GB2447181A - (EN) air-fuel ratio judging method in internal combustion engine based in ion current (JA) - Google Patents
(EN) air-fuel ratio judging method in internal combustion engine based in ion current (JA) Download PDFInfo
- Publication number
- GB2447181A GB2447181A GB0811244A GB0811244A GB2447181A GB 2447181 A GB2447181 A GB 2447181A GB 0811244 A GB0811244 A GB 0811244A GB 0811244 A GB0811244 A GB 0811244A GB 2447181 A GB2447181 A GB 2447181A
- Authority
- GB
- United Kingdom
- Prior art keywords
- fuel ratio
- ion current
- air fuel
- generation period
- combustion engine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 104
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 60
- 238000000034 method Methods 0.000 title claims abstract description 8
- 238000002347 injection Methods 0.000 description 10
- 239000007924 injection Substances 0.000 description 10
- 239000000203 mixture Substances 0.000 description 6
- 239000003054 catalyst Substances 0.000 description 5
- 238000005259 measurement Methods 0.000 description 4
- 230000000979 retarding effect Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000003213 activating effect Effects 0.000 description 2
- 230000006399 behavior Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000004913 activation Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000008034 disappearance Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
- F02D35/02—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions
- F02D35/021—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions using an ionic current sensor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
- F02D41/1454—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio
- F02D41/1458—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio with determination means using an estimation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D37/00—Non-electrical conjoint control of two or more functions of engines, not otherwise provided for
- F02D37/02—Non-electrical conjoint control of two or more functions of engines, not otherwise provided for one of the functions being ignition
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
- Ignition Installations For Internal Combustion Engines (AREA)
Abstract
An air-fuel ratio judging method of an internal combustion engine based on an ion current in which a generation period during which an ion current generated in the combustion chamber of the internal combustion engine exceeds a preset value is measured, and an air-fuel ratio under operating state of the internal combustion engine is judged based on the measured generation period. A decision is made that an air-fuel ratio is other than a theoretical air-fuel ratio when the measured generation period is below a reference value. The reference value is set based on a generation period corresponding to ignition timing when an actual air-fuel ratio is a theoretical air-fuel ratio, and a larger reference value is set as the delay angle of ignition timing increases.
Description
DESCR12T1O METflOD E'OR DETERMINING AIR FUEL RATIO OF INTERNAL
COMBUSTION
ENGINE ON THE BASIS OF ION CURRENT
TECHNICAL FIELD
The present invention relates to a method for determining an air fuel ratio of an internal combustion engine on the basis of an ion current, which determines an air fuel raLlo of the internal combustion engine by detecting an ion current generated within a combustion chamber after an ignition of the internal combustion engine.
BACKGROUND ART
Conventionally, in a spark ignition type internal combustion engine (hereinafter, refer to as an engine) mounted on a vehicle such as a motor vehicle, there has been known a structure which detects an ion current generated within a combustion chamber after an ignition by utilizing a spark plug, measures a characteristic a the detected ion current, for example, a period or a time for which the current value of the detected ion current is equal to or greater than a predetermined value, and determines a combustion state in an operating state of the engine on the basis of the measured period. For example, the structure described in Patent Document 1 detects a lean limit (a limit of an operation in a lean burn) in which a fluctuation :1 is generated in a torque or the like in the case that the period becomes equal to or greater than a set determination value, on the basis of a length of the measured period of the ion current.
Patent Document 1: Japanese Unexamined Patent Publication No. 6-34491 In this case, in recent years, it is confirmed by an experiment that the ion current is changed by reflecting a combustion state in the case of operating the engine by controlling such that an actual air fuel ratio come close to a Stojchjorrietrjc air fuel ratio, however, is changed by an influence of an ignition timing in addition to the change on the basis of the change of the actual air fuel ratio as mentioned above. In particular, for example, in the case of operating the engine approximately on the basis of the stoichiornetric air fuel ratio, if the ignition timing is retarded, the period for which the ion current is generated becomes longer in accordance that an amount of spark retard of the ignition timing is increased.
