| 摘要 |
PURPOSE:To have optimum control of direct coupling force in accordance with the running condition of a vehicle by installing pilot type solenoid valves, which give an oil pressure to a cylinder in a direct coupling mechanism of a torque converter, as in series and by controlling electronically. CONSTITUTION:When the running condition of a vehicle is judged to lie in the range A on the basis of a car speed signal S1 and a throttle degree-of-opening signal S22, a direct-coupling control circuit 29 energizes a solenoid 45 of a solenoid valve 25 to drive its valve element 42 to the open side, so as to put the direct coupling mechanism of torque converter into the state out of direct coupling. At this time, an oil pressure control circuit 22 performs control of normal automatic speed convertion using torque converter. Then in the range B, a solenoid 36 of another solenoid valve 24 is energized to drive its valve element 33 to the close side, so as to supply the pressure oil weakened thereby to the above-mentioned solenoid valve 25. In the range C, the valve 33 is driven to the open side so as to supply a stronger pressure oil to the solenoid valve 25. |
