JPS60243339A - Fuel supply controlling apparatus for engine - Google Patents

Abstract

PURPOSE:To obtain a sufficient engine output irrespective of the density of air, by determining an aimed air-fuel ratio on the basis of the mass flow rate when the detected density of air is higher than the standard density of air while determining the aimed air-fuel ratio on the basis of the volumetric flow rate when the detected density of air is lower than the standard density of air. CONSTITUTION:A control apparatus of this invention comprises a controller 29 to which output signals of various detecting means such as an air-flow sensor 16, an engine-speed sensor 17, an intake-temperature sensor 18 and an atmospheric-pressure sensor 19 are furnished. The controller 29 detects the density of air from the atmospheric-pressure signal and the intake-temperature signal. The density of air thus detected is compared with the standard density of air under normal temperature and pressure conditions by a comparing means M1 provided in the controller 29. In case that the detected density of air is higher than the standard density of air, an aimed air-fuel ratio is determined by an airfuel ratio determining means M2 on the basis of the mass flow rate. On the other hand, in case that the detected density of air is lower than the standard density of air, the aimed air-fuel ratio is determined by the means M2 on the basis of the volumetric flow rate. Further, fuel injection valves 9, 10 are controlled by control signals having data of the air-fuel ratio determined in the above-mentioned manner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel supply control device for an engine (internal combustion engine).

[Conventional technology]

In conventional electronic fuel supply control systems, information A/N obtained by dividing air flow sensor output information (intake air amount information) A by engine speed information N is used as engine load information, and these A/N, It has been proposed to set a target air-fuel ratio based on the N information and further perform density correction (correction that changes the target air-fuel ratio according to the air density).

[Invention or problem to be solved]

However, with the conventional electronic fuel supply control system as described above, due to the above correction, at high altitudes where the air density is low, the empty temperature when the throttle valve is fully open; the thermalization is equivalent to the partial operation range on flat ground. As a result, there is a problem in that the sense of output is insufficient even though it is in an enriched state.

Therefore, if density correction is completely discontinued, there is a problem in that the sense of output will be insufficient in cold regions where the air density is high.

In addition, when the air flow sensor output falls below a predetermined value, fuel is controlled to be cut, but if this fuel cut timing is not corrected in accordance with the intake air temperature or atmospheric pressure, for example, the engine This is not desirable as it may cause hunting.

The present invention aims to solve these problems, and by devising a way to determine the target air-fuel ratio depending on the size of the air density, it is possible to exert a sufficient feeling of power regardless of the air density. An object of the present invention is to provide a fuel supply control device for an engine.

In addition, the present invention provides the following advantages in determining the fuel power/to-time: 1)
By making the above determination based on information obtained by correcting the volumetric flow rate by intake air temperature or information obtained by correcting the mass flow rate by atmospheric pressure, which is substantially the same information as this information, 1),
Another object of the present invention is to provide a fuel supply control device for an engine that is capable of appropriately controlling the heating cut timing.

[Means for solving problems]

Therefore, the engine fuel supply control device of the present invention includes a fuel supply means for supplying fuel to the ennon, an air flow sensor that detects the intake air amount, a rotation speed sensor that detects the engine rotation speed, and an atmospheric pressure sensor. An atmospheric pressure sensor to detect the intake air temperature and an intake air temperature sensor to detect the intake air temperature are provided, and the detected air density and standard air density at normal temperature and pressure are obtained based on the detection signals from the above atmospheric pressure sensor and the intake air temperature sensor. and a comparison means for comparing the above, and when the detected air density is equal to or higher than the standard air density, the air-fuel ratio is determined based on the mass flow rate, and the detected air density is determined as the standard air density. In the following cases, an air-fuel ratio determining means that determines the air-fuel ratio based on the volumetric flow rate and a fuel supply control means that outputs a control signal having air-fuel ratio information obtained by the air-fuel ratio determining means to the fuel supply means. It is characterized by the fact that it was established.

