JP2625435B2 - Stencil printing machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a plate making section for making a plate on a roll-shaped heat-sensitive stencil sheet, a cutting section for cutting the roll-shaped stencil sheet, and a pre-formed heat-sensitive stencil sheet wound around its periphery. The present invention relates to a stencil printing machine having a printing drum unit to be replaced, a printing drum attaching / detaching unit that can be detachably slid to replace the printing drum, and a printing pressure unit that presses a printing sheet against the outer peripheral surface of the printing drum with a press roller.

(Prior art)

A stencil-type stencil printing machine of the type that makes a stencil on a roll-shaped heat-sensitive stencil sheet, cuts it and automatically winds it around the outer periphery of the printing drum, and presses the fed paper to the outer periphery of the printing drum with a press roller to obtain printed matter. Already known. At the same time, a system in which the printing drum unit is detached and replaced for color change is already known.

However, in the conventional plate-making printing apparatus as described above,
The base paper cutting length is always constant, and is determined irrespective of the size of a document to be used or the size of printing paper.

By the way, it is known that when printing a small number of copies using such a printing machine, the base paper cost has the greatest effect on the printing cost per sheet.

For this reason, it is required that the length of the base paper used for one plate making be as short as possible.

However, in a conventional machine, even when performing postcard-size plate-making printing, a base paper having the same size as that used in plate-making printing of B4 size or larger is used, which is extremely wasteful. Especially in the case of a machine with a printing area of A3, every time a user who mainly prints A4 size paper
A4 size base paper must be used for A4 size printing, which is a great waste of base paper.

〔Purpose〕

The present invention has been made based on such a background, and overcomes the above-mentioned disadvantages of the prior art. In the case of a small-sized print, it is only necessary to replace the print drum for the small-size print. An object of the present invention is to provide a stencil type stencil printing apparatus capable of automatically reducing the length of a stencil used and reducing the cost of the stencil.

〔Constitution〕

In order to achieve the above object, the present invention provides a determining device for determining a type of a printing drum mounted on an apparatus main body, and controlling a cutting unit in accordance with the type of the printing drum determined by the determining device to extract the drawn drum. Cutting length adjusting means for changing and adjusting the cutting length of the perforated heat-sensitive stencil sheet, preferably controlling the printing pressure section according to the type of printing drum determined by the determining means, The printing apparatus further includes a printing pressure period adjusting unit that changes and adjusts a printing pressure period in which the sheet fed from the sheet feeding unit is pressed against the outer peripheral surface of the printing drum by the pressing unit.

 Hereinafter, examples of the present invention will be described.

FIG. 1 is a schematic diagram of a plate-making printing apparatus according to the present invention.
This configuration and operation will be described.

Reference numeral 1 denotes a stencil sheet wound in a roll, and reference numeral 2 denotes a thermal head for perforating and making a stencil sheet. Reference numeral 3 denotes a platen roller for transporting the base paper 1 while pressing the base paper 1 against the heating element of the thermal head 2, and reference numeral 4 denotes a cutter for cutting the base paper. Reference numeral 5 denotes a clamper 11 for the printing drum 10
This is a plate feeding roller for guiding the user.

The thermal head 2 perforates the stencil sheet 1 based on an image signal sent from a scanner (not shown).

The leading edge of the pre-processed base paper is
The drum 10 rotates in the direction of the arrow in the drawing while the stencil making is continued, and the base paper is wound around the outer periphery.
The feed amount of the base paper is controlled by a pulse motor 6 for driving the platen roller 3. When a predetermined amount of feed is completed based on a command from the control device, a cutter drive motor 7 rotates the eccentric cam 8 to rotate the cutter 4. To cut the base paper. Then, the drum 10 completes the winding of the stencil sheet and completes the stencil making, thereby completing the stencil feeding.

The printing drum 10 has a cylindrical plate cylinder 12 having a porous structure, an ink supply roller 13 inscribed in the plate cylinder 12 and supplying printing ink to the inner wall of the plate cylinder, and an ink reservoir 14 between the ink supply roller 13 and the ink reservoir 14. The drum unit is composed of a doctor roller 15 and the like, which are provided so as to make the drum unit.In addition to this, a drum unit is formed by combining with an ink supply container, an ink supply pump, and the like. It can be attached to and detached from the machine body by sliding.

The details of the drum attaching / detaching mechanism are disclosed in Japanese Utility Model Application Laid-Open No. 61-85462 by the same applicant.

The printing paper 20 is stacked on the paper feed table 21 and fed one by one from the uppermost one by the rotation of the paper feed roller 22, and is reliably separated into only one sheet between the separation roller 23 and the separation blade 24. To the feed roller pair 25.

The feed roller pair 25 rotates at a timing synchronized with the rotation of the drum 10 to transfer the paper 20 to the drum 10 and the press roller.
Send between 30 and. The press roller 30 swings around an axis 31 according to a printing pressure cam (not shown) to drum the printing paper 20.
Press toward 10. As a result, the ink passes along the apertures of the stencil paper wound around the drum 10, and the ink is transferred to the printing paper 20 to form a printed image.

