Abstract: The object of the invention is to impart a suitable target slip amount depending on a state of change in an output from a driving power source to a torque converter, while simplifying control. A controller has a calculation part for calculating an engine torque change rate that is a rate of change in the output, and a target slip addition amount calculation part for calculating a negative value as an addition amount, when the engine torque change rate is less than or equal to a predetermined value that is a positive value, and for calculating a positive value as the addition amount, when the engine torque change rate is greater than the predetermined value. The controller is configured to set the target slip amount of a lockup clutch by arithmetic processing that integrates the addition amount, determined based on the calculated engine torque change rate, every control period.

Abstract: An output power of the internal combustion engine (1) is transmitted to a drive wheel via a torque converter (2B) having a pump impeller and a turbine runner. A lockup clutch (2C) directly connects the pump impeller and the turbine runner during a coast running of a vehicle. When the accelerator pedal is slightly depressed during a coast running of a vehicle in a fuel cut-off state, the lockup clutch (2C) disengages. In addition, fuel recovery of the internal combustion engine (1) is suppressed until the engaging pressure of the lockup clutch (2C) decreases, thereby preventing a vehicle speed change caused by an output power increase of the internal combustion engine (1) before the lockup clutch (2C) substantially disengages.

Abstract: A device for controlling an automatic transmission including a lock-up clutch control portion and a zero slip control portion for bringing a lock-up clutch into a zero slip state immediately before slippage occurs in accordance with a zero slip request outputted during a non-gear shift, wherein in a case where a target slip amount is equal to or smaller than a slip amount threshold value upon transition to the zero slip state, the zero slip control portion fixes the target slip amount to the slip amount threshold value and retains the fixed target slip amount for a predetermined period of time, and after the predetermined period of time has elapsed, gradually decreases the target slip amount from the slip amount threshold value to a zero slip amount with a predetermined gradient with time.

Abstract: The object of the invention is to impart a suitable target slip amount depending on a state of change in an output from a driving power source to a torque converter, while simplifying control. A controller has a calculation part for calculating an engine torque change rate that is a rate of change in the output, and a target slip addition amount calculation part for calculating a negative value as an addition amount, when the engine torque change rate is less than or equal to a predetermined value that is a positive value, and for calculating a positive value as the addition amount, when the engine torque change rate is greater than the predetermined value. The controller is configured to set the target slip amount of a lockup clutch by arithmetic processing that integrates the addition amount, determined based on the calculated engine torque change rate, every control period.

Abstract: A device for controlling an automatic transmission including a lock-up clutch control means, and a zero slip control means for bringing a lock-up clutch into a zero slip state immediately before slippage occurs in accordance with a zero slip request outputted during a non-gear shift, wherein in a case where a target slip amount is equal to or smaller than a slip amount threshold value upon transition to the zero slip state, the zero slip control means fixes the target slip amount to a slip amount threshold value and retains the fixed target slip amount for a predetermined period of time, and after the predetermined period of time has elapsed, gradually decreases the target slip amount from the slip amount threshold value to a zero slip amount with a predetermined gradient with time.

Abstract: An output power of the internal combustion engine (1) is transmitted to a drive wheel via a torque converter (2B) having a pump impeller and a turbine runner. A lockup clutch (2C) directly connects the pump impeller and the turbine runner during a coast running of a vehicle. When the accelerator pedal is slightly depressed during a coast running of a vehicle in a fuel cut-off state, the lockup clutch (2C) disengages. In addition, fuel recovery of the internal combustion engine (1) is suppressed until the engaging pressure of the lockup clutch (2C) decreases, thereby preventing a vehicle speed change caused by an output power increase of the internal combustion engine (1) before the lockup clutch (2C) substantially disengages.

Abstract: A lockup clutch control apparatus controls slippage of a lockup clutch to a desired slippage by manipulating clutch engagement force of the lockup clutch, wherein an engine is provided with a supercharger, and a torque converter is disposed between the engine and an automatic transmission, and provided with the lockup clutch. The lockup clutch control apparatus includes a controller configured to: set the clutch engagement force based on a measured value of torque inputted to the lockup clutch; determine whether the engine is operating in a predetermined supercharger lag region in which the measured value deviates from an actual value of the torque; and perform a first operation of correcting the clutch engagement force by reducing the clutch engagement force in response to determination that the engine is operating in the supercharger lag region.

Abstract: This invention is a lock-up clutch control device for an automatic transmission, comprising lock-up clutch control means for controlling a slip amount of the lock-up clutch to a target slip amount. When a variation rate in a required load of an engine reaches or exceeds a predetermined threshold, the target slip amount is increased at a predetermined increase rate, whereupon the target slip amount, having been increased by target slip amount increasing means, is reduced at a predetermined reduction rate. At this time, the predetermined reduction rate is set to decrease as an operating condition when the variation rate of the required load reaches or exceeds the predetermined threshold approaches an operating condition in which an increase rate of a rotation speed on the automatic transmission side of a torque converter relative to an increase in the required load is low.

Abstract: When an inertia phase of an upshift of the transmission is started during a lockup clutch engagement operation, a following command oil pressure to be used during a following lockup clutch engagement operation is learned on the basis of a slip rotation speed, which is a rotation speed difference between an input side rotation speed of the torque converter and an output side rotation speed of the torque converter, at or after a start point of the inertia phase.

Abstract: When an upshift is performed while a traveling condition of a vehicle corresponds to a driving condition or a downshift is performed while the traveling condition of the vehicle corresponds to a coasting condition, a second target slip amount is set as a target slip amount for a period extending from the start of gear ratio variation following issuance of a gear position change start command to completion of the gear ratio change, and when a downshift is performed in the driving condition or an upshift is performed in the coasting condition, a first target slip amount is set as the target slip amount for a period extending from issuance of the shift command to completion of the shift.

