JP2005088469A - Printing device in screen printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable set precision of a lifting reference position of a squeegee 15 by a simple structure. <P>SOLUTION: When left and right stepping motors 24 are driven in a state before start of printing, an air cylinder 13 for the squeegee at a non printing position Q descents together with the squeegee 15, the squeegee 15 is brought into pressure contact with a printing table 3 and a load is generated to the stepping motor 24. When the maximum load adjusted by an electric current adjusting volume is reached, the stepping motor 24 starts an out-of-step phenomenon and rise of the load of the stepping motor is limited. When both left and right stepping motors 24 start the out-of-step phenomenon, pressure force of the squeegee 15 to the printing table 3 is almost equalized on both sides in elongating direction of the squeegee 15. When printing is started, heights of the squeegee 15 to the printing table 3 become almost the same on both sides in the extension direction at a non printing position Q of an air cylinder 13 for squeegee. In printing, the printing pressure of the squeegee 15 becomes constant. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a printing apparatus provided with means for setting a lift reference position of a squeegee with respect to a printing table in order to make the printing pressure of the squeegee with respect to the screen plate substantially equal on both sides in the extending direction of the squeegee. Is.

In the following Patent Document 1, particularly as shown in FIGS. 1, 2 and 5, both sides of the lower edge of the squeegee 17 are detected by both photoelectric sensors 32 of the detection control means 31, and the squeegee 17 is pushed in both based on the detected data. By moving up and down by the amount adjusting device 20, the up / down reference position of the squeegee 17 relative to the print table 3 is set as the non-printing position. The height of the squeegee 17 with respect to the printing table 3 at the elevation reference position (non-printing position) is substantially the same on both sides of the lower edge of the squeegee 17. The squeegee 17 is brought into pressure contact with the screen printing plate S on the printing table 3 at a printing position lowered by the both squeegee lift cylinders 9 from the elevation reference position (non-printing position). At that time, the printing pressure of the squeegee 17 can be made constant.
Japanese Utility Model Publication No. 7-18839

  However, if both photoelectric sensors 32 move carelessly, an error may occur in the actual position with respect to the initial setting position of both photoelectric sensors 32, so that printing is performed despite the setting of the lift reference position of the squeegee 17. The height of the squeegee 17 with respect to the table 3 does not match on both sides of the lower edge of the squeegee 17, and the printing pressure of the squeegee 17 may not be constant. As described above, not only the setting accuracy of the reference position for raising and lowering the squeegee 17 is inferior, but since both the photoelectric sensors 32 of the detection control means 31 are required, the number of parts increases and the structure becomes complicated.

  An object of the present invention is to improve the setting accuracy of the reference position of the squeegee with a simple structure.

The present invention will be described with reference to the reference numerals of the drawings (FIGS. 1 to 3) of the embodiments described later.
The printing apparatus of the screen printer according to the invention of claim 1 is configured as follows.
In this screen printing machine, the screen plate (6) to which ink is applied is pressed against the printing material (2) on the printing table (3) by the squeegee (15), and the ink is passed through the screen plate (6) (the printing material ( 2) is provided with a printing mechanism (1) for printing. In this printing apparatus, the squeegee elevating pressure contact driving means (13 etc.) is provided on both sides in the extending direction (Y) of the squeegee (15), and the squeegee elevating reference position setting driving means (24 etc.) is provided. 15) on both sides in the extending direction (Y). The squeegee lifting pressure contact driving means (13, etc.) on both sides take a printing position (P) where the squeegee (15) approaches the screen plate (6) and a non-printing position (Q) where the squeegee (15) moves away from the screen plate (6). The squeegee (15) is supported so that it can be moved up and down, and the squeegee (15) is pressed against the screen plate (6) at this printing position (P). The squeegee elevation reference position setting drive means (24 etc.) on both sides raise and lower the squeegee (15) of this squeegee elevation press contact drive means (13 etc.). The squeegee raising / lowering reference position setting driving means (24 and the like) on both sides are provided with an electric motor (24) having a torque limiter function for restricting an increase in load when overloaded. When the electric motor (24) lowers the squeegee (15) of the squeegee up-and-down pressure contact driving means (13 etc.) and presses it against the printing table (3) or the screen plate (6) on the printing table (3). The maximum load generated in the electric motor (24) is limited by the torque limiter function. For example, the squeegee lifting pressure contact driving means (13 and the like) on both sides are lifted and lowered together with the squeegee (15) by the electric motor (24).

