Title of Invention

A FUEL INJECTION SYSTEM AND A METHOD FOR A DIRECT FUEL INJECTION ENGINE

Abstract A fuel injection system for a direct fuel injection (DFI) engine is provided. The system includes: injection mode module selects a fuel injection mode to be one of a single injection mode and a dual injection mode during DFI engine idle operation based on a torque request; and a fuel injection command module that commands fuel injection events based on a crankshaft position and the fuel injection mode.
Full Text GP-307887-PTE-CD
1
APPARENT TORQUE RESERVE AT IDLE FOR
DIRECT INJECTED ENGINES
FIELD
[0001] The present disclosure relates to methods and systems for
direct fuel injection engines.
BACKGROUND
[0002] The statements in this section merely provide background
information related to the present disclosure and may not constitute prior art.
[0003] 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.
[0004] The placement of fuel injectors within the engine and the
control of fuel injection timing also impacts engine performance. Port fuel
injection engines locate one fuel injector per cylinder, mounted in the intake
manifold near the cylinder head. Each injector may be controlled either
individually or by groups to inject fuel near the intake valve. Spark-ignited
direct injected (SIDI) engines locate one fuel injector per cylinder, mounted
directly over the cylinder head. Each injector is controlled individually to inject
fuel directly into the cylinder.

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[0005] Conventional methods of controlling fuel during idle
conditions, whether in a port fuel injected engine or a SIDI engine,
intentionally retard spark timing in order to provide a reserve torque. Spark
timing is then advanced when a request for torque is initiated. This allows the
engine to respond to load demands (i.e. power steering "cramp" input) during
idle operation. Retarding spark at idle provides for sub-optimal efficiency.
SUMMARY
[0006] Accordingly, a fuel injection system for a direct fuel injection
(DFI) engine is provided. The system includes: injection mode module selects
a fuel injection mode to be one of a single injection mode and a dual injection
mode during DFI engine idle operation based on a torque request; and a fuel
injection command module that commands fuel injection events based on a
crankshaft position and the fuel injection mode.
[0007] In other features, a fuel injection method for a direct fuel
injection (DFI) engine is provided. The method includes: operating the engine
in an idle state. During the idle state: commanding fuel at a first rate during a
combustion cycle; receiving a request to increase torque; transitioning to a
dual injection mode based on the request; and commanding fuel at a second
rate and at a third rate during the combustion cycle.
[0008] Further areas of applicability will become apparent from the
description provided herein. It should be understood that the description and
specific examples are intended for purposes of illustration only and are not
intended to limit the scope of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The drawings described herein are for illustration purposes
only and are not intended to limit the scope of the present disclosure in any
way.
[0010] Figure 1 is a functional block diagram illustrating an internal
combustion engine system including direct fuel injection hardware.

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[0011] Figure 2 is a dataflow diagram illustrating a fuel injection
system.
[0012] Figure 3 is timing diagrams illustrating the scheduling of fuel
injection events during a single injection mode and a dual injection mode.
[0013] Figure 4 s a graph illustrating the effects of switching
between the single injection mode and the dual injection mode on engine
speed and fuel flow rates.
DETAILED DESCRIPTION
[0014] The following description is merely exemplary in nature and
is in no way intended to limit the disclosure, 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.
[0015] 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.
[0016] 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 the 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

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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.
[0017] A crankshaft sensor 34 senses a position of the crankshaft
and generates a crankshaft signal. A control module 36 receives the
crankshaft signal, interprets the signal as degrees of rotation and schedules
fuel injection events based on the interpretation of the signal. The control
module 36 sends a fuel injection signal to the fuel injector to control the
amount and the timing of the fuel delivery. The fuel injection signal can be a
pulse width modulated signal where the pulse width regulates the amount of
fuel delivered to the cylinder.
[0018] Referring now to Figure 2, the present disclosure provides a
control method and system that governs the transitions between single and
dual fuel injection modes during idle conditions. A dataflow diagram illustrates
various embodiments of the fuel injection system that may be embedded
within the control module 36. Various embodiments of fuel injection systems
according to the present disclosure may include any number of sub-modules
embedded within the control module 36. The sub-modules shown may be
combined and/or further partitioned to similarly govern the transitions between
the single injection mode and the dual injection mode during idle conditions.
[0019] In various embodiments, the control module 36 of Figure 2
includes an injection mode module 50 and a fuel injection command module
52. The injection mode module 50 receives as input a torque request 54. As
can be appreciated, the inputs to the system may be sensed from the system
10, received from other control modules (not shown) in the system, or
determined from other sub-modules within the control module 36. The
injection mode module 50 selects an injection mode 56 to be one of a single
injection mode and a dual injection mode based on the torque request 54.

