally driven around the circumference, and arranged parallel to the central axis of the cylindrical plate cylinder in a space between the rotating shaft and the inner peripheral surface of the cylindrical plate cylinder. an ink supply roller that is supported by a rotating shaft that rotates around its own central axis and is arranged so that its outer circumferential surface contacts the inner circumferential surface of the cylindrical plate cylinder; an ink applicator for applying an entire ink layer on the cylinder, a press roller having an outer circumferential surface disposed opposite to the outer circumferential surface of the cylindrical plate cylinder and rotating around its own central axis, and the cylindrical plate. The cylindrical plate cylinder includes two pulleys having the same diameter that are respectively attached to the rotation axis of the cylinder and the rotation axis of the ink supply roller, and an endless belt that is passed between the two pulleys. and a driving force transmitting means for rotating the ink supply roller as the ink supply roller rotates.

The ink inside the cylindrical plate cylinder is pressed by the squeegee action (squeezing effect) of the ink supply roller that is in contact with the inner peripheral surface of the cylindrical plate cylinder, and is pushed out to the outside of the cylindrical plate cylinder. Leach.

Further, a screw cylinder for twisting the ink is rotatably provided in the cylindrical plate cylinder, and an electrostatic charge is applied between the screw cylinder and the inner circumferential side of the cylindrical plate cylinder. The applicant of the present application has already proposed a plate cylinder for a rotary copying machine in which an ink groove (space) in which an electrode for detecting the ink is installed (Japanese Patent Laid-Open No. 72987/1987).

Problems to be Solved by the Invention In the plate cylinder for a rotary copying machine shown in the above-mentioned Japanese Patent Application Laid-Open No. 57-51483, as described above, the ink supply roller comes into contact with the cylindrical plate cylinder. The ink is leached to the outside of the cylindrical plate cylinder by the squeegee action of the contact pressure1.Therefore, the ink is always leached to the outside at a constant pressure, and the ink decreases as the temperature changes. If the physical properties change and the viscosity decreases, excessive leaching of ink may occur, and if the viscosity increases, there is a risk that insufficient leaching of ink will occur.

In addition, since the pressure is constant, only a certain amount of ink is leached out regardless of the size of the aperture area of the base paper, and if the density of the calligraphy image formed on the base paper is high, it will cause ink leakage. If the density of the calligraphy image is low, there is a risk that there will be too much ink.

Furthermore, in the plate cylinder for a rotary copying machine shown in Japanese Patent Application Laid-Open No. 56-72987, although a curling cylinder is provided, an ink supply roller is not provided. There is simply a space formed on the inner peripheral side surface in which the electrodes are housed.

Therefore, the ink inside the cylindrical plate cylinder is not subjected to leaching pressure by the torsion cylinder, and the ink is leached out by the differential action between the inner and outer cylinders, which causes the problem mentioned when explaining the conventional technique above. is not resolved.

B) Means to Solve All Problems The present invention provides a method in which a cylindrical body having at least a portion of its circumferential surface is porous is fixed to a rotating shaft that extends through the cylindrical body and extends in a direction parallel to the generatrix of the cylindrical body. and an inking roller extending in a direction parallel to the extending direction of the rotating shaft is rotatably installed between the rotating shaft and the inner circumferential side of the cylindrical body. In the inking roller, the inking roller is connected to the rotating shaft through a rotation transmission means, and ink can pass between the outer circumferential side of the inking roller and the inner circumferential side of the cylindrical body. This plate cylinder for a rotary copying machine is characterized in that a gap is formed.

(E) Function In the present invention, the inking roller (ink supply roller)
is provided near the inner peripheral side of the cylindrical body (plate cylinder), and a gap is formed between the inking roller and the inner peripheral side of the cylindrical body to allow ink to pass through. The pressure generated by the relative velocity between the inking roller and the inner circumferential surface of the cylinder causes the ink to ooze out from the cylinder.

Note that the pressing force on the cylindrical body of the ink deposited on the upstream side along the rotational direction of the inking roller at the closest position between the inking roller and the cylindrical body is equal to The higher the relative velocity of the cylinder, the higher the pressure.

(F) Embodiment The drawings all show one embodiment of the present invention, with FIG. 1 being a longitudinal cross-sectional view and FIG. 2 being a cross-sectional view.

In these figures, reference numeral 4 denotes an inner cylinder which is loosely fitted onto the plate cylinder shaft (rotation shaft) 2 so as to be freely rotatable. 9as91) is the side body, and the inner cylinder 4
The plates are provided on both sides of the cylinder and are fixed to the plate cylinder shaft 2 so that they can rotate together. A predetermined radial ink gap 3 for ink flow is provided between the outer circumference of the side barrels 9a, 9N) and the inner cylinder 4, and a large number of small through holes are formed in a metal mesh, metal plate, or synthetic resin film. A perforated porous net-like body 1a is wrapped and fixed, and a cloth screen Ibf made of silk, cotton, synthetic resin, etc. is wrapped and covered around the outer periphery, and both form an outer cylinder (cylindrical body) 1. , the screen joint is the base paper fixing pin 10
A presser plate 11 provided with a presser plate 11 is used as a presser.

