Method for starting an internal combustion engine

• US 8,600,649 B2
• Filed: 06/26/2008
• Issued: 12/03/2013
• Est. Priority Date: 07/09/2007
• Status: Expired due to Fees

• Current Assignee: Peugeot Citroen Automobiles SA (Stellantis NV)
• Original Assignee: Peugeot Citroen Automobiles SA (Stellantis NV)
• Inventors: Gourves, Frdric
• Primary Examiner(s): Gimie, Mahmoud
• Assistant Examiner(s): HAMAOUI, DAVID E
• Application Number:
  US12/668,316
• Publication Number:
  US 20100191447A1
• Time in Patent Office: 1,986 Days
• Field of Search: 701/113, 701/104, 701/115, 123/491, 123/179.3, 123/179.16, 123/436, 123/480, 123/486, 123/674, 731/143.8
• US Class Current: 701/113
• CPC Class Codes: F02D 19/084 Blends of gasoline and alcohols, e.g. E85
• CPC Class Codes: F02D 19/088 by estimation, i.e. without using direct measurements of a corresponding sensor
• CPC Class Codes: F02D 2200/0612 determined by estimation
• CPC Class Codes: F02D 2200/1012 Engine speed gradient
• CPC Class Codes: F02D 33/006 depending on engine operating conditions, e.g. start, stop or ambient conditions
• CPC Class Codes: F02D 41/0025 Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

The invention relates to a method for starting an internal combustion engine associated with means for adapting, during an engine start operation, an amount of fuel injected based on an estimation of the volatility (PVR) of the fuel based on the comparison between a gradient of the engine speed measured upon a preceding start operation and a reference gradient (110) corresponding to a predetermined fuel, characterized by the step (111) of correcting the reference gradient based on a change (ΔCMF) in the engine friction torque.

Claims

1. A method for starting an internal combustion engine;

the method comprising adjusting, during the start operation of the engine of a vehicle, the quantity of injected fuel as a function of the estimated volatility (RVP) of the fuel based on a comparison between an engine speed gradient measured during a preceding start operation and an engine speed reference gradient corresponding with a predefined fuel; and

applying a correction to the reference gradient;

the correction being a function of the evolution (Δ

CMF) of the engine friction torque.

2. The method according to claim 1 wherein the vehicle comprises an engine control means;

the method further including measuring the evolution (Δ

CMF) of the friction torque for the needs of the engine control means.

3. The method according to claim 1 wherein the engine speed gradient is determined starting from a first combustion that occurred during the start operation.

4. The method according claim 1 wherein the correction of the engine speed gradient is proportional to a ratio between the evolution of the friction torque and the engine inertia.

5. The method according claim 4 wherein the engine speed gradient is determined as a difference in engine speed between two successive combustions;

and the correction of the engine speed gradient is proportional to a time (T_PMH) separating the two successive combustions.

6. The method according to claim 1 wherein the engine speed reference gradient is a function of the engine temperature (T_water) and of the number (Nb_PMH) of combustions that occurred since the first combustion.

7. The method according to claim 1 wherein several engine speed reference gradients are defined for distinct values of the vaporizing capacity of the fuel and the quantity of fuel to be injected is defined in a linear manner as a function of the measured gradient value with respect to the reference values.

8. The method according to claim 1 wherein several engine speed reference gradients are defined for distinct values of the vaporizing capacity of the fuel and the quantity of fuel to be injected is defined in a discrete manner as a function of the measured gradient value with respect to the reference values.

9. The method according to claim 1 wherein during a start operation the engine speed gradient measured during one or several preceding first start operations is taken into account.

10. The method according to claim 1 implemented in an internal combustion engine with spark ignition.

11. The method according to claim 10, implemented in an internal combustion engine with FLEXFUEL type spark ignition.