JP2001132511A - Air-fuel ratio control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect fuel density and EGR gas density in an intake passage directly without increasing intake resistance for air-fuel ratio control. SOLUTION: A pair of optical elements 27a, 27b are provided with a fixed interval inside of a hollow swirl control valve shaft 26 that rotates a swirl control valve 25. Light is guided from a light source to an optical element 27a through an optical fiber 24. Light is turned at right angle in direction by the optical element 27a to be parallel with the axis of the swirl control valve shaft 26 and is attenuated receiving absorption corresponding to fuel density and CO2 density in a gap part 28. The attenuated light is turned at right angle in direction by the optical element 27b, separated by a dichroic mirror 22 through the optical fiber 24 and is converted photo-electrically by a detector for fuel measurement 40 and a detector for CO2 measurement 41, respectively. The photoelectric conversion signal becomes to be an input to an air-fuel ratio calculation unit 12 and an EGR density calculation unit 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air-fuel ratio control apparatus for controlling an air-fuel ratio of an internal combustion engine, and more particularly to an internal combustion engine capable of controlling the air-fuel ratio based on a result of directly measuring a fuel concentration in an intake passage. Related to an air-fuel ratio control device.

[0002]

2. Description of the Related Art A conventional air-fuel ratio control device for an internal combustion engine is disclosed in, for example, JP-A-11-36993 and JP-A-5-36993.
-263679 and JP-A-8-74651. The technology described in Japanese Patent Application Laid-Open No. 11-36933 measures the amount of air and fuel taken into the combustion chamber and detects misfire in the combustion chamber in order to optimize the air-fuel ratio at the time of engine start or misfire. The fuel injection amount is controlled to purify exhaust gas from the start.

The technique described in Japanese Patent Application Laid-Open No. Hei 5-263679 measures the intake air amount for each cylinder, and determines the EG for each cylinder.
By adjusting R and optimizing the air-fuel ratio, smoke and NO
It is intended to reduce exhaust gas such as x. Furthermore, the technique described in Japanese Patent Application Laid-Open No. 8-74651 emits light having a wavelength that gasoline vapor selectively absorbs, and based on a change in intensity when the light passes through the combustion chamber, the gasoline concentration in the cylinder, That is, the air-fuel ratio, the presence or absence of ignition, and the like are detected.

However, in these prior arts, the amount of fuel and EGR taken into the engine are not directly measured but are calculated mainly from the amount of intake air and the temperature of the intake passage wall. In addition, it is difficult to optimize the amount of fuel to be supplied.In addition, when the engine is started or restarted, the fuel attached to the intake passage wall evaporates and the fuel leaks from the injector tip. There is a problem that it is not possible to correct the amount of fuel already existing in the vehicle.

Conventionally, the in-cylinder air-fuel ratio is generally measured by an O ₂ sensor provided on the exhaust passage. However, even in this method, the O ₂ sensor cannot be measured at the time of starting because the O ₂ sensor is not activated. However, there is a problem that the fuel concentration in the intake passage before the start of combustion cannot be known.

On the other hand, it is considered that the air-fuel ratio in the intake passage can be measured by applying the technique disclosed in Japanese Patent Laid-Open No. 8-74651 to the intake passage. There is a problem in that the detection unit provided in the inside becomes an obstacle to intake and increases intake resistance at full load to lower engine output.

In view of the above problems, an object of the present invention is to provide an air-conditioning system for an internal combustion engine that can always directly measure the fuel concentration and the EGR gas concentration in the intake passage without providing a new obstacle on the intake passage. It is to provide a fuel ratio control device.

[0007]

According to one aspect of the present invention, there is provided a fuel injection valve provided in an intake passage for each cylinder and a portion of the intake passage depending on operating conditions. A gas flow control valve for opening and closing a cylinder, a hollow shaft for rotating the gas flow control valve in the cylinder, and a pair of optical elements each comprising a light emitting side and a light receiving side disposed to face each other at a predetermined interval in the hollow shaft. A light source that emits light having a wavelength that is absorbed by the fuel, a first light guiding unit that guides light from the light source to the light emitting side optical element, and a light intensity that is incident on the light receiving side optical element. A photodetector to detect, a second light guiding means for guiding light incident on the optical element on the light receiving side to the photodetector, and an air-fuel ratio calculating means for calculating an air-fuel ratio based on an output of the photodetector Air-fuel ratio control of an internal combustion engine, comprising: It is the location.

