Patent ID: 9422911
Filing Date: 2016-08-23
CPC Classification: F02P,H01T,Y10S

Claim Text:
1. A gasket for attaching a spark plug to an internal combustion engine, the spark plug having a screw portion and a plug large diameter portion, the screw portion engaging with a wall member forming an combustion chamber of an internal combustion engine, the plug large diameter portion being disposed across from the combustion chamber with the screw portion disposed between the plug large diameter portion and the combustion chamber, the plug large diameter portion having a larger diameter than the screw portion, the gasket comprising: an annular portion surrounding the spark plug and having a flat plate-like structure between the wall member and the spark plug when the spark plug is fastened to the wall member; and contact surfaces formed on both axial ends of the annular portion and configured to be sandwiched between the spark plug and the internal combustion engine in surface contact with a plug seating surface and an attachment seating surface, the plug seating surface being formed on the plug large diameter portion of the spark plug, the attachment seating surface being formed on the wall member of the internal combustion engine, wherein at least the contact surfaces are made of copper alloy containing aluminum oxide, and the aluminum oxide content of the copper alloy is 0.7 wt %, and a Vickers hardness of the copper alloy is 160 Hv or more.