The Study On Evaluation Technology Of The Mechanical Transmission Shift Performance

Gear-shift performance of mechanical gearbox is a key point in quality control of automobile. Poor quality gear-shift performance not only affects the comfort but the lifetime of clutch is also reduced, so the research of Gear-shift performance of gearbox has great actual value and high value in engineering.Currently, the shifting evaluation system is mostly based on the score provided by drivers, this method break away from the shift quality data of transmission, the subjectivity is too strong.This paper raise a thought of manual gearbox working principle---index selection---evaluation methods selection---evaluation system software develop---experimental data collection--- shifting performance evaluation to construct the manual gearbox shift performance evaluation system. This evaluation method is based on objective test data, taking into account the subjective evaluation. This paper main contents are summarized as follows:Firstly, Theoretical analysis on the manual gearbox shifting process,working principle of synchronizer, and the force of the process of manual automobile transmission, including the calculation of shifting concussion, the maximum shift force and synchronization time. Analysis the influencing factors of shifting performance, on this basis, the testing scheme of the shift performance been formulated;Secondly, shift performance evaluation index including synchronizing time, the max shift force, the linear relationship between the force and displacement, synchronizing impulse and rate of change of force is obtained, introduced the kinds of evaluation method, puts forward five shift quality evaluation indexes. And use the method of correlation matrix to establish the weight of each index and shift quality level, establish the shift quality compositive evaluation system;Correlation matrix method is used to establish a comprehensive evaluation system which contains index weight and the rate of evaluation. The gearshift quality compositive evaluation system is designed by using Lab View and Lab Windows/CVI software;Moreover, based on the bench test methods of the manual gearbox and experiences at home and abroad, built the bench of gearbox shifting performance. The basic principles of the test bench were emphatically introduced. Also, the mechanical parts and the measurement and control software part. Detailed analysis the all equipment selection and working principle by shift actuator module, power-drive module and data acquisition module. The data from test bench provides an objective basis for shifting performance evaluation;Lastly, on the test bench, a gearbox has been test and test data was analyzed, the performance curve accord with the shifting process theory analysis. Select the fit test data, using the shifting performance evaluation system to analyze and evaluate, count the shift performance evaluation grade.