| 摘要 |
PROBLEM TO BE SOLVED: To stably retain engagement pressure by applying suitable feedback control while hardly accumulating air. SOLUTION: This hydraulic control device for an automatic transmission is provided with an upper valve body 40 having an oil passage 41 for connecting an output port 12c of a control valve unit 10 and an engagement element and a feedback oil passage 42 branched from the oil passage 41. The control valve unit 10 has a spool 11 for opening and closing the output port 12c; and a feedback port 12e communicated with a feedback chamber 15 for urging it so that control oil pressure from the feedback oil passage 42 is inputted and the spool 11 closes the output port 12c. The feedback oil passage 42 has a guide surface 42a for guiding air from immediately above the feedback port 12e to immediately above the output port 12c utilizing the buoyancy of air in operation oil in such a state that the upper valve body 40 is arranged at an upper side of the control valve unit 10. COPYRIGHT: (C)2007,JPO&INPIT
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