CPC F02P 13/00 (2013.01) [F02B 19/12 (2013.01); F02P 15/10 (2013.01)] | 9 Claims |
1. 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;
a gas flow speed in the discharge gap is lower during the discharge pause period than during discharge periods immediately before and immediately after the discharge pause period;
the discharge pause period is set to a low flow speed period during which the gas flow speed in the discharge gap is lower than a predetermined flow speed 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.
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