According to a second aspect of the present invention, there is provided an air-fuel ratio control apparatus for an internal combustion engine according to the first aspect, wherein the light source includes, in addition to the first wavelength light absorbed by the fuel, The photodetector emits light of a second wavelength that is absorbed by CO ₂ , and the photodetector separately detects the light of the first and second wavelengths, whereby the fuel concentration and the EGR gas concentration in the intake passage. The gist is to detect.

According to a third aspect of the present invention, there is provided an air-fuel ratio control apparatus for an internal combustion engine according to the first or second aspect, wherein the light source, the pair of optical elements, and the photodetector are provided. And that the first and second light guide means are disposed in each cylinder.

According to a fourth aspect of the present invention, there is provided an air-fuel ratio control apparatus for an internal combustion engine according to any one of the first to third aspects, wherein the air-fuel ratio calculated by the air-fuel ratio calculation means is provided. The gist is to control the fuel injection amount and / or fuel injection timing of the fuel injection valve according to the fuel ratio.

According to a fifth aspect of the present invention, there is provided an air-fuel ratio control apparatus for an internal combustion engine according to the second aspect, wherein an independent EGR flow control valve is provided for each cylinder, and the detection is performed by the photodetector. The gist is to control the EGR flow control valve in accordance with the EGR gas concentration in the intake passage calculated from the obtained light intensity.

According to a sixth aspect of the present invention, there is provided an air-fuel ratio control apparatus for an internal combustion engine according to any one of the second to fifth aspects, wherein the operating condition is such that EGR is not returned to the intake air. The gist is that the output value of the photodetector is corrected based on the transmitted light intensity for detecting the EGR gas concentration.

According to a seventh aspect of the present invention, there is provided an air-fuel ratio control apparatus for an internal combustion engine according to any one of the first to sixth aspects, wherein the first wavelength is absorbed by fuel. Is 3.39 μm.

[0014] To achieve the above object, an invention according to claim 8, in the air-fuel ratio control apparatus for an internal combustion engine according to any one of claims 2 to 7, the second to be absorbed CO ₂ The gist is that the wavelength is 4.4 μm.

[0015]

According to the first aspect of the present invention, a fuel injection valve provided in each intake passage for each cylinder, and in-cylinder gas flow control for opening and closing a part of the intake passage according to operating conditions. A valve, a hollow shaft for rotating the in-cylinder gas flow control valve, a pair of optical elements including a light-emitting side and a light-receiving side disposed opposite to each other within the hollow shaft at a predetermined interval, and a wavelength absorbed by the fuel. A light source that emits light, and a first light guide unit that guides light from the light source to the light-emitting side optical element,
A photodetector for detecting the intensity of light incident on the light receiving side optical element, second light guiding means for guiding light incident on the light receiving side optical element to the photodetector, and Air-fuel ratio calculating means for calculating the air-fuel ratio based on the output, the fuel concentration is directly measured without providing a new obstacle in the intake passage, and the air concentration is accurately determined based on the measurement result. Since the fuel ratio can be controlled, unburned fuel, C
This has the effect of suppressing the emission of O and NOx.

According to the second aspect of the invention, in addition to the effect of the first aspect, the light source is absorbed by CO ₂ in addition to the first wavelength light absorbed by the fuel. Second
Since the light detector emits light having a wavelength of, and the light detector detects the fuel concentration and the EGR gas concentration in the intake passage by separately detecting the light having the first and second wavelengths, Since the EGR gas concentration can be directly measured, there is an effect that the EGR control can be performed more accurately than in the past and the emission amount of NOx can be reduced.

According to the third aspect of the invention, in addition to the effects of the first or second aspect, the light source and
The pair of optical elements, the photodetector, first and second
Is arranged in each cylinder, so that accurate air-fuel ratio and EGR gas amount can be directly measured for each cylinder, and fine air-fuel ratio control and EGR control can be performed. There is.

