JPH02196148A - Electronic control fuel injection system for multicylinder interval combustion engine - Google Patents

Abstract

PURPOSE:To perform an actual fuel injection supply so accurately in response to the operation setting of highly accurate interrupting injection quantity by performing compensation conformed to a battery voltage at need, in the case of fuel interrupting injection control conformed to an acceleration driving state. CONSTITUTION:A fuel injection valve A set up at each cylinder is opened or closed by a sequential control means B, and normal fuel injection is thus carried out in accord with the intake stroke and timing of each cylinder. In the above system, an acceleration driving state of an engine is detected by a means C, while according to this detected result, an accelerating increased fuel quantity is set by a means D. In addition, a voltage compensation fuel quantity corresponding to any operating delay of the fuel injection valve A is set by a means F on the basis of voltage of an electric source E driving the fuel injection valve A. Moreover, on the basis of this voltage compensation fuel quantity, the accelerating increased fuel quantity is set for increment compensation by a means G. Then, a driving signal corresponding to the accelerating increased fuel quantity is outputted to the required fuel injection valve A at time of requirements by a means H.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an electronically controlled fuel injection device for a multi-cylinder internal combustion engine. The present invention relates to an electronically controlled fuel injection system of a so-called GENERAL injection type, which performs normal fuel injection in synchronization with the intake stroke of each cylinder by opening the cylinder.

<Prior Art> Conventionally, as this type of electronically controlled fuel injection device, there is one described, for example, in Japanese Patent Laid-Open No. 57-8328, etc., and such an injection device injects fuel and air into each cylinder. It has the advantages of being able to supply a sufficiently mixed air-fuel mixture, eliminating fuel variations between cylinders, and reducing torque fluctuations.

However, in such conventional electronically controlled fuel injection devices, the fuel injection amount is calculated according to the engine operating state at that time, for example, at predetermined minute intervals, and when the predetermined fuel injection timing for each cylinder comes, the latest calculation is performed. Since a drive signal corresponding to the fuel injection amount is output to the fuel injection valve of the corresponding cylinder to cause fuel injection to be performed for each cylinder, the following problems occur when the engine accelerates.

That is, during acceleration operation, the actual amount of intake air taken into each cylinder increases rapidly, and accordingly, the amount of fuel required for each cylinder also increases rapidly. Therefore, a deviation based on the time difference will occur between the required fuel amount at the predetermined fuel injection timing and the required fuel amount during the actual intake stroke.
However, there is a detection response delay in the intake air flow rate and intake pressure data detected by the sensor to determine the fuel injection amount, and this causes the amount to be significantly lower than the required amount under normal fuel injection control, especially in the early stages of acceleration. Only a small amount of fuel will be supplied to the

As a result, the air-fuel ratio becomes over-lean, especially in the early stages of acceleration, resulting in a reduction in engine output or misfire, leading to a reduction in acceleration performance, the occurrence of longitudinal vibration of the vehicle, and deterioration of exhaust characteristics. .

As a technique to solve such problems, the applicant previously proposed the following:
At the first time of acceleration determination, a drive signal corresponding to the fuel amount set according to the acceleration operation state is output to the cylinder immediately after the end of normal fuel injection (sequential fuel injection), and a drive signal corresponding to the fuel amount set according to the acceleration operation state is output. We have proposed a system configured to perform so-called interrupt fuel injection (see Fig. 11).

In addition, when the first acceleration determination is during normal fuel injection under sequential control, a drive signal corresponding to the fuel amount set according to the acceleration operation state is sent after the drive signal for normal injection control to the cylinder under injection. A system configured to output data has also been previously proposed (see Japanese Patent Application No. 148036/1983, etc.).

<Problem to be solved by the invention> By the way, in normal sequential injection control,
In order to compensate for the delay in the operation of the fuel injector depending on the voltage of the battery, which is the power source for opening the electromagnetic fuel injector, the fuel injection amount set according to the engine demand is increased in accordance with the battery voltage. However, as mentioned above, when performing interrupt injection according to the acceleration state between fuel injections under normal sequential control, the above-mentioned battery is used to set the interrupt injection amount. There is no voltage-based correction, and even if the amount of fuel required from the accelerated driving state is set, there is a problem in that only an amount of fuel smaller than the set amount is actually supplied.

That is, the fuel injection amount is set as the pulse width of the drive pulse signal output to the fuel injection valve, and the fuel injection amount is controlled via the valve opening driving time of the fuel injection valve. There is a delay time in the operation of the valve, and in particular, the valve-opening delay time, which results in an invalid injection amount, changes depending on the voltage of the battery, which is the power source for driving the fuel injection valve to open. In this system, an increase in the amount of fuel is corrected to the normal fuel injection amount.

Here, in the case of rough fuel control in which the fuel injection amount in the interrupt injection is always set to a large amount so as to ensure the maximum predicted required amount, the battery voltage as described above It is possible to inject the necessary and sufficient amount of fuel without making any correction. However, in particular, the time difference between the time of interrupt injection start control and the predetermined timing of the intake stroke at which the true required fuel amount for that cylinder appears,
If the interrupt injection amount is configured to be set with high accuracy according to the true demand amount, such as when the interrupt injection amount is set based on the changing state of the engine load, If this correction is not made, there is a risk that even if the interrupt injection amount is set with high accuracy, the amount of fuel actually injected and supplied will not be enough and it will not be possible to save the air-fuel ratio from becoming over-lean during acceleration. This is what happened.

However, if the drive signal for interrupt injection is within the predetermined time period corresponding to the delay in the closing operation of the fuel injector from the valve closing control by the drive signal for normal fuel injection, interrupt injection will actually occur following normal injection. is performed, so if the interrupt injection amount is corrected according to the battery voltage, an extra correction will be made and more interrupt injection will be performed than the requested amount, so in the above case, the battery voltage It is better to avoid correcting the interrupt injection amount accordingly.

The present invention has been made in view of the above-mentioned problems, and calculates the interrupt injection amount with high accuracy by performing correction according to the battery voltage as necessary in the interrupt injection control according to the acceleration driving state. The purpose is to ensure that actual fuel injection supply is performed with high precision in accordance with the settings.

Means for Solving the Problems> Therefore, in the present invention, as shown in FIG. In an electronically controlled fuel injection system for a multi-cylinder internal combustion engine, the electronically controlled fuel injection system for a multi-cylinder internal combustion engine is equipped with a sequential fuel supply control means for performing normal fuel injection in synchronization with the intake stroke of each cylinder. a detection means, an acceleration increase fuel amount setting means for setting an increase fuel amount during acceleration according to the detected acceleration operation state, and an operation delay of the fuel injection valve according to the voltage of the power supply for opening the fuel injection valve. voltage correction fuel amount setting means for setting a voltage correction fuel amount corresponding to the voltage correction fuel amount; acceleration injection amount voltage correction means for setting the increase fuel amount during acceleration based on the set voltage correction fuel amount; When the sequential fuel supply control means is controlling the non-opening operation of the fuel injection valve at the first time of operation detection, the fuel injection valve provided in the cylinder immediately after normal fuel injection is corrected by the acceleration injection amount voltage correction means. Acceleration interrupt injection control means is provided for outputting a drive signal corresponding to the set acceleration increase fuel amount to perform interrupt fuel injection.

