JPH1018890A - Electrically controlled fuel injection device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the decrease of an injection pulse width till the accuracy of quantity measurement in a fuel injection valve becomes low caused by a canister purge in a direct injection engine. SOLUTION: While a basic injection pulse width TP corresponding to a target air-fuel ratio is calculated (S1), the basic injection pulse width TP is corrected so as to suppress richness in an air-fuel ratio caused by a canister purge and then a final injection pulse width Ti (S2) is set. During injection control under a relatively lean target air-fuel ratio condition at which injection is performed in a compression stroke (S5) and at the time when the injection pulse width Ti become smaller than a minimum pulse width A (S4), the target air-fuel ratio is forcedly corrected to a relatively rich air-fuel ratio at which the injection is performed in an intake stroke (S6).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronically controlled fuel injection device for an internal combustion engine, and more particularly to an electronically controlled fuel injection device configured to control the amount of fuel injected by a fuel injection valve by an injection pulse width (valve opening time). Related to the device.

[0002]

2. Description of the Related Art Conventionally, a fuel injection valve is driven to open in accordance with an injection pulse width calculated in accordance with operating conditions of an engine, so that an amount of fuel proportional to the injection pulse width is supplied to the engine. A configured electronically controlled fuel injection device is known. Further, there is known a direct-injection gasoline engine which is configured to control the fuel amount by the injection pulse width as described above and configured to inject fuel directly into the combustion chamber of each cylinder.

In the direct-injection gasoline engine, for example, by injecting fuel in the latter stage of the compression stroke, it is possible to suppress the dispersion of the fuel and form a rich mixture sufficient for ignition near the spark plug. Accordingly, stable combustion can be performed even with a mixture having a lean air-fuel ratio (for example, air-fuel ratio = 40) (see Japanese Patent Application Laid-Open No. Sho 60-30420). Also, in such a direct injection gasoline engine, under operating conditions that require output, a relatively rich and homogeneous air-fuel mixture is formed by the intake stroke injection so that the output can be secured.

[0004]

By the way, there is provided an evaporative fuel processing device which adsorbs and collects evaporative fuel generated from a fuel tank in a canister, purges the evaporative fuel adsorbed and collected in the canister into an intake passage and burns the evaporative fuel. In this case, the fuel supplied to the engine by the canister purge enriches the air-fuel ratio and deviates from the target air-fuel ratio.Therefore, the fuel amount injected from the fuel injection valve, that is, the injection pulse width is corrected to be shorter. It is necessary to maintain the target air-fuel ratio.

[0005] However, in the direct injection gasoline engine, when performing lean combustion by injection in the compression stroke, a high injection pressure is required, so that the amount of injection per unit time is large, and the target idle Since the fuel-air ratio is a lean air-fuel ratio of about 40, the requirement for the injection pulse width is originally short. For this reason, when the canister purge is performed in a lean burn state under a condition where the required fuel amount is small, such as an idle state, the linearity of the fuel measurement is reduced by correcting the decrease of the injection pulse width to maintain the target air-fuel ratio. In some cases, it is necessary to shorten the injection pulse width until it is no longer possible to secure the width (FIG. 6).
reference).

The linearity indicates that the fuel amount changes in proportion to the injection pulse width, and that the linearity cannot be ensured indicates that the measurement accuracy of the fuel with respect to the injection pulse width varies. 5). Therefore, if the linearity cannot be ensured due to the correction of the decrease of the injection pulse width due to the canister purge, the injection amount varies and the air-fuel ratio fluctuates, and there is a concern that the operability and the exhaust characteristics are deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and even if a demand for reducing the injection pulse width due to canister purging is generated, the injection pulse width can be reliably maintained within a range where the linearity of fuel measurement can be ensured. It is an object of the present invention to control the air-fuel ratio and thereby to prevent the occurrence of air-fuel ratio fluctuation due to the variation of the injection amount.

[0008]

Therefore, the invention according to claim 1 is configured as shown in FIG. In FIG. 1, a basic injection pulse width calculating means calculates a basic injection pulse width corresponding to a target air-fuel ratio based on engine operating conditions. The pulse width correction means corrects the calculated basic injection pulse width to set a final injection pulse width so as to maintain the air-fuel ratio of the combustion mixture at the target air-fuel ratio.

[0009] The injection control means controls the fuel injection valve based on the final injection pulse width. On the other hand, the target air-fuel ratio correcting means forcibly corrects the target air-fuel ratio to a richer side when the final injection pulse width falls below a preset minimum pulse width.

