JPS61268836A - Fuel supply amount control device for mixture supply system in internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve fuel consumption and exhaust emission, by eliminating a study error caused by a delay time after a load in an internal-combustion engine is detected till exhaust gas from a main unit of the engine, operated under the condition of said detected load, is detected by an exhaust gas detecting means. CONSTITUTION:The captioned device provides a study means 5 which studies an engine operative condition in accordance with an output from an exhaust gas detecting means 4b, detecting an exhaust gas ingredient, in every load region, assigned in accordance with an output from a load amount detecting means 4a detecting an engine load amount, and calculates a study value in said every assigned load region. And the device, calculating in accordance with the calculated study value a supply amount of fuel by a fuel supply amount arithmetic means 6a so that air-fuel ratio obtains a target value, controls a fuel supply means 3. Here the device, counting in a time counting means 8 a time before an ingredient of exhaust gas discharged from an engine main unit 1 operated by the detected load amount is detected, studies the study value in the assigned load region on the basis of the exhaust gas ingredient when the time counting is finished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel supply amount control device that is adopted in a mixture supply system of an internal combustion engine, and in particular, the present invention relates to a fuel supply amount control device that is adopted in a mixture supply system of an internal combustion engine. The present invention relates to a fuel supply amount control device that controls the amount of fuel supplied to an air-fuel mixture supply system so that the air-fuel ratio of the air-fuel mixture becomes a target value by learning based on exhaust gas components for each load region.

[Prior art]

Conventionally, this type of fuel supply amount control device was disclosed in Japanese Patent Application Laid-open No. 57-1.
As shown in Publication No. 43134, the load range of the internal combustion engine is divided into a plurality of regions based on the respective values of engine speed and intake air amount, and the operating state of the internal combustion engine is determined for each of the divided load regions in the exhaust pipe. Based on the oxygen concentration detection signal in the exhaust gas output from the exhaust gas sensor installed in the is controlled.

[Problem that the invention seeks to solve]

However, in the conventional device described above, since the operating state of the internal combustion engine is learned based on the oxygen concentration in the exhaust gas at the time of detecting the engine rotation speed and intake air amount, the oxygen concentration used for this learning is After the air-fuel mixture is supplied to the engine body, it is discharged as exhaust gas and is caused by exhaust gas combusted under a load region that precedes the time it takes to reach the exhaust gas sensor, making it possible to perform accurate learning for each load region. Therefore, the amount of fuel supplied to the mixture supply system cannot be controlled so that the air-fuel ratio of the mixture reaches the target value, and as a result, the amount of harmful components in the exhaust gas due to such an inappropriate air-fuel ratio is reduced. There are problems such as increase in fuel consumption, deterioration of fuel efficiency, and deterioration of vehicle drivability.

The purpose of the present invention is to deal with such problems, and it is an object of the present invention to detect the load on the internal combustion engine until the exhaust gas sensor detects the exhaust gas emitted by the engine body operated under the detected load condition. It is an object of the present invention to provide a fuel supply amount control device for an internal combustion engine air-fuel mixture supply system that eliminates learning errors caused by delay time.

[Means for solving problems]

In order to solve the above-mentioned problem d, the structural feature of the present invention is, as shown in FIG. 3, which is commonly used in a mixture supply system that mixes the supplied fuel with the air flow flowing into the intake pipe la in the trachea la to form a mixture and supplies the mixture to the engine main body 1. , load amount detection means 4a for detecting the load amount of the internal combustion engine, exhaust gas detection means 4b for detecting components of exhaust gas discharged into the exhaust pipe lb extending from the engine body 1, and the detected load amount. a learning child ¥15 that calculates a learning value for each designated load region by learning the operating state of the internal combustion engine based on the detected exhaust gas components for each load region of the internal combustion engine designated according to the size of the engine; a fuel supply amount calculation means 6a that calculates the amount of the supplied fuel according to the calculated learning value so that the air-fuel ratio of the air-fuel mixture becomes a target value; and a calculation result of the fuel supply amount calculation means 6a as an output signal. In the fuel supply amount control device comprising an output signal generating means 6b that generates an output signal and applies it to the fuel supply means 3, information representing the detected load amount is stored when the load amount detection means 4a detects the load amount of the internal combustion engine. The storage means 7 and the timing from when the load amount is detected until the components of the exhaust gas emitted by the engine main body 1 operated at the detected load amount are detected by the exhaust gas detection means 4b. A clock means 8 for measuring time is provided, and the learning means 5 calculates a learned value of the load region specified by the stored information based on the detected exhaust gas component at the end of measuring the time by the time measuring means 8. The reason is that it is calculated.

[Function and effect of the invention]

By configuring the present invention in this way, the storage means 7 stores the information representing the load amount of the internal combustion engine detected by the load amount detection means 4a, and the timer means 8 stores the information representing the load amount of the internal combustion engine detected by the load amount detection means 4a, and the time measurement means 8 stores the information representing the load amount of the internal combustion engine detected by the load amount detection means 4a, The time required for the air-fuel mixture combusted in the engine body 1 under the detected load amount to become exhaust gas and for the components of the exhaust gas to be detected by the exhaust gas detection means 4b after starting time measurement from To measure time. Then, when the clocking means 8 finishes counting the above-mentioned time, the learning means 5 calculates a value representing the load amount of the internal combustion engine stored in the storage means 7 based on the exhaust gas component detected by the exhaust gas detection means 4b. A learning value of the load range of the internal combustion engine determined as t is calculated.

