JP3769588B2 - Screen cleaning system for screen printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a screen printing machine for printing a viscous printing material on a substrate using a screen having a plurality of printed pattern openings, and in particular, to the printed pattern openings of the screen, for example, a viscous material such as a solder paste or an adhesive. those related to a screen cleaning system that put a suitable screen printing machine to remove it when the dirt adhesion of clogging or residue by printing material occurs.
[0002]
[Prior art]
When dirt such as clogging occurs in the screen printing pattern opening during screen printing by the screen printing machine, gas is blown out from a cleaning nozzle movably provided on the surface side of the screen, and the blowing pressure A cleaning technique is already known in which a viscous printing material such as a solder paste remaining in the printed pattern opening is extruded and removed to the back side of the screen.
[0003]
[Problems to be solved by the invention]
However, a cleaning nozzle that is generally employed in a conventionally known technique is a slit-like nozzle having a horizontally long nozzle hole with a wide opening area, and air or nitrogen fed from one pressure accumulating tank from the horizontally long nozzle hole. Since the gas such as gas is merely continuously blown out, the jet pressure of the gas blown out by the gas is relatively low. For example, the printing material is relatively strong on the inner surface of the pattern opening. This may be the case when there is clogging that is stuck, or when a highly viscous printing material such as solder paste remains in narrow or fine pattern openings as in high-density printing screens. Therefore, it is difficult to remove and clean the dirt, and in order to increase the jet pressure, a large pressure storage tank that requires a large installation space Since a large amount of pressurized gas must be fed to the nozzle using a thick air pipe, it is uneconomical and costly. Furthermore, if the jet pressure of the gas blown from the nozzle with a wide opening area is high, the screen Since the jets collide over a wide range, the screen is deformed by the jet pressure, and precision printing becomes impossible or extremely difficult.
[0004]
Therefore, the present invention has been made to eliminate the above-mentioned disadvantages and disadvantages of the prior art.
[0005]
Therefore, an object of the present invention is to provide screen printing that can easily and efficiently remove and clean dirt such as clogging of print pattern openings on the screen by effectively using a pressure gas such as compressed air. it is to provide a screen Cleaning Gushi system in the machine.
[0006]
Another object of the present invention is to reduce the consumption of pressure gas required for cleaning dirt such as clogging of printed pattern openings on the screen, and to reduce the cost. to provide a screen Cleaning Gushi stem in the preferred screen printing machine to perform.
[0007]
It is still another object of the present invention to provide a jet pressure of a printing material residue remaining inside or around a printed pattern opening of a screen while performing a cleaning operation by ejecting a high-pressure gas from a cleaning nozzle. It is an object of the present invention to provide a screen cleaning system in a screen printer capable of effectively preventing scattering due to the above.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a screen cleaning system for a screen printer according to the present invention is a screen printer for printing a viscous printing material on a substrate using a screen having a plurality of print pattern apertures. Main piping for supplying pressure gas to the nozzle from a cleaning nozzle provided movably on the front side or the back side, a pressure accumulating tank, and the pressure accumulating tank formed between the nozzle and the pressure accumulating tank and the air circuit comprising a plurality of branch pipes connected to the branched and the nozzle from the main pipe, and opening and closing valves of normally closed attached respectively to the branch pipes of the plurality, each of these opening and closing valves and a control apparatus that can control the opening and closing of the Rukoto is opened and closed several times within a short period of time all or part of the on-off valve, Characterized in that the serial high-pressure pulse gas was pressure adjustably ejected from the nozzle, and configured to be able to remove the viscous printing material remaining attached to the inner surface of the printing pattern openings of the screen by the pulse jet pressure It is what.
[0009]
Also, the screen cleaning system according to the present invention, in the screen printing machine, a cleaning nozzle provided to each movable in both the X-axis and Y-axis on the surface side or back side of the screen, and accumulator tank, A main pipe and a plurality of branch pipes branched from the main pipe and connected to the nozzle for supplying pressure gas from the pressure accumulation tank formed between the nozzle and the pressure accumulation tank to the nozzle An air supply circuit, a normally closed open / close valve attached to each of the plurality of branch pipes, and a control device capable of controlling the open / close of each of the open / close valves. Alternatively, a part of the nozzle is opened and closed a plurality of times within a short period of time so that a high-pressure pulse gas is ejected from the nozzle in a pressure-adjustable manner, and the script jet pressure causes the script to flow. It is characterized in that it has adapted to be able to remove the viscous printing material remaining attached to the inner surface of the printing pattern openings of emissions.
