| 摘要 |
PURPOSE:To provide a speed ratio controller which enables sped change in a wide range, by producing an oil pressure signal corresponding to an appropriate speed ratio, from throttle valve response pressure and vehicle speed response pressure and driving a follow-up-type speed ratio control actuator by the signal. CONSTITUTION:The oil pressure of a main pump 102 is adjusted to line pressure PL by a pressure control valve 120. Since response pressure corresponding to the degree of opening of a throttle valve 160 is applied to the pressure control valve 120, the line pressure PL is heightened. Governor pressure corresponding to the speed of a vehicle is applied by a cover valve 170 to heighten the line pressure PL further. The heightened line pressure PL is apllied to the port (b) of a speed ratio control servomechanism 200 through a line P1 to move a valve element 201 and an actuator 205 to change a port combination. According to this constitution, stepless speed change can be effected in a wide range. |
