Method and system for controlling a turbocharged engine during an upshift

Patent metadata

Field	Value
Publication number	US-2016138495-A1
Application number	US-201414787066-A
Country	US
Kind code	A1
Filing date	Apr 29, 2014
Priority date	Apr 30, 2013
Publication date	May 19, 2016
Grant date	—

Abstract

A method for propulsion of a vehicle ( 100 ): The vehicle ( 100 ) includes a combustion engine ( 101 ), and a gearbox ( 103 ) that can be adjusted to a number of gear ratios for transfer of force between the combustion engine ( 101 ) and at least one driving wheel ( 113, 114 ), at least one combustion chamber with at least one inlet for the supply of combustion gas and at least one outlet for the evacuation of an exhaust gas flow that has resulted from combustion in the combustion chambers and a turbocharger unit ( 203 ) for pressurizing the combustion gas. In the method, during the change of gear from a first higher gear ratio to a second lower gear ratio, the rate of revolution of the combustion engine ( 101 ) is reduced, to control the turbocharger unit such that the pressure of the combustion gas is reduced, to increase the pressure at the outlet by constriction of the exhaust gas flow, and when the rate of revolution of the combustion engine ( 101 ) has at least partially fallen towards a second rate of revolution, to control the turbocharger unit such that the combustion gas pressure is increased. Also a system and a vehicle including the system.

First claim

1 . A method for propulsion of a vehicle, wherein the vehicle comprises:
a combustion engine, a gearbox adjustable to a number of gear ratios for transfer of a force between the combustion engine and at least one driving wheel, wherein the combustion engine comprises at least one combustion chamber with at least one inlet for supply of combustion gas and at least one outlet for evacuation of an exhaust gas flow that has resulted from combustion in the combustion chamber, and further comprising a turbocharger unit for pressurisation of the combustion gas; the method comprising, during a change of gear from a first higher gear ratio to a second lower gear ratio, wherein a rate of revolution of the combustion engine is reduced from a first rate of revolution (n 1 ) to a second rate of revolution (n 2 ): controlling the turbocharger unit such that the pressure (P in ) of the combustion gas is reduced, increasing the pressure (P ut ) at the outlet from the combustion chamber by constriction of the exhaust gas flow, and when the rate of revolution (n) of the combustion engine has at least partially fallen towards the second rate of revolution (n 2 ), controlling the turbocharger unit such that combustion gas pressure (P in ) is increased.

2 . The method according to claim 1 , further comprising the controlling the turbocharger unit causes the combustion gas pressure (P in ) to increase before the rate of revolution (n) of the combustion engine has fallen to the second rate of revolution (n 2 ).

3 . The method according to claim 2 , further comprising starting the increasing of the combustion gas pressure (P in ) when the rate of revolution (n) of the combustion engine has fallen to a rate of revolution (n lim ) that is constituted of the said second rate of revolution (n 2 ) plus a selected value in the range of 10-50% of the difference in the rate of revolution between the first rate of revolution (n 1 ) and the second rate of revolution (n 2 ).

4 . The method according to claim 1 , further comprising starting the increasing of the combustion gas pressure (P in ) when the rate of revolution (n) of the combustion engine has fallen to the second rate of revolution (n 2 ), but before the said combustion engine is reconnected with the driving wheels through the gearbox.

5 . The method according to claim 1 , further comprising, maintaining a difference in pressure (ΔP) between the inlet ( 201 ) and the outlet of the combustion chamber essentially constant during the reduction of the rate of revolution (n) for the combustion engine.

6 . The method according to claim 1 , further comprising the increasing of the pressure (P ut ) at the outlet of the combustion chamber to a second outlet pressure is performed through use of a constriction device arranged downstream of the outlet of the combustion chamber, whereby the pressure (P ut ) at the outlet of the combustion chamber is maintained essentially constant during the reduction in the rate of revolution, at least partially with the aid of the constriction device, and at least until the raising of the combustion gas pressure has started.

