JPH03121849A - Cleaning device for screen printing machine - Google Patents

Abstract

PURPOSE:To remove smear on a screen plate efficiently and lessen bleeding which occurs at the time of printing by a method wherein depending on the degree or condition of smear which adheres on the rear surface of a screen plate, a wiping member is operated with a solvent being fed or not. CONSTITUTION:For a dry wiping motion to wipe off unset smear under, which adheres on the lower surface of a screen plate 3, a part of a cleaning paper 10, on which a solvent is not applied, is stretched along the lower surface of the screen plate 3, and the part of the cleaning paper 10 is pressed to the lower surface by a squeegee for cleaning 16 and moved in the X direction. For a wiping motion with a solvent, by which smear under a half set condition is softened and wiped off, a solvent is applied on the cleaning paper 10 by a solvent applying pipe 38, and the cleaning paper 10 is stretched along the lower surface of the screen plate 3 and pressed to the lower surface by the squeegee 16, and move in the X direction. For a mesh blockage removing motion to remove mesh blockage of the screen plate 3 by air blowing, air is blown to the lower surface of the screen plate 3 from a pipe for air cleaner 17 to perform the cleaning. At this moment, drying of the screen plate 3 which is wet by the solvent is quickened by raising the temperature of air or increasing the flow rate of air.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention primarily relates to a cleaning device for a screen printing machine that prints cream solder, thick film circuit paste, etc. onto printed circuit boards.

Prior art A first conventional example of a cleaning device for removing dirt from a screen plate of a screen printing machine is one that wipes away dirt by pressing a cleaning paper 10 against the lower surface of a screen plate 3, as shown in FIG. It is. In the figure, reference numeral 11 denotes a fixed roll that stores the cleaning vapor 10 in a removable manner, and 12 denotes the cleaning vapor 10.
It is a take-up roll that winds up.

If the stain is uncured, the dry portion of the cleaning paper 10 is pressed against the lower surface of the screen plate 3 by the cleaning squeegee 16 and moved in the direction of the arrow X.

In addition, in the same figure, 15 is a cleaning squeegee 16.
It is an air cylinder that moves up and down.

If the dirt is hardening, apply the solvent to the cleaning paper 10 by sandwiching the cleaning paper 10 between the solvent application pipe 14 and the cleaning squeegee 16, and then use the cleaning squeegee 16 to apply the solvent to the cleaning paper 10. The part is moved in the direction of the arrow X while being pressed against the lower surface of the screen plate 3. In this case, the screen plate 3 gets wet with the solvent, so after removing the dirt, use the take-up roll 12 to remove the cleaning paper 1.
The cleaning paper 10 is wound up for a certain length until there is a part not coated with the solvent, and the solvent is wiped off with the dry part of the cleaning paper 10.

In the second conventional example, as shown in FIG. 7, air is blown onto the lower surface of the screen plate 3 using an air cleaner pipe 17 to blow away dirt.

In addition, in the same figure, 18 is the air cleaner pipe 1.
7 along the guide rail 19 in the direction of the arrow X.

Problems to be Solved by the Invention According to the first conventional example, since the cleaning paper comes into contact with the lower surface of the screen plate and wipes it off, the solder adhering to the surface can be wiped off.

However, it is difficult to remove clogging caused by solder clogging in the holes of the printed pattern provided on the screen plate. Furthermore, if the bottom surface of the screen plate is wiped with a cleaning paper supplied with a solvent, the surface will become wet, but even if wiped with a dry part of the cleaning paver to which the solvent is not supplied, the screen plate will not dry easily. This may cause printing to smear, or the printing material may stick to the bottom surface of the screen plate, causing problems in continuous printing.

According to the second conventional example, by blowing air from an air cleaner pipe onto the bottom surface of the screen plate, the solder clogging in the pattern holes of the screen plate is blown to the top surface of the screen plate and removed. It is possible.

However, since it is difficult to blow away the dirt adhering to the bottom surface of the screen plate through the pattern holes, it is not possible to remove it sufficiently, and instead, the solder that has become lumps ends up being scattered all over the bottom surface. Another cause of print smearing.

In view of the above-mentioned problems, an object of the present invention is to provide a cleaning mechanism for a screen printing machine that can efficiently remove dirt from a screen plate and reduce problems such as bleeding that occur during printing. do.

Means for Solving the Problems In order to achieve the above object, the present invention includes a wiping means for wiping the back side of the screen plate with a wiping material, a solvent supply means for supplying a solvent to the wiping material, and a wiping means for wiping the back surface of the screen plate with a wiping material, and a solvent supply means for supplying a solvent to the wiping material. an air supply means for supplying air, and a mode in which air is supplied to the screen plate after the wiping material is operated in a state where the solvent is not supplied, and a mode in which the wiping material is operated in a state where the solvent is supplied. It is characterized by having a mode in which air is later supplied to the screen plate.

Further, it is preferable that the air supply means is provided with a temperature/flow rate control section for adjusting the temperature and flow rate of the air blown onto the screen plate.

