Production method of graphite plane commutator

Abstract

The invention relates to a method for manufacturing graphitic plane commutator, which includes the following steps:(1) making an accurate cuprum case; (2) plating nickel on one surface of a molded annular graphite sheet matched with an operation end of the accurate cuprum case, and then plating copper, to form a connection end of the annular graphite sheet; (3) Connecting the accurate cuprum caseand the annular graphite sheet by welding mode, wherein the connection surfaces are the operation end of the accurate cuprum case and the connection end of the annular graphite sheet, to obtain a composite piece; (4) compression-injection molding the composite piece, and milling groove as well as hooking to obtain the completed product graphitic plane commutator. The graphitic commutator made by the method, is characterized in that the connection of the graphite sheet and the accurate cuprum case is firm, the electroconductivity is well, the performance is stabile and the longevity is long.

Description

technical field [0001] The invention relates to a method for manufacturing a graphite planar commutator, in particular to a method for manufacturing a graphite planar commutator for an automobile oil pump motor, and belongs to the field of commutator manufacturing. Background technique [0002] The manufacturing process and structure of the commonly used graphite planar commutators are basically the same. The graphite sheet is connected to the base frame, and then the filler is added to the body composed of the graphite sheet and the base frame to solidify, and then the groove is milled. , milling the graphite sheet into multiple independent carbon segments to obtain the finished graphite planar commutator. [0003] In the above process, the manufacturing process of the base frame and the process of adding fillers to the body for curing are very mature, but there is no relatively mature process for the connection of the graphite sheet and the base frame so far. In the prior...

AI Technical Summary

Problems solved by technology

In the prior art, there are two basic connection methods between the graphite sheet and the base frame. One is to use superglue between the graphite sheet and the base frame. Although superglue bonding can temporarily firmly bond the graphite sheet to the However, when the graphite commutator has been used for a long time, the glue will age, the glue will be lost, and the graphite flakes will fall off, causing the entire commutator to be scrapped; another connection method is to weld the graphite flakes It is integrated with the base frame, as disclosed in the Chinese patent literature with the publication number CN101022199A, which discloses a process of welding the graphite sheets of the graphite commutator on the copper base. It first cleans the graphite, and then cleans the graphite. Dry it, then clean it with ethanol graphite, and finally blow it dry, then degrease and degrease the copper base with metal cleaning agent in the washing machine, dry it after degreasing, and then remove the scale with dilute hydrochloric acid, after drying Clean it with ethanol, dry it at last, and use resistance heating welding to melt the solder for welding, and then cool it after welding

The shortcoming that this method exists is, first, does not carry out surface metallization treatment to graphite sheet, so the electrical conductivity between copper base and graphite sheet is not good; Second, the present invention adopts resistance heating welding, and this welding method can not make graphite The entire contact surface between the sheet and the copper base frame is heated and welded at the same time, so the welding surface is uneven, resulting in a decrease in the service life and performance of the graphite commutator

In the prior art, the welding method of brazing is usually used to realize the above connection. Because the existing brazing for welding graphite sheet and copper base frame is all under natural conditions, that is, under the condition of not controlling the temperature, through infrared, electron beam , flame, etc., so the welding state is unstable, and voids often appear, and the voids directly lead to the weak connection between the graphite sheet and the copper base frame, shortened life and unstable performance. There are also problems that lead to the production of Graphite commutators are sometimes good and sometimes bad, with many defective products and unstable quality

[0004] In addition, the electroplating of graphite sheets disclosed in the prior art is simply to plate a layer of copper or copper-silver alloy. Since the bonding force between copper or copper-silver alloy and the graphite sheet is not strong, the With the increase of service time, the copper coating or copper-silver alloy coating will slowly fall off from the graphite sheet, resulting in poor conductivity of the graphite commutator

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