JPH0224667B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an ink supply device for a printing device.
In particular, the present invention relates to an ink supply device that supplies printing ink to the inner peripheral surface of a cylindrical plate cylinder in a single-cylinder stencil printing device.

BACKGROUND OF THE INVENTION An ink supply device used in a single-cylinder stencil printing device includes a pair of side plates facing each other, and a cylindrical plate cylinder disposed between the pair of side plates on the outer peripheral surface. A squeegee roller that is in sliding contact with an inner circumferential surface and is rotatable around its own central axis, and a predetermined gap is provided between the pair of side plates along one generatrix of the squeegee roller and on the outer circumferential surface of the squeegee roller. and a doctor rod arranged therein.
an ink reservoir defined by the outer peripheral surfaces of the squeegee roller and the doctor rod on the rotational direction lag side of the gap when viewed in the rotational direction of the squeegee roller, and whose both ends are limited by the inner surfaces of each of the pair of side plates; An ink supply device equipped with this type of ink supply device has already been proposed, and the basic structure of this type of ink supply device is disclosed in a Japanese patent application filed in 1983 by the same applicant as the present applicant.
It is disclosed in No. 128043 (Japanese Unexamined Patent Publication No. 55-55889).

In the ink supply device as described above, the squeegee roller rotates around its own central axis in the same direction as the rotation direction of the cylindrical plate cylinder in synchronization with the rotation of the cylindrical plate cylinder, thereby removing the ink reservoir. The printing ink passes through the gap between the squeegee roller and the doctor rod, adheres to the outer circumferential surface of the squeegee roller in a layered state, and is conveyed toward the inner circumferential surface of the ink reservoir as the squeegee roller rotates. , the printing ink is supplied to the inner circumferential surface of the cylindrical plate cylinder in a region where the outer circumferential surface of the squeegee roller contacts the inner circumferential surface of the cylindrical plate cylinder.

The squeegee roller is sandwiched between a pair of side plates in the portion defining the ink pool, and the end surface of the squeegee roller is on the inner peripheral surface of the side plate in the portion corresponding to the ink pool. The gap is in a range where the rotation of the squeegee roller relative to the side plate is not prevented so that the printing ink in the ink reservoir does not leak to the outside through the gap between the end face of the squeegee roller and the inner face of the side plate. It is set as small as possible inside. However, in reality, even if the gap is made as small as possible, as the squeegee roller rotates, a portion of the printing ink in the ink reservoir is drawn into the gap and adheres to the end surface of the squeegee roller. arise. in general,
The squeegee roller has a portion that protrudes downward from the lower end edges of the pair of side plates, and the outer circumferential surface of this protruding portion is in sliding contact with the inner circumferential surface of the cylindrical plate cylinder. In the side plate, the lower edge defines a boundary between a region where the end surface of the squeegee roller substantially slides on the inner surface of the side plate and a region where it does not substantially slide, and the lower edge is generally a substantially horizontal plane (lower bottom surface) perpendicular to the end surface of the squeegee roller.
The corner portion on the side of the inner surface is a right angle. Therefore, when the end face of the squeegee roller enters the inner side of the lower edge of the side plate, the printing ink adhering to the end face of the squeegee roller is scraped off by the corner, and the scraped printing ink is is attached to the horizontal bottom surface of the side plate,
If the amount of adhesion increases, it will fall from the bottom surface and cause the inside of the device to become dirty.

OBJECTS OF THE INVENTION In view of the above-mentioned problems in conventional ink supply devices, the present invention provides a method in which printing ink adhering to the end face of a squeegee roller is difficult to be scraped off by the edge of a side plate, and the printing ink is Even if the printing ink is scraped off by the edge of the side plate, the printing ink is caught again between the end surface of the squeegee roller and the inner surface of the side plate, so that a large amount of scraped printing ink does not accumulate on the edge of the side plate. It is an object of the present invention to provide an improved ink supply device for a printing device, which is configured as shown in FIG.

