Patent ID: 7568996

Claim:
A speed-ratio control apparatus for controlling a speed ratio of a continuously variable transmission disposed in a power transmitting path between a drive power source and a drive wheel of a vehicle, such that an actual input speed of said continuously variable transmission coincides with a target input speed set on the basis of a running condition of the vehicle, said speed-ratio control apparatus comprising: an acceleration-requirement determining portion operable, on the basis of a vehicle accelerating member, to determine whether non-rapid acceleration of the vehicle is required by an operator of the vehicle, and whether rapid acceleration of the vehicle is required by the operator; and a target-input-speed setting portion operable, upon determination by said acceleration-requirement determining portion that said non-rapid acceleration of the vehicle is required by the operator, to (i) implement an instantaneous stepping increase of said target input speed to a first transient target input speed which is higher than said actual input speed, (ii) hold said target input speed at said first transient target input speed in a first portion of a rapid shifting period, (iii) instantaneously reduce, at the end of said first portion of the rapid shifting period, said target input speed to an initial value of a second transient target input speed which initial value is close to said actual input speed and lower than said first transient target input speed, and (iv) gradually increase, in a second portion of the rapid shifting period following said first portion, the target input speed back toward said first transient target input speed, and upon determination by said acceleration-requirement determining portion that said rapid acceleration of the vehicle is required by the operator, said target-input-speed setting portion holding the target input speed at said first transient target input speed during said rapid shifting period, without setting at said second transient target input speed.