JPH11195358A - Vacuum interrupter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a durable electrode without reducing strength of the calking part by fixing the contact part through an installing member of a material nonreactive with low melting point metal contained in the contact part of an electrode in a ceramic vessel. SOLUTION: The contact part 12 is fixed to an electrode main body 10 of a fixed electrode and a movable electrode in a vacuum vessel composed of an insulating cylinder of ceramics, and low melting point metal such as Bi, Te and Sb is contained in this contact part 12. The electrode main body 10 and the contact part 12 are formed as a structure to fix the contact part 12 by bending the end part 11 of the installing member 13 by fitting the contact part 12 in the cup-shaped installing member 13 brazed/fixed in the recessed part of the electrode main body 10. An intermetallic compound is not generated even if the low melting point metal infiltrates since the installing member 13 is made of a Cu-Cr alloy, stainless steel and a Cu-Ag alloy of a material nonreactive with the low melting point metal of the contact part 12 deposited by a heat load, so that the reduction of strength of the calking part can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum interrupter using a ceramic container as a vacuum container, and more particularly to a vacuum interrupter having a contact portion containing a low melting point metal which is difficult to braze.

[0002]

2. Description of the Related Art There are various types of performance required for a vacuum interrupter. For example, in order to satisfy the performance of a low breaking current value, a contact portion is generally formed of a material containing a low melting point metal. ing.

[0003] The contact portion is fixed to a pair of current-carrying members which can be opened and closed, for example, an inner end portion of a lead rod and an arc portion.
Since the brazing is difficult, the contact portion 12 is fixed by caulking due to plastic deformation at the end portion 11 of the electrode body (arc portion) 10 as shown in FIG.

[0004]

However, in manufacturing a vacuum interrupter, when a vacuum container is formed of a ceramic container, a brazing heat load of 800 ° C. or more is applied. In particular, high-temperature heating of 800 ° C. or more is required for exhausting and brazing in a non-oxidizing atmosphere instead of exhausting air.

Accordingly, when a heat load at a temperature higher than the temperature at which such a low-melting-point metal is precipitated (above the melting point) acts, the deposition of the low-melting-point metal contained in the contact portion increases and the end portion 11 in FIG. The reaction of the low-melting-point metal on the Cu member at a certain caulked portion becomes remarkably brittle, and the caulked portion lowers mechanical strength to lower durability.

The present invention has been made in view of the above problems, and provides a durable vacuum interrupter which does not react with the low melting point metal and does not reduce the strength of the swaged portion even if a low melting point metal is deposited at the contact portion. Aim.

[0007]

The present invention that achieves the above object has the following matters specifying the invention. That is, as a first invention, a contact portion is provided at the inner end of a pair of current-carrying members at least one of which can freely approach and separate via a bellows in a vacuum vessel provided with a ceramic member, and is provided in a non-oxidizing gas atmosphere. In the vacuum interrupter formed by brazing, at least one contact portion contains a low-melting-point metal, and a mounting member made of a material that does not react with the low-melting-point metal contained in the contact portion is brazed to the current-carrying member. The contact portion is formed by plastically deforming a part of the mounting member and surrounding and fixing the contact portion.

According to a second aspect, in the first aspect, the energizing member is one of a lead rod and an electrode body.

A third invention is based on the first invention,
The attachment member has one of a cup shape and a ring shape.

A fourth invention is based on the first invention, wherein:
The mounting member is a Cu-Cr alloy, stainless steel, Cu
-Ag alloy is formed.

A fifth invention is based on the first invention, wherein:
The low melting point metal is made of any material of Bi, Te, and Sb and is characterized by containing 10 to 20% by weight.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an embodiment of the vacuum interrupter of the present invention will be described. FIG. 1 is an overall view of a vacuum interrupter. In FIG. 1, fixed ends and movable end plates 2a, 2 are provided at both ends of an insulating cylinder 1 made of ceramics.
b is attached to form a vacuum container, and a shield 3 is arranged in the insulating cylinder 1. Movable end plate 2b
The movable lead bar 5b is hermetically pierced through the bellows 4, and a movable electrode 6b made of Cu is provided at the tip of the movable lead bar 5b. On the other hand, a fixed lead bar 5a is provided through the fixed side end plate 2a in an airtight manner, and a fixed electrode (Cu) 6a containing a welding resistant component is provided at the tip of the fixed lead bar 5a. Then, the fixed electrode 6a
The movable electrode 6b is provided with, for example, a plurality of arcuate radial slits. In such a configuration, the current is opened and closed by the movable electrode 6b being brought into contact with and separated from the fixed electrode 6a in a vacuum.

