| 摘要 |
A hydraulic control system for a continuously variable transmission which has an input and an output variable-diameter pulley, a belt connecting the input and output pulleys, and a pair of cylinders for changing effective diameters of the pulleys. The control system includes a hydraulic source to supply a pressurized fluid for applying first and second line pressure to one and the other of the cylinders via a first and a second line, respectively. The control system comprises: a first regulator, connected to the first line, for regulating the first line pressure to be applied to the one cylinder, and thereby controlling a tension of the belt; a flow control device, disposed in the second line, for controlling flows of the fluid into and from the other cylinder, for controlling a speed ratio of the transmission; a second regulator, disposed between the hydraulic source and the first regulator, for controlling a rate of relief flow of the fluid therethrough from the second line into the first line, and thereby regulating the second line pressure which is higher than the first line pressure; and a controller for controlling the second regulator to regulate the second line pressure according to a predetermined condition.
|
