JPH0759395B2 - Gravure plate doctor blade device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a doctor blade device for a gravure plate cylinder,
In particular, the present invention relates to a doctor blade device for a gravure plate cylinder that can easily set the contact position and contact pressure between the doctor blade and the plate cylinder regardless of the size of the plate cylinder.

(Prior Art) Generally, the plate cylinder of a gravure printing machine prints a photographic original plate on a roll of copper plated on iron or the like, and then makes the plate by etching,
Then, it is formed by performing chrome plating.

The plate cylinder has fine recesses, and after the ink is applied to the entire width while rotating, the ink is left only in the recesses by the doctor blade, and the ink in other parts is completely scraped off.

After that, the plate cylinder in which only the recesses are filled with ink transfers the ink filled in the recesses to the printing object while rotating.

In this case, the contact between the plate cylinder surface and the doctor blade is extremely important, and the quality of this contact directly results in the quality of printing.

Therefore, when the plate cylinder and the doctor blade are brought into contact with each other, it is necessary to adjust the contact position. In general, this adjustment is performed by moving the doctor blade independently in the vertical direction, rotation direction, and retreat direction, and adjusting the contact pressure on the surface of the plate cylinder to set the best contact condition. is doing. However, the work of setting the optimum conditions requires skill and takes time. By moving back and forth, the distance between the fulcrum of the doctor and the blade edge changes, so the blade edge contact pressure changes even if the pressure is constant.

(Problems to be Solved by the Invention) As described above, skill is required to adjust the contact condition between the plate cylinder and the doctor blade to the best condition.

By the way, plate cylinders having various diameters are used depending on the length of the printing original plate. Therefore, it is necessary to adjust the contact position and the contact pressure described above each time the size of the plate cylinder is changed, which requires more time and skill.

The present invention has been made in consideration of such points,
It is an object of the present invention to provide a doctor blade device for a gravure plate cylinder that can easily adjust the contact position and contact pressure between the plate cylinder and the doctor blade regardless of the size of the plate cylinder.

[Structure of Invention]

(Means for Solving the Problems) The present invention relates to a blade holding device that holds a doctor blade that comes into contact with a plate cylinder, and moves the blade holding device while inclining the blade holding device with respect to the vertical direction. In a doctor blade device of a gravure plate cylinder having a blade moving device that is movably held, the blade moving device is formed by a rack attached to the blade holding device, and a pinion that is rotationally controlled by an automatic control device. , The moving direction of the blade holding device,
The arc length between the contact point of the doctor blade and the substrate to be printed and the contact angle of the doctor blade are substantially equal to the direction in which each position of the blade holding device of the maximum plate cylinder diameter and the minimum plate cylinder diameter is connected by a straight line, When the cylinder has a value of plate cylinder diameter between the maximum plate cylinder diameter and the minimum plate cylinder diameter, after moving the blade holding device to a predetermined position corresponding to the value of the plate cylinder diameter, A doctor blade device for a gravure plate cylinder, characterized in that the blade holding device is swung to bring the doctor blade into contact with the plate cylinder.

(Operation) According to the present invention, when the plate cylinder has a value of the plate cylinder diameter between the maximum plate cylinder diameter and the minimum plate cylinder diameter, the blade holding device is used to change the arc length between the doctor blade and the contact point of the printing material. Of the maximum plate cylinder diameter and the minimum plate cylinder diameter where the contact angles of the blade and the doctor blade are approximately equal, move in a direction that connects each position of the blade holding device with a straight line to a predetermined position that corresponds to the value of the plate cylinder diameter. After that, by swinging the blade holding device to bring the doctor blade into contact with the plate cylinder, the contact state between the plate cylinder and the doctor blade is changed even when the diameter of the plate cylinder is variously changed. The contact position can be adjusted easily and easily so that the contact pressure is good, and the condition that the contact pressure is good is maintained.

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

1 to 3 are views showing an embodiment of a doctor blade device for a gravure plate cylinder according to the present invention. In FIG. 1, a doctor blade device 10 is arranged on the side of the gravure plate cylinder 1. The doctor blade device 10 includes a blade holding device 11 that holds the doctor blade 12, and a blade moving device 15 that moves the blade holding device 11 while inclining it with respect to the vertical direction.

In FIG. 1, the plate cylinder 1 has a maximum plate cylinder diameter 1a and a minimum plate cylinder diameter 1b.

