JPS6240809B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum chamber disconnector, and more specifically, the present invention relates to a vacuum chamber disconnector, in which a vacuum chamber is formed by closing both ends of a metal cylinder with an insulating disk made of an inorganic insulator, and a vacuum chamber is formed within the vacuum chamber. This invention relates to a vacuum shield breaker in which a pair of electrodes are provided so as to be able to come into contact with each other and separate from each other.

Conventionally, a cylindrical vacuum vessel in a vacuum chamber or disconnector is made of a cylindrical insulating tube made of hard glass or ceramic, with both ends made of Kovar, etc. whose coefficient of thermal expansion is similar to that of the ceramic that forms the insulating tube. It is formed by being airtightly closed either directly by a metal end plate made of a metal material, or by a metal end plate with a sealing metal such as Kovar interposed therebetween. However, as the diameter of the insulating tube increases, the price of the insulating tube increases rapidly, and there is a risk that the vacuum shield or disconnector itself will become expensive.

In addition, metals that can be airtightly bonded to ceramics, etc. that form the insulating tube include Fe-Ni-Co alloy (Kovar), which has a thermal expansion coefficient similar to that of ceramics, etc.
-Ni alloys, but these metals have the disadvantage of being very expensive and their coefficient of thermal expansion (α) [α-T characteristics] at each temperature (T) does not necessarily match that of ceramics, etc. , and because it is a ferromagnetic material, it is necessary to provide the metal end plate with a stress relaxation structure to relieve the thermal stress caused by the joining of the two by brazing. There are problems such as noise caused by the magnetostriction phenomenon caused by the magnetic field.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a cylindrical vacuum container in a vacuum shield cutter by cooling ceramics etc. at both ends of a metal cylinder after brazing. The auxiliary member is made of a metal material that can be plastically deformed during the slow cooling process after brazing due to the thermal stress generated, or a metal material with a thermal expansion coefficient similar to that of ceramic, etc., and is formed into a ring shape and an L-shaped cross section. At the same time, each auxiliary member is provided with an insulating disk made of an inorganic insulator through a metallized layer provided on one end surface near the outer peripheral edge of the metallized layer so that the metallized layer is oriented in the same direction. By configuring the vacuum container by airtightly joining it, it is possible to easily and inexpensively increase the diameter of the vacuum container, and the brazing between its constituent members can be done effectively and well. The purpose of the present invention is to provide a vacuum shield and disconnector that achieves this goal. Hereinafter, one embodiment of the present invention will be described in detail using the drawings.

The figure is a half-cut sectional view of a vacuum sheath disconnector according to the present invention. 3, 3 are interposed and airtightly joined to form a vacuum vessel 4, and a pair of fixed and movable electrodes are introduced into the vacuum vessel 4 from the center of each insulating disk 2 so as to be able to approach and separate from each other. A pair of fixed and movable electrodes 7 and 8 are provided via rods 5 and 6 so as to be able to come into contact with and separate from each other.

That is, the metal cylinder 1 constituting a part of the vacuum vessel 4 is made of austenitic stainless steel (hereinafter simply referred to as "stainless steel"), which is a non-magnetic material and has relatively high mechanical strength. , stepped fitting portions 9 having an appropriately larger diameter than the inner diameter are formed on the inner peripheral portions of both ends thereof. Note that the metal cylinder 1 is not limited to being made of stainless steel, but may be made of a non-magnetic material, for example, and may be made of a non-magnetic material after brazing due to thermal stress caused by cooling after brazing with the auxiliary member 3. If copper is plastically deformable during the slow cooling process, or if the current carrying capacity of the vacuum shield or disconnector is small, use a magnetic material.
In addition, a material made of iron that can be plastically deformed during the slow cooling process after brazing due to thermal stress generated by cooling after brazing with the auxiliary member 3 may be used. Near both ends of the metal cylinder 1 are cup-shaped auxiliary shields 10 made of stainless steel.
10 are arranged facing each other with their respective bottoms positioned inward, and the auxiliary shield 10 (on the upper side in the figure) is fitted into the stepped fitting part 9 at one end via the flange part 10a integrally formed on the edge of the opening. The other auxiliary shield 10 is fitted near the stepped fitting part 9 at the other end via the flange part 10a integrally formed on the edge of the opening, and is then fixed to the stepped part by brazing. As will be described later, it is fixed to the flange portion of the auxiliary member 3. Note that each auxiliary shield 10 is not limited to being made of stainless steel; for example, if the current carrying capacity of the vacuum shield or disconnector is small, a material made of iron may be used. A hole 11 for inserting the fixed electrode rod 5, movable electrode rod 6, etc. is provided at the bottom of the electrode.

