JPS5851429A - Vacuum interrupter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present WAFi relates to a vacuum ink clutter whose vacuum container is composed of a metal container and an insulating end plate, and particularly relates to an auxiliary fitting interposed between a metal cylinder and an insulating end plate. be.

A conventional vacuum interrupter is generally constructed as shown in FIG.

That is, at both ends of the insulating cylinder 11 made of glass or alumina ceramic, for example, F.--Ni-Oo or y.-N is applied.
1, the metal end plates n and 13f are hermetically brazed to form the required vacuum vessel 1, and one of the metal end plates 12 is provided with a fixed electrode rod 14'i that penetrates through the air. A fixed contact 15 is provided at the inner end, and the other metal end plate 1
3, a movable electrode rod 16 is provided airtightly through a bellows 1st so as to be movable in the vertical direction in the figure, and a movable contact 17 is provided at the inner end thereof. 15 to switch on and off the current.

By the way, the vacuum container 1 of the vacuum interface container as shown in FIG. I studied while I was becoming something.

For this reason, the cylindrical part forming the vacuum container 1 is made of a metal container, and the end plate is made of an insulating material to reduce the price.IIf! , a vacuum interrupter as shown in Figure 2 has been proposed.

That is, in the vacuum interrupter shown in FIG. 2, a vacuum container 1 is formed by interposing ring-shaped auxiliary fittings 4 at both ends of a cylindrical metal container 2 and providing insulating end plates 3a and 3b made of an insulating material. It is.

Here, metal container 2 and IIi! ! The reason why the auxiliary fitting 4 is interposed between the edge plates 3a and 3b will be explained below.

When the insulating end plates 31 and 3b are made of alumina ceramic, for example, the metals to be joined by brazing are as follows:
Fe-Ni-0o or Fe-N with similar coefficient of thermal expansion
i is used because there is no peeling due to thermal stress,
It is common because it allows airtight brazing. However, if the metal container 2 is made of this type of metal, it is not possible to join the insulating end plates 3a and 3b by brazing, since this type of metal is very expensive. Manufacturing the metal container 2 by this method is contrary to the purpose of reducing the cost of the vacuum interrupter.

Therefore, we investigated whether it was possible to perform reliable airtight brazing with metals that have a coefficient of thermal expansion greater than that of alumina ceramics, and found that during brazing, metals are sometimes heated to high temperatures that soften them, and then during cooling. By slowly cooling the metal container 2 made of this metal and plastically deforming the vicinity of the joint with the insulating end plates 3a and 3b by thermal stress, the thermal stress caused by the difference in the coefficient of thermal expansion can be buffered, and the brazing It was found that this did not affect the joints and did not cause any cracks such as peeling. For this reason, there are various metals that can be used, but copper, iron, and stainless steel are preferable in terms of cost, vacuum characteristics, workability, etc.

However, when the metal container 2 is made of copper,
Although brazing with the insulating end plates 3a and 3b is preferable from the point of view of joining, this 111m is difficult to connect to the pair of insulating end plates 3a and 3b because brazing tends to become pure at the heating temperature, which reduces mechanical stress. In order to withstand repeated opening/closing operations of the fixed and movable contacts 15 and 17, the wall thickness must be considerably thicker, resulting in a problem of being heavy and expensive.

On the other hand, when forming the metal container 2 from iron or stainless steel, the material itself has mechanical strength compared to copper, so it can be formed into a metal container with a thinner wall compared to copper. However, if the insulating end plates 3a and 3b are joined by brazing to the insulating end plates 3a and 3b with that thickness, the thermal stress due to the difference in coefficient of thermal expansion cannot be buffered by the m-type deformation, and as a result, the brazing causes peeling at the joint. There's a problem. However, it is extremely thin (for example, 11al columnar degree)
If it is made, thermal stress can be buffered by plastic deformation, but if it is extremely thin like this, it cannot withstand repeated impacts during opening and closing operations.

For the above reasons, the metal container 2 is made of steel or stainless steel, and is brazed to the insulating end plates 3a and 3b made of alumina ceramic through the auxiliary fitting 4 made of copper. .

As shown in FIG. 3, the auxiliary fitting 4 is provided with a notch 4a that is long in the axial direction and shallow in the radial direction on the outer circumferential side located at the insulating end plate 3b@, so that the notch 4a is plastically deformed due to thermal stress. It is thought that this occurs mainly in this area. In addition, in Fig. 3, brazing shows the previous conditions, and what is the symbol 31 in these -?
This is a metallized layer applied to the surface of the end plate 3b.

