JPH05124327A - Stencil printing device - Google Patents

Abstract

PURPOSE:To obtain a stencil printing device capable of reducing residual ink which sticks to a stencil sheet or accumulates in an area between the peripheral surface of a plate cylinder and a mesh screen after being supplied from an ink feed part, and thereby minimizing ink consumption. CONSTITUTION:A stencil printing device is equipped with an ink feed means which presses a printing sheet P transported in a tangential direction of a cylindrical plate cylinder 1, on the peripheral surface of which a stencil sheet 3 is deposited, using a pressing means consisting of a press roller 14 installed on the peripheral surface of the plate cylinder 1, and feeds printing ink to an ink roller 5 which comes in contact with the inner circumferential surface of the plate cylinder 1. In addition, this stencil printing device is equipped with an information generation means 21 which generates information, if the remaining number of unused printing sheets P reaches a specified limit, and a control member 11 which controls the amount of ink supply to the ink roller 5 based on information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing machine for winding a perforated base paper on a plate cylinder for printing.

[0002]

2. Description of the Related Art In a stencil printing machine, a stencil document is mounted on the outer peripheral surface of a cylindrical plate cylinder, the ink for printing is uniformly supplied to an ink roller located inside the plate cylinder, and the roller is used to plate the plate. Ink is supplied through the holes of the plate cylinder, the screen layer, and the stencil original by contacting with the inner peripheral surface of the cylinder, and the press roller presses the paper to perform printing. In such a device, the printing ink supplied is pressed by the press roller, transferred to the paper and consumed sequentially, but in order to prevent ink shortage, more ink is supplied than the ink consumed for printing. ing.

Therefore, excess ink is accumulated as excess ink on the back side of the stencil sheet or screen, that is, between the outer peripheral surface of the plate cylinder and the stencil sheet. When a predetermined number of sheets have been printed, the base paper is peeled off from the plate cylinder and discarded, but at this time, since a large amount of excess ink is attached to the base paper, the attached excess ink is wasted. It will be. In particular, when the number of printed sheets is small, the supplied ink is larger than the consumed ink, and the ink is wasted. In addition, if the stencil sheet is left on the plate cylinder, the ink components may volatilize, causing a shortage of ink on the plate cylinder.

In such a case, it is necessary to fill the ink, and one example thereof is Jitsukai Sho 61-78671.
It is known to fill ink with an ink supply device or the like described in No.

[0005]

When the ink supply device runs out of ink, this ink supply device accelerates ink filling by temporarily increasing the pressing force of the ink roller and the ink supply amount. In the case of the ink supply means, it is possible to improve the ink filling, but the problem that the amount of surplus ink adhering to the peeling base paper cannot be reduced remains unsolved.

[0006]

Therefore, in the present invention, a cylindrical plate cylinder on the outer peripheral surface of which a stencil sheet is mounted, and a plate which presses a sheet conveyed in the tangential direction of the plate cylinder against the plate cylinder. In a stencil printing apparatus having a pressing means composed of a press roller arranged to face the outer peripheral surface of the cylinder, an ink roller contacting the inner surface of the plate cylinder, and an ink supply means for supplying ink to the outer peripheral surface of the ink roller. An information generating means for generating information when the remaining number of prints of the paper reaches a predetermined number and a regulating member for regulating the ink supply amount to the ink roller based on the information.

[0007]

Since the information generating means for generating information when the remaining number of printing sheets reaches the predetermined number and the regulating member for regulating the ink supply amount to the ink roller based on the information are provided. When the remaining number of printing sheets reaches a predetermined number, the information from the information generating means is transmitted to the regulating member, and the ink supply amount to the ink roller is regulated.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes a cylindrical plate cylinder having an opening 1a perforated as an ink passage and a mesh screen 2 wound around an outer peripheral surface thereof. 1 is driven to rotate clockwise in the figure by a drive motor (not shown).

A clamper 4 for locking the stencil sheet 3 is mounted on the outer peripheral surface of the plate cylinder 1 where there is no aperture 1a,
The stencil sheet 3 whose one end is locked by the clamper 4 is held in close contact with the outer peripheral surface of the plate cylinder 1 by the viscosity of the printing ink.