Each stepped fitting part 9 of the metal cylinder 1 has a ring-shaped cylindrical part 3a extending in the axial direction (vertical direction in the figure) and connected to one end of the cylindrical part 3a and in the radial direction (horizontal direction in the figure). The auxiliary member 3, which is formed into an L-shaped cross section by the flange portions 3b extending inward, is fitted through the cylindrical portion 3a such that the respective flange portions 3b are positioned in the same direction (upward in the figure). They are fitted together and airtightly joined by brazing. Each auxiliary member 3 is constructed so that the joint between the metal cylinder 1 and the insulating disk 2, which have different coefficients of thermal expansion, is reduced in airtightness and mechanical bonding strength due to thermal stress caused by cooling after brazing. It is made of non-magnetic material to prevent
In addition, it is made of copper that can be plastically deformed during the slow cooling process after brazing due to thermal stress generated by cooling after brazing with the insulating disk 2. Note that the multi-auxiliary member 3 is not limited to being made of copper; for example, if the current carrying capacity of the vacuum shield or disconnector is small, it may be made of a magnetic material and the Fe-Ni-Co alloy, Fe-Ni-Co alloy, Fe-Ni-Co alloy, Fe-Ni-Co alloy, Fe-Ni-Co alloy, Fe-Ni-Co alloy, Fe-Ni-Co alloy, Fe-Ni-Co alloy, Fe-Ni-Co alloy, Fe-Ni-Co alloy, Fe-Ni-Co alloy, Fe-Ni-Co alloy, Fe-Ni-Co alloy, etc. A material made of Ni alloy may be used, and the other auxiliary shield 10 is fixed to the flange portion 3b of the other auxiliary member 3 via the flange portion 10a by brazing. .

In each of the auxiliary members 3, the insulating disk 2 is fitted into the cylinder part 3a, and the flange part 3 is fitted into the cylinder part 3a.
It is hermetically joined to b. That is, each insulating disk 2 is made of an inorganic insulator such as alumina ceramic or crystallized glass, and has a hole 1 in the center.
2 and is formed into a disk shape with a suitably larger diameter than the inner diameter of the metal cylinder 1, and near the outer periphery and on one end surface around the hole 12, Mn having a thermal expansion coefficient similar to that of alumina ceramic etc. is provided. -Metallized layers 13 and 14 made of a Ti alloy or a Mo-Mn-Ti alloy are formed. Incidentally, when forming the metallized layers 13 and 14 of the insulating disk 2, a grinding process is performed, and in order to facilitate this grinding process, a gap of about 0.1 to 0.5 mm is placed between each metallized layer 13 and 14. A deep groove 15 is formed in a circular shape. Each insulating disk 2 is fitted into the cylindrical portion 3a of the auxiliary member 3 such that the respective metallized layers 13 and 14 are located in the same direction (upward in the figure), and It is hermetically joined to the flange portion 3b of the auxiliary member 3 by brazing via the metallized layer 13.

In the metallized layer 14 around the hole 12 in the one insulating disk 2, the fixed electrode rod 5 made of copper or copper alloy, which is introduced into the vacuum vessel 4 through the hole 12, is attached at its outer end. The large-diameter portion 5a is integrally molded with the large-diameter portion 5a, and is airtightly joined by brazing through a stepped portion having a different diameter. At the inner end of the fixed electrode rod 5,
A dish-shaped arc shield 16 is fitted into the central portion of the arc shield 16 through an integrally formed cylindrical portion 16a, and is secured by brazing. arc shield 1
Numeral 6 is for preventing metal vapor from adhering to the inner end surface (vacuum side) of one of the insulating discs 2 together with the one of the auxiliary shields 10, and is made of the same metal material as each of the auxiliary shields 10. Consisting of The fixed electrode 7, which is formed in a substantially disk shape, is fitted into the inner end of the fixed electrode rod 5 through a recess 7a formed in the center of the contact back surface (upper surface in the figure). It is fixed by brazing.

