US 12,085,032 B2
Controller and control method for engine
Atsushi Tabata, Okazaki (JP); Koichi Okuda, Toyota (JP); Nobuhiko Satake, Toyota (JP); and Daiki Sato, Toyota (JP)
Assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP)
Filed by TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP)
Filed on Feb. 6, 2024, as Appl. No. 18/434,226.
Claims priority of application No. 2023-018545 (JP), filed on Feb. 9, 2023.
Prior Publication US 2024/0271581 A1, Aug. 15, 2024
Int. Cl. F02D 41/02 (2006.01)
CPC F02D 41/0235 (2013.01) [F02D 2200/0802 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A controller configured to control an engine that includes a cylinder that defines a space for burning hydrogen serving as a fuel, an exhaust passage that is connected to the cylinder, and a catalyst that is located in the exhaust passage and reduces nitrogen oxides, the controller comprising processing circuitry, wherein
the processing circuitry is configured to execute:
an obtaining process that obtains a catalyst temperature that is a temperature of the catalyst; and
a setting process that sets a target air-fuel ratio that is a target value of an air-fuel ratio in the cylinder,
a temperature of the catalyst at which an efficiency of nitrogen oxide reduction by the catalyst is the highest is referred to as a prescribed temperature, and
the processing circuitry is configured to, in the setting process, set the target air-fuel ratio to be higher when the catalyst temperature is a first value that is lower than the prescribed temperature, than when the catalyst temperature is a second value that is lower than or equal to the prescribed temperature and higher than the first value.