JPH0512589B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shuttle valve in a lower 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 a lower mold clamper circuit as shown in FIG. Movable die lifter 83 and cylinder 84
It can move up and down by being driven by a spring 85.
The die clamper 86 is biased upward by the die clamper 86.

These cylinders 82 and 84 are driven by pressurized air, which can be switched by a switching valve 91, through switching valves 90 that can alternately switch to supply or discharge pressurized working oil to each cylinder. 92
A pressurizing device 93 that can pressurize and supply working oil pumped up from the cylinder is connected, and a check valve 94 is provided between the switching valve 90 and the cylinder 84, and a pressurizing device that can be switched by a switching valve 95 is connected. A pilot-operated check valve 96 is provided which can be operated by compressed air and which can forcibly drain the working oil from the cylinder 84.

In a press device equipped with such a lower die clamper circuit, when replacing the lower die 80, the switching valve 90 is switched to supply pressurized working oil to the cylinder 82, and the die lifter 83 moves the lower die 80 to the bolster. 81 for quick and easy replacement. On the other hand, when fixing the lower mold 80, the pressurized working oil in the cylinder 82 is returned to the oil reservoir 92 by returning the switching valve 90, and the die lifter 83 is lowered to place the lower mold 80 on the bolster 80. Pressurized working oil is supplied to the cylinder 84 and clamped by a die clamper 86 that descends against a spring 85 to quickly, easily and reliably fix the lower die 80.

At this time, the pressurized working oil in the cylinder 84 is subjected to a high load during press work, which may cause the oil pressure to rise unnecessarily.
Also, it was necessary to use a check valve 94.

On the other hand, this pilot operation check valve 96 is
It is opened by switching the switching valve 95, returns the working oil in the path from the pressurizing device 93 to the cylinder 84 to the oil reservoir 92, lowers the oil pressure in the cylinder 84, loosens the clamping of the die clamper 86, and lowers the lower die 80.
It is possible to adjust the position while placing it on the bolster 81. However, since the pressurizing device 93 has a structure that operates according to its load, it is not preferable to operate when the load is close to zero, so a switching valve 91 is provided to stop this. It was necessary to switch over and stop the supply of pressurized air.

In addition, a spool-type four-way switching valve is used as the switching valve 90, which has the disadvantage that working oil leaks easily and causes a drop in oil pressure. In place of the valve 91 and the pilot operation check valve 96, it is necessary to use four pilot operation check valves, etc., and a control means using electric or control fluid is required to control these operations, making the device complicated. It had the disadvantage of becoming.

[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 disposed facing each other so as to be able to open and close each of the suction port circuit and the drain port circuit independently; A spring biases the body to close the inlet circuit and the drain port circuit, and a valve body on the drain port side releases the blockage of the drain port circuit, and the valve body on the suction port forcefully closes the inlet circuit. A shuttle valve is constructed by integrally providing a valve body drive cylinder that is closed to the valve body and a valve body drive switching valve capable of supplying or discharging pressurized fluid from the outside to the valve body drive cylinder.

In a shuttle valve with such a configuration, when the hydraulic pressure of pressurized working oil supplied to the suction port exceeds the biasing force of the spring, the suction port circuit is blocked by the valve body on the suction port side. When released, the working oil flows to the discharge port side and increases 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, which simplifies the structure.

On the other hand, when the valve body drive switching valve is switched, pressurized fluid from the outside is supplied to the valve body drive cylinder, and the piston or plunger in this cylinder is moved, and the drain port is opened by the valve body on the drain port side. When the circuit is unblocked, the working oil that had already been sent to the discharge port side is discharged from the drain port circuit to the drain port, and the suction port circuit is blocked by the valve body on the suction port side, allowing pressurized work. Stops the supply of oil to the discharge port side and lowers 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 this embodiment, the shuttle valve 1 shown in FIG.
The shuttle valves 5 and 5 shown in FIG. 2 are each based on the present invention, and both are incorporated into the lower mold clamper circuit shown in FIG. 3.

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. , which are placed opposite 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, the casing 10 is provided with a valve body drive switching valve 3 and a valve body drive cylinder 4.

