Aisin Aw Co., Ltd.

Aisin Aw Kabushiki Kaisha

Kazuhiro Mikami

Yoshihisa Yamamoto

Muneo Kusafuka

Masahiro Hayabuchi

Hiroshi Tsutsui

Akihito Iwata

Kazumasa Tsukamoto

Kenji Suzuki

Masaaki Nishida

Yasunobu Ito

Kazuomi Okasaka

Kazuhito Yamada

Masayuki Sugiura

Kiyoshi Nagami

Jiro Nishiwaki

Koji Hayakawa

A control device for an automatic transmission having a hydraulic power transmission with a lock-up clutch includes a device for setting a predetermined pressure that is less than a pressure at which a target value convergence control is started. The predetermined pressure is set as the hydraulic pressure applied to the lock-up clutch by a predetermined pressure setting device for a predetermined time. The predetermined time is a time from a satisfaction of conditions for the slip control start until an input rotation speed is stabilized, as set by a time setting device.

Lock-up slip control device for automatic transmission

A control system for an automatic transmission including a hydraulic power transmission, a clutch, and a brake which is engaged to prevent a vehicle from rolling backward thereby establishing a hill-hold state in the speed change unit. The control system includes a stop state detector which detects the vehicle stopped state when the forward driving range is selected, the accelerator pedal is released and the brake pedal is depressed. The control system further includes a clutch disengaging system which provides a neutral control, and a brake engaging system which provides a hill-hold control and performs a neutral control with the engine not under a load.

Control system for automatic transmission

A slip control system for an automatic transmission includes a fluid coupling including a release side oil chamber, an apply side oil chamber and a lockup clutch unit that is applied and released on an basis of the oil pressure that is fed to at least one of the release side oil chamber and the apply side oil chamber; an oil pressure generating unit for generating the oil pressure; a vehicular running state detecting unit for a detecting vehicular running state; an electronic control unit for determining whether a slip control is to be made, on the basis of a determination upon whether the present vehicular running state, as detected by the vehicular running state detecting unit, belongs to a predetermined slip control region; and an oil pressure regulating unit for regulating the oil pressure in response to a signal coming from the electronic control unit, to make the slip control by sliding the lockup clutch unit. The electronic control unit determines the state of a heat, as generated according to the slip control; and changes the slip control region on the basis of the heat state.

Slip control system

The control system for a linear solenoid valve controls output of an oil pressure according to a current value to be fed to the linear solenoid which operates the linear solenoid valve. A solenoid current monitor detects the current value fed to the linear solenoid and an IG voltage monitor detects the voltage level of the battery. A linear solenoid current value setting unit sets a target current value according to a target oil pressure level and a duty ratio setting unit sets a duty ratio for applying the battery voltage to the linear solenoid on the basis of signals coming from the current monitor, the voltage monitor and the current value setting unit. A solenoid driver applies the battery voltage to the linear solenoid for a predetermined period in accordance with the duty ratio set by the duty ratio setting unit. The duty ratio setting unit, in turn, includes: a feedback correction unit for feedback correction of the duty ratio, in accordance with the difference between the current value detected by the monitor and the target current value set by the current value setting unit, so that the current value fed to the linear solenoid approaches the target current value; and a voltage correction unit for further correcting the duty ratio, as previously corrected by the feedback correction unit, on the basis of the voltage level of the battery, as detected by the voltage monitor.

Control system for linear solenoid valve

A control system for an automatic transmission which includes a fluid transmission unit. The control system includes a clutch applied in a forward running range; a hydraulic servo for applying the clutch responsive to an oil pressure; input and output R.P.M. sensors for detecting the input and output R.P.M.s of the fluid transmission unit; a stop state detector for detecting that the vehicle is stopped; a start detector for detecting start of the vehicle from a stop; and a control unit for controlling the oil pressure fed to the hydraulic servo. The oil pressure of the hydraulic servo is reduced, when the vehicle is stopped, to establish a neutral control state in which the clutch is released. A completely applied state of the clutch is established by boosting the oil pressure fed to the hydraulic servo when the shift of the vehicle from a stop to start is detected, in two stages. In the first stage the oil pressure fed to the hydraulic servo is boosted by adding a set shelf pressure to the base pressure until the clutch comes into a partially applied state and then, in the second stage, the oil pressure fed to the hydraulic servo is further boosted until the clutch becomes completely applied.

A control system for an automatic transmission, has a fluid transmission unit for transmitting the rotation of an engine to a speed change unit; a clutch adapted to be applied when a forward running range is selected to transmit the rotation of the fluid transmission unit to the transmission mechanism of the speed change unit; a stopped state detector for detecting a stopped state of a vehicle wherein the stopped state is defined as a forward running range being selected, the throttle opening being fully closed, the brake pedal being depressed, and the vehicle speed being substantially zero; engine speed detector for detecting the engine speed; clutch operation force generating means for generating the application force of the clutch; and a control unit. The control unit releases the clutch by reducing the engaging force of the clutch when the stopped state of the vehicle is detected by the stopped state detecting means. The engine RPM when the clutch is released is stored as an initial engine RPM in storage means so that a neutral ending engine RPM is set on the basis of the initial engine RPM. The clutch is applied by strengthening its application force if the stopped state of the vehicle is not detected when the clutch is released and if the engine RPM exceeds the neutral ending engine RPM.

