Patent ID: 8204659

Claim:
An engine start control system for a hybrid vehicle including an engine, a motor/generator, a first clutch disposed between the engine and the motor/generator, a transmission connected to the motor/generator and configured to provide a driving torque to at least one driving wheel, wherein the first clutch is configured to engage and disengage the engine with respect to the motor/generator to define an electric drive mode in which the first clutch is disengaged and the driving torque is provided only by the motor/generator, and a hybrid drive mode in which the first clutch is engaged and the driving torque is provided by both the engine and the motor/generator, the control system comprising: a controller configured to: determine when an engine start request for a mode change from the electric drive mode to the hybrid drive mode arises; select an engine start downshift pattern for the transmission when the engine start request arises, the engine start downshift pattern being a high-geared pattern as compared with the normal downshift pattern for the transmission; perform shift control of the transmission in accordance with the engine start downshift pattern when the engine start request arises; and engage the first clutch and start the engine using an engine-cranking-torque of the motor/generator after performing the shift control.