JPS5928027A - Fuel injection device for internal combustion engine - Google Patents

Abstract

PURPOSE:To obtain an appropriate air-fuel ratio always, by a method wherein feed back through the output of an O2 sensor is suspended and a set level is made to vary to an appropriate value when accelerating operation and high load operation are detected by a parameter showing a variation of a suction air quantity. CONSTITUTION:An air metering valve 38 is provided downstream a thermal flow sensor 32 and an opening of the valve 38 is controlled so that an output of a flow sensor 32 is converged upon a set level to be fixed through an O2 sensor 80 provided in an exhaust system, in a bypass air duct 30 provided by detouring around a venturi 28. In this instance, when an increase of a suction air quantity to be obtained by an output of the flow sensor 32, that is, a matter that states are in accelerating operation and high load operation is detected by a variation detecting device of suction air quantity, feed back through the output of the O2 sensor 80 is suspended. A set level of a level setting device to be compared with an output of a flow sensor 32 is corrected by a correction valve corresponding to a variation of a suction air quantity set beforehand.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection device for an internal combustion engine, and more particularly to a fuel injection device for an internal combustion engine that can supply fuel to all cylinders of an internal combustion engine from one fuel injection part. It is.

Generally, fuel injection devices for internal combustion engines that supply fuel to all cylinders of an internal combustion engine from one fuel injection part are known.

This known fuel injection device is constructed as follows.

That is, a throttle valve is provided in the intake passage connected upstream of the gathering part of each intake pipe connected to each cylinder, a fuel injection part is opened upstream of this throttle valve, and a solenoid valve forming the fuel injection part is set in a predetermined position. The fuel is intermittently injected into the intake passage by driving with a valve opening pulse width of . This valve opening pulse width is controlled by an intake signal detected by an air flow meter provided in the intake passage.

However, this known fuel injection device has the following drawbacks.

(1) a Since the fuel injection unit intermittently injects fuel into the intake passage connected upstream of the collecting part of the trachea, when considering from the intake passage to the collecting part of the intake pipe, there is a rich mixture in between. A phenomenon occurs in which thin air-fuel mixture portions and thin air-fuel mixture portions are formed alternately, making the air-fuel mixture non-uniform. Therefore, when each cylinder of the internal combustion engine sequentially inhales an air-fuel mixture, some cylinders inhale a rich air-fuel mixture and some cylinders inhale a lean air-fuel mixture, resulting in poor distribution performance. This manifests itself as torque fluctuations in the internal combustion engine.

(2) Since the air flow meter measures the intake air over a wide range of conditions, from idling to high-speed and high-load operation, and determines when the valve is open, accuracy is required over a wide range of air flow meters. Ru. That is, the air flow meter must detect the true amount of air actually taken into the internal combustion engine over a wide range from idle operation to high-speed, high-load operation. This is manifested in the increased accuracy of air flow meters over a wide range and in the complexity of signal processing circuits connected downstream of the air flow meters.

The present applicant has developed a fuel injection device for an internal combustion engine that supplies fuel from one fuel injection section to all cylinders of an internal combustion engine, in which the fuel injected from the fuel injection section is sufficiently mixed with intake air. The air-fuel mixture can be made homogeneous, and the accuracy of the air flow meter that determines the fuel injection part is as high as 4.
In order to provide a fuel injection device for an internal combustion engine that can simplify the signal processing circuit connected to the air flow meter after the airflow meter and control the air-fuel ratio precisely, a fuel injection device is installed upstream of the intake pipe assembly. a connected intake passage, a venturi part formed in the intake passage, a nine-throttle valve provided in the intake passage downstream of the venturi part, a bypass air passage connecting the upstream of the venturi part and the venturi part, and the bypass air passage. an air flow meter for detecting the amount of air passing through the bypass air passage; a valve for air ffj provided in the bypass passage downstream of the air flow meter; A fuel passage for continuously feeding fuel, a fuel metering valve provided in the fuel passage, and an opening degree of the air metering valve and the fuel metering valve are controlled so that the air metering valve reduces the amount of air flowing through the bypass air passage. a driving means for displacing the fuel subtraction value valve in a direction in which fuel increases when the airflow meter is displaced in a direction in which the fuel quantity increases; proposes a fuel injection device for an internal combustion engine comprising a control signal generating means for supplying a control signal to the drive means to control the opening degree of the metering valve. 3 First, the fuel for an internal combustion engine proposed by the applicant The structure of the injection device and its operation will be explained.

