JP2784130B2 - Ink supply device 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 a stencil printing machine, and more particularly to an ink supply device provided inside a plate cylinder of a stencil printing machine.

[0002]

2. Description of the Related Art An ink supply device generally used in a stencil printing machine is provided with an ink roller which is disposed so as to be in contact with the inner peripheral surface of a porous cylinder and is rotatable in synchronization with the rotation of a plate cylinder.
A rotatable doctor roller disposed with a small gap with respect to the outer peripheral surface of the ink roller, and a wedge-shaped ink pool formed on the gap; Is supplied to the outer peripheral surface of the plate cylinder and transferred to the inner peripheral surface of the plate cylinder. The ink supplied to the inner peripheral surface of the plate cylinder is pressed by a pressing means such as a press roller provided opposite the plate cylinder to continuously print the printing paper on the pre-made base paper wound around the outer peripheral surface of the plate cylinder. Press
Printing is performed by exuding ink from the opening of the plate cylinder, the mesh screen, and the perforated portion of the base paper and transferring the ink to printing paper.

[0003] The bleeding of ink from the opening of the plate cylinder is as follows.
The slower the rotation of the plate cylinder, that is, the lower the rotation speed, the better, and the higher the rotation speed, the more difficult it is to exude due to the resistance of the apertures. As a result, the density of the printed matter is low at high speed, and high at low speed. Therefore, in the conventional ink supply device in which the gap between the ink roller and the doctor roller is held and fixed at a constant value and the ink supply amount is always constant, the above-described problem occurs. Therefore, in order to solve the above-mentioned problem, to reduce the amount of ink to be supplied at a low speed and increase the speed at a high speed to obtain a print having a stable density, for example, as disclosed in JP-A-61-108557,
The doctor roller (doctor rod) is urged by a spring means in the direction approaching the ink roller (squeegee roller). At high speed, the doctor roller is pushed up using the pressure rise due to the high-speed flow of the ink, and the ink film is thickened to increase the ink film thickness. At low speeds, use the pressure decrease due to the low-speed flow of ink to reduce the amount of push-up of the doctor roller, reduce the ink film thickness, reduce the amount of ink supply, and always try to obtain a print with a constant density. There is something to do.

[0004]

However, in the above technique, precise adjustments are required to equalize the pressing forces of the spring means provided on the left and right sides of the shaft portion of the doctor roller, and the operation is very troublesome. Yes, and the force with which ink tries to pass between the doctor roller and the ink roller varies greatly with the rotation speed of the ink roller (it is simply proportional to the square of the rotation speed when compared with the energy).
I do. Therefore, when the rotation speed of the ink roller is increased, the pushing force on the doctor roller is rapidly increased, so that the thickness of the ink becomes thick and the density of the printed matter becomes too high. There is a problem that only a film thickness can be supplied, and only a print having a low density can be obtained. In particular, a new stencil sheet for stencil printing is wound around the outer peripheral surface of the plate cylinder, the plate cylinder is rotated at an extremely low speed, and pressing means such as a press roller is pressed on the stencil sheet through the printing paper to form the stencil sheet. Fill the ink with
During the so-called printing process, there is a problem that several sheets of waste paper (scrap paper) are generated before the ink supplied to the pre-made base paper becomes insufficient and the image density becomes normal.

Accordingly, the present invention has been made in order to solve the above-mentioned problems, so that a printed matter having a substantially constant density can be obtained even when the rotation speed of the ink roller is changed, and a stencil printing plate which requires a small number of waste sheets in plate printing. An object of the present invention is to provide an ink supply device for a printing press.