In this way, the storage means 7 and the timing means 8 detect the timing of specifying the load range of the internal combustion engine based on the output of the load amount detection means 4a with respect to the learning timing of the operating state of the internal combustion engine based on the output of the exhaust gas detection means 4b. The air-fuel mixture combusted under the load becomes exhaust gas, and the exhaust gas detection means 4
Since we delayed the time required to reach b,
The time-based learning error is eliminated, and the learning rate of the operating state of the internal combustion engine is improved. Thereby, the amount of fuel to be supplied into the intake pipe la by the fuel supply means 3, that is, the air-fuel ratio of the air-fuel mixture formed in the intake pipe la, can be controlled to the target value with high precision, and as a result, It brings about improvements in internal combustion engine exhaust emissions, fuel efficiency, and vehicle drivability.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.
The figure shows an example in which the fuel supply amount control device according to the present invention is applied to a mixture supply system of a vehicle internal combustion engine 10. Mixture supply system is variable venturi type carburetor 2
0 and this vaporization! Reference numeral 20 indicates an intake pipe 12 extending from the engine body 11 of the internal combustion engine 10 and an air cleaner 1.
It is interposed between the intake pipe 14 extending from the intake pipe 3 and the intake pipe 14 extending from the intake pipe 3 . The vaporizer 20 has a carburetor body 21 connected between the two membrane tracheas 12.14, and this carburetor body 21 allows communication between the two membrane tracheas 12.14 through its intake passage 21a.

As shown in FIGS. 2 and 3, the carburetor body 21 includes:
The cup-shaped casing 22 is a peripheral wall of the carburetor main body 21.
A float chamber 23 is attached to the cylindrical portion 21b which faces the opening of the casing 22 from the other side of the peripheral wall of the carburetor body 21 and protrudes in the opposite direction from the casing 22. The zero-stage annular piston 24, which is assembled in a hanging manner, connects the carburetor main body 21 with its large diameter portion 24a.
is slidably fitted into the casing 22 in a direction perpendicular to the intake passage 21a to form an atmospheric chamber 22a and a pressure transformation chamber 22b. The intake passage 21a passes through the communication hole 21c provided in the
It is connected to the upstream of

The small diameter portion 24b of the piston 24 is formed by a through hole 21 formed on the peripheral wall side of the carburetor body 21 upstream of the throttle valve 25.
d so that the upper head part 2 is slidably fitted in an airtight manner.
4c forms a variable venturi in cooperation with a protrusion zte protruding into the intake passage 21a of the carburetor main body 21, and a communication hole 24d bored in this small diameter portion 24b.
The variable pressure chamber 22b is connected to the throttle valve 25 of the intake passage 21a.
It communicates with the upstream of the In addition, in the transformation chamber 22b,
A coil spring 26 is interposed between the annular post 22c of the casing 22 and the head of the piston 24 to bias the piston 22 toward the protrusion 21e, and the spring constant of the coil spring 26 is extremely large. is set to a small value.

In addition, the cylindrical body 27 fitted into the center of the head of the piston 24 is connected to the cylindrical body 27 which is press-fitted into the boss 22c of the casing 22.
A needle-shaped valve body 27a is slidably inserted into the guide rod 27 and extends from the guide rod 27 into the intake passage 21d. It passes through the nozzle 28 and enters the cylindrical body 29 fitted in the cylindrical portion 21b. The cylindrical body 29 has a base 29
At a, under the spring force of the coil spring 29b,
The inner end of a male threaded plug 29C screwed onto the outer end of the cylindrical portion 21b is engaged with the inner end of the male screw plug 29C. It's communicating.

An annular metering jet 29e is provided on the inner peripheral surface of the tip of the cylinder 29.
protrudes in the circumferential direction, and the annular area formed between the inner circumferential surface of the metering jet 29e and the outer circumferential surface portion of the valve body 27a facing the metering jet 29e determines the amount of air flowing through the intake passage 21a. It is almost proportional to . In addition, the cylinder body 2
The communication hole 29f drilled in the radial direction at the tip of the air bleed passage 21 formed on the other side of the peripheral wall of the carburetor main body 21
The air bleed passage 21f communicates with the upstream side of the protrusion 21e in the intake passage 21a. In addition, in FIG. 3, the symbol 22e indicates a press-fit plug,
Moreover, each code|symbol 29g and 29h show an O-ring.

The fuel supply amount control device has a drive mechanism 30 assembled on the other side of the peripheral wall of the carburetor main body 21, as shown in FIGS. 2 and 3, and this drive mechanism 30 is shown in FIG. The plunger 30b is assembled into a step motor 30a so as to be displaceable in the axial direction. The step motor 30a is assembled on one side of the stator 31 and on the other side of the peripheral wall of the carburetor body 21 so as to face an intermediate portion of the air bleed passage 21f.
The hollow rotor 33 has a pair of ball bearings 32.3.
2, it is coaxially and rotatably supported within the stator 31.

The plunger 30b has a male threaded portion 35 formed in the axial direction at an intermediate portion of the outer circumferential surface of the plunger 30b, and a female threaded portion 34 formed in the axial direction at an intermediate portion of the inner circumferential surface of the hollow portion of the rotor 33. The needle-shaped valve body 3, which is the tip of the plunger 30b, is displaceably fitted into the plunger 30b.
Reference numeral 6 denotes an annular valve seat portion 21g that is fed from the center of one side of the stator 31 and formed in the middle portion of the air bleed passage 21f.
It is worshiped inside. This means that the plunger 3ob controls the annular area between the valve body portion 36 and the valve seat portion 21g (i.e., the amount of air bleed inflow from the upstream to the downstream of the air bleed passage 21f) by its axial displacement. means. Note that the plunger 3ob cannot rotate around the axis with respect to the stator 31, but can be displaced in the axial direction. Further, in FIG. 4, reference numeral 37 indicates a coil spring that biases the plunger member 30b toward the valve body portion 36 thereof.