According to the fourth aspect of the present invention, in addition to the effects of the first to third aspects, the fuel of the fuel injection valve is controlled according to the air-fuel ratio calculated by the air-fuel ratio calculating means. Since the injection amount and / or the fuel injection timing is controlled, the fuel injection amount and / or the fuel injection timing can be more accurately controlled based on the directly measured air-fuel ratio.

According to the fifth aspect of the present invention, in addition to the effects of the second aspect of the present invention, an independent EGR flow control valve is provided for each cylinder, and the EGR flow control valve is calculated from the light intensity detected by the photodetector. Since the EGR flow control valve is controlled according to the measured EGR gas concentration in the intake passage, the EGR flow can be more accurately controlled based on the directly measured EGR flow.

According to the sixth aspect of the invention, in addition to the effects of the second to fifth aspects of the present invention, the transmitted light intensity for detecting the EGR gas concentration under the operating condition in which the EGR is not recirculated to the intake air is reduced. Since the output value of the photodetector is corrected based on this, there is an effect that the measurement accuracy can be maintained even if aging, contamination of the optical element, deviation of the optical axis, and the like occur.

According to the seventh aspect of the present invention, in addition to the effects of the first to sixth aspects, the first wavelength absorbed by the fuel is set to 3.39 μm.
When gasoline is used as the fuel, there is an effect that the concentration of the fuel vapor can be accurately measured without being affected by other substances contained in the intake air.

According to the eighth aspect of the invention, in addition to the effects of the second to seventh aspects, the second wavelength absorbed by CO ₂ is set to 4.4 μm. There is an effect that the CO ₂ concentration and the EGR gas concentration can be accurately measured without being affected by the fuel concentration or other substances contained in the intake air.

[0023]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a system configuration diagram illustrating a configuration of an embodiment of an air-fuel ratio control device for an internal combustion engine according to the present invention.

In FIG. 1, an air-fuel ratio control device 1 includes a water temperature sensor 2, an oil temperature sensor 3, a throttle opening sensor 4
, An air flow sensor 5, a crank angle sensor 6, and an engine control unit (hereinafter abbreviated as ECU) 1
0, the fuel measurement laser 20 that emits light of a first wavelength that is absorbed by the fuel, and CO ₂ measurement laser 21 that emits light of a second wavelength which is absorbed by the CO _2, the first wavelength Dichroic mirrors 22, 22 for superimposing or separating light and light of the second wavelength, optical fibers 24, 24 as first and second light guide means, and a swirl control valve 25 as a gas flow control valve in the cylinder A swirl control valve shaft 26 which is a hollow shaft for rotating the swirl control valve; and a pair of a light emitting side optical element 27a and a light receiving side optical element 2 which are arranged inside the swirl control valve shaft 26 at a predetermined interval.
7b, a fuel measurement detector 40, a CO ₂ measurement detector 41, and an amplifier (hereinafter, AMP) for amplifying the detector signal.
And EGR valves 4 provided for each cylinder.
4 and a fuel injection valve 45 provided in an intake passage for each cylinder.

The first wavelength absorbed by the fuel emitted by the fuel measuring laser 20 is, for example, infrared light having a wavelength of 3.39 μm when using gasoline as fuel. The second wavelength absorbed by CO ₂ emitted from the CO ₂ measuring laser 21 is, for example, infrared light having a wavelength of 4.4 μm.

The fuel measurement laser 20 and CO ₂ measurement laser 21, for example a gas laser, a liquid laser, can utilize solid-state lasers and semiconductor lasers, the dimensions of the laser device, the power consumption, a vehicle such as shockproof A semiconductor laser is preferable from the viewpoint of mountability.

As a semiconductor laser that can be used as an infrared light source of the first and second wavelengths, a lead chalcogenide semiconductor laser and a GaInAsSb semiconductor laser are known. The lead chalcogenide-based semiconductor is a semiconductor containing a compound of lead (Pb) and an oxygen group element (sulfur group element, S, Se, Te in a narrow sense), and includes EuPbSeTe, Eu.
PbTe, PbCdS, PbSSe, etc. can be used as the semiconductor laser in the above wavelength band.

