JPH0465268B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shuttle valve in an upper clamper circuit of a press machine, and more particularly to a switching valve for a fluid circuit that can be used to control the operation of general hydraulic equipment, etc. .

[Background technology and its problems]

Generally, in devices that are equipped with a fluid circuit and operate using fluid pressure such as oil pressure or air pressure, pressurized fluid is supplied to or discharged from a cylinder, etc., and a driving force is generated by moving an internal piston or plunger. generate.

Conventionally, many hydraulic circuits have been used in press equipment. For example, in an upper clamper circuit as shown in FIG. 9
The operating oil from 1 is supplied to or discharged from the cylinder 92. Here, when operating oil is supplied into the cylinder 92, the piston 93 is moved by the spring 94.
When the mold is ejected, the piston 93 is lowered by gravity and the biasing force of the spring 94, thereby driving the clamp rod 95 connected to the piston 93 up and down to clamp the upper mold.

At this time, a slide type spool valve or the like can be used as the switching valve 90, but it must be able to withstand use in a high-load hydraulic system and prevent leakage when the oil pressure is high. For this purpose, two pilot-operated check valves 96, which are forcibly opened by pistons, are used instead of spool valves, etc., as shown in FIG. 4, and pressurized air is alternately supplied to these valves as control fluid. constitute a circuit capable of switching the supply or discharge of the operating oil,
A switching valve 90 is used. In such a circuit,
If the two pilot operation check valves 96 are controlled not to open and close at the same time, but with a slight time difference using the two control switching valves 97 and 98, a sudden hydraulic pressure is applied to the cylinder 92 and the piston 93. It is possible to prevent the occurrence of changes, allowing for smoother operation and improved durability and reliability.

However, the switching valve 90 having such a configuration
However, the piping is complicated and installation is not easy, and maintenance is also difficult, and furthermore, a control means is required to operate the two control switching valves 97 and 98 in a predetermined procedure.

[Purpose of the invention]

An object of the present invention is to provide a shuttle valve that is simple in structure, easy to install, and allows easy switching of fluid circuits that handle hydraulic pressure and the like.

[Means and actions for solving problems]

In the present invention, a casing has an inlet port, a discharge port, and a drain port, and includes a suction port circuit that communicates the suction port and the discharge port, and a drain port circuit that communicates the discharge port and the drain port. a pair of valve bodies are provided facing each other so as to be able to independently open and close each of the inlet port circuit and the drain port circuit, and the valve bodies are interposed between the valve bodies so as to be able to urge each other in a direction away from each other;
A spring is provided that biases each valve body to close the inlet port circuit and the drain port circuit, respectively, and further releases the blockage of the drain port circuit by the valve body on the drain port side, and also closes the suction port circuit by the valve body on the suction port side. A valve body driving means for forcibly closing the port circuit is provided, and thus a shuttle valve as a switching valve is constructed.

In a shuttle valve with such a configuration, when the hydraulic pressure of the pressurized operating oil supplied to the suction port exceeds the biasing force of the spring, the valve body on the suction side closes the suction circuit. The blockage is released, and the operating oil flows to the discharge port side, increasing the oil pressure on the discharge port side. At this time, these valve bodies act as check valves, so when the pressure on the discharge port side becomes higher than that on the suction port side, they are blocked again to prevent backflow and prevent leakage to the drain port side. The oil pressure on the discharge port side can be maintained to prevent an unnecessary drop in oil pressure, and there is no need to provide a check valve, making the circuit configuration simple. On the other hand, when the valve body driving means is operated, the drain port circuit is unblocked by the valve body on the drain port side, and the operating oil that has already been sent to the discharge port side is transferred from the drain port circuit to the drain port. At the same time, the suction port circuit is closed by the valve body on the suction port side, stopping the supply of pressurized operating oil to the discharge port side, and lowering the oil pressure on the discharge port side. As described above, the present invention enables switching of hydraulic circuits with a simple structure and aims to achieve the above object.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, a casing 1 of a shuttle valve 1
A suction port 11, a discharge port 12, and a drain port 13 are formed on the surface of the 0, and a valve body accommodating portion 2 is formed inside. Inlet circuit 14 communicated with
and a drain port circuit 15 that communicates from the discharge port 12 to the drain port 13 via the valve body accommodating portion 2.

