【発明の詳細な説明】[Detailed description of the invention]
本発明は、小型モータの整流子用摺動接点材料
の改良に関する。
従来、小型モータの整流子用摺動接点材料とし
てAg−Cdが用いられてきたが、Cdの含有する小
型モータの整流子用摺動接点材料は製造上、使用
上公害問題が発生する為、近時Cdの含有しない
小型モータの整流子用摺動接点材料が望まれてい
る。また前記Ag−Cdの小型モータの整流子用摺
動接点材料で小型モータの整流子の外周の接点片
を製作して使用した場合は、摺動中Cdが機械的、
電気的に消耗し、CdOとなつて接触抵抗が高く且
つ不安定になるという欠点があり、実用的には、
接点消耗量が10μｍ以下、接触抵抗は10〜15ｍΩ
程度の接点消耗量の少ない、接触抵抗が低く且つ
安定した小型モータの整流子用摺動接点材料の出
現が望まれている。
本発明は、上記要望を満たすことのできる小型
モータの整流子用摺動接点材料を開発すべく鋭意
攻究の結果、満足できる小型モータの整流子用摺
動接点材料を見い出したものである。
本発明の小型モータの整流子用摺動接点材料
は、GeとCuを合計で１〜５重量％及び残部Agの
Ag合金から成るものである。
かかる本発明の小型モータの整流子用摺動接点
材料に於いて、GeとCuを合計で１〜５重量％残
部AgのAg合金とするのは、これらの元素がCdよ
りも酸化物の生成の自由エネルギーが低いので、
これらの元素の含有された材料で作つた小型モー
タの整流子の外周の接点片は、GeとCuの複合含
有による相乗効果と相俟つて摺動中の機械的、電
気的消耗が抑制され、接触抵抗が低く安定するか
らであり、GeとCuの合計が１重量％未満の添加
ではAgの機械的性質が向上せず、摺動中に凝着
現象を引き起こすことがあり、GeとCuの合計が
５重量％を超えると酸化物の発生量が多くなつ
て、接点片の接触抵抗が高く且つばらつきが大き
くなつて不安定となるものである。
次に本発明による小型モータの整流子用摺動接
点材料と従来の小型モータの整流子用摺動接点材
料にて作つた小型モータの整流子外周の接点片に
ついて説明する。
後記の表の左欄に示す成分組成の本発明の実施
例である小型モータの整流子用摺動接点材料と従
来例の小型モータの整流子用摺動接点材料にて図
面に示す如く小型モータの直径10mm、長さ10mmの
整流子１の外周に厚さ0.1mmの接点片１ａを形成
し、この接点片１ａの外周面の上下に、Au−Ag
−Cu−Pt系合金より成る直径0.3mm、長さ10mmの
３本の刷子線材２を有する刷子接点３を相対向す
るように摺接させて後記の試験条件にて整流子の
回転試験を行い、接点消耗量と接触抵抗を測定し
た処、後記の表の右欄に示すような結果を得た。
試験条件
電圧：12ボルト
電流：直流250ミリアンペア
整流子の回転数：2000回転／分
整流子の回転時間：300時間
摺動接点の接触力：５ｇ／３本
The present invention relates to improvements in sliding contact materials for commutators of small motors. Conventionally, Ag-Cd has been used as a sliding contact material for the commutator of small motors, but since the sliding contact material for the commutator of small motors containing Cd causes pollution problems during manufacturing and use. Recently, there has been a demand for sliding contact materials for small motor commutators that do not contain Cd. In addition, when a contact piece for the outer periphery of a commutator of a small motor is manufactured using the Ag-Cd sliding contact material for the commutator of a small motor, Cd is mechanically damaged during sliding.
It has the disadvantage that it is electrically consumed and becomes CdO, resulting in high contact resistance and instability.
Contact wear amount is 10 μm or less, contact resistance is 10 to 15 mΩ
There is a desire for a sliding contact material for a commutator of a small motor that has low and stable contact resistance and has a small amount of contact wear. The present invention has been made as a result of intensive research to develop a sliding contact material for a commutator of a small motor that can satisfy the above-mentioned requirements, and as a result, a satisfactory sliding contact material for a commutator of a small motor has been discovered. The sliding contact material for a commutator of a small motor of the present invention contains 1 to 5% by weight of Ge and Cu in total, and the balance is Ag.