That is, when the injection pulse width is shorter than the minimum pulse width (A shown in FIG. 5) capable of maintaining the linearity, the target air-fuel ratio is richly corrected to thereby maintain the target air-fuel ratio. The pulse width is increased so that the injection pulse width can be controlled within a range where linearity can be ensured. According to the second aspect of the present invention, the pulse width correction means detects the air-fuel ratio of the combustion mixture of the engine based on the exhaust gas component concentration, and the actual air detected by the air-fuel ratio detection means. Air-fuel ratio feedback means for feedback-correcting the basic injection pulse width so that the fuel ratio approaches the target air-fuel ratio.

According to this configuration, when the air-fuel ratio becomes richer than the target air-fuel ratio due to, for example, canister purging, the air-fuel ratio enrichment is detected by the air-fuel ratio detecting means, and the injection pulse is maintained so as to maintain the target air-fuel ratio. The width will be feedback corrected. According to the third aspect of the present invention, there is provided an evaporative fuel processing device which adsorbs and collects the evaporative fuel generated from the fuel tank in the canister and purges the evaporative fuel which is adsorbed and collected in the canister into the intake passage. However, the basic injection pulse width is corrected based on the vaporized fuel purge control by the vaporized fuel processing device.

In such a configuration, the injection pulse width is subjected to feedforward correction in anticipation of enrichment of the air-fuel ratio due to the canister purge. According to a fourth aspect of the present invention, in the correction control of the basic injection pulse width based on the purge control of the evaporated fuel, the pulse width correcting means may be configured to control the temperature of the engine and the start of the purge in the purge state of the evaporated fuel processing apparatus. The correction degree of the basic injection pulse width is changed based on at least one of the elapsed time and the elapsed time.

That is, since the degree of influence of the canister purge on the air-fuel ratio varies depending on the engine temperature and the elapsed time from the start of the purge, the basic injection pulse width is corrected in accordance with such a change in the degree of influence. In the invention described in claim 5, the fuel injection valve is configured to directly inject fuel into the combustion chamber, while the target air-fuel ratio is set for each operating region of the engine, and A target air-fuel ratio for performing fuel injection in a stroke, and a target air-fuel ratio leaner than the target air-fuel ratio and performing fuel injection in a compression stroke. By forcibly changing the target air-fuel ratio for performing the fuel injection from the target air-fuel ratio for performing the fuel injection to the target air-fuel ratio for performing the fuel injection in the intake stroke,
The target air-fuel ratio is forcibly corrected to the rich side.

In a so-called direct injection type engine, lean combustion with an air-fuel ratio of, for example, about 40 is realized by stratified charge by fuel injection in a compression stroke, while in an operating condition requiring an output, air-fuel mixture is injected by intake stroke injection. When the injection pulse width becomes smaller than the minimum pulse width during lean burn in which fuel injection is performed in the compression stroke, a relatively rich fuel injection is performed in the intake stroke. Thus, the conditions for performing the fuel injection control with the injection pulse width equal to or larger than the minimum pulse width are forcibly created by forcibly switching to the target air-fuel ratio.

In general, when the fuel supply pressure to the fuel injection valve is switched between the fuel injection in the compression stroke and the fuel injection in the intake stroke, the forcible rich correction of the target air-fuel ratio is performed. When switching to the intake stroke injection, it is preferable to switch the fuel pressure as in the case where the target air-fuel ratio is normally switched with a change in the operating conditions. According to a sixth aspect of the present invention, there is provided an evaporative fuel processing device for adsorbing and collecting evaporative fuel generated from a fuel tank in a canister and purging the evaporative fuel adsorbed and collected in the canister into an intake passage, while the target air-fuel ratio A purge air amount correcting means is provided for increasing and correcting the purge air amount in the evaporated fuel processing device when the target air-fuel ratio is forcibly corrected to the rich side by the correcting means.

In order to maintain the target air-fuel ratio with the canister purging, it is necessary to reduce the injection pulse width to the minimum pulse width or less. When the target air-fuel ratio is corrected to a rich side, the purge air amount is increased. In some cases, it is possible to perform the injection control with the minimum pulse width or more. Therefore, the purge air amount is increased to promote the canister purge.

[0017]

According to the first aspect of the present invention, it is possible to prevent the injection pulse width from being equal to or less than the minimum pulse width capable of maintaining the linearity of the fuel metering. This has the effect of preventing the occurrence of fluctuations and maintaining good operability and exhaust properties.

