Hybrid vehicle drive system adapted to assure smooth brake application by motor/generator or engine

摘要

A hybrid drive system for a motor vehicle, including an engine, a motor/motor, an automatic transmission disposed between the engine and a vehicle drive wheel, a regenerative braking device for applying to the vehicle a regenerative braking force corresponding to an amount of electric energy generated by the motor/generator during an operation of the motor/generator by a kinetic energy of the running vehicle, and at least one of (a) a shift inhibiting device for inhibiting a shifting action of the automatic transmission during an operation of the regenerative braking device so as to prevent a change of an engine braking force applied to the vehicle, (b) a braking shift control device which is operated when the regenerative braking device is inoperable to provide the required regenerative braking force, for changing the speed ratio of the automatic transmission to increase the engine braking force, or operated prior to the operation of the regenerative braking device, for controlling the speed ratio of the transmission so as to apply the engine brake to the vehicle, and (c) a mode change inhibiting device for inhibiting a change of operation mode between regenerative braking mode and engine braking mode during regenerative braking or engine braking.