In this case, the fixed electrode 6a and the movable electrode 6b
The contact portion 12 is fixed to the electrode body (arc portion) 10 of this embodiment, and the contact portion 12 contains a low melting point metal as described above. Specifically, a metal such as Bi, Te, or Sb is contained in an amount of 10 to 20% by weight.

Further, the electrode body 10 and the contact portion 12 constituting the fixed electrode 6a and the movable electrode 6b have a structure as shown in FIG. 2, and are fitted into the recesses of the electrode body 10 and fixed by brazing. Contact portion 1 in the cup-shaped mounting member 13
2 is fitted, and the end portion 11 of the mounting member 13 is bent to fix the contact portion 12.

Here, the mounting member 13 has a uniform thickness and is appropriately selected in consideration of the durability required for the applied vacuum interrupter, for example, 0.5 mm to 2 m.
m is selected. Further, since the mounting member 13 is brazed to the electrode body 10, the brazing portion of the mounting member 13 may be made thicker and the bent end portion may be made relatively thinner.

Here, the mounting member 13 is made of a material which does not react with the low melting point metal (Bi, Te, Sb, etc.) of the contact portion 12 deposited by the heat load, in other words, the low melting point metal enters. It is made of a material that does not generate intermetallic compounds even if it does.

More specifically, the mounting member 13 is made of Cu--Cr.
Alloy, stainless steel, Cu-Ag alloy, Cu-
As a Cr alloy, Cu containing 0.1 to 5% by weight of Cr is used.
-Cr alloy, 0.5 to 1.0% by weight of Cr and 0.
A Cu—Cr—Zr alloy containing 15 to 0.25% by weight can be used. As stainless steel, austenitic SU
It is an S plate having different components of Ni and Cr and Mn.
SUS34 with different components such as being distinguishable depending on the presence or absence of
7, SUS304, SUS316, and Cu
Examples of the -Ag alloy include a Cu-Ag alloy containing 0.5 to 5% by weight of Ag.

The shape of the mounting member 13 is shown in FIG.
3 (a), a cylindrical ring-shaped mounting member 13 may be used as shown in FIG. 3 (a), or an L-shaped ring-shaped mounting member as shown in FIG. 3 (b). The member 13 may be used. In this case, the mounting member 13 is fitted in or around the concave portion of the electrode body 10, brazed and fixed, the contact portion 12 is fitted into the concave portion, and the protruding end of the mounting member 13 is bent to form the contact portion 12. The structure of fixing is the same as that of FIG.

Further, the tip of the protruding end portion 11 of the mounting member 13 is cut in a normal perpendicular direction as shown in FIG. 4A, and cut diagonally as shown in FIG. Then, it may be formed so that a step does not occur between the contact portion 12 and the bent portion.

Returning to FIG. 1, FIG. 1 shows a structure in which the contact portion 12 is fixed to the electrode body 10. The electrode body 10 is a spiral or disk-shaped arc diffusion portion. It may be of a structure that is directly fixed to the device.

The mounting member 13 in this embodiment is preferably provided on both the fixed and movable sides in view of the breaking current and welding characteristics, but may be provided on either the fixed side or the movable side. In this case, it is better to provide on the fixed side where only the compressive load at the time of closing the electrode acts than on the movable side where the reciprocating impact acts.

Here, an example of a method for forming an electrode will be described with reference to FIG. In forming the electrode, as shown in FIG. 5A, the cup-shaped mounting member 1 is inserted into the concave portion of the electrode body 10 with a brazing material interposed therebetween.
At the time of insertion of 3, a weight 20 is placed from above and brazed in a non-oxidizing atmosphere. Then, as shown in FIG. 5 (b), the contact portion 12 is fitted into the cup-shaped mounting member 13 of the electrode body 10 from above with a jig 21 and another jig 22 is operated from the lateral direction to mount the cup. End portion caulking portion 1 of member 13
1 is bent to the contact portion 12 side. Further, the jig 21 is operated to bring the end caulking portion 11 of the cup-shaped mounting member 13 into close contact with the contact portion 12 from above. Thus, the electrode shown in FIG. 5C is completed.

