JPH0211965B2 - - Google Patents

Description

[Detailed Description of the Invention] A. Industrial Application Field The present invention relates to a vacuum interrupter and a method for manufacturing the same, and particularly relates to a vacuum interrupter formed by bonding a ceramic member and a copper member without using a brazing material to form a vacuum interrupter. Concerning an interrupter and its manufacturing method.

B. Summary of the Invention The first invention is a vacuum interrupter in which a pair of electrodes are disposed facing each other in a vacuum container so as to be able to move toward and away from the vacuum container. By forming an airtight connection through copper containing 0.1 to 0.6% by weight of chromium, it is possible to airtightly connect the ceramic member and the copper member that make up the vacuum container without using a brazing material. It is.

Further, a second invention is a method for manufacturing a vacuum interrupter according to the first invention, in which the ceramic member and the copper member are contained in an amount of 0.1 to 0.6% by weight.
heated through a copper foil containing chromium,
By airtightly joining, there is no need to form a metallized layer, sintering, etc., no brazing filler metal is used, and the cost is low and the number of steps is small.
This makes it possible to easily manufacture a vacuum interrupter.

C. Prior Art In general, a vacuum interrupter has an insulating tube 1 made of an insulating material such as ceramics, as shown in FIG.
Fe-Ni alloy with both openings fixed to this end,
A vacuum container 4 is formed by airtightly closing a metal end plate 3 made of stainless steel through a sealing fitting 2 made of Fe-Ni-Co alloy (Kovar) or the like.
A pair of electrodes 5 are introduced from the center of each metal end plate 3 into the vacuum vessel 4 through a pair of electrode rods 6, which are arranged so as to be relatively approachable and detachable while maintaining the airtightness of the vacuum vessel 4. (Contact/separation) It is configured to be freely provided.

In FIG. 2, 7 is a metal bellows that prevents the movable electrode rod 6 from impairing the airtightness of the vacuum container 4, 8 is a cylindrical shield that concentrically surrounds the pair of electrodes 5, etc. The intermediate portion of the insulating cylinder 1 is supported via a ring-disc-shaped support fitting 9 installed on the inner wall surface of the insulating cylinder 1.

D Problems to be Solved by the Invention However, in the above-mentioned general vacuum interrupter, since the insulating tube 1, which together with the metal end plate 3 forms the vacuum container 4, is made of an insulator such as ceramics, For bonding, it is necessary to use a sealing fitting 2 made of a ferromagnetic material such as Kovar, which has a coefficient of thermal expansion similar to that of ceramics, etc., which may cause noise due to magnetostrictive vibration of the sealing fitting 2 when a large current is applied. The temperature rises due to the eddy current caused by the induced magnetic field, and the joint part of the insulating cylinder 1 is metalized to prevent it from joining with the sealing fitting 2 by brazing.
In addition, the surface of the metallized layer must be subjected to nickel plating, sintering, etc. to improve wettability with the brazing material, and is also used for joining the insulating tube 1 and the metal end plate 3 to the sealing fitting 2. There are problems such as limited brazing filler metals.

In order to deal with this problem, a vacuum interrupter has been devised in which a vacuum vessel is formed by brazing metal end plates made of copper to both ends of an insulating cylinder, but in such a vacuum interrupter, the metal end plates are made of copper. Therefore, there is no need for sealing fittings, and since copper is non-magnetic, it does not generate heat due to magnetostrictive vibrations or induced magnetic fields during energization, and the application range of brazing filler metal can be expanded. A metallized layer mainly composed of molybdenum, tungsten, etc. is formed at the joint of the metallized layer, and the surface of the metallized layer is subjected to nickel plating and sintering, and a brazing material is used to join the insulating cylinder and the metal end plate. There are problems such as having to do this.

E. Means for Solving the Problems In order to solve these conventional problems, the first invention provides a cylindrical body made of an insulating material or a metal and having at least one end open, and an end plate made of a metal or an insulating material. In this vacuum interrupter, a ceramic member (the insulator) and a copper member (the metal) are combined, and both members are separated by 0.1.
A vacuum container is formed by airtightly joining copper containing ~0.6% by weight of chromium.

Further, in manufacturing the vacuum interrupter according to the first invention, a second invention provides an airtight bonding between a ceramic member and a copper member by heating with a copper foil containing 0.1 to 0.6% by weight of chromium interposed therebetween. This is what I did.

F Effect According to the vacuum interrupter and its manufacturing method as described above, the ceramic member and the copper member are
Copper containing 0.1-0.6% by weight of chromium provides a bond with excellent airtightness and strength.

G Example Hereinafter, the present invention will be explained in detail based on an example shown in FIG.

The vacuum interrupter according to the present invention includes, for example, a first
Alumina formed into a cylindrical shape, as shown in the figure,
At both ends of an insulating tube (cylindrical body) 10 made of ceramics such as mullite, zircon, steatite, etc., end plates 11 made of copper and formed in a disc shape are attached with a thickness of 0.1 to 0.6 mm.
It is airtightly joined through a copper foil containing 12% chromium by weight, and the internal temperature is 13.33mPa.
Vacuum container 1 is evacuated to a high vacuum of (10 ^-4 Torr) or less.
3, and inside this vacuum vessel 13, a pair of electrodes 14 can be moved relatively toward and away from the center of each end plate 11 while maintaining airtightness of the vacuum vessel 13, similarly to a normal vacuum interrupter. The structure is such that the electrode rods 15 can be freely moved toward and away from each other through a pair of electrode rods 15 which are introduced and arranged opposite to each other.

