JPH05286224A - Ink supply device of screen printing machine - Google Patents

Abstract

PURPOSE:To increase the supply capacity of ink without making the control of the ink supply amount to a squeezee mechanism unstable and to increase the printable number of papers in continuous printing requiring no replenishing work of printing ink to a large extent. CONSTITUTION:An ink reservoir 15 storing a predetermined amount of printing ink is provided in a plate cylinder 5 and printing ink is sucked from the ink reservoir 15 by a first ink supply pump 13 to be supplied to a squeezee mechanism. The operation of the first ink supply pump 13 is controlled by a control unit 27 so that the ink amount in the squeezee mechanism is held to a predetermined value. An ink tank 31 storing a predetermined amount of printing ink is provided to the outside of the plate cylinder and printing ink is supplied to the ink reservoir 15 from the ink tank 31 by a second ink supply pump 39. The operation of the second ink supply pump 39 is controlled by a control unit 47 so that the ink amount in the ink reservoir 15 is held to a predetermined value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink supply device for a stencil printing machine.

[0002]

2. Description of the Related Art As a rotary stencil printing machine, a squeegee mechanism is provided inside a plate cylinder having an ink permeation structure, and the printing ink is transferred from the inner peripheral surface of the plate cylinder to the outer circumference of the plate cylinder by the rotation of the plate cylinder. Stencil printing machines are known which are adapted to apply to a stencil sheet mounted on a surface.

In the ink supply device of this type of stencil printing machine, generally, the printing ink is sucked by an ink supply pump from an ink tube replaceably attached to an ink tube attachment portion provided inside the plate cylinder. The ink amount sensor monitors the ink amount in the squeegee mechanism and controls the operation of the ink supply pump so that the ink amount is maintained at a predetermined value. There is.

[0004]

In the ink supply device as described above, since the ink tube which is the ink storage portion is provided inside the plate cylinder, the size thereof is the inner diameter of the plate cylinder and the inside of the plate cylinder. Other mechanisms such as squeegee mechanism installed,
It cannot be made too large because it is restricted by the members.

Therefore, in the conventional ink supply device as described above, there is a limit to the increase in the ink capacity in one ink tube, and it is necessary to replace the ink tube, in other words, to supply the printing ink. It is impossible to significantly increase the number of prints that can be continuously printed without the above.

On the other hand, it is conceivable that a large-capacity ink tank is installed outside the plate cylinder, the printing ink is sucked from the ink tank by an ink supply pump, and the ink is pressure-fed to the squeegee mechanism. When the ink tank is installed outside the plate cylinder, the ink supply capacity is not limited by the inner diameter of the plate cylinder, but in this case, the ink supply passage between the ink tank and the squeegee mechanism is not limited. The passage length becomes longer, and accordingly, it becomes necessary to increase the discharge pressure of the ink supply pump.

When the length of the ink supply passage is long and the discharge pressure of the ink supply pump is high, control of the ink supply amount to the squeegee mechanism by turning the ink supply pump on and off causes inertia of the printing ink flowing through the ink supply passage, etc. This makes it difficult to control the ink supply amount to the squeegee mechanism as compared with the case where the printing ink is supplied to the squeegee mechanism from the ink tube provided in the plate cylinder.

The present invention has been made by paying attention to the above-mentioned problems in the ink supply device of the conventional stencil printing machine, without making the ink supply amount control for the squeegee mechanism unstable. Ink supply capacity can be increased,
It is an object of the present invention to provide an ink supply device of a stencil printing device that can significantly increase the number of prints that can be continuously printed without requiring a printing ink supply operation.