Further, the engine fuel supply control device of the present invention includes a fuel supply means for supplying fuel to the engine, and includes an air flow sensor that detects the amount of intake air, a rotation speed sensor that detects the engine rotation speed, and an atmospheric pressure sensor. An atmospheric pressure sensor is provided to detect the intake air temperature, and an intake air temperature sensor is provided to detect the intake air temperature. and a comparison means for comparing the air-fuel ratio to determine the air-fuel ratio based on the mass flow rate when the detected air density is equal to or higher than the standard air density according to the comparison result by the comparison means. In this case, an air-fuel ratio determining means for determining an air-fuel ratio based on the volumetric flow rate, and a fuel supply control means for outputting a control signal having air-fuel ratio information obtained from the air-fuel ratio determining means to the fuel supply means are provided. Further, fuel cut control means is provided for determining a fuel cut timing based on information obtained by correcting the volumetric flow rate by the intake air temperature or information obtained by correcting the mass flow rate by the atmospheric pressure, and controlling the fuel cut timing. It is characterized by

[For production]

With the above configuration, according to the first invention, when the detected air density is equal to or higher than the standard air density, the target air-fuel ratio is determined based on the mass flow rate, and conversely, when the detected air density is equal to or lower than the standard air density, the target air-fuel ratio is determined based on the mass flow rate. In this case, the air-fuel ratio is determined based on the volumetric flow rate, and the air-fuel ratio is controlled accordingly.

Further, according to the second invention, when determining the target air-fuel ratio, the above-mentioned determination is made based on the mass flow rate or the volumetric flow rate depending on the magnitude of the detected air density, and the air-fuel ratio is controlled accordingly. In addition, in determining the fuel cut timing, the above determination is made based on information obtained by correcting the volumetric flow rate with intake air temperature or information obtained by correcting the mass flow rate with atmospheric pressure, and the fuel cut timing is controlled accordingly. is also carried out.

〔Example〕

Hereinafter, an engine fuel supply control device as an embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a complete configuration diagram thereof, and FIG. 2 is a graph for explaining its operation.
3 to 5 are flowcharts for explaining the operation.

As shown in FIG. 1, an internal combustion engine E (hereinafter simply referred to as "U engine E") such as a gasoline engine for use in an automobile according to this embodiment is equipped with a turbocharger 3. The turbocharger 3 includes a turbine 4 interposed in the exhaust passage 2 of the engine E, and a compressor 5 interposed in the intake passage 1 of the engine E and rotationally driven by the turbine 4.

Further, in the intake passage 1 of the engine E, from the upstream side (air cleaner side), air 70 - sensor 16 . Turbocharger 3 Funbrensa 5. Intercooler 8. a
Electromagnetic fuel injection valves 9 and 10 (these valves 9 and 10 have different injection capacities) and a throttle valve 11 are provided in the exhaust passage 2 of the engine E, and the upstream side (engine combustion Turbine 4 of turbocharger 3 in order from the room side). A catalytic converter 31 and a muffler (not shown) are provided.

The air flow sensor 16 detects the number of Karman vortices generated by a columnar body disposed in the intake passage 1 using ultrasonic modulation means, thereby determining the actual intake air amount A of the intake passage 1 as a volumetric flow rate\7air. (volume air flow rate)
The digital output from the volumetric flow rate detection type air sensor 16 is input to the controller 29. In addition, the air flow sensor 16
For example, the digital output of the
After being passed through a /2 frequency divider, it is subjected to various processes such as fuel supply control.

In addition, it is generally said that the air 70-sensor 16 malfunctions due to intake pulsation etc. when the engine E is at low speed and under high load.
By installing the ink cooler 8 on the downstream side of the air cleaner and appropriately adjusting the dimensions of the air cleaner part, the above-mentioned intake pulsation almost no longer occurs.
The measurement reliability or accuracy is considered to be sufficiently high.