Operation According to the above structure, depending on the degree and condition of the dirt attached to the back surface of the screen plate, the wiping material can be activated with no solvent being supplied or with the solvent being supplied. By operating it, the dirt can be removed. After removing the dirt on the back side of the screen plate in this way, by blowing air on the back side of the screen plate, only the clogging of the pattern holes in the screen plate can be blown away and removed. It is possible to avoid a situation where dirt on the back side of the screen plate is scattered all over the back side of the screen plate.

Also, if the wiping material is operated while the solvent is being supplied,
Drying of the screen plate wetted by the solvent can be accelerated by the air blowing. In this case, the screen plate can be dried efficiently by adjusting the temperature and flow rate of the air.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 5.

As shown in FIG. 5, the screen printing machine of this embodiment has the following features:
A printing squeegee 8 (see FIG. 4) is arranged in the print head section 1 so as to be movable up and down, and a screen plate 3 is attached to the screen holding section 2. A printing material 6 (see FIG. 4) is supplied to a position below the screen plate 3 by a conveyor 4.

FIG. 4 shows the main parts of the screen printing machine of this embodiment. The printing table 7 on which the printing material 6 supplied from the conveyor 4 is placed reciprocates in the direction Y of the arrow. During printing, the printing table 7 is raised to the position shown by the solid line in the figure so that the upper surface of the printing material 6 comes into contact with the lower surface of the screen plate 3. Next, the printing squeegee 8 that reciprocates in the arrow direction
to print. When printing is completed, the printing table 7 is lowered to the position indicated by the imaginary line in the figure, and then the screen plate 3 is cleaned by the cleaning device 5 of this embodiment, which is disposed on the lower side of the screen plate 3.

1 and 2 show the cleaning mechanism 5 in detail. Below the screen plate 3, as shown in Fig. 2, there are branch offices 20a and 20b at the front (left side in the figure) on both left and right sides (both upper and lower sides in the figure), and pillars 21 at the rear (right side in the figure).
a, 21b are arranged, and the column 20 on the left side (upper side in the figure)
a, the support 20b between 21a and the right side (lower side in the same figure),
Respective guide rails 19a and 19b are installed horizontally between 21b. Short specified shafts 22a, 22 fixed to the inside of the upper ends of the front struts 20a, 20b so as to face each other
Each pulley 23a, 23b is rotatably attached to b. A long rotating shaft 27 is horizontally installed between bearings 41a and 41b provided at the upper ends of the rear struts 21a and 21b so as to be rotatable in forward and reverse directions. At both ends of this rotating shaft 27, respective belts 2 are connected between the pulleys 23a and 23b.
4a, 24b are wound around Boo'J 25a, 25
b is provided. A pulley 26 to which rotational driving force is transmitted from an electric motor (not shown) is fixed to one end of the rotating shaft 27.

The sliding members 28a and 28b are guided and supported by the guide rails 19a and 19b and are movable back and forth in the direction of the arrow X.
Parts of the belts 24a and 24h are fixed and reciprocated in the direction of the arrow X by the forward and reverse rotation of the rotating shaft 27. A carriage 29 is installed horizontally between these sliding members 28a and 28b. The take-up roll 12 of the cleaning paper (wiping material) 10 is rotatably supported by brackets 30a and 30b fixed to both front sides of the carriage 29, and is driven by an electric motor 31 provided outside the left bracket 30a. Rotationally driven. Also, the bracket 30
An air supply pipe 17 is installed horizontally between a and 30b. The upper half of the air supply pipe 17 is provided with a large number of air injection holes (not shown). A cleaning squeegee 16 (wiping means) that presses the cleaning paper 10 against the lower surface of the screen plate 3 is moved up and down by an air cylinder 15 erected and fixed on a carriage 29.

Brackets (33a, 33b) attached to both sides of the back of the mounting base 32 installed between the rear struts 21a, 21b
A fixed roll 11 for storing cleaning paper 10 in a removable manner is rotatably installed horizontally, and is rotationally driven by an electric motor 34 provided on the outside of the right side bracket 33b. At the upper ends of three support arms 35 erected on the upper surface of the mounting base 32, a guide roller 36 for regulating the running height of the cleaning paper 10 is rotatably installed horizontally. Above the guide roller 36, this guide roller 36
A winding length detecting device 13 is disposed to sandwich the cleaning paper 10 between the winding length detecting device 13 and the winding length detecting device 13 .

A solvent application pipe 38 fixed to support arms 37 on both left and right sides is attached to the upper front part of the mounting base 32 with the lower end of its outer periphery facing the rear extension surface of the lower surface of the screen plate 3. A tube 39 for supplying a solvent is connected to one end of the solvent application pipe 38. These solvent application pipes 38
In this embodiment, the tube 39 constitutes the solvent supply means of the present invention. The air supply pipe 17 is connected to a temperature/flow rate control device 41 via an air tube 40, and controls the temperature and flow rate of the air blown out from the air supply pipe 17 to prevent clogging and solvent leakage during cleaning. In addition to the removal action, it can also perform the action of creating an optimal ambient temperature during printing. These air supply pipe 17, air tube 40, and temperature/flow control device 41 constitute the air supply means of the present invention in this embodiment.