A pair of valve bodies 20 and 21 are housed in the valve body housing part 2, and the valve body 20 on the side of the suction port 11 connects to the suction port circuit 14, and the valve body 21 on the side of the drain port 13 connects to the drain port circuit 15. , are arranged facing each other so that they can be opened and closed independently.

A space between the valve bodies 20 and 21 is such that the valve bodies 20 and 21 can be biased away from each other.
energizes the suction port circuit 14 and drain port circuit 1.
A spring 22 is interposed to close the opening 5.

On the other hand, a cylinder 30 and an air supply port 31 are formed in the casing 10 as a valve body driving means 3, and a piston 32 and a spring 33 capable of biasing the piston 32 in the right direction in the figure are housed in the cylinder 30. ing. One end of a piston rod 34 is connected to this piston 32 so that it can operate integrally, and the other end is in contact with a valve body 21 that reaches into the drain port circuit 15 and closes it. The valve body 21 is moved to the left in the figure by pressurized air as a control fluid supplied to the port 31 from the outside, and the valve body 21 is moved via the piston rod 34.
1 can be released from the blockage of the drain port circuit 15, and further, by pressing the valve body 21 through the valve body 21, the valve body 20 is biased to the left in the figure, and the inlet circuit 14
It is said that it is possible to forcibly block the

Furthermore, a limit switch 4 for pressure detection is attached to the surface of the casing 10, and a limit switch 4 for pressure detection is attached to the surface of the casing 10.
If pressure is applied to the side, the valve body housing portion 2
The limit switch 4 is pushed through a piston 42 and a piston rod 43, which are inserted into a cylinder 40 communicated with the cylinder 40 and normally biased rightward in the figure by a spring 41, indicating that the pressurization is normal. Predetermined operations such as

The shuttle valve 1 of this embodiment configured as described above is connected as shown in FIG. 2, and constitutes an upper mold clamper circuit of a press machine.

In FIG. 2, the discharge port 12 of the shuttle valve 1 is connected to the cylinder 50 of the upper clamper 5, the suction port 11 is connected to the oil pressurizing device 6 for operation, and the drain port 13 is connected to the oil sump 60. Further, the air supply port 31 is connected to an electromagnetic control switching valve 62 which is connected to a pressurized air supply device (not shown) via an internal pilot type pressure reducing valve 61 with a relief.

A piston 51 and a spring 52 are provided in the cylinder 50 of the upper clamper 5, and the piston 51 is always urged downward by the spring 52, and is able to rise by being supplied with high-pressure operating oil from the shuttle valve 1. , and when the hydraulic pressure of the operating oil from the shuttle valve 1 is released, it can be lowered by the spring 52 and gravity. A rotatable clamp rod 54 is supported on the piston 51 via a piston rod 53.
is normally biased vertically by a spring 55, but is rotatable by a piston 56 connected to a control switching valve 62 and movable by pressurized air.

The oil pressurizing device 6 for operation consists of a pressurizing pump 63 that can be operated by pressurized air, and an operation control valve 64 that can supply or discharge pressurized air to this pump, and the operation control valve 64 has two switching valves. It operates with continuous pressurized air sent from a pressurized air supply device (not shown) via a pressure reducing valve 61, and is intermittent depending on the load of the pressurizing pump 63. Pressure pump 63 is driven by repeated supply and discharge of pressurized air, pumps up operating oil from oil reservoir 60, pressurizes it, and pumps it to the shuttle. It can be supplied to the inlet 11 of the valve 1.

The operation in this embodiment as described above is as follows.