As described above, if the time for which the ion current is generated is changed, by changing the ignition timing, a case that the lean limit IS erroneously detected is generated, in the structure described in the Patent Document 1 mentIoned above.
In other words, for example, if the ignition timing is retarded greatly in the case that a temperature of a catalyst is raised to an activation temperature in an early time, there is a POSsibility of determining an erroneous combustion state tt-dicatii-g te 1ean U.mit, because the period for whIch the Ion current is generated is longer than the case of being operated in a normal combustion state, in spite of operating the engine while maintaining the air fuel ratio near the stoichiometric air fuel ratio.
DISCLOSURE OF THE INVENTION
ccordingly, an object of the present invention is to dissolve the problem mentioned above.
In other words, in accordance with the present invention, there is provided a method for determining an air fuel ratio of an internal combustion engine on the basis of an ion current, comprising the steps of: measuringageneratjoflpej0j which Lhe ion current generated within a combustion chamber of the internal combustion engine is greater than a predetermined value; determining an air fuel rtio in an operating state of the internal combustion engine on the basis of the measured generation period; and determining that the air fuel ratio is except a stoichiorretric air fuel ratio in the case that the measured generation period is lower than a reference value, wherein the reference value is set on the basis of a generatjon period corresponding to an ignition timing in the case that an actual air fuel ratio is equal to the stoichioriietrjc air fuel ratio and is set larger in accordance that an amount of spark retard of the ignition timing is larger.
In accordance with the structure of the present invention, the reference value is set on the basis of the generation period corresponding to the ignition timing in the case that the actual air fuel ratio is equal to the stoichiometric air fuel ratio and is set larger in accordance that the amount of spark retard of the ignition timing is larger, thereby considering an influence applied to the ion current of the ignition timing.
In other words, if an ignition timing is retarded over a specific ignition timing i.n the case that the air fuel ratio is high and an air-fuel mixture is lean, the generation period of the ion current tends to be shorter in accordance with performing the spark retard.
It is possible to determine the case that the air fuel bysetting the reference value on the basis of the generation period measured in the operat:ing state in the stoichiometric air fuel ratio, while utilizing the tendency of the generation period of the ion current with respect to the ignition timing as mentioned above. Further, since the reference value is set in connection with the amount of spark retard of the ignition timing, it is possible to determine that the air fuel ratio is higher than the stoichiometric air fuel ratio and the air-fuel mixture is lean, in the case that the generation period of the ion current is short on the basis of the spark retard.
In order to accurately determine the air fuel ratio in the case that the ignition timing is retarded, it is preferable to determine that the air fuel ratio is leaner than the stoichiometrjc air fuel ratio and the air-fuel mixture is in the lean state, in the case that the measured generation period is smaller than the reference value.
The present invention is structured as described above, can determine the case that the air fuel ratio is not equal to thestojchjometrjc air fuel ratio, bysetting the reference value lager in accordance that the amount of spark retard of the ignition timing is larger on the basis of the generation period measured in the operating state in the stoichiometric air fuel ratio, and can determine that the air fuel ratio is leaner than the stoichiometric air fuel ratio and the air-fuel mixture is lean, in the case that the generation period of the ion current is short on the basis of the spark retard.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. I is an explanatory view of a structure showing a schematic structure of an engine in accordance with an embodiment of the present invention.
Fig. 2 is a graph showing a tendency of a reference time with respect to an amount of spark retard of an ignition timing In the embodiment.
Fig. 3 is a flow chart showing a control procedure of the embodiment Fig. 4 is a graph showing an ion current wave form in the case of a different combustion state of the embodiment.
BEST MODE FOR CARRYING OUT THE INVENTION
One embodiment of the present invention will be described below with reference to the drawings.