Further, as shown in FIG. 2, the fuel supply amount control device includes various sensors 40a to 4Of, an air temperature sensor 40a, a throttle sensor 40b, a negative pressure sensor 40C, and a water temperature sensor 4Of.
Each A-D converter B50a, 50b connected to 0d
, 50c and 50d, a waveform shaper 50e connected to a rotation angle sensor 406, and a comparator 50g connected to an oxygen concentration sensor 40f and a reference signal generator 550f. temperature is detected and generated as an analog temperature signal. The throttle sensor 40b detects the opening degree of the throttle valve 25 and generates an analog opening signal.

The negative pressure sensor 40c detects the negative pressure generated within the intake pipe 12 and generates it as an analog negative pressure signal. The water temperature sensor 4Qd detects the cooling water temperature in the cooling system of the engine body 11, and the zero rotation angle sensor 40e generates an analog water temperature signal.
The rotation angle of the cam surface in the distributor 15 attached to the engine body 11 is detected and generated as a rotation angle signal representing the rotation angle of the internal combustion engine 10. The oxygen concentration sensor 40f detects the concentration of oxygen contained in the exhaust gas in the exhaust pipe 16 exiting the engine body 11, and generates an analog concentration signal.

The A-D converter 50a converts the analog temperature signal from the temperature sensor 40a into a digital temperature signal, and performs the A-D conversion 5.
50b converts the analog opening signal from the throttle sensor 40b into a digital opening signal, and the A-D converter 50
c converts the analog negative pressure signal from the negative pressure sensor 40C into a digital negative pressure signal, and the A-D converter Sod converts the analog water temperature signal from the water temperature sensor 40d into a digital water temperature signal. The waveform shaper 50e is the rotation angle sensor 40
The rotation angle signal from s is waveform-shaped and generated as a shaped signal. The reference signal generator 50f generates a reference signal at a level corresponding to a predetermined oxygen concentration necessary for specifying the stoichiometric air-fuel ratio. The comparator 50g compares the analog concentration signal from the oxygen concentration sensor 40 with the reference signal from the reference signal generator asor, and outputs a high level (or low level) when the level of the analog concentration signal is higher (or lower) than the level of the reference signal. level). In such a case, a high level of the oxygen concentration level signal from the comparator 50g indicates that the air-fuel ratio adjusted in the carburetor 20 is richer than the stoichiometric air-fuel ratio, and a low level indicates that the air-fuel ratio adjusted in the carburetor 20 is higher than the stoichiometric air-fuel ratio. It means thinner.

The microcomputer 60 receives power from the DC power #B in response to opening of the ignition switch IC of the vehicle and enters the operating state, and executes the main program, the first interrupt control program, and the first interrupt control program stored in advance. The subprogram, the second subprogram, and the second interrupt control program are each 5'fI! According to each flowchart shown in FIG. Various calculation processes necessary for controlling the relay 30a and the relay 70 are performed as described below.

In such a case, the bank amplifier RAM built into the micro combinator 60 serves as a temporary memory for the arithmetic processing contents of the micro combinator 60,
This back amplifier RAM has a bank amplifier power supply of 60 m (
(See Figure 2) to maintain the operating state.

Further, in this embodiment, the interrupt of the first interrupt control program is started every time a predetermined time value (for example, 1 millisecond) is counted by the timer built in the microcomputer 60, while the second interrupt Interruption of the control program is started in response to the interruption of the power supply voltage from the DC power supply B to the micro combiator 60 via the ignition switch IG when the ignition switch IC is opened. The relay 70 has an electromagnetic coil 71 and a normally open switch 72 that closes (or opens) when the electromagnetic coil 71 is excited (or demagnetized).
2 are both connected between the DC power supply B and the microcomputer 60.

In this embodiment configured as described above, the piston 24 of the carburetor 20 is in the state shown by the two-dot chain line in FIG. 3, and the drive mechanism 30 and the throttle valve 25 are in the state shown in FIG. shall be taken as a thing.

At such a stage, if the internal combustion engine 10 is started by closing the ignition switch tC and the vehicle is driven with the opening degree of the throttle valve 25 corresponding to the depression of the accelerator pedal, this state can be avoided. In this case, the air flow flowing into the intake pipe 14 through the air cleaner 13 is activated by a coil spring based on the difference between the negative pressure generated in the variable pressure chamber 22b and the atmospheric pressure in the atmospheric chamber 22a depending on the opening degree of the throttle valve 25. Under the variable venturi action of the piston 24 and the protruding portion 21e, which slide against the piston 26
forming an air-fuel mixture with the annular region between the valve body 27a and the metering jet and the fuel sucked out through the nozzle 28;
The air flows through the intake passage 21a1 of the carburetor body 21, the throttle valve 25, and the intake pipe 12 into the engine body 11 at the currently required air-fuel ratio, burns in the combustion chamber of the engine body 11, and then It is discharged as an exhaust gas stream into the exhaust pipe 16.

Further, the micro combiator 60 becomes activated in response to the above-mentioned opening of the ignition switch IC, starts executing the main program in step 80 according to the flowchart of FIG. starts counting the predetermined time value. Thereafter, this timer issues an interrupt command every predetermined time (for example, 1 millisecond), and the microcomputer 60 interrupts the execution of the main program, the first subprogram, or the second subprogram, and returns to the flowchart of FIG. A feedback counter used to execute the calculations of steps 100 to 102 of the first interrupt control program according to the calculation timing and determine the calculation timing of the feedback correction value Af and learning values C(1) to G (rl), which will be described later. Value AfT
After incrementing the learning counter value GKT by 1 at predetermined time intervals, the program returns to execution of the interrupted program.

Therefore, before the above-mentioned ignition switch IC is closed, the microcomputer 600 backup RA
If the state judgment value F (described later) stored in M has not changed at this stage, the microcomputer 60
Based on the determination that the storage contents of the backup RAM are normal, it is determined in step 81 that it is rNOJ, and the process proceeds to step 82. On the other hand, if the determination in step 81 is rYESJ, the backup RA
Based on the judgment that the memory contents of M are abnormal, the micro combinator 60 sets each learning value G(1) in step 81a.
.about.G(8) together to the reference value KO (for example, 1).

