JPS5896139A - Engine control device - Google Patents

Abstract

PURPOSE:To perform a proper operation by calculating a fuel quantity signal based on a preset air-fuel ratio in accordance with an engine speed and load and a detected air quantity signal and by correcting the fuel quantity by means of alcohol content ratio data and engine temperature changes. CONSTITUTION:The fuel quantity Z is controlled by phi(Y.A/F.epsilon), where, Y is the air quantity, A/F is the preset air-fuel ratio, and epsilon is the measurement error of the intake air quantity. A/F is determined by the engine operating condition, and the ratio k0 against a reference value is previously stored in a memory unit 27, the intake quantity Y is measured by an air flow meter 4, and the fuel quantity Z is controlled by a microcomputer 20 through a drive circuit 11 and a metering valve 9. When the alcohol content ratio X measured by a content ratio meter 10 is changed, the content k1 of a register 28 varying in response to the content ratio X is further corrected to k2, the microcomputer 20 calculates Z= ko.k1.k2.Y, e.g., the air-fuel ratio is adjusted using k1=1 for gasoline and k1= 1.15 for 20% methanol to maintain the fuel quantity properly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine control device used in automobiles and the like, and particularly to an engine control device suitable for using fuel mixed with alcohol or the like.

In conventional engine control devices that use gasoline as fuel,
If alcohol-containing fuel is used, the air-fuel ratio, ignition timing, and exhaust gas recirculation amount will deviate from optimal values, resulting in a decrease in engine performance. This is reported in the following documents.

Society of Automotive Engineers of Japan, Academic Lecture Preprint Collection 811゜A1
8 (May 1981) Generally, as the alcohol content X increases, the stoichiometric air-fuel ratio decreases, and in conventional devices for gasoline, the mixture becomes leaner. For example, when gasoline mixed with 20% methanol is used, the stoichiometric air-fuel ratio A/F drops from 15 to 13, so if the conventional device is used, the air-fuel mixture will be diluted by about 15%. When this happens, the operating performance of the engine deteriorates, and the exhaust gas composition changes, causing problems such as deterioration of the purifying action of the catalyst.

The object of the present invention is to provide an engine control device that can perform good control by obtaining the optimum air-fuel ratio depending on the mixing ratio of alcohol, etc., and its characteristics are as follows.
A program is provided to modify the signal regarding the fuel amount according to the information from the second storage device and changes in engine temperature, and the air-fuel ratio of the mixture to be supplied to the engine is determined according to the alcohol content in the fuel. It's because it's configured.

FIG. 1 is a system diagram of an engine control device that is an embodiment of the present invention. A throttle valve 3 is installed in the intake pipe 2 connected to the engine 1. The upstream side of the throttle valve 3 is connected to a feed cylinder equipped with an air flow meter 4, and the downstream side of the throttle valve 3 is a fuel injection valve 5. It is installed. Further, a spark plug 6 is attached to each cylinder of the engine 1, and an exhaust pipe 8 of the engine 1 is installed.
An exhaust gas sensor 7 is installed. Furthermore, the exhaust pipe 8 and the intake pipe 2 are in communication via an exhaust gas recirculation device (hereinafter referred to as EGR) 34, and the EGR 34 is connected to the output device 1.
It is controlled by a solenoid valve 33 connected to 7.

The fuel injection valve 5 includes a metering valve 9 and an alcohol mixing rate detector 1
The pressure regulator 12 is in communication with the filter 13 and the pump 14 via 0. Further, both the pump 14 and the pressure regulator 12 communicate with a fuel tank 15.

That is, the pump 14 sucks the alcohol-containing fuel in the fuel tank 15 and sends it under pressure to the fuel injection valve 5 and pressure regulator 12 via the filter 13, and the remaining fuel not injected by the fuel injection valve 5 is returned via the return passage. The fuel is returned to the fuel tank 15, and a predetermined fuel pressure is constantly applied to the fuel injection valve 5.

