Research On The Dynamics And Reliability Of A Dual-clutch Automatic Transmission Parking Mechanism

The parking mechanism is one of the key components of the dual-clutch automatic transmission.It is used to ensure that cars equipped with automatic transmission can be parked safely for a long time under various working conditions.The dynamic characteristics and fatigue reliability of the parking mechanism play a vital role in parking safety..In this thesis,the rigid-flexible coupling dynamics simulation model of the parking mechanism is established based on multi-body dynamics theory and modal theory and the actual vehicle test is studied.Based on fatigue analysis theory,modal analysis theory and multiflexible body dynamics theory The fatigue life analysis model of the push rod is established in the software n Code,and the endurance test research of the bench is carried out.The main contents of the thesis are as follows:(1)From the perspective of theoretical calculations,the various parking performances of the parking mechanism are studied.Firstly,the structure and working principle of the parking mechanism of this dual-clutch automatic transmission are described,and then the static parking performance and dynamic parking performance of the parking mechanism are theoretically analyzed to obtain the corresponding calculation method and judgment conditions.(2)From the perspective of dynamics simulation and vehicle test,the parking dynamic characteristics are studied.First,a three-dimensional model of the whole vehicle,transmission,and parking mechanism is established.Then,the vehicle is combined with the finite element software Hypermesh and the multi-body dynamics software ADAMS The flexible coupled dynamics simulation model simulates and analyzes the critical parking speed,parking time,and maximum parking acceleration during the dynamic parking process,and performs a real vehicle dynamic parking test.The results of the real vehicle test show the above three key The error between the simulation result and the test result of the performance index is less than 1.6%,which verifies the accuracy of the rigid-flexible coupling dynamic model.(3)The influencing factors of parking performance are studied.The critical parking speed,parking time,and maximum parking acceleration are selected as the evaluation indicators.According to the theoretical calculation of parking performance and engineering experience,the factors affecting the parking performance are identified,and the parking mechanism is remodeled and simulated Through analysis,the sensitivity parameters of each parking performance are obtained.(4)Based on the flexible body dynamics theory,modal theory,and fatigue theory,the quasi-static method and the modal stress recovery method were used to conduct fatigue life simulation research on the push rods of the key parts of the parking mechanism,and a fatigue endurance test bench was built for The experimental research shows that the above two methods can accurately predict the location of fatigue risk points.The quasi-static method based on putter fatigue life prediction error is 18.5% and the prediction result is radical,the modal stress recovery method based on the putter The fatigue life prediction error is 4.25% and the prediction result is conservative.