In such a case, each learning value G (11 to G (8) means a correction value by learning for learning the operating state of the internal combustion engine and controlling the air-fuel mixture to the target air-fuel ratio, and each of these learning values G ( 1), G (2], ..., G (81 fluctuates around the reference value KO, and is the IT (hereinafter referred to as air flow IQ) of the air flow flowing into the intake passage 21a of the carburetor 20. The first region (O≦Q<Ql), the second region (Ql≦
Q<Q2), ..., 8th region (Q7≦Q<Q8)
correspond to each.

However, each air flow rate Q1. Q2. . . , Q8 corresponds to each value obtained by dividing the air flow rate Q, which changes during the period from fully closing to fully opening the throttle valve 25, into eight. When the calculation in step 8ta is completed as described above, the micro combinator 60, in step 82, sets the feedback correction value Af and the integral control value Afl to the reference value Ko, and sets the feedback counter value AFT and the learning counter value GKT. is set to zero, a transfer time waiting flag F1 to be described later is set to "O", and an excitation signal necessary for excitation of the electromagnetic coil 71 of the relay 70 is generated. In such a case, the feedback correction value Af represents a correction value for controlling the air-fuel mixture to the target air/fuel efficiency based on the oxygen concentration in the exhaust gas flow, and the integral control value Af1 is the feedback correction value Af.
represents the integral control portion of these feedback correction values A
f and the integral control value Afl fluctuate around the reference value KO.

As described above, when the excitation signal is generated from the microcomputer 60, the relay 70 excites the electromagnetic coil 71, closes the switch 72, and applies the power supply voltage to the micro combinator 60 from the DC power supply B via the switch 72. Allow. Further, when the main program proceeds to step 83, the micro combinator 60 calculates the internal combustion engine 100 rotation speed N based on the shaped rotation angle signal generated from the waveform shaper 50e in cooperation with the rotation sensor 408. After calculating the 0 rotation speed N, which temporarily stores the rotation speed N, the microcomputer 60 performs A in step 84.
- A digital temperature signal generated from the D converter 50a in cooperation with the temperature sensor 40a, a digital negative pressure signal generated from the A-D converter 50c in cooperation with the negative pressure sensor 40C, A-D The value of the digital water temperature signal generated from the converter 50d in cooperation with the water temperature sensor 40d, and the value of the oxygen concentration signal generated from the comparator 50g in cooperation with the oxygen concentration sensor 40f and the reference signal generator 50f are read, and the values of the oxygen concentration signal are read, respectively. Air temperature THA, intake pipe pressure PIM, water temperature TH
It is temporarily stored as W and oxygen concentration OHL, and the process moves to step 85.

In step 85, the microcomputer 60 performs the following (
1) Based on the formula, an air flow rate Q is calculated according to the engine speed N and intake pipe pressure PIM stored above, and the air flow rate Q is temporarily stored.

Q-to-PIM-N... (Formula 1) However,
K is a proportionality constant. Furthermore, microcomputer 6
0 is the temperature correction value Aa for adjusting the air-fuel mixture to the target air-fuel ratio based on the intake temperature THA stored above in this step.
The water temperature correction value AW for making the air-fuel mixture to the target air-fuel ratio is calculated based on the water temperature THW, and each correction value Aas is calculated.
Aw is temporarily stored. In addition, these temperature correction values A
a and the water temperature correction value AW are values that fluctuate around the reference value KO.

Next, in step 86, the micro combinator 60 selects a region to which the air flow rate belongs from the first to eighth regions based on the stored air flow rate Q, and sets the learning value corresponding to this selected region to each learning value. C(1) to G(8) to G(1)
The step motor 30a of step 87 is selected as
It is used to calculate the target rotation step number SO. However, i
is an integer from 1 to 8.

The target rotation step number 3o is calculated based on the following equation (2) according to the air temperature correction value Aa, the water temperature correction value A W % selection learning value G (11), and the feedback correction value Af.

So=1 (Aa+Aw+G(1)+Af-3・K
o)... (Formula 2) This target rotation step number So is
Target air bleed inflow amount at 1f, that is, the carburetor 20
The coefficient 1 corresponds to the number of steps of the step motor 30a for controlling the air-fuel mixture to be adjusted to the target air-fuel ratio.
C; (1), A [correction amount by step motor 30a
This is a constant for converting to the number of steps. In addition, the term 3-Ko in the above (Formula 2) is each correction Aa, 8w,
The total value of the reference value Ko by adding G(IJ, A) is 4・K
This is a correction term for returning O to the standard value Ko, and is K1.K.

The value represents the basic air-fuel ratio, ml, which is the basic rotational step number of the step motor 30a corresponding to the basic air bleed flow rate.

When the main program proceeds to step 88 after the calculation in step 87, the microcomputer 60 calculates the difference between the target rotation step number SO in step 87 and the actual rotation step number of the step motor 30a (hereinafter referred to as the current rotation step number S). Generated as a rotation signal. In this case, the current rotational step number S-0 corresponds to the original position of the plunger 30b (corresponds to when the annular area between the valve body part 36 and the valve seat part 21g is zero), and the increase in S corresponds to the original position of the plunger 30b. This corresponds to an increase in the amount of displacement resisting the coil spring 37. Next, the step motor 3 of the drive mechanism 30
0a rotates the rotor 33, that is, the female screw 1334, in the normal direction according to the value of the rotation signal from the microcomputer 60, and accordingly, the plunger 30b, I! The male threaded portion 35 is displaced against the elastic force of the coil spring 37, and the valve body portion 36 is displaced.
The annular area between the valve seat portion 21g and the valve seat portion 21g is increased in accordance with the forward rotation of the rotor 33. Then, the air flow existing upstream of the protrusion 21e of the intake passage 21a causes communication between the air bleed passage 21f and the cylindrical body 29 as an air bleed amount corresponding to the annular area between the valve body part 3G and the valve seat part 21g. Hole 2
9f, the metering jet 29e, and the nozzle 28, and is sucked out from the communication hole 29d into the intake passage 21a together with the fuel.

