JPH0780300B2 - Ink supply device in printing machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ink supply device in a printing machine.

2. Description of the Related Art Conventional technology and its problems In a printing press, it is necessary to control the amount of ink supplied to the printing surface, and depending on the design, it may be necessary to change the amount of ink depending on the position in the width direction of the printing surface.

In a conventional printing machine, one ink amount adjusting plate that forms the bottom of the ink fountain is provided close to the ink source roller, and the gap between the ink source roller and the ink amount adjusting plate ( The ink discharged from the surface of the ink source roller through the ink passage) is transferred to the ink kneading roller by the ink feeding roller, and is supplied to the printing surface via a plurality of ink kneading rollers. And, control of the amount of ink on each part of the printing surface is done by adjusting the gap with the adjusting screw,
This is performed by adjusting the thickness of the ink film on the surface of the ink source roller. However, it is difficult to set the gap to a desired value with screws, and it is particularly difficult to change the ink amount depending on the position in the width direction of the printing surface with only one ink amount adjusting plate and screws.

Therefore, the ink film thickness is controlled by arranging multiple ink amount adjustment members that make up the ink fountain side by side in the length direction of the ink source roller without gaps and adjusting the opening of the ink passage for each ink amount adjustment member. Then, an ink supply device in a printing machine has been proposed in which the amount of ink is controlled for each position in the width direction of the printing surface (see Japanese Patent Laid-Open No. 59-78854).

However, it is very difficult to numerically control the opening degree of the ink passage, and it is difficult to control the ink amount by adjusting the opening degree of the ink passage. Therefore, it is necessary to adjust the opening of the ink passage while performing trial printing many times, and since such adjustment is required for all ink amount adjusting members, it takes a very long time to prepare for printing. In addition, a large amount of test paper is required for each trial printing, the product unit price is high, and it is uneconomical. Even if the opening of the ink passage is adjusted to a desired value, if the pressure exerted by the ink in the ink fountain on the ink amount adjustment member, the viscosity of the ink, the rotation speed of the ink source roller, etc., changes, Since the film thickness changes, the stability of the ink amount is very poor, and it is difficult to control the ink amount accurately for each position in the width direction of the printing surface.

In order to solve such a problem, a plurality of ink amount adjusting members arranged side by side in the length direction of the ink source roller without gaps so as to form an ink fountain, and between the ink source roller and each ink amount adjusting member. A plurality of ink passage opening / closing means for switching each ink amount adjusting member between an open position where the ink passage is opened to a constant opening and a closed position where this ink passage is closed, and an ink amount setting in which the ink amount is set for each ink amount adjusting member And a control means for individually controlling the ink passage opening / closing means so that the time during which each ink amount adjusting member is switched to the open position becomes a value according to the set value of the ink amount setting means. An ink supply device has been proposed in Japanese Patent Laid-Open No. 55-25060.

In this device, the ink amount adjusting member is a plate-like member whose one end is fixed to the member forming the ink fountain, and elastically deforms around the fixed end to open and close the ink passage. ing. The ink passage opening / closing means has a spring band whose one end is fixed to a member forming the ink fountain and the other end is connected to the tip of the ink amount adjusting member, and one end of which is fixed to the spring band. Is composed of a lever for elastically deforming, a mover having one end fixed to the other end of the lever to drive the lever, and an electromagnet for switching the position of the mover. Then, by switching the position of the mover with the electromagnet, the spring band is deformed via the lever, and as a result, the ink amount adjusting member hits the member forming the ink fountain and opens the ink passage to a certain opening. The position is switched to the closed position for closing the ink passage.

However, in the above apparatus, since the movement of the mover by the electromagnet is transmitted to the ink amount adjusting member via the lever and the spring band, the number of parts is large and a time delay occurs in the switching operation of the ink amount adjusting member. Further, since the ink amount adjusting member is a flat plate and is elastically deformed at right angles to open and close the ink passage, the pressure exerted by the ink in the ink fountain on the ink amount adjusting member is in the direction to open the ink passage. Therefore, unless the ink amount adjusting member is received by another member, the opening of the ink passage changes due to the change of the ink pressure, and the ink amount control becomes inaccurate. Therefore, it is necessary to receive the ink amount adjusting member by another member that constitutes the ink fountain, and the number of parts increases accordingly.

An object of the present invention is to solve the above problems and provide an ink supply device in a printing machine in which the amount of ink can be easily and accurately controlled individually for each position in the width direction of a printing surface and the number of parts is small. Will be done.

