To provide a hydraulic control device for an automatic transmission capable of accurately performing the engagement/disengagement control or slip control of a clutch even if circulation pressure fluctuates.
The circulation pressure is supplied to a start device 2, and a linear solenoid valve 10 regulates operating pressure which is engaged with and disengaged from a lockup clutch 3 by a difference between the operating pressure and the circulation pressure. A spool 121 of the linear solenoid valve 101 is provided with a first feedback oil chamber 12b which feeds back and applies the operating pressure to a spool 12p, and also with a second feedback oil chamber 12a which feeds back and applies the circulation pressure to the spool 12p in a direction opposite to the first feedback oil chamber 12b. A configuration makes equal a hydraulic operational force to the spool 12p by the operating pressure in the first feedback oil chamber 12b and that of the circulation pressure in the second feedback oil chamber 12a. Consequently, the difference between the circulation pressure and the operation pressure in the start device 2 can be keep at intended pressure.
KOKUBU TAKAHIRO
HYODO YOSHIMITSU
KOJIMA KAZUTERU
ISHIKAWA KAZUNORI
SUGIURA HIRONORI
NAKAI MASAYA
| JPS62233559A | 1987-10-13 | |||
| JP2001116138A | 2001-04-27 | |||
| JPH0396758A | 1991-04-22 | |||
| JPH0814381A | 1996-01-16 |