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The fuel injection command module 52 receives as input the injection mode
56 and a crankshaft position 58. The fuel injection command module 52
schedules fuel injection events and commands fuel 60 based on the injection
mode 56 and the crankshaft position 58.
[0020] Referring now to Figure 3, timing diagrams for scheduling
fuel injection events according to the present disclosure are shown. During
engine idle operating conditions, control begins in the single injection mode
shown generally at 100. During the single injection mode, one injection event
is scheduled per cylinder per combustion cycle. If during idle Conditions, an
increase in torque is requested, control switches to a dual injection mode
shown generally at 200. During the dual injection mode, two injection events
are scheduled per cylinder per combustion cycle. This generates an increase
in torque without increasing fuel consumption.
[0021] More specifically, fuel injection events can be scheduled
according to the crankshaft position indicated by degrees of crank rotation. A
crankshaft signal can be interpreted as a position in crank degrees. Each
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
110. The piston begins the combustion stroke at one hundred eighty (180)
crank rotation degrees before top dead center (also referred to bottom dead
center (BDC)) at 120. The piston ends the combustion stroke at top dead
center or zero (0) crank rotation degrees shown at 130. Firing of spark for
both the single injection mode 100 and the dual injection mode 200 occurs
near top dead center of the combustion stroke at 140. In an exemplary
embodiment firing occurs between ten (10) and zero (0) crank degrees before
top dead center.

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[0022] When in the single injection mode 100, a single injection
event is scheduled early in the combustion cycle. The 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. An exemplary range for scheduling the fuel
delivery is between two hundred and seventy (270) and three hundred and
thirty (330) crank degrees before firing of spark as shown at 150. The single
injection mode 100 delivers less torque than dual injection for the same
conditions but allows for spark timing to be near minimum best torque (MBT)
to improve efficiency.
[0023] If an increase in torque is requested, control switches to the
dual injection mode 200 and 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. 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 160. The amount of fuel delivered 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.
[0024] 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 170. 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.

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[0025] Referring now to Figure 3, a graph illustrates the impact on
engine speed and fuel economy when controlling the fuel injection events
according to the present method. Engine speed in RPM is shown along the y-
axis at 300. Time in seconds is shown along the x-axis at 310. Fuel flow rate
in g/s is shown along the y-axis at 320. Dual pulse active data is shown at
330. Engine speed data is shown at 340. Fuel flow rate data is shown at
350. As shown by the data, when the dual injection mode is active, engine
speed increases, thus compensating for the increase in load. Fuel flow rate
decreases to improve fuel economy.
[0026] Those skilled in the art can now appreciate from the
foregoing description that the broad teachings of the present disclosure can
be implemented in a variety of forms. Therefore, while this disclosure has
been described in connection with particular examples thereof, the true scope
of the disclosure 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-307887-PTE-CD
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CLAIMS
What is claimed is:
1. A fuel injection system for a direct fuel injection (DFI) engine,
comprising:
an injection mode module that selects a fuel injection mode to
be one of a single injection mode and a dual injection mode during DFI engine
idle operation based on a torque request; and
a fuel injection command module that commands fuel injection
events based on a crankshaft position and the fuel injection mode.
2. The system of claim 1 wherein the fuel injection command
module commands fuel at a first rate when the crankshaft position is within a
first predetermined range during the single injection mode.
3. The system of claim 1 wherein the fuel injection command
module commands fuel at a second rate and at a third rate when the
crankshaft position signal indicates a crankshaft position within second and
third predetermined ranges respectively during the dual injection mode.
4. The system of claim 2 wherein the first predetermined range is
between two hundred and fifty and three hundred and eighty crank rotation
degrees before spark is commanded near top dead center.
5. The system of claim 3 wherein the second predetermined range
is between two hundred and fifty and three hundred and eighty crank rotation
degrees before spark is commanded near top dead center.
6. The system of claim 3 wherein the third predetermined range is
between zero and one hundred and eighty crank rotation degrees before
spark is commanded near top dead center.

