JPS61228982A - Stencil printing press - Google Patents

Abstract

PURPOSE:To obviate a trailing phenomenon of a printing ink, by controlling the pressure with which an inking roller is pressed against the inner peripheral surface of a form cylinder. CONSTITUTION:The form cylinder 1 rotated about a center axis, the inking roller (squeegee roller) 15 for supplying a printing ink to the inner peripheral surface of the cylinder 1 and a means (pressure-adjusting cam) 24 for controlling the pressure with which the roller 15 is pressed against the inner peripheral surface of the cylinder 1 are provided. When the roller 15 comes to a position corresponding to the boundary region between an ink-permeable structure part 7 of the cylinder 1 and an ink-impermeable part 8, the pressing against the cylinder 1 is released, whereby a printing ink squeezing action of the roller 15 is released, and the ink is prevented from being pushed to the lagging side in the rotating direction of the cylinder 1 concurrently with the rotation of the cylinder 1. Accordingly, the trailing phenomenon of the printing ink can be obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a stencil printing apparatus, and more particularly to an ink supply system of a single-cylinder rotary stencil printing apparatus.

Conventional technology Mono-cylinder rotary type stencil printing devices generally have a cylindrical plate cylinder with a porous structure that rotates around its central axis, around which stencil printing paper is wound around the outer periphery, an ink supply roller, generally called a squeegee roller, that contacts the inner circumferential surface of the cylindrical plate cylinder and rotates around its own central axis to supply printing ink to the inner circumferential surface of the cylindrical plate cylinder; This type of stencil printing device is known, for example, from Japanese Patent Application Laid-open No. 5
5-55889.

Problems to be Solved by the Invention In the stencil printing apparatus having the structure described above, the printing ink supplied to the inner peripheral surface of the cylindrical plate cylinder by the ink supply roller is applied to the cylindrical plate by the squeegee action of the ink supply roller. The excess printing ink passes through the porous structure of the cylinder and is used to form a printed image, but as the cylindrical plate cylinder rotates, the excess printing ink is sequentially pushed to the lag side in the rotational direction, and when there is a large amount of excess printing ink, it is finally There is a risk that printing ink may leak out from the rear edge of the stencil printing paper that is wrapped around the outer circumferential surface of the cylindrical plate cylinder. This printing ink leakage phenomenon has been considered to be a troublesome problem.

An object of the present invention is to provide an improved stencil printing apparatus that solves the above-mentioned problems.

Means for Solving the Problems According to the present invention, the above-mentioned object is achieved by forming part of the structure into an ink-impermeable structure and the rest into an ink-permeable structure, and wrapping or attaching stencil printing paper around the outer peripheral surface. a cylindrical plate cylinder that rotates around its own central axis; and a cylindrical plate cylinder that contacts the inner circumferential surface of the cylindrical plate cylinder with its outer peripheral surface and rotates around its own central axis to rotate the inner periphery of the cylindrical plate cylinder. an ink supply roller that supplies printing ink to the surface; and when the ink supply roller corresponds to a boundary area between an ink-permeable structure portion and an ink-impermeable structure portion of the cylindrical plate cylinder, the ink supply roller This is achieved by a stencil printing apparatus having a pressing force control means for releasing the pressing force on the inner circumferential surface of the cylindrical plate cylinder.

Effects and Effects of the Invention According to the configuration as described above, when the ink supply roller corresponds to the boundary area between the ink-permeable structure portion and the ink-impermeable structure portion of the cylindrical plate cylinder, the pressure against the cylindrical plate cylinder is reduced. By releasing the squeegee action of the printing ink by the ink supply roller, the printing ink is prevented from being pushed to the lag side in the rotational direction as the cylindrical plate cylinder rotates, and the phenomenon of bottom leakage of the printing ink occurs. is avoided.