As a specific example of the actual formation of the electrode, when the size of the concave portion of the electrode body made of Cu having an outer diameter of 50 mmφ is 29 mm in inner diameter and 6.3 mm in depth, Bi1
8% by weight Cu contact portion 12 is attached to cup-shaped mounting member 13
When fitted inside, the contact portion 12 at the end of the mounting member 13
The contact portion was sufficiently fixed with an engagement margin of 2 mm and a caulking pressure of 2000 kgf.

In forming the vacuum interrupter, first, as an electrode, a mounting member is brazed and fixed to the electrode body, a contact portion is fitted into the mounting member, and a protruding tip of the mounting member is bent. Secure the contact. The electrodes are formed on the movable side and the fixed side shown in FIG. 1, and the fixed lead rod is airtightly penetrated through the fixed end plate, and the movable lead rod is also airtightly penetrated through the bellows of the movable end plate. Between the fixed end plate and the movable end plate and the insulating cylinder made of ceramic,
Ag plate brazing material is interposed, and wire brazing material or plate brazing material is interposed as appropriate for the other. Then, the vacuum interrupter is temporarily assembled, heated in a vacuum furnace, and heated to a temperature of 800 ° C. or higher (8
(40 ° C. to 860 ° C.) and then cooled in a vacuum furnace to obtain a vacuum interrupter.

More specifically, each of the obtained electrodes is mounted on the inner end of the lead rod together with a brazing material (Ag brazing), and the other components of the vacuum interrupter are temporarily assembled together with the brazing material (Ag brazing). Then, heating was performed in a vacuum furnace, and brazing was performed at a temperature of 840 ° C. for 10 minutes, and then cooled to 700 ° C. at which the Ag brazing material was solidified in 30 minutes. To cool the furnace to obtain a vacuum interrupter.

Table 1 shows a comparison of durability between the cup-shaped mounting member of the present invention and a conventional projection as a comparative example. The thickness of the cup-shaped mounting member, the margin of engagement of the end portion, and the mounting member are shown. Material is specified.

[Table 1]

As can be seen from the table, the durability is 10%.
% To 20%.

[0028]

As described above, according to the present invention, the contact portion is fixed at the electrode of the ceramic container via the mounting member made of a material that does not react with the low melting point metal, and the strength of the caulked portion is reduced. Thus, a durable vacuum interrupter could be obtained.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an example of a vacuum interrupter.

FIG. 2 is a cross-sectional configuration diagram of an electrode.

FIG. 3 is a sectional view showing a modification of the mounting member.

FIG. 4 is a cross-sectional view showing a modification of the cut surface of the mounting member.

FIG. 5 is a cross-sectional view illustrating a method for forming an electrode.

FIG. 6 is a cross-sectional view of a conventional electrode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electrode main body 11 End part 12 Contact part 13 Mounting member

Claims (5)

[Claims] At least one of a pair of current-carrying members, at least one of which can approach and separate via a bellows, in a vacuum vessel having a ceramic member, is provided with a contact portion at an inner end thereof, and is joined by brazing in a non-oxidizing gas atmosphere. At least one contact portion contains a low melting point metal, and a mounting member made of a material that does not react with the low melting point metal contained in the contact portion is brazed and fixed to the conductive member. A vacuum interrupter, wherein a part of a member is plastically deformed to surround and fix a contact portion. 2. The vacuum interrupter according to claim 1, wherein the current-carrying member is one of a lead rod and an electrode body. 3. The vacuum interrupter according to claim 1, wherein the mounting member has one of a cup shape and a ring shape. 4. The vacuum interrupter according to claim 1, wherein said mounting member is formed of one of a Cu—Cr alloy, stainless steel, and a Cu—Ag alloy. 5. The vacuum interrupter according to claim 1, wherein the low-melting-point metal is made of any of Bi, Te, and Sb and contains 10 to 20% by weight.