Fuel injection controller and controlling method for engine
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsSohichi IMAI, Masanao IDOGAWA
Life of this patent
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Abstract
A fuel injection controller updates an air-fuel ratio learning value such that the amount of correction of a fuel injection amount according to an air-fuel ratio feedback correction value approaches zero. Further, the fuel injection controller makes an update rate of the air-fuel ratio learning value lower when the variation among respective-cylinder correction values, which are set for the respective cylinders in order to differentiate air-fuel ratios of a plurality of cylinders, is great than when the variation among the respective-cylinder correction values of the cylinders is small.
Claims6
A fuel injection controller for an engine, the engine including a plurality of cylinders and a plurality of fuel injection valves provided respectively in the cylinders, wherein
- the fuel injection controller is configured to control each of fuel injection amounts of the fuel injection valves,
- the fuel injection controller is configured to have, as correction values for fuel injection amounts of the fuel injection valves,
- an air-fuel ratio feedback correction value, which is updated such that a difference between an exhaust air-fuel ratio, which is detected by an air-fuel ratio sensor installed in an exhaust passage, and a target air-fuel ratio approaches zero,
- an air-fuel ratio learning value, which is updated based on the air-fuel ratio feedback correction value such that an amount of correction of the fuel injection amount according to the air-fuel ratio feedback correction value approaches zero, and
- respective-cylinder correction values, which are set for the respective cylinders to differentiate the air fuel ratios of the cylinders, and
- the fuel injection controller is configured to make an update rate of the air-fuel ratio learning value lower when a variation among the respective-cylinder correction values of the cylinders is great than when the variation among the respective-cylinder correction values of the cylinders is small.
A fuel injection controller for an engine, the engine including a plurality of cylinders and a plurality of fuel injection valves provided respectively in the cylinders, the fuel injection controller comprising circuitry that is configured to
- control each of fuel injection amounts of the fuel injection valves,
- have, as correction values for fuel injection amounts of the fuel injection valves,
- an air-fuel ratio feedback correction value, which is updated such that a difference between an exhaust air-fuel ratio, which is detected by an air-fuel ratio sensor installed in an exhaust passage, and a target air-fuel ratio approaches zero,
- an air-fuel ratio learning value, which is updated based on the air-fuel ratio feedback correction value such that an amount of correction of the fuel injection amount according to the air-fuel ratio feedback correction value approaches zero, and
- respective-cylinder correction values, which are set for the respective cylinders to differentiate the air fuel ratios of the cylinders, and
- make an update rate of the air-fuel ratio learning value lower when a variation among the respective-cylinder correction values of the cylinders is great than when the variation among the respective-cylinder correction values of the cylinders is small.
A fuel injection controlling method for an engine, the engine including a plurality of cylinders and a plurality of fuel injection valves provided respectively in the cylinders, the method comprising:
- controlling each of fuel injection amounts of the fuel injection valves;
- having, as correction values for fuel injection amounts of the fuel injection valves,
- an air-fuel ratio feedback correction value, which is updated such that a difference between an exhaust air-fuel ratio, which is detected by an air-fuel ratio sensor installed in an exhaust passage, and a target air-fuel ratio approaches zero,
- an air-fuel ratio learning value, which is updated based on the air-fuel ratio feedback correction value such that an amount of correction of the fuel injection amount according to the air-fuel ratio feedback correction value approaches zero, and
- respective-cylinder correction values, which are set for the respective cylinders to differentiate the air fuel ratios of the cylinders;
- and
- making an update rate of the air-fuel ratio learning value lower when a variation among the respective-cylinder correction values of the cylinders is great than when the variation among the respective-cylinder correction values of the cylinders is small.
Dependencies are inferred from the claim text.