GP-307887-PTE-CD
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7. The system of claim 3 wherein the fuel injection command
module determines the second and the third rates based on a total fuel
required for the combustion cycle and wherein the total fuel required is
determined from engine operating conditions and torque requests.
8. The system of claim 3 wherein the second and the third rate is
based on a first and a second predetermined percentage of the total fuel
required for the combustion cycle, wherein the first predetermined percentage
is greater than the second predetermined percentage.
9. The system of claim 8 wherein the first predetermined
percentage is between twenty and ninety percent of the total fuel and wherein
the second predetermined percentage is between ten and eighty percent of
the total fuel.
10. A fuel injection method for a direct fuel injection (DFI) engine,
comprising:
operating the engine in an idle state; and
wherein during the idle state:
commanding fuel at a first rate during a combustion cycle;
receiving a request to increase torque;
transitioning to a dual injection mode based on the request; and
commanding fuel at a second rate and at a third rate during the
combustion cycle.
11. The method of claim 10 wherein the commanding fuel at a first
rate and the commanding fuel at a second and at a third rate is based on a
crankshaft position.

GP-307887-PTE-CD
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12. The method of claim 11 wherein the commanding fuel at a first
rate further comprises commanding fuel at a first rate when the crankshaft
position is within a first predetermined range during the combustion cycle of
an engine cylinder.
13. The method of claim 11 wherein the commanding fuel at a
second rate and at a third rate further comprises commanding fuel at a
second rate when the crankshaft position is within a second predetermined
range and commanding fuel at a third rate when the crankshaft position is
within a third predetermined range during the combustion cycle of the engine
cylinder.
14. The method of claim 10 further comprising commanding spark
when the crankshaft position is near top dead center during the single
injection mode and the dual injection mode.
15. The method of claim 10 wherein the commanding fuel at a first
rate further comprises commanding fuel at a first rate when an engine
crankshaft position is within a range of two hundred and fifty and three
hundred and eighty degrees of crank rotation before top dead center firing.
16. The method of claim 10 wherein the commanding fuel at a
second rate further comprises commanding fuel at a second rate when an
engine crankshaft position is within a range of two hundred and fifty and three
hundred and eighty degrees of crank rotation before top dead center firing
and wherein the commanding fuel at a third rate further comprises
commanding fuel at a third rate when a crankshaft position is within a range of
zero and one hundred and eighty degrees of crank rotation before top dead
center firing.

GP-307887-PTE-CD
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17. The method of claim 10 wherein the commanding fuel at a
second rate is based on a predetermined percentage of a total fuel desired for
the combustion cycle.
18. The method of claim 17 wherein the commanding fuel at a
second rate is based on the predetermined percentage that is between twenty
and ninety percent of total fuel desired for the combustion cycle.

19. The method of claim 10 wherein the commanding fuel at the
third rate is based on a predetermined percentage of a total fuel desired for
the combustion cycle.
20. The method of claim 19 wherein the commanding fuel at the
third rate is based on the predetermined percentage that is between ten and
eighty percent of total fuel desired for the combustion cycle.

A fuel injection system for a direct fuel injection (DFI) engine is
provided. The system includes: injection mode module selects a fuel injection
mode to be one of a single injection mode and a dual injection mode during
DFI engine idle operation based on a torque request; and a fuel injection
command module that commands fuel injection events based on a crankshaft
position and the fuel injection mode.

