JPS5855606B2 - vacuum interrupter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum interrupter with improved withstand voltage.

In general, the following measures can be taken to improve the withstand voltage of vacuum interrupters.

First, the shield member installed in the vacuum container of the vacuum interrupter is made of copper, nickel, or stainless steel, and its shape is rounded to avoid creating an acute angle at the tip of the member. degassing treatment in a vacuum.

In addition, depending on the purpose of use, materials such as vacuum melted copper with as little internal residual gas as possible may be used for the electrode members, such as Cu-W.
Thread material is used, its shape is formed so as to eliminate acute corners as described above, and the treatment is to perform degassing treatment in a vacuum as described above.

However, recently, vacuum interrupters have been made to have ultra-high voltages and large capacities, but even if the above-mentioned means are used to satisfy these demands, it is not possible to obtain sufficiently satisfactory results.

Therefore, one way to make the vacuum interrupter extremely high-voltage is to appropriately select the setting of the gap between the electrodes and the setting of the gap between the lead rod including the electrode, which is the conductive part, and each shield.

The interelectrode gap length is in the axial direction of the vacuum interrupter,
The gap length between each shield and the lead rod including the scraped electrode is adjusted in the radial direction of the vacuum interrupter.

Generally, a vacuum interrupter is housed in an insulator for the purpose of strengthening the dielectric strength of the outer surface, and a medium such as SF6 gas or insulating oil is sealed in the insulator.

By using this method of housing the vacuum interrupter in the insulator, even if the vacuum interrupter is lengthened in the axial direction as described above, the axial direction of the insulator can be changed relatively freely, and this also reduces the weight increase. The impact of price etc. is small.

However, if the radial direction of the vacuum interrupter is increased as described above, there arises the disadvantage that the weight of the insulator increases significantly and the price also increases sharply.

Note that between the interelectrode gap l and the withstand voltage V, yO(1
It has been experimentally confirmed that there is a relationship of 0°5 to 0°75, and that the withstand voltage V improves as the gap length l increases.

FIG. 1 is a characteristic diagram showing the experimental results of the interelectrode gap l and the withstand voltage V.

Therefore, an ultra-high voltage ratio is possible depending on the length of the inter-electrode gap.

However, the shield is placed concentrically with the insulating material such as glass or ceramic, which is the container of the vacuum interrupter, and is placed intermediate between the lead rod and the insulating material such as glass. becomes susceptible to the withstand voltage of insulating materials such as glass.

Figure 2A shows the glass rod GB and the stainless steel shield S1.
This is a schematic diagram of a structure in which the shields S2 and S2 are integrated in a vacuum.
is applied, and the shield S1. When the withstand voltage characteristics are measured while changing the gap length l of S2, the characteristics are as shown in FIG. 2B.

From this Fig. 2B, it is found that between the withstand voltage ■ and the gap length l,
(2) Obtain the relationship between lO°25 and 035.

From this relationship, the gap effect is significantly smaller than when no glass is interposed (in the case of FIG. 1), and even if the gap length is increased somewhat, the withstand voltage does not improve at all.

Therefore, in order to achieve ultra-high voltage in a vacuum interrupter, it is not possible to obtain an ultra-high voltage interrupter simply by increasing the gap between the electrodes in addition to material selection; It will also have to be made larger in the direction.

For this reason, as described above, the vacuum interrupter inevitably becomes larger and weighs more.

In order to eliminate the above-mentioned drawbacks, this invention plated the entire shield, the tip of the shield, the residue, or the tip of the current-carrying part with a relatively low withstand voltage with at least one metal selected from beryllium, boron, and carbon. The object of the present invention is to provide a vacuum interrupter which improves the withstand voltage by surface treatment using methods such as the above, and which enables ultra-high voltage using a vacuum vessel having the same structure as the conventional one.

An embodiment of the present invention will be described below with reference to the drawings.

In Figure 3, 11 is a vacuum container, and this vacuum container 11
is formed from glass insulating cylinders 12, 13i and fixed and movable flanks 4, 15.

