Title of Invention

A CONTROL METHOD AND A CONTROL SYSTEM FOR AN INTERNAL COMBUSTION ENGINE WITH A GASOLINE DIRECT FUEL INJECTION SYSTEM

Abstract A fuel injection method for internal combustion engines with gasoline direct fuel injection systems comprises receiving a crankshaft position signal from a crankshaft position sensor. A position of a crankshaft is determined from the crankshaft position signal. Fuel is commanded at a first rate when the position of the crankshaft is within a first selectable range during a combustion cycle of an engine cylinder and fuel is commanded at a second rate when the position of the crankshaft is within a second selectable range during the combustion cycle of the engine cylinder.
Full Text GP-306826-PTE-CD
1
IDLE STABILITY IMPROVEMENT FOR DIRECT INJECTED ENGINES
FIELD OF THE INVENTION
[0001] The present invention relates to methods and systems for
gasoline direct fuel injection and particularly for improving idle stability for
internal combustion engines with gasoline direct fuel injection.
BACKGROUND OF THE INVENTION
[0002] Controlling the amount of fuel and air to be delivered per
cylinder for a four stroke internal combustion engine is important to achieve
optimum performance. Proper timing of intake and exhaust valves also
provide for better performance. Conventional engines include camshafts that
regulate the timing of the valves. The rotation of the camshaft can be
controlled to ensure proper timing of each valve. In addition cam phasers
may be included to alter the position of the camshafts relative to the
crankshaft which provides for further opportunities to properly adjust the
timing of each valve.
[0003] In order to achieve greater engine power, conventional
engine valve lift profiles and valve timing designs favor high revolution per
minute (RPM) conditions. These designs tend to compromise engine
performance at low RPM conditions. This compromise can result in
combustion instability at idle, a low RPM condition. Combustion instability
may be perceived by a driver as undesirable.

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SUMMARY OF THE INVENTION
[0004] Accordingly, a fuel injection method for internal combustion
engines with gasoline direct fuel injection systems according to the present
invention comprises receiving a crankshaft position signal from a crankshaft
position sensor. A position of a crankshaft is determined from the crankshaft
position signal. Fuel is commanded at a first rate when the position of the
crankshaft is within a first selectable range during a combustion cycle of an
engine cylinder and fuel is commanded at a second rate when the position of
the crankshaft is within a second selectable range during the combustion cyle
of the engine cylinder.
[0005] In one other feature, the method further comprises
commanding spark when the position of the crankshaft is near top dead
center.
[0006] In another feature, commanding fuel at the first rate and
commanding fuel at the second rate is performed during idle operating
conditions.
[0007] In other features, the first selectable range is between a
range of two hundred and fifty and three hundred and eighty degrees of crank
rotation before top dead center firing. The second selectable range is
between a range of zero and one hundred and eighty degrees of crank
rotation before top dead center firing.
[0008] In still other features, the second selectable range is defined
by twenty and ninety degrees of crank rotation before top dead center firing.
The first selectable range is defined by two hundred and seventy and three
hundred and thirty degrees of crank rotation before top dead center firing.
[0009] In still other features, the first rate is based on a selectable
percentage of a total fuel desired for the combustion stroke. The second rate
is based on a selectable percentage of a total fuel desired for said combustion
stroke.

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3
[0010] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter. It should
be understood that the detailed description and specific examples, while
indicating the preferred embodiment of the invention, are intended for
purposes of illustration only and are not intended to limit the scope of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will become more fully understood
from the detailed description and the accompanying drawings, wherein:
[0012] Figure 1 is a functional block diagram illustrating an internal
combustion engine system including direct fuel injection hardware;
[0013] Figure 2 is a timing diagram illustrating the scheduling of fuel
injection events according to the present invention; and
[0014] Figure 3 is a bar graph illustrating the effects of commanding
fuel injection events according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the invention, its
application, or uses. For purposes of clarity, the same reference numbers will
be used in the drawings to identify the same elements. As used herein, the
term module and/or device refers to an application specific integrated circuit
(ASIC), an electronic circuit, a processor (shared, dedicated, or group) and
memory that execute one or more software or firmware programs, a
combinational logic circuit and/or other suitable components that provide the
described functionality.

