US 12,467,417 B2
Internal combustion engine control device and internal combustion engine control method
Akihiro Komori, Hitachinaka (JP); and Kunihiko Suzuki, Hitachinaka (JP)
Assigned to Hitachi Astemo, Ltd., Hitachinaka (JP)
Appl. No. 18/834,871
Filed by Hitachi Astemo, Ltd., Hitachinaka (JP)
PCT Filed Apr. 15, 2022, PCT No. PCT/JP2022/017915
§ 371(c)(1), (2) Date Jul. 31, 2024,
PCT Pub. No. WO2023/199508, PCT Pub. Date Oct. 19, 2023.
Prior Publication US 2025/0129755 A1, Apr. 24, 2025
Int. Cl. B60T 7/12 (2006.01); F01N 3/20 (2006.01); F01N 3/22 (2006.01); F02D 41/30 (2006.01)
CPC F02D 41/30 (2013.01) [F01N 3/20 (2013.01); F01N 3/22 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An internal combustion engine control device that controls an internal combustion engine including an air-fuel ratio sensor that is disposed upstream of a three-way catalyst provided in an exhaust pipe and detects an air-fuel ratio of exhaust gas and an oxygen concentration sensor that is disposed downstream of the three-way catalyst and detects an oxygen concentration of the exhaust gas, the internal combustion engine control device comprising
an oxygen storage amount integration unit that integrates an oxygen storage amount stored in the three-way catalyst in a period from an integration start position where the air-fuel ratio of exhaust gas starts to change from lean to rich or from rich to lean to an integration stop position where the oxygen concentration that has increased or decreased from before the integration start position is reversed;
an integration stop determination unit that determines the integration stop position;
an oxygen flow rate estimation unit that estimates an oxygen flow rate of the exhaust gas based on a flow rate of the exhaust gas and the air-fuel ratio; and
an integration start determination unit that determines the integration start position based on the air-fuel ratio,
wherein the oxygen storage amount integration unit integrates the oxygen storage amount based on the oxygen flow rate, the integration start position, and the integration stop position,
wherein the oxygen storage amount integration unit sets a timing at which a voltage value, output from the oxygen concentration sensor delayed from an integration start position under a rich condition where the air-fuel ratio of exhaust gas starts to change from rich to lean after changing from lean to rich, becomes a voltage value exceeding a voltage upper limit threshold by a maximum electromotive force under rich of the air-fuel ratio, and thereafter, decreases and falls within a range of the voltage upper limit threshold and a voltage lower limit threshold, and a differential value of the voltage value when the voltage value decreases exceeds a differential value threshold, as an integration stop position under the rich condition, and a timing at which a voltage value, output from the oxygen concentration sensor delayed from an integration start position under a lean condition where the air-fuel ratio of exhaust gas starts to change from lean to rich after changing from rich to lean, becomes a voltage value lower than the voltage lower limit threshold by a minimum electromotive force under lean of the air-fuel ratio, and thereafter, increases and falls within the range of the voltage upper limit threshold and the voltage lower limit threshold, and a differential value of the voltage value when the voltage value increases exceeds a differential value threshold, as an integration stop position under the lean condition.