After that, the main program proceeds to step 89, where the micro combinator 60 receives the value of the digital opening signal from the A-D converter 50b, the value of the digital negative pressure signal from the A-D converter 50c, and the value of the A-D converter 50c. Reads the value of the digital water temperature signal from the converter 50d and the high-level ordered detection signal from the comparator 50g, and determines whether the operating state of the internal combustion engine is in the feed puncture correction region based on the oxygen concentration of the exhaust gas. do. Note that this feedback correction area is determined when the water temperature is high, the engine is not in the full load area or the idle area, and the oxygen concentration sensor 40f is
This is done on the condition that the is activated. If the calculation in step 89 is "NO", that is, it is determined that it is not in the feedback correction region, the microcomputer 60
In step 90, the feedback correction value Af and integral control value Afl are set to the reference value Ko, and the feedback counter AfT is set to zero, and then in step 91, the transfer time waiting flag F1, which will be described later, is set to 0'. ,
Set the learning counter value GKT to rOJ by 4-7. The calculation in step 90 is performed when the operating state of the internal combustion engine is not in the feedback correction region, Nagisa variables At, Af 1. This means that AfT is set to an initial state, and the calculation in step 91 is performed by setting various variables F1. This means setting the GKT to its initial state. The microcomputer 60 then returns to the execution of the calculation in step 83, executes the circulation calculation in steps 83-91, calculates the target rotation step number So based on the air temperature correction value Aa and the water temperature correction value Aw, and calculates the fuel supply amount. Control.

During the cyclic operation in steps 83-91, the microcomputer 60 returns rYES in step 89 based on the above conditions.
In other words, if it is determined that the internal combustion engine is in the feedback correction region, a feedback correction value is calculated in step 92. , the program is executed from step 92a. In step 92b, the microcomputer 60 compares the feedback counter value AfT with the predetermined value AfTo, so that the feedback counter value A[T becomes the predetermined value AfT.
If it is smaller than o, the process moves to the calculation in step 93 of the main program, which will be described later, via the calculation in step 92c, and after the calculation in step 93.91, the process proceeds to step 83.
Return to the calculation.

As a result, the micro combinator 60 performs step 83.
-89.92.93.91 continues to be executed, and during this circular operation, when the feedback counter value AfT increases due to the execution of the first interrupt control program and becomes larger than the predetermined value ArTo, the first At step 92b of the subprogram, the microcomputer selects rYESJ.
After determining that, the process moves to step 92d. Step 92
At d, the microcomputer 60 determines the oxygen concentration OHL.
When the oxygen concentration OHL is at a high level, it is judged as rYESJ and the process moves to execution of the calculation in step 926. When the oxygen concentration OHL is at a low level, it is judged as rNOJ and the process moves on to the execution of the calculation in step 92f. In the calculation of step 92e,
The micro combinator 60 adds the integral increment value ΔAf1 to the current integral control value Afl, thereby setting the integral control a(iiA
A feedback correction value Af is calculated by updating fl and adding the updated integral control value Afl and proportional control value KP. In the calculation of step 92f, the microcomputer 60 updates the integral control value Afl by subtracting the integral decrement value ΔAf2 from the current integral control value Afl, and subtracts the proportional control value KP from the updated integral control value Af1. The feed bank correction value A" is calculated by. After the calculation in step 92e or step 92f,
The microcomputer 60 sets the feedback counter AfT to "0" in step 92g, and proceeds to the calculation of the main program 93 via step 92c.

Then, the micro combinator 60 performs step 83-
The cyclic operations 89.92 and 93.91 are executed, and during these cyclic operations, step 92 (92a
-92g) is taken into consideration to determine the target rotation step number So, and the air-fuel mixture adjusted in the carburetor 20 is controlled to the target air-fuel ratio. The air-fuel ratio is controlled by this feedback correction value Af when the oxygen concentration OHL is at a high level, that is, when the air-fuel ratio adjusted to rli in the carburetor 20 is high, the feedback correction value Af is set to a feedback counter value AfT and a predetermined value AfTo. The target step number So is increased by an increment value ΔAft every time determined by , thereby acting to make the air-fuel ratio leaner. On the other hand, when the oxygen concentration OHL is at a low level, that is, when the air-fuel ratio adjusted in the carburetor 20 is low, the feedback correction value Ar is decreased by the decrement value ΔAf2 at each time interval, and the target step number So is decreased. This acts to enrich the air-fuel ratio. The above predetermined value ArTO1 increment value ΔA
fl and the decrement value ΔAf2 are set to values that cause the feedback correction value Af to change by 2 to 5 percent per second, depending on the relationship with the rate of change of the feedback counter value AfT. The decrement value ΔAf2 is set larger than the increment value ΔAfl in order to avoid deterioration of the exhaust gas components by increasing the control speed in the direction of making the exhaust gas richer than in the direction of increasing the concentration. Note that the proportional control value KP represents a proportional control amount in feedback control of the air-fuel ratio based on the oxygen concentration in the exhaust gas.