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4
[0016] Referring now to Figure 1, an engine system 10 includes an
engine 12 that combusts an air and fuel mixture to produce drive torque. Air
is drawn into an intake manifold 14 through a throttle 16. The throttle 16
regulates mass air flow into the intake manifold 14. Air within the intake
manifold 14 is distributed into cylinders 18. Although a single cylinder 18 is
illustrated, it can be appreciated that the engine can have a plurality of
cylinders including, but not limited to, 2, 3, 5, 6, 8, 10, 12 and 16 cylinders.
[0017] A fuel injector 20 is electronically controlled to inject fuel into
the cylinder 18. Fuel is combined with air as it is drawn into the cylinder 18
through an intake port. An intake valve 22 selectively opens and closes to
enable the air to enter the cylinder 18. The intake valve position is regulated
by an intake camshaft 24. A piston (not shown) compresses the air/fuel
mixture within the cylinder 18. A spark plug 26 initiates combustion of the
air/fuel mixture, driving the piston in the cylinder 18. The piston drives a
crankshaft (not shown) to produce drive torque. Combustion exhaust within
the cylinder 18 is forced out through an exhaust manifold 28 when an exhaust
valve 30 is in an open position. The exhaust valve position is regulated by an
exhaust camshaft 32. The exhaust can then be treated in an exhaust system
(not shown). Although single intake and exhaust valves 22,30 are illustrated,
it can be appreciated that the engine 12 can include multiple intake and
exhaust valves 22,30 per cylinder 18.
[0018] A crankshaft sensor 34 senses a position of the crankshaft
and generates a crankshaft signal. A control module 36 according to the
present invention receives the crankshaft signal, interprets the signal as
degrees of rotation and schedules the injection of fuel in a cylinder based on
the interpretation of the signal. The control module 36 sends a fuel delivery
signal to the fuel injector to control the amount and the timing of the fuel
delivery. The fuel delivery signal can be a pulse width modulated signal
where the pulse width regulates the amount of fuel delivered to the cylinder.

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5
[0019] Referring now to Figure 2, a timing diagram for scheduling
fuel injection delivery events according to the present invention is shown.
Fuel injection events can be scheduled according to the crankshaft position
indicated in degrees of crank rotation. The crankshaft signal can be
interpreted as a position in crank degrees. The diagram illustrates the
position of the crankshaft in crank degrees during a combustion cycle. The
combustion cycle includes the piston performing the intake stroke and the
combustion stroke. The piston begins the intake stroke at three hundred sixty
(360) crank rotation degrees before top dead center at 100. The piston
begins the compression stroke at one hundred eighty (180) crank rotation
degrees before top dead center or at bottom dead center (BDC) at 110. The
piston ends the compression stroke at top dead center or zero (0) crank
rotation degrees shown at 120. Firing of spark occurs near top dead center of
the compression stroke at 130. In an exemplary embodiment firing occurs
between ten (10) and zero (0) crank degrees before top dead center.
[0020] During idle operating conditions, according to the present
invention, the control module commands two fuel injection events per cylinder
per combustion cycle. The first injection event is scheduled early in the
combustion cycle and can be scheduled anywhere between two hundred fifty
(250) and three hundred eighty (380) crank degrees before firing of spark.
This timing is normal for homogeneous operating conditions. An exemplary
range for scheduling the first fuel delivery is between two hundred and
seventy (270) and three hundred and thirty (330) crank degrees before firing
of spark as shown at 140. The amount of fuel delivery however, is reduced
compared to homogeneous operating conditions. In an exemplary
embodiment, the amount of fuel delivered is between twenty (20) and ninety
(90) percent of the total required fuel for the combustion stroke.

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6
[0021] The second fuel injection event is scheduled late in the
combustion cycle and can be scheduled anywhere between zero (0) and one
hundred eighty (180) crank degrees before firing of spark. An exemplary
range for scheduling the second fuel delivery is between twenty (20) and
ninety (90) crank degrees before firing of spark as shown at 150. The second
injection event injects the remainder of fuel necessary for the combustion
cycle. An exemplary amount includes ten (10) to eighty percent (80) of the
total fuel required for the combustion stroke.
[0022] Referring now to Figure 3, a bar graph illustrating the effects
of commanding two fuel injection events per combustion cycle per cylinder for
an eight cylinder engine is shown. Cylinders one (1) through eight (8) of the
engine are represented along the x-axis in firing order at 200. A coefficient of
variance (COV) of the indicated mean-effective pressure (IMEP) is
represented along the y-axis ranging from zero (0) to thirty (30) at 210.
Results for a single injection are indicated at 230. Results for a dual injection
are indicated at 220. As shown, the COV of IMEP improves with the second
injection. The second injection increases in-cylinder motion and creates a rich
area near the spark plug. The richness increases combustion stability. The
increased combustion stability can be perceived as a "smooth" idle by the
operator of the vehicle including the engine system.
[0023] In an alternative embodiment the use of dual injection events
can be implemented in displacement on demand engines where the control
module selectively deactivates cylinders of the engine under low load
operating conditions. For example, an eight cylinder engine can be operated
using four cylinders to improve fuel economy by reducing pumping losses.
Results of the total average for a non-DOD engine and DOD engine are
shown by the last two columns of the bar graph at 240.