The metering valve 9 is intermittently opened by a drive circuit 11 operated by an output signal from an output device 17, and injects an amount of fuel into the intake pipe 2 appropriate for the operating condition.

Further, a fuel quantity needle 16 is attached to the fuel tank 15, and its output signal is sent to an input device 18. Note that this input device 18 includes the fuel amount needle 16, air flow meter 4,
Output signals from a mixing ratio detector 10 that detects the mixing ratio of alcohol and an exhaust gas sensor 7 are inputted and sent to a microprocessor 20.

On the other hand, the output device 17 outputs to the drive circuit 11 and also outputs to the coil 30 via a switch 31 connected to a power source 32 to control the power distributor 29. By this operation, the ignition timing, that is, the advance angle, is determined in accordance with the operating condition and the alcohol mixing rate, and the spark plug 6 is ignited. Further, this output device 17 outputs a signal to the electromagnetic valve 33.

The output device 17 and the input device 18 are connected to a microprocessor 20, which includes registers 21, 28, storage devices 22, 23, 24, 25, 2.
6.27, and serves to temporarily store data processed by the microprocessor 20 and data from the output device 17 and input device 18. In addition, setting device 1
9 is a device for inputting data by the operator.

In the engine control device configured in this manner, the air flow meter 4 outputs an electrical signal corresponding to the amount of intake air, and may be of various types such as a vane type, Kalmar type, hot wire type, or swirl type. There is no problem. That is, the analog voltage Q proportional to the amount of intake air, the ffi wave number f1 period, the duty ratio, etc. are determined by these factors.

Now, let Y be the information corresponding to these air amounts, and let the corresponding information be '&Z regarding the fuel amount. Since the fuel amount is controlled according to changes in the intake air amount, Z=φ(Y, A/ E
, ε) ......, (1) However, A/F is the set value of the air-fuel ratio, and ε is the measurement error of the intake air amount.

The A/F is a function of the operating state of the engine, for example, the temperature θ of the engine 1, the rotational speed N1, the load y, and the A/F is stored in the storage device 27 in advance. Note that it is not necessary to store the absolute value of A/F, but the ratio k to the reference value. All you have to do is remember it. The intake air amount Y is input to the microprocessor 20 via the input device 18. This microprocessor 20 is connected to a storage device 27. is read out, information Z regarding the fuel amount is determined based on the information Y, and the information Z is outputted to the output device 17 by assuming that ε=0.

The output device 17 operates the drive circuit 11 to supply fuel according to Y from the metering valve 9 to the engine 1.

Pump 14, filter 13, fuel pressure regulator 12
The same configuration as a conventional control device can be used. When the alcohol mixing rate X of the fuel supplied from the pump 14 changes, the contents of the register 28 are changed.

Now, the contents of register fζ8 that change in response to X k k
t, the microprocessor 20 calculates the fuel information 21 by calculating the following equation. In this way, Z changes in accordance with the change in X, and the fuel amount is maintained appropriately. If 1=1.0 in the case of gasoline, then 1=1.15 in the case of 20% methanol. This rewriting of 1 is performed in the following manner.

(a) Manually set on the setting device 19, and input a signal to the storage device 23 and the register 28 via the input device 18 and the microprocessor 20tl. The setting device 19 may be a simple changeover switch, a push button switch, or a magnetic card. In this case, as can be seen from FIG. 1, the fuel present in the pipe between the fuel tank 15 and the metering valve 9 is not immediately replaced with new fuel, so the value in the register 28 changes after a certain period of time. and then replaced with the new value. This replacement is controlled by a timer in microprocessor 20. In addition, if the previous fuel remains in the fuel tank 15, the alcohol-containing air is generated when it is mixed with the previous fuel.

Now, the amount of residual fuel is iFt, the alcohol mixing rate is x8,
If the amount of newly injected fuel is tF, and its alcohol mixing rate is N2, then the actual mixing rate X is expressed by the following equation.

