【発明の詳細な説明】[Detailed description of the invention]
本発明は封入型マグネツトスイツチ、封入型ブ
レーカー、封入型リレー等の電気接点に用いる材
料に関する。
従来、マグネツトスイツチ、ブレーカー、リレ
ー等の電気接点材料としては、耐溶着性、耐消耗
性に優れた銀−酸化カドミウム系が使用されてき
たが、何分にも材料が高価である為、低廉な銅−
酸化カドミウムの使用が考えられていた。
然し、銅−酸化カドミウムは耐溶着性について
は問題無いが、接触抵抗は銀−酸化カドミウム系
に比べ著しく劣いた。これは接点開閉時のアーク
により、酸化カドミウムが、カドミウムと酸素に
分解し、分解した酸素が地の銅を酸化させてしま
い、このため、接触抵抗が高く、不安定になる。
そしてこのような接触抵抗が高く、不安定な状態
は10〜400Aという中電流域での使用に於いて顕
著に現われる。
本発明はかかる問題を解消すべくなされたもの
であり、高価な銀−酸化カドミウム系より成る電
気接点材料と同等の低接触抵抗、耐溶着性に優れ
た封入用電気接点材料として、前記銅−酸化カド
ミウムより成る封入用電気接点材料にかわる封入
用電気接点材料を提供せんとするものである。
本発明の封入用電気接点材料は、酸化コバルト
５〜20w／ｏと残部銅より成るものである。
本発明の封入用電気接点材料は、従来考えられ
ていた銅−酸化カドミウムより成る封入用電気接
点材料中の酸化カドミウムを酸化コバルトに代え
たもので、その添加量を酸化コバルト５〜20w／
ｏとした理由は、接点開閉時のアークにより、酸
化カドミウムよりも分解しにくい酸化コバルトを
用い、銅の地の酸化を防止し、接触抵抗を安定さ
せる為で、酸化コバルト5w／ｏ未満では耐溶性
が不充分であり、また酸化コバルト20w／ｏを超
えると酸化コバルトにより接触抵抗が高く、不安
定になるからである。上記成分範囲内であれば、
銅−酸化コバルトに更に少量の鉄、ニツケル、ク
ロム、マンガン、チタニウム又はこれらの酸化物
を添加しても特性は阻害されないものである。
以下本発明の封入用電気接点材料の効果を明瞭
ならしめる為に、その具体的な実施例の封入用電
気接点材料と従来例の封入用電気接点材料により
作つた封入用電気接点の耐溶着性、接触抵抗につ
いて述べる。
実施例 １
重量比で銅粉末92.5％、酸化コバルト粉末7.5
％を混合圧縮して30mm口×150mmの圧粉体を作
り、これを真空中850℃で焼結し、然る後溝ロー
ル加工と真空中850℃の熱処理を繰返し、10mm口
の棒になつたところで真空中850℃で熱処理し、
スエジング加工と真空中850℃の熱処理を繰返し
て5.0mmφの銅−酸化コバルト7.5w／ｏより成る
線材となし、更にこの線材を施盤加工により頭部
４mmφ×1.2mmｔのリベツトとなした。
実施例 ２
重量比で銅粉末85％、酸化コバルト粉末15％、
を混合圧縮して30mm口×150mmの圧粉体を作り、
これを窒素ガス雰囲気中850℃で焼結し、然る後
溝ロール加工と窒素ガス雰囲気中850℃の熱処理
を繰返し、10mm口の棒になつたところで、窒素ガ
ス雰囲気中850℃で熱処理し、スエージング加工
と窒素ガス雰囲気中850℃の熱処理を繰返して5.0
mmφの銅−酸化コバルト15w／ｏより成る線材と
なし、更にこの線材を施盤加工により頭部４mmφ
×1.2mmｔのリベツトとなした。
従来例 １
Cu粉末88w／ｏとCdO粉末12w／ｏを混合圧縮
して30mm口×150mmの圧粉末を作り、これを窒
素ガス雰囲気中830℃で焼結し、然る後溝ロール
加工と窒素ガス雰囲気中830℃の熱処理を繰返し、
10mm口の棒になつたところで、窒素ガス雰囲気中
830℃で熱処理し、スエージング加工と窒素ガス
雰囲気中830℃の熱処理を繰返して５mmφのCu−
CdO12w／ｏより成る線材となし、更にこの線材
を施盤加工により頭部4φmm×12tmmのリベツトと
なした。
従来例 ２
Ag中にCd11w／ｏ溶解してAg−Cd合金の2.3
mmφ×2.3mmの粒を作り、これを酸素ガス雰囲
気中７気圧800℃で内部酸化してAg−CdO12w／
ｏの粒となし、然る後この粒を圧縮、焼結、押出
加工し、次いで線引加工と大気中700℃の熱処理
を繰返して２mmφのAg−CdO12w／ｏより成る
線材となし、更にこの線材をヘツダー加工により
頭部４mmφ×1.2mmｔのリベツトとなした。而し
て市販のヒンジ型リレーに固定、可動接点をベー
スにかしめ付け、試験用リレーを作りこれを夫々
真空又は不活性ガス（N2、Ar、N2−H2、Ar−
H2、He、N2−O2、Ar−O2、CO2、N2−CO2、
Ar−CO2、CO2−O2）充填容器、本例ではArガ
ス充填容器中に封入して、下記の試験条件にて開
閉試験を行ない電気接点の溶着回数及び接触抵抗
を測定した処、下記の表に示すような結果を得
た。
試験条件
負荷 抵抗２段切換
電圧 100V
周波数 50Hz
電流 投入電流40A
定常電流10A
開閉頻度 20回／分
通電時間 0.62秒
休止時間 2.35秒
接触力 20ｇ
開離力 40ｇ
開閉回数 ５万回
The present invention relates to materials used in electrical contacts such as encapsulated magnetic switches, encapsulated breakers, encapsulated relays, and the like. Conventionally, silver-cadmium oxide based materials have been used as electrical contact materials for magnetic switches, breakers, relays, etc. due to their excellent welding and abrasion resistance, but since the materials are extremely expensive, Cheap copper
The use of cadmium oxide was considered. However, although copper-cadmium oxide had no problem in welding resistance, its contact resistance was significantly inferior to that of silver-cadmium oxide. This is because cadmium oxide decomposes into cadmium and oxygen due to the arc generated when the contacts are opened and closed, and the decomposed oxygen oxidizes the underlying copper, resulting in high contact resistance and instability.
