US 11,939,943 B2
Ignition apparatus for internal combustion engine
Akimitsu Sugiura, Kariya (JP)
Assigned to DENSO CORPORATION, Kariya (JP)
Filed by DENSO CORPORATION, Kariya (JP)
Filed on Feb. 16, 2023, as Appl. No. 18/110,539.
Application 18/110,539 is a continuation of application No. PCT/JP2021/026588, filed on Jul. 15, 2021.
Claims priority of application No. 2020-140349 (JP), filed on Aug. 21, 2020.
Prior Publication US 2023/0193870 A1, Jun. 22, 2023
Int. Cl. F02P 13/00 (2006.01); F02B 19/12 (2006.01); F02P 15/10 (2006.01)
CPC F02P 13/00 (2013.01) [F02B 19/12 (2013.01); F02P 15/10 (2013.01)] 9 Claims
OG exemplary drawing
 
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.