Reduced engine load at stop apparatus and method
AssigneeGeneral Motors Corporation
InventorsCharles Long, Jeffrey Cole, Phillip McCauley
Life of this patent
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Abstract
Provided is an apparatus to enable a torque transmitting mechanism within an automatically shiftable power transmission to disengage at vehicle stop such that the slip within a fluid drive device is reduced. When vehicle movement is required a main pressure regulator trims the torque transmitting mechanism into engagement. A method of reducing engine load at vehicle stop by employing the apparatus of the present invention is also provided.
Claims13
A reduced engine load at stop apparatus for a vehicular transmission comprising:
- a selectively engageable torque transmitting mechanism having a piston member operable to effect engagement of said selectively engageable torque transmitting mechanism in response to a fluid pressure;
- a return spring assembly operable to disengage said selectively engageable torque transmitting mechanism when said fluid pressure provided to said selectively engageable torque transmitting mechanism falls below a predetermined value;
- a main pressure regulator valve in selective fluid communication with said selectively engageable torque transmitting mechanism, said main pressure regulator valve being operable to reduce said fluid pressure below said predetermined value to effect disengagement of said selectively engageable torque transmitting mechanism in response to a first operator input;
- and
- wherein said main pressure regulator valve is operable to increase said fluid pressure communicated to said selectively engageable torque transmitting mechanism above said predetermined value to engage said selectively engageable torque transmitting mechanism in response to a second operator input.
A method of controlling a vehicle having a transmission and a brake pedal having a brake position sensor operable to determine whether the brake pedal is in a depressed state or a released state, the method comprising:
- providing the transmission with a selectively engageable torque transmitting device within the transmission;
- providing a main pressure regulator valve operable to selectively provide pressurized fluid to selectively engage said selectively engageable torque transmitting mechanism;
- determining if the brake pedal is in the depressed state;
- controlling said main pressure regulator valve to decrease fluid pressure to said selectively engageable torque transmitting mechanism to effect one of disengagement and slip while the brake pedal is in the depressed state;
- determining if the brake pedal is in the released state;
- and
- controlling said main pressure regulator valve to increase fluid pressure to said selectively engageable torque transmitting mechanism to effect engagement of said selectively engageable torque transmitting mechanism when the brake pedal is in the released state.
A reduced engine load at stop apparatus for a vehicle comprising:
- a selectively engageable torque transmitting mechanism operable to enable a low forward range of vehicle operation and having a piston member operable to effect engagement of said selectively engageable torque transmitting mechanism in response to a fluid pressure;
- a return spring assembly operable to disengage said selectively engageable torque transmitting mechanism when said fluid pressure provided to said selectively engageable torque transmitting mechanism falls below a predetermined value;
- a main pressure regulator valve in selective fluid communication with said selectively engageable torque transmitting mechanism, said main pressure regulator valve being operable to reduce said fluid pressure below said predetermined value to effect disengagement of said selectively engageable torque transmitting mechanism in response to the depression of a brake pedal;
- and
- wherein said main pressure regulator valve is operable to increase said fluid pressure communicated to said selectively engageable torque transmitting mechanism above said predetermined value to engage said selectively engageable torque transmitting mechanism in response to the release of said brake pedal.
Dependencies are inferred from the claim text.