| 摘要 |
An apparatus and a method for controlling hydraulic pressure are provided, which has such advantages that a generation of peak pressure (shoot pressure ) can be lowered, mis-operation due to biting of particles can be reduced, or the cost thereof can be reduced. Firstly, a large amount inflow command current is supplied to a proportional solenoid from a time point t1 to a time point t2. Consequentially, pilot pressure rises in a pilot pressure receiving chamber, so that a pressure control valve allows a large amount of hydraulic fluid to flow in a clutch or brake cylinder. At this time, potential detected by a pressure switch becomes zero level. Next, at the time point t2, a filling command small current is supplied to the proportional solenoid thereby decreasing the amount of hydraulic fluid, which flows from an input port to an output port. Such state keeps from the time point t2 to a time point t3. At the termination of filling, peak pressure may be not generated, and a speed-changing shock in a clutch may be not generated, so that smooth switching can be accomplished.
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