JPS58171541A - Contact material for circuit breaker - Google Patents

Abstract

PURPOSE:To obtain a contact material for a circuit breaker with superior resistance to the generation of reignition and superior blister resistance by restricting the Si content of an alloy as a contact material for a circuit breaker. CONSTITUTION:A contact material used in a vacuum circuit breaker having a fixed electrode and a movable electrode in a tightly sealed and insulated container is made of Cu-Bi, Cu-Te, Cu-Pb or cu- having S content restricted to 0- 10ppm. By the restricted S content, the generation of reignition from the contact material is reduced, and troubles such as blister and expansion can be prevented. Cu-Sb, Ni-Bi, Ni-Te, Ni-Pb or Ni-Sb may be used in place of said alloy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a contact material used, for example, in a vacuum breaker, and particularly to a contact material for a breaker with improved restriking characteristics and blistering resistance.

[Technical background of the invention and its problems]

In general, contact materials are subjected to various treatments such as forging, rolling, and various heat treatments in order to improve productivity and reliability. When a contact material made in this manner is evacuated and used for an interrupter, blistering or excessive expansion in the diametrical direction may occur during this manufacturing process, which may impede the manufacturing process. or,
Blistering is also considered to be a cause of the restriking phenomenon, and improvement of this phenomenon is desired.

[Purpose of the invention]

The present invention was made in order to improve the above-mentioned drawbacks, and an object of the present invention is to provide a contact material for a circuit breaker having excellent restriking characteristics and blistering resistance.

[Courtesy of invention]

The present invention provides a vacuum breaker having a fixed electrode and a movable pole in a sealed insulating container, and a contact material of the interrupter.
- B i r Cu - T e r Cu - P
b + Cu − S b * N i − B
i +Ni-T・, Ni-Pb. The above-mentioned object is achieved by being formed of any one of the Nl-Sb alloys and by setting the sulfur content in the alloy raw material to 0 to 10 ppm.

[Embodiments of the invention]

The present invention will be described below, but first, among the circuit breakers to which the present invention is applied, a vacuum interrupter that provides the most excellent effect will be described. Fig. 1 shows an example of a vacuum interrupter.
It is vacuum-tightly constituted by an insulating container 2 formed in a cylindrical shape and metal lids 4 and 5 provided at both ends of the insulating container 2 through sealing mechanisms 3 and 3'. In the above-mentioned interruption chamber l, there is a pair of electrodes 8 attached to opposite ends of the conductive electrodes 6 and 7.
, 9 are arranged, with the upper electrode 8 being a fixed electrode and the lower electrode 9 being a movable electrode. A bellows 10 is attached to the electrode rod 1 of the movable electrode 9, allowing the electrode 9 to reciprocate while keeping the interior of the breaker guide 1 vacuum-tight.

Further, the upper part of the bellows 1o is covered with a metal casso 11 to prevent the bellows 10 from being covered with arc vapor. Reference numeral 12 denotes a cylindrical metal container provided in the interruption chamber 1 to cover the electrodes 8 and 9, and an insulating container 2.
・Prevents being covered with arc vapor. Furthermore, as shown in the enlarged sectional view of FIG. 2, the electrode 9 is fixed to the conductive rod 7 by a brazed portion 13 or is crimped and connected by caulking. The movable side contact 14 is attached to the movable electrode 9 by a soldering part 15 or by caulking, Cu-B1 +Cu-Ts+Cu-Pb+Cu-
8b alloy, or Ni-B1.

It is made of N1-Te, N1-Pb, and Nl-8b alloys. The fixed @contact 14 is attached to the fixed electrode 8 by brazing or caulking.

The movable contact 14' and the fixed contact 14 can be manufactured as follows. Cu-BLCu-Te,
Vacuum degree 1o-5 for Cu-Pb and Cu-8b alloys
Torr, melt Cwt at a temperature of 1200°C, increase the pressure with argon gas, and add a predetermined amount of Bi, Te, Pb or sb.
It is obtained by applying the coloring and cooling it in a mold to solidify it. Ni-B1. For N1-To, Ni-Pb, Ni-8b alloys, vacuum degree 10-5T@rr, temperature 16
It is obtained by melting at 00 DEG C., increasing the pressure with argon gas, adding a predetermined amount of Bi, T., Pb, or sb't, and cooling and solidifying in a mold.

When processing and heat-treating the alloy obtained in this way, avoid sulfur-containing atmospheres (e.g. heavy oil combustion gas atmosphere, etc.), heat the alloy, remove surface oxides, and perform various heat treatments. Form 14f.

