JPH0825625B2 - Pusher device in article transfer device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pusher device for transferring articles using a fluid cylinder.

[0002]

2. Description of the Related Art An elevator car capable of accommodating a large number of thin plate-shaped articles such as circuit boards in a vertically multi-stage manner is provided. The circuit boards are pushed out and supplied one by one by using a pusher such as or the like, or the empty elevator car is moved up and down by one pitch, and the circuit boards are pushed and stored therein by using the pusher such as an air cylinder. There is an article transfer device.

In the above apparatus, it is possible to efficiently store a large number of boards in the car by inserting the board in the elevator car horizontally and in multiple stages. Therefore, the circuit board is normally moved horizontally by the pusher. However, because the circuit board is thin, the position of the elevator car to be stored may be misaligned or the rail on the receiving side may be deformed, causing it to stop at the entrance or catch on the way. In such a case, a pressing force is applied from the pusher in the direction in which the circuit board is bent, which causes a problem of breaking the board.

Since there is a limit in preventing the displacement of the elevator car and the deformation of the receiving rail, when the circuit board approaches a place other than the predetermined storage position or gets caught in the middle of the approach, the pusher immediately pushes. It is easily conceived that the pressing force should be reduced or the pushing of the pusher should be stopped. Therefore, it is easily conceivable that the fluid pressure for pushing the pusher should be detected. When producing as, there were the following problems.

[0005]

That is, in the air cylinder that is often used as a pusher for transferring the above-mentioned articles, a phenomenon that a fairly high resistance is applied immediately after the start of the projection of the cylinder rod and the air pressure is increased, and this is simply caused. If the air pressure of the air cylinder is monitored and it is judged that a trouble has occurred if the pressure becomes higher than the set value, it is judged that there is a trouble just before the cylinder rod begins to extend. There is a risk that The present invention solves the above problems.

[0006]

SUMMARY OF THE INVENTION According to the present invention, in a pusher device in an article transfer device for pushing an article by utilizing expansion and contraction of a fluid cylinder, a pressure sensor for detecting the pressure of fluid and the pressure sensor for detecting the pressure of the fluid. When the pressure value is high, control means for lowering the fluid supply pressure to the fluid cylinder, and at the start of the expansion operation of the fluid cylinder, a signal for lowering the fluid supply pressure is issued from the control means even if the detection value of the pressure sensor is high. It is a pusher device provided with a blocking means that does not prevent it.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The overall structure of the article transfer apparatus of this embodiment will be described first. That is, this embodiment relates to a system in which a large number of circuit boards (1) are supplied to the central work robot (2) one by one, and the completed circuit boards (1) are discharged one by one. 3) is on the supply side (Fig. 1)
(On the left side of FIG. 4), the circuit boards (1) are lifted one pitch at a time (arrow a) with a large number of circuit boards (1) fully loaded. ), It is pushed forward (arrow b) to be supplied to the work robot (2), and an empty elevator car (5) waiting at the upper position on the discharge side (right side in FIG. 1). The pusher (6), which also consists of an air cylinder, pushes out the circuit board (1) from the work robot (2) and inserts it into the elevator car (arrow c), and after that insertion, the elevator car (5) is one pitch at a time. It descends (arrow d).

In this embodiment, a shelf-like storage body (7) capable of storing a large number of circuit boards (1) can be freely loaded and unloaded into the elevator cars (3) and (5). On the supply side, the storage body (7) in which the circuit board (1) is fully stored is transferred by the conveyor (8) to the empty elevator car (3) waiting at the lower position (arrow e), The empty storage body (7) which has taken out all the circuit boards (1) and brought to the upper position is also transferred by the conveyor to the left side of the drawing (arrow f). Further, on the discharge side, a conveyor was used to feed and transfer an empty storage container (7) to an empty elevator car (5) waiting at the upper position (arrow g), and circuit boards were inserted into all shelves. The full storage body (7) is also transferred to the right side of the drawing by the conveyor (9) (arrow h).

The pushers (4) and (6) of the above system are pusher devices according to the present invention, but since both pusher devices have the same structure, the pusher (6) will be described in detail below. . That is, as shown in FIG. 2, the pusher (6) including the air cylinder is
An air pressure source (11) is connected via a one-side solenoid two-position switching valve (10), and a pusher (6) is branched from a line (12) extending to a pressure sensor (14). Are connected. The terminals (15) (16) (17) of the pressure sensor (14) are connected to the ports (P1) (P2) (P3) of the programmable controller (18) equipped with a microcomputer, respectively. Reference numeral (19) is a cylinder rod, (20) is a silencer, and (21) is a pressure gauge (in this example, it is set to 3 kg / cm 2).

The pressure sensor (14) is composed of a switch main circuit (22) for converting air pressure into an electric quantity and a transistor (T) connected to the output from the main circuit (22).
r) and a Zener diode (D). (P
1) is a common port, so if high air pressure is detected in the main circuit (22), the port (P2) will be "low".
Becomes (P3) is a +24 volt port.

Further, the solenoid (22) of the switching valve (10) is connected to the programmable controller (18) via a DC source (23), and a signal from the controller (18) is sent at a timing described in detail later. When it is emitted, the switching valve (10) is switched. Further, at the front and rear ends of the pusher (6), the cylinder rod (1
A limit sensor (23) that uses magnetism to detect whether 9) has protruded to the front end and a limit sensor (24) that also uses magnetism to detect whether it has retracted to the rear end are provided. (23) (2
The output of 4) is also the programmable controller (18).
It has been input (25) (26) to. Of course, the limit sensors (23) and (24) are not limited to those using magnetism, and may be mechanical limit switches.

