US 7,516,731 B2
Apparatus and method for controlling internal combustion engine
Shiro Yamaoka, Hitachi (Japan); Hiromu Kakuya, Hitachi (Japan); Kunihiko Suzuki, Hitachinaka (Japan); Shinya Satou, Hitachinaka (Japan); and Atsushi Shimada, Hitachinaka (Japan)
Assigned to Hitachi, Ltd., Tokyo (Japan)
Filed on Sep. 14, 2006, as Appl. No. 11/520,740.
Claims priority of application No. 2005-268644 (JP), filed on Sep. 15, 2005.
Prior Publication US 2007/0062485 A1, Mar. 22, 2007
Int. Cl. F02B 17/00 (2006.01)
U.S. Cl. 123—295  [123/433; 123/681] 13 Claims
OG exemplary drawing
 
1. A control apparatus of an internal combustion engine in which a combustion mode is changed-over between a spark ignition combustion mode in which an air-fuel mixture is spark-ignited by an igniter and a compression ignition combustion mode in which the air-fuel mixture is self-ignited by piston compression, comprising a combustion mode selector configured such that
a spark ignition operation area in which the engine is capable to be operated in the spark ignition combustion mode, a compression ignition operation area in which the engine is capable to be operated in the compression ignition combustion mode and a switching stable area which is arranged within the compression ignition operation area are previously set depending on operation conditions of the engine,
(a) when a present operation of the engine in the spark ignition combustion mode falls within the switching stable area, the combustion mode of the engine is changed to the compression ignition combustion mode,
(b) when a present operation of the engine in the spark ignition combustion mode falls within the compression ignition operation area other than the switching stable area, the combustion mode of the engine is continued in the spark ignition combustion mode,
(c) when a present operation of the engine in the compression ignition combustion mode falls within the spark ignition operation area, the combustion mode of the engine is changed to the spark ignition combustion mode, and
(d) when a present operation of the engine in the compression ignition combustion mode is still within the compression ignition operation area other than the switching stable area, the combustion mode of the engine is continued in the compression ignition combustion mode.