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7
[0024] Those skilled in the art can now appreciate from the
foregoing description that the broad teachings of the present invention can be
implemented in a variety of forms. Therefore, while this invention has been
described in connection with particular examples thereof, the true scope of the
invention should not be so limited since other modifications will become
apparent to the skilled practitioner upon a study of the drawings, the
specification and the following claims.

GP-306826-PTE-CD
8
CLAIMS
What is claimed is:
1. A fuel injection method for internal combustion engines with
gasoline direct fuel injection systems, comprising:
receiving a crankshaft position signal from a crankshaft position
sensor;
determining a position of a crankshaft from said crankshaft
position signal;
commanding fuel at a first rate when said position of said
crankshaft is within a first selectable range during a combustion cycle of an
engine cylinder, and
commanding fuel at a second rate when said position of said
crankshaft is within a second selectable range during said combustion cycle
of said engine cylinder.
2. The method of claim 1 further comprising commanding spark
when said position of said crankshaft is near top dead center.
3. The method of claim 1 wherein said commanding fuel at said
first rate and said commanding fuel at said second rate is performed during
idle operating conditions.
4. The method of claim 1 wherein said first selectable range is
between a range of two hundred and fifty and three hundred and eighty
degrees of crank rotation before top dead center firing.

GP-306826-PTE-CD
9
5. The method of claim 1 wherein said second selectable range is
between a range of zero and one hundred and eighty degrees of crank
rotation before top dead center firing.
6. The method of claim 1 wherein said second selectable range is
defined by twenty and ninety degrees of crank rotation before top dead center
firing.
7. The method of claim 1 wherein said first range is defined by two
hundred and seventy and three hundred and thirty degrees of crank rotation
before top dead center firing.
8. The method of claim 1 wherein said first rate is based on a
selectable percentage of a total fuel desired for said combustion cycle.
9. The method of claim 8 wherein said selectable percentage is
between twenty and ninety percent of total fuel desired fuel for said
combustion cycle.
10. The method of claim 1 wherein said second rate is based on a
selectable percentage of a total fuel desired for said combustion cycle.
11. The method of claim 10 wherein said selectable percentage is
between ten and eighty percent of fuel desired for said combustion cycle.

GP-306826-PTE-CD
10
12. A gasoline direct fuel injection system for an internal combustion
engine, comprising:
a crankshaft position input device that receives a crankshaft
position signal; and
a control module that commands fuel at a first rate and again at
a second rate during a single combustion cycle while said engine is operating
under idle conditions, wherein said first and second rates are commanded
based on said crankshaft position signal.
13. The system of claim 12 wherein said control module commands
fuel at said first rate and said second rate when said crankshaft position signal
indicates a crankshaft position within first and second selectable ranges
respectively.
14. The system of claim 13 wherein said first selectable range is
between two hundred and fifty and three hundred and eighty crank rotation
degrees before spark is commanded near top dead center.
15. The system of claim 13 wherein said second selectable range is
between zero and one hundred and eighty crank rotation degrees before
spark is commanded near top dead center.
16. The system of claim 12 wherein said control module determines
said first and second rates based on a total fuel required for the combustion
cycle and wherein said total fuel required is determined from engine operating
conditions and torque requests.

GP-306826-PTE-CD
11
17. The system of claim 16 wherein said first and second rates are
based on a first and a second selectable percentage of said total fuel required
for the combustion cycle, wherein said first selectable amount is greater than
said second selectable amount.
18. The system of claim 17 wherein said first selectable percentage
is between twenty and ninety percent of said total fuel.
19. The system of claim 17 wherein said second selectable
percentage is between ten and eighty percent of said total fuel.
20. The system of claim 12 wherein said internal combustion engine
is a displacement on demand engine.

