Vehicle lock-up clutch control device

Patent metadata

Field	Value
Publication number	US-9856976-B2
Application number	US-201415327201-A
Country	US
Kind code	B2
Filing date	Sep 3, 2014
Priority date	Sep 3, 2014
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

A lock-up clutch control device is provided for a vehicle having a torque converter with a lock-up clutch disposed between an engine and a continuously variable transmission such that the occurrence of shocks during lock-up engagement is suppressed. The vehicle lock-up clutch control device is provided with a control unit that controls the lock-up capacity based on an engine torque signal when engaging the lock-up clutch. The control unit uses a predictive engine torque as the engine torque signal for use in the lock-up capacity control. The predictive engine torque is calculated based on an engine torque air response delay and a hydraulic response delay in the lock-up differential pressure and is faster in response than the actual engine torque.

First claim

The invention claimed is:

1. A vehicle lock-up clutch control device for a vehicle provided with a torque converter having a lock-up clutch between an engine and a transmission, the vehicle lock-up clutch control device comprising:
a control unit programmed to include
a lock-up capacity control that controls a lock-up capacity based on an engine torque signal, when engaging the lock-up clutch,
the lock-up capacity control using a predictive engine torque as the engine torque signal, the predictive engine torque being calculated based on an engine torque air response delay and a hydraulic response delay in a lock-up differential pressure and being faster in response than actual engine torque, and
the lock-up capacity control using time obtained by subtracting a lock-up differential pressure hydraulic response delay time from an engine torque air response delay time as a dead time, and calculates the predictive engine torque from an engine torque command value and the dead time.

2. The vehicle lock-up clutch control device according to claim 1 , wherein
the control unit is further programmed such that the lock-up capacity control calculates the engine torque air response delay time according to an engine rotational speed.

3. The vehicle lock-up clutch control device according to claim 2 , wherein
the control unit is further programmed such that the lock-up capacity control calculates the lock-up differential pressure hydraulic response delay time according to the hydraulic oil temperature of the lock-up clutch.

4. The vehicle lock-up clutch control device according to claim 2 , wherein
the control unit is further programmed such that the lock-up capacity control:
sets a target slip rotational speed characteristic of a lock-up engagement transition period to a characteristic with which the target slip rotational speed increases with a gradual gradient compared to a racing gradient of an engine rotational speed and then decreases with a gradual gradient from a raised target slip rotational speed toward a zero slip rotational speed;
calculates a converter capacity based on the target slip rotational speed; and
calculates a lock-up capacity command value by subtracting the converter capacity from the predictive engine torque.

5. The vehicle lock-up clutch control device according to claim 1 , wherein
the control unit is further programmed such that the lock-up capacity control calculates the lock-up differential pressure hydraulic response delay time according to the hydraulic oil temperature of the lock-up clutch.

6. The vehicle lock-up clutch control device according to claim 5 , wherein
the control unit is further programmed such that the lock-up capacity control:
sets a target slip rotational speed characteristic of a lock-up engagement transition period to a characteristic with which the target slip rotational speed increases with a gradual gradient compared to a racing gradient of an engine rotational speed and then decreases with a gradual gradient from a raised target slip rotational speed toward a zero slip rotational speed;
calculates a converter capacity based on the target slip rotational speed; and
calculates a lock-up capacity command value by subtracting the converter capacity from the predictive engine torque.

7. The vehicle lock-up clutch control device according to claim 1 , wherein
the control unit is further programmed such that the lock-up capacity control:
sets a target slip rotational speed characteristic of a lock-up engagement transition period to a characteristic with which the target slip rotational speed increases with a gradual gradient compared to a racing gradient of an engine rotational speed and then decreases with a gradual gradient from a raised target slip rotational speed toward a zero slip rotational speed;
calculates a converter capacity based on the target slip rotational speed; and
calculates a lock-up capacity command value by subtracting the converter capacity from the predictive engine torque.

Assignees

• Nissan Motor

Inventors

• Tohta Yuzuru

Classifications

• F16H59/18

  dependent on the position of the accelerator pedal · CPC title

• F16D48/06

  Control by electric or electronic means, e.g. of fluid pressure · CPC title

• F16H2061/145

  for controlling slip, e.g. approaching target slip value · CPC title

• F16H61/143 Primary

  using electric control means · CPC title

• F16D2500/3065

  Torque of the engine · CPC title