1. Field of the Invention
The present invention relates to a control device for a hybrid vehicle, whereby the engine-start condition for initiating mode transition from electric vehicle mode to hybrid vehicle mode can be made to differ depending on the condition.
2. Background Information
In the prior art, when torque demand information reflective of demand by the driver exceeds an engine start line that was set according to vehicle speed, the engine is started to bring about mode transition from electric vehicle mode to hybrid vehicle mode. That is, a zone for travel in electric vehicle mode (hereinafter termed an EV travel zone) is determined according to the magnitude of the engine start line with respect to the torque demand information.
Control devices for a hybrid vehicle which are designed to set the engine start line to a relatively small value to minimize expansion of the EV travel zone when the driver has definite intent to accelerate, while setting the engine start line to a relatively large value to expand the EV travel zone when the driver has tenuous intent to accelerate, are known (see Japanese Laid-Open Patent Application No. 2007-261442, for example).