Patent ID: 8899394

Claim:
A hydraulic control apparatus for a hydraulic torque converter which is provided with a lock-up clutch operated or not by hydraulic pressure difference between an engagement-side oil chamber and a disengagement-side oil chamber, the hydraulic control apparatus comprising: a first hydraulic line supplying hydraulic pressure to the disengagement-side oil chamber or exhausting the hydraulic pressure from the disengagement-side oil chamber; a second hydraulic line supplying hydraulic pressure to the engagement-side oil chamber or exhausting the hydraulic pressure from the engagement-side oil chamber; and a third hydraulic line exhausting the hydraulic pressure exhausted from the second hydraulic line; a lock-up clutch switch valve supplying drive pressure supplied from a regulator valve through a first path selectively to the first hydraulic line or the second hydraulic line, and selectively supplying the hydraulic pressure exhausted from the second hydraulic line or the drive pressure supplied from the regulator valve through a second path to a cooler; and a slip switch valve directly receiving the hydraulic pressure exhausted from the third hydraulic line and selectively exhausting the hydraulic pressure exhausted from the third hydraulic line.