Further, a rotation speed sensor 17 is provided, and this rotation speed sensor 17 detects the engine rotation speed N by detecting engine rotation speed information from, for example, the primary side negative terminal of the 7-way coil 32. be.

Furthermore, the opening degree of the throttle valve 11 (throttle opening degree) θ
A throttle sensor 2o is provided to detect this, and a potentiometer is used as the throttle sensor 20.

Also, an intake air temperature sensor 18 that detects the intake air temperature. In addition to an atmospheric pressure sensor 19 for detecting atmospheric pressure, a water temperature sensor 21 for detecting the cooling water temperature TW as the engine temperature is provided in the pond. Q2 sensor 2 detects oxygen concentration in exhaust gas
2. Knock sensor 23 for detecting engine running condition.
Vehicle speed sensor 24 that detects vehicle speed. An idle switch for detecting an idle state 25. A cranking switch 26 detects when the engine is cranking, a crank angle sensor 27 detects the crank angle by a photoelectric conversion means with a distributor 33, and detects the reference position of the DC motor 12 for controlling the engine speed when idling. A motor position switch 28 and the like are provided, and signals from these sensors and switches are input to a controller 29.

Note that the intake air temperature sensor 18. Atmospheric pressure sensor 19. Water temperature sensor 21. Since the throttle sensor 2 (1,0□ sensor 22, knock sensor 23, etc.) has its detection signal or analog signal, it is sent to the controller 29 via the A/D converter.
is input to. Further, the atmospheric pressure sensor 19 may be incorporated into the controller 29.

Furthermore, an ignition fill 32 is provided,
This ignition fill 32 is a power transistor (
The primary side current is turned on and off by a switching tranostor (30). Note that the power transistor 30 receives an on/off signal from the controller 29.

By the way, the air weight Mass, the air flow sensor output, and the actual air-fuel ratio (A/F
) r and the engine output (horsepower) PS, as well as the relationship between the target air-fuel ratio (A/F) m (this is stored in advance in the map) and the air flow sensor output, are summarized in Figure 2. become that way.

In this Figure 2, among the air weight - air 70 - sensor output characteristics, the solid line 100 shows the characteristics at standard air density, and the dotted line 101 shows the characteristics when the air density is low, such as in highlands. A characteristic 102 indicated by a dashed-dotted line indicates a characteristic when the air density is high, such as in a cold region.

In addition, in Fig. 2, the value is constant 2 (
', 10a indicates a region fed by the signal from the 02 sensor 22, where the value gradually decreases, 200b indicates a high load region where the feedback has stopped, and the value suddenly becomes infinite. 200c indicates that the fuel has been cuffed.

Furthermore, in FIG. 2, the air weight vs. actual air fuel ratio characteristics and the air weight vs. engine output characteristics shown by solid lines, 300 and 400, respectively, are compensated for by the air density iEf -1. 1 review; 1
Those shown with dotted lines 301 and 401 respectively show the characteristics when no activity correction is performed in the high load region where feedbank is not performed even when the air density is small. 3 (12, 402) indicated by a dashed dotted line indicates the characteristic when density correction is not performed in a high load region where feedbanking is not performed even if the air density becomes abnormal.

Similarly, in Fig. 2, among the air weight-actual air-fuel ratio characteristics and the air weight-engine output characteristics, the solid lines 30i)' and 4t)0' indicate the characteristics corrected in the fuel cut region, and the dotted lines indicate the characteristics, respectively. Showing 301
' and 401' indicate the characteristics when no correction is made in the fuel cut region even if the air density becomes small, and 302' and 402' respectively show the characteristics when no correction is made in the fuel cut region even when the air density becomes large. show.

Now, consider the fully open state WOT of the throttle valve 11 in the air weight-air flow sensor output characteristic 101 when the air density is low (see point α' on characteristic 1()1).

The target air-fuel ratio in this case is, for example, 10.0, as indicated by point α' on the characteristic 200b.

