JP3192246B2 - Printing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus and, more particularly, to an ink supply mechanism provided inside a plate cylinder.

[0002]

2. Description of the Related Art Conventionally, a stencil printing apparatus is known as one of the printing apparatuses. This printing apparatus winds a printing base paper having a hole corresponding to an image by plate making onto a plate cylinder having an ink passing structure. Ink is leached from the inside of the plate cylinder to transfer the ink to the paper in close contact with the base paper. In this printing apparatus, there is an ink supply apparatus having a structure shown in FIG. That is, the ink supply device is located inside the plate cylinder A having the opening A1 and the non-opening A2 on the peripheral wall, and is arranged with a slight gap between the plate cylinder A and the inner surface of the peripheral wall of the plate. A doctor roller C disposed with a small gap for carrying ink between the ink supply roller B and the peripheral surface of the ink supply roller B; And an ink supply pipe D for discharging ink toward the ink pool formed by the ink supply.

[0003] The ink supply roller B and the doctor roller C are both rotatably supported by an ink roller side plate E fixed to an ink supply pipe D. Is applied on the ink supply roller B with a constant thickness through a gap between the rollers. Then, the ink carried on the ink supply roller B exudes from the perforated portion of the printing base paper F via the porous metal base and the screen layer of the plate cylinder, and is transferred to the printing paper.

Incidentally, in a structure in which ink is supplied to the inner peripheral surface of the plate cylinder via the ink supply roller B, a thickness for maintaining a predetermined supply amount between the inner peripheral surface of the plate cylinder A and the ink supply roller B is provided. The ink supplied while being set to the predetermined value may be crushed when the press roller G is pressed, and a part of the ink may protrude from the axial end of the ink supply roller B. In other words, the ink supplied from the ink supply roller B passes through the opening in the peripheral wall of the plate cylinder and transfers to the printing paper.
In the axial direction of the ink supply roller B and the plate cylinder A, it exudes, albeit a small amount, to a portion other than the abutting portion. For this reason, the extruded ink is gradually accumulated between the end plate fixed to the axial end of the plate cylinder A and the end face of the ink supply roller B, and when the accumulated amount increases, for example, Leakage from the joining portion of the end plate of the plate cylinder A leaks the components inside the printing apparatus.

In order to avoid such a situation, conventionally, as shown in FIG. 5, a printing plate is provided at a position opposite to the ink introduction side by the ink supply roller B in the rotation direction of the plate cylinder A. A scraping piece H contacting the inner peripheral surface of the body A
Is proposed (for example, Japanese Patent Publication No. 59-54039). The scraping piece H described above exerts a component force for moving ink toward an opposing contact portion between the ink supply roller B and the inner peripheral surface of the plate cylinder A in the rotation direction of the plate cylinder A in plan view. Tilted in the direction to cause it,
At the time of printing in which the press roller G abuts on the plate cylinder A, the ink that bleeds out of the contact portion between the ink supply roller B and the plate cylinder A and tries to accumulate on the end plate side of the plate cylinder A is supplied to the ink supply roller B.
Can be guided toward the center in the axial direction. In addition,
In FIG. 5, reference numeral J indicates a clamp mechanism for holding the leading end of the printing base paper F.

[0006]

However, in general, the exuded ink becomes unstable due to a change in fluidity when the printing apparatus is used at a low environmental temperature or is operated at a high speed. is there. For this reason, if the extruded ink collects on the scraped pieces and accumulates to form a lump, the flatness of the scraped pieces is impaired, and the ink cannot be guided. Also, even if there is a lump and ink can be guided in a state where the flatness is impaired, the lump of ink is scattered or overflows from the scraping pieces due to the operation of the printing device, and When the ink easily reaches the position of the plate cylinder end plate, there is a possibility that the leakage of the ink from the inside of the plate cylinder becomes remarkable. Therefore, when such leakage from the plate cylinder end occurs, the components inside the apparatus are soiled, and the ink supply in the axial direction of the plate cylinder is not performed uniformly due to the presence of the ink mass. As a result, a defective printed matter having uneven density is obtained.

In view of the above, there has been proposed a structure for recovering extruded ink without using such a scraping piece. This structure includes an ink supply roller and a plate cylinder provided on an axial side of the ink supply roller. (See Japanese Patent Application Laid-Open No. 24667/1990). However, in the structure described in the above publication, unless the axial end of the ink supply roller and the side plate are properly positioned, the extruded ink cannot be captured and collected. The arrangement accuracy between the side plate and the ink supply roller must be strict, and there is a possibility that the cost may be increased in terms of processing cost and the like.

