Hybrid vehicle and control method for hybrid vehicle

摘要

A hybrid vehicle intermittently operates and stops an engine, travels through control over torque generated by the engine and torque generated by a second motor generator, causes a fuel vapor gas purge system to carry out purging of fuel vapor gas when a predetermined condition, including a condition that a coolant temperature is higher than or equal to a permissible temperature, is satisfied, and sets the permissible temperature to a value lower when a specific driving operation state that includes a state where the number of times of accelerator operation per unit time is higher than or equal to a threshold has been detected than when the specific driving operation state has not been detected. When the specific driving operation state has been detected, the hybrid vehicle increases the updating rate of a concentration learned value of fuel vapor gas, and decreases the rate of increase in target purge rate.

主权项

1. A hybrid vehicle comprising:
an internal combustion engine serving as a drive source of the hybrid vehicle; an electric motor serving as a drive source of the hybrid vehicle; a fuel vapor gas purge system configured to carry out purging of fuel vapor gas for introducing fuel vapor produced inside a fuel tank into an intake passage of the internal combustion engine, the fuel tank storing fuel supplied to the internal combustion engine; a drive control unit configured to carry out intermittent operation for stopping operation of the engine when a predetermined operation stop condition is satisfied and starting the operation of the engine when a predetermined start condition is satisfied, the drive control unit being configured to cause the hybrid vehicle to travel by applying torque based on an accelerator operation amount to a drive shaft through control over torque generated by the engine and torque generated by the electric motor; and a purge control unit configured to carry out the purging of fuel vapor gas when a temperature of the engine is higher than or equal to a permissible temperature and a variation per unit time in a load of the engine is smaller than a first threshold, the purge control unit being configured to set the permissible temperature to a value lower when a specific driving operation state has been detected than when the specific driving operation state has not been detected, the specific driving operation state including a state where the number of times the accelerator operation amount has changed from zero to non-zero per unit time or the number of times the accelerator operation amount has changed from non-zero to zero per unit time is larger than or equal to a predetermined second threshold, the purge control unit is configured to gradually increase a purge rate from a time point at which the temperature of the engine becomes higher than or equal to the permissible temperature, the purge rate being the ratio of a flow rate of fuel vapor gas introduced into the intake passage with respect to an intake air flow rate of the engine, and the purge control unit is configured to reduce a rate of increase in the purge rate when the specific driving operation state has been detected as compared with when the specific driving operation state has not been detected.