JPS6221180Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a vacuum gate valve used to open and close piping of various vacuum devices and containers.

Conventionally, as a vacuum gate valve, JP-A-57-
As shown in Publication No. 114065, a gate valve having an annular groove on both sides of the front and back is movably arranged in a valve box having a front opening and a rear opening. An inner bellows and an outer bellows are arranged between both sides and a part surrounding the front opening and a part surrounding the rear opening of the valve body, respectively, and the gate valve side ends of the inner bellows and the outer bellows are connected to the gate valve. The other ends of the inner bellows and the outer bellows are fixed to the valve body, and the annular recess is connected to a surface of the annular fitting opposite to the annular protrusion. A thin annular plate that closes the opening is fixed, and the annular metal fitting is provided with a communication hole that communicates the airtight chamber between each bellows with the annular recess, and the valve box has a fluid supply hole that opens into the airtight chamber. A vacuum gate valve having a structure in which a port is provided has been proposed.

However, in the case of a vacuum gate valve with this structure, the width of the annular recess in the annular metal fitting is larger than the width of the annular protrusion provided on the gate valve, so the thin annular plate is held firmly against the annular protrusion. When pressed, the annular protrusion comes into pressure contact with the middle part of the annular thin plate in the width direction, and the annular thin plate is bent and deformed. Therefore, the inner and outer edges of the annular protrusion are strongly pressed against the annular thin plate, and the annular thin plate is pressed against the annular thin plate. There is a problem in that an excessive force is applied locally to the vacuum gate valve, and the annular thin plate is damaged or broken at an early stage, resulting in low durability and safety of the vacuum gate valve.

The purpose of this invention is to advantageously solve the above-mentioned problem, and the gist of this invention is to provide a smooth surface inside the valve body 3 having a front opening 1 and a rear opening 2. A gate valve 5 having a front surface and a back surface is movably disposed, and between the front and back surfaces of the gate valve 5 and the portion surrounding the front opening 1 and the rear opening 2 of the valve box, there are inner sides, respectively. A bellows 7 and an outer bellows 8 are arranged, and the ends of the inner bellows 7 and the outer bellows 8 on the gate valve side are connected by welding to an annular metal fitting 10 having an annular recess 9 facing the gate valve 5. The other end of the bellows 8 is fixed to the valve box 3 by welding, and a mirror thin plate 11 that closes the opening of the annular recess 9 is fixed by welding to the surface of the annular metal fitting 10 facing the gate valve. 10 is provided with a communication hole 13 that communicates the airtight chamber 12 between each bellows 7, 8 with the annular recess 9, and the valve box 3 is provided with a communication hole 13 that communicates the airtight chamber 12 between the bellows 7, 8 with the annular recess 9.
The vacuum gate valve is provided with a fluid supply port 14 that opens into the gate valve 5, and is configured such that the entire surface of the portion of the mirror thin plate 11 that closes the opening of the annular recess 9 faces the planes of the front and back surfaces of the gate valve 5. The vacuum gate valve is characterized by:

Next, this invention will be explained in detail using illustrated examples.

The drawing shows an embodiment of this invention, in which a front plate 16 and an oval rear pipe 17 are fitted with an oval front pipe 15 and fixed by welding.
and the rear plate 18 which is fitted and fixed by welding.
A flange fitting 20 for connecting an exhaust pump is fixed to the front open portion and the rear open portion of the valve box body 19 by welding, and is attached to the open portion of one end of the valve box body 19.
are fixed by welding to form the valve body 3, the inside of the front pipe 15 becomes the front opening 1, and the inside of the rear pipe 17 becomes the rear opening 2, and each of the pipes 15, 17 is connected to the piping system of vacuum equipment, containers, etc. by welding.

