JP5534960B2 - Vacuum valve - Google Patents

Description

  The present invention relates to a vacuum valve having a fixed side electrode and a movable side electrode that are detachably attached to a vacuum vessel.

In the conventional vacuum valve, a metalized layer is formed on both ends of a cylindrical insulating container made of an insulator such as alumina ceramic, and a metal end plate is formed on the metalized layer in order to keep the container airtight in a high vacuum. It is fixed by brazing.
Fixed end electrode rods and movable side electrode rods are coaxially opposed to the metal end plates fixed to both ends of the insulating container, and the fixed electrode and the movable side are respectively opposed to the opposing surfaces of each electrode rod. The electrode is fixed.

  Further, a bellows is provided between the movable electrode rod and the metal end plate so that the movable electrode can move on the axis of the insulating container while maintaining airtightness. In order to prevent the bellows from being polluted by an arc generated when the current is interrupted, an umbrella-shaped bellows protector is fixed to the movable electrode rod, and one end of the bellows is movable via the bellows protector. The other end is attached to the movable metal end plate.

  The arc shield is provided so as to surround two opposing electrodes along the inner creepage surface of the insulating container, and prevents the inner creepage surface of the insulating container from being soiled by an arc generated when current is interrupted.

JP 2004-362918 A

  In such a vacuum valve, the arc shield surrounding the electrode and the umbrella-shaped bellows protector prevent diffusion of metal spatter due to the arc generated when the current is interrupted, but it does not surround the entire bellows. For this reason, there has been a problem that metal spatter enters and adheres to the bellows valley and the like, thereby causing the bellows to become dirty and deteriorate.

The present invention has been made to solve the above-described problems. It is an object of the present invention to obtain a highly reliable vacuum valve that prevents the bellows from being damaged by metal sputtering caused by an arc and suppresses the vacuum deterioration of the bellows. Objective.

The vacuum valve according to the present invention includes a cylindrical insulating container having metallized layers at both ends, a fixed end plate having a first hole bonded to one end of the insulating container, and the fixed side. It is joined to the first hole of the edge of the end plate, a fixed electrode rod having a fixed electrode, engaged against the other end of the dielectric casing, a movable-side end plate drilled with a second bore A movable side electrode rod having a movable side electrode penetrating the second hole of the movable side end plate so as to be able to advance and retreat and facing the fixed side electrode, and one end joined to the movable side end plate by but which is joined to the periphery of the movable side electrode rod, and the bellows to ensure the insulation container inside and the outside of the airtight while stretching with the advance and retreat of the movable side electrode rod, said insulating container interior side of the bellows surrounds the outer peripheral surface of the cantilever of the bellows is joined at one end to the same potential as the movable side end plate In the vacuum valve with a Rudo, between the ends of said bellows shield, there is a tapered portion to vary the inner diameter, and wherein the point at which the inner diameter toward the fixed electrode side of the tapered portion is gradually reduced To do.

The vacuum valve according to the present invention is
The bellows shield part surrounds the outer periphery of the bellows by the bellows shield part so that the bellows can be prevented from being polluted by metal sputtering due to an arc. Therefore, a vacuum valve capable of improving the reliability of the bellows against vacuum deterioration can be obtained.

It is a schematic sectional drawing in Embodiment 1 of the vacuum valve which concerns on this invention. It is a principal part expanded sectional view of the vacuum valve in Embodiment 1 of the vacuum valve which concerns on this invention. It is a figure which shows the modification of the bellows shield metal fitting in Embodiment 1 of the vacuum valve which concerns on this invention. It is a figure which shows the modification of the bellows shield metal fitting in Embodiment 1 of the vacuum valve which concerns on this invention. It is a schematic sectional drawing in Embodiment 2 of the vacuum valve which concerns on this invention. It is a figure which shows the modification of the bellows shield part in Embodiment 2 of the vacuum valve which concerns on this invention. It is a figure which shows the modification of the bellows shield part in Embodiment 2 of the vacuum valve which concerns on this invention.

Embodiment 1 FIG.
Embodiment 1 of a vacuum valve according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of a vacuum valve 100. In FIG. 1, an insulating container 1 is a cylindrical container made of an insulating material such as alumina ceramic. Thin metallized layers 2 are provided at both ends of the insulating container 1. The fixed-side end plate 3 is a flange-shaped metal lid such as stainless steel, and has a side surface portion 3a coaxial with the insulating container 1 and an end surface portion 3b for sealing the end of the insulating container 1 to the outside. It consists of The fixed-side end plate 3 is fixed to the metallized layer 2 at one end of the insulating container 1 by vacuum brazing.

