JPH09320412A - Vacuum bulb - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the vacuum bulb which is high in vacuum air-tightness, and also high in strength. SOLUTION: A reinforcing member 13 makes its center hole larger than the hole diameter of the center hole of a stationary side end plate 2, but makes it smaller than the outer diameter of the large diameter part of a stationary side electrode bar 4. The stepped part between the small diameter part 4a and the large diameter part 46 of the stationary side electrode bar 4 is hermetically brazed around the center hole of the stationary side end plate 2 so as to be joined, and the small diameter part 4a is thereby projected out of the center hole of the side end plate 2. Furthermore, the center holes of the reinforcing member 13 and the stationary side end plate 2 are coaxially disposed over the outer surface of the stationary side end plate so as to be brazed with the outer surface of the stationary side end plate 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve, and more particularly to a structure for reinforcing a fixed end plate of the vacuum valve.

[0002]

2. Description of the Related Art FIG. 7 shows, for example, JP-A-60-205929.
FIG. 8 is a cross-sectional view showing a conventional vacuum valve disclosed in Japanese Patent Publication No. In the figure, reference numeral 1 is an insulating container made of a cylindrical alumina ceramic or the like, and a metallized layer (not shown) made of Mo—Mn of about 20 μm is provided at both ends of the insulating container 1. Reference numeral 2 is a fixed side end plate, 3 is a movable side end plate, and these fixed side and movable side end plates 2 and 3 are coaxially attached to both ends of the insulating container 1 by brazing. The assembly is mainly performed by using a silver-based brazing material. The fixed-side electrode plate 4 is attached to the fixed-side end plate 2, and the movable-side electrode rod 5 is attached to the movable-side end plate 3 via a bellows 6. It is brazed and joined. Reference numerals 7 and 8 denote electrodes, which are brazed to the fixed-side electrode rod 4 and the movable-side electrode rod 5 and are arranged to face each other. The bellows 6 is made of thin stainless steel in the form of a bellows, and the movable side electrode rod 5 is kept airtight.
Are allowed to move. 9 and 10 are shields,
It is arranged so as to cover the inner surface of the insulating container 1 and the bellows 6, and prevents the inner surface of the insulating container 1 and the bellows 6 from being contaminated by the metal vapor generated by the arc. Reference numeral 11 denotes a resin guide that guides the movement of the movable side electrode rod 5. After the assembly of the vacuum valve by brazing of the vacuum valve is completed, the resin guide 11 is screwed to the guide mounting plate 12 fixed to the movable side end plate 3 (see FIG. Mounted (not shown).

Here, since the fixed side end plate 2 and the movable side end plate 3 are used by brazing to the insulating container 1, that is, alumina ceramics, the material is Fe--Ni having a thermal expansion coefficient close to that of alumina ceramics. -Co alloy or Fe-N
An i alloy and a Cu—Ni alloy having a large difference in thermal expansion coefficient but a small residual stress due to plastic deformation are used. In either case, if the area of the brazed part with the ceramic increases, the residual stress increases, the ceramic is easily damaged, and the material is expensive, so the thickness is thin (about 0.5 to 1 mm). Things are commonly used.

When the vacuum valve thus constructed is used for a high voltage application or a large current application, the fixed end plate 2 is required to have high strength. That is, in the case of high voltage application, since the movable side electrode 8 operates at high speed during opening and closing, a large repetitive load is applied to the fixed side end plate 2 in the axial direction. Further, when a large current is applied, a large electromagnetic force is generated in the direction perpendicular to the shaft. At this time, the movable electrode rod 5 receives a force in the direction perpendicular to the shaft, and the resin guide 11 → guide mounting plate 12 → movable. Side end plate 3 → insulating container 1
→ The force is transmitted to the fixed-side end plate 2, and a large bending stress is applied to the fixed-side end plate 2 with the fixed-side electrode rod 4 as a fulcrum. Therefore,
In the conventional vacuum valve, a large repetitive load or a bending stress is applied to the fixed side end plate 2, and the vacuum tightness of the brazed joint between the fixed side electrode rod 4 and the fixed side end plate 2 is impaired. . Furthermore, there are approximately 2
A metallization layer of 0 μm Mo—Mn is provided, and when the vacuum valve is used at a higher voltage,
There is also a problem that the electric field becomes extremely high because the edge of the insulating container 1 has a sharp edge.

