| 摘要 |
PURPOSE:To reduce the number of solenoid valves and simplify the construction of a speed change control circuit, by providing a solenoid valve which adjusts the opening of a hydraulic power source side input port and a drain port, between an oil pressure chamber for controlling transmission gear ratio and the hydraulic power source. CONSTITUTION:A pipeline 70 which connects a hydraulic power source to an oil pressure chamber 18 controlling the transmission gear ratio formed on a driven side pulley 14 is provided with a solenoid valve 40 which has the input port 42 of the hydraulic power source side, the output port 43 of the oil pressure chamber 18 side and a drain port 44. As the solenoid valve 40 controls simultaneously the opening of the input port 42 and the opening of the drain port 44 based on the signal of a control circuit 60, any other solenoid valve is unnecessary, and an oil hydraulic circuit for controlling speed change can be simplified. |
