Method for Operating an Automatic or Semi-Automatic Manual Transmission of a Heavy Vehicle When in Idle-Driving Mode

• US 20080248920A1
• Filed: 09/06/2006
• Published: 10/09/2008
• Est. Priority Date: 09/07/2005
• Status: Active Grant

• Current Assignee: Volvo Lastvagnar AB (Volvo AB)
• Original Assignee: Volvo Lastvagnar AB (Volvo AB)
• Inventors: Berglund, Sixten, Eriksson, Anders
• Granted Patent: US 8,235,864 B2
• Time in Patent Office: Days
• US Class Current: 477/74
• CPC Class Codes: F16H 2061/202 Active creep control for slow driving, e.g. by controlling clutch slip
• CPC Class Codes: F16H 2312/06 Creeping
• CPC Class Codes: F16H 59/22 Idle position
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals

Abstract

A method for operating a semi-automatic or automatic manual transmission of a heavy truck when driving at idle speed. The method includes supplying fuel to the engine of the heavy truck at a rate that facilitates engine-idle operation. In another step, the method engages the automatic or semi-automatic transmission in a gear higher than the starting gear of the transmission and permits the truck to operate at a first substantially uniform driving velocity under engine-idle power. Depending upon traffic and environmental requirements which require a slower or higher speed, the driver downshifts or upshifts the semi-automatic or automatic transmission by depressing a control pedal of the truck and then drives the truck at a second substantially uniform driving velocity under engine-idle power. For a downshift, the second substantially uniform driving velocity is less than the first substantially uniform driving velocity. For an upshift, the second substantially uniform driving velocity is greater than the first substantially uniform driving velocity.

Claims

1. A method for operating an automatic or semi-automatic manual transmission of a heavy vehicle when in idle-driving mode, the method comprising:

supplying fuel to an engine of the heavy vehicle at a rate that facilitates engine-idle operation;

engaging the automatic transmission in a gear higher than the starting gear of the transmission and permitting the heavy vehicle to operate at a first substantially uniform driving velocity under engine-idle power;

downshifting the automatic transmission by depressing a control pedal of the heavy vehicle and then driving the heavy vehicle at a second substantially uniform driving velocity under engine-idle power, wherein the second substantially uniform driving velocity is less than the first substantially uniform driving velocity.

2. The method as recited in claim 1, wherein the control pedal is an accelerator pedal of the heavy vehicle.

3. The method as recited in claim 1, wherein the control pedal is a brake pedal of the heavy vehicles.

4. The method as recited in claim 1, wherein the control pedal is a service brake pedal of the heavy vehicle.

5. The method as recited in claim 4, wherein the downshifting of the transmission is actuated using bump-depression of the service brake pedal.

6. The method as recited in claim 5, wherein the bump-depression of the service brake pedal is less than one quarter of the total range of motion of the service brake pedal.

7. The method as recited in claim 5, wherein the bump-depression of the service brake pedal is for a period of time less than 2 seconds.

8. The method as recited in claim 5, wherein the bump-depression of the service brake pedal is detected by a brake light sensor.

9. The method as recited in claim 5, wherein the bump-depression of the service brake pedal does not engage vehicle service brakes.

10. The method as recited in claim 5, wherein the bump-depression of the service brake pedal is detected by a dedicated sensor.

11. The method as recited in claim 10, wherein the service brake pedal is maintained at a position that continues to trigger the dedicated sensor.

12. The method as recited in claim 11, wherein the transmission is caused to continually downshift until the transmission reaches a lowest gear.

13. The method as recited in claim 11, wherein the transmission is caused to continually downshift until the transmission reaches a lowest gear and then disengages an automated clutch.

14. A method for operating an automatic or semi-automatic transmission of a heavy vehicle in idle-driving mode, the method comprising:

engaging the automated or semi-automated transmission of a heavy vehicle in a gear greater than a starting gear of the transmission, wherein the gear permits the heavy vehicle to travel at substantially uniform velocity under engine-idle power;

the method characterized in downshifting the automatic transmission in response to a bump-depression of a service brake pedal.

15. The method as recited in claim 14, wherein the bump-depression of the service brake pedal causes the transmission to downshift one gear.

16. The method as recited in claim 14, wherein multiple bump-depressions of the service brake pedal downshifts the transmission according to occurrences of the bump-depressions.

17. The method as recited in claim 14, wherein the downshifting of the automatic transmission operates the heavy vehicle at an engine-idle speed that is lower than a previous engine-idle speed.

18. A method for operating an automatic or semi-automatic transmission of a heavy vehicle in idle-driving mode, the method comprising:

engaging the automated or semi-automated transmission of a heavy vehicle in an idle drive gear, which is greater than a starting gear of the transmission;

fueling engine of the heavy vehicle at a rate such that the engine operates at idle speed;

the method characterized in downshifting the automatic transmission in response to a bump-depression of a brake pedal.

19. A method for operating an automatic or semi-automatic manual transmission of a heavy vehicle when in idle-driving mode, the method comprising:

supplying fuel to an engine of the heavy vehicle at a rate that facilitates engine-idle operation;

engaging the automatic transmission in a gear higher than the starting gear of the transmission and permitting the heavy vehicle to operate at a first substantially uniform driving velocity under engine-idle power;

the method characterized in upshifting the automatic transmission by depressing a control pedal of the heavy vehicle and then driving the heavy vehicle at a second substantially uniform driving velocity under engine-idle power, wherein the second substantially uniform driving velocity is greater than the first substantially uniform driving velocity.

20. The method as recited in claim 19, wherein the control pedal is an accelerator pedal of the heavy vehicle.