[0010]
Furthermore, the screen cleaning system according to the present invention according to claim 1 or 2 prevents the dispersion of the pulse gas ejected from the nozzle in close contact with the screen when cleaning the pattern openings of the screen. The cap-shaped body made possible is detachably fitted to the nozzle in such a manner as to surround the periphery of the tip of the nozzle.
[0011]
A screen cleaning system according to the present invention is the screen cleaning system according to claim 1 or 2, wherein the cleaning nozzle is movably provided on one side, and the screen is cleaned by the pulse jet pressure. intended to the printed pattern apertures with collecting the residue of viscous printing material to be blown to the other side of the screen, characterized in that movable cleaning aid which is adapted to prevent the scattering There is .
[0012]
Still further, the screen cleaning system according to the present invention is characterized in that the pressure gas is a mixed gas obtained by atomizing a solvent and mixing with air.
[00 13 ]
[Action]
When the normally closed open / close valve is opened and closed several times in a state where the cleaning nozzle movably provided on one side of the screen is directed to the print pattern opening clogged with the printing material, the nozzle high-pressure pulse gas vigorously ejected, balloon printing material residue is causing clogging by its pulsating vibration shaped pulse jet pressure on the other side of the screen through the pattern opening, in a very short time the opening to clean up. In the case having the cap-like body, the dispersion of the pulse gas ejected from the nozzle is prevented, and the scattering of the printing material residue due to the dispersion is prevented. Other operations will be described later in connection with the embodiment.
[00 14 ]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings showing examples of the present invention.
[00 15 ]
FIG. 1 shows an example of the implementation of a screen cleaning method and a screen cleaning system in a screen printing machine according to the present invention. In the figure, reference numeral 1 denotes compression as a pressure gas compressed by the compressor 2 from the atmosphere. An accumulator tank 3 for storing air is an air supply open circuit for supplying compressed air to the cleaning nozzle 4 movably provided from the accumulator tank 1 to one side of the screen S. The opening / closing valve 5 is normally closed, the inlet pipe 6 is connected to the pressure accumulating tank 1 on the inlet side thereof, and the outlet pipe 7 is connected to the cleaning nozzle 4 on the outlet side of the opening / closing valve 5.
[00 16 ]
In the illustrated example, the opening / closing valve 5 is configured as a normally-closed two-port solenoid valve that is automatically operated by electromagnetic force, and is connected to the control device 8, and receives an electrical signal from the control device 8. To be controlled. In this example, the 2-port solenoid valve is preferably a pilot operated type capable of controlling high pressure and large flow rate rather than a direct acting type. When the normally closed open / close valve 5 opens and closes a plurality of times within a short time in response to an electrical signal from the control device 8, the air supply circuit 3 opens and closes a plurality of times within a short time. The high-pressure pulse gas from 4 becomes a pulsating wave-like pulse jet and is ejected vigorously.
[00 17 ]
FIG. 2 shows a second embodiment of the present invention, in which 1 is an accumulator tank, 2 is a compressor, and 3 is an air supply circuit. The air supply circuit 3 in this example is different in configuration from the air supply circuit 3 in the first embodiment described above, and includes a plurality of branch pipes 7A, 7B, 7C branched from the main pipe 9, and these branch pipes. It consists of a common outlet line 10 connecting the cleaning nozzle 4. Further, in this example, a normally-closed electromagnetic on-off valve 5 similar to the above-described on-off valve is provided in each branch pipe 7A, 7B, 7C and connected to the control device 8, respectively. In response to the electrical signals from the control device 8, they can be opened or closed simultaneously in whole or in part. Then, such that by controlled opening and closing multiple times Open Closed to the air supply circuit 3 within a short period of time, the momentum pulses gas required pressure level becomes a pulsating wave form of the pulse jet from the cleaning nozzle 4 Well erupted. In this example, the opening / closing valve 5 as a two-port solenoid valve is provided in each of the branch pipes 7A, 7B, 7C, so that a relatively small solenoid valve can be used.