During the circulation calculation in steps 83-89.92 and 93.91, the water temperature THW becomes larger than the predetermined value and the intake air temperature TH
If A is lower than a predetermined value, the microcomputer 6
0, it is determined in step 93 that the internal combustion engine is in the learning region, that is, rYESJ, and the process moves to execution of the calculation in step 94. The microcomputer 60 starts the calculation in step 94 from step 94a whose details are shown as a second subprogram in FIG. 8, and compares the learning counter value GKT and the predetermined value GkTo in step 94b. When the internal combustion engine has just entered the learning region, the microcomputer 60 has set GKT to "0" in step 91 of the above-mentioned cyclic calculation in step 94b.
The learning counter value GKT is smaller than the predetermined value, that is, "
NO”, and the process goes to step 8 via step 94C.
3-89.92-94 (94a-94c) continue to execute the i-layer top operations. Note that the predetermined value GKTo corresponds to the time until the exhaust gas component used for learning becomes stable in relation to the rate of increase of the learning counter value GKT in the first interrupt control program.

During the above-mentioned cyclic calculation, when the learning counter value GKT becomes larger than the predetermined value GKTo due to the increase in the learning counter value GKT by the first interrupt control program, the microcomputer 60 determines rYEsJ in step 94b, and steps 94d It is determined whether the transfer time waiting flag F1 is "1" or not.

At the beginning of learning the operating state of the internal combustion engine, the transfer time waiting flag F1 is set to 10'', so the microcomputer 60 determines rNOJ in step 94d and advances the second subprogram to step 94e. At step 94e, the microcomputer 60 determines the transfer time prestored in the read-only memory ROM in the microcomputer 60 based on the engine rotational speed N calculated at step 83 and the intake pipe pressure PIM read at step 84. Refer to table and transfer time T
Calculate D. As shown in the %10A diagram, the transfer time table divides the engine speed N and intake pipe pressure PIM into n parts each, and calculates the transfer time TD (
i, j). However, i and j are integers from 1 to n. Further, this transfer time TD is determined by the negative pressure sensor 40c.
The air flow whose intake pipe pressure PIM has been detected is supplied to the engine body 11 via the intake pipe 12, and
This corresponds to the time it takes for the oxygen concentration of the exhaust gas discharged through the exhaust pipe 16 to be detected by the oxygen concentration sensor 40f after being combusted by the intake pipe pressure P.
The air flow at the time when the region to which the air flow rate Q belongs (the load region of the internal combustion engine) is determined based on the IM is detected by the oxygen concentration sensor 4.
This is the time until it affects 0f.

After calculating the transfer time TD in step 94e, the microcomputer proceeds to step 94f with a transfer time wait flag F1.
is set to "1", and the current air flow rate Q is set at step 94g.
(calculated in step 85) is stored as the delayed air flow rate Qd. After storing the delayed air flow rate Qd, the micro combinator 60 returns to the calculation of step 83 via step 94C, and returns to step 83-89.92.9.
3 is executed, and the operation of step 94 is restarted from step 94a of the second subprogram. At this time, similar to the above, the learning counter value GKT is set to the predetermined value GKTo.
Since it is larger, the microcomputer 60 determines rYEsJ in step 94b and advances the second subprogram to step 94d. At step 94d, the microcomputer 60 determines that the transfer time waiting flag F1 set at 11° at step 94f is "1", advances the second subprogram to step 94h, and performs learning at step 94h. counter value GKT and predetermined value GK
A value GKTo +TD, which is the sum of To and transfer time TD, is compared.

Then, the learning counter value GKT is the added value GKTa
Micro Combiator 60 until it becomes larger than +TD
is judged as [NO] in step 94h, and the process proceeds to step 83.
-94 (94a, 94b.

94d, 94h, 94c) are executed.

During the above circular calculation, the learning counter value GKT is increased by the execution of the first interrupt control program, and the above added value GKT is increased.
If it is larger than o+TD, the micro combinator 60
is determined to be rYES in step 94h, and the second subprogram is executed as a learning routine 94i-1 to 94i-8 and 94j-1 to 94j-8 for the operating state of the internal combustion engine for each region of the delayed air flow rate Qd. Proceed to. Step 94i-
The calculations 1 to 94i-8 determine the region to which the delayed air flow rate Qd belongs by comparing each of the delayed air flow rates Qd and each boundary value Q1 to Q8 obtained by dividing the air flow rate into eight. In addition, each calculation in steps 94j-1 to 94j-8 is performed using each learning value G.
(11 to G(8) are updated by executing the following (Formula 3).

G (t) = G (t) + 2 (Af-, Ko)
(Equation 3) However, i is a positive number from 1 to 8 and represents the region to which the delayed air flow rate Qd belongs. This (Equation 3) calculates the deviation from the reference value KO by subtracting the reference value KO from the feedback correction value Af, and this calculation result Af
- Weighting that determines the degree of change in the learning value G (i) by one learning to Ko is a constant multiplied by 2, and the multiplication result is 2
(Af-Ko) is added to the old learned value G(i) and updated as the new learned value G(i).

That is, in the learning routines 94i-1 to 94i-8 and 94j-1 to 94J-8, the delayed air flow rate Qd
is in the first region (qa<Ql), the microcomputer 60 determines rYEsJ in step 94i-1, and sets the learned value G(1) in the first region in step 94j-1.
is updated and the process proceeds to step 94. Also,
If the delayed air flow rate Qd is in the second region (Ql≦Qd<Q2), the microcomputer 60 performs step 94i.
-1: “NO”, step 94i-2: rYEsJ
Then, in step 94j-2, the learned value G of the second area is determined as
(2) is updated and the process moves to execution of the calculation in step 94. Thereafter, learning values G(3) to G(8) are updated in the same manner, and i! ! If the air flow device d does not belong to any of the first to eighth regions, the microcomputer 60 performs all comparison operations in steps 94i-1 to 94i-8.
If NOJ is determined, the process moves to step 94 to execute the calculation.

In step 94k, the microcomputer 60 sets the learning counter value GKT to a predetermined value GKTo, sets the transfer time waiting flag F1 to "0", and sets the next learning value G.
Prepare for updates of (1) to G(8).

