JPH0438233B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a screen tear detection device in screen printing.

[Prior art and its problems] A pattern (pattern, etc.) to be printed on a printing target (product) is processed on a screen (gauge), and the screen is fixed in a stretched state against a screen frame (print frame). In screen printing, in which a predetermined pattern (for example, a circuit pattern on a printed circuit board) can be printed on a printing medium (for example, a printed circuit board) through ink applied to a screen, the screen is It is necessary to quickly detect damage (tear) in the printing machine and stop the printing machine. This is because a torn screen not only leads to the production of defective products, but also causes the ink leaking through the tear in the screen to stain the lower printing mechanism, which requires a lot of cleaning time. This is because it requires a lot of time and there is a risk that the adhered ink may cause malfunction of the machine.

In view of the above requests, we developed (1) a means of detecting screen tearing by pasting adhesive tape connected to a sensor (detector) on the screen surface and using vibrations when the screen breaks; and (2) a method for detecting screen tearing. Attempts have been made to detect a tear in the screen by detecting this.

[Problems to be Solved by the Invention] However, in the case of the means (1) above, there is a drawback that malfunction may occur due to changes in the setting position of the adhesive tape or the screen during screen printing, and ( In the case of method 2), there is a drawback that the sound detector may malfunction due to the large background noise (external sound) around the screen printing machine.
None of the above detection means could reliably detect the tear in the screen.

The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to prevent the screen frame from breaking by 0.15 mm in each direction when the screen is torn.
A screen tear detection device for screen printing that can solve all of the above conventional problems by focusing on the fact that the screen frame changes by about 0.6 mm (according to the applicant's research results) and detecting the change in the screen frame when the screen is broken. The goal is to provide the following.

[Means and effects for solving the problems] The present invention includes a sensor 4 for detecting changes in the screen frame 2 when the screen is damaged, a positioning cylinder 7, and a sensor positioning sensor fixed to the tip of the piston rod 8 of the cylinder 7. A sensor positioning mechanism 3 constituted by a regulating member 9 and a regulating member 10 for regulating the operating amount of the sensor positioning member 9 to a predetermined set amount, a moving operation cylinder 21, and a sensor positioning mechanism 3 that cooperates with the moving operation cylinder 21. and a sensor moving mechanism 5 constituted by a sensor support rod 22 for setting the sensor 4 at a predetermined set position, a clamping cylinder 32, and the clamping cylinder 3.
Screen tear detection in screen printing is performed by the clamp mechanism 6, which is constituted by a clamp section 34 that cooperates with the piston rod 33 of the sensor moving mechanism 5 to clamp or unclamp the piston rod 24 of the moving operation cylinder 21 of the sensor moving mechanism 5. By configuring the device, it is possible to accurately detect screen damage while detecting minute changes in the screen frame when the screen is damaged, and to properly set up the device to prevent damage to the sensor and other safety considerations. It is safe and easy to do.

[Example] Hereinafter, an example of the present invention will be described in detail using the drawings.

1 and 2 show a bottom view and a side view of a screen tear detection device 1 according to the present invention. As shown in the figure, the screen tear detection device 1 detects a screen frame 2 which is an object to be detected.
Sensor positioning mechanism 3 that can freely come into contact with
a sensor moving mechanism 5 for moving the sensor 4 to a predetermined set position pre-positioned by the sensor positioning mechanism 3; Clamp mechanism 6 for
It is composed of etc.

The sensor positioning mechanism 3 includes a double-rod type positioning cylinder 7, a sensor positioning member 9 fixed to the tip of the piston rod 8, and a regulation mechanism for regulating the operating amount of the sensor positioning member 9 to a predetermined set amount. Component (stopper component) 1
It is composed of 0, etc. Positioning cylinder 7
is held via a cylinder holding member 12 provided on the bottom surface 11a of the support base 11 of the device 1. The cylinder holding member 12 is the fixed holding member 1
3 and a movable holding member 15 which is freely fixed to the fixed holding member 13 via a bolt 14, and the positioning cylinder 7 is movable in the axial direction by both the two divided holding members 13 and 15. Retained. The piston rod 8 of the positioning cylinder 7 is configured in a so-called double rod type, and the tip in the forward direction (rightward in FIG. 1) has a rod that can freely come into contact with the screen frame 2, which is the object to be detected. A sensor positioning member 9 is fixedly provided. The amount of movement of the piston rod 8 in the forward direction is regulated by a regulating member 10 screwed onto the rear end (the left end in FIG. 1) of the piston rod 8. Positioning cylinder 7
is electrically connected to SOL (solenoid and below)-C and SOL-D, whose parts are not shown, and SOL-D as shown in the sequence diagram in Figure 3.
The configuration is such that the piston rod 8 can be operated forward when the switch 17 of C16 is turned on. Further, the SOL-D18 is held in a demagnetized state as shown in FIG. The control structure is such that the piston rod 8 is moved backward via D18.

