| 摘要 |
A plasma jet spark plug and a manufacturing method therefor are disclosed. In a state in which a noble-metal chip (36) having a flange-like outwardly projecting portion (37) is disposed in a communication section (31) of a ground electrode (30), an electrode base metal (33) of the ground electrode (30) is disposed in a stepped engagement portion (57) of a metallic shell (50), which retains an insulator (10) therein. While being pressed against a front end portion (16) of the insulator (10), the noble-metal chip (36) is joined to the electrode base metal (33), whereby a clearance between the ground electrode (30) (electrode base metal (33)) and the front end portion (16) of the insulator (10) can be closed. Therefore, energy of plasma generated within the cavity (60) does not leak. |