Both ends of the plate cylinder shaft 2 are supported by passing through the frames 12a and 12b'i, and a sprocket 13 for rotationally driving the plate cylinder is fixed to one end, and a sprocket (not shown) on the motor shaft side and a chain are fixed to one end. etc. are connected.

A protruding fixed spur gear 14 is provided on the inner surface of the shaft support of the frame 1.2a, and a planetary gear 1 is pivotally supported on the side shell 9a.
5a and 15b rotate together, and 15a freely moves around the outer periphery of the fixed spur gear 14.

The planetary gear 15b is a spur gear 16 fixed to the side surface of the inner cylinder 4.
It meshes with and drives.

The ink pump 17 has an ink tank 18 connected to its suction side and an ink pipe 19 connected to its discharge side.

The other end of the ink pipe 19 is connected to a joint 2 with leak prevention means.
0 is connected to one end of the plate cylinder shaft 2, and is further bored in the plate cylinder shaft, communicating with an inlet passage 21, and opening at the center of the inner cylinder 4.

Bearings 22a122b1 oil seats, zb23a, 23b are inserted into the plate cylinder shaft portions at both ends of the inner cylinder 4 to provide rotary support and prevent leakage of the ink that is force fed into the inner cylinder 4.

The inside of the inner cylinder 4 is mostly hollow, but a part is filled with ink grooves 7.
It is occupied by an ink supply path 8 (described in detail below) that leads to. The ink supply path 8 starts from an ink supply path front chamber 8a in which the discharge hole of the ink introduction path 21 is opened in the center,
a, 24. b and the narrow dispersion gap 26 between the dispersion roller 25
a, 26bQ, the ink supply path reaches the rear chamber 8b and communicates with the ink groove 7. An inking roller 6 is supported in the ink groove 7 by an inking roller shaft 27 parallel to the plate cylinder axis 2, and the outer circumferential side of the ink supply roller 6 is spaced between the inner circumferential side of the mesh body 1a. The rollers rotate while maintaining a predetermined roller gap 5 through which ink can pass.

The dispersion roller 25 is rotated by the dispersion roller gear 29 that meshes with the drive gear 28 fixed to the plate cylinder shaft 2, and the inking roller gear 31 meshes with the idle gear 30 to rotate the inking roller 6. be moved. This inking roller 6 has a width approximately equal to the printing width.

Note that the inking roller 6 may be connected to the plate cylinder shaft 2 via a rotation transmission means such as a pulley or a belt.

An impression cylinder 32 is attached to the outer periphery of the outer cylinder 1 by a spring 33 so as to be freely rotatable and to be pressed against the cylinder 32 as the outer cylinder rotates 10 times.

In FIG. 2, reference numeral 34 denotes a paper tray, and a paper feeding rubber roll 35 is provided at a part of the front end, and a paper sliding plate 36 is provided in front of the paper feeding rubber roll 35.
, the paper sliding upper plate 37 is opposite to each other.

A synchronous roll 38 is supported below the paper sliding plate 36, and a synchronous upper roll 39 is supported above the paper sliding upper plate 37 so as to be opposed to each other.

Reference numeral 40 denotes printing paper placed on the paper tray 34.

When all of the printing paper 40 is placed on the paper tray 34 and printing is started, the printing paper 40 is fed one by one by the paper feeding rubber roll 35, and the printing is kept constant by the synchronous roll 38 and the synchronous upper roll 39. The ink that emerges from the perforations of the plate-making base paper stuck to the outer periphery of the outer cylinder 1 is transferred when it is pressed between the outer cylinder 1 of the plate cylinder 1 and the impression cylinder 32. The printing process is completed when the paper is discharged in the printed state, and the plate cylinder which is the object of the present invention will be described below.

Fixed spur gear 14 fixed to frame 12a and side body 9
Planetary gears 15a, 15b1 and inner cylinder 4 pivotally supported by a
A gear train consisting of mo gears 16 fixed to the side surface of the cylinder forms a so-called planetary gear train, and differentially rotates the outer cylinder 1 and the inner cylinder 4.

If the amount of ink set appropriately to achieve the proper printing density is pumped from the ink pump 17, the ink will flow through the ink pipe 1.
9, the ink supply channel front chamber 8a via the joint 20 and the introduction channel 21
It gushes out and fills the center of the body.

Furthermore, the ink spreads to the left and right while being resisted by the grooved gaps of the dispersion gaps 26a and 26b, and is guided to the ink supply path rear chamber 8b as the dispersion roller 25 slowly rotates. When the ink appears in the ink groove 7 from the ink supply path 8b, it is deposited on the inking roller 6, rotates, and is transferred and coated on the inner circumference of the net-like body 1a.