A plate-shaped gate valve 5 having mirror-finished smooth front and back surfaces and a through hole 4 for emitting an electron beam or the like is disposed in the center of the space 21 within the valve box 3, one end of a joint rod 22 is fixed to the base end of the gate valve 5, a flange 24 is fixed to one end of a sealing bellows 23 through which the joint rod 22 is inserted and is fixed to the other end of the valve box 3 by a bolt 25, and one end of a plurality of support rods 27 having guide grooves 26 is fixed to the other end of the valve box 3, and a support base 28 is fixed to the other end of the support rod 27. A cylinder 29 of a fluid pressure cylinder 6 is fixed to the support base 28, and a piston rod 30 of the fluid pressure cylinder 6 is fixed to the joint rod 22.
A guide member 32 is connected to the other end of the joint rod 22 via a screw coupling 31 and fixed to the other end of the joint rod 22. The guide projections of the guide member 32 are fitted into the guide grooves 26 of the support rods 27.

A wedge-shaped end 33 is formed at the tip of the gate valve 5, and the wedge-shaped end 33 of the gate valve 5 is formed at one end inside the valve box 3.
A wedge-shaped guide groove 34 is provided opposite to the valve body 3, and the gate valve 5 is moved into the valve body 3 by the expansion of the fluid pressure cylinder 6.
When the gate valve 5 is moved toward one end and the wedge-shaped end 33 of the gate valve 5 is fitted into the wedge-shaped guide groove 34 of the valve housing 3, the gate valve 5 is held at the center position of the space 21 within the valve housing 3. Ru.

An elliptical inner bellows 7 and an outer bellows 8 are disposed between the front and back surfaces of the gate valve 5 and the portions surrounding the front opening 1 and the rear opening 2 in the valve box 3, respectively.
The gate valve side ends of the inner bellows 7 and the outer bellows 8 are fixed by welding to annular fitting 10 which has a shallow annular recess 9 facing the gate valve 5, and a mirror-finished thin plate 11 made of a 0.1 mm thick aluminum alloy sheet which covers the opening of the annular recess 9 is hermetically fixed by welding to the surface of the annular fitting 10 facing the gate valve, and the other ends of each bellows 7, 8 are fixed to the valve box 3 by welding.

The annular fitting 10 is provided with a plurality of communication holes 13 that communicate the airtight chamber 12 between the bellows 7 and 8 with the annular recess 9, and the valve box 3 is provided with a plurality of communication holes 13 that communicate the airtight chamber 12 between the bellows 7 and 8 with the annular recess 9.
A fluid supply port 14 that opens at 2 is provided, and a fluid supply pipe for bellows extension is connected to this fluid supply port 14. Furthermore, when fluid is not pressurized into the airtight chamber 12, a gap is provided between the gate valve 3 and the mirror-finish plate 11 fixed to the annular metal fittings 10 on both the front and back sides of the gate valve 3, which obstructs the gate valve. When the fluid pressure cylinder 6 is shortest, the passage hole 4 of the gate valve 5 and the annular fitting 10
are arranged substantially concentrically, and the entire surface of the portion of the mirror thin plate 11 that closes the opening of the annular recess 9 faces the planes of the front and back surfaces of the gate valve 5. .

Note that flange fittings may be used in place of the front pipe 15 and the rear pipe 17.

When the piping system is to be evacuated, in the state ^shown in FIG. .
1 is brought into pressure contact with both the front and back surfaces of the gate valve 5. In this case, the pressure fluid supplied into the airtight chamber 12 is also sent to the annular cavity 35 between the annular recess 9 and the mirror thin plate 11 through the communication hole 13.
The annular mirror thin plate 11 is brought into pressure contact with the portion surrounding the passage hole 4 on both the front and back surfaces of the gate valve 5 by the fluid pressure in the pipe, thereby ensuring vacuum pressure inside the pipe.

In addition, in order to release the airtight connection of the piping, the pressure in the airtight chamber 12 should be reduced to zero or negative pressure to create a gap between the front and back surfaces of the gate valve 5 and the mirror thin plate 11. good.

If it becomes necessary to shut off the piping system, the fluid pressure cylinder 6 is extended so that the portion of the gate valve without the passage hole 4 faces the mirror thin plate 11, and then each bellows 7, 8 is opened as described above. The mirror thin plates 11 may be brought into pressure contact with the gate valve 5 by extending the mirror thin plates 11.