When the ink supply roller corresponds to the boundary area, the pressure on the cylindrical plate cylinder is released and the ink supply roller may be separated from the inner circumferential surface of the cylindrical plate cylinder. In this case, the ink supply roller corresponds to the boundary area. At the corresponding time, the squeegeeing effect of the printing ink by the ink supply roller is released and the ink supply to the cylindrical plate cylinder is completely interrupted, so that the effect of avoiding the printing ink leakage phenomenon becomes even more remarkable.

EXAMPLES The present invention will now be described in detail by way of examples with reference to the accompanying drawings.

The attached drawings show the main parts of one embodiment of a stencil printing apparatus according to the present invention. In the figure, reference numeral 1 indicates a cylindrical plate cylinder, and the cylindrical plate cylinder has a support cylinder 2 made of kudzu metal that has a land member 3 for clamping the base paper on a part of its outer circumferential surface.
It has a three-layer structure including an intermediate screen layer 4 wrapped around the outer peripheral surface of the support cylinder 2, and an outer screen layer 5 wrapped around the outer peripheral surface of the intermediate screen layer 4. The supporting cylindrical body 2 has an ink-permeable structural part 7 having a porous structure having a large number of small holes (not shown) for ink passage in other parts except for the attachment part of the base paper clamp land member 3 and its surrounding parts. The mounting portion of the base paper clamp land member 3 and its surrounding area are made into a non-porous, ink-impermeable structure 8 having no small holes at all.

A permanent magnet 9 is fixed to the base paper clamp land member 3, and a metal member rotates around a pivot 10 to sandwich one end of the stencil printing base paper S and is magnetically attracted to the permanent magnet 9. A clamp piece 11 made of a thin plate is attached.

On the outer peripheral surface of the cylindrical plate cylinder 1, a stencil printing base paper S having a constant length is attached at one end to a permanent magnet 9 and a clamp piece 1.
The winding is installed in a state in which it is held in place by the cylindrical plate cylinder 1, and the trailing edge of this stencil printing base paper S has an ink-permeable structure part 7 and an ink-impermeable structure part. It is located closer to the ink-impermeable structural portion 8 than the boundary with the ink-impermeable structure portion 8.

A holder blade 12 for an ink supply device is arranged in the cylindrical plate cylinder 1 . The holder blade 12 has a pivot 1
3, one end of the squeegee roller support arm 14 is rotatably attached. The squeegee roller support arm 14 rotatably supports a squeegee roller 15 about its central axis 16, and the squeegee roller 15 is adapted to come into sliding contact with the inner peripheral surface of the cylindrical plate cylinder 1 at its lower region. One end of a pressing force adjustment arm 17 is rotatably attached to the central shaft 16 of the squeegee roller 15.
The pressing force adjusting arm 17 is fixed to the squeegee roller support arm 14 at a rotational position adjusted by an eccentric cam 20 by a screw 19 engaged with a long hole 18 at the other end. A cam follower roller 22 that rolls and rotates around a shaft 21 is located in the middle of the pressing force adjustment arm 17.
is rotatably mounted. A pressing force adjusting cam 24 is rotatably attached to the holder plate 12 by a cam shaft 23. Pulleys 25 and 26 are attached to the center shaft 16 and the camshaft 23, respectively. It rotates once per rotation of the cylindrical plate cylinder 1 in the same direction as the rotational direction of the cylindrical plate cylinder 1.

The pressing force adjustment cam 24 has a recessed portion 24b at one location, and when engaged with the cam follower roller 22 at a normal circumferential portion 24a other than the recessed portion 24b, the squeegee roller 15 is adjusted to a predetermined pressing force. The squeegee roller 15 is pressed against the inner circumferential surface of the cylindrical plate cylinder 1, and when the squeegee roller 15 is engaged with the cam follower roller 22 at the recessed portion 24b, the pressure of the squeegee roller 15 against the cylindrical plate cylinder 1 is released. .

