Patent ID: 8761986

Claim:
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, 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, a transmission ratio changing unit for changing a ratio of electrical transmission to mechanical transmission of an output of the engine, and an engaging/disengaging control unit for controlling the power transmission engaging/disengaging unit, when the hybrid vehicle is shifted from an engine-directly-connected drive mode in which the power transmission engaging/disengaging unit is engaged and at least the engine works as a drive source to a series drive mode in which the power transmission engaging/disengaging unit is disengaged and the electric motor being driven by the electric power generated from the generator driven by the engine works as a drive source, so that the power transmission engaging/disengaging unit is released after the transmission ratio changing unit gradually increases the ratio of electrical transmission to mechanical transmission of the output of the engine.