  Incidentally, the squeegee lifting pressure contact driving means on both sides is provided with a fluid cylinder such as an air cylinder (13) or a hydraulic cylinder, and the squeegee (15) is moved up and down between the printing position (P) and the non-printing position (Q). The fluid cylinder (13) to be brought into contact with the fluid cylinder (13) for bringing the squeegee (15) into pressure contact with the screen plate (6) at the printing position (P), as in the embodiment described later, The fluid cylinder (13) may be provided separately.

  In the invention of claim 1, when the squeegee (15) is lowered by the electric motor (24) and brought into pressure contact with the printing table (3) or the screen plate (6) on the printing table (3), the electric motor (24). Since the maximum load generated in the squeegee is limited by the torque limiter function, the pressure contact force of the squeegee (15) against the screen plate (6) becomes substantially equal on both sides in the extending direction (left-right direction Y) of the squeegee (15). Therefore, at the start of printing, the height (H) of the squeegee (15) with respect to the printing table (3) at the non-printing position (Q) is substantially the same on both sides in the extending direction (left-right direction Y). Therefore, the printing pressure of the squeegee (15) can be kept constant during printing. In addition, since the electric motor (24) having a torque limiter function for limiting the increase of the load at the time of overload is adopted, both photoelectric sensors 32 as in the prior art are not required, and the number of parts is reduced and the structure is simple. become.

  In the invention of claim 2 premised on the invention of claim 1, the squeegee lifting reference position setting drive means on both sides include an overload adjusting section (28, 29) for adjusting a maximum load generated in the electric motor (24). I have. In the invention of claim 2, the maximum load generated in the electric motor (24) can be easily adjusted by the overload adjusting portions (28, 29).

  In the invention of claim 3 premised on the invention of claim 2, the electric motor is a stepping motor (24), and the overload adjusting unit is a current adjusting unit capable of adjusting an operating current of the stepping motor (24). (28, 29). According to the third aspect of the present invention, the squeegee lifting reference position setting drive means can be made simple by using the stepping motor (24) and the current adjusting section (28, 29).

  The present invention can improve the setting accuracy of the lift reference position of the squeegee (15) with a simple structure.

Hereinafter, a printing apparatus of a screen printer according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1A, 1B, and 2, the printing mechanism 1 of the screen printing machine is installed above a printing table 3 that positions a substrate 2 and is supported so as to be tiltable in the vertical direction Z. ing. A plate frame 5 is attached to the lower side of the machine frame 4 of the printing mechanism 1, and a screen plate 6 is stretched inside the plate frame 5. Guide rails 7 are provided on both sides in the left-right direction Y in the machine frame 4, and a support base 8 is supported between the left and right guide rails 7 so as to be movable in the front-rear direction X. Left and right squeegee support mechanisms 9 and 10 and left and right doctor support mechanisms 11 are installed on the left and right sides of the support base 8.

  In the left and right squeegee support mechanisms 9 and 10, a support cylinder 12 is attached to a support base 8, and a squeegee air cylinder 13 is supported in the support cylinder 12 so as to be movable up and down in the vertical direction Z. Between the piston rods 13 a of the left and right squeegee air cylinders 13, a support body 14 is installed above the screen plate 6, and a squeegee 15 is detachably attached to the lower side of the support body 14 so that the surface of the screen plate 6 is mounted. It extends in the left-right direction Y so as to face. In the left and right doctor support mechanisms 11, a support cylinder 16 is attached to the support base 8, and a doctor air cylinder 17 is supported in the support cylinder 16 so as to be movable up and down in the vertical direction Z. A support 18 is installed above the screen plate 6 between the piston rods 17a of the left and right doctor air cylinders 17, and a doctor 19 is detachably attached to the lower side of the support 18 so that the surface of the screen plate 6 can be removed. It extends in the left-right direction Y so as to face. A reciprocating rotary belt 22 is stretched between a driven pulley 20 and a drive pulley 21 supported on both the left and right sides in the machine casing 4, and the support base 8 is connected to the reciprocating rotary belt 22. The rotation of the drive motor 23 is transmitted to the drive pulley 21. When the piston rod 13a of the squeegee air cylinder 13 moves up and down in the left and right squeegee support mechanisms 9 and 10, the squeegee 15 takes a printing position P approaching the screen plate 6 and a non-printing position Q separated from the screen plate 6. At this printing position P, it is pressed against the screen plate 6.

  Incidentally, in the left and right squeegee support mechanisms 9, 10, a squeegee up / down pressure contact driving means is constituted by the support cylinder 12, the squeegee air cylinder 13, the support 14, the squeegee 15, and the like.

