| 摘要 |
A spark plug and manufacturing method. The spark plug (1) includes a metallic shell (3) extending along an axis CL1, a ceramic insulator (2), a center electrode (5), and a ground electrode (27) having a base end portion joined to a front end face (26) of the metallic shell (3). The method includes assembling the metallic shell (3) and a center electrode assembly (41); and joining the ground electrode (27) to the front end face (26). The distance between a reference plane SP perpendicular to the axis CL1 and the front end face (26) as measured along the axis CL1 varies in the circumferential direction. In the joining step, the position of the distal end portion of the ground electrode (27) relative to the front end portion of the center electrode assembly (41) along the axis CL1 is adjusted by changing the region of the front end face (26) to which the ground electrode (27) is joined. |
