Development Of On Line Measuring System For Differential Case

The differential case is an important steering part of the wheeled tractor drive axle,and its processing accuracy have a great impact on the handling performance and safety of the vehicle.The differential case is measured through caliper and CMM currently,which cannot adapt to automatic production line processing,on-line measurement system of differential case is studied.According to the geometric characteristics and tolerance requirements of the differential case,combined with the actual processing conditions,automatic on-line measurement is achieved through the measurement system hardware design and software development.Specific research contents are as follows:1.The mathematical model of the measurement of the geometric tolerance is established according to the requirement of the part drawing,the evaluation method is determined.Through the actual needs,the traditional algorithm is improved to simplify the calculation process.The correctness of the proposed algorithm is verified by comparison;2.According to the measurement model and error evaluation method,combined with the functional requirements,the overall plan of the system is determined,the key components such as mechanical parts,sensor unit,acquisition module and motion control module are designed and selected.The hardware system is developed;3.The measurement software is developed based on Visual Basic language,database technology and PLC communication protocol.Communication among IPC,data acquisition card and PLC is established to realize coordination among movement of measurement machine,data acquisition and measurement results output,to meet the needs of online automatic measurement;4.The automatic measurement system is developed and the actual measurement test is carried out.Compared with the measurement result of CMM,the authenticity of the measured result of the developed measuring machine is verified,and the correctness and engineering applicability of the proposed method is verified.Through the actual operation of the automatic on-line measurement system,the equipment can meet the accuracy requirements of differential housing,and the measurement time of a single part is reduced to less than 30 seconds,improve the measurement efficiency and eliminate the error introduced by human factors,can be used for unmanned detection of automatic production process.