Patent ID: 7931551

Claim:
A hydraulic control apparatus comprising: a continuously-variable transmission including a pair of drive pulleys including a first movable pulley and a first fixed pulley, a pair of driven pulleys including a second movable pulley and a second fixed pulley, and a belt wound between the pair of drive pulleys and the pair of driven pulleys, the continuously-variable transmission being adapted to be continuously shifted by moving at least one of the first movable pulley and the second movable pulley by means of hydraulic pressure and thereby varying at least one of a groove width between the pair of drive pulleys and a groove width between the pair of driven pulleys to vary a winding radius of the belt; a line-pressure control section configured to produce a line pressure by adjusting a discharge pressure of an oil pump; a first hydraulic-pressure control section configured to adjust a first hydraulic pressure based on the line pressure, the first hydraulic pressure being supplied to the drive pulleys; and a second hydraulic-pressure control section configured to adjust a second hydraulic pressure based on the line pressure, the second hydraulic pressure being supplied to the driven pulleys, wherein the line-pressure control section is configured: to adjust the line pressure to a value set by adding a margin pressure to higher one of the first hydraulic pressure and the second hydraulic pressure, and to set the margin pressure lower when the first hydraulic pressure is higher than the second hydraulic pressure.