An engine 100 schematically shown in Fig. I is of a spark and is structured such that a throttle valve 2 opening and closing in response to an accelerator pedal (not shown) is arranged in an intake system 1, and a surge tank 3 is provided at a downstream sideof the throttlevalve2. A fuel injectionvalve 5 is further provided near one end portion communicating with the surge tank 3, and the fuel injection valve 5 is structured such as to be controlled by an electronic control device 6. An incake valve 32 and an exhaust valve 33 are arranged in a cylinder head 31 forming a combustion chamber 30, and a spark plug l forming an electrode for generating a spark and detecting an ion current I is attached to the cylinder head 31. Further, an 02 sensor 21 for measuring an oxygen concentration in the exhaust gas is attached to an upstream position of a three-way catalyst 22 corresponding to a catalyst device arranged in a pipe line until reaching a muffler (not shown), in the exhaust system 20. Here, Fig. 1 illustrates as a representative of a structure of one cylinder of the engine 100.
The electronic control device s mai'nly constructed by a microcomputer system which includes a central. processing unit 7, a memory device 8, an input interface 9, an output interface ii, and an A/D converter 10. To the input interface 9, there are input an intake pressure signal a which is output from an intake air pres5ure sensor 13 for detecting a pressure within the surge tank 3, that is, an intake pipe pressure, a cylinder determination signalGi, acrankangle reference posftion signal G2 and an engine rotating speed signal b which are output from a cam position sensor 14 for detecting a rotating state of the engine 100, avehicle speed signalcwhich is output froma vehicle speed sensor 15 for detecting a vehicle speed, an IDL signal d which is output from an idle switch 16 for detecting an opened and closed state of the throttle valve 2, a water temperature signal. e which is output from a water temperature sensor 17 for a current signal h which is output from the above 02 sensor 21 and the like. On the other hand, a fuel ignition signal I is output to che fuel injection valve 5, and an ignition pulse g is output to a spark plug 18, from the output interface 11.
A power supply 24 for bias for measuring an ion current I is connected to the sparkplug 18, andacircujt 25 formeasuring the ion current is connected between the input interface 9 and the bias power supply 24. An ion current detection system 40 is constructed by the spark plug 18, the bias power supply 24 arjd t're ion cutrent reasuiinq circuit 2. TheIas power supply 24 is structured such as to apply a measuring voltage (a bias voltage) for measuring the ion current to the spark plug 18 at a point of time when the ignition pulse g disappears. Further, the ion current I flowing between an inner wall of the combustion chamber3Dandacenterelectrodeofthesparkplug 18, andhetween theelectrodesof thesparkpiugl8, onthebasisofanapplication of the measuring voltage is measured by the ion current measuring circuit 25. The bias power supply 24 and the ion current measuring circuit 25 can employ various structures which have
been well known in the field.
In the electronic control device 6, there is installed a program for injecting the fuel in correspondence to an engine load to the intake system 1 by correcting a basic injection time (a basic injection amount) on the basis of various correction coefficients decided in correspondence to the operating state of the engine 100 by mainly using the intake air pressure signal a output from the intake air pressure sensor 13 and the rotating speed signal h output from the cam position sensor 14 so as to decide a fuel injection valve opening time, that is, an injector final exciting time T, controlling the fuel injection valve 5 or) the basis of the decided exciting time. Further, while the fuel injection of the engine 100 is controlled, the electronic control device 6 is programmed such as to detect the ion current I generated within the combustion chamber 30 per ignition, measure the period, that is, the generation period P of the ion current I in which the detected ion current I i.s greater than the predeterminea value, and determine that the stoichiornetrjc air fuel ratio is not established in the case that the measured generationperjodpof the ioncurrent I is shorter thana reference time corresponding to a reference value for determining the air fuel ratio.
In the air fuel ratio determining program in accordance with this embodiment, the reference time mentioned above is structured such as to control such that the actual air fuel ratio comes close to the stojchjornetrjc air fuel ratio so as to retard measure the generation period P of the ion current I per the spark retard of the ignition timing, and store the measured generation period P of the ion current I in correspondence to the amount of spark retard of the ignition timing so as to set to a referent time map. The generation period P of the ion current I is obtained by measuring a period (or a time) fo which the current value of the ion current I is generated while being greater than a threshold level SL corresponding to a predetermined determination value. In the case of measuring the generation period P of the actual ion current I in the case of operating the engine 100 on the basis of an elapsed time thereof, the reference time is set in accordance with a time in correspondence thereto, and in the case of detecbig a crank angle so as to measure the generation period P. the reference time is set on the basis of a value having a crank angle as a unit.