The fixed side electrode rod 4 and the fixed side end plate 2
In order to solve the problem that the vacuum airtightness of the brazed joint portion of the and is deteriorated, conventionally, as shown in FIG. 8, a reinforcing member 13 is provided between the fixed side end plate 2 and the fixed side electrode rod 4. The method of brazing and reinforcing is generally adopted. That is, the small-diameter portion 4a is provided at the end of the fixed-side electrode rod 4, a hole through which the small-diameter portion 4a is inserted is provided at the center of the fixed-side end plate 2, and the small-diameter portion is provided at the center of the disc-shaped reinforcing member 13. A center hole through which 4a is inserted is provided. At this time, the fixed side end plate 2
The center holes formed in the reinforcing member 13 and the reinforcing member 13 have the same inner diameter. Then, as shown in FIG. 9, the reinforcing member 13 and the fixed-side end plate 2 are overlapped with each other, and the small-diameter portion 4a of the fixed-side electrode rod 4 is inserted into the center holes thereof. Reinforcement member 1
3 and the fixed-side end plate 2 are positioned by the small-diameter portion 4a of the fixed-side electrode rod 4 and arranged coaxially. Next, a brazing material 16b is disposed between the reinforcing member 13 and the step between the large-diameter portion 4b and the small-diameter portion 4a of the fixed-side electrode rod 4, and the brazing material 16b is further provided between the reinforcing member 13 and the fixed-side end plate 2. The material 16a is arranged, and the brazing materials 16a and 16b are melted and joined in a high-temperature reducing atmosphere.

Further, in order to solve the problem that the electric field at both ends of the insulating container 1 becomes extremely high, conventionally, as shown in FIG. 10, a method of attaching an electric field relaxation ring is generally adopted. It was being done. That is, the small-diameter portion 4a is provided at the end of the fixed-side electrode rod 4, the center hole through which the small-diameter portion 4a is inserted is provided at the center of the fixed-side end plate 2, and the bottom center of the bottomed cylindrical electric field relaxation ring 17 is provided. Is provided with a central hole through which the small diameter portion 4a is inserted. At this time, the central holes formed in the fixed-side end plate 2 and the electric field relaxation ring 17 have the same inner diameter. Then, as shown in FIG. 10, the electric field relaxation ring 17 and the fixed-side end plate 2 are overlapped with each other, and the small-diameter portion 4a of the fixed-side electrode rod 4 is inserted through the center holes thereof. The electric field relaxation ring 17 and the fixed-side end plate 2 are connected to the fixed-side electrode rod 4
It is positioned by the small-diameter portion 4a and is coaxially arranged. Next, the large diameter portion 4b and the small diameter portion 4a of the fixed side electrode rod 4
The brazing material 16b is provided between the step portion and the electric field relaxation ring 17.
(Not shown), and a brazing material 16a (not shown) between the electric field relaxation ring 17 and the fixed end plate 2 to melt the brazing materials 16a and 16b in a high-temperature reducing atmosphere. Are joined together. At this time, the electric field relaxation ring 17 extends outward along the fixed-side end plate 2 and then hangs downward so that the end portion extends to the inside of the insulating container 1. Therefore, the end portion side of the insulating container 1 is covered with the electric field relaxation ring 17 to prevent the electric field at the end portion of the insulating container 1 from increasing. Further, the electric field relaxation ring 17 is brazed to the inner wall surface of the fixed-side end plate 2 to reinforce the fixed-side end plate 2.

