【発明の詳細な説明】[Detailed description of the invention]
本発明は組み合わせ電気接点の改良に関する。
近時、電気、電子技術の発展に伴い各種電気、
電子機器が小型化され、それに応じてリレースイ
ツチも小型化されている。
然し乍ら、リレー、スイツチ等が小型化される
と、沿面距離や絶縁距離がとりにくくなる。つま
り絶縁抵抗や耐電圧の劣化を招くという問題が生
じる。また電気接点の接触力、開離力が小さくな
つて、溶着が起き易くなるという問題や接触抵抗
や温度上昇が高くなるという問題が起きる。なお
温度上昇については接触抵抗と比例の関係にあ
る。
この為、耐消耗性にすぐれた材料を使用し、絶
縁抵抗、耐電圧劣化を防ぎ、又接触抵抗、温度上
昇が低く安定、かつ耐溶着性に優れた組み合わせ
電気接点が要望され、種々の組み合わせ電気接点
の開発がなされているが、今だ満足すべきものが
ない。
従来、組み合わせ電気接点にはAg中に金属酸
化物を分散したAg−酸化物より成る接点が用い
られ、その中でもAg−SnO2−In2O3−Bi2O3より
成る接点同志を対向させた組み合わせ電気接点
は、Ag−CdOより成る接点同志を対向させた組
み合わせ電気接点に比し耐溶着性、耐消耗性が優
れているが、開閉中にSnO2が凝集し接触抵抗が
が不安定なものである。またAg−CdOより成る
接点同志を対向させた組み合わせ電気接点は、低
接触力でも接触抵抗が低く安定しているが、Ag
−SnO2−In2O3−Bi2O3に比し、耐溶着性、耐消
耗性に劣るものである。
このように従来の組み合わせ電気接点は、相対
向する固定接点と可動接点に同じ電気接点材料を
用いていたので、耐溶着性、耐消耗性は良いが、
接触抵抗の安定性が悪かつたり、また逆に接触抵
抗の安定性は良いが耐消耗性、耐溶着性が悪い等
の問題があつた。そこで本発明は、小型化された
リレー、スイツチ等に於いても接触抵抗の安定性
が良く、耐消耗性、耐溶着性に優れた組み合わせ
電気接点を開発すべく鋭意攻究の結果、相対向す
る固定接点と可動接点に異なる接点材料を用いる
ことにより耐溶着性、耐消耗性及び接触抵抗の安
定性が向上し得ることを見い出した。
本発明はこの点に着目してなされたものであ
り、耐溶着性、耐消耗性及び接触抵抗の安定性を
確実に向上させることのできる組み合わせ電気接
点として、Ag−SnO2−In2O3−Bi2O3系の接点と
Ag−CdO系の接点とを相対向させて成る組み合
わせ電気接点を提供せんとするものである。
本発明による組み合わせ電気接点は、相対向す
る接点にSn3〜７重量％、In0.5〜３重量％、
Bi0.1〜３重量％含むAg−SnO2−In2O3−Bi2O3
系の接点とCd10〜20重量％を含むAg−CdO系の
接点を用いたことを特徴とするものである。
本発明の組み合わせ電気接点に於いて、上記の
如く相対向する接点の材料を限定した理由は、
Ag−SnO2−In2O3−Bi2O3系の優れた耐溶着性、
耐消耗性を生かし、またAg−CdO系の接触抵抗
の安定性を生かし、これらの相乗効果により従来
の同じ材料の接点を相対向させた組み合わせ電気
接点に於ける劣悪な耐溶着性、或いは耐消耗性、
接触抵抗の安定性の悪さを解消する為である。ま
たAg−SnO2−In2O3−Bi2O3系のSnの含有量を３
〜７重量％と限定した理由は、３重量％未満では
Biとの相乗効果での耐溶着性が不充分であり、
７重量％を超えると耐溶着性には問題がないが、
開閉中にSnO2が凝集し、接触抵抗が極度に高く
なるからである。Inを0.5〜３重量％と限定した
理由は0.5重量％以下では耐溶着性向上の効果が
なく、３重量％以上では接触抵抗が高くなるから
である。Biについて0.1〜３重量％と限定した理
由は、0.1重量％以下では耐溶着性向上効果がな
く、３重量％を超えると耐消耗性が極度に劣化す
るからである。上記成分範囲内であればNiを0.1
〜0.5重量％添加しても特性は阻害されないもの
である。
Ag−Cd系のCdの含有量を10〜20重量％と限定
した理由は、10重量％未満では耐溶着性が極端に
悪くなり、20重量％を超えると接触抵抗が高くな
り、寿命が短かくなるからである。上記成分範囲
内であればNiを0.1〜0.5重量％添加しても特性は
阻害されないものである。
尚、本発明の組み合わせ電気接点における接点
の材料として使用するAg−SnO2−In2O3−
Bi2O3、Ag−SnO2−In2O3−Bi2O3−NiO、Ag−
CdO、Ag−CdO−NiOは、Ag中にSnO2、In2O3、
Bi2O3、NiO、CdOが細かく分散してさえいれ
ば、内部酸化法、粉末冶金法、内部酸化法と粉末
冶金法の併用等のいずれの方法によつて作られた
ものでも良いものである。
次に本発明による組み合わせ電気接点の効果を
明瞭ならしめる為にその具体的な実施例と従来例
について説明する。
実施例 １
Cd11重量％を含むAg−CdOより成る5φmmの固
定接点と、Sn4.5重量％、In1重量％、Bi0.1重量
％を含むAg−SnO2−In2O3−Bi2O3より成る4φmm
の可動接点とを相対向させて組み合わせ電気接点
を構成した。
実施例 ２
Cd15重量％、Ni0.3重量％を含むAg−CdO−
NiOより成る5φmmの固定接点とSn6重量％、In2
重量％、Bi0.5重量％を含むAg−SnO2−In2O3−
Bi2O3から成る4φmmの可動接点とを相対向させて
組み合わせ電気接点を構成した。
実施例 ３
Cd17重量％を含むAg−CdOより成る5φmmの固
定接点とSn5.5重量％、In1.5重量％、Bi0.7重量
％、Ni0.2重量％を含むAg−SnO2−In2O3−
Bi2O3−NiOから成る4φmmの可動接点とを相対向
させて組み合わせ電気接点を構成した。
従来例 １
Cd11重量％を含むAg−CdOより成る5φmmの固
定接点と4φmm可動接点とを相対向させて組み合
わせ電気接点を構成した。
従来例 ２
Sn4.5重量％、In1.5重量％、Bi0.2重量％を含む
Ag−SnO2−In2O3−Bi2O3より成る5φmmの固定接
点と4φmmの可動接点とを相対向させて組み合わ
せ電気接点を構成した。
然してこれら各組み合わせ電気接点を下記の試
験条件にて溶着、消耗及び接触抵抗を測定したと
ころ下表の右欄に示すような結果を得た。
