HYDRAULIC CONTROL DEVICE OF AUTOMATIC TRANSMISSION

To provide a hydraulic control device of an automatic transmission which can block the supply of range pressure to a prescribed solenoid valve without increasing the number of part items even if using two pieces of changeover valves.SOLUTION: A hydraulic control device of an automatic transmission comprises: a first selector valve 10 which can switch an output state to a state that line pressure PL is outputted as forward range pressure PD, and a state that the line pressure PL is outputted as non-forward range pressure PnD; and a second selector valve 20 which can switch the output state to a first state that the forward range pressure PD inputted into a first input port 20c is outputted from a first output port 20e, and a second state that the non-forward range pressure PnD inputted into a second input port 20d is outputted from the first output port 20e by the supply and discharge of second signal hydraulic pressure PSC3. The second selector valve 20 is maintained at the second state while a first clutch is brought into at least an engagement state from a release state when a gear change stage is switched to a forward first speed stage from a reverse stage.SELECTED DRAWING: Figure 3 【課題】２本の切換えバルブを使用しながらも、部品点数を増やすことなく、所定のソレノイドバルブへのレンジ圧の供給を遮断できる自動変速機の油圧制御装置を提供する。【解決手段】ライン圧ＰＬを前進レンジ圧ＰＤとして出力する状態と、ライン圧ＰＬを非前進レンジ圧ＰｎＤとして出力する状態とに、切換可能な第１の切換えバルブ１０と、第１の入力ポート２０ｃに入力された前進レンジ圧ＰＤを第１の出力ポート２０ｅから出力する第１の状態と、第２の入力ポート２０ｄに入力された非前進レンジ圧ＰｎＤを第１の出力ポート２０ｅから出力する第２の状態とに、第２の信号油圧ＰＳＣ３の給排により切換可能な第２の切換えバルブ２０と、を備え、第２の切換えバルブ２０は、変速段が後進段から前進１速段に切り換わる際に、第１のクラッチが解放状態から少なくとも係合状態になるまでの間、第２の状態に維持される。【選択図】図３