VEHICLE WITH AN ENGINE AND AN AUTOMATIC TRANSMISSION

• US 20100022350A1
• Filed: 06/26/2009
• Published: 01/28/2010
• Est. Priority Date: 06/27/2008
• Status: Abandoned Application

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: CHAUDRON, Jean-Baptiste, GUYOT, Nicolas, WRIGHT, David, SANDER, Sebastien
• Application Number:
  US12/492,335
• Publication Number:
  US 20100022350A1
• Time in Patent Office: Days
• US Class Current: 477/121
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift

Abstract

A vehicle is provided with an engine and an automatic transmission and a process for controlling an automatic transmission. In order to reduce the reaction time after a slight tip in of less than 50% during a closed throttle downshift, it is proposed to send a positive torque request to the engine at the beginning of the tip in on the accelerator. This is based on the idea to use a transmission positive torque request to force the engine to override its tip in torque management functions and provide a faster torque increase. This positive torque request at the beginning of the tip in improves considerably the engine response time. The vehicle reaction time when tipping in during a closed throttle downshift has been reduced by about 250 ms or 30%.

Claims

1. A vehicle, comprising:

an engine; and

means for sending a positive torque request to the engine at a beginning of a tip on an accelerator.

2. The vehicle of claim 1, wherein the positive torque request is about 80 to 100 Nm.

3. A process for controlling an automatic transmission in a vehicle with an engine, comprising the step of sending a positive torque request to the engine at the beginning of a tip on an accelerator.

4. The process of claim 3, wherein sending the positive torque request is conducted only if a driver tips on the accelerator and a foot is maintained on the accelerator, an actual engine torque is lower than the positive torque request, or a transmission and an engine oil temperature is between about 0°

C. and about 130°

C.

5. The process of claim 3, wherein a driver demand level is used for the positive torque request.

6. The process of claim 3, wherein a maximum calibration value set is used for the positive torque request to avoid flares.

7. The process of claim 3, wherein a pressure offset is used accelerate filling a clutch.