Inside the plate cylinder 1, an ink roller 5, a doctor rod 6 as an ink supply means and an ink supply pipe shaft 7 are arranged. The ink roller 5 is rotatably supported by a pair of support plates 8 (only one of which is shown in the figure) supported by the ink supply pipe shaft 7, and the axial dimension thereof is slightly smaller than that of the plate cylinder 1. It is arranged slightly apart from the inner peripheral surface of the cylinder 1, and is rotationally driven in the same direction as the plate cylinder 1 by a driving unit (not shown).

The doctor rod 6 is rotatably supported above the ink roller 5 by an eccentric shaft 6a with a constant clearance from the outer peripheral surface thereof, and is formed on a V portion 6b sandwiched between the rod 6 and the ink roller 5. An ink fountain is formed.

An ink supply pipe shaft 7 having an opening 7a directed downward is disposed above the doctor rod 6, and the ink supply pipe 7 extends from the opening 7a to the ink roller 5.
Supply printing ink to.

A doctor rod lever 9 is fixed to one end of the eccentric shaft 6a of the doctor rod, and the lever 9 is connected to a movable piece 11a of a solenoid 11 via a link 10.

The solenoid 11 is of the PULL type which is connected to the CPU 23 shown in FIG. 4 and pulls in the movable piece 11a when energized by an operation signal from the CPU 23. The link 10 is held in a state of being pressed against the stopper 13 by the compression spring 12 so as to maintain a gap between the doctor rod 6 and the ink roller 5 when the power is not supplied.

When the doctor rod 6 is in this state, a certain amount of printing ink is supplied to the ink roller 5 from the gap, and when the energization is performed, the doctor rod 6 is brought close to the ink roller 5 by retracting the movable piece 11a, and the ink is ejected. The supply has been significantly reduced or cut.

Here, the operation signal of the solenoid 11 will be described. This operation signal is a signal issued from the CPU 23 when the preset remaining number of prints is reached. In the present embodiment, the operation signal is issued when the remaining number of prints reaches 5. That is, the operation signal is the "ink cut command signal".

On the other hand, below the plate cylinder 1, there is a press roller 14 that faces the outer peripheral surface of the plate cylinder 1 with the plate cylinder 1 interposed therebetween.
5 is rotatably supported by one end 16a of an arm 16 rotatably supported by the arm 5, and can be brought into and out of contact with the stencil sheet 3 wound around the plate cylinder 1 as the arm 16 rotates. ing.

An end 17a of a coil spring 17 for pressing the press roller 14 toward the plate cylinder 1 is attached to the other end 16b of the arm 16, and the other end 17b of the coil spring 17 is connected to a stepping motor 18 (hereinafter, referred to as a stepping motor 18). S
It is connected to a drive shaft 18a of the P motor 18).

The SP motor 18 is connected to the CPU 23 via the motor driver 22 shown in FIG. And
When a printing sheet is conveyed between the press roller 14 and the plate cylinder 1 from a sheet feeding device (not shown), it rotates normally and reverses when the printing is completed. The rotation is regulated.

As shown in the enlarged view of FIG. 2, the drive shaft 18a is formed with a threaded portion 19, while the other end 1 of the spring is formed.
7b is provided with a nut portion 20 that is screwed into the screw portion 19, and the nut portion 20 moves along the screw portion 19 on the drive shaft 18a by the operation of the SP motor 18 to adjust the tension of the spring 17. .. That is, when the SP motor 18 rotates forward, the nut portion 20 moves along the threaded portion 19 of the motor 18.
Side to increase the tension of the spring, press roller 1
4 is pressed to the outer peripheral surface side of the plate cylinder 1.

A micro SW 21 for detecting the initial position of the spring 17 is provided on the side of the other end 17b of the spring. When the micro SW 21 operates, the reverse rotation of the SP motor 18 is stopped. That is, when the motor 18 rotates in the reverse direction and the coil spring 17 reaches the initial position, the micro SW 21 operates to hold the spring 17 at the initial position.