Means for Solving the Problems An ink supply device in a printing machine according to the present invention comprises a plurality of ink amount adjusting members arranged side by side in the length direction of an ink source roller without gaps so as to form an ink fountain, and an ink source. A plurality of ink passage opening / closing means for switching each ink amount adjusting member between an open position where the ink passage between the roller and each ink amount adjusting member is opened to a constant opening and a closed position where this ink passage is closed, and the ink amount is the ink amount. The ink amount setting means set for each adjusting member and the ink passage opening / closing means individually so that the time during which each ink amount adjusting member is switched to the open position becomes a value according to the set value of the ink amount setting means. In an ink supply device for a printing press equipped with control means for controlling, each ink passage opening / closing means includes a spring for urging an ink amount adjusting member in a direction in which the ink passage opens, and an air An air cylinder that positions the ink amount adjusting member biased by the spring to the closed position when the air is not supplied, and switches the ink amount adjusting member to the closed position against the biasing force of the spring when air is supplied. Each of the ink amount adjusting members has a substantially L shape, and a notch is formed in the upper portion of the ink amount adjusting member, and the portion above the notch of the ink amount adjusting member is fixed to the frame side of the printing machine. A protrusion is formed below the adjustment member in the vicinity of the ink fountain roller, and a spring and an air cylinder are provided below the cut of the ink amount adjustment member.

By controlling the air cylinder that constitutes the ink passage opening / closing means, the ink amount adjusting member is switched between the open position and the closed position with a constant opening.

Since the ink amount adjusting member is switched between the open position and the closed position by elastic deformation of the cut portion, and the portion below the cut portion of the ink amount adjusting member is directly driven by the air cylinder, there is a time delay in the switching operation. Never. Since the ink amount adjusting member is directly driven by the air cylinder, the number of parts is small. Since the ink amount adjustment member is switched by elastic deformation of the cut portion, there is no rattling and there is no variation in the opening of the ink passage when switched to the open position. Therefore, the opening is stable and the ink amount The control of is accurate. In addition, the pressure exerted by the ink in the ink fountain on the protruding portion of the ink amount adjusting member acts in a direction perpendicular to the opening / closing direction of the ink amount adjusting member, and the opening of the ink passage does not change even if the pressure of this ink changes. Absent. Therefore, even if the ink amount adjusting member does not need to be received by other members constituting the ink fountain, the control of the ink amount is accurate, and the bottom of the ink fountain can be configured only with the ink amount adjusting member, so the number of parts is also reduced. It needs less.

Example 1 FIGS. 1 and 2 show the outline of the mechanical structure of the ink supply device provided on the upper part of the frame (10) of the printing machine, and FIG. 3 shows the outline of the electrical structure thereof.

Both ends of the ink fountain roller (12) are rotatably supported by the left and right side plates (11) of the frame (10), and both ends of a mounting member (13) of which the cross section is inverted L-shaped are parallel to the both ends. The part is fixed. A plurality of rows (for example, six rows) of blades (ink amount adjusting members) (15) forming the ink fountain (14) are arranged side by side in the length direction of the ink source roller (12) without any gap, and each blade (15) The upper part is the mounting screw (1
It is fixed to the upper part of the mounting member (13) by 6). Further, the left and right side plates (17) of the ink fountain (14) are clamped between both end surfaces of the attachment member (13) and the frame side plate (11). The blade (15) is substantially L-shaped, and these lower protrusions (15a) are close to the ink source roller (12),
An ink passage (18) is formed between them. The blade (15) in the length direction of the ink source roller (12)
Are all equal in width.

A notch (19) is formed in the upper part of each blade (15), and the lower protrusion (15a) of each blade (15) individually moves toward and away from the ink source roller (12) to move the ink. The passage (18) can be opened and closed. The portion of the blade (15) above the cut (19) is fixed to the mounting member (13), and the blade (15) can elastically deform at the cut (19) to open and close the ink passage (18). It is like this. A tension coil spring (20) is provided between the lower part of each blade (15) and the mounting member (13) to urge the lower part of the blade (15) in the direction in which the ink passage (18) opens. Further, the attachment member (13) is provided with six air cylinders (21) for pushing the respective blades (15) in the direction in which the ink passages (18) are closed, and each air cylinder (21) is Each is connected to a compressed air source such as an air compressor (not shown) via an air solenoid valve (22). The six valves (22) are connected to a valve control device (24) and turned on and off by this. While the valve (22) is off, the air cylinder (21) is opened to the atmosphere and the lower protrusion (15a) of the blade (15) is pulled by the spring (20) to open the ink passage (18). Located in position. When the valve (22) is turned on, compressed air is supplied to the air cylinder (21), and the lower protrusion (15a) of the blade (15) is pushed by this,
The ink passage (18) is moved to the closed position against the biasing force of the spring (20). The opening of the ink passage (18) is
Adjusted to be equal for all blades (15).