The fluid supplied to the airtight chamber 12 may be either gas or liquid, and the fluid pressure cylinder 6
may be either a pneumatic cylinder or a hydraulic cylinder.

According to this invention, the gate valve side ends of the inner bellows 7 and the outer bellows 8, which are arranged on both the front and back sides of the gate valve 5 provided in the valve box 3, have an annular recess 9 facing the gate valve 5. The other ends of the inner bellows 7 and the outer bellows 8 are fixed to the valve body 3 by welding, and the opening of the annular recess 9 is formed on the surface of the annular fitting 10 facing the gate valve. A mirror thin plate 11 for closing is fixed by welding, and the annular metal fitting 10 is provided with a communication hole 13 that communicates the annular recess 9 with the airtight chamber 12 between the bellows 7 and 8. Since the entire surface of the part that closes the opening of the recess 9 is configured to face the front and back planes of the gate valve 5, by supplying pressure fluid to the airtight chamber 12 between each bellows 7 and 8, While extending each bellows 7, 8, a pressure fluid is sent to the annular cavity formed by the annular recess 9 and the mirror thin plate 11, and the mirror thin plate 11 is expanded.
When pressed against the front and back surfaces of the gate valve 5,
The mirror thin plate 11 and the gate valve 6 are pressed against each other over a wide area, and excessive force is not locally applied to the mirror thin plate 11, so that early damage or breakage of the mirror thin plate 11 can be prevented. Therefore, the durability and safety of the vacuum gate valve can be improved, and since the mirror thin plate 11 is easily deformed by the fluid pressure in the annular cavity, the gate valve 5 cannot be damaged mechanically or thermally. Even if there are undulations due to surface distortion or fine metal powder is caught between the mirror thin plate 11 and the gate valve 5, the annular mirror thin plate 11 can be pressed against the gate valve 5 over its entire circumference. Effects such as being able to ensure sealing performance can be obtained.

[Brief explanation of the drawing]

The drawings show one embodiment of this invention, in which Fig. 1 is a side view of the gate valve, Fig. 2 is a partially cutaway front view thereof, and Fig. 3 is an enlarged longitudinal section showing the vicinity of the gate part of the gate valve. The side view and FIG. 4 are enlarged sectional views showing the vicinity of the annular metal fitting with a mirror-finished thin plate. In the figure, 1 is a front opening, 2 is a rear opening, 3 is a valve body, 4 is a passage hole, 5 is a gate valve, 6 is a fluid pressure cylinder, 7 is an inner bellows, 8 is an outer bellows, and 9 is an annular shape. Recessed portion, 10 is an annular metal fitting, 11 is a mirror thin plate, 12 is an airtight chamber, 13 is a communication hole, 14 is a fluid supply port, 22 is a joint rod, 23 is a sealing bellows, 26 is a guide groove, 27 is a support rod, 32 is a guide member, 33 is a wedge-shaped end, 34 is a wedge-shaped guide groove,
35 is an annular cavity.

Claims (1)

[Scope of utility model registration request] A gate valve 5 having a smooth front surface and a back surface inside a valve body 3 having a front opening 1 and a rear opening 2.
is movably arranged, and an inner bellows 7 and an outer bellows 8 are arranged between the front and back surfaces of the gate valve 5 and the portion surrounding the front opening 1 and the rear opening 2 of the valve box, respectively. The ends of the inner bellows 7 and the outer bellows 8 on the gate valve side are connected by welding to an annular fitting 10 having an annular recess 9 facing the gate valve 5, and the other ends of the inner bellows 7 and the outer bellows 8 are connected to the valve side. box 3
A mirror thin plate 11 that closes the opening of the annular recess 9 is fixed by welding to the surface of the annular fitting 10 facing the gate valve. In the vacuum gate valve, a communication hole 13 is provided to communicate the airtight chamber 12 with the annular recess 9, and the valve box 3 is provided with a fluid supply port 14 that opens into the airtight chamber 12. 1. A vacuum gate valve characterized in that the entire surface of the portion of 11 that closes the opening of the annular recess 9 faces the planes of the front and back surfaces of the gate valve 5.