Design of Hydraulic Control System for Press Machine and Analysis on Its Fluid Transmission Features

The stability and reliability of hydraulic control system have a direct bearing on the overall dynamic performance of the press machine. Hydromechanical analysis on the hydraulic control system is of theoretical and practical significance to improving the transmission performance and structural design of the entire press machine. From a quantitative perspective, this paper firstly analyzes the fluid transmission features of the hydraulic control system for the press machine, and presents the fluid transmission route and design drawings of the hydraulic control system. The next step is the design of the hydraulic control system. The authors specified the steps of design and calculation for the hydraulic control cylinder, and the principles for determining the power of the diesel engine. After that, experiments were carried out to verify the dynamic and static features of the designed system, and prove that our system is scientific and rational.

Internal leakage analysis and experiment in hydraulic control system of steam turbine inlet valve

In this paper, the transformation of steam turbine regulating system from mechanical hydraulic regulation to electro-hydraulic regulation is realized. And the internal leakage mechanism of the hydraulic control switch valve and the electro-hydraulic proportional valve in the system is analyzed. With the use of hydraulic simulation software AMESim, the mathematical model of the electro-hydraulic control system after transforming is established. The parameters of the hydraulic control switch valve and the electro-hydraulic proportional valve in the hydraulic control system of steam turbine inlet valve are studied under different internal leakage locations and different leakage degree, such as piston regulating time, steady position of piston, oil pressure and leakage flow flux. The fault characteristic table of internal leakage is obtained. An experimental platform for simulating internal leakage is built. The experimental curves of several physical quantities under different internal leakage conditions are obtained. The experimental results prove that the internal leakage has a great impact on the performance of the electro-hydraulic control system. The results of internal leakage experiment are consistent with those of internal leakage simulation.