Hydraulic regulator for a V-belt type continuously variable transmission for vehicles

Claim 1

A hydraulic regulator device in a V-belt type continuously variable transmission for vehicles having an input and an output pulleys mounted respectively on an input and an output shaft and having variable effective diameters, and a V-belt drivingly connected to said input and output pulleys, wherein the torque ratio between the input and output shafts is continuously controlled by adjusting said effective diameter of each pulley by hydraulic pressure; characterized in that said hydraulic regulator device comprises a hydraulic pressure source, a regulator valve means for receiving hydraulic pressure supplied by said hydraulic pressure source and supplying line pressure, a throttle valve means, the action of said throttle valve means depending upon a throttle opening, a torque ratio valve means, the action of said torque ratio valve means depending upon the torque ratio between the input and output shafts, an exhaust port arranged on said torque ratio valve means, a primary hydraulic passage inputting the line pressure to the throttle valve means, a secondary hydraulic passage connecting the throttle valve means with the regulator valve means, a tertiary hydraulic passage connecting the throttle valve means with the torque ratio valve means through an orifice, wherein said throttle valve means causes throttle pressure in said secondary hydraulic passage by controlling the connection between said primary and secondary hydraulic passages, and a feedback fluid passage at least supplying said throttle pressure to said throttle valve means through an orifice of said tertiary hydraulic passage, wherein said hydraulic pressure of the tertiary hydraulic passage is led and controlled to said exhaust port according to the torque ratio, said regulator valve means is controlled by changing stepwisely the throttle pressure, and the resultant stepwised line pressure depends on the torque ratio.