A hole is formed in the center of the end surface portion 3 b of the fixed-side end plate 3, and the fixed-side electrode rod 4 is coaxial with the insulating container 1 through the hole toward the inside of the insulating container 1. It extends toward the center of the insulating container 1. The fixed electrode rod 4 is fixed to the end surface portion 3b, and the connection portion between the fixed electrode rod 4 and the end surface portion 3b is sealed.
A movable side end plate 5 having substantially the same shape as the fixed side end plate 3 described above is fixed to the other end of the insulating container 1. The end surface portion 5b of the movable side end plate 5 has a hole at the center, and the movable side electrode rod 6 is inserted coaxially with the insulating container 1 toward the center of the insulating container through the hole. . The movable electrode rod 6 moves in the vertical direction in FIG. 1 according to the opening and closing of the electrode. Therefore, the movable electrode rod 6 is not fixed to the end surface portion 5 b of the movable end plate 5.

A bellows-like bellows 7 is attached to the edge of the hole of the end surface portion 5 b on the insulating container 1 side so as to surround the movable electrode rod 6. The upper end portion of the bellows 7 is fixed tightly around the movable side electrode rod 6. Thereby, even if the movable electrode rod 6 moves in the vertical direction in FIG. 1, the inside and outside of the insulating container 1 can be secured.
A fixed side electrode 8 and a movable side electrode 9 are fixed to the opposing surfaces of the fixed side electrode rod 4 and the movable side electrode rod 6, respectively. When the movable electrode rod 6 moves, it can be closed and opened.

  The end face part 5b of the movable side end plate 5 is fixed with a side shield part 10a and a bellows shield metal fitting 10 as a bellows shield part provided with the end face shield part 10b. The side shield part 10 a has a cylindrical shape and is provided so as to surround the periphery of the bellows 7. The end shield part 10b is an annular protective plate, and prevents metal spatter scattered when the electrode is opened from entering between the bellows 7 and the side shield part 10a. The bellows shield metal fitting 10 maintains the same potential as the movable side end plate 5.

  An arc shield 11 is provided on the creeping surface inside the insulating container 1 so as to surround the fixed side electrode 8 and the movable side electrode 9 facing each other. The arc shield 11 has a constricted portion 11a to prevent scattering of metal spatter due to an arc generated between the electrodes when the current is interrupted.

  As described above, the bellows shield metal fitting 10 is fixed to the movable side end plate 5. By joining the bellows shield metal fitting 10 to the movable side end plate 5, the brazing surface that affects the airtightness of the vacuum valve 100 is between the bellows 7 and the movable side end plate 5 as in the prior art. And only two places between the insulation container 1 and the insulation container 1. The attachment of the bellows shield fitting 10 does not impair the reliability of the vacuum valve 100 with respect to the airtightness.

  The bellows shield metal fitting 10 extends from the joint surface with the movable side end plate 5 to a position beyond the metallized layer 2 of the insulating container 1 so as to extend between the inner surface of the insulating container 1 and the bellows 7. Since the side shield part 10 a and the metallized layer 2 that are brazed and joined have the same potential, it is possible to alleviate electric field concentration at the end of the metallized layer 2. Further, the side shield part 10a is extended to a position beyond the fixing portion between the bellows 7 and the movable electrode bar 6, and is bent in the direction of the movable electrode bar 6 to form an end face shield part 10b. As a result, the entire surface of the bellows 7 is surrounded, and it becomes possible to protect the bellows 7 and the creeping surface inside the insulating container 1 from scattering of metal spatter due to an arc generated when current is interrupted.

FIG. 2 is an enlarged cross-sectional view of a main part of the vacuum valve 100.
As shown in FIG. 2, when the outer diameter of the movable electrode rod 6 is r, the inner diameter of the arc shield squeezing part 11a is R, and the diameter of the hole of the end shield part 10b of the bellows shield fitting 10 is φ, φ is r < φ <R. Further, in consideration of the rebound of metal spatter in the arc shield 11 and the axis deviation at the time of manufacturing the vacuum valve 100, it is desirable that φ is φ ≧ r + 2 mm.