According to the second aspect of the present invention, there is an effect that the actual air-fuel ratio can be maintained at the target air-fuel ratio with high accuracy without causing a variation in the injection amount even when, for example, canister purging is performed. . According to the third aspect of the invention, there is an effect that it is possible to prevent the occurrence of the variation in the injection amount while suppressing the occurrence of the air-fuel ratio deviation due to the canister purge.

According to the fourth aspect of the invention, the basic injection pulse width can be corrected in response to the degree of influence of the canister purge on the air-fuel ratio depending on the engine temperature and the elapsed time from the start of the purge. Accordingly, there is an effect that the occurrence of the air-fuel ratio deviation due to the canister purge can be accurately suppressed. According to the fifth aspect of the present invention, in the direct injection engine in which the lean combustion by the injection in the compression stroke and the combustion at the output air-fuel ratio by the injection in the intake stroke are performed, the lean target air-fuel ratio in the compression stroke injection is minimum. When the pulse width is smaller than the pulse width, the control is switched to the injection pulse control under the relatively rich target air-fuel ratio by the intake stroke injection, so that the variation in the fuel injection amount due to the injection pulse width being smaller than the minimum pulse width is ensured. There is an effect that it can be avoided.

According to the present invention, since the purge air amount is increased in accordance with the rich correction of the target air-fuel ratio, it is possible to promote canister purging while avoiding the occurrence of variation in the injection amount. effective.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a system configuration of the embodiment. A fuel injection valve 2 is provided to face each combustion chamber of the internal combustion engine 1. The fuel injection valve 2 is opened intermittently by an injection pulse signal, and directly injects fuel (gasoline) in an amount proportional to the valve opening time (injection pulse width) into the combustion chamber. The stratified combustion is performed by a direct injection method to the fuel, thereby enabling lean combustion. That is, the engine 1 is a so-called direct injection gasoline engine.

In the engine 1, air adjusted by a throttle valve 4 interposed in an intake passage 3 is sucked, and an air-fuel mixture is formed by the fuel injected from the fuel injection valve 2. The air-fuel mixture is ignited and burned by spark ignition by a spark plug 5, and the combustion exhaust is discharged through an exhaust passage 6. The engine 1 is provided with a fuel vapor treatment device 10 for a fuel tank 9. The evaporative fuel processing apparatus 10 causes an adsorbent such as activated carbon filled in the canister 11 to adsorb and collect the evaporative fuel generated in the fuel tank 9 and purges the fuel adsorbed by the adsorbent. Purge passage 12 for purge air
Is supplied to the intake passage 3 on the downstream side of the throttle valve 4 through the throttle valve 4.

The evaporative fuel in the fuel tank 9 is introduced into the canister 11 through an evaporative fuel passage 14 in which a check valve 13 which opens when the pressure in the fuel tank 9 becomes higher than a predetermined value. The purge passage 12 is provided with a purge valve 15. The canister 11, the purge passage 12, the check valve 13, the evaporated fuel passage 14, and the purge valve 15 constitute an evaporated fuel processing device.

The control unit 16 for controlling the fuel injection by the fuel injection valve 2 and the ignition timing by the spark plug 5 and controlling the canister purge (opening and closing of the purge valve 15) in the evaporative fuel treatment device 10 includes a microcomputer. And performs various controls based on signals from various sensors described later. The following are provided as the various sensors.

The air flow meter 17 detects the amount of intake air from outside air on the upstream side of the throttle valve 4. The crank angle sensor 18 generates a unit angle signal and a reference angle signal for each unit crank angle. Here, the engine rotation speed Ne can be detected by measuring the number of occurrences of the unit angle signal per unit time, or by measuring the generation cycle of the reference angle signal.

