JPH0132387B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a valve device, and the present invention relates to a valve unit in which the seating force of a seat ring is variable, and when switching the valve unit, the seating force of the seat ring is released, the valve body is displaced, and the seat ring is changed. It is an object of the present invention to provide a valve device equipped with a piston-cylinder mechanism and a supply control mechanism that drive a seat ring and a valve body in accordance with the order of seat force return.

For example, a switching valve is known in which a flow path is formed in a spherical valve body, and a valve shaft of the spherical valve body is rotated from the outside to switch the connection state of a port. The valve body of this type of switching valve is usually seated on a seat ring by the spring force of a coil spring, so the seating force of the valve body is weak, and the valve body is subject to high differential pressure, similar to butterfly valves. Do not normally use it in areas where it is active. Therefore, if the valve body must be used under conditions where a high differential pressure acts on the valve body, it is necessary to have a configuration in which, for example, the seating force of the seat ring serving as the valve seat can be varied.

However, in conventional valve devices in which the seat force of the seat ring is variable, it is necessary to release the seat force by the seat ring while the valve body is being rotated. A limit switch is provided, and the release or return of the seat force is controlled by the opening/closing signal of the limit switch. Therefore, the configuration of the seat force release/return mechanism is complicated, and the failure rate is correspondingly high.For example, the valve body may be rotated even though the seat ring has not released its tightening against the valve body. . For this reason, the sliding contact area between the valve body and the seat ring is prone to wear, which can significantly reduce the sealing effect of the seat ring, and furthermore, the valve body may be damaged and become unusable. had. In addition, in order to vary the seating force of the seat ring, conventionally, a flow path for hydraulic oil is formed in the annular seat ring, and the seat ring is pressed against the valve body or released from the pressure depending on the hydraulic pressure of the hydraulic oil. The structure was very complicated, and the hydraulic oil supplied to the seat ring was from the same piping system as the hydraulic oil for driving the valve body, so the pressing force on the seat ring and the pressure on the valve body were very different. This has disadvantages such as the inability to adjust the driving force individually.

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described below with reference to the drawings. 1st
The figure is a schematic configuration diagram of an embodiment of the valve device of the present invention, Figures 2 and 3 are longitudinal and cross-sectional views, respectively, of an embodiment of the valve part, and Figures 4 and 5 are one embodiment of the piston-cylinder mechanism. 3 shows longitudinal cross-sectional views of the example in different operating states; FIG.

In FIG. 1, a valve device 1 includes a 4-port, 2-position switching type valve section 2 in this embodiment, a piston-cylinder mechanism 3 that drives the valve section 2 to open and close, and a valve section 2 and a piston-cylinder mechanism. 3, and a supply control mechanism 5 that controls the supply of pressure fluid from the fluid pressure source 4 to the valve portion 2.

As shown in FIGS. 2 and 3, the valve part 2 has a spherical valve body 11 within a valve body 10 in which four ports 6, 7, 8, and 9 are formed in communication in a cross shape, and a spherical valve body 11 is disposed in a range of about 90 degrees. It is configured to be rotatably supported. A pair of channels 12 and 13 are formed symmetrically within the valve body 11, and the communication state between each port 6, 7, 8, and 9 is determined according to the rotational displacement position of the valve body 11 in this embodiment. In this case, it can be switched in two ways. Further, a seat ring 6 made of plastic material, rubber material, etc. is attached to the opening of each port 6, 7, 8, 9 in the valve body 10.
a, 7a, 8a, and 9a are provided. Each seat ring 6a, 7a, 8a, 9a has a port 6,
The pressure members 6b, 7b, 8b, 9b are displaceable in the axial direction of the valve body 10. Fluid supply and drainage channels 6c, 7c,
The working fluid supplied via 8c, 9c can press the seat rings 6a, 7a, 8a, 9a in a direction that increases the seating force against the valve body 11. These working fluid supply and discharge passages 6c, 7
c, 8c, and 9c are one pipe line 14 outside the valve body 10.
One end of the pipe line 14 is connected to a pump 15 in the fluid pressure source 4, and the other end is connected to the piston-cylinder mechanism 3.

