JP2001346363A - Carbon brush material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide carbon brush material which can maintain normal slide contact even in a sliding state under an impact vibration and in a low temperature - high temperature region, exhibits excellent commutation capability and, further, has high abrasion-resistant properties. SOLUTION: Carbon brush base material is impregnated with organic lubricant and thermoplastic fluorine resin to obtain carbon brush material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a carbon brush material.

[0002]

2. Description of the Related Art Generally, a carbon brush material is considered to be porous and to maintain a rectifying ability because it absorbs shock vibration transmitted from a mating sliding body and improves sliding contact.
However, when the impact vibration of the mating sliding member becomes severe, normal sliding contact cannot be maintained. Therefore, if the carbon brush material is made more porous, the bonding force between the particles is essentially reduced, the particles are likely to fall off, and when used as a carbon brush, the abrasion increases.

In order to improve this, in the case of a brush material such as electrographite, as shown in Japanese Patent Application Laid-Open No. 2-219439, the pores are impregnated with a thermosetting resin such as a phenol resin to bond the particles. A method of reinforcing the force, a method of improving lubricity by impregnating an organic lubricant such as coconut oil, tung oil or the like as disclosed in JP-A-3-49546, or a method of coexisting a thermosetting resin and an organic lubricant Was taken.

[0004] However, those impregnated with a thermosetting resin such as a phenol resin have a high friction coefficient when cured by heat, so that the sliding characteristics tend to deteriorate. Also, since the cured product is hard, the elastic modulus of the carbon brush material is high and it is difficult to absorb impact, so when it receives impact vibration from a partner sliding body, the carbon brush jumps due to insufficient vibration absorbing ability, When mechanical stress is generated in the sliding contact portion, the massive particles fall off, causing a depression hole in the sliding contact surface, or the dropped particles intervene in the sliding contact surface between the carbon brush and the mating sliding body. There have been problems such as the occurrence of sliding contact failure and a reduction in rectification ability.

[0005] Coconut oil, for the purpose of improving lubricity,
Those impregnated with organic lubricants such as paulownia oil are effective when the Joule heat, frictional heat, ambient temperature, etc. of the carbon brush and the sliding body of the mating partner are low. Out of the system and the effect is reduced. Further, even in the case where a thermosetting resin and an organic lubricant are used in combination, at present, satisfactory effects cannot be obtained due to the above-mentioned problems.

[0006]

According to the first aspect of the present invention, normal sliding contact is maintained even under impact vibration and sliding in a low temperature range to a high temperature condition, the rectifying ability is excellent, and the wear resistance is improved. It is intended to provide a carbon brush material having high performance. A second aspect of the present invention provides a carbon brush material having a particularly excellent rectifying ability.

[0007]

The present invention relates to a carbon brush material obtained by impregnating a carbon brush substrate with an organic lubricant and a thermoplastic fluororesin. Also, the present invention
The present invention relates to the carbon brush material, wherein the total amount of the organic lubricant and the thermoplastic fluororesin is 0.5 to 7% by weight.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the material of the carbon brush base material is not particularly limited, but it is preferable to use, for example, electrographite which requires rectification. The organic lubricant to be impregnated into the carbon brush substrate is not particularly limited, and examples thereof include the above-mentioned coconut oil, tung oil and the like.

The thermoplastic fluororesin used in addition to the organic lubricant is not particularly limited. For example, tetrafluoroethylene (PTFE), fluorinated ethylene polypropylene copolymer (FEP), and tetrafluoroethylene-perfluoroalkyl Vinyl ether copolymer (PFA), tetrafluoroethylene-ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF)
And the like.

The total amount of impregnation of the carbon brush base material with the organic lubricant and the thermoplastic fluororesin is 0.5 to 7
% By weight, preferably 1 to 6% by weight,
3% by weight is more preferred. When the content is less than 0.5% by weight, the rectifying ability is inferior and the wear resistance tends to be low.
If it exceeds 7% by weight, the sliding characteristics tend to deteriorate.

