JPH032064Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a sliding valve, and more specifically, the invention includes a pair of annular valve seats that individually contact and seal the front and back surfaces of a sliding valve body. A valve body expanding and contracting mechanism is provided, which is fitted into the valve body, presses the front and back surfaces of the valve body against the corresponding valve seat when the valve body is in the fully open and fully closed positions, and separates the valve body during the valve body sliding process. The present invention relates to a valve seat mounting structure for a sliding valve that is able to exhibit extremely high sealing performance while achieving both the operability of sliding the valve body and the valve body expanding and contracting function.

[Conventional technology]

Conventionally, in the above sliding valve, as shown in FIG. 5, the annular valve seat 4 fitted in the valve body 2 is prevented from slipping out toward the valve body 1 due to the fluid pressure acting on the back end surface 4a. In order to do this, the annular valve seat 4 is press-fitted into the valve body 2.

(No references can be provided.) [Problems that the invention aims to solve] However, because of the press-fitting structure, high dimensional accuracy is required in the processing of the valve body and annular valve seat, and it is difficult to assemble and disassemble the valve. During inspection and repair, a special device was required to attach and detach the annular valve seat, which was disadvantageous in terms of manufacturing and maintenance.

Moreover, even if a press-fitting structure is adopted, in a high-pressure fluid system where the fluid pressure is, for example, 5000 psi or more, the annular valve seat may come out unexpectedly, and the valve seat that has come out comes into contact with the valve body. Due to the interference, there still occur cases where the sliding operation of the valve body lacks smoothness and the expansion/contraction function of the valve body is inhibited.

An object of the present invention is to effectively prevent the annular valve seat from slipping out due to fluid pressure, regardless of the press-fitting configuration, through reasonable improvements.

[Means for solving problems]

The characteristic structure of the valve seat mounting structure according to the present invention is that the cylindrical member is placed between the annular valve seat and the valve box into which it is fitted, and the end surface of the cylindrical member on the valve seat side is annular. The valve seat is recessed from the contact surface of the valve body and fitted inside, and a seal ring is interposed between the cylindrical member, the annular valve seat, and the valve body, respectively, and its function and function are as follows. The effects are as follows.

[Effect]

That is, as shown in FIG. 3, the barrier action of the cylindrical member 8 and the sealing action of the seal rings 9A and 9B prevent fluid pressure from acting on the back side end surface 4a of the annular valve seat 4. Because it is possible to create an annular valve seat 4 using fluid pressure without using a press-fit configuration.
It is possible to reliably prevent this from slipping out.

Further, the valve seat side end surface 8a of the cylindrical member 8 is connected to the annular valve seat 4.
By retiring from the valve body contact surface 7a of the cylindrical member 8, the valve seat side end surface 8a and the valve body side end surface 8
By applying fluid pressure to both end surfaces 8a and b,
The valve seat 4, the valve body 2, and the cylindrical member 8 can be prevented from coming off due to the fluid pressure by canceling out the fluid pressures acting on each of the cylindrical members 8b and 8b.
There is also no need for a press-fit fitting configuration for fitting with.

[Effect of idea]

As a result of the above, there is no need for the conventional press-fit fitting configuration, which makes manufacturing and processing of each fitting member easier, and also requires special equipment for valve assembly and overhaul inspection and repair. The annular valve seat and the cylindrical member can be attached and detached extremely easily without any trouble, and productivity and maintainability can be greatly improved.

Moreover, the annular valve seat is designed to cut off the fluid pressure action itself on its back side end surface, and the cylindrical member is designed to cancel out the fluid pressures acting on each other to prevent each from slipping out. Even when used in a fluid system, leakage due to fluid pressure can be reliably avoided, and the sliding operability of the valve body and expansion/contraction function can always be maintained in good condition, greatly improving the reliability of the valve for high-pressure fluids. I was able to improve.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

As shown in FIG. 1, a plate-shaped valve body 1 having a flow passage hole f is slidably installed inside a valve box 2, and a flow passage F in the valve body is formed through the flow passage hole f of the valve body 1. A valve rod 3 is provided for slidingly operating the valve body 1 between an open position where the valve body communicates with the valve body and a closed position where the flow path F in the valve box is blocked by the valve body 1. A pair of annular valve seats 4 that individually contact and seal against the back surface are fitted into the flow passage openings in the valve box, thereby forming a gate valve.

As shown in FIGS. 1 and 2, the valve body 1 is divided into two parts 1A, which contact each valve seat 4 separately,
1B, and those divided parts 1
Inclined cam surfaces a, b in the form of concave and convex engagement that act as a cam on the contact surfaces between A and 1B in the direction of sliding operation of the valve body.
divided portion 1 formed with a concave cam surface a.
A valve stem 3 is interlocked and connected to A.

