Method for starting a combustion engine in a hybrid driveline

• US 10,384,671 B2
• Filed: 03/17/2015
• Issued: 08/20/2019
• Est. Priority Date: 03/20/2014
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: Bjorkman, Mathias, Pettersson, Niklas, Lindstrom, Johan, Bergquist, Mikael
• Primary Examiner(s): Patel, Shardul D
• Application Number:
  US15/124,845
• Publication Number:
  US 20170015310A1
• Time in Patent Office: 1,617 Days
• Field of Search: 701 22, 701 54, 477 3, 477 5, 123 2, 903930, 903945, 180 65265, 475 5, 475209, 290 32
• CPC Class Codes: B60K 2006/266 with two coaxial motors or generators
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/44 Series-parallel type
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• 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 10/111 with separate change-speed gear trains arranged in series
• 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 20/40 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 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: B60Y 2200/92 Hybrid vehicles
• CPC Class Codes: B60Y 2300/19 Improvement of gear change, e.g. synchronisation or smoothing gear shift
• CPC Class Codes: B60Y 2300/42 Control of clutches
• CPC Class Codes: B60Y 2300/70 Control of gearings
• CPC Class Codes: F02N 11/006 : using a plurality of electric motors
• CPC Class Codes: F02N 15/046 : of the planetary type
• CPC Class Codes: F02N 2300/104 : Control of the starter motor torque
• CPC Class Codes: F16H 2003/008 : comprising means for selectively driving countershafts
• CPC Class Codes: F16H 2200/2007 : with two sets of orbital gears
• CPC Class Codes: F16H 3/728 : with means to change ratio in the mechanical gearing
• CPC Class Codes: F16H 37/042 : change gear transmissions in group arrangement
• CPC Class Codes: F16H 37/046 : with an additional planetary gear train, e.g. creep gear, overdrive
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y10S 903/911 : with two or more gear sets
• CPC Class Codes: Y10S 903/93 : Conjoint control of different elements
• CPC Class Codes: Y10S 903/945 : Characterized by control of gearing, e.g. control of transmission ratio
• CPC Class Codes: Y10S 903/946 : Characterized by control of driveline clutch

Abstract

A method is provided to start a combustion engine in a hybrid powertrain, comprising a gearbox with input and output shafts; a first planetary gear, connected to the input shaft and a first main shaft; a second planetary gear connected to the first planetary gear and a second main shaft; first and second electrical machines respectively connected to the first and second planetary gears; one gear pair connected with the first main shaft, and therefore with the first planetary gear and the output shaft; and one gear pair connected with the second main shaft. The method comprises: a) connecting an output shaft of the combustion engine with the input shaft of the gearbox, via a coupling device arranged between the output shaft and the input shaft; and b) controlling the first and second electrical machines to start the combustion engine.

Claims

1. A method to start a combustion engine in a hybrid powertrain, comprising a gearbox with an input shaft and an output shaft;

a first planetary gear, connected to the input shaft and a first main shaft;

a second planetary gear, connected to the first planetary gear and a second main shaft;

a first electrical machine, connected to the first planetary gear;

a second electrical machine, connected to the second planetary gear;

at least one gear pair, connected with the first main shaft, and therefore with the first planetary gear and the output shaft;

at least one gear pair, connected with the second main shaft, and therefore with the second planetary gear and the output shaft; and

a coupling device arranged between an output shaft of the combustion engine and the input shaft of the gear-box, wherein the input shaft is connected with a first planetary wheel carrier, arranged in the first planetary gear, and wherein the second main shaft is directly connected with a second planetary wheel carrier, arranged in the second planetary gear, said method comprising the steps;

a) connecting the output shaft of the combustion engine with the input shaft of the gearbox, via the coupling device, wherein connecting the output shaft of the combustion engine with the input shaft of the gearbox comprises controlling the first electrical machine such that the input shaft of the gearbox stops, and controlling the second electrical machine such that a desired torque in the output shaft is achieved; and

b) controlling the first and the second electrical machine in such a way that the combustion engine is started, by balancing the desired torque in the output shaft and a required toque to start the combustion engine, for a selected gear.

2. The method according to claim 1, wherein in step a) controlling the first electrical machine in such a way that a synchronous rotational speed is achieved between the output shaft of the combustion engine and the input shaft of the gearbox, following which the coupling device is controlled in such a way that the output shaft and the input shaft are connected.

3. The method according to claim 1, further comprising before step a):

c) disconnecting the first planetary wheel carrier, arranged in the first planetary gear, and the first sun wheel, from each other.

