Continuously variable transmission apparatus

Abstract

A continuously variable transmission apparatus has clutch device having a low speed clutch; a high speed clutch; and, a controller switching the transmission state into any one of a low speed mode and a high speed mode by connecting any one of the clutches, wherein timings for signaling by the controller for switching the connected and disconnected states of the clutches vary according to the switching directions of the low speed and high speed modes; and, a timing for signaling for connecting the low speed clutch with respect to the moment for signaling for cutting off the connection of the high speed clutch in order to switch the high speed mode over to the low speed mode is set earlier than a timing for signaling for connecting the high speed clutch with respect to the moment for signaling for cutting off the connection of the low speed clutch.

1 . A continuously variable transmission apparatus, comprising: 
 an input shaft connected to a drive source and rotationally driven by the drive source;    an output shaft for taking out power obtained based on the rotational movement of the input shaft;    a toroidal-type continuously variable transmission including an input side disk, an output side disk, power rollers interposed between the input side and output side disks so as to be swingly rotatable, and trunnions for supporting the power rollers;    a transmission control valve for shifting the trunnions;    a feedback mechanism for transmitting the shift amounts of the trunnions to the transmission control valve for feedback so that a transmission ratio between the input and output disks provides a target value;    a planetary gear mechanism including three elements, that is, a sun gear, a carrier and a ring gear;    a first power transmission system for transmitting the power input to the input shaft to the output shaft through the toroidal-type continuously variable transmission;    a second power transmission system for transmitting the power input to the input shaft to the output shaft without passing through the toroidal-type continuously variable transmission, the power to be transmitted through the first power transmission system and the power to be transmitted through the second power transmission system being joined to two of the three elements of the planetary gear mechanism, the remaining one of the three elements being connected to the output shaft;    a clutch mechanism, when advancing a vehicle, for switching over a first mode on the low speed side and a second mode on the high speed side to each other; and,    a control device, when switching over the first and second modes to each other, for controlling the transmission control valve simultaneously with the switching operation of the clutch mechanism within the time during which the clutch mechanism is switched, thereby restricting variations in the transmission ratio of the toroidal-type continuously variable transmission.