Abstract: An engaging-force control apparatus for a friction-engagement element controls a slip rotational speed between an input-side rotational speed and an output-side rotational speed of the friction-engagement element by increasing or decreasing an engaging force of the friction-engagement element. The engaging-force control apparatus includes an engaging-force feedback control section configured to control the engaging force of the friction-engagement element to bring the slip rotational speed of the friction-engagement element closer to 0 by way of feedback control; and an engaging-force restricting section configured to restrict the engaging force of the friction-engagement element to prevent the engaging force from exceeding a minimum engaging-force value necessary to maintain the slip rotational speed at 0.

Abstract: A lockup clutch control apparatus controls slippage of a lockup clutch to a desired slippage by manipulating clutch engagement force of the lockup clutch, wherein an engine is provided with a supercharger, and a torque converter is disposed between the engine and an automatic transmission, and provided with the lockup clutch. The lockup clutch control apparatus includes a controller configured to: set the clutch engagement force based on a measured value of torque inputted to the lockup clutch; determine whether the engine is operating in a predetermined supercharger lag region in which the measured value deviates from an actual value of the torque; and perform a first operation of correcting the clutch engagement force by reducing the clutch engagement force in response to determination that the engine is operating in the supercharger lag region.

Abstract: When an inertia phase of an upshift of the transmission is started during a lockup clutch engagement operation, a following command oil pressure to be used during a following lockup clutch engagement operation is learned on the basis of a slip rotation speed, which is a rotation speed difference between an input side rotation speed of the torque converter and an output side rotation speed of the torque converter, at or after a start point of the inertia phase.

Abstract: When an upshift is performed while a traveling condition of a vehicle corresponds to a driving condition or a downshift is performed while the traveling condition of the vehicle corresponds to a coasting condition, a second target slip amount is set as a target slip amount for a period extending from the start of gear ratio variation following issuance of a gear position change start command to completion of the gear ratio change, and when a downshift is performed in the driving condition or an upshift is performed in the coasting condition, a first target slip amount is set as the target slip amount for a period extending from issuance of the shift command to completion of the shift.

Abstract: An engaging-force control apparatus for a friction-engagement element controls a slip rotational speed between an input-side rotational speed and an output-side rotational speed of the friction-engagement element by increasing or decreasing an engaging force of the friction-engagement element. The engaging-force control apparatus includes an engaging-force feedback control section configured to control the engaging force of the friction-engagement element to bring the slip rotational speed of the friction-engagement element closer to 0 by way of feedback control; and an engaging-force restricting section configured to restrict the engaging force of the friction-engagement element to prevent the engaging force from exceeding a minimum engaging-force value necessary to maintain the slip rotational speed at 0.

Abstract: This invention is a lock-up clutch control device for an automatic transmission, comprising lock-up clutch control means for controlling a slip amount of the lock-up clutch to a target slip amount. When a variation rate in a required load of an engine reaches or exceeds a predetermined threshold, the target slip amount is increased at a predetermined increase rate, whereupon the target slip amount, having been increased by target slip amount increasing means, is reduced at a predetermined reduction rate. At this time, the predetermined reduction rate is set to decrease as an operating condition when the variation rate of the required load reaches or exceeds the predetermined threshold approaches an operating condition in which an increase rate of a rotation speed on the automatic transmission side of a torque converter relative to an increase in the required load is low.

Abstract: A lock-up clutch control device which controls a lock-up clutch (6) provided in a torque converter (5) interposed between an engine (3) and a transmission (4) used with a vehicle, is disclosed. The lock-up clutch control device has a differential pressure generating device (7,8), a vehicle speed sensor (13), a throttle valve opening sensor (14), an transmission input shaft rotation speed sensor (16), engine torque detection means (2), and a controller (1). The controller (1) determines, based on the detected vehicle speed (VSP) and the detected throttle valve opening (TVO), whether or not a control region of a torque converter is a converter region wherein control is performed to disengage the lock-up clutch.

Abstract: A controller (5) performs open loop control of the engaging state of a lockup clutch (2) through a switching mechanism (3, 4) when a torque converter (1) transitions from a first state in which the lockup clutch (2) is disengaged to a second state in which the lockup clutch (2) is at least partially engaged. At this time, the controller (5) estimates the engine torque at the time when open loop control ends, estimates a necessary lockup capacity required for the converter (1) at the time when open loop control ends, based on the estimated engine torque, and controls the engaging state of the lockup clutch (2) through the switching mechanism (3, 4) to make the lockup capacity at the time when open loop control ends become the necessary lockup capacity.

Abstract: A lock-up clutch control device which controls a lock-up clutch (6) provided in a torque converter (5) interposed between an engine (3) and a transmission (4) used with a vehicle, is disclosed. The lock-up clutch control device has a differential pressure generating device (7,8), a vehicle speed sensor (13), a throttle valve opening sensor (14), an transmission input shaft rotation speed sensor (16), engine torque detection means (2), and a controller (1). The controller (1) determines, based on the detected vehicle speed (VSP) and the detected throttle valve opening (TVO), whether or not a control region of a torque converter is a converter region wherein control is performed to disengage the lock-up clutch.

Abstract: A shift pressure control apparatus for an automatic transmission is arranged to hold the shift pressure during a shift at a starting input-torque-dependent pressure determined from a transmission input torque at a start of a shift. A controller is configured to monitor an operating parameter representing an engine load of an engine, to detect an engine load change. When the engine load change is detected, the controller modifies the shift pressure to a modified pressure determined by modifying the starting input-torque-dependent pressure with a difference between a second engine-load-dependent pressure determined from the engine load after the engine load change and a first engine-load-dependent pressure determined from the engine load at the start of the shift.