The Study On The Design And Simulation Of New Hydraulic Counterbalance Valve

Hydraulic counterbalance valve, which belongs to pressure valve, is a key compo-nent of hydraulic balanced loop and is applied abroad in modem engineering equipment especially in elevating machinery. The performance of the appliance is influenced by the property of the counterbalance valve. There are many disadvantages in conventional counterbalance valves, such as the low frequency vibration, the high pilot pressure, the rough working condition, the large power loss, etc. Especially in the event that the back pressure is settled, when pressure brought by load is higher than pressure setup by counterbalance valve, the low-frequency vibration can't be eliminated completely. When pressure produced by load is lower than the one set by the valve, the pilot pres-sure is very high and the power loss is large. For some of these deficiencies, this paper presents a new type of low pilot pressure counterbalance valve.Based on computational fluid mechanics and Hydro-mechanics, combined with the requirement for reducing power of lifting appliance, a new type of low pilot pressure counterbalance valve is designed in the manner of general steps to design hydraulic components and systems. In this paper, the dimension design and spring design, struc-tural features and working principles of this new type counterbalance valve are intro-duced, and the performance of the valve is analyzed. Through the reasonable simplifica-tion of this valve, the model of every parts and oil chambers is created. After the math-ematical transformation, a fairly comprehensive model of pump-counterbalance valve-cylinder is built. According to the mathematical model, a SIMULINK program is developed. Finally, the analysis of static characteristics, dynamic characteristic and stability of the new valve is realized and the conclusion is that the new counterbalance valve responses quickly and declines in the working pressure obviously lower than the old ones, and with the same load and the same flow step signal, the pilot pressure is 1/7～1/6 as much as FD's, so the power loss in the working condition of lowering is reduced.