Further, as shown by the dotted line in FIG. 1, the time when the drive signal is output by the acceleration interrupt injection control means is a predetermined time corresponding to the operation delay time of the fuel injector from the end of the opening operation control of the fuel injector in normal fuel injection. outputting a drive signal corresponding to the increased fuel amount during acceleration set by the increased fuel amount during acceleration set by the increased fuel amount during acceleration instead of the increased fuel amount during acceleration corrected by the increased fuel amount during acceleration set by the injection amount voltage correction means when the amount is within It is also possible to provide a voltage correction avoidance means that causes the voltage correction to be performed.

According to this configuration, the sequential fuel supply control means individually opens the fuel injection valves provided for each cylinder at a predetermined injection start time, and supplies normal fuel in synchronization with the intake stroke of each cylinder. Let the injection take place.

Further, the acceleration operation state detection means detects the acceleration operation state of the engine, and the acceleration increase fuel amount setting means sets the acceleration increase fuel amount to be injected and supplied separately from the normal injection according to the acceleration operation state. .

On the other hand, the voltage-corrected fuel amount setting means sets a voltage-corrected fuel amount corresponding to the delay in operation of the fuel injection valve in accordance with the voltage of the power source (battery, battery) for opening the fuel injection valve provided for each cylinder.

Then, the acceleration injection amount voltage correction means increases and sets the increased fuel amount during acceleration based on the voltage-corrected fuel amount set according to the power supply voltage, and the actual injection amount is adjusted due to the delay in the operation of the fuel injection valve. Avoid running out.

The acceleration interrupt injection control means controls the fuel injection valve provided in the cylinder immediately after normal fuel injection when the fuel injection valve is not controlled to open by the sequential fuel supply control means at the first time of acceleration operation detection. A drive signal corresponding to the increased fuel amount during acceleration corrected based on the power supply voltage is output to perform interrupt fuel injection.

In other words, when normal fuel injection is not performed in any cylinder when acceleration is determined for the first time, the amount of fuel is set according to the acceleration operation state and in consideration of the delay in the operation of the fuel injection valve. A drive signal is output to the fuel injection valve of the cylinder that has recently received normal fuel injection, so that interrupt injection is performed between normal fuel injections to correct fuel control response delay during acceleration.

Further, when the time when the drive signal is output by the acceleration special injection control means is within a predetermined time corresponding to the operation delay time of the fuel injector from the end of the opening operation control of the fuel injector in normal fuel injection, voltage correction is performed. The avoidance means outputs a drive signal corresponding to the increased fuel amount during acceleration set by the increased fuel amount during acceleration set by the increased fuel amount during acceleration instead of the increased fuel amount during acceleration corrected by the accelerated injection amount voltage correction means. let

In other words, when the interrupt injection timing is reached within the time corresponding to the delay in the operational response of the fuel injection valve from the normal fuel injection end control, the interrupt injection will be performed following the normal fuel injection, and the power supply voltage will change. Since the desired amount can be injected without performing correction based on the fuel injection amount, the increase correction of the increased fuel amount during acceleration (interrupt injection amount) using the voltage corrected fuel amount is avoided.

<Example> The present invention will be explained in detail below.

In FIG. 2 showing the system configuration of one embodiment, an internal combustion engine 1 includes an air cleaner 2. Air is taken in through the intake duct 3, the throttle chamber 4, and the intake manifold 5. The air cleaner 2 has an intake air (atmospheric) temperature TA ('
An intake air temperature sensor 6 is provided to detect C). The throttle chamber 4 is provided with a throttle valve 7 that operates in conjunction with an accelerator pedal (not shown), and controls the intake air flow i.
Control tQ. The throttle valve 7 has its opening degree T.
A throttle sensor 8 including an idle switch 8A that is turned ON at its fully closed position (idle position) is attached along with a potentiometer that detects VO.

The intake manifold 5 downstream of the throttle valve 7 is provided with an intake pressure sensor 9 that detects the intake pressure Pm.
An electromagnetic fuel injection valve IO is provided for each cylinder.

The fuel injection valves 10 are individually driven to open by injection pulse signals output from a control unit 11 built in a microcomputer (to be described later) in synchronization with the ignition timing, for example, and in synchronization with the intake stroke of each cylinder. Fuel that is pressure-fed from a fuel pump (not shown) and controlled to a predetermined pressure by a pressure regulator is injected and supplied into the intake manifold 5. In other words, the amount of fuel supplied by the fuel injection valve 10 is determined by the valve opening driving time of the fuel injection valve 10. It's about to be controlled.

Furthermore, a water temperature sensor 12 for detecting the cooling water temperature Tw in the cooling jacket of the engine 1 is provided, and the exhaust passage 1
An oxygen sensor 14 is provided within the engine 3 to detect the air-fuel ratio of the intake air-fuel mixture by detecting the oxygen concentration in the exhaust gas.

The control unit 11 counts the crank unit angle signal PO3 output from the crank angle sensor 15 in synchronization with engine rotation for a certain period of time, or outputs a crank reference angle signal REF (for 4 cylinders) at each predetermined crank angle position. engine rotation speed N by measuring the period (every 180")
Detect.

In addition, the transmission attached to the engine l is provided with a vehicle speed sensor 16 for detecting vehicle speed and a neutral sensor 17 for detecting the neutral position, and these signals are input to the control unit 11. A voltage signal from a battery 20, which is a power source for opening the engine, is input to the control unit 11 via an ignition switch 21. Further, an auxiliary air passage 18 that bypasses the throttle valve 7 is provided with an electromagnetic idle control valve 19 that controls the idle rotation speed via the amount of auxiliary air.

The control unit 11 calculates the fuel injection fjtTi (pulse + 11 of the injection pulse signal) based on the various detection signals detected as described above, and also controls the fuel injection for each cylinder based on the set fuel injection amount TI. valve 10
Individually open drive system? 11 (sequential injection control). Further, the control unit 11 feedback-controls the idle rotation speed to the target idle rotation speed by controlling the opening degree of the idle control valve 19 during idle operation detected based on the idle switch 8A and the neutral sensor 17.

Next, various calculation processes for fuel control performed by the control unit 11 will be explained according to the routines shown in the flowcharts of FIGS. 3 to 9, respectively.

In this embodiment, sequential fuel supply control means,
Acceleration increase fuel amount setting means, voltage correction fuel amount setting means,
The functions of the acceleration injection amount voltage correction means, the acceleration interruption injection control means, the voltage correction avoidance means, and the acceleration operation state detection means are performed by software as shown in flowchart 1 of FIGS. 3 to 9 above. It is equipped.

