Hybrid vehicle drive apparatus

A drive apparatus of a hybrid vehicle, comprising:

• an internal combustion engine;
• a first motor-generator;
• a drive shaft connected to a wheel;
• a power division mechanism connected to an output shaft of the internal combustion engine to divide and output a power generated by the internal combustion engine to the first motor-generator and a power transmission path configured to connect the power division mechanism and the drive shaft;
• a second motor-generator disposed in the power transmission path;
• a planetary gear mechanism interposed between the second motor-generator and the power division mechanism in the power transmission path;
• a speed change mechanism including a first engagement mechanism configured to be engageable and disengageable and a second engagement mechanism configured to be engageable and disengageable so as to change a speed ratio defined as a value of a ratio of a rotational speed of an input shaft of the planetary gear mechanism relative to a rotational speed of an output shaft of the planetary gear mechanism, in accordance with an engagement action of the first engagement mechanism and the second engagement mechanism;
• and
• an electronic control unit including a microprocessor configured to perform controlling the internal combustion engine, the first motor-generator, the second motor-generator and the speed change mechanism in accordance with a drive mode, wherein
• the speed change mechanism is configured so that the speed ratio is a first speed ratio when the first engagement mechanism is disengaged and the second engagement mechanism is engaged and the speed ratio is a second speed ratio less than the first speed ratio when the first engagement mechanism is engaged and the second engagement mechanism is disengaged,
• the drive mode includes an EV reverse mode driven by a power of the second motor-generator with the internal combustion engine inactivated to travel in reverse,
• the microprocessor is configured to further perform determining whether a driving force increase instruction is output during traveling in the EV reverse mode, and
• the microprocessor is configured to perform
• the controlling including controlling the speed change mechanism so as to disengage the first engagement mechanism and engage the second engagement mechanism before the driving force increase instruction is output during traveling in the EV reverse mode and so as to engage the first engagement mechanism and disengage the second engagement mechanism when it is determined that the driving force increase instruction is output during traveling in the EV reverse mode.