Analysis Of Temperature Influence On Vehicle’s Shifting Buffer Valve And Study Of Shifting Quality

During the starting and shifting of vehicles,passengers usually feel a bit uncomfortable,some wear and tear of vehicle’s machines always come along.In pursuing of superior comfort and safety,modern vehicles always include shifting buffer valves.With the working process of electric and hydraulic system of vehicles’ going on,power loss cannot be avoided,which will finally turn into heat and rise up temperature oil.These changes will cause oil viscosity change,which is very sensitive for the output pressure characteristic of our shifting buffer valve.Also,the output change will influence vehicle’s shifting quality.Therefore,it’ s essential to study the oil temperature change.This paper researches traditional vehicles’transmission system and determines the major influence factor of shifting quality is jerk.Viscosity model of 10W/40CD oil is set up via 15 sets of experiment data.Studies of SY3005 buffer valve reveal its working principle,which is later used in setting up its AMESim model.3-D model of spool’s flow field is created through SolidWorks and then analyzed through FLUENT.Bench test data of a real gasoline is replenished and used to draw up a torque characteristic surface,which finally used in creating an AMESim model that simulates vehicle’ s transmission system and study shifting buffer valve and temperature changes and their effect on jerk.An experiment of pressure characteristic of shifting buffer valve is carried out under various temperature to prove the correctness of simulation results.This paper obtains temperature characteristic of shifting buffer valve through simulation and verifies it through experiments,also,some phenomenon are analyzed.The paper also builds up transmission mechanism of vehicle chassis according to reality,and sets up a rather comprehensive motor-clutch-shifting buffer valve AMESim simulation system to study the influence of involving shifting buffer valve to vehicle’s shifting quality.Also,simulation experiments on temperature characteristics and leakage are carried out.In addition,this paper also analyzes the steady-state characteristics of the flow field in the spool of the shifting buffer valve.The major differences between this paper and former studies lay in:(1)establishing a thermal hydraulic AMESim model to study the temperature influence,taking oil viscosity change into serious consideration;(2)establishing a vehicle transmission model including the shifting buffer valve via AMESim by using the real engine and clutch parameters.