試験条件
AC 200V 50Hz
投入電流 40A
定常電流 12A
開閉頻度 25回／分
開閉回数 20万回
The present invention relates to improvements in combination electrical contacts. Recently, with the development of electrical and electronic technology, various electrical
As electronic devices have become smaller, relay switches have also become smaller. However, as relays, switches, etc. become smaller, it becomes difficult to maintain sufficient creepage distance and insulation distance. In other words, a problem arises in that insulation resistance and withstand voltage deteriorate. Furthermore, the contact force and separation force of the electrical contacts are reduced, resulting in problems such as easy welding and increased contact resistance and temperature rise. Note that the temperature rise is proportional to the contact resistance. For this reason, there is a demand for combination electrical contacts that use materials with excellent wear resistance, prevent deterioration of insulation resistance and withstand voltage, are stable with low contact resistance and temperature rise, and have excellent welding resistance, and various combinations are required. Electrical contacts have been developed, but none are yet satisfactory. Conventionally, contacts made of Ag-oxide, in which metal oxide is dispersed in Ag, have been used for combined electrical contacts.Among these, contacts made of Ag-SnO 2 -In 2 O 3 -Bi 2 O 3 are placed facing each other. This combination electrical contact has superior welding resistance and wear resistance compared to a combination electrical contact made of Ag-CdO that faces each other, but SnO 2 aggregates during opening and closing, resulting in unstable contact resistance. It is something. In addition, a combination electrical contact consisting of Ag-CdO contacts facing each other has low contact resistance and stability even with low contact force, but Ag-CdO
-SnO2 - In2O3 -Bi2O3 It is inferior in welding resistance and abrasion resistance . 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 and wear resistance, but
There were problems such as poor contact resistance stability, and conversely good contact resistance stability but poor wear resistance and welding resistance. Therefore, the present invention was developed as a result of intensive research to develop a combination electrical contact that has good contact resistance stability, wear resistance, and welding resistance even in miniaturized relays, switches, etc. We have found that welding resistance, wear resistance, and stability of contact resistance can be improved by using different contact materials for the fixed and movable contacts. The present invention has been made with attention to this point, and uses Ag-SnO 2 -In 2 O 3 as a combination electrical contact that can reliably improve welding resistance, wear resistance, and stability of contact resistance. −Bi 2 O 3 system contacts and