Here, the spark retard indicates retarding the ignition timing in comparison with the previous ignition timing, and retarding to an ignition timing which is retarded from the ignition timing of the most spark advance. Further, the threshold level SL mentioned above is an identical value to the threshold level SL set for measuring the generation period P of the ion current I corresponding to the parameter for determining the combustion state of each of the cylinders in the air fuel ratio determining program.
The reference time based on the generation period with respect to the amount of spark retard of the ignition timing obtained as mentioned above is set to a value which is larger (longer) in accordance that the ignition timing is retarded, as shown in Fig. 2. Fig. 2 shows a tendency of a change of the reference time with respect to the amount of spark retard of the ignition timing as mentioned above. In this case, there is a case that the generation period P measured at the same amount of spark retard is dispersed in spite that the amount of spark retard is fixed. Accordingly, the generation period P may measured at plural times in a state of being operated at the same amount of spark retard, the generation period Pwith respect to each of the amounts of spark retard may be decided on the basis of the average value, and the reference time may be set on the basis of this value. In the reference time set in the reference time map, the reference time with respect to the amount of spark retard of the typical ignition timing is stored, and the reference time with respect to the other amounts of spark retard is set in accordarce with an interpolation calculation.
Next, a processing procedure for determining the air fuel ratio with an air fuel ratio determining programwill be described with reference to Fig. 3.
In a step Si, the generation period P of the ion current I is measured, which is a parameter for detecting that the combustjor of each of the cylinders is not good. The generation period P of the ion current I is measured on the basis of the period for which a current value of the ion current I is greater than the threshold level SL as mentioned above. The measured generation period P of the ion current I is temporarily stored in the memory device 8 together with the amount of spark retard of the ignition timing at a point, in time carrying out the measurement The ion current I is generated within the combustion chamber 30 by applying the measuring voltage to the spark plug 18 after the ignition. In the normal combustion state, as shown n Fig. I (a), the ion current i rapidly flows just after the generation, is reduced before a top dead center, then, is again increased together with the elapse of the time, and the current value becomes maximum near a crank angle at which the combuStion pressure becomes maximum, and is thereafter reduced little by little so as to normally disappear near an end of an expansion stroke.
In the ion current I indicating the current wave form mentioned above, the generation period P thereof is obtained by measuring the period for which the current value of the ion current I or the voltage caused by the current is greater than the threshold lever SL. In this case, the generation period P of the ion current I is measured by any one of an actual time from a start of the measurement to an end of the measurement andacrankanale.
period Pof the ion current I is set, for example, froman ignition to an end of a expansion stroke, and tne generation period P of the ion current I is set by measuring the period for which the iron current I is greater than the threshold level SL during the measuring period. Here, the lower threshold value SL is better, however, the threshold value SL is set greater than a noise level in the case of detecting the ion current I, thereby preventing the ion curxent I from being erroneously detected.
The ion current I indicates various behaviors in accordance with the combustion state. For example, the behavior as mentioned above is indicated in the case of a good combustion nearastoichiometricairfuel ratio, however, there isatendency that the maximum current value becomes smaller in accordance that the air fuel ratio becomes lean and the air-fuel mixture becomes lean, and the generation period P of the ion current I becomes shorter in accordance with an amount of the fuel. In addition, there is a tendency that the generation period P of the ion current I is elongated in accordance that the air fuel ratio becomes rich. Further, if the combustion state becomes no good due to some kind or another reason, there is a case that a disappearance and a regeneration are repeated during the measuring period in the iOn Current I, as shown in Fig. 4(b).
In this case, the ion current I is generated, the periods (P1 and P2 in the case in Fig. 4(b)) that the current value of the ion current I exceeds the threshold level SL are summed, and the sum is set to the generation period P of the ion current I. Tote that, since the ion current I is hardly generated intermittently as mentioned above in the case that the combustion is good, the measurement of a whole thereof may be replaced by measuring the generation period of an initial ion current (corresponding to an ion current waveform value shown in Fig. 4(a)) generated just after the ignition before repeating the intermit Lence.