In view of the above-mentioned problems in the conventional printing apparatus, it is an object of the present invention to prevent the ink from leaking to the side of the plate cylinder without increasing the cost. An object of the present invention is to provide a printing apparatus having a structure capable of preventing ink from leaking from the plate cylinder end plate side.

[0009]

In order to attain this object, the invention according to claim 1 comprises a rotatable porous cylindrical plate cylinder having a structure for passing ink supplied to an inner peripheral surface thereof, and A rotatable ink supply roller provided so as to be able to contact the inner peripheral surface of the cylindrical plate cylinder, and a rotatable doctor roller disposed with a slight gap set with respect to the surface of the ink supply roller; A printing device comprising an ink supply mechanism for uniformly supplying ink to the surface of the ink supply roller via the gap, wherein the sliding contact is disposed opposite the axial end of the ink supply roller. A member, wherein the sliding contact member is capable of coming into contact with an axial end surface of the ink supply roller and an inner peripheral surface of the cylindrical plate cylinder in a range that can cover a portion facing the ink supply roller, and Inner peripheral surface of the plate cylinder It is characterized in that is provided rotatably in a direction.

[0010] According to a second aspect of the present invention, the sliding contact member includes:
It is a plate member rotatable around a doctor roller as a fulcrum.

According to a third aspect of the present invention, the sliding contact member is
When the press roller comes into contact with the cylindrical plate cylinder by the bias of the elastic member, the press roller comes into contact with the inner peripheral surface of the cylindrical plate cylinder.

According to a fourth aspect of the present invention, the sliding contact member is
It is characterized in that it has a configuration in which it is set to a shape that can be flexibly deformed and comes into contact with the inner peripheral surface of the plate cylinder by a resetting force at the time of flexure deformation.

According to a fifth aspect of the present invention, the sliding contact member is
A surface facing the axial end surface of the ink supply roller is provided with at least one or more concave ink recovery grooves extending in the direction from the center to the outside of the roller outer peripheral surface along the rotation direction of the ink supply roller. And

[0014]

According to the present invention, the sliding contact member which comes into contact with the axial end surface of the ink supply roller and the inner peripheral surface of the plate cylinder protrudes from the side of the ink supply roller toward the axial side of the plate cylinder. The ink to be prevented is not blocked and reaches the end plate of the plate cylinder.

Further, according to the present invention, the sliding member is forcibly brought into contact with the end surface of the ink supply roller and the inner peripheral surface of the plate cylinder by the urging of the elastic member. It is possible to prevent the bleeding of the ink without management.

Further, according to the present invention, since the elastic member can be brought into contact with the end face of the ink supply roller due to the biasing of the elastic member or its own habit, it can inevitably face the ink recovery groove, so that the ink is protruded. The desired ink can be introduced into the ink recovery groove.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 is a schematic diagram showing a configuration of an ink supply mechanism which is a main part of the present invention. In FIG. 1, an ink supply mechanism 2 provided inside a plate cylinder 1 includes an ink supply roller 2A, a doctor roller 2B, and an ink supply pipe 2C. The ink supply roller 2A and the doctor roller 2B are rotatably supported by a side plate 3 attached to an ink supply pipe 2C. Of these rollers, the ink supply roller 2A is slightly in contact with the inner peripheral surface of the plate cylinder 1. It is arranged with a gap, and is rotated in the same direction as the plate cylinder 1 by a drive mechanism (not shown). In addition, the doctor roller 2B is
A gap for ink application is set between the doctor roller 2B and the surface of the ink supply roller 2A, and an ink pool is formed in a wedge-shaped space formed at the opposite portion between the doctor roller 2B and the ink supply roller 2A. ing.

In the ink supply section 2, an ink supply pipe 2
The ink discharged from C is deposited on an ink reservoir formed at a position facing the ink supply roller 2A and the doctor roller 2B, and after being kneaded by these two rollers, the ink is supplied to the plate cylinder 1 by the ink supply roller 2A. The kneaded ink is transported to the opposing position.

On the other hand, a sliding contact member 4 is provided at the axial end of the ink supply roller 2A, as shown in FIGS. The sliding member 4 is for preventing ink from escaping from the axial end surface of the ink supply roller 2B, and is provided on the axial end surface of the ink supply roller 2A and the axial end surface of the plate cylinder 1. In the case of this embodiment, the doctor roller 2
It is composed of a rotatable plate member having B as a fulcrum. The sliding contact member 4 has a curvature of a peripheral portion located in a range in which a peripheral portion facing the inner peripheral surface of the plate cylinder 1 can cover the facing portion between the inner peripheral surface of the plate cylinder 1 and the ink supply roller 2A. It is formed in the shape according to.

