JPS616231A - Sliding contact material - Google Patents

Abstract

PURPOSE:To obtain the titled material having low and stable contact resistance by adding prescribed percentages of Cu, Cd, Si and Zr 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 3-12wt% Cu, 0.5-5wt% Cd and 0.5-10wt% Si and Zr 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 hardly softens 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 bruch 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 use bone WP) The present invention relates to improvements in sliding contact materials.

<Prior Art and Problems> Conventionally, Ag-Cd alloy has been used as one of the sliding contact materials, but Ag-Cd alloy softens 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.

(Purpose of Qming) The present invention has been made to eliminate such drawbacks,
It is an object of the present invention to provide a sliding 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 3 to 12 f of Cu in Ag.
% fi, 0.5 to 5% by weight of Cd, and 0.5 to 10% by weight of 81 and Zr.

Further, some of the above-mentioned additive elements of the sliding contact material of the present invention are added to 0.
Fe group elements (Fe) in the range of 0.01 to 0.5%.

Nl, Co) may be substituted.

In the sliding contact material of the present invention, 0.5
3-12 wt% C in addition to adding ~5 wt% Cd
The reason why u is added is to increase the hardness of the Ag-Cd alloy and improve its wear resistance.If it is less than 3% by weight, the effect will not appear, and if it exceeds 12% by weight, the amount of oxides produced will increase. The contact resistance is high and unstable.
The reason why 0.5 to 10% by weight of Zr is added is to suppress softening during sliding and improve wear resistance.
If it is less than 4% by weight, softening cannot be suppressed and wear resistance will not be improved, and if it exceeds 4% by weight of 1O, a large amount of oxides will be generated, resulting in high contact resistance and instability. Furthermore, some of the above-mentioned additional elements are added in the range of 0.01 to 0.5% by weight.
When substituted with e-group elements (Fe, Ni, Co), the crystal grains can be made finer and wear resistance can be further improved.
If it is less than 0.01% by weight, crystal grains cannot be refined;
In terms of weight percentage, it does not form an alloy, but precipitates as a single large lump in Ag, resulting in high contact resistance, large variations, and instability.

(Example and Conventional Example) As shown in the drawing, the diameter of a small motor is 12 mm = A contact piece 1a having a thickness of 2N is formed on the outer periphery of the commutator 1 having a length of 81.
Pd-Ag-Cu-Pt-Au on the top and bottom of the outer peripheral surface of a
- Brush contacts 3 having two brush wires 2 with a diameter of 0.7 mm and a length of 811 made of Zn were brought into sliding contact so as to face each other, and the test bacteria I. A rotation test was conducted on the commutator 1 at , and the wear amount of the contact piece 1a and the contact resistance were determined by α1, and the results shown in the right column of the table below were obtained.

Test conditions Voltage: DC12V if Current: 0.6A Commutator rotation speed: ]000rpm Commutator rotation time = 7 hours Brush contact contact force n 100g (blank below) [Ra] Evidently from the above table 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 softening and has excellent wear resistance. There are excellent effects such as extremely little generation of abrasion powder, therefore no noise, and 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. 1-1-commutator, 1a--contact piece, 2--1 brush wire, 3-111--brush contact.

Claims (1)

[Claims] 1) 3 to 12% by weight of Cu and 0.5% of Cd in Ag
~5% by weight and 0.5 to 10% by weight of Si and Zr. 2) The sliding contact material according to claim 1, wherein a part of the additive element is substituted with an Fe group element in a range of 0.01 to 0.5% by weight.