JP2535458Y2 - Pilot type 2 port valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot type two-port valve.

[0002]

2. Description of the Related Art When a fluid at a supply port is supplied to a pressure working chamber behind a main valve body, the main valve body closes a main valve seat by a fluid pressure in the pressure working chamber, and a fluid in the pressure working chamber is fluidized by a pilot valve. Is discharged, the main valve body opens the main valve seat by the fluid pressure of the supply port.
Already known. The known pilot type two-port valve shown in FIG. 2 includes a main valve 1 and a pilot valve 2, and the main valve 1
The valve body 4 has a supply port P for pressure fluid, an output port A, and a main valve seat 5 in a flow path connecting these ports.
The main valve body 6 that opens and closes the main valve seat 5 is configured as a diaphragm whose periphery is sandwiched between the valve body 4 and a bonnet 7 that covers the valve body. A pressure action chamber 8 is defined in the bonnet 7, and a return spring 9 is contracted between the bonnet 7 and the main valve element 6. On the other hand, the valve chamber 10 of the pilot valve 2 has an inlet orifice 11
The outlet orifice 13 having a larger opening area than the inlet orifice 11 between the valve chamber 10 and the output port A is opened and closed by the pilot valve element 14. . The pilot type two-port valve has a configuration in which the pilot valve element 14 closes the outlet orifice 13 in the illustrated state.
The main valve body 6 closes the main valve seat 5 by the fluid pressure of the supply port P supplied to the pressure action chamber 8 and the urging force of the return spring 9. When the pilot valve element 14 opens the outlet orifice 13, the fluid in the pressure action chamber 8 is released from the outlet orifice 13.
The main valve body 6 opens the main valve seat 5 against the urging force of the return spring 9 by the fluid pressure of the supply port P acting on the main valve body 6.

However, the known pilot type 2
When the fluid pressure in the supply port P rises due to the fluctuation of the supply fluid pressure, the increased fluid pressure acts immediately on the supply port P side of the main valve body 6, but the fluid pressure in the pressure action chamber 8 becomes Since the gas passes through the inlet orifice 11 having a small opening area, a time delay occurs in the pressure rise. For this reason, the main valve element 6 temporarily opens the main valve seat 5 due to the pressure difference between the supply port P side and the pressure action chamber 8 side acting opposite to the main valve element 6, and the fluid leaks. Sometimes. The leak of the fluid is remarkable in the case where the pressure fluid is compressed air having compressibility, but even if the pressure fluid is an incompressible liquid such as water, these liquids contain a small amount of air. Therefore, if the fluid pressure in the supply port P rises rapidly, it may be difficult to maintain the valve closed state.

[0004]

A problem to be solved by the present invention is to provide a pilot type two-port valve in which fluid does not leak even if the fluid pressure on the inlet side increases.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a pressure fluid supply port, an output port, a main valve seat in a flow passage connecting these ports, and opening and closing of the main valve seat. In a pilot type two-port valve including a main valve having a main valve body and a pilot valve, the main valve includes:
A first pressure action chamber for driving the main valve body in the opening direction of the main valve seat and a second pressure action chamber opposite to the first pressure action chamber, and a supply flow communicating the supply port with the first pressure action chamber; A passage, a passage communicating the output port with the second pressure acting chamber, an orifice having an opening area smaller than that of the supply passage communicating the first pressure acting chamber with the second pressure acting chamber, and a main valve seat having the main valve body. And a return spring that urges in the closing direction, and the pilot valve that allows the supply flow path to be cut off is provided in the supply flow path.

[0006]

When the supply valve is closed by the pilot valve, the first pressure action chamber is provided with a passage and an orifice.
Since the fluid at the output port is supplied to each of the second pressure action chambers by the passage, the main valve body closes the main valve seat by the urging force of the return spring. In this case, since the fluid pressure of the supply port does not act on the first and second pressure action chambers, even if the fluid pressure of the supply port increases, the main valve seat is opened and the fluid does not leak.

When the pilot valve opens the supply passage, the fluid in the supply port flows into the first pressure action chamber and the fluid pressure in the first pressure action chamber increases, whereby the action force is reduced by the urging force of the return spring. Since the pressure becomes larger, the pressure receiving member is displaced in the opening direction of the main valve seat, the main valve body opens the main valve seat, and the fluid in the supply port flows out of the output port. In this case, since the opening area of the orifice connecting these pressure action chambers is smaller than that of the supply passage, the fluid pressure of the second pressure action chamber is lower than the fluid pressure of the first pressure action chamber. The open state is maintained. When the pilot valve closes the supply flow path,
Since the fluid in the first pressure action chamber flows out to the output port and the fluid pressures in the first and second pressure action chambers become substantially equal, the main valve body closes the main valve seat by the urging force of the return spring.

