JPH02264141A - Method and device for controlling fuel injection - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a fluctuation in an air-fuel ratio between cylinders and at each cycle by a method wherein an intake air amount at each suction stroke of each cylinder is sampled and integrated a plurality of times to detect an intake air amount, which is used as next fuel amount calculating data. CONSTITUTION:In a control unit 15, a cylinder under a suction stroke is discriminated by a cylinder discriminating means A by means of a crank signal, an intake air amount detected at a suction stroke by means of an airflow sensor is sampled a plurality of times and at intervals of a given time and integrated by a detecting means B. The intake air amount is detected as an amount of intake air to the cylinder, and the pulse width of next fuel injection is calculated by a calculating means C, and stored in a memory means D. At a next fuel injection timing based on a crank angle signal, a fuel injection pulse width signal is read from the memory means D, and the injector of the cylinder is driven and controlled through a fuel injection valve drive means E. This constitution prevents production of unevenness in an air-fuel ratio between cylinders and a fluctuation in an air-fuel ratio between cycles.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine fuel injection control method and apparatus.

[Conventional technology]

An example of conventional fuel injection control for an automobile engine will be explained with reference to FIG.

FIG. 13 shows a timing chart in conventional fuel injection control, showing the sampling timing of the intake air amount, the calculation timing of the fuel injection pulse width, the relationship between the engine stroke and the fuel injection timing, etc.

This conventional example is an example of an independent injection method in which fuel injection is performed at independent timing for each cylinder using a multi-point fuel injection (MI) method, and fuel injection for each cylinder is performed during the exhaust stroke as shown in the figure. It is executed in the second half of . In addition, the sampling of the intake air amount is timed, and is sampled in work units of 4 ms (hereinafter referred to as jobs), and the fuel injection pulse width Ti is the intake air amount qa (sampling) sampled in the job every 4 ms. data) is processed (calculated) in a job every 10m5.

Then, fuel injection is performed based on the fuel injection pulse width T i calculated immediately before the fuel injection timing among the fuel injection pulse widths calculated for every 10 m5 job. In addition, intake air amount data q used to calculate the fuel injection pulse width Ti
The latest value of a is taken in when calculating Ti.

For example, the amount of fuel injected into No. 1 cylinder (fuel injection pulse width Ti) is calculated from the intake air amount sampled at point a of the intake stroke of cylinder No. 2, and the amount of fuel injected into No. 3 cylinder. is No. b of the intake stroke of one cylinder
Calculated from the amount of intake air sampled at the point.

In addition, as other conventional examples, Japanese Patent Application Laid-Open No. 5543292
As disclosed in the above publication, there is a method of detecting the intake air amount at intervals of 360 degrees of crank angle and calculating the fuel injection pulse width.

[Problem to be solved by the invention]

By the way, among the conventional technologies mentioned above, the one shown in FIG. 13 calculates the fuel pulse width based on the intake air amount data (sampling data) immediately before the fuel injection timing, so it is difficult to control the fuel injection with good driving response. However, there were the following points that needed to be improved: Firstly, each cylinder has its own individual air intake, so even in steady driving, the cylinder There are variations between them. Therefore, ideally,
It is desirable to use the intake air amount of the own cylinder as the calculation data for the fuel injection pulse width. However, as mentioned above, in this conventional example, since the data is used to calculate the fuel injection pulse width,
It is not possible to supply a fuel injection amount that adapts to variations in intake air amount between cylinders.

Second, since the intake air amount is sampled at predetermined interval jobs and at instantaneous points, a
As shown at points and points b, the timing of sampling during the intake stroke is different, and the level of the intake air amount is also different.

The first and second phenomena described below are the cause of not being able to obtain the amount of injected fuel commensurate with the true amount of intake air, which hinders the improvement of the control accuracy of the air-fuel ratio. Ta. Also, JP-A-5-5-4. 3 2 9 When detecting the intake air amount at intervals of 360 degrees of crank angle as in No. 2,
There was a problem with detection accuracy.

The present invention has been made in view of the above points, and its purpose is to accurately capture the intake air amount based on the calculation data of the amount of injected fuel in each cylinder, and to eliminate variations in the air-fuel ratio between cylinders and The aim is to prevent fluctuations in the air-fuel ratio of the engine, thereby improving fuel efficiency, exhaust gas performance, and drivability.

