Method of controlling an injection apparatus of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-10954881-B2
Application number	US-201916274834-A
Country	US
Kind code	B2
Filing date	Feb 13, 2019
Priority date	Mar 16, 2018
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

It is hereby disclosed a method of controlling an injection apparatus of an internal combustion engine including setting a minimum value (QMIN) of a fuel quantity that can be injected into the internal combustion engine by the injection apparatus with one injection; preventing the injection apparatus from performing post-injections of fuel quantities having a smaller value than the minimum value (QMIN).

First claim

The invention claimed is:

1. A method of controlling an injection apparatus of an internal combustion engine, the method comprising:
setting a minimum value (QMIN) of a fuel quantity that can be injected into the internal combustion engine by the injection apparatus with one injection;
preventing the injection apparatus from performing post-injections of fuel quantities having a smaller value than the minimum value (QMIN),
determining a requested value (QREQ) of a fuel quantity to be injected into the internal combustion engine by one post-injection;
determining or calculating a number of power strokes (N) on a basis of the requested value (QREQ) of the fuel quantity;
preventing the injection apparatus from performing post-injections until that number (N) of power strokes have been done; and
commanding the injection apparatus to perform a post-injection of a fuel quantity having a value which is equal to or greater than the minimum value (QMIN).

2. The method according to claim 1 , wherein the number (N) of power strokes is determined as output of a calibration vector receiving the requested value (QREQ) of the fuel quantity as input.

3. The method according to claim 1 , wherein the number (N) of power strokes is determined as a function of both the requested value (QMIN) of the fuel quantity and the minimum value (QMIN) thereof.

4. The method according to claim 3 , wherein the number (N) of power strokes is determined with the following equation:

Floor
⁡

(

QMIN
QREQ

+
K

)

=
N

wherein N is the number of power strokes, QMIN is the minimum value of the fuel quantity, QREQ is the requested value of the fuel quantity and K is a constant.

5. The method according to claim 1 , wherein determining the requested value (QREQ) of the fuel quantity comprises:
measuring a temperature of an engine aftertreatment system;
calculating a difference between the measured temperature and a target value thereof; and
calculating the requested value (QREQ) of the fuel quantity as a function of the difference.

6. The method of claim 1 , wherein the minimum value (QMIN) of the fuel quantity is a calibration parameter determined by an experimental activity.

7. The method of claim 1 , wherein the injection apparatus is prevented from performing post-injections of fuel quantities having a smaller value than the minimum value by repeating a control cycle.

8. The method of claim 7 , further comprising:
determining a requested value (QREQ) of a fuel quantity to be injected into the internal combustion engine by one post-injection;
adding the requested value (QREQ) to an aggregate fuel quantity value (QA) obtained in a latest preceding execution of the control cycle;
preventing the injection apparatus from performing post-injections, if the aggregate fuel quantity value (QA) is smaller than the minimum value (QMIN);
commanding the injection apparatus to perform one post-injection of a fuel quantity having a value equal to the aggregate fuel quantity value (QA), when the aggregate fuel quantity value (QA) is equal to or larger than the minimum value (QMIN); and
resetting the aggregate fuel quantity value (QA) to zero, when the one post-injection is performed.

9. The method of claim 1 , wherein the post-injections are injections performed after a main injection or after a power stroke.

10. The method of claim 1 , wherein the post-injections are injections performed during an exhaust stroke.

11. An internal combustion engine comprising:
an injection apparatus; and
an electronic control unit configured to set a minimum value (QMIN) of a fuel quantity that can be injected into the internal combustion engine by the injection apparatus with one injection and prevent the injection apparatus from performing post-injections of fuel quantities having a smaller value than the minimum value (QMIN),
wherein the electronic control unit is configured to determine a requested value (QREQ) of a fuel quantity to be injected into the internal combustion engine by one post-injection, determine a number of power strokes (N) on a basis of the requested value (QREQ) of the fuel quantity,
wherein the electronic control unit is configured to prevent the injection apparatus from performing post-injections until the number (N) of power strokes have been performed and command the injection apparatus to perform a post-injection of a fuel quantity having a value which is equal to or greater than the minimum value (QMIN).

12. The internal combustion engine according to claim 11 , wherein the number (N) of power strokes is determined as output of a calibration vector receiving the requested value (QREQ) of the fuel quantity as input.

13. The internal combustion engine according to claim 11 , wherein the number (N) of power strokes is determined as a function of both the requested value (QMIN) of the fuel quantity and the minimum value (QMIN) thereof.

14. The internal combustion engine according to claim 11 , wherein the minimum value (QMIN) of the fuel quantity is a calibration parameter determined by an experimental activity.

15. A non-transitory computer readable medium including instructions that when executed by processor are configured to perform:
setting a minimum value (QMIN) of a fuel quantity that can be injected into an internal combustion engine by an injection apparatus with one injection;
preventing the injection apparatus from performing post-injections of fuel quantities having a smaller value than the minimum value (QMIN);
determining a requested value (QREQ) of a fuel quantity to be injected into the internal combustion engine by one post-injection;
determining or calculating a number of power strokes (N) on a basis of the requested value (QREQ) of the fuel quantity;
preventing the injection apparatus from performing post-injections until that number (N) of power strokes have been done; and
commanding the injection apparatus to perform a post-injection of a fuel quantity having a value which is equal to or greater than the minimum value (QMIN).

Assignees

• Lombardini Srl
• Kohler Co

Inventors

• Panini Fabio
• Di Iorio Felice
• De Monte Mario

Classifications

• F02D41/027

  to purge or regenerate the exhaust gas treating apparatus · CPC title

• F02D41/402

  Multiple injections · CPC title

• F02D41/30

  Controlling fuel injection {(F02D41/182, F02D41/24 take precedence)} · CPC title

• F02D41/405 Primary

  with post injections · CPC title

• F02D41/0087

  Selective cylinder activation, i.e. partial cylinder operation (deceleration cut-off F02D41/123) · CPC title