Aisin Aw Co., Ltd.

Yutaka Teraoka

Hiroshi Tsutsui

Masaaki Nishida

Masatake Ichikawa

Kouichi Kojima

Masahiro Hayabuchi

Kazumasa Tsukamoto

Nobuhiro Iwai

Shoji Omitsu

Kiyoshi Akutsu

Koji Maeda

Makoto Yamaguchi

Hiroyasu Amano

Satoru Kasuya

Shuzo Moroto

Tetsuya Shimizu

Takao Taniguchi

Shoichi Miyagawa

Hiromasa Takai

Masaki Nishide

Hiroyuki Fujioka

Keishi Morita

Yasuhiro Fujiwara

Hidekazu Funakoshi

A control device for an automatic transmission mounted on a vehicle to establish a plurality of shift speeds by engaging engagement elements that need to be engaged for each shift speed. The control device includes a target shift speed setting device, a during-travel neutral control device and a prediction control device. The prediction control device takes action when a predicted prechange time becomes equal to or less than a predetermined time while the automatic transmission is in the neutral state, the predicted prechange time being a time predicted on the basis of variations in vehicle speed and being a time before implementation of a change of the target shift speed that involves changing the particular engagement element from a disengaged state to an engaged state in order to maintain the neutral state.

Control device and control method for automatic transmission

If it is determined that a D range is in use and determined that a vehicle is stopped, neutral control means () commands and controls an engagement pressure of a clutch (C-) so as to achieve a state in which a piston of the clutch (C-) contacts a clutch drum by a biasing force of a spring, and a state in which oil fills an oil passage from a linear solenoid valve (SLC) to a hydraulic oil chamber and fills the hydraulic oil chamber. There is thus no drag loss in the clutch (C-) during a neutral control, and the same fuel economy as when, for example, a manual shift to the neutral range is made can be achieved during the neutral control.

Control device of automatic transmission

A control apparatus of an automatic transmission including a start intended operation detecting unit detecting a vehicle starting operation; and a clutch control unit engaging the clutch from the clutch disengaged state and the automatic speed change mechanism is placed in a neutral state, when the vehicle starting operation is detected. The clutch control unit includes an initial engagement control unit performing initial engagement control that starts frictional contact of the clutch by supplying hydraulic pressure to a hydraulic servo of the clutch, and a slip start control unit establishing a speed ratio of the automatic speed change mechanism at the start by slip-controlling the clutch after the initial engagement control is terminated, thereby increasing output shaft rotational speed of the automatic speed change mechanism without reducing the input shaft rotational speed of the automatic speed change mechanism to less than the input shaft rotational speed at the end of initial engagement control.

A control apparatus of an automatic transmission having an automatic speed change mechanism for changing a driving source speed of rotation and a clutch engaged at a start, a fluid transmission apparatus between the driving source and the automatic speed change mechanism, and a lock-up clutch for locking up the fluid transmission apparatus. The control apparatus includes a range unit that determines a shift range including a drive range, a vehicle stop unit that determines a stop of a vehicle, a start intended operation unit that detects an intended start vehicle operation, a clutch control unit that controls the clutch to be disengaged to place the automatic speed change mechanism in a neutral state while the shift range is determined to be the drive range and the vehicle is determined to be stopped, and performs engagement control of the clutch to control the start of the vehicle when the operation intended for starting the vehicle is detected, and a lock-up clutch control unit that controls the lock-up clutch to be engaged while the shift range is determined to be the drive range and the vehicle is determined to be stopped, and controls the lock-up clutch so that the lock-up clutch is at least engaged in a slip region in which a predetermined torque capacity is obtained, when the operation intended for starting the vehicle is detected.

Control apparatus of automatic transmission

A device with a stepped automatic transmission to transfer power from a power source to an axle using changeable shift speeds includes an input-side fluid transmission element connected to the power source, an output-side fluid transmission element connected to the transmission input shaft, a lock-up clutch engaging and disengaging the input-side and the output-side fluid transmission elements; a unit adjusting the lock-up clutch; a unit setting, when a downshift is to be performed in response to a predetermined request for a large drive force, a predetermined target slip speed value larger than a non-shifting-time value before a rotational speed of the power source exceeds a input shaft rotational speed after the downshift, and setting the target slip speed to decrease toward the non-shifting-time value along with lapse of time after the power source rotational speed source exceeds the post-shifting input shaft speed; and a unit controlling the engagement force so the slip speed becomes the set target slip speed. The target slip speed is a difference between the rotational speeds of the power source and the input shaft, and the non-shifting-time value is set when no shifting is performed.

Power transfer device and control method thereof, and lock-up clutch device

A control device controlling a vehicle's automatic transmission. The automatic transmission engages first and second friction engagement elements by fluid pressure from a pump operating using motive power from the vehicle's motor when a shift position is at a reverse traveling position, places the first friction engagement element on standby at a predetermined pressure that is higher than a stroke starting pressure by which a piston stroke is started and lower than a complete engagement pressure or engages the first friction engagement at the complete engagement pressure when the shift position is at a non-traveling position, and engages a third friction engagement element as a starting shift speed when the shift position is at a forward traveling position. When the shift position is at the forward traveling position, the first friction engagement element is placed on standby at the predetermined pressure if a vehicle speed is lower than a predetermined vehicle speed, or releases the predetermined standby pressure if the vehicle speed is equal to or higher than the predetermined vehicle speed.