The sliding member 4 is provided with a locking piece formed on the side plate 3 at a position opposite to the peripheral edge and at a position corresponding to the swing end when the doctor roller 2B is used as a fulcrum. 3A is provided between the spring 5
The biasing force of the spring 5 imparts a displacement behavior toward the inner peripheral surface of the plate cylinder 1. Therefore, the sliding contact member 4
When the inner peripheral surface of the plate cylinder 1 comes into contact with the plate cylinder 1, even if there is a convex portion on the inner peripheral surface, the doctor roller 2 </ b> B can pivot against the bias of the spring 5 with the doctor roller 2 </ b> B as a fulcrum. It can adhere to the inner peripheral surface regardless of the irregularities of the inner peripheral surface. The displacement of the sliding member 4 by the spring 5 is
Is restricted by the stopper pin 3B fixed to the
A small gap is set between the peripheral portion and the inner peripheral surface of the plate cylinder 1. This gap is set so that when the press roller 6 comes into contact with the outer peripheral surface of the plate cylinder, the pressing force of the press roller 6 allows the inner peripheral surface of the plate cylinder 1 to contact the peripheral edge of the sliding contact member 4. Has been
When the press roller 6 is not in contact with the plate cylinder 1, wear of the peripheral portion, which occurs when the sliding contact member 4 comes into contact, and an increase in frictional resistance when rotating on the plate cylinder 1 side are prevented. .

Further, on the surface of the sliding member 4, the plate cylinder 1
An elastic body 7 such as rubber is arranged on the surface facing the end plate (not shown) by a sticking process or the like. The elastic body 7 allows the sliding contact member 4 via the end plate of the plate cylinder 1. The ink supply roller 2A is pressed against the axial end face.

Next, the operation will be described. When the press roller 6 is in contact with the outer peripheral surface of the plate cylinder 1 to perform so-called printing, the plate cylinder 1 is pushed up toward the peripheral edge of the sliding contact member 4 by the pressing force of the press roller 6.
As a result, the inner peripheral surface of the plate cylinder 1 comes into contact with the peripheral edge of the sliding member 4. On the other hand, in this state, the sliding member 4 is pressed against the axial end face of the ink supply roller 2B by the bias of the elastic body 7, so that the shaft of the ink supply roller 2A facing the inner peripheral surface of the plate cylinder 1 is pressed. The end face in the direction is separated from the end plate side of the plate cylinder 1 by the sliding contact member 4. Therefore, at a position where the inner peripheral surface of the plate cylinder 1 where ink is transferred and the peripheral surface of the ink supply roller 2B face each other, the ink is likely to protrude on the ink introduction side corresponding to the upstream side in the rotation direction of the plate cylinder 1. Is stopped and the ink is guided into the ink reservoir on the ink discharge side corresponding to the downstream side in the rotation direction so as not to leak out.

According to the present embodiment, the peripheral portion of the sliding contact member 4 is not always brought into contact with the inner peripheral surface of the plate cylinder 1, but is brought into contact by utilizing the deformation of the peripheral wall of the plate cylinder caused by the pressing of the press roller 6. As a result, it is possible to prevent abrasion of the peripheral portion of the sliding member 4 and to prevent a gap between the inner peripheral surface of the plate cylinder and the outer periphery of the plate cylinder from allowing ink to leak out. .

In the above embodiment, a spring is used as an urging means for bringing the sliding contact member 4 into contact with the inner peripheral surface of the plate cylinder, and a means for pressing against the end face of the ink supply roller 2B. Although an elastic body such as rubber is used for the above, the action of the added components is used, but the present invention is not limited to such a structure. For example, the above-mentioned urging means may be provided in the sliding contact member itself.

FIGS. 3 and 4 show an example in which the sliding contact member itself is provided with a biasing structure.
On the surface opposing the plate cylinder end plate at 0, projections 40A radially formed around the support shaft of the ink supply roller 2B are provided at evenly distributed positions in the circumferential direction. The protrusion 40A is
The base end is composed of a single piece integrated with the sliding member 40, and the free end is pressed against the plate cylinder end plate, whereby the sliding member 40 is pressed against the end face of the ink supply roller by the reaction force. I have. At the position where the spring shown in FIG. 1 was provided, a notch 4
0B is provided, a cantilever-shaped branch portion 40C is formed adjacent to the notch, and a stopper 8 fixed to the side plate 3 is disposed on the upper surface of the branch portion 40C. Stopper 8
Is a regulating member for bringing the peripheral portion of the sliding contact member 40 into contact with the inner peripheral surface of the plate cylinder 1.

