| 摘要 |
PURPOSE:To operate a line pressure control valve and a speed change control valve smoothly to get a smooth speed change, by controlling the line pressure with a duty pressure produced responding to an object line pressure computed from the gear change rate and the engine torque. CONSTITUTION:In a control unit 70, an object line pressure is computed from the gear shift rate and the engine torque 7, and a signal of duty ratio responding to the said object line pressure is output. Then the said signal is input to a line pressure control solenoid valve 65 to produce a specific level of duty pressure. And by applying the duty pressure to activate a line pressure control valve 40, a line pressure responding to the duty ratio and changing continuously is gained accurately. Furthermore, it is also possible to set the line pressure higher than the necessary line pressure. As a result, an abnormal speed change such as a speed change shock owing to an uncontinued line pressure change can be prevented. |