[0007]

The fixed side end plate 2 of the conventional vacuum valve has the above-described reinforcing structure or electric field relaxing structure, but the brazing portion with the fixed side electrode rod 4 is vacuum-tight. Since it is a place related to the above, uniform brazing without voids is required. However, in practice, since the brazing area between the fixed-side end plate 2 and the reinforcing member 13 or the electric field relaxation ring 17 is large, uniform brazing is difficult, and a precise flat surface is formed so that no gap is formed when the parts are stacked. There was a problem that it was necessary and expensive.

The present invention has been made in order to solve the above problems, and an object thereof is to economically provide a vacuum valve having high reliability of vacuum airtightness and high strength.

[0009]

A vacuum valve according to the first aspect of the present invention includes a cylindrical insulating container, fixed end plates attached to both ends of the insulating container so as to close the insulating container, and The movable side end plate and a small diameter portion are formed on one end side of the large diameter portion in the axial direction, and the small diameter portion is projected from the center hole of the fixed side end plate to fix the step portion between the small diameter portion and the large diameter portion. The fixed side electrode is airtightly brazed and joined around the center hole of the side end plate, and the fixed side electrode is attached to the other end in the axial direction so as to be located in the insulating container, and the movable side electrode is attached to one end. Is attached to the movable end plate through a bellows in an airtight manner so that the movable electrode is located in the insulating container.
In a vacuum valve provided with a movable side electrode rod that brings the movable side electrode into contact with and separates from the fixed side electrode, a disk-shaped reinforcing member having a central hole whose hole diameter size is larger than the hole diameter size of the center hole of the fixed side end plate. The center holes are coaxially arranged on the outer wall surface of the fixed side end plate, and are brazed to the outer wall surface of the fixed side end plate.

Further, in the vacuum valve according to the second invention, in the first invention, the hole diameter of the central hole of the reinforcing member is such that the outer diameter of the small diameter portion and the outer diameter of the large diameter portion of the fixed side electrode rod. It is a size intermediate between and.

The vacuum valve according to the third aspect of the present invention is the vacuum valve according to the first aspect of the invention, in which a bottomed cylindrical electric field relaxation ring having a central hole whose hole diameter size is substantially equal to the central hole of the fixed side end plate, It is interposed between the step portion between the small diameter portion and the large diameter portion and the fixed side end plate, and the inner wall surface of the bottom surface around the center hole is airtightly brazed to the step portion between the small diameter portion and the large diameter portion. The outer wall surface of the bottom surface is airtightly brazed to the inner wall surface of the fixed end plate, and the hole diameter of the center hole of the reinforcing member is such that the electric field relaxation ring and the fixed end plate are brazed. It is smaller than the maximum dimension of the portion and larger than the outer diameter dimension of the small diameter portion of the fixed side electrode rod.

The vacuum valve according to the fourth aspect of the present invention is the vacuum valve according to any one of the first to third aspects of the invention, wherein the fixed end plate and the reinforcing member are made of the same material. .

The vacuum valve according to the fifth aspect of the present invention is the vacuum valve according to any one of the first to third aspects of the invention, wherein the fixed end plate is monel metal and the reinforcing member is SUS3.
10 are produced respectively.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1. 1 is a sectional view showing a vacuum valve according to Embodiment 1 of the present invention.
The same or corresponding parts as those of the conventional vacuum valve shown in 0 are designated by the same reference numerals, and the description thereof will be omitted. In the figure, 1
Reference numeral 3 denotes a disc-shaped reinforcing member, and the reinforcing member 13 has a center hole having a larger diameter than the center hole formed in the fixed-side end plate 2 at the center thereof.

