【発明の詳細な説明】[Detailed description of the invention]
本発明は、電気接点材料に関するものである。
従来より酸化物系電気接点材料としては、主とし
て銀−酸化カドミウムや銀−酸化錫系の材料が用
いられてきた。特に銀−酸化カドミウム系接点材
料は耐溶着性、耐消毛性、接触抵抗等の総合的接
点特性に於いてバランスのとれた性能を示し、さ
らに加工性もすぐれていることから様々な電気条
件にわたつて広く使われてきた。しかし、最近こ
れを上まわる性能を有する接点材料の開発が、電
子部品の小型化に伴ない小さな接点径でより大き
な電流を流そうとする要求から高まつている。こ
うした動向の中で、特に耐溶着性に関して、銀−
酸化カドミウムを上まわる性能を備えた接点材料
が求められている。銀−酸化カドミウム接点材料
は開閉回数が増加するにつれ、酸化カドミウムが
昇華して接点表面層に銀層が形成され、これが銀
−酸化カドミウムの耐溶着性劣化させる原因とな
つている。
そこで本発明者は、銀−酸化カドミウム電気接
点材料を上まわる耐溶着性を有し、接触抵抗及び
耐消耗性に於いても銀−酸化カドミウム電気接点
材料に優るとも劣らない性能を有する電気接点材
料を開発すべく鋭意考究の結果、満足できる電気
接点材料を見い出したものである。
酸化チタンは銀−酸化チタン電気接点材料とし
た場合、優れた耐溶着性を示すものの、接触抵抗
が高く、消耗量も多い為、満足のゆく結果は得ら
れない。また銀−酸化ニツケルは銀−酸化カドミ
ウムを上まわる安定した接触抵抗と、優れた耐消
耗性を示すが、耐溶着性に関しては銀−酸化カド
ミウムと同程度の性能を示すものである。本発明
の特許請求の範囲に於ける添加物はこれらの点を
考慮し、選定されたもので、酸化チタン0.1〜８
重量％と酸化ニツケル0.5〜10重量％とした理由
は、酸化チタンが0.1重量％未満、酸化ニツケル
が0.5重量％未満では銀量が多くなり、低接触抵
抗特性は得られるものの耐溶着性に関しては良好
な結果は得られず、また酸化チタンが８重量％を
超えるかあるいは酸化ニツケルが10重量％を超え
ると加工性が悪く、また使用中接点表面に酸化物
の凝集層ができ、接触抵抗が上昇するので、酸化
チタン0.1〜８重量％、酸化ニツケル0.5〜10重量
％の範囲内では、耐溶着特性、耐消耗特性、低接
触抵抗特性の充分満足できる電気接点材料が得ら
れるものである。
次に本発明による電気接点材料の効果を明瞭な
らしめる為に、具体的な実施例と従来例について
説明する。
下記の表の左欄に示す実施例及び比較例１、２
の成分組成の材料粉末をそれぞれ粉砕混合し、こ
の混合粉末を圧縮、焼結を繰り返したのち、熱間
押出、冷間伸線した。そして、この線材をヘツダ
ー加工により、頭径2.5mmの可動接点と頭径2.8mm
の固定接点を得た。
また、従来例に関しては銀及びカドミウムを溶
解し、アトマイズ粉となした後、800℃、５気圧
で内部酸化し、この銀−酸化カドミウム粉を圧縮
焼結し、これを押出し、引抜加工した後切断して
ヘツダー加工し、頭径2.5mmの可動接点と頭径2.8
の固定接点を得た。
然してこれら実施例１〜３及び従来例によるリ
ベツト型電気接点を下記の試験条件にて開閉試験
を行つた処、下記の表の右欄に示すような結果を
得た。
試験条件
電 圧 AC100V、50Hz
電 流 投入40A、定常10A
負 荷 抵抗負荷
開閉頻度 20回／分
接触力 40ｇ
開離力 45ｇ
The present invention relates to electrical contact materials.
