【発明の詳細な説明】[Detailed description of the invention]
本発明は、刷子用摺動接点材料の改良に関す
る。
従来、摺動接点材料としては各種材料が用いら
れ、とりわけ刷子用摺動接点材料としては、
Pd30〜70重量％、Ag30〜70重量％より成る合金
材料が広く用いられていた（昭和40年７月８日に
工業日日新聞社から発行された日本電子材料技術
協会編の新しい接点材料第114、115頁参照）。
然し乍ら、この合金材料で製作した刷子接点で
は、整流子との摺動時の耐摩耗性が劣り、摩耗粉
が生じ易く、接触抵抗が不安定でノイズ発生の原
因となつていた。
本発明は、斯かる欠点を解消すべくなされたも
のであり、前記合金材料を基材としてこれに特定
の材料を僅かに添加させて、発生する酸化物を潤
滑剤として、耐摩耗性を向上させた刷子用摺動接
点材料を提供せんとするものである。
本発明の刷子用摺動接点材料は、組成比で
Pd30〜70重量％、Ag30〜70重量％のPd−Agが
90〜99重量％及び残部がＢ、Ge及びTlの少なく
とも一種を合計で１〜10重量％から成るものであ
る。
本発明の刷子用摺動接点材料に於いて、組成比
でPd30〜70重量％、Ag30〜70重量％のPd−Ag
が90〜99重量％及び残部がＢ、Ge及びTlの少な
くとも一種を合計で１〜10重量％としている理由
は、前記従来の合金材料の耐摩耗性を向上すべく
潤滑剤となる酸化物を適量発生させる為で、Ｂ、
Ge及びTlのうち少なくとも一種を合計で1.0重量
％未満では酸化物の発生量が少なくて潤滑剤とし
ての効果を発揮できず、Ｂ、Ge及びTlのうち少
なくとも一種を合計で10.0重量％を超えると酸化
物の発生量が多くなり、接触抵抗が高くなり、そ
の上不安定となるものである。また、Pd、Agの
含有量は、前記従来の合金材料の組成比に変更を
加えない範囲とすることにより、従来の合金材料
の特性は損なわれることなく発揮されることとな
るものである。
次に従来の合金材料を基材とし、これにＢを添
加し、表の実施例１に示す成分組成の刷子用摺動
接点材料とし、以下同様にして表に示す成分組成
の本発明による刷子用摺動接点材料と従来の刷子
用摺動接点材料を用いて夫々線径0.7mmの刷子線
材を作り、これを各々長さ８mmに切断し、２本並
列させて一端を幅10mm、長さ13mm、厚さ0.2mmの
台材に溶接し、他端に2Rの円弧状の接触部を曲
成して刷子接点を作つた。そして夫々の刷子接点
を円盤状の整流子に接触させ、整流子を正逆回転
させて下記の試験条件にて摺動試験を行い、摩耗
量及び接触抵抗を測定した処、下記の表の右欄に
示すような結果を得た。
試験条件
電 流：直流0.6A
電 圧：12V
負 荷：抵抗負荷
回転速度：1000回転／分
周 速：130〜120ｍ／min
接触力 ：100ｇ
試験時間：７時間
The present invention relates to improvements in sliding contact materials for brushes. Conventionally, various materials have been used as sliding contact materials, and in particular, as sliding contact materials for brushes,
Alloy materials consisting of 30-70% by weight of Pd and 30-70% by weight of Ag were widely used. (See pages 114 and 115). However, brush contacts made of this alloy material have poor abrasion resistance when sliding with the commutator, tend to generate abrasion powder, and have unstable contact resistance, causing noise generation. The present invention has been made in order to eliminate such drawbacks, and uses the above-mentioned alloy material as a base material and adds a small amount of a specific material to it, and uses the generated oxide as a lubricant to improve wear resistance. It is an object of the present invention to provide a sliding contact material for a brush that has a high quality. The sliding contact material for brushes of the present invention has a composition ratio of
Pd-Ag with Pd30~70wt% and Ag30~70wt%
90 to 99% by weight, and the balance consists of a total of 1 to 10% by weight of at least one of B, Ge, and Tl. In the sliding contact material for brushes of the present invention, the Pd-Ag composition ratio is 30 to 70% by weight of Pd and 30 to 70% by weight of Ag.
The reason why the balance is 90 to 99% by weight and the balance is 1 to 10% by weight in total of at least one of B, Ge, and Tl is that in order to improve the wear resistance of the conventional alloy material, oxides that act as lubricants are added. In order to generate an appropriate amount, B.
If the total amount of at least one of Ge and Tl is less than 1.0% by weight, the amount of oxide generated is small and the lubricant cannot be effective, whereas the total amount of at least one of B, Ge, and Tl exceeds 10.0% by weight. This results in an increased amount of oxides, increased contact resistance, and instability. Further, by setting the contents of Pd and Ag within a range that does not change the composition ratio of the conventional alloy material, the characteristics of the conventional alloy material can be exhibited without being impaired. Next, a conventional alloy material is used as a base material, and B is added thereto to obtain a brush sliding contact material having the composition shown in Example 1 of the table. Brush wires with a wire diameter of 0.7 mm were made using sliding contact materials for commercial use and conventional sliding contact materials for brushes, each cut into 8 mm lengths, and two wires were placed in parallel with one end having a width of 10 mm and a length of 10 mm. A brush contact was made by welding to a base material of 13 mm and 0.2 mm thickness, and curving a 2R arc-shaped contact part on the other end. Then, each brush contact was brought into contact with a disk-shaped commutator, and the commutator was rotated in forward and reverse directions to perform a sliding test under the following test conditions, and the wear amount and contact resistance were measured. The results shown in the column were obtained. Test conditions Current: DC 0.6A Voltage: 12V Load: Resistance load Rotation speed: 1000 rotations/divided speed: 130-120m/min Contact force: 100g Test time: 7 hours
【表】
上記の表で明らかなように実施例１〜12の刷子
接点は従来例１〜３の刷子接点に比し摩耗量が著
しく少なく、接触抵抗が低く安定していることが
判る。これはひとえに実施例１〜12の刷子接点の
刷子線材を構成している本発明の刷子用摺動接点
材料が、摺動時にＢ、Ge、Tl等の酸化物が発生
し、この酸化物が潤滑剤となり、耐摩耗性が向上
されるからに他ならない。また、酸化物の発生量
が摩耗量とバランスしているため、接触抵抗は変
わらないからに他ならない。
以上詳記した通り本発明による刷子用摺動接点
材料によれば、従来の刷子用摺動接点材料に比べ
著しく耐摩耗性に優れ、摩耗粉の発生量が極めて
少なく、ノイズの発生が殆んど無く、また従来の
刷子用摺動接点材料による場合よりも低く安定し
た接触抵抗を有する刷子接点を得ることができる
という効果がある。[Table] As is clear from the above table, the brush contacts of Examples 1 to 12 have significantly less wear than the brush contacts of Conventional Examples 1 to 3, and it can be seen that the contact resistance is low and stable. This is because the sliding contact material for brushes of the present invention, which constitutes the brush wire of the brush contacts of Examples 1 to 12, generates oxides such as B, Ge, and Tl during sliding. This is because it acts as a lubricant and improves wear resistance. Furthermore, since the amount of oxide generated is balanced with the amount of wear, the contact resistance remains unchanged. As detailed above, the sliding contact material for brushes according to the present invention has significantly superior wear resistance compared to conventional sliding contact materials for brushes, generates extremely little wear powder, and generates almost no noise. This has the advantage that it is possible to obtain a brush contact having a lower and more stable contact resistance than when using conventional brush contact materials.