System for detecting a leakage in an intake line of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9856814-B2
Application number	US-201414493072-A
Country	US
Kind code	B2
Filing date	Sep 22, 2014
Priority date	Sep 24, 2013
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

A system for detecting a leakage/failure in in an intake line of an internal combustion engine comprising an intake line (IL) and an exhaust line (EL), means (HFM) for measuring or for estimating a quantity of fresh air ({dot over (m)} HFM ) entering said intake line (IL), means for measuring or for estimating a quantity of fuel ({dot over (m)} FUEL ) injected in the engine (E), measurement or estimation means (λ and/or NOx), on the exhaust line, adapted to provide a first value (λ measured ) of an air/fuel ratio introduced in the internal combustion engine (E), the system comprising processing means (ECU) adapted to calculate a second value (λ exp ) of said air/fuel ratio, calculated on the basis of the measured and estimated quantities of fresh air ({dot over (m)} HFM ) and fuel ({dot over (m)} FUEL ) to calculate an error (λ err ) between the first and the second value (λ measured −λ exp ) and to detect a condition of leakage/failure if said error is outside a predefined interval [λ err −, λ err +] containing the value zero.

First claim

The invention claimed is:

1. A system for detecting a leakage/failure in an intake line of an internal combustion engine comprising
an intake line (IL) and an exhaust line (EL),
means (HFM) for measuring or for estimating a quantity of fresh air ({dot over (m)} HFM ) entering said intake line (IL),
a fuel injection system for measuring or for estimating a quantity of fuel ({dot over (m)} FUEL ) injected into the engine,
measurement or estimation means (λ and/or NOx), on said exhaust line, adapted to provide a first value (λ measured ) of an air/fuel ratio introduced in the internal combustion engine (E), the system comprising processing means (ECU) configured to calculate a second value (λ exp ) of said air/fuel ratio, calculated on the basis of said measured or estimated quantities of fresh air ({dot over (m)} HFM ) and fuel ({dot over (m)} FUEL ) injected into the engine (E), to calculate an error (λ err ) as the difference between said first and second value of air/fuel ratio (λ measured −λ exp ) and to detect a condition of leakage/failure if said error exceeds positively a predefined interval [λ err −, λ err +] containing the value zero and detect a condition of leakage/failure if said error exceeds negatively said predefined interval [λ err −, λ err +].

2. System according to claim 1 , wherein when said engine is supercharged by means of a supercharger (C) and comprises low-pressure and/or high-pressure recirculation means,
when said error (λ err ) exceeds positively said predefined interval [λ err −, λ err +], said processing means (ECU) are configured to generate a warning message indicating
a leakage in a duct comprised between said means for measuring or estimating a quantity of fresh air ({dot over (m)} HFM ) entering the engine (E) and an inlet of said supercharger (C) and/or
a leakage in a portion of a low-pressure recirculation EGR duct (EL) or in a portion of duct comprised between a respective low-pressure EGR valve (ELV) and said inlet of said supercharger (C);

or
when said error (λ err ) exceeds negatively said predefined interval ([λ err −, λ err +]), said processing means (ECU) are adapted to generate a warning message indicating
a leakage in a duct comprised between an outlet of said supercharger (C) and an intake manifold (IP) of the engine and/or
a leakage in a high-pressure recirculation EGR duct comprised between a respective EGR valve (EHV) and said intake manifold (IP) and/or
a leakage in a low-pressure EGR line (EL) when a respective EGR valve (ELV) is not completely closed and at the same time the EGR line is at a pressure higher than the atmospheric pressure.

3. System according to claim 1 , wherein said engine is not supercharged and comprises recirculation means EGR,
when said error (λ err ) exceeds positively said predefined interval ([λ err −, λ err +]), said processing means (ECU) are adapted to generate a warning message indicating
a leakage in a duct comprised between said means for measuring or estimating a quantity of fresh air ({dot over (m)} HFM ) entering the engine (E) and an intake manifold of the engine and/or
a leakage in a portion of a low-pressure recirculation EGR duct (EL) or in a portion of duct comprised between a respective low-pressure EGR valve (ELV) and intake manifold (IP);

or
when said error (λ err ) exceeds negatively said predefined interval ([λ err −, λ err +]), said processing means (ECU) are adapted to generate a warning message indicating
a leakage in a low-pressure EGR line (EL) when a respective low-pressure EGR valve (ELV) is not closed and the EGR line is at a pressure higher than the atmospheric pressure.