The printed paper is conveyed by a paper discharge conveyance belt 32 and is accumulated on a paper discharge tray 33.

The used base paper is stripped of its rear end from the outer periphery of the drum by a plate discharge roller 34, is conveyed to the plate discharge roller 35 at the same time as the drum is reversed, and is stored in a plate discharge storage box 36.

Next, how the cutting length of the base paper is determined will be described.

There are two types of drum units, A3 and A4. FIG. 2 is a partially developed view of the plate cylinder 12 of the drum unit for A3, and FIG. 3 is a partially developed view of the plate cylinder 12 of the drum unit for A4. Reference numeral 11 denotes a base paper clamper, which locks the front end of the base paper.

The print image length of the drum unit for A3 is 410 mm,
Therefore, the plate making length A of the base paper is also 410 mm. The printing pressure length B is a length within a range in which the press roller 30 presses the printing paper, and is slightly larger than the plate making length A and is about 430 mm. The length C of the opening of the cylindrical plate cylinder 12 is also about 430 mm. Reference numeral 16 denotes a mesh screen wound around the outer periphery of the cylindrical plate cylinder 12.
The cylindrical plate cylinder 12 is made of a thin metal plate, and has countless small holes having a diameter of about 0.5 mm in a predetermined range for ink transmission. This is a so-called opening area.

The base paper length D is obtained by adding the leading margin E and the trailing margin F to the printing pressure length B. The leading margin E is approximately 80 mm, and the trailing margin F is approximately 20 mm. Is about 530mm.

The print image length of the A4 drum unit is 200 mm,
Accordingly, the plate making length A 'of the base paper is also 200 mm. The printing pressure length B 'is slightly larger than A' and about 220 mm. Cylindrical plate cylinder 12
Has a hole length C 'of about 220 mm. The leading margin E and the trailing margin F are the same as in the case of the A3 drum unit, E is approximately 80 mm, F is approximately 20 mm, and the base paper length D 'is 320 mm.

FIG. 4 is a plan view showing the printing area of the A3 drum unit and the printing area of the A4 drum unit.

That is, the A3 sheet passes in the vertical direction, but the A4 sheet passes in the horizontal direction. B5 size paper is passed in the horizontal direction and the A4 drum unit is used.

 FIG. 5 is a block diagram showing an outline of the control.

When the A3 drum unit 17a is mounted on the machine, the drum unit sensor 40 detects this, and the machine control device 41 controls the platen roller drive pulse motor 6 and cutter drive motor 7 according to the program. Then, the base paper is conveyed and cut so that the base paper cutting length is approximately 530 mm.

At the time of printing, the printing pressure cam switching motor 42 is operated to switch the cams so that the printing pressure length becomes about 430 mm.

When the A4 drum unit 17b is mounted on the machine, the drum unit sensor 40 detects this, and the machine controller 41 controls the platen roller drive pulse motor 6 and the cutter drive motor 7 according to the program. It works to make the base paper cutting length approximately 320 mm. When printing, the printing pressure cam is switched so that the printing pressure length is about 220 mm.

Thus, by using the device according to the present invention, provisional instructions,
If you want to print an A4 or smaller print image on a plate-making printing press with an A3 size image area, simply replace the machine's drum unit with an A4 drum unit and save more than 200 mm of base paper per plate. Since the printing is performed, not only the printing cost per sheet is reduced, but also the number of editions of one roll base paper is increased, so that the frequency of troublesome roll base paper replacement is reduced and Since the amount of discarded ink also decreases, the amount of ink used also decreases in total.

 FIG. 6 shows an embodiment of the detection of the drum unit.

The drum unit 17 has one small magnet 18 attached thereto. When the drum unit is set in the machine body, two Hall element sensors (drum unit sensors) are provided at positions opposing the magnet 18 of the machine body. Sensor) 40 is provided.

The position of the magnet differs depending on the type of the drum unit. In the case of the A3 drum unit 17a, the position of the magnet is on the upper side, and in the case of the A4 drum unit 17b, it is on the lower side.

Accordingly, of the two Hall element sensors, the drum unit for A3 can be detected when the upper side is turned on, the drum unit for A4 can be detected when the lower side is turned on, and no drum can be detected when both are off.

 Next, FIG. 7 shows an embodiment of switching the printing pressure cam.

FIG. 8 is a sectional view taken along line GG of FIG. The press roller 30 is rotatably supported by an arm 50, and the arm 50 can swing about a shaft 51 and is pressed by a spring 52.
Are urged in a direction to be pressed against the printing drum 10. At the other end of the arm 50, a cam follower 53 is rotatably supported, and the cam follower 53 moves up and down along the outer peripheral surface by the rotation of the cam plate set 54 so that the printing pressure is applied or released. It has become. Cam plate set 54 is 2
Consists of a cam plate 54a and 54b, 54a is for A3 drum 54b
Is for A4 drums.