The sensor moving mechanism 5 is comprised of a cylinder 21 for movement operation, a sensor support rod 22 for setting the sensor 4 at a predetermined set position in cooperation with the cylinder 21, and the like. cylinder 21
is connected to the support base 11 via the bracket 23 at a position above the positioning cylinder 7.
The piston rod 24 of the cylinder 21 is configured to be able to expand and contract in the same direction as the piston rod 8. The cylinder 21 is SOL-A, whose members are not shown in the illustration.
It is electrically connected to SOL-B, and as shown in Figure 3, it is electrically connected to SOL-B.
As shown in the figure, switch 26 of SOL-A25 is
The piston rod 24 is configured to be moved in the forward direction (rightward in FIGS. 1 and 2) when turned on. Also, SOL-B27
As shown in FIG. 3, the piston rod 24 is normally held in a demagnetized state, and is energized only when a backward operation command is received, so that the piston rod 24 can be operated backward. The piston rod 24 is connected to the connecting plate 2
8 in a lower position of the piston rod 24 and said piston rod 8.
The sensor support rod 22 is supported by the cylinder holding member 12 so as to be movable in the axial direction. The sensor support rod 22 is connected to the cylinder body 7 of the positioning cylinder 7 via the connecting plate 29, as shown in FIG.
A sensor 4 capable of detecting a change of ±0.01 mm in the screen frame 2 is housed and fixed at the tip of the sensor support rod 22 in the forward direction.
The tip of the sensor support rod 22 and the tip of the cylinder body 7a of the cylinder 7 are shown in FIGS.
As shown in Figure 5 (front view of Figure 2),
They are integrally connected via a bracket 30.
Reference numeral 31 indicates a hole through which the wires of the sensor 4 can be taken in and taken out.

As shown in FIG. 6, the clamping mechanism 6 is composed of a clamping cylinder 32 and a clamping portion 34 for clamping and unclamping the piston rod 24 in cooperation with the piston rod 33 of the clamping cylinder 32. be. The clamp part 34 is composed of a fixed clamp member 35 fixed to the lower surface 11a of the support base 11, and a movable clamp member 37 rotatably attached to the fixed clamp member 35 via a pin 36. The free end side of the movable clamp member 37 is fixed to the piston rod 33 via a bolt 38. Piston rod 2 in each clamp member 35, 37
4 are formed with semicircular grooves 39 and 40 having substantially the same radius as the piston rod 24, and the semicircular groove 3
By opening and closing 9 and 40, the piston rod 24 of the sensor movement cylinder 21 can be clamped and unclamped. The clamping cylinder 32 is electrically connected to SOL-E, whose members are not shown.
As shown in Figure 3, switch 42 of SOL-E41
The control structure is such that when the SOL-E41 is turned on, the SOL-E41 is excited, the piston rod 33 is contracted, and the piston rod 24 can be clamped. The switch 42 is activated when the timer 43 for setting the travel time of the cylinder 21 times up.
It is set to be turned ON. Note that the set time of the timer 19 is set longer (larger) than that of the timer 43.

In Fig. 3, 44 indicates the power supply 45 is turned on.
- OFF switch, 46 is a set switch, 47 is a set display, 48 is a reset switch, 49 is a reset display, 50 is a power stabilizer (controller) ), 51 and 52 are positive and negative detection indicators of the sensor 4, and 53 is a buzzer for warning in case of abnormal output.

In the above configuration, the operation of the present invention will be explained. When setting the sensor 4 at a predetermined position close to the screen frame 2, which is the object to be detected, first the power switch 44 is turned on, and then the setting switch 46 is turned on. Then, SOL−
A25 and SOL-C16 are excited, and the piston rod 8 of the positioning cylinder 7 and the piston rod 24 of the sensor movement operation cylinder 21 are moved forward. At this time, the piston rod 8
As shown by the imaginary line in FIGS.
moves to a position where it abuts the rear end of the cylinder body 7a, and the tip of the positioning member 9 advances beyond the head of the sensor 4. The amount by which the tip of the positioning member 9 protrudes from the head of the sensor 4 is set to a predetermined amount e as shown in FIG. The setting of this predetermined amount e is based on the adjustment of the adjustable regulating member 1.
0 on the piston rod 8 and adjusting the operating stroke l of the piston rod 8 as appropriate. Further, the predetermined amount e is set to a predetermined detection distance between the sensor 4 and the screen frame 2, which is the object to be detected.