Pressurized air that is continuously supplied from a pressurized air supply means (not shown) is appropriately reduced in pressure by a pressure reducing valve 61 when the pressure is excessive, and is maintained at a predetermined pressure before being supplied. A portion of this pressurized air is sent to the operating oil pressurizing device 6, where it is used as driving force to pressurize the operating oil in the oil reservoir 60 and supply it to the shuttle valve 1.

Under normal conditions, the control switching valve 62 closes the circuit from the pressure reducing valve 61 as shown in FIG. 2, while the circuit connected to the shuttle valve 1 and the upper clamper 5 is opened to the atmosphere, and
6 is considered to be atmospheric pressure, that is, low pressure.

Therefore, in the shuttle valve 1, the piston 32 is moved to the right end position in the cylinder 30 by the biasing force of the spring 33, and the valve body 21, which is not pressed by the piston rod 34, is moved to the drain port circuit 15 by the biasing force of the spring 22. However, the valve body 20 that closes the suction port circuit 14 is pushed open by the pressure of the working oil supplied from the working oil supply means 6 to the suction port 11, and the working oil is supplied to the suction port circuit 14. 14 to the discharge port 12, and is sent to the upper mold clamper 5.

In the upper clamper 5, the operating oil sent from the shuttle valve 1 pushes up the piston 51 within the cylinder 50 against the biasing force of the spring 52, and moves the clamp rod 54 upward. At this time, the pressure in the cylinder 56 is low, and the clamp rod 54 is moved upward while maintaining its posture in the vertical direction by the biasing force of the spring 55, thereby clamping the upper die.

At this time, these valve bodies 20 and 21 operate as check valves, so when the biasing force on the discharge port 12 side becomes higher than that on the suction port 11 side, the valve body 20 is closed again to prevent backflow. Since the valve body 21 prevents leakage to the drain port 13 side, the discharge port 12
The side oil pressure is maintained to prevent an unnecessary drop in the oil pressure of the upper clamper 5.

On the other hand, when the control switching valve 62 is switched, pressurized air from the pressure reducing valve 61 is sent to the shuttle valve 1, the piston 32 moves to the left end position of the cylinder 30 against the urging force of the spring 33, and the piston rod 34 is pressed against the valve body 21 that closes the drain port circuit 15 and is pushed open, thereby causing the discharge port 1 to flow from the suction port circuit 14.
A part of the operating oil leading to the drain port 13
The pressure of the operating oil sent to the upper mold clamper 5 is reduced. Further, the piston rod 34 moves the valve body 21 to the left, brings the valve body 21 into pressure contact with the valve body 20 arranged oppositely, and closes the inlet circuit 14 with the valve body 20, cutting off the oil for operation. The drain port circuit 15 is released and the operating oil that was being sent to the upper clamper 5 is transferred to the oil sump 6.
Return to 0.

At this time, in the upper mold clamper 5, the oil pressure in the cylinder 50 decreases, the piston 51 descends, and the clamping of the upper mold by the clamp rod 54 is released. Furthermore, the piston 56 is connected to the control switching valve 6.
Clamp rod 5 is moved from 2 by pressurized air.
4 is rotated and released to facilitate replacement of the upper mold.

According to this embodiment, it is possible to switch the supply and discharge of operating oil with one shuttle valve 1 operated by one control switching valve 62, and the operation of hydraulic cylinders etc. can be easily controlled. This has the advantage that it can be easily performed with the configuration. In addition, the inlet 11
When the side oil pressure is high, these valve bodies 20, 2
No. 1 acts as a check valve and has the effect of maintaining oil pressure and preventing accidents due to an inadvertent drop in oil pressure. For this reason, conventionally, as shown in FIG. 4, the upper clamper circuit required two pilot operation check valves 96 and two switching valves 97 and 98 that could generate a time difference in their opening and closing operations. , it is possible to have an extremely simple configuration. Furthermore, if the valve body driving means 3 is operated at low speed when switching between supply and discharge, the valve body 21 on the drain port 13 side
Since there is a distance between the two valve bodies 20 and 21 due to the interposed spring 22, there is a time delay between when the valve body 20 on the suction port 11 side is closed after the valve body 20 is opened, and the valve body 20 closes. , 21 operate separately with appropriate time differences, and at the intermediate position of switching, the suction port 11, the discharge port 12, and the drain port 13 are communicated with each other.
Sudden changes in oil pressure can be avoided without using special means.

