Cylinder-by-cylinder air-fuel ratio controller for internal combustion engine
AssigneeDenso Corporation
InventorsMasayuki Kita, Noriaki Ikemoto
Life of this patent
Estimating the term…
Abstract
An air-fuel ratio sensor detects an air-fuel ratio of an exhaust gas at a confluent portion of an exhaust gas. An air-fuel ratios in each cylinder are estimated to be controlled based on an output of the air-fuel ratio sensor. A computer determines whether an air-fuel detecting timing deviates according to a dispersion of the estimated air-fuel ratio among cylinders. When the deviation is detected, the air-fuel ratio detecting timing is varied to estimate an air-fuel ratio before and after correcting amount of fuel. The air-fuel ratio detecting timing is adapted as a proper timing when the variation amount of the estimated air-fuel ratio before and after the correction of fuel amount corresponds to the correct amount of fuel.
Claims14
A cylinder-by-cylinder air-fuel ratio controller for an internal combustion engine, comprising:
- an air-fuel ratio sensor detecting an air-fuel ratio of an exhaust gas, the air-fuel ratio sensor being disposed in a confluent portion into which the exhaust gas from each cylinder flows;
- an air-fuel ratio estimating means which estimates air-fuel ratios cylinder-by-cylinder based on an output of the air-fuel ratio sensor every air-fuel ratio detecting timing;
- an air-fuel ratio control means which controls the air-fuel ratio of each cylinder based on an estimated air-fuel ratios;
- and
- a determining means which determines a deviation of the air-fuel ratio detecting timing based on a dispersion of the estimated air-fuel ratio among the cylinders while the air-fuel ratio control means controls the air-fuel ratio.
A cylinder-by-cylinder air-fuel ratio controller for an internal combustion engine, comprising:
- an air-fuel ratio sensor detecting an air-fuel ratio of an exhaust gas, the air-fuel ratio sensor being disposed in a confluent portion into which the exhaust gas from each cylinder flows;
- an air-fuel ratio estimating means which estimates air-fuel ratios cylinder-by-cylinder based on an output of the air-fuel ratio sensor every air-fuel ratio detecting timing;
- an air-fuel ratio control means which controls the air-fuel ratio of each cylinder based on an estimated air-fuel ratios;
- and
- a determining means which determines a deviation of the air-fuel ratio detecting timing based on a dispersion of a correct amount of fuel among the cylinders and a dispersion of the estimated air-fuel ratio among the cylinders while the air-fuel ratio control means controls the air-fuel ratio.
A cylinder-by-cylinder air-fuel ratio controller for an internal combustion engine, comprising:
- an air-fuel ratio sensor detecting an air-fuel ratio of an exhaust gas, the air-fuel ratio sensor being disposed in a confluent portion into which the exhaust gas from each cylinder flows;
- an air-fuel ratio estimating means which estimates air-fuel ratios cylinder-by-cylinder based on an output of the air-fuel ratio sensor every air-fuel ratio detecting timing;
- an air-fuel ratio control means which controls the air-fuel ratio of each cylinder based on an estimated air-fuel ratios;
- and
- a determining means which determines a deviation of the air-fuel ratio detecting timing based on a variation direction of a correct amount of fuel and an estimated air-fuel ratio.
A cylinder-by-cylinder air-fuel ratio controller for an internal combustion engine, comprising:
- an air-fuel ratio sensor detecting an air-fuel ratio of an exhaust gas, the air-fuel ratio sensor being disposed in a confluent portion into which the exhaust gas from each cylinder flows;
- an air-fuel ratio estimating means which estimates air-fuel ratios cylinder-by-cylinder based on an output of the air-fuel ratio sensor every air-fuel ratio detecting timing;
- an air-fuel ratio control means which controls the air-fuel ratio of each cylinder based on an estimated air-fuel ratios;
- and
- a parameter correction means which corrects a parameter used by the air-fuel estimating means based on a relationship between a variation amount of an estimated air-fuel ratio of at least one cylinder and a variation amount of a correct amount of fuel of the cylinder.
A cylinder-by-cylinder air-fuel ratio controller for an internal combustion engine, comprising:
- an air-fuel ratio sensor detecting an air-fuel ratio of an exhaust gas, the air-fuel ratio sensor being disposed in a confluent portion into which the exhaust gas from each cylinder flows;
- an air-fuel ratio estimating means which estimates air-fuel ratios cylinder-by-cylinder based on an output of the air-fuel ratio sensor every air-fuel ratio detecting timing;
- an air-fuel ratio control means which controls the air-fuel ratio of each cylinder based on an estimated air-fuel ratios;
- and
- an adaptations means which estimates an air-fuel ratio of each cylinder by varying an air-fuel ratio detecting timing, and adapts a proper air-fuel ratio detecting timing in which a variation amount of the estimated air-fuel ratio corresponds to a correct amount of fuel.
A cylinder-by-cylinder air-fuel ratio controller for an internal combustion engine, comprising:
- an air-fuel ratio sensor detecting an air-fuel ratio of an exhaust gas, the air-fuel ratio sensor being disposed in a confluent portion into which the exhaust gas from each cylinder flows;
- an air-fuel ratio estimating means which estimates air-fuel ratios cylinder-by-cylinder based on an output of the air-fuel ratio sensor every air-fuel ratio detecting timing;
- an air-fuel ratio control means which controls the air-fuel ratio of each cylinder based on an estimated air-fuel ratios;
- and
- an adaptations means which estimates an air-fuel ratio of each cylinder by varying an air-fuel ratio detecting timing, and adapts a proper air-fuel ratio detecting timing in which a dispersion of an estimated air-fuel ratio among the cylinders and a dispersion of a correct amount of fuel among the cylinders are minimum or less than a predetermined value.
A cylinder-by-cylinder air-fuel ratio controller for an internal combustion engine, comprising:
- an air-fuel ratio sensor detecting an air-fuel ratio of an exhaust gas, the air-fuel ratio sensor being disposed in a confluent portion into which the exhaust gas from each cylinder flows;
- an air-fuel ratio estimating means which estimates air-fuel ratios cylinder-by-cylinder based on an output of the air-fuel ratio sensor every air-fuel ratio detecting timing;
- an air-fuel ratio control means which controls the air-fuel ratio of each cylinder based on an estimated air-fuel ratios;
- and
- an adaptations means which adapts a proper air-fuel ratio detecting timing of a cylinder in which a fuel-cut is terminated first based on a timing in which the output of the air-fuel ratio sensor becomes a value corresponding to an air-fuel ratio after a fuel injection is re-conducted.
Dependencies are inferred from the claim text.