Characteristics And Test Of Electro-hydraulic Control System For Wet Clutch

With the continuous improvement of the quality of human life,people have higher requirements for the dynamic performance,economy,and comfort of automobiles.Moreover,compared with developed countries,China's automatic transmission related technology has a very broad for improvement,so it is necessary to study the automatic transmission.The electro-hydraulic control system is one of the core technologies of automatic transmissions such as AT,AMT,CVT,and DCT,and it has a particularly critical impact on the shift performance of automatic transmissions.According to the research focus of many domestic enterprises and universities,this paper studies the wet clutch electro-hydraulic control system and important hydraulic components as the research object.Based on the working process of the hydraulic system when the clutch is shifted,the corresponding mathematical model and AMESim simulation model are established.The model was tested and verified on a self-developed hydraulic valve test bench,and the effects of various important parameters and chattering effects on the engagement performance of the wet clutch were studied and analyzed.(1)This paper briefly introduces the principle of wet DCT and wet DCT electro-hydraulic control system,summarizes the research status at home and abroad,and analyzes the research emphasis of this paper.The working principle of wet DCT mechanical part,control system and hydraulic system is analyzed.Based on the working principle of wet clutch hydraulic system,the hydraulic system of wet clutch is divided into three parts: main oil circuit system,clutch lubrication system and clutch control subsystem,and the corresponding mathematical model is established.(2)Aiming at the working process of the wet clutch,according to the principle of the wet clutch electro-hydraulic control system and the mathematical model established above,AMESim software was used to establish the model of the wet clutch electro-hydraulic control system,and the simulation model was used for simulation,and relevant characteristic curves were obtained and analyzed.(3)Based on the simulation model of the electro-hydraulic control system of the wet clutch,the influence of important parameters on the dynamic characteristics of the electro-hydraulic control system of the wet clutch was studied.According to the clutch shift performance evaluation index,the influence of important parameters on the clutch shift performance is analyzed.The principle of parasitic flutter and independent flutter is analyzed and the influence of superposition independent flutter on clutch engagement performance is studied.(4)According to the development of wet DCT design requirements,design structures,the automatic transmission hydraulic valve performance test rig,and established the simulation model test,respectively to extract the main hydraulic system pressure control characteristics,the clutch oil road traffic control,pressure control of the clutch control subsystem characteristic of simulation data and experimental data were analyzed,through the analysis shows that the built model is more accurate.