(19) Japan Patent Office (JP) (12) JAPANESE UNEXAMINED PATENT (11) Patent Application
` APPLICATION PUBLICATION (A) Disclosure
`
`No.
`
`
`
`Ident. Code
`325
`
`
`
`
`
`
`JP 2002-227697
`(P2002-227697 A)
`(43) Publication Date: August 14, 2002 (Heisei 14)
`FI
`
`Theme Code (Reference)
`F02D 41/22
`325B
`3G023
`F02B 17/00
` C
`3G066
`23/08
` Z
`3G084
`23/10
` Z
`3G301
`F02D 41/34
` C
`
` (51) Int.Cl.7
`
` F02D
`41/22
`
`F02B
`17/00
`23/08
`23/10
`41/34
`
`F02D
`
`
`
`January 31, 2001
`(22) Date of Filing
` (Heisei 13)
`
` Total No. of Claims: 2 OL (Total 8 pages) Continued on last page
`Examination Request: Not Yet
`(21) Application No. JP 2001-23596
`(71) Applicant
`000006286
`(P2001-23596)
` Mitsubishi Motors Corporation
` 5-33-8 Shiba,
` Minato-ku,
` Tokyo-to
`(72) Inventor
`Kinjiro Okada
` c/o Mitsubishi Motors
`Corporation
` 5-33-8 Shiba,
` Minato-ku,
` Tokyo-to
`(72) Inventor
`Osamu Nakayama
` c/o Mitsubishi Motors
`Corporation
` 5-33-8 Shiba,
` Minato-ku,
` Tokyo-to
`(74) Agent 100092978
`Tamotsu Sanada
` Attorney
`
`Continued on last page
`
`(54) [Title of Invention] FUEL INJECTION
`APPARATUS FOR INTERNAL
`COMBUSTION ENGINE
`
`(57) [Abstract]
`[Problem] The present invention relates to a fuel
`injection apparatus for an internal combustion
`engine that is capable of reliably suppressing
`knocking without causing a decrease in output.
`[Resolution Means] If knocking is detected by a
`knock detection means 7, fuel is injected from both
`fuel injection valves in a first fuel injection valve 5
`provided in an intake passage 2 and a second fuel
`injection 6 valve for injecting fuel directly into a
`combustion chamber. Thus, when knocking
`actually occurs, it is reliably switched to an
`appropriate fuel injection mode, and knocking is
`suppressed without causing a decrease in output.
`
`FORD Ex. 1008, page 1
` IPR2019-01400
`
`

`

`[Scope of Claims]
`What is claimed is:
`[Claim 1] A fuel injection apparatus for an internal combustion engine, comprising:
`a first fuel injection valve provided in an intake passage,
`a second fuel injection valve for injecting fuel directly into a combustion chamber, and
`a knock detection means for detecting knocking, wherein:
`if knocking is detected by the knock detection means, fuel is injected from both fuel injection
`valves in the first fuel injection valve provided in the intake passage and the second fuel
`injection valve for injecting fuel directly into the combustion chamber.
`[Claim 2] The fuel injection apparatus for an internal combustion engine according to claim
`1, wherein if knocking is detected by the knock detection means, fuel of an amount such that
`the air to fuel ratio is about 30 to 60 is injected from the first fuel injection valve during
`intake stroke, and fuel of an amount such that the total air to fuel ratio is stoichiometric or
`rich is injected from the second fuel injection valve during compression stroke.
`[Detailed Description of the Invention]
`[0001]
`[Technical Field of the Invention] The present invention relates to a fuel injection apparatus
`for an internal combustion engine suitable for use in an internal combustion engine that
`injects fuel into an intake passage.
`[0002]
`[Prior Art] Generally, in an engine, as shown in FIG. 6(B), the higher the temperature of the
`combustion chamber or the higher the pressure of the combustion chamber, the more easily
`the fuel self-ignites, and the engine is more susceptible to knocking. Furthermore, as shown
`in FIG. 6(A), the self-ignition region also depends on the air to fuel ratio, and if the air to fuel
`ratio is too high, the air to fuel mixture is too lean to be able to self-ignite, and furthermore, if
`the air to fuel ratio is too low, then the mixture will be too rich and will also not self-ignite. In
`contrast to this, knocking is likely to occur in the region of an air to fuel ratio of about 12 to
`18.