According to the stencil printing apparatus having the above structure, a printing instruction is issued and the plate cylinder 1 and the ink roller 5 rotate. Then, the opening portion 1a, which is the ink passage portion, has the plate cylinder 1
When it reaches the contact area between the press roller 14 and the press roller 14, the printing paper timed by a paper feeding device (not shown)
And the press roller 14. Then SP
When the motor 18 rotates forward, the nut portion 20 moves to the motor 18
To the side, the spring tension increases and the press roller 1
4 moves from the standby state shown by the two-dot chain line to the position of the solid line. Then, the roller 14 presses the printing paper P against the plate cylinder 1, and the inner peripheral surface of the plate cylinder 1 is pressed by the pressing to the ink roller 5.
Printing is performed on the printing paper P with the printing ink that has been pressed against the outer peripheral surface of the sheet and has passed through the plate cylinder 1.

When the remaining number of prints reaches the set number,
The solenoid 11 operates to bring the doctor rod 6 close to the ink roller 5, narrowing the ink passage and reducing or cutting the ink supply amount. When the number of printed sheets reaches the set number, the solenoid 11 is de-energized,
In preparation for the next printing, the doctor rod 6 is returned to the position before the movement.

On the other hand, the SP motor 18 has a printing paper P.
Rotate forward according to the paper feed timing of the press roller 1
4 is pressed against the stencil sheet 3, and when the printing is completed, the stencil sheet 3 is rotated in the reverse direction, the tension of the spring 17 is weakened, and the press roller 14 is separated from the sheet 3. At this time, when the spring 17 moves and returns to the initial position and the micro SW 21 operates, the reverse rotation is stopped and the press roller 14 is held at the standby position shown by the chain double-dashed line in FIG.

When the remaining number of prints reaches the set number, the amount of one rotation of the motor 18 increases, the tension of the spring 17 increases, and the pressing force of the press roller 14 increases.

At this time, the supply of the printing ink is cut off by the action of the solenoid 11, but the surplus ink that has been supplied and is not used up is collected on the back surface of the base paper 3 and between the plate cylinder 1 and the mesh screen 2. Press roller 14
By increasing the pressing force of, the ink can be used for printing after the ink cut.

The present inventor constructed a stencil printer "Preport VT2300" manufactured by Ricoh Co., Ltd. in the same manner as in this example, and conducted an experiment to obtain data as shown in FIG.

In the experiment, the ink supply amount from the ink supply pipe shaft 7 was made constant, and the image density was measured when the pressing force of the press roller 14 was constant with respect to the remaining number of prints, and when the image density was increased. Indicates the print density, the horizontal axis indicates the number of remaining prints, the solid line indicates the image density when the pressing force of the press roller 14 is constant, and the dashed line indicates the image density when the pressing force of the press roller 14 is increased according to the number of remaining prints. Shown respectively.

According to this experiment, the ink supply to the ink roller 5 was cut when the remaining number of prints was about 5,
By increasing the pressing force of the press roller 14 accordingly, it is possible to obtain substantially the same image density as when the ink is supplied.

[0030]

As described above, according to the present invention, the amount of excess ink to be discarded can be reduced, so that the ink accumulation can be suppressed and the malfunction of the excess ink or the contamination of the equipment due to the excess ink scattering can be prevented. Can be done. Also,
Since the pressing force of the press roller is increased according to the remaining number of prints, it is possible to keep the density of the printed image by the excess ink constant, the consumption of the excess ink is further promoted, and a stencil printing machine with less ink consumption can be provided. ..

[Brief description of drawings]

FIG. 1 is a schematic side view showing a configuration of a stencil printing apparatus of the present invention.

FIG. 2 is an enlarged view of a press roller pressing unit shown in FIG.

FIG. 3 is experimental data showing an image density of a printed matter due to a change in the pressing force of the press roller with respect to the remaining number of prints.

FIG. 4 is a block diagram showing an outline of control of the present invention.

[Explanation of symbols]

 1 plate cylinder 3 stencil sheet 5 ink roller 7 ink supply means 11 regulating member (solenoid) 14 press rollers 15, 16, 17, 18 pressing means 21 information generating means (CPU) P printing paper

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[Procedure amendment]

[Submission date] December 6, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

The Stencil mark device, the stencil original paper is mounted on the outer peripheral surface of the cylindrical printing drum, and uniformly supplies the ink for printing the ink rollers located inside the plate cylinder, the same roller opening of the plate cylinder by contacting the plate cylinder inner peripheral surface, a screen layer, the ink is fed through the stencil original paper, printing by pressing the paper press roller has been made. In such a device, the printing ink supplied is pressed by the press roller, transferred to the paper and consumed sequentially, but in order to prevent ink shortage, more ink is supplied than the ink consumed for printing. ing.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