The cam plate set 54 is fixed in the rotation direction with respect to the cam shaft 55, and is slidable in the thrust direction (axial direction). The printing pressure cam switching motor 56 rotates the screw shaft 57 according to a command from the control device. Then, the slider 58 meshed with the screw shaft 57 moves in the axial direction because its rotation is regulated by the shaft 59, and when the slider 58 moves, the cam plate set 54 also moves in the axial direction, thus the cam follower.
It is possible to switch between a cam plate 54a in contact with 53 and a cam plate 54b. For a 54a cam plate, the printing pressure length is 430mm, and for a 54b cam plate, the printing pressure length is 220mm. Here, the correspondence between the components of the present invention and the functional elements of the present embodiment will be described. The press roller 30 in the present embodiment serves as the pressing means in the present invention, and similarly, the press roller 30 and the printing pressure cam or Arm 50, spring 52, cam follower 53, cam plate set 54, cam shaft 55
The control device 41 and the control device 41 serve as the discriminating means, the control device 41 serves as the cutting length adjusting means, and the cam plate set 54, the printing pressure cam switching motor 56, the screw shaft 57, the slider 58 and the shaft 59 serve as the printing pressure period adjusting means. Each corresponds.

〔effect〕

As described above, according to the first aspect of the present invention, the type of the printing drum mounted on the apparatus main body is determined, and the plate making drawn out according to the determined type of the printing drum is determined. The cutting length of the heat-sensitive stencil base paper is changed and adjusted, so that waste of base paper consumption when forming small-sized printed matter is eliminated, and the consumption efficiency per roll paper is greatly improved. be able to.

According to the invention described in claim 2, the printing pressure period is changed and adjusted according to the type of the print image length of the print drum mounted on the apparatus main body. Can be pressed against the outer peripheral surface of the printing drum for a period necessary for printing, so that it is possible to prevent the sheet from being stained due to the ink adhering to the margin.

[Brief description of the drawings]

FIG. 1 is a schematic view of a plate-making printing apparatus to which the present invention is applied, FIGS. 2 and 3 are partial development views of plate cylinders of A3 and A4 drum units, respectively, and FIG. Plan view,
FIG. 5 is a block diagram of the cutting control of the base paper length according to the present invention, FIG. 6 is a diagram showing an example of a mechanism for detecting the type of drum, FIG. 7 is a front view showing a switching mechanism of the printing pressure cam, FIG. 8 is a sectional view taken along the line GG. 1 ... stencil paper, 4 ... cutting section, 10 ... printing drum, 30
...... Press roller.

Claims (2)

(57) [Claims] 1. A plate making section for drawing a roll of heat-sensitive stencil sheet and making a plate with a heat-sensitive head, a cutting section for cutting the drawn plate made of heat-sensitive stencil sheet to a predetermined cutting length, and an ink inside. A supply mechanism, a plurality of types of printing drums corresponding to different print image lengths around which the heat-sensitive stencil sheet cut in the cutting section is wound around the outer circumference thereof, and a different type of printing drum which is detached from the apparatus main body to detach the printing drum. A print drum attaching / detaching section configured to be exchangeable with the print drum, a paper feed section for feeding a cut sheet, and a press drum outer peripheral surface of a sheet fed from the paper feed section by pressing means A stencil printing machine having a printing pressure unit for pressing the printing drum against the printing drum, a determining unit for determining the type of the printing drum mounted on the apparatus main body, and the printing drum determined by the determining unit. Of controlling the cutting unit in accordance with the type, the stencil type plate-making printing machine, characterized in that the cut length of the heat-sensitive stencil sheet having a cut length adjusting means for changing adjustment. 2. A stencil section for drawing a roll-shaped heat-sensitive stencil sheet and performing plate making by a heat-sensitive head; a cutting section for cutting the drawn-out heat-sensitive stencil sheet to a predetermined cutting length; A supply mechanism, a plurality of types of printing drums corresponding to different print image lengths around which the heat-sensitive stencil sheet cut in the cutting section is wound around the outer circumference thereof, and a different type of printing drum which is detached from the apparatus main body to detach the printing drum. A print drum attaching / detaching section configured to be exchangeable with the print drum, a paper feed section for feeding a cut sheet, and a press drum outer peripheral surface of a sheet fed from the paper feed section by pressing means A stencil printing machine having a printing pressure unit for pressing the printing drum against the printing drum, a determining unit for determining the type of the printing drum mounted on the apparatus main body, and the printing drum determined by the determining unit. Cutting length control means for controlling the cutting section in accordance with the type of the printing drum to change and adjust the cutting length of the heat-sensitive stencil sheet; and the printing pressure section in accordance with the type of the printing drum determined by the determination means. And a printing pressure period adjusting means for changing and adjusting the printing pressure period in which the sheet fed from the paper feeding unit is pressed against the outer peripheral surface of the printing drum.