[00 18 ]
In both the first and second embodiments, the cleaning nozzle 4 has a single spot having a tapered cylindrical body 4A having a circular or square cross section and a nozzle 4B having a shape corresponding to the cross sectional shape. It is desirable to form as a nozzle. The opening area of the nozzle hole 4B is preferably set to be slightly larger than the area or the width of the opening 11 when the screen S to be cleaned has the small printed pattern opening 11. Further, when cleaning the print pattern openings 11, the cleaning nozzle 4 directs the nozzle holes 4B to the individual print pattern openings 11 where clogging 12 is caused by the viscous printing material, as shown in FIG. The cap-shaped body 13 is used in a state where the dispersion of the pulse gas ejected from the nozzle 4 in close contact with the screen S is prevented, and the scattering of the printing material residue due to the dispersion is prevented. It is preferable that the nozzle 4 is detachably fitted to the nozzle in such a manner as to surround the periphery of the tip of the nozzle 4. The cap-shaped body 13 may be made of a material having both flexibility and elasticity, such as an elastomer.
[00 19 ]
Further, the cleaning nozzle 4 is preferably structured so as to be assembled and disassembled. As shown in FIG. 3, the outer nozzle 4C is detachably attached to the outer tube 4C using a bolt, nut and other fastening members together with a cap-like body 13. It is preferable that the nozzle hole 4B is attached so as to be interchangeable. If it does in this way, since it can replace | exchange suitably according to the size of the pattern opening 11 of the screen S, the application range as a cleaning system can be widened. In both the first and second embodiments, the cleaning nozzle 4 is provided so as to be movable in both the X-axis and Y-axis directions using a known XY table and its driving mechanism (not shown). It has been.
[00 20 ]
The screen cleaning system according to the present invention is operated by computer control. Next, this point will be described with reference to FIG. 4. First of all, whether or not clogging or the like that has an adverse effect on the printing result occurs in any of the printing pattern apertures 11 of the screen S is shown in FIG. The screen S in which the input device 14 detects and then the image detection signal from the image input device is digitally converted by the image processing device 15 and the binarized pattern to be confirmed is stored in the memory in the microcomputer 16 in advance. Only when it is determined that clogging or the like that requires cleaning has occurred in comparison with the shape and size of the print pattern aperture 11, it responds to an output signal that is sequentially sent from the control device 8 according to the program. Thus, an operation for cleaning by each operation mechanism is started. Although an automatic control method by a combination of these devices 14, 15, 16, and 8 is known per se, for the screen cleaning system according to the present invention, the print pattern is opened before the actual cleaning operation is started. Since it is extremely important to accurately detect the clogged state of the hole 11, the illumination means 17 that cooperates with the image input device (optical sensor) 14 is connected to the screen S as shown in FIG. Is arranged so as to be movable in both the X-axis and Y-axis directions, and the beam 17A 'from the light source 17A is reflected vertically upward via the mirror 17B. Yes. According to such a configuration, only the transmitted beam 17A ″ that has passed through the pattern aperture 11 is incident on the image input device 14, so that the recognition pattern image showing the clogged state becomes extremely sharp, Comparison and comparison with the shape and dimensions of the stored pattern apertures is easy and accurate, and the image input device (optical sensor) 14 is installed so as to be movable in the XY direction in synchronization with the illumination means 17. Is done.