[0009]

According to the present invention, there is provided a squeegee mechanism inside a plate cylinder having an ink permeable structure, and printing ink is printed by the squeegee mechanism as the plate cylinder rotates. In an ink supply device of a stencil printing machine configured to give to a stencil sheet mounted on an outer peripheral surface of a plate cylinder from an inner peripheral surface thereof, an ink reservoir provided inside the plate cylinder for storing a predetermined amount of printing ink. A first ink supply pump for sucking the printing ink from the ink reservoir and supplying the printing ink to the squeegee mechanism, and the first ink supply for maintaining the ink amount in the squeegee mechanism at a predetermined value. A first ink supply pump control device that controls the operation of the pump, an ink tank that is provided outside the plate cylinder to store a predetermined amount of printing ink, and suctions the printing ink from the ink tank. A second ink supply pump that supplies printing ink to the ink reservoir, and a second ink supply pump that controls the operation of the second ink supply pump so that the amount of ink in the ink reservoir is maintained at a predetermined value. And an ink supply device for a stencil printing machine.

[0010]

According to the above-mentioned structure, the printing ink is temporarily sent from the ink tank outside the plate cylinder to the ink reservoir inside the plate cylinder by the second ink supply pump and is stored in the ink reservoir. The printing ink thus obtained is sent to the squeegee mechanism by the first ink supply pump.

[0011]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a stencil printing machine to which the ink supply device according to the present invention is applied. In FIG. 1, reference numeral 1 indicates a stencil printing apparatus, and the stencil printing apparatus 1 is mounted on a frame 3 for use. Stencil printer 1
Has a cylindrical printing cylinder 5 having an ink permeable structure, which is mounted around the outer peripheral surface of the stencil and is replaceable in a unit state. The plate cylinder 5 is exchanged by a pull-out method, and this structure may be the same as that shown in Japanese Patent Laid-Open No. 59-12893.

As shown in FIG. 2, a squeegee blade 7 is provided in the plate cylinder 5. The squeegee blade 7 is in slidable contact with the inner peripheral surface of the plate cylinder 5 at a predetermined squeegee angle, and forms an ink reservoir P of printing ink on the side of the plate cylinder 5 that is delayed in the rotational direction.

A delivery pipe 9 for supplying printing ink to the ink reservoir P is arranged in the plate cylinder 5, and the delivery pipe 9 is arranged in the plate cylinder 5 by an ink supply hose 11. It is connected to the discharge port of the inner ink supply pump (first ink supply pump) 13. The delivery pipe 9 and the in-cylinder ink supply pump 13 are located close to each other on the plate cylinder 5, so that the ink supply hose 11 is relatively short.

In the plate cylinder 5, an ink reservoir 15 is arranged in place of the ink tube (ink bottle), instead of the ink tube. The ink reservoir 15 is provided with a cylindrical reserve container 16 having the same shape as the ink tube, and inwardly fitted to the reserve container 16 so as to be movable in the reserve container 16 in the axial direction. Ink reserve chamber 1 between 17 and
And a piston member 21 that defines 9 and the ink outlet 23 formed in the end wall 17 is connected to the in-body ink supply pump 1
3 is connected to the suction port. Printing ink is supplied to the ink reserve chamber 19 from an ink supply port 25 formed in the piston member 21, and this printing ink is sucked out from the ink discharge port 23 by the operation of the in-body ink supply pump 13, and the ink supply hose 11 By delivery pipe 9
It is being sent to.

The operation of the in-body ink supply pump 13 is controlled by an in-body pump control device (first ink supply pump control device) 27. The in-body pump control device 27 is provided with information about the amount of printing ink in the ink reservoir P by an electrostatic capacitance type ink amount sensor 29 that detects the amount of printing ink in the ink reservoir P, and the printing ink in the ink reservoir P is printed. When the amount is below a predetermined value, the in-body ink supply pump 13 is turned on, and when the amount of printing ink in the ink reservoir P is above a predetermined value, the in-body ink supply pump 13 is turned off. Is becoming

An ink tank 31 is provided on the base 3 so that it can be pulled out (see FIG. 1). The ink tank 31 is provided with an ink filling cap 33 and an ink take-out port 35, and the ink take-out port 35 is connected to an outside cylinder ink supply pump 39 (second ink supply pump) by a hose 37.
Is connected to the suction port of.

