JPS616240A - Sliding contact material - Google Patents

Abstract

PURPOSE:To obtain the titled material having low and stable contact resistance by adding prescribed percentages of Cd, Mn and one or more among In, Sn, Sb, P, Ti and Zr 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 1-15wt% Cd, 1-7wt% Mn and 0.5-5wt% one or more among In, Sn, Sb, P, Ti and Zr to Ag. In the material, 0.01-0.5wt% Fe group element may be substituted for part of said added elements. Since the sliding contact material is hardly stuck and has superior wear resistance, when the contact chips 1a of a commutator 1 for a small-sized motor are made of the sliding contact material, the contact chips 1a produce very little dust due to wear during sliding along brush contacts 3. 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 adheres during sliding and does not have sufficient wear resistance. When a Cd alloy is used as a contact piece for the outer periphery of a commutator of a small motor, 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 1 to 15% by weight of Cd, 1 to 7% by weight of Mn, and In and Sn in Ag.

It is made by adding 0.5 to 5% by weight of at least one of Sb, P, TI, and Zr.

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, 1 to 1
The reason why 1 to 7% by weight of Mn is added in addition to 5% by weight of Cd is to increase the adhesion resistance of the Ag-Cd alloy and improve the wear resistance. If this effect does not appear and the amount exceeds 7% by weight, the amount of oxide produced increases, resulting in high contact resistance and instability. Also in, S
n, Sb.

The reason for adding 0.5 to 5% by weight of at least one of P, Ti, and Zr is that oxides of the above elements generated during sliding act as a lubricant and improve wear resistance. If it is less than 5% by weight, it will not be possible to suppress the adhesion of the Ag-Cd alloy and the wear resistance will not improve, and if it exceeds 5% by weight, the amount of oxide generated will be large, resulting in high contact resistance and instability. It is. Furthermore, when some of the above-mentioned additive elements are replaced with Fe group elements (Fθ, Ni, Co) in the range of 0.01 to 0.5% by weight, 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 crystal grains cannot be refined, and if it exceeds 0.5% by weight, it will not form an alloy and will precipitate as a single large lump in Ag, resulting in high contact resistance and wide variation. (This is 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 fl as shown in the drawings was used. , a contact piece 1a having a thickness of 2n is formed on the outer periphery of a commutator 1 having a length of 8H.
Brush contacts 3 having two brush wires 2 made of Au-Ag-Cu-Pt with a diameter of 0.1+n and a length of 8n are brought into sliding contact with each other so as to face each other below the outer peripheral surface of a. A rotation test was conducted on the commutator 1 under the test conditions described later, and the wear amount and contact resistance of the contact piece 1a were measured, and the results shown in the right column of the table described later were obtained.

Test conditions Voltage: DC12V Current: 0.6A Commutator rotation speed: 1000rpm Commutator rotation time Near time Brush contact contact crab 100g (Left below) [R] As is clear from the table above, conventional It can be seen that the amount of wear of the contact piece of the example is significantly reduced compared to the amount of wear of the contact piece of the example, indicating that the contact piece of the example has 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 adhesion and has excellent wear resistance. There are very few abrasion particles generated during operation, so there is no noise, and there are excellent effects such as 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--commutator, LA-contact piece, 2--brush wire, 3--brush contact.

Claims (1)

[Claims] 1) 1 to 15% by weight of Cd and 1 to 7% by weight of Mn in Ag.
% by weight and 0.5 to 5% by weight of at least one of In, Sn, Sb, P, Ti, and Zr. 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.