The valve body driving section 3' includes a pinion 16 fixed to the valve shaft 11a of the valve section 2, a rack 17 that meshes with the pinion 16, and a seat of the valve section 2 that rotates the valve body 11 by reciprocating the rack 17. Rings 6a, 7
It is generally composed of a piston/cylinder mechanism 3 that presses or releases the pressure on the cylinders a, 8a, and 9a. In addition, the pinion 16 and rack 17
An opening/closing mechanism for opening and closing the valve portion 2 is constituted by the above. As shown in FIGS. 4 and 5, the piston/cylinder mechanism 3 has a large diameter main piston 20 fitted in one space 19 of the cylinder 18, and a small diameter first piston 20 fitted in the space inside the main piston 20. Slave piston 21
It is roughly constructed by fitting. Supply control mechanism 5
The main piston 20 is generally constructed by fitting a second slave piston 24 connected to the main piston 20 by a piston rod 23 into the other space 22 of the cylinder 18. The piston rod 25 of the first slave piston 21 is slidably inserted through the main piston 20 and the wall of the cylinder, and has a rack 17 at its tip.
are integrally installed. Also, the first slave piston 21 is provided with a through hole 21a, which allows the first slave piston 21 to move independently of the main piston 20 within the space within the main piston 20. Therefore, even if the main piston 20 starts to operate, the first slave piston 21 will relatively slide within the internal space of the main piston 20, and the first slave piston 21 will be delayed for a predetermined period of time from the start of the operation of the main piston 20. It will work. Moreover, the first slave piston 21
When the main piston 20 operates, fluid within the space of the main piston 20 passes through the through hole 21a. Therefore, the delay time of the first slave piston 21 is set to an arbitrary time by selecting the inner diameter of the through hole 21a.

One space 19 of the cylinder 18 is partitioned by a main piston 20 into a pair of chambers 19a and 19b. Each chamber 19a, 19b is connected to a pipe 2, respectively.
6 and 27 to a 2-position, 4-port solenoid valve 28 in the fluid pressure source 4, and is selectively connected to the pump 14 or reservoir 29 by switching the solenoid valve 28.

The other space 22 of the cylinder 18 is divided into a pair of chambers 22a and 22b by a second slave piston 24, and both chambers 22a and 22b are defined by a communication passage 30 bored inside the cylinder 18. communicate with each other. Here, the chamber 22a is connected to the pump 15 through a conduit 14, and the chamber 22b is connected to a reservoir 29 through a conduit 31. Furthermore, sealing members such as O-rings are provided at the left and right ends of the inner wall of the space 22.

Here, in the pipe line 32 connecting between the solenoid valve 28 and the pump 15 and in the pipe line 14 connecting between the valve part 2 and the pump 15, throttle valves are provided for variably adjusting the pressure of the working fluid. 32a and 14a are provided. Therefore, by individually adjusting the opening degree of each throttle valve 32a, 14a, the pressing force on the main piston 20 (i.e., the driving force for the valve body) and the seat ring 6 can be adjusted.
The pressing forces for a, 7a, 8a, and 9a can be adjusted individually.

Now, the main piston 2 of the piston cylinder mechanism 3
0 is at the left sliding limit position shown in Figure 4,
As shown in FIG. 3, the valve body 11 is at its rotation limit position in the counterclockwise direction in the figure, and ports 6 and 7 and ports 8 and 9 communicate with each other.

Also, at this time, the second slave piston 24 of the supply control mechanism 5 is at the sliding limit position on the left side in the figure, as shown in FIG. 4, and is in contact with the seal member at the left end of the inner wall of the space 22. . For this reason, the pipe line 31 and the communication path 3
0 are separated from each other by the second slave piston 24. Therefore, the high-pressure working fluid is confined in the working fluid supply/discharge passages 6c, 7c, 8c, and 9c in the valve part 2, and the seat rings 6a, 7a, 8a, and 9a in the valve part 2 are closed to the pump. The valve body 11 is pressed with a predetermined seat force by the working fluid pumped from the valve body 15 . Therefore, the valve body 10
Even when a high differential pressure is applied to the valve body 11 due to the fluid flowing therein, no fluid leakage occurs between the ports 6 and 9 or between the ports 7 and 8.

