JPS595581A - Contact piece material for commutator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a material for making a contact piece that is fixed to the outer peripheral surface of a cylindrical commutator and brought into contact with a comb-like sliding brush.

Conventionally, this type of commutator contact piece material includes Cu.

Cu alloys such as Cu-Zn have been used, and a contact made of these materials is fixed to the outer surface of the cylindrical rectifier A, and a comb-shaped sliding brush is brought into contact with this. Use 1
-, when the contact pieces slide due to the rotation of the rectifier r-, the contacts wear out significantly due to electrical and mechanical erosion, the contact pressure of the sliding brush decreases, and the contact resistance increases significantly. This causes uneven rotation of the commutator. For this reason, it may be possible to increase the contact pressure of the sliding brush in advance, but if this is done, the contact piece will wear out more and more due to electrical and mechanical erosion, making it unusable in a short period of time and significantly shortening its life. It is something. Further, since the contact piece made of the above-mentioned material is chemically unstable, initial welding may occur immediately after the contact piece starts sliding with the sliding brush.

The present invention has been made to solve these problems, and aims to provide a contact material that does not wear and does not cause initial welding.

In the commutator contact piece material of the present invention, two layers of coating are applied to the surface of Cu or Cu alloy, and the first layer is Cr.

Either Ni, Ni alloy, or Re has a thickness of 1 to 309 m,
The second layer is characterized by being a coating of Au, Ag, Au-Ag, or Ag-Pd with a thickness of 0.1 to 20 μm.

In this way, Cr is added to the surface of Cu or Cu alloy.

The reason why Ni, Ni alloy, or Re is coated with a thickness of 1 to 30 μm is to impart mechanical hardness to the contact piece material made of Cu or Cu alloy, and if the thickness is less than 1 μm, this effect is lost. This is because if the thickness exceeds 30 μm, it mechanically corrodes the sliding brush on the other side with which it comes into contact, accelerating wear. The reason why the surface of the CrNi, Ni alloy, or Re coating is coated with Au, Ag, Au-Ag, or Ag-Pd to a thickness of 0.1 to 20 μm is that the first layer This is to further chemically stabilize the surface of the coating, prevent electrical corrosion, and prevent initial welding immediately after sliding starts.
There is no effect when the thickness is less than 0.1 μm, and when the thickness is 20 μm
This is because, if it exceeds 100%, the chemical stability of the surface will not be improved any further, and expensive precious metals will only be wasted.

Next, in order to clarify the effects of the commutator contact piece material according to the present invention, specific examples and conventional examples thereof will be explained.

[Example 1] A contact piece material was obtained by applying Cr plating to a thickness of 10 μm on the surface of a Cu plate having a thickness of 1, and applying Au plating to a thickness of 108 m on the surface of the Cr plating.

[Example 2] A plate with a thickness of 7 on the surface of a Cu-Zn 20% by weight plate with a thickness of 1ml1
A contact piece material was obtained by subjecting it to μm Ag plating.

[Example 3] A 20μ thick plate was placed on the surface of a Cu-Zn 20% by weight plate with a thickness of 1.
Ni-Cr plating of 3% by weight is applied, and the Ni-Cr
A contact piece material was obtained by plating the plated surface with a thickness of 15 μm and 1% by weight of Au-Ag.

[Example 4] Re plating with a thickness of 15 μm was applied to the surface of a 30 wt % Cu-Ni plate with a thickness of 11 ll, and a 30 wt % Ag-Pd plating was applied to the surface of the Re plating to a thickness of 10 μm to obtain a contact piece material. Obtained.

[Example 5] A contact piece material was obtained by applying Ni plating to a thickness of 10 μm on the surface of a Cu plate having a thickness of 1 mm, and applying Au plating to a thickness of 5 μm to the surface of the Ni plating.

[Example 6] A 10μ thick plate was placed on the surface of a Cu-Zn 20% by weight plate with a thickness of 1 fin.
m Re plating is applied, and a thickness of 2 m is applied to the surface of the Re plating.
A contact piece material was obtained by plating with .mu.m Au-AglO weight %.

[Conventional example 1. 2. 3. ) A contact piece material consisting of a Cu plate having a thickness of 1 fin, 20% by weight of Cu-Zn having a thickness of lam, and 30% by weight of Cu-Zn having a thickness of 1 fin.

Now, using the contact piece materials of Examples 1 to 6 and Conventional Examples 1 to 3, contact pieces with a width of 7 mm and a length of 1 mm are made, and these are attached to the outer periphery of a commutator with a diameter of 7 mm and a length of 10 mm. Three comb-shaped sliding brushes made of phosphor bronze are attached to the surface at equal intervals.
Thickness 0.2m++, width 8 dragons.

A sliding test was conducted at a contact resistance of 20 mΩ by contacting brush strips with a length of 10 mm, width of 2 fins, and length of 8 length, with 3 strips per fin interval), and conventional examples 1 to 1. A commutator with a contact piece made of contact piece material No. 3 has a thickness of 0.21 to 0.24 V after a 10-hour continuous test.
The contact resistance increased significantly to 110 to 340 mΩ, and the rotation of the commutator became uneven.

Furthermore, when the sliding test was continued, all of them became unusable after 25 to 30 hours. On the other hand, commutators with contact pieces made of the contact piece materials of Examples 1 to 6 had a contact piece with a thickness of 0.0 after a 10-hour continuous test.
There was only slight wear of 5 mm to 0.11, and the contact resistance was 4.
There was only a slight increase of 0 to 50 mΩ, and no unevenness occurred in the rotation of the commutator. Furthermore, when the sliding test was continued for 25 hours, the amount of wear was slight and none became unusable.

In addition, there were as many as 3 out of 100 commutators with contact pieces made from the conventional examples 1 to 3 contact piece materials that were initially welded to the sliding brush immediately after the start of the sliding test, whereas in the example example 1
There were no commutators out of 100 with contact pieces made of contact piece materials of ~6.

In the embodiments of the present invention, the contact piece material is coated by plating, but the coating is not limited to this, and may be coated by sputtering, ion blasting, thermal spraying, vapor deposition, or other means.

As detailed above, the commutator contact piece material of the present invention has CI
The surface of I or Cu alloy is coated with Cr, Ni, Ni alloy, or Re, and the surface is coated with Au, Ag, or Au.
-Since the surface layer is coated with either Ag or Ag-Pd, the surface layer has high mechanical hardness and is chemically stable, so the contact piece was made with this material. The contact pieces of the commutator wear out only a very small amount due to electrical and mechanical erosion during rotation and sliding with the sliding brush. Therefore, the contact pressure of the sliding brush hardly changes and the contact resistance does not increase significantly, so that the rotation of the commutator does not occur unevenly and the life of the commutator is extended. Furthermore, since the surface layer is chemically stable as described above, it has excellent effects such as being able to prevent initial welding with the sliding brush immediately after the rotation and sliding start.

Applicant: Tanaka Kikinzoku Kogyo Co., Ltd.

Claims (1)

[Claims] In the commutator contact material made of Cu or Cu alloy, the surface of the contact piece material is coated with two layers, the first layer being made of Cr, Ni, Ni alloy, Re. Either thickness is I-30
μm, and the second layer is Au and Ag. Either Au-Ag or Ag-Pd, thickness 01~20μ
4. A contact material for a commutator, characterized in that it has a coating of m.