Research On Synchronizer Optimization Design Based On The Working Condition Demand Of AMT

With the development of automotive technology, low fuel consumption and high comfort have been taken as the main target in terms of vehicle driving, which is closely related to the shifting process. As the main component of shifting execution, transmission plays an important role in the automobile transmission system. The development of automatic transmission satisfies the demand of shift operation, as well as puts forward higher requirements on synchronous capacity. Automatic transmission, represented by electronically controlled automated mechanical transmission, requires a higher synchronous capacity of synchronizer to meet the needs of shift.The insufficient synchronous capacity in the process of shift will cause the phenomenon of synchronous time extension and shift impact. Through the optimization of the synchronizer structure, the above phenomenon can be effectively improved, as well as the application range of the synchronizer expanded, making it also conform to the working condition of AMT shift so as to improve the shift quality. Nevertheless, in order to meet the high requirement of synchronizer, a method for synchronizer structural optimization based on the condition demand of AMT shift is proposed according to the analysis of AMT control strategy on shifting.In this paper, the micro impact new transmission applicable to a light truck model in the automotive transmission project of Wuzheng Group is taken as a research subject, based on the dynamics theory, using computer 3d entity modeling technology and dynamic simulation technology, for the purpose to improve the shift quality of synchronizer, through research on the synchronous time and impact in the process of shift so as to obtain the influence of structure optimization on the synchronous performance, and then get the synchronizer with good shift quality.Firstly according to the basic structure parameters of micro impact new transmission, with reference to the method of parametric modeling of gear splines, a mathematical model of synchronizer splines and the whole transmission three-dimensional entity model are established based on UG. Based on the basic structure of three and four speed synchronizer, the operating principle of the lock ring synchronizer is introduced, as well as the mathematical model in the process of synchronization is established. The synchronous capacity is defined, expression of synchronous capacity is proposed, and the effect of various parameters on synchronous capacity are respectively described. According to the transmission powertrain chart, through respectively analyzing the internal power transfer process and moment of inertia in the transmission, the matrix expressions of angular velocity and synchronous torque are established. Then we establish the virtual prototype model of three and four speed synchronizer based on UG and perform dynamic simulation so as to get the simulation results of the synchronous time and impact.Finally, combined with the demand for synchronous time of AMT shift, the optimization design scheme is put forward under the problem of insufficient capacity for synchronization to place emphasis on the optimization of the half angle and radius of friction conical surface. Considering the fluctuation range of the equivalent radius in the single cone synchronizer is very limited, the usual way to increase the size of synchronous ring radius cannot meet the requirements of AMT for synchronous capacity. Therefore, through adding a friction ring between the synchronous ring and engagement ring to double the equivalent radius, the synchronous capacity is improved, which shortens the synchronous time and improves the synchronous performance. At the same time, by optimizing the teeth shoulder of splines to change the acceleration and reduce secondary impact, the shift quality is improved. Finally, through dynamic simulation of the double-cone synchronizer optimized, the necessity and effectiveness of the optimal design of synchronizer are verified. an optimal design method of improving the working performance of synchronizer is proposed.