Structure of the Invention According to the present invention, the above objects include a pair of side plates provided facing each other, and a plate disposed between the pair of side plates that slides on the inner circumferential surface of the cylindrical plate cylinder with its outer circumferential surface. A doctor rod that provides a predetermined distance between a squeegee roller that is in contact with the squeegee roller and that is rotatable around its own central axis and an outer peripheral surface of the squeegee roller that is disposed between the pair of side plates along a generatrix of one of the squeegee rollers. and defined by the outer circumferential surfaces of the squeegee roller and the doctor rod on the rotational direction lag side of the gap when viewed in the rotational direction of the squeegee roller, and having both ends defined by the inner surfaces of each of the pair of side plates. In an ink supply device of a printing device having a limited ink reservoir, the end surface of the squeegee roller is in substantial sliding contact with the inner surface of the side plate in a portion corresponding to the ink reservoir. , the side plate is a boundary between a first region where the end surface of the squeegee roller substantially slides on the inner surface of the side plate and a second region where the end surface does not substantially slide on the inner surface of the side plate, and is located at a radius from the center of rotation of the squeegee roller. from the second area toward the first area to the end face of the squeegee roller along the rotational direction of the squeegee roller to a boundary along a line that deviates in the rotational direction of the squeegee roller as the direction goes outward. This is achieved by an ink supply device that is inclined in a direction that gradually approaches the squeegee roller and defines a wedge-shaped space between it and the end surface of the squeegee roller.

Effects of the Invention According to the above-described configuration, the end face of the squeegee roller moves from the boundary on the side where it moves from the second area to the first area, that is, from the edge of the side plate to the edge. The region into which the end surface of the squeegee roller enters is inclined in a direction that gradually approaches the end surface of the squeegee roller when viewed in the rotational direction of the squeegee roller, that is, the squeegee roller at the end edge of the side plate Since the corner near the end face of the side plate is relatively largely chamfered, the printing ink adhering to the end face of the squeegee roller is violently scraped off by the corner of the end edge of the side plate. This reduces the amount of printing ink scraped off. Further, at the boundary, the side plate defines a tapered wedge-shaped space when viewed in the rotational direction of the squeegee roller by the surface given by the above-mentioned inclination and the end surface of the squeegee roller, and the end surface of the squeegee roller The printing ink scraped off by the side plate collects in the wedge-shaped space, and as the squeegee roller rotates, this printing ink enters the gap between the end surface of the squeegee roller and the inner surface of the side plate. By applying a force in the direction of the printing ink, the printing ink enters the gap again, and a large amount of printing ink does not accumulate in the wedge-shaped space. This avoids the occurrence of the so-called dripping phenomenon in which the scraped printing ink falls downward from the side plate as described above, prevents the inside of the device from being contaminated by printing ink, and also prevents wasted printing ink. Consumption is reduced.

DESCRIPTION OF EMBODIMENTS The invention will now be described in detail with reference to embodiments with reference to the accompanying drawings.

1 to 4 show one embodiment of an ink supply device for a printing device according to the present invention. In the figure, reference numeral 1 indicates a side plate, and there are two side plates, and these two side plates 1 are arranged facing each other at a predetermined interval.

A squeegee roller 2 is disposed between the two side plates 1, that is, a pair of side plates 1. The squeegee roller 2 has support shaft portions 3 projecting from both ends thereof, respectively, and the support shaft portions are connected to respective pivot shafts 4.
Therefore, by being rotatably supported by a support lever 5 that is pivotally supported on the side plate 1, it can rotate about its own central axis relative to the side plate 1.
In the illustrated embodiment, the squeegee roller 2 has its lower half protruding downward from the lower end of the side plate 1, and the outer circumferential surface of this protruding portion touches the inner circumference of the cylindrical plate cylinder 20. It is designed to slide into contact with the surface. The side plate 1 is fixed at a predetermined position inside the cylindrical plate cylinder 20, and therefore the pressing force of the squeegee roller 2 against the inner surface of the cylindrical plate cylinder 20 can be adjusted by attaching it to the side plate 1 with screws 6. Eccentric cam 7
This is done by adjusting the angle at which the support lever 5 is attached to the side plate 1.
A pulley 18 (see FIG. 2) is attached to one support shaft 3 of the squeegee roller 2, and rotational force is applied to the pulley by a transmission belt (not shown) that engages with the pulley. As shown by the arrow in FIG. It is designed to be rotated at high speed.