This plate cylinder 1 is formed by drum-plating the outer circumference of an iron roll or the like, printing a pattern on the drum-plated layer by photolithography, etching the plate later, and then chrome-plating the pattern.
Therefore, fine recesses are present on the surface of the plate cylinder 1 depending on the design. Since the ink is supplied to the plate cylinder 1 over the entire width regardless of the pattern, the doctor blade 12 is brought into contact with the plate cylinder 1 over the entire width after the ink is applied, and excess ink other than the recesses is scraped off.

In this way, the ink applied only to the necessary portion is completely transferred at the contact point where it contacts the printing material.

Next, the doctor blade device 10 will be described in detail.

A rack 16 is connected to a blade holding device 11 holding a doctor blade 12 via a rotating shaft 18 so as to be vertically movable. The rack 16 engages with the pinion 17 and is guided by a guide guide (not shown) so as to be inclined with respect to the vertical direction. Further, the pressing action of the blade holding device 11 around the rotation shaft 18 is performed by a pressing device (not shown), but the pressing device can press the doctor blade 12 against the plate cylinder 1 at a predetermined pressure. You can do it.

Further, the rack 16 is guided along the guide groove of the guide plate, and on the side opposite to the pinion 17, a guide roller 19 that comes into contact with the rack 16 and pressurizes the rack 16 is provided.
The rack 16 and the pinion 17 constitute a blade moving device 15. The doctor blade device 10 is movable in the horizontal direction with respect to the plate cylinder 1.

Next, the drive mechanism of the pinion 17 will be described with reference to FIG. As shown in FIG. 2, the pinion drive mechanism 20 includes a motor 21 and a worm 22 driven by the motor 21.
And a worm gear 23 that engages with the worm 22 and transmits the rotational force to the pinion 17. Also pinion
An encoder 24 is provided to measure the number of revolutions of the worm gear 23 and the worm gear 23, and the motor 21 is driven by the automatic control device 26 based on a signal from the encoder 24.

Next, the moving direction of the rack 16, that is, the blade holding device 11
The moving direction of will be described with reference to FIG. As shown in FIG. 3, first, the contact point 35 between the impression cylinder and the plate cylinder in the maximum plate cylinder 1a.
The position 31 of the fulcrum 18 of the blade holding device 11 where the arc length between a and the doctor blade is A and the tangent angle of the doctor blade (angle formed by the tangent line of the doctor blade and plate cylinder) is θ is determined. . Next, the arc length between the contact point 35a of the printing material and the doctor blade on the minimum plate cylinder 1b is A,
And a blade holding device in which the contact angle of the doctor blade is θ
Position 32 of 11 fulcrums 18 is defined. Next, the respective positions 31 and 32 are connected to form a straight line 33 having an inclination angle Q. And this straight line
The direction of 33 is the moving direction of the blade holding device 11. In this case, the moving stroke of the blade holding device 11 is L.

Next, the operation of this embodiment having such a configuration will be described.

As the plate cylinder 1, a plate cylinder 1 having a size suitable for each case is used depending on the length of a pattern to be printed. For example, first, the maximum plate diameter 1a
To use. Next, the contact point 35 between the doctor blade 12 and the substrate
The arc length between a and A is A, and the doctor blade 12
The contact position is adjusted in advance so that the contact angle of is θ. In this case, the fulcrum 18 of the blade holding device 11 is at the position 31.

The contact position is adjusted by moving the doctor blade device 10 up and down and moving it, and also by a blade holding device having a pressing device.
This is done by bringing 11 into close proximity to the plate cylinder. Also,
The pressing device presses the doctor blade 12 against the plate cylinder 1a with a predetermined pressure.

The arc length A and the contact angle θ are conditions under which the contact state between the doctor blade 12 and the plate cylinder 1 is optimum.

In this state, the ink is applied over the entire width of the plate cylinder 1a, excess ink is scraped off by the doctor blade 12, and transferred to the printing material at the contact point 35a of the plate cylinder 1a.

Next, the case of printing by exchanging the maximum plate cylinder diameter 1a with the plate cylinder having the minimum plate cylinder diameter 1b will be described.

First, the motor 21 is driven to rotate the pinion 17 via the worm 22 and the worm gear 23. The rotation speed of the pinion 17 is measured by the encoder 24. When the pinion 17 rotates by a predetermined number of rotations, a signal is input from the encoder 24 to the automatic control device 26, and the motor 21 is stopped by the automatic control device 26. During this time, the blade holding device
11 moves on a straight line 33, after which the blade holding device 11 reaches position 32.

In this case, the arc length between the doctor blade 12 and the contact point 35b of the printed material is A, and the contact angle of the doctor blade 12 is θ. Next, the blade holding device by the pressing device
11 is rotated to press the doctor blade 12 against the plate cylinder 1b with a predetermined pressure. Then, in this state, the contact point 35 of the plate cylinder 1b
Transfer to the substrate at b.