The valve body drive switching valve 3 includes a cylinder 30 formed in a casing 10, a first port 31 and a second port 32 that communicate between the cylinder 30 and the outside of the casing 10, and a valve body drive cylinder 4 that communicates with the cylinder 30. Further, inside the cylinder 30 is a spool 34 that can be slid inside to alternately switch the communication between the communication hole 33 and either the first port 31 or the second port 32. , a spring 35 that can bias this spool 34 upward and hold it at the upper limit position of movement within the cylinder 30 (a state in which the communication hole 33 and the second port 32 are in communication as shown), and an external energization. This guides the spool 34 downward, and moves the spool 34 to the lower limit position of movement within the cylinder 30 (lower than shown in the figure) against the biasing force of the spring 35, so that the communication hole 33 and the first port 31 communicate with each other. A solenoid 36 that can be driven to a state) is housed therein. Note that the side pressure of the spool 34 is balanced by a bypass connecting both ends of the cylinder 30, and the spool 34 can be moved with a slight force.

The valve body drive cylinder 4 includes a cylinder 40 formed in the casing 10, a piston 41 housed in the cylinder 40, and a spring 42 that biases the piston 41 in the right direction in the figure. The piston rod 43 is connected at one end to the piston rod 43 and operates integrally with the piston rod. The other end of the piston rod 43 is in contact with a valve body 21 that reaches into the drain port circuit 15 and closes it.
1 moves to the left in the figure, the valve body 21 is moved via the piston rod 43, and the blockage of the drain port circuit 15 by the valve body 21 can be released.
Furthermore, by pressing through the valve body 21, the valve body 20 is biased to the left in the figure, and the suction port circuit 14 can be forcibly closed.

In addition, the shuttle valve 1 configured in this way is as follows:
It is abbreviated as shown within the chain line frame in FIG.

In contrast to such a shuttle valve 1, a shuttle valve 5 as shown in FIG. 2 has substantially the same structure as the shuttle valve 1, and further includes a limit switch 50 for pressure detection.

In FIG. 2, the shuttle valve 5 has a limit switch 50 for pressure detection attached to a part of the surface of its casing 10, and a cylinder 51 that communicates with the valve body accommodating portion 2 is formed inside. . Furthermore, it is inserted into this cylinder 51,
It includes a piston 53 and a piston rod 54, which are normally biased toward the right in the figure by a spring 52.
When pressure is applied to the discharge port 12 side, a limit switch 50 is pressed via these, allowing predetermined operations such as displaying that the pressurization is normal.

In addition, the shuttle valve 5 configured in this way is as follows:
It is abbreviated as shown within the chain line frame in FIG.

The shuttle valves 1 and 5 of this embodiment configured as described above are connected as shown in FIG. 3, and constitute a lower mold clamper circuit of the press machine.

In FIG. 3, the suction ports 11 of the shuttle valves 1 and 5 are both connected to a working oil pressurizing device 6, and each drain port 13 is connected to an oil sump 60. Further, the discharge port 12 of the shuttle valve 1 is connected to the cylinder 74 of the lower mold clamper 7, and the discharge port 12 of the shuttle valve 5 is connected to the cylinder 76 of the lower mold clamper 7. Furthermore, shuttle valve 1
the second port 32 of the shuttle valve 5 and the first port 3 of the shuttle valve 5
1 is connected to a pressurized air supply device (not shown).

The working oil pressurizing device 6 includes a pressurizing pump 61 that can be operated by pressurized air, and an operation control valve 62 that can supply or discharge pressurized air to the pressurizing pump 61. The operation control valve 62 is equipped with two switching valves, an air reservoir and a throttle that generate a time delay, and is operated by continuous pressurized air sent from a pressurized air supply device (not shown) to reduce the load on the pressurizing pump 61. Pressurized air can be supplied or discharged intermittently depending on the situation.
The pressurizing pump 61 is driven by repeatedly supplying or discharging the pressurized air, pumps up working oil from the oil reservoir 60, pressurizes it, and can supply it to the suction ports 11 of the shuttle valves 1 and 5. There is.

The lower die clamper 7 includes a die lifter 70 and a die clamper 71, and is provided on a bolster 73 to which a lower die 72 of the press device is attached. The die lifter 70 includes a cylinder 74 driven by hydraulic pressure, is supplied with pressurized working oil from the shuttle valve 1 and is raised, and can lift the lower mold 72 onto the bolster 73 to support it. When the hydraulic pressure is released, it is possible to descend due to gravity. The die clamper 71 includes a spring 75 that urges it upward and a cylinder 7 that is driven by hydraulic pressure.
6, and is supplied with pressurized working oil from the shuttle valve 5 and descends to bring the lower die 72 into pressure contact with the bolster 73 so that it can be installed reliably and easily, and the hydraulic pressure from the shuttle valve 5 is released. It is made possible to rise by the urging force of the spring 75.

