【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、耐消耗性は銀―酸化カドミウム系
に比べ著しく劣いた。これは接触時に局部的に異
常発熱し、つまり接触開始時に最初に接触した部
分に瞬間的に電流が集中して流れて異常発熱し、
これにより該部分の銅の結晶粒が粗大化し、銅地
が劣化する為、開閉により銅が微細なフレークと
なつて剥落して消耗するからである。そしてこの
ような消耗は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耐溶着性、耐消耗性に優れた
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を改良した封入
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、酸化すず0.5
〜25w／ｏ、酸化亜鉛0.5〜25w／ｏ及び酸化イン
ジウム0.5〜25w／ｏが合計で５〜26w／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すず、酸化亜鉛
及び酸化インジウムに代えたもので、その添加量
を酸化すず0.5〜25w／ｏ、酸化亜鉛0.5〜25w／
ｏ、酸化インジウム0.5〜25w／ｏとなし合計で
５〜26w／ｏとした理由は、銅地の高温での結晶
粒の粗大化を防ぎ、銅地の機械的強さを向上さ
せ、劣化を防止してフレークの剥落による消耗を
防止する為で、酸化すず0.5w／ｏ未満では酸化
亜鉛及び酸化インジウムが夫々0.5w／ｏ以上で
あつても耐溶着性が不充分であり、逆に酸化亜鉛
又は酸化インジウムが0.5w／ｏ未満では酸化す
ず0.5w／ｏ以上あつても耐消耗性が不充分であ
る。また酸化すず25w／ｏを超えると酸化亜鉛が
及び酸化インジウムが夫々0.5w／ｏ以上あつて
も耐消耗性が低下し、逆に酸化亜鉛又は酸化イン
ジウムが25w／ｏを超えると酸化すずが0.5w／ｏ
以上あつても耐溶着性が低下する。そして耐溶着
性、耐消耗性共に満足させる為には酸化すず，酸
化亜鉛及び酸化インジウムが共に0.5〜25w／ｏ
の範囲にあつて、全酸化物の合計が５〜26w／ｏ
必要であるからである。
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及び比較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、耐
消耗性について述べる。
実施例 １
重量比でCu粉末82.6％，SnO2粉末10.3％，
ZnO2.1％及びIn2O3粉末５％を混合圧縮して30mm
ロ×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ロ
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8.5mmのCu―
SnO210.3w／ｏ―ZnO2.1w／ｏ―In2O35w／ｏよ
り成る線材となした。
実施例 ２
重量比でCu粉末79.5％，SnO2粉末６％，ZnO
粉末8.2％，In2O3粉末6.3％を混合圧縮して30mmロ
×150mmｌ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ロの
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8.5mmのCu―
SnO26w／ｏ―ZnO8.2w／ｏ―In2O36.3w，ｏよ
り成る線材となした。
従来例 １
Cu粉末88w／ｏとCdO粉末12w／ｏを混合圧縮
して30mmロ×150mmの圧粉体を作り、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ロの棒となつたところで、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8.5mmのCu―
CdO12w／ｏより成る線材となした。
従来例 ２
Ag中にCd12.5w／ｏ，Zn1.5w／ｏを溶解して
Ag―Cd―Zu合金の2.3mm×2.3mmの粒を作り、
これを酸素ガス雰囲気中８気圧、800℃で内部酸
化してAg―CdO13.5w／ｏ―ZnO2w／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8.5mmのAg―CdO13.5w／ｏ―ZnO2w／ｏよ
り成る線材となした。
比較例 １，２
下表左欄に示す成分組成の材料を実施例１と同
一の方法で線材となした。
然してこれら実施例１，２、従来例１，２及び
比較例１，２の線材を長さ1.5mmに切断して市販
のマグネツトスイツチにろう付し、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、封入用電気接点の溶着回数、消耗
量を測定した処、下記の表に示すような結果を得
た。
試験条件
固定接点 8.5mm×1.5mmｔ
可動接点 8.5mm1.5mmｔ（30mmＲ付）
電 圧 200V
周波数 50Hz
負 荷 誘導負荷
電 流 投入時165A（0.1秒）
遮断時33A（1.1秒）
力 率 投入時0.4
開閉頻度 20回／分
通電時間 1.2秒
休止時間 1.8秒
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 the materials are extremely expensive. Inexpensive copper
The use of cadmium oxide was considered. However, although copper-cadmium oxide had no problem with welding resistance, its wear resistance was significantly inferior to that of the silver-cadmium oxide system. This is because when contact occurs, abnormal heat is generated locally; in other words, when contact begins, current is momentarily concentrated and flows in the first contact area, causing abnormal heat generation.