[0006]

To achieve the above mentioned SUMMARY OF THE INVENTION The object, in the invention of claim 1, wherein a porous cylindrical plate cylinder, the plate cylinder is disposed on the inner peripheral surface of the plate cylinder A stencil having an ink roller rotatable in synchronization with the rotation of the ink roller, a doctor roller disposed with a small gap with respect to the outer peripheral surface of the ink roller, and a wedge-shaped ink reservoir formed on the gap. in the ink supply apparatus for a printing press, and a pair of arms for supporting at its free end the opposite ends of the shaft of the wiping roller, met supporting point shaft provided in the base end of the arm pairs
When viewed in the axial direction of the plate cylinder, it is movable in a direction in which an angle between a straight line connecting the ink roller axis and the doctor roller axis and a straight line connecting the doctor roller axis and the fulcrum axis changes.
Depending on the fulcrum axis and the pressure increase of the ink in the ink pool
Moving in the direction to increase the angle by the fulcrum axis
So that the above angle is reduced so that
And a biasing means provided in the fulcrum shaft for moving the serial fulcrum shaft, and setting the angle obtuse.

According to a second aspect of the present invention, a porous cylindrical plate cylinder, an ink roller disposed on the inner peripheral surface of the plate cylinder and rotatable in synchronization with the rotation of the plate cylinder, and the ink roller In a stencil printing machine ink supply device having a doctor roller arranged to hold a small gap with respect to the outer peripheral surface of the stencil and a wedge-shaped ink reservoir formed in the gap, the both ends of the shaft of the doctor roller are a pair of arms for supporting at its free end, met supporting point shaft provided in the base end of the arm pairs
When viewed in the axial direction of the plate cylinder, it is movable in a direction in which an angle between a straight line connecting the ink roller axis and the doctor roller axis and a straight line connecting the doctor roller axis and the fulcrum axis changes.
The fulcrum shaft and a movement holding means for selectively moving and holding the fulcrum shaft in a direction to decrease the angle are set, and the angle is set to an obtuse angle.

[0008]

The function of claim 1 will be described with reference to the accompanying drawings. As shown in FIGS. 5 and 7, a straight line L1 (shown by a dashed line) connecting the ink roller shaft 2a and the doctor roller shaft 3a when viewed from an end surface direction of a plate cylinder not shown, a doctor roller shaft 3a and a fulcrum shaft 5 are shown. Is set to an obtuse angle greater than 90 ° with a straight line L2 (shown by a dashed line) connecting the ink and the ink in the ink pool 6 in the same rotational direction as the ink roller 2. As a result, the pressure of the ink in the ink fountain 6 rises, and due to the rise in the pressure of the ink, F ′ acts on the doctor roller 3 in a tangential direction to the ink roller 2, and a component force F of F ′ is generated on the fulcrum shaft 5. . In addition, the fulcrum shaft 5
, A moment M1 which pushes up the doctor roller 3 in a counterclockwise direction acts. Further, a moving component F1 for moving the fulcrum shaft 5 upward in a movable direction is generated as a component of the force F. Due to the mass W of the doctor roller 3, a moment M2 for bringing the doctor roller 3 close to the ink roller 2 in a clockwise direction around the fulcrum shaft 5 and a moment M3 acting by a component F3 of F ′ act on the doctor roller 3 in the opposite directions. The doctor roller 3 stops at the position where the moment M1, the moment M2, and the moment M3 that act are balanced. When the rotation speed v of the ink roller 2 is low and the moving component force F1 is smaller than the urging force (set load) of the urging means, the fulcrum shaft 5 is restricted from moving, and the fulcrum shaft 5 stops at a fixed position. ing.

When the rotation speed v of the ink roller 2 increases to a certain rotation speed and the moving component force F1 becomes larger than the urging force (set load) of the urging means, the fulcrum shaft 5 causes the doctor roller 3 to move the doctor roller 3 to the ink roller 2. Move in the direction to increase the moment M3 acting to approach the doctor roller,
Is moved in a direction to reduce the ink film thickness of the ink roller 2. These moments M1 acting in opposite directions to each other
The doctor roller 3 stops at a point where the moment M2 and the moment M3 are balanced, and the ink film thickness supplied to the ink roller 2 is determined. Therefore, even if the pressure of the ink in the ink pool 6 increases due to the rotation speed v of the ink roller 2 and the force for pushing up the doctor roller 3 increases, the force F for pushing down the doctor roller 3 is obtained.
3 also increases in response to the rotational speed v of the ink roller 2, and the moments M1 in the opposite directions generated by these forces.
And the moment M3 cancel each other, the change in the gap between the ink roller 2 and the doctor roller 3 becomes small, and the thickness (not shown) of the ink roller supplied to the ink roller 2 sharply changes with the change in the rotation speed v of the ink roller 2. Will not change.

