JPS616230A - Sliding contact material - Google Patents

Abstract

PURPOSE:To obtain a sliding contact material having low and stable contact resistanct by adding presceibed amounts of Cu, Cd and one or more among Cr, Mg, Zr and P 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 0.1-5wt% one or more among CR, Mg, Zr and P 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 produced by sliding with the brush contact, causing noise.

(Object of the invention) 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% by weight of Cu, 0.5 to 5% by weight of Cd, and Cr, MgZr, and P in Ag.
At least one of the following is added in an amount of 0.1 to 5 times.

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, 0.5
3-12 wt% C in addition to adding ~5 wt% Cd
The purpose of adding u is to increase the hardness of the Ag-Cd alloy and improve its wear resistance.If it is less than 3% by weight, this effect will not appear, and if it exceeds 12% by weight, the amount of oxides produced will increase. If the number of contacts increases, the contact resistance becomes high and unstable. Further Cr
, Mg, Zr.

Adding 0.1 to 5% by weight of at least one type of P is
This is to suppress softening during sliding and improve wear resistance.
If it is less than 5% by weight, softening cannot be suppressed and wear resistance will not improve, and if it exceeds 5% by weight, a large amount of oxides will be generated, resulting in high contact resistance and instability. Furthermore, a part of the additional elements is Fe group element (Fe) in a range of 0.01 to 0.5% by weight.

When substituted with (Ni, Co), the crystal grains can be made finer and the wear resistance can be further improved.If it is less than 0.01% by weight, the grains cannot be made finer, and if it is more than 0.5% by weight, the grains cannot be made finer. 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) 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 12mm was used as shown in the drawing. A contact piece 1a with a thickness of 2M1 is formed on the outer periphery of a commutator 1 with a length of 3 mm, and Pd-Ag-Cu-Pt-A is formed on the upper and lower sides of the outer peripheral surface of this contact piece 1a.
Direct pI consisting of u-Zn! A rotation test was conducted on the commutator 1 under the test conditions described below by sliding brush contacts 3 having two brush wires 2 having a length of 8 fins and 8 fins in sliding contact with each other so as to face each other. When the wear amount and contact resistance were measured, the results shown in the right column of the table with 1 entry were obtained.

Test conditions Voltage: DC12V Current: 0.6A Commutator rotation speed: 1000rpm Commutator rotation time Near time Brush contact contact crab ]OOg (Hereafter the margin) As is clear from the table above, the conventional example It can be seen that the amount of wear of the contact pieces of the example is significantly reduced compared to the amount of wear of the contact pieces, indicating that the contact pieces of the examples have 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 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-m-contact piece, 2-1--brush wire, :L--1 brush contact.

Claims (1)

[Claims] 1) 3 to 12% by weight of Cu and 0.5% of Cd in Ag
~5% by weight and 0.1 to 5% by weight of at least one of Cr, Mg, Zr, and P. 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.