`[0003] Furthermore, at low engine speeds, the mixture is exposed to a high temperature
`combustion chamber wall for a long time, the mixture temperature rises, so it is easy to self-
`ignite, therefore it is extremely prone to knocking under low speed and high load conditions.
`Conventionally, when such knocking occurs, it is common to suppress the knocking by
`retarding the ignition timing, but when the ignition timing is retarded a decrease in output
`cannot be avoided.
`[0004] Incidentally, Patent No. 2668680 discloses a technique that controls knocking without
`decreasing output, wherein a fuel injection mode only for in-cylinder injection, a fuel
`injection mode combining in-cylinder injection and intake injection, and a fuel injection
`mode only for intake injection are appropriately switched according to the respective
`operating conditions in a spark ignition type in-cylinder direct injection type engine.
`[0005]
`[Problem to be Solved by the Invention] However, with such a technique, switching of the
`fuel injection mode is performed for each operation region set in advance, so it is not possible
`to accurately coordinate with the actual operation status. Furthermore, there have been cases
`where the pre-set operating region was incompatible with the actual engine due to
`manufacturing variations and the like of individual engines. For this reason, although
`knocking actually occurs, there is a possibility that the appropriate fuel injection mode cannot
`be set.
`[0006] The present invention was devised in view of such a problem, therefore the object is
`to provide a fuel injection apparatus for an internal combustion engine that is capable of
`reliably suppressing knocking without causing a decrease in output.
`
`FORD Ex. 1008, page 2
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`

`[0007]
`[Means for Solving the Problem] With the fuel injection apparatus of an internal combustion
`engine in the present invention according to claim 1, if knocking is detected by a knock
`detection means, fuel is injected from both fuel injection valves in a first fuel injection valve
`provided in an intake passage and a second fuel injection valve for injecting fuel directly into
`a combustion chamber.
`[0008] Thus, when knocking actually occurs, it is reliably switched to the appropriate fuel
`injection mode, and knocking is suppressed without causing a decrease in output.
`Furthermore, in the fuel injection apparatus for an internal combustion engine of the present
`invention according to claim 2, if knocking is detected by the knock detection means, fuel
`with an air to fuel ratio of about 30 to 60 is injected from the first fuel injection valve during
`intake stroke, and fuel of an amount such that the total air to fuel ratio becomes
`stoichiometric or rich is injected from the second fuel injection valve during compression
`stroke.
`[0009] Thus, a partially fuel-rich mixture by fuel injection from the second fuel injection
`valve flows into the combustion chamber in which a lean mixture (air to fuel ratio 30 to 60)
`formed in advance by fuel injection from the first fuel injection valve spreads within the
`cylinder. In this case, the mixture formed by fuel injection from the first fuel injection valve
`is sufficiently lean and does not self-ignite, and furthermore, the rich mixture formed by fuel
`injection from the second fuel injection valve does not self-ignite as there is no time for a pre-
`knock reaction to proceed before ignition with a spark plug after this. As a result, knocking is
`suppressed without causing the fuel to self-ignite. Furthermore, since the overall air to fuel
`ratio is stoichiometric or rich, a decrease in output is also suppressed.
`[0010]
`[Embodiments of the Invention] The fuel injection apparatus for an internal combustion
`engine according to one embodiment of the present invention will be described with
`reference to drawings below. FIG. 1 is a schematic view showing the main configuration
`thereof. In the present embodiment, the internal combustion engine (engine) is based on a
`general intake injection engine 1 that injects fuel into an intake passage and mixes intake and
`fuel, and particularly in the present embodiment, a multipoint injection type engine in which
`an injector (referred to as a first fuel injection valve or main injector) 5 is provided in the
`intake passage of each cylinder is applied.
