| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hydraulic control device of an automatic transmission having a selector valve at a failure of which part of a spool is moved in stopping a hydraulic pressure source. <P>SOLUTION: In the selector valve 5 at the failure, a plug 5q and a spool body 5p are changed to left half positions against energizing forces of the springs 5s and 5t when line pressure PL caused by driving the hydraulic pressure source is inputted to an oil chamber 5a to supply the line pressure PL, or only the plug 5q is changed to a right half position by the energizing force of the spring 5s when the line pressure PL is not supplied. When hydraulic pressure is simultaneously supplied to hydraulic servos 6, 7, and 8 of clutches C-1 and C-2 and a brake B-1 during the failure, the hydraulic pressure is inputted into oil chambers 5f, 5g, and 5h and operated to the spool body 5p, and the the spool body 5p is changed to the right half position. The plug 5q is moved by stopping the hydraulic pressure source in a normal time, oil in the oil chamber 5a is discharged, and micro foreign matters are not accumulated in the oil chamber 5a, so that the spool body 5p is changed to the right half position without causing malfunction even when a failure occurs. <P>COPYRIGHT: (C)2004,JPO |