The pressing force adjustment cam 24 is arranged so that the squeegee roller 15 is wound around the boundary area between the ink-permeable structure portion 7 and the ink-impermeable structure portion 8 of the cylindrical plate cylinder 1, in other words, the outer peripheral surface of the cylindrical plate cylinder 1. The recessed portion 24b engages with the cam follower roller 22 at a rotational position corresponding to the rear edge region of the stencil printing base paper S, that is, the region indicated by A in the figure. Its phase is set.

Squeegee roller support arm 14 and holder plate 12
A tension coil spring 29 is attached to , and the tension coil spring 29 lifts and urges the squeegee roller support arm 14 in the direction of releasing the pressing force.

The holder plate 12 supports a doctor rod 30 in parallel with the squeegee roller 15, and the doctor rod 30 engages with a long hole 32 provided in the holder plate 12 with protruding shaft portions 31 provided at both ends thereof. are doing. A stay rod 33 passes through the protruding shaft portion 31, and the tip of the stay rod 33 is connected to the center shaft 16 of the squeegee roller 15.
The nut 3 is attached to the connecting block 34 which is rotatably supported by the nut 3.
5 is fixed with screws. A compression coil spring 36 is attached between the protruding shaft portion 31 and the connecting block 34 so as to surround the steel rod 33, and the compression coil spring 36 is attached in a direction that pulls the doctor O. This forces a very small II [37] between the squeegee roller 15 and the doctor rod 30 at all times.

A press roller 38 is provided on the outside of the cylindrical plate cylinder 1. During normal printing operation, the press roller 38 is pressed towards the outer circumferential surface of the cylindrical plate cylinder 1 when it corresponds to the ink-permeable structure 7, whereas when it corresponds to the ink-impermeable structure 8 It is designed to be pulled away from the outer peripheral surface of the cylindrical plate cylinder 1, and this press roll 5
The operation of 38 may be similar to that of conventional stencil printing devices.

The squeegee roller 15 is connected to the cylindrical plate cylinder 1 by a pulley 26.
The cylindrical plate cylinder 1 rotates around its own central axis in synchronization with the rotation of
It is rotationally driven in the counterclockwise direction in the figure, which is the same direction as the rotation direction. As the squeegee roller 15 rotates, the printing ink P in the ink pool formed in the horizontal space between the squeegee roller 15 and the doctor rod 30 is supplied from the ink supply vibrator 39 and passes through the gap 37 to the squeegee roller 15. The number μ determined by the wood notch in the gap 37 on the outer peripheral surface of
is deposited in a layer with a thickness of

At this time, printing paper (not shown) is supplied between the cylindrical plate cylinder 1 and the press row 538 in synchronization with the rotation of the cylindrical plate cylinder 1, and the printing paper is transferred to the cylindrical plate cylinder by the press roller 38. The printing ink that has passed through the ink-permeable structure portion 7 of the cylindrical plate cylinder 1 and the perforated portion of the stencil printing base paper S is pressed against the stencil printing base paper S wrapped around the outer peripheral surface of the stencil printing cylinder 1. It is applied to carry a printed image by printing ink.

When the squeegee roller 15 is in a position corresponding to the ink-permeable structural portion 7 of the cylindrical plate cylinder 1, in other words, the cylindrical plate cylinder 1 is in a rotational phase in which the ink-permeable structural portion 7 slides into contact with the squeegee roller 15. At some point, the pressing force adjusting cam 24 normally moves around the cam follower roller 22 at the circumferential portion 24a.
, the squeegee roller 15 is pressed against the inner circumferential surface of the cylindrical plate cylinder 1 with a predetermined pressing force, and the squeegee roller 15 performs the required squeegee action, thereby pressing the squeegee roller 15 against the inner peripheral surface of the cylindrical plate cylinder 1. Printing ink is supplied to.