[00 21 ]
FIG. 5 is a diagram illustrating a method for adjusting the operation of the normally closed on-off valves 5, 5, 5 in the second embodiment described above. In A, B, C, D, the vertical axis indicates the pressure level. The horizontal axis shows the control time. A shows a case where all of the open / close valves 5, 5 and 5 are simultaneously controlled with the same impulse duration IT. In this case, it is assumed that the open / close valves have the same dimensions and performance. Then, compared with the flow of the pulse gas flowing through the individual opening / closing valves, the flow rate is almost three times higher, and the pressure level is higher. Therefore, this case is suitable for cleaning when the degree of contamination such as clogging due to a highly viscous solder paste or the like is high. In the case of B, all the open / close valves are opened and closed in the same manner as in A, but the impulse duration IT is about one half of that in the case of A. Therefore, the total flow rate of the pressure gas is also about two minutes in the case of A. It becomes 1 of. C shows a case in which only one on-off valve 5 is controlled with the same impulse duration IT as in the case of B. In this case, the flow rate of the pressure gas is less than one third of that in the case of B. It becomes. Therefore, this case is suitable for cleaning when the clogging stains or the amount of the printing material attached is small. D shows a case where only one open / close valve 5 is controlled with an impulse duration about twice that of C. In this case, the flow rate of the pressure gas is about twice that of C. It becomes. In addition, it is possible to operate each open / close valve 5, 5, 5 at the same time with different impulse durations, or to control two of them with the same duration. These methods may be appropriately selected according to the weight of the printing material attached amount or the like. In the first embodiment described above, a pressure regulating valve 7 'is attached to the outlet pipe 7 of the on-off valve 5, and the operation of the regulating valve 7' is limited, The pressure of the pressure gas can be adjusted.
[00 22 ]
In FIG. 3, reference numeral 18 denotes a solder paste blown from the pattern opening 11 of the screen S to the back side of the screen by the jet pressure of a pulse gas ejected from a cleaning nozzle 4 movably provided on the surface side of the screen S. A cleaning assisting device that collects residues such as the like and prevents the scattering thereof, and has an opening 18A that opens toward the screen S, and is movable along the back surface of the screen. It is provided and is set at a position facing the nozzle 4 with the screen interposed therebetween during cleaning. The cleaning assisting device 18 may be configured to have a suction function.
[00 23 ]
The cleaning nozzle 4 is in a standby position separated from the screen S when not being cleaned, and any pattern opening 11 of the screen S is clogged or the like that requires cleaning in a regular or occasional inspection. When it is determined that the nozzle hole 4B is generated, the nozzle 4B is moved to the area of the pattern hole 11 where it is determined that clogging or the like has occurred, and at the same time, the nozzle hole 4B is inserted into the pattern hole 11 together with the cap-shaped body 13. When approaching in the state of being directed and the opening of the cap-like body 13 comes into close contact with the screen S, the cap 13 is stopped on the spot. When the nozzle 4 is stopped in this way, the open / close valve 5 for opening and closing the air supply circuit 3 is opened and closed several times, for example, 3 to 4 times within 1 to 2 seconds. A high-pressure gas is ejected from the nozzle 4 in the form of a pulse jet toward the pattern opening 11, and the printing material remaining on the inner surface of the pattern opening 11 by the pulse jet pressure passes through the opening. It is blown off to the opposite side of the screen S and removed. At that time, the printing material residue blown off by the pulse jet pressure is prevented from diffusing by the cap-like body, and the residue blown to the opposite side of the screen S through the pattern opening 11 is the above-described cleaning auxiliary device. 18 and the scattering is prevented. Therefore, contamination due to reattachment of residues on the front and back surfaces of the screen S during cleaning is prevented. When the cleaning of the pattern opening 11 is completed as described above, the cleaning nozzle 4 is returned to its standby position. Needless to say, the above-described operations of the cleaning nozzle 4 are all controlled in accordance with a program input to the microcomputer 16 in advance, similar to the opening / closing operation of the opening / closing valve 4 described above.
[00 24 ]
In the present invention, as the pressure gas, in addition to air, inert gas, etc., a mixed gas obtained by atomizing a solvent and mixing with air can also be used.
[00 25 ]
As mentioned above, although it explained in full detail with reference to drawings which showed the example about the embodiment of the present invention, the present invention is not limited to the example, and within the limits as described in each claim, they Can be implemented with various modifications.
[00 26 ]
Since the present invention is configured as described above, according to this, dirt such as clogging of the printed pattern opening of the screen is easily and efficiently removed and cleaned by effectively using a pressure gas such as compressed air. be able to.
