| 摘要 |
<p>PURPOSE:To reduce pump loss of an oil pump and speed change shock by rectilinearly decreasing line pressure with an increase in car velocity when a car velocity is less than a designated value, correcting line pressure to be fixed when it is more than the designated value and duty-controlling the line pressure. CONSTITUTION:A hydraulic control device has sensors 16-18 for a throttle opening, a car velocity and line pressure and a control unit 15 for a duty solenoid 19 according to output signals of the sensors, and the unit comprises correction line pressure calculating means 27 for correcting line pressure and duty ratio calculating means 28. In the correction line pressure calculating means 27, when a car velocity is less than a designated value, line pressure is rectilinearly decreased with an increase in car velocity, and when it is more than the designated value, line pressure is corrected to be fixed to duty-control the line pressure. Accordingly, margins of line pressure to driving force becomes substantially uniform extending over the whole car velocity range, so that pump loss of an oil pump for hydraulic control can be reduced, and further speed change shock can be reduced.</p> |