X=X, Fl +x2p, /F, +F2...
... (2) This operation is performed by the microprocessor 20
F, , F2 is the fuel quantity needle 16 of the float type, etc.
is measured and input to the microprocessor 20.

(b) The mixture rate detector 10 utilizes changes in dielectric constant, etc., and is installed upstream of the fuel injection valve 5. As a result, X is detected, and the fuel correction coefficient is rewritten using a function of 1 for X and X. In this case, the signal from the contamination rate detector 10 is input to the microprocessor 20 via the input device 18, and is determined and input to the register 28 according to the signal value. The relationship between X and 8 is stored in advance in the storage device 23. For example, the one shown in FIG. 2 is suitable.

(C) As the exhaust gas sensor 7, an oxygen sensor or the like made of a zirconia solid electrolyte material is used. This detects the oxygen concentration in the exhaust gas and controls the stoichiometric air-fuel ratio A/F of the mixture supplied to the engine 1 to be 14.7 (when using gasoline).

In equation (2), if 1 is set in the operating range of 1 (o=l), when the alcohol mixing rate X changes, the fuel information Z deviates from the appropriate value.If k is a correction coefficient, the following equation holds true.

Z ” Ka・ni1 ・ktaY ・・・・・・・・・
(If 3Jk2=1, it deviates from the proper value, but 2 is corrected based on the signal from the exhaust gas sensor 7, and Z is feedback-controlled so that it becomes the stoichiometric air-fuel ratio.

For example, in the case of methanol contamination rate of 20%, the final
= approximately 1.15. This value of 2 is stored in the storage device 22.

During feedback control, the value of is temporarily stored in the register 21. Feedback control is stopped in the operating range of ko\1. Now, when switching from fuel containing 20% methanol to gasoline, the mixture is in a state where k = 1.15, so the mixture temporarily becomes rich, but feedback control quickly changes it to 2 = 1. It returns to the zero state, that is, the proper air-fuel ratio state. This feedback control is ko=1
Operates only in steady state operating range.

In this method, 2 also includes the influence of the measurement error ε of the intake air amount, but since the influence of ε varies depending on the operating conditions, the value of k2 also varies depending on the operating conditions. This will be explained later in FIG. 9. Therefore, the storage device 22 storing k2 has multiple addresses.

(d) When a sensor that outputs a signal proportional to the excess air ratio λ is used as the exhaust gas sensor 7, the detected value of 1/λ and k. 1/λ is koO
Feedback control is performed to maintain the value. Then, 2 is stored in the storage device 22 as a correction value during this feedback control.

In this case, the engine 1 does not need to be operated at the stoichiometric air-fuel ratio as in the case (e) below.

In this way, the memory device 27 sets the excess air ratio λ according to the operating conditions, and the memory device 23 or the memory device 22 stores 1 in the coefficient that corrects the relationship between the amount of fuel and the amount of air depending on the alcohol mixing rate X. By providing this, appropriate fuel can be supplied to the engine 1.

When the engine 1 is at a low temperature, it is necessary to set the excess air ratio λ smaller in the case of using 20% methanol fuel and only gasoline under the same operating conditions to ensure stable operation of the engine 1.

For this reason, the set values in the storage device 27 are stored as a function of operating conditions, for example, the rotational speed n of the engine 1, the engine temperature θ, the load y, and information on X.

FIG. 2 is a diagram showing the relationship between the alcohol mixing ratio X and the A/F. As X increases, the A/F decreases and the amount of air decreases. As explained in (C) and Cd) above, in the method using the exhaust gas sensor 7, it is not possible to distinguish between ethanol and methanol. However, as you can see from this figure, with the same A/F, the mixing rate of ethanol is large, so
Even if the set value of λ at low temperature is determined using the value of 1 m k2 determined from the correction value of the feedback control, there will be no major problem.

FIG. 3 is a diagram showing the relationship between the alcohol mixing rate X and the calorific value, and as the alcohol mixing rate increases, the calorific value decreases. However, as shown in Figure 4, when the same amount of air as in the case of gasoline is mixed, as X increases, the calorific value increases slightly. Therefore, if the A/F is given more for X as shown in FIG. 2, the engine output will increase slightly as X increases.

