Research And Developmnet Of Hydraulic Actuator For The Heavy Vehicle With AMT

AMT is an economical automatic transmission; therefore it has extensive application space in the heavy truck. Currently, national heavy vehicles are all equipped with manual transmission, and forms production capacity on a quite scale. AMT is more suitable for automotive industry reality in china than AT. The development and production of AMT may retain previous product line of manual transmission and greatly save the investment for reconstruction of professional production line and equipment, so it has important reality meaning.During the design and development of AMT, design and optimization of selection-shift actuator is one of key and special difficulties for AMT design. The performance will have direct effect on the whole performance of AMT system. In this paper, Taking focus on a manual transmission of heavy truck, combing with science and technology research plan of Chongqing, shift actuator with hydraulic drive for AMT system is developed and designed and its performance is researched.In this paper, the main contents are showed as follows:1. The development of automatic transmission technique for heavy truck both home and abroad is introduced. The key technique of automatic transmission for heavy truck and operation system configuration are illustrated.2. During the design and development for AMT, one of the objects is to make it good shift quality. So the study on the shift quality has been the key part of technique system research in the AMT. In this paper, various factors affecting shift quality is analyzed.3. Clutch and transmission characteristic in the driving system is analyzed. Maneuvering, engagement and torque transfer characteristic for diaphragm spring clutch is analyzed systematically, torque transfer formula is given and clutch control rule is drawn up. And then the characteristic of transmission maneuvering and synchronizer are analyzed, shift forces are studied.4. Design requirement of hydraulic driving system for AMT is analyzed. In connection with a 12 speed synchronizer shift transmission provided by a company, in combination with previous operation mechanism of transmission, new hydraulic driving automatic actuator is designed. At the same time, the sensor needed in operation system is selected based on the actuator. 5. Hydraulic actuator for AMT is designed, simulated and analyzed. Motor parameters for the clutch actuator and its maximum engagement speed is calculated and analyzed, and hydraulic cylinder during the engagement is modeled and simulated, it is compared with the real condition; and the working reliability of mechanism is verified. The load of hydraulic cylinder and working velocity during shift are analyzed, and the type of some important elements in the hydraulic loop is selected as well as dynamic response of hydraulic cylinder is analyzed dynamically.