Tn a step S2, a reference time corresponding to the amount of spark retard of the ignition timing is set by searching a reference time map on the basis of the amount of spark retard of the ignition timing stored in the step Si. In a step S3, it is determined whether or not the generation period P of the measured ion current i is greater than the reference time se in the step S2. As a result of the determination in the step S3, in the case that the generation period P is greater, the step S4 will be carried out succeedirigly, and in the case that the generation period P is equal to or lower, the step S5 will be carried out succeedingly.
Since the reference time is set on the basis of the generation period P of the ion current I measured in the case that the ignition timing is retarded in the stoichiometrjc air fuel ratio, ioncurrent I is greater thanthe reference time, it is determined that the air fuel ratio is substantially equal to the stojchjometric air fuel ratio or such an air fuel ratio that can maintain the good combustion state. Accordingly, in the case that the generation period P of the measured ion current I is equal to or lower than the reference time, it is detected that the air fuel ratio is such an air fuel ratio that can not maintain the good combustion state as is different from the case of the stolchjornetrjc air fuel ratio.
In a step S4, it is determined that the combustion is good because the generation period P of the measured ion current I is greater than the reference time. In this case, the state in which the con'hustjon is good indicates a state in which an actual air fuel ratio in the cylinder measuring the generation period P of the ion current I is close to the stoichjometrjc air fuel ratio, and is not come near the lean side so that the combustion becomes unstable due to the spark retard of the ignition timing.
In a step S5, it is determined that the combustion is not good because the generation period P of the measured ion current I is equal to or lower than the reference time. The state in which the combustion is not good indicates a state in which an actual air fuel ratio in the cylinder measuring the generation period P of the ion current I comes to a leaner state than the stoichjometrjc air fuel ratio, for example, in which there is a possibility of a torque fluctuation, a rotation fluctuation or misfire.
In a step S6, a combustion control (an air fuel ratio control) of the engine 100 is executed in correspondence to the determination in the step S4 arid the step 55. Specifically, in the case that it is determined that the combustion is good inthestepS4, a fuel injection amount such that the actual air fuel ratio becomes lean within a range that does not cause the state in which the combustion is not good. On the other hand, in the case that in the step S5 it is determined that the combustion is not good, the fuel injection amount as changed so as to increase such that the actual air fuel ratio comes to the good combustion, in other words, such that the actual air fuel ratio comes near the Stoichionietric air fuel ratio from the lean state.
In the structure mentioned above, for example, at a time of a cold start, the fuel injection amount is generally increased SOastoternporarjIymaketheactua1ajrfue1ratjojch however, in recent years, there is a qase that it becomes a mainstream to control so as to make the air fuel ratio as lean as possible and make the air-fuel mixture thin, while taking a reduction of an emission into consideration. However, since the 02 sensor 21 does not reach the activating temperature generally, it is impossible to detect the actual air foel ratio. Even in the case mentioned above, this embodiment can comprehend the cornbustjons-e, thatis, thestateoftheactuaj airfuelratjo.
In other words, if the engine 100 is started, the generation period P of the ion current I is measured for each of the cylinders just after the start (the step Si) Thereafter, the control makes progress, the reference time is set on the basis of the amount of spark retard of the ignition timing in the combustion of each of the cylinders in accordance with the reference time map (the step S2), the combustion state is determined on the basis of the set reference time (the step S3, the step S4 and the step S5), and the combustion control is executed in correspondence to the result of determination. Accordingly, in this embodiment, it is possible to securely determine whether the actual air fuel ratio is close to the stoichiornetrjc air fuel ratio, or the state of the lean air fuel ratio causing the state in which the combustion is not good and which does not correspond to the stoichiometrjc air fuel ratio, regardless of the state of the 02 sensor 21.
