Although the shape of the hydraulic valve body casting is simple, its quality differs greatly and the section structure is complicated. Especially, the multi-way valve (as shown in the figure) has narrow and long grooves with different numbers, cross-section shapes and sizes in its cavity. The casting process of this highly integrated multi-layer complex internal cavity valve body is extremely complex and has poor versatility. In addition, the design of the casting system is unreasonable during the casting process.Hard core fabrication can result in more or less casting defects in valve body castings.
As shown in the diagram, these casting defects result in uneven body matrix, reduced compactness of the castings, more obvious local stress concentration, and reduced valve body strength. In addition, because the hydraulic valve body is subjected to high loads and pressure fluctuations, this impact load increases the stress unevenness, which leads to local valve body fracture and leakage.In addition, casting defects on the mating surface between the spool and the valve body (Fig. a) not only affect the strength of the valve body, but also degrade the sealing performance of the hydraulic valve, and even cause the valve to stick during operation.
As one of the key parts of the whole hydraulic valve, the quality of the valve body casting is closely related to the performance of the hydraulic valve.How to produce high-quality hydraulic valve body castings with compact material, smooth surface, high pressure resistance and long service life is a bottleneck in China’s hydraulic industry, which seriously restricts the development of high-end hydraulic components.Therefore, this paper makes analysis and Research on casting defects and strength of hydraulic valve body, which is of far-reaching significance for optimum design of hydraulic valve body.