In FIG. 1, reference number 10 is the main body;
An intake passage 12 is formed inside.

The intake passage 12 is an intake pipe 14 communicating with each cylinder of the internal combustion engine.
It is connected to the gathering part 16 of A, 14B, 14C, and 14D. A throttle valve 18 is rotatably disposed within an intake passage 12 formed in the main body 10, and is operated by an accelerator pedal. The upper and lower reaches of the throttle valve 18 are detoured and communicated by a correction air passage 20, and an orifice 22 is provided in the middle of this correction air passage 20, and a valve body 26 driven by an electromagnetic device 24 is connected to the orifice 22. The needles make up the inguinal region. A venturi portion 28 is formed in the intake passage 12 upstream of the throttle valve 18.
8, the entrance portion 28A and the narrowest portion 28B are the main body 10.
They are connected by a detour 30 formed in . A heat flow sensor 32 such as a hot wire sensor, hot film sensor, l-mass meter, etc. is provided in the middle of the detour path 30. Fixedly attached to fc information intake circuit TNI34
Processed by: An air Hljt orifice 36 is provided in the downstream detour 30 of the PA type flow rat seventer 32,
This air metering orifice 36 cooperates with a metering valve 38 to form a tapered air I4 portion.

The air metering valve 38 is then connected to the proportional fIL via the output shaft 40.
It is connected to a magnetic device 42 .

On the other hand, a fuel injection section 44 is opened between the throttle valve 18 and the venturi section 28, and this fuel injection section 44 is connected to the main body lO
It communicates with a fuel passage 46 formed in the. fuel passage 4
In the middle of 6, an orifice 48 is provided in the fuel,
This fuel cutter 48 forms a fuel metering section with the tapered fuel gauge 11 valve 50 and the UJiJ movement. The fuel metering valve 5o is connected to the proportional electromagnetic device 4 via the output shaft 52.
It is connected to 2. The output shaft 52 and the main body 1o are partitioned by a bellow ram 54 to prevent the fuel in the fuel passage 46 from leaking to the outside of the main body 10. Here, the air metering valve 38, the fuel II1 valve 50, and the proportional electromagnetic device 42 have the configuration shown in FIG. In FIG. 2, the proportional electromagnetic device 42 includes a coil 58 wound around a medium-sized bobbin 56, a fixed coil f60 inserted and fixed into the hollow part of the bobbin 56, and a proportional electromagnetic device 42 arranged slidably in the hollow part of the bobbin 56. It is composed of a '6J dynamic core 62, a case 64, and the like. The output shaft 40 is fixed to one end of the movable core 62, and the output Ikt1 is fixed to the other end.
52 is fixed. Accordingly, air 51' volume valve 38, fuel metering valve 50 and 1. If the working core 62 has one axis, the air i1 amount valve 38 and the fuel metering valve 50 are simultaneously driven by the movable core 62.

The fuel in the fuel tank 66 is supplied to the fuel passage 46 by the fuel pump 6.
After being pressurized at 8 and regulated by a pressure regulator 7o, it is fed. Here, the pressure regulator 70 and the fuel pump 68 are well-known ones, and are configured so that the fuel pressure of the pressure regulators 70tiO, 71'+/the saw 2 can be obtained.

Next, the relationship between the signals manually input to the microcomputer 72 and the signals output will be explained.

The microcomputer 72 includes a signal from the thermal flowmeter sensor 32 (equivalent to the signal from the signal acquisition circuit 34), a signal from the water temperature sensor 74 that detects the engine cooling water temperature, and a rotation speed sensor 76 that detects the engine speed. A signal from a throttle valve opening sensor 78 indicating the opening degree of the throttle valve 18, and a signal from an oxygen sensor 80 provided in the exhaust pipe are input. Needless to say, other engine operating parameters may be input for correction of each building.

