Patent ID: 8784248

Claim:
An engine start control device of a hybrid vehicle, comprising: a differential mechanism that includes first to third rotating elements with which a rotating shaft of a first electric rotating machine, an output shaft of an engine, and a rotating shaft of a second electric rotating machine are coupled, respectively, a fourth rotating element having a center axis of rotation common to the first to third rotating elements, and rolling members which have a center axis of rotation different from the center axis of rotation as well as can transmit power via contact portions between the first rotating element, the third rotating element, and the fourth rotating element and are held by the second rotating element and by which differential rotating operations between the first to third rotating elements are controlled using an alignment chart on which rotation speeds of the first to third rotating elements are disposed in the sequence of the first rotating element, the second rotating element, and the third rotating element and shown by straight lines and in which a rotation speed axis of the second rotating element internally divides between a rotation speed axis of the first rotating element and a rotation speed axis of the third rotating element by a relation of 1:ρ, wherein the differential mechanism changes an internally divided ratio of 1:ρ by changing a planetary gear ratio ρ which is obtained by dividing an absolute value of a relative rotation speed of the third rotating element to the second rotating element on the alignment chart by an absolute value of a relative rotation speed of the first rotating element to the second rotating element by changing a tilt angle of the rolling members, and when the engine is cranked at the time the engine starts by transmitting a rotation of the first electric rotating machine to the output shaft of the engine, the planetary gear ratio ρ is controlled on the alignment chart so that a rotation speed of the first rotating element is increased.