Patent ID: 11939943
Assignee: DENSO CORPORATION
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  H  Y | IPC F

Claim 6:
7. An ignition apparatus for an internal combustion engine, the ignition apparatus comprising:
a spark plug having an auxiliary combustion chamber in which a discharge gap is arranged;
an ignition coil configured to apply a voltage to the spark plug; and
a controller configured to perform a multiple-discharge mode in which discharge is generated at least twice, with a discharge pause period intervening therebetween, across the discharge gap within a period from a compression stroke to an expansion stroke of the internal combustion engine,
wherein:
in the multiple-discharge mode, the controller causes the discharge to be generated at least once in the expansion stroke;
the discharge pause period is set to start when a discharge sustaining voltage or an attenuation rate of discharge current of the discharge generated immediately before the discharge pause period becomes lower than a predetermined threshold; and
in the multiple-discharge mode, a first discharge is generated immediately before a compression top dead center (TDC), then the discharge pause period is provided between a time instant immediately before the TDC and a time instant immediately after the TDC, and then a second discharge is generated immediately after the TDC.