JP3023033B2 - Ink supply unit for stencil printing machine - Google Patents

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 type stencil printing apparatus, a squeegee mechanism is provided inside a plate cylinder having an ink-permeable structure, and printing ink is supplied from the inner peripheral surface of the plate cylinder by the squeegee mechanism as the plate cylinder rotates. 2. Description of the Related Art Stencil printing apparatuses configured to apply a stencil sheet mounted on a surface are known.

The ink supply device in this type of stencil printing apparatus generally sucks a printing ink by an ink supply pump from an exchangeable ink tube attached to an ink tube installation portion provided inside the plate cylinder. The ink is supplied to the squeegee mechanism by pressure, and the ink amount in the squeegee mechanism is monitored by an ink amount sensor, and the operation of the ink supply pump is controlled so that the ink amount is maintained at a predetermined value. I have.

[0004]

In the above-described ink supply device, the ink tube, which is an ink reservoir, is provided inside the plate cylinder. Other mechanisms such as a squeegee mechanism to be installed,
It cannot be too large due to restrictions from the members.

For this reason, in the conventional ink supply apparatus 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 replenish the printing ink. It is impossible to greatly increase the number of prints that can be continuously printed without performing the above.

In response to this, it is conceivable to install a large-capacity ink tank outside the plate cylinder, suction printing ink from the ink tank by an ink supply pump, and pressure-feed the printing ink to a squeegee mechanism. When an ink tank is installed outside the plate cylinder, the ink supply capacity is no longer 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 provided. The passage length becomes longer, and accordingly, it is necessary to increase the discharge pressure of the ink supply pump.

If the length of the ink supply passage is long and the discharge pressure of the ink supply pump is high, the amount of ink supplied to the squeegee mechanism by turning on and off the ink supply pump is controlled by the inertia of the printing ink flowing through the ink supply passage. And the control of the amount of ink supplied to the squeegee mechanism becomes less stable than when printing ink is supplied to the squeegee mechanism from an ink tube provided in the plate cylinder.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the ink supply device of the conventional stencil printing machine, and has been made without making the ink supply amount control to the squeegee mechanism unstable. Ink supply capacity can be increased,
An object of the present invention is to provide an ink supply device of a stencil printing machine capable of greatly increasing the number of prints that can be performed in continuous printing without requiring a supply operation of printing ink.

[0009]

According to the present invention, a squeegee mechanism is provided inside a plate cylinder having an ink-permeable structure, and printing ink is supplied by the squeegee mechanism as the plate cylinder rotates. In an ink supply device of a stencil printing machine configured to supply a stencil sheet mounted on an outer peripheral surface of a plate cylinder from an inner peripheral surface, an ink reservoir provided inside the plate cylinder and storing a predetermined amount of printing ink. A first ink supply pump that sucks printing ink from the ink reservoir and supplies printing ink to the squeegee mechanism; and a first ink supply pump that maintains the ink amount in the squeegee mechanism at a predetermined value. A first ink supply pump control device for controlling operation of a pump, an ink tank provided outside the plate cylinder for storing a predetermined amount of printing ink, and suctioning printing ink from the ink tank A second ink supply pump for supplying printing ink to the ink reservoir, and a second ink supply pump for controlling the operation of the second ink supply pump so that the amount of ink in the ink reservoir is maintained at a predetermined value. The present invention is achieved by an ink supply device of a stencil printing machine having a control device.

[0010]

According to the above construction, 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 stored in the ink reservoir, and is stored in the ink reservoir. The printing ink is sent to the squeegee mechanism by the first ink supply pump.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 1 shows an embodiment of a stencil printing apparatus to which the ink supply apparatus according to the present invention is applied. In FIG. 1, reference numeral 1 denotes a stencil printing apparatus, and the stencil printing apparatus 1 is used by being mounted on a gantry 3. Stencil printing machine 1
The stencil sheet is wound around and mounted on the outer peripheral surface, and has a plate cylinder 5 having a cylindrical ink transmission structure, which can be replaced in a unit state. The exchange of the plate cylinder 5 is performed in a drawer type, and the structure may be the same as that shown in Japanese Patent Application Laid-Open No. 59-12893, for example.