However, brazing is not possible with the inner diameter d of the auxiliary fitting 40 (the third
Figure #1) is heated to a high temperature that softens this subsidy 744, so that the inner diameter becomes 6-* d 1 ((11>(
1) Expands.

However, after brazing, the inner diameter of the joint with the insulating end plate 3b is limited by the shrinkage of the insulating end plate 3b.
It can only contract up to 6<eLs<(11). Of course, it is possible to return to the original inner diameter 'd after leaving this joint (see Figure 4).

For this reason, in the vicinity of the joint, d, −(1=Δ
d is generated, and this stress is buffered by the plastic deformation of the auxiliary metal fitting 4. However, the plastic deformation due to the thermal stress is not effectively carried out at the notch 4a, and the auxiliary metal fitting 4 The entire structure may be deformed, giving a bad shape w to the joint with the metal container 2, and furthermore, since the auxiliary fitting 4 is cylindrical, the joint with the insulating end plate 3b is subject to stress that occurs in the radial direction (C plane direction). σB and the stress σb generated in the direction of deformation in the joint part and in the direction of peeling off the auxiliary fitting 4, and the joint part is particularly vulnerable to the stress of σb, causing peeling and cracking, resulting in vacuum leakage.

In addition, when the auxiliary fitting 4 is made of re-Ni-Oo7 Fe-Ni alloy, the coefficient of thermal expansion is close to that of alumina ceramic, so although there is little residual stress due to the difference in coefficient of thermal expansion, There was a risk that the impact caused by the opening and closing of the pair of contacts would cause peeling and cracks at the joint.

The present invention has been made in view of the above points, and includes bending one end in the axial direction to form a crack portion located in the radial direction, and also forming a curved outer surface of the bent portion to form an auxiliary metal fitting. The flange part is joined to the insulating end plate by #f brazing. The object of the present invention is to obtain a vacuum interrupter that does not have any adverse effects such as peeling or cracking, especially on the joint between an auxiliary fitting and an insulating end plate, is free from vacuum leakage, and is highly durable.

Next, an embodiment of the present invention will be described with reference to the vacuum interrupter shown in FIG. 5 and FIGS. 6 to 14, which are detailed views of section B in FIG. 5. In addition, in Fig. 5, the above-mentioned first
Components denoted by the same reference numerals as those in FIG. 2 and FIG. 2 are equivalent products, and detailed explanations thereof will be omitted.

In FIG. 5, 2 is a cylindrical metal container with an open inner end in the lateral direction, and is made of 8US or Fe. Reference numeral 4 denotes a ring-shaped auxiliary metal fitting that completely joins the metal container 2 and the insulating end plates 3a and 3b made of alumina ceramic.
IJi, also 1. (It is made of Cu. This auxiliary metal fitting 4um6 is constructed as shown in Fig. 6.

That is, this auxiliary metal fitting 4 consists of a crack part 41 located on the radially inward side, an inclined part 42, and a cylindrical part 43,
The curved portion 4 is located between the crack portion 41 and the inclined portion 42.
4, it is bent at an α angle & (90 degrees or more), and the outer surface side of the curved portion is formed to be a curved surface.

In this auxiliary fitting 4, an X-shaped cylindrical portion 43 is connected to the metal container 2, and a flange portion 41 is brazed between insulating end plates.

In the present invention, the flange portion 41 of the auxiliary fitting 4
and slope tl + city C, there is
This song s44 effectively prevents the adverse effects of thermal stress.

In other words, the heat of the auxiliary metal fitting 4! #If the elongation is greater than that of the insulating end plate made of aluminum ceramic, the auxiliary fitting 4 will try to shrink to its original size by brazing and joining, but its contraction will be regulated by the insulating end plate. At the joint, a stress σB directed inward in the radial direction is generated as shown in FIG.

However, the cylindrical portion and the inclined portion 42 of the auxiliary fitting 4
#: t, since it can be contracted to its original size by collapsing in the direction shown by the arrow X in FIG. Since the curved portion 44Fi contracts with the border of the curved portion 44Fi in FIG. Airtight brazing has the least negative effect on the effect, and brazing generates a stress σb in a direction that intersects the joint surfaces and in a direction that peels off the crack portion 41. However, the magnitude of the stress σb is extremely small because the curved portion 44 is provided continuously in the flange portion 41 that is joined by soldering for several seconds.

In addition, since the auxiliary metal fitting 4 is provided with the curved portion 44, it is easily deformed, and each stress σ8 generated as described above is
．． σ8', σb, and σC are much smaller, and a vacuum interrupter with high durability without peeling or cracking at the joint can be obtained.

Next, FIGS. 8 to 14 show other embodiments of the auxiliary fitting 4 according to the present invention.

