Study On A Gearshift Performance Of Synchronizer Based On FEM

The gearshift performance of automobile transmission is an important factor influencing vehicle shifting smooth and driving comfort. The domestic and foreign study status of the automobile transmission gearshift performance is analyzed. Associating with the development project of DFSK's manual transmission combined with enterprise, based on the theory of multi-body dynamics and the Finite Element Analysis technology is used to research the transmission gearshift performance. According to the conclusions of the study, the component structure parameters of DFSK's transmission are calculated and designed, which ensure a good gearshift performance.In this paper, the following main jobs have been done:(1) According to the structure and working principle of synchronizer, the mathematical models of synchronization process are established, which lay a foundation for the simulation tests.(2) The part and assembly 3D models of gearshift are completed in UG. The boundary conditions of simulation test are defined by calculation.(3) According to the boundary conditions in the process of designing parameters, the FEM model of shifting process is modeled by the ANSA software and the simulation results are calibrated from the qualitative and quantitative aspects.(4) Parameters and shift performance of synchronizer as locking Angle and friction cone Angle are studied by simulation.(5) Through studies of structure and working principle of multiple cone synchronizers, the shift performance differences of three cone, double-cone synchronizer and single cone synchronizer are compared by establishing FEM models.The results indicate that, when the shifting force is steady, synchronization time is increasing with the friction cone angle increasing, decreasing with the conical surface friction coefficient increasing, decreasing with the friction cone mean diameter increasing, and increasing with the input moment of inertia increasing. The synchronizer locking angle has no effect on synchronization time; The friction cone angle and conical surface friction coefficient have no effect on twice impact force. The twice impact force of multi-cone synchronizer is smaller than single-cone synchronizer. The twice impact force is increasing with the input moment of inertia increasing and increasing with the synchronizer locking angle increasing.According to the research achievements above, the optimization design methods of the component parameters, which take the shift impulse and twice impact force minimization as the goal, are established and used to design the transmission.