E'urther, since the combustion control is executed on the basis of the result of deterrninaLion in the case of determining that the actual air fuel ratio is lean, it is possible to operate the engine 100 in the good combustion state without setting the combustion state to the no-good state even in the operating state in which the actual air fuel ratio can not he detected by the O2sensor2l, andwhilesuppressingthe reductionoftheemissjon This activates the three-way catalyst 22 in an early time at a time of the cold start, it is possible to particularly expect the effect in the case that the ignition timing is retarded greatly.
In addition to the cold starting time as mentioned above, in the case of controlling the actual air fuel ratio to the lean side for the purpose of improving the fuel consumption in the it is possible to securely determine such an operating state that the combustion becomes unstable by retarding the igriit ion timing. Further, it is possible to securely prevent the operating state of the engine 100 from becoming no-good, by carrying out the suitable ignition timing control, the fuel ignition control and the like in the operating state mentioned above.
It is tobe noted that, thepresent invention is not limited to the embodiment mentioned above.
In addition, the particular structure of each of the portions is not limited to the embodiment.. mentioned above, but may be variously modified within the scope of the present invention.
INDUSTRIAL APPLICABILITY
The present invention can be widely applied to the structure in which the ion current is generated by using the spark plug just after starting the combustion, in the spark ignition type internal, combustion engine mounted on the vehicle orthe like Further, in the internal combustion engine mentioned above, it is possible to determine the case that the air fuel ratio is not the stoichiometric air fuel ratio, including the case that theairfupl mi xt-ure is leaner than the stoichjometrjc air fuel ratio, while taking the influence of the ignition timing into consideration.
Accordingly, it is particularly effective to apply the present invention to the determination of the air fuel ratio, in the case of the operation in which the ignition timing is retarded greatly for the purpose of activating the catalyst arranged in the exhaust system in an early time, at a time of starting the internal combustion engine.
Claims (2)
- CLMYiS 1. A method for dtrmining an air fuel ratio of an intern1combustion engine on the basis of an ion current, comprising the steps of: measuring a generation period in which the ion current generated within a combustion chamber of the internal combustion engine is greater than a predetermined value; determining an air fuel ratio in an operating state of the internal combustion engine on the basis of the measured generation period; and determining that the air fuel ratio is except a stoichjornetrjc air fuel ratio in the case that the measured generation period is lower than a reference value, wherein the reference value is set on the basis of a generation period corresponding to an ignition timing in the case that an actual air fuel ratio is equal to the stoichiometric air fuel ratio and is set larger in accordance that an amount of spark retard of the ignition timing is larger.
- 2. Themethodrordetermininganajr fuel ratioof an internal combustion engine on the basis of an ion current according to claim 1, wherein the method determines that the air fuel ratio is leaner than the stoichiometric air fuel ratio, in the case smaller than the reference value.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006002524A JP2007182845A (en) | 2006-01-10 | 2006-01-10 | Air-fuel ratio-determining method for internal combustion engine based on ion current |
| PCT/JP2006/326135 WO2007080800A1 (en) | 2006-01-10 | 2006-12-27 | Air-fuel ratio judging method of internal combustion engine based on ion current |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB0811244D0 GB0811244D0 (en) | 2008-07-30 |
| GB2447181A true GB2447181A (en) | 2008-09-03 |
Family
ID=38256211
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0811244A Withdrawn GB2447181A (en) | 2006-01-10 | 2008-06-19 | (EN) air-fuel ratio judging method in internal combustion engine based in ion current (JA) |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JP2007182845A (en) |
| CN (1) | CN101356354A (en) |
| DE (1) | DE112006003637T5 (en) |
| GB (1) | GB2447181A (en) |