The screen printing machine cleaning device 5 configured as described above can perform various cleaning operations.

The first basic operation is a dry wiping operation (Dry) to wipe off uncured dirt attached to the bottom surface of the screen plate 3.
Spread the part of the cleaning paper 10 to which the solvent is not applied along the bottom surface of the screen plate 3, press the part against the bottom surface of the screen plate 3 with a cleaning squeegee 16, and move the cleaning squeegee 16 in the X direction. Perform cleaning.

The second basic operation is a wiping operation (wet) with a solvent that softens and wipes hardened dirt, in which a solvent is applied to the cleaning paper 10 using a solvent application pipe for 3 days, and the solvent on the cleaning paper 10 is The coated portion is spread along the lower surface of the screen plate 3, the portion is pressed against the lower surface of the screen plate 3 by a cleaning squeegee 16, and cleaning is performed by moving the cleaning squeegee 16 in the X direction.

The third basic operation is a clogging removal operation (Air(c)) in which clogging of the screen plate 3 is removed by air blowing.
), cleaning is performed by blowing air onto the lower surface of the screen plate 3 from the air cleaner pipe 17.

The fourth basic operation is a drying operation (Air (
C)).

By combining these basic operations, various cleaning modes can be configured. FIG. 3 illustrates various cleaning modes.

Mode 1 is a wiping operation (with solvent) during the movement of the carriage 29.
Wet), and when the carriage 29 returns, a dry wiping operation (
Dry).

Mode 2 is a dry wiping operation (D
After removing the dirt adhering to the back side of the screen plate 3 using A i
clogging of the pattern holes of the screen plate 3 is removed by (c)).

In mode 3, a solvent-combined wiping operation (Wet) and a clogging removal operation (Air (c)) are performed when the carriage 29 moves back and forth. When restoring, the air temperature is raised to dry (Air color))
I do.

Mode 4 is a clogging removal operation (
Air(c)).

In mode 5, the solvent-combined wiping operation (Wet) is performed once and then the dry wiping operation (Dry) is performed once.

In mode 6, the wiping operation with solvent (Wet) and the clogging removal operation (Air (c)) are performed once and then the dry wiping operation (Dry) and the drying operation (Air (c)) are performed once.
Go back and forth.

Mode 7 is a clogging removal operation (Air (Cl)) performed once and then a solvent wiping operation (Wet) at the next time.
and clogging removal operation (Air (C)), and at the time of recovery, a wiping operation with a solvent (Wet) and a drying operation (Air (C)) are performed.
5))).

The present invention can be configured in various ways other than those shown in the above embodiments.

For example, cleaning modes based on combinations of basic operations can be arbitrarily configured in addition to those shown in the above embodiments depending on the degree of contamination of the screen plate.

Effects of the Invention By removing clogging of pattern holes in a screen plate by air blowing, the present invention not only reduces bleeding during printing caused by the clogging, but also reduces stains on the back side of the screen plate. By using the cleaning mode that blows air onto the back side of the screen plate after removing the dirt, only the clogging of the pattern holes on the screen plate can be blown away. This makes it possible to avoid the situation in the conventional example where the dirt is scattered all over the back surface of the screen plate, and it is possible to reduce bleeding during printing caused by the scattered dirt.

Also, if the wiping material is operated while the solvent is being supplied,
Since drying of the screen plate wetted by the solvent can be accelerated by the air blowing, problems caused by wetting the screen plate with the solvent can be reduced during continuous printing.

[Brief explanation of drawings]

Fig. 1 is a side view showing the main parts of the embodiment of the present invention, Fig. 2 is a plan view showing the main parts, Fig. 3 is an explanatory diagram showing the cleaning mode of the embodiment, and Fig. 4 is the embodiment of the present invention. FIG. 5 is a perspective view showing the screen printing machine of this embodiment, FIG. 6 is a schematic side view of the first conventional example, and FIG. 6 is a schematic side view of the second conventional example. 0-6 17.40.41 38.39 Screen plate wiping material Wiping means Air supply means Solvent supply means

Claims (2)

[Claims] (1) A wiping means for wiping the back side of the screen plate with a wiping material, a solvent supply means for supplying a solvent to the wiping material, and an air supply means for supplying air to the screen plate, so that no solvent is left unused. It is characterized by having a mode in which air is supplied to the screen plate after operating the wiping material in a state where the solvent is supplied, and a mode in which air is supplied to the screen plate after the wiping material is operated in a state in which the solvent is supplied. Cleaning equipment for screen printing machines. (2) The cleaning device for a screen printing press according to claim 1, wherein the air supply means includes a temperature/flow rate controller that adjusts the temperature and flow rate of the air that is blown onto the screen plate.