Such high contact resistance and unstable conditions become noticeable when used in the medium current range of 10 to 400 A. The present invention has been made to solve this problem, and uses the copper-cadmium oxide-based electrical contact material as an encapsulating electrical contact material that has the same low contact resistance and excellent adhesion resistance as the expensive silver-cadmium oxide electrical contact material. It is an object of the present invention to provide an encapsulating electrical contact material that can replace the encapsulating electrical contact material made of cadmium oxide. The electrical contact material for encapsulation of the present invention consists of 5 to 20 w/o of cobalt oxide and the balance copper. The electrical contact material for encapsulation of the present invention replaces the cadmium oxide in the electrical contact material for encapsulation made of copper-cadmium oxide, which was conventionally considered, with cobalt oxide, and the amount of cobalt oxide added is 5 to 20 w/w.
The reason for setting the o value is to use cobalt oxide, which is more difficult to decompose than cadmium oxide due to arcing when opening and closing the contacts, to prevent oxidation of the copper base and stabilize the contact resistance. This is because the solubility is insufficient, and if the amount of cobalt oxide exceeds 20 w/o, the cobalt oxide causes high contact resistance and becomes unstable. If the ingredients are within the above range,
Even if small amounts of iron, nickel, chromium, manganese, titanium, or oxides thereof are added to the copper-cobalt oxide, the properties are not impaired. In order to clarify the effects of the electrical contact material for encapsulation of the present invention, the welding resistance of electrical contacts for encapsulation made from the electrical contact material for encapsulation of specific examples and the electrical contact material for encapsulation of the conventional example will be described below. , we will discuss contact resistance. Example 1 Copper powder 92.5%, cobalt oxide powder 7.5% by weight
% is mixed and compressed to make a 30mm opening x 150mm green compact, which is sintered in a vacuum at 850°C, followed by repeated groove rolling and heat treatment at 850°C in a vacuum to form a 10mm opening rod. Heat treated at 850℃ in vacuum,
Swaging and heat treatment at 850° C. in vacuum were repeated to obtain a wire rod of 5.0 mmφ made of copper-cobalt oxide 7.5 w/o, and this wire was further processed with a lathe to form a rivet with a head size of 4 mmφ×1.2 mmt. Example 2 Copper powder 85%, cobalt oxide powder 15% by weight,
Mix and compress to make a 30mm x 150mm green compact.