`[0011] Furthermore, in FIG. 1, 1A is a cylinder, 1B is a piston, and 2 is an intake passage. A
`surge tank 8 and an intake manifold 9 or the like are connected to the upstream side of the
`intake passage 2, and the intake passage 2 is configured to include the surge tank 8 and the
`intake manifold 9. Moreover, as shown in FIG. 1, the engine 1 has a spark plug 3 provided at
`the top of the combustion chamber, and it is configured as a spark ignition type engine in
`which fuel is ignited by ignition of this spark plug. Additionally, the engine 1 is provided
`with an injector (referred to as a second fuel injection valve or sub-injector) 6 with an
`injection hole preferably disposed in the combustion chamber so as to inject fuel directly into
`the combustion chamber.
`[0012] This sub-injector 6 is an injector capable of injecting fuel at high pressure during the
`compression stroke, and fuel pressurized by a high-pressure pump (not illustrated) is
`supplied. On the other hand, the engine 1 is provided with a knock sensor (knock detection
`means) 7 that detects knocking when knocking occurs. A knock sensor that is a type that
`detects abnormal vibrations in the cylinder block of engine 1 is applied in the present
`embodiment as the knock sensor 7, yet a knock sensor that detects knocking based on
`rotational speed fluctuations of the engine in addition to this may also be used.
`[0013] Information detected by the knock sensor 7 is to be input to an electronic control unit
`(ECU) 10, and the ECU 10 sets an operation control signal for each of the injectors 5 and 6
`
`FORD Ex. 1008, page 3
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`above based on information from the knock sensor 7. Also, in the present embodiment if it is
`determined by the ECU 10 that knocking has occurred based on detection information from
`the knock sensor 7, fuel injection is performed from the two injectors 5 and 6 to suppress this
`knocking. Note that the fuel injection mode that injects fuel from the two injectors 5 and 6 in
`this way will hereinafter be referred to as split injection mode, and furthermore, the operating
`state in which knocking occurs will be referred to as the specified operating state.
`[0014] Furthermore, while in a normal operating state where knocking is not occurring, the
`operation of the sub-injector 6 is inhibited by the ECU 10 and switches to a fuel injection
`mode to the intake passage 2 with the main injector 5 (hereinafter referred to as intake pipe
`injection mode). As in the foregoing, in engine 1, the operation is performed by injecting fuel
`from the main injector 5 during normal operation, and while in the specified operation state
`where knocking is detected, fuel injection is performed from the two injectors 5 and 6 to
`suppress knocking.
`[0015] Here, if knocking is detected, a small amount of fuel which cannot self-ignite is
`injected from the main injector 5 into the intake passage 2 while the remaining fuel is directly
`injected from the sub-injector 6 into the cylinder (combustion chamber) during the
`compression stroke. Specifically, while in this split injection mode, the fuel injection amount
`is set so that a stoichiometric or rich mixture (that is, a mixture whose total air to fuel ratio is
`the theoretical air to fuel ratio or is smaller than the theoretical air to fuel ratio) is formed due
`to the total injection amount of intake pipe injection and in-cylinder direct injection.
`[0016] In this case, as for fuel injection timing, intake pipe injection with the main injector 5
`is performed during the exhaust stroke or intake stroke (preferably exhaust stroke in which
`the fuel atomization time in the intake pipe can be lengthened), and in-cylinder direct
`injection with the sub-injector 6 is performed during the compression stroke. Although in-
`cylinder direct injection with the sub-injector 6 is performed after intake pipe injection with
`the main injector 5 is performed, fuel supplied into the cylinder by intake pipe injection self-
`ignites which promotes knocking, therefore during intake pipe injection, fuel injection of an
`amount where fuel concentration is lean is performed so that the injected fuel does not self-
`ignite.
`[0017] That is, as shown in FIG. 6(A), for example, when the air to fuel ratio A/F is about 18
`to 12 in the vicinity of the theoretical air to fuel ratio, the fuel is likely to self-ignite, but the
`fuel is less likely to self-ignite as the fuel concentration of the mixture deviates from being in
`the vicinity of the theoretical air to fuel ratio. In order to apply fumigation, it is necessary to
`mix fuel into the intake to the extent that the mixture does not cause self-ignition while
`atomizing or evaporating the fuel in the intake stroke, therefore it is sufficient to create a
`mixture with an extremely lean fuel concentration (air to fuel ratio A/F is significantly larger
`than in the vicinity of the theoretical air to fuel ratio) by intake pipe injection. Note that
`fumigation means that fuel is mixed into the intake to such an extent that the mixture does not
`cause self-ignition while atomizing or evaporating the fuel during the intake stroke in a diesel
`engine, shortening the ignition delay with a pre-flame reaction during the compression stroke
`to prevent knocking. Conventional fumigation could only be applied to diesel engines, but it
`is now possible to implement the same technique in spark ignition engines.