The water temperature sensor 19 detects the cooling water temperature Tw of the engine 1.
Is detected. The air-fuel ratio sensor 20 is a sensor that detects the oxygen concentration in the exhaust gas that is correlated with the air-fuel ratio of the combustion mixture to detect the air-fuel ratio, and corresponds to an air-fuel ratio detecting unit. The control unit 16 calculates the basic injection pulse width Tp corresponding to the target air-fuel ratio based on the intake air amount Q detected by the air flow meter 17 and the engine rotation speed Ne (basic injection pulse width calculating means), while cooling. Various correction coefficients CO according to the water temperature, etc., an air-fuel ratio feedback correction coefficient α (air-fuel ratio feedback means) set based on a comparison between the detection result of the air-fuel ratio sensor 20 and the target air-fuel ratio, and a voltage correction according to the battery voltage The final injection pulse width Ti is calculated by correcting the basic injection pulse width Tp with the various correction coefficients CO, the air-fuel ratio feedback correction coefficient α, and the voltage correction Ts (pulse width correction). means). Then, an injection pulse signal having this injection pulse width Ti is output to the fuel injection valve 2 at a predetermined timing, and fuel corresponding to the injection pulse width Ti is injected from the fuel injection valve 2 into the combustion chamber (injection control). means).

The air-fuel ratio feedback correction using the air-fuel ratio sensor 20 makes it possible to suppress the air-fuel ratio from being enriched due to the canister purge and to maintain the actual air-fuel ratio near the target air-fuel ratio (air). Fuel ratio feedback means). In order to suppress the air-fuel ratio from being enriched due to the canister purge, the basic injection pulse width Tp may be corrected by feedforward correction. For example, when the canister purge is performed, the basic injection pulse width Tp is corrected by a predetermined correction coefficient. The configuration may be such that the injection pulse width Tp is reduced and corrected. Preferably, as shown in FIG. 3 or FIG. 4, as soon as the canister purge starts, or as the water temperature representing the engine temperature becomes lower (in other words, as shown in FIG. 3 or FIG. 4). It is preferable that the basic injection pulse width is corrected to be reduced to a greater extent immediately after the engine is started.

Here, the target air-fuel ratio is stored in advance for each operating region divided by the engine load and the rotation speed. On the low load and low rotation side, the target air-fuel ratio is set to about 40 lean air-fuel ratio. At the same time, the injection timing is set during the compression stroke to enable combustion at the lean target air-fuel ratio, and the stratified supply is performed near the spark plug to form a rich mixture sufficient for ignition. ing. On the high-load, high-speed side, the target air-fuel ratio is set to a relatively rich air-fuel ratio (hereinafter referred to as the output air-fuel ratio) sufficient for ignition, and the mixture is homogeneous in the combustion chamber with the injection timing during the intake stroke. Is set to

The pressure of the fuel supplied to the fuel injection valve 2 may be switched according to the switching of the injection timing. In this case, the target air-fuel ratio between the lean air-fuel ratio and the output air-fuel ratio may be changed. Is accompanied by both the switching of the injection timing and the switching of the fuel pressure. By the way, the fuel injection valve 2 is configured so that the injection pulse width (valve opening time) and the actual injection amount are in a proportional relationship by adjusting the supplied fuel pressure, as shown in FIG. When the pulse width becomes equal to or less than the predetermined minimum pulse width A, the proportional relationship between the injection amount and the injection pulse width, that is, the linearity is broken, and a constant injection amount cannot be obtained with respect to the injection pulse width. Will happen.

In particular, in the direct injection type engine according to this embodiment,
In a state where the target air-fuel ratio is set to a lean air-fuel ratio of about 40, when the canister purge is performed and the operation conditions such as the idling operation and the amount of intake air are small, the injection pulse width may be smaller than the minimum pulse width A. (See FIG. 6). Therefore, control unit 16
Controls the injection pulse width Ti so as not to fall below the minimum pulse width A as shown in the flowchart of FIG.

In the flowchart of FIG. 7, first, in step 1 (indicated as S1 in the figure, the same applies hereinafter), a basic injection pulse width Tp corresponding to the target air-fuel ratio is calculated (basic injection pulse width calculating means). In the next step 2,
The basic injection pulse width Tp is corrected by the various correction coefficients CO, the air-fuel ratio feedback correction coefficient α, the voltage correction Ts, and the like to calculate the final injection pulse width Ti (pulse width correction means). Here, instead of the correction by the air-fuel ratio feedback correction coefficient α, or together with the correction by the correction coefficient α, the feedforward correction of the injection pulse width for the above-described canister purge may be executed. .

In step 3, it is determined whether or not the canister purge is being executed.
Then, it is determined whether or not the final injection pulse width Ti is smaller than the minimum pulse width A. If it is determined in step 4 that the final injection pulse width Ti is smaller than the minimum pulse width A, the process proceeds to step 5 and determines whether the current target air-fuel ratio is a lean air-fuel ratio for performing the compression stroke injection. It is determined whether or not.

