CASTING TECHNOLOGY FOR DIRECTIONAL CONTROL VALVE

Disclosed is a casting technology for a directional control valve, the casting technology comprising the following processes : a pattern producing process : producing a shell (1) and a clay core (2), a core skeleton (4) and a vent needle (5) are arranged in the clay core (2); polishing after producing of the clay core (2) is accomplished, core skeleton protruding portions (41) being provided at two ends of the polished clay core (2), placing the clay core (2) in the shell (1), and the core skeleton protruding portions (41) and the interior of the shell (1) are in overlap joint; a metal melting process : placing a raw material into a melting furnace to be melted down, and then adding a nodulizing agent and a nucleating agent into the material in sequence, the nucleating agent consisting of a silicon-strontium nucleating agent and a silicon-rare earth nucleating agent, the silicon-strontium nucleating agent having a weight ratio ranging from 0.2% to 0.4%, and a particle size ranging from 2 mm to 6 mm, and the silicon-rare earth nucleating agent having a weight ratio ranging from 0.1% to 0.3%, and a particle size ranging from 2 mm to 6 mm; a casting shaping process : liquid enters the shell through a sprue formed on one side; and a casting treatment process : conducting polishing and heat treatment on the casting. According to the casting technology of the directional control valve, cutting performance of the product can be improved while improving the hardness of the cast product, and a high-precision flow channel can be formed, and the linearity of the flow channel and the accuracy of the gear size can also be guaranteed.