With hydraulic valve body as carrier, the filling and solidification process of valve body casting were studied by combining theoretical analysis with numerical calculation, and the influence of casting defects on valve body strength was analyzed in depth.The research has important guiding significance for further understanding of valve body strength and reliability design and development of hydraulic valves.
(1) Predict the location and size of casting defects.Considering the complex internal structure of the hydraulic valve body, which leads to long production cycle, high production cost and poor casting quality, the filling and solidification process of the valve body casting is simulated by PROCAST software, the position and size of casting defects are predicted, and the position and size of casting defects of the valve body with different pouring temperature, different materials and structures are compared and analyzed.The optimum casting material and pouring temperature are sought to determine the optimum valve body structure, which provides basis for the design of hydraulic valve.
(2)Using PROCAST post-processing software to measure the position of casting defects and calculate the size, and then using the method of “artificial defects”, the casting defects are built in the valve body model by using three-dimensional modeling software, the stress values of valve body with shrinkage holes under different pressures are calculated by Workbench, and the fatigue characteristics of valve body are obtained by fatigue analysis under alternating loads, and the ideal values are compared and analyzed.Strength index of valve body and valve body with casting defects, and influence rule of casting defects on strength of hydraulic valve body are summarized.
(3)In addition to the high pressure load, the hydraulic valve body is subjected to thermal load due to throttling. By establishing watershed model of multi-way valve under different conditions, the flow field distribution and temperature distribution of hydraulic valve under different conditions are analyzed, and the calculated pressure and temperature loads are introduced into Workbench. The fluid-solid coupling method is used.The stress values of the multi-way valve under different conditions are obtained, and the strength indexes of the ideal valve body and the valve body with casting defects are compared and analyzed to reveal the influence of casting defects on the strength of the valve body.