| 摘要 |
PROBLEM TO BE SOLVED: To provide a spark plug incorporating a pressure sensor which can be attached without requiring any special extra work of a combustion chamber.SOLUTION: A spark plug including a cylindrical insulator, and a conductive socket being screwed into the external wall of an internal combustion engine while housing the insulator partially from one end side thereof and fixed in place, is further provided with a piezoelectric element having a hollow cylindrical shape and being held, in the axial direction, between the end face at an enlarged diameter part of the insulator fitted to the hollow cylinder and a flange provided in the socket. |