  In the left and right squeegee support mechanisms 9 and 10, a stepping motor 24 (an electric motor having a torque limiter function) is mounted on the support cylinder 12, and the rotation of the stepping motor 24 is performed by a male and female screw mechanism portion 24a. 13 ascending and descending movements. A manual operation knob 25 is mounted on the stepping motor 24, and the rotation of the manual operation knob 25 is transmitted as an up and down movement of the squeegee air cylinder 13 by the male and female screw mechanism 24a. In the left and right doctor support mechanisms 11, a manual operation knob 26 is attached on the support cylinder 16, and the rotation of the manual operation knob 26 is transmitted as an up-and-down movement of the doctor air cylinder 17 by a male and female screw mechanism 26 a.

  The controller 27 to which various input / output devices (not shown) are connected has current adjustment volumes 28 and 29 (current adjustment units as overload adjustment units) that can adjust the operating current (maximum load) of the left and right stepping motors 24. It is connected. The stepping motor 24 rotates in synchronization with the input pulse. However, the stepping motor 24 loses the synchronization in an overload or the like, and causes a step-out phenomenon that does not synchronize with the input pulse. The step-out phenomenon functions as a torque limiter that limits the increase in load during an overload.

  Incidentally, in the left and right squeegee support mechanisms 9 and 10, a squeegee lifting reference position setting drive means is constituted by the stepping motor 24, the manual operation knob 25, the current adjustment volumes 28 and 29, and the like.

  When the stepping motor 24 is driven in each of the left and right squeegee support mechanisms 9 and 10 in a state before starting printing with the screen plate 6 removed from the printing table 3, the squeegee air cylinder 13 at the non-printing position Q is moved. The squeegee 15 is lowered with the pressure 15 and pressed against the printing table 3, and a load is generated on the stepping motor 24. When the load of the stepping motor 24 reaches the maximum load adjusted by the current adjustment volumes 28 and 29, the stepping motor 24 causes a step-out phenomenon, and the increase in the load of the stepping motor 24 is limited. When the left and right stepping motors 24 cause a step-out phenomenon, the pressure contact force of the squeegee 15 against the printing table 3 becomes substantially equal on both sides in the extending direction of the squeegee 15 (left-right direction Y). When such a squeegee lifting reference position setting operation is performed at least once, preferably two or more times, as shown in FIG. 3, the height H of the squeegee 15 relative to the printing table 3 at the non-printing position Q of the air cylinder 13 for squeegee. Are substantially the same on both sides of the extending direction (left and right direction Y) regardless of the extending direction dimension (left and right direction Y dimension) of the squeegee 15. Further, the height H of the squeegee 15 is finely adjusted with the left and right manual operation knobs 25 as necessary. At the start of printing, the screen plate 6 is mounted on the printing table 3 below the squeegee 15 at the non-printing position Q. During printing, when the squeegee 15 is lowered from the non-printing position Q to the printing position P by the squeegee air cylinder 13 and pressed against the screen plate 6 on the printing table 3, the printing pressure of the squeegee 15 can be made constant. .

(A) and (b) are the partial side views which show schematically the printing apparatus of the screen printer concerning this embodiment. It is the fragmentary front view similarly shown schematically. It is action | operation explanatory drawing which shows the height of the squeegee in a squeegee raising / lowering reference position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printing mechanism, 2 ... Substrate, 3 ... Printing table, 6 ... Screen plate, 13 ... Squeegee air cylinder, 15 ... Squeegee, 24 ... Stepping motor (electric motor), 28, 29 ... Current adjustment volume (overload) Current adjusting section as adjusting section), P ... printing position, Q ... non-printing position, Y ... left-right direction (squeegee extending direction).

Claims (3)

In a screen printing machine having a printing mechanism in which a screen plate coated with ink is pressed against a printing material on a printing table with a squeegee and ink is printed on the printing material through the screen plate.
A squeegee lift and pressure contact driving means for supporting the squeegee so as to be movable up and down so that the squeegee can take a printing position approaching the screen plate and a non-printing position separated from the screen plate and press the squeegee against the screen plate at this printing position Squeegee lifting reference position setting drive means for raising and lowering the squeegee lifting pressure contact driving means on both sides in the extending direction of the squeegee,
The squeegee lifting reference position setting drive means on both sides includes an electric motor having a torque limiter function for limiting an increase in load in the event of an overload. A printing apparatus in a screen printing machine, wherein a maximum load generated in the electric motor when pressed against the upper screen plate is limited by the torque limiter function. 2. The printing apparatus for a screen printing machine according to claim 1, wherein the squeegee lifting reference position setting driving means on both sides includes an overload adjusting unit for adjusting a maximum load generated in the electric motor. The printing apparatus for a screen printing machine according to claim 2, wherein the electric motor is a stepping motor, and the overload adjusting unit is a current adjusting unit capable of adjusting an operating current of the stepping motor.

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