After the calculation in step 94, the microcomputer 60 returns to the execution of the calculation in step 83 via step 94c, and performs the cyclic calculations in steps 83-89, 92-94 when the internal combustion engine is in the feedback correction region and in the learning region. Keep running for a while.

During the above-mentioned cyclic calculation, the microcomputer 60 determines the target rotation step number So in step 87, taking into account the learning values G(1) to G(8) obtained by executing steps 94 (94a to 94k). The air-fuel mixture to be adjusted in vaporization 520 is controlled to a target air-fuel ratio.

As can be understood from the above explanation of the operation, in the second subprogram for learning the operating state of the internal combustion engine for each load range of the internal combustion engine, the microcomputer 60 determines the air flow for determining the load range by the calculation in step 94e. The transfer time TD from when it is detected by the negative pressure sensor 40c until it becomes exhaust gas and its oxygen concentration is detected by the oxygen concentration sensor 4Of is calculated, and the air flow rate Q of the air flow is delayed by the calculation in step 94g. It is stored as the air flow rate Qd, and the learning routines 94i-1 to 94
94i-8, 943-1 to 94j-8 are executed for the above transfer time TD, and each learning value is determined according to the output of the oxygen concentration sensor 40f for each region divided by the stored delayed air flow rate Qd. Since G+1) to G(8) are calculated, it is possible to eliminate learning errors caused by the above-mentioned transfer time.

Therefore, the target rotation step number So in step 87
can be obtained with higher accuracy according to the learning results of each learning value G (11 to G(8)) as described above, and as a result, the amount of fuel flowing into the intake passage 21a, that is, the air-fuel ratio of the mixture can be It is possible to control the target value with even more precision.This means that it leads to improvements in exhaust gas countermeasures, vehicle drivability, and fuel efficiency.

In the above-described operation, when the ignition switch IC is opened after the running vehicle has stopped, the microcomputer 60 controls the electromagnetic coil 7 of the relay 70.
After the switch 72 is closed under the excitation of 1, the interrupt execution of the second interrupt control program is executed in step 110 according to the flowchart of FIG. In step 111, the sum of the learned value G(1) immediately before opening of the ignition switch IG and the complement of this learned value G(1) is stored as the state determination value F, and in step 112, the step A rotation signal necessary for the current rotation step number S-0 of the motor 30a is generated, and in response to this, the step morph 30
The plunger 30b rotates until a becomes S-0, and the plunger 30b moves to the original position shown in FIG. 3, so that the valve body 36 is seated on the valve seat 21g.

When the second interrupt control program proceeds to step 113, the micro combinator 60 eliminates the excitation signal, and in response, the relay 70 switches to 1! The switch 72 is opened by demagnetizing the magnetic coil 71, and the arithmetic processing of the microcomputer 60 is stopped in step 114. At this time, the backup RAM of the microcomputer 60 cooperates with the bank-up power supply 60a to store the state judgment value F in step 111 as it is together with each learned value G (11 to G(8)) immediately before the opening of the ignition switch IG. Note that the ignition switch I of the internal combustion engine lO
The transformation chamber 22b of the carburetor 20 is stopped when G is opened.
The internal pressure becomes atmospheric pressure, and the piston 24 slides under the action of the coil spring 26 to the position shown by the two-dot chain line in FIG.

In the above embodiment, in step 94e, the first
Although the transfer time TD was calculated by referring to the table in Fig. 0A, the transfer time TDO value for the air flow rate Q is stored in the micro combinator 60 instead of the above table as shown in Fig. 10B. The transfer time TD may be calculated by referring to the table based on the air flow rate Q calculated in step 85.

Next, a modification example in which the second subprogram of the above embodiment is replaced with the third subprogram shown in the flowchart of FIG. 11 will be explained.
3-89. During the cyclic calculation of 92-94, the microcomputer 60 executes the calculation of step 94 in the third subprogram 9.
Start from 5a. The comparison of the learning counter value GKT in step 95b and the determination based on the transfer time waiting flag F1 in step 95d are performed in step 9 of the second subprogram.
The calculations are the same as those in 4b and 94d. During the above circular operation,
At the start of learning, the microcomputer 60 determines "NO" in step 95d, calculates the transfer time TD in step 95e by the same method as step 94e of the second subprogram, and sets the transfer time wait flag in step 95f. Set F1 to "11".

Next, the microcomputer 60 executes the third subprogram in steps 95g-1 to 95g-8 and step 95h.
Proceed to the region determination routine for the air flow rate Q consisting of -1 to 95h-9. The calculations in steps 95g-1 to 95g-8 are performed using the air flow rate Q and each boundary value Q1 obtained by dividing the air flow rate into 8.
By comparing Q8, the region to which the air flow rate Q belongs is determined. Further, the calculations in steps 95h-1 to 95h-9 memorize and save the determined area. That is, in this area determination routine, steps 83-89, 92-
During the circulation calculation in step 94, the air flow rate Q calculated in step 85
is in the first region (Q<Ql), the microcomputer 60 determines rYESj in step 95g-1, and sets the region discrimination value n to "1" in step 95h-1. Also, the air flow rate Q is in the second @ region (Ql≦Q<Q2)
, the microcomputer 60 performs step 95.
"NO" in g-1, rYES in step 95g-2
J is determined, and the area discrimination value n is set to "2" in step 95h-2. Similarly, when the air flow rate Q is in the third to eighth regions, the region discrimination value n is set to "3 to 8".
numeric data is set. If the air flow rate Q does not belong to any region, steps 95g-1 to 95g
-8 calculations are all determined to be "NO", and step 95
At h-9, the area discrimination value n is set to "0".

This set of area discrimination values n is set in step 95j, which will be described later.
This means that the learned values G (11 to G(8)) are not updated.

