JPH074917B2 - Initial printing pressure setting device in screen printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an initial printing pressure setting device in a screen printing machine.

(Prior Art) Printing in a screen printing machine is performed by appropriately pressing the surface of a screen plate on which ink is sprayed with a squeegee, and bringing the back surface of the screen plate into contact with a printing object such as printing paper.

In the above-mentioned screen printing, since the expansion and contraction of the plate have a delicate effect on the density of printing, the initial value of the pressure of the squeegee is set in advance before printing, and the pressure of the squeegee is increased appropriately based on this initial value. Then, the density of the printed matter is adjusted.

That is, the squeegee position adjustment screw provided on the machine base is manually operated to move the squeegee up and down, and the initial value of the squeegee pressure is set in a state where the lower end of the squeegee rubber comes into contact with the printing paper or the like through the screen plate. decide. Then, printing is performed with a squeegee pressure slightly higher than the initial value, and the squeegee pressure is adjusted according to the shade of printing by operating the adjustment screw.

(Problems to be Solved by the Invention) However, the determination of the initial value of the squeegee pressure is performed according to the position determination of the squeegee by the manual operation of the adjusting screw, and this position determination depends on the intuition of the operator. . Therefore, an incorrect squeegee pressure initial value is determined due to an incorrect determination of the squeegee position, leading to defective printing,
This may cause a decrease in the commercial value of printed matter.

Therefore, it is an object of the present invention to provide an initial printing pressure setting device in a screen printing machine that can always set the squeegee pressure initial value to a constant value, avoid printing defects, and produce printed matter with excellent commercial value. It is in.

Configuration of the Invention (Means for Solving Problems) In order to solve the above-mentioned problems, the present invention relates to an initial printing pressure setting device in a screen printing machine for moving a squeegee up and down to set printing pressure of the squeegee. , An axially oriented vertical direction, an adjustment bolt that is rotated by a motor is provided so as to be movable along the axial direction, and a nut integrally connected to the squeegee is attached to the adjustment bolt of the motor. The piston rod of the air cylinder is provided so as to be able to move up and down together with the adjusting bolt so as to be screwed so as to descend with rotation.

(Operation) That is, since the adjusting bolt rotates when the motor is rotated in the predetermined direction, the nut descends as the adjusting bolt rotates, and the squeegee integrally connected to the nut also descends.
When the squeegee moves to the initial printing pressure position and comes into contact with the printed material, the pressure from the printed material accompanying this contact prevents the nut from descending, while the motor rotates slightly excessively and then The drive is stopped. Then, due to the excessive rotational force of the motor, the adjusting bolt screwed into the nut moves upward, and the piston cylinder also moves upward accordingly. Then, when the pressure in the cylinder is increased, the squeegee is held at the initial printing pressure position where it comes into contact with the printing material through the piston cylinder, the adjusting bolt and the nut.

Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 2, a screen plate 2 is provided above a table 1 of the printing machine, and an object to be printed such as a printing paper P on the table 1 moves from the paper feed side (right side) to the paper discharge side as the conveyor belt 3 moves. To be sent to. A squeegee 4 is disposed above the screen plate 2, and in the lowered position shown by the chain double-dashed line, the lower end of the squeegee rubber 5 provided in the lower half portion is used to print the printing paper P through the screen plate 2.
Printing pressure is applied to the printing paper P and printing is performed on the printing paper P by moving the screen plate 2 or the squeegee 4.

Now, the squeegee 4 and its peripheral mechanism will be described in detail.

As shown in FIGS. 1, 3, and 4, a holding bar 6 is mounted above the table 1 in a direction orthogonal to the feeding direction of the printing paper P, and a motor 7 is fixedly mounted on the upper surface thereof. . The rotating shaft 8 of the motor 7 projects downward through an insertion hole 9 formed through the holding bar 6, and an entry shaft 8a having a spline groove is formed below the rotating shaft 8. The entry shaft 8a is fitted into the adjustment bolt 11 extending in the vertical direction in the case 10 via the upper blocking plate 12a of the case 10. As a result, the adjustment bolt 11 is connected to the motor 7 so as to be integrally rotatable and vertically movable. The lower end of the adjusting bolt 11 is connected to the lower closing plate 12b of the case 10, the central portion is screwed into the nut 13 inside the case 10, and the protruding portion 14 of the nut 13 is transparent to one side surface of the case 10. It projects outward from the provided long groove 15.

An interposition plate 16 and an angle adjusting plate 17 are provided on the protrusion 14 of the nut 13.
The squeegee mounting bar 18 is attached via the
The squeegee 4 described above is provided at 18. Therefore, the vertical position of the squeegee 4 is determined by the vertical position of the nut 13 adjusted by the rotation of the adjusting bolt 11.

In addition, one mark 19 is drawn on the upper end surface of the interposer plate 16,
A plurality of adjustment marks on the upper end surface of the adjustment plate 17 for the same mark 19
By selectively aligning 20, the angle of the squeegee 4 can be adjusted via the adjusting plate 17 and the mounting bar 18.

Further, a vertically extending groove 21 is formed on the front surface of the case 10, and a sliding member 23 provided in the groove 21 is connected to the nut 13 in the case 10. Then, by the rotation operation of the lock lever 22 attached to the sliding member 23, the sliding member 23 moves up and down in the through groove 21, the moving amount is visually recognized on the scale 24, and the vertical position of the nut 13 is changed. It can be confirmed.

In FIG. 1, reference numeral 25 denotes a potentiometer provided outside the case 10, which is connected to the nut 13 in the case 10 and electrically connected to the digital indicator 25a, and is connected via the position of the nut 13. The position of the squeegee 4 is digitally displayed.