Next, a method of manufacturing the vacuum valve according to the first embodiment will be described. First, the assembly of the fixed side portion will be described with reference to FIG. The brazing filler metal 14b is arranged at the step between the small diameter portion 4a and the large diameter portion 4b of the fixed side electrode rod 4,
The small-diameter portion 4a is inserted into the center hole of the fixed-side end plate 2 from above, and the fixed-side end plate 2 is arranged. Next, fixed end plate 2
The brazing material 14a is arranged on the upper side, and the small diameter portion 4a is inserted into the central hole of the reinforcing member 13 from above to arrange the reinforcing member 13. Further, the cylindrical ceramic jig 15 is attached to the small diameter portion 4a.
And the reinforcing member 13 is positioned. At this time, the ceramic jig 15 is formed such that the inner diameter thereof is substantially equal to the outer diameter of the small diameter portion 4a and the outer diameter thereof is substantially equal to the hole diameter of the center hole of the reinforcing member 13. Therefore, the reinforcing member 13 has its center hole engaged with the ceramic jig 15 and is positioned coaxially with the small diameter portion 4a, while the fixed end plate 2 has its center hole engaged with the small diameter portion 4a. It is positioned coaxially with the small diameter portion 4a. Further, the fixed electrode 7 is arranged at one end of the fixed electrode rod 4 via the brazing material 14c. Then, the brazing materials 14a, 14b, 14 are heated in a reducing atmosphere at high temperature.
c is melted, the fixed side end plate 2, the fixed side electrode rod 4 and the reinforcing member 13 are joined, the fixed side electrode rod 4 and the fixed side electrode 7 are joined, and the fixed side portion is assembled.

Next, the assembly of the movable side portion will be described with reference to FIG. The movable side end plate 3 and the shield 10 are arranged on both ends of the bellows 6 with a brazing material interposed therebetween. further,
The movable electrode 8 and the shield 10 are arranged on the movable electrode rod 5 via a brazing material. Then, the brazing material is melted in a high-temperature reducing atmosphere, and the movable-side electrode rod 5 and the movable-side electrode 8 are melted.
And the shield 10 is joined, and the movable side portion is assembled.

Next, the assembly of the insulating container portion will be described with reference to FIG. At both ends of the insulation container 1, about 2
A metallized layer of 0 μm of Mo—Mn is formed. Then, a step is provided on the inner wall surface of the insulating container 1, and the shield 9 is fixed to the step portion by crimping or welding to assemble the insulating container portion.

After that, the fixed-side subassembly and the movable-side subassembly are placed at both ends of the insulating container subassembly, and the brazing material is placed at both ends of the insulating container 1 and placed in a vacuum furnace. Then, the inside of the vacuum furnace is evacuated to a high vacuum of 10 ⁻⁴ Torr or less,
After baking at a high temperature of 0 to 600 ° C. for sufficient degassing, the brazing material at both ends of the insulating container 1 is melted by further heating to the melting point of the brazing material, then cooled, and finally air-sealed. .
Then, the guide mounting plate 12 is fixed to the outer surface of the movable side end plate 3, the resin guide 11 is further inserted into the movable side electrode rod 5, and the guide mounting plate 12 is fastened and fixed to assemble the vacuum valve.

