Key Measuring Techniques In Assembly Line For Main Reducer Of Rear Axle

The paper fully investigates the current situation of civil and foreign assembly lines. From the automobile's situation in our country, the assembly and key measuring techniques application for main reducer of rear axle are studied.Based on the structure feature of main gear compound in main reducer, two important things in assembly technique of rear axle (the pre-tightened fixing of bearing and the adjusting of gear gearing) are analyzed. The controlled variable (pre-tightening moment) in the process of assembly is then decided and the method for improvement of assembly quality is pointed out (adjustment of bearing pre-tightening state by control of the gasket thickness). From this, a common question of space measuring is then suggested in this paper.Through theoretical analysis on relationship between the screwed moment and the axle force, the way of passing force among different parts is studied. By experiment, the relation between pre-tightening moment and axle force is found out. This not only states the feasibility of adjustment of pre-tightening moment by control of gasket thickness (control of pre-tightening moment by changing of distribution of axle force), but also guides the modeling of the measurement. Different factors for affecting the measured pre-tightening moment are studied and this supplies the principles of theoretical compensation for improvement of measuring precision.Above the foundation of theoretical research, the measuring mechanism which is based the industry control computer system is developed. The machine can meet the requirement of assembly precision and can be used in rapid production of assembly line. The optimized combination way for different-thickness gaskets are also suggested. This makes the developed machine practical in production. After the selected gasket is assembled in main reducer of rear axle, the on-line detecting equipment is used to measure the quality of assembly. This not only can control the quality of assembled product, but also can evaluate the correction, reasonability and usability of the machine. Through the practical application in production spot, it runs well. This proves it is reasonable in its principle, construction design and measuring method.The developed device has a good flexibility, which can be used for the on-linemeasuring of several products such as ISUZIK STERY etc.