Vehicle control method and vehicle control device

A vehicle control device comprising:

• an internal combustion engine structured to be motored by an electric motor generator while a vehicle is running;
• an exhaust purification catalyst structured to purify exhaust gas of the internal combustion engine;
• an air fuel ratio sensor located upstream of the exhaust purification catalyst and structured to sense an air fuel ratio;
• and
• a control section configured to:
• determine whether or not a quantity of oxygen stored in the exhaust purification catalyst is larger than a preset reference value;
• in response to a determination that the quantity of oxygen stored in the exhaust purification catalyst is larger than the preset reference value, perform a first process, wherein the first process includes:
• stopping fuel injection of the internal combustion engine;
• motoring the internal combustion engine by the electric motor generator;
• and
• performing air fuel ratio learning for learning of a sensed value of the air fuel ratio sensor;
• and
• in response to a determination that the quantity of oxygen stored in the exhaust purification catalyst is not larger than the preset reference value, not performing the first process.

A vehicle control method for a vehicle, wherein the vehicle includes an internal combustion engine, an exhaust purification catalyst, and an air fuel ratio sensor, wherein the internal combustion engine is structured to be motored by an electric motor generator, wherein the exhaust purification catalyst is structured to purify exhaust gas of the internal combustion engine, and wherein the air fuel ratio sensor is located upstream of the exhaust purification catalyst and structured to sense an air fuel ratio, the vehicle control method comprising:

• when a quantity of oxygen stored in the exhaust purification catalyst is larger than a reference value, determining that inflow of oxygen into the exhaust purification catalyst has an insignificant effect on exhaust performance;
• when inflow of oxygen into the exhaust purification catalyst is determined to have an insignificant effect on exhaust performance,
• stopping fuel injection of the internal combustion engine,
• motoring the internal combustion engine, and
• performing air fuel ratio learning for learning of a sensed value of the air fuel ratio sensor;
• and
• when a catalyst temperature of the exhaust purification catalyst is below a predetermined activation temperature at a run start of the vehicle by a driver's key switch operation,
• motoring the internal combustion engine, and
• performing the air fuel ratio learning after termination of motoring of the internal combustion engine or during motoring of the internal combustion engine.

A vehicle control method for a vehicle, wherein the vehicle includes an internal combustion engine, an exhaust purification catalyst, and an air fuel ratio sensor, wherein the internal combustion engine is structured to be motored by an electric motor generator, wherein the exhaust purification catalyst is structured to purify exhaust gas of the internal combustion engine, and wherein the air fuel ratio sensor is located upstream of the exhaust purification catalyst and structured to sense an air fuel ratio, wherein the vehicle includes a throttle valve for controlling an intake air quantity of the internal combustion engine, a supercharger of an exhaust turbine type for supercharging intake air of the internal combustion engine, and a variable valve mechanism structured to vary valve timing of an intake valve of the internal combustion engine, the vehicle control method comprising:

• when a quantity of oxygen stored in the exhaust purification catalyst is larger than a reference value, determining that inflow of oxygen into the exhaust purification catalyst has an insignificant effect on exhaust performance;
• when inflow of oxygen into the exhaust purification catalyst is determined to have an insignificant effect on exhaust performance,
• stopping fuel injection of the internal combustion engine,
• motoring the internal combustion engine, and
• performing air fuel ratio learning for learning of a sensed value of the air fuel ratio sensor;
• and
• during the motoring of the internal combustion engine, controlling a quantity of air flowing through the air fuel ratio sensor by controlling the throttle valve, a wastegate valve of the supercharger, the variable valve mechanism, and a rational speed of the internal combustion engine.