Automobile gearbox intermediate gear shaft blank three-time wedging mould and rolling method thereof

Abstract

The invention discloses an automobile gearbox intermediate gear shaft blank three-time wedging mould and a rolling method thereof, comprising a mould and a rolling method, and characterized in that the mould comprises a feeding blank section, a first-time wedging section, a second wedging section, a third wedging section and a finishing forming section. By three-time wedging rolling, on the premise that the shrinking percentage of central axis is not greater than 75% every time, the main shrinking percentage reaches at 95.2%. When using the special mould, firstly the fixed-length rolling part is cut for feeding blanks and heating and then rolling and shaping are carried out between the upper and lower rollers fed with special mould. The automobile gearbox intermediate gear shaft blank three-time wedging mould and the rolling method are simple in technique, low in processing cost and high in rate of finished products, and material can be saved. Because of using three-time wedge, the shrinking percentage of the complex shaft is greatly improved and the production quality of the automobile gearbox intermediate gear shaft is ensured.

Description

technical field [0001] The invention relates to an improvement of a production method for an intermediate gear shaft of an automobile gearbox, in particular to a three-time wedging die for an intermediate gear shaft blank of an automobile gearbox and a rolling method thereof. Background technique [0002] The intermediate gear shaft of the automobile gearbox is the connecting transmission part between the input shaft and the output shaft of the automobile gearbox. Its structure includes the central shaft, the first middle gear, the second middle gear, the left pinion and the right pinion, among : The diameter of the first large gear in the middle is 160 mm, and the thickness is 30 mm; the diameter of the second largest gear in the middle is 130 mm, and the thickness is 30 mm; the diameter of the left pinion is 100 mm, and the thickness is 38 mm; the diameter of the right pinion is 80 mm, and the thickness is 20mm; the diameter of the central shaft is 35mm. The length of the...

AI Technical Summary

Problems solved by technology

However, for cross wedge rolling dies, the shrinkage rate of the wedge rolling section at one time is less than 75%. If it exceeds 75%, it is easy to produce defects such as non-rotation of the rolled piece, difficulty in ensuring the size, and loose center.

For shafts with a simple structure and a reduction of area greater than 75%, there are reports of using the secondary wedge rolling process. For example, for the cross wedge rolling process of the automobile engine valve blank, due to the simple structure, the secondary wedge rolling process can be used. , its primary rolling area reduction rate is 57.8%, its secondary rolling area reduction rate is 57.2%, and its total rolling area reduction rate is 81.9%. Meet product quality requirements, but it is difficult to complete shaft parts with complex structures

FAW Jiefang gearbox 1701212-14 The maximum outer diameter R of the intermediate gear shaft is 160mm, and the diameter r of the central shaft is 35mm. According to 1-(r 2 ÷R 2 ) formula calculation, its section shrinkage rate is 95.2%, the shrinkage rate is relatively large, and the structure is complex, if two times of wedge rolling, the total shrinkage rate of the two times is only greater than 75%, and the shrinkage rate of 95.2% cannot be reached. requirements, so if it is made according to the traditional cross wedge rolling design scheme, it cannot meet the technical requirements and quality assurance of the product

Therefore, there is no report on the production of intermediate gear shafts of automobile gearboxes by the cross wedge rolling process.

Images