An air cylinder is provided on the holding bar 6 adjacent to the motor 7.
26 is fixed and connected to a blower (not shown). Then, the piston head 26a moves as the atmospheric pressure in the cylinder 26 increases and decreases due to the action of the blower, and the protrusion amount of the piston rod 27 is determined accordingly. The piston rod 27 extends downward from the through hole 28 of the holding bar 6, and the lower end thereof is an L-shaped support member 29 fixed to the outer wall of the case 10.
The piston rod 27 and the case 10, and by extension, the piston rod 27 and the adjusting bolt 11 are integrally moved up and down.

Further, a sensor dog 30 is provided on the outer wall of the case 10 below the support member 29, and as the case 10 moves up and down, the optical sensor 33 including a light projecting section 31 and a light receiving section 32 that are arranged facing each other near the case 10 is provided. It is designed to cut off communication.

The sensor 33 includes a blower motor 34, a buzzer 35, and an indicator 36.
Is electrically connected, and when the communication between the light emitter 31 and the light receiver 32 is cut off, the rotation speed of the blower motor 34 is increased, the buzzer 35 emits a recognition sound, and the display 36 emits a light emission display. Is supposed to do.

Now, the operation of the initial printing pressure setting device configured as described above will be described below.

In FIG. 3, the squeegee 4 is held in the non-printing position,
The squeegee rubber 5 is located apart from the screen plate 2. In this state, when the motor 7 is slowly rotated in the predetermined direction, the adjustment bolt is passed through the rotary shaft 8 and the entry shaft 8a.
11 is rotated. Therefore, the nut 13 descends on the adjusting bolt 11, and the squeegee 4 descends via the interposition plate 16, the angle adjusting plate 17, and the mounting bar 18.

As shown in FIG. 4, when the squeegee rubber 5 reaches the screen plate 2 and comes into contact with the printing paper P through the screen plate 2, it is indicated by the digital indicator 25 that the squeegee 4 has reached the initial printing pressure position.
This is confirmed in a. The rotation of the motor 7 is stopped by the switch operation. When the motor 7 is stopped,
It is extremely rare for the squeegee 4 to be in the correct initial printing pressure position by accident, and generally, even after the squeegee 4 has moved to the initial printing pressure position, the motor 7 makes a slight excess rotation and is stopped.

However, when the squeegee 4 moves to the initial printing pressure position,
The squeegee 4 receives the pressure of the printing paper P from below, and this pressure is transmitted from the squeegee 4 to the nut 13 via the mounting bar 18 and the like, and the downward movement of the nut 13 is prevented. Then, with the excessive rotation of the motor 7, the adjusting bolt 11 moves upward while rotating on the approach shaft 8a.

With the upward movement of the adjusting bolt 11, the case 10 moves upward,
Further, the piston rod 27 rises via the sensor dog 30 and the support member 29. When the sensor dog 30 rises and the optical communication of the optical sensor 33 is interrupted, the blower motor 34 is rotated at high speed by the signal from the optical sensor 33, and the cylinder 26
The flow rate of the air flowing in is increased, the pressure in the cylinder 26 is increased, and the position of the piston head 26a is fixed. Therefore,
The squeegee 4 is held at the initial printing pressure position via the case 10 and the mounting bar 18. At this time, the buzzer 35 emits a recognition sound, and the display 36 makes a light emission display to notify the operator of the completion of the setting of the initial printing pressure.

After that, printing is performed and the motor 7 is appropriately rotated according to the density of the printed matter to adjust the density.

As described above, in this embodiment, after the squeegee 4 is moved to the initial printing pressure position by the rotation of the motor 7, the excess rotation of the motor 7 is transferred to the entry shaft 8a provided on the rotation shaft 8 of the motor 7. On the other hand, when the adjusting bolt 11 is moved upward, it is absorbed and the pressure from the motor 7 is prevented from being applied to the squeegee 4. After that, the adjusting bolt 11 is fixed at the upper position by the action of the air cylinder 26, so that the initial printing pressure of the squeegee 4 can be reliably held.

It should be noted that the present invention is not limited to the above-described embodiment, and any modification is naturally possible without departing from the spirit of the invention, such as using an electromagnetic valve in the air circuit system instead of the blower motor 34. is there.

Effects of the Invention As described in detail above, according to the present invention, the squeegee can be reliably moved to the initial printing pressure position where it comes into contact with the object to be printed by descending the nut screwed to the adjustment bolt rotated by the motor, The squeegee can be held by the cylinder pressure at the initial printing pressure position, and the excess rotation force when the motor is stopped is absorbed by the upward movement of the adjusting bolt to move the squeegee to the initial printing pressure position. It has an excellent effect of preventing unnecessary pressure based on force.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an essential part of the present invention, FIG. 2 is a schematic view showing a screen printing machine, FIG. 3 is a sectional view showing an operating principle of the present invention, and FIG. It is sectional drawing which shows the change of a figure. Screen plate 2, squeegee 4, motor 7, adjusting bolt 1
1, a nut 13, an air cylinder 26, a piston rod 27, a printing paper P as an object to be printed.

Claims (1)

[Claims] 1. An initial printing pressure setting device for a screen printing machine in which a squeegee (4) is moved up and down to set the printing pressure of the squeegee (4), the axis of which is oriented vertically and rotated by a motor (7). The adjusting bolt (11) is provided so as to be movable along its axial direction, and the adjusting bolt (11) has a nut (13) integrally connected to the squeegee (4) by the motor (7). A screen characterized in that the adjusting bolt (11) is screwed down so as to rotate with rotation, and further, the piston rod (27) of the air cylinder (28) is provided so as to be vertically movable together with the adjusting bolt (11). Initial printing pressure setting device for printing machine.