Apparatus for controlling continuously variable transmission

Claim 1

A continuously variable transmission for a vehicle provided with an internal combustion engine, which engine has a throttle valve, said transmission comprising: transmission means arranged between the engine and the vehicle for obtaining a continuously changeable speed ratio; means for controlling a speed ratio of the transmission means; means for storing a desired engine speed versus positions of the throttle valve for providing the minimum fuel consumption; means for detecting an actual position of the throttle valve; calculating means for calculating, by using the storing means, a desired engine speed value corresponding to the detected throttle position; means for providing an area of the engine speed determined for every throttle opening, which area is slightly lower than the desired engine speed although capable of providing sufficient power to attain a smooth acceleration even if the speed ratio is fixed, due to the absence of transmission loss; means for detecting an actual engine speed; means for providing a signal issued to the speed ratio controlling means for obtaining a fixed speed ratio so that the actual engine speed is controlled toward the desired engine speed when the actual engine speed is in said area; and means for providing a signal issued to the speed ratio controlling means for varying the speed ratio so that the actual engine speed is controlled toward the desired engine speed when the actual engine speed is in an area other than said area.