JPS5814267Y2 - Sealing device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a sealing device that improves the sealing performance of a sealing surface by using a soft metal coated on the surface of a gasket.

The conventional sealing device applied to an ultra-high vacuum flange is explained with reference to FIG. 1, where a is the central axis, b is the upper flange,
C is a lower flange, b is an annular groove with a square cross section provided in the upper flange b, el is an annular groove with a rectangular cross section provided in the lower flange C, b2. C2 is a bolt hole provided in the flanges b and c, and d is a gasket made of a truncated cone-shaped annular metal base material e and a soft metal f coated on the surface of the metal base material e. It is installed in the annular groove b1 tel, and the seal surfaces A and B are brought into contact with the annular groove b1 and c1 surface to seal between the atmosphere side X and the vacuum side Y.

The gasket d is used not only for the above-mentioned ultra-high vacuum flange but also for large-diameter vacuum gate valves and the like.

These ultra-high vacuum flanges and large diameter vacuum gate valves
Bakeout, that is, heating degassing is required, in which the gasket d is exposed to high temperatures and the soft metal f is oxidized.

Therefore, with the passage of time in ultra-high vacuum flanges, and with repeated opening and closing operations in large-diameter vacuum gate valves,
There was a defect in that the sealing performance deteriorated.

This proposal deals with the above-mentioned apex, and includes a gasket in which the surface of a truncated cone-shaped annular metal base material is coated with a soft metal, and a pair of abutments that respectively abut on both end surfaces of the gasket to form a seal. The sealing device has a contact member, and the outer space defined by the contact member and the gasket is connected to an inert gas supply source. Another object of the present invention is to provide an improved sealing device that does not deteriorate its sealing performance even when exposed to high temperatures.

As described above, the sealing device of the present invention includes a gaskerato whose surface is coated with a soft metal on the surface of a truncated cone-shaped annular metal base material, and a pair of contact members that respectively abut on both end surfaces of the gasket to form a seal portion. The outer space defined by the contact members and the gasket is connected to an inert gas supply source, so that when the gasket is exposed to high temperatures, the supply source and the space are connected to each other. and the inert gas flows out to the atmosphere side through the space and between the pair of abutting members, and the soft metal coated on the outer peripheral surface of the gasket is covered with the inert gas, and At this time, the soft metal and the metal base material are cooled with the same inert gas,
Prevents oxidation of the same soft metal.

Therefore, deterioration in sealing performance due to oxidation of the soft metal can be prevented for a long period of time.

Next, the sealing device of the present invention will be explained with reference to the embodiment shown in FIG. 2 in which the sealing device is applied to an ultra-high vacuum flange. 1 is a central axis, 2 is an upper flange, 3 is a lower flange, and 2a is a rectangular cross section provided on the upper flange 2. 3a is an annular groove with a square cross section provided in the lower flange 3; 2b and 3b are annular grooves in the flanges 2 and 3;
The gasket 4 is made of a metal base material 4a in the shape of a truncated cone and a soft metal 4b coated on the surface of the metal base material 4a, and the gasket 4 is connected to the annular grooves 2a, 3.
a, and seal surfaces A and B are connected to the same annular grooves 2a and 3a.
It is designed to make a seal between the atmosphere side X and the vacuum side Y by contacting the surface.

Further, 5 is an inert gas supply cylinder, and 8 is the lower flange 3.
, I is an inert gas introduction pipe connecting the cylinder 5 and the introduction hole 8, and b is the same pipe 1.
This is a valve installed in the

Next, the operation of the sealing device will be explained.

When the gasket 4 is exposed to high temperatures, the valve 6 is opened to supply inert gas from the inert supply cylinder 5 through the pipe 7 introduction hole 8 into the space 9 outside the gasket 4.

Further, the inert gas in the space 9 is caused to flow out from between the upper and lower flanges 2 and 3 to the atmosphere side X as shown by the dotted line.

Note that from the viewpoint of maintenance of the device and reduction of operating costs, it is desirable to reduce the amount of inert gas supplied as much as possible, and for this purpose, the gap 10 between the upper flange 2 and the lower flange 3 is made as small as possible.

When the sealing device is used at room temperature, the valve 6 is closed to interrupt the supply of inert gas.

Next, the seal device of the present invention will be explained with reference to the embodiment shown in FIG. 3 in which the sealing device of the present invention is applied to a large-diameter vacuum gate valve. 11 is a valve, 12 is a guide ring fixed to the opening valve 11, and 13 is a gasket fixed to the opening valve 11. A gasket 4 having the same structure as the gasket 4 of FIG. 2 is attached to the valve 11 by the support ring 13.

In addition, 14 is a valve seat, and 15 is a valve outer cylinder 16 that is integrated with the valve seat 14.
is a connection flange provided on the quantity valve outer cylinder 15, 1γ is a lid fixed to the upper end of the quantity valve outer cylinder 15, and 18 is a connection flange provided on the quantity valve outer cylinder 15 and the opening lid 1.
7, a metal gasket 11 is a handle part provided on the opening lid 17, 20 is a handle, and 21 is a valve attached to the outer cylinder 19 so as to be raised and lowered when the handle 20 is rotated. The valve 11 is attached to the lower end of the valve rod 21 by a rod.

Further, 22 is a bellows, 5 is an inert gas supply cylinder, 7 is an inert gas introduction pipe, 6 is a valve installed in the same pipe 7, 2
3 is an inert gas discharge pipe, and 24 is a throttle valve provided in the pipe 23.

Next, the operation of the sealing device will be explained.

When the handle 20 is operated to raise the valve 11, the low vacuum side X and the high vertical side 11JY are brought into communication.

Further, when the handle 20 is operated to lower the valve 11, the gasket 4 still contacts the valve seat 14, and the low vacuum side height and the high vacuum side Y' are cut off.

In addition, when the gasket 4 is exposed to high temperatures, the valve 6 is opened to supply inert gas from the inert supply cylinder 5 to the pipe T.
The gas is supplied into the space 9 outside the gasket 4 through the gasket.

Further, the inert gas in the space 9 is released to the atmosphere through the pipe 23.

In this case as well, when the gasket 4 is exposed to high temperatures, the soft metal 4b coated on the outer peripheral surface of the gasket 4 is covered with inert gas, and the soft metal 4b and metal The base material 4a is cooled by the same inert gas, and oxidation of the soft metal 4b is prevented.

Therefore, deterioration in sealing performance due to oxidation of the soft metal 4b can be prevented, but the following effects can also be expected with this type of valve.

That is, when the soft metal 4b is oxidized, it peels off and becomes fragments as the valve opens and closes.

Although this debris may adhere to or become lodged in the sealing surface and cause leakage, it does not oxidize the soft metal 4b as described above and does not cause leakage.

[Brief explanation of the drawing]

Figure 1 is a vertical side view showing a conventional sealing device, Figure 2 is a vertical side view showing an example of the proposed sealing device applied to an ultra-high vacuum flange, and Figure 3 is a side view showing an embodiment of the proposed sealing device applied to a large-diameter vacuum gate valve. FIG. 7 is a longitudinal side view showing another embodiment of the sealing device of the present invention. 2.3 or 11.14... a pair of abutting members,
4... Gasket, 4a... Metal base material, 4b... Soft metal, 5... Inert gas supply source, 9... Space department.

Claims (1)

[Scope of utility model registration request] The gasket has a truncated cone-shaped annular metal base material coated with a soft metal on the surface thereof, and a pair of abutting members that respectively abut on both end faces of the gasket to form a seal portion, each of the abutting members and the gasket, and the inside of the outer space defined by the gasket is connected to an inert gas supply source.