As shown in FIG. 6, when the angle A is set at about 90 °, the increase in the pressure of the ink caused by the ink in the ink reservoir 6 moving in the same rotation direction as the ink roller 2 is almost the same. Acts as a force for pushing up the doctor roller 3 with the fulcrum shaft 5 as the center of rotation. Therefore, as in the above-described conventional technique, when the rotation speed v of the ink roller 2 changes, the thickness (not shown) of the ink roller rapidly changes.

FIG. 7 is a graph for comparing the operation of FIGS. 5 and 6. As shown in the figure,
The change in the thickness t of the ink roller with respect to the rotation speed v of the ink roller will be described as two parameters of the angle A near 90 ° and an obtuse angle larger than 90 °. The change width of the ink roller thickness t becomes small even if the rotation speed v of the ink roller changes, and a printed matter having a substantially constant density can be obtained even if the rotation speed v of the ink roller changes. Conversely, when the angle A is around 90 °, the change width of the ink roller film thickness t increases when the rotation speed v of the ink roller changes, and when the rotation speed v of the ink roller changes to a higher value, the print quality of the printed matter increases. The density is so high that a printed matter of a certain density cannot be obtained.

According to the second aspect of the invention, a pair of arms for supporting at its free end the opposite ends of the shaft of the wiping roller, met supporting point shaft provided in the base end of the arm pairs
Te, set the angle which the straight line and forms connecting the straight line and the wiping roller axis and the fulcrum shaft as viewed in the axial direction connecting the ink roller axis and the doctor roller shaft of the plate cylinder at an obtuse angle, the fulcrum shaft in a direction to reduce the angle And the moving and holding means for selectively moving and holding, the angle is reduced, that is, the fulcrum shaft is moved and held at a fixed position approaching 90 °, so that the film thickness formed on the ink roller is increased. Will be retained.

[0013]

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

First, the configuration of an ink supply device of a stencil printing machine according to an embodiment of the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 1 denotes a porous cylindrical plate cylinder. The plate cylinder 1 has a predetermined width in the axial direction of the center of rotation, and has a support cylindrical body 1A in which a porous cylindrical portion 1a having a large number of openings and an ink non-passing portion (not shown) are formed.
And an ink-permeable mesh screen 1b that covers the outer peripheral surface of the support cylinder 1A. The plate cylinder 1 is rotatably driven in a counterclockwise direction indicated by an arrow by a drive motor (not shown) around an ink pipe 7 having an ink supply hole 7h and also serving as a rotation center axis. A locking member (not shown) for locking the leading end of a stencil sheet (not shown) for stencil printing is provided on the outer peripheral surface of the plate cylinder 1. Base paper (not shown)
, The leading end of which is sandwiched, a plate-made stencil sheet (not shown) is wrapped around its outer peripheral surface and held by the viscosity of the supplied ink.

