HYBRID VEHICLE AND CONTROL METHOD THEREOF

摘要

A hybrid vehicle which runs on power from at least one of an electric motor and an engine includes a transmission ratio changing unit for changing a ratio of electrical transmission to mechanical transmission of an output of the engine, an engaging/disengaging control unit for releasing a clutch when the hybrid vehicle is shifted from a drive mode in which at least the engine works as a drive source to a series drive mode, and a required output calculation unit for calculating a required output based on an accelerator pedal opening and a running speed. When the required output exceeds a sum of an output of the electric motor which is driven by electric power supplied from the battery and the output of the engine while the hybrid vehicle is running on the drive mode in which at least the engine works as a drive source with the clutch engaged, the transmission ratio changing unit increases the ratio of electrical transmission to mechanical transmission of the output of the engine, and the engaging/disengaging control unit releases the clutch at a time point when the mechanically-transmitted output of the engine becomes 0, with the clutch engaged. Consequently, when the hybrid vehicle is shifted from the drive mode in which at least the engine works as a drive source to the series drive mode in which the electric motor works as a drive source, the power transmission engaging/disengaging unit can be released while satisfying the required output.

主权项

1. A hybrid vehicle including
an engine, a generator which is driven by the engine to generate electric power, a battery for supplying electric power to an electric motor, the electric motor which is connected to a drive wheel and which is driven by electric power supplied from at least one of the battery and the generator, and a power transmission engaging/disengaging unit which is disposed between the generator and the drive wheel for engaging and disengaging a power transmission line from the engine to the drive wheel via the generator, the hybrid vehicle being capable of running on power supplied from at least one of the electric motor and the engine, the hybrid vehicle further including a transmission ratio changing unit for changing a ratio of electrical transmission to mechanical transmission of an output of the engine, an engaging/disengaging control unit for controlling the power transmission engaging/disengaging unit to be released when the hybrid vehicle is shifted from a drive mode in which at least the engine works as a drive source to a series drive mode in which the electric motor works as a drive source, and a required output calculation unit for calculating a required output required of the hybrid vehicle based on an accelerator pedal opening which corresponds to an operation of an accelerator pedal and a running speed of the hybrid vehicle, wherein, when the required output calculated by the required output calculation unit exceeds a sum of an output of the electric motor which is driven by electric power supplied from the battery and the output of the engine while the hybrid vehicle is running on the drive mode in which at least the engine works as a drive source with the power transmission engaging/disengaging unit engaged, the transmission ratio changing unit increases the ratio of electrical transmission to mechanical transmission of the output of the engine, and the engaging/disengaging control unit controls the power transmission engaging/disengaging unit to be released at a time point when the mechanically-transmitted output of the engine becomes 0, with the power transmission engaging/disengaging unit engaged.