In addition, in FIG. 1, 16 is a metal bellows;
Reference numeral 7 denotes a cylindrical shield that concentrically surrounds the pair of electrodes 14, etc., and its intermediate portion is supported by a ring-disc-shaped support fitting 18 implanted on the inner wall surface of the insulating cylinder 10. be.

In order to manufacture the vacuum interrupter of the first invention described above, first, the insulating cylinder 1 with the shield 17 attached thereto is
At both ends of 0, each end plate 11 with electrodes 14, 14, electrode rod 15, etc. attached is placed between the joints of the two with a copper foil having a thickness of 0.1 to 2 mm and containing 0.1 to 0.6% by weight of chromium. Temporarily assemble the vacuum interrupter as shown in Figure 1, and then heat the temporarily assembled vacuum interrupter to 13.33 mPa (10 ^-4 Torr).
Store in the following vacuum atmosphere or in a gas atmosphere such as helium or hydrogen that does not oxidize copper. Next, the temporarily assembled vacuum interrupter is continuously heated at a temperature of 900° C. or higher for 10 minutes or more in these atmospheres to airtightly bond the insulating cylinder 10 and each end plate 11, and then slowly cooled in these atmospheres. The desired vacuum interrupter is completed by reducing the residual stress in each end plate 11 made of copper through its plastic deformation. In addition, when manufacturing in a gas atmosphere such as helium or hydrogen, the electrode rod 1
5, 15 or the end plates 11, 11 is an additional step of heating and exhausting the inside of the vacuum vessel 13 through an exhaust pipe or an exhaust hole provided in either the end plates 11, 11.

In the vacuum interrupter of the above embodiment, a case has been described in which the vacuum vessel 13 is formed by an insulating tube 10 made of ceramics and an end plate 11 made of copper that airtightly closes both open ends of this insulating tube 10. However, the formation of the vacuum container is not limited to these, but includes, for example, a metal tube (cylindrical body) made of copper and an end plate made of ceramic such as alumina or mullite that airtightly closes both open ends of the metal tube. Alternatively, a vacuum container may be formed by a bottomed cylindrical (cup-shaped) metal case (cylindrical body) made of copper and an end made of ceramic such as alumina that airtightly closes the open end of this metal case. Furthermore, the cylindrical body is not limited to the case where it is formed from a single insulating cylinder 10 made of ceramics, but may also be made of copper or 0.1 to 0.6% by weight of chromium, for example. A single insulating cylinder may be formed by two or more insulating cylinders made of ceramics (ceramic members) connected in series through thin annular sealing fittings (copper members) made of copper, or A cylindrical copper member or a copper member containing a trace amount of chromium is airtightly joined in series to both ends of a ceramic member to form a single cylindrical body, and both ends are hermetically closed with a plate-shaped copper member to form a vacuum vessel. Alternatively, a vacuum container may be formed by airtightly closing both ends of a cylindrical ceramic member with a bottomed cylindrical copper member, and the same effect as that of the above-mentioned embodiment is achieved. Of course, each of these vacuum containers can be manufactured by the method described above.

H. Effects of the invention As described above, the first invention provides a
In a vacuum interrupter in which a pair of electrodes are arranged facing each other so as to be able to freely approach and separate, the vacuum container is made of a ceramic member and a copper member, and both members are combined.
Since it is formed by airtightly joining copper containing 0.1 to 0.6% by weight of chromium, the two parts can be joined with excellent airtightness and strength. There is no need to use it, and as a result, the vacuum interrupter can have excellent airtightness and impact resistance, and can be made inexpensive.

Further, the invention of the method for manufacturing a vacuum interrupter according to the first invention includes a ceramic member and a copper member.
Since the vacuum container is formed by heating and air-tightly bonding a copper foil containing 0.1 to 0.6% by weight of chromium, unlike the conventional method,
There is no need to form a metallized layer using expensive molybdenum or the like on the bonding surfaces of ceramic parts, or perform sintering, etc., and there is no need to use a brazing filler metal, so manufacturing costs can be significantly reduced and the number of processes can be reduced. It also has the advantage of facilitating manufacturing.

[Brief explanation of drawings]

FIG. 1 is a half-cut sectional view of a vacuum interrupter according to the present invention, and FIG. 2 is a longitudinal sectional view of a general vacuum interrupter. 10... Insulating cylinder (cylindrical body), 11... End plate, 1
2... Foil-shaped copper, 13... Vacuum container, 14... Electrode.

Claims (1)

[Scope of Claims] 1. A vacuum interrupter in which a pair of electrodes are disposed facing each other in a vacuum container so as to be able to move toward and away from the vacuum container. A vacuum interrupter characterized by being formed by airtightly bonding copper containing 0.6% by weight of chromium. 2. A method for manufacturing a vacuum interrupter, which comprises forming a vacuum container by heating and airtightly bonding a ceramic member and a copper member with a copper foil containing 0.1 to 0.6% by weight of chromium interposed therebetween. 3 A vacuum container in which a ceramic member and a copper member are temporarily assembled with a copper foil containing 0.1 to 0.6% by weight of chromium interposed is placed in a vacuum atmosphere and heated at a temperature of 900°C or higher for 10 minutes. 3. The method of manufacturing a vacuum interrupter according to claim 2, wherein the vacuum interrupter is continuously heated to form an integral airtight seal, and then slowly cooled in the same atmosphere. 4. A vacuum container in which a ceramic member and a copper member are temporarily assembled by interposing a copper foil containing 0.1 to 0.6% by weight of chromium is placed in a gas atmosphere that does not oxidize the copper, and at a temperature of 900°C or higher. 3. The method of manufacturing a vacuum interrupter according to claim 2, wherein the vacuum interrupter is continuously heated at a temperature for 10 minutes or more to form an integral airtight seal, and then slowly cooled in the same atmosphere.