Research On Shifting Quality Improvement Of Manual Transmission

Over the past five years domestic automobile industry has developed rapidly.As an important part of the power-train,manual transmission shifting performance has gradually caught researchers' attention.Although manual transmission is relatively mature,its shift performance evaluation criteria still has not been shaped.Facing customers' increasing demands,defining shift performance evaluation methods and criteria of manual transmission is the focus of current study.Based on manual transmission shift performance project,this thesis chose a mini-car with five-speed manual transmission as the research object.It has researched the shift quality evaluation methods and evaluation criteria,analyzed the relationship between design of the shift mechanism and evaluation criteria.It also focused on the working principle of operating mechanism and synchronizer,utilized dimensional chain principles to calculate some key gaps in shift mechanism.After modeling shift mechanism in UG,it has achieved ADAMS multibody dynamics simulation,simulated the whole shift process of inner control mechanism and synchronizer.During the kinetic analysis process of synchronizer,it made use of flexible body for the synchronizer ring spring to achieve ANSYS-ADAMS rigid-flexible mixing dynamics simulation,so as to approach the actual shift process.Finally,the test results were compared with the results of the test vehicle,it has explored a new research perspective on transmission shift performance and some shift performance design principles.From a wide view of the thesis,eight criteria of shift quality were centered on closely,and connected to the structure and size of the shift mechanism design principles correspondingly.The main contents are as follows:(1)According to the literature data and the actual vehicle test data,the thesis combined the shift performance evaluation criterion of the enterprise,proposed shift quality evaluation methods and standards,analyzed the meaning of each criterion.(2)It calculated the critical size of transmission shifting mechanism,including: the shift travel,select travel,synchronizer assembly gap,the relative position of the synchronizer gear hub while the operating mechanism is in neutral gear and so on.(3)It also created the UG 3D model of shift mechanism,including the shift fork assembly,self-locking mechanism,interlocking mechanism and synchronizer.Additionally it completed the dynamics simulation analysis of self-locking mechanism,synchronizer and the entire shifting mechanism in Adams.In the end,it summarized up the design principles to improve shift quality.This thesis provided reference proposals and methods about enhancing the shift quality of whole vehicle for the relevant transmission shift performance researchers.Especially the analysis of the operating mechanism design parameters and entire synchronize process of synchronizer resulting in the influence disciplinary on operating mechanism structural parameters,at last summarized a sort of improving shift quality performance suggestions.This not only provides a criterion the for vehicle testers,but also an important reference for transmission component design staff in the development and optimization phase.