After completing the calculation of the area discrimination routine as above,
As explained in the second subprogram, the microcomputer 60 sets the learning counter value GKT to the predetermined value G.
Steps 83-89, 92-94 (95a,
95b, 95d.

95i, 95c) continues to be executed. During this circular calculation, the learning counter value GKT is changed to the above sum value GKTo.
If it is larger than +TD, the microcomputer 60
is determined to be rYEsJ in step 95i, and in step 95j, based on the calculation of the following (Equation 4), the learning value G of the area determined by the value of the area discrimination value n stored above is calculated.
Calculate (n).

C, (n)-G(nl+K 2 (A f-K o)・
... (Formula 4) The above (Formula 4) is executed in the second subprogram (
This is the same as the calculation in equation 3). After that, the micro combinator 60 sets the learning counter value GKT in step 95k.
is set to a predetermined value GKTo, and the transfer time wait flag F1 is set.
to O” and repeat step 83-89.92-
94, the air-fuel mixture to be adjusted in the carburetor 20 is controlled to the target air-fuel ratio based on the learning values G(1) to G(8) updated in step 95j.

As can be understood from the above explanation of the operation, in the third subprogram for learning the operating state of the internal combustion engine for each load range of the internal combustion engine, the microcomputer 60 performs the comparison determination in steps 95g-1 to 95g-8. Flow rate Q
Determine the negative rFI region of the internal combustion engine according to Step 9
The load area determined by the calculations in steps 5h-1 to 95h-8 is stored as a load area discrimination value n, and after the transfer time TD calculated by the calculation in step 95e has elapsed, the learned value G is set for each load area in step 95j. Since (1) to G(8) are calculated, the learning error caused by the transfer time can be eliminated, and the same effect as when using the second subprogram can be achieved.

In addition, in the above-mentioned embodiment and its modification, an example was explained in which the present invention was applied to a mixture supply system having a variable venturi type carburetor 20, but instead of this,
The present invention may also be applied to a mixture supply system for growing a fixed Benchelli type carburetor.

Further, in implementing the present invention, the present invention may be applied to a fuel injection control device equipped with a fuel injection valve that injects fuel from a fuel supply source into an intake pipe of an internal combustion engine.
In such a case, the target valve opening time of the fuel injector corresponding to the target rotation step number So is determined by each learning value G (1),
. . . If determined according to Gf81, substantially the same effects as those of the above embodiment can be achieved. In this case, the present invention is not limited to feedback control, but can also be implemented in open loop control.

[Brief explanation of drawings]

11jlJ is a diagram corresponding to the structure of the invention described in the claims, FIG. 2 is a block diagram showing an embodiment of the present invention, FIG. 3 is an enlarged sectional view of the carburetor in FIG. 2, and FIG.
The figure is an enlarged partial cutaway view of drive #8 in 2nd vgJ,
Figure 5 is a flowchart of the main program executed by the microcomputer in Figure 2. 6 is a flowchart of the first interrupt control program executed by the microcomputer of FIG. 2, and FIG. 7 is a flowchart of the first subprogram showing details of the routine for calculating the feedback correction value in the main program of FIG. 5. ,
8 is a flowchart of the second subprogram showing the details of the routine for calculating the learned correction value in the main program of FIG. 5, and FIG. 9 is a flowchart of the second interrupt control program executed by the microcomputer of FIG. 2. Flowcharts, FIGS. 10AII and 10B are diagrams showing the contents of a table that stores parameters for calculation based on transfer time, and FIG. 11 is a flowchart of a third program that is a modification of the second subprogram in FIG. be. Explanation of symbols 10...Internal combustion engine, 11... Engine body, 12°14
... Intake pipe, 20... Carburetor, 21... Carburetor body, 21a... Intake passage, 23... Float chamber, 2
1... Carburetor body, 21f... Air bleed passage,
28... Nozzle, 29... Cylindrical body, 29e... Metering jet, 30... Drive mechanism, 40a... Air temperature sensor, 40b... Throttle sensor, 40C... Negative pressure sensor, 40d ...Water temperature sensor, 40e...Rotation angle sensor, 40f...Oxygen concentration sensor, 60...Microcomputer.

Claims (1)

[Claims] A fuel supply means for supplying fuel from a fuel supply source into an intake pipe extending from an engine body of an internal combustion engine, and the supplied fuel is mixed with an air flow flowing into the intake pipe in the same intake pipe. load amount detection means for detecting the amount of load on the internal combustion engine by being used in a mixture supply system that forms gas and supplies the engine body to the engine body; and components of exhaust gas discharged into an exhaust pipe extending from the engine body. an exhaust gas detection means for detecting the detected load amount; and an exhaust gas detection means that learns the operating state of the internal combustion engine based on the detected exhaust gas component for each load range of the internal combustion engine specified according to the magnitude of the detected load amount, and detects the specified load area. a learning means for calculating a learned value for each time; a fuel supply amount calculating means for calculating the amount of the supplied fuel according to the calculated learning value so that the air-fuel ratio of the air-fuel mixture becomes a target value; and the fuel supply amount In a fuel supply amount control device comprising an output signal generation means for generating a calculation result of the calculation means as an output signal and applying it to the fuel supply means, when the load amount detection means detects the load amount of the internal combustion engine, the detected load amount is a storage means for storing information representing the amount of load; and a component of the exhaust gas emitted by the engine body operated at the detected load amount by starting time measurement from the time of the detection of the load amount and detecting by the exhaust gas detection means. and a time measuring means for measuring the time until the time elapses, and the learning means calculates a learned value for the load region specified by the stored information based on the detected exhaust gas component at the end of measuring the time by the time measuring means. A fuel supply amount control device for an internal combustion engine air-fuel mixture supply system, characterized in that the fuel supply amount control device calculates the amount.