关键词: 液力缓速器, 动态充液, 制动转矩, 压力油箱, 液力液压耦合

Abstract: Hydrodynamic retarders play a key role in the driving assist braking system, and the main challenge they face is the problem of rapid response and accurate prediction of braking torque. To achieve rapid onset, heavy equipment uses a pressure tank to accelerate liquid filling, but the changes in tank pressure and wheel speed during the filling process will dynamically affect the filling flow and braking torque. Therefore, this paper constructs a prediction model for the filling process of the hydraulic retarded braking system considering the pressure tank, realizes the two-way dynamic update of the boundary conditions of the flow parameters at the inlet and outlet of the wheel cavity, and deeply explores the hydrodynamic -hydraulic coupling relationship between the wheel cavity system and the charging and discharging control system. The simulation and experimental results show that the prediction error of the model for peak torque is 15.61%, and the response time error is 15.04%, which verifies that the constructed model can effectively explore the braking characteristics of the hydraulic retarder under the condition of fuel supply from the real vehicle pressure tank. The influence of the pressure tank characteristics on the braking torque characteristics at a given inertia and initial speed is further analyzed, and the regulation mechanism of the pressure tank parameters on the dynamic process of liquid filling is clarified.

Key words: hydrodynamic retarder, dynamic oil filling process, braking torque, pressure tank, hydrodynamic and hydraulic characteristic coupling