This was sintered at 850°C in a nitrogen gas atmosphere, followed by repeated groove rolling and heat treatment at 850°C in a nitrogen gas atmosphere, and when it became a rod with a diameter of 10 mm, it was heat treated at 850°C in a nitrogen gas atmosphere. 5.0 by repeating swaging processing and heat treatment at 850℃ in a nitrogen gas atmosphere.
A wire rod made of copper-cobalt oxide 15w/o with a diameter of mmφ is made, and this wire is lathed to a head of 4mmφ.
It was made with a rivet of ×1.2mmt. Conventional example 1 Cu powder 88w/o and CdO powder 12w/o are mixed and compressed to make a 30mm opening x 150mm compacted powder, which is sintered at 830°C in a nitrogen gas atmosphere, followed by subsequent groove rolling and nitrogen sintering. Repeated heat treatment at 830℃ in a gas atmosphere,
When the rod has a 10 mm opening, place it in a nitrogen gas atmosphere.
Heat treated at 830℃, swaging process and heat treatment at 830℃ in a nitrogen gas atmosphere were repeated to form a 5mmφ Cu-
A wire rod made of CdO12w/o was made, and this wire rod was further machined into a rivet with a head size of 4φmm x 12tmm. Conventional example 2 2.3% of Ag-Cd alloy is made by dissolving Cd11w/o in Ag.
Ag-CdO12w/
The particles were then compressed, sintered, and extruded, and then wire drawn and heat treated at 700°C in the atmosphere were repeated to make a wire rod of 2 mmφ made of Ag-CdO12w/o. The wire rod was processed into a rivet with a head size of 4 mmφ x 1.2 mmt by header processing. The fixed and movable contacts were then caulked to the base of a commercially available hinge-type relay, and a test relay was made, and each relay was exposed to vacuum or inert gas (N 2 , Ar, N 2 −H 2 , Ar−
H2 , He, N2 - O2 , Ar- O2 , CO2 , N2 - CO2 ,
Ar-CO 2 , CO 2 -O 2 ) was sealed in a filled container, in this example an Ar gas-filled container, and an opening/closing test was conducted under the following test conditions to measure the number of welding times and contact resistance of the electrical contacts. The results shown in the table below were obtained. Test conditions Load 2-stage resistance switching Voltage 100V Frequency 50Hz Current Closing current 40A Steady current 10A Opening/closing frequency 20 times/minute Energizing time 0.62 seconds Rest time 2.35 seconds Contact force 20g Breaking force 40g Number of opening/closing 50,000 times
【表】
上記の表で明らかなように実施例１、２のリレ
ーに於ける電気接点は、従来例１のリレーに於け
る電気接点よりも溶着回数が少なく且つ接触抵抗
が低く、また従来例２のリレーに於ける高価な電
気接点と同等に溶着回数が少なく且つ接触抵抗が
低く、耐溶着性及び接触抵抗特性に優れているこ
とが判る。
以上詳記した通り本発明の封入用電気接点材料
は、貴金属を全く使用しない安価な材料であつ
て、しかも銀−酸化カドミウムより成る高価な封
入用電気接点材料と同等の優れた耐溶着性及び低
接触抵抗特性を有するので、これにとつて代わる
ことのできる画期的な封入用電気接点材料と言え
る。[Table] As is clear from the above table, the electrical contacts in the relays of Examples 1 and 2 have fewer welding times and lower contact resistance than the electrical contacts in the relay of Conventional Example 1. It can be seen that the number of times of welding is small and the contact resistance is as low as that of the expensive electrical contacts in relay No. 2, and the welding resistance and contact resistance characteristics are excellent. As detailed above, the electrical contact material for encapsulation of the present invention is an inexpensive material that does not use any precious metals, and has excellent welding resistance and properties equivalent to the expensive electrical contact material for encapsulation made of silver-cadmium oxide. Since it has low contact resistance characteristics, it can be said to be an innovative electrical contact material for encapsulation that can replace this.