In the fixed side portion of the vacuum valve thus assembled, the hole diameter of the central hole of the reinforcing member 13 is made larger than the hole diameter of the central hole of the fixed side end plate 2, and the reinforcing member 1
Since 3 is brazed to the outer surface of the fixed-side end plate 2, the fixed-side end plate portion can have high strength. Therefore, even if repetitive load or bending stress is applied to the fixed-side end plate 2, the vacuum-tightness of the brazed joint between the fixed-side electrode rod 4 and the fixed-side end plate 2 is not impaired, and the reliability of the vacuum-tightness is ensured. It is possible to improve the sex. Further, in the fixed side portion of the vacuum valve, the reinforcing member 13 is brazed and joined to the outer surface of the fixed side end plate 2, so that the reinforcing member 13 is not vacuum-tightly sealed, that is, uniform without voids, that is, Perfect brazing is not required. Therefore, the amount of expensive brazing material can be reduced, and further, only the joint surface between the fixed-side end plate 2 and the stepped portion between the small-diameter portion 4a and the large-diameter portion 4b of the fixed-side electrode rod 4 related to the vacuum tightness. It suffices if the flatness is secured, the fixed-side component is easily processed, and the cost is reduced. Further, in the conventional vacuum valve shown in FIG. 8, as factors that affect the inclination of the vacuum valve with respect to the axial center, the flatness of the step between the small diameter portion 4a and the large diameter portion 4b of the fixed side electrode rod 4 and the fixed side Flatness of the end plate 2, flatness of the reinforcing member 13,
Also, there are variations in the amount of sinking when the brazing filler metals 16a and 16b at two locations are melted, but in the first embodiment,
Only the flatness of the step between the small-diameter portion 4a and the large-diameter portion 4b of the fixed-side electrode rod 4, the flatness of the fixed-side end plate 2, and the variation in the amount of depression when the brazing material 14b at one location is melted Is. Therefore, in the first embodiment, the inclination of the vacuum valve with respect to the axial center can be reduced.

Here, if the hole diameter of the central hole of the reinforcing member 13 is an intermediate size between the small diameter portion 4a and the large diameter portion 4b of the fixed side electrode rod 4, the fixed side end plate to which the reinforcing member 13 is joined is formed. Two
A thin portion is not formed in the central part of the, and the strength can be high considering the bending moment. Therefore,
The hole diameter of the central hole of the reinforcing member 13 is preferably set to an intermediate size between the small diameter portion 4a and the large diameter portion 4b of the fixed electrode rod 4.

Embodiment 2 FIG. 5 is a sectional view showing a vacuum valve according to a second embodiment of the present invention. In the second embodiment, the fixed-side end plate 18 has a small-diameter portion 4a at the center thereof.
Is provided with a central hole having a hole diameter substantially equal to the outer diameter thereof, and a positioning protrusion 18a protruding outward is provided on the outer peripheral portion thereof. The other configuration is the same as that of the first embodiment.

In the second embodiment, a brazing material 14b (not shown) is arranged at the step between the small diameter portion 4a and the large diameter portion 4b of the fixed side electrode rod 4, and the fixed side end plate 18 is covered with the brazing material 14b. The fixed-side end plate 18 is arranged by inserting the small diameter portion 4a into the center hole.
Then, a brazing material 14a (not shown) is provided on the fixed side end plate 18.
The small diameter portion 4a is inserted into the hole of the reinforcing member 13 from above, and the reinforcing member 13 is arranged. Therefore, the fixed-side end plate 18 has its center hole engaged with the small-diameter portion 4a.
The reinforcing member 13 is coaxially positioned with respect to the small diameter portion 4a by engaging the positioning protrusion 18a with the outer peripheral end surface of the reinforcing member 13. Further, the fixed side electrode 7 has a brazing filler metal 14c (not shown) at one end of the fixed side electrode rod 4.
It is arranged through. After that, the brazing materials 14a, 14b, 14c are melted in a high-temperature reducing atmosphere, and the fixed side end plate 18 and the fixed side electrode rod 4 and the reinforcing member 13 are joined,
The fixed side electrode rod 4 and the fixed side electrode 7 are joined, and the fixed side portion is assembled. Therefore, according to the second embodiment, when assembling the fixed side portion, the ceramic jig 15 for positioning the reinforcing member 13 is not required, and the assemblability can be improved accordingly.

