JPS61280937A - Ink-returning device for screen printer - Google Patents

Abstract

PURPOSE:To obtain exact and clear printings without staining and disordering by using a system in which ink is scooped upwards from a screen plate by synergistic action of a squeegee and an ink scooper at the ending position of printing and then returned to the starting position of printing. CONSTITUTION:When a squeegee 26 reaches the ending position of printing, an operating cylinder 39 is put into a submerging action, and an ink scooper 59 together with a supporting cylinder 30 is lowered onto a screen 4. When a piston rod 56 is projected, the ink scooper 59 is pressingly slided, together with a movable connector 51, on the screen 4 forwardly, and ink X is scooped between the tip of the ink scooper 59 and the squeegee 26. When a supporting frame 15 is moved upwards on a receiving base 13, the squeegee 26 and the ink scooper 59 are raised, together with the frame 15 integrally, fro the screen plate 5. When a motor 7 is reversely turned, ink X scooped as the frame 15 returns is fed to the starting position side of printing.

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) This invention is a screen printing method in which printing is performed by pushing out ink on a screen plate by sliding a squeegee on the screen plate under pressure. The present invention relates to an ink return device configured to scoop up ink after a printing operation is completed and return it to a printing start position.

(Prior art) In a conventional screen printing machine of this type, printing is performed by a squeegee sliding under pressure on a screen plate from a printing start position to a printing end position, and then a doctor stops printing. The ink is spread over the screen plate by sliding back from the position to the printing start position.

(Problem to be Solved by the Invention) However, when the doctor returns to its original position, some of the ink oozes out to the lower surface of the screen plate through the mesh in the image area of the screen and adheres to the periphery of the image area. do. Therefore,
When the next printing is performed in this state, problems arise in that the bleeding ink causes chattering on the image pad printed on the printing paper, and that the ink gets stuck in undesired areas, making the printing unclear.

In particular, when ink with low viscosity is used, there is a problem that the ink flows down onto the printing paper through the mesh of the image area of the screen as the doctor performs the ink return operation.

In addition, when resist printing is performed on a printed circuit board using a conventional screen printing machine, ink remains on the print area of the screen when the doctor returns the ink, so the remaining ink disappears over time. The fluidity of the ink decreases, and the ink adheres to the printed circuit board during the 11th printing. Moreover, air bubbles are likely to form between the remaining ink and the newly supplied ink, and especially when the printing surface is slightly uneven, such as in resist printing, the air bubbles may interfere with the image. This also resulted in the inconvenience of being inaccurate. Therefore, when conventionally resist printing is performed, it is necessary to periodically clean the screen plate, which is a very troublesome process.

Structure of the Invention (Means for Solving the Problems) The present invention has been made to solve each of the problems described above. An actuation mechanism 39 for moving the ink scooping member 59 toward and away from the screen plate 5 separately from the squeegee 26 between the ink scooping member 59 and the support frenim 15. and a lifting mechanism 18 for raising and lowering at least one of the support frame 15 and the screen plate 5 relative to the other, and moving the squeegee 26 and the ink scooping member 59 together toward and away from the screen plate 5, and the support frame 15. The ink scooping member 59 is reciprocated along the screen plate 5 between the ink scooping member 59 and the ink scooping member 59 is disposed between an original position away from the squeegee 26 and an active position where it contacts the squeegee 26 to scoop up ink X. It is composed of a scooping mechanism 55.