Incidentally, these light sources for measurement do not necessarily require coherent light, and an infrared light emitting diode using the above-mentioned semiconductor material can be used as a light source.

As the fuel measuring detector 40 or the CO ₂ measuring detector 41, a photoconductive element of InAs-based or lead-chalcogenide-based semiconductor (PbS, PbSe, PbTe, etc.) can be used.

The ECU 10 detects the fuel measuring detector 40.
Air-fuel ratio calculator 12 for calculating the air-fuel ratio based on the output signal
And the fuel based on the air-fuel ratio calculated by the air-fuel ratio calculation unit 12.
The fuel injection amount and the fuel injection timing from the injection valve 45 are controlled.
Fuel injection control unit 13 and CO ₂Measuring detector 41
EGR gas for calculating the EGR gas concentration based on the detection signal
Concentration calculation unit 14 and EGR gas concentration calculation unit 14
EGR valve 44 is controlled based on the detected EGR gas concentration
EGR valve control unit 15 and CO₂Detection of measuring detector 41
Output the amplification control signal of the AMP42 based on the output signal.
And a gain setting unit 11.

Next, the overall operation of this embodiment will be described with reference to FIG. The light emitted from the laser 20 for fuel measurement and the laser 21 for CO ₂ measurement is reflected by the dichroic mirror 2.
The optical fiber 24 is superposed coaxially at a and enters the optical fiber 24 from a holder 23 provided at one end of the optical fiber 24. The light conveyed by the optical fiber 24 is incident on one (light emitting side) optical element 27a through a slit hole 30 from a holder 23 provided at the other end, and the optical element 27a causes the swirl control valve shaft 26 to rotate. The light is turned 90 ° in the axial direction and enters the other (light receiving side) optical element 27 b via the gap 28.

As the light crosses the gap 28, it is attenuated by absorption according to the fuel concentration and the CO ₂ concentration existing in this space. The other optical element 27b converts the light incident from the coaxial direction with the swirl control valve shaft 26 in the direction of 90 ° and makes the light enter the optical fiber 24 from the holder 23 at one end of the optical fiber 24. Optical fiber 24
Is incident on the dichroic mirror 22 from the holder 23 at the other end and is separated by wavelength.
The light enters the fuel measurement detector 40 and the CO ₂ measurement detector 41, respectively, and is photoelectrically converted into an electric signal.

The output signal of the fuel measuring detector 40 is AM
The signal is amplified at P42 and input to the air-fuel ratio calculation unit 12. The air-fuel ratio calculation unit 12 calculates the fuel concentration or the air-fuel ratio in the intake passage based on the signal of the fuel measurement detector 40, and transmits this value to the fuel injection control unit 13. The fuel injection control unit 13 controls the fuel injection amount at the time of starting or restarting the engine with reference to the fuel concentration or the air-fuel ratio in the intake passage.

The fuel injection control unit 13 uses signals obtained from the water temperature sensor 2, the oil temperature sensor 3, the throttle opening sensor 4, the air flow meter 5, and the crank angle sensor 6. Since the operation is the same as the operation of the fuel injection control unit in the technology, detailed description will be omitted.

The output signal of the CO ₂ measuring detector 41 is amplified by the AMP 43 and is output from the EGR gas concentration calculating unit 1.
4 is input. The EGR gas concentration calculator 14 calculates the CO ₂ concentration and E based on the measured CO ₂ concentration signal.
The GR gas concentration is calculated, and the calculated concentration value is delivered to the EGR valve control unit 15. The EGR valve control unit 15 controls the degree of opening of the EGR valve 44 for each cylinder based on the concentration value, and controls the EGR valve 44 so that the optimal EGR concentration according to the operating state is obtained.

FIGS. 2 to 4 are views showing the structure of the concentration measuring section according to the embodiment of the present invention. FIG. 5 shows the relationship between the light transmission path and the hollow shaft in the embodiment. These configurations will be described generally along the traveling direction of light.