As shown in FIG. 2, a squeegee blade 7 is provided in the plate cylinder 5. The squeegee blade 7 is in sliding 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 rotation direction.

A delivery pipe 9 for supplying printing ink to the ink reservoir P is arranged in the plate cylinder 5. The delivery pipe 9 is connected to the cylinder arranged in the plate cylinder 5 by an ink supply hose 11. It is connected to a discharge port of an 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 disposed at a position where an ink tube (ink bottle) is originally disposed instead of the ink tube. The ink reservoir 15 has a cylindrical reservoir container 16 having the same shape as the ink tube, and an end wall of the reservoir container 16 which is provided so as to be inscribed in the reservoir 16 so as to be movable in the axial direction in the reservoir 16. 17 and ink reserve chamber 1
And a piston member 21 for defining the ink jet pump 9.
3 is connected to the inlet. Printing ink is supplied to the ink reserve chamber 19 from an ink supply port 25 formed in the piston member 21, and the printing ink is sucked out from the ink outlet 23 by the operation of the in-cylinder ink supply pump 13, and is supplied to the ink supply hose 11. By delivery pipe 9
To be sent out.

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 on the amount of printing ink in the ink fountain P by a capacitance type ink amount sensor 29 that detects the amount of printing ink in the ink fountain P. When the amount is equal to or less than a predetermined value, the in-cylinder ink supply pump 13 is turned on, and when the amount of printing ink in the ink reservoir P is equal to or more than the predetermined value, the on-off ink supply pump 13 is turned on and off. Has become.

The gantry 3 is provided with an ink tank 31 which can be pulled out (see FIG. 1). The ink tank 31 is provided with an ink filling cap 33 and an ink outlet 35, and the ink outlet 35 is connected to a hose 37 by an outer ink supply pump 39 (second ink supply pump).
Connected to the suction port.

The external ink supply pump 39 is provided in the vicinity of the position where the ink tank 31 is disposed, that is, outside the plate cylinder 5. The discharge ports of the external ink supply pump 39 are interconnected by a joint 41. Ink supply hose 4
3, 45, the ink supply port 2 of the ink reservoir 15
5 and is adapted to feed the printing ink to the ink supply port 25 under pressure.

The operation of the extra cylinder ink supply pump 39 is controlled by an extra cylinder pump controller (second ink supply pump controller) 47. The external pump control device 47 is supplied with an ON / OFF signal from a limit switch 49, and performs ON / OFF control of the external ink supply pump 39 in response thereto.

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 integral with the piston member 21.
When the piston member 21 moves forward by a predetermined amount or more and the internal volume of the ink reserve chamber 19 becomes a predetermined value or less, the actuator 49a is pushed by the switch operation plate 53. Outputs an ON signal, and at other times, the pressing of the actuator 49a is released and an OFF signal is output.

In this case, the extracorporeal pump control device 47
Is configured to turn on the outside ink supply pump 39 by receiving an ON signal from the limit switch 49, and to turn off the outside 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 table 59 which is pivotally mounted at one end to a tank base 55 by a pivot 57. The tilting tank base 59 has a spring 6
1, the ink tank 31 filled with a required amount of printing ink is placed in the ascending direction, and the weight of the ink tank 31 against the spring force of the spring 61 causes the rotating position as shown in the drawing. To descend. The tilting tank base 59 is rotated in the upward direction by the spring force of the spring 61 due to the decrease in the amount of printing ink in the ink tank 31, and when the amount of printing ink in the ink tank 31 becomes equal to or less than a predetermined value, the position of the ink tank 31 is increased. Is turned on. The limit switch 63 turns on and off an electric circuit of a warning lamp 67 including a power supply 65. As a result, the warning lamp 67 turns on the limit switch 63 when the amount of printing ink in the ink tank 31 falls below a predetermined value. Is turned on to inform that the amount of printing ink in the ink tank 31 has fallen below a predetermined value.

According to the above-described configuration, the operation of the in-cylinder ink supply pump 13 is controlled as described above by the in-cylinder pump control device 27 in accordance with the amount of printing ink in the ink reservoir P detected by the ink amount sensor 29. As a result, the printing ink in the ink reservoir 19 of the ink reservoir 15 is sucked out from the ink outlet 23, sent to the delivery pipe 9 through the ink supply hose 11, and flows out of the delivery pipe 9 to flow out of the ink reservoir P. Supplied to As a result, the amount of printing ink in the ink pool P is maintained at a predetermined value.

