Hydraulic control apparatus and hydraulic control method for automatic transmission
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsTomohiro Kondo, Masami Kondo, Toshimitsu Sato
Life of this patent
Estimating the term…
Abstract
A hydraulic control apparatus of an automatic transmission estimates the possibility of there being a demand for a shift into a gear lower than the current gear during a power-off downshift operation. If there is a possibility that there will be a demand for a shift into the next gear during the shift, the hydraulic control apparatus starts an operation for supplying an apply preparation hydraulic pressure in preparation for the shift into that next gear.
Claims19
A hydraulic control apparatus of an automatic transmission which is provided with a plurality of friction apply elements and in which a gear ratio is established by selectively applying the plurality of friction apply elements by controlling hydraulic pressure with respect to the plurality of friction apply elements, comprising:
- a next-shift estimating device that estimates whether there is a possibility that, during a shift operation during a power-off downshift, there will be a demand for a shift into a second predetermined gear which has a larger gear ratio than a first predetermined gear that is to be established by this shift operation;
- and
- a next-shift preparing device that, when it is estimated by the next-shift estimating device that there is the possibility that there will be the demand for the shift into the second predetermined gear, starts an operation for supplying an apply preparation hydraulic pressure in preparation for the shift into the second predetermined gear, with respect to the friction apply element that will be applied in the second predetermined gear for which there is the possibility that there will be the demand for the shift thereinto and placing this friction apply element in a state right before the applied state, while continuing that shift operation,
- wherein when there is the demand for the shift into the second predetermined gear, an operation for applying the friction apply element that has been placed in the state right before the applied state is started.
A hydraulic control apparatus of an automatic transmission which is provided with a plurality of friction apply elements and in which a gear ratio is established by selectively applying the plurality of friction apply elements by controlling hydraulic pressure with respect to the plurality of friction apply elements, comprising:
- a next-shift estimating device that estimates whether there is a possibility that, during power-off, there will be a demand for a shift into a second predetermined gear which has a larger gear ratio than a first predetermined gear which is the current gear of the automatic transmission;
- and
- a next-shift preparing device that, when it is estimated by the next-shift estimating device that there is the possibility that there will be the demand for the shift into the second predetermined gear, starts an operation for supplying an apply preparation hydraulic pressure in preparation for the shift into the second predetermined gear, with respect to the friction apply element that will be applied in the second predetermined gear for which there is the possibility that there will be the demand for the shift thereinto and placing this friction apply element in a state right before the applied state,
- wherein when there is the demand for the shift into the second predetermined gear, an operation for applying the friction apply element that has been placed in the state right before the applied state is started.
A hydraulic control apparatus of an automatic transmission in which a gear ratio is changed by selectively applying a plurality of friction apply elements by controlling hydraulic pressure with respect to the plurality of friction apply elements, comprising:
- a next-shift estimating device that estimates whether there is a possibility that, during a shift operation during a power-off downshift, there will be a demand for a shift into a second predetermined gear which has a larger gear ratio than a first predetermined gear that is to be established by this shift operation;
- and
- a next-shift preparing device that, when it is estimated by the next-shift estimating device that there is the possibility that there will be the demand for the shift into the second predetermined gear, starts an operation for supplying an apply preparation hydraulic pressure in preparation for a shift, with respect to the friction apply element that will be applied in the second predetermined gear for which there is the possibility that there will be the demand for the shift thereinto and placing this friction apply element in a state right before the applied state, while continuing the shift operation,
- wherein when there is the demand for the shift into the second predetermined gear, an operation for applying the friction apply element that has been placed in the state right before the applied state is started after the shift operation into a gear into which the shift operation is performed is complete.
A hydraulic control apparatus of an automatic transmission in which a gear ratio is changed by selectively applying a plurality of friction apply elements by controlling hydraulic pressure with respect to the plurality of friction apply elements, comprising:
- a next-shift estimating device that estimates whether there is a possibility that, during power-off, there will be a demand for a shift into a second predetermined gear which has a larger gear ratio than a first predetermined gear which is the current gear of the automatic transmission;
- and
- a next-shift preparing device that, when it is estimated by the next-shift estimating device that there is the possibility that there will be the demand for the shift into the second predetermined gear, starts an operation for supplying an apply preparation hydraulic pressure in preparation for a shift, with respect to the friction apply element that will be applied in the second predetermined gear for which there is the possibility that there will be the demand for the shift thereinto and placing this friction apply element in a state right before the applied state,
- wherein when the operation for supplying the apply preparation hydraulic pressure in preparation for a shift is started while a shift operation is performed, and there is the demand for the shift into the second predetermined gear, an operation for applying the friction apply element that has been placed in the state right before the applied state is started after the shift operation is complete.
A hydraulic control apparatus of an automatic transmission in which a gear ratio is changed by selectively applying a plurality of friction apply elements by controlling hydraulic pressure with respect to the plurality of friction apply elements, comprising:
- a next-shift estimating device that estimates whether there is a possibility that, during a shift operation during a power-off downshift, there will be a demand for a shift into a second predetermined gear which has a larger gear ratio than a first predetermined gear that is to be established by this shift operation;
- and
- a next-shift preparing device that, when it is estimated by the next-shift estimating device that there is the possibility that there will be the demand for the shift into the second predetermined gear, starts an operation for supplying an apply preparation hydraulic pressure in preparation for a shift, with respect to the friction apply element that will be applied in the second predetermined gear for which there is the possibility that there will be the demand for the shift thereinto and placing this friction apply element in a state right before the applied state, while continuing the shift operation,
- wherein when there is the demand for the shift into the second predetermined gear, an operation for applying the friction apply element that is to be applied in the second predetermined gear is started without waiting until the shift operation is complete, when supply of a predetermined apply preparation hydraulic pressure according to the operation for supplying the apply preparation hydraulic pressure in preparation for the shift into the second predetermined gear is complete before completion of the shift operation into a gear into which the shift operation is being performed at a time point at which the operation for supplying the apply preparation hydraulic pressure is started.
Dependencies are inferred from the claim text.