On the other hand, the output of the microcomputer 72 is
, a proportional electromagnetic device 42, an EG (exhaust gas recirculation) control device 82, an ignition timing control device 84, and a control device 86 for the fuel pump 68.

The signal sent to the proportional electromagnetic device 42 is a duty pulse signal whose ON time per cycle is controlled, and this duty pulse signal is generated by a circuit as shown in FIG. FIG. 3 shows a part of the drive circuit connected to the microcomputer 72, and the signal from the thermal flow sensor 32 is input to the inverting input terminal of the differential amplifier 88.
A level signal from a level setting circuit 90 is input to the non-inverting input terminal. Then, the deviation signal determined by the differential amplifier 88 is sent to the duty pulse generation circuit 92 at the subsequent stage, where it is converted into a duty pulse, and the proportional electromagnetic device 42
It is sent to.

The duty pulse generation circuit 92 includes a comparator 94 and a sawtooth wave generation circuit 96.

For example, in FIG. 4, as shown in chart (a), the difference signal H/W obtained by determining the values of the thermal flow rate sensor 32 and the level setting circuit 90 by the differential amplifier 88 is transmitted to the comparator 9.
4 is compared with the sawtooth wave T from the sawtooth wave generation circuit 96, and the comparison result becomes a duty pulse as shown in chart (b). This duty pulse is given to the proportional electromagnetic device 42 as described above, and the proportional electromagnetic device 42
controls the air metering valve 38 so that the output of the thermal flow sensor 32 approaches the set level. That is, the time Tc in (b) has a component that closes the air H1 valve 38, and the time To has a component that opens the air metering valve 38. Therefore, the proportional electromagnetic device 42 controls the air metering valve 38 so that the output signal of the thermal flow sensor 32 becomes a constant value.
can be controlled.

Next, the operation of the above configuration will be explained.

Now, when the engine is operated, air flows through the intake passage 12, a venturi negative pressure is generated in the narrowest part 28B of the venturi part 28, and a pressure difference is created between the artificial parts 28A.

Therefore, the narrowest part 28B of the venturi part 28 is passed from the inlet part 28A of the venturi part 28 to the narrowest part 28B of the venturi part 28 via the bypass passage 30.
Air flows to. The thermal flow rate sensor 32 detects the amount of air based on this air flow.

Incidentally, the signal from the thermal liquid flow sensor 32 is discriminated by a set level and a differential M width gauge 88 shown in FIG. Therefore, when the throttle valve 18 is closed and the amount of air supplied to the engine is reduced, the venturi negative pressure generated in the venturi portion 28 is reduced.

Since the venturi negative pressure is small, the bypass passage 30
If the amount of air passing through is small, the differential amplifier 88
A large number of components at time To shown in chart (b) of the figure are sent to the duty pulse generation circuit 92.

As a result, the computer 72, including the duty pulse generating circuit 92, controls the air metering valve 38 and the air needle orifice 36.
A duty pulse is applied to the proportional electromagnetic device 42 to lower the air metering valve 38 downward in FIG. 1 so that the amount of air passing through the air metering section reaches a set level determined by At this time, the movable core 62 of the proportional electromagnetic device [42] moves the fuel metering valve 50 in the same direction as the air metering valve 38 at the same time, so that the fuel metering section which is filled with the fuel metering valve 50 and the fuel metering orifice 48 Naturally, the amount of fuel passing through the engine is reduced in accordance with the decrease in the amount of air taken into the engine.Furthermore, the fuel passing through the fuel metering valve 50 is injected into the intake passage 12 by the fuel injection section 44. Here, the fuel injected from the fuel injection part 44 is in a continuous flow. Of course, the shape of the fuel metering valve 50 is adjusted so that the air-fuel ratio at this time is close to the target air-fuel ratio. must be decided.

