Blind hole internal gear precision forming method and internal tooth forming mold

Abstract

The invention provides a blind hole internal gear fine forming method and an internal gear forming die relating to the metal machinery processing and metal pressing fields of no cutting. The technical steps includes: computer simulation analyzing to study out a process forming scheme-baiting to manufacture roughs-surface intenerating and lubricating processing-fine forming-cutting off redundant part. A convex die profile of an internal gear forming die is corrected according to a gear precision grade tolerance belt and the gear precision is 6 to 5 grade. The surface roughness of the convex die is smaller than 0.5 micron. The thickness of a surface nanometer coat is 0.002 to 0.004 millimeter. A die entrance angle of at end surface of the gear is transited by a semi-arc. An effective width of a minor first flank is between 1.5 and 3 millimeter. A double surface back gap of the minor first flank is 0.3 millimeter smaller than the minor first flank by average. The transition cone angle between the minor first flank of the convex die and a basic die is 3 to 6 degrees. A concave die is formed through interference pressure distribution by adopting 2 to 3 layers of compound dies. The magnitude of interference is 0.4 to 0.5 percent of a matched dimension of a die. The invention has the advantages of short technique line, high manufacture efficiency, good consistence of the gear precision and high intensity.

Description

technical field [0001] The invention relates to the field of metal machining and metal stamping without cutting, especially the plastic precision forming method of blind hole internal gear mechanical parts and the internal tooth forming die. Background technique [0002] At present, the manufacturing of internal gears with blind holes mainly adopts the cutting method of gear machine tools. This manufacturing method has the following defects: (1) the process route is long, and generally requires multiple machining processes such as forging billet, rough and fine turning, and gear shaping; (2) the production efficiency is low; (3) the gear The consistency of precision is poor; (4) Since an overtravel groove must be left during gear shaping processing, the product structure is increased and the strength is reduced. Contents of the invention [0003] The purpose of the present invention is to overcome the disadvantages of the existing blind hole internal gear cutting method, ...

AI Technical Summary

Problems solved by technology

This manufacturing method has the following defects: (1) the process route is long, and generally requires multiple machining processes such as forging billet, rough and fine turning, and gear shaping; (2) the production efficiency is low; (3) the gear The consistency of the accuracy is poor; (4) Since the overrun groove must be left during the gear shaping process, the product structure is increased and the strength is reduced

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