JPS61130444A - Sliding contact point material - Google Patents

Abstract

PURPOSE:To control the adhesive property and to improve the wear resistance by adding prescribed percenrtages of C, In, Sn and Fe group element to Ag. CONSTITUTION:A sliding contact point material is obtd. by adding 0.1-5wt% C and 0.5-10wt% in total of In and Sn to Ag. An Fe group element may be substituted for part (0.01-0.5wt%) of said added elements. The adhesion 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 adheres during sliding operation 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 the sliding action with the brush contact, which causes noise generation.

(Object of the Invention) The present invention has been made to eliminate such drawbacks, and provides a sliding contact material that suppresses the adhesion of Ag-Cd alloy, improves wear resistance, and has low and stable contact resistance. This is what we intend to provide.

(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 0.5 to 10% by weight of In and Sn in total to Ag.

In addition, some of the additive elements of the sliding contact material of the present invention are o, ot
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, the reason why In and Sn are added in a total of 0.5 to 10% by weight is that the oxides of the above elements generated during the sliding action act as a lubricant and improve wear resistance. If it is less than 10% by weight, the effect will not be apparent, and if it exceeds 10% by weight, a large amount of oxides will be generated, resulting in high contact resistance and instability.

Furthermore, when some of the added elements are replaced with Fe group elements (Fe, Co, Ni) in the range of o, oi to 0.5% by weight, the crystal grains can be made finer and wear resistance can be further improved. If it is less than 0.01% by weight, the crystal grains cannot be refined;
．． If it exceeds 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 composition shown in the left column of the table below, the outer periphery of a commutator 1 of a small motor with a diameter of 12n and a length of 8fl as shown in the drawings is used. A contact piece 1a having a thickness of 2 mm is formed on the contact piece 1.
Brush contacts 3 having two brush wires 2 made of AuA g -Cu -pt with a diameter of 0.7 mm and a length of 8 wires are brought into contact with the upper and lower sides of the outer peripheral surface of a so as to face each other, as described below. A rotation test was conducted on the commutator 1 under the test conditions, and the contact piece 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 crab 100g (blank below) As is clear from the table above, the conventional contact It can be seen that the amount of wear on the contact piece of the example is significantly reduced compared to the amount of wear on the piece, indicating that it 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 (has excellent abrasion resistance), so the contact piece of the commutator of a small motor made using this material can be used to contact brush contacts. It has excellent effects such as very little generation of contact wear 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. ■・--- Commutator, 1a---One contact piece, 2-
...-Brush wire, 3.-m-.Brush contact.

Claims (1)

[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 In and Sn in total 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.