The present invention aims to provide a combination electrical contact consisting of Ag-CdO-based contacts facing each other. The combined electrical contact according to the present invention includes 3 to 7% by weight of Sn and 0.5 to 3% by weight of In in opposing contacts.
Ag-SnO 2 −In 2 O 3 −Bi 2 O 3 containing 0.1 to 3% by weight of Bi
It is characterized by using an Ag-CdO system contact containing 10 to 20% by weight of Cd. In the combined electrical contact of the present invention, the reason why the materials of the opposing contacts are limited as described above is as follows.
Excellent welding resistance of Ag−SnO 2 −In 2 O 3 −Bi 2 O 3 system,
By taking advantage of the wear resistance and the stability of the contact resistance of Ag-CdO system, the synergistic effect of these will eliminate the poor welding resistance and resistance of conventional electrical contacts made of the same material and facing each other. consumable,
This is to eliminate poor stability of contact resistance. In addition, the Sn content in the Ag−SnO 2 −In 2 O 3 −Bi 2 O 3 system was
The reason for limiting it to ~7% by weight is that less than 3% by weight
The welding resistance due to the synergistic effect with Bi is insufficient,
If it exceeds 7% by weight, there will be no problem with welding resistance, but
This is because SnO 2 aggregates during opening and closing, resulting in extremely high contact resistance. The reason why In is limited to 0.5 to 3% by weight is that if it is less than 0.5% by weight, there is no effect of improving the welding resistance, and if it is more than 3% by weight, the contact resistance becomes high. The reason why Bi is limited to 0.1 to 3% by weight is that if it is less than 0.1% by weight, there is no effect of improving the welding resistance, and if it exceeds 3% by weight, the abrasion resistance is extremely deteriorated. If within the above component range, add 0.1 Ni
The properties are not impaired even when added at ~0.5% by weight. The reason for limiting the Cd content of the Ag-Cd system to 10 to 20% by weight is that if it is less than 10% by weight, the welding resistance will be extremely poor, and if it exceeds 20% by weight, the contact resistance will be high and the life will be shortened. This is because it becomes like this. As long as the components are within the above range, the properties will not be impaired even if Ni is added in an amount of 0.1 to 0.5% by weight. In addition, Ag-SnO 2 −In 2 O 3 − used as a contact material in the combined electrical contact of the present invention.