However, when considering air weight, point α' on characteristic 101 is the same as point α on characteristic 1()0 at standard air density,
The target air-fuel ratio corresponding to point α on this characteristic 100 is characteristic 2.
001), and the value of the target air-fuel ratio in this case is larger than the value 10.0 corresponding to the above α'.

That is, if density correction is performed in such a case, the value of the target air-fuel ratio will be set to an extreme value (on the lean side). If density correction is performed in the same manner, the value of the actual air-fuel ratio will also be significantly different (see comparison of points α and α' on characteristics 300 and 301).

By the way, when density correction is performed for the target air-fuel ratio as described above, the engine output at that time (see point α on characteristic 400) is lower than when density correction is not performed (see point a' on characteristic 401). small.

For this reason, as mentioned in the conventional problem, when the throttle valve is fully open WOT at high altitudes, it causes a lack of output. The conclusion is drawn that it is better to determine the air-fuel ratio based on the main volumetric flow rate.

Next, consider the feedback cancellation start load state (see point β' on the characteristic 102) in the air weight-air 70-sensor output characteristic 102 when the air density is high.

The target air-fuel ratio in this case is, for example, 14.7, as indicated by point β' on the characteristic 200b.

However, when considering air weight, point β' on characteristic 102 is the same as point β on characteristic 100 at standard air density1),
The target air-fuel ratio corresponding to point β on this characteristic 100 is characteristic 2.
00), which is the upper point β, and the value of the target air-fuel ratio in this case is smaller than the value 14.7 corresponding to the above β'.

That is, when density correction is performed in such a case, the value of the target air-fuel ratio is set to be small (towards the rich side). If density correction is performed in the same manner, the value of the actual air-fuel ratio will also increase (see comparison of points β and β' on characteristics 300 and 302).

By the way, when the density correction is performed for the target air-fuel ratio as described above, the enon output at that time (see point β on characteristic 400) is lower than that when density correction is not performed (see point β' on characteristic 402). It's big.

For this reason, as in the case of the highlands mentioned above, density correction is not performed, resulting in insufficient output.

Therefore, in this case, the conclusion is drawn that it is better to perform density correction on the target air-fuel ratio, that is, it is better to determine the target air-fuel ratio based on the mass flow rate.

That is, the above conclusions regarding the method of determining the target air-fuel ratio in the high load region for canceling the feed bank control by the 02 sensor 221 are summarized as follows.

(1) In places where the air density is low, such as at high altitudes, it is better to determine the target air-fuel ratio based on the volumetric flow rate.

(2) In places where the air density is high, such as in cold regions, it is better to determine the target air-fuel ratio based on the mass flow rate.

Note that the target air-fuel ratio at standard air density is the volumetric flow rate,
It may be determined based on either mass flow rate.

Based on this knowledge, the controller 29 is provided with the following functions.

That is, the load roller 2 includes a comparing means M1 for comparing the detected air density obtained based on the detection signals from the atmospheric pressure sensor 19 and the intake air temperature sensor 8 with the standard air density at normal temperature and normal pressure, and this comparing means. According to the comparison result in M1, when the detected air density is higher than the standard air density, the target air-fuel ratio is determined based on the mass flow rate, but when the detected air density is lower than the standard air density, the target air-fuel ratio is determined based on the volumetric flow rate. It has the function of air-fuel ratio determination means M2 that determines the air-fuel ratio.

Further, the controller 29 also has the functions of the fuel supply control means M3 for outputting a control signal having the air-fuel ratio information obtained by the air-fuel ratio determination means M2 to the electromagnetic fuel injection valves 9 and 10.

Next, the flow of the fuel injection amount determination process performed by the controller 29 having the functions of these means M1 to M3 will be explained using FIG.

First, in step a1, data such as intake air amount information Vair, engine speed information N, atmospheric pressure information P, and intake air temperature information T are read, and basic injection is performed based on the intake air amount information\'air and engine speed information N. no(=ConstX
vair) is determined (step a2). here,
Con5't has a certain constant value.