The total impregnation amount of the organic lubricant and the thermoplastic fluororesin is as described above, and among these, the impregnation amount of the organic lubricant is preferably in the range of 0.3 to 3% by weight.
A range of 0.5 to 2% by weight is more preferable. On the other hand, the impregnation amount of the thermoplastic fluororesin is preferably in the range of 0.2 to 5% by weight, and more preferably in the range of 0.5 to 2% by weight. In particular, in the present invention, it is preferable to impregnate the thermoplastic fluororesin in the above-mentioned range since stability of sliding contact and reduction of friction coefficient can be achieved.

The carbon brush substrate is impregnated with a thermoplastic fluororesin first, and then with an organic lubricant. This is preferable because a carbon brush material that maintains contact, has excellent rectifying ability, and has high wear resistance can be obtained.

[0013]

The present invention will be described below with reference to examples.

Example 1 An electro-graphite brush substrate (trade name: GH135, manufactured by Hitachi Chemical Co., Ltd.) was used as a carbon brush substrate, and a thermoplastic fluororesin (trade name, manufactured by Dyneon Co., Ltd., trade name) was used as the brush substrate. THV-200P) was impregnated with the amount shown in Table 1 by a vacuum impregnation method, and then heated up to 100 ° C. at a heating rate of 10 ° C./hour, and kept at 100 ° C. for 8 hours to be a thermoplastic fluororesin impregnated carbon brush. Wood was obtained. The thermoplastic fluororesin used for the impregnation is based on 25% by weight of the thermoplastic fluororesin.
A resin solution in which acetone was added in an amount of 75% by weight and uniformly mixed was used.

Next, the carbon brush material impregnated with the thermoplastic fluororesin obtained above was impregnated with tung oil in an amount shown in Table 1 by a vacuum impregnation method, and then heated to 70 ° C. at a rate of 10 ° C./hour. At 70 ° C. for 3 hours to obtain a carbon brush material.
As the tung oil used for the impregnation, a resin solution was used in which 75% by weight of toluene was added to 25% by weight of the tung oil and uniformly mixed.

[0016]

[Table 1]

Comparative Example 1 The carbon brush base material used in Example 1 was impregnated with 2.2% by weight of a phenol resin (trade name: VP11N, manufactured by Hitachi Chemical Co., Ltd.) by a vacuum impregnation method, and then at 10 ° C./hour. Then, the temperature was raised to 180 ° C. at the temperature raising rate and maintained at 180 ° C. for 8 hours to obtain a carbon brush material. The phenol resin used for the impregnation was prepared by adding acetone to 25% by weight of the phenol resin.
A resin solution to which 5% by weight was added and uniformly mixed was used.

Next, the carbon brush material obtained in Example 1 and Comparative Example 1 was processed into a carbon brush, and slid on the surface of the copper ring for 100 hours at a peripheral speed of 30 m / sec. A wear test was performed. The carbon brush of Example 1 was subjected to a wear test at temperatures of 30 ° C. and 140 ° C., and the carbon brush of Comparative Example 1 was subjected to a wear test at a temperature of 140 ° C. The result is shown in FIG.

As shown in FIG. 1, it is clear that the carbon brush material according to the embodiment of the present invention has a smaller wear amount than the carbon brush material of the comparative example. Further, the total amount of the organic lubricant and the thermoplastic fluororesin is 0.2 to 8
It is clear that, in the range of 0.5 to 7% by weight, the abrasion amount is as small as 2 mm / 100 hours or less, which is favorable.

[0020]

The carbon brush material according to the first aspect maintains a normal sliding contact even under impact vibration or sliding at low to high temperatures, has excellent rectifying ability, and has excellent wear resistance. It is a carbon brush material which is highly industrial and extremely suitable for industrial use. The carbon brush material according to the second aspect is a carbon brush material having particularly excellent rectifying ability among the carbon brush materials according to the first aspect.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the total amount of impregnation and the amount of brush wear.

Claims (2)

[Claims] 1. A carbon brush material obtained by impregnating a carbon brush base material with an organic lubricant and a thermoplastic fluororesin. 2. The carbon brush material according to claim 1, wherein the total impregnation amount of the organic lubricant and the thermoplastic fluororesin is 0.5 to 7% by weight.