A doctor rod 8 is provided between the pair of side plates 1 along one generatrix of the squeegee roller 2. The doctor rod 8 has support shaft portions 9 projecting from both ends thereof, and each of the support shaft portions is fitted into an elongated hole 10 provided in the side plate 1. The support shaft portions 9 each include a ring member 1 mounted on the outer peripheral surface of the support shaft portion 3 so as to be rotatable with respect to the support shaft portion.
3 and a compression coil spring 14 connected by a connecting rod 11 and mounted around the connecting rod 11.
is urged in a direction away from the center axis of the squeegee roller 2. As a result, the doctor rod 8 faces a part of the outer peripheral surface of the squeegee roller 2 with a predetermined gap 15 extending along one generatrix of each of the squeegee rollers.

On the lag side of the gap 15 when viewed in the rotational direction of the squeegee roller 2, there is an ink reservoir defined by the outer peripheral surfaces of the squeegee roller 2 and the doctor rod 8, and whose both ends are limited by the inner surfaces 1a of each of the pair of side plates 1. A portion 12 is provided, and printing ink having an appropriate viscosity is supplied to the ink reservoir portion from an ink supply pipe 16.

The inner surface 1a of the side plate 1 has an end surface of the squeegee roller 2 extending from the lower end 1b on the side where the end surface of the squeegee roller 2 enters the inside of the side plate 2 toward the advancing side in the rotational direction of the squeegee roller 2. A depression 17 is provided in the area where the two face each other. The recess 17 is a gap between the side plate 1 and the end face of the squeegee roller 2 in a region where the end face of the squeegee roller 2 enters inside the lower end 1b of the side plate 1 to prevent printing ink adhering to the end face of the squeegee roller 2. It is made to be sufficiently larger than the thickness of the layer. Hollow 1
The peripheral edge 17a that forms the frontmost boundary of the squeegee roller 2 in No. 7 when viewed in the rotational direction does not substantially come into sliding contact with the first region A where the end surface of the squeegee roller 2 substantially comes into sliding contact with the inner surface 1a of the side plate 1. It forms a boundary with the second region B on the inner surface 1a, and the boundary is along a line that deviates in the rotational direction of the squeegee roller 2 as it goes radially outward from the rotation center of the squeegee roller 2. At the boundary, as clearly shown in FIG. The slanted surface 17b is inclined to define a wedge-shaped space between the slanted surface 17b and the end surface. As clearly shown in FIG. 1, the boundary line 17a
a and intersects both the central axis of the squeegee roller and the boundary line 17a. It is inclined with respect to the radius line of the squeegee roller 2.

In addition, in FIG. 1, 21 is a press roller, 2
Reference numeral 2 indicates stencil printing paper sheets attached to the outer circumferential surface of the cylindrical plate cylinder 20, respectively.

By rotationally driving the squeegee roller 2 in the same direction as the cylindrical plate cylinder 20 and at a circumferential speed that is substantially the same as the circumferential speed of the inner circumferential surface of the cylindrical plate cylinder 20, printing ink in the ink reservoir 12 is removed. As the squeegee roller 2 rotates, the squeegee roller passes through the gap 15 between the squeegee roller and the doctor rod 8, and is weighed at this time and adheres to the outer peripheral surface of the squeegee roller 2 in a layered state. The material is transported toward the inner circumferential surface of the material. A part of the printing ink in the ink reservoir 12 is distributed between the inner surface 1a of the side plate 1 and the squeegee roller 2.
and the end surface of the squeegee roller 2, and adheres to the end surface of the squeegee roller 2 in a layered manner. The printing ink adhering to the end surface of the squeegee roller 2 travels from the first area A to the second area B as the squeegee roller 2 rotates, and then returns to the first area A again. A part of this printing ink is indented 17
When passing through the boundary line 17a, it is scraped off by the edge thereof and comes to adhere to the slope 17b of the depression 17. This printing ink adheres to the inclined surface 17b and accumulates in a wedge-shaped space defined by the inclined surface 17b and the end surface of the squeegee roller 22.
Due to the rotation of the squeegee roller 2, a force is applied in the rotational direction of the squeegee roller 2, so that the squeegee roller 2 passes through the boundary line 17a and is taken away by being caught between the inner surface 1a of the side plate 1 and the end surface of the squeegee roller 2. , a large amount of printing ink does not accumulate in the space. Therefore, squeegee roller 2
The printing ink scraped off from the edge of the side plate 2 is prevented from falling from the side plate 1.