In the lower mold clamper circuit configured as described above, during press work, the die clamper 7
1, the lower mold 72 is brought into pressure contact with the bolster 73 and tightened, thereby quickly, easily and reliably fixing the lower mold 72. On the other hand, when replacing the lower mold 72,
At the same time as releasing the clamping by the die clamper 71, the die lifter 70 is raised, and the lower mold 72 is floated and supported by the bolster 73, so that the lower mold 72 can be replaced quickly and easily. At this time, the operation of the die clamper 71 and the die lifter 70 is controlled by supplying or discharging pressurized working oil, which is switched by the shuttle valves 1 and 5, respectively.
The operations of these shuttle valves 1 and 5 will be explained using an example of the shuttle valve 5 that controls the operation of the die clamper 71.

During press work, the shuttle valve 5 is pressurized, pressurized working oil is supplied to the cylinder 76, the die clamper 71 is moved downward, and the lower mold 7 is moved downward.
2 is securely fixed to the bolster 73.

In the shuttle valve 5, when the solenoid 36 is not energized, the spool 34 of the valve body drive switching valve 3 is at the upper limit position of movement within the cylinder 30, and the cylinder 40 of the valve body drive cylinder 4 is connected to the second port through the communication hole 33. 32 and open to atmospheric pressure.

Therefore, in the shuttle valve 5, the piston 41 is moved to the right end position in the cylinder 40 by the urging force of the spring 42, and the valve body 21, which is not pressed by the piston rod 43, is moved to the drain port circuit 15 by the urging 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 pressurizing means 6 to the suction port 11, and the working oil passes through the suction port circuit 14 to the discharge port. 12 and sent to the die clamper 71.

In the die clamper 71, the working oil sent from the shuttle valve 5 is applied to the spring 75 in the cylinder 76.
The die clamper 71 is moved downward against the urging force of , and the lower die 72 is tightened to quickly and easily fix it to the bolster 73.

At this time, the valve bodies 20 and 21 of the shuttle valve 5 operate as check valves, and the lower mold 7 is
When the pressure in the cylinder 76, that is, the pressure on the discharge port 12 side becomes higher than that on the suction port 11 side due to a load being applied to the valve body 2 and the die clamper 71, the valve body 20 is closed again to prevent backflow and the valve body 20 is closed again. body 21
Even if the pressure on the discharge port 12 side is high, it prevents leakage to the drain port 13 side, maintains the oil pressure on the discharge port 12 side, prevents the oil pressure of the die clamper 71 from decreasing, and secures fixation.

On the other hand, when replacing the lower mold 72 or adjusting the position of the lower mold 72 on the bolster 73, the clamping of the lower mold 72 by the die clamper 71 is released.

In the shuttle valve 5, when the solenoid 36 is energized, the spool 34 of the valve body drive switching valve 3 is moved to the solenoid 36, and is moved to the lower limit position of the movement inside the cylinder 30 against the biasing force of the spring 35, and is moved to the first lower limit position.
Pressurized air supplied to the port 31 from a pressurized air supply device (not shown) is supplied to the cylinder 40 of the valve body drive cylinder 4 through the communication hole 33.

In the valve body driving cylinder 4, the pressurized air moves the piston 41 to the left end of the cylinder 40 against the biasing force of the spring 42, and the piston rod 43 comes into pressure contact with the valve body 21 that closes the drain port circuit 15. By pushing it open, a part of the working oil flowing from the suction port circuit 14 to the discharge port 12 is transferred to the drain port 1.
3 to reduce the pressure of the working oil sent to the die clamper 71. Further, the piston rod 43 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 suction port circuit 14 with the valve body 20.
The supply of pressurized working oil to the cylinder 76 of No. 1 is cut off, and the drain port circuit 15 is opened to return the working oil that has already been sent to the cylinder 76 to the oil sump 60. Therefore, the cylinder 7 of the die clamper 71
The hydraulic pressure inside the mold 6 decreases, the die clamper 71 rises, and the lower die 72 is unclamped.

Further, when replacing the lower mold 72, the shuttle valve 1 is switched to raise the die lifter 70, thereby floating the lower mold 72 above the bolster 73 and supporting it.