| WO (1) | WO2007080800A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103603738B (en) * | 2013-11-18 | 2016-10-19 | 同济大学 | Method based on ion current prediction air-fuel ratio in engine cylinder |
| CN110501100A (en) * | 2019-09-23 | 2019-11-26 | 重庆长安汽车股份有限公司 | A kind of motor torque detection method based on ignition discharge ionization signal |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0634491A (en) * | 1992-07-21 | 1994-02-08 | Daihatsu Motor Co Ltd | Lean limit detecting method utilizing ion current |
| JPH06249121A (en) * | 1993-02-23 | 1994-09-06 | Ngk Spark Plug Co Ltd | Combustion condition detecting device for gasoline engine |
| JPH10176594A (en) * | 1996-12-18 | 1998-06-30 | Daihatsu Motor Co Ltd | Combustion fluctuation detecting method for internal combustion engine |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07293315A (en) * | 1994-04-27 | 1995-11-07 | Daihatsu Motor Co Ltd | Air-fuel ratio detecting method |
| JP3234418B2 (en) * | 1994-11-25 | 2001-12-04 | ダイハツ工業株式会社 | Lean limit detection method |
| JP2003184635A (en) * | 2001-12-20 | 2003-07-03 | Fuji Heavy Ind Ltd | Engine misfire detecting device using ion current and recording medium recording program to be used for the same |
| JP2003184725A (en) * | 2001-12-20 | 2003-07-03 | Honda Motor Co Ltd | Misfire detection device for internal combustion engine |
-
2006
- 2006-01-10 JP JP2006002524A patent/JP2007182845A/en active Pending
- 2006-12-27 WO PCT/JP2006/326135 patent/WO2007080800A1/en active Application Filing
- 2006-12-27 DE DE112006003637T patent/DE112006003637T5/en not_active Withdrawn
- 2006-12-27 CN CNA200680050860XA patent/CN101356354A/en active Pending
-
2008
- 2008-06-19 GB GB0811244A patent/GB2447181A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0634491A (en) * | 1992-07-21 | 1994-02-08 | Daihatsu Motor Co Ltd | Lean limit detecting method utilizing ion current |
| JPH06249121A (en) * | 1993-02-23 | 1994-09-06 | Ngk Spark Plug Co Ltd | Combustion condition detecting device for gasoline engine |
| JPH10176594A (en) * | 1996-12-18 | 1998-06-30 | Daihatsu Motor Co Ltd | Combustion fluctuation detecting method for internal combustion engine |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2007182845A (en) | 2007-07-19 |
| WO2007080800A1 (en) | 2007-07-19 |
| CN101356354A (en) | 2009-01-28 |
| GB0811244D0 (en) | 2008-07-30 |
| DE112006003637T5 (en) | 2008-11-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7448253B2 (en) | Combustion state determination method of internal combustion engine | |
| JP3150429B2 (en) | Lean limit detection method using ion current | |
| US7971571B2 (en) | Operation control method on the basis of ion current in internal combustion engine | |
| US20100154509A1 (en) | Method for determining air fuel ratio of internal combustion engine on the basis of ion current | |
| US20090013772A1 (en) | Method for determining combustion state of internal combustion engine | |
| GB2447181A (en) | (EN) air-fuel ratio judging method in internal combustion engine based in ion current (JA) | |
| JP2004232568A (en) | Method of determining combustion state of internal combustion engine | |
| JP4381253B2 (en) | Combustion state detection method for internal combustion engine | |
| JP3234418B2 (en) | Lean limit detection method | |
| JP4432572B2 (en) | Control device for internal combustion engine | |
| JP3234419B2 (en) | Lean limit detection method | |
| JP4592612B2 (en) | Air-fuel ratio detection method using ion current of internal combustion engine | |
| JP4293939B2 (en) | Control method for internal combustion engine | |
| JP3154304B2 (en) | Lean limit control method using ion current | |
| JP3046465B2 (en) | MBT control method using ion current | |
| JP3153465B2 (en) | Burning time measurement method | |
| JP4749171B2 (en) | Air-fuel ratio determination method for internal combustion engine based on ion current | |
| GB2447177A (en) | Air-fuel ratio judging method of internal combustion engine based on ion current | |
| JP4443522B2 (en) | Method for determining lean combustion of an internal combustion engine | |
| JP5009843B2 (en) | Method for determining the combustion state of an internal combustion engine | |
| JP5009844B2 (en) | Method for determining the combustion state of an internal combustion engine | |
| JPH10176595A (en) | Measuring method for combustion period in internal combustion engine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |