JPH0240150B2 - KINZOKUSHIIRUBARUBU - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a metal seal valve using metal for a sealing gasket, and particularly to an all-metal vacuum valve used in ultra-high vacuum equipment.

(Prior technology) As a gasket for sealing a seal valve,
Conventionally, elastomer materials such as rubber have been widely used. Elastomers are highly elastic,
Although reliable sealing is possible even with repeated sealing operations, the usable temperature range is narrow due to thermal deterioration, etc. Also, as a sealing material for vacuum valves, gas release and gas permeation occur frequently. There were other difficulties. As a means to overcome these difficulties, relatively soft metal gaskets have recently been used in certain applications.

(Problems to be Solved by the Invention) However, unlike elastomer gaskets, this type of metal gasket is accompanied by some plastic deformation during the sealing operation of the gasket.
There is a problem in that it becomes difficult to use the gasket repeatedly, and the life of the gasket (the number of times it can be sealed) is inevitably shortened. In other words, as sealing is repeated, the pressing force required for the seal gradually increases, and as the pressing force increases, plastic deformation progresses further, resulting in seal leakage.

The present invention was made to solve the above-mentioned drawbacks of the conventional metal seal valve, and its purpose is to:
To provide a metal seal valve which can obtain a stable sealing force for repeated sealing use, does not cause leakage, and has a long gasket life.

(Means for Solving the Problems) In order to achieve the above object, the present invention is configured as follows. That is, the present invention includes a valve seat having a valve hole, a valve plate disposed opposite to the valve seat, and a metal gasket interposed between the valve seat and the valve plate. In the metal seal valve that is pressed against the valve seat via the metal gasket to airtightly seal the valve hole, the metal gasket is made of a shape memory alloy that has a shape memory function at a temperature above a transformation point. Further, the metal seal valve is provided with at least one of a heating means for heating the metal gasket and a cooling means for cooling the metal gasket in an area where the metal gasket is provided.

(Function) In the present invention having the above configuration, the valve closing of the metal seal valve is achieved by pressing the valve plate against the valve seat via the metal gasket, as in the conventional example. In this case, if the metal gasket is made of, for example, a shape memory alloy whose transformation point temperature is higher than the operating temperature, the metal gasket is in its initial state before being pressed against the valve seat. maintains the memorized initial shape accurately, while, when pressed against the valve seat, the valve hole is reliably closed hermetically with some plastic deformation.

When the pressure on the valve seat is released from this state and the valve hole is opened, the metal gasket still has some deformation from the pressure, but it is possible to heat the metal gasket above its transformation point using the heating means. The metal gasket reliably restores to its original initial shape and the plastic deformation completely disappears.On the other hand, the metal gasket is replaced by a shape memory alloy whose transformation temperature is lower than the operating temperature. In this case, if the metal gasket is kept cooled to a temperature lower than its transformation point when pressed against the valve seat, a reliable sealing effect can be obtained in the same way as in the above case, and When the pressure on the valve seat is released, the shape restoration of the metal gasket is achieved by stopping the cooling (or heating after stopping the cooling) and raising the temperature to the transformation point.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the drawings. FIG. 1 shows the overall configuration of an embodiment,
Further, FIG. 2 shows details of the main parts of FIG. 1.
In the figure, a valve seat 1 is fixed to a vacuum vessel (not shown), and a valve hole 2 formed in the center of the valve seat 1 communicates with the inside of the vacuum vessel. Valve hole 2
A gasket arrangement groove 3 surrounding the valve hole 2 is circumferentially provided at a slightly outer peripheral position of the valve hole 2, and a protruding seal receiving portion 4 is formed between the gasket arrangement groove 3 and the valve hole 2. ing. The upper surface of the seal receiving part 4 has a V
A groove in the shape of a letter is provided, and this groove surface serves as a sealing surface 5.

On the other hand, an annular metal gasket 6 is fitted into the gasket arrangement groove 3. This metal gasket 6 is composed of a body part 6a and a seal flange plate 6b that protrudes inward from the upper surface of the body part 6a and covers the sealing surface 5. Both the body part 6a and the seal flange plate 6b are It is made of a shape memory alloy (for example, an alloy of chromium and copper) that has a shape memory function at a temperature above 100 m.

The transformation point temperature of this shape memory alloy can be appropriately selected depending on the type of the shape memory alloy, etc. For example, depending on the usage of the seal valve, the transformation point temperature may be the normal operating temperature of the seal valve. A metal gasket 6 having a desired transformation point temperature can be obtained by appropriately selecting a temperature higher than the normal operating temperature of the seal valve or a temperature lower than the normal operating temperature of the seal valve. Generally, the metal gasket 6 is made of a shape memory alloy having a transformation temperature higher than the operating temperature of a metal seal valve (hereinafter simply referred to as a seal valve).

