【発明の詳細な説明】[Detailed description of the invention]
本発明は、摺動接点材料の改良に関する。
従来より摺動接点材料の一つとして耐硫化性、
潤滑性に優れたAg−Zn合金が用いられてきた
が、Ag−Zn合金の摺動接点材料は酸化し易く、
接触抵抗が高く不安定になるという欠点があり、
従つてこの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には刷子接
点との接触抵抗が変化し、整流子の回転速度が大
きくばらついて不安定なものとなつていた。
本発明は、かかる欠点を解消すべくなされたも
のであり、Ag−Zn合金の酸化による接触抵抗の
増大を抑制し、耐硫化性、潤滑性を維持しつつ耐
消耗性を向上させ、しかも、接触抵抗を低く安定
させた摺動接点材料を提供せんとするものであ
る。
Pt、Ru及びPdの内の少なくとも一種を合計で
0.5〜２重量％、Zn1〜10重量％及び残部Agの銀
合金より成るものである。
かかる本発明の摺動接点材料に於いて、Ag中
に１〜10重量％（以下ｗ／ｏという。）のZnを添
加した以外にPt、Ru及びPdの内の少くとも一種
を合計で0.5〜2w／ｏ添加するのは、これらの元
素の添加された材料より成る整流子の外周の接点
片はAg−Zn合金での酸化による接触抵抗の増大
が抑制され、Ag−Zn合金の有する耐硫化性、潤
滑性が維持されて耐消耗性が向上すると共に接触
抵抗が低く安定するからであり、0.5w／ｏ未満
ではAg−Zn合金での酸化による接触抵抗の増大
が抑制されず、つまりZnOが生成されて接触抵抗
が高く不安定になり、2w／ｏを超えると加工困
難となり、またAg−Zn合金の有する耐硫化性、
潤滑性等の特性を損ない耐消耗性が低下するの
で、結局0.5〜2w／ｏの添加が必要である。
次に本発明による摺動接点材料と従来の摺動接
点材料にて作つた小型モータの整流子の接点片に
ついて説明する。
後記の表の右欄に示す成分組成の本発明の実施
例である摺動接点材料と従来例の摺動接点材料に
て、図面に示す如く小型モータの直径６mm、長さ
９mmの整流子１の外周に厚さ0.2mmの接点片１ａ
が形成され、この接点片１ａの外周面の上下に、
Au−Ag−Cu−Pt合金より成る直径0.25mm、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１の回転試験を行い、接点片１ａの消耗量
と整流子１の回転数のばらつきを測定した処、後
記の表の右欄に示すような結果を得た。
試験条件
電 圧：12V
電 流：直流60ｍＡ
整流子の回転数：2800回転／分
整流子の回転時間：500時間
刷子接点の接触力：５ｇ／３本
The present invention relates to improvements in sliding contact materials. As one of the sliding contact materials, sulfur resistance and
Ag-Zn alloys with excellent lubricity have been used, but sliding contact materials made of Ag-Zn alloys are easily oxidized.
It has the disadvantage of high contact resistance and instability.