The ink source roller (12) rotates in the direction of the arrow in FIG. 1, whereby the ink (I) in the ink fountain (14) opens from the ink passage (18) to the ink source roller (12). It comes out on the surface and is transferred to an ink kneading roller by an ink feeding roller (not shown). At this time, since the width and film thickness of the ink film (23) appearing on the surface of the ink source roller (12) are constant, the ink amount is the length of the ink film (23) in the circumferential direction of the ink source roller (12). That is, it is proportional to the time when the ink passage (18) is open (open time). Therefore, by controlling the opening time of the ink passages (18) of each row by the valve control device (24), the amount of ink that appears on the surface of the ink source roller (12) can be adjusted for each row. Then, by making the opening time of the ink passages (18) of all rows the same, it is possible to make the ink amount uniform over the entire length of the ink source roller (12), and to open the ink passages (18) for each row. By changing the time, it is possible to add the ink amount for each row depending on the position of the ink source roller (12) in the length direction. Further, since the adjacent blades (15) are independent of each other, the ink amount can be accurately adjusted for each row.

Six ink amount setters (25) corresponding to the six rows of blades (15) are connected to the valve control device (24), and the ink amount is set for each blade (15) as follows. To be done.

For example, in the case of the pattern shown in FIG. 4, the printing surface is divided into 6 rows so as to correspond to the blades (15) in 6 rows, and the pattern accumulation area of each row is determined as shown in FIG. Then, a value proportional to the accumulated area of each column is set as an ink amount in the setter (25) of each column.

The valve control device (24) has a setting device 25 set as described above.
Based on the ink amount setting value of, the ink passage (1
8) Control the opening time. As a result, six rows of ink films (23) having a circumferential length proportional to the opening time of the ink passage (18) are formed on the surface of the ink source roller (12). It is clear that the ink amount of the ink film (23) in each row is proportional to the set value. Therefore, by setting the proportional constant appropriately, the set amount of ink can be accurately supplied. There is a deviation between the time when the valve (22) is off and the actual opening time of the ink passage (18) due to friction of each component. Therefore, the time for turning off the valve (22) is the necessary opening time of the ink passage (18) plus a deviation.

If the printing speed changes, the ink source roller (12)
The rotation speed of the ink may be changed in proportion to the printing speed, or the opening speed of the ink passage (18) may be changed in proportion to the printing speed by keeping the rotation speed of the ink source roller (12) constant. Good.

FIG. 6 shows a specific example of the valve control device (24). The valve control device (24) includes six comparison circuits (26) corresponding to the six rows of blades (15) and six irenoid drive circuits (27) respectively connected to these. The six valves (22) are connected to the corresponding solenoid drive circuit (2
7) connected to each. In addition, each comparison circuit (2
The output of the integration counter (28) for detecting the rotation amount of the ink source roller (12) and the output of the corresponding ink amount setting device (25) are connected to 6). In this case, the ink source roller (12) rotates at a speed proportional to the printing speed.
Further, as shown in FIG. 7, the output of the counter (28) returns to zero every time the ink source roller (12) rotates by a predetermined amount.
When the output of the counter (28) becomes zero, a valve off signal is output from all the comparison circuits (26), whereby all the solenoid drive circuits (27) turn off the valve (22). As a result, the ink passages (18) in all rows are opened, and ink is ejected onto the surface of the ink source roller (12). And the counter (2
When the output of 8) exceeds the set value of the ink amount, the comparison circuit (26) of that row outputs a valve ON signal, and the corresponding solenoid drive circuit (27) turns on the valve (22). For this reason,
The valve (22) is turned on and the ink passage (18) is closed in order from the row with the smallest set value of the ink amount. For example, in FIG. 7, the ink passages (18) of the first and sixth rows, then the fourth row, then the second and fifth rows, and finally the third row are closed, and the ink amount of each row is It is controlled to be set.