[Means to solve the problem]

The first means to solve the problem is to invent a method, the content of which is to detect the intake air amount of the engine, and based on this detected value, the amount of fuel injected by the fuel injection valve (the amount of injected fuel is determined by the width of the fuel injection pulse, for example). In an electronically controlled fuel injection system that calculates the amount (including converted values) and executes fuel injection at a predetermined timing, sampling of the intake air amount is performed multiple times at a predetermined time interval for each intake stroke of each cylinder, These sampling values qas. r'T a2...qan is integrated to detect the intake air amount Qan of each cylinder (n is the code indicating which cylinder), and this intake air amount detection value Qan is calculated by detecting the intake air amount. It is characterized in that it is used as fuel amount calculation data for the next fuel injection to be performed in its own cylinder.

In addition, when performing such control, if the fuel injection timing of each cylinder is set at the exhaust stroke stage, there is a time lag between the intake stroke and the exhaust stroke for the cylinder in which the intake air amount was calculated. Therefore, it is preferable to execute this control method during steady driving when the amount of intake air is continuously substantially constant.

The second means of solving the problem takes this point into consideration, and its contents are as follows: During steady running operation, the fuel control method used in the first means of solving the problem described above is adopted.

On the other hand, during transient operation such as acceleration/deceleration, the intake air amount qa of other cylinders in the intake stroke is detected immediately before the fuel injection timing of each cylinder, and this detected value qatI - the cylinder currently targeted for fuel injection It is characterized by being used as fuel amount calculation data.

The third problem solving means is the first. A method different from the second problem solving means is adopted, and its content is to detect the intake air amount of the engine, and based on this detected value, the amount of fuel injected by the fuel injection valve Ti
In an electronically controlled fuel injection system that calculates the amount of air and executes fuel injection at a predetermined timing, the intake air amount of other cylinders in the intake stroke is detected immediately before the fuel injection timing of each cylinder, and this detected value qa is used as the current When using this as fuel amount calculation data for the cylinder targeted for fuel injection (this point is common to the intake air amount detection of the conventional example shown in FIG. 13), and when calculating this injected fuel amount Ti, It has a correction mode, and this correction mode performs sampling of the intake air amount a plurality of times at predetermined time intervals for each intake stroke of each cylinder, and calculates these sampling values qaxr qaz.
...The intake air amount Qa of each cylinder is calculated by integrating qan.
n is determined, and then the average value ΣQa of the intake air amounts of the cylinders is determined, and the deviation of the intake air amount of each cylinder from this average value ΣQa is calculated, and the injected fuel amount Ti is determined based on this deviation value. It is characterized by correction.

Note that the sampling values of the intake air amount of each problem-solving means described above are integrated, for example, by adding the sampling values or by dividing the total value added by the number of sampling times.

The fourth problem-solving means mainly consists of the above-mentioned first problem-solving means. This is an apparatus for the invention of the method of the second problem-solving means, and its contents are explained by referring to the reference numerals of the embodiment shown in FIG. 4. means A for determining which cylinder is in the intake stroke in an electronically controlled fuel injection device for driving and controlling a fuel injection valve by calculating a fuel injection pulse width based on the value; Means B detects the intake air amount Qan of each cylinder by sampling the intake air amount a plurality of times at predetermined time intervals and integrating these sampling values qat+qaz...qan; Fuel injection pulse width T based on the detected quantity Qan
means C for calculating i; and means C for storing the calculated fuel injection pulse width Ti for each cylinder to which fuel is injected; means E for selecting a fuel injection pulse width signal Ti calculated based on the intake air amount detection value Qan of the previous intake stroke from the storage means and driving the fuel injection valve; Features.

