JPS58103717A - Combination electric contact - 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 invention relates to improvements in combination electrical contacts.

Recently, with the development of electrical and electronic technology, various electrical and electronic devices (1) 73- have become smaller, and relays, breakers,
Mechanical parts such as magnetic switches are also becoming smaller.

However, when these mechanical parts are miniaturized, the contact gap becomes narrower, and the ability to block arc discharge becomes worse. In other words, the problem arises that the arc cannot be cut. Further, there is a problem that the contact force 5 of the electrical contact and the separation force become small, making it easier for welding to occur.

For this reason, there is a demand for a combination electrical contact that has good arc-blocking properties and excellent welding resistance, and various combination electrical contacts have been developed, but so far none have been satisfactory.

Traditionally, combination electrical contacts have been made of silver-metal oxide contacts with a metal oxide dispersed in the chain, or contacts made of a silver-refractory metal system. Among these, many combination electrical contacts are used, in which contacts made of a silver-tin oxide alloy are placed facing each other.

This is because the welding resistance of silver-tin oxide is stable and excellent, but on the other hand, tin oxide tends to aggregate, and the layer rich in silver and the layer rich in acid(2) oxide coagulate, respectively. There was a drawback in that gentle unevenness was formed on the contact surface, resulting in a narrow contact gap (which resulted in poor arc blocking performance, and in extreme cases, the arc could not be blocked).Also, contacts made of silver-nisokel system Combination electrical contacts in which the contacts face each other are also frequently used.This is because silver-nisokel based electrical contacts wear out uniformly, have little wear, have excellent arc resistance, and have stable contact resistance. However, silver-nisokel type electrical contacts have the disadvantage that their welding resistance varies widely and the fields of use are therefore limited.

In this way, conventional combination electrical contacts use the same electrical contact material for the opposing fixed and movable contacts, so they have good welding resistance but poor arc blocking properties, and conversely, they have good arc blocking properties but have poor arc blocking properties. There were problems such as poor welding resistance.

Therefore, the inventors of the present invention have worked hard to develop a combination electrical contact with excellent arc interrupting properties (and excellent welding resistance) even in miniaturized mechanical parts. (3) Welding resistance is achieved by using different contact materials at the points.

It has been found that arc blocking performance can be improved.

The present invention has been made with attention to this point, and is a combination electrical contact that can reliably improve welding resistance and arc interrupting properties, and is a combination electrical contact that is formed by opposing a silver-tin oxide contact. It provides:

The combined electrical contact according to the present invention includes a silver-tin oxide contact containing 2% to 15% of tin by weight in opposing contacts, and 5 to 10% of nickel by weight, tungsten, chromium, molybdenum, tungsten carbide, At least one of chromium carbide, molybdenum carbide, tantalum, zirconium, and titanium
It is characterized by using a silver-nickel contact containing a total of 0.5 to 4% of seeds.

The reason for limiting the materials for the opposing contacts in the present invention as described above is to take advantage of the excellent welding resistance of the silver-tin oxide system and to
Taking advantage of the good arc-blocking properties of the Nisokel series, the synergistic effect of these eliminates the poor welding resistance and poor arc-blocking properties of conventional electrical contacts made of the same material and facing each other (4). It is for the purpose of In addition, the content of tin in silver-tin oxide system is 2% to 1.
The reason for limiting it to 5% is that if it is less than 2%, the welding resistance is insufficient, and if it exceeds 15%, there is no problem with the welding resistance, but the amount of tin oxide that collects on the contact surface increases. This is because contact resistance increases. Within the above range, a small amount of zinc + lead + one or more of germanium, bismuth, zirconium, and iron group may be added to silver-tin oxide.
This property is not inhibited even if i~1°0% is added. Furthermore, 5 to 10% of nickel in the silver-di-nokel system was used.
This is because if it is less than 10%, the arc breakage resistance will be extremely poor, and if it exceeds 10%, the contact resistance will become unstable. and tungsten, tungsten carbide.

The reason why at least one of chromium carbide, molybdenum carbide, tantalum, zirconium, and titanium is added in a total amount of 0.5 to 4% is to improve the welding resistance.

Next, in order to clarify the effects of the combined electrical contact according to the present invention, a specific example and a conventional (5) example will be described.

[Example 1] A 516tm fixed contact made of silver-tin oxide containing 7.3% tin and a 4φn movable contact made of silver-nickel-tungsten carbide containing 5% nickel and 2.5% tungsten carbide were compared. Roughly aligned electrical contacts were constructed.

[Example 2] 5≠Dragon fixed contact consisting of silver-nisokeru-chromium carbide-molybdenum carbide containing 8% nickel and 0.5% tungsten carbide and silver-oxide containing 9.3% tin and 0.6% germanium An electrical contact was constructed by combining a 4φ crane movable contact made of tin-germanium oxide and facing each other.

[Example 3] Fixed contact of 5fw made of silver-2.2-kel-chromium containing 10% di-nokel and 0.5% chromium and silver-tin oxide containing 7.3% tin and 0.8% bismuth. - A 4ψ movable contact made of bismuth oxide was placed facing each other to form an electric contact.

(6) [Conventional Example 1] A fixed contact of 5≠lI and a movable contact of 4≠1 m were made of silver-nickel containing 10% nickel, and were combined to form an electric contact by facing each other.

[Conventional Example 2] Fixed contacts of 5≠Tsuru and 4ψ made of silver-tin oxide containing 7.3% tin.
We made movable dragon contacts and put them facing each other to form an electric contact.

However, when nine sets of electrical contacts of each combination were subjected to a welding resistance test and the arc interruption time at the time of interruption was measured according to the following test regulations, the following results were obtained.

Welding resistance test conditions Voltage AC100V 502 input current
40A Breaking current 10A Opening/closing frequency 20 times/min Contact force 40g Breaking force 40g Number of opening/closing Measurement conditions for arc duration when breaking until welding occurs (7) DC24V 3A Contact gap before Hatake type test 0.7m11 Breaking speed
5cm/5ec (8) As is clear from the above table, the combined electrical contact of the present invention, in which a silver-tin oxide thread contact and a silver-nickel base contact are opposed to each other, is said to have exceptionally good welding resistance. Conventional silver
Combination of tin oxide based contacts facing each other The conventional silver-nickel based contacts are said to have excellent welding resistance equal to or better than electrical contacts, and have good arc blocking properties. Shows arc interrupting properties equivalent to a pair of electrical contacts facing each other.

As detailed above, the combined electrical contact of the present invention has exceptionally excellent welding resistance and arc interrupting properties, so when it is miniaturized and used in I-circuit breakers, magnetic switches, etc.
It has the effect of suppressing the occurrence of welding and ensuring arc interruption.

Applicant: Tanaka Kikinzoku Kogyo Co., Ltd. (9) 75

Claims (1)

[Claims] (1) Silver-tin oxide contacts containing 2% to 15% tin by weight, 5% to 10% nickel by weight, tungsten,
Chromium, molybdenum, tungsten carbide, chromium carbide,
A combination electrical contact comprising at least one of molybdenum carbide, tantalum, zirconium, and titanium and a silver-nisokel type contact consisting of a total of 0.5 to 4% balance silver, facing each other. (2. In the combined electrical contact set forth in claim 1, a portion of tin is zinc, lead, and germanium in a range of 0.01 to 1.0% by weight. Bismuth, zirconium, and iron group elements. A combination electrical contact characterized by being replaced with one or more types of .