Embodiment 3 FIG. 6 is a sectional view showing a vacuum valve according to a third embodiment of the present invention. In the third embodiment, the electric field relaxation ring 19 has a bottom surface shape having an outer diameter larger than the outer diameter of the large diameter portion 4a of the fixed side electrode rod 4, and is bent inward at the end portion of the bottom surface. It extends to an inner diameter portion slightly smaller than the inner diameter of the insulating container 1 and is formed into a bottomed cylindrical shape that is bent there in a direction orthogonal to the bottom surface. A central hole having a hole diameter substantially equal to the outer diameter of the small diameter portion 4a is provided at the center of the bottom surface. In addition, the reinforcing member 20 has a central hole formed at the center thereof in the electric field relaxation ring 1.
9 is smaller than the outer diameter of the bottom surface of 9 and larger than the outer diameter of the large diameter portion 4b of the fixed electrode rod 4. The other configuration is the same as that of the first embodiment.

In the third embodiment, a brazing filler metal is placed in the step portion between the small diameter portion 4a and the large diameter portion 4b of the fixed side electrode rod 4, and the small diameter portion 4a is placed in the center hole of the electric field relaxation ring 19 from above. The electric field relaxation ring 19 is inserted and arranged. Next, a brazing material is arranged on the electric field relaxation ring 19, and the small diameter portion 4a is inserted into the center hole of the fixed side end plate 2 from above to fix the fixed side end plate 2.
Is placed. Further, a brazing material is arranged on the fixed side end plate 2, and the small diameter portion 4a is inserted into the center hole of the reinforcing member 20 from above to arrange the reinforcing member 20. Furthermore, a cylindrical ceramic jig (not shown) is inserted into the small diameter portion 4a to position the reinforcing member 20. At this time, the ceramic jig is formed such that the inner diameter thereof is substantially equal to the outer diameter of the small diameter portion 4a, and the outer diameter thereof is substantially equal to the hole diameter of the center hole of the reinforcing member 20. Therefore, the reinforcing member 20 has its center hole engaged with the ceramic jig and is coaxially positioned with respect to the small-diameter portion 4a, while the fixed-side end plate 2 and the electric field relaxation ring 19 have its center hole engaged with the small-diameter portion 4a. Then, they are coaxially positioned with respect to the small diameter portion 4a. A fixed electrode 7 is arranged at one end of the fixed electrode rod 4 via a brazing material. Then, the brazing material is melted in a high-temperature reducing atmosphere to bond the electric field relaxation ring 19, the fixed-side electrode rod 4 and the fixed-side end plate 2 to each other,
The fixed side end plate 2 and the reinforcing member 20 are joined together, and the fixed side electrode rod 4 and the fixed side electrode 7 are joined together to assemble the fixed side portion.

As described above, in the fixed side portion of the vacuum valve according to the third embodiment, the hole diameter of the central hole of the reinforcing member 20 is smaller than the maximum size of the brazed portion between the electric field relaxation ring 19 and the fixed side end plate 2. Since the reinforcing member 20 is joined to the outer surface of the fixed-side end plate 2 by making it larger than the outer diameter of the large-diameter portion 4b of the fixed-side electrode rod 4, the fixed-side end plate portion should have high strength. You can Therefore, as in the first embodiment,
The reliability of vacuum tightness can be improved. Further, since the reinforcing member 20 is brazed to the outer surface of the fixed-side end plate 2, the reinforcing member 20 is not vacuum-tight, so that uniform void-free brazing is not required. Therefore, the amount of expensive brazing material can be reduced. In addition, since the brazing area between the electric field relaxation ring 19 and the fixed-side end plate 2 relating to vacuum airtightness can be made small, uniform brazing without voids, that is, perfect brazing can be performed, and the reliability of vacuum airtightness is impaired. Never. Further, the flatness of the joint surface between the electric field relaxation ring 19 and the fixed-side end plate 2 and the joint surface between the electric field relaxation ring 19 and the step between the small-diameter portion 4a and the large-diameter portion 4b of the fixed-side electrode rod 4 should be ensured. In addition, it is easy to process the fixed parts, and the cost can be reduced.
In the third embodiment, the hole diameter of the central hole of the reinforcing member 20 is larger than the outer diameter of the large diameter portion 4b of the fixed electrode rod 4, but the hole diameter of the central hole of the reinforcing member 20 is It suffices if it is larger than the outer diameter of the small diameter portion 4a of the fixed electrode rod 4.

