JPS58110640A - Sliding contact material - Google Patents

Abstract

PURPOSE:To obtain a sliding contact material with superior wear resistance, a hardly dissipative property and low contact resistance by adding a specified amount of at least one among V, W, Ta and Nb to Ag and by carrying out internal oxidation treatment. CONSTITUTION:The contact chips 1a of the commutator 1 of a small-sized motor are made of a material obtd. by adding 0.5-5wt% in total of at least one among V, W, Ta and Nb to Ag and by carrying out internal oxidation treatment at a high temp. Ag is reinforced by dispersing V, W, Ta or Nb and oxide of the added metal is dispersed uniformly and finely by the internal oxidation treatment to disperse and harden the Ag. The resulting sliding contact material for the contact chips 1a of the commutator 1 has low contact resistance to the wire rods 2 of brushes and a hardly dissipative property.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in sliding contact materials for making contacts and pieces around the commutator of small motors.

Conventionally, Ag has been mainly used as a sliding contact material to make contact pieces around the commutator of small motors, but
Since the softening temperature of g is low, the contact pieces tend to stick together while the commutator rotates and slides, causing a lot of wear and tear, resulting in high contact resistance and instability, resulting in large variations in the commutator rotation speed. was there.

For this reason, it has been attempted to increase the softening temperature of Ag by adding KCd, In, Cu, an, etc. to Ag to improve wear and contact resistance, but when the amount of the above elements added increases, Although the abrasion resistance is improved to some extent, the contact resistance has not been sufficiently improved because the additive elements are oxidized during sliding.

The present invention was made in view of the above circumstances, and aims to provide a sliding contact material in which oxide is uniformly and finely dispersed in ~ to strengthen the dispersion of Ag, thereby reducing wear and keeping the contact resistance low and stable. It is something to do.

The sliding contact material of the present invention contains V and W in Ag.

At least one of Ta and Nb is added in a total amount of 0.5 to 5% by weight, and internally oxidized at high temperature.

In the sliding contact material of the present invention, V,
The reason why at least one of W, Ta, and Nb is added in a total amount of 5 to 5% by weight is to disperse and strengthen Ag; less than 0.5% by weight has no effect, and more than 5% by weight This makes processing difficult.

Furthermore, a material in which the above-mentioned elements are added to Ag,
The reason for performing internal oxidation at high temperature is to disperse and strengthen Ag by uniformly and finely dispersing the oxide of the additive element, thereby reducing consumption and lowering and stabilizing the Ag-oxide contact resistance.

Next, a contact piece for the outer periphery of a commutator of a small motor made of a sliding contact material made by Honshumei and a conventional sliding contact material will be explained.

The sliding contact material according to the embodiment of the present invention and the conventional sliding contact material having the compositions shown in the left column of the table below have a thickness of 0.2
M O contact piece was made), and this contact piece was placed outside as shown in the drawing.
A u -A g -Cu -pt above and below the outer peripheral surface of
A commutator rotation test was conducted under the test conditions described below by slidingly contacting brush contacts 3 having three brush wires 2 each having a diameter of 0.25 M and a length of 10 mm so as to face each other. When the wear amount of the piece 1a and the variation in the rotation speed of the commutator were measured, the results shown in the right column of the table below were obtained.

Test Voltage: 12 Current: DC60mA Commutator rotation speed: 2800 rpm Commutator rotation time: 500 hours Brush contact contact crabs 5173 As is clear from the table above, the contact pieces of the conventional example were worn out. m is 2
While it was 0μ, the amount of wear of the contact piece in the example was 4~
It can be seen that the wear resistance is significantly reduced at 5μ, indicating that the wear resistance is excellent. Also, the variation in the rotation speed of the commutator with the conventional contact piece is 1! is 1 to 15 times, whereas the variation in the rotational speed of the commutator with the contact piece of the example 'f! #″t3～
It can be seen that there is a significant decrease at 4%. This is simply because in the contact piece of the example, the oxide of the additive element is uniformly and finely dispersed through high-temperature internal oxidation, the Ag is dispersed and strengthened, and the contact resistance is low and stable.

The sliding contact material of the present invention as described in detail above has oxides uniformly and finely dispersed in Ag to strengthen the dispersion of Ag, so that contact pieces for commutators of small motors made using this material can be used. The abrasion resistance of is significantly improved. In addition, since oxide particles are not generated on the moving surface of the sliding contact material, the contact resistance is low and stable, which has excellent effects such as greatly reducing variations in the rotation speed of the commutator of small motors. There is.

[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, 1a... Contact piece, 2.
...Brush wire, 3...Brush contact. Applicant Tanaka Kikinzoku Kogyo Co., Ltd.

Claims (1)

[Claims] A sliding contact material made by adding a total of 0.5 to 5% by weight of at least one of V, W, Ta, and Nb to Ag and internally oxidizing the mixture at high temperature.