The routine shown in the flowchart of FIG. 3 is executed at every predetermined minute time (for example, 101118).
First, in step 1, the opening degree TVO of the throttle valve 7 detected by the throttle sensor 8 is A/D converted and input.

In step 2, based on a value obtained by multiplying the intake pressure PB detected by the intake pressure sensor 9 and the engine rotational speed N calculated based on the detection signal from the crank angle sensor 15, a preset map is Find 2 by searching for the volumetric efficiency correction coefficient.

The volumetric efficiency correction coefficient 2 is a coefficient for correcting the basic volumetric efficiency QHφ, which is determined depending on the opening area A, in accordance with the true engine load fluctuation, as will be described later.

In step 3, the opening area A of the engine 1 intake system is searched from the map based on the throttle valve opening degree TVO input in step 1, and this opening area A is divided by the engine rotational speed N, and the result of this division is Based on this, the basic volumetric efficiency QHφ is searched in the next step 4.

In step 4, the basic volumetric efficiency QHφ is searched and determined from the map based on the A/N calculated in step 3.

Then, in step 5, the basic volumetric efficiency QHφ obtained by searching in step 4, the volumetric efficiency QCYLO calculated in step 5 during the previous execution of this routine, and the volumetric efficiency correction coefficient obtained by searching in step 2. using 2 and
The final volumetric efficiency QCYI is calculated according to the formula below.

QCYL 4-QHφXK2+QCYLO (1- to 2)
If the volumetric efficiency QCYL is calculated according to the above calculation formula, the volumetric efficiency QCYL becomes Q I - 1φ - QCYLO during steady operation, and the volumetric efficiency QCYL stabilizes at a constant value, but when the engine l is operated transiently, the engine load at that time Depending on the state, changes in volumetric efficiency QCYL will be slowed down relative to the map search value, and as a result, volumetric efficiency that approximately corresponds to actual engine load changes that lag behind changes in opening area A and engine rotational speed N. QCYL is now set.

In step 6, the basic fuel injection amount T pqcy i! is based on the volumetric efficiency QCYI according to the opening area A and the engine rotational speed N according to the following formula. , is calculated.

Tpqcyf4-KCONAXQCYLXKTA2 Here, KCONA is a constant, QCYL is the volumetric efficiency calculated in step 5 above, and KTA2 is set based on the intake air temperature TA ('C) detected by the intake air temperature sensor 6 in the background job described later. This is the intake air temperature correction coefficient.

In the next step 7, the basic fuel injection amount MTpqey calculated in step 6 during the previous execution of this routine (10111s ago) is changed from the basic fuel injection I T pqcy 1 calculated in step 6 this time! ! , the basic fuel injection per execution cycle of this routine is 1tTpqeyj! The change 1iDLTTp is calculated.

In the next step 8, the fuel supply stop control 1ll (Fuel
cut) Determine whether or not the vehicle is in the immediately following acceleration state. The fuel supply stop control is performed to stop the fuel injection supply from the fuel injection valve 10 during deceleration operation of the engine 1, and to reduce the amount of unburned gas discharged and improve fuel efficiency.

When it is determined in step 8 that the acceleration state is immediately after the fuel supply stop control, the process proceeds to step 9, where the amount of change DLTTp obtained in step 7 is multiplied by the re-acceleration correction coefficient KQACC to perform an increase correction, and the result is used as the final Let the change be NZ.

As described later, the amount of change Z is treated as indicating the rate of change in the fuel amount required by the engine 1, and the interrupt injection amount and the normal fuel injection amount Ti are corrected based on this amount of change Z. . In addition, during normal fuel supply, the wall flow (fuel adhering to the intake passage wall) is in an equilibrium state at an amount corresponding to the engine load at that time, but when the fuel supply stop control as described above is performed, the wall flow is drastically reduced compared to when fuel is supplied.

Therefore, when accelerating immediately after stopping fuel supply,
It is necessary to perform fuel control by estimating the rate of change in the basic fuel injection amount T pqcy l higher than usual, and in order to respond to this request, the increase correction of the amount of change DLTTp is performed in step 9.

On the other hand, if it is determined in step 8 that the acceleration is not occurring immediately after the fuel supply is stopped, the fuel is being supplied normally and there is no drastic decrease in the wall flow rate, so the process proceeds to step 10 and the amount of change calculated in step 9 is Set DLTTp to Z as is.

In the next step 11, the basic fuel injection amount T pqcy l calculated in step 6 this time is set to the previous value M T pqc
yl.

The next time this routine is executed, the current basic fuel injection amount Tpqcyj! The amount of change DLTT is set as the previous value.
Let p be calculated.

Then, in step 12, it is determined whether the amount of change Z set as described above is zero.

Here, when it is determined that the amount of change Z is substantially zero, it can be considered that the engine 1 is in a steady operating state where the basic fuel injection amount T pqcy l is stable at a substantially constant value. Proceeding to step 13, the transient flag Ftr is set to zero indicating a steady operating state.

In addition, in the next step 14, the interrupt injection amount corresponding to each cylinder)'11-)'44 and the normal injection addition amount y1~
y4 (Engine 1 in this example is a 4-cylinder engine)
are all set to zero, so that transient correction control of the fuel supply amount according to the amount of change Z is not performed.

That is, when the engine l is in a steady operating state, the required fuel amount (intake air amount) of the engine 1 is approximately constant, so the fuel injection NTi set according to the engine operating state at a predetermined fuel injection timing is: Even if there is a delay in the detection of various sensors, it is still the same as the true engine required amount that appears in the intake stroke after the start of injection, but there is a time difference between the injection start timing (fuel injection amount setting) and the timing when the true engine required fuel amount appears. Therefore, when steady operation is determined as described above, the interrupt injection amount y++~y44 and the normal injection addition amount)'l-)'
4 is set to zero, and correction control corresponding to the time difference is not performed.

On the other hand, when it is determined in step 12 that the change amount Z is not approximately zero, there is a change in the basic fuel injection amount Tpqcyl (intake air amount), and the injection start timing and true engine required fuel amount appear as described above. Since this is a transient operating state in which there is a response delay in fuel supply control due to a time difference with the timing, the process proceeds to step 15 and subsequent steps to perform setting control of the interrupt injection amount Vlr-Vaa and the normal injection addition amount y, to yaa. That is, during transient operation of the engine 1 where the amount of intake air increases or decreases, the amount of intake air corresponding to the amount of intake air at a predetermined fuel injection start timing and the true required fuel amount of the engine 1 that appears in the intake stroke after the start of injection. Since a deviation will occur between the two due to the passage of time, the deviation is predicted based on the above-mentioned Z, which is the amount of change in the basic fuel injection amount Tpqcyf, and the response delay of fuel supply control during transient operation is eliminated. This is what I am trying to do.

In step 15, it is determined whether the transient flag Ftr is zero or one. The transient flag Ftr is set to zero in step 13 during the steady operation of the engine I in which the change IZ is determined to be approximately zero in step 12. Therefore, at the first time when the transition from steady to transient operation is made, In step 15, it is determined that the transient flag Ftr is zero.

