| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent a gasket from falling out of a thread neck, and effectively preventing a male screw from biting into the gasket, in the gasket provided around the thread neck of an automobile component. <P>SOLUTION: A spark plug is comprised of an insulator, a metal shell holding the insulator and the like, and mounted to a cylinder head by screwing a male screw into a screw hole of the cylinder head. The gasket 18 provided around the thread neck of the metal shell is compressed and crushed when the spark plug is screwed into the cylinder head. The gasket 18 comprises: an inner tube 51 extending in an axial direction and constituting the inner circumference face of the gasket 18; an upper large diameter portion 52 and a lower large diameter portion 53 extending from the upper end and the lower end of the inner tube 51 in the axial direction so that an inner diameter of the gasket gradually increases; an upper plate-shaped portion 54 and a lower plate-shaped portion 55 extending from the upper large diameter portion 52 and the lower large diameter portion 53, respectively, toward a radial direction perpendicular to the axial direction; and an upper intervening plate-shaped portion 58 and a lower intervening plate-shaped portion 59 are interposed between the upper plate-shaped portion 54 and the lower plate-shaped portion 55. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
