JPH11141699A - Ball valve seal structure - Google Patents

Abstract

(57) Abstract: The present invention relates to a seal structure of a ball valve. The present invention provides a seal structure for a ball valve, wherein an annular seal body integrally formed with a ball press contact portion and a retainer is interposed between a ball valve and a valve case. Things.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a seal structure for a ball valve.

[0002]

2. Description of the Related Art Conventionally, in a seal structure of a ball valve, an annular seal is provided between a sliding surface of the ball valve and a ball holding portion of a valve case, and the annular seal is formed by a retainer mounted inside the case. Held on the side.

[0003] That is, a seal member between the ball and the case is constituted by a combination of a retainer and an annular seal.

[0004]

However, when the flow path is rapidly closed or a sudden change in the water pressure occurs, the water pressure enters the gap between the retainer and the annular seal, peeling off the annular seal, There is a possibility that an unexpected situation such as the retainer jumping out due to a water pressure applied to the back surface may occur.

[0005]

According to the present invention, there is provided a ball valve sealing structure in which an annular seal body integrally formed with a ball press contact portion and a retainer is interposed between a ball valve and a case. It will not be provided.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the annular seal is formed integrally with the ball pressure contact portion and the retainer, and the annular iron core is buried inside the annular seal. Without peeling or popping, especially
Since the seal interposed between the case and the ball valve is a retainer integrated with the ball pressure contact part, if it is configured to match the holding part of the annular seal inside the case as much as possible, the back pressure will be reduced. It is hard to be applied and the peeling phenomenon can be prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a ball valve A having a seal structure of the present invention.
The valve case C has a main body case 3 interposed between a cylindrical inflow case 1 and a cylindrical outflow case 2, and is disposed vertically in the main body case 3. A ball valve 5 is housed and connected to the lower end of the valve shaft 4.

[0008] The ball valve 5 is housed in the main body case 3, and is held in pressure contact with the inlet and outlet sides at the open end surfaces of the inflow case 1 and the outflow case 2.

That is, between the end faces of the flanges 1 ′ and 2 ′ provided at the openings of the inflow case 1 and the outflow case 2 and both end faces of the main body case 3, only an annular seal body M is interposed. A concave portion 6 is formed, and an annular seal body M is formed in the concave portion 6.
Are clamped and fixed.

As shown in FIGS. 2, 3 and 4, the annular seal body M has an annular iron core 7 embedded in an annular body made of an elastic material, and has an inner peripheral surface of the annular body, that is, a ball valve. The pressure contact surface of FIG. 5 forms a slightly curved ball pressure contact portion M-1, and a large portion of the annular seal body M is constituted by a retainer M-2 at the rear thereof. M-1 and retainer M-2 are more integrally formed.

The shape of the annular seal M is such that the shape of the conventional retainer and the shape of the annular seal are integrally formed. Are also formed in the same shape.

FIG. 3 is an overall cross-sectional view of the annular seal body M. It can be seen that the seal body is also integrally formed with a retainer portion.

FIG. 4 is an enlarged view of a part thereof.
In order to cope with such a step 8, the recess 6 is
It is formed on the flange 1 ′, 2 ′ end face of the inflow case 1 and the outflow case 2.

Reference numerals 9 and 10 denote an inlet and an outlet of the ball valve 5, respectively.

In the above-described embodiment, the annular seals M are disposed on both the inflow side and the outflow side of the ball valve 5, but the outflow side of the ball valve 5, that is, the water pressure is reduced by the ball valve. In some cases, the annular seal body M may be provided only on the side directly interposed through the joint 5.

Reference numeral 11 denotes a handle for rotating the ball valve 5.

Reference numeral 12 denotes a seal member between the main body case 3 and the inflow case 1 or the outflow case 2.

If necessary, the outer surface of the ball pressure contact portion M-1 may be coated with Teflon to improve wear resistance and slidability.

[0019]

According to the present invention, the annular seal interposed between the ball valve and the inside of the valve case is formed integrally with the ball pressure contact portion and the retainer. As compared to the separate structure of the above, the gap where water pressure is applied is small, and it is securely held inside the valve case, so there is no danger of jumping out due to back pressure, and there is an effect that the sealing function can be sufficiently performed. Since the conventional two members become one member, the structure is simplified and the assembling work is also simplified.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of a ball valve having a seal structure of the present invention.

FIG. 2 is an enlarged explanatory view of a main part thereof.

FIG. 3 is a sectional view of an annular seal having the seal structure of the present invention.

FIG. 4 is a partially enlarged view of a cross section of a main part thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inflow case 2 Outflow case 3 Main case 4 Valve shaft 5 Ball valve 6 Recess 7 Annular iron core 8 Step

Claims (1)

[Claims] 1. A ball valve, wherein an annular seal body (M) integrally formed with a ball press contact portion and a retainer is interposed between a ball valve (5) and a valve case (C).
(5) Seal structure.