At the first time of such a transient determination, in step 16, the interrupt injection amount y++")' aa (fuel injection amount to be interposed between normal injections) is determined for each cylinder (#lcy/!~#4cyi,). ) is calculated according to the following formula.

)'＋＋←Tat resistance X Z XI/IOX Kteva
ccX 2'/ zz←Tatm2X Z X 1/I
OX K twiceX 2Vzs←Tatm3X Z
Xi/IOX KtwaceX 2yaa←Tatm
4X Z xi/10x Ktwaee In this embodiment, the intake BDC is set as the target timing time (
ms). In addition, K twacc is the water temperature sensor 12
Cooling water temperature Tw representative of the engine temperature detected by
This is a water temperature correction coefficient that is set according to. However, during deceleration when the change amount Z (change amount DLTTp) becomes a negative value, the above-mentioned interrupt injection amounts y, -y44 are set to zero.

The amount of change Z is the amount of change in the basic fuel injection amount Tpqeyl (the basic fuel injection amount based on the opening area and the engine rotational speed N) between Ions, which is the execution cycle of this routine, and on the other hand, the amount of change in the basic fuel injection amount Tpqeyl (the basic fuel injection amount based on the opening area and the engine rotational speed N) is Since Tatm4 indicates the time until the target timing in ms units, the amount of change Z is multiplied by 1710 to convert it to the amount of change per 1 ms. Furthermore, in the electronically controlled fuel injection system of this embodiment, the normal fuel injection amount Ti is calculated by doubling the basic fuel injection amount T ppb based on the intake pressure PB for convenience of calculation, as will be described later. Therefore, it is necessary to multiply by 2 accordingly.

Interrupt injection amount y calculated in this way.

~yaa is to predict and set the amount of change in the basic fuel injection amount Tpqeyl from the current time to the target timing of each cylinder, that is, the amount of change in the engine required fuel amount until the target timing. This indicates that in the cylinders where injection has ended, the amount corresponding to the interrupt injection amount "jrI-" f4a is insufficient due to the accelerated operation of the engine 1 from at least the current point in time.

When the interrupt injection amount yI8 to y44 is set in step 16, the normal injection addition it y +
~y4 are each set to zero. That is, at the first time of transient determination (acceleration determination) of the engine 1, response delay in fuel supply due to acceleration operation is handled by interrupt injection, and control is not performed to correct the normal fuel injection amount Ti by the amount of response delay.

In the next step 18, the transient flag Ftr is set to 1 in response to the transient determination in the current step 12, so that the continuation state of the transient operation is determined by the transient flag Ftr.

Then, in step 19, it is determined whether or not normal fuel injection is being performed in any cylinder, and if fuel injection is being performed in any cylinder, the main routine is executed without executing interrupt injection control. However, if fuel injection is not being performed in any cylinder, the process proceeds to step 22 and subsequent steps to perform interrupt injection in the cylinder immediately after normal fuel injection has ended.

On the other hand, when it is determined in step 15 that the transient flag Ftr is 1, a transient (acceleration) determination is performed in step 12 based on the change 1z, and the flag setting in step 18 has been performed before the previous time. Since it is a transient continuation determination state, instead of correcting the response delay of fuel supply control by interrupt injection, the normal fuel injection amount T is
A correction for the response delay is added to i. Therefore, at this time, the routine proceeds to step 20, and the normal injection addition amounts y, to y4 used for the increase correction of the normal fuel injection amount Ti are calculated according to the following formula.

3'l"-TatmlX Z XI/10y, ←Ta
tm2X Z X 1/10)' 13←Tatai3
X Z Xi/10V a4”-Tatm4X Z X
i/10 Here, Tatml to Tatm4 is the time (+1
! At this time, Tatml~Tatm4 and ls
Basic fuel injection amount Tpqcyi1 per s. By multiplying the amount of change by ZXI/10, the change in the required fuel amount from the current time to the target timing is predicted and set.

However, in the calculation of the normal injection addition amount y1 to y4, the temperature correction coefficient K twacc multiplied in the case of the calculation of the interrupt injection amount y, ~7aa is not used, and the reason why it is not doubled is because of this. The normal injection addition amounts y1 to y4 are added to the basic fuel injection amount Tppb calculated based on the intake pressure PB as described later, and this addition result is doubled, and further correction based on the cooling water temperature Tw is performed. This is because the final fuel injection amount Ti is calculated based on the calculation.

Note that the normal injection addition amount y, ~y4 calculated using the above formula is:
When the engine 1 accelerates, it becomes a positive value and the normal injection is corrected to increase, but when the engine 1 decelerates, it becomes a negative value and the normal injection is corrected to decrease.

When the normal injection addition amounts y, ~y4 are calculated in step 20, the interrupt injection amounts y1°~Va are calculated in the next step 21.
Let all a be zero. As a result, when the transient (acceleration) of the engine 1 continues, the normal injection amount y, ~ y4 is added to the fuel injection performed at the normal timing instead of the interrupt injection.
A correction based on the acceleration response delay is applied.

Here, to explain again by returning to step 19, the transient (
When determining the initial acceleration (acceleration), the interrupt injection amount ylI-y4
4 is calculated and it is determined in step 19 whether or not there is a cylinder in which normal fuel injection is being performed at the present time, but it is determined here that there is no cylinder in which normal fuel injection is being performed. Then, the process proceeds to step 22, where it is determined whether or not a predetermined time (for example, 1 ms) or more has elapsed since the normal fuel injection.

Then, depending on the determination result, it is switched whether or not to add the voltage correction numerator s for correcting the invalid injection amount due to the delay in the operation of the fuel injection valve 10 according to the buffer voltage to the interrupt injection amount y, ~Vaa. Make it.

That is, when performing interrupt injection to cope with a transient response delay, is the valve closing drive control of the fuel injection valve 10 in normal fuel injection? A predetermined time corresponding to the closing operation delay time of the fuel injector lO from Il (when the drive pulse signal is OFF) (a time shorter than the time from when the drive pulse signal is OFF until the fuel injector 10 is actually fully closed) ), the interrupt injection will be performed following the normal injection, so the desired amount can be injected without the need for correction using the voltage correction molecule s as a countermeasure against the delay in valve opening operation. The voltage correction numerator s ends up being overcorrected.

On the other hand, if more than the predetermined time has elapsed since the end of normal fuel injection, the same conditions as normal injection (fuel injection valve 10
When the fuel injection valve 10 is opened in the fully closed state of This is because only an amount of fuel smaller than the set amount is actually injected.

Whether the current time is within a predetermined time from the end of normal fuel injection control is determined by the count value cnt, which is incremented by 1 every 1 ms, as described later, and the count value cnt at the end of normal injection control (drive pulse). (when the signal is OFF) Tiend
This is done by comparing the value cntota at . Since the count value cnt is counted up every 1 ms as described above, cnt and cnto
The word that La is not equal means that there is a difference of 1 or more between the two and at least ins from T tend.
Indicates that the above has passed.

