Vehicle control apparatus and method

• US 20070197343A1
• Filed: 01/18/2007
• Published: 08/23/2007
• Est. Priority Date: 02/22/2006
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Sakamoto, Hiroyuki, Ibamoto, Masahiko, Kuroiwa, Hiroshi
• Granted Patent: US 7,628,720 B2
• Time in Patent Office: Days
• US Class Current: 477/70
• CPC Class Codes: F16H 2061/0433 by torque supply with an electric motor
• CPC Class Codes: F16H 2306/46 Uncoupling of current gear
• CPC Class Codes: F16H 3/126 using an electric drive
• CPC Class Codes: F16H 61/0403 Synchronisation before shifting

Abstract

A transmission system in a vehicle using a motor to transmit power can assist acceleration by generating auxiliary engine power during acceleration in addition to gear changing by the motor. In this system, however, the acceleration assistance is interrupted in gear changing since the motor power is used to drive a vehicle when a gear-shifting is made. In a conventional geared transmission mechanism, the torque decreases after a gear change for up-shifting is made. If acceleration assistance is added, the torque reduction in shifting becomes greater and gives uncomfortable shocks and feelings to the driver.

Torque transition is conducted along a torque transmission route of dog clutch, second intermediate shaft, motor, first intermediate shaft, and gear position of first intermediate shaft before shifting.

Claims

1. A vehicle control apparatus which transmits torque from a vehicle-driving power plant to first and second intermediate shafts respectively via first and second clutches, transfers torque from the two intermediate shafts to the output shaft via transmission gears and transmission clutches that are respectively provided on the transmission gears and transferring torque from a shifting position of the first intermediate shaft to a shifting position of the second intermediate shaft by a motor which is differentially connected between the intermediate shafts;

wherein

the torque transition is conducted along a torque transmission route of the second input clutch, the second intermediate shaft, the motor, the first intermediate shaft, and a gear position of the first intermediate shaft before shifting.

2. The vehicle control apparatus of claim 1, wherein

the above torque transition is conducted when a shifting command is submitted while torque of the motor is applied to the output shaft by the second intermediate shaft before shifting.

3. The vehicle control apparatus of claim 1, wherein,

when a shifting command is submitted while torque is transmitted from a vehicle-driving power plant to the output shaft via the first intermediate shaft, the transmission gear of the first intermediate shaft, and the shifting clutch while the first input clutch is engaged and the second input clutch is disengaged,

the control apparatus disengages the shifting clutch and engages the input clutch of the second intermediate shaft to form the above torque transmission route of the vehicle-driving power plant, the second input shaft, the motor, the first input shaft, the transmission gear on the first intermediate shaft, and the shifting clutch, disengages the input clutch, engages the shifting clutch of the transmission gear on the second intermediate shaft, and disengages the shifting clutch of the transmission gear on the first intermediate shaft.

4. The vehicle control apparatus of claim 1, wherein the vehicle control apparatus controls the transmission mechanism while the input clutch of the first intermediate shaft is engaged

5. The vehicle control apparatus of claim 1, wherein the vehicle control apparatus engages the two input clutches simultaneously when starting transmission.

6. The vehicle control apparatus of claim 3, wherein the vehicle control apparatus outputs a torque equivalent to the torque of the vehicle-driving power plant from the motor and disengages the input clutch.

7. The vehicle control apparatus of claim 6, wherein, when outputting a torque equivalent to the torque of the vehicle-driving power plant from the motor at the start of transmission, the vehicle control apparatus applies a little thrust to disengage the input clutch, gradually increases the torque from the motor, and thus disengages the input clutch.

8. The vehicle control apparatus of claim 3, wherein the vehicle control apparatus changes or vibrates so that the difference between the torque from the motor and the torque of the vehicle-driving power plant may be inverted when disengaging the input clutch.

9. The vehicle control apparatus of claim 3, wherein the vehicle control apparatus increases the rate of change of the torque from the motor to disengage the input clutch when the state of charge of the battery unit of the motor is low, when the temperature of the motor is high, or when the shifting duration must be shortened.

10. The vehicle control apparatus of claim 3, wherein the vehicle control apparatus increases the range of change in torque vibration to disengage the input clutch when the state of charge of the battery unit of the motor is low, when the temperature of the motor is high, or when the shifting duration must be shortened.

11. The vehicle control apparatus of claim 3, wherein the vehicle control apparatus increases the gear-disengaging thrust to disengage the input clutch when the difference between the torque from the motor and the torque of the vehicle-driving power plant is small and the input clutch is not disengaged for a preset time period.

12. The vehicle control apparatus of claim 3, wherein the vehicle control apparatus controls the torque from the motor to increase the speed positively or negatively while one of the input clutches is disengaged.

13. The vehicle control apparatus of claim 3, wherein the torque from the motor is further increased during shifting to improve the power performance of the vehicle.

14. The vehicle control apparatus of claim 3, wherein the output of the motor is determined according to the torque of the vehicle-driving power plant.

15. The vehicle control apparatus of claim 3, wherein the output of the motor is determined according to the target driving torque of the vehicle.

16. The vehicle control apparatus of claim 3, wherein the vehicle control apparatus is equipped with a shift lever freely operated by a driver for up- or down-shifting and works to decrease the torque of the vehicle-driving power plant and increase the torque of the motor when the shift lever is up-shifted or to increase the torque of the vehicle-driving power plant and decrease the torque of the motor when the shift lever is down-shifted.

17. The vehicle control apparatus of claim 3, wherein the vehicle control apparatus holds the torque output from the motor without disengaging the previous shifting clutch at the end of shifting.

18. The vehicle control apparatus of claim 17, wherein the vehicle control apparatus gradually decreases the torque output from the motor without disengaging the previous shifting clutch at the end of shifting.

19. The vehicle control apparatus of claim 1, wherein the vehicle control apparatus switches between the above torque transition and the ordinary torque transition according to vehicle status.

20. A vehicle controlling method comprising the steps of transmitting torque from a vehicle-driving power plant to first and second intermediate shafts respectively via first and second clutches, transferring torque from the two intermediate shafts to the output shaft via transmission gears and transmission clutches that are respectively provided on the transmission gears, and transferring torque from a shifting position of the first intermediate shaft to a shifting position of the second intermediate shaft by a motor which is differentially connected between the intermediate shafts;

wherein

the torque transition is conducted along a torque transmission route of the second input clutch, the second intermediate shaft, the motor, the first intermediate shaft, and a gear position of the first intermediate shaft before shifting.