[0008]

FIG. 1 shows an embodiment of the present invention. This pilot type two-port valve 20 includes a main valve 21 and a pilot valve 22, like a known two-port valve. Main valve 2 above
The first valve body 24 includes a supply port P for pressure fluid, an output port A, and a main valve seat 2 in a flow path connecting these ports.
5, and an opening facing the main valve seat 25, and the main valve seat 2
5 of the main valve body 27 that opens and closes the supply port 5 from the supply port P side
Extends outside the valve body 24 through the plate 29 fitted in the opening. The space between the valve main body 24 and the plate 29 and the bonnet 31 attached to the valve main body 24 is formed by a diaphragm 32 which is an example of a pressure-receiving body and whose peripheral edge is sandwiched between the valve main body 24 and the bonnet 31. The first pressure action chamber 33 on the 29 side and the second pressure action chamber 34 on the bonnet 31 side are partitioned, and the center of the diaphragm 32 is fixed to the tip of the valve rod 28.
A return spring 35 is contracted between the plate 29 and the valve rod 28.

The valve chamber 40 of the pilot valve 22 has a supply port P and a first pressure action chamber 33 through supply channels 41 and 42.
And an inlet orifice 43 is formed at the opening of the supply channel 42 to the valve chamber 40. When the solenoid is excited, the pilot valve body 44 opens the inlet orifice 43 to communicate the supply flow path, and when the solenoid is de-energized, the pilot valve body 44 moves the inlet orifice 43 to , And is configured as an electromagnetic valve that shuts off communication with the supply flow path. However, the pilot valve 22 of the present invention is not limited to an electromagnetic valve, and may drive the pilot valve body 44 by, for example, fluid pressure.

The second pressure action chamber 34 communicates with the output port A through a passage 36 formed in the valve rod 28. The opening area of the passage 36 is larger than the opening areas of the supply passages 41 and 42 and the inlet orifice 43. Has been made smaller. Also, the first
The pressure action chamber 33 has an orifice 37 opened in the valve stem 28.
Thus, the opening area of the orifice 37 is made smaller than the opening area of the passage 36. Although not shown, the orifice 37 is connected to the valve stem 2.
Instead of 8, for example, it may be provided on the diaphragm 32.

In the illustrated embodiment, the pilot valve 22 closes the inlet orifice 43 and the communication of the supply flow path is interrupted, and the first pressure action chamber 33 and the second pressure action chamber 34 are closed. Since the fluid pressure at the output port A is acting, the main valve body 27 closes the main valve seat 25 by the urging force of the return spring 35. Therefore, the supply port P
Even if the fluid pressure increases, the fluid pressure in the pressure action chambers 33 and 34 does not fluctuate, and the diaphragm 32 does not displace. When the pilot valve 22 opens the inlet orifice 43, the supply flow paths 41 and 42 communicate with each other, and the fluid in the supply port P flows into the first pressure action chamber 33 and its fluid pressure rises. Is displaced toward the bonnet 31 side against the urging force of the return spring 35, so that the main valve body 27 opens the main valve seat 25 and the fluid in the supply port P flows out to the output port A. In this case, the orifice 3
Since the fluid at the supply port P, which has been decompressed in step 7, is supplied,
The main valve body 27 holds the open state of the main valve seat 25, and this state does not change even if the fluid pressure of the supply port P increases or decreases.

[0012]

According to the present invention, when the main valve body closes the main valve seat, the pilot type two-port valve supplies the pressure to the two pressure action chambers divided by the pressure receiving member that drives the main valve body. Since the fluid pressure at the port does not act, it is possible to reliably prevent fluid leakage due to an increase in fluid pressure at the supply port.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an embodiment.

FIG. 2 is a sectional view of a main part of a known pilot type two-port valve.

[Explanation of symbols]

 Reference Signs List 20 pilot type 2 port valve 21 main valve 22 pilot valve 25 main valve seat 27 main valve body 32 diaphragm 33 first pressure action chamber 34 second pressure action chamber 36 passage 37 orifices 41, 42 supply flow path P, A port

Claims (1)

(57) [Scope of request for utility model registration] 1. A main valve having a supply port and an output port for a pressure fluid, a main valve seat in a flow path communicating these ports, a main valve body for opening and closing the main valve seat, and a pilot valve. In the pilot type two-port valve, the main valve is divided by a pressure receiving body, and a first pressure action chamber for driving the main valve body in an opening direction of a main valve seat and a second pressure action chamber on the opposite side; A supply passage communicating the supply port with the first pressure action chamber, a passage communicating the output port with the second pressure action chamber, and an opening from the supply flow path communicating the first pressure action chamber with the second pressure action chamber; An orifice having a small area, and a return spring for urging the main valve body in the closing direction of the main valve seat, wherein the pilot valve for cutting off the supply flow path is provided in the supply flow path. Features a pilot type 2-port valve.