초록 ▼

A toroidal type continuously variable transmission whose gear ratio is varied by changing the position of a trunnion is provided with double-slider valves driven by stepping motors and linear solenoid valves. The gear ratio control is performed by controlling position of the double-slider valves whe

A toroidal type continuously variable transmission whose gear ratio is varied by changing the position of a trunnion is provided with double-slider valves driven by stepping motors and linear solenoid valves. The gear ratio control is performed by controlling position of the double-slider valves when the vehicle travels at speeds higher than a specified speed or by controlling directly line and relief pressures applied to the trunnion through the solenoid valves.

대표청구항 ▼

[ What is claimed is:] [1.] A control system for controlling a toroidal type continuously variable transmission for an automotive vehicle which is comprised of a rotary input disk having a torus surface and connected to a drive apparatus of the automotive vehicle, a rotary output disk having an toru

[ What is claimed is:] [1.] A control system for controlling a toroidal type continuously variable transmission for an automotive vehicle which is comprised of a rotary input disk having a torus surface and connected to a drive apparatus of the automotive vehicle, a rotary output disk having an torus surface facing said rotary input disk, through which driving force is transmitted to drive wheels of the automotive vehicle, a roller interposed between and in contact with said torus surface of said input and rotary output disks for transmitting rotation to said rotary output disk from said rotary input disk at a variable transmission ratio, a roller support for supporting said roller, said roller support having first hydraulic drive means for hydraulically driving said roller to vary an angle of inclination of said roller with respect to said input and rotary output disks in one direction so as to increase said transmission ratio and second hydraulic drive means for hydraulically driving said roller to vary said angle of inclination of said roller with respect to said input and rotary output disks in another direction so as to decrease said transmission ratio, said control system comprising:first hydraulic pressure generating means for generating and supplying a first hydraulic pressure to said first and second hydraulic drive means;second hydraulic pressure generating means for generating and supplying a second hydraulic pressure lower than said first hydraulic pressure to said first and second hydraulic drive means;valve means for switching said supply of hydraulic pressure to said first and second hydraulic drive means between said first and second hydraulic pressures;hydraulic pressure varying means for varying at least one of said first and second hydraulic pressures;driving condition detecting means for detecting driving conditions of the vehicle including at least a value relating to a ratio of rotation between said drive apparatus and said drive wheels; andcontrol means for controlling said valve means and said hydraulic pressure varying means according to said driving conditions to vary said transmission ratio, said control means controlling said valve means to vary said transmission ratio when said value indicates that said ratio of rotation is lower than a specified ratio for low speed control and controlling said hydraulic pressure varying means to vary said transmission ratio when said value indicates that said ratio of rotation is higher than said specified ratio.