Method and drive train for performing a gear shift in a vehicle

• US 8,608,617 B2
• Filed: 05/09/2008
• Issued: 12/17/2013
• Est. Priority Date: 05/09/2008
• Status: Active Grant

• Current Assignee: Volvo Lastvagnar AB (Volvo AB)
• Original Assignee: Volvo Lastvagnar AB (Volvo AB)
• Inventors: Stervik, Hans
• Primary Examiner(s): KNIGHT, DEREK DOUGLAS
• Application Number:
  US12/936,519
• Publication Number:
  US 20110034296A1
• Time in Patent Office: 2,048 Days
• Field of Search: 477/3, 477/5, 477/32
• US Class Current: 477/32
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/30 Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2710/0616 Position of fuel or air injector
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: B60Y 2300/72 Facilitate disengaging of gears, e.g. by inducing a torque reversal
• CPC Class Codes: B60Y 2400/435 Supercharger or turbochargers
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility

Abstract

A method and drive train for performing a gearshift from a first gear to a second gear in a vehicle provided with a manual or automated manual transmission is provided. A drivetrain incorporating the automated manual transmission includes an engine, connected via a clutch to an electric motor/generator, which in turn is connected to the manual or automated manual transmission and wherein the electric motor/generator is connected to a battery, other energy storing devices or a heating element. The method includes controlling the motor/generator to absorb a torque equalling the torque provided by the engine, such that the manual or automated manual transmission transfers a only minor, or no, torque, disengaging the first gear, controlling the torques absorbed by the motor/generator and provided by the engine such that an engine speed correlates to the engine speed necessary for propelling the vehicle at the second gear, and engaging the second gear.

Claims

1. Method for performing a gearshift in a vehicle provided with a manual or automated manual transmission, wherein a drivetrain incorporating the automated manual transmission comprises a combustion engine connected via a clutch to the manual or automated manual transmission, and an electric motor/generator drivingly connected to the drive train and arranged between the clutch and the transmission or between the combustion engine and the clutch, and where the electric motor/generator is further connected to an energy storing means and/or an energy consumer, the method comprising:

i. controlling the motor/generator to absorb a torque equalling or almost equalling the torque provided by the combustion engine, such that the manual or automated manual transmission transfers a only minor, or no, torque,

ii. disengaging a gear with a first gear ratio,

iii. controlling the torques absorbed by the motor/generator and provided by the combustion engine such that a rotational speed of the combustion engine correlates or almost correlates to a rotational speed necessary for propelling the vehicle at a new selected gear with a second gear ratio, and

iv. engaging the new selected gear,

wherein the engine and the motor/generator are controlled in such a way as to avoid a super charger of the combustion engine being unloaded before, during and after the gearshift.

2. The method according to claim 1, comprising delaying an injection timing or ignition timing for the engine during the prior steps i. to iv.

3. The method according to claim 1, wherein the engine and the motor/generator are controlled in such a way as to adapt a turbo pressure of the super charger of the combustion engine during the gearshift to the new selected gear that will be engaged.

4. The method according to claim 1, wherein the engine and the motor/generator are controlled in such a way as to mainly maintain a turbo pressure of the super charger of the combustion engine before, during and after the gearshift.

5. The drive train as defined in claim 1 further comprising a control unit for controlling at least the engine and the electric motor/generator, wherein the control unit is arranged to perform the steps of claim 1.

6. The drive train as in claim 5, wherein the motor/generator is arranged to transfer electrical energy, produced by the motor/generator, to the energy storing means and/or an energy consumer.

7. The drive train as in claim 6, wherein the energy storing means is at least one of a battery or a capacitor.

8. The drive train as in claim 6, wherein the energy consumer is a heating element.

9. The drive train as in claim 5, wherein the drive train is a parallel hybrid where propulsive power from the combustion engine is arranged to reach driven wheels of the vehicle via one way through the clutch, the motor/generator and one selected gear ratio of several in the transmission.