In Fig. 2, the outer periphery of the inking roller 6 is drawn to approach in the opposite direction to the moving direction of the net-like body 1a and transfer ink, but due to the relationship with the porosity of the net-like body 1a, it moves in the same direction. You may get better results by rotating it.

In any case, a predetermined roller gap 5 is provided between the inking roller 6 and the net-like body 1a so as not to cause an excessive increase in pressure in the outer circumferential direction, and a gap 5 is provided between the inking roller 6 and the net-like body 1a. The amount of leaching is obtained naturally.

The ink transferred to the inner peripheral surface of the mesh body 1a by the inking roller 6 is sequentially transferred to the ink gap 3 by the differential action between the inner and outer cylinders.
It is fed into the air, and circulates while being given a slight pressure increase due to the differential.

Both the ink gap 3 and the roller gap 5 were approximately Q in the experiment.
Good results were obtained between 5 vtyx and 1.5 mm.

Depending on the characteristics of the ink, if the ink gap 3 or roller gap 5 exceeds 1.5 blades, ink transfer and circulation may become difficult.

Due to the weak pressure in the ink gap 3 and the capillary action of the screen 1b, the ink appears on the surface layer of the screen 11) and adheres to it. The image is printed on the printing paper 40 through the perforations of the plate-making base paper.

Incidentally, the faster the relative speed between the inking roller 6 and the inner circumferential side of the outer cylinder 1, the higher the pressure on the ink, and the more likely it is to seep out from the screen 1b.

(G) Effects of the Invention In the present invention, an inking roller is provided near the inner circumferential side of the cylindrical body, and a gap is formed between the inking roller and the cylindrical body to allow ink to pass through. Therefore, even if the components of the ink separate,
The ink is subjected to a forced twisting action by the inging roller, and is easily mixed and restored by this twisting action.

Unfortunately, even if the physical properties of the ink change due to temperature changes, there is a characteristic that the inside pressure is proportional to the change as described above (if the viscosity increases and the degree of leaching decreases, the internal pressure increases by 1Jf4° and compensates for it). ) Since mechanical force is applied, problems such as excessive or insufficient printing density or uneven printing density are eliminated.

Furthermore, since the inking roller is not in contact with the inner circumferential surface of the cylindrical body, excessive ink does not ooze out from the plate cylinder, and an appropriate amount of ink is always leached out.

Furthermore, by changing the relative speed of the inking roller and the cylinder, the leaching pressure on the ink changes, making it easy to bring it to an optimum value.

If an inspection hole (not shown) is provided at a location other than the printing surface type portion of the outer cylinder 1, the ink groove 7 portion of the inner cylinder 4 can be easily exposed, and even if the ink solidifies, it can be checked. , the plate cylinder can be cleaned while attached to the entire machine, and there is no need to replace the entire plate cylinder, significantly reducing maintenance costs. Therefore, even during printing, when the ink pump 17 is activated, the printing immediately reacts and becomes darker, so there is an advantage that the ink replenishment operation is very easy to understand.

Note that ink still leaches out appropriately depending on the size of the aperture area corresponding to the calligraphic image formed on the base paper, so even if the density of the book image changes, the appropriate amount of ink will always be immersed. , it is possible to obtain printed matter of a certain quality.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a plate cylinder according to an embodiment of the present invention, and FIG.
An explanatory diagram showing the relationship between the cross section of the flame in the figure and the paper feeding device. 1...Outer cylinder (cylindrical body), 1a, net-like body, ■b screen, 2, plate cylinder shaft (rotating shaft), 5 roller gap, 6,
- Inking roller, 28... Drive gear, 29 - Dispersion roller gear, 30... Idle gear, 31... Inking roller gear.

Claims (1)

[Scope of Claims] 1. A cylindrical body having at least a portion of its circumferential surface porous is fixed to a rotating shaft that extends through the cylindrical body and extends in a direction parallel to the generatrix of the cylindrical body; In a plate cylinder for a rotary copying machine, an inking roller extending in a direction parallel to the extending direction of the rotating shaft is rotatably installed between the inner circumferential side surface of the cylindrical body and the inking roller. The roller is connected to the rotating shaft via a rotation transmission means, and a gap is formed between the outer circumferential side of the inking roller and the inner circumferential side of the cylindrical body through which ink can pass. Characteristic printing cylinder for rotary copying machines. 2. The plate cylinder for a rotary copying machine according to claim 1, wherein the gap through which ink can pass is 1.5 mm or less. 3. The plate cylinder for a rotary copying machine according to claim 1 or 2, wherein the gap through which ink can pass is 0.5 mm or more. 4. The plate cylinder for a rotary copying machine according to any one of claims 1 to 3, wherein the inking roller rotates in the same direction as the cylindrical body. 5. The plate cylinder for a rotary copying machine according to any one of claims 1 to 3, wherein the inking roller rotates in a direction opposite to that of the cylindrical body.