In the above embodiment, the ink amount blade (15) can be easily switched between the open position and the closed position by controlling the air cylinder (21).

If the blade swings around the pivot pin to switch between the open position and the closed position, the blade switching operation is delayed due to rattling of the pivot pin, Also, the opening degree of the ink passage varies each time it is switched to the closed position, and the opening degree is not stable. Therefore, the control of the ink amount becomes inaccurate. If the blade is flat and swings at a right angle to open and close the ink passage, the pressure exerted by the ink in the ink fountain on the blade acts in the direction to open the ink passage. When the pressure of the ink changes, the opening of the ink passage changes. Therefore, the control of the ink amount becomes inaccurate. On the other hand, in the case of the above-mentioned embodiment, the blade (15) has a substantially L-shape, and the notch (1
9) is formed, and a protrusion (15a) that is close to the ink source roller is formed in the lower part of the blade (15), and the portion below the cut (19) of the blade (15) is the air cylinder (21). Since it is directly driven by, the amount of ink can be accurately controlled and the number of parts can be reduced as follows. That is, the blade (15) has a notch (1
The elastic deformation of the part (9) switches between open and closed positions, and the cutting of the blade (15) and the part below (19) are directly driven by the air cylinder (21), so the switching operation takes time. There will be no delay. Since the blade (15) is directly driven by the air cylinder (21), the number of parts can be reduced. Since the blade (15) is switched by elastic deformation of the cut portion, there is no rattling, and the opening of the ink passage (18) does not vary when switched to the open position. Therefore, the opening is stable. The control of the amount of ink is accurate. Further, the pressure exerted by the ink in the ink fountain (14) on the protruding portion (5a) of the blade (15) acts in a direction perpendicular to the opening and closing direction of the blade (15), and even if the pressure of this exhaust changes, The opening of the ink passage (18) does not change. Therefore, insert the blade (15) into the ink fountain (1
Even if it is not received by other members constituting 4), the control of the ink amount is accurate, and the bottom of the ink fountain (14) can be constituted by only the blade (15), so the number of parts can be reduced.

EFFECTS OF THE INVENTION According to the ink supply device of the printing machine of the present invention, as described above, the amount of ink can be easily and accurately controlled individually for each position in the width direction of the printing surface, and the number of parts is small. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the device according to the present invention,
2 is a plan view of the same, FIG. 3 is a block diagram showing its electrical configuration, FIG. 4 is a plan view of a printed surface showing an example of a pattern, FIG. 5 is a graph showing a pattern accumulation area, and FIG. FIG. 7 is a block diagram showing an example of the valve control device, and FIG. 7 is a graph showing the output of the integrating counter and the ink amount of each column. (10) …… Frame, (12) …… Ink source roller, (1
4) ... ink fountain, (15) ... blade (ink amount adjusting member), (15a) ... lower protrusion, (18) ... ink passage, (19) ... notch, (20) ... spring , (21) …… Air cylinder, (22) Air solenoid valve, (24) …… Valve control device, (25) …… Ink amount setter.

Claims (1)

[Claims] 1. A plurality of ink amount adjusting members which are arranged side by side in the longitudinal direction of an ink source roller without a gap so as to form an ink fountain, and an ink passage between the ink source roller and each ink amount adjusting member is constant. A plurality of ink passage opening / closing means for switching each ink amount adjusting member between an open position that opens to the opening of the ink passage and a closed position that closes the ink passage, and ink amount setting means that sets the ink amount for each ink amount adjusting member, An ink supply device in a printing machine, which is provided with a control means for individually controlling the ink passage opening / closing means such that the time during which the ink quantity adjusting member is switched to the open position becomes a value according to the set value of the ink quantity setting means. In each of the ink passage opening / closing means, a spring for urging the ink amount adjusting member in the direction in which the ink passage opens and an ink amount adjusting member urged by the spring when air is not supplied It consists of an air cylinder that is positioned at the open position and switches the ink amount adjusting member to the closed position against the biasing force of the spring when each air amount is supplied. A notch is formed in the upper part of the adjustment member, the part above the notch of the ink amount adjustment member is fixed to the frame side of the printing machine, and a protrusion is formed in the lower part of the ink amount adjustment member close to the ink source roller. An ink supply device for a printing press, wherein a spring and an air cylinder are provided in a portion below a notch of the amount adjusting member.