Therefore, when it is determined in step 22 that cnt=cntota, less than 1lIIs has elapsed from the normal injection end time Tiend or the end time T Interrupt injection is controlled without adding the voltage correction numerator s to the amount)'11-)'44. On the other hand, when it is determined in step 22 that Cnt+Cnjota, at least 1w+ from T tend at the end of normal injection.
Since the time period greater than or equal to s has elapsed, the process advances to step 30 and subsequent steps to control the interrupt injection by adding the voltage correction numerator s to the interrupt injection amounts y, to y44.

In this way, at the interrupt injection timing that is the first time of transient determination, if a predetermined time period corresponding to the operation delay of the fuel injection valve IO has elapsed from the end of normal fuel injection control or more has elapsed, and under the same conditions as normal fuel injection control, When it is necessary to control the opening drive of the fuel injector 10, if the voltage correction numerator s is added and correction is made in accordance with the operation delay of the fuel injector lO, the amount of change Z such as target timing time Tatml to Tatm4 can be reduced. Interrupt injection amount y1. ~
The fuel corresponding to y44 can actually be injected and supplied, and the actual amount of injected fuel will not be insufficient due to a delay in the operation of the fuel injection valve 10.

Further, when interrupt injection is performed following normal fuel injection within a predetermined time from the end of normal fuel injection control, there is no need for increase correction by the voltage correction numerator s, and the voltage correction valve Ts
If the voltage correction numerator s is added, the actual supply amount will become larger than the set amount, so the interruption injection of an excessive amount is prevented by not adding the voltage correction numerator s.

Here, to explain the interrupt injection control that is continuous to normal fuel injection that is performed without adding the voltage correction numerator s, in step 23, the #1 cylinder injection discrimination flag FICYL
Determine whether is 1 or zero. The injection discrimination flag FICYL for the #1 cylinder indicates that the cylinder to which fuel is to be injected at the next predetermined injection timing is the #1 cylinder when the engine is in operation, and is the injection discrimination flag F for the #1 cylinder.
When ICYL is 1, the injection discrimination flag F2CYL for the #22 cylinder to the injection discrimination flag F4 for the #4 cylinder, which will be described later.
CYL is set to zero. still,
The settings of the injection discrimination flag FI CYL for the #1 cylinder to the injection discrimination flag F4CYL for the #4 cylinder will be described in detail later.

In the four-cylinder internal combustion engine 1 of this embodiment, fuel injection is #1e
yffi-+# 3cyj2-+# 4cyffi-+
#2cyI! , is performed every 180 degrees of crank angle in this order, so when the #1 cylinder injection discrimination flag FICYL is 1, the #2 cylinder has finished normal injection.

Therefore, when it is determined in step 23 that the flag FICYL is 1, the process proceeds to step 24 and interrupt injection is performed in the #2 cylinder. That is, in step 24, a drive pulse signal with a pulse width corresponding to the interrupt injection amount y2□ is output to the fuel injection valve 10 provided in the #2 cylinder,
Following normal fuel injection, an interrupt corresponding to response delay correction of fuel control is performed.

As mentioned above, the interrupt injection performed on the #2 cylinder is performed based on the amount of change in the fuel requirement from immediately after the normal injection in the #2 cylinder to a predetermined target timing in the intake stroke of the #2 cylinder. As a result, when accelerating, an amount equivalent to the response delay is additionally injected into the #2 cylinder, where normal fuel injection has already ended, and the lean air-fuel ratio due to the fuel control response delay is suppressed. be done.

Further, if it is determined in step 23 that the flag F I CYL is zero, the process proceeds to step 25, and this time #33
It is determined whether the cylinder injection flag F3CYL is 1 or zero. Here, when it is determined that the flag F3CYL is 1, it is a state in which fuel should be injected into the #3 cylinder at the next injection timing and it is immediately after the end of injection in the #1 cylinder, so in this case, step 2G Please proceed to
A drive pulse signal of pulse l corresponding to an interrupt injection amount of 7++ is output to the fuel injection valve 10 provided in the cylinder, and an interrupt corresponding to response delay correction of fuel control is performed following normal fuel injection. .

Further, if it is determined in step 25 that the flag F3CYL is zero, the process proceeds to step 27, where it is determined whether the injection specific flag F4CYL for the #44 cylinder is 1 or zero. Here, if it is determined that the flag F4CYL is 1, step 28 is performed in the same manner as described above.
By proceeding to , the fuel injection valve 10 of the #3 cylinder is caused to perform an interrupt injection corresponding to the interrupt injection amount Fss.

When it is determined in step 27 that the flag F 4 CY L is zero, the remaining injection specific flag F for the #22 cylinder
2CYL should be 1, but proceed to step 29 and set the interrupt injection amount 3' to the fuel injection valve 10 of the #4 cylinder.
Interrupt injection equivalent to 44 is performed.

As described above, when it is the first time of transient discrimination and it is still within a predetermined period of time from the end of normal fuel injection, interrupt injection Ny1. This is to perform interrupt injection according to ~yag, and as a result, additional injection is performed in the cylinder where the air-fuel ratio becomes leaner due to a delay in the response of fuel control, and this can prevent the air-fuel ratio from becoming leaner. be.

On the other hand, in step 22, cn t qb cn to t
When it is determined that the value is a, unless the voltage correction numerator s is added to the interrupt injection amounts y, ~y44 as described above, fuel equivalent to the interrupt injection amounts y, ~y44 will not actually be injected and supplied. Interrupt injection amount y, ~'Jaa
An interrupt injection drive pulse signal with a pulse width corresponding to the sum of the voltage correction numerator s and the voltage correction numerator s is output to the fuel injection valve 10 provided in each cylinder. This is the same as when it is determined that

First, in step 30, the #1 cylinder injection discrimination flag F
Determine whether ICYL is 1 or zero. If the flag F I CYL=1 here, the normal injection of the #2 cylinder has ended and the state is waiting for the next fuel supply to the #1 cylinder, so proceed to step 31 and inject the fuel for the #2 cylinder. An interrupt drive pulse signal with a pulse width corresponding to the voltage correction numerator s converted to the interrupt injection amount 'jtt set to ``jtt'' is output to the fuel injection valve 10 provided in the #2 cylinder (
(See Figure 10).

Thereafter, the arithmetic processing in steps 32 to 36 is performed in the same manner, and the cylinder where normal fuel injection has ended is interrupted with a pulse width corresponding to the sum of the interrupt injection amount VII-Yaa and the voltage correction numerator s. This is what causes the injection to take place.

In this way, when the transient determination is performed for the first time and more than a predetermined time has elapsed since the end of normal injection, the operation delay of the fuel injector 10 by the voltage correction molecule s is performed in the same manner as normal injection control. Interrupt injection is performed by correcting the time, so that fuel corresponding to the response delay is accurately additionally injected into the cylinder after normal injection.

