Material overlapping and cold precision forging technique for straight toothed spur gear

Abstract

The invention discloses a material overlapping and cold precision forging technique for a straight toothed spur gear, which comprises the steps of: 1) putting two pieces of cylindrical blanks with the same volume in a circular female die along the axial lines thereof in an overlapping manner, overlapping the cylindrical blanks, and primarily extruding the cylindrical blanks; 2) stopping extrusionand taking out the cylindrical blanks if the joining surface of the two cylindrical blanks and the female die is larger than 1 / 2 of the blank height; 3) exchanging the upper and the lower positions of the two blanks, overlapping the blanks and extruding the blanks again; 4) stopping the extrusion operation if the two blanks are fully joined with the female die and if the tooth forms are fulfilled; and 5) leveling the parts extruded for twice to obtain a final workpiece. The technical can be used for fully filling the material overlapping corner of the straight toothed spur gear under a low extrusion force so that qualified parts are successfully formed by pressing; and the invention has the advantages of forming easiness, filling completeness, simple and reliable mould structure and long service life.

Description

technical field [0001] The invention belongs to the cold precision forging process in the machinery manufacturing industry, in particular to a stacked precision forging process suitable for the production of spur gears. Background technique [0002] At present, the most widely used processing technology for spur gears is still the traditional cutting processing technology, which uses forged blanks or bars, and is finally formed after turning, milling and subsequent heat treatment. Large and energy-consuming, its economic and social benefits are poor, and the material fibers of the tooth-shaped part are cut off during the cutting process, which reduces the strength and service life of the gear. [0003] With the rapid development of the industry, the gear parts used in the automobile and aviation industries require weight reduction and increased strength. At the same time, due to the needs of competition, cost reduction is also required. Gear precision forging is a process th...

AI Technical Summary

Problems solved by technology

[0004] For spur gears, especially gears with relatively small height and diameter, due to the difficulty in filling the tooth profile (especially the upper and lower corners) during precision forging, the corners will eventually be insufficiently filled. And there is a high degree of stress concentration, which is easy to cause the die to crack. Therefore, the precision forging of spur gears is much more difficult than that of bevel gears. At present, it is still in the stage of process exploration and laboratory research. It is one of the hotspots of forging technology research at home and abroad in recent years. one

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