At the same time that the positioning member 9 protrudes to the position shown by the imaginary line in FIGS. 1 and 2, the piston rod 24 of the sensor movement operation cylinder 21 advances in the direction of arrow A (ie, contracts). As a result, the cylinder 7 and the sensor support rod 22 move forward while holding the predetermined amount e via the connecting plates 28 and 29. Therefore, when the tip of the positioning member 9 comes into contact with the screen frame 2, a predetermined distance e between the end surface 2a of the screen frame 2 and the tip surface 4a of the sensor 4 is maintained. The sensor 4 is set at a predetermined detection distance from the screen frame 2, which is the object to be detected.

When the sensor 4 is set at a predetermined position as described above, the timer 43 times up and at the same time the switch 42 is turned on. This allows SOL−E41
is excited, the piston rod 33 of the clamping cylinder 32 is contracted, and the piston rod 24 of the sensor moving operation cylinder 21 is clamped. As a result, the sensor 4 is clamped while maintaining the predetermined detection distance e.

When the piston rod 24 of the sensor movement operation cylinder 21 is clamped, the timer 19 times up and the switch 20 is turned on at the same time. As a result, SOL-D18 is excited, and the piston rod 8 of the positioning cylinder 7 moves backward to its original position. This completes the setting of the sensor 4 and completes the lighting of the set indicator.

The sensor 4 set up as described above constantly detects changes in the screen frame 2 during printing work, and when the screen of the screen frame 2 is torn, the sensor 4 detects changes in the screen frame 2 when the screen is damaged (for example, It detects vibrations of approximately 0.01 to 0.6 mm and can be used as a signal indicating screen damage. Therefore, by linking the sensor 4 and the printing machine drive mechanism (not shown), it is possible to stop all of the drive mechanisms by a signal from the sensor 4 when the screen is damaged. As a result, it is possible to prevent ink from flowing (falling) onto the printing machine when the screen is damaged, and it is also possible to prevent the occurrence of defective printed products as much as possible, significantly reducing the incidence of defective products. . In other words, in the past, the only way to detect screen tears was to inspect the printed product.
It has been difficult to reduce the incidence of defective products, but according to the detection device 1 according to the present invention, it is possible to quickly detect a tear in the screen and control the entire drive mechanism to stop, thereby reducing the number of defective products. This can significantly reduce the incidence of outbreaks. In addition, since it is possible to prevent ink from leaking when the screen is damaged, there is no need to clean various machines due to ink stains, and machine malfunctions due to ink stains can be prevented, reducing loss time during printing operations. It can be prevented as much as possible. As a result, productivity and overall reliability of the printing machine can be improved.

Furthermore, if the sensor 4 and the digital display are connected to each other and the electrical signal from the sensor 4 is converted into digital data and displayed as a numerical value, the detection signal of the sensor 4 can be observed numerically from the outside. This makes management easier and improves work efficiency.

[Effects of the Invention] As described above, according to the present invention, minute changes in the screen frame when the screen is torn can be detected, and by linking the sensor and the drive mechanism, the drive mechanism when the screen is broken can be detected. can be stopped. As a result, it is possible to quickly detect screen damage, reduce the incidence of defective products, and improve the reliability of printing machines.

In particular, the present invention provides a sensor positioning mechanism,
By providing a sensor moving mechanism and a clamp mechanism, the sensor can be automatically set and placed at a predetermined detection distance with respect to the screen frame, which is the object to be detected, and fixedly set while maintaining that state. .

[Brief explanation of drawings]

FIG. 1 is a bottom view of the device according to the present invention, FIG. 2 is a side view of the same, FIG. 3 is a sequence diagram of the device according to the present invention, and FIG. 4 is a sectional view taken along the line ˜ in FIG. 1. FIG. 5 is a front view of the device according to the present invention, and FIG.
The figure is a front view of essential parts of the present invention. 2... Screen frame, 4... Sensor, 7...
Positioning cylinder, 9...positioning member,
10...Regulation member, 21...Cylinder for sensor movement operation, 32...Cylinder for clamp.

Claims (1)

[Claims] 1. A sensor 4 that detects changes in the screen frame 2 when the screen is damaged, a positioning cylinder 7, a sensor positioning member 9 fixed to the tip of the piston rod 8 of this cylinder 7, and a predetermined operating amount of the sensor positioning member 9. A sensor positioning mechanism 3 constituted by a regulating member 10 for regulating the set amount, a moving operation cylinder 21, and a moving operation cylinder 21.
A sensor moving mechanism 5 constituted by a sensor support rod 22 for setting the sensor 4 at a predetermined set position in cooperation with a clamp cylinder 32 and a piston rod 33 of this clamp cylinder 32 A screen tear detection device in screen printing comprising a clamping mechanism 6 constituted by a clamping section 34 for clamping or unclamping a piston rod 24 of a moving operation cylinder 21 of a moving mechanism 5.