In addition, in the routine shown in the flowchart of FIG. 3 above,
If any cylinder is in the middle of normal fuel injection at the first time of transient determination, the routine is supposed to end without performing an interrupt injection, but in such a situation,
When the fuel injection in the cylinder currently injecting is completed according to the routine shown in the flowchart of FIG. 4 (actually, when the drive pulse signal is OFF), in step 22, Cnt
The same interrupt injection as when it is determined that ntoLa is performed is performed. However, such interrupt injection after waiting for the end of the normal injection is executed only when the normal injection ends within 10 ns (the execution cycle of the third illustrated flowchart) after the initial determination of the transient operation.

The routine shown in the flowchart of FIG. 4 is executed when there is valve closing drive control in any of the drive pulse signals output for each fuel injection valve 10. First, in step 41, #l Cylinder injection discrimination flag I
Determine whether CYL is 1 or zero. If it is determined that the flag F I CYL is 1 here, fuel will be injected and supplied to the #1 cylinder at the next injection timing, and the current drive pulse signal OFF is set to #1. This indicates that the fuel supply control is for two cylinders. Therefore, in step 41, the flag FICYL=
If it is determined that the value is 1, the process proceeds to step 42, where an interrupt injection driving pulse signal having a pulse width corresponding to the interrupt injection IEV t is outputted to the fuel injection valve 10 of the #2 cylinder.

The above-mentioned interrupt injection control is performed in step 23 described above.
〜This is the same as step 29, so the following steps 43〜
47 will be omitted.

When the interrupt injection control for the cylinder that has finished normal fuel injection during execution of this routine ends, in step 48, 1
The current value of the count value cnt which is increased by 1 every ns is c
ntota, so that the determination in step 22 is made based on this CnLoLd.

Note that when the transient operation of the engine l continues and the normal injection addition amounts y1 to y4 are set in step 2° and the interrupt injection amounts y and to y44 are set to zero in the next step 21, this routine This prevents interrupt injection from occurring. Further, even when it is determined in step 12 that the engine 1 is in steady operation based on the amount of change Z, the interrupt injection according to the routine shown in FIG. 4 is not performed.

Next, a description will be given of setting control of the fuel injection amount Ti used in normal fuel injection control that is performed in synchronization with the intake stroke of each cylinder according to the routine shown in the flowchart of FIG.

The routine shown in the flowchart of FIG. 5 is executed at predetermined minute intervals of about 10 m5. First, in step 51, the basic volumetric efficiency correction coefficient Kpb is calculated based on the intake pressure PB detected by the intake pressure sensor 9. In the next step 52, the basic volumetric efficiency correction coefficient Kpb obtained by searching from the map in step 51 is added to the minute correction coefficient KFL set in the background job described later.
Multiply by AT and correct it to obtain the final volumetric efficiency correction coefficient KQ
Calculate CYI, (←KpbXKPLAT).

In the next step 53, a basic fuel injection amount T1llPb based on the intake pressure PB is calculated according to the following formula.

T ppb←KCONDX P B XK(ICYLX
KTA Here, KCOND is a constant, PB is the intake pressure detected by the intake pressure sensor 9, KQCYL is the volumetric efficiency correction coefficient set in step 52 above, and KTA is set based on the intake air temperature TA in the background job described later. It is in the intake air temperature correction coefficient.

Then, in the next step 54, the fuel injection amounts Til to Ti4 for each cylinder are calculated according to the following formulas.

Til←2(Tppb+'! +) XCOEFXLA
MBDA+ T5Ti24-2(Tppb+)'
z) XCOEFXLAMBDA+ T 5Ti3←2
(Tppb+)' 3) XCOEFXLAMBDA+
T sT i4←2(Tppb+-)' 4) XC
0EF It is quantity. Further, CO key is various correction coefficients that are set depending on the engine operating state mainly based on the cooling water temperature Tw detected by the water temperature sensor 12, and LAMBDA is the engine intake air-fuel mixture detected via the oxygen sensor 14. This is a feedback correction coefficient for bringing the air-fuel ratio of the target air-fuel ratio closer to the target air-fuel ratio.

Further, Ts is a voltage correction value corresponding to the activation delay of the fuel injection valve 10, which is the same as that used in the interrupt injection control, and by adding this voltage correction value, the activation delay time of the fuel injection valve 10 can be adjusted. A desired amount of fuel is injected and supplied even if it changes depending on the bacterial voltage.

As described above, if the normal injection addition amount y, ~y4 is added to the basic fuel injection tTppb, the predetermined injection timing (the drive pulse signal to the fuel injection valve 10) is determined during the transient operation of the engine 1. Even when a deviation occurs in the actual required fuel amount in the intake stroke from the required fuel amount of the engine 1 at the output timing), the deviation is predicted and corrected based on the normal injection addition amount y, ~y4, This can eliminate the response delay in supply control (see FIG. 10).

Next, the setting control of various coefficients will be explained according to the background job (BGJ) shown in the flowchart of FIG.

In step 61, an intake air temperature correction coefficient KTA2 is searched and obtained from a preset map based on the intake air temperature TA ("C) detected by the intake air temperature sensor 6. This intake air temperature correction coefficient KTA2 is It is used to calculate the basic fuel injection amount T pqey l in .

Further, in step 62, the intake air temperature correction coefficient KTA is similarly searched, but this intake air temperature correction coefficient KT
A is the basic fuel injection amount 'rpp in step 53
This is used to calculate b.

In the next step 63, a water temperature correction coefficient K twaee is searched from a preset map based on the cooling water temperature Tw detected by the water temperature sensor 12. This water temperature correction coefficient K tsvaec is the interrupt injection amount y1. -Used for calculation of y44.

Furthermore, in the next step 64, a small correction is made from a preset map based on the intake pressure PB detected by the intake pressure sensor 9 and the engine rotation speed N calculated based on the detection signal from the crank angle sensor 15. Search and find the coefficient KFLAT. This minute correction coefficient FLAT is used in the correction calculation of the basic volumetric efficiency correction coefficient Kpb in step 52.

Next, follow the routine shown in the flowchart in Figure 7.
1 cylinder injection discrimination flag F I CYL ~ #4 cylinder injection discrimination flag F 4 C, Y L setting control and normal fuel injection amount? II (output of drive pulse signal) will be explained. In this embodiment, as shown in FIG. 10, the fuel injection timing is variably controlled from the fuel injection amounts Til to Ti4 so that the end timing of the normal fuel injection amount coincides with the opening timing of the intake valve of each cylinder. That's what I do.

This routine is executed when it is determined that a predetermined fuel injection timing (injection start timing) has arrived based on the detection signal output from the crank angle sensor 15. First, in step 71, It is determined whether the #1 cylinder injection determination flag FICYL is 1 or zero.

