Ratio control for continuously variable transmission

Claim 1

A ratio control for a continuously variable transmission for an automotive vehicle having an engine with a throttle, comprising: means for detecting load condition on the engine and generating a load condition indicative signal which is indicative of the load condition detected; means for detecting an actual value variable with a reduction ratio established in the continuously variable transmission; a control unit; and means under the control of said control unit for adjusting the reduction ratio of the continuously variable transmission in such a direction as to bring said actual value into agreement with a target value; wherein a first value that is variable with said load condition indicative signal is normally set as said target value. when said load condition indicative signal is subject to a predetermined change and thus said first value is subject to a change accordingly, said first value is replaced with a second value that is disposed between said first value after said change and said actual value such that said second value is set as said target value, and the reduction ratio of the continuously variable transmission is adjusted in such a direction as to bring said actual value into agreement with second value; and subsequently when a deviation of said actual value from said second target value becomes less than a predetermined value, said second value is replaced with a third value that varies from said second value to said first value such that said third value is set as said target value, and the reduction ration of the continuously variable transmission is adjusted in such a direction as to bring the said actual value into agreement with said third value.