| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hydraulic control device of an automatic transmission, with which transition of an engagement/release state of a friction engagement element is not effected even in fail time, and a small number of assist pressure output valves can assist for a plurality of pressure control valves. <P>SOLUTION: The hydraulic control device 1 includes a plurality of linear solenoid valves (for example, SL1) and a signal solenoid valve capable of outputting signal pressure to an oil path, and each of valve parts 70 of the respective linear solenoid valves has an assist oil chamber 75 for making a spool 72 perform assist operation when signal pressure is input, and an assist pressure input port (for example, SL1e) for blocking signal pressure when in a non-operation position and inputting signal pressure to the assist oil chamber 75 by communicating when in an operation position. Even if signal pressure is output, transition of the engagement/release state of the friction engagement element is not effected, and the small number of signal solenoid valves can assist the plurality of linear solenoid valves. <P>COPYRIGHT: (C)2013,JPO&INPIT |