FIG. 5 is a diagram showing the relationship between the alcohol mixing ratio X and the ignition timing, where the ignition timing is shown by the crank angle of the engine l, and the excess air ratio λ is shown as a parameter. X
Even if λ changes, the ignition timing hardly changes, but as λ increases, it becomes necessary to advance the ignition timing.

The set ignition timing for the operating conditions is stored in the storage device 26, and the switch 31 is operated based on this information.
A circuit between the power source 32 and the coil 30 is opened and closed to generate high voltage. This high voltage is applied to the spark plug 6 via a power distributor 29.
ignite.

Since the set ignition timing has been given an appropriate value in advance for the engine speed and intake pipe pressure, the set ignition timing for the corresponding operating conditions can be retrieved from the storage device 26 using the address related to the engine speed and intake pipe pressure. The time is read out. In the embodiment shown in FIG. 1, the pressure inside the intake pipe 2 is not directly detected, so the corresponding ignition timing is determined from the intake air amount information Y, that is, the signal from the air flow meter 4. The ignition timing can also be controlled by conventional mechanical ignition timing controllers, such as governors and vacuum valves.

Further, depending on the food for the engine 1, it is necessary to change the ignition timing depending on the alcohol mixing ratio X, and even if λ is not corrected, it is necessary to change the ignition timing. In this case, the ignition timing correction value for X is stored in the storage device 25.

Some gasoline engines are equipped with EGR34i, but the operating point of EGR34 is usually determined by the pressure in the intake pipe 2 and the opening degree of the throttle valve 3. If the excess air ratio λ and ignition timing are properly controlled using the above method,
As can be seen from the change in the amount of heat generated in FIG. 4, the change in the amount of heat generated for the same amount of air, that is, the change in the generated torque, is small, and the operating point of the EGR 34 does not change much.

FIG. 6 is a diagram showing the relationship between the alcohol mixing rate X and the amount of NOx in the exhaust gas, and the amount of N08 is shown in ppm. NOo tends to decrease as X increases, but E
Even if the setting value at which GR, 34 operates is lowered, NO,'r can be reduced.

The EGR 34 has a diaphragm valve that operates under suction load. The exhaust gas recirculation amount can be controlled according to X by storing a set value for X in the storage device 24 in advance and operating the electromagnetic valve 33 using this information to adjust the negative pressure applied to the diaphragm valve.

Figure 7 shows engine temperature θ and fuel correction coefficient k.

This is a diagram showing the relationship between alcohol content and alcohol content, and shows different values depending on the alcohol content ratio X. The solid line shows the case when X=00, the broken line shows the case when X=0, and the broken line shows the case when X=0, 1.

FIG. 8 is a flowchart showing an example of the control operation of the engine control device shown in FIG. Block 10 for gasoline fuel
1, engine rotation speed N, engine temperature θ, air amount information Y
t - measured air-fuel ratio setpoint k, which is the corresponding operating condition;
Read o. In this case, since X=0 or is very small, the fuel amount is directly calculated in block 104 and the process returns to block 101.

When the alcohol mixing rate X cannot be ignored, the above correction is performed and X is measured in block 100. Further, in block 105, 1 is calculated corresponding to X, and then the process moves to block 104. When performing feedback control using the exhaust gas sensor 7, the measured value 1/
λ and k. If 1/λo-ko is positive (1/
If λ-KG>0), 2 is decreased in block 107, and if negative, Ktk is increased in block 108, and in block 109
The fuel amount zl increases or decreases.

Control of ignition timing and exhaust gas recirculation amount is also performed using a similar flowchart. Fuel correction during acceleration is also performed by controlling the correction amount based on the acceleration and the value of X. Further, although the embodiment shown in FIG. 1 deals with a fuel injection device, the fuel amount is corrected using a similar control method in the case of a carburetor as well.

