Automatic transmission and control method of automatic transmission
AssigneeHonda Motor Co., Ltd.
InventorsAkio Muto, Shohei Taka, Hiroki Murasawa
Life of this patent
Estimating the term…
Abstract
A dual clutch automatic transmission includes a one-way clutch provided in a driving force transmission path that establishes a certain gear ratio in a first set of gear ratios. A driving transmission direction of the one-way clutch is set such that a rotation inputted from a wheel side to an output member in a predetermined rotational direction is transmitted to the input shaft. The predetermined rotational direction corresponds to a backward movement of a vehicle. On condition that the vehicle has stopped, backward movement prevention control of causing the switching mechanism to engage a transmission gear for another gear ratio in the first set with the input shaft can be executed.
Claims11
An automatic transmission comprising:
- a first transmission mechanism to which a driving force of a driving source is input through a first clutch and which is configured to switch driving force transmission paths to an output member to establish a first set of gear ratios;
- a second transmission mechanism to which the driving force of the driving source is input through a second clutch and which is configured to switch driving force transmission paths to the output member to establish a second set of gear ratios;
- and
- a control unit,
- wherein a one-way clutch is provided in a driving force transmission path that establishes a first certain gear ratio in the first set,
- the first transmission mechanism comprises:
- an input shaft to which the driving force of the driving source is input through the first clutch;
- a first transmission gear provided on the input shaft and configured to establish the first certain gear ratio;
- a plurality of second transmission gears provided on the input shaft and configured to establish remaining gear ratios in the first set;
- and
- a switching mechanism configured to perform engagement and disengagement between the input shaft and the plurality of second transmission gears,
- a driving transmission direction of the one-way clutch is set such that a rotation inputted from a wheel side to the output member in a predetermined rotational direction is transmitted to the input shaft, the predetermined rotational direction corresponding to a backward movement of a vehicle, and
- the control unit can execute backward movement prevention control of causing the switching mechanism to engage a third transmission gear that is one of the plurality of second transmission gears with the input shaft on condition that the vehicle has stopped.
A control method of an automatic transmission which comprises:
- a first transmission mechanism to which a driving force of a driving source is input through a first clutch and which is configured to switch driving force transmission paths to an output member to establish a first set of gear ratios;
- and
- a second transmission mechanism to which the driving force of the driving source is input through a second clutch and which is configured to switch driving force transmission paths to the output member to establish a second set of gear ratios,
- wherein a one-way clutch is provided in the driving force transmission path that establishes a first certain gear ratio in the first set,
- the first transmission mechanism comprises:
- an input shaft to which the driving force of the driving source is input through the first clutch;
- a first transmission gear provided on the input shaft and configured to establish the first gear ratio;
- a plurality of second transmission gears provided on the input shaft and configured to establish remaining gear ratios in the first set;
- and
- a switching mechanism configured to perform engagement and disengagement between the input shaft and the plurality of second transmission gears, and
- a driving transmission direction of the one-way clutch is set such that a rotation inputted from a wheel side to the output member in a predetermined rotational direction is transmitted to the input shaft, the predetermined rotational direction corresponding to a backward movement of a vehicle,
- the control method comprising:
- determining whether a predetermined condition including at least a stop of the vehicle is met;
- and
- upon determining that the predetermined condition is met, causing the switching mechanism to engage a third transmission gear that is one of the plurality of second transmission gears with the input shaft.
Dependencies are inferred from the claim text.