As described later, the #1 cylinder injection discrimination flag F I CYL is the injection start timing of the #2 cylinder and is the #1 cylinder injection determination flag F I CYL.
Since the flag FICYL is set to 1 when the output of a drive pulse signal with a pulse width corresponding to the fuel injection amount Ti2 set for two cylinders is started, the flag FICYL is set to 1.
When it is determined that this is the case, it can be determined that it is the injection timing for the #1 cylinder, where fuel should be injected next to the #2 cylinder. Therefore, when the flag FICYL=1, the process proceeds to step 72 and the fuel injection valve 1 of the #1 cylinder
0, the output of a drive pulse signal with a pulse width corresponding to the fuel injection amount Til set for the #1 cylinder is started.

Then, in the next step 73, the injection specific flag F3CYL for the #33 cylinder is set to 1, while the other flags FICYL, F2CYL, and F4CYL are each set to zero.

In this way, if the flag F3CYL is set to 1 when fuel injection is supplied to the #1 cylinder, the next time the injection timing is reached and this routine is executed, step 71
When it is determined that the flag F I CYL is zero, the process proceeds to step 74. At this step 74, it is determined that the flag F3CYL is 1, so the process proceeds to step 7.
4 to step 75. In step 75, the fuel injection amount Tia set for the #3 cylinder in step 54 is
A drive pulse signal with a considerable width is output to the fuel injection valve 1o provided in the #3 cylinder.

When fuel supply control is performed for the #3 cylinder in step 75, in the next step 76, 1 is set in the injection specific flag F4CYL for the #44 cylinder, which corresponds to the #4 cylinder whose fuel injection is to be controlled next to the #3 cylinder. On the other hand, the other flags FICYL, F2CYL, and F3CYL are each set to zero.

As a result, when this routine is executed at the next injection timing, steps 71 → 74 will be executed.
→Proceed to step 77, and in this step 77 flag F
When 4CYL is determined to be 1, the process proceeds to step 78, where a drive pulse signal is outputted to the fuel injection valve 10 of the #4 cylinder in the same manner as in step 72.75 described above. Then, in the next step 79, the injection specific flag F2 for the #22 cylinder, which is the next fuel injection cylinder, is
Set CYL to 1 and set other flags to zero.

After setting the flag F2CYL to 1 and terminating this routine, when the injection timing comes and this routine is executed again, it is determined in step 77 that the flag F4CYL is zero, so that steps 77 to 80 are executed. Proceed to.

In step 80, the aforementioned step? Similarly to the case of 2.75.78, the drive pulse signal is outputted to the fuel injection valve 10 of the #2 cylinder. Then, in the next step 81, the flag F I CYL is set to 1, and the other flags are set to zero.

In this way, the flag FICYL-F4CYL is set to 1 only in the flag corresponding to the cylinder to which fuel is to be injected next time when the injection timing is reached and a drive pulse signal is output to the injection cylinder at that time. , flags corresponding to other cylinders that do not inject fuel are set to zero, and when the injection timing comes, it can be determined that the cylinder whose flag is set to 1 is the cylinder that should inject fuel. It is.

Next, Tatml indicates the time (ms) until the target timing for setting the fuel supply amount for each cylinder (the predetermined timing in the intake stroke at which the amount of intake air corresponding to the true required amount appears).
The setting control of ~Tatm4 will be explained according to the routine shown in the flowchart of FIG.

In the case of the four-cylinder engine 1 of this embodiment, the routine shown in the flowchart of FIG. 8 is executed every time the reference angle signal REF, which is output from the crank angle sensor 15 at every 180° crank angle, is input. .

The reference angle signal REF is set to be output at the ignition reference position of each cylinder (for example, BTDC90'), and the reference angle signal The ignition reference position of which cylinder is determined by the signal REF.

When the reference angle signal REF is output from the crank angle sensor 15 and this routine is executed, first, step 91
TREF is the period (ms) that is the interval time from the previous reference angle A No. 3 REF output to the current reference angle signal REF.
Set to . Therefore, in the case of this embodiment, the TREF
corresponds to the time required for the crankshaft to rotate by 180', and the engine rotational speed N can be calculated based on the TREF.

In the next step 92, the current reference angle signal REF is #
It is determined whether the position corresponds to the 1st cylinder (#1cy7) or not (is the ignition reference position of the #1 cylinder).

Here, if it is determined that the current reference angle signal REF corresponds to the #1 cylinder, the process proceeds to step 93, and the target timing times Tatn+1 to Tatm4 are updated as shown in the following formula.

Tats+1←TREFX3+%TREFTattm3
'-'AT RE F Tatm4+-T RE F +'AT RE FTa
ts+2←TREFX2+'/2TREF Since the current reference angle signal REF corresponds to the ignition reference position of the #1 cylinder, after the ignition of the #1 cylinder is performed, the ignition of the #3 cylinder is performed, and the #3 cylinder is ignited. Intake of #3 cylinder is performed before cylinder ignition.

In the case of this embodiment, the reference angle signal REF is the intake B of each cylinder.
It is output at the TDC 90° position, and the predetermined timing at which the intake air amount corresponding to the true fuel requirement appears during the intake stroke (intake valve oven) is the intake BDC, which is the center position between the reference angle signals REF. I'm assuming.

Therefore, the target timing crank angle position for fuel setting of #3 cylinder (intake BDC of #3 cylinder) is a position rotated 90'' from the current reference angle signal REF (intake BTDC of #1 cylinder), and until then The crankshaft is at 90° for the time
The time required to rotate is TRE F x90@/1
80', the target timing time T for #3 cylinder
'A T RE F is set in atm3.

The target timing crank angle position of #4 cylinder, which is the next intake stroke after #3 cylinder, is delayed by 180' with respect to the target timing crank angle position of the fuel setting of #3 cylinder, so Ta tm4 is Tatm3 + TREF. becomes. Similarly, Tat, m2 is Tatm3+2XTR
EF (Tat+w4+TREF) and Tatml
is Tatm3+3XTREF (Tats+2+TRE
F).

Incidentally, when the target timing crank angle position for fuel setting is not at the center position between the reference angle signals REF, a predetermined target timing crank angle from the reference angle signal REF (assuming the crank angle up to the upright position is Xo, Tatm3=Tatm3= TRE F X X”/180° may be used.

On the other hand, in step 92, the current reference angle signal REF is #1.
If it is determined that the position does not correspond to the ignition reference position of the cylinder, the process advances to step 94. In step 94, it is determined whether the current reference angle signal REF corresponds to the ignition reference position of the #3 cylinder. When it is determined that the ignition reference position corresponds to the ignition reference position of the #3 cylinder, the closest intake stroke is that of the #4 cylinder, and the fuel setting target timing during the intake stroke is approximately at the center position between REF. , Proceed to step 95 and now enter +AT R in Tatm4
Set E F and set other target timing times Tatml~Ta according to the 180° delay according to the firing order.
Set tm3.

Furthermore, in step 94, the current reference angle signal REF is set to #3.
If it is determined that the reference angle signal REF does not correspond to the ignition reference position of the cylinder, the process proceeds to step 96, where it is determined whether the current reference angle signal REF corresponds to the ignition reference position of the #4 cylinder. If the ignition reference position is reached, step 9
Proceed to step 7 and set y2TREF in Tatm2 in the same manner as described above, and make other settings corresponding to delays of 180°.