It is known to control the amount of fuel in a carburetor by adjusting the jet diameter and air bleed diameter. This is K in Figure 8.
. This is equivalent to adjusting the fuel amount by changing In this case, Ko for the temperature θ of the engine 1
is not corrected uniformly and needs to be changed with respect to X as follows.

This can be achieved by controlling the current of the heater, which controls the opening of the choke valve, in accordance with X.

Alternatively, the amount of cooling water used to heat the wax temperature sensitive body may be adjusted. By making the storage device replaceable, it is possible to accommodate a wide range of fuel changes.

When measuring fuel intermittently with respect to the metering valve 9, 1 to 5
If controlled with a valve opening time of ms, methanol 20
%, the valve opening time increases by 15%. At high speeds and high loads, the front and back of the valve opening/closing operation tends to get stuck. For this reason, it is necessary to determine the opening area of the metering valve 9 with a margin. However, if there is too much margin, the valve opening time during idling operation becomes too short. Therefore, if X changes significantly, it is necessary to replace the metering valve 9 itself.

FIG. 9 is a program for rewriting information in the second storage means using a magnetic card in which information regarding the properties of fuel is stored. When a magnetic card is inserted, the microprocessor 20 reads the information on the magnetic card by an interrupt operation. After counting and incrementing the number of programs to be executed thereafter, that is, after a certain operating time has elapsed, the second storage device is rewritten.

FIG. 10 is a numerical table showing the fuel correction coefficients in the third storage means that are rewritten by the exhaust gas sensor.

It is addressed by the rotational speed nnpm of the engine 1 and the load factor y, and the value at an intermediate speed rotation and an intermediate load factor is the maximum value. That is, the feedback control is 2000<11<4
If the range is limited to 000.0.2<Y<0.8,
In the case of a mixing rate X of 20% methanol, such a fuel correction coefficient k is stored.

If n and y exceed the above range, no correction is made. Since 2=1.00 remains in this region, the amount of fuel decreases. Therefore, the average value of 2 within the above range is transferred to 1, and k in equation (3).

= 1.00, or it is necessary to extrapolate the value of 2 within the above range to find the value of 2 outside the above range.

FIG. 11 is a diagram showing the relationship between the alcohol mixing rate X and the fuel correction coefficient kl. This straight line relationship is stored in advance in the second storage means and then 1 is obtained.

If this is corrected, the deviation of the air-fuel ratio due to the properties of the fuel can be corrected. However, with the air-fuel ratio set for gasoline, it is difficult to operate the engine smoothly at low temperatures. Therefore, the following modification method is used.

FIG. 12 shows a numerical table showing correction values determined by the alcohol mixing rate X and the engine temperature θ.

The values shown in FIG. 12 determined by the above are stored in the fourth storage means.

This modified value is stored in the memory device that addressed X and θ. Alternatively, it may be derived from a functional relationship such as the following polynomial.

ko=φ(X, 0m”*Y) ・・・・・・・・・
(4) As the temperature of the engine 1, cooling water temperature, intake pipe 2 temperature, oil temperature, cylinder temperature, etc. are used.

Although the air flow meter 4 is used as the air amount detection means in this case, a method of determining the air amount from the intake pressure and the rotational speed of the engine 1 may also be used.

FIG. 13 is a diagram showing the relationship between engine temperature θ and engine speed n. It is common practice to temporarily cut off fuel when decelerating a car.

For example, if the fuel is cut off when the engine rotational speed is n, the rotational speed will decrease as shown by the solid line B, and when the target n is reached, a suitable amount of fuel will be supplied. This is the case when gasoline is used, but as the alcohol content X increases, even at the same engine temperature, the dashed line B
A function for increasing the set rotation speed, such as , is added to the program of the microprocessor 20. That is, in the case of alcohol-containing fuel, the engine temperature will not rise unless the engine speed is increased. Note that the case of n2, which has a high rotational speed, also exhibits the same characteristics as the case of n.

