【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、それに応じてブレーカー
マグネツトスイツチ等も小型化されている。
然し乍ら、ブレーカー、マグネツトスイツチ等
が小型化されると、機械の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坑が高くなるという問題が起
きる。
この為、接触抵抗の安定性が良く、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−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−Niより成
る接点同仕を対向させた組み合わせ電気接点に比
し耐溶着性が優れているが、Biは低温昇華でか
つ酸化物がもろく解離しやすいため消耗が大きく
接触抵抗が不安定なものである。またAg−Ni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、耐消耗性
も優れているが、耐溶着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を同じ電気接点材料を
用いていたので、耐溶着性は良いが耐消耗性、接
触抵抗の安定性が悪かつたり、また逆に耐消耗
性、接触抵抗の安定性は良いが耐溶着性が悪い等
の問題があつた。そこで本発明者は、小型化され
たブレーカー、マグネツトスイツチ等に於いても
耐消耗性、接触抵抗の安定性が良く、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−Bi2O3系の接点とAg−Ni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Bi0.5重量％〜10重量％を含むAg−
Bi2O3系の接点とNi5重量％〜20重量％を含むAg
−Ni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
−Bi2O3系の優れた耐溶着性を生かし、またAg−
Ni系の良好なアーク遮断性、接触抵抗の安定性、
耐消耗性を生かし、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、
接触抵効の安定性の悪さを解消する為である。ま
たAg−Bi2O3系のBiの含有量を0.5重量％〜10重
量％と限定した理由は、0.5重量％未満では耐溶
着性が不充分であり、10重量％を超えると耐溶着
性には問題がないが、消耗がひどくなり接触抵抗
が極度に高くなるからである。上記成分範囲内で
あれば、Ag−Bi2O3に更に少量のFe族の酸化物
を添加しても特性は阻害されないものである。
Ag−Ni系のNiの含有量を５重量％〜20重量％
と限定した理由は、５重量％未満では耐溶着性が
極端に悪くなり、20重量％を超えると耐溶着性は
問題ないが消耗量が多くなつて、寿命が短かくな
るからである。
尚、本発明の組み合わせ電気接点における一方
の接点の材料として使用するAg−Bi2O3は、Ag
中にBi2O3が細かく分散してさえいれば、内部酸
化法、粉末治金法、内部酸化法と粉末治金法の併
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
Ni10重量％を含むAg−Niより成る5φmmの固定
接点と、Bi0.8重量％を含むAg−Bi2O3より成る
5φmm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
Ni15重量％を含むAg−Niよる成る5φmmの固定
接点とBi8重量％を含むAg−Bi2O3にNiO0.4重量
％と含有させて成る5φmm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
Ni10重量％を含むAg−Niより成る5φmmの固定
接点と5φmm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
Bi0.8重量％を含むAg−Bi2O3より成る5φmmの
固定接点と5φmm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
ΓAC 200V 50Hz
Γ投入電流 40A
Γ定常電流 12A
Γ開閉頻度 25回／分
Γ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, breaker magnet switches and the like have also become smaller. However, as breakers, magnetic switches, etc. become smaller, it becomes difficult to maintain sufficient creepage distance and insulation distance for the machine. 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, causing problems such as easy welding and increased contact resistance. For this reason, there is a demand for a combination electrical contact with good stability in contact resistance and excellent welding resistance, and various combination electrical contacts have been developed, but so far none have been satisfactory. Conventionally, contacts made of Ag-oxide, in which metal oxide is dispersed in Ag, have been used for combined electrical contacts, and among these, the combined electrical contacts, in which contacts made of Ag-Bi 2 O 3 are made to face each other, are made of Ag-Ni. It has superior welding resistance compared to electrical contacts made of a combination of contacts of the same type facing each other, but Bi sublimes at low temperatures and the oxide is brittle and dissociates easily, resulting in high wear and unstable contact resistance. . Further, a combination electrical contact in which contacts made of Ag-Ni are opposed to each other has low contact resistance and stability even at low contact force, and has excellent wear resistance, but is inferior in welding resistance. In this way, conventional combination electrical contacts use the same electrical contact material for the opposing fixed and movable contacts, which has good welding resistance but poor abrasion resistance and contact resistance stability. On the contrary, although wear resistance and contact resistance stability were good, there were problems such as poor welding resistance. Therefore, the inventor of the present invention has conducted intensive research to develop a combination electrical contact that has good wear resistance, stable contact resistance, and excellent welding resistance even in miniaturized breakers, magnetic switches, etc. 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 that face each other. The present invention has been made with attention to this point, and uses Ag-Bi 2 O 3 type contacts and Ag-Bi 2 O 3 type contacts as a combination electrical contact that can reliably improve welding resistance, wear resistance, and stability of contact resistance. The present invention aims to provide a combination electrical contact consisting of Ag-Ni type contacts facing each other. The combined electrical contact according to the present invention has an Ag-containing structure containing 0.5% to 10% by weight of Bi in opposing contacts.