Next, when the throttle valve 18 is opened and the amount of air taken into the engine increases, the venturi negative pressure generated in the venturi portion 28 increases, and as a result, the amount of air passing through the bypass passage 30 increases. Therefore, the differential amplifier 88 sends a large amount of the time Tc component shown in Char 1-(b) of FIG. 4 to the tute pulse circuit 92. The computer 72 then uses a proportional electromagnetic device to raise the air metering valve 38 upward in FIG. Give 42 heduty pulses. At this time, the movable core 62 of the proportional electromagnetic device 42 simultaneously moves the fuel metering valve 50 in the same direction as the air metering valve 38, so that the fuel passes through the fuel metering section defined by the fuel metering valve 50 and the fuel metering orifice 48. will naturally increase as the amount of air taken into the engine increases. Then, the fuel that has passed through the fuel metering valve 50 is transferred to the fuel injection section 44.
) is injected into the intake passage 12 as a continuous stream. Of course, as described above, the shape of the fuel metering valve 50 is determined so that the air-fuel ratio at this time is close to the target air-fuel ratio.

Next, while the throttle valve 18 is opened to a constant opening degree, the proportional electromagnetic device 42 maintains its current state, and the fuel metering valve 5
The fuel metering portion formed by the fuel metering orifice 48 and the fuel metering orifice 48 can be substantially regarded as a fixed orifice. Needless to say, the shape of the fuel metering valve 50 is determined so that the air-fuel ratio approaches the target air-fuel ratio at this time as well.

The above is an explanation of the basic configuration and operation of the fuel injection device for internal combustion engines proposed by the applicant. Because the fuel injection unit continuously injects fuel,
The air-fuel mixture can be made uniform spatially from the intake passage to the end of the intake pipe.Secondly, the airflow meter signal basically only needs to indicate whether it is above or below the set level.
This makes it possible to achieve the effect that the accuracy of the air flow meter is not required so much, and the signal processing circuit connected downstream to the air flow meter can be simplified. Further, since the air flow meter is located upstream of the air metering valve, the air metering valve attenuates the intake pulsation, which has the effect that the air 70-meter is less susceptible to the intake pulsation.

Although this type of device can basically control the air-fuel ratio to a constant value, there are changes in the characteristics of the thermal flow value sensor over time, the proportional electromagnetic device 42, the fuel side welfare valve 50, and the air-fuel ratio.
There may be a problem in which the air-fuel ratio deviates from the set value due to changes in the characteristics of the i-valve 38 over time.

Therefore, the air-fuel ratio can be maintained at a predetermined air-fuel ratio by changing the setting level, which is determined by the differential amplifier 88 as the signal of the thermal flow sensor 32, based on the output signal of the 02 sensor installed in the exhaust pipe. It is structured as follows. That is, the microcomputer 72 applies a signal to the level setting circuit 90 to change the set level of the level setting circuit 90, and this can be realized by the flowchart shown in FIG.

First, in FIG. 5, in step 100, the output of the 0□ sensor is taken in, and in step 102, the reference voltage 021.
It is determined whether the size is large or not. Reference voltage 02set
represents the voltage when the air-fuel ratio of the exhaust gas in the exhaust pipe is the stoichiometric air-fuel ratio. Therefore, if the oxygen component in the current exhaust gas is low in step 102, the output of the 02 sensor will be at the reference voltage of 0□1. , becomes larger (this indicates a richer mixture supplied to the engine), step 10
Move to 4. In step 116, a predetermined voltage G0 is added to the set level R0I, and the set level R0I is set to I(, A M in step 106, and the level setting circuit 90
The level can be determined by

Conversely, in step 102, the output of the 0□ sensor becomes the reference voltage 02.
g5t (this indicates that the air-fuel mixture supplied to the engine is lean), the process proceeds to step 108, where a predetermined voltage Go is subtracted from the set level IC-t,
The set level FLat is set in the RAM at step 106, and the level is determined at the level setting port 1190. In this way, the setting level determined by the level setting circuit 90 is always corrected so that the oxygen component in the exhaust gas is at the stoichiometric air-fuel ratio, so the air-fuel ratio accuracy of the mixture can be maintained at a high level over a long period of time. be. Here, the set level R0 is set based on the deviation between the reference voltage 03a*l and the output signal 0□ of the 0□ sensor.
A predetermined voltage G applied to f. It goes without saying that it may be a value that depends on the amount of deviation. This can be done by reading out the predetermined voltage Go corresponding to the amount of deviation from a memory stored therein.

