| 摘要 |
A hydraulic actuation system (10) and method of assembly for disconnecting a secondary driveline (27) can be used in an all-wheel drive (AWD) vehicle (14) having a power take-off unit (PTU) (42) for transferring rotary power to the secondary driveline (27). The hydraulic actuation system (10) can include a source of pressurized fluid (50), a hydraulically actuated synchronizer (44) for synchronizing rotary motion between the PTU (42) and the secondary driveline (27), at least one hydraulically actuated clutch assembly (11a, 11b) for connecting and disconnecting secondary vehicle wheels (29a, 29b) with respect to the secondary driveline (27), an area control solenoid (ACS) valve (54) in fluid communication with the source of pressurized fluid (50) to modulate pressure to engage and disengage the synchronizer (44), and at least one variable force solenoid (VFS) valve (56a, 56b) in fluid communication with the source of pressurized fluid (50) to modulate pressure to the at least one hydraulically actuated clutch assembly (11a, 11b). |
| 主权项 |
1. In a hydraulic actuation system (10) for disconnecting a secondary driveline (27) of an all-wheel drive (AWD) (14) vehicle including a power take-off unit (PTU) (42) for transferring rotary power to the secondary driveline (27), the improvement comprising:
a source of pressurized fluid (50) and a fluid sump (67); a hydraulically actuated synchronizer (44) for synchronizing rotary motion between the PTU (42) and the secondary driveline (27); at least one hydraulically actuated clutch assembly (11a, 11b) for connecting and disconnecting secondary vehicle wheels (29a, 29b) with respect to the secondary driveline (27); an area control solenoid (ACS) valve (54) in fluid communication with the source of pressurized fluid (50) and the synchronizer (44), the ACS valve (54) having at least a first position (54a), a second position (54b), and a third position (54c), the first position (54a) of the ACS valve (54) allowing fluid communication between the source of pressurized fluid (50) and the synchronizer (44) for engaging the synchronizer (44), the second position (54b) of the ACS valve (54) preventing fluid communication between the source of pressurized fluid (50) and the synchronizer (44) for holding the synchronizer in one of the first and third positions (54a, 54b), and the third position (54c) of the ACS valve (54) allowing fluid communication between the synchronizer (44) and the fluid sump (67) for disengaging the synchronizer (44); and at least one variable force solenoid (VFS) valve (56a, 56b) having an open position (94b) allowing fluid communication between the source of pressurized fluid (50) and the at least one hydraulically actuated clutch assembly (11a, 11b) for moving the at least one clutch assembly (11a, 11b) toward a first position and a closed position (94a) preventing fluid communication between the source of pressurized fluid (50) and the at least one hydraulically actuated clutch assembly (11a, 11b) while discharging pressurized fluid from the at least one hydraulically actuated clutch assembly (11a, 11b) for moving the at least one clutch assembly (11a, 11b) toward a second position. |
