| 摘要 |
A continously variable transmission for transmitting the power of an internal combustion engine (1) to driving wheels (19) of a motor vehicle, is described. The transmission includes a drive pulley (7) including a hydraulically shiftable disc (7a) and a first hydraulic cylinder (9a) for shifting the disc (7a), a driven pulley (8) including a hydraulically shiftable disc (8a) and a second hydraulic cylinder (6a) for operating the disc (8), and a belt (11) engaged with both pulleys (7, 8). A first hydraulic circuit (20) including a pump (21), supplys oil to the first and second cylinders (9a, 6a); and includes a transmission ratio control valve (50) for controlling the ratio provided by the belt drive transmission. A control system (70) detects operating conditions of the engine and controls transmission ratio control valve accordingly. The closure of a throttle valve of the engine and any fluctuation of engine speed are detected and the transmission ratio control valve is adjusted on the basis of the signals to change the transmission ratio. |
