JPS616233A - Sliding contact material - Google Patents

Abstract

PURPOSE:To obtain the titled material having low and stable contact resistance by adding prescribed percentages of Cd, Mn and one or more among Si, Bi and Ge to Ag so as to control the stickiness of an Ag-Cd alloy and to improve the wear resistance. CONSTITUTION:A sliding contact material is obtd. by adding 0.5-15wt% Cd, 1-7wt% Mn and 0.5-5wt% one or more among Si, Bi and Ge to Ag. In the material, 0.01-0.5wt% Fe group element may be substituted for part of said added elements. Since the sliding contact material is hardly stuck and has superior wear resistance, when the contact chips 1a of a commutator 1 for a small- sized motor are made of the sliding contact material, the contact chips 1a produce very little dust due to wear during sliding along brush contacts 3. No noise is generated and a beneficial effect such as low and stable contact resistance is shown.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to improvements in sliding contact materials.

(Prior art and problems) Ag-Cd alloy has conventionally been used as one of the sliding contact materials, but Ag-Cd alloy adheres during sliding and does not have sufficient wear resistance. When a Cd alloy is used as a contact piece for the outer periphery of a commutator of a small motor, abrasion powder is produced by sliding with the brush contact, causing noise.

(Object of the invention) The present invention has been made to eliminate such drawbacks,
It is an object of the present invention to provide a tH dynamic contact material which suppresses the adhesion of Ag-Cd alloy, improves wear resistance, and has low and stable contact resistance.

(Structure of the Invention) The sliding contact material of the present invention contains 0.5 to 1 Cd in Ag.
5% by weight, Mn from 1 to 7% by weight, Si, Bi.

At least one type of Ge is added in an amount of 0.5 to 5% by weight.

Further, some of the above-mentioned additive elements of the sliding contact material of the present invention are added to 0.
Fe group element (Fe.

Nl, Co) may be substituted.

In the sliding contact material of the present invention, 0.5
The reason for adding 1 to 7fi1% of Mn in addition to ~15% by weight of Cd is to increase the adhesion resistance of the Ag-Cd alloy and improve its wear resistance. No effect is obtained, and if the amount exceeds 7%, the amount of oxide produced increases, resulting in high contact resistance and instability. Also S
i, bi, g.

The reason for adding 0.5 to 5% by weight of at least one of the above is that the oxide of the above element generated during sliding acts as a lubricant and improves wear resistance.If it is less than 0.5% by weight, Ag
The adhesion of the -Cd alloy cannot be suppressed and the wear resistance is not improved, and if it exceeds 5% by weight, a large amount of oxides are generated, resulting in high contact resistance and instability. Furthermore, some of the above-mentioned additive elements are added to F in a range of 0.01 to 0.5 fl amount%.
Group a elements (Fe.

When substituted with (Nl, Co), the crystal grains can be made finer and the wear resistance can be further improved. If it is less than 0.01% by weight, the crystal grains cannot be made finer, and if it exceeds 0.5% by weight, it is not possible to make the grains finer. It does not alloy with Ag and precipitates as a single large lump in Ag, resulting in high contact resistance and large variations, resulting in instability.

(Example and Conventional Example) A sliding contact material according to an example of the present invention and a conventional sliding contact material having the compositions shown in the right column of the table below were used as shown in the drawings (direct pi 12 mm of a small motor). , commutator 1 with length 8
A contact piece 1a with a thickness of 2 fl is formed on the outer periphery of the contact piece 1a, and two brush wires 2 made of Au-Ay-Cu-PL with a diameter of 0.7 mm and a length of 8 mm are placed above and below the outer peripheral surface of the contact piece 1a. A rotation test was performed on the commutator 1 under the test conditions described below, with the brush contacts 3 having the brush contacts 3 facing each other in sliding contact, and the wear amount and contact resistance of the contact piece 1a were measured. We obtained 19 results as shown in the right column.

Test conditions Voltage: DC12V Current: 0.6A Commutator rotation speed: ]00Orpm Commutator rotation time Near time Brush contact contact crab ]000g or less (margin) [5] As shown in the table above As can be seen, the amount of wear of the contact piece of the example is significantly reduced compared to the amount of wear of the contact piece of the conventional example, and it can be seen that the contact piece of the example has excellent wear resistance. Furthermore, it can be seen that the contact resistance of the commutator having the contact pieces of the example is lower and more stable than the contact resistance of the commutator having the contact pieces of the conventional example.

(Effects of the Invention) As detailed above, the sliding contact material of the present invention is resistant to adhesion and has excellent wear resistance. There are very few abrasion particles generated during operation, so there is no noise, and there are excellent effects such as low and stable contact resistance.

[Brief explanation of drawings]

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--One brush contact.

Claims (1)

[Claims] 1) 0.5 to 15% by weight of Cd and 1% by weight of Mn in Ag
~7% by weight and at least one of Si, Bi, and Ge and 0.0% by weight.
A sliding contact material containing 5 to 5% by weight. 2) The sliding contact material according to claim 1, wherein a part of the additional element is substituted with an Fe group element in a range of 0.01 to 0.5% by weight.