When the plate cylinder 1 has a diameter between the maximum plate cylinder diameter 1a and the minimum plate cylinder diameter 1b, the blade holding device 11 is brought to a predetermined position on the straight line 33.

In this case, the arc length between the doctor blade 12 and the contact point of the printing material is an arc length close to A, and the contact angle of the doctor blade 12 is an angle close to θ.

As described above, according to the present embodiment, even when the diameter of the plate cylinder 1 is variously changed, by moving the blade holding device 11 on the straight line 33, the blade holding device 11 is moved between the plate cylinder 1 and the doctor blade 12. The contact position and contact pressure can be adjusted so that the contact state is good. As described above, since it is not necessary to move the doctor blade 12 in the vertical direction, the forward direction and the backward direction for adjustment as in the conventional case, the contact position can be easily and easily adjusted and the contact pressure can be substantially reduced. Can be constant. In addition, the rotation speed of the pinion 17 is encoder
Since the measurement is performed by 24 and the signal from the encoder 24 is input to the automatic control device 26 to turn on / off the motor 21, the blade holding device 11 can be automatically moved to a predetermined position.

This automation method can be realized not only by the rack and pinion method but also by rotating the screw shaft in place of the rack and pinion, basically according to the same principle, and therefore this method is also included in the scope of claims. Be done.

〔The invention's effect〕

As described above, according to the present invention, even if the diameter of the plate cylinder is variously changed, the contact state between the plate cylinder and the doctor blade can be improved simply by moving the blade holding device on a straight line. The contact position can be adjusted easily and easily, and the contact pressure can be made substantially constant. Further, since the blade moving device for moving the blade holding device is composed of the rack and the pinion, and the pinion is rotationally controlled by the automatic control device, the blade holding device can be automatically moved to a predetermined position, and the contact position The adjustment of can be automated.

Further, since the straight line in the moving direction of the blade holding device is determined based on the maximum plate cylinder diameter and the minimum plate cylinder diameter, the straight line in the moving direction of the blade holding device is extremely easy without performing a complicated calculation by a computing device or the like. Can be set to, and a great simplification of the blade device and its operation can be achieved. Further, when the plate cylinder diameter is between the maximum plate cylinder diameter and the minimum plate cylinder diameter, after moving the blade holding device to a predetermined position corresponding to the value of the plate cylinder diameter, the blade holding device is shaken. Since it is moved to abut on the doctor blade plate cylinder, even when the value of the plate cylinder diameter is changed variously, the arc length of the contact point of the doctor blade and the printing material and the contact angle of the doctor blade, It is possible to easily and surely adjust the values to those close to those of the maximum plate cylinder diameter and the minimum plate cylinder diameter.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an embodiment of a doctor blade device for a gravure plate cylinder according to the present invention, FIG. 2 is a schematic side view showing a drive mechanism of a pinion, and FIG. 3 is a blade holding device. It is the schematic which shows a moving direction geometrically. 1 ... plate cylinder, 1a ... maximum plate diameter, 1b ... minimum plate diameter, 10
...... Doctor blade device, 11 …… Blade holding device, 12
...... Doctor blade, 15 …… Blade moving device, 16 ……
Rack, 17 ... pinion, 20 ... pinion drive mechanism,
21 …… motor, 26 …… automatic control device, 31,32 …… each position, 33 …… straight line, 35a, 35b …… contact point.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-60-83743 (JP, A) JP-A-62-251140 (JP, A) Jitsuko Sho-49-37285 (JP, Y2)

Claims (1)

[Claims] 1. A blade holding device for holding a doctor blade in contact with a plate cylinder, and a blade moving device for tiltably moving the blade holding device and holding the blade holding device in a swingable manner. In the doctor blade device of the gravure plate cylinder with, the blade moving device is formed by a rack attached to the blade holding device, and a pinion rotationally controlled by an automatic control device, the moving direction of the blade holding device. The direction in which the arc length between the doctor blade and the contact point of the printing material and the contact angle of the doctor blade are substantially equal to each other and the positions of the blade holding devices of the maximum plate cylinder diameter and the minimum plate cylinder diameter are connected by a straight line And, when the plate cylinder has a value of the plate cylinder diameter between the maximum plate cylinder diameter and the minimum plate cylinder diameter, the blade holding device to the value of the plate cylinder diameter After moving to the predetermined position by a gravure plate cylinder of the doctor blade device, characterized in that it is brought into contact with the doctor blade to the plate cylinder by swinging the blade holding device.