| 摘要 |
PROBLEM TO BE SOLVED: To suppress deformation of an unbaked insulator by releasing a mold.SOLUTION: In a manufacturing method of a spark plug insulator, a molding block of the spark plug insulator comprises at least: a bar part extending in an axial direction; a first molding block which includes a large diameter part having the largest inner diameter; and a second molding block which is continuously arranged with the first molding block in the axial direction. The manufacturing method of the spark plug insulator comprises: a first step in which a material is injected into a molding space formed by a plurality of surfaces including an outer peripheral surface of the bar part, an inner peripheral surface of the first molding block, and an inner peripheral surface of the second molding block; and a second step in which elements constituting the molding block are relatively moved in an axial direction to remove from the insulator formed in the first step. The second step is performed while force is applied to the insulator in an opposite direction to the relatively moving direction of the elements removed from the molding block.SELECTED DRAWING: Figure 4 |
