Research On The Controll System Of Lock-up Clutch In Bulldozer’s Torque Converter

The torque converter can make the engineering vehicles start smoothly,shift smoothly, easy to operate and can prevent overload halt.However,the torque converter has low efficiency,especially when the bulldozer is moving without load or working with small load. According to the actual working environment,the locking control of the bulldozer’s torque converter is researched with the aim of reducing thefuel consumption and improving the transmission efficiency.In this working,the mathematical model of the lock-up clutch was established according to the theoretical basis of the torque converter and the blocking conditions needed by the torque converter when it locking,and the matching between the engine and torque converter was analyzed.The locking control parameters was selected according to the actual working situation of the bulldozers,that is,the output speed of the turbine and the stall signal was selected as the main control parameters,and the accelerator pedal travel,the brake pedal signal and the turn signal as auxiliary signal.Then the locking control laws,including the power performance locking laws,economy locking laws and the comprehensive locking laws,was designed reasonably,and the quality control of the latch-up course was analyzed.The slipping control of the torque converter was described,and the mathematical model was established,and then,the simulation experiment was conducted.The locking control systems,including the circuit control system and the hydraulic control system,were designed.The function of all the separate parts and the controlling flow of the hydraulic control system were analysis.The entire controlling flow of the locking control system was described,and the controlling flow chart was drawn and the control procedures were programed.Finally,the controller experiment was carried out.The test result shows that the control system,control scheme and the control procedures were feasible.