The fifth problem-solving means is an apparatus for the invention of the method of the third problem-solving means, and its content is as follows:
To explain with reference to the reference numerals of the embodiment shown in FIG. 9, electronically controlled fuel injection detects the intake air amount of the engine, calculates the fuel injection pulse width based on this detected value, and controls the drive of the fuel injection valve. The device detects the intake air amount qa of other cylinders in the intake stroke immediately before the fuel injection timing of each cylinder, and uses this detected value qa as fuel injection pulse width calculation data for the cylinder currently being injected. Means A for determining which cylinder is in the intake stroke
', means B' that performs sampling of the intake air amount a plurality of times at predetermined time intervals for each intake stroke of each cylinder, and integrates these sampling values qazy qaz...qan to obtain the intake air amount Qan; , calculate the average value ΣQa of the intake air amounts of the cylinders from these intake air amount detection values Qan, and calculate the intake air amount Qa of each cylinder with respect to this average value ΣQa.
means G' for calculating the deviation of n; means F' for determining the operating range of the engine in which the deviation has been calculated; and means F' for determining the engine operating range in which the deviation has been calculated; a storage means D'; and selecting a deviation from the storage means as a correction element based on the detected value qa of the intake air amount of the other cylinder and that matches the current engine operating range among the deviations. means C' for calculating the fuel injection pulse width Tj; means D' for storing the fuel injection pulse width T calculated with correction for each cylinder to be injected; It is characterized by comprising means E' for selecting a fuel injection pulse width signal Ti corresponding to the cylinder to which fuel is currently injected from the storage means D' and driving the fuel injection valve.

[Effect]

According to the first problem solving means, for each intake stroke of each cylinder,
The intake air amount Qan is detected by performing intake air amount sampling multiple times and integrating these sampling values qas, +qa2...qan, so the intake air amount of each cylinder can be measured without variation. . In addition,
The typical sampling integration method used in this control method is to calculate the average value of the sampling values during the intake stroke by adding the sampling values and dividing the total value by the number of samplings.
In addition, the amount of intake air in one intake stroke can also be determined by using a value obtained by adding the sampling value to jli. In this case, when the average value or the added value of the intake air amount is used as the injected fuel amount calculation data, the coefficients of the calculation formula for determining the fuel injection pulse width may be adjusted to the way these are integrated.

In addition, since the intake air amount detection value Qan is used as the next fuel injection data for the cylinder in which this intake air amount was detected (for example, the intake air amount detection value detected in the intake stroke of the first cylinder is The intake air amount detected during the intake stroke of the 6th cylinder will be used as data for the next fuel injection in the 2nd cylinder. Even if there is variation in the amount, the amount of injected fuel can be calculated by capturing the amount of intake air that corresponds to the variation.

Therefore, due to the synergistic effect of the following, it is possible to calculate the fuel injection amount and execute fuel injection control using the intake air amount detection value that is extremely close to the true intake air amount of each cylinder. It is possible to effectively prevent variations in the air-fuel ratio and fluctuations in the air-fuel ratio from cycle to cycle.

Next, according to the second problem-solving means, during steady running operation, the same effect as the first problem-solving means can be expected, and during transient operation, the same conventional method is used instead of the above control method, i.e., Immediately before the fuel injection timing of each cylinder, the intake air amount of other cylinders in the intake stroke is detected, and this detected value is used as fuel amount calculation data for the cylinder that is currently the target of fuel injection. In this way, in the case of transient operation, by changing the intake air amount detection method and fuel amount calculation method from those in steady operation, the fuel injection timing can be set in the exhaust stroke, especially as in the conventional example shown in Fig. 1. This can eliminate delays in responsiveness.

The third problem-solving means is to detect the intake air amount of other cylinders in the intake stroke just before the fuel injection timing of each cylinder, as in the conventional case, when the fuel injection timing is set to the exhaust stroke, for example. This detected value qa is used as fuel amount calculation data for the cylinder currently targeted for fuel injection, but the following correction is performed when calculating the fuel amount.

That is, for each cylinder's intake stroke, sampling of the intake air amount is performed multiple times at predetermined time intervals, and the intake air amount Qan of each cylinder is calculated based on the integrated value of these sampling values qas, +qa2・qan. Then, find the average value ΣQa of the intake air amount between the cylinders, and calculate this average value Σ
The deviation of the intake air amount Qan of each cylinder from Qa is calculated, and the injected fuel amount T is corrected based on this deviation value. That is, the deviation value indicates the degree of variation in each cylinder, and by correcting the amount of injected fuel based on this value, it is possible to obtain the amount of fuel injected that corresponds to the variation in each cylinder. Therefore, according to this fuel injection control method, even if the intake air amount detection value of another cylinder is used as the injected fuel amount calculation data for the own cylinder, the appropriate injected fuel amount is calculated and fuel injection is executed. can do.

The fourth problem-solving means and the fifth problem-solving means are devices for implementing each of the fuel injection control methods described so far.
The fourth problem-solving means will be explained in detail in FIG. 4 in the first embodiment in the Examples section below, and the fifth problem-solving means will be explained in detail in FIG. 9 in the third embodiment. There is, so please refer to this for its effect.