16 is a fixed electrode, 17 is a movable electrode, both electrodes 16.17
Fixed and movable contacts 18, 19 are provided on opposite sides of.

Reference numeral 20 denotes a fixed lead rod, one end of which is fixed with a fixed electrode 16, and the other end led out to the outside via a fixed flange 14.

Reference numeral 21 denotes a movable lead rod, one end of which is fixed to the movable electrode 17, and the other end led out to the outside via a bellows 22 attached to the movable flange 15.

23 is a main shield disposed along the inner circumferential wall surface of the glass insulating tubes 12 and 13; 24; 25 is a shaft shield button and a bellows shield fixed to the fixed and movable lead rods 20 and 21; 26° is 2γ. is a fixed and movable flange 14
．． This is an outer shield fixed to 15.

A conductive lath plate 30.31 is connected to the outside of the fixed and movable lead rod 20.21 via current collecting contacts 28 and 29.

All or a part of each shield, etc. of the vacuum interrupter having the above configuration, for example, parts a to j (bold line part in the diagram) shown in the figure, have a tendency to be lighter and harder than copper and iron-based metals, and have melting points and boiling points equal to or higher than those of copper and iron-based metals. When voltage is applied to the interrupter,
Materials that can prevent voltage drop due to the influence of electron, Surface treatment of metal by plating, etc.

The optimal amount of surface treatment at this time is about 2 to 30 μm.

By surface treatment in this way, the lead rod 20°2
Between 1 and shields 23 to 25, between shield 23 and shield 2
6.27, the withstand voltage of shields 23, 26, 27, etc., which are close to glass, ceramics, etc., is dramatically improved.

Therefore, it can withstand an extremely high voltage compared to an interrupter having the same structure as a conventional interrupter.

As an example, when the structure shown in FIG. 2A was treated with Be in an experiment in which the stainless steel surface was electroplated, an improvement in withstand voltage of approximately 1.5 to 2 times was obtained.

Figure 4 is a cross-sectional view of a vacuum interrupter that can withstand relatively high voltages. By using the same metal as in the previous embodiment and surface-treating this interrupter, it can be sufficiently applied to ultra-high voltages. .

In addition, in Fig. 4, 32 and 33 are inner shields, and 34
35 is an intermediate shield 36, and 37 is an inner shield supporting insulator, and the same parts as in FIG. 3 are designated with the same reference numerals.

As described above, according to the present invention, at least one of Be + By C, which is a metal with a small number of electron orbits and a small orbital energy, is applied to the surface of a member that requires a withstand voltage inside the container of a vacuum interrupter. Since one type of metal is applied, even if electrons and photons rush into the metals such as Be, B, and C, the generation of electrons and photons will be extremely small, and the withstand voltage will not deteriorate when cut off. , the current can be cut off reliably at the zero point, and the withstand voltage during dynamic operation can be dramatically improved, and ultra-high voltage can be easily achieved without increasing the size or weight. Moreover, it has the advantage that the interrupter can be extremely miniaturized if the same withstand voltage as the conventional one is obtained.

[Brief explanation of the drawing]

Figure 1 is a characteristic diagram showing withstand voltage characteristics with respect to electrode gap length, Figure 2A is an experimental configuration diagram when the glass rod and shield are integrally formed, and Figure 2B is Figure 2A. FIG. 3 is a sectional view showing an embodiment of the present invention, and FIG.
The figure is a sectional view showing another embodiment of the invention. 11... Vacuum container, 16... Fixed electrode, 17...
Movable electrode, 18... Fixed contact, 19... Movable contact,
20...Fixed lead rod, 21...Movable lead rod, 2
3... Main shield, 24... Axis shield, 25...
・Bellows shield, 26.27...outer shield, 3
2.33...Inner shield, 34,35...Middle shield.

Claims (1)

[Claims] 1. Contacts that can be relatively detached and contacted are arranged in a vacuum container, and on the surface of a member in the container that requires a withstand voltage,
A vacuum interrupter characterized by being coated with at least one metal selected from beryllium Be, boron B, and carbon C. 2. The vacuum interrupter according to claim 1, wherein the members include shields or current-carrying parts for each part within the vacuum container.