According to such a structure, it is possible to eliminate the necessity of incorporating the elastic means only by incorporating the sliding contact member 40, thereby reducing the number of parts and the number of assembling steps.

On the other hand, in the present invention, as described above, in addition to damming the ink which is about to protrude from the end face of the ink supply roller 2B, it is also possible to forcibly collect the ink toward the ink reservoir. It is possible. 3 and 4, the surface of the sliding contact member 40 facing the end surface of the ink supply roller 2B is provided with an ink supply roller 2B.
Along the rotation direction of the ink supply roller 2B, a concave recovery groove 40D having a starting point near the rotation center position on the ink discharge side and a terminating point outside the outer peripheral surface of the ink supply roller 2B corresponding to the ink pool. Are formed. The recovery groove 40D introduces ink moving on the surface of the sliding contact member 40 while being blocked by the sliding contact member 40, and is guided toward the ink reservoir by the rotational force of the ink supply roller 2B. According to such a structure,
In the rotation direction of the ink supply roller 2B, the sliding contact member 4
When the ink that is about to run off from the end face of the ink supply roller 2B is blocked by 0, the ink tends to accumulate between the end face of the ink supply roller 2B and the surface of the sliding contact member 40 facing the end face. Can be forcibly collected in the ink reservoir, so that the formation of a lump of ink can be prevented.

[0029]

As described above, according to the present invention, the ink supply is achieved only by providing the sliding contact members which can be brought into close contact with the inner peripheral surface of the plate cylinder and the end surface of the ink supply roller facing the inner peripheral surface. Ink that is about to protrude from the end face of the roller can be blocked. Therefore, with a simple structure in which only the sliding contact members are brought into close contact with each other, it is possible to prevent the accumulation of ink inside the plate cylinder end plate and prevent the inside of the apparatus from being stained due to the leakage of ink from the end plate. .

Further, according to the present invention, the sliding member is forcibly brought into contact with the end surface of the ink supply roller and the inner peripheral surface of the plate cylinder by the bias of the elastic member, so that the positioning accuracy for each contact portion is strictly controlled. Even without doing so, it is possible to stop the ink to be leached and to inevitably introduce the ink to the opposite collecting position and collect it in the ink reservoir.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a main configuration of a printing apparatus according to the present invention.

FIG. 2 is a perspective view showing a part of a main part shown in FIG.

FIG. 3 is a schematic diagram showing a modification of the main part configuration shown in FIG. 1;

FIG. 4 is a perspective view showing a part of a main part shown in FIG.

FIG. 5 is a schematic view showing a conventional example regarding the structure of an ink supply mechanism in a printing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate cylinder 2 Ink supply mechanism 2A Ink supply roller 2B Doctor roller 3 Side plate 4 Sliding member 5 Spring which is an elastic member 6 Press roller 7 Elastic body 8 Stopper 40 Sliding member 40A Projection 40C Branch 40D Collection groove

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41L 13/18 B41F 31/02

Claims (5)

(57) [Claims] 1. A rotatable porous cylindrical plate cylinder having a structure for passing ink supplied to an inner peripheral surface thereof, and a rotatable ink supply provided so as to be in contact with the inner peripheral surface of the cylindrical plate cylinder. A roller and a rotatable doctor roller disposed with a small gap set with respect to the surface of the ink supply roller, and uniformly apply ink to the surface of the ink supply roller via the gap. A printing apparatus having an ink supply mechanism for supplying ink, comprising: a sliding contact member disposed to face an axial end of the ink supply roller; wherein the sliding contact member is an axial end surface of the ink supply roller. And an inner peripheral surface of the cylindrical plate cylinder that can be brought into contact with an area that can cover a portion facing the ink supply roller and that is rotatable in a direction toward the inner peripheral surface of the plate cylinder. Printing equipment characterized by . 2. The printing apparatus according to claim 1, wherein said sliding member is a plate member rotatable around a doctor roller. 3. The printing apparatus according to claim 1, wherein the sliding contact member comes into contact with the inner peripheral surface of the cylindrical plate cylinder when the press roller comes into contact with the cylindrical plate cylinder by urging of the elastic member. A printing device having a configuration. 4. The printing apparatus according to claim 1, wherein the sliding contact member is set to have a shape capable of bending deformation, and is configured to come into contact with the inner peripheral surface of the plate cylinder by a resetting and accumulating force at the time of bending deformation. Printing device. 5. The printing apparatus according to claim 1, wherein the sliding contact member is provided on a surface facing the axial end surface of the ink supply roller, from the center side along the rotation direction of the ink supply roller, to the outside of the roller outer peripheral surface. A printing apparatus provided with at least one or more concave ink recovery grooves in the direction toward.