`[0018] Also, here at the time of intake pipe injection, fuel injection is performed by setting
`the injection amount so that the air to fuel ratio becomes about 30 to 60. On the other hand,
`fuel is directly injected from the sub-injector 6 so that the fuel becomes a stoichiometric or
`rich mixture due to the total injection amount of in-cylinder direct injection and intake pipe
`injection. In the present embodiment, in order to be able to form an air to fuel mixture having
`a total air to fuel ratio of about 12, fuel injection is performed by setting an injection amount
`corresponding to an air to fuel ratio of approximately 15 to 20 during in-cylinder direct
`injection.
`
`FORD Ex. 1008, page 4
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`[0019] That is, if the air to fuel ratio at the time of intake pipe injection is about 60, and if
`fuel injection is performed with an injection amount corresponding to the air to fuel ratio of
`about 15 at the time of in-cylinder direct injection, the total air to fuel ratio according to the
`total injection amount can be set to about 12 (that is, 1/12 = 1/60 + 1/15). If the air to fuel
`ratio at the time of intake pipe injection is about 30, and if fuel injection is performed with an
`injection amount corresponding to the air to fuel ratio of about 20 at the time of in-cylinder
`direct injection, the total air to fuel ratio according to the total injection amount can be set to
`about 12 (that is, 1/12 = 1/30 + 1/20).
`[0020] Also, as mentioned above, this kind of split injection mode is implemented if it is
`determined by the ECU 10 that the engine 1 is in the specified operation state (that is, where
`knocking is occurring) based on detection information from the knock sensor 7, and
`furthermore, the engine 1 operates by general premixed combustion due to fuel injection
`from the main injector 5 during normal operation where knocking does not occur.
`[0021] Here, when describing the action of knock suppression with this kind of split
`injection, during in-cylinder direct injection, as shown in FIG. 2(A), a partially fuel-rich
`mixture (air to fuel mixture having a high fuel concentration since a fuel corresponding to the
`total air to fuel ratio A/F = 15 to 20 is injected) by in-cylinder injection forms a laminar flow
`within the combustion chamber in which a lean mixture (air to fuel ratio A/F = 30 to 60)
`formed in advance by fuel injection spreads, and flows in the vicinity of the spark plug 3.
`[0022] In this case, the mixture formed by intake pipe injection from the main injector 5 is
`sufficiently lean and does not self-ignite, and furthermore, the rich mixture formed so as to
`form a laminar flow by in-cylinder direct injection from the sub-injector 6 does not self-ignite
`as there is no time for a pre-knock reaction to proceed before ignition with the spark plug 3
`after this. It is conceivable that this is the effect of suppressing knocking with split injection,
`and as a result, ignition is performed by the spark plug 3 without causing self-ignition of fuel.
`[0023] As a result, first, the rich mixture in the vicinity of the spark plug 3 is ignited, and the
`rich mixture forming a laminar flow begins combustion. Since this rich mixture causes a lack
`of air during combustion, a large amount of soot is produced due to combustion, yet as shown
`in FIG. 2(B), the lean mixture formed by intake pipe injection is presumed to combust with
`this generated soot as the ignition source.
`[0024] That is, the lean mixture formed by the intake pipe injection effectively utilizes the
`surplus air around the layered rich mixture formed by in-cylinder direct injection, and the
`combustion energy can be sufficiently increased and a large output can be obtained, and
`while a relatively rich mixture is combusted by stratified combustion with in-cylinder direct
`injection, the occurrence of soot in the combustion chamber, which is a problem, can be
`greatly suppressed.