The supply of printing ink to the ink reservoir P by the in-cylinder ink supply pump 13 is performed with good responsiveness 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-cylinder ink supply pump 13 does not have to be very high.

When the printing ink in the ink reservoir 19 is sucked out, the piston member 21 moves forward, and when the internal volume of the ink reservoir 19, that is, the amount of printing ink in the ink reservoir 15 becomes a predetermined value or less, the switch operation plate 53
As a result, the actuator 53a of the limit switch 49 is pressed, and the limit switch 49 is turned on.

Thus, the operation of the external ink supply pump 39 is controlled by the external pump control device 47, and the printing ink in the ink tank 31 is passed through the ink supply hoses 43 and 45 by the external ink supply pump 39 and supplied to the ink supply port. From 25, the ink is sent to the ink reservoir 19 of the ink reservoir 15, and the ink reservoir 19 is supplied with printing ink.

In response to the supply of the printing ink, the piston member 21 retreats, and the pressing of the actuator 53a of the limit switch 49 by the switch operation plate 53 is released. Actuator 5 of limit switch 49
3a is released, the extra-cylinder ink supply pump 39
Is stopped, and the supply of the printing ink from the ink tank 31 to the ink reserve chamber 19 is stopped. As a result, the state where a predetermined amount of printing ink is present in the ink reservoir chamber 19 of the ink reservoir 15 is maintained as long as the printing ink in the ink tank 31 is not completely 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, but may be performed by another type of ink amount sensor. 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 operation plate 53 presses the actuator 49a to perform a switching operation. You may. Further, the detection of the inner volume of the ink reservoir chamber 19, in other words, the amount of ink in the ink reservoir 15 is not limited to the detection by the limit switch 49, and the detection of the amount of ink by the switch operation
And the position of the piston member 21 may be detected.

Further, in the ink supply device according to the present invention, the siege mechanism provided inside the plate cylinder is not limited to the blade type, but is described in Japanese Patent Application Laid-Open No. 55-55.
It may be of a roller type as disclosed in JP-A-889-89.

[0030]

As will be understood from the above description, according to the ink supply device of the stencil printing machine according to the present invention, the printing ink is temporarily supplied from the ink tank outside the plate cylinder to the inside of the plate cylinder by the second ink supply pump. It is sent to the ink reservoir and stored in the ink reservoir, and the printing ink stored in the ink reservoir is sent out to the squeegee mechanism by the first ink supply pump, so that the ink supply amount control to the squeegee mechanism becomes unstable. Therefore, the ink supply capacity can be increased in accordance with the capacity of the ink tank, and the possible number of continuous prints that does not require the printing ink replenishment operation can be greatly increased without any trouble.

[Brief description of the drawings]

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

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

[Explanation of symbols]

REFERENCE SIGNS LIST 1 stencil printing machine 3 gantry 5 plate cylinder 7 squeegee blade P ink reservoir 9 delivery pipe 13 internal ink supply pump (first ink supply pump) 15 ink reservoir 19 ink reserve chamber 21 piston member 27 internal 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)

(57) [Claims] 1. A squeegee mechanism is provided inside a plate cylinder having an ink-permeable structure, and the squeegee mechanism applies printing ink to the stencil sheet mounted on the outer peripheral surface of the plate cylinder from the inner peripheral surface of the plate cylinder as the plate cylinder rotates. In an ink supply device of a stencil printing machine configured to supply the printing ink, an ink reservoir is provided inside the plate cylinder and stores a predetermined amount of printing ink, and the printing ink is sucked from the ink reservoir to discharge the printing ink into the squeegee. A first ink supply pump for supplying to a mechanism, a first ink supply pump control device for controlling the operation of the first ink supply pump such that the amount of ink in the squeegee mechanism is maintained at a predetermined value, and An ink tank provided outside the plate cylinder and storing a predetermined amount of printing ink, and a second ink tank for sucking the printing ink from the ink tank and supplying the printing ink to the ink reservoir. Ink supply pump, and a second ink supply pump control device 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. Stencil printing machine ink supply device.