1 and 2, a pair of metal side plates 8R and 8L are arranged inside the plate cylinder 1 in parallel with each other. The side plate pairs 8R and 8L are attached to the ink pipe 7 by fixing means (not shown).
In the figure of the pair of side plates 8R and 8L, near the left end, a long hole-shaped moving guide hole 1 inclined at an angle of θ ° to the left with respect to the vertical line.
1 are each opened. An ink roller 2 and a doctor roller 3 are arranged between the side plate pairs 8R and 8L in parallel with each other. The ink roller 2 is an ink roller shaft 2
a and is rotatably supported by the pair of side plates 8R and 8L by the ink roller shaft 2a. The ink roller 2 is disposed so as to be able to come into contact with the inner peripheral surface of the support cylinder 1A of the plate cylinder 1, and is driven in the same direction (counterclockwise direction indicated by an arrow in the drawing) with the plate cylinder 1 by a driving device (not shown). It is driven to rotate in synchronization with the rotation of the plate cylinder 1. The doctor roller 3 is substantially integrally attached to the doctor roller shaft 3a, and is disposed in contact with the outer peripheral surface of the ink roller 2 when stopped. A pair of arms 4L and 4R are provided at both ends of the doctor roller 3, and both ends of the doctor roller shaft 3a are rotatably supported by free ends of the arm pairs 4L and 4R. An ink pipe 7 is provided above the ink roller 2, and ink is supplied from an ink supply hole 7 h to form an ink reservoir 6 having a wedge-shaped cross section in a gap between the ink roller 2 and the doctor roller 3.

A fulcrum shaft 5 is attached to the base ends of the arm pairs 4L and 4R substantially in parallel with the doctor roller shaft 3a. Rollers 10 are provided at both shaft ends of the fulcrum shaft 5, and each roller 10 can roll within the long hole range of each moving guide hole 11. Therefore, the fulcrum shaft 5 is provided movably within the long hole range of each movement guide hole 11.
Further, the fulcrum shaft 5 has shaft ends on both sides thereof and side plate pairs 8R, 8L.
In the drawing, a tension spring 12 as a biasing means is stretched between a pin 13 implanted on the lower left side and is always urged downward in the drawing. With the above configuration, the doctor roller 3 and the fulcrum shaft 5 move in the axial direction of the plate cylinder 1 with respect to the ink roller 2 as shown in FIG.
To the straight line L1 connecting the ink roller shaft 2a and the wiping roller shaft 3a as viewed, as angles A formed by the straight line L2 connecting the wiping roller axis 3a and the fulcrum shaft 5 is set to an obtuse angle, are arranged respectively I have. Thus, the fulcrum shaft 5, habits you move in the direction to reduce the angle A is set at an obtuse angle by a tension spring 12 is provided.

FIG. 8 shows another embodiment of the present invention. This embodiment is different from the above embodiment in that the fulcrum shaft 5 is moved in a direction to reduce the angle A instead of the tension spring 12 as the urging means.
The only difference is that a solenoid 14 is provided as a moving holding means for selectively moving and holding. The solenoid 14 is fixedly provided below the movement guide hole 11 of the side plate 8L. Reference numeral 14a indicates a plunger of the solenoid 14 attached to the shaft end of the fulcrum shaft 5, and reference numeral 14b indicates a lead wire of the solenoid 14.

In FIG. 1, FIG. 3 and FIG. 8, a press roller (not shown) is arranged in the vicinity of the lower side of the outer peripheral surface of the plate cylinder 1 facing the ink roller 2, and this press roller (not shown) A printing position and a printing position, which are rotatably supported by an arm (not shown) provided to be swingable by a support shaft (not shown), and press against the outer peripheral surface of the plate cylinder 1 via a printing paper (not shown). 1 and a non-printing position separated from the outer peripheral surface. The press roller (not shown) is held at a non-printing position separated from the outer peripheral surface of the plate cylinder 1 except when the sheet is passed. On one side of the press roller (not shown), a pair of upper and lower registration rollers (both not shown) for sending out printing paper at a predetermined timing are arranged between the plate cylinder 1 and the press roller (not shown). Have been.