Next, when switching the valve portion 2, the solenoid valve 28 is energized and excited. As a result, the solenoid valve 28 is switched, and the working fluid is supplied from the pump 15 to the chamber 19b of the piston-cylinder mechanism 3. As a result, the main piston 20 in the cylinder 18 is moved into the chamber 19b.
It is pushed to the right in FIG. 4 by the working fluid supplied inside.

In addition, in FIG. 4, the main piston 20 is located in the chamber 19b.
When the main piston 20 is at the left sliding limit position within
Although there appears to be no gap between the left inner wall of the chamber 19b and the left inner wall of the chamber 19b, a person skilled in the art who deals with hydraulic equipment, etc. would understand that a protrusion or a recess is provided in the left inner wall of the chamber 19b to communicate with the conduit 27. Since it is common sense to provide a gap, it is omitted in this embodiment.

When the main piston 20 separates from the left end of the inner wall of the space 19 , the second slave piston 24 integrated therewith also moves away from the left end of the inner wall of the space 22 , thereby causing the communication passage 30 to communicate with the pipe line 31 . For this reason, until then, each seat ring 6a, 7a, 8 of the valve part 2
The working fluid that was pressing a and 9a is in the reservoir 29
The seat rings 6a, 7 are discharged to the side.
The seating forces of a, 8a, and 9a against the valve body 11 are released. Note that the seat force can be canceled by lowering the pressure of the working fluid, and is therefore immediately canceled when the second slave piston 24 starts operating.

Here, since the first slave piston 21 in the main piston 20 is spaced a certain distance from the left end of the inner wall of the main piston 20, the first slave piston 21 is stopped at the beginning of the displacement of the main piston 20. It remains as it is. Also, as mentioned above, the first piston 21
By changing the hole diameter of the through hole 21a of the first piston 2 after the main piston 20 starts operating.
Since the delay time until valve 1 operates can be easily set, it is impossible for valve stem 11a to rotate before the pressure on seat rings 6a, 7a, 8a, and 9a is released.

When the left end of the inner wall of the main piston 20 comes into contact with the first slave piston 21, the first slave piston 21 can be displaced integrally with the main piston 20, and the rack 17
Displace it while pushing it to the right in Fig. 1. Therefore, along with the displacement of the rack 17, the pinion 16 is approximately
The valve body 11 is rotated by 90 degrees, and the valve body 11 is rotated by the valve shaft 11a.
It can be rotated 90 degrees. As a result, the valve body 1
The connection states of ports 6, 7, 8, and 9 of 0 are switched, and ports 6 and 9 are brought into communication with ports 7 and 8, respectively. Note that the flow path 12 of the valve body 11,
13 are symmetrical to each other, the forces that the valve body 11 receives from the fluid in the valve body 10 during rotational displacement cancel each other out, and therefore the rotational load on the valve body 11 is small.

When the main piston 20 is displaced to the sliding limit position on the right side of the figure as shown in FIG. and the communication path 30 are blocked from each other. As a result, the working fluid that had been released to the reservoir 29 side is blocked in the conduit 14, and the seat rings 6a, 7a, 8a, 9 of the valve portion 2
a is pressed against the valve body again. As a result, the valve part 2
The ports 6 and 7 and the ports 8 and 9 are sealed to prevent fluid leakage.

In this way, the valve device 1 operates the piston/cylinder mechanism 3 and the supply control mechanism 5 by energizing the solenoid valve 28 to switch the valve section 2, and both mechanisms 3 and 5 operate the main piston 28. ,2
1, 24 and the seat rings 6a, 7.
A, 8a, 9a are released from the pressure, the valve body 11 is rotated, and the seat rings 6a, 7a, 8a, 9a are pressed.
It is certain.

Next, in order to rotationally displace the valve body 11 of the valve portion 2 in the counterclockwise direction, the power supply to the solenoid valve 28 is cut off.
As a result, the working fluid is supplied to the chamber 19a, and the main piston 20 is displaced from the right sliding limit position shown in FIG. 5 to the left. In the process of this displacement, the seat ring 6 relative to the valve body 11
A series of operations are performed, including releasing the pressure on the valve body a, 7a, 8a, and 9a, rotationally displacing the valve body 11, and pressing the seat rings 6a, 7a, 8a, and 9a.