`[0025] Note that this split injection mode may be provided with an inhibition region. Here,
`this inhibition region is a region where the engine coolant temperature (it may be a detectable
`parameter corresponding to the engine temperature as well as the cooling water temperature,
`yet here it is an easily detectable cooling water temperature) is a specified temperature or less
`(for example, -10°C). This is because when the engine temperature is low, atomization of the
`fuel deteriorates, and when the fuel of intake pipe injection is difficult to atomize, the
`fumigation conditions are not satisfied, so there is a possibility that the knock prevention
`effect cannot be obtained.
`[0026] Next, how to set the ratio of the injection amount and the injection timing for in-
`cylinder direct injection in such a split injection mode will be described with reference to
`FIGS. 3 and 4. Note that FIGS. 3 and 4 are each drawings that illustrate an example of the
`characteristics in a spark ignition in-cylinder injection type internal combustion engine
`having different specifications, and for each drawing, (A) is one that describes that engine
`rotation speed Ne, the ignition timing and the intake pipe injection timing are fixed to
`
`FORD Ex. 1008, page 5
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`predetermined values respectively, and describes the setting of the injection amount ratio (in-
`cylinder direct injection pulse/total injection pulse) and the injection timing of in-cylinder
`direct injection when the total air to fuel ratio is set to 12, while (B) shows the knock limit
`output characteristics obtained by the setting shown in (A).
`[0027] Firstly, when describing based on FIG. 3, as shown in FIG. 3(A), when advancing the
`in-cylinder direct injection time, the pre-knock reaction progresses, therefore there is a knock
`range, and if the ratio of the in-cylinder direct injection amount to the total injection amount
`is increased, the total HC (THC), that is, the total amount of hydrocarbons, becomes
`excessive, and as the timing of the in-cylinder direct injection is delayed and the proportion
`of the in-cylinder direct injection amount is increased, the generation of smoke becomes
`excessive. Furthermore, there is large rotational fluctuation in the region shown in the
`drawing according to the in-cylinder direct injection timing and the in-cylinder direct
`injection amount ratio, and there is a region causing misfire. Moreover, there is an equal
`output line of the minimum required torque in the form of a curve as illustrated according to
`the in-cylinder direct injection timing and the in-cylinder direct injection amount ratio.
`[0028] Under these various conditions, it is largely assumed that knocking will not occur
`(that is, is not in the knock range) and misfiring will not occur (that is, is not in the misfire
`region), and moreover, a split injection region A1 indicated by hatching in FIG. 3(A) exists
`as a region where THC is not excessive, the generation of smoke is not excessive, and the
`minimum required torque can be obtained.
`[0029] Here, although this region A1 is mainly defined by the equal output line of the
`minimum required torque, depending on the setting of the generation limit value of THC and
`smoke and the value of the minimum required torque, the requirements to define the region
`A1 will differ even in the same engine. If the operating conditions of the same engine are
`different, the requirements for defining the region A1 are also different.
`[0030] Furthermore, if the engine specifications are different, and even if the operating
`conditions are equal and the respective specified conditions are equal (knocking and
`misfiring do not occur, and THC and smoke generation limit values and minimum required
`torque values are also equal), as in region A2 illustrated by hatching in FIG. 4(A), the split
`injection region A2 is different from the region A1 shown in FIG. 3. Also, even among the
`split injection regions A1 and A2 as shown above, points P1 and P2 which satisfy each of the
`respective prescribed conditions in the most balanced manner are indicated by a O in FIG.
`3(A) and FIG. 4(A), respectively.
`[0031] As shown in regions A1 and A2 in FIG. 3(A) and FIG. 4(A), the region suitable for
`performing split injection is where the in-cylinder direct injection timing is about 30 to 100°
`BTDC, and the in-cylinder direct injection amount ratio is about 60 to 90%. Taking these two
`engines as an example, this kind of numerical range can be set as a split injection region, and
`although it is within this numerical range in most engines, it is conceivable that deviation
`would occur in the split injection region depending on changes in engine characteristics,
`operating conditions, and region requirements, so the standard is setting the in-cylinder direct
`injection timing to about 30 to 100° BTDC and the in-cylinder direct injection amount ratio
`to about 60 to 90%, so it is desirable that the settings are according to the characteristics of
`each engine, the operating conditions, and the region specific conditions.