Next, the operation of the ink supply device will be described below. In the printing process of the stencil printing machine, FIG.
As shown in FIG. 5, when an appropriate amount of ink is dropped and supplied from the ink supply hole 7h of the ink pipe 7 into the ink reservoir 6, and the plate cylinder 1 starts rotating in the direction of the arrow (counterclockwise), The ink roller 2 is rotated in a direction indicated by an arrow (counterclockwise) at a rotation speed v1 by a driving device (not shown) in synchronization with the rotation of the plate cylinder 1. When the ink roller 2 is rotated in the arrow direction at a speed v1, by the ink of the ink reservoir 6 tends to move in the same rotational direction as the ink roller 2, the pressure of ink in the ink reservoir 6 is raised, the ink Due to the pressure increase, F ′ acts on the doctor roller 3 in the tangential direction to the ink roller 2, and a component force F of F ′ is generated on the fulcrum shaft 5. In addition, the fulcrum shaft 5
, A moment M1 which pushes up the doctor roller 3 in a counterclockwise direction acts. Further, as a component force of the force F, a moving component force F1 for moving the fulcrum shaft 5 upward in parallel with the inclination of the moving guide hole 11 having the inclination angle θ ° is generated. Doctor roller way clockwise to try to close the de Kutaro <br/> la 3 to the ink roller 2 around pivot shaft 5 by 3 mass W
And the moment M3 acting by the component force F3 of F ′ acts on the doctor roller 3, and the doctor roller 3 stops at a position where the moment M1, moment M2, and moment M3 acting in the opposite directions are balanced. . In the case of FIG. 1, the tension (set load) of the tension spring as the urging means is larger than the component force F1, and the fulcrum shaft 5 is stopped at the lower position of the moving guide hole 11 via the roller 10. Is shown.

As shown in FIGS. 3 and 5, when the rotation speed v of the ink roller 2 increases to a certain rotation speed v2 and the moving component force F1 becomes larger than the tension (set load) of the tension spring 12, As the roller 10 of the fulcrum shaft 5 rolls through the movement guide hole 11, the fulcrum shaft 5 moves upward, and the moment M3 acting to move the doctor roller 3 closer to the ink roller 2 increases. Roller 2
(See FIG. 3).
Moments M1 and M2 acting in opposite directions to each other
The doctor roller 3 is stopped where M3 and M3 balance, and the ink film thickness supplied to the ink roller 2 is determined. Therefore, even if the pressure of the ink in the ink reservoir 6 increases due to the rotation speed v of the ink roller 2 and the force for pushing up the doctor roller 3 increases, the doctor roller 3
Is also increased in accordance with the rotation speed v of the ink roller, and the moments in the opposite directions generated by these forces cancel each other out, so that the change in the gap between the ink roller 2 and the doctor roller 3 is reduced, and the ink roller is changed. The abrupt change in the thickness t of the ink roller supplied to the ink roller 2 with the rotation speed v of the ink roller 2 does not occur. That is, the ink supply device of the above embodiment has an automatic ink density adjustment mechanism.

Next, in FIG. 1 or FIG. 3, a printing sheet (not shown) is sent to a pair of registration rollers (both not shown) by a sheet conveying means, and further, the printing cylinder 1 is fed by a pair of registration rollers (not shown). At a predetermined timing synchronized with the rotation of the plate cylinder 1 and a press roller (not shown). Then, a press roller (not shown) separated from the outer peripheral surface of the plate cylinder 1 to a non-printing position below.
Is moved upward by the swing of an arm (not shown) to occupy the printing position, and the printing paper (not shown) is pressed against the stencil sheet (not shown) wound around the outer peripheral surface of the plate cylinder 1. From the perforated portion of the perforated stencil sheet (not shown), an ink having an appropriate density is transferred to the surface of the printing paper (not shown).

As shown in the graph of FIG.
The change in the thickness t of the ink roller with respect to the rotation speed v of the ink roller will be described as two parameters of an obtuse angle near 90 ° and an obtuse angle larger than 90 °. Does not change, the change width of the ink roller film thickness t becomes small, and even if the rotation speed v of the ink roller changes, a printed matter having a substantially constant density can be obtained. On the contrary, if the angle A is 9
In the vicinity of 0 °, when the rotation speed v of the ink roller changes, the width of change of the ink roller film thickness t increases, and when the rotation speed v of the ink roller changes to the larger one, the density of the printed matter increases and the printed matter having a certain density Can not be obtained.

