IGNITION DEVICE OF INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To provide an ignition device of an internal combustion engine, securing a ventilation path with a simple construction and attaining reduction of a production cost. SOLUTION: When gas inside a plughole expands, the gas inside the plughole is led to an annular space PL through a communication hole HL of a rain cover 800. Such a gas flow moves along a semi-circular annular space PL. The gas flow reached a communication hole 430b is then discharged to an outside space through the communication hole 430b. Since an open end of the communication hole 430b is arranged at a high place, even when a hole rib HR of an engine head is temporarily flooded, intrusion of water into the plughole is inhibited. Formation of a groove for ventilation is avoided in a case body 400 of the ignition device 1000 and the case 400 can be manufactured with use of a mold of a simple construction. COPYRIGHT: (C)2010,JPO&INPIT