Bi 2 O 3 , Ag−SnO 2 −In 2 O 3 −Bi 2 O 3 −NiO, Ag−
CdO, Ag-CdO-NiO contains SnO2 , In2O3 ,
As long as Bi 2 O 3 , NiO, and CdO are finely dispersed, it can be made by any method such as internal oxidation, powder metallurgy, or a combination of internal oxidation and powder metallurgy. be. Next, in order to clarify the effects of the combined electrical contact according to the present invention, specific examples and conventional examples thereof will be described. Example 1 A 5φmm fixed contact made of Ag-CdO containing 11% by weight of Cd, and Ag-SnO 2 -In 2 O 3 -Bi 2 O 3 containing 4.5% by weight of Sn, 1% by weight of In, and 0.1% by weight of Bi. Consisting of 4φmm
A movable contact and a movable contact were made to face each other to form a combination electric contact. Example 2 Ag-CdO- containing 15% by weight of Cd and 0.3% by weight of Ni
5φmm fixed contact made of NiO, Sn6 wt%, In2
wt%, Ag−SnO 2 −In 2 O 3 − with Bi0.5 wt%
An electric contact was constructed by combining a 4φmm movable contact made of Bi 2 O 3 and facing each other. Example 3 Fixed contact of 5φmm made of Ag-CdO containing 17% by weight of Cd and Ag-SnO 2 -In 2 containing 5.5% by weight of Sn, 1.5% by weight of In, 0.7% by weight of Bi, and 0.2% by weight of Ni. O 3 −
An electric contact was constructed by combining a 4φmm movable contact made of Bi 2 O 3 −NiO and facing each other. Conventional Example 1 An electric contact was constructed by combining a 5φmm fixed contact made of Ag-CdO containing 11% by weight of Cd and a 4φmm movable contact facing each other. Conventional example 2 Contains 4.5% by weight of Sn, 1.5% by weight of In, and 0.2% by weight of Bi
An electric contact was constructed by combining a 5φmm fixed contact made of Ag-SnO 2 −In 2 O 3 −Bi 2 O 3 and a 4φmm movable contact facing each other. When the welding, wear and contact resistance of each of these combinations of electrical contacts were measured under the following test conditions, the results shown in the right column of the table below were obtained. Test conditions AC 200V 50Hz Closing current 40A Steady current 12A Opening/closing frequency 25 times/min Number of openings/closing 200,000 times
【表】
上記表で明らかなようにAg−SnO2−In2O3−
Bi2O3系の接点とAg−CdO系の接点を相対向させ
た本発明の組み合わせ電気接点は、格別に耐溶着
性、耐消耗性が良いと言われている従来のAg−
SnO2−In2O3−Bi2O3の接点同志を相対向させた
組み合わせ電気接点と同等の優れた耐消耗性、耐
溶着性を有し、また接触抵抗の安定性が良いと言
われている従来のAg−CdOの接点同志の相対向
させた組み合わせ電気接点と同様、接触抵抗の安
定性に優れている。
以上詳記した通り本発明の組み合わせ電気接点
は、耐溶着性、耐消耗性及び接触抵抗の安定性共
に優れているので、小型化されたリレー、スイツ
チ等に使用した際、消耗が少なく、溶着の発生を
抑えることが出来、接触抵抗を低く安定すること
が出来る等の効果がある。[Table] As is clear from the table above, Ag−SnO 2 −In 2 O 3 −
The combined electrical contact of the present invention, in which a Bi 2 O 3 type contact and an Ag-CdO type contact are opposed to each other, is superior to the conventional Ag-CdO type contact, which is said to have exceptionally good welding resistance and wear resistance.
It has excellent abrasion resistance and welding resistance equivalent to that of a combination electrical contact in which SnO 2 −In 2 O 3 −Bi 2 O 3 contacts are opposed to each other, and is said to have good contact resistance stability. It has excellent contact resistance stability, similar to the conventional electrical contacts made of Ag-CdO contacts facing each other. As detailed above, the combined electrical contact of the present invention has excellent welding resistance, abrasion resistance, and contact resistance stability, so when used in miniaturized relays, switches, etc., there is little wear and tear and welding This has the effect of suppressing the occurrence of contact resistance and keeping contact resistance low and stable.