Nozzle blocking valve for metal injection molding device

PURPOSE:To prevent the leakage of material and to avoid mixing impurity caused by oxidation by forming a through-hole in a taper shape with a smaller diameter at the injector side and a larger diameter at the metallic mold side and providing a spherical shaped abutting face. CONSTITUTION:A spherical shaped valve main body 41 is rotated by a rotating mechanism and a material flow path 9 is opened/closed by changing the communicating state of the taper shaped through-hole 43. The flow path 9 is closed when the material is measured and opened when the injecting work is carried out. After the injection work is done, a formed product in a metallic mold 3 is solidified and released from the metallic mold. Since the through-hole 43 is formed to have a larger diameter at the metallic mold side, the solidified body in the through-hole is pulled out with the formed product. Immediately after the product is released from the metallic mold, the contact between molten metal in the injector 1 side and air is shut by closing the flow path 9 by rotating the valve main body 41 and an inconvenience such as oxidation is not generated. Since the through-hole 43 is tapered to have a smaller diameter toward the injector side, this structure is effective to prevent a back flow. Furthermore, a valve mechanism as this is convenient for maintenance from the outside.