Conventionally, silver-cadmium oxide and silver-tin oxide-based materials have been used as oxide-based electrical contact materials. In particular, silver-cadmium oxide contact materials exhibit well-balanced performance in terms of overall contact properties such as welding resistance, hair loss resistance, and contact resistance, and are also excellent in processability, making them suitable for various electrical conditions. It has been widely used. However, recently, there has been an increasing demand for the development of contact materials with performance exceeding this, due to the need to flow larger currents through smaller contact diameters as electronic components become smaller. Amid these trends, especially with regard to welding resistance, silver
There is a need for contact materials with performance superior to cadmium oxide. As the number of times the silver-cadmium oxide contact material is opened and closed increases, the cadmium oxide sublimes and a silver layer is formed on the contact surface layer, which causes the deterioration of the welding resistance of the silver-cadmium oxide contact material. Therefore, the present inventor has developed an electrical contact which has a welding resistance superior to that of a silver-cadmium oxide electrical contact material, and which has performance comparable to that of a silver-cadmium oxide electrical contact material in terms of contact resistance and abrasion resistance. As a result of intensive research to develop materials, we have discovered a satisfactory electrical contact material. Although titanium oxide exhibits excellent adhesion resistance when used as a silver-titanium oxide electrical contact material, satisfactory results cannot be obtained because the contact resistance is high and the amount of wear is large. Furthermore, silver-nickel oxide exhibits stable contact resistance that exceeds that of silver-cadmium oxide and excellent abrasion resistance, but in terms of welding resistance, it exhibits performance comparable to that of silver-cadmium oxide. The additives in the claims of the present invention were selected taking these points into consideration, and titanium oxide 0.1 to 8
The reason for setting the weight% and nickel oxide to 0.5 to 10% by weight is that if titanium oxide is less than 0.1% by weight and nickel oxide is less than 0.5% by weight, the amount of silver will increase, and although low contact resistance characteristics can be obtained, welding resistance will be reduced. Good results cannot be obtained, and if titanium oxide exceeds 8% by weight or nickel oxide exceeds 10% by weight, processability is poor, and an agglomerated layer of oxide forms on the contact surface during use, resulting in poor contact resistance. Therefore, within the range of 0.1 to 8% by weight of titanium oxide and 0.5 to 10% by weight of nickel oxide, an electrical contact material with sufficiently satisfactory welding resistance, wear resistance, and low contact resistance characteristics can be obtained. Next, in order to clarify the effects of the electrical contact material according to the present invention, specific examples and conventional examples will be described. Examples and Comparative Examples 1 and 2 shown in the left column of the table below
Material powders having the following component compositions were pulverized and mixed, and this mixed powder was repeatedly compressed and sintered, followed by hot extrusion and cold wire drawing. Then, by header processing this wire, we made a movable contact with a head diameter of 2.5mm and a head diameter of 2.8mm.
A fixed contact was obtained. Regarding the conventional example, after melting silver and cadmium to form an atomized powder, internal oxidation was performed at 800°C and 5 atm, this silver-cadmium oxide powder was compressed and sintered, and this was extruded and drawn. Cut and head-processed to create a movable contact with a head diameter of 2.5 mm and a head diameter of 2.8
A fixed contact was obtained. However, when the rivet type electrical contacts of Examples 1 to 3 and the conventional example were subjected to opening/closing tests under the following test conditions, the results shown in the right column of the table below were obtained. Test conditions Voltage AC100V, 50Hz Current Input 40A, steady 10A Load Resistive load Switching frequency 20 times/min Contact force 40g Breaking force 45g
【表】
前記の表で明らかなように実施例の電気接点材
料で作つたリベツト型電気接点は、従来例及び比
較例２の接点に比し、耐溶着性が遥かに優れ、ま
た比較例１の接点に比し、接触抵抗、耐消耗性が
遥かに優れ、更に従来例の接点に比し、接触抵
抗、耐消耗性に優るとも劣らぬことが判る。
以上詳記した通り本発明の電気接点材料は、従
来の電気接点材料よりも総合的に優れた接点特性
を有するので従来の電気接点材料にとつて代わる
ことのできる画期的なものと云える。[Table] As is clear from the table above, the rivet-type electrical contacts made with the electrical contact materials of Examples have much better welding resistance than the contacts of the conventional example and Comparative Example 2. It can be seen that the contact resistance and abrasion resistance are far superior to those of the conventional contacts, and the contact resistance and abrasion resistance are comparable to those of the conventional contacts. As detailed above, the electrical contact material of the present invention has contact characteristics that are comprehensively superior to that of conventional electrical contact materials, so it can be said to be an epoch-making material that can replace conventional electrical contact materials. .