〔Example〕

Embodiments of the present invention will be described based on the drawings.

FIG. 1 is a timing chart of fuel injection control showing a first embodiment of the present invention, FIG. 4 is a block circuit diagram for executing this, and FIG. 5 is a flowchart thereof. Referring to FIG. 3, a fuel supply (injection) system for an engine to which this embodiment is applied will be explained.

In FIG. 2, air enters an air cleaner 1 through an inlet 2, and an air flow meter (for example, a hot wire flow meter) 3. The duct 4 passes through a throttle valve 5 that controls the air flow rate and enters the collector 6. Here, the air is
The cylinders (
cylinder). On the other hand, fuel is sucked and pressurized from the fuel tank 9 by the fuel pump 10, and the fuel is sucked and pressurized from the fuel tank 9 by the fuel damper 11. The fuel passes through a filter 12, is regulated to a constant pressure by a fuel pressure regulator 14, and is injected into the intake pipe 8 from an injector (fuel injection valve) 13.

The output from the air flow meter 3 is sent to the control unit 15.
is input. The control unit 15 receives an output from a throttle sensor 18 that detects the opening of the throttle valve, a signal from a crank angle sensor built into the distributor 16, and the like.

As shown in FIG. 3, this control unit 15 includes an MPU, ROM, RAM, and A/D converter.

Consists of arithmetic devices including input/output circuits,
Predetermined arithmetic processing is performed using the output signal of the distributor, the output signal of the distributor, etc., and the injector 13 is operated based on the result of this calculation, and the required amount of fuel is supplied to each intake pipe 8. The ignition timing is controlled by sending a signal to the power transistor of the ignition coil 17.

Here, detection of the amount of intake air and calculation of the amount of injected fuel in the fuel injection control of this embodiment will be explained with reference to FIGS. 1, 4, and 5.

FIG. 1 shows, as an example, a multi-point fuel injection system (MPI system) in a four-cylinder engine, in which the fuel injection timing is set to the latter half of the exhaust stroke of each cylinder. Here, for convenience of explanation, the explanation will focus on the NO12 cylinder.

The time chart in Figure 1 is executed during steady operation, and the REF signal (reference signal) is generated for each stroke, and the N
o. When the 2nd cylinder enters the intake stroke, plowing occurs based on the REF signal,
During the intake stroke, data qa regarding the intake air amount of the cylinder is collected at a predetermined time interval (2 m s, although this example is a 4 ms job).

6 m s), these sampling values are added, and the added value is divided by the number of samplings N to obtain the intake air amount Q a n of each cylinder. Then, at the time of generation of the next REF signal, this Q a
Calculate the fuel injection pulse width Ti based on n, store the calculation result in a local register, and when the next fuel injection time for the N002 cylinder comes, output the Ti calculation value and execute fuel injection. . The same applies to other cylinders, and the fuel injection pulse width of each cylinder is calculated based on its own intake air amount, and is output at the next fuel injection timing of its own cylinder. In this way, even when the intake air amount detected during the intake stroke of each cylinder is used as data for the next fuel injection of its own cylinder, the intake air amount remains approximately constant during steady operation, so there is no time lag. There are no problems with response delays. Note that during transient operations such as acceleration and deceleration, there are large changes in the amount of intake air from cycle to cycle, so in this case, the fuel injection shown in Figure 1 above is not performed in consideration of the time lag, and in this case, The fuel injection control mode is switched to mode 1-, which is similar to the conventional mode shown in FIG.

When executing the fuel injection control method shown in FIG. 1, the system 11 configuration shown in FIG. 4 is used, and this will be explained with reference to the flowchart shown in FIG. 5. SL in FIG. 5, S2. S3
・represents a step.

Everything from the cylinder discriminating means A to the fuel injection valve driving means E shown in FIG. 4 is constructed in the form of a circuit.

First, as a premise, the intake air amount q is adjusted according to the REF signal.
a. The engine speed Ne is read (Sl), and if the engine is in steady running operation, the cylinder determining means A determines which cylinder is currently in the intake stroke using the crank signal (S2);
Further, the intake air amount detection means B samples the signals qa, .
These sampling values are added and the total value is divided by the sampling number N to obtain the intake air amount Q a n (S3).

