| 摘要 |
The spark plug according to the invention comprises a shell (1), a central electrode (3) surrounded by an insulator (2) and a ground electrode (4) which, according to the invention, has a cross section (4a) such that the surface of the ground electrode (4) which is located nearest to the bottom end of the central electrode (3) is larger than the surface of the ground electrode (4) which is located farthest away from said bottom end of the central electrode (3). The ground electrode (4) may be provided with a copper core and its surface nearest to the bottom end of the central electrode (3) may be provided with a precious metal insert. The surface of the ground electrode which is farthest away from the bottom end of the central electrode (3) may be reduced to a line and the lateral surfaces of the ground electrode may be curved surfaces.
|
