JPS6246003Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a stacked servo valve bypass valve suitable for industrial robots such as painting robots.

Generally, industrial robots have a robot arm or the like that is driven by a hydraulic actuator.
This arm needs to be moved manually so as to follow the shape of the object to be painted, for example, for so-called teaching to teach the robot its movements for painting, etc. If hydraulic pressure is applied to the actuator during this manual copying operation,
The movement of the arm becomes extremely heavy. In order to lighten the movement of this arm, it is conceivable to connect the inlet port and outlet port of the actuator. 1 and 2 are shown in which a bypass is provided for the above-mentioned conduction, and 1 is the actuator described above, which is driven and controlled by hydraulic pressure from a hydraulic power source 2 via a servo valve 3. 4 indicates a return tank. Reference numeral 5 in FIG. 1 is an electromagnetic switching valve, and the bypass is formed by the switching valve. Reference numeral 6 in FIG. 2 is a pilot hydraulic switching valve, and the bypass is formed by this switching valve. 7 is an electromagnetic switching valve for controlling the switching valve 6 described above.

In the one shown in Fig. 1 above, the electromagnetic switching valve 5 must be installed in the robot body, and therefore, in the case of a painted robot, there is a drawback that it cannot be used because it does not comply with explosion-proof measures. In the illustrated example, a pilot hydraulic switching valve 6 is used, which has the disadvantage that a pilot pipe 8 and a drain pipe 9 must be installed.

The present invention aims to eliminate the above-mentioned drawbacks, and is an additional valve to be attached to the servo valve that controls the actuator.
and return port R are blocked, and when there is no pilot oil pressure, the spring force
A spring offset switching valve with ABR communication connection is provided, in which the actuator connection ports A and B are respectively connected to the inlet and outlet ports of the actuator, and the return port is connected to a tank, so that the ABR communication is connected. When connected, both the inlet and outlet ports are connected to the tank, and the servo valve is configured to receive the pilot oil pressure from the oil pressure source, thereby achieving a compact shape and reduced weight. , it is possible to selectively switch between the servo flow path and the bypass flow path without using a special switching signal, the teaching function can be satisfied with zero hydraulic pressure without driving the hydraulic pump, and it can be installed near the actuator. This allows the resistance of the bypass passage to be reduced, and the servo valve function allows both the inlet and outlet ports of the actuator to communicate with the tank in any case.

An embodiment of the present invention will be described in detail below with reference to FIGS. 3 and 4.

3 and 4, 10 is the main body, 11 is the spool, 12 is the spring, 13 is the spring receiver, 14 is the retainer, and 15 is the O-ring. FIG. 4 shows a state in which the spool 11 is moved against the spring 12. P is pilot pressure introduction port A,
B indicates the cylinder actuator connection port, and R indicates the return port. When the pressure at the pilot pressure introduction port P decreases, the pressure in chamber a decreases, and the spool 11 is moved by the spring 12 as shown in Fig. 3. is,
They are connected to each other to communicate with each connection port of the ABR. At this time, the pressure oil in chamber b is discharged from return port R. When pressure oil enters the pilot pressure introduction port P, the pressure in the chamber a increases, the spool 11 is moved against the spring 12, and the communication between the cylinder connection ports A, B and the return port R is cut off. Ru.

FIG. 5 shows a circuit when the stacked bypass valve 16 shown in FIGS. 3 and 4 is connected to the actuator 1 of the robot, and the stacked bypass valve 16 is connected as shown in FIG. It is installed under the servo valve 3, and the cylinder connection port A,
B are connected to the inlet port and outlet port of the actuator 1, respectively, and the return port R is connected to the tank 4.
It is connected to the.

When there is no pressure from the hydraulic source 2, for example when the pump is stopped, the bypass valve 16 is activated by the force of the spring 12 as described above.
A bypass is formed connecting both the inlet and outlet ports of the actuator to the tank. In this state, actuator 1 is manually moved for teaching operation. in this case,
Even if the actuator 1 is a single-rod type hydraulic cylinder as shown in the figure, the problem of the difference in the amount of operating pressure oil due to the difference in volume between the cylinder chamber on the rod side and the cylinder chamber on the head side is that both the inlet and outlet ports are connected to the tank. This can be solved by pumping water into and out of the tank.

On the other hand, when pressure oil is supplied from the oil pressure source 2 and pressure is applied to the pilot port P by the oil pressure,
Since the spool 11 is moved against the spring 12 and the bypass valve 16 is in the blocked position,
Hydraulic pressure from hydraulic source 2 is applied to servo valve 3,
The actuator 1 is driven and controlled by the hydraulic pressure controlled by this servo valve.

The present invention is as described above, and since the laminated bypass valve 16 is attached to the servo valve 3, no extra valve piping is required, the overall valve shape can be made compact, and the teaching operation is improved. can be easily done manually.

[Brief explanation of the drawing]

1 and 2 are circuit diagrams for explaining the conventional example, FIG. 3 is a vertical cross-sectional front view showing an embodiment of the present invention, and FIG. 4 is a cross-sectional plane showing an operating state different from that in FIG. 3. 5 is a circuit diagram in which the present invention is applied to a robot, and FIG. 6 is an external view of the laminated servo valve bypass valve of the present invention. 1...actuator, 2...hydraulic source, 3...
Servo valve, 16...Stacked bypass valve.

Claims (1)

[Scope of utility model registration request] Attached to the servo valve that controls the actuator, it blocks all ports, actuator connection ports A and B and return port R, when it receives pilot oil pressure, and connects the ABR via spring force when there is no pilot oil pressure. It consists of a spring offset switching valve, and the actuator connection ports A and B are connected to the inlet and outlet ports of the actuator, respectively, and the return port R is connected to the tank, so that when the ABR communication connection is made, both the inlet and outlet ports are connected. A stacked servo valve bypass valve, characterized in that it is connected to a tank and is configured to receive the pilot hydraulic pressure from a hydraulic source to the servo valve.