Patent ID: 8684884

Claim:
A transmission control device of a hybrid vehicle equipped with an internal combustion engine and an electric motor as a driving source, comprising: a transmission configured to perform a gear-change on a driving force input from the internal combustion engine and the electric motor and output the changed driving force, and a control unit configured to control the transmission, the transmission is configured to include a first input shaft which is input with the driving force from the electric motor and the driving force from the internal combustion engine via a first switching unit, and has at least two transmission gears; a second input shaft which is input with the driving force from the internal combustion engine via a second switching unit and has at least one transmission gear; a first selection unit configured to select a transmission gear of the first input shaft; a second selection unit configured to select a transmission gear of the second input shaft; and an output shaft coupled with the first input shaft or the second input shaft via the first selection unit or the second selection unit, and the transmission is configured to perform the gear-change on the driving force input from the first input shaft or the second input shaft and output it from the output shaft through the selection of the transmission gear by the first selection unit or the second selection unit, respectively, under a condition that the first switching unit or the second switching unit is in a coupled state, a plurality of ratios which are determined by characteristics of the electric motor according to a revolution speed and the driving force of the electric motor and obtained by dividing an output energy of the electric motor by an input energy thereof are set, and a plurality of ratio groups having the equivalent ratio among the plurality of ratios are prepared preliminarily, under a condition that the first switching unit is in a decoupled state, the second switching unit is in a coupled state and a transmission gear is selected by the second selection unit to input the driving force from the internal combustion engine to the second input shaft, the control unit determines the ratio for each transmission gear of the first input shaft on the basis of a travelling speed and a required driving force of the vehicle, determines to which group among the plurality of ratio groups that each determined ratio is pertained, and selects a transmission gear of the first input shaft corresponding to a ratio group having the highest ratio among the determined ratio groups to which the determined ratio is pertained via the first selection unit.