Next, the operation of the ink supply device shown in FIG. 8 will be described. Typically, you discard the old spent the base paper, which is wrapped around the plate cylinder 1 (not shown), a new plate-making already the base paper (not shown) performs the printing is wound around the plate cylinder 1, the use SumiHara paper A large amount of ink is removed from the plate cylinder 1 by discarding the ink, and a large amount of ink must be supplied to make up for the removed ink. Therefore to fill the ink is pressed through the printing sheet pressing means such as the flop <br/> Resurora the plate cylinder 1 at a low speed, operation of the so-called plate mounting is performed. The rotation speed of the plate cylinder 1 at the time of this printing is usually very low, for example, about 10 rpm.
Since the thickness of the ink film formed on the outer peripheral surface of the ink roller 2 is also small, several sheets of the first print due to the lack of ink become waste paper (scratched paper) due to uneven density or the like.

For this reason, during normal printing, as shown in FIGS. 8 and 9, the solenoid 14 is turned on by the transmission of a signal and a drive current from a control device (not shown), and the plunger 14a is attracted in the direction of the arrow. When the fulcrum shaft 5 is moved and held below the movement guide hole 11 by the operation, the angle A (shown in FIG. 4 and not shown) is 90 °.
And the ink film thickness of the ink roller 2 becomes thicker, and ink is supplied to supplement the large amount of ink removed by the base paper (not shown) wound around the outer peripheral surface of the plate cylinder 1. . When the rotation speed v of the ink roller 2 increases and a steady ink film thickness is secured, the solenoid 14 is turned off by a control device (not shown).
In this way, the lack of ink at the time of printing is eliminated, and a printed matter having a higher density than that of the first printing can be obtained.
8A and 8B, FIG. 8A and FIG. 9A show the application timing of the solenoid 14, and FIG.
4 is a timing chart showing the relationship between the thickness of the ink roller film formed on the ink roller corresponding to the application timing of No. 4;

Next, when the stencil printing machine is left for a long period of time and the like, the ink in the printing cylinder 1 evaporates, and when the stencil printing machine is restarted, a large amount of ink for stencil printing is insufficient. As shown in FIGS. 8 and 10, the solenoid 14 is turned on by sending a signal and a drive current from a control device (not shown), and the fulcrum shaft 5 is moved below the movement guide hole 11 by the suction operation of the plunger 14a in the arrow direction. , The angle A (shown in FIG. 4 and not shown in the figure) changes toward 90 °, and the ink film thickness of the ink roller 2 increases. The holding of the solenoid 14 by the solenoid 14 is longer than the holding time only at the time of printing shown in FIG. 9, and is performed until the time of the printing step in a normal case. When a large amount of the insufficient ink is supplied to the inner peripheral surface of the plate cylinder 1 and the rotation speed v of the ink roller 2 increases and a steady ink film thickness is secured, the solenoid 14 is controlled by a control device (not shown). It is turned off, and thereafter, a printed matter having a substantially constant density can be obtained.

The support shaft 5 is not limited to a rod-shaped member connected as in the above embodiment and having both shaft ends fixed by the arm pairs 4L, 4R. 8
R may have the same phase and be fixed on the left and right sides. Further, the support shaft 5 is not limited to the mechanism fixed to the arm pair 4L, 4R as in the above-described embodiment, but a bearing is provided at the corresponding portion of the arm pair 4L, 4R to provide the arm 4L, 4R. It goes without saying that a rotatable mechanism may be used.

It should be noted that, in addition to the configuration of the embodiment shown in FIGS. 1 and 2, a solenoid 14 as a movement holding means shown in FIG. 8 is added, that is, the invention according to claim 1 and the invention according to claim 2 The ink film thickness of the ink roller 2 may be adjusted so as to be switched in two stages by using the invention together.

[0028]

As described above, according to the first aspect of the present invention, even if the pressure of the ink in the ink pool increases due to the rotation speed of the ink roller and the force for pushing up the doctor roller increases, the doctor roller can be moved. The force to push down also increases in accordance with the rotation speed of the ink roller, cancels out the moments in the opposite directions generated by these forces, and the change in the gap between the ink roller and the doctor roller is reduced, and the rotation speed of the ink roller is reduced. Since the film thickness of the ink roller supplied to the ink roller does not suddenly change with the change, it is possible to obtain a printed matter having a substantially constant density even when the rotation speed of the ink roller changes.