Then, based on this Qan, the calculation means C calculates the fuel injection pulse width T] (S4), and this pulse width calculation value is stored in a predetermined address of the storage means (register) D for each cylinder based on the cylinder discrimination signal. It is stored (S5). The fuel injection valve driving means E determines the fuel injection timing from the crank angle signal, and when the timing comes, the storage means reads the corresponding fuel pulse width signal Tj (here, the intake air of the previous intake stroke of the cylinder to which the current injection is to be performed). The fuel pulse width signal calculated based on the selected fuel pulse width signal is selected, and the corresponding fuel injection valve is driven based on the selected fuel pulse width signal (S6).

Figures 6 and 7 show the results of the fuel injection control of this embodiment in Figure 1 and the conventional fuel injection control in the engine, and Figure 6 shows the results between each cylinder. FIG. 7 shows the variation in the air-fuel ratio A/F from cycle to cycle. According to this embodiment, the experimental results shown in FIG. 6 show that the A/F variation between cylinders is reduced to 1/3 of the conventional example, and the experimental results shown in FIG. I was able to improve it to 1/4.

=23 FIG. 8 is a timing chart 1 of fuel injection control showing a second embodiment of the present invention. This example is applied to an MPI system that injects fuel directly into the cylinders, and as shown in the figure, the amount of intake air in each cylinder is detected, the fuel injection pulse width is calculated, and each cylinder is The way in which this is reflected is the same as in the first embodiment, but only the timing of fuel injection is different. That is, in the case of this embodiment, fuel injection is performed in the compression stroke, which is a stroke after the intake stroke, contrary to the case of the first embodiment. This is because it uses an in-cylinder injection system.
This is because fuel can be injected directly into the cylinder. This embodiment can also achieve the same effects as the first embodiment.

9 and 10 show a third embodiment of the present invention, FIG. 9 is a block circuit diagram of the main part of the third embodiment, and FIG. 10 is a flowchart thereof.

In this embodiment, the intake air amount is detected and the fuel injection pulse width is calculated in the first step. It is fundamentally different from the second embodiment,
The content is that, as in the conventional example shown in Fig. 13, the fuel injection timing is set during the exhaust stroke of each cylinder, and during this exhaust stroke, the intake air amount qa of the other cylinders in the intake stroke is controlled for a predetermined period of time. 10 calculated per interval (e.g. 4ms job)
The fuel injection pulse width Tjk is calculated in a job every m5, and fuel injection is executed using Ti data close to the fuel injection timing.Furthermore, when calculating this fuel injection pulse width, the following correction mode is used. It is characterized by having.

This correction mode will be explained with reference to FIGS. 9 and 10. In this correction mode, the fuel injection pulse width is corrected when the cylinder-specific correction region (steady operation) continues.

That is, each time the REF signal is generated, the engine operating range determining means F' reads the engine rotational speed Ne and the intake air amount qa, and determines whether it is in the cylinder-specific correction range (SL, S2).
In the case of the cylinder-specific correction region, the engine operating region is determined from the data Ne and qa, and the cylinder determining means A' determines which cylinder is in the intake stroke based on the crank angle signal (S3).

In addition, the intake air amount detection means B' detects S7. 4ms on S8
Based on this sampling signal, the fuel injection pulse width injection means C' calculates the basic fuel injection pulse width Tp for a predetermined job, and the intake air amount detection means B' Intake air amount sampling value 'TE1 sampled every 4 m s during the intake stroke
11 qa2t...integrate qan (specifically, qa
□Add l'Ta21...qan and divide these by the number of sampling) to calculate the intake air amount Q for each cylinder.
S4 to detect an (n does not indicate which cylinder)
), the deviation calculation means G' calculates these intake air amount detection values Q.
Find the average value ΣQa of the intake air amount of the cylinders from a n, and calculate the intake air amount Qa of each cylinder with respect to this average value ΣQa.
Calculate (K=Qan/ΣQa) for the deviation of n (S
5). Then, the deviation of each cylinder is associated with the signal of the engine operating range determining means F', and the deviation is distinguished for each engine operating range, and stored in the storage means (predetermined register) D.
' (S6). Then, the fuel pulse width calculation means C' calculates the above-mentioned 87. Based on the basic fuel pulse width Tp calculated based on the intake air amount sampling value qa of the intake stroke of other cylinders in S8, and the cylinder currently being injected (
In this embodiment, a deviation corresponding to the cylinder in the exhaust stroke) is selected as a correction element from the storage means D'', and a deviation that matches the current engine operating range is selected as a correction element, and the fuel injection pulse width T
i is calculated (S9). The formula for calculating Ti is: Ti=Tp-COEF-+Ts, where Tp is the basic fuel pulse width, COEF is the open loop correction coefficient, K is the deviation, and Ts is the voltage correction pulse width.

