| 摘要 |
Provided is a method for manufacturing a hollow poppet valve for which a large amount of a cooling material can be filled into a hollow part. This method for manufacturing a hollow poppet valve, wherein a cooling material (19) is filled into a hollow part extending from an umbrella part (14) to a shaft (12), is equipped with: a rod insertion step, in which a clay-like cooling material (19) extruded from an extruder (20) is cut to a prescribed length by a cutter (20) to form a cooling material rod (19a), which is inserted into the hollow part (S) from the opening of a hole in an intermediate valve product (11) and corresponding to the hollow part (S); and a sealing step, in which the opening of the hole (S) is sealed. In the rod insertion step the insertion of cooling material rods (19a, 19b) into the hole (S) is performed multiple times. A shorter length for the cooling material rod (19a) results in less deformation and bending, so there is little interference between the rod and the inner circumferential surface of the hole (S); therefore, the diameter of the rod can be increased and the filling amount of the cooling material (19) can be increased. |