Bi 2 O 3 based contacts and Ag containing 5% to 20% Ni by weight
-It is characterized by the use of Ni-based contacts. The reason for limiting the materials of the opposing contacts as described above in the combined electrical contact of the present invention is that Ag
−By taking advantage of the excellent welding resistance of Bi 2 O 3 system, and also using Ag−
Good arc-blocking properties of Ni-based, stable contact resistance,
Taking advantage of the wear resistance, the synergistic effect of these can eliminate the poor welding resistance or wear resistance of conventional electrical contacts made of the same material and facing each other.
This is to eliminate the poor stability of contact resistance. In addition, the reason why the content of Bi in the Ag-Bi 2 O 3 system was limited to 0.5% to 10% by weight is that if it is less than 0.5% by weight, the welding resistance will be insufficient, and if it exceeds 10% by weight, the welding resistance will be poor. Although there is no problem with this, the wear is severe and the contact resistance becomes extremely high. As long as the components are within the above range, the properties will not be impaired even if a small amount of Fe group oxide is added to Ag-Bi 2 O 3 . Ag-Ni system Ni content from 5% to 20% by weight
The reason for this limitation is that if it is less than 5% by weight, the welding resistance will be extremely poor, and if it exceeds 20% by weight, there will be no problem in the welding resistance, but the amount of wear will increase and the life will be shortened. The Ag-Bi 2 O 3 used as the material for one contact in the combined electrical contact of the present invention is Ag-Bi 2 O 3 .
As long as Bi 2 O 3 is finely dispersed, it may 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-Ni containing 10% by weight of Ni and Ag-Bi 2 O 3 containing 0.8% by weight of Bi.
A 5φmm movable contact was placed facing each other to form an electric contact. Example 2 A 5φmm fixed contact made of Ag-Ni containing 15% by weight of Ni and a 5φmm movable contact made of Ag-Bi 2 O 3 containing 8% by weight of Bi and 0.4% by weight of NiO were placed opposite each other. A combination electrical contact was constructed. Conventional Example 1 An electric contact was constructed by combining a 5φmm fixed contact made of Ag-Ni containing 10% by weight of Ni and a 5φmm movable contact facing each other. Conventional Example 2 An electric contact was constructed by combining a 5φmm fixed contact made of Ag-Bi 2 O 3 containing 0.8% by weight of Bi and a 5φmm 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 Γ AC 200V 50Hz Γ closing current 40 A Γ steady current 12 A Γ switching frequency 25 times/min Γ switching frequency 200,000 times
【表】
上記表で明らかなようにAg−Bi2O3系の接点と
Ag−Ni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、格別に耐溶着性が良いと言われ
ている従来のAg−Bi2O3の接点同志を相対向させ
た組み合わせ電気接点よりも耐消耗性に優れ更に
同等の優れた耐溶着性を有し、また接触抵抗の安
定性が良いと言われている従来のAg−Niの接点
同志を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、小型化されたブレーカー、マ
グネツト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でき、接触抵抗を
低く安定することができる等の効果がある。[Table] As is clear from the table above, Ag-Bi 2 O 3 system contacts and
The combination electrical contact of the present invention, which has Ag-Ni contacts facing each other, is different from the conventional combination electrical contact, which has Ag-Bi 2 O 3 contacts facing each other, which is said to have exceptionally good welding resistance. It is similar to the conventional combination electrical contact, which has Ag-Ni contacts facing each other, which is said to have better wear resistance than the conventional Ag-Ni contacts, and has the same excellent welding resistance as the conventional Ag-Ni contacts. Excellent contact resistance stability. As detailed above, the combined electrical contact of the present invention has excellent welding resistance, wear resistance, and stability of contact resistance, so when used in miniaturized breakers, magnetic switches, etc., there is less wear and tear. , the occurrence of welding can be suppressed, and the contact resistance can be kept low and stable.