Method and system for operating a vehicle powertrain

Patent metadata

Field	Value
Publication number	US-9499170-B2
Application number	US-201414543424-A
Country	US
Kind code	B2
Filing date	Nov 17, 2014
Priority date	Jul 25, 2012
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

A system and method for operating a vehicle powertrain are described. In one example, a torque converter that has a variable K factor is adjusted to improve vehicle operation. The system and method may improve vehicle launch and vehicle operation at lower vehicle speeds.

First claim

The invention claimed is:

1. A method for operating a vehicle powertrain, comprising:
adjusting a K factor of a torque converter in response to a difference between a desired vehicle creep speed and an actual vehicle creep speed and absent a driver input demand torque while a transmission is operated in first gear; and
increasing engine speed and engine air flow in response to an engine temperature less than a threshold temperature.

2. The method of claim 1 , where the K factor is adjusted responsive to vehicle movement in a reverse direction.

3. The method of claim 1 , wherein the powertrain includes an engine, the method further comprising direct injecting fuel to the engine.

4. The method of claim 1 , where adjusting the K factor includes increasing the K factor.

5. A method for operating a vehicle powertrain, comprising:
adjusting a K factor of a torque converter in response to a difference between a desired boost pressure and an actual boost pressure, where the K factor is adjusted via adjusting an axial position of a turbine relative to an impeller.

6. The method of claim 5 , where the actual boost pressure is provide via a turbocharger, and further comprising increasing the K factor in response to an increasing engine torque demand when adjusting the K factor will increase engine output torque.

7. The method of claim 5 , further comprising increasing the K factor in response to an indication of engine knock.

8. The method of claim 5 , further comprising reducing the K factor in response to an engine temperature greater than a threshold temperature.

9. The method of claim 5 , where the K factor is increased in response to a desired boost pressure being greater than an actual boost pressure.

10. The method of claim 5 , further comprising increasing engine speed.

11. The method of claim 7 , further comprising adjusting the K factor in response to a vehicle speed condition.

Assignees

• Ford Global Tech Llc

Inventors

• Cunningham Ralph Wayne

Classifications

• F02B37/12

  Control of the pumps · CPC title

• F16H61/54

  by means of axially-shiftable blade runners · CPC title

• Y02T10/144

  Cross-Sectional Technologies · mapped topic

• B60W2710/105

  Output torque · CPC title

• F02D13/0269

  Controlling the valves to perform a Miller-Atkinson cycle · CPC title