Control system for clutch reengagement during an in-gear stopped state

A control system for an automatic transmission, having a fluid transmission unit for transmitting the rotation of an engine to a speed change unit. The control system includes a clutch which is applied responsive to selection of forward running range; a one-way clutch which is locked, when the clutch is applied, to establish a forward first speed; a brake for locking the one-way clutch, to block reverse rotation of the output shaft of the speed change unit. First and second hydraulic servos apply, respectively, the clutch and the brake responsive to receipt of oil pressures. A control unit controls the oil pressures fed to the first and second hydraulic servos. The control unit starts the feed of oil pressure to the second hydraulic servo responsive to selection of a forward running range, provided the vehicle is substantially stopped, the engine is idling and the foot brake is engaged. The control unit starts the reduction of the pressure of the first hydraulic servo upon expiration of a set time period and starts transition of the clutch from the applied state to the slipping state of the clutch upon completion of the piston stroke of the second hydraulic servo which applies the brake.

A control system for an automatic transmission, which receives the rotation of the engine through a fluid coupling, and which has a clutch applied when a forward running range is selected and released when a neutral range is selected and a range selecting mechanism for selecting a range. The control system includes a range detector for detecting the selected range, a hydraulic circuit and a control unit. The hydraulic circuit includes a hydraulic servo which is fed an oil pressure for applying the clutch and a manual valve movable between at least a forward range position for generating a forward range oil pressure and a neutral range position, by operation of the range selecting mechanism. A regulator valve regulates the forward range oil pressure to generate a regulated oil pressure. A solenoid valve is turned ON/OFF by the control unit to generate a signal oil pressure for switching a change-over valve between a first position feeding the forward range oil pressure to the hydraulic servo and a second position feeding the regulated oil pressure to the hydraulic servo. The control unit delays output of the signal solenoid valve, if a switching from the forward running range to the neutral range is detected by the range detector, so that the change-over valve remains in the second position until lapse of a set time period, and is then moved to a first position after the set time period has elapsed.

Drive to neutral shift control system

A control system for an automatic transmission in a vehicle powertrain including an engine and a fluid coupling for transmitting the rotation of an engine to the transmission, the transmission having a clutch which is applied responsive to selection of a forward running range and a hydraulic servo for applying the clutch responsive to an oil pressure. The control system includes a control unit for controlling the oil pressure to the hydraulic servo; an input torque detector for detecting the input torque to be inputted to the transmission; and a specific state detector for detecting satisfaction of a set of specific starting conditions including: (1) that the forward running range has been selected, (2) that the vehicle is stopped and (3) that the engine is in an idling state. The control unit sets the oil pressure to the hydraulic servo to correspond to the input torque at the instant of detection of satisfaction the specific starting conditions, and includes: a first pressure-reducer for abruptly reducing the oil pressure of the hydraulic servo to a set oil pressure immediately before the release of the clutch is started; and a second pressure-reducer for gradually reducing the oil pressure of the hydraulic servo, which has been reduced to the set oil pressure by the first pressure-reducer.

An automatic transmission control system providing a neutral control state in which there is no slipping engagement of a first clutch which is engaged upon selection of a forward range and, as a result, the vehicle is not subjected to idling vibration. The fuel consumption reducing effect of the neutral control state is maintained and there is no heating and consequent deterioration of the friction material of the clutch. The control system includes a hydraulic servo for operation of the clutch, an input side speed sensor for detecting the input side speed of a fluid power coupling device connecting the transmission to the output of an engine, an output side speed sensor for detecting the output side speed of the fluid power coupling device, and a controller. The controller includes differential speed calculator, differential speed change detector, a pressure increasing device for increasing the hydraulic pressure of the hydraulic servo by a set pressure when the differential speed has not changed, and a pressure reducing device for reducing the hydraulic pressure of the hydraulic servo by a set pressure when the differential speed has changed.

Automatic transmission control apparatus

A fail-safe control device for an electronically controlled automatic transmission to be mounted on a vehicle arranged in such a manner that the number of engine revolution or the number of revolution input to a T/M is detected, the duration of the engine revolving state is counted, and it is determined that a failure of the engine water temperature sensor occurs if the engine water temperature detected by the engine water temperature sensor after a predetermined time elapse counted is lower than a predetermined temperature. As a result of this, a proper fail-safe control against the failure of the engine water temperature sensor can be performed.

Fail-safe operation of a vehicle automatic transmission responsive to

A fail-safe control device for an electronically controlled automatic transmission to be mounted on a vehicle, the fail-safe control device: detects the battery voltage; previously stores a standard battery voltage; makes a comparison between the thus-detected battery voltage and the above-described standard battery voltage; and switches to an emergency mode of turning off all of shift solenoids when the voltage deviates from the standard upon the comparison. As a result of this, generation of defects that shifting from high speed gear stage to a lower speed gear stage due to defective operation of the shift solenoid and disconnection or the like due to the overvoltage of the solenoid can be prevented. Furthermore, if a failure is detected, it can be notified to a drive.

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Kariya, Japan

Kazuhiro Mikami