FIG. 14 is a flowchart showing an embodiment of a program for modifying a signal related to the amount of fuel injected by the fuel injection device. The basic injection amount Δ1o is determined by the intake air amount and the engine speed. This Δto is k.

Then, the fuel injection valve is operated based on the correction value Δt. ko is a basic correction value determined by X, and in the case of gasoline, 0=1. k.

is a coefficient for correcting the fuel evaporation delay when the engine cooling water temperature θ1 is low, and it also changes depending on X, and becomes 1=1 when θ=)60r.

When the engine/engine/engine ignition key is in the start position or when the engine coolant temperature θ1 is below θto 00, increase cranking.

θ in case of gasoline only. Flash is 25r, and as X increases, it increases ovQ and makes cranking easier. If θ is less than θwo, the cranking rotation speed is low, so set Δ1° by θ and X, and set J*
k! Δt is determined by correcting it.

t is the duration of cranking, and 3 becomes zero at about t=12 seconds. Here, is set to increase as X increases. k4 is a constant correction coefficient during cranking. Further, to is the cranking increase time.

This practical engine control device can change the cranking increase operation range, which determines the fuel amount regardless of the air amount, according to information such as fuel property information, so even when alcohol is mixed, it can be quickly The engine can be started. For 12 hours after startup, separate correction coefficients are prepared for the cooling water temperature θ and the mixing rate X, respectively.

Further, this t and time vary depending on the type of idle switch and the mixing rate X.

Also, θf (when starting or accelerating at 80C, Δt
Correct with ik. This correction time t3 is a function of θW and X, and when X is Xi and X2, 6 m'8 is given by a curve as shown in FIG.

Fig. 15 is a diagram showing the relationship between the engine cooling water temperature θ and 61'+1, Fig. 15 (a) shows the relationship between the correction coefficient 6 and time t3
This is the relationship between The second storage means for storing information regarding the properties of the fuel, such as the alcohol content ratio X, is a rewritable storage device.

Information stored in storage devices such as flip-flops disappears as soon as the power is turned off. Manual setting device 1
In the method using 9 or the alcohol contamination rate detector 10,
Even with such a storage device, no particular problem occurs. but,
In the case of correction using feedback control, it is desirable to use the corrected value upon restart, and it may be possible to retain the information without cutting off the power to this storage device.

The pump 14 is driven by an electric motor or an electromagnet.

In the configuration shown in FIG. 1, the pump 14 is driven to rotate at a constant speed.

As shown in FIG. 11, when X increases, the fuel correction coefficient increases by 1, so it becomes necessary to increase the amount of liquid fed by the pump 14.

FIG. 16 is a circuit diagram of the pump motor. pump 14
The motor 35 that drives the
5 rotation speed can be adjusted. Current control circuit 36
is connected to the microprocessor 20 via the input device 18 and the output device 17.
= 100%), the rotation speed automatically increases to about 2ooorpm. The current control circuit 36 processes the output of the mixing ratio detector 10 and is activated by the signal sent from the output device 17, so that the alcohol mixing ratio X
is automatically detected and the current control circuit 36 is automatically operated in an appropriate state. Therefore, the power consumption of the motor 35 can be saved.

The engine control device of this embodiment has engine rotational speed,
a first storage means for storing a set air-fuel ratio as a function of load; an air amount detection means for outputting an electrical signal; and a fuel amount determined from the output signal of the air amount detection means and the set air-fuel ratio of the first storage means. a second storage means for storing information regarding fuel properties such as alcohol content, a program for modifying a signal regarding the fuel amount using information in the second storage means; and a microprocessor input device for rewriting the information in the second storage means, and has the effect that a program for modifying the information in the second storage means and the signal regarding the fuel amount according to the change in engine temperature can be obtained.

The engine control device of the present invention has the effect that even if alcohol or the like is mixed into gasoline, the mixing rate can be automatically measured and calculated by the electronic control device to ensure suitable operation. .