Incidentally, a valve plate 7 is provided above the valve seat 1 and facing the valve seat 1. The valve plate 7 has a V-shaped groove that fits into the V-shaped groove of the sealing surface 5.
A letter-shaped seal protrusion 8 is provided circumferentially. This valve plate 7 can freely move forward and backward toward the valve seat 1 by driving a mechanism (not shown) disposed in the housing 9, and by this forward and backward movement, the valve hole 2 is opened and closed, and switching between circulation and blocking of airflow between the valve hole 2 and the ventilation hole 10 is controlled. That is, if the metal gasket 6 in this embodiment has a transformation point temperature higher than the valve operating temperature, the metal gasket 6 itself has the initial shape shown in FIG. remembered.

In the state shown in FIG. 2, the valve seat 1 and the valve plate 7 are in a separated state, indicating an open state of the seal valve.

When closing the seal valve from this open state, the mechanism section is operated to advance the valve plate 7.
may be pressed against the valve seat 1 via the metal gasket 6. Due to this pressure contact, as shown in FIG. 3, the seal flange plate 6b of the metal gasket 6 is deformed by being sandwiched between the seal surface 5 of the seal receiver 4 and the seal protrusion 8 of the valve seat 7, and its restoring stress is As a result, the seal flange plate 6b comes into close contact with the seal surface 5 and the seal protrusion 8, and airtight sealing of the valve hole 2 is achieved. Next, when opening the seal valve, operate the mechanism section to open the valve plate 7.
The valve plate 7 may be returned to its original position by retracting the valve plate 7. This return movement of the valve plate 7 creates a gap between the valve seat 1 and the valve plate 7 as shown in FIG. 2, and as a result, the valve hole 2 is opened.

However, when the valve hole 2 is opened, the seal flange plate 6b is also released from the pressed state and tries to restore its shape to its initial state, but since a slight plastic deformation occurs when the seal valve is closed, the seal flange plate 6b is not completely restored. Unable to restore shape. Therefore, in this embodiment, in order to completely restore the shape, the heating means 1
5 is provided in the area where the metal gasket 6 is provided. In this embodiment, the heating means 15 includes a heater 11 embedded in the body portion 6a of the metal gasket 6, and a
The lead wire 12 and lead wire 13 are used to supply electricity to the lead wire 1. As shown in FIGS. 2 and 3, these lead wires 12 and 13 are guided to the outside while being insulated from other conducting members (valve seat 1 and housing 8) by an insulating stone 14, not shown. Electric power can be supplied to the heater 11 from the power source. Therefore, after opening the seal valve, the heater 11 is energized and the metal gasket 6 is heated to a temperature higher than the transformation point temperature, whereby the metal gasket 6 (seal flange plate 6b) is heated.
The plastic deformation disappears, and the metal gasket 6 is completely restored to its memorized initial shape.

In this way, the metal gasket 6 can be completely restored to its initial shape by the heating means 15.
During the next valve closing operation, the valve hole 2 is completely closed with normal pressing force.
Since the metal gasket 6 can be closed airtight, and the plastic deformation disappears after each use, the metal gasket 6 can be used repeatedly, thereby significantly extending the life of the metal gasket 6. be able to.

By the way, in the above description, the case where the transformation point temperature of the metal gasket 6 is higher than the normal operating temperature of the seal valve is shown as an example.
Depending on the application, a metal gasket 6 whose transformation point temperature is lower than the operating temperature may be used.
In such a case, it is necessary to provide a cooling means 16 in the area where the metal gasket 6 is placed and to lower the temperature of the metal gasket 6 below its transformation point to perform the valve closing operation. For example, as shown in FIGS. 2 and 3, this cooling means 16 includes a flow hole 17 provided inside the seal receiving portion 4 along the metal gasket 6, and a refrigerant liquid in the flow hole 17. Alternatively, it may be configured to allow fluid gas to flow through it (most simply, cooling water as a refrigerant liquid). This kind of metal gasket 6
When using the heating means 15, it is also possible to omit the heating means 15 and operate only the cooling means 16 to open and close the valve. That is, at the time of closing the seal valve, the metal gasket 6 is cooled to a temperature below the transformation point by the cooling means 16, and then the valve plate 7 is closed to press and deform the metal gasket 6.
The seal valve is kept closed while keeping the metal gasket 6 at a temperature below the transformation point, but when the seal valve is opened, the valve plate 7 is opened and the cooling means 16 is opened.
All you have to do is stop the operation. Due to this cooling stop, the metal gasket 6 naturally rises to the ambient temperature, that is, the temperature above the transformation point, and returns to its shape. By the way, the heating means 15 and the cooling means 1
By installing 6, the following utility values can be obtained. For example, when the transformation point temperature is higher than the normal operating temperature and the seal valve is closed, if it is necessary to heat the entire seal valve to a temperature higher than the transformation point of the metal gasket 6, the cooling means 16 is operated. By doing so, it is possible to prevent the temperature of the metal gasket 6 from rising to a temperature higher than the transformation point. In this regard, it is particularly effective to apply the seal valve of the present invention as a gate valve of ultra-high vacuum equipment, and for example, there is an advantage that there is no fear that the temperature of the metal gasket 6 will rise above the transformation point due to baking. There is.

