JPS61130446A - Sliding contact point material - Google Patents

Abstract

PURPOSE:To control the softening property and to improve wear resistance by adding prescribed percentages of C, Sn, Ti and Fe group element to Ag. CONSTITUTION:A sliding contact point material is obtd. by adding 0.1-5wt% C and 0.5-10wt% Sn and/or Ti to Ag. An Fe group element may be substituted for part (0.01-0.5wt%) of said added elements. The softening of the contact material during sliding action is suppressed, and wear resistance is improved.

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 action and does not have sufficient wear resistance. When a contact number on the outer periphery of a commutator of a small motor was manufactured and used, abrasion powder was generated due to the rubbing action with the brush contact, causing noise.

(Object of the Invention) The present invention has been made to eliminate these drawbacks, and aims to provide a sliding contact material that has improved wear resistance and low and stable contact resistance.

(Structure of the Invention) The sliding contact material of the present invention is made by adding 0.1 to 5% by weight of C and small amounts of Sn and Ti (0.5 to 10% by weight of each type) to Ag. .

In addition, some of the additive elements of the sliding contact material of the present invention are 0.01
-0.5% by weight of Fe group elements (Fe, Co.

Ni) may be substituted.

In the sliding contact material of the present invention, 0.1
The reason for adding up to 5% by weight of C is to improve the wear resistance of Ag; if it is less than 0.1% by weight, the effect will not appear, and if it exceeds 5% by weight, it will be difficult to process. In addition, small amounts of Sn and Ti (both 0.5 to 10% by weight are added in order to suppress softening during sliding action and improve wear resistance; less than 0.5% by weight cause softening of Ag. If it exceeds 10% by weight, the amount of oxides generated is large, resulting in high contact resistance and instability.Furthermore, some of the added elements are reduced by 0.01%. ~0.5
When substituted with Fe group elements (Fe, Co, N'i) in a range of 0.01% by weight, crystal grains can be made finer and wear resistance can be further improved. It 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, making it impossible to obtain any further effects.

(Embodiments and Conventional Examples) A contact piece for 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.

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 left column of the table below, a commutator l of a small motor with a diameter of 12fi and a length of 8cm is used as shown in the drawing. A contact piece 1a having a thickness of 2fi is formed on the outer periphery, and two brush wire rods 2 made of Au-Ag-Cu-Pt with a diameter of 0.7 mm and a length of 8 mm are placed above and below the outer peripheral surface of the contact piece 1a. A rotation test was conducted on the commutator 1 under the test conditions described below, with the brush contacts 3 facing each other in sliding contact, and the contact pieces 1a
The wear amount and contact resistance were measured, and the results shown in the right column of the table below were obtained.

Test conditions Voltage: DC12V Current: 0.6A Commutator rotation speed: 1000rpm Commutator rotation time Near time - Brush contact contact time (blank below) 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 very little powder generation, 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. l...- Commutator, 1a... Contact piece, 2-...
・Brush wire, 3...Brush contact.

Claims (1)

[Scope of Claims] 1) A sliding contact material made by adding 0.1 to 5% by weight of C and 0.5 to 10% by weight of at least one of Sn and Ti to Ag. 2) The sliding contact material according to claim 1, wherein a part of the additional element is substituted with an Fe group element in a range of 0.01 to 0.5% by weight.