At this time, the supply of the printing ink is cut off by the action of the solenoid 11, but the surplus ink that has been supplied and is not used up is collected on the back surface of the base paper 3 and between the plate cylinder 1 and the mesh screen 2. Press roller 14
By increasing the pressing force of, the ink can be used for printing after the ink cut. Example above
Now, adjust the tension of the spring 17 and press roller 1
4 was in contact with and separated from the plate cylinder 1, but the press roller 1
It is shown below that the contact and separation of No. 4 with the plate cylinder 1 is performed by a cam.
It is a second embodiment. It should be noted that the description of the second embodiment was made.
Which has the same function as that of the first embodiment
Are denoted by the same reference numerals, and description thereof will be omitted. Figure 5 Smell
The arm 16 has a substantially T shape, and one end 16a thereof is
Has a press roller 14 rotatably attached,
One end 17a of the coil spring 17 is attached to the lower end 16b.
The extension 16c is attached to the left side and extends to the left.
A roller 24 is pivotally supported in the. The coil ring 17 is
It is set to the tension required for normal printing press. In addition,
A step portion A is formed at the tip of the long portion 16c and
On one side, a swing lever 25 is rotatably supported.
The swing lever 25, as shown in FIG.
In a direction in which the press roller 14 is pressed against the plate cylinder 1 by engaging with
It prevents the arm 16 from rotating, and is normally used (when not printing).
Is pressed against the stopper 27 by the compression spring 26.
When the printing paper P is fed,
Direction of arrow by solenoid 30 connected to bar 25
Removed in the opposite direction. The solenoid 30 is the CPU 23 shown in FIG.
Connected to the CPU2, and the operation signal at the start of printing is the CPU2.
Sent from 3. On the other hand, below the roller 24,
A cam 29 that rotates in synchronization is provided. Cam 29
Has a substantially fan-like shape, and the large-diameter outer peripheral portion 29a has a roller 2
4, when the arm 16 contacts the coil spring 17,
Direction of separating the press roller 14 from the plate cylinder 1 against the elastic force
Slide on. The range of the large-diameter outer peripheral portion 29a is the opening of the plate cylinder 1.
It corresponds to the length of the outer peripheral surface where the hole 1a does not exist. SP model
When the remaining number of prints reaches the set number, the data 18
Rotate in the direction that increases the tension of the pulling 17 and reverse after printing is completed.
It is designed to rotate. Printing paper P is fed
When the solenoid 30 is activated, the swing lever 25 and the step A
Is disengaged and the press roller 14 prints the printing paper P.
The large-diameter outer peripheral portion 29 is pressed against the body 1 side and rotates with the cam 29.
When a contacts the roller 24, the press roller 14 is the plate cylinder 1
Separated from. Then, the number of prints reaches the specified number (5).
Then, the operation of the SP motor 18 causes the press roller 14 to move.
The pressing force is controlled. Press roller like this
Since the 14 contacting / separating means are provided separately, they are different from those of the first embodiment.
Do not rotate the SP motor 18 frequently to bring it into and out of contact
I'm done.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 5

[Correction method] Added

[Correction content]

FIG. 5 is a schematic side view showing the configuration of a stencil printing machine in which a second embodiment of the present invention is implemented.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 6

[Correction method] Added

[Correction content]

FIG. 6 is an enlarged view showing a main part of the second embodiment.

[Procedure Amendment 5]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Added

[Correction content]

[Figure 5]

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Added

[Correction content]

[Figure 6]

Claims (2)

[Claims] 1. A cylindrical plate cylinder on the outer peripheral surface of which a stencil sheet is mounted, and a print cylinder conveyed in the tangential direction of the plate cylinder, which is arranged so as to face the outer peripheral surface of the plate cylinder. In a stencil printing machine having a pressing means composed of a press roller, an ink roller that comes into contact with the inner surface of the plate cylinder, and an ink supply means that supplies ink to the outer peripheral surface of the ink roller, An stencil printing machine comprising: an information generating means for generating the information when the number of sheets reaches the number; and a regulating member for regulating the ink supply amount to the ink roller based on the information. 2. The stencil printing apparatus according to claim 1, wherein the pressing force of the press roller is increased according to the number of remaining printing sheets.