JPS61133345A - Sliding contact point material - Google Patents

Abstract

PURPOSE:To reduce and stabilize the contact resistance of the sliding contact point material, by dispersing an oxide of Cd and each oxide of B, Si, Ge, and Tl in Ag finely and uniformly. CONSTITUTION:The sliding contact point material is manufactured by dispersing, by weight, 0.5-15% CdO and 0.1-5% of >=1 kind among B2O3, SeO2, GeO2, and Tl2O3 in Ag finely and uniformly. The softening temp. as well as the lubricating ability of this material is increased because of the fine and uniform dispersion of the above oxides in the Ag, so that the wear resistance of, e.g., contact segments of a commutator of a small-sized motor made of this material can be improved. Moreover, no oxide film is formed on the sliding surface, so the contact resistance can be reduced and stabilized and the variance in the number of revolutions of the commutator can be reduced.

Description

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

(Prior art and problems) Conventionally, Ag-Cd alloy has been mainly used as a sliding contact material for making contact pieces around the commutator of small motors, but it softens during the rotational sliding operation of the commutator. There were disadvantages in that the contact pieces adhered to each other, causing a lot of wear, and oxidized, making the contact resistance unstable and causing variations in the commutator rotational speed.

(Object of the Invention) The present invention was made in view of the above circumstances, and an object thereof is to provide a sliding contact material that reduces wear by uniformly and finely dispersing oxides in Ag, and has a low and stable contact resistance. It is.

(Structure of the Invention) The sliding contact material of the present invention contains 0.0% Cd oxide in Ag.
5-15% by weight and B + S t + G e , T
It is characterized in that at least one oxide of I is uniformly and finely dispersed in an amount of 0.1 to 5% by weight.

In the sliding contact material of the present invention, Cd is added to Ag.
The purpose of uniformly and finely dispersing 0.5 to 15% by weight of oxides is to increase the lubricity and improve the wear resistance of Ag.
If it is less than 0.5% by weight, there is no effect (and if it exceeds 15% by weight, the contact resistance becomes high and unstable.

Furthermore, the reason for adding 0.1 to 5% by weight of at least one of the oxides of B, Si, Ge, and Ti is to increase the softening temperature, suppress adhesion during the rubbing operation, and improve wear resistance. ,0
．． If it is less than 1% by weight, there is no effect, and if it exceeds 5% by weight, processing becomes difficult.

(Embodiments and Conventional Examples) Contact pieces on the outer periphery of 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 described.

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 (made by internal oxidation method) and a conventional sliding contact material having the composition shown in the left column of the table below. A commutator 1 with a diameter of 12 mm and a length of 8 mm has three contact pieces on the outer periphery as shown in the drawing.
A commutator rotation test was carried out under the test conditions described below by bringing two brush contacts 3 having two brush wire rods 2 of diameter 0.1ta and length 8fi made of -Pt into contact with each other so as to face each other,
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: DC12V Current: 0.6A Commutator rotation speed: 1000 rpm Commutator rotation time Near time Brush contact contact force = 100g As is clear from the table above, the wear of the conventional contact piece The amount is 9
．． 2 ■, whereas the amount of wear of the contact piece in the example was 5
．． It can be seen that the wear resistance is significantly reduced from 8 to 6.8 . 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 has oxides uniformly and finely dispersed in Ag, and has high lubricity and softening temperature. The wear resistance of the child contact piece is significantly improved. Further, since no oxide film is formed on the sliding surface, the contact resistance is low and stable, and there are excellent effects such as extremely small variations in the rotation speed of the commutator of a small 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, 1a.--One contact piece, 2-.-
Brush line size, 3----- one brush contact.

Claims (1)

[Claims] In Ag, 0.5 to 15% by weight of Cd oxide and B, Si
A sliding contact material characterized in that 0.1 to 5% by weight of at least one of oxides of , Ge, and Ti is uniformly and finely dispersed.