The hydraulic valve body of MXA-300 shearer is designed and manufactured by means of casting oil duct in coal mine machinery plant and installed test is carried out.In order to make the valve body core withstand the scouring of hot iron without deformation and have good collapsibility, the normal temperature self-hardening cold box resin sand – F70 type cast resin is selected as the core material.A set of combined metal core box was designed and manufactured to solve the difficult problem of core box fabrication caused by complex oil passages and strict size requirements of valve body.
By utilizing the good fluidity of coated sand, the Institute of Mechanical and Electrical Research is able to shoot sand cores with complex shapes and high strength; by utilizing the advantages of good collapsibility of moulded sand, the multi-way valve body cores are manufactured to produce multi-way valve castings.They proposed that the coated sand core has high strength, good collapsibility, and can cast complex-shaped smooth surface flow paths with high casting size accuracy, thus reducing the machining of hydraulic valve casting flow paths.
Ning Youjun, Zhao Guiqing and Li Suhua of Yuci Hydraulic Co., Ltd. have studied the influence of the position of sand core in the casting on the size and shape accuracy of the casting.They proposed that in order to ensure the accuracy requirement, the core positioning should not cause over-fixing while not interfering with each other; for the casting holes with relative position requirement, in order to ensure the position accuracy of each other, there should be an assembly main core; for the complex shell cores, the inlay core assembly method is used to improve the accuracy of cavity size and relative position of hydraulic castings; for the longer valve holesThe problem of poor bending resistance of sand core produced by the method of core head formation is put forward. Frame core head is put forward to solve the bending phenomenon of main valve bore of casting. Reasonable riser design can prevent the floating core produced during pouring.