Automatic transmission control device

A shift control apparatus has first, second, third and fourth engagement elements, and a shift control processing unit engaging the first and the second engagement elements in order to realize a first shift speed, engaging the third and the fourth engagement in order to realize a second shift speed, and inhibiting an increase in torque capacity of one of the first and second engagement elements before starting of release of the second engagement element when shifting from the first to the second shift speed. During shifting from the first to the second shift speed, an increase in torque capacity of one of the first and second engagement elements is inhibited before starting of release of the second engagement element. This prevents a step-like shift shock from being caused by the slowed progression of shifting when release of the second engagement element is started.

Shift control apparatus for an automatic transmission

An automatic transmission achieves a desired shift through an initial stage shift in which a first engagement element is released and a third engagement element is engaged, and a final stage shift in which a second engagement element is released and a fourth engagement element is engaged. A control apparatus sets an estimated rotation acceleration for a transmission input shaft in accordance with an input torque and an input torque rotation acceleration speed, and controls the release of the second engagement element for moving to the final stage shift according to the estimated rotation acceleration. As a result, it is possible to prevent a shifting delay and/or degradation that occurs between the initial stage and the latter stage by continuous transmission of the input rotation (engine rotation) change when moving from the initial stage to the later stage.

Shift control apparatus for automatic transmission

The invention has been made to eliminate a feeling of two-phase speed-change operations by causing a speed-change operation to proceed continuously when the speed-change operation is performed through two-phase control of engagement and release of four engagement elements. To accomplish this purpose, the invention provides a control apparatus for an automatic transmission wherein a predetermined speed-change operation is achieved through a pre-phase speed-change operation in which a first engagement element and a third engagement element are released and engaged respectively and through a post-phase speed-change operation in which a second engagement element and a fourth engagement element are released and engaged respectively. The control apparatus sets a target rotational acceleration of an input shaft of the transmission, and controls release of the second engagement element for a transition to the post-phase speed-change operation in accordance with the target rotational acceleration. Thus, the input speed during the transition from the pre-phase speed-change operation to the post-phase speed-change operation changes continuously, so that bluntness is prevented from being caused between the pre-stage and post-stage speed-change operations.

Speed-change control apparatus for automatic transmission

A lock-up control apparatus for an automatic transmission in which operations of four engagement elements are required when shifting is performed from a first shift speed to a second shift speed, the first shift speed being achieved by engagement of a first engagement element and a second engagement element, the second shift speed being achieved by engagement of a third engagement element and a fourth engagement element. The lock-up control apparatus includes a lock-up control unit that performs a control for bringing a lock-up clutch into one of a disengagement state and a slip state at a start of shifting, and that prevents reengagement of the lock-up clutch at a completion of engagement of the third engagement element when shifting is performed from the first shift speed to the second shift speed during lock up.

Lock-up control apparatus for automatic transmission

The invention eliminates the feeling of two-phase speed-change operations by causing a speed-change operation to proceed continuously when the speed-change operation is performed through two-phase control of engagement and release of four engagement elements. An automatic transmission is such that a predetermined speed-change operation is achieved through a pre-phase speed-change operation in which a first engagement element and a third engagement element are released and engaged respectively and through a post-phase speed-change operation in which a second engagement element and a fourth engagement element are released and engaged respectively. A control apparatus has a torque control capability for adjusting an input torque of a transmission during the pre-phase speed-change control, and ensures continuous changes in the input speed during the pre-phase and post-phase speed-change operations through adjustment of the input torque (torque reduction) to prevent bluntness from being caused between the pre-phase and post-phase speed-change operations.

Control apparatus for automatic transmission

At the time of the 6&rarr;3 speed shift, an automatic transmission achieves a 6&rarr;4&rarr;3 speed shift by controlling the servo pressures of four engageable elements. A control apparatus controls the servo pressure of one engageable element in accordance with the servo pressures of other engageable elements. The engagement and release timings are adjusted by determining and controlling the oil pressures of the hydraulic servos, taking into consideration the 6&rarr;4 shift state (torque sharing) during a shift transitional period. Therefore, engine blow and prolongation are prevented during the 6&rarr;3 shift control.

Speed shift control apparatus of automatic transmission

A shift control apparatus that advances activation of an engagement element to be engaged during a shift requiring engagement and release of four engagement elements, thereby reducing the shift time. The automatic transmission achieves a sixth-to-fourth-to-third shift by controlling servo pressures for the four engagement elements. The control apparatus starts, during the time of the sixth-to-third shift, supply of the hydraulic pressure for activating the engagement element to be engaged at the time of the fourth-to-third shift, thereby advancing the establishment of the engagement stand-by state at the time of the fourth-to-third shift. Accordingly, the reduction in the servo pressure of the engagement element to be released at the time of the fourth-to-third shift can be advanced, thereby reducing the time for the sixth-to-third shift.

Quick shifting is achieved while preventing a shift shock when shifting is caused by grip change of four engagement elements. The automatic transmission requires activation of the four engagement elements when shifting from a first shifting position (sixth speed) to a second shifting position (third speed) is performed. This shifting control apparatus includes shift control means for starting disengagement of a second engagement element after starting disengagement of a first engagement element; completing engagement of a fourth engagement element after completing engagement of a third engagement element; and starting disengagement of the second engagement element before completing engagement of the third engagement element.

In a torque converter, in order to reduce the cost, simplify the manufacturing process and ensure the centering precision of of the stator relative to the outer race of a one-way clutch, the stator and the outer race of the one-way clutch have first engaging surface portions preventing relative rotation therebetween and second engaging surface portions providing concentricity therebetween. The first and second surface portions are axially offset from each other.

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Anjo, Japan

Yutaka Teraoka