4. System according to claim 1 , wherein λ err − and λ err + have an absolute value comprised between 0.1 and 0.3, so that, in a “normal” condition, wherein there is no leakage/failure, λ err −<λ err <λ err + results.

5. System according to claim 4 , wherein said thresholds λ err − and λ err + have an absolute value equal to 0.2.

6. Internal combustion engine (E) comprising:
the system according to claim 1 ; and
one or more cylinders, wherein said fuel injection system is for measuring or for estimating a quantity of fuel ({dot over (m)} FUEL ) injected into said one or more cylinders.

7. Engine according to claim 6 , further comprising a supercharger (C) arranged on said intake line (IL) and low-pressure and/or high-pressure recirculation means EGR, and wherein said processing means are configured to detect a leakage/failure
when said error (λ err ) exceeds positively said predefined interval [λ err −, λ err +], indicating
a leakage in a duct comprised between said means for measuring or estimating a quantity of fresh air ({dot over (m)} HFM ) entering the engine (E) and an inlet of said compressor (C) and/or
a leakage in a portion of a low-pressure recirculation EGR duct (EL) or in a portion of duct comprised between a respective low-pressure EGR valve (ELV) and said inlet of said supercharger (C);

or
when said error (λ err ) exceeds negatively said predefined interval [λ err −, λ err +], indicating
a leakage in a duct comprised between an outlet of said supercharger (C) and an intake manifold (IP) of the engine and/or
a leakage in a high-pressure recirculation EGR duct comprised between a respective EGR valve (EHV) and said intake manifold (IP) and/or
a leakage in a low-pressure EGR line (EL) when a respective EGR valve (ELV) is not completely closed and at the same time the EGR line is at a pressure higher than the atmospheric pressure.

8. Engine according to claim 6 , being of the type non supercharged and comprising recirculation means EGR, and wherein said processing means are configured to detect a leakage/failure
when said error (λ err ) exceeds positively said predefined interval [λ err −, λ err +], said processing means (ECU) are adapted to generate a warning message indicating
a leakage in a duct comprised between said means (HFM) for measuring or estimating a quantity of fresh air ({dot over (m)} HFM ) entering the engine (E) and an intake manifold (IP) of the engine and/or
a leakage in a portion of a low-pressure recirculation EGR duct (EL) or in a portion of duct comprised between a respective low-pressure EGR valve (ELV) and said intake manifold (IP);

or
when said error (λ err ) exceeds negatively said predefined interval [λ err −, λ err +], said processing means (ECU) are adapted to generate a warning message indicating
a leakage in a low-pressure EGR line (EL) when a respective low-pressure EGR valve (ELV) is not closed and the EGR line is at a pressure higher than the atmospheric pressure.

9. Engine according to claim 6 , wherein λ err − and λ err + have an absolute value comprised between 0.1 and 0.3, so that, in a “normal” condition, wherein there is no leakage/failure, λ err −<λ err <λ err + results.

10. Engine according to claim 9 , wherein said thresholds have an absolute value equal to 0.2.

11. Engine according to claim 6 , further comprising an intercooler (C) on the intake line (IL) and/or a cooler on a recirculation duct EGR.

12. Engine according to claim 6 , further comprising an anti-pollution device (DPF, SCR, NSC) on the exhaust line (EL).

13. Vehicle or fixed apparatus comprising the internal combustion engine according to claim 6 .

14. Method for detecting a leakage in an intake line (IL) of an internal combustion engine comprising
an intake line (IL) and an exhaust line (EL),
means (HFM) for measuring or for estimating a quantity of fresh air ({dot over (m)} HFM ) entering said intake line (IL),
a fuel injection system for measuring or for estimating a q

Assignees

• Fpt Ind Spa

Inventors

• Odello Fabio
• Musumeci Salvatore
• Dell'Unto Francesco

Classifications

• F02D41/1456

  with sensor output signal being linear or quasi-linear with the concentration of oxygen · 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

• F02D41/0007

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

• F02D41/146

  the characteristics being an NOx content or concentration · CPC title

• F02D2200/0614

  Actual fuel mass or fuel injection amount · CPC title