It is made of Ag alloy. In the sliding contact material for a commutator of a small motor of the present invention, the reason why the Ag alloy containing Ge and Cu is 1 to 5% by weight and the balance is Ag is that these elements are more likely to form oxides than Cd. Since the free energy of is low,
Contact pieces on the outer periphery of the commutator of small motors made of materials containing these elements suppress mechanical and electrical consumption during sliding due to the synergistic effect of the combined content of Ge and Cu. This is because the contact resistance is low and stable, and if the total of Ge and Cu is less than 1% by weight, the mechanical properties of Ag will not improve and adhesion may occur during sliding, and the If the total amount exceeds 5% by weight, the amount of oxides generated increases, and the contact resistance of the contact piece becomes high and varies widely, making it unstable. Next, a contact piece for the outer periphery of a commutator of a small motor made of the sliding contact material for a commutator of a small motor according to the present invention and a conventional sliding contact material for a commutator of a small motor will be described. The sliding contact material for a commutator of a small motor according to an embodiment of the present invention and the conventional sliding contact material for a commutator of a small motor having the compositions shown in the left column of the table below can be used to create a small motor as shown in the drawings. A contact piece 1a with a thickness of 0.1 mm is formed on the outer periphery of the commutator 1 with a diameter of 10 mm and a length of 10 mm.
- A commutator rotation test was conducted under the test conditions described below by slidingly contacting brush contacts 3 having three brush wires 2 made of Cu-Pt alloy with a diameter of 0.3 mm and a length of 10 mm so as to face each other. When the contact wear amount and contact resistance were measured, the results shown in the right column of the table below were obtained. Test conditions Voltage: 12 volts Current: DC 250 mA Commutator rotation speed: 2000 revolutions/min Commutator rotation time: 300 hours Contact force of sliding contacts: 5 g/3 pieces
【表】
前記の表で明らかなように従来例の整流子外周
の接点片の接点消耗量は15〜20μｍであるのに対
し、実施例の整流子外周の接点片の接点消耗量は
7.5〜8.4μｍで、著しく少なく耐消耗性に優れて
いることが判る。また従来例の接点片の接触抵抗
は20〜30ｍΩであるのに対し、実施例の接点片の
接触抵抗は10.5〜13.1ｍΩで、著しく低く且つば
らつきが小さく安定していることが判る。
以上詳記した通り本発明の小型モータの整流子
用摺動接点材料は、Cdを含有しないので、整流
子外周の接点片の製造上及び使用上公害問題が発
生することがない。またCdよりも酸化物生成の
自由エネルギーの低いGe、Cuの元素が複合含有
されているので、機械的、電気的消耗が抑制され
る。従つて、これにより作つた整流子外周の接点
片は接点消耗量が少なく、接触抵抗が低く且つば
らつきが少なく安定するので、もつて、回転数の
安定なばらつきの少ない小型モータが得られると
いう優れた効果がある。[Table] As is clear from the above table, the amount of contact wear of the contact pieces on the outer periphery of the commutator in the conventional example is 15 to 20 μm, whereas the amount of contact wear on the contact pieces on the outer periphery of the commutator in the example is 15 to 20 μm.
It can be seen that the thickness is 7.5 to 8.4 μm, which is extremely small and has excellent abrasion resistance. Further, while the contact resistance of the contact piece of the conventional example is 20 to 30 mΩ, the contact resistance of the contact piece of the example is 10.5 to 13.1 mΩ, which is extremely low and stable with little variation. As detailed above, since the sliding contact material for a commutator of a small motor of the present invention does not contain Cd, no pollution problem occurs in manufacturing and using the contact piece around the commutator. In addition, since the elements Ge and Cu, which have lower free energy for oxide formation than Cd, are contained in a composite manner, mechanical and electrical consumption is suppressed. Therefore, the contact piece on the outer circumference of the commutator made using this method has less contact wear, has low contact resistance, and is stable with little variation, resulting in the advantage of being able to obtain a small motor with stable rotational speed and little variation. It has a positive effect.
【図面の簡単な説明】[Brief explanation of drawings]
図は小型モータの整流子と摺動接点との接触状
態を示す斜視図である。
１……整流子、１ａ……接点片、２……刷子線
材、３……刷子接点。
The figure is a perspective view showing a state of contact between a commutator and a sliding contact of a small motor. 1...Commutator, 1a...Contact piece, 2...Brush wire, 3...Brush contact.