A swirl control valve 25 as an on-off valve for controlling the in-cylinder gas flow in the intake passage of each cylinder;
A hollow swirl control valve shaft 26 that rotates the swirl control valve 25 through an intake port wall 46 that is an intake passage is provided. The swirl control valve shaft 26 is provided with a pedestal 26a having a screw hole.
The swirl control valve 25 is fixed to the swirl control valve shaft 26 by two screws 31, 31 through the 5 screw holes 25 a. This allows
The swirl control valve 25 is opened and closed by the rotation of the swirl control valve shaft 26, so that the in-cylinder gas flow can be controlled according to the operating conditions.

The infrared light having a wavelength of 3.39 μm absorbed by gasoline fuel vapor emitted from a light source (not shown) is transmitted by an optical fiber 24 to an optical element 27 a provided inside a swirl control valve shaft 26 in an intake passage. Is conveyed.

As shown in FIG. 4, holders 23 each having a built-in convex lens 23a are attached to both ends of the optical fiber 24 so as to reduce loss when light enters and exits.
The holder 23 at one end of the optical fiber 24 is fixed to the intake passage, and light is emitted to the optical element 27a on the incident side through the slit hole 30 provided in the swirl control valve shaft 26.

As shown in FIG. 5, since the swirl control valve 25 is rotated within a range of approximately 90 °, the swirl control valve shaft 26 is adapted to transmit light regardless of the open / close position of the swirl control valve 25.
Are provided with two slit holes 30, 30 extending in the circumferential direction.

The pair of optical elements 27a and 27b bends the light incident from the radial direction of the swirl control valve shaft 26 by approximately 90 ° in the axial direction of the swirl control valve shaft 26, and passes through the gap 28 for measurement.
The swirl control valve shaft 26 has a reflection surface inclined at approximately 45 degrees with respect to the axial direction of the swirl control valve shaft 26 so as to bend the light in the axial direction of the swirl control valve shaft by approximately 90 ° and emit the light in the radial direction of the swirl control valve shaft. are doing.

The optical elements 27a and 27b may be configured to rotate integrally with the swirl control valve shaft 26, or the optical elements 27a and 27b may not rotate and the swirl control valve shaft 26 and the swirl control valve shaft 26 may rotate. The swirl control valve 25 may be configured to rotate.

In the configuration in which the optical elements 27a and 27b and the swirl control valve shaft 26 rotate integrally, the optical path becomes the same for about 90 ° rotation about the axis of the swirl control valve shaft 26. The reflecting surfaces of the optical elements 27a and 27b can be formed as partial conical surfaces having the same height and bottom radius and having at least a central angle of 90 °.

In a configuration in which the optical elements 27a and 27b do not rotate, the optical elements 27a and 27b
Can be fixed, and light can enter and exit through the slit holes 30.

Swirl control valve shaft 26
The light incident on the light emitting side optical element 27a from the direction substantially perpendicular to the axial direction through one slit hole 30 is reflected by the reflection surface and travels to the measurement gap portion 28 in the intake passage. A pair of optical elements 27a and 27b are provided for each cylinder so as to face each other with a predetermined gap in the intake passage, and light passing through the light-emitting side optical element 27a and crossing the intake passage is: The optical element 2 on the light receiving side is absorbed and attenuated by the vaporized fuel existing between the optical elements 27a and 27b.
7b.

Further, the swirl control valve shaft 26 and the swirl control valve 25 are arranged as shown in FIG.
As shown in FIG. 3, a hole 29 and a notch 25b are provided so that the intake air can pass near the gap 28 between the optical elements 27a and 27b. The light attenuated by the absorption of the fuel vapor existing in the gap 28 is transmitted to the optical element 2 on the light receiving side.
After being incident on 7b, the light is reflected by the 45-degree surface and changes its direction, is incident on an optical fiber 24 similar to the incident side, and is conveyed to a photodetector (not shown).

When the light of the second wavelength is simultaneously incident to detect the EGR concentration, the light path is the same as described above. In this case, as shown in FIGS. 6 and 7, the dichroic mirror 22 that transmits one wavelength of light and reflects the other wavelength of light is inclined at 45 degrees, and the two light sources are integrated at approximately 90 degrees. The optical fiber 24 is coaxially incident on the optical fiber 24 by arranging the optical fiber 24 and incident on the dichroic mirror 22.