Next, in steps a3 and a4, the atmospheric pressure correction coefficient KAp (=P/Po) and the intake temperature correction coefficient KA are determined.
T (=To/T) is calculated. Here, Po and To represent standard pressure and standard intake air temperature, respectively, and the unit of To is absolute temperature (Ko).

Once the correction coefficient KAPIKAT is calculated in this way, the target air-fuel ratio is determined in the next step a5. That is, first, in step a6, it is determined whether KAP-KAT>1, that is, whether the detected air density is greater than the standard air density. If YES, the calculation in step a7 is performed, and if No, then the calculation in step a7 is performed. , step a8 is performed.

Step a7 sets the volumetric flow rate Vair to the mass flow rate W a
It calculates the load parameter ABYN by converting it to i r, and A B 'l' N of this and b is A B Y N = (body 1 empty % flow fc) X KATX
KAp/(: number of revolutions) = VairX K
Defined by ATX KAP/N.

Further, step a8 is to calculate the load parameter ABYN while keeping the volumetric flow rate\'air, and the next ABYN is ABYN-(volume air flow rate)/(engine speed)=V
Defined as air/N.

After that, in step a9, select one of the above stainless steels 7.
'a? , the target air-fuel ratio coefficient KAF (equivalent ratio; when KAF is 1.0, the stoichiometric air-fuel ratio,
1.0 means rich, and less than 1.0 means lean).

In this way, when the air density is greater than the standard air density, the target air-fuel ratio is determined based on the mass flow rate Wair, while when the air density force is less than the quasi-air density, the volumetric flow rate\7air is determined. A target air-fuel ratio is determined based on the target air-fuel ratio.

Note that the standard air density Toshima may determine the target air-fuel ratio based on either mass flow rate or volumetric flow rate, so even if you ask that KAP-KAT≧1 in step a6 above, good.

After the target air-fuel ratio is determined in step a5 in this way, the target injection amount Qi is set to Q in step a10. ×KA
PX KATX KAF (=ConstX~'airX
KApXKATXKAF), and the calculation result is stored in memory in step all. Thereafter, based on the stored information, the electromagnetic fuel injection valve 9. The H1 solenoid valve is duty-controlled, and a desired amount of fuel is injected into the intake passage 1.

By the way, as the air flow sensor 16, it is also possible to use a mass flow rate detection type air flow sensor that detects the amount of intake air as a mass flow rate 'vV a i r by detecting a change in the resistance value of a hot wire. The target air-fuel ratio determination flow when using this type of air flow sensor is as follows.

That is, as shown in FIG. 4, first, step +11
Then, intake air amount information Wair, engine rotation speed information N,
Data such as atmospheric pressure information P and intake air temperature information T are read, and basic injection amount Q is determined based on intake air amount information Wair and engine speed information N. (=Cons1.XWair=Con
stX\'airXKAP,XKAT) is determined (step 1)2). Here, Con5t is a certain constant value.

Then, in step)]3 and step 1]4, the atmospheric pressure correction coefficient KAP (=P/Po) and the intake air temperature correction coefficient KAT (=To/T) are calculated.

Once the correction coefficient KAPIKAT is calculated in this way, the target air-fuel ratio is determined in the next step 1]5. That is, first, in step)]6, it is determined whether KAp-KAT>1 is greater than the detected air density or the standard air density, and if ')' is ES, step l
)7 is performed, and if No, step 1)8 is performed.

Step 1]7 is to calculate the load parameter A B '1' N while keeping the mass flow rate Wair, and ABYN at this time is ABYN - (mass flow rate) / (engine rotation speed) = Wai
r/N=(\7 airX KAPX KAT)/N
Defined by

In addition, step 1] means converting the mass flow rate Wair into the volume flow rate \・"air and setting the load parameter A B 'l'
This is to calculate N, and the outside A B "1' N is ABYN = 4 (mass flow rate) / KA7" KAPI / (
Engine speed) = (Wa:r/KAT-KAp)/N
=Vair/N.