The above is the fuel injection system for internal combustion engines proposed by the applicant, but when the setting level is changed by feeding back the output of the 02 sensor in this way, the intake air is There is a problem in that the air-fuel ratio of the air-fuel mixture is not appropriate because the set level is dependent on the output of the 0□ sensor regardless of the large change.

The purpose of the present invention is to stop the feedback from the output of the 02 sensor when there is a large change in the amount of intake air, such as during acceleration or high-load operation, and to change the set level to match the operating condition. Its feature is that when the parameter representing the change in the amount of intake air detects acceleration or high-load operation, the set level is corrected using a predetermined correction value. It controls the air-fuel ratio to an appropriate level.

A detailed explanation will be given below according to the drawings.

[High load operating condition]

Output is generally required during high load operation, but at this time 0
When feedback is performed using two sensors, the air-fuel ratio is controlled to be close to the stoichiometric air-fuel ratio, so there is a problem that no output can be obtained. Therefore, in a high load state, it is necessary to stop the 02 feedback and make the set level lower than in the case of the 02 feedback. However, simply 02
Even when feedback is stopped and the setting level is set to a fixed setting level, it has been found that it is better to change the fixed setting level depending on the engine speed.

Figure 6 shows a characteristic diagram of the correction value with respect to changes in the rotational speed. It has the characteristic of making the air-fuel mixture larger (that is, making the air-fuel mixture leaner).

The reason for having such a characteristic is that when 02 feedback is stopped under high load, the lower the rotation speed, the heavier the load, and when the rotation speed exceeds the specified speed, the vehicle is running at high speed. This is because the vehicle itself has inertia, so there is no problem even if the mixture is thin.

Next, a specific flowchart will be explained based on FIG.

First, in step 110, the rotational speed N of the internal combustion engine is determined.

Incorporate. This step 110 is for reading out the correction value G1 from the characteristic diagram shown in FIG.

Next, in step 112, a high load condition is detected.

A boost switch (BoostSW) that detects a change in negative pressure in the intake pipe is used to detect a high load state.

If the boost switch is OFF', the internal combustion engine is not under high load, so it jumps to step 100 and returns to normal 02.
Feedback is performed, and if it is ON, the internal combustion engine is in a high load state, and the 02 feedback is stopped in step 114. 1, and when the 02 feedback is stopped, the process goes to step 11.
6, the correction value G1 corresponding to the rotation speed N1 is read out. Here, the correction value G1 has a characteristic as shown in FIG.
).

When the correction value GI is read from the ROM, step 11
Setting level R at 8, 1 at R @ t = Re r±01
It is calculated using the formula. The result of this calculation is step 1
RAM (Rand am Accesses) at 20
Memory), and a setting level is set in the level setting circuit 90 by these R and AM.

Here, the correction value Gt stored in the ROM is set so that its value tends to increase as the rotational speed increases. In other words, under high load conditions 02
Even if the feedback is stopped, the fixed setting level is changed so that the higher the rotational speed, the leaner the mixture becomes.

In this way, an appropriate air-fuel mixture can be obtained under high-load operating conditions.

[Acceleration operation state]

In the case of accelerated operation, output is required in the same way as in high-load operation,
If the 02 feedback is executed at this time, the air-fuel ratio will be controlled to near the stoichiometric air-fuel ratio, causing the problem that no output will be obtained. Therefore, in the acceleration state, the 02 feedback is stopped and the set level is set to a relatively small fixed set level to enrich the air-fuel mixture.

