HYDRAULIC CONTROL CIRCUIT AND METHOD FOR CONTROLLING SAME

摘要

In the present invention, a hydraulic control circuit provided with a solenoid valve for adjusting, on the basis of a designated pressure, a hydraulic pressure supplied to a hydraulic device operated by hydraulic pressure, in which if the designated pressure enters a dead zone range lower than a dead zone threshold value, the actual-pressure change responsiveness of the solenoid valve worsens with respect to a change in the designated pressure, wherein if the designated pressure has been set to the dead zone range and the designated pressure increases to such an extent that a change gear ratio does not fluctuate and so as to be within the dead zone range, then the designated pressure is raised stepwise to a charge pressure higher than the dead zone threshold value, and thereafter a lower limit of the designated pressure is set to the dead zone threshold value and use of the dead zone range is prohibited for a given period of time.