After that, in step b9, one of the above steps b7. 2 of ABYN obtained in b8 and engine speed
Target air-fuel ratio coefficient KA from map using variables as parameters
Calculate F (equivalence ratio; the significance of the value of KAF in this case is the same as above).

In this case as well, when the air density is greater than the standard air density, the target air-fuel ratio is determined based on the mass flow rate W a i r , while when the air density is less than the standard air density, the target air-fuel ratio is determined based on the volumetric flow rate \7air. The target air-fuel ratio is determined.

Note that when the air density is standard, the target air-fuel ratio may be determined based on either the mass flow rate or the volumetric flow rate, so you may ask in step b6 above whether KAP-KAT≧1. .

After the target air-fuel ratio is determined in step 1) 5 in this way, in step 1) 10, the injection amount Qinj is
oXKAF=ConstXWairXKAp=Cons
tX VairX KATX KAPX Kp, p, and the subtraction result is stored in the memory in step b1.1. Thereafter, based on the stored information, the solenoid valves of the electromagnetic fuel injection valves 9 and 10 are duty-controlled, and a desired amount of fuel is injected into the intake passage 1.

By the way, as shown in FIG. 2, when the air flow sensor output becomes less than a predetermined value, the fuel is canted or the controller 29 determines the fuel cut timing and controls the fuel cut timing. It also has 44 functions.

Hereinafter, the processing by the fuel cut control means M4 will be explained using FIG. 5.

First, in step c1, various data are read, and in step c2, a load parameter A B Y N 2 is set. This load parameter A B Y N 2 is
It is defined as follows.

ABYN22 ((volume flow rate) VairX KATX KAI)/KAP)/
N=(\7 airX KAT)/N That is, (Wair/KAP)/N and (Vair
X KAT)/N represent exactly the same information.

Thereafter, in step c3, it is determined whether ABYN2>setting value. This setting value sets the fuel cant at a smooth value.
Selected near the no-load line (no-1 oacl 1ine).

In addition, the no-load line is numbered 500 in FIG.

As shown by 501, two types are set, one for flatlands and one for highlands.

If YES in step c3, that is, the operating state is under a certain load, a confirmation timer is set in step c4.

Note that once this confirmation timer is set, it is decremented at regular intervals in a separate routine.

Then, in the next step c5, it is determined whether the confirmation timer is 0 or not.

Note that if the answer in step c3 is 'No', that is, the operating state is near the no-load line, step c4 is skipped and the process directly proceeds to step c5.

While the confirmation timer is not (), it is 1'40 in step c5.
The fuel cant 7 lag is reset in step c6, but when the confirmation timer reaches 0, the YES route is taken in step c5, and the fuel cut flag is set in step c7.

Here, while the fuel cut flag is being reset,
Although a fuel cut is not executed, if the fuel cut flag is set, fuel is cut. In addition, the judgment timing at this time is that the fuel injection tri-signal is input (interrupted manually) and then stops at 1, and the load HA is higher than near the no-flow line.
In Ja, step c3 takes the YES route, and step c=4 sets the confirmation timer again before it reaches 0 (this is because the routine execution cycle in Figure 5 is longer than the time when the confirmation timer reaches 0). In the next step c5, the No route is always taken and fuel cut is not performed.

However, when it comes to the vicinity of the no-rotation line, step c3
In order to take the No route, the confirmation timer goes off after a certain time.
At this point, the fuel is cut by the fuel cut flag setting process in step c7.

In this way, when determining fuel power and timing,
By making the above determination based on information obtained by correcting the volumetric flow rate by intake air temperature, or information obtained by correcting the mass flow rate by atmospheric pressure, which is actually the same information as this information,
Appropriate fuel cant timing can be controlled, and hunting near the no-load line will not occur.7 In addition, a display meter 35 is provided in the vehicle interior.