In this case, at the beginning of acceleration, the bypass passage 30 shown in FIG.
Since the amount of air passing through is huffing, the proportional electromagnetic device 42
g:,+, The air gauge valve 38 is suddenly raised so that the output of the thermal sensor 32 converges to a relatively small fixed set level. At this time, the proportional electromagnetic device
11 of 12 movable cores 62 (air ■ 1″ because the sex is thick)
The quantity valve 38 is made to change by more than a predetermined stroke, and as a result, the fuel quantity valve 50 fixed to the movable core 62 also follows this movement, resulting in a problem that the air-fuel mixture becomes abnormally rich.

To explain the above based on Figure 8, the chart (a
) indicates the change in the opening degree of the throttle valve 18, the characteristic of TIi indicates rapid acceleration, and THz indicates slow acceleration. Char 1(b) represents the amount of air passing through the bypass passage 30, char AI represents rapid acceleration, and A2 represents slow acceleration. Due to such acceleration, the amount of air passing through the bypass passage 30 temporarily decreases, and this also changes depending on the degree of acceleration. As a result of this phenomenon, the amount of fuel also temporarily increases as shown in chart (C), causing the problem that the mixture becomes too rich. Here, Fl represents rapid acceleration and F2 represents slow acceleration.

In order to solve this problem, it is proposed to increase the fixed setting level by a predetermined value at the beginning of acceleration so as to eliminate excessive displacement of the movable core 62 of the proportional electromagnetic device 42.

Figure 9 shows the characteristics of the correction value G2 added to the fixed setting level, and shows that a large correction value G2 is added to the fixed setting level at the beginning of acceleration, and then the correction value () increases as time passes.
2 will be gradually reduced. Here, 021 represents a correction value in the case of sudden acceleration, and G22 represents a correction value in the case of slow acceleration.Next, a flowchart for carrying out this process will be explained based on FIG. 10.

In step 122, the current throttle valve opening TH,
Detect. The throttle valve opening TIIo is detected by a well-known potentiometer.Then, in step 124, the previous throttle valve opening THe or the previous throttle valve opening THe and the current throttle valve opening TT are determined.
Calculate the deviation ΔTl(δ) of Iθ.

When the deviation ΔTIIθ is detected, in step 126 this deviation ΔTIIθ is set to a predetermined value ΔTllθ6. ．． It is determined whether the This step 126 detects the acceleration state. At this time, if ΔT Hθ is smaller than ΔTHoa*t, it is determined that acceleration is not being performed, and step 1
Perform normal 02 feedback by pressing 00 hey/b. Next, when it is determined in step 126 that the vehicle is in an accelerated state, it is determined in step 128 what value ΔTH is.

In the case of sudden acceleration, the value of ΔHe is large, and in step 12B, ΔT)1θ is set to the predetermined value ΔT l−I
θ1. ．． If it is determined that the value is greater than 1, then in step 130 the correction value G21 in FIG.
at is read out and added to the fixed setting level R0°, and then in step 132 this calculation result is stored in the RAM.

The fixed level stored in the RAM of the driver is given to the level setting circuit 9o to set the level.

On the other hand, in the case of slow acceleration, ΔTH#
is small, and in step 128 ΔTllθ becomes ΔTll
If it is determined that it is smaller than □ail, then in step 134 Gz2 is read from the ROM in which the correction value G22 of FIG. 9 is stored and added to the fixed setting level R0I, and then in step 132 this calculation result is stored in the RAM.

Therefore, when the acceleration state is sudden acceleration, the fixed setting level value is small and it takes a long time to return to the original fixed setting level, whereas when the acceleration state is slow acceleration, the fixed setting level value is small and it takes a long time to return to the original fixed setting level. The time it takes to return to the fixed setting level is shortened, and changing the fixed setting level according to the acceleration level becomes i'TM failure. As shown in FIG. 2, it is possible to prevent the abnormal Jw needle of the fuel due to excessive displacement of the moving core 62 that occurs at the beginning of acceleration.