Fuel injection pulse width signal Ti calculated with this correction
is stored in the storage means D' separately for each cylinder to be injected (SIO), and when the fuel injection timing comes, the fuel injection valve drive means selects the cylinder to which fuel is currently injected from the storage means D'. Fuel injection is performed by selecting a corresponding fuel injection pulse width signal Ti. Note that FIG. 11 shows an example of the cylinder discrimination area of this embodiment, and the shaded area is the engine operating area.
Although only two engine operating ranges are shown in the figure, there are actually many engine operating ranges that are subject to correction. FIG. 12 shows how the storage means D'' stores correction (deviation) values for each cylinder and engine operating range as shown in the figure.

These correction data are updated as needed.

According to this embodiment, the intake air amount for calculating the fuel injection pulse width of each cylinder is calculated based on the intake air amount qa during the intake stroke of other cylinders, as in the conventional case. Since the fuel injection pulse width is corrected by taking into account deviations (variations) in the amount of intake air in each cylinder, it is possible to supply each cylinder with the amount of injected fuel that has been corrected in response to the variations in each cylinder. It is possible to eliminate variations in fuel ratio and correct variations in air-fuel ratio between cycles.

In addition, according to each of the above embodiments, with the improvement of air-fuel ratio accuracy, the fuel consumption was reduced by 2.7% compared to the conventional example, and the exhaust gas performance was improved under the operating conditions of -300 mm Hg at 120 Orpm. It was confirmed that HC could be improved by 8.7%. Regarding drivability, a responsive evaluation confirmed that engine speed fluctuations during idling could be reduced by 16.7%, and surges during extremely low-speed driving could be improved.

〔Effect of the invention〕

As described above, according to the present invention, when calculating the fuel injection amount (fuel injection pulse width) of each cylinder, either (1) it is performed using the integrated value of the intake stroke amount of its own intake air amount, or (2)
Alternatively, if the intake air amount detected during the intake stroke of other cylinders is used, the fuel amount is determined by making corrections based on the intake air amount deviation value of each cylinder, so the air-fuel ratio between cylinders is determined. It is possible to prevent variations and fluctuations in the air-fuel ratio from cycle to cycle. In addition, as a result of producing such an effect,
Fuel efficiency, exhaust gas performance, and drivability can be improved.

[Brief explanation of drawings]

FIG. 1 is a timing chart showing a first embodiment of the present invention, FIG. 2 is a configuration diagram of an automobile engine system to which the present invention is applied, FIG. 3 is a control system diagram thereof, and FIG.
A block circuit diagram when performing fuel injection control of the embodiment,
FIG. 5 is a flowchart, and FIGS. 6 and 7 are comparative explanatory diagrams showing the results of engine test 1 of the present invention and the conventional example.
FIG. 8 is a timing chart showing a second embodiment of the present invention, FIG. 9 is a block circuit diagram showing a third embodiment of the present invention,
FIG. 10 is a flowchart, FIG. 11 is a cylinder-by-cylinder correction area diagram showing an example of the engine operating range in terms of the relationship between engine speed and intake air amount, and FIG. 12 is a cylinder-by-cylinder correction register used in the third embodiment. The explanatory diagram, FIG. 13, is a timing chart showing an example of conventional fuel injection control. 3... Air flow meter, 7... Engine, 15... Control unit, 16... Distributor with built-in crank angle sensor, A, A'... Cylinder discrimination means, B. B'...Intake air amount detection means, c, c'...Fuel injection pulse width calculation means (correction means), D, D'...Storage means, E, E'...Fuel injection valve drive means , F'... 工〆〆〆〆〆〆〆〆〆〆〆〆 (〆〆〆〆〆〆) $7

Claims (1)

