Method and system for diagnosing unintended fuelling from fuel injectors of an engine

Patent metadata

Field	Value
Publication number	US-10704490-B2
Application number	US-201716315518-A
Country	US
Kind code	B2
Filing date	Jun 19, 2017
Priority date	Jul 12, 2016
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

Provided is a method for diagnosing unintended fuelling from one or more fuel injectors of a multi cylinder internal combustion engine during engine operation. Pressurized fuel is intended to be distributed by means of said fuel injectors from said accumulator tank to the cylinders for combustion. An oxidation catalyst is arranged downstream said cylinders. The method comprises: determining the pressure in the fuel accumulator tank and whether said pressure is decreasing; and determining whether the actual amount of fuel provided by the pump unit exceeds the demanded amount of fuel. The method further comprises the steps of: determining whether the temperature associated with the oxidation catalyst is above a certain level and/or determining whether the air/fuel ratio is below a certain level and/or determining whether an amount of particulate matter is above a certain level; and confirming an unintended fuelling based on the determined conditions.

First claim

The invention claimed is:

1. A method for diagnosing unintended fuelling from one or more fuel injectors of a multi cylinder internal combustion engine during engine operation, a pump unit being arranged to provide pressurized fuel to a fuel accumulator tank based on a fuel demand, pressurized fuel being intended to be distributed by means of said fuel injectors from said accumulator tank to the cylinders for combustion, an oxidation catalyst being arranged downstream said cylinders, the method comprising the steps of:
determining a pressure in the fuel accumulator tank and whether said pressure is decreasing;
determining whether an actual amount of fuel provided by the pump unit exceeds a demanded amount of fuel;
determining whether a temperature associated with the oxidation catalyst is above a certain level and/or determining whether an air/fuel ratio is below a certain level and/or determining whether an amount of particulate matter is above a certain level; and
confirming an unintended fuelling, if the pressure in the accumulator tank is decreasing and/or the amount of fuel provided by the pump unit exceeds the demanded amount of fuel by a certain amount, and said temperature is above said certain level and/or said air/fuel ratio is below said certain level and/or said particulate matter is above said certain level.

2. A method according to claim 1 , further comprising the step of excluding presence of unintended fuelling if the pressure in the accumulator tank is decreasing and/or the amount of fuel provided by the pump unit exceeds the demanded amount of fuel by a certain amount, and said temperature is below said certain level and said air/fuel ratio is above said certain level and said particulate matter is below said certain level.

3. A method according to claim 2 , further comprising the step of taking the fact that the pressure in the accumulator tank is decreasing and/or the amount of fuel provided by the pump unit exceeds the demanded amount of fuel by a certain amount, and said temperature is below said certain level and said air/fuel ratio is above said certain level and said particulate matter is below said certain level as an indication of a fuel leakage.

4. A method according to claim 1 , further comprising the step of excluding presence of unintended fuelling if the pressure in the accumulator tank is at a predetermined level and the amount of fuel provided by the pump unit does not exceed the demanded amount of fuel by said certain amount, and said temperature is above said certain level and/or said air/fuel ratio is below said certain level and/or said particulate matter is above said certain level.

5. A method according to claim 1 , further comprising the step of excluding presence of unintended fuelling if the pressure in the accumulator tank is at a predetermined level and the amount of fuel provided by the pump unit does not exceed the demanded amount of fuel by said certain amount, and said temperature is below said certain level and said air/fuel ratio is above said certain level and said particulate matter is below said certain level.

6. A system for diagnosing unintended fuelling from one or more fuel injectors of a multi cylinder internal combustion engine during engine operation, where a pump unit is arranged to provide pressurized fuel to a fuel accumulator tank based on a fuel demand, pressurized fuel being intended to be distributed by means of said fuel injectors from said accumulator tank to the cylinders for combustion, and an oxidation catalyst is arranged downstream said cylinders, the system comprising:
means for determining the pressure in the fuel accumulator tank and whether said pressure is decreasing;
means for determining whether the actual amount of fuel provided by the pump unit exceeds the demanded amount of fuel;
means for determining whether the temperature associated with the oxidation catalyst is above a certain level and/or means for determining whether the air/fuel ratio is below a certain level, and/or means for determining whether an amount of particulate matter is above a certain level; and
means for confirming an unintended fuelling if the pressure in the accumulator tank is decreasing and/or the amount of fuel provided by the pump unit exceeds the demanded amount of fuel by a certain amount, and said temperature is above said certain level and/or said air/fuel ratio is below said certain level and/or said particulate matter is above said certain level.

7. A system according to claim 6 , further comprising means for excluding presence of unintended fuelling if the pressure in the accumulator tank is decreasing and/or the amount of fuel provided by the pump unit exceeds the demanded amount of fuel by a certain amount, and said temperature is below said certain level and said air/fuel ratio is above said certain level and said particulate matter is below said certain level.

8. A system according to claim 7 , further comprising means for taking the fact that the pressure in the accumulator tank is decreasing and/or the amount of fuel provided by the pump unit exceeds the demanded amount of fuel by a certain amount, and said temperature is below said certain level and said air/fuel ratio is above said certain level and said particulate matter is below said certain level as an indication of a fuel leakage.

9. A system according to claim 6 , further comprising means for excluding presence of unintended fuelling if the pressure in the accumulator tank is at a predetermined level and the amount of fuel provided by the pump unit does not exceed the demanded amount of fuel by said certain amount, and said temperature is above said certain level and/or said air/fuel ratio is below said certain level and/or said particulate matter is above said certain level.

10. A system according to claim 6 , further comprising means for excluding presence of unintended fuelling if the pressure in the accumulator tank is at a predetermined level and the amount of fuel provided by the pump unit does not exceed the demanded amount of fuel by said certain amount, and said temperature is below said certain level and said air/fuel ratio is above said certain level and said particulate matter is below said certain level.

11. A vehicle comprising a system for diagnosing unintended fuelling from one or more fuel injectors of a multi cylinder internal combustion engine during engine operation, where a pump unit is arranged to provide pressurized fuel to a fuel accumulator tank based on a fuel demand, pressurized fuel being intended to be distributed by means of said fuel injectors from said accumulator tank to the cylinders for combustion, and an oxidation catalyst is arranged downstream said cylinders, the system comprising:
means for determining the pressure in the fuel accumulator tank and whether said pressure is decreasing;
means for determining whether the actual amount of fuel provided by the pump unit exceeds the demanded amount of fuel; means for determining whether the temperature associated with the oxidation catalyst is above a certain level and/or means for determining whether the air/fuel ratio is below a certain level, and/or means for determining whether an amount of particulate matter is above a certain level; and
means for confirming an unintended fuelling if the pressure in the accumulator tank is decreasing and/or the amount of fuel provided by the pump unit exceeds the demanded amount of fuel by a certain amount, and said temperature is above said certain level and/or said air/fuel ratio is below said certain level and/or said particulate matter is above said certain level.

12. A vehicle according to claim 11 , wherein said system further co

Assignees

• Scania Cv Ab

Inventors

• Kylström Kim
• Hälleberg Roger
• Stenlåås Ola

Classifications

• F02D2200/0802

  Temperature of the exhaust gas treatment apparatus · CPC title

• F02D2200/0812

  Particle filter loading · CPC title

• F01N2560/025

  for measuring or detecting O2, e.g. lambda sensors · CPC title

• F02D2200/0602

  Fuel pressure · CPC title

• F02D41/22 Primary

  Safety or indicating devices for abnormal conditions {(in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809)} · CPC title