`[0032] Also, if in-cylinder direct injection is performed under point P1 and P2 conditions in
`the split injection regions A1 and A2, the knock limit output is greatly improved as shown in
`FIG. 3 (B) and FIG. 4 (B) respectively in comparison with fuel injection by intake pipe
`injection only with the same air to fuel ratio (= 12). Note that this knock limit output can be
`obtained by advancing the ignition timing within a range in which knocking does not occur.
`For this reason, the effect is particularly great during low to medium rotational speed of the
`engine and a high load region where knocking easily occurs.
`
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`[0033] Furthermore, in fuel injection with intake pipe injection only, knocking is caused
`unless the ignition timing is significantly retarded in a region where the engine rotational
`speed is low, whereas in split injection, the ignition timing is equivalent to that of intake pipe
`injection in a very low range such as cranking or the like where engine speed is less than
`idling speed, yet it can be advanced to a rotation speed range beyond this, and such
`advancement of the ignition timing also helps to significantly improve the knock limit output.
`[0034] Since the fuel injection apparatus for an internal combustion engine according to one
`embodiment of the present invention is configured as described above, for example, as shown
`in FIG. 5, split injection mode (split injection control) is performed. That is, firstly, the
`temperature of the coolant in engine 1 is read (step S10), while information from the knock
`sensor 7 is read (step S20).
`[0035] Also, whether there is a split injection inhibition region is determined based on the
`coolant temperature (step S30). That is, if the coolant temperature is at the predetermined
`temperature or lower, it is determined that there is a split injection inhibition region. If there
`is a split injection inhibition region, it proceeds to step S80, and the flag A is determined.
`This flag A is set to 1 at the time of split injection control and is set to 0 if split injection
`control is not performed. Here, if flag A is 1 (that is, during split injection control), it
`proceeds to step S90, split injection is cancelled (split injection control end), and flag A
`returns 0. Furthermore, if flag A is not 1 (that is, during split injection control), it is returned
`as is.
`[0036] Meanwhile, if there is no split injection inhibition region, it proceeds to S40 from step
`S30, and it determines whether knocking has actually occurred. In the case where it has been
`determined that knocking has not occurred in step S40, it proceeds to step S80 and thereafter,
`and the process described above is performed, yet if it is determined that knocking has
`occurred in step S40, it proceeds to step S50, and determines flag A. Here, if flag A is 1 (that
`is, during split injection control), it is returned as is.
`[0037] Meanwhile, if flag A is not 1 in step S50, it proceeds to step S60, and implements split
`injection control (split injection mode). Also, after split injection control ends, it proceeds to
`step S70, and flag A is set to 1 and returned. According to the fuel injection apparatus in an
`internal combustion engine of the present embodiment, there is an advantage that knock
`suppression processing that accurately reflects the operating state of the engine can be
`performed by injecting fuel from both the main injector 5 and sub-injector 6 when knocking
`has actually occurred. Furthermore, there is an advantage where knocking can be reliably
`suppressed during knocking occurrence by injecting fuel from both the main injector 5 and
`sub-injector 6 during knocking occurrence. Moreover, conventionally, ignition timing has to
`be retarded at the time of knocking occurrence and the output decreases, whereas this has an
`advantage where the ignition timing can be advanced, and output can be improved.
`[0038] Furthermore, it is possible to create an engine that has an advantage against knocking,
`and the original compression ratio can be set higher. Thus, output can be further improved,
`and fuel consumption can be improved. Note that the present invention is not limited to the
`above embodiment, and various modifications are possible. For example, in the embodiment
`described above, the case where the present invention has been applied to a multipoint
`injection type engine has been described, yet the present invention may be applied to a single
`point injection type engine in which fuel injection (intake pipe injection) of all cylinders is
`performed with one injector. In this case, the main injector 5 may be provided in the surge
`tank 8 or the intake manifold 9. Of course, when the main injector 5 is provided in the intake
`manifold 9, the main injector 5 is provided at a position further upstream than the position
`where the manifold branches into each cylinder.
`[0039] Furthermore, if split injection is performed, it may be defined not by the air to fuel
`ratio, but by the amount of fuel injected from each injector 5 and 6. For example, it is also
`
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`possible to inject 1/4 of the total fuel amount at the time of intake pipe injection by the main
`injector 5 and to inject the remaining 3/4 of the fuel amount at the time of in-cylinder direct
`injection by the sub-injector 6.