Next, sulfur was added to the Ct+-B1 alloy formed by the above manufacturing method, and the contact material made by greatly changing the sulfur blending ratio was used as the first contact material.
The test results for the tube assembled in the vacuum interrupter shown in the figure are shown in Table 1 as an example. In addition, as another example, Cu
-T alloy (sulfur = 3.6 ppm), Cu-Pb alloy (sulfur: 3.3 ppm), Cu-gb gold alloy sulfur: 3.2 ppm), Ni-Bi alloy (sulfur:
3.5 ppm), N1-To gold alloy sulfur: 2.4
ppm ), Ni-Pb alloy (sulfur: 2.OPP!!1
), Ni-sb gold alloy sulfur: 3 ppm) contact materials were also published at the same time. This test method includes a vacuum degree of I x 10-' Torr, a temperature of 1150°C for Cu alloys, and -r of 160°C for Ni alloys.
01: Comparison of the amount of H2S (hydrogen sulfide) released from the alloy after holding for 30 minutes, and measurement of blistering when alloy t810'c was heated in a hydrogen furnace after holding for 10 minutes.

In addition, to measure the probability of restriking, each disk-shaped sample with an outer diameter of 300φ was opposed to a machined iron having a spherical surface with an outer diameter of 30 fJφ and a tip of 100R, and was heated in a vacuum of 10-'Torr with a 6kV X 605A t-cut off 2000 times,
The probability was calculated from the number of restriking occurrences. As a result? It is shown in Table 1.

As is clear from ml&, when the sulfur content in the copper alloy is 10 ppra or less (Examples 1 to 3), the probability of restriking is approximately 1≦or less. When the sulfur content is 10 ppm or more (Comparative Examples-1 and 2), restriking tends to occur significantly frequently. Above Examples-1 to 3
, Comparative Examples 1 and 2 have B of about 0.4 fold'fi whisper on Cu.
Although it is a Cu alloy containing l', the tendency is for Cu to have T.
Contact material containing @i (Example-4), contact material containing pb'l (Example-5), contact material containing sbl (Example-6), and contact material containing N1KBl (Example-5) 7), contact material containing T@ (Example-8),
The same phenomenon was observed in the contact material containing pbl (Example 9) and the contact material containing 5bt (Example 10).

On the other hand, the degree of vacuum is 1X10 Torr, the temperature is 1150℃
, The amount of H2S (hydrogen sulfide) observed and measured during heating after holding for 30 minutes was 0.1 ppm or less of sulfur (Example-1),
3, 2 pprn (Example-2), 10 ppm (
In Example-3), it was about 0. When the sulfur content was 1ppm+ or less, several ppnl or more of H2S was observed when the sulfur content was more than 1ppm+ (Comparative Examples 1 and 2).

In this way, good agreement is observed between the sulfur 1 and the probability of restriking, and there is a clear correlation between the occurrence of the restriking phenomenon and the amount of sulfur or H2S contained.

Furthermore, each alloy after processing was subjected to a heat treatment (800'CX10mtn) simulating the manufacturing process of a vacuum interrupter,
When the occurrence of expansion was investigated, as is clear from Table 1, in Comparative Examples 1 and 2, in which the amount of H2S was large, expansion was observed to the extent that production was hindered.

According to the results of gas analysis, comparative examples 1 to 2 with significant expansion
0 alloy contains % B21 from Example-1 to 60 alloys.
It was found that H2s was present in a significantly large amount. Also, Cu-BiyCu-Ta+Cu-Pb+Cu-8b alloy, and Ni-B1, N1-T., Ni-Pb, N1
It is recognized that B28 in the -8b alloy is released when heated above 800 to 900°C, and it is combined or dissolved in the alloy during normal baking of vacuum pulp at 400 to 600°C. There is. For example, in Comparative Examples 1 and 2 containing a large amount of sulfur, it exists as H2S, and during the brazing process, which is carried out at around 800°C, some H scales off during the process and combines with O in the alloy, resulting in H2O? While forming and developing into expansion, some H2S is believed to be involved in triggering the restriking phenomenon when discharged by an instantaneous arc. Therefore, it is necessary to reduce the amount of sulfur in the alloy as much as possible. [Effects of the Invention] As is clear from the above, according to the present invention, the contact material Cu
-B i , Cu-To * Cu-Pb + Cu-
8b alloy, Ni-B1°N1-T・, N1-Pb, Ni
Since the sulfur content in any one of the -8b alloys is 0 to 10 ppm, we provide a contact material for a circuit breaker that can reduce the occurrence of restriking and prevent problems such as blistering and expansion. can.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view showing the structure of a vacuum interrupter to which the present invention is applied. DESCRIPTION OF SYMBOLS 1... Interruption chamber, 2... Insulating container, 8... Fixed electrode, 9... Movable electrode, 6.7... Conductive rod, 10...
・Bellows, t 4'--Fixed side electrode contact, 14'-
...Movable side electrode contact.

Claims (1)

[Claims] (1) A contact material for a circuit breaker made of an alloy containing 0 to 10 ppm of sulfur. (2. The alloy described in claim 1 is Cu-Bl
. Cu-Tl, Cu-Pb, Cu-8b, Ni-
B i , N i -Tl , Ni-11Jh2Ni-
8b. A contact material for a circuit breaker, characterized by being one of the following.