PLASMA IGNITION DEVICE

PROBLEM TO BE SOLVED: To suppress output deterioration due to a delay in ignition of an air-fuel mixture when consuming an electrode, in a plasma ignition device using creeping discharge on the inner surface of the sidewall of an insulator in combination with aerial discharge so that gas in a chamber is converted into plasma. SOLUTION: In this plasma ignition device, voltage is applied between a center electrode 3 and an earth electrode 4, the creeping discharge S1 on the inner surface of the sidewall 2 of the insulator is firstly generated, and the aerial discharge S2 is subsequently generated, thereby the gas in the chamber 1 is converted into the plasma, and the high-temperature high-pressure plasma generated in the chamber is injected as plasma jet P from a nozzle port 5 allowing the chamber to communicate with the inside of a cylinder. When it is determined that the output deterioration due to the delay in the ignition of the air-fuel mixture occurs, voltage application between the center electrode and earth electrode for the aerial discharge is stopped and also creeping discharge start timing is advanced. COPYRIGHT: (C)2010,JPO&INPIT