Power distribution control method and apparatus for four-wheel drive vehicle

摘要

A four-wheel drive vehicle has front wheels and rear wheels driven by an engine, and a coupling for changing the distribution ratio of torque to the front wheels and the rear wheels. An ECU determines whether engine braking is being applied based on the vehicle speed V and the throttle opening degree Od. When determining that engine braking is being applied, the ECU temporarily performs the engine braking related control. The ECU controls the engaging force of the coupling such that the distribution ratio of torque to the front wheels and the rear wheels is changed to a more equalized state in the engine braking related control than that before the engine braking related control is started. Accordingly, the fixing force of the front wheels and the rear wheels is temporarily increased without delay when engine braking is applied.