Electro-hydraulic transmission system with a torque converter clutch control
AssigneeGeneral Motors Corporation
InventorCharles Francis Long
Life of this patent
Estimating the term…
Abstract
An electro-hydraulic transmission control has a plurality of shift valves or relay valves controlling the selective delivery of pressure fluid to friction devices and for exhausting pressure from the friction devices. One of the shift valves is operable in reverse and low drive range to prevent engagement of a torque converter clutch and is also operable to permit engagement of the torque converter clutch in neutral and in low hold range.
Claims4
An electro-hydraulic controlled power transmission having a torque converter clutch and a plurality of operating conditions including a first range, a neutral range, a reverse range and a first hold condition:
- a hydraulic control for selectively establishing the operating conditions and for controlling the disengagement of the torque converter clutch comprising:
- a source of fluid pressure;
- a first solenoid controlled shifter valve having an energized condition and a de-energized condition;
- a second solenoid controlled shift valve having an energized condition and a de-energized condition;
- and
- a selectively operable torque converter clutch valve including a selectively energizable solenoid control having an engaged condition and a disengaged condition, said first valve being energized in the first range and the reverse range to direct the control pressure to the torque converter clutch valve to enforce the disengaged condition, said second shift valve being energized in the first hold condition and the neutral range to prevent enforcement of the torque converter clutch valve to the disengaged condition, and to permit establishment of the engaged condition when said solenoid control is engaged to direct fluid pressure from said source to a torque converter clutch.
An electro-hydraulic controlled power transmission having a torque converter clutch and a plurality of operating conditions including a first range, a neutral range, a reverse range and a first hold condition:
- a hydraulic control for selectively establishing the operating conditions and for controlling the disengagement of the torque converter clutch comprising:
- a source of fluid pressure;
- a first solenoid controlled shifter valve having an energized condition and a de-energized condition;
- a second solenoid controlled shift valve having an energized condition and a de-energized condition;
- and
- a selectively operable torque converter clutch valve including a selectively energizable solenoid control valve having an engaged condition and a disengaged condition, a control chamber and a feedback chamber, said first valve being energized in the first range and the reverse range to direct the control pressure to the control chamber of the torque converter clutch valve to enforce the disengaged condition, said second shift valve being energized in the first hold condition and the neutral range to exhaust the control chamber and prevent enforcement of the torque converter clutch valve to the disengaged condition, and to permit establishment of the engaged condition when said selectively energizable solenoid control valve is engaged to direct fluid pressure from said source to a torque converter clutch.
An electro-hydraulic control in a power transmission having a torque converter clutch and a plurality of operating conditions including a first range, a neutral range, a reverse range and a first hold condition:
- a hydraulic control for selectively establishing the operating conditions and for controlling the disengagement of the torque converter clutch comprising:
- a source of fluid pressure;
- a first solenoid controlled relay valve having an energized condition and a de-energized condition;
- a second solenoid controlled relay valve having an energized condition and a de-energized condition;
- and
- a selectively operable variable output pressure torque converter clutch valve having an engaged condition for providing an output pressure and a disengaged condition, including a selectively energizable solenoid control providing a variable control pressure, a first chamber, a second chamber, a feedback chamber, a first slidable valve element disposed between said first and second chambers and a second slidable element disposed between said second chamber and said feedback chamber, said first relay valve being energized in the first range, the neutral range, the reverse range and the first hold condition to direct a control pressure through said second relay valve to said second chamber of said torque converter clutch valve to enforce the disengaged condition, said second relay valve being energized in the first hold condition and the neutral range to block the control pressure from the first relay valve and exhaust said second chamber to prevent enforcement of the torque converter clutch valve to the disengaged condition, and to permit establishment of the engaged condition when said selectively energizable solenoid control is energized to pressurize said first chamber to enforce the engaged condition to direct fluid pressure from said source to said feedback chamber to limit output pressure of the torque converter clutch valve and said first slidable valve element being operable to direct the output pressure to a torque converter clutch.
Dependencies are inferred from the claim text.