As a result, the copper crystal grains in the area become coarse and the copper base deteriorates, causing the copper to flake off as fine flakes and be worn out when opened and closed. This kind of consumption becomes noticeable when used in the medium current range of 10 to 400A. 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 excellent welding resistance and wear resistance equivalent to that of the expensive silver-cadmium oxide electrical contact material. It is an object of the present invention to provide an encapsulating electrical contact material that is an improved encapsulating electrical contact material made of cadmium oxide. The electrical contact material for encapsulation of the present invention has a tin oxide content of 0.5
~25 w/o, zinc oxide 0.5~25 w/o, and indium oxide 0.5~25 w/o in a total amount of 5~26 w/o, the balance being copper. The electrical contact material for encapsulation of the present invention replaces cadmium oxide in the electrical contact material for encapsulation consisting of copper-cadmium oxide, which was conventionally considered, with tin oxide, zinc oxide, and indium oxide, and the added amount is reduced by oxidation. Tin 0.5~25w/o, zinc oxide 0.5~25w/o
The reason for setting the total of 5 to 26 w/o without indium oxide is to prevent coarsening of the crystal grains of the copper base at high temperatures, improve the mechanical strength of the copper base, and prevent deterioration. This is to prevent wear due to peeling of flakes.If tin oxide is less than 0.5w/o, even if zinc oxide and indium oxide are each 0.5w/o or more, welding resistance will be insufficient; If the amount of zinc or indium oxide is less than 0.5 w/o, the wear resistance will be insufficient even if the amount of tin oxide is 0.5 w/o or more. Furthermore, when tin oxide exceeds 25 w/o, wear resistance decreases even if zinc oxide and indium oxide exceed 0.5 w/o, and conversely, when zinc oxide or indium oxide exceeds 25 w/o, tin oxide increases by 0.5 w/o or more. w/o
Even if it is more than that, the welding resistance decreases. In order to satisfy both welding resistance and abrasion resistance, tin oxide, zinc oxide and indium oxide must be mixed at 0.5 to 25 w/o.
In the range of 5 to 26 w/o total of all oxides
This is because it is necessary. In order to clarify the effects of the electrical contact material for encapsulation of the present invention, the electrical contacts for encapsulation made using the electrical contact material for encapsulation of specific examples and the electrical contact material for encapsulation of conventional examples and comparative examples will be described below. We will discuss welding resistance and abrasion resistance. Example 1 Cu powder 82.6%, SnO 2 powder 10.3% by weight,
Mix and compress ZnO2.1% and In2O3 powder 5% to 30mm
A green compact of 150 mm in diameter is made, sintered at 850℃ in a nitrogen gas atmosphere, followed by repeated groove rolling and heat treatment at 850℃ in a nitrogen gas atmosphere. Heat treated at 850℃ in gas atmosphere, swaging process and nitrogen gas atmosphere
After repeated heat treatment at 850℃, 8.5mm Cu―
A wire rod consisting of SnO 2 10.3w/o-ZnO2.1w/o-In 2 O 3 5w/o was made. Example 2 Cu powder 79.5%, SnO 2 powder 6%, ZnO by weight ratio
8.2% powder and 6.3% In 2 O 3 powder were mixed and compressed to make a compact of 30 mm x 150 mml, which was sintered at 850℃ in a nitrogen gas atmosphere, followed by groove rolling and nitrogen gas atmosphere. Heat treatment was repeated at 850℃ in a medium temperature, and when it became a 10mm rod, heat treatment was performed at 850℃ in a nitrogen gas atmosphere, followed by swaging processing and a process in a nitrogen gas atmosphere.