[0048] The photodetector side like the light source side dichroic mirror 22 is provided, the light of the two wavelengths are separated are incident for each wavelength in the fuel measuring detector 40, CO ₂ measuring detector 41 , The intensity of the light transmitted through the gap 28 is detected.

FIG. 8 shows a configuration in which the air-fuel ratio control device of the embodiment is applied to an in-line four-cylinder engine. One fuel injection valve 45 is provided for each cylinder, and the flow rate can be adjusted for each cylinder. An EGR valve 44 is provided to measure the fuel concentration and the EGR gas concentration in the intake passage for each cylinder. Transmittance and fuel concentration of the light wavelength for the fuel concentration measurement, the CO ₂ concentration relationship between the transmittance and the CO ₂ concentration of the light of a wavelength for measurement, and CO ₂ concentration of the relationship between the measured value and the EGR gas concentration previously Investigation, built into ECU10, E10 of ECU10
The GR concentration calculator 14 calculates the EGR gas concentration from the detector output.

According to the results of these measurements and, as shown in FIG. 1, the outputs of the water temperature sensor 2, the oil temperature sensor 3, the throttle opening sensor 4, the air flow meter 5, the crank angle sensor 6, etc. The fuel injection amount, the fuel injection timing, and the opening of the EGR valve 44 are set so as to supply the fuel ratio to each combustion chamber. Further, for example, when the EGR valve 44 is closed during full load operation and the exhaust gas is not recirculated to the intake,
_{Since the} absorption by _two molecules is almost eliminated, the C
Based on the output signal of the O ₂ measuring detector 41 AMP4
The detection sensitivity of the fuel concentration and the CO ₂ concentration can be calibrated by changing the amplification factor of 2,43.

In FIG. 8, the optical elements 27a,
The swirl control valve shaft 26 provided with 27b communicates with all cylinders, and is rotated simultaneously according to switching of operating conditions.

As a modification of this embodiment, the fuel concentration measurement
If only EGR concentration measurement is not performed, CO
₂Measurement laser 21, dichroic mirror 22, C
O₂ Measurement detector 41, AMP43, and EGR gas concentration
By removing the degree calculation unit 14, the fuel in the intake passage
The concentration can be measured directly and used for air-fuel ratio control.
You.

Further, if the EGR itself is not performed, the EGR valve controller 15 and the EGR valve 44 are not required.

[0054]

According to the configuration of the embodiment described above, the measurement of the air-fuel ratio in the intake passage and the direct measurement of the EGR gas concentration can be performed without providing any new obstacles or recesses that may increase the intake resistance in the intake passage. It is possible to measure the fuel concentration existing in the intake passage before fuel injection such as fuel adhering to the intake port wall or fuel leaking from the injector tip at the time of starting and restarting the engine. The fuel concentration and the EGR gas concentration in each cycle can be optimized, and the engine exhaust gas can be reduced.

Although the preferred embodiment has been described above, this does not limit the present invention. In the embodiment, an example in which the invention is applied to a gasoline engine has been described. However, for example, the invention can be applied to an internal combustion engine using another fuel such as alcohol. In this case, it goes without saying that the wavelength of the light source is adjusted to the wavelength of the light absorbed by the fuel alcohol. Also, a tumble control valve that generates a vertical swirling flow in the cylinder can be used as the in-cylinder gas flow control valve instead of the swirl control valve. Further, in a horizontally opposed engine or a V-type engine, a hollow shaft for opening and closing the in-cylinder gas flow control valve can be provided for each bank.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram illustrating a configuration of an embodiment of an air-fuel ratio control device for an internal combustion engine according to the present invention.

FIG. 2 is a plan view (a) and a side view (b) showing the structure of a measuring unit.

FIG. 3 is a view showing a shape (a) of a swirl control valve as an in-cylinder gas flow control valve and a mounting structure (b) thereof.

FIG. 4 is a cross-sectional view illustrating the structure of a holder at the tip of an optical fiber.

FIG. 5 is a perspective view illustrating the shape of a swirl control valve shaft and a measurement optical path.

FIG. 6 is a partial cross-sectional view showing a structure of a connection portion between a two-wavelength light source and an optical fiber.