As mentioned above, if the present invention is applied, acceleration: i! ! qh<
When there are many large changes in air flow, such as during load operation, stop the 02 feedback and change the setting level to match the operating condition. As an excellent product, it is possible to obtain good drivability.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a fuel injection device for an internal combustion engine to which the present invention is applied, Fig. 2 is a sectional view of the proportional electromagnetic device shown in Fig. 1, and Fig. 3 is a control alarm signal sent to the proportional electromagnetic device. Fig. 4 is a chart of the control signal generated by the circuit shown in Fig. 3, Fig. 5 is a flowchart for executing 02 feedback control, and Fig. 6 is a diagram during high load operation. Figure 7 is a flowchart for executing control during high load operation, Figure 8 is a diagram showing the throttle valve opening during acceleration, the amount of air in the bypass passage, and the fuel injection system. FIG. 9 is a characteristic diagram showing correction values during acceleration, and FIG. 10 is a flow chart for executing control during acceleration. 10... Main body, 12... Intake passage, 14.
... Intake pipe, 16... Gathering part, 18... Throttle valve, 20
...correction air passage, 22...orifice, 24...
- Electromagnetic device, 26... Valve body, 28... Venturi section, 30... Detour, 32... Thermal flow sensor, 38
...Air metering valve, 42...Proportional electromagnetic device, 44...
-Fuel injection unit, 46... Fuel passage, 50... Fuel metering valve, 68... Fuel pump, 72... Computer, 74... Water temperature sensor, 76... Rotation speed sensor, 7
8... Throttle valve sensor, 80... Oxygen sensor, 88...
- Differential amplifier, 90... Level setter, 94... Comparator, 96... Sawtooth wave generator. 1-- =-J 茗、6″m 茗t(ZJ 2 薯论

Claims (1)

[Scope of Claims] 1. An intake passage connected upstream of the intake pipe collection part, a venturi part formed in the intake passage, a throttle valve provided in the intake passage downstream of the venturi part, and an upstream part of the venturi part and a bypass air passage connecting the venturi portion, an air flow meter provided in the bypass air passage to detect the amount of air passing through the bypass air passage, an air metering valve provided in the bypass passage downstream of the air flow meter, and the intake air A fuel passage that continuously supplies fuel from a fuel pump into the passage during operation of the internal combustion engine, a fuel metering valve provided in the fuel passage, the air metering valve and the fuel ilt'1.
'A driving means for controlling the opening degree of the air metering valve and displacing the fuel metering valve in a direction that increases the amount of fuel when the air metering valve is displaced in a direction that decreases the amount of air flowing through the bypass air passage; - control means for applying a control signal to the drive means to control the opening degree of the air metering valve so that the output of the meter converges to a set level determined based on the output of an exhaust gas sensor installed in the exhaust system; In the fuel injection device for an internal combustion engine, when the intake air amount change detection means detects an increase in the intake air amount taken into the internal combustion engine, the intake air amount change detection means detects an increase in the intake air amount, based on the output of the exhaust gas sensor. The internal combustion engine is characterized in that the control means is provided with a correction means for stopping the control of the set level based on the change in intake air amount and correcting the set level with a separately preset correction value corresponding to a change in the amount of intake air. Fuel injection device for. 2. In claim 1, when the intake air amount change detection means detects high load operation, the correction means adjusts the setting level to the set level with a correction value having a characteristic that the lower the engine speed, the more fuel is increased. A fuel injection device for an internal combustion engine, characterized in that it corrects. 3. The fuel injection device for an internal combustion engine according to claim 2, wherein the intake air amount detection means is a boost switch. 4. In claim 1, when the intake air amount detection means detects acceleration operation, the correction means uses a correction value having a characteristic of reducing the amount of fuel only for a predetermined period of time from the time of detection of acceleration operation. A fuel injection device for an internal combustion engine, characterized by correcting a set level. 5. The fuel injection device for an internal combustion engine according to claim 4, wherein the correction value has a characteristic that the rate at which the amount of fuel is reduced decreases over time. 6. The fuel injection device for an internal combustion engine according to claim 4, wherein the correction value has a characteristic that the greater the degree of acceleration driving, the greater the degree to which the amount of fuel is reduced. 7. The fuel injection device for an internal combustion engine according to claim 4, wherein the correction value breaks the characteristic that the predetermined time is longer as the degree of acceleration is greater.