Here, the valve device 1 having the above configuration has a valve body 11
A first slave piston 21 that rotates and a second slave piston 24 that controls pressing or release of the seat rings 6a, 7a, 8a, and 9a are driven in accordance with the movement of the main piston 20. Since it is built into the cylinder 18, which has an integral structure, the structure is simple and the operation is extremely reliable.

In the above embodiment, the cylinder 18 may have a configuration in which the piston/cylinder mechanism 3 and the supply control mechanism 5 are separate from each other.

In the above embodiment, the number of ports in the valve portion 2 is not limited to four, but may be any other suitable number.

Further, in the above embodiment, the working fluid for the piston/cylinder mechanism 3 and the supply control mechanism 5 is not limited to oil, but other liquids, gases, etc. may be used.

As described above, in the valve device of the present invention, the valve body is displaced after reducing the seating force of the seat ring against the valve body by the operation of the supply control device, so that the valve body is not pressed by the seat ring. The valve body can be displaced smoothly, and after the valve body has finished rotating to a predetermined position, the seating force of the seat ring is increased to press the seat ring toward the valve body contact side. The valve body and seat ring can reliably seal between the ports except during switching operation, and the pressure on the seat ring can be released.
Since a series of operations such as displacing the valve body and pressing the seat ring can be performed extremely easily, it can be safely applied even under conditions where a high differential pressure acts on the valve body. Furthermore, the fluid pressure that presses the seat ring against the valve body can be reduced by the displacement of the second slave piston that is linked to the movement of the main piston, so the pressure on the valve body by the seat ring can be released in a short time, and the The operation delay time of the first slave piston that drives the valve body can be easily changed by changing the hole diameter of the through hole of the first slave piston that is slidably provided in the seat ring. It has features such as being able to reliably prevent the valve body from being driven before it is released.

In addition, the valve device of the present invention has a structure in which the valve body is a spherical valve body and the seat ring is pressed or released by the force of the fluid. The seating force of the seat ring against the valve body can be extremely easily varied simply by varying the valve opening degree, and the seat ring pressing drive system is separate from the drive system for rotationally displacing the valve body. Furthermore, by configuring the piston/cylinder mechanism and the supply control mechanism by assembling the main piston and two slave pistons into an integrated cylinder, the valve body can be controlled more precisely. It has the advantage of being able to control the two operations of driving and pressing the seat ring with an extremely simple configuration.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an embodiment of the valve device of the present invention, Figs. 2 and 3 are longitudinal and transverse sectional views of an embodiment of the valve portion, respectively, and Figs. 4 and 5 are diagrams of a piston-cylinder mechanism. FIG. 3 is a longitudinal cross-sectional view of an embodiment in different operating states; 1... Valve device, 2... Valve section, 3... Piston.
Cylinder mechanism, 4... Fluid pressure source, 5... Supply control mechanism, 6a, 7a, 8a, 9a... Seat ring, 6b, 7b, 8b, 9b... Pressing member, 11
... Valve body.

Claims (1)

[Claims] 1. A valve portion having a seat ring pressing member that urges the seat ring toward the valve body using fluid pressure;
A piston that drives the opening/closing mechanism that opens and closes the valve part.
a cylinder mechanism; a fluid pressure source that supplies working fluid to the piston/cylinder mechanism and the valve; and a fluid pressure source that supplies working fluid to the valve from the fluid pressure source in conjunction with the operation of the piston/cylinder mechanism; The piston/cylinder mechanism includes a main piston having a space inside, a first slave piston that is slidably fitted into the internal space of the main piston, and one end of which is connected to the first slave piston. a piston rod coupled to a slave piston, the other end of which extends through the main piston and is coupled to the opening/closing mechanism, the first slave piston having a through hole extending in the sliding direction; The fluid in the space passes through the through hole and is displaced after a predetermined time delay from the main piston, and the displacement displaces the valve body of the valve portion, and the supply control mechanism The second slave piston has a structure in which the second slave piston is displaced together with the main piston, and the displacement lowers the fluid pressure and releases the pressure on the valve body by the seat ring. Features a valve device. 2. The valve body of the valve portion is composed of a spherical valve body that can be rotated by a predetermined angle around the axis, and the seat ring that presses the valve body is adapted to respond to the pressure of the working fluid supplied from outside the valve body. 2. The valve device according to claim 1, wherein the valve device is configured such that the seating force against the valve body can be varied.