Embodiment 4 In the fourth embodiment, the reinforcing member 13 and the fixed end plate 2 are the same as those in the first embodiment.
And are made of the same material. When the fixed-side end plate 2 and the reinforcing member 13 have large thermal expansion coefficients, the fixed-side end plate 2 has different contraction in the cooling process after brazing.
Causes some deformation depending on the difference in thermal expansion coefficient,
In the fourth embodiment, the material of the reinforcing member 13 is made of the same material as that of the fixed end plate 2, so that the vacuum valve can be manufactured with high accuracy and with little deformation.

In the fourth embodiment, the reinforcing member 1
Although 3 and the fixed-side end plate 2 are made of the same material, the reinforcing member 13 and the fixed-side end plate 2 may be made of different materials. As a combination of different materials, when Monel metal which is a Cu-Ni alloy is used as the material of the fixed side end plate 2, SU is used as the material of the reinforcing member 13.
S310 is the most suitable. Austenitic stainless steel is generally excellent in corrosion resistance and has good workability. Among them, SUS310 has good versatility and has a thermal expansion coefficient closest to that of Monel metal, so that a vacuum valve with little deformation and high precision can be manufactured.

[0028]

Since the present invention is configured as described above, it has the following effects.

According to the first aspect of the present invention, the cylindrical insulating container, the fixed-side end plate and the movable-side end plate attached to both ends of the insulating container so as to close the insulating container, respectively, have a large diameter. A small diameter portion is formed on one end side in the axial direction of the portion, the small diameter portion is projected from the center hole of the fixed side end plate, and a step portion between the small diameter portion and the large diameter portion is formed around the center hole of the fixed side end plate. A fixed-side electrode rod that is airtightly brazed and joined, and the fixed-side electrode is attached to the other end in the axial direction so as to be located in the insulating container,
A movable side electrode is attached to one end, and the movable side electrode is airtightly attached to the movable side end plate via a bellows so that the movable side electrode is located in the insulating container, and the movable side electrode is brought into contact with and separated from the fixed side electrode. In a vacuum valve equipped with a movable electrode rod, a disk-shaped reinforcing member having a central hole whose hole diameter is larger than the hole diameter of the center hole of the fixed end plate is provided on the outer wall surface of the fixed end plate. Since they are arranged coaxially with each other and brazed to the outer wall surface of the fixed end plate, the strength of the fixed end plate is increased, and the occurrence of defective joining of the brazed joint portion which is related to vacuum tightness. In addition, the brazing area related to vacuum tightness is small, uniform brazing without voids is possible, the reliability of vacuum tightness can be improved, and precise flatness is not required for the fixed side parts Cost can be reduced Sky valve can be obtained.

According to the second invention, the first
In the invention, since the hole diameter of the central hole of the reinforcing member is an intermediate size between the outer diameter of the small diameter portion and the outer diameter of the large diameter portion of the fixed side electrode rod, the fixed side end integrated with the reinforcing member is provided. A thin portion is not formed in the central portion of the plate, the strength of the fixed side end plate portion is increased, and the reliability of vacuum tightness can be improved.

According to the third invention, the first
In the invention, a bottomed cylindrical electric field relaxation ring having a central hole whose hole diameter size is substantially equal to the central hole of the fixed side end plate,
It is interposed between the step portion between the small diameter portion and the large diameter portion and the fixed side end plate, and the inner wall surface of the bottom surface around the center hole is airtightly brazed to the step portion between the small diameter portion and the large diameter portion. The outer wall surface of the bottom surface is airtightly brazed to the inner wall surface of the fixed end plate, and the hole diameter of the center hole of the reinforcing member is such that the electric field relaxation ring and the fixed end plate are brazed. Since it is smaller than the maximum size of the fixed part and larger than the outer diameter of the small diameter part of the fixed side electrode rod, a thin part cannot be formed in the central part of the fixed side end plate integrated with the reinforcing member, and the fixed side end plate is not formed. The strength of the portion is increased, and the reliability of vacuum tightness can be improved.

