Patent ID: 6317672
Filing Date: 2001-11-13
Classification: F16H,Y10T

Abstract:
A speed change controller for an infinite speed ratio transmission for a vehicle, the infinite speed ratio transmission comprising an input shaft, a continuously variable transmission which transmits a rotation speed of the input shaft to a first output shaft at an arbitrary speed ratio, a fixed speed ratio transmission which transmits the rotation speed of the input shaft to a second output shaft at a fixed speed ratio, a planetary gear set comprising a first rotation element joined to the first output shaft, a second rotation element, and a third rotation element which varies a rotation direction and a rotation speed according to a difference of a rotation speed of the first rotation element and a rotation speed of the second rotation element, and a clutch joining the second output shaft and second rotation element, the controller comprising:a selector lever which selects one of a stationary range, forward motion range and reverse motion range;a sensor which detects a range selected by the selector lever;an actuator which varies the speed ratio of the continuously variable transmission according to an operating position; anda microprocessor programmed to:determine whether or not the range selected by the selector lever has changed from the stationary range to one of the forward motion range and the reverse motion range;change the operation position of the actuator to a predetermined position when the range selected by the selector lever has changed from the stationary range to one of the forward motion range and the reverse motion range, the predetermined position being different from a position corresponding to a geared neutral point at which a rotation speed of the third rotation element becomes zero; andchange the operation position of the actuator from the predetermined position to the position corresponding to the geared neutral point.