[Claims] 1. In an electronically controlled fuel injection method that detects the intake air amount of the engine, calculates the amount of fuel injected by the fuel injection valve based on this detected value, and executes fuel injection at a predetermined timing, For each cylinder's intake stroke, the intake air amount is sampled multiple times at predetermined time intervals, these sampling values are integrated to detect the intake air amount of each cylinder, and this detected value of the intake air amount is A fuel injection control method characterized in that the intake air amount is used as fuel amount calculation data for the next fuel injection of the detected cylinder. 2. In an electronically controlled fuel injection system that detects the intake air amount of the engine, calculates the amount of fuel injected by the fuel injection valve based on this detected value, and executes fuel injection at a predetermined timing, the fuel injection timing is adjusted to each cylinder. During steady driving, the intake air amount is sampled multiple times at predetermined time intervals during each cylinder's intake stroke.
The intake air amount of each cylinder is detected by integrating these sampling values, and this detected value of the intake air amount is used as the fuel amount calculation data for the next fuel injection for the cylinder whose intake air amount has been detected. During transient operations such as acceleration and deceleration, the intake air amount of other cylinders in the intake stroke is detected immediately before the fuel injection timing of each cylinder, and this detected value is used to calculate the fuel of the cylinder currently being injected. A fuel injection control method characterized in that the fuel injection control method is used as quantity calculation data. 3. In an electronically controlled fuel injection system that detects the intake air amount of the engine, calculates the amount of fuel injected by the fuel injection valve based on this detected value, and executes fuel injection at a predetermined timing, the fuel injection timing of each cylinder is determined. When detecting the intake air amount of another cylinder that is currently in the intake stroke and using this detected value as fuel amount calculation data for the cylinder that is currently subject to fuel injection, and when calculating this injected fuel amount. has a correction mode, and this correction mode is for each intake stroke of each cylinder.
Sampling the intake air amount multiple times at predetermined time intervals, integrating these sampling values to determine the intake air amount for each cylinder, then finding the average value of the intake air amount for each cylinder, and calculating the amount of intake air from this average value. A fuel injection control method comprising: calculating a deviation in intake air amount of each cylinder, and correcting the injected fuel amount using this deviation value. 4. In any one of claims 1 to 3, the integration of the sampling values of the intake air amount is performed by adding the sampling values or dividing the total value by the number of sampling times. Control method. 5. In an electronically controlled fuel injection system that detects the intake air amount of the engine and calculates the fuel injection pulse width based on this detected value to drive and control the fuel injection valve, it is determined which cylinder is in the intake stroke. and means for detecting the intake air amount of each cylinder by sampling the intake air amount a plurality of times at predetermined time intervals for each intake stroke of each cylinder of the engine and integrating these sampling values. a means for calculating a fuel injection pulse width based on a detected value of the intake air amount; a means for storing the calculated fuel injection pulse width separately for each cylinder to be injected; A fuel injection pulse width signal calculated based on the intake air amount detection value of the previous intake stroke of the cylinder corresponding to the cylinder to which fuel is to be injected is selected from the storage means, and the fuel injection valve is driven. A fuel injection control device comprising: means. 6. In an electronically controlled fuel injection system that detects the intake air amount of the engine, calculates the fuel injection pulse width based on this detected value, and controls the fuel injection valve, the intake stroke is started immediately before the fuel injection timing of each cylinder. Detect the intake air amount of other cylinders located in the cylinder, and set this detected value to be used as fuel injection pulse width calculation data for the cylinder that is currently the target of fuel injection, and in the intake stroke of any cylinder. means for sampling the intake air amount a plurality of times at predetermined time intervals for each intake stroke of each cylinder, and integrating these sampling values to detect the intake air amount for each cylinder; Means for determining the average value of the intake air amount between cylinders from these intake air amount detection values and calculating the deviation of the intake air amount of each cylinder from this average value, and the engine operating range in which the deviation was calculated. means for discriminating the deviation of each cylinder for each engine operating range; and means for storing the deviation of each cylinder separately for each engine operating range, based on the detected value of the intake air amount of the other cylinder, means for calculating the fuel injection pulse width by selecting the deviation from the storage means as a correction element; and means for separately storing the fuel injection pulse width calculated with the correction for each cylinder to be injected;
When the set fuel injection timing comes, the fuel injection pulse width signal corresponding to the cylinder to which fuel is currently injected is selected from the storage means to drive the fuel injection valve. Characteristic fuel injection control device.