The extra-cylinder ink supply pump 39 is provided near the position where the ink tank 31 is arranged, that is, outside the plate cylinder 5, and the ejection ports of the extra-cylinder ink supply pump 39 are interconnected by a joint 41. Ink supply hose 4
Ink supply port 2 of ink reservoir 15 by 3, 45
5, the printing ink is pressure-fed to the ink supply port 25.

The operation of the outside cylinder ink supply pump 39 is controlled by an outside cylinder pump control device (second ink supply pump control device) 47. The out-of-body pump control device 47 is provided with an on / off signal from the limit switch 49 and controls on / off of the out-of-body ink supply pump 39 in response to this signal.

The limit switch 49 is attached to the piston member 21 of the ink reservoir 15 by a rod member 51 so as to be integrated with the piston member 21.
When the piston member 21 is moved forward by a predetermined amount or more and the inner volume of the ink reserve chamber 19 becomes a predetermined value or less, the actuator 49a is pushed by the switch operation plate 53. Thus, the ON signal is output, and at other times, the pressing of the actuator 49a is released and the OFF signal is output.

In this case, the out-of-body pump control device 47
Is configured to turn on the outside-cylinder ink supply pump 39 by receiving an ON signal from the limit switch 49 and turn off the outside-cylinder ink supply pump 39 by receiving an OFF signal from the limit switch 49. Good.

The ink tank 31 is mounted on a tilting tank base 59, one end of which is pivotally mounted on a tank base 55 by a pivot shaft 57. The tilting tank base 59 is the spring 6
1, the ink tank 31 filled with a required amount of printing ink is urged in the ascending direction by 1 and the weight of the ink tank 31 resists the spring force of the spring 61 so that the rotation position is as shown in the figure. It is supposed to descend. The tilting tank base 59 is rotated in the upward direction by the spring force of the spring 61 due to the reduction of the printing ink amount of the ink tank 31, and when the printing ink amount of the ink tank 31 becomes a predetermined value or less, the ink tank 31 is disposed above the position where the printing ink is placed. The limit switch 63, which is fixedly arranged in the position, is turned on. The limit switch 63 is adapted to turn on and off an electric circuit of a warning lamp 67 including a power source 65, whereby the warning lamp 67 causes the printing ink amount of the ink tank 31 to fall below a predetermined value and the limit switch 63. Is turned on to indicate that the amount of printing ink in the ink tank 31 has fallen below a predetermined value.

According to the above-mentioned structure, the operation of the in-body ink supply pump 13 is controlled by the in-body pump control device 27 in accordance with the printing ink amount of the ink reservoir P detected by the ink amount sensor 29 as described above. As a result, the printing ink in the ink reserve chamber 19 of the ink reservoir 15 is sucked out from the ink outlet 23, is sent to the delivery pipe 9 through the ink supply hose 11, and is discharged from the delivery pipe 9 to reach the ink reservoir P. Is supplied to. As a result, the amount of printing ink in the ink reservoir P can be maintained at a predetermined value.

The supply of printing ink to the ink reservoir P by the in-body ink supply pump 13 is performed responsively because the ink supply hose 11 is short. Further, since the ink supply hose 11 is short, the discharge pressure of the printing ink of the in-body ink supply pump 13 need not be so high.

When the printing ink in the ink reserve chamber 19 is sucked out, the piston member 21 advances, and when the internal volume of the ink reserve chamber 19, that is, the amount of printing ink in the ink reservoir 15 falls below a predetermined value, the switch operating plate. 53
As a result, the actuator 53a of the limit switch 49 is pressed, and the limit switch 49 is turned on.

As a result, the operation of the out-of-body ink supply pump 39 is controlled by the out-of-body pump control device 47, and the printing ink in the ink tank 31 passes through the ink supply hoses 43 and 45 by the out-of-body ink supply pump 39 and the ink supply port. 25, the ink is sent to the ink reserve chamber 19 of the ink reservoir 15 and the printing ink is replenished in the ink reserve chamber 19.