(Operation) Each of the above-mentioned means functions as follows. First, as shown in FIG. 5, the squeegee 26 is moved from the print start position to the print end position on the screen 4 with the ink scoop member 59 separated above the screen plate 5 by the actuation mechanism 39. When the screen 4 is pressed and slid, the ink X on the screen 4 is pushed out from the printing area and printing is performed on the printed material. Next, when the squeegee 26 reaches the printing end position as shown in FIG. The ink scooping member 59 is slid on the screen 4 by the picking mechanism 55 toward the operating position where it contacts the squeegee 26 . In this state, as shown in FIG. 8, the ink scooping member 59 and the squeegee 26 are moved upwardly from the screen plate 5 together by the elevating mechanism 18, and the ink X on the screen 4 is scooped out. Subsequently, in this state, as the support frame 15 moves, the squeegee 26 and the ink scoop member 59 are integrally moved back toward the printing start position, and then lowered onto the screen plate 5 again. Then, the ink scooping member 59 is moved away from the squeegee 26 to its original position, and after the ink X is placed on the screen 4 at the printing start position, the state shown in FIG. 5 is restored.

(Example) Hereinafter, an example embodying the present invention will be described based on the drawings.

As shown in Fig. 2, a table 2 for placing printed matter is arranged on the top surface of the machine stand 1 of the screen printing machine, and the table 2 is placed between the printing position indicated by the solid line and the setting position indicated by the chain line in the figure. It is possible to move back and forth. Further, a rectangular upper frame 3 is provided above the machine stand 1, and a screen plate 5 on which a screen 4 is stretched is supported within the lower side of the upper frame 3.

A drive belt 6 is stretched inside the left and right side walls of the upper frame 3, and is driven around by a motor 7 capable of forward and reverse rotation.

As shown in FIG. 3, an upper traveling body 9 and a lower traveling body 10 are fixed to the drive belt 6 so as to sandwich the belt 6, and the lower traveling body 10 is attached to the upper frame 3.
It is supported by linear bearings 11 on rails 12 fixed to the inside of the left and right side walls. A pedestal 13 is fixed to the upper traveling body 9 in a state of protruding inwardly, and as the drive belt 6 rotates, the screen plate 5 moves inside the upper frame 3.
It is designed to be moved back and forth along the line.

A support frame 15 extending left and right inside the upper frame 3 is placed on the upper surface of the pedestal 13 at both ends thereof.

A pair of front and rear guide rods 17 (only seven are shown) are fixed to the lower surfaces of both ends of the support frame 15 by screws 14 at their upper ends, and both guide rods 17 are vertically movable into through holes 16 formed in the pedestal 13. Possibly inserted. Further, an elevating cylinder 18 is installed and fixed on the upper surface of both ends of the support frame 150, and its piston rod 19 is connected to the support frame 15.
It is in contact with the upper surface of the pedestal 13 through the hole 21 . An elevating mechanism is constituted by the pedestal 13, the guide rod 17, the elevating cylinder 18, etc., and when the piston rod 19 of the elevating cylinder 18 protrudes, the support frame 15 is guided by the guide rod 17, as shown in chain lines in FIG. It is arranged in the raised position shown by .

As shown in Fig. 1.2.4, a squeegee support tube 23 is supported in the front side of both ends of the support frame 15 in the vicinity of the lifting cylinder 18 so as to be movable up and down, and a connecting member 24 and a mounting rod are attached to the lower end of the squeegee support tube 23. A squeegee 26 is supported via 25 so as to extend from side to side inside the upper frame 3. Note that the angle of this squeegee 26 can be adjusted by an adjustment member (not shown).

On the other hand, as shown in FIG. 3, a through hole 28 is formed in the support frame 15 near the rear side of the squeegee support tube 23.
A support tube 30 is inserted through the slide guide member 29 so as to be slidable up and down.

