Aisin Aw Co., Ltd.

Masatake Ichikawa

Hiroshi Tsutsui

Yutaka Teraoka

Shoji Omitsu

Masaaki Nishida

Kouichi Kojima

Hiroyasu Amano

Masahiro Hayabuchi

Tetsuya Shimizu

Hiromasa Takai

Nobuhiro Iwai

Hitoshi Asano

Kiyoshi Nagami

Hiroyuki Fujioka

Keishi Morita

Makoto Hashizume

Haruki Sato

Takahiro Morimoto

Yoshinori Maki

Hidekazu Funakoshi

Yasuhiro Fujiwara

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

A lock-up device supplies hydraulic pressure to a lock-up clutch when lock-up capacity becomes insufficient with increasing accelerator operation amount during slip control. The lock-up device (1) sets a hydraulic unit pressure command value corresponding to drive source torque so rotational speed difference becomes target slip speed when a variation in accelerator operation amount is in a predefined range, and deriving an estimated drive source output torque corresponding to the accelerator operation amount to set the pressure command value corresponding to the estimated drive source torque so the rotational speed difference becomes target slip speed when accelerator operation amount variation exceeds the range's upper limit, and (2) controls the hydraulic unit to supply hydraulic pressure corresponding to hydraulic pressure command value to the lock-up clutch.

Lock-up device and control method for lock-up device

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 that disconnects and connects respective pairs of friction engagement elements during downshift to a speed spaced apart by two or more steps through an intermediate shift speed. A shift controller controls a hydraulic pressure of a second shift release element by feedback control, and in accordance with the increase in the torque capacity of the second shift release element, also controls the torque capacity of a first shift engagement element so as to be sufficiently higher than the amount of change in the torque capacity of the second shift release element. The occurrence of adverse consequences in which a shift shock is generated is effectively suppressed because a sufficient reaction force cannot be ensured during engagement switching due to insufficient torque capacity of the first shift engagement element, and since the second shift release element cannot be appropriately feedback-controlled, difficulty in control of rotation change results.

Shift control apparatus for automatic transmission

In clutch-to-clutch upshifting, the occurrence of inertia shock is suppressed while racing of the engine is prevented. Corresponding to a first sweep control in which an engaging-side pressure sweeps up toward a target hydraulic pressure P, a releasing-side hydraulic pressure Psweeps down as an initial control. When the releasing-side hydraulic pressure Pbecomes a minute torque capacity [fP(0)+P+P], a hold control, which has a very low gradient &#x3b4;P, is started so that the pressure is substantially held, and, after a rotation change is started, the pressure sweeps down with a low gradient &#x3b4;Puntil release.

Hydraulic control system for automatic transmission

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

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.

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Kariya, Japan

Masatake Ichikawa