When it is determined in step 96 that the current reference angle signal REF does not correspond to the ignition reference position of the #3 cylinder, since it should be the ignition reference position of the #2 cylinder, the process advances to step 98 and this time T a tm2 to y2TREE
is set, and other settings are made in accordance with the delay of 1806.

As described above, target timing time Tatml=Tatm
3 is updated and set as the time until the next fuel setting target timing for each cylinder based on the latest TREF (engine rotational speed N) every time the crank angle sensor 15 outputs the reference angle signal REF. It is. Therefore, the target timing time for one cylinder is defined as the time from when the first reference angle signal REF of engine operation is output until the next intake BDC, and then
It decreases with the passage of time, and when the reference signal REF is outputted again, it becomes zero at the intake BDC of that cylinder while being corrected to increase or decrease according to the engine rotational speed N at that time.

The target timing times Tatml to Tatm3 (ms) for each cylinder, which are updated and set for each reference angle signal REF in the routine shown in the flowchart of FIG. 8, are counted down according to the routine shown in the flowchart of FIG. 9, respectively.

The routine shown in the flowchart of FIG. 9 is executed every ll1lS, which is the minimum unit of the target timing time Tatml to Tatm3 (ms), and in step 101, each Tatml to Tatm3 to III
New value after subtracting IS from Tatml~T a tn+
3, and each time this routine is executed, the target timing times Ta tml to Ta tm3 (m
s) is decreased by 1 ms, and the target timing time Tatml=Tatm3 (
ms) sequentially represents the time until the target timing. - In this way, according to the flowchart in Fig. 8, each reference angle signal REF is updated based on the latest engine rotational speed N, and is then subtracted every 1 ms to set the value for each cylinder from the current time to the fuel setting target timing. T indicating time
atml~T a tm3 is the above-mentioned interrupt injection amount y
11 to y44 and the normal injection addition amount y, to y, and is used to calculate and set the normal injection addition amount y, to y, and perform correction control of fuel supply according to the response delay of fuel control due to engine transient operation for each cylinder.

Also, in the next step 102, the count value cnt (free run counter) is incremented by 1, and this count value cn
t is the end of normal injection (when the drive pulse signal is OFF) Ti
At end, cn to La is set, and at step 22, cntota is compared with the latest count value ant to determine whether or not it is immediately after normal fuel injection.

In this embodiment, the basic fuel injection amount Tppb in normal sequential injection control is calculated based on the intake pressure PB detected by the intake pressure sensor 9, but instead of the intake pressure sensor 9, An air flow meter such as a hot wire type that detects the intake air flow rate Q may be provided, and the basic fuel injection tTp may be calculated based on the intake air flow IQ.

<Effects of the Invention> As explained above, according to the present invention, there is provided a multi-cylinder internal combustion engine configured to individually control the opening of the fuel injection valve provided for each cylinder in synchronization with the intake stroke of each cylinder. An electronically controlled fuel injection device that, when normal injection is not performed at the first time of acceleration determination, interrupts and supplies fuel set according to the acceleration driving state to the cylinder after normal injection, In a device configured to correct response delay of fuel supply control during acceleration, a correction amount corresponding to the operation delay of the fuel injector is set according to the voltage of the power supply for opening the fuel injection valve, and the correction amount is adjusted to the correction amount. Based on this, the injection amount is increased based on the acceleration state. This prevents the injection of less fuel than the set amount due to an invalid injection amount due to a delay in the operation of the fuel injector, and allows fuel injection to be accurately set according to the response delay of fuel control during acceleration. The amount of fuel can actually be injected and supplied to the engine via the fuel injection valve, and the amount of fuel to be supplied for correcting response delay during acceleration can be managed with high precision.

In addition, in the first interrupt injection of acceleration determination performed as described above, if the predetermined time corresponding to the operation delay time of the fuel injector is from the end of the opening operation control of the fuel injector in normal fuel injection, the acceleration operation is performed. Since the injection amount set according to the condition is not corrected based on the power supply voltage mentioned above and is injected in an interrupt manner, the injection amount is incremented to correspond to the delay in the operation of the fuel injection valve when the interrupt injection is performed following the normal injection. It is possible to prevent unnecessary fuel increase correction from injecting and supplying more than the necessary amount of fuel when it is not necessary.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a system schematic diagram showing an embodiment of the present invention, FIGS. 3 to 9 are flowcharts showing control details in the above embodiment, and FIG. 10 11 is a time chart showing characteristics of injection control performed during acceleration in the above embodiment, and FIG. 11 is a time chart showing an example of conventional injection control during acceleration. Engineering...i section 7...Throttle valve 8...Throttle sensor 9...Intake pressure sensor 10...
・Fuel injection valve 11...control unit ]5
... Crank angle sensor 20 ... Battery patent applicant Japan Electronics Co., Ltd. Agent Patent attorney Fujio Sasashima

Claims (2)

[Claims] (1) A sequential system in which fuel injection valves are provided for each cylinder, and these fuel injection valves are individually opened at a predetermined injection start time to perform normal fuel injection in synchronization with the intake stroke of each cylinder. In an electronically controlled fuel injection device for a multi-cylinder internal combustion engine, the electronically controlled fuel injection device for a multi-cylinder internal combustion engine includes: an acceleration operation state detection means for detecting an acceleration operation state of the engine; and an increased fuel amount during acceleration according to the detected acceleration operation state. a voltage-corrected fuel amount setting means for setting a voltage-corrected fuel amount corresponding to an operation delay of the fuel injector in accordance with the voltage of the power supply for opening the fuel injector; Acceleration injection amount voltage correction means for increasing and setting the increased fuel amount during acceleration based on a set voltage corrected fuel amount, and non-opening operation control of the fuel injection valve by the sequential fuel supply control means at the first time of detection of acceleration operation. interrupt fuel injection by outputting a drive signal corresponding to the increased fuel amount during acceleration corrected by the acceleration injection amount voltage correction means to the fuel injection valve provided in the cylinder immediately after the normal fuel injection. What is claimed is: 1. An electronically controlled fuel injection device for a multi-cylinder internal combustion engine, characterized in that an electronically controlled fuel injection device for a multi-cylinder internal combustion engine is provided. (2) When the time when the drive signal is output by the acceleration interrupt injection control means is within a predetermined time corresponding to the operation delay time of the fuel injector from the end of the opening operation control of the fuel injector in normal fuel injection, the acceleration voltage correction avoidance means for outputting a drive signal corresponding to the increased fuel amount during acceleration set by the increased fuel amount during acceleration set by the increased fuel amount during acceleration instead of the increased fuel amount during acceleration corrected by the increased fuel amount during acceleration set by the increased fuel amount during acceleration setting means; 2. An electronically controlled fuel injection system for a multi-cylinder internal combustion engine according to claim 1.