Controller for internal combustion engine and control method for internal combustion engine
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsKeisuke NAGAKURA, Kuniyuki SASAKI
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Abstract
A controller for an internal combustion engine including a plurality of cylinders, a fuel injection valve for supplying a fuel to each cylinder, an EGR passage connecting an exhaust passage and an intake passage, and an EGR valve adjusting a flow rate of exhaust flowing into the intake passage from the exhaust passage via the EGR passage, the controller includes an electronic control unit. The electronic control unit is configured to execute determination processing for determining that a degree of an imbalance abnormality is larger when a torque fluctuation amount is relatively large than when the torque fluctuation amount is relatively small.
Claims11
A controller for an internal combustion engine including a plurality of cylinders, a fuel injection valve for supplying a fuel to each cylinder, an EGR passage connecting an exhaust passage and an intake passage, and an EGR valve adjusting a flow rate of exhaust flowing into the intake passage from the exhaust passage via the EGR passage, the controller comprising
- an electronic control unit configured to execute determination processing for determining that a degree of an imbalance abnormality is larger when a torque fluctuation amount is relatively large than when the torque fluctuation amount is relatively small,
- the torque fluctuation amount being a difference between torques respectively generated by the cylinders;
- the degree of the imbalance abnormality being a degree of variation in air-fuel ratios in respective combustion chambers of the cylinders at a time when the fuel injection valve is operated such that the air-fuel ratios in the respective cylinders are controlled to be equalized;
- and
- the determination processing being processing for determining that the degree of the imbalance abnormality is smaller when an EGR rate is relatively large than when the EGR rate is relatively small even at the same torque fluctuation amount, the EGR rate being a value obtained by dividing an amount of exhaust flowing into the intake passage from the EGR passage by an amount of air flowing into the intake passage.
A control method for an internal combustion engine including a plurality of cylinders, a fuel injection valve for supplying a fuel to each cylinder, an EGR passage connecting an exhaust passage and an intake passage, and an EGR valve adjusting a flow rate of exhaust flowing into the intake passage from the exhaust passage via the EGR passage, the control method comprising:
- determining, by an electronic control unit, that a degree of an imbalance abnormality is larger when a torque fluctuation amount is relatively large than when the torque fluctuation amount is relatively small, the torque fluctuation amount being a difference between torques respectively generated by the cylinders and the degree of the imbalance abnormality being a degree of variation in air-fuel ratios in respective combustion chambers of the cylinders at a time when the fuel injection valve is operated such that the air-fuel ratios in the respective cylinders are controlled to be equalized;
- and
- determining, in the determination processing and by the electronic control unit, that the degree of the imbalance abnormality is smaller when an EGR rate is relatively large than when the EGR rate is relatively small even at the same torque fluctuation amount, the EGR rate being a value obtained by dividing an amount of exhaust flowing into the intake passage from the EGR passage by an amount of air flowing into the intake passage.
Dependencies are inferred from the claim text.