Acceleration launch strategy for an electromechanical automatic transmission

• US 7,090,617 B2
• Filed: 08/18/2004
• Issued: 08/15/2006
• Est. Priority Date: 08/18/2004
• Status: Active Grant

• Current Assignee: FCA US LLC (Stellantis NV)
• Original Assignee: Daimler Chrysler Corporation (Mercedes-Benz Group AG)
• Inventors: Bassler, Juergen
• Primary Examiner(s): HO, HA DINH
• Application Number:
  US10/921,022
• Publication Number:
  US 20060040788A1
• Time in Patent Office: 727 Days
• Field of Search: 477/170, 477/171, 477/173, 477/176, 477/180
• US Class Current: 477/180
• CPC Class Codes: F16D 2500/10412 Transmission line of a vehicle
• CPC Class Codes: F16D 2500/1085 Automatic transmission
• CPC Class Codes: F16D 2500/30404 Clutch temperature
• CPC Class Codes: F16D 2500/30415 Speed of the input shaft
• CPC Class Codes: F16D 2500/3067 Speed of the engine
• CPC Class Codes: F16D 2500/30825 Speed of the output shaft
• CPC Class Codes: F16D 2500/31433 Brake pedal position threshold, e.g. switch
• CPC Class Codes: F16D 2500/3144 Accelerator pedal position
• CPC Class Codes: F16D 2500/5045 Control of engine at idle, i.e. controlling engine idle conditions, e.g. idling speed
• CPC Class Codes: F16D 2500/5106 Overheat protection
• CPC Class Codes: F16D 2500/7041 Position
• CPC Class Codes: F16D 2500/70488 Selection of the gear ratio
• CPC Class Codes: F16D 48/062 of a clutch system with a plurality of fluid actuated clutches
• CPC Class Codes: F16D 48/064 Control of electrically or electromagnetically actuated clutches F16D48/062, F16D48/068 take precedence
• CPC Class Codes: F16D 48/08 Regulating clutch take-up on starting
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A method for launching an automatic vehicle transmission utilizing dual clutches in place of a torque converter avoids clutch overheating, sudden launch or roll-back by placing a clutch in a slip mode only after the vehicle'"'"'s brakes have been actuated and fully disengaging the clutch upon over-heating detection. When launch is initiated, a first gear engaged and the brakes are released, the associated clutch is fully engaged to avoid overheating.

Claims

1. A method for launching an automatic vehicle transmission utilizing dual clutches in place of a torque converter, the method comprising:

recognizing a vehicle transmission launch request;

engaging a first gear;

monitoring an activation condition of a vehicle brake;

when the vehicle brake is released, fully engaging a clutch associated with the first gear enabling the vehicle to accelerate to an idling speed;

partially disengaging the clutch to a slip condition whenever the brake is activated; and

fully disengaging the clutch from the slip condition whenever clutch temperature exceeds a predetermined overheating threshold.

2. The method of claim 1 wherein fully engaging the clutch enables the vehicle to more rapidly accelerate to idling speed whenever a temperature of the clutch is above a predetermined level.

3. The method of claim 1 wherein the vehicle accelerates linearly to the idling speed.

4. The method of claim 2 wherein the vehicle accelerates linearly to the idling speed.