[Brief explanation of the drawing]

Fig. 1 is a system diagram of an engine control device that is an embodiment of the present invention, Fig. 2 is a diagram showing the relationship between alcohol mixing ratio X and air-fuel ratio A/F, and Fig. 3 is a diagram showing the relationship between X and calorific value. Figure 4 is a diagram showing the relationship between X and calorific value when the amount of air is the same as in the case of gasoline. Fig. 6 is a diagram showing the relationship between X and the amount of NOx in exhaust gas, and Fig. 7 is a graph showing the temperature θ and fuel correction coefficient k. FIG. 8 is a flowchart showing an example of the control operation of the engine control device shown in FIG. 1, FIG. 9 is an information rewriting program using a magnetic card in which fuel property information is stored, The diagram is rewritten by the exhaust gas sensor of FIG. An example of a numerical table. Fig. 11 is a diagram showing the relationship between X and fuel amount correction value. Fig. 12 is a numerical table showing the correction value determined by X and θ. Fig. 13 is a graph showing the relationship between θ and engine rotation. Figure 14 is a flowchart showing an example of a program for modifying the signal related to the amount of fuel injected by the fuel injection device, and Figure 15 is a diagram showing the relationship between the engine cooling water temperature θ and the fuel correction coefficient 6 and Clamp. /king time t, and FIG. 16 is a circuit diagram of the pump motor. 1... Engine, 2... Intake pipe, 3... Throttle valve,
4...Mechanical flow meter, 5...Fuel injection valve, 6.
...Spark plug, 7.. Exhaust gas sensor, 8.. Exhaust pipe, 9.. Metering valve, IO.. Mixing ratio detector, 11.
...Drive circuit, 12...Pressure regulator, 13...
- Filter, 14... Pump, 15... Fuel tank, 16... Fuel position needle, 17... Output device, 18...
- Input device, 19... Setting device, 20... Microprocessor, 21.28... Register, 22° 23.2
4, 25, 26. 27...Storage device, 29...Distributor, 30...Coil, 31...Switch, 32...
・Power supply, 33... Solenoid valve, 34... Exhaust recirculation device (
EGR, ), 35... Motor, 36... Current control circuit, X... Impaired with alcohol, A/F... Air-fuel ratio,
θ...Engine temperature, N...Engine rotation speed, n...Engine rotation speed, y...Load, k...Fuel modification coefficient, λ1st mouth Z figure man, 5 figure Figure 4 Figure 5 Figure 7L] -+!艷X1- ME、YACHITA et al. Figure 7 [Z Work: / Affected area of the fish θ FIG. 8 199- FIG. 9 FIG. <oir,> 13th drawing; warm to Jin θ 14th 15th drawing IC entrance

Claims (1)

[Claims] 1. A first storage device that stores an optimum air-fuel ratio related to the rotational speed and load of the engine, an air 70-meter that detects the intake air amount of the engine, and an air flow meter for detecting the intake air amount of the engine. a microprocessor that calculates a signal regarding the amount of fuel from the output signal and the optimum air-fuel ratio of the first storage device; a second storage device that stores information regarding the properties of the fuel such as alcohol content; In the engine control device, the engine control device has a program for modifying the signal regarding the fuel amount with information stored in the storage device, and has an input/output device for the microprocessor that rewrites the storage information in the second storage device. A program is provided to modify the signal regarding the fuel amount according to the information from the storage device and the change in engine temperature, and the air-fuel ratio of the air-fuel mixture to be supplied to the engine is determined according to the alcohol mixing ratio in the fuel. An engine control device characterized by: 2. Claim 1, wherein the second storage device is a device having a program that rewrites information based on a signal from the alcohol mixing rate detector installed in the fuel flow path upstream of the fuel injection valve. The engine control device described. 3. The first storage device compares the excess air ratio detected by the exhaust gas sensor with the optimum air-fuel ratio formula or the optimum excess air ratio of the first storage device, and adjusts the fuel amount so as to approach the set value. 2. The engine control device according to claim 1, wherein the engine control device includes a program that automatically performs feedback control, and a third storage device that stores the modified value.