4. The method according to claim 3, wherein in step c) controlling the first and/or the second electrical machine in such a way that torque balance is achieved in the first planetary gear, following which a first coupling device is shifted, so that the first planetary wheel carrier and a first sun wheel are disconnected from each other.

5. The method according to claim 1, further comprising before step a):

d) disconnecting the second planetary wheel carrier, arranged in the second planetary gear, and the second sun wheel, from each other.

6. The method according to claim 5, wherein, in step d) controlling the first and/or the second electrical machine in such a way that torque balance is achieved in the second planetary gear, following which a second coupling device is shifted, so that the second planetary wheel carrier and a second sun wheel are disconnected from each other.

7. The method according to claim 5, further comprising before step d):

c) disconnecting the first planetary wheel carrier, arranged in the first planetary gear, and the first sun wheel, from each other; and

subsequently

e) connecting a gear pair, which is connected with the second planetary gear, to a countershaft, which is connected with the output shaft.

8. The method according to claim 7, wherein in step e) controlling the second electrical machine, in such a way that a synchronous rotational speed is achieved between the gear pair connected with the second planetary gear and the countershaft.

9. The method according to claim 1, further comprising:

before step a);

d) disconnecting a second planetary wheel carrier, arranged in the second planetary gear, and a second sun wheel, from each other; and

after step b);

f) connecting a gear pair, which is connected with the first planetary gear to a countershaft, which is connected with the output shaft.

10. The method according to claim 9, wherein in step f) controlling the first electrical machine in such a way that a synchronous rotational speed is achieved between the gear pair connected with the first planetary gear and the countershaft.

11. The method according to claim 1, wherein the desired torque is achieved in the output shaft via a fifth gear pair, arranged between the output shaft and the countershaft.

12. A vehicle comprising a hybrid drive line, said hybrid drive line comprising:

a gearbox with an input shaft and an output shaft;

a first planetary gear, connected to the input shaft and a first main shaft;

a second planetary gear, connected to the first planetary gear and a second main shaft;

a first electrical machine, connected to the first planetary gear;

a second electrical machine, connected to the second planetary gear;

at least one gear pair, connected with the first main shaft, and therefore with the first planetary gear and the output shaft;

at least one gear pair, connected with the second main shaft, and therefore with the second planetary gear and the output shaft;

a coupling device arranged between an output shaft of the combustion engine and the input shaft of the gear-box, wherein the combustion engine is connected with a first planetary wheel carrier, arranged in the first planetary gear via the input shaft, and wherein the second main shaft is directly connected with a second planetary wheel carrier, arranged in the second planetary gear; and

an electric control device configured to;

a) connect the output shaft of the combustion engine with the input shaft of the gearbox, via the coupling device, wherein connecting the output shaft of the combustion engine with the input shaft of the gearbox comprises controlling the first electrical machine such that the input shaft of the gearbox stops, and controlling the second electrical machine such that a desired torque in the output shaft is achieved; and

b) control the first and the second electrical machine in such a way that the combustion engine is started, by balancing the desired torque in the output shaft and a required toque to start the combustion engine, for a selected gear.

13. A computer program product comprising computer program code stored on a non-transitory computer readable medium readable by a computer, said computer program product used to start a combustion engine in a hybrid powertrain, comprising a gearbox with an input shaft and an output shaft;

a first planetary gear, connected to the input shaft and a first main shaft;

a second planetary gear, connected to the first planetary gear and a second main shaft;

a first electrical machine, connected to the first planetary gear;

a second electrical machine, connected to the second planetary gear;

at least one gear pair, connected with the first main shaft, and therefore with the first planetary gear and the output shaft;

at least one gear pair, connected with the second main shaft, and therefore with the second planetary gear and the output shaft; and

a coupling device arranged between an output shaft of the combustion engine and the input shaft of the gear-box, wherein the input shaft is connected with a first planetary wheel carrier, arranged in the first planetary gear, and wherein the second main shaft is directly connected with a second planetary wheel carrier, arranged in the second planetary gear,

said computer program code comprising computer instructions to cause one or more computer processors to perform the operations of;

a) connecting the output shaft of the combustion engine with the input shaft of the gearbox, via the coupling device, wherein connecting the output shaft of the combustion engine with the input shaft of the gearbox comprises controlling the first electrical machine such that the input shaft of the gearbox stops, and controlling the second electrical machine such that a desired torque in the output shaft is achieved; and

b) controlling the first and the second electrical machine in such a way that the combustion engine is started, by balancing the desired torque in the output shaft and a required toque to start the combustion engine, for a selected gear.