For example, if the transformation point temperature of the metal gasket 6 is higher than the operating temperature, the metal gasket 6 is heated by a heating means to restore the shape of the metal gasket 6 when the valve is opened. When it is necessary to close the seal valve later, if the metal gasket 6, which has been restored to its shape, is forcibly cooled down to below the transformation point temperature using a cooling means, it will be ready for use in a short time, and the metal gasket 6 can be closed. The time can be reduced compared to natural cooling.

Further, when the transformation point temperature of the metal gasket 6 is lower than the operating temperature, the seal valve is kept closed in the cooling state, but when the seal valve is opened, the metal gasket 6 is heated by the heating means 15.
By forcibly heating the metal gasket 6, the transformation point temperature can be reached in a shorter time than waiting for the temperature of the metal gasket 6 to rise naturally due to room temperature, and the shape recovery of the metal gasket 6 can be greatly accelerated. This means that you will be able to achieve this goal.

As mentioned above, the heating means 15 and the cooling means 16
By appropriately combining one or both of them according to the transformation point temperature of the metal gasket 6 and the operating temperature of the seal valve, the metal gasket 6 can be
The temperature of the metal gasket 6 is kept below its transformation point at the latest from immediately before closing the seal valve throughout the entire period of closing the seal valve, and when the seal valve is opened, the temperature of the metal gasket 6
By raising the temperature above the transformation point, it is possible to restore the deformed shape to its initial shape, and this allows
Repeated sealing operations are possible, and the life of the metal gasket 6 can be extended.

Further, by bringing the temperature of the metal gasket 6 above the transformation point temperature when the seal valve is opened, the plastic deformation of the metal gasket 6 is completely eliminated.

Therefore, the next valve closing operation can be performed with a normal pressing force, and an extremely reliable valve operation without any seal leakage can be performed.

The above explanation is just one embodiment of the present invention, and for convenience of explanation, an example of application to a gate type vacuum valve is shown, but it can be used in exactly the same way for other types of vacuum valves or non-vacuum seal valves. It is possible. Furthermore, many other combinations of the shapes of the metal gasket 6 and the sealing surface 5, the types and arrangement of the heating means 15 and the cooling means 16, etc. can be made using known methods.

(Effects of the Invention) Since the present invention has the configuration and operation described above, it is possible to repeatedly restore the shape of the metal gasket, thereby extending the life of the metal gasket. It is possible to provide an extremely reliable metal seal valve with no seal leakage.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment according to the present invention, and FIG.
The drawings are a detailed view of the main part of FIG. 1, FIG. 3 is an explanatory view of the operation of this embodiment, and FIG. 4 is a plan view of the metal gasket in this embodiment. DESCRIPTION OF SYMBOLS 1... Valve seat, 2... Valve hole, 3... Gasket arrangement groove, 4... Seal receiver, 5... Seal surface, 6...
...Metal gasket, 6a...Body part, 6b...
Seal flange plate, 7...Valve plate, 8...Seal protrusion, 9
... Housing, 10 ... Ventilation hole, 11 ... Heater, 12, 13 ... Lead wire, 14 ... Insulating stone,
15... Heating means, 16... Cooling means, 17...
Flow hole.

Claims (1)

[Scope of Claims] 1. A valve plate comprising: a valve seat having a valve hole; a valve plate disposed opposite to the valve seat; and a metal gasket interposed between the valve seat and the valve plate. In the metal seal valve in which the valve hole is hermetically sealed by pressing the metal gasket against the valve seat through the metal gasket, the metal gasket is made of a shape memory alloy that has a shape memory function at a temperature above a transformation point. The metal seal valve is further characterized in that at least one of a heating means for heating the metal gasket and a cooling means for cooling the metal gasket is provided in the area where the metal gasket is provided. . 2. The metal seal valve according to claim 1, wherein the metal gasket is made of a shape memory alloy having a transformation temperature higher than the operating temperature of the seal valve.