JPS616229A - Sliding contact material - Google Patents

Abstract

PURPOSE:To obtain a sliding contact material having low and stable contact resistance by adding prescribed amounts of Cu, Cd and one or more among Al, Ga and Mn 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% one or more among Al, Ga and Mn to Ag. When 0.01-0.5wt% Fe group element such as Fe, Ni or Co is substituted for part of said added elements, the grains can be made fine and the wear resistance is further improved. Since the sliding contact material hardly softens and has superior wear resistance, when the contact chips of a commutator for a small-sized motor are made of the sliding contact material, the contact chips produce very little dust due to wear during sliding along brush contacts. 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 softens during sliding and does not have sufficient wear resistance. When a contact piece for the outer periphery of a commutator of a small motor is made of alloy and used, abrasion powder is generated due to sliding with the brush contact, which causes noise generation.

(Object of the invention) The present invention has been made to eliminate such drawbacks,
It is an object of the present invention to provide an fFJ moving contact material that 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% by weight of Cu, 0.5 to 5% by weight of Cd, Al, and Ga in Ag.

At least one type of Mn is added in an amount of 0.5 to 10% 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.

Ni, Co) may be substituted.

In the sliding contact material of the present invention, 71. g I
In addition to adding 0.5 to 5% by weight of Cd to p.
The reason why Cu is added at % by weight 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, oxides will be formed. As the amount increases, the contact resistance becomes high and unstable.

Furthermore, A1. 0.5 to 1 of at least one of Ga and Mn
The reason for adding 0% by weight is to suppress softening during sliding and improve wear resistance, and 0.5ff! If it is less than 1%, softening cannot be suppressed and wear resistance will not improve, and if it exceeds 10% by weight, a large amount of oxides will be generated, resulting in high contact resistance and instability. Furthermore, a part of the above-mentioned additional elements is added in the range of 0.01 to 0.5% by weight of Fe group elements (Fe, N
i.

When substituted with Co), the crystal grains can be refined and the wear resistance can be further improved. If it is less than 0.01% by weight, the grains cannot be refined, and if it exceeds 0.5% by weight, the alloy cannot be made. First, it precipitates as a single large lump in Ag, resulting in high contact resistance and large variations, making it unstable.

(Example and Conventional Example) Using the sliding contact material according to the embodiment of the present invention and the conventional sliding contact material having the compositions shown in the right column of the table below, a small motor with a diameter of 12 nm and a diameter of 12 nm as shown in the drawings were used. A contact piece 1a having a thickness of 2R is formed on the outer periphery of a commutator 1 having a length of 8fi.
Pd-Ag-Cu-PL-Au-
Brush contacts 3 having two brush wire rods 2 made of Zn with a diameter of 0.7 mm and a length of 8 fi were brought into sliding contact so as to face each other, and a rotation test was performed on the commutator l under the test conditions described below. When the wear amount and contact resistance of the contact piece 1a were measured, the results shown in the right column of the table below were obtained.

Test conditions Voltage = DC12 Current: 0.6 A Commutator rotation speed: 1000 rpm Commutator rotation time Near time Brush contact contact loop (blank below) (5) As is clear from the table above Compared to the amount of wear of the contact pieces of the conventional example, the amount of wear of the contact pieces of the example is significantly reduced, indicating that it has excellent wear resistance.Also, the contact resistance of the commutator with the contact pieces of the conventional example is On the other hand, it can be seen that the contact resistance of the commutator having the contact pieces of the example is low and stable.

(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---One contact piece, 2-
...-Brush wire, 3--Brush contact.

Claims (1)

[Claims] 1) 3 to 12% by weight of Cu and 0.5% of Cd in Ag
~5% by weight and at least one of Al, Ga, and Mn.
A sliding contact material containing 5 to 10% by weight. 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.