According to the fourth invention, the first
In any one of the third to third inventions, since the fixed side end plate and the reinforcing member are made of the same material, the fixed side generated due to the difference in thermal expansion coefficient in the cooling step after brazing The deformation of the end plate is suppressed.

According to the fifth invention, the first
In any one of the third to third inventions, since the fixed side end plate is made of Monel metal and the reinforcing member is made of SUS310, the same effect as the fourth invention can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing a vacuum valve according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a fixed side subassembly of the vacuum valve according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a movable side subassembly of the vacuum valve according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing an insulating container subassembly of the vacuum valve according to the first embodiment of the present invention.

FIG. 5 is a sectional view showing a vacuum valve according to a second embodiment of the present invention.

FIG. 6 is a sectional view showing a vacuum valve according to a third embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a conventional vacuum valve.

FIG. 8 is a sectional view showing another example of a conventional vacuum valve.

FIG. 9 is a sectional view showing a subassembly in another example of the conventional vacuum valve.

FIG. 10 is a sectional view showing still another example of a conventional vacuum valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Insulating container, 2 and 18 Fixed end plate, 3 Movable end plate, 4 Fixed side electrode rod, 4a small diameter part, 4b large diameter part,
5 movable side electrode rod, 6 bellows, 7 fixed side electrode, 8
Movable electrode, 13, 20 Reinforcing member, 14a, 14b
Brazing material, 19 electric field relaxation ring.

Claims (5)

[Claims] 1. A cylindrical insulating container, a fixed-side end plate and a movable-side end plate attached to both ends of the insulating container so as to close the insulating container, and one end side in the axial direction of the large-diameter portion. A small diameter portion is formed on the fixed side end plate, and the small diameter portion is projected from the center hole of the fixed side end plate, and the step portion between the small diameter part and the large diameter part is airtightly brazed around the center hole of the fixed side end plate. Is
The fixed side electrode is attached to the other end of the axial direction so as to be located inside the insulating container, and the movable side electrode is attached to one end so that the movable side electrode is located inside the insulating container. A vacuum valve having a movable side electrode rod that is airtightly attached to the movable side end plate via a bellows and that moves the movable side electrode to and from the fixed side electrode. A disk-shaped reinforcing member having a central hole larger than the hole diameter dimension of the central hole of the plate, the central holes are arranged coaxially with each other on the outer wall surface of the fixed-side end plate,
A vacuum valve, which is brazed to the outer wall surface of the fixed-side end plate. 2. The vacuum according to claim 1, wherein the hole diameter of the center hole of the reinforcing member is an intermediate size between the outer diameter of the small diameter portion and the outer diameter of the large diameter portion of the fixed side electrode rod. valve. 3. A bottomed cylindrical electric field relaxation ring having a center hole having a hole diameter dimension substantially equal to the center hole of the fixed end plate is provided between the fixed end plate and the step between the small diameter part and the large diameter part. And the inner wall surface of the bottom surface around the center hole is airtightly brazed to the step between the small diameter portion and the large diameter portion, and the outer wall surface of the bottom surface is the inner wall surface of the fixed side end plate. And the hole diameter of the center hole of the reinforcing member is smaller than the maximum size of the brazed portion between the electric field relaxation ring and the fixed side end plate, and the outside of the small diameter portion of the fixed side electrode rod. The vacuum valve according to claim 1, wherein the vacuum valve is larger than the diameter dimension. 4. The vacuum valve according to claim 1, wherein the fixed end plate and the reinforcing member are made of the same material. 5. The vacuum valve according to claim 1, wherein the fixed side end plate is made of Monel metal and the reinforcing member is made of SUS310.