When the rotation of the cylindrical plate cylinder 1 progresses and the squeegee roller 15 comes to a position corresponding to the boundary area between the ink-permeable structure part 7 and the ink-impermeable structure part 8 of the cylindrical plate cylinder 1, the squeegee roller 15 moves. The wrapping on the outer peripheral surface of the cylindrical plate cylinder 1 corresponds to the rear edge area of the stencil printing base paper S attached,
At this time, the pressing force adjusting cam 24 engages with the cam follower roller 22 at the recessed portion 24b, and as a result, the pressing force of the squeegee roller 15 against the cylindrical plate cylinder 1 is released, and at the same time, the squeegee roller 15 is moved together with the squeegee roller support arm 14. The stencil printing paper S, which is lifted up by the spring force of the compression coil spring 21 and separated from the inner circumferential surface of the cylindrical plate cylinder 1, is wound around the outer circumferential surface of the cylindrical plate cylinder 1. No printing ink is supplied to the area where the trailing edge region is located, and the squeezing action of the squeegee roller 15 is released in this area. As a result, in the portion corresponding to the trailing edge area of the stencil printing base paper S,
The printing ink is not supplied, and the printing ink contained in the cylindrical plate cylinder 1 is not pushed to the lag side in the rotational direction of the cylindrical plate cylinder 1, and the excess printing ink is transferred to the rear end of the stencil printing base paper S. The occurrence of the so-called widening/shallowing phenomenon in which the liquid leaks from the inside to the outside is avoided.

The pressure of the squeegee roller 15 on the cylindrical plate cylinder 1 is released from the boundary between the ink-permeable structure part 7 and the ink-impermeable structure part 8 of the cylindrical plate 1111 on the outer peripheral surface of the cylindrical plate cylinder 1. The winding starts at a position about 1011 points before the rotational direction (advanced side in the rotational direction), and the winding is started from the part where the trailing edge of the stencil printing base paper S attached is located on the outer peripheral surface of the cylindrical plate Ii1. It may end at a position on the outer peripheral surface of the cylindrical plate cylinder 1 at a position on the rotational direction delay side of about 1011 or more in the circumferential direction.

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

[Brief explanation of drawings]

The attached figure is a longitudinal sectional view showing the main parts of one embodiment of the stencil printing apparatus according to the present invention. DESCRIPTION OF SYMBOLS 1... Cylindrical plate cylinder, 2... Support cylinder, 3... Land member for clamp, 4... Intermediate screen layer, 5
... Outer screen layer body, 7... Ink-permeable structure portion. 8... Ink-impermeable structural part, 9... Permanent magnet,
DESCRIPTION OF SYMBOLS 10... Pivot, 11... Clamp piece, 12... Holder plate, 13... Pivot, 14... Squeegee roller support arm, 15... Squeegee roller, 16
...Central axis. 17...Pushing force adjustment arm, 18...Long hole, 19.
.... Screw, 20... Eccentric cam, 21... Shaft, 22...
Cam follower roller, 23... cam shaft, 24... cam for pressure adjustment, 25.26... pulley, 27...
Endless belt. 28... Drive pulley, 29... Tension coil spring,
30...Doctor rod, 31...Protruding shaft portion, 32...
・Long hole. 33...Stee rod, 34...Connection block,
35...fixing nut, 36...compression coil spring, 3
7... Gap, 38... Press roller, 39... Ink supply pipe

Claims (1)

[Claims] A cylindrical plate cylinder which has a part impermeable to ink and the other part has a structure which allows ink to pass through, has stencil printing paper wrapped around its outer circumferential surface, and rotates around its central axis; an ink supply roller that contacts the inner peripheral surface of the cylindrical plate cylinder and rotates around its own central axis to supply printing ink to the inner peripheral surface of the cylindrical plate cylinder; pressing force control means for releasing the pressing force of the ink supply roller against the inner circumferential surface of the cylindrical plate cylinder when the cylinder corresponds to a boundary area between an ink-permeable structural part and an ink-impermeable structural part; It has a stencil printing device.