FIG. 7 is a partial cross-sectional view showing a structure of a connecting portion between a two-wavelength photodetector and an optical fiber.

FIG. 8 is a diagram showing a configuration in which the air-fuel ratio control device of the present invention is applied to a four-cylinder engine.

[Explanation of symbols]

1 air-fuel ratio control system 10 ECU 11 gain setting unit 12 air-fuel ratio calculating section 13 the fuel injection controller 14 EGR gas concentration calculating section 15 EGR valve control unit 20 the fuel measurement laser 21 CO ₂ measurement laser 22 dichroic mirror 24 optical fibers 25 swirl control valve 26 swirl control valve shaft 27a, 27b the optical element 28 gap 29 holes 40 fuel measuring detector 41 CO ₂ measuring detector 42, 43 AMP 44 EGR valve 45 fuel injection valve

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02M 25/07 F02M 25/07 G01N 21/35 G01N 21/35 Z (72) Inventor Teruyuki Ito Yokohama, Kanagawa 2F0-term in Nissan Motor Co., Ltd. 2 Takaracho, Kanagawa-ku, Nissan (reference) BA20 BA21 CA01 CA04 DA04 DA10 EA04 EC03 FA00 FA07 FA10 FA37 FA38 3G092 AA01 AA05 AA10 AA15 AA17 AB02 AB05 BA04 BB01 BB06 DC06 DC09 DC10 DF05 EA25 EB05 FA15 GA01 GA06 HA00Z HA01Z HA06Z HB05Z07Z08 HD07X07 LA05 LB01 MA01 MA11 MA18 NB03 NB18 PA00Z PA01Z PA11Z PD15Z PE03Z PE08Z

Claims (8)

[Claims] A fuel injection valve provided in an intake passage for each cylinder; an in-cylinder gas flow control valve for opening and closing a part of the intake passage in accordance with operating conditions; A pair of optical elements each including a light-emitting side and a light-receiving side that are arranged opposite to each other at a predetermined interval in the hollow shaft; a light source that emits light having a wavelength that is absorbed by fuel; and the light-emitting side. First light guiding means for guiding light from the light source to the optical element, a photodetector for detecting the intensity of light incident on the light receiving side optical element, and light incident on the light receiving side optical element. An air-fuel ratio control device for an internal combustion engine, comprising: a second light guide unit that guides the light to the photodetector; and an air-fuel ratio calculation unit that calculates an air-fuel ratio based on an output of the photodetector. 2. The light source emits light of a second wavelength absorbed by CO ₂ in addition to light of the first wavelength absorbed by fuel, and the light detector comprises first and second light. The fuel concentration and the EGR gas concentration in the intake passage are detected by separately detecting the light having the wavelengths of:
An air-fuel ratio control device for an internal combustion engine according to the above. 3. The light source, the pair of optical elements, the photodetector, and the first and second light guide means are respectively provided corresponding to each cylinder. Claim 1
3. An air-fuel ratio control device for an internal combustion engine according to claim 2. 4. The fuel injection valve according to claim 1, wherein the fuel injection amount and / or the fuel injection timing of the fuel injection valve is controlled in accordance with the air-fuel ratio calculated by the air-fuel ratio calculation means. The air-fuel ratio control device for an internal combustion engine according to claim 1. 5. An independent EGR flow control valve is provided for each cylinder, and the EGR flow control valve is controlled in accordance with an EGR gas concentration in an intake passage calculated from a light intensity detected by the photodetector. 3. The air-fuel ratio control device for an internal combustion engine according to claim 2, wherein: 6. An output value of the photodetector is corrected based on transmitted light intensity for detecting an EGR gas concentration under an operating condition in which EGR is not recirculated to intake air. 6. The air-fuel ratio control device for an internal combustion engine according to claim 5. 7. The first wavelength absorbed by the fuel is 3.39.
7. The air-fuel ratio control device for an internal combustion engine according to claim 1, wherein the air-fuel ratio is μm. 8. The second wavelength absorbed by CO ₂ is 4.
8. The structure according to claim 2, wherein the thickness is 4 μm.
An air-fuel ratio control device for an internal combustion engine according to any one of the preceding claims.