First, the auxiliary metal fitting 4 shown in FIG.
and 45 to form a figure 8 shape, which is 1+, intended to further reduce stress and facilitate plastic deformation.

#! In the auxiliary metal fitting 4 shown in FIG. 9, a large single curved portion 44 is formed between a 7 flange portion 41 located on the inner side in the radial direction and a cylindrical portion 43.

The auxiliary fitting 4 shown in FIG. 10 includes seven radially inward flange portions 41 and 46, which are connected at a weakly curved portion to form a substantially U-shaped cross section.

Next, the auxiliary metal fitting 4 #i shown in FIGS. 11 to 14, and the auxiliary metal fitting 4 shown in FIGS. 6 and 8 to 10 described above.
The flange portion 41 of FIG. The auxiliary metal fitting 4 in FIG. 12 is replaced with the auxiliary metal fitting 4 in FIG. 8, the subsidy 744 in FIG. Since each of them is a priest, explanation of these structures will be omitted.

In the auxiliary fitting 4 shown in FIGS. 11 to 14, the curved member continuous with the flange portion 41 is located on the inward side, so for example, as shown in FIG.
Since it can be contracted in the direction of the three-company arrow Y to its original dimensions, stress is generated in the bending area in the direction of widening the bending, and airtight brazing has the most negative effect on the effectiveness. In gluing, stress #bFi in the direction crossing the bonding surface is rarely generated.

As is clear from the above description, in the present invention, the auxiliary fitting 4 has seven radially positioned flange portions 41 that are brazed to the disconnected end plate 3a (3b), and seven radially located flange portions 41 that are brazed to the disconnected end plate 3a (3b). Part 4
Since the curved portion 44 is continuous with the curved portion 44, the stress #b in the direction of peeling off the joined flange portion 41 from the insulating end plate 3a (3b) during brazing is extremely low. Since the wire is easily plastically deformed due to the presence of the curved portion 44, this stress σbH becomes even smaller, which solves the problem of peeling of the joint or cracking during brazing. This makes it possible to improve the durability of airtight brazing.

Historically, the auxiliary metal fittings 4 shown in FIGS. 11 to 14 have been formed such that the flange portion 41 is located on the outer side in the radial direction and the curved portion 44 is located on the inner side. In addition, the stress σb for peeling off the 7 flange portion 41t of the auxiliary fitting 4 is even smaller, and the durability is further improved.

In addition, since the auxiliary metal fitting 4 is equipped with a curved part 44, it can absorb the impact caused by the opening and closing of the pair of contacts, and brazing will not have a negative impact on the joint, and the highly durable vacuum There are 4 interrupters that can be obtained.

The vacuum inverter according to the present invention as described above has insulating end plates 3 at both ends of the cylindrical metal container 20.
- Although the vacuum container 1 has been described as being equipped with the metal container 2, the present invention is not limited thereto. A vacuum interrupter formed by forming a vacuum container with a plate can also be implemented in the same manner, and the same effect can be achieved.

[Brief explanation of the drawing]

181 and 2 are front sectional views of a conventional vacuum intambuter, and FIGS. 3 and 4 are section A of FIG.
FIG. 5 is a front sectional view of a vacuum interrupter according to an embodiment of the present invention, and FIGS. 6 and 7 are enlarged detailed views of before and after brazing. FIGS. The enlarged detailed views of FIGS. 8-914 are cross-sectional views of main parts of other embodiments of the present invention. 1...Vacuum container, 2...Gold jII reactor, 3a, 3b
...Insulating end plate, 4...Auxiliary fitting, 41...Flange part, Shrine...Curved part. Figure 1 Figure 2 Figure 3 Figure 4 Figure 9 Figure 1 Figure 1 Figure 12 Figure 13 Figure 14

Claims (1)

[Scope of Claims] (1) A metal container having an opening in at least one location, an insulating end plate made of ceramic that airtightly closes the opening of the metal container, and a spinning container. and a ring-shaped auxiliary fitting interposed between the insulating end plate, and a pair of grade points that can be freely moved in and out of the armpit vacuum container, The ring-shaped auxiliary fitting is configured such that at least one end in the axial direction of the auxiliary fitting is bent and has a clutter portion positioned in the radial direction, and the outer surface of the bent portion is directed toward @t-, A vacuum interrupter characterized in that the clutter portion t of a metal fitting is airtightly brazed to the insulating end plate. (b) The vacuum interrupter according to claim 1, characterized in that the clutter portion of the auxiliary fitting is oriented outward in the radial direction, and the curved portion is directed inward. (3) A vacuum interrupter according to claim 1, characterized in that the deviating clutter portion of the auxiliary fitting is directed inward in the radial direction, and the curved portion is directed outward.