For example, the display meter 35 is configured such that the needle drive section receives a control signal (current) from the controller 29 and the buttons move simultaneously to display 1) negative pressure area, supercharging area, and supercharging area. (
This supercharging area is also called a red zone), and a segment type display in which light emitting diodes (LEDs) are arranged in a row and these LEDs blink as appropriate. 3S1]. In addition, when the display meter 35 has an oblique display section 35a, a control signal is supplied from the controller 29 to the display meter 35 via the f-\° funverter and the current drive circuit.

Further, the controller 29 includes an intake passage pressure display control means for outputting a signal corresponding to the intake passage pressure to the display meter 35, an ignition timing control means for outputting an ignition timing control signal according to the operating state of the engine E, and an ignition timing control means for outputting an ignition timing control signal according to the operating state of the engine E. An idle speed control means that outputs an idle speed control signal to the actuator 12 to control the engine speed, and a two-diaphragm type pressure response to adjust the opening timing of the waste gate valve 6 to obtain different boost pressure characteristics. It also has the function of a waste date valve control means that outputs a signal to an electromagnetic switching valve 34 (this valve 34 has a return spring (not shown) for the valve body) that controls the actuator 7 comprising the device.

In addition, the reference numeral 33 in FIG. 1 is a distributor, and 36
indicates an ignition key switch, and 37 indicates a battery.

Additionally, this device is also applicable to non-turbo cars.

Furthermore, this device can be applied not only to Ennons that have fuel supply means using electromagnetic fuel injection valves, but also to Ennons that have fuel supply means that have a carburetor structure.

〔Effect of the invention〕

As described in detail above, the engine fuel supply control device of the present invention includes an air flow sensor that includes a fuel supply means for supplying fuel to the engine and detects the amount of intake air;
A rotation speed sensor that detects engine rotation speed, an atmospheric pressure sensor that detects atmospheric pressure, and an intake air temperature sensor that detects intake air temperature are provided, and based on detection signals from the above atmospheric pressure sensor and intake air temperature sensor, A comparison means for comparing the obtained detected air density with the standard air density at room temperature and normal pressure, and when the detected air density is higher than the standard air density, based on the mass flow rate according to the comparison result by the comparison means. an air-fuel ratio determining means that determines the air-fuel ratio based on the volumetric flow rate when the detected air density is equal to or less than the standard air density; and a control having air-fuel ratio information obtained by the air-fuel ratio determining means. The simple configuration includes a fuel supply control means that outputs a signal to the fuel supply means, and when the detected air density is below the standard air density, the target air-fuel ratio is determined based on the mass flow rate, and the detected air density is When the air density is below the standard air density, the target air-fuel ratio is determined based on the volumetric flow rate, which has the advantage of providing sufficient power in both highlands where the air density is low and in cold regions where the air density is high. There is.

Further, the engine fuel supply control device of the present invention includes a fuel supply means for supplying fuel to the engine, and includes an air 70-sensor for detecting the amount of intake air, a rotation speed sensor for detecting the engine rotation speed, and an atmospheric pressure sensor. An atmospheric pressure sensor that detects intake air temperature and an intake air temperature sensor that detects intake air temperature are provided, and the detected air density and air density obtained based on the detection signals from the above atmospheric pressure sensor and intake air temperature sensor are and a comparison means for comparing the detected air density with the standard air density. When the detected air density is greater than or equal to the standard air density, the air-fuel ratio is determined based on the mass flow rate and the air-fuel ratio is determined based on the mass flow rate. an air-fuel ratio determining means for determining the air-fuel ratio based on the volumetric flow rate when the air-fuel ratio is less than the standard air density; and a fuel for outputting a control signal having air-fuel ratio information obtained by the air-fuel ratio determining means to the fuel supply means. supply control means, and determines a fuel cut timing based on information obtained by correcting the volumetric flow rate with the intake air temperature or information obtained by correcting the mass flow rate with the atmospheric pressure, and controls the fuel cut timing. With a simple configuration that includes a fuel cut control means, when determining the target air-fuel ratio, the above determination is made based on the mass flow rate or volumetric flow rate depending on the magnitude of the detected air density, and the optimum air-fuel ratio is determined accordingly. In addition to controlling the fuel cut timing, the above judgment is made based on information obtained by correcting the volumetric flow rate with intake air temperature or information obtained by correcting the mass flow rate with atmospheric pressure, and the optimum timing is determined accordingly. It also has the advantage of being able to control the fuel cant timing.

