JPH04107377A - Seal device for high vacuum valve - Google Patents

Abstract

PURPOSE:To reduce a cost and to increase a seal effect by adhering a metallic film on the seal surface of the one of a valve seal and a valve desk, covering the metallic film with a synthetic resin film, and providing a mechanism to press the metallic film against an opposing surface through the synthetic resin film. CONSTITUTION:A metallic film 11 is adhered to the edge part of the seal surface of a valve desk 2, the metallic film 11 is further covered with a heat resisting synthetic resin film 13, and the synthetic resin film 13 is brought into opposite contact with the seal surface of a valve seat 1. The portion, except an end part, of the metallic film 11 is pressurized against the seal surface of the valve seat 1 through the synthetic resin film 13 by means of a pressure mechanism. This constitution reduces a cost since there is no need to provide a mirror finish for the seal surface of the metallic film 11. Further, since the synthetic resin film 13 is soft, it is well doped with lodging of refuse and thus, a seal effect is high.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sealing device for a high vacuum valve.

[Conventional technology]

Figures 2 and 3 show a conventional high vacuum gate valve,
1 is a large-diameter valve seat with a diameter path of 200 mm, 2 is a disc-shaped valve desk that is in contact with this, and 3 is a valve disk that connects the valve disk 2 to the valve seat 1.
4 is a protruding inlet (horizontal direction) direction movable body that supports the valve suppressor 3 via a link 5; 8 is a valve stopper, and 9 is a roller provided at the end of the valve stopper 3 so as to abut against the stopper 8.

In such a gate valve, when the piston cylinder 6 is driven to move the piston rod 7 downward in FIGS. 2 and 3, the moving body 4 moves downward together with the valve stopper 3 and the valve desk 2, and the valve stopper moves downward. After the roller 9 of No. 3 hits the stopper 8, the valve stopper 3 and the valve disk 2 are moved in the axial direction of the valve disk via the link 5, and the valve disk 2 is brought into contact with the valve seat 1 to achieve sealing. be done.

Conventional high-temperature (20°C or higher) valves used in high vacuum
Valves used in radioactive or radioactive atmospheres are made of metal, including the valve desk. The biggest weakness in this case is that if minute dust gets caught in the sealing surface, it will immediately lead to leakage. In order to compensate for this drawback, it has been proposed that a plurality of ridges 10 having a triangular cross section are provided concentrically on the annular sealing surface of the valve desk 2 facing the valve seat 1, as shown in FIG.

Further, as shown in FIG. 5, an annular metal thin film 11 is placed in contact with the annular sealing surface of the valve disk 2 facing the valve seat 1, and the edge of this metal thin film 11 is hermetically welded to the valve disk 2. 2
Air pressure is applied to the gap between the metal thin film 11 and the metal thin film 1 through an air passage 12 formed in the valve desk 2.
There is one in which the sealing surface of valve seat 1, excluding the above-mentioned edge, is brought into contact with the sealing surface of valve seat 1.

[Problem to be solved by the invention]

However, the conventional sealing device shown in FIG. 4 has the drawback that the effective sealing area is small and the sealing effect is low, while the sealing device shown in FIG. 5 allows a wide sealing surface. Although there are advantages, metal thin film 1
It takes a lot of man-hours to give the first sealing surface a mirror finish, and the sealing ability is still insufficient.

The present invention seeks to eliminate the above-mentioned drawbacks.

[Means to solve the problem]

The high vacuum valve sealing device of the present invention includes a thin metal film whose edges are hermetically bonded to the sealing surface of either the valve seat or the valve desk, and a thin metal film that is adhered to the sealing surface of either the valve seat or the valve desk. a synthetic resin thin film that is in contact with one of the other sealing surfaces;
The present invention is characterized by comprising a pressurizing mechanism for pressurizing a portion of the thin metal film other than the edge portion of the thin metal film against the sealing surface facing the synthetic resin thin film.

[For production]

In the high vacuum valve sealing device of the present invention, when the metal thin film is inflated by air pressure, it is brought into contact with the opposing sealing surfaces via the synthetic resin thin film to form a seal.

〔Example〕

The present invention will be explained in detail below with reference to the drawings.

In the present invention, as shown in FIG. 1, a heat-resistant and radiation-resistant thin film 13 made of polyimide resin, for example, is adhered to the sealing surface of the thin film 1 facing the valve seat in the conventional valve desk shown in FIG. The synthetic resin thin film 13 is brought into contact with the sealing surface of the valve seat 1.

The metal thin film 11 described above may be applied to the valve seat 1 instead of being adhered to the valve desk 2.

Since the high-vacuum valve sealing device of the present invention has the above-described configuration, it is not necessary to give the sealing surface of the metal thin film 11 a mirror finish, and for example, if dirt gets into the sealing surface, the synthetic resin thin film has less elasticity and softness than a metal thin film, and absorbs dirt easily, so the effective sealing area decreases less than a metal thin film.

〔Effect of the invention〕

As described above, the present invention has the great advantage of being able to extremely easily obtain a sealing device for a high vacuum valve that is low in cost (and has a high sealing effect).

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a sealing device for a high vacuum valve of the present invention;
FIG. 2 is a longitudinal sectional front view of a conventional gate valve, FIG. 3 is a longitudinal sectional side view thereof, and FIGS. 4 and 5 are explanatory diagrams of a conventional sealing device, respectively. 1...Valve seat, 2...Valve desk, 3...Valve suppressor, 4
... Moving body, 5... Link, 6... Piston cylinder, 7... Piston rond, 8... Stopper, 9
...roller, 10...mountain, 11...metal thin film, 1
2...Air passage, 13...Synthetic resin thin film. Sai 4 times ke 5 diagram

Claims (1)

[Claims] A thin metal film whose edges are airtightly bonded to the sealing surface of either the valve seat or the valve desk; A sealing device for a high vacuum valve, comprising: a synthetic resin thin film; and a pressurizing mechanism for pressurizing a portion of the metal thin film other than the edge onto an opposing sealing surface via the synthetic resin thin film. .