As one of the key components in the hydraulic transmission system, the working environment of the hydraulic valve is extremely bad. It not only bears the pressure load, but also receives all kinds of impact loads. At the same time, it involves the knowledge of thermodynamics, tribology, surface technology, materials and other disciplines.
Therefore, the quality of the hydraulic valve body is closely related to the performance of the whole hydraulic valve. The casting of the valve body is accompanied by casting defects such as shrinkage porosity, shrinkage cavity and sand hole, which leads to the decrease of the compactness of the casting. When the valve body bears the load, the casting defects cause the stress concentration, and the impact load will aggravate the stress heterogeneity, weaken the strength of the valve body, and even cause the local fracture and leakage.
In this chapter, on the basis of the previous chapter, a hydraulic valve body model with casting defects is established for a single hydraulic valve body. The stress values of the valve body with shrinkage cavity under different pressures are calculated by workbench, and the strength indexes of the ideal valve body and the valve body with defects are compared and analyzed. This study is of great significance to further understand the valve body strength and reliability design and development of hydraulic valve.