Patent attributes
A transmission mechanism including a switching clutch or brake that is switchable between a continuously-variable shifting state and a step-variable shifting state, and has both an advantage of improved fuel economy provided by a transmission, the speed ratio of which is electrically variable, and an advantage of high power transmitting efficiency provided by a gear type power transmitting device constructed for mechanical transmission of power. While a clutch-to-clutch shifting action of an automatic transmission portion is in a tie-up state, a differential portion is placed in a continuously-variable shifting state by switching control, and engine speed is changed under the control of hybrid control, so as to prevent a drop of the engine speed for thereby reducing a shock of the shifting action, unlike in a non-continuously-variable shifting state of the differential portion in which the engine speed is directly influenced by the tie-up state.