| With the application of hydraulic transmission technology more and more widely, how to ensure the stability of the hydraulic system work has been the balance valves and balance hydraulic circuits to solve the key problems all along. This papers analysis the basic working principle of the key hydraulic components balancing valve and its dynamic and static characteristics according to the use of common tower crane system in mechanical engineering.Also the pilot-operated check valve and sequence valve and its characteristics are compared to the balance valve in the papers. Then build three tower crane hydraulic system model which use the pilot-operated check valves, sequence valves, and balance valves three different pressure valves respectively in the software AMESim, simulating the changes of important performance parameters in the whole process when the tower crane hydraulic system working. Finally, analysis and comparison of the different simulation results.The main contents are extracted and listed as below:(1) In the first chapter, the background and significance of the research are discussed.Also the development and application of balance valve is introduced, and the domestic and international development status of the balance valve is described in this paper. At last the main research contents of this paper are listed in detail.(2) In the second chapter, first introduces the basic principle of the balance valve, and several typical balance valves for a brief introduction. Then, the balance circuit which most frequently used in engineering application is compared and analyzed.(3) In the third chapter, the operating principle of the three kinds of different pressure control valve such as the pilot-operated check valve, sequence valve and balance valve are introduced. Their dynamic and static characteristics are analyzed. And also the static and dynamic characteristic equation are is presented in this chapter. The comparison is carried out at last.(4) The fourth chapter, built three different tower crane hydraulic principle diagram which adopted respectively three different pressure control valve like the pilot-operated check valves, sequence valves, and balance valves. And AMESim software is used to build the simulation model of three kinds of different hydraulic control system above.when the load unchanged, we find that the pressure and flow at the cylinder rod cavity and rodless cavity, and the velocity and displacement at the piston rod in the system on the condition of above three different valve control is not difference obviously when the hydraulic cylinder rising, stopping and falling in the whole working process. However, when the cylinder drop with load, the balance valve can be very good to improve pressure fluctuation which appearance in the other two kinds of valves due to the impact of pressure fluctuations,improve the stability of the system furthermore. And then in the other conditions keep constant value of the original, we analysis the load weight were 8000 kg, 10000 kg, 12000 kg,respectively, the cylinder in the weight-bearing rise and fall with the rod chamber pressure and dynamic characteristics of rod cavity flow and piston rod speed. This paper focuses on the analysis of the drop in the process of, the change of system parameters, in contrast to the last analysis and draws the conclusion, balance valve compared to the other two valve, in the system weight loss can effectively reduce the vibration caused by the impact load. |
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