As the printing ink is replenished, the piston member 21 retracts, and the pressing of the actuator 53a of the limit switch 49 by the switch operating plate 53 is released. Limit switch 49 actuator 5
When the pressure of 3a is released, the extra-body ink supply pump 39
Is stopped, and the delivery of printing ink from the ink tank 31 to the ink reserve chamber 19 is stopped. As a result, the state in which the predetermined amount of printing ink is present in the ink reserve chamber 19 of the ink reservoir 15 is maintained unless all the printing ink in the ink tank 31 is consumed.

The detection of the printing ink amount in the ink reservoir P is not limited to the detection by the capacitance type ink amount sensor 29, and it may be performed by another type of ink amount sensor. Further, the limit switch 49 is arranged so that when the piston member 21 moves backward by a predetermined amount or more and the internal volume of the ink reserve chamber 19 becomes a predetermined value or more, the switch operating plate 53 pushes the actuator 49a to perform a switching operation. May be. Further, the detection of the inner volume of the ink reserve chamber 19, in other words, the ink amount of the ink reservoir 15 is not limited to the detection by the limit switch 49. This is a photoelectric switch operation plate 53.
May be detected by detecting the position of the piston member 21 or the position of the piston member 21.

Further, in the ink supply device according to the present invention, the spigot mechanism provided inside the plate cylinder is not limited to the blade type, and it is disclosed in JP-A-55-55.
It may be of a roller type as shown in Japanese Patent No. 889.

[0030]

As can be understood from the above description, according to the ink supply device of the stencil printing apparatus of the present invention, the printing ink is temporarily stored inside the plate cylinder by the second ink supply pump from the ink tank outside the plate cylinder. The ink is sent to the ink reservoir and stored in the ink reservoir, and the printing ink stored in this ink reservoir is sent out to the squeegee mechanism by the first ink supply pump, which makes the ink supply amount control for the squeegee mechanism unstable. In this way, the ink supply capacity can be increased according to the capacity of the ink tank, and the number of prints that can be continuously printed without the need for replenishing the printing ink can be greatly increased without any trouble.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a stencil printing machine to which an ink supply device according to the present invention is applied.

FIG. 2 is a schematic view showing an embodiment of the ink supply device of the stencil printing machine according to the present invention.

[Explanation of symbols]

1 Stencil printer 3 Frame 5 Plate cylinder 7 Squeegee blade P Ink reservoir 9 Delivery pipe 13 In-body ink supply pump (first ink supply pump) 15 Ink reservoir 19 Ink reserve chamber 21 Piston member 27 In-body pump control device ( First ink supply pump controller) 29 Ink amount sensor 31 Ink tank 39 Outer cylinder ink supply pump (second ink supply pump) 47 Outer cylinder pump controller (second ink supply pump controller) 49 Limit switch

Claims (1)

[Claims] 1. A stencil sheet having a squeegee mechanism inside the plate cylinder having an ink permeation structure, and the printing ink is attached from the inner peripheral surface of the plate cylinder to the outer peripheral surface of the plate cylinder by the rotation of the plate cylinder. In an ink supply device of a stencil printing device configured to provide, an ink reservoir that is provided inside the plate cylinder and stores a predetermined amount of printing ink, and suctions the printing ink from the ink reservoir to transfer the printing ink to the squeegee. A first ink supply pump for supplying to the mechanism, a first ink supply pump controller for controlling the operation of the first ink supply pump so that the amount of ink in the squeegee mechanism is maintained at a predetermined value, and An ink tank which is provided outside the plate cylinder and stores a predetermined amount of printing ink, and a second ink which sucks the printing ink from the ink tank and supplies the printing ink to the ink reservoir. An ink supply pump and a second ink supply pump control device for controlling the operation of the second ink supply pump so that the ink amount in the ink reservoir is maintained at a predetermined value. Ink supply device for stencil printer.