JPS58107456A - Material for slide contact - Google Patents

Abstract

PURPOSE:To provide a slide contact material of which wear resistance is enhanced and contact resistance is stabilized at a low level, by respectively adding Zn and one kind or more of Si, Zr, Bi and Ga to Ag in a predetermined ratio to increase the hardness of an Ag-Zn alloy. CONSTITUTION:This slide contact material is constituted of an Ag-Zn alloy obtained by adding 1-10wt% Zn and 0.1-3wt% one kind or more Si, Zr, Bi and Ga and additional 0.01-0.5wt% Fe group element. Because this slide contact material is high in hardness and excellent in wear resistance, the contact element of the rectifier of a small motor produced by using this material generates no powder by abrasion in slide contact with a brush contact point. Therefore, because noise is not generated and contact resistance is stabilized at a low level, irregularity in the number of rotation of the rectifier of the small motor is reduced remarkably.

Description

[Detailed description of the invention] The present invention relates to improvements in sliding contact materials.

A with superior sulfidation resistance than conventional sliding contact materials.
g Zn alloy has been used, but since Ag-Zn alloy has low hardness and poor wear resistance, it is difficult to use this Ag-Zn alloy when manufacturing and using contact pieces around the commutator of a small motor. Contact with the brush contacts produced abrasion powder, which caused noise, and the contact resistance with the brush contacts changed, causing the commutator's rotational speed (1) to vary widely and become unstable.

The present invention has been made in order to eliminate these drawbacks, and it improves the hardness of the Ag-Zn alloy, improves its wear resistance, and also reduces and stabilizes the variation in commutator rotational speed by reducing and stabilizing the contact resistance at a low level. The purpose of this invention is to provide a sliding contact material.

One of the sliding contact materials of the present invention contains Z by weight in Ag.
It is made by adding n1 to 10% and at least one of Sl, Zr, Bl, and Ga in a total of 0.1 to 3%.

Another of the sliding contact materials of the present invention contains 1 to 10% Zn and Si, Zr, and Bi in a weight ratio of Ag.

A total of 0.1 to 3% of at least one type of Ga and 0 of Fe group
．． It is made by adding 01 to 0.5%.

In the sliding contact material of the present invention, in Ag, 1 to
The reason why 10% Zn is added is to improve the sulfidation resistance of Ag; if it is less than 1%, the effect will not appear, and if it exceeds 10%, the amount of oxide generated will increase, resulting in high contact resistance and instability. It is something that becomes. Also Sl.

At least one of Zr, Bi, and Ga in a total of 0.1 to 3 (
2) The purpose of adding 0% is to disperse the eutectic precipitates of the above elements and Ag in addition to the solid solution of Ag and Zn, thereby increasing the hardness of Ag-Zn and improving the wear resistance. A if less than .1%
Ag-Zn has few eutectic precipitates and insufficient dispersion.
The hardness cannot be increased, the wear resistance cannot be improved,
If it exceeds 3%, the number of precipitated eutectic particles with Ag will increase and the particles will oxidize, resulting in high contact resistance and unstable t.
It depends. Furthermore, 0.01 to 0.5% of Fe group
It is added to make the crystal grains finer and improve wear resistance.If it is less than 0.01%, the crystal grains cannot be made finer, and 0.
．． When it exceeds 5%, alloying does not occur, and it precipitates as a single large lump in Ag, resulting in high contact resistance and large variations, resulting in instability.

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 contact piece with a thickness of 0.2 mm was made using a sliding contact material according to an embodiment of the present invention and a conventional sliding contact material having the composition shown in the right column of the table below, and this contact piece was drawn in the drawing. As shown in (3), three commutators 1 with a diameter of 6-1 and a length of 9 cm are provided on the outer periphery, and three commutators made of Au-Ag-Cu-Pt with a diameter of 125 cm and a length of 10 m are placed above and below the outer peripheral surface of the commutator 1. A rotation test of the commutator 1 was performed under the test conditions described below by sliding the brush contacts 3 having the brush wires 2 so as to face each other, and the wear amount of the contact piece 1a and the variation in the rotation speed of the commutator 1 were evaluated. As a result of the measurements, the results shown in the right column of the table below were obtained.

Test conditions Voltage: 12V Current: DC60mA Number of commutators: 2800rpm (4) As is clear from the table above, the amount of wear on the contact piece of the conventional example was 5.
The wear amount of the contact piece in the example was 3μ, whereas the wear amount of the contact piece in the example was 3μ.
It can be seen that the wear resistance is significantly reduced at ~4μ, indicating that the wear resistance is excellent. Furthermore, while the variation in rotational speed of the commutator with the contact piece of the conventional example was 8 to 11%, the variation of the rotational speed of the commutator with the contact piece of the example was 3 to 4.5%, which was significant. It can be seen that it is decreasing.

As detailed above, the sliding contact material of the present invention has high hardness and excellent wear resistance, so the contact pieces of the commutator of the /11 motor made using this material are abrasion particles when sliding with the brush contacts. Since the contact resistance is low and stable without the occurrence of noise, it has excellent effects such as greatly reducing variations in the rotation speed of the commutator of the /11 motor.

[Brief explanation of the drawing]

The figure is a perspective view showing the state of contact between the commutator and brush contacts of a small motor. 1--Commutator, la--Contact piece, 2--Brush wire, 3---One brush contact. (6)

Claims (2)

[Claims] (1) In Ag, weight ratio t'Znl~10% and si. A sliding contact material containing at least one of Zr*Bl and Ga in a total amount of 0.1 to 3%. (2) 1 to 10% Zn and si by weight in Ag. A total of 0.1 to 3% of at least one of Zr, Bi, and Ga
A sliding contact material made by adding 0.01-0.5% of Fe group.