Earth Pressure Balance Shield Machine Hydraulic Propulsion System Research And Design

The shield machine is a large-scale construction machinery to achieve the automatically mining and disposable shaping of tunnel excavation. Its structure is complicated, collecting mechanical, electrical, hydraulic, aerodynamics and so on, and a series of actions of tunnel excavation can be achieved through the combination of function of each part. This paper made a detailed research and design of key technologies and difficulties of the thrust hydraulic system through simulations and experiments to do our part to promote the progress of the shield technology.Firstly, this paper mainly made a detailed stress analysis of the forward and turning of the shield to calculate the pressure and friction resistance of the soil and water by digging and made the resistance distribution map and mechanical model of the shield machine. And an error function of the forces from hydraulic cylinder to tunnel segments was established based on stress analysis, as to develop a design of the hydraulic cylinder partition of thrust hydraulic system through Lagrange equation, which provided a theoretical basis for the partition design of the hydraulic cylinder. Secondly, the design method of thrust hydraulic system has been made on the basis of traditional shield machine, and the control mode of thrust hydraulic system was pressure and flow compound control mode to enhance the efficiency of the system and control accuracy. Thirdly, this paper also established the thrust hydraulic system model by AMESIM, and open-loop control, closed-loop control, PID control and fuzzy PID control of thrust hydraulic system were simulated by the AMESIM and MATLAB joint simulation, the results show that the fuzzy PID control could greatly reduce the fluctuations and the overshoot of the system when the pressure or flow was changing, which enabled the system to be more safe and stable. And then we made an on-site commissioning to verify the feasibility of the design. Finally, this article provided a summary and outlook, and pointed out the inadequacies and research directions.