Therefore, if this sliding contact material is used to manufacture and use a contact piece for the outer circumference of a commutator of a small motor, the contact resistance with the brush contact will change, and the rotation speed of the commutator will vary widely and become unstable. It was becoming. The present invention has been made to eliminate these drawbacks, and suppresses the increase in contact resistance due to oxidation of the Ag-Zn alloy, improves wear resistance while maintaining sulfidation resistance and lubricity, and further, The object of the present invention is to provide a sliding contact material with low and stable contact resistance. Total amount of at least one of Pt, Ru and Pd
It consists of a silver alloy of 0.5 to 2% by weight, Zn1 to 10% by weight, and the balance Ag. In the sliding contact material of the present invention, in addition to adding 1 to 10% by weight (hereinafter referred to as w/o) of Zn to Ag, a total of 0.5% of at least one of Pt, Ru, and Pd is added. The reason for adding ~2w/o is that contact pieces on the outer periphery of the commutator made of materials to which these elements are added suppress the increase in contact resistance due to oxidation in the Ag-Zn alloy, and increase the resistance of the Ag-Zn alloy. This is because sulfidation and lubricity are maintained, wear resistance is improved, and contact resistance is low and stable.If it is less than 0.5w/o, the increase in contact resistance due to oxidation in the Ag-Zn alloy is not suppressed. ZnO is generated and the contact resistance becomes high and unstable, and if it exceeds 2w/o, it becomes difficult to process, and the sulfidation resistance of Ag-Zn alloy
Since it impairs properties such as lubricity and reduces wear resistance, it is necessary to add 0.5 to 2 w/o. Next, a contact piece for a commutator of a small motor made of a sliding contact material according to the present invention and a conventional sliding contact material will be explained. A commutator 1 of a small motor with a diameter of 6 mm and a length of 9 mm as shown in the drawings was prepared using the sliding contact material according to the embodiment of the present invention and the conventional sliding contact material having the compositions shown in the right column of the table below. A contact piece 1a with a thickness of 0.2 mm is placed on the outer periphery of the
are formed above and below the outer peripheral surface of this contact piece 1a,
Made of Au-Ag-Cu-Pt alloy, diameter 0.25mm, length
A rotation test was performed on the commutator 1 under the test conditions described below by sliding the brush contacts 3 having three 10 mm brush wires 2 so as to face each other, and the wear amount of the contact piece 1a and the commutator 1 were measured. When we measured the variation in rotational speed, we obtained the results shown in the right column of the table below. Test conditions Voltage: 12V Current: DC 60mA Commutator rotation speed: 2800 rotations/min Commutator rotation time: 500 hours Contact force of brush contacts: 5g/3 pieces
【表】
前記の表で明らかなように従来例の接点片の消
耗量は５〜7μｍであつたのに対し、実施例の接
点片の消耗量は3.5〜5μｍで著しく減少していて
耐消耗性に優れていることが判る。また従来例の
接点片を有する整流子の回転数のばらつきは８〜
11％であつたのに対し、実施例の接点片を有する
整流子の回転数のばらつきは4.5〜６％で著しく
減少していることが判る。これはひとえに実施例
の接点片がAg−Zn合金での、酸化による接触抵
抗の増大が抑制されて接触抵抗が低く安定してい
るからに他ならない。
以上詳記した通り本発明の摺動接点材料は、
Ag−Zn合金の酸化による接触抵抗の増大が抑制
され、耐硫化性、潤滑性が維持されているので、
これにより作つた小型モータの整流子の接点片の
耐消耗性は著しく向上するものである。またAg
−Zn合金の酸化による接触抵抗の増大が抑制さ
れて接触抵抗が低く安定しているので、小型のモ
ータの整流子の回転数のばらつきが大幅に減少す
る等の優れた効果がある。[Table] As is clear from the above table, the amount of wear of the contact piece of the conventional example was 5 to 7 μm, while the amount of wear of the contact piece of the example was 3.5 to 5 μm, which was significantly reduced, indicating that the contact piece of the conventional example had wear resistance. It turns out that they have excellent sex. In addition, the variation in the rotation speed of the commutator with the conventional contact piece is 8~
It can be seen that the variation in the rotational speed of the commutator having the contact piece of the example was 4.5 to 6%, which was significantly reduced, whereas it was 11%. This is simply because the contact piece of the example is made of an Ag-Zn alloy, and the increase in contact resistance due to oxidation is suppressed, resulting in a low and stable contact resistance. As detailed above, the sliding contact material of the present invention is
Increase in contact resistance due to oxidation of Ag-Zn alloy is suppressed, and sulfidation resistance and lubricity are maintained.
The wear resistance of the contact piece of the commutator of the small motor made by this method is significantly improved. Also Ag
- Since the increase in contact resistance due to oxidation of the Zn alloy is suppressed and the contact resistance is low and stable, it has excellent effects such as significantly reducing variations in the rotation speed of the commutator of small motors.
【図面の簡単な説明】[Brief explanation of drawings]
図は小型モータの整流子と刷子接点との接触状
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 the state of contact between the commutator and brush contacts of a small motor. 1...Commutator, 1a...Contact piece, 2...Brush wire, 3...Brush contact.