Next, the pushing operation of the pusher device (6) will be described with reference to a flow chart. Of course, it is assumed that the elevator car (5) has been brought to a predetermined position by the command of the programmable controller (18) by the time the operation starts. That is, when the process of pushing out the circuit board is started, the solenoid (22) of the switching valve (10) is excited to the position shown in FIG.
The air from the air pressure source (11) causes the cylinder rod (1
9) projects (to the left in FIG. 2), and the rear end limit sensor (24) is turned off (S-1). This rod (19)
Although the pressure of the line (12) suddenly increases with the start of the protrusion, the output value of the pressure sensor (14) cannot be received for 1 second measured by the timer after the start of the protrusion (S-2). . (Of course, this time of 1 second can be changed arbitrarily.)

After 1 second, the pressure sensor (1
4) receives the output from the output value (port (P
It is determined whether the pressure sensor (14) is on or off, that is, whether the pressure in the line (12) is higher than a predetermined pressure or not (S-3). ). If the pressure sensor (14) remains off here, it means that the pressure in the line (12) is not high, that is, the circuit board (1) is being smoothly pushed by the pusher. , Determines whether the front limit sensor (23) is on (S-
4). If the front end limit sensor (23) is turned on, it means that the cylinder rod (19) has already been fully extended, and the pushing process is completed. If the front end limit sensor (23) remains off, the cylinder rod (1
Since 9) is the process of expansion, the detection value of the pressure sensor (14) is taken in again (S-3).

However, in step (S-3),
If it is determined that the pressure sensor (14) is on, it means that the pressure in the line (12) is abnormally high.
Immediately perform abnormal processing (S-5). In the case of this example, the abnormality processing is the following three operations. That is, first, a signal is output from the port (P4) of the programmable controller to stop the excitation of the solenoid (22), and the switching valve (10) is moved to the right from the position of FIG. 19) immediately in the direction of degeneration, and secondly, by issuing a command from another port of the programmable controller (18) to turn on the pusher NG LED (27) on the display unit of the main body. The third is to sound a buzzer (not shown).

Since the cylinder rod (19) is immediately retracted by the first treatment described above, even if the substrate (1) is caught by the elevator car (5) or the like, the pressure applied to the substrate (1) is lost. Therefore, damage to the substrate (1) is prevented. Depending on the second and third processing, the operator is notified of the trouble.

FIG. 4 shows a timing chart of signals during the above operation. That is, (a) is a cylinder (6)
Output signal of the limit sensor (24) at the rear end, (b2) the output signal of the limit sensor (23) at the front end, and (c) the pressure sensor (1).
4) shows the output signal, and (d) shows the reception timing of the output from the pressure sensor (14). In the chart of FIG. 4, since the output value of the pressure sensor "low" does not exist at the reception timing of the output of the pressure sensor (14), the pusher (6) is shown to be fully extended without being caught. Further, although a "low" signal is output from the pressure sensor, since this signal is not the reception timing, the abnormality processing such as switching of the switching valve (10) is not performed.

Further, FIG. 5 shows a block diagram (claim correspondence diagram). In this figure, the same members as those shown in FIG. 2 are designated by the same reference numerals. Pressure control driver (28)
Is for controlling the pressure in the extension direction of the pusher (6), and of course, the switching valve (10) for switching the direction to make the pressure in the extension direction substantially a negative pressure is included in this, and other extension A switching type throttle valve for reducing the directional pressure is also included in this. If this throttle valve is used, the direction of pressure does not change, but the pusher extension pressure drops significantly.

The programmable controller (1
8) includes the following as functional blocks of the microcomputer. That is, when the detection output from the pressure sensor (14) is taken and the output is larger than the set value, a signal is sent to the control means (30), and the control means (30) causes the pressure control driver (28). A determining means (29) for outputting a signal for lowering the pusher extension pressure and this determining means (2
A block means (31) for blocking the signal from 9) to the control means (30) for a certain period of time, and a timer (32) for setting the time when the block function of this block means (31) operates. There is. Therefore, the timer (3
By changing the setting of 2), it is possible to arbitrarily change the reception timing of the overpressure signal from the pressure sensor (14).

[0019]

As described above, according to the present invention, only at an appropriate time (that is, when an article to be pushed such as a circuit board is really caught) without causing the trouble described at the beginning. The pushing force of the pusher can be reduced, and problems such as damage to the article to be pushed can be reliably prevented.

[Brief description of drawings]

FIG. 1 is a schematic side view of an article transfer system including a pusher device according to the present invention.

FIG. 2 is a diagram showing a configuration of a pusher device.

FIG. 3 is a flowchart showing the operation of the pusher device.

FIG. 4 is a timing chart of signals during the above operation.

FIG. 5 is a complaint correspondence diagram.

[Explanation of symbols]

 (6) Pusher (10) Switching valve (11) Air pressure source (14) Pressure sensor (18) Programmable controller (24) Limit sensor (28) Pressure control driver (29) Judgment means (30) Control means (31) Block Means (32) Timer

Claims (1)

[Claims] 1. A pusher device in an article transfer device for pushing an article by utilizing expansion and contraction of a fluid cylinder,
A pressure sensor for detecting the pressure of the fluid, a control means for reducing or lowering the article pressing force of the fluid cylinder when the pressure value detected by the pressure sensor is high, and the above-mentioned at the time of starting the pushing operation of the fluid cylinder. A pusher device in an article transfer device, comprising: a block means that does not emit a signal for reducing or reducing the article pressing force from the control means to zero even if the detection value of the pressure sensor is high.