A rake pressure adjustment member 31 composed of a dial portion 32 and an inner cylinder 33 is attached to the upper end of the support cylinder 30.
A male thread 35 is carved on the outer circumferential surface of the lower end of the support cylinder 30 to be screwed into a female thread 34 provided on the inner surface of the circumferential wall of the support cylinder 30.
A screw hole 36 is formed in the lower surface of the inner cylinder 33. or,
An operating cylinder 39 is attached at the lower end of the support arm 38 fixed to the lower surface side of the support frame 15, and the upper end thereof is inserted into the lower end of the support cylinder 30. and,
The piston rod 41 of the working cylinder 39 is connected to the inner cylinder 33.
When the piston rod 41 protrudes, the support cylinder 30 is moved upwardly with respect to the support frame 15 separately from the squeegee 26, as shown by the chain line in FIG. It has become so. or,
When the dial portion 32 of the rake pressure adjusting member 31 is rotated, the vertical position of the support cylinder 30 with respect to the operating cylinder 39 is adjusted through the action of the screws 34 and 35. Note that the squeegee support tube 23 is the same as the support tube 3 described above.
It has almost the same structure as 0, and there is a squeegee 2 at the top end.
A pressurizing force adjustment member 42 for 6 is provided, and a cylinder 43 for driving the squeegee up and down is accommodated in the lower end.

A planar U-shaped mounting member 46 is attached to a mounting piece 44 protruding inward from the lower end of the support tube 30 via a pin 45.
is supported, and a mounting member 48 is fixed to the mounting member 46 via a connecting plate 47. As shown in Figure 1,
A pair of upper and lower guide shafts 50 are installed between the front and rear side plates 49 of the mounting member 48, and a movable coupling body 51 is installed on both guide shafts 50.
is slidably supported by a sliding tube portion 52 at its upper end. Accommodation section 5 provided within the upper end of the movable coupling body 51
A skimming cylinder 55 parallel to the screen plate 5 is accommodated in the cylinder 3, and is screwed and fixed to the rear wall of the movable coupling body 51 by a threaded portion 54 on the rear end side. The piston rod 56 of the skimming cylinder 55 is connected to the mounting member 4.
The front end of the cylinder body 55a is screwed and fixed to the rear side plate 49 of the cylinder body 8, and the cylinder body 55a serves as a movable part.

is loosely fitted into an insertion hole 57 provided in the front side plate 49. A scooping mechanism is constituted by the mounting member 48, the movable connecting body 51, and the scooping cylinder 55, and when the piston rod 56 protrudes, the movable connecting body 51 is moved forward (squeegee 2) integrally with the cylinder body 55a.
6 side).

As shown in FIGS. 3 and 4, a horizontal plate 60 is fixed to the lower end of the movable coupling body 51, and an elongated hole 61 is provided in the inner side of the horizontal plate 60 so as to extend back and forth.

An adjusting body 6 is mounted on the horizontal plate 60 so as to sandwich it from above and below.
2 is supported, and a pin 64 is fitted into a supporting hole 63 which is transparent at a position corresponding to the elongated hole 61 and is inserted through the elongated hole 61. Further, an adjustment screw 66 is screwed into the horizontal plate 60 at a position corresponding to the elongated hole 61 so as to extend back and forth, and the threaded portion thereof is screwed into the screw hole 67 of the pin 64, and the front end is connected to the horizontal plate 60. It is rotatably supported on the front end of 60. Then, the horizontal plate 60. An interval adjusting member is constituted by the adjusting body 62, the adjusting screw 66, etc., and when the knob 68 of the adjusting screw 66 is rotated, the adjusting body 62 is moved to the fourth It is designed to be moved between a rear position shown by a solid line in the figure and a front position shown by a chain line.

A mounting rod 65 extending left and right inside the upper frame 3 is supported at both ends on the front surface of the adjustment body 62, and as shown in FIG. A plate-shaped ink scooping member 59 is attached to face the front surface. An operating mechanism is constituted by the support cylinder 30, the operating cylinder 39, the mounting rod 65, etc., and the ink scooping member 59 is moved up and down as the support cylinder 30 moves up and down as the piston rod 41 of the operating cylinder 39 moves in and out. As shown in Figures 5 and 6, the squeegee 26
The screen plate 5 is brought into contact with and separated from the screen plate 5 separately from the screen plate 5.

