HYDRAULIC CONTROLLER OF AUTOMATIC STEPLESS SPEED CHANGER FOR VEHICLE

PURPOSE:To enable a fluid coupling to be prevented from an excessive rise of its temperature, by supplying the pressure oil to the hydraulic servo of an oil pump from a secondary regulator valve so as to decrease a delivery amount of oil when the secondary line pressure increases higher than a preset range. CONSTITUTION:An engine, being operated in a range of high speed, causes an oil pump 20 to increase its delivery amount of oil and an amount of oil, discharged to an oil path 2 from a primary regulator valve 30, to increase, and the secondary line pressure increases higher than an accurate range, moving downward a spool 37 of a secondary regulator valve 35 and communicating the third and the first ports 373, 371, then pressure oil is supplied to a hydraulic servo 203 of the oil pump 20 from an oil path 8, thus the delivery amount is decreased. In such way, the secondary line pressure being decreased can prevent an excessive rise of temperature in a fluid coupling, further an engine output consumed in the oil pump is decreased, that is, fuel consumption can be improved.