In the metallized layer 14 around the hole 12 in the other insulating disk 2 (lower in the figure), a bellows 17 made of stainless steel and housed concentrically in the vacuum container 4 is attached with the inner diameter side of one end extending in the axial direction. They are airtightly joined by brazing through the end portion of the cylindrical portion 17a formed by extending the cylindrical portion 17a. The other end of the bellows 17 is provided with a mounting portion 17b formed by extending the inner diameter side radially inward, and this mounting portion 17b
includes the hole 12 and bellows 17 in the other insulating disc.
The movable electrode rod 6 made of copper or copper alloy is introduced into the vacuum vessel 4 by passing through the center thereof, and is made airtight by brazing through the stepped portion of the large diameter portion 6a formed integrally with the inner end thereof. is joined to. The large-diameter portion 6a of the movable electrode rod 6 has an arc shield 18 made of the same metal material as the arc shield 16 fixed to the fixed electrode rod 5 and formed in a similar dish shape in the center thereof. It is fitted through the integrally molded cylindrical portion 18a and is fixed by brazing. Further, the movable electrode 8 formed in a substantially disk shape is fitted into the inner end of the movable electrode rod 6 via a recess 8a bored in the center of the contact back surface (lower surface in the figure). They are also fixed together by brazing. A circular groove 8b is formed in the contact surface of the movable electrode rod 8 with its center as the center, and a ring-shaped contact 19 is fitted into the groove 8b, protruding appropriately from the contact surface. They are also fixed together by brazing.

In addition, in the embodiment described above, the metal cylinder 1
The case has been described in which the auxiliary member 3 is positioned relative to the metal cylinder 1 by providing stepped fitting parts 9 on the inner periphery of both ends and fitting the auxiliary member 3 into the stepped fitting parts 9. Instead of providing stepped fitting parts on the inner periphery of both ends of the cylinder 1, the linear auxiliary member 3 is airtightly joined to the end face by brazing, or stepped fitting parts are provided on the outer periphery of both ends of the metal cylinder 1. established,
The auxiliary member 3 may be positioned with respect to the metal cylinder 1 by fitting the auxiliary member 3 into this stepped fitting portion via its cylindrical portion 3a, and may also be fixed to one of the insulating discs 2. In order to restrict the movement of the electrode rod 5, the method is not limited to providing the large diameter portion 5a at the outer end. For example, it is also possible to provide a circumferential groove near the outer end and fit a retaining ring such as a snap spring into this circumferential groove. It is also possible to make it match.

To manufacture the vacuum shield and disconnector having the above configuration, first, the other insulating disc 2 is supported horizontally with its metallized layers 13 and 14 facing upward, and each insulating disc 2 is The structural members are temporarily assembled as shown in the figure by interposing a brazing material between the joints. Then,
Place the temporarily assembled vacuum shield and disconnector in a vacuum furnace and heat it. This heating also serves to exhaust, degas, and remove the oxide film on the brazed parts, so it is desirable that the temperature be as high as possible, below the temperature at which the brazing material does not melt, and the pressure inside the vacuum furnace should be below 10 ^-4 Torr. It is desirable to do so. Then, inside the vacuum furnace,
Above 900℃ for activation of stainless steel surface
With an increase in temperature below 1050℃,
While evacuating to a pressure of 10 ^-5 Torr or less, each component is airtightly joined using a brazing filler metal. Finally, the inside of the vacuum furnace is lowered from the brazing temperature to a predetermined temperature by slow cooling (furnace cooling), held at this temperature for a predetermined time, and then lowered to room temperature by slow cooling again, or the inside of the vacuum furnace is slowly cooled. If the vacuum shield and disconnector are removed after the brazing temperature has been lowered to room temperature, the desired result can be obtained.