As shown above, the shuttle valve 1 of this embodiment
Although the present invention has been explained using an example in which the above is applied to an upper clamper circuit, the present invention is not limited to such use, but can be applied to various hydraulic devices or circuits. As shown, by combining two shuttle valves 1, it can be used as a four-way valve.Compared to the conventional four-way valve using a spool, the shock during switching can be reduced, and the blockage by the valve bodies 20 and 21 can be avoided. This has the effect of extremely reducing leakage since the flow path is switched.

In addition, in the above embodiment, the valve body driving means 3
The piston rod 34 was brought into pressure contact with the valve body 20 via the valve body 21, and the suction port circuit 14 was forcibly closed.
The valve body driving means 3 may be directly pressed against the valve body 20 by inserting the piston 32 into the piston 32, which is movable by a control fluid supplied from the outside. The cylinder 30 is equipped with a piston rod 34, which is equipped with an electrically operated solenoid and a piston rod 34.
The valve body driving means may include a rod that can be operated by being driven by the valve body, or a valve body driving means may include a motor and a transmission mechanism that converts the rotational motion of the motor into reciprocating motion.

As described above, the present invention is not limited to a specific embodiment, and in short, the present invention includes the suction port circuit 14 that communicates the suction port 11 and the discharge port 12, and the discharge port 12.
A drain port circuit 15 communicating between the drain port 13 and the drain port 13 is connected to a pair of valve bodies 20 and 21 which are arranged facing each other so as to be able to open and close independently. be able to intervene,
a spring 22 that biases each valve body to close the suction port circuit 14 and the drain port circuit 15, respectively;
The valve body 21 on the drain port 13 side is moved to release the blockage of the drain port circuit 15, and the inlet port 11
This means that the shuttle valve 1 is provided with a valve element driving means 3 that forcibly closes the inlet circuit 14 by the side valve element 20.

〔Effect of the invention〕

As described above, according to the shuttle valve of the present invention,
The structure is simple and easy to install, and the hydraulic circuit can be easily switched.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a shuttle valve according to an embodiment of the present invention, Fig. 2 is a circuit diagram showing an upper clamper circuit to which the above-mentioned shuttle valve is applied, and Fig. 3 is a sectional view showing another application example of the above-mentioned shuttle valve. FIG. 4 is a circuit diagram showing a conventional example. DESCRIPTION OF SYMBOLS 1... Shuttle valve, 3... Valve body drive means, 11... Suction port, 12... Discharge port, 13... Drain port, 14... Suction port circuit, 15... Drain port circuit, 20, 21... Valve body, 22... Spring.

Claims (1)

[Claims] 1. An inlet circuit that communicates an inlet and an outlet;
A drain port circuit that communicates between the discharge port and the drain port is connected to a pair of valve bodies disposed facing each other so as to be able to open and close each independently, and a pair of valve bodies disposed between these valve bodies so as to be biasable in a direction away from each other. , a spring that biases each valve body to close the suction port circuit and the drain port circuit, and a spring that moves the valve body on the drain port side to release the blockage of the drain port circuit, and the valve body on the suction port side A shuttle valve characterized by comprising a valve body driving means for forcibly closing an inlet circuit. 2. In claim 1, the valve body driving means is a pressure cylinder equipped with a piston movable by a control fluid supplied from the outside, and a piston rod connected to the piston and movable as a unit. A shuttle valve characterized by: 3. The shuttle valve according to claim 1, wherein the valve body driving means includes a solenoid and a rod operable by being driven by the solenoid. 4. The shuttle valve according to claim 1, wherein the valve body driving means includes a motor and a transmission mechanism that converts rotational motion of the motor into reciprocating motion.