FIG. 3 is a view showing a modification of the bellows shield metal fitting.
Moreover, as shown in FIG. 3, the space | interval of the insulating container 1 inner surface and the bellows shield metal fitting 10 can be taken large by providing the step part 10c in the side shield part 10a of the bellows shield metal fitting 10. As shown in FIG. As a result, the interval between equipotential lines between the inner surface of the insulating container 1 and the bellows shield metal fitting 10 can be increased, and the electric field on the movable side in the container can be further relaxed.

As shown in FIG. 4, even if the side shield part 10a is provided with the tapered part 10d, the electric field on the movable side in the container can be reduced.
When the bellows shield metal fitting 10 having such a structure is used, the metal spatter scattered on the tapered portion 10d falls downward, that is, in the direction of the movable side end plate 5, so that the metal spatter floats during the operation of the vacuum valve 100. Can be suppressed. Thereby, the dynamic withstand voltage performance of the vacuum valve 100 can be improved.

Thus, according to the vacuum valve 100 shown in the first embodiment, the electric field relaxation in the vicinity of the metallized layer 2 and the suppression of the contamination on the inner side of the movable side of the bellows 7 and the insulating container 1 can be realized at the same time.
In particular, regarding the contamination prevention of the bellows 7, unlike the conventional bellows protector, the side shield portion 10a and the end face shield portion 10b of the bellows shield metal fitting 10 surround the entire bellows 7, so that the metal spatter scattered at the time of arc occurrence is generated. Can be drastically reduced and the reliability of the bellows 7 against vacuum deterioration can be improved. In addition, since the probability that metal spatter adheres to the valleys of the bellows 7 can be drastically reduced, an effect excellent in application to a vacuum valve for frequent opening and closing is exhibited.
In addition, the number of parts can be reduced by providing one part with an electric field relaxation function in the vicinity of the metallization layer and a fouling suppression function for the bellows 7. Furthermore, since the bellows shield metal fitting 10 can be manufactured by press working, the parts cost is low, and it can contribute to the cost reduction of the vacuum valve 100 whole.

Embodiment 2. FIG.
The second embodiment of the present invention will be described with reference to the drawings, focusing on the differences from the first embodiment.
FIG. 5 is a schematic sectional view of a vacuum valve 200 according to this embodiment.
In the first embodiment, the insulating container 1 is hermetically sealed by connecting the movable side end plate 5 itself to the metallized layer 2 provided at the end of the insulating container 1 and the end of the bellows 7. In this embodiment, the side surface portion 2051, the end surface portion 2052, and the bellows shield portion 2053 are integrally molded as a flange-shaped member 2050, and the insulating container 1 is sealed between the end surface portion 2052 and the end of the bellows 7. The airtight holding plate 2060 is used.
By combining these two parts, the same effects as the combination of the movable side end plate 5 and the bellows shield metal fitting 10 of the first embodiment can be obtained.
Since other configurations are the same as those of the first embodiment, a description thereof will be omitted.

The reason why the flange-like member 2050 has such a shape is to improve the mechanical strength of the movable side end of the vacuum valve 200. For example, in order to improve the mechanical strength of the fixed portion between the movable side end plate 5 and the bellows 7 of Embodiment 1, the thickness of the movable side end plate 5 may be increased.
However, since there is a difference in thermal expansion coefficient between the insulating container 1 and the end plate, the stress generated in the insulating container 1 at the time of vacuum brazing increases as the plate thickness is increased, and there is a risk that the insulating container 1 is cracked. . Therefore, in the present embodiment, the flange-shaped member 2050 is integrally formed, a flange-shaped portion is provided at the end thereof, and the joint portion of the bellows 7 is changed to the air-tight holding plate 2060, thereby reducing the thickness of the air-tight holding plate 2060. As a changeable structure, the mechanical strength of the joint portion of the bellows 7 can be improved.

As in the first embodiment, since the side shield part 2053a and the end face shield part 2053b are formed on the bellows shield part 2053, the electric field concentration at the end part of the metallized layer 2 is alleviated and the metal spatter caused by the arc generated when the current is interrupted. It becomes possible to protect the bellows 7 and the creeping surface in the insulating container 1 from scattering.
Similarly to the first embodiment, when the outer diameter of the movable electrode rod 6 is r, the inner diameter of the narrowed portion 11a of the arc shield 11 is R, and the diameter of the hole of the end face shield portion 2053b is φ, φ is r It is desirable that <φ <R, and φ is φ ≧ r + 2 mm.
Similarly to the first embodiment, a stepped portion 2053c is provided on the side shield portion 2053a of the bellows shield portion 2053 as shown in FIG. 6, or a tapered shape portion 2053d is provided on the side shield portion 2053a as shown in FIG. The space between the inner surface of the insulating container 1 and the bellows shield part 2053 may be widened so that the electric field at the movable side end of the insulating container 1 can be reduced.

