Patent ID: 7059435

Claim:
A control apparatus for a hybrid vehicle, the hybrid vehicle: an internal-combustion engine and a motor as a power source; and a power storage unit which transfers electric energy with said motor, and at least one of said internal-combustion engine and said motor is connected to driving wheels of the vehicle through a torque converter having a lock-up clutch, and a transmission, so as to transmit a driving force to said driving wheels, wherein the control apparatus of the hybrid vehicle comprises: a state of charge detecting device which detects a state of charge of said power storage unit; and a lock-up clutch controlling device which controls an operating state of said lock-up clutch based on said state of charge detected by said state of charge detecting device, or a state quantity related to said state of charge, wherein said lock-up clutch controlling device includes: a lock-up clutch setting device for setting the lock-up clutch in an engaged state when quantities representing the vehicle state are in a predetermined region, and an engagement region enlarging device which enlarges said predetermined vehicle state quantity region which sets said lock-up clutch in the engaged state, when said state of charge or the state quantities related to said state of charge is greater than a predetermined first threshold, wherein said control apparatus further comprising a canceling device which cancels an operation of said engagement region enlarging device when, while said engagement region enlarging device is in operation, said state of charge or the state quantity related to said state of charge is less than a predetermined second threshold, and a target torque for a power plant torque output from a power plant having said internal combustion engine and said motor is increased greater than a predetermined first torque, or decreased less than a predetermined second torque.