`[0040]
`[Effect of the Invention] As described in detail above, according to the fuel injection
`apparatus in an internal combustion engine according to claim 1, there is an advantage that
`knock suppression processing that accurately reflects the operating state of the engine can be
`performed by injecting fuel from both the main injector 1 and sub-injector 2 when knocking
`has actually occurred. Furthermore, there is an advantage where knocking can be suppressed
`while improving output by injecting fuel from both the first and second fuel injection valves
`during knocking occurrence.
`[0041] Moreover, according to the fuel injection apparatus for an internal combustion engine
`of the present invention according to claim 2, if knocking is detected by the knock detection
`means, fuel of an amount such that the air to fuel ratio is about 30 to 60 is injected from the
`first fuel injection valve during intake stroke, and fuel of an amount such that the total air to
`fuel ratio becomes stoichiometric or rich is injected from the second fuel injection valve
`during compression stroke, making it possible to reliably suppress knocking and to improve
`output.
`[Brief Description of the Drawings]
`FIG. 1 is a schematic diagram illustrating the main structure of a fuel injection apparatus in
`an internal combustion engine according to the embodiment of the present invention.
`FIG. 2 is a drawing for describing the principle of knocking suppression with a fuel injection
`apparatus for an internal combustion engine according to the embodiment of the present
`invention, while (A) illustrates a state during in-cylinder direct injection, and (B) illustrates a
`post-combustion state after ignition.
`FIG. 3 is a drawing illustrating a setting example of in-cylinder direct injection in a fuel
`injection apparatus for an internal combustion engine according to the embodiment of the
`present invention and the effects thereof, while (A) is a drawing describing the ratio of in-
`cylinder direct injection and injection timing, and (B) illustrates the improvement of knock
`limit output by split injection.
`FIG. 4 is a drawing illustrating a setting example of in-cylinder direct injection in a fuel
`injection apparatus for an internal combustion engine according to the embodiment of the
`present invention and the effects thereof, while (A) is a drawing describing the ratio of in-
`cylinder direct injection and injection timing, and (B) illustrates the improvement of knock
`limit output by split injection.
`FIG. 5 is a flowchart for describing the operation of a fuel injection apparatus in an internal
`combustion engine according to the embodiment of the present invention.
`FIG. 6 is a drawing illustrating a general knock occurrence characteristic (self-ignition limit),
`while (A) is related to mixture concentration and temperature, and (B) is related to
`temperature and pressure.
`[Description of Reference Symbols]
`1 Internal combustion engine (engine)
`5 First fuel injection valve (main injector)
`6 Second fuel injection valve (sub-injector)
`7 Knock detection means (knock sensor)
`10 Control means (ECU)
`
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`[FIG. 1]
`
`[FIG. 2]
`
`Compression stroke
`latter (injection
`period)
`
`(1) Mixture
`formed with
`to intake pipe
`(A/F: 30 to
`60)
`
` stroke early period
`(combustion latter
`period)
`
`(2) Mixture
`formed with
`to cylinder
`(A/F: 15)
`
`(3)-Combustion
`of thin mixture
`where soot is the
`ignition source
`-Re-combustion
`of soot
`
`FORD Ex. 1008, page 9
` IPR2019-01400
`
`

`

`

`

`

`

`

`

`(19) ARE (JP)
`
`(11) 9834HBAS
`42002 — 227697
`(P2002 — 227697A)
`(43)43BR A aR144F 8 A144 (2002. 8.14)
`
`(2) 3s Bel Re BF OR OA)
`
`Balan
`325
`
`(1) Int.Cl."
`FO2D 41/22
`FO2B 17/00
`93/08
`73/10
`FO2D 41/34
`
`7-TI-b (Bs)
`FI
`325B 38G023
`FO2D 41/22
`C
`38G066
`FO2B 17/00
`Z
`36084
`23/08
`Z
`86301
`23/10
`c
`FO2D 41/34
`RRAKH<
`ork ABR SRAOR2 OL (48 BH)
`
`
`
`
`(71) HERA 000006286