| In the commercial vehicle sector,AMT automatic transmission technology is one of the mainstream technical solutions for transmission automation.However,the clutch actuator,the core component of AMT automatic transmission,has some problems in the process of working,such as long response time,low efficiency and low reliability.These problems affect the performance of transmission and vehicle driving experience.This paper takes the quick response,high efficiency and high reliability of the clutch actuator as the design goal.The software of 3D design,multi-body dynamics and finite element analysis are used to analyze clutch actuator.Then,the bench test and vehicle test are carried out to verify the analysis results.By this method,the work characteristic analysis,structure design,dynamic and static simulation optimization and test verification of clutch actuator are studied.The main research work of this paper is as follows:(1)The technical scheme of AMT automatic transmission clutch actuator adapted for a commercial vehicle is confirmed as follows.The drive gear assembly is coaxial with the turbine and meshes with the fan gear.The sector gear assembly is hinged to the power spring assembly.Clutch motor as the driving force,hydraulic rod,hydraulic cylinder,hydraulic separation bearing as the hydraulic part,clutch actuator quick and reliable response and other performance requirements as traction.The mathematical model of working theory characteristics of clutch actuator is established.Then,the size and selection of relevant parts are determined.Finally,a 3D model is built to lay a foundation for subsequent analysis.(2)A set of plastic turbine and metal worm components are designed,thus conducting parameter design and strength check.ANSYS finite element analysis software is used to carry out statics analysis on the hydraulic rod of the clutch actuator,the joint surface of the shell and the support.The results show that the above components meet the material strength and design requirements.(3)The ADAMS multibody dynamics analysis software is used to optimize the clutch actuator and simulate the response time.The optimization results by fitting calculation show that the double spring structure can reduce the maximum load of the motor by 16% compared with the single spring structure.When the angle C between the assisted thrust spring position and the rocker arm is 10°,the thrust effect is the best.The response time of the turbine and the optimized clutch actuator of different materials is simulated and analyzed.The results show that compared with metal turbines,plastic turbines can effectively reduce motor output power by 10%.The optimized clutch actuator’s 12 mm separation travel time is 0.347 s,which meets the design requirements of separation time less than 0.35 s.(4)A clutch actuator test bench is established to verify the performance comparison before and after optimization.High and low temperature performance,3 million fatigue durability and vehicle test are carried out to test on the optimized clutch actuator.The test results show that the clutch actuator can work normally in the environment of-30 °C-120 °C.The separation time under the condition of 100% duty cycle at room temperature is 0.338 s,and the maximum separation force is 2941.01 N.The calculated results are close to the simulation results and meet the design requirements.After 3 million times of fatigue endurance test,the disassembly and inspection of the mechanism show that the contact surface between the worm,reduction gear and sector gear showed normal wear.The thrust spring does not fail and the clutch actuator can still work normally.The analysis of the test signal data of the whole vehicle shows that the clutch actuator signal is stable and changes periodically during the operation of the vehicle.The initial time interval of a single separation stage is less than 0.35 s,which meets the design requirements. |
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