Shuttle valve 1 during normal operation or press work, etc.
When the solenoid 36 is not energized, the spool 34 of the valve body drive switching valve 3 is at the upper limit position of movement within the cylinder 30, and pressurized air supplied from the outside to the second port 32 passes through the communication hole 33 to the valve. It is supplied to the cylinder 40 of the body drive cylinder 4. At this time, the operation of the shuttle valve 1 is similar to the operation of the shuttle valve 5, and the hydraulic pressure in the cylinder 74 of the die lifter 70 is released and the die lifter 70 is in the lowered position.

Here, when the solenoid 36 of the shuttle valve 1 is energized, the spool 34 of the valve body drive switching valve 3 is moved by the solenoid 36 and is brought to the lower limit position of movement within the cylinder 30 against the biasing force of the spring 35. The cylinder 40 of the valve body drive cylinder 4 is connected to the first port 31 through the communication hole 33 and is opened to atmospheric pressure. The operation of the shuttle valve 1 at this time is similar to the operation of the shuttle valve 5, and pressurized working oil is supplied into the cylinder 74 of the die lifter 70, so that the die lifter 70 rises and lifts the lower mold 72. It is floated and supported on the bolster 73 to facilitate quick and easy replacement of the lower mold 72.

According to this embodiment, switching between supplying and discharging working oil to the cylinders 74 and 76 using hydraulic pressure or the like can be easily performed using one shuttle valve 1 and 5. At this time, the switching operation is performed by the solenoid 36.
This can be easily done by energizing the first port 3.
Depending on the arrangement of the pressurized air and the like connected to the first and second ports 32, it is possible to freely select how to switch depending on whether or not the solenoid 36 is energized.
Furthermore, when the oil pressure on the suction port 11 side is high, the valve bodies 20 and 21 each act as a check valve, which prevents leakage and backflow of working oil, and furthermore, prevents accidents caused by an inadvertent drop in oil pressure in the cylinders 74 and 76. etc. can be avoided. Therefore, the structure can be extremely simple compared to a conventional lower clamper circuit using a spool valve and a pilot operation check valve.

Furthermore, if the valve body drive cylinder 4 is operated at low speed when switching between supply and discharge, after the valve body 21 on the drain port 13 side is opened, the valve body 21 on the suction port 11 side is opened.
Until the valve is closed, there is a time delay due to the distance between the valve bodies 20 and 21 due to the interposed spring 22, and the pair of valve bodies 20 and 21 are separated at an appropriate time difference. In order to operate, the suction port 11, discharge port 12, and drain port 13 are communicated with each other at the intermediate position of switching, and sudden changes in oil pressure can be avoided without using any special means.

As shown above, although the shuttle valves 1 and 5 of the present embodiment have been described by way of an example in which they are applied to a lower clamper circuit, the shuttle valves 1 and 5 of the present invention are not limited to such uses, but can be applied to various hydraulic devices. Alternatively, it can be used in circuits.

In the above embodiment, the piston rod 43 of the valve body drive cylinder 4 was brought into pressure contact with the valve body 20 via the valve body 21 to forcibly close the suction port circuit 14. It is also possible to directly press the valve body 20 by inserting it through the body 21 or the like. In addition, the valve body drive cylinder 4 is a cylinder 40 that includes a piston 41 that is movable by a control fluid supplied from the outside, and a piston rod 43 that is connected to the piston 41 and can be operated as a unit. It may also be a cylinder with a ram or plunger. Furthermore, although the valve element drive switching valve 3 is switched by the solenoid 36, a pilot fluid or the like may be used therebetween, or it may be switched directly by a control fluid such as pressurized air.

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
A valve body drive cylinder 4 that forcibly closes the inlet circuit 14 with a side valve body 20, and a valve body drive switching valve that can supply or discharge pressurized fluid supplied from the outside to the valve body drive cylinder 4. This means that the shuttle valves 1 and 5 are integrally equipped with 3 and 3.

〔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 sectional view showing a shuttle valve equipped with a pressure detection limit switch according to the embodiment, and FIG. A circuit diagram showing a lower clamper circuit. FIG. 4 is a circuit diagram showing a conventional example of a lower clamper circuit. 1, 5... Shuttle valve, 3... Valve body drive switching valve, 4
... Valve body drive cylinder, 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 inlet port circuit and 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 closes the suction port circuit. The present invention is characterized by integrally comprising a valve body drive cylinder that forcibly closes the port circuit, and a valve body drive switching valve capable of supplying or discharging pressurized fluid supplied from the outside to the valve body drive cylinder. Shuttle valve.