After repeated heat treatment at 850℃, 8.5mm Cu―
A wire rod consisting of SnO 2 6w/o-ZnO8.2w/o-In 2 O 3 6.3w, o was made. Conventional example 1 Cu powder 88w/o and CdO powder 12w/o are mixed and compressed to make a compact of 30mm × 150mm, which is sintered at 830℃ in a nitrogen gas atmosphere, followed by subsequent groove rolling. Repeated heat treatment at 830℃ in nitrogen gas atmosphere,
At the point where it becomes a 10mm rod, it is placed 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 8.5mm Cu-
The wire rod was made of CdO12w/o. Conventional example 2 Cd12.5w/o, Zn1.5w/o dissolved in Ag
Make 2.3mm x 2.3mm grains of Ag-Cd-Zu alloy,
This was internally oxidized in an oxygen gas atmosphere at 8 atm and 800°C to form Ag-CdO13.5w/o-ZnO2w/o grains, and then these grains were compressed, sintered, and extruded.
Next, wire drawing and heat treatment at 700°C in the atmosphere were repeated to obtain a wire rod of 8.5 mm made of Ag-CdO13.5w/o-ZnO2w/o. Comparative Examples 1 and 2 Materials having the compositions shown in the left column of the table below were made into wire rods in the same manner as in Example 1. However, the wire rods of Examples 1 and 2, Conventional Examples 1 and 2, and Comparative Examples 1 and 2 were cut into lengths of 1.5 mm, brazed to commercially available magnetic switches, and then heated in vacuum or inert gas (N). 2 , Ar, N 2 ―H 2 , Ar―
H 2 , He, N 2 ―O 2 , Ar―O 2 , CO 2 , N 2 ―CO 2 ,
Ar-CO 2 , CO 2 -O 2 ) was sealed in a container filled with Ar gas (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 amount of wear of the electrical contacts for sealing. The results shown in the table below were obtained. Test conditions Fixed contact 8.5mm x 1.5mmt Movable contact 8.5mm1.5mmt (with 30mmR) Voltage 200V Frequency 50Hz Load Inductive load current 165A (0.1 seconds) when turned on 33A (1.1 seconds) when turned off Power factor 0.4 when turned on and closed Frequency: 20 times/min Energization time: 1.2 seconds Resting time: 1.8 seconds
【表】
上記の表で明らかなように実施例１，２のマグ
ネツトスイツチに於ける電気接点は、165Aとい
う中電流域で従来例１のマグネツトスイツチに於
ける電気接点と同等に溶着回数が少なく、消耗量
については一段と少ない。また従来例２のマグネ
ツトスイツチに於ける高価な電気接点と同等に溶
着回数ならびに消耗量が少なく、耐溶着性、耐消
耗性に優れていることが判る。また、実施例１，
２と類似の材料である比較例１，２の材料と比較
しても、酸化錫及び酸化亜鉛に対する酸化インジ
ウムという材料の特殊性から消耗量がすぐれてい
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、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、耐消耗性を有するので、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 magnetic switches of Examples 1 and 2 have the same number of welding times as the electrical contacts in the conventional magnetic switch of Example 1 in the medium current range of 165A. , and the amount of consumption is even lower. Furthermore, it can be seen that the number of times of welding and the amount of wear are as small as the expensive electrical contacts in the magnetic switch of Conventional Example 2, and the welding resistance and wear resistance are excellent. In addition, Example 1,
Even when compared with the materials of Comparative Examples 1 and 2, which are similar materials to No. 2, it can be seen that the amount of wear is superior due to the special characteristics of the material of indium oxide compared to tin oxide and zinc oxide. As detailed above, the electrical contact material for encapsulation of the present invention is an inexpensive material and has excellent welding resistance and abrasion resistance equivalent to the expensive electrical contact material for encapsulation made of silver-cadmium oxide. Therefore, it can be said to be an epoch-making electrical contact material for encapsulation that can replace this.