Next, the operation of the screen printing machine configured as above will be explained. Now, FIG. 5 shows the printing start state, in which the piston 0 and 1 of the lifting cylinder 18 are
9 is retracted and the support frame 15 is placed on the pedestal 13 (the solid line position in FIG. An ink scooping member 59 is disposed at an upper position spaced apart from the screen 4 (position indicated by the chain line in FIG. 3) and integrally with the support [30].

In this state, the motor 7 is started and the drive belt 6
When the support frame 15 is moved rearward through the support frame 15, the ink Predetermined printing is performed on the printed matter.

As shown in FIG. 6, when the squeegee 26 reaches the printing end position, the operating cylinder 39 is retracted and the support cylinder 30
Together with this, the ink scooping member 59 is lowered onto the screen 4. Next, in this state, the scooping cylinder 5
When the piston rod 56 of No. 5 is projected, the ink scooping member 59 is vibrated under pressure on the screen 4 together with the movable connecting body 51 toward the front (towards the printing start position side), as shown in FIG. 4 is scooped up between the tip of the ink scooping member 59 and the squeegee 26.

In the subsequent work, when one piston rod of the lifting cylinder 18 is protruded and the support frame 15 is moved above the pedestal 13, the squeegee 26 and the ink scooping member 59 scoop up the ink X as shown in FIG. In this state, it is lifted up from the screen plate 5 together with the support frame 15. and,
When the motor 7 is reversely rotated in this state, the ink X that has been scooped up as the support frame 15 returns is transferred to the printing start position.

Thereafter, the piston rod 19 of the p-falling cylinder 18 is retracted, and the squeegee 26 and the ink scooping member 59 are lowered together onto the screen 4, and then, as the piston rod 56 of the scooping cylinder 55 is retracted, the ink scooping member 59 is separated backward from the squeegee 26, and the ink X is placed on the screen 4 again. Subsequently, the five ink scooping members are raised together with the support cylinder 30 by the protruding operation of the operating cylinder 39, and the above-described printing start state shown in FIG. 5 is achieved.

By the way, in the screen printing machine of this embodiment, since the scooping pressure adjusting member 31 is provided on the support cylinder 30, the pressing force of the ink scooping member 59 against the screen plate 5 can be adjusted to an appropriate value by rotating the dial portion 32. By adjusting this, the ink scooping member 59 can be operated to scoop up the ink X reliably depending on the type or amount of ink X. Furthermore, if the distance between the ink scooping member 59 and the squeegee 26 is appropriately adjusted by operating the adjustment screw 66, the squeegee 26 can be adjusted regardless of the inclination angle of the squeegee 26.
The ink X can be scooped up by bringing the ink scooping member 59 into reliable contact with the ink X.

In addition, when performing printing that does not require ink return by scooping in the screen printing machine of this embodiment, the cylinder 43 for driving the squeegee up and down in the squeegee support cylinder 23 is operated. In this case, the mounting rod 6
5 is attached with a doctor whose tip has a gentle inclination angle in place of the ink scooping member 59, and the doctor and the squeegee 26 are alternately raised and lowered with respect to the screen plate 5, and as the doctor returns and slides, the ink It is painted on screen 4 and spread.

Furthermore, the present invention is not limited to the configuration of the above-mentioned embodiment, but can be applied to, for example, a cylinder type screen printing machine configured so that printing paper can be supplied and printed at the same time as the cylinder rotates. It is also possible to make it concrete.

