Car automatic transmission sun gear manufacturing process and cold forging extrusion female die adopting process

Abstract

The invention discloses a car automatic transmission sun gear manufacturing process. The car automatic transmission sun gear manufacturing process comprises following steps of firstly, discharging; secondly, spheroidizing annealing; thirdly, blank making; fourthly, shot blasting; fifthly, lubricating; sixthly, cold forging extrusion forming, wherein a blank obtained after lubricating is put into the cold forging extrusion female die, and through cold forging extrusion, a first-stage transmission gear is formed; seventhly, upsetting, wherein the blank obtained after cold forging extrusion forming is put into an upsetting female die, and a solid shaft segment corresponding to a second-stage transmission gear is formed through upsetting; eighthly, cutting, wherein the blank obtained after upsetting is cut, and a second-stage transmission gear, an annular groove and a hollow shaft are machined; ninthly, heat treatment. Through cold forging extrusion, the sun gear one-stage transmission gear is formed, the small-size sun g ear cutting machining difficulty and the cutting machining amount are reduced, production efficiency is high, the material utilization rate is high, the machining cost is low, the metal assembly line is not cut, the grain structure is compact, the first-stage transmission gear tooth face strength is improved, the mechanical performance is high, the quality is good, and the car part complete requirement is met.

Description

technical field [0001] The invention relates to a sun gear of an automatic transmission for automobiles, in particular to a manufacturing process and an extrusion die for a sun gear of a small-sized automatic transmission for automobiles. Background technique [0002] The sun gear is an important part of the car automatic transmission for shifting gears and transmitting variable loads. It generally includes a hollow shaft body. The outer surface of the hollow shaft body is provided with a primary transmission gear 1 and a secondary transmission gear 2. The primary An annular groove 3 is provided between the transmission gear 1 and the secondary transmission gear 2, and the primary transmission gear 1 and the secondary transmission gear 2 are helical gears. Due to the small size of the sun gear, it is more difficult to cut the helical tooth surface. The diameter of the dedendum circle of some primary transmission gears is only 20mm. The existing manufacturing process is to s...

AI Technical Summary

Problems solved by technology

The existing manufacturing process is to select the bar and directly use the cutting process to produce it. The disadvantage of this process is that the production efficiency of cutting is low, and it is only suitable for single piece or small batch production; the other is hot forging and then cutting to form the inner wall. For gears, the two production processes adopt the traditional cutting method to form gears, which are suitable for small batch production, with large capital investment in equipment, low production efficiency, low material utilization rate, long production cycle and high processing cost; secondly, the cutting process The middle metal flow line is cut off, the tooth surface is not compact, and the mechanical properties are poor, which makes it difficult to meet the quality requirements of auto parts.

In short, the existing manufacturing process: 1. Large investment in machine tool equipment; 2. Large tool loss; 3. Especially due to the small size of the primary transmission gear, the cutting of the helical tooth surface is difficult and the production efficiency is low; 4. The cost is high; 5. The base material is directly processed, the metal flow line is cut off, the tooth strength is low, and the quality is poor; 6. Waste metal materials

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