[Brief explanation of drawings]

The figures show an engine fuel supply control device as an embodiment of the present invention, in which Fig. 1 is an overall configuration diagram thereof, Fig. 2 is a graph for explaining its operation, and Figs. is also a flowchart for explaining its operation. 1...Intake passage, 2...Exhaust passage, 3...Turbocharger, 4...Turbine, 5...Hump presser, 6...Waist gate valve, 7...Actuator, 8...
Intercooler, 9, 10... Electromagnetic fuel injection valve as fuel supply means, 11... Throttle valve, 12... Actuator, 16... Air 70-sensor, 17... Rotational speed sensor,] 8... Intake temperature Sensor, 19... Atmospheric pressure sensor, 20... Throttle sensor, 21... Water temperature sensor, 2
2...02 sensor, 23...knock sensor, 24...vehicle speed sensor, 25...idle switch, 26...cranking switch, 27...crank angle sensor, 28...
・Motor Bonjon switch, 2 controllers,
30... Power transistor, 31... Catalytic converter, 32... Ignition coil, 33... Distributor, 34... Electromagnetic switching valve, 35... Display meter, 3
5a...Segment type display section, 3Sb...Segment type display section,
36...Ignition key switch, 37...Battery, E...Engine, Ml...Comparison means, M2...Air-fuel ratio determining means, M3...Fuel supply control means, M4...Fuel cut control means. Agent Patent Attorney Yoshihiko Iinuma Figure 4 Figure 5

Claims (2)

[Claims] (1) Equipped with a fuel supply means for supplying fuel to the ennon, an air 70-sensor that detects the intake air amount, a rotation speed sensor that detects the engine rotation speed, an atmospheric pressure sensor that detects the atmospheric pressure, and the intake air temperature. and a comparison means for comparing the detected air density obtained based on the detection signals from the above-mentioned atmospheric pressure sensor and the intake air temperature sensor with the standard air density at normal temperature and normal pressure. and,
Depending on the comparison result by the comparison means, when the detected air density is above the standard air density, the air-fuel ratio is determined based on the mass flow rate, and when the detected air density is below the standard air density, the air-fuel ratio is determined based on the volumetric flow rate. It is characterized by being provided with an air-fuel ratio determining means for determining an air-fuel ratio, and a fuel supply control means for outputting a control signal having air-fuel ratio information obtained by the air-fuel ratio determining means to the fuel supply means, Engine fuel supply control device. (2) Equipped with a fuel supply means for supplying fuel to the engine, including an air flow sensor that detects the intake air amount, a rotation speed sensor that detects the engine rotation speed, an atmospheric pressure sensor that detects the atmospheric pressure, and the intake air temperature. a comparison means for comparing the detected air density obtained based on the detection signals from the atmospheric pressure sensor and the intake temperature sensor with a standard air density at normal temperature and normal pressure;
Depending on the comparison result by the comparison means, when the detected air density is above the standard air density, the air-fuel ratio is determined based on the mass flow rate, and when the detected air density is below the standard air density, the air-fuel ratio is determined based on the volumetric flow rate. an air-fuel ratio determination means for determining an air-fuel ratio; and a fuel supply control means for outputting a control signal having air-fuel ratio information obtained by the air-fuel ratio determination means to the fuel supply means; A fuel cut control means is provided which determines a fuel cut timing based on information obtained by correcting the amount by the intake air temperature or information obtained by correcting the mass flow rate by the atmospheric pressure, and controls the fuel cut timing. Engine fuel supply control device.