| 摘要 |
<p>The present invention relates to a hydraulic pressure control apparatus for an automatic transmission which comprises a solenoid valve selectively supplying hydraulic pressure to a low reverse brake and a control unit controlling the solenoid valve. The control unit, if a transmission state enters a first gear, applies hydraulic pressure to a clutch of the low reverse brake to control the solenoid valve for a planetary gear system to be fixated by the clutch. The control unit, if the transmission state is released from the first gear, releases hydraulic pressure from the clutch of the low reverse brake to control the solenoid valve for the planetary gear system which is fixated by the clutch to be released. The hydraulic pressure control apparatus for an automatic transmission removes a one-way clutch and substitutes the one-way clutch by applying and releasing hydraulic pressure to and from the clutch of the low reverse brake used in an L-gear when entering the first gear or being released from the first gear, thereby reducing manufacturing costs of the automatic transmission and improving fuel efficiency through the weight of a vehicle.</p> |
