| 摘要 |
<p>A spark plug (1) for an internal combustion engine includes: a cylindrical insulator (2) as defined herein; a center.electrode (5) as defined herein; a cylindrical metal shell (3) as defined herein; and a ground electrode (27) as defined herein, an annular gasket receiving portion (16a) projecting radially outward being provided on a rear end side of the externally threaded portion (15) of the metal shell (3), and a metallic gasket (18) capable of abutting against the gasket receiving portion (16a) being provided on the outer periphery of the metal shell (3), wherein the gasket (18) has a solid annular shape, an inside diameter (A) of the gasket (18) is smaller than an outside diameter (D) of the externally threaded portion (15), and a groove portion (54) whose depth coincides with the direction of the axis (C1) is provided over an entire circumference of the gasket (18).</p> |
