Simulation Analysis And Test Of Full Hydralic Steering System With Flow Amplification

With the development of large scale engineering machinery, the steering resistance moment is on the increase. It could not meet the requirement of rotation just depending on the hydraulic system controlled by single hydraulic steering control unit. Full hydraulic steering system of TLF is a kind of large displacement with flow amplification and load-senseing, the system has lots of advantages, such as compact structure, small volume, light weight, fewer oil links, laborsaving operation, sensitive steering, convenient fixing, reliable operation and high efficiency, etc. So during the development of engineering machinery, other hydraulic steering systems cannot compare of all the strong points processed by TLF hydraulic steering system. Thus, it is very important to do the simulation and experiment of this system in order to improve the reliability and high efficiency at work.Working principle and all the components of the TLF hydraulic steering control system are firstly analyzed in the thesis, and static mathematical model based on the equations of mass conservation and force balance is established. Then based on the mathematical model and the system principle, the dynamic simulation model of the system is established by using the special simulation software AMESim8.0.0, and working performances of the system is studied by using simulation model with different input signals. After that, experimental research of the steering system is done in the thesis, and the experimental results turn out to quite coincide with the simulation results, showing that the simulation model is accurate and credible. At last, load-senseing characteristics in TLF hydraulic steering system are studied in the thesis, which emphatically analyzes the impacts on the stiffness and the force at zero displacement of the spring in priority valve.The mainly contents of this thesis include the following parts;In chapter 1, research status and development of the current hydraulic steering system are dissertated, then the structure of TLF hydraulic steering system is introduced and the research background, significance and contents of the subject are expatiated. In chapter 2, the structure and working principle of the steering system are introduced, and the mathematical model is established.In chapter 3, dynamic simulation model is established by selecting the simulation software AMESim8.0.0; by calculating the simulation model with different input signals, the simulation results are abtained.In chapter 4, the test stand of full hydraulic steering system is built, and experiments of step response on the angular displacement, velocity and load are carried on, then the differences between the results of experiment and simulation are analyzed.In chapter 5, the load-senseing characteristics of steering system are studied, emphatically analyzed the impacts on the stiffness and the force at zero displacement of the spring in priority valve.In chapter 6, the study work of the subject is summarized and future research orientations are put forward.