Effects of the Invention As detailed above, according to the present invention, ink is scooped upward from the screen plate at the printing end position by cooperation of the squeegee and the ink scooping member, and then the ink is returned to the printing start position. Because of this structure, there is no risk that part of the ink will bleed to the bottom side of the screen plate due to the refill operation, and it is possible to perform accurate and clear printing without chatter or stains, and it is also possible to perform resist printing on printed circuit boards. It has an excellent effect in that it can be carried out without any problems.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a scooping mechanism in an embodiment embodying the present invention, FIG. 2 is a side view showing the entire screen printing machine, and FIG. 3 is a view showing an operating mechanism and a lifting mechanism. 4 is a sectional view taken along the line A--A in FIG. 3, and FIGS. 5 to 8 are action explanatory diagrams showing different operating states. Sleeve plate 5, support frame 15, lifting cylinder 18,
Squeegee support cylinder 23, squeegee 26, support cylinder 30, rake pressure adjustment member 31, operating cylinder 39, squeegee lifting cylinder 43, mounting member 48, movable coupling body 51, scooping cylinder 55, ink scooping member 59, mounting rod 65, adjustment screw 66, ink X0゛

Claims (1)

[Claims] 1. A support frame (15) is provided so as to be able to reciprocate along the screen plate (5), and a squeegee (26) can be attached to and separated from the screen plate (5) on the support frame (15). The squeegee (
26) on the screen plate (5) to push out the ink (X) on the screen plate (5) to perform printing, wherein the sliding of the squeegee (26) An ink scoop member (
59), its ink scooping member (59) and support frame (15)
an operating mechanism (39, etc.) provided between the ink scooping member (59) and the screen plate (5) separately from the squeegee (26); and the support frame (15). Raise and lower at least one side of the screen plate (5) relative to the other, and use the squeegee (26
) and the ink scooping member (59), an elevating mechanism (18, etc.) for integrally moving the ink scooping member (59) toward and away from the screen plate (5), and the support frame (15) and the ink scooping member (59).
The ink scooping member (59) is reciprocated along the screen plate (5), and the ink scooping member (59) is moved back and forth along the screen plate (5), and the ink (
An ink returning device for a screen printing machine, characterized in that it is comprised of a scooping mechanism (such as 55) for disposing an ink collecting mechanism (such as 55) at a scooping action position. 2. The operating mechanism includes an operating cylinder (39) fixed to the support frame (15);
A support tube (30) connected to the movable part (41) and movable up and down with respect to the support frame (15), and a mounting rod (30) supported by the support tube (30) so as to extend parallel to the screen plate (5). 65) and the first claim consisting of
An ink return device for a screen printing machine as described in Section 1. 3. A screen plate (5) of the ink scooping member (59) is provided between the operating cylinder (39) and the support cylinder (30).
rake pressure adjustment member (3) for adjusting the pressing force against
1) An ink return device for a screen printing press according to claim 2, wherein the ink returning device is provided with the following. 4. Between the support tube (30) and the mounting rod (65),
The screen according to claim 2, further comprising a distance adjusting member (66, etc.) for adjusting the distance between the ink scooping member (59) and the squeegee (26) arranged at the original position. Ink return device for printing presses. 5. The elevating mechanism includes a pedestal (13) fixed on the drive belt (6) so as to run along the screen plate (5) and on which the support frame (15) is placed; The movable part (19) is installed on the top surface of the frame (15).
), a lifting cylinder (18) whose tip comes into contact with the top surface of the pedestal (13), a support frame (15), and the pedestal (13).
The ink return device for a screen printing press according to claim 1, further comprising a guide rod (17) for guiding the lifting and lowering movement of the support frame (15) between the ink return device and the support frame (15). 6. The scooping mechanism includes a mounting member (48) supported by the support frame (15), and a scooping cylinder (48) mounted on the mounting member (48) so as to extend parallel to the screen plate (5). 55) and a movable connecting body (51) that connects the movable part (55a) of the scooping cylinder (55) and the ink scooping member (59). Ink return device for screen printing machines. 7. The ink return device for a screen printing press according to claim 2 or 6, wherein the mounting member (48) is supported by the support cylinder (30). 8. Between the support frame (15) and the squeegee (26), the squeegee (26) is connected to an ink scooping member (59).
The ink return device for a screen printing press according to claim 1, further comprising a squeegee lifting cylinder (43) for separating the screen plate (5) from the screen plate (5).