According to the second aspect of the present invention, a pair of arms supporting both ends of the shaft of the doctor roller at their free ends, a movable fulcrum shaft provided at each base end of the arm pair, and a plate set angles a straight line and forms connecting the straight line and the wiping roller axis and the fulcrum shaft connecting the viewed in the axial direction of the cylinder the ink roller axis and doctor roller shaft obtuse, selectively pivot shaft in a direction to reduce the angle Since the fulcrum shaft is moved and held at a fixed position approaching 90 °, the angle is reduced.
Since the film thickness formed on the ink roller is maintained in a thick state, it can be used for plate printing when printing the next document.
It is possible to obtain a printed matter having a better density than the first sheet of printing paper, and it is possible to reduce the number of waste sheets.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of an ink supply device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of FIG.

FIG. 3 is a sectional view showing the operation of the present invention.

FIG. 4 is a configuration diagram schematically shown to supplement the configuration of FIG. 1;

FIG. 5 is a side view of a main part showing the operation of the present invention.

FIG. 6 is a side view of a main part supplementarily showing the operation of the present invention.

FIG. 7 is a graph showing the operation of the present invention.

FIG. 8 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 9 is a timing chart showing the operation of FIG.

FIG. 10 is a timing chart showing the operation of the modified example of FIG.

[Explanation of symbols]

 A Angle L1, L2 Straight line 1 Plate cylinder 2 Ink roller 2a Ink roller shaft 3 Doctor roller 3a Doctor roller shaft 4L, 4R A pair of arms 5 Axle shaft 6 Ink reservoir 8L, 8R Side plate pair 12 Tension spring as biasing means 13 Pin 14 Solenoid 14a as moving and holding means Plunger of solenoid

Claims (2)

(57) [Claims] 1. A porous cylindrical plate cylinder, an ink roller disposed on an inner peripheral surface of the plate cylinder and rotatable in synchronization with rotation of the plate cylinder, and an outer peripheral surface of the ink roller. In an ink supply device for a stencil printing machine having a doctor roller disposed with a small gap and a wedge-shaped ink reservoir formed on the gap, both ends of the shaft of the doctor roller are supported at their free ends. a pair of arms, a supporting point shaft provided in the base end of the upper Symbol arm pairs, straight line and said wiping roller axis and the pivot connecting the ink roller axis and the doctor roller axis when viewed in the axial direction of the plate cylinder The fulcrum is movable in the direction in which the angle between the straight line connecting the axis and the straight line changes.
The shaft and the fulcrum according to the pressure increase of the ink in the ink pool
Cancel the movement of the axis to increase the angle.
The Migihitsuji, and a biasing means provided in the fulcrum shaft Before moving the pivot shaft in a direction to decrease the angle, the stencil printing machine, characterized in that the parameter set to Symbol angle obtuse Ink supply device. 2. A porous cylindrical plate cylinder and an inner peripheral surface of the plate cylinder.
Ink roll that is installed and can rotate in synchronization with the rotation of the plate cylinder
And a small gap between the roller and the outer peripheral surface of the ink roller.
And the doctor roller, which is
Ink of a stencil printer having a wedge-shaped ink reservoir
In the feeding device, both ends of the shaft of the doctor roller are supported at their free ends.
With a pair of arms, Up Provided at each base end of the arm pair.SupportPoint axisAndUp
Of the printing cylinderaxisInk roller shaft and doctor roller shaft
Between the doctor roller shaft and the fulcrum shaft.
Straight lineThe fulcrum that can be moved in the direction in which the angle changes
Axis and  Selectively move the fulcrum axis to reduce the angle
Moving holding means for holding, Up A stencil printing machine characterized in that the angle is set to an obtuse angle.
Ink supply device.