[00 27 ]
Further, according to the present invention, it is possible to reduce the consumption amount of the pressure gas necessary for cleaning the dirt such as clogging of the printed pattern opening of the screen, and the cost can be reduced. According to the third aspect of the present invention, the effect is particularly remarkable, and an excellent cleaning effect can be obtained, so that it is suitable for performing high density and precision printing.
[00 28 ]
Still further, according to the present invention, while performing a cleaning operation by ejecting a high-pressure pulse gas from the cleaning nozzle, a pulse jet of printing material residue remaining inside or around the printed pattern opening of the screen. Scattering due to pressure can be effectively prevented.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an embodiment of the present invention.
FIG. 2 is a configuration diagram of another embodiment of the present invention.
FIG. 3 is an enlarged schematic cross-sectional view showing an example of a cleaning nozzle employed in the cleaning system according to the present invention.
FIG. 4 is a schematic diagram of an example of a control system used to implement the cleaning system according to the present invention.
FIG. 5 is a waveform diagram illustrating a method for adjusting the operation of a normally closed on-off valve in a second embodiment of the invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pressure accumulation tank 3 Air supply circuit 4 Cleaning nozzle 5 Normally closed type on-off valve 6 Inlet pipe 7 Outlet pipe 7A Branch pipe 7B Branch pipe 7C Branch pipe 8 Controller 9 Main pipe 10 Outlet pipe S Screen 11 Print pattern opening 12 Clogging with printing material 13 Cap-shaped body 18 Cleaning assist device

Claims (5)

In a screen printing machine for printing a viscous printing material on a substrate using a screen having a plurality of printed pattern openings, a cleaning nozzle provided movably on the front surface side or the back surface side of the screen, a pressure accumulation tank, A main pipe and a plurality of branch pipes branched from the main pipe and connected to the nozzle for supplying pressure gas to the nozzle from the pressure accumulation tank formed between the nozzle and the pressure accumulation tank An air supply circuit; normally closed on / off valves attached to the plurality of branch pipes; and a control device configured to control the opening / closing of each of the on / off valves. the Rukoto is opened and closed several times partially within a short time, then the pressure adjustably jetting high-pressure pulse gas from the nozzle, indicia of the screen by the pulse jet pressure Screen cleaning system characterized by being configured so as to remove the viscous printing material remaining attached to the inner surface of the pattern hole.   In a screen printing machine for printing a viscous printing material on a substrate using a screen having a plurality of printed pattern openings, cleaning is provided on the front side or the back side of the screen so as to be movable in both the X-axis and Y-axis directions. -A main pipe for feeding pressure gas to the nozzle from the pressure accumulation tank formed between the nozzle, the pressure accumulation tank, and the nozzle and the pressure accumulation tank, and a branch from the main pipe and connected to the nozzle An air supply circuit comprising a plurality of branched pipes, normally closed on-off valves attached to the plurality of branch pipes, and a control device capable of controlling the opening and closing of each of the on-off valves And by opening and closing all or part of the open / close valve a plurality of times within a short time, a high-pressure pulse gas is ejected from the nozzle in a pressure-adjustable manner. Screen cleaning system characterized by being configured so as to remove the viscous printing material remaining attached to the inner surface of the printing pattern openings of the screen by fluid pressure. 3. The tip of the nozzle according to claim 1, wherein a cap-like body that is brought into close contact with the screen to prevent dispersion of a pulse gas ejected from the nozzle during cleaning of the pattern opening of the screen is provided. A screen cleaning system characterized in that it is detachably fitted to the nozzle in such a manner as to surround the periphery of the part. 3. The apparatus according to claim 1 , wherein a cleaning nozzle is movably provided on one side of the screen, and the pulse jet pressure causes the screen to have a printed pattern opening on the other side of the screen. A screen cleaning system characterized in that a cleaning auxiliary device that collects the residue of the viscous printing material that is blown out and prevents the scattering thereof is movably provided. 3. The screen cleaning system according to claim 1, wherein the pressure gas is a mixed gas obtained by atomizing a solvent and mixing it with air .

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