Patent ID: 7249589

Claim:
A hybrid vehicle, comprising: an internal combustion engine; a purifying device including a catalyst that purifies exhaust gas discharged from the internal combustion engine; an electric power storage device; an electric power/power reception/output device that is connected to a first axle and an output shaft of the internal combustion engine, and that receives power from the output shaft and outputs the power to the first axle or receives power from the first axle and outputs the power to the output shaft while exchanging electric power with the electric power storage device and exchanging power with the internal combustion engine; an electric motor that receives power from the first axle or a second axle that differs from the first axle or outputs power to the first axle or the second axle, and that exchanges electric power with the electric power storage device; an operation mode setting device that sets an execution operation mode to one of multiple operation modes which define respective different ranges where a required drive power required to cause the vehicle to run can be set, and that allows, when the execution operation mode is set to a predetermined operation mode that is one of the multiple operation modes, a driver to select any one of operation modes included in the predetermined operation mode; a target air-fuel ratio setting device that sets a target air-fuel ratio for the internal combustion engine under a first constraint when the driver is not allowed to select any one of the operation modes included in the predetermined operation mode, and that sets the target air-fuel ratio under a second constraint, under which the target air-fuel ratio tends to be set to a value richer than the target air-fuel ratio set under the first constraint, when the driver is allowed to select any one of the operation modes included in the predetermined operation mode; a required drive power setting device that sets the required drive power according to the execution operation mode set by the operation mode setting device; and a controller that controls the internal combustion engine, the electric power/power reception/output device, and the electric motor so that an air-fuel ratio in the internal combustion engine becomes equal to the target air-fuel ratio set by the target air-fuel ratio setting device and a drive power corresponding to the required drive power set by the required drive power setting device is output.