Thus, also by the vacuum valve 200 shown in the second embodiment, the electric field relaxation in the vicinity of the metallized layer 2 and the suppression of the contamination of the bellows and the inner surface of the insulating container movable side can be realized at the same time.
Further, by providing the flange-like member 2050, which is one component, with an electric field relaxation function in the vicinity of the metallized layer 2 and a fouling suppression function for the bellows 7, the number of components can be reduced.
Moreover, since the flange-like member 2050 can be easily manufactured by press working in terms of structure, the parts cost is cheap, leading to a reduction in the manufacturing cost of the vacuum valve 200 as a whole.
In addition, with the structure shown in the second embodiment, the mechanical strength of the movable side end can be flexibly improved.
Furthermore, since the state of the flange-shaped member 2050 and the brazed portion of the security plate can be visually recognized from the outside, the quality of the vacuum valve 200 after assembly can be ensured uniformly.

100, 200 vacuum valve, 1 insulating container, 2 metallized layer,
3 fixed side end plate, 3a side surface part, 3b end surface part, 4 fixed side electrode rod,
5 movable side end plate, 5a side surface portion, 5b end surface portion, 6 movable side electrode rod,
7 Bellows, 8 Fixed side electrode, 9 Movable side electrode,
10 Bellows shield bracket, 10a Side shield part,
10b End face shield part, 10c, 2053c Step part,
10d, 2053d taper shape part, 11 arc shield, 11a squeezed part,
2050 Flange-shaped member, 2051 Side surface portion, 2052 End surface portion,
2053 Bellows shield part, 2053a Side shield part,
2053b End face shield part, 2060 Airtight holding plate.

Claims (4)

A cylindrical insulating container having metallized layers at both ends ;
A fixed-side end plate joined to one end of the insulating container and having a first hole ;
A fixed side electrode rod joined to the edge of the first hole of the fixed side end plate and provided with a fixed side electrode;
The engaged against the other end of the insulating container, a movable-side end plate drilled with a second bore,
A movable-side electrode rod provided with a movable-side electrode that penetrates the second hole of the movable-side end plate so as to be able to advance and retract, and faces the fixed-side electrode ;
One end is joined to the movable side end plate, and the other end is joined to the periphery of the movable side electrode rod, so that the inside and outside of the insulating container are hermetically expanded and contracted as the movable side electrode rod advances and retreats. A bellows to secure ,
In a vacuum valve comprising an outer peripheral surface of the bellows on the inner side of the insulating container and having a cantilevered bellows shield having one end joined to the movable side end plate at the same potential ,
Between the both ends of the bellows shield, there is a taper-shaped portion that changes the inner diameter, and the inner diameter of the taper-shaped portion toward the fixed electrode gradually decreases. A cylindrical insulating container having metallized layers at both ends;
A fixed-side end plate joined to one end of the insulating container and having a first hole;
A fixed side electrode rod joined to the edge of the first hole of the fixed side end plate and provided with a fixed side electrode;
A movable side end plate joined to the other end of the insulating container and having a second hole;
A movable-side electrode rod provided with a movable-side electrode that penetrates the second hole of the movable-side end plate so as to be able to advance and retract, and faces the fixed-side electrode;
One end is joined to the movable side end plate, and the other end is joined to the periphery of the movable side electrode rod, so that the inside and outside of the insulating container are hermetically expanded and contracted as the movable side electrode rod advances and retreats. A bellows to secure,
In a vacuum valve comprising an outer peripheral surface of the bellows on the inner side of the insulating container and having a cantilevered bellows shield having one end joined to the movable side end plate at the same potential,
Between the both ends of the bellows shield, there is a step portion for changing the inner diameter, and the inner diameter of the fixed electrode side is reduced with the step portion as a boundary. The vacuum valve according to claim 1 or 2, wherein an arc shield surrounding the movable side electrode and the fixed side electrode is supported on an inner peripheral surface of the insulating container. The vacuum valve according to any one of claims 1 to 3, wherein the cylindrical insulating container has a cylindrical shape.

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