In addition, in the illustrated embodiment, as described above, the boundary line 17a extends on the inner surface 1a of the side plate 1, and the squeegee roller The squeegee roller is inclined with respect to the radius line of the squeegee roller so that as it moves away from the center axis of the squeegee roller 17b, the squeegee roller is displaced toward the advancing side in the rotational direction of the squeegee roller 2, so that the printing ink attached to the inclined surface 17b is removed from the squeegee roller. As the squeegee roller 2 rotates, the printing ink becomes a thinner layer along the wedge-shaped space, and then crosses the boundary line 17a and is rolled up between the end surface of the squeegee roller 2 and the inner surface of the side plate 1. A velocity component is applied along the boundary line 17a in a direction away from the central axis of the squeegee roller 2, that is, toward the outer circumference, so that the printing ink moves outward from the center side of the squeegee roller 2 along the boundary line 17a. squeegee roller 2
The ink reaches the outer periphery of the ink and is returned to the ink reservoir 12 provided on the outer periphery.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to the above-mentioned embodiments, and various other embodiments are possible within the scope of the present invention. It will be clear to those skilled in the art that

[Brief explanation of drawings]

FIG. 1 is a side view showing one embodiment of an ink supply device for a printing apparatus according to the present invention, FIG. 2 is a sectional view taken along the line of FIG. 1, and FIG. 3 is a cross-sectional view taken along the line of FIG. 1. The sectional view and FIG. 4 are partial perspective views showing essential parts of the ink supply device according to the present invention. 1...Side plate, 2...Squeegee roller, 3...
Support shaft portion, 4... Pivot, 5... Support lever, 6...
...Screw, 7...Eccentric cam, 8...Doctor rod,
9... Support shaft portion, 10... Long hole, 11... Connection rod, 12... Ink reservoir portion, 13... Ring member, 14... Compression coil spring, 15... Gap, 1
6... Ink supply pipe, 17... Recess, 18...
...Pulley, 20... Cylindrical plate cylinder, 21... Press roller, 22... Plate cylinder for stencil printing, A... First region, B... Second region.

Claims (1)

[Claims] 1 a pair of side plates 1 provided facing each other,
A squeegee roller 2 is disposed between the pair of side plates and is rotatable around its own central axis with its outer circumferential surface in sliding contact with the inner circumferential surface of the cylindrical plate cylinder; a doctor rod 8 disposed along two generatrix lines and providing a predetermined distance of 15 between the squeegee roller and the outer circumferential surface of the squeegee roller;
The distance shown in the rotational direction of the squeegee roller is
An ink supply device for a printing device, comprising an ink reservoir 12 defined by the outer peripheral surfaces of the squeegee roller and the doctor rod on the lag side in the rotational direction, and whose both ends are limited by the inner surfaces 1a of each of the pair of side plates. The end surface of the squeegee roller is in substantial sliding contact with the inner surface of the side plate in a portion corresponding to the ink reservoir, and the end surface of the squeegee roller is in substantial sliding contact with the inner surface of the side plate. A boundary between a first area A that substantially slides in contact with the squeegee roller and a second area B that does not substantially slide in the rotation direction of the squeegee roller as it goes radially outward from the rotation center of the squeegee roller. The end surface of the squeegee roller is inclined in a direction that gradually approaches the end surface of the squeegee roller along the rotating direction of the squeegee roller from the second region toward the first region toward the boundary along the line of deviation. An ink supply device characterized in that a wedge-shaped space is defined between the ink supply device and the ink supply device.