Ratio shift control for a multiple ratio automatic transmission
AssigneeFord Global Technologies, LLC
InventorsYuji Fujii, Marvin Kraska, Gregory Pietron, William Tobler, Walter Ortmann, Bradley Riedle, Ronald Cowan, Davorin Hrovat
Life of this patent
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Abstract
A gear ratio shift control and control method controls gear ratio upshifts in a multiple-ratio transmission for an automotive vehicle. Pressure actuated friction elements establish torque flow paths in transmission gearing as they are selectively engaged and released. A net torque reduction at a transmission torque output shaft during an upshift event is reduced by increasing transmission input torque prior to the start of the inertia phase of the upshift event.
Claims15
A gear ratio shift control for a multiple-ratio automatic transmission in a powertrain for an automotive vehicle, the transmission including gearing defining multiple torque flow paths from a transmission input torque source to a transmission torque output member and first and second torque establishing elements for selectively establishing, respectively, a first gear configuration with a high speed ratio and a second gear configuration with a lower speed ratio during a ratio upshift event;
- a ratio upshift event being characterized by a preparatory phase followed by a torque phase;
- means for maintaining torque capacity of the first torque establishing element against slippage during the preparatory phase and releasing torque capacity of the first torque establishing element during the torque phase;
- means for increasing torque capacity of the second torque establishing element during the preparatory phase and the torque phase;
- the torque phase being followed by an inertia phase;
- means for increasing input torque prior to the inertia phase;
- and
- means for reducing input torque during the inertia phase.
A synchronous gear ratio shift control for a multiple-ratio automatic transmission in a powertrain for an automotive vehicle, the transmission including gearing defining multiple torque flow paths from a transmission input torque source to a transmission torque output member and first and second pressure actuated torque establishing elements for selectively establishing, respectively, a first gear configuration with a high speed ratio and a second gear configuration with a lower speed ratio during a synchronous ratio upshift event;
- a ratio upshift event being characterized by a preparatory phase followed by a torque phase;
- the first and the second torque establishing elements being independently, but synchronously, controlled during the torque phase whereby the upshift event is synchronous;
- means for maintaining torque capacity of the first torque establishing element against slippage during the preparatory phase and releasing torque capacity of the first torque establishing element during the torque phase;
- means for increasing torque capacity of the second torque establishing element during the preparatory phase and the torque phase;
- means for increasing input torque during the preparatory phase;
- the torque phase being followed by an inertia phase;
- and
- means for reducing torque from the torque source during the inertia phase.
A non-synchronous gear ratio shift control for a multiple-ratio automatic transmission in a powertrain for an automotive vehicle, the transmission including gearing defining multiple torque flow paths defining multiple torque flow paths from a transmission input torque source to a transmission torque output member and first torque establishing element and second pressure activated torque establishing element for selectively establishing, respectively, a first gear configuration with a high speed ratio and a second gear configuration with a lower speed ratio during a ratio upshift event;
- a non-synchronous ratio upshift being characterized by a preparatory phase followed by a torque phase;
- the first torque establishing element being an overrunning or one-way coupling whereby the upshift event is non-synchronous;
- means for increasing transmission input torque during the torque phase as torque capacity of the second torque establishing element is increased during the torque phase;
- the torque phase being followed by an inertia phase;
- and
- means for reducing torque from the transmission input torque source during the inertia phase.
A method for controlling synchronous gear ratio shifts in a multiple-ratio automatic transmission for an automotive vehicle powertrain, the automatic transmission including gearing defining multiple torque flow paths from a transmission input torque source to a transmission torque output member and first and second pressure actuated torque establishing elements for establishing, respectively, a first gear configuration with a high speed ratio and a second gear configuration with a lower speed ratio during a synchronous ratio upshift event, a synchronous ratio upshift event being characterized by a preparatory phase, a torque phase and an inertia phase, the method comprising the steps of:
- maintaining torque capacity of the first torque establishing element against slippage during the preparatory phase;
- decreasing torque capacity of the first torque establishing element during the torque phase;
- increasing torque capacity of the second torque establishing element during the preparatory phase and the torque phase;
- increasing input torque during the preparatory phase;
- and
- means for reducing torque from the torque source during the inertia phase.
A method for controlling non-synchronous gear ratio shifts in a multiple-ratio automatic transmission for an automotive vehicle powertrain, the automatic transmission including gearing defining multiple torque flow paths from a transmission input torque source to a transmission torque output member and first torque establishing element and second pressure actuated torque establishing element for establishing, respectively, a first gear configuration with a high speed ratio and a second gear configuration with a lower speed ratio during a non-synchronous ratio upshift event, a non-synchronous ratio upshift event being characterized by a preparatory phase, a torque phase and an inertia phase, the method comprising the steps of:
- increasing transmission input torque during the torque phase as torque capacity of the second torque establishing element is increased during the torque phase;
- and
- reducing torque from the transmission input torque source during the inertia phase.
Dependencies are inferred from the claim text.