Documents:

01213-kol-2007-abstract.pdf

01213-kol-2007-assignment.pdf

01213-kol-2007-claims.pdf

01213-kol-2007-correspondence 1.2.pdf

01213-kol-2007-correspondence others 1.1.pdf

01213-kol-2007-correspondence others.pdf

01213-kol-2007-description complete.pdf

01213-kol-2007-drawings.pdf

01213-kol-2007-form 1.pdf

01213-kol-2007-form 2.pdf

01213-kol-2007-form 3.pdf

01213-kol-2007-form 5.pdf

01213-kol-2007-priority document.pdf

1213-KOL-2007-(25-10-2011)-ABSTRACT.pdf

1213-KOL-2007-(25-10-2011)-AMANDED CLAIMS.pdf

1213-KOL-2007-(25-10-2011)-CORRESPONDENCE.pdf

1213-KOL-2007-(25-10-2011)-DESCRIPTION (COMPLETE).pdf

1213-KOL-2007-(25-10-2011)-FORM 2.pdf

1213-KOL-2007-(25-10-2011)-FORM 3.pdf

1213-KOL-2007-(25-10-2011)-OTHERS.pdf

1213-KOL-2007-ABSTRACT 1.1.pdf

1213-KOL-2007-AMANDED CLAIMS.pdf

1213-KOL-2007-ASSIGNMENT.pdf

1213-KOL-2007-CORRESPONDENCE 1.1.pdf

1213-KOL-2007-CORRESPONDENCE OTHERS 1.3.pdf

1213-KOL-2007-CORRESPONDENCE.pdf

1213-KOL-2007-DESCRIPTION (COMPLETE) 1.1.pdf

1213-KOL-2007-DRAWINGS 1.1.pdf

1213-KOL-2007-EXAMINATION REPORT REPLY RECIEVED.pdf

1213-KOL-2007-EXAMINATION REPORT.pdf

1213-KOL-2007-FORM 1-1.1.pdf

1213-KOL-2007-FORM 18.pdf

1213-KOL-2007-FORM 2-1.1.pdf

1213-KOL-2007-FORM 26 1.1.pdf

1213-KOL-2007-FORM 26.pdf

1213-KOL-2007-FORM 3-1.1.pdf

1213-KOL-2007-FORM 3.pdf

1213-KOL-2007-FORM 5.pdf

1213-KOL-2007-GRANTED-ABSTRACT.pdf

1213-KOL-2007-GRANTED-CLAIMS.pdf

1213-KOL-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

1213-KOL-2007-GRANTED-DRAWINGS.pdf

1213-KOL-2007-GRANTED-FORM 1.pdf

1213-KOL-2007-GRANTED-FORM 2.pdf

1213-KOL-2007-GRANTED-LETTER PATENT.pdf

1213-KOL-2007-GRANTED-SPECIFICATION.pdf

1213-KOL-2007-OTHERS 1.1.pdf

1213-KOL-2007-OTHERS.pdf

1213-KOL-2007-PA.pdf

1213-KOL-2007-PETITION UNDER RULE 137.pdf

1213-KOL-2007-REPLY TO EXAMINATION REPORT 1.1.pdf

abstract-01213-kol-2007.jpg


Patent Number 250761
Indian Patent Application Number 1213/KOL/2007
PG Journal Number 04/2012
Publication Date 27-Jan-2012
Grant Date 24-Jan-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 MATTHEW A. WILES 812 CAATALPA DRIVE ROYAL OAK, MICHIGAN 48067
2 MICHAEL J. LUCIDO 42372 COTSWOLD COURT NORTHVILLE, MICHIGAN 48168
3 JESSE M. GWIDT 7791 FULLER STREET BRIGHTON, MICHIGAN 48116
4 DAVID P. SCZOMAK 1407 TWAIN COURT TROY, MICHIGAN 48083
PCT International Classification Number F02M27/04; F02M57/00; F02M57/06
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/530,678 2006-09-11 U.S.A.