7 . The method according to claim 6 , wherein the second outlet pressure is constituted by a pressure of at least double the pressure that surrounds the vehicle.

8 . The method according to claim 1 , wherein when the pressure (P in ) of the combustion gas is reduced, controlling the pressure towards essentially the pressure that surrounds the vehicle, or at least towards a pressure lower than a pressure prevalent at the beginning of the pressure-reduction process.

9 . The method according to claim 1 , further comprising during the raising of the inlet pressure at the inlet to the combustion chamber, the increasing of the pressure (P ut ) at the outlet from the combustion chamber to a pressure higher than the pressure that was prevalent at the outlet before the raising of the inlet pressure in order to reduce the fall in differential pressure across the combustion engine during the raising of the inlet pressure.

10 . The method according to claim 9 , wherein the further raising of the outlet pressure essentially follows the increase in pressure of the inlet pressure.

11 . The method according to claim 10 , wherein during the further raising of the outlet pressure, increasing the outlet pressure to a level that exceeds a limitation on pressure with respect to non-instantaneous pressure that is prevalent at the outlet.

12 . The method according to claim 1 , further comprising during the raising of the inlet pressure, controlling the turbocharger unit to obtain an essentially maximum rate of the build up of pressure of the inlet pressure (P in ).

13 . The method according to claim 1 , further comprising performing the method essentially when the combustion engine is disengaged from the, at least one driving wheel.

14 . The method according to claim 1 , further comprising the starting of at least one of the constriction of the exhaust gas flow and the reduction of the inlet pressure before or when the combustion engine has been completely disengaged from the driving wheel.

15 . The method according to claim 1 , further comprising performing the constriction of the said exhaust gas flow through use of a constriction device comprising at least one of an exhaust gas brake system and a compression brake.

16 . The method according to claim 14 , further comprising performing the constriction of the exhaust gas flow through use of a constriction device arranged downstream of the turbocharger unit.

17 . (canceled)

18 . A computer program product comprising a non-transitory medium that can be read by a computer and a computer program comprising program code stored on the medium and the stored program can be read by a computer and when the program code is executed in a computer, the computer carries out the method according to claim 1 .

19 . A system for propulsion of a vehicle, wherein the said vehicle comprises:
a combustion engine, a gearbox adjustable to a plurality of gear ratios for transfer of a force between the combustion engine and at least one driving wheel, wherein the combustion engine comprises at least one combustion chamber with at least one inlet for supply of combustion gas and at least one outlet for the evacuation of an exhaust gas flow that has resulted from combustion in the combustion chamber, and a turbocharger unit configured for pressurisation of the combustion gas; the system being configured such that, during adjustment of a change of gear in the gearbox from a first higher gear ratio to a second lower gear ratio, wherein a rate of revolution of the combustion engine is reduced from a first rate of revolution to a second rate of revolution, the system further comprising: means for controlling the turbocharger unit such that pressure of the combustion gas is reduced, means for increasing the pressure at the outlet by constriction of the exhaust gas flow, and when the rate of revolution of the combustion engine has at least partially fallen towards the said second rate of revolution, means for controlling the turbocharger unit such that the combustion gas pressure is increased.

20 . The system according to claim 19 , wherein the combustion engine is configured for any one of the group of controlling of a vehicle engine, a marine engine, and an industrial engine.

21 . The system according to claim 19 , wherein the combustion engine is comprised of several of the combustion chambers.

Assignees

• Scania Cv Ab

Inventors

• Granström Magnus
• Larsson Anders

Classifications

• F02D41/023 Primary

  in relation with the gear ratio shifting (conjoint control for improving gear change B60W30/19) · CPC title

• F02D41/26

  using computer, e.g. microprocessor · CPC title

• F02D41/0007 Primary

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02D41/2406

  using essentially read only memories · CPC title

• F02B37/22

  by varying cross-section of exhaust passages or air passages {, e.g. by throttling turbine inlets or outlets or by varying effective number of guide conduits} (F02B37/24 takes precedence) · CPC title