A spring 5 for elastically biasing the divided portions 1A and 1B is attached to the side that brings the divided portions 1A and 1B closer to each other, and the divided portion 1B is formed with a convex cam surface b.
A stopper 6 is provided to restrict the sliding range of the valve body 1, and as shown in FIG.
The two divided parts 1A and 1B are brought close to each other by the urging force of , in other words, the front and back surfaces of the valve body 1 are separated from the corresponding valve seat 4, and the divided parts 1A and 1B are uneven cam surfaces a, b
so that they slide integrally due to the engagement action of
Further, as shown in FIG. 2B, the stopper 6 is activated near the valve fully closed position and near the valve fully open position to prevent the sliding of the divided portion 1B forming the convex cam surface b, and the concave cam As only the divided portion 1A forming the surface a continues to be slid, both the divided portions 1 are separated by the cam action of the cam surfaces a and b.
A and 1B are separated against a spring 5, and the front and back surfaces of the valve body 1 are respectively pressed against the corresponding valve seats 4 in the valve fully closed position and the valve fully open position.

In other words, due to the expansion/contraction function of the valve body 1 as described above,
It is constructed so that extremely high sealing performance can be achieved while maintaining high sliding operability of the valve body 1.

As shown in FIGS. 3 and 4, when fitting the annular valve seat 4 with the contact sealing seat ring 7 attached to the end valve on the valve body side into the annular recess 2A of the valve body 2, A cylindrical member 8 having the same inner diameter as the in-box flow path F is placed between the annular valve seat 4 and the small diameter annular recess 2B of the valve box 2, and extends between the valve seat 4 and the valve box 2.
In addition, the end surface 8a of the cylindrical member 8 on the valve seat side is recessed from the valve body contact surface 7a of the seat ring 7 and is fitted inside, and the cylindrical member 8, the annular valve seat 4, and the valve body 2 are connected to each other. O-rings 9A and 9B are interposed between them, and the barrier action of the cylindrical member 8 and both O-rings 9
The sealing action of A and 9B prevents fluid pressure from acting on the back side end surface 4a of the annular valve seat 4, and prevents the annular valve seat 4 from slipping out toward the valve body side due to the fluid pressure action. It is structured as follows.

That is, during the valve body sliding operation process, the annular valve seat 4 comes out due to fluid pressure and comes into contact with the valve body 1.
Due to the abutting action, the valve body segment 1B forming the convex cam surface b acts as a wedge against the valve body segment 1A forming the concave cam surface a, and the wedge action causes the valve body segment 1B to form a convex cam surface b. It is configured to prevent the sliding movement of the body 1 from being obstructed.

Furthermore, by recessing the valve seat side end surface 8a of the cylindrical member 8 from the valve body contact surface 7a on the valve seat side, fluid pressure is applied to both end surfaces 8a and 8b of the cylindrical member 8, respectively. By canceling these fluid pressures, it is possible to prevent the cylindrical member 8 itself from coming off due to the fluid pressure.

10 in the figure is an O-ring interposed between the annular valve seat 4 and the valve box 2.

[Another example]

Next, another embodiment of the present invention will be described.

Various improvements can be made to the specific structure for expanding and contracting the valve body 1, and these structures are collectively referred to as expansion and contraction mechanisms a and b.

The cylindrical member 8 can be modified in various ways, such as a simple cylindrical shape, or a tapered peripheral surface, instead of having a stepped portion on the outer periphery as shown in FIG.

The slide valve employing the valve seat mounting structure according to the present invention is suitable for use with high-pressure fluid, but the fluid to be used does not matter.

[Brief explanation of drawings]

1 to 4 show embodiments of the present invention,
Fig. 1 is a longitudinal sectional view of the sliding valve, Fig. 2 A and B are enlarged sectional views showing the operating state of the valve body, Fig. 3 is an enlarged sectional view of the main parts, and Fig. 4 is the same as in Fig. 3. It is a line arrow view. FIG. 5 is an enlarged sectional view showing a conventional structure. 1... Valve body, 2... Valve box, 4... Annular valve seat, 7
a... Valve body contact surface, 8... Cylindrical member, 8a...
Valve seat side end surface, 9A, 9B...Seal ring, a,
b...Expansion/contraction mechanism.

Claims (1)

[Scope of utility model registration request] A pair of annular valve seats 4 that individually contact and seal the front and back surfaces of the sliding valve body 1 are fitted into the valve box 2, and the front and back surfaces are pressed against the corresponding valve seats 4. In the sliding valve, the cylindrical member 8 is provided with valve body expansion/contraction mechanisms a and b that are brought into pressure contact when the cylindrical member 8 is in the fully open and fully closed positions, and are separated during the valve body sliding process.
with respect to the valve seat 4 and the valve body 2, and so that the valve seat side end surface 8a of the cylindrical member 8 is lower than the valve body contact surface 7a of the valve seat 4. A seal ring 9 is provided between the cylindrical member 8, the valve seat 4, and the valve box 2, respectively.
Valve seat mounting structure for a sliding valve with A and 9B interposed.