In addition, in the above-mentioned manufacturing method, by applying nickel plating treatment to the brazed parts of the metal cylinder 1 or bellows 17 made of stainless steel in advance, the upper limit of the heating temperature can be increased to 900°C.
℃ or less.

Here, the insulating disk 2 made of an inorganic insulator such as alumina ceramic and the metal cylinder 1 made of stainless steel, copper, or iron are bonded to each other in an airtight and mechanical manner, despite the large difference in coefficient of thermal expansion between the two. It is thought that the reason why the bonding force can be made good is as follows.

That is, it is known that the tensile strength of copper or iron with respect to temperature increases as the temperature decreases, and that the elongation of copper or iron with respect to temperature decreases as the temperature decreases. Therefore, copper,
The auxiliary member 3 or metal cylinder 1 made of iron is
An insulating disk 2 made of an inorganic insulator such as alumina ceramic or
When brazed to the auxiliary member 3 made of Fe-Ni-Co alloy or Fe-Ni alloy, the auxiliary member 3 made of copper or iron or the metal cylinder 1 is Since the mechanical strength of the disc 2 is extremely small compared to the mechanical strength of the disc 2, it is plastically deformed during the slow cooling process after brazing due to thermal stress generated by cooling after brazing. Therefore, it is considered that the airtightness of the joint between the two is not impaired when the two are cooled to room temperature, and the residual thermal stress is extremely small.

Although iron has a higher tensile strength at various temperatures than copper, and its creep elongation with respect to loading time under constant temperature conditions is smaller than that of copper, it is similar to copper when it is used with inorganic insulators such as alumina ceramics. It is thought that the reason why it can be bonded well is because its coefficient of thermal expansion is smaller than that of copper.

In addition, the reason why the insulating disc 2 made of an inorganic insulating material such as alumina ceramic and the bellows 17 made of stainless steel can be made to have high airtightness and mechanical strength is because the bellows 17 is
It is formed extremely thin, about 0.1 to 0.2 mm, and
Since the thermal stress generated by cooling the two after brazing is extremely small compared to the mechanical strength of the insulating disk 2 made of an inorganic insulator, the bellows 17 itself is plastically deformed during the slow cooling process after brazing. It is thought that this is because of this.

As described above, the present invention provides an auxiliary member having a ring shape at both ends of a metal cylinder and comprising a cylindrical portion and a flange portion extending radially inward from one end of the auxiliary member, the flange portions of which are located in the same direction. At the same time, an insulating disk is attached to the flange portion of each auxiliary member, which is formed into a disk shape with a diameter larger than the inner diameter of the metal cylinder 1, and has a metallized layer formed on one end surface near the outer peripheral edge. are airtightly joined through the respective metallized layers to form a vacuum container, and a pair of electrode rods are introduced into the vacuum container from the center of each insulating disk so as to be able to approach and separate from each other. Since the electrodes are provided so as to be able to come into contact with each other and separate from each other, the diameter of the vacuum container can be increased easily and at low cost. Moreover, the brazing between the constituent members of the vacuum container can be effectively and satisfactorily performed. Furthermore, since the auxiliary members and the insulating disks at both ends can be made to have the same shape, it is suitable for mass production.

[Brief explanation of the drawing]

The figure is a half-cut sectional view of a vacuum shield disconnector according to the present invention. DESCRIPTION OF SYMBOLS 1...Metal cylinder, 2...Insulating disk, 3...Auxiliary member, 3a...Cylinder part, 3b...Flange part, 4...
...Vacuum container, 5, 6... Electrode rod, 7, 8... Electrode, 13... Metallized layer.

Claims (1)

[Claims] 1 At both ends of a metal cylinder, an auxiliary member made of a ring-shaped cylindrical part and a flange part extending radially inward from one end of the cylindrical part is installed so that each flange part is located in the same direction so as to be airtight. At the same time, an insulating disk formed in the shape of a disk with a diameter larger than the inner diameter of the metal cylinder 1 and having a metallized layer formed on one end surface near the outer peripheral edge is attached to the flange portion of each auxiliary member. A pair of electrodes can be brought into contact with and separated from each other through a pair of electrode rods which are introduced into the vacuum container from the center of each insulating disk so that they can be relatively approached and separated. A vacuum cutter installed in