A fuel injection method for internal combustion engines with gasoline
direct fuel injection systems comprises receiving a crankshaft position signal
from a crankshaft position sensor. A position of a crankshaft is determined
from the crankshaft position signal. Fuel is commanded at a first rate when
the position of the crankshaft is within a first selectable range during a
combustion cycle of an engine cylinder and fuel is commanded at a second
rate when the position of the crankshaft is within a second selectable range
during the combustion cycle of the engine cylinder.

Documents:

01216-kol-2007-abstract.pdf

01216-kol-2007-assignment.pdf

01216-kol-2007-claims.pdf

01216-kol-2007-correspondence others 1.1.pdf

01216-kol-2007-correspondence others 1.2.pdf

01216-kol-2007-correspondence others.pdf

01216-kol-2007-description complete.pdf

01216-kol-2007-drawings.pdf

01216-kol-2007-form 1.pdf

01216-kol-2007-form 2.pdf

01216-kol-2007-form 3.pdf

01216-kol-2007-form 5.pdf

01216-kol-2007-priority document.pdf

1216-KOL-2007-ABSTRACT 1.1.pdf

1216-KOL-2007-AMANDED CLAIMS.pdf

1216-KOL-2007-AMANDED PAGES OF SPECIFICATION.pdf

1216-KOL-2007-ASSIGNMENT.pdf

1216-KOL-2007-CORRESPONDENCE 1.5.pdf

1216-KOL-2007-CORRESPONDENCE OTHERS 1.3.pdf

1216-KOL-2007-CORRESPONDENCE OTHERS 1.4.pdf

1216-KOL-2007-CORRESPONDENCE-1.4.pdf

1216-KOL-2007-DESCRIPTION (COMPLETE) 1.1.pdf

1216-KOL-2007-DRAWINGS 1.1.pdf

1216-KOL-2007-EXAMINATION REPORT REPLY RECIEVED.pdf

1216-KOL-2007-EXAMINATION REPORT.pdf

1216-KOL-2007-FORM 1-1.1.pdf

1216-KOL-2007-FORM 18.pdf

1216-KOL-2007-FORM 2-1.1.pdf

1216-KOL-2007-FORM 26.pdf

1216-KOL-2007-FORM 3 1.2.pdf

1216-KOL-2007-FORM 3-1.1.pdf

1216-KOL-2007-FORM 5.pdf

1216-KOL-2007-GRANTED-ABSTRACT.pdf

1216-KOL-2007-GRANTED-CLAIMS.pdf

1216-KOL-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

1216-KOL-2007-GRANTED-DRAWINGS.pdf

1216-KOL-2007-GRANTED-FORM 1.pdf

1216-KOL-2007-GRANTED-FORM 2.pdf

1216-KOL-2007-GRANTED-LETTER PATENT.pdf

1216-KOL-2007-GRANTED-SPECIFICATION.pdf

1216-KOL-2007-OTHERS 1.1.pdf

1216-KOL-2007-OTHERS.pdf

1216-KOL-2007-PETITION UNDER RULE 137.pdf

1216-KOL-2007-REPLY TO EXAMINATION REPORT.pdf

abstract-01216-kol-2007.jpg


Patent Number 252461
Indian Patent Application Number 1216/KOL/2007
PG Journal Number 20/2012
Publication Date 18-May-2012
Grant Date 16-May-2012
Date of Filing 31-Aug-2007
Name of Patentee GM GLOBAL TECHNOLOGY OPERATIONS, INC
Applicant Address 300 GM RENAISSANCE CENTER DETROIT, MICHIGAN
Inventors:
# Inventor's Name Inventor's Address
1 JESSE M. GWIDT 7791 FULLER STREET BRIGHTON, MICHIGAN 48116
2 MICHAEL J. LUCIDO 42372 COTSWOLD COURT NORTHVILLE, MICHIGAN 48167
3 JAMES R. REEDER JR. 3217 PINEVIEW TRAIL HOWELL, MICHIGAN 48843
4 DAVID P. SCZOMAK 1407 TWAIN COURT TROY, MICHIGAN 48083
PCT International Classification Number F02B5/00; F02D41/40
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/531,444 2006-09-13 U.S.A.