If the injection pulse width Ti <A and the target air-fuel ratio = the lean air-fuel ratio (the target air-fuel ratio of the compression stroke injection) during the canister purge, the routine proceeds to step 6.
Even if the current operating condition is a condition in which the compression stroke injection is to be performed with the lean air-fuel ratio as the target air-fuel ratio, the processing for forcibly switching the target air-fuel ratio to the output air-fuel ratio is performed (target air-fuel ratio correcting means).

When the target air-fuel ratio is switched from the lean air-fuel ratio to the output air-fuel ratio in step 6, the injection timing is normally changed in the same manner as when the lean air-fuel ratio is switched from the lean air-fuel ratio to the output air-fuel ratio based on the operating conditions. Is also switched from the compression stroke to the intake stroke, and further, when the fuel pressure is switched at the time of the normal switching of the target air-fuel ratio,
It is assumed that the switching of the fuel pressure is also performed along with the switching of the target air-fuel ratio in step 6.

If the target air-fuel ratio is forcibly corrected to the rich side as described above, the required fuel amount increases even if there is no change in the operating conditions, and the injection pulse width Ti
Therefore, the injection can be performed by giving a pulse width equal to or larger than the minimum pulse width A (see FIG. 6). Accordingly, it is possible to prevent the injection pulse width Ti from becoming smaller than the minimum pulse width A due to the canister purging, thereby preventing a variation in the injection amount.

In the case where the fuel pressure is not switched together with the switching of the target air-fuel ratio, the above-mentioned step 6 is performed.
When the target air-fuel ratio is switched from the lean air-fuel ratio to the output air-fuel ratio, the fuel pressure may be forcibly reduced. In this case, by enriching the target air-fuel ratio,
The required pulse width increases, and the required pulse width also increases due to a decrease in fuel pressure (see the dotted line in FIG. 5), so that the pulse width can be reliably controlled within a range in which the injection amount variation does not occur. . Further, when the injection pulse width Ti becomes smaller than the minimum pulse width A while controlling the output air-fuel ratio, the required pulse width is increased by forcibly reducing the fuel pressure to increase the injection amount. Fuel injection can be performed with a pulse width that does not cause variation.

When the target air-fuel ratio is corrected to the rich side in step 6, in step 7, the valve opening duty for duty control of the purge valve 15 is forcibly increased, the purge air amount increases, and the canister purge is reduced. It is promoted (purging air amount correcting means). Due to the forcible rich correction of the target air-fuel ratio, a margin for absorbing the air-fuel ratio enrichment caused by the canister purge is increased, and the air-fuel ratio is enriched by the increased purge air without falling below the minimum pulse width A. Therefore, the canister purge can be accelerated.

As described above, after the target air-fuel ratio is forcibly corrected to the rich side, the return to the target air-fuel ratio setting in accordance with the preset target air-fuel ratio map is performed, for example, as follows. It shall be performed when such conditions are met. a. Stop canister purge b. Return of the air-fuel ratio feedback correction coefficient α to near the reference value c. When the elapsed time from the start of the canister purge is equal to or longer than a predetermined time d. When the temperature of the engine exceeds a predetermined temperature e. When the engine load is increased, that is, a to d are for estimating that the evaporated fuel supplied to the engine by the canister purge has been sufficiently reduced (or completely eliminated). Since the target air-fuel ratio can be maintained without significantly reducing the injection pulse width, the injection control can be performed with the pulse width equal to or larger than the minimum pulse width A even if the target air-fuel ratio is returned to the lean air-fuel ratio.

Further, when the engine load increases and changes, more specifically, when the engine is accelerated from the idling operation state, even if the required injection amount increases and the target air-fuel ratio returns to the lean air-fuel ratio, the minimum pulse width does not change. It is possible to control the injection with a pulse width of A or more. However, in order to avoid hunting of the target air-fuel ratio, it is preferable to return to the normal target air-fuel ratio after a lapse of a predetermined time after exiting the idling operation.

In addition to the injection pulse width Ti actually output to the fuel injection valve 2, even after the forcible switching of the target air-fuel ratio, the injection pulse width Ti according to the normal target air-fuel ratio according to the operating conditions is obtained. Is calculated and the injection pulse width T
When it is determined that i has stabilized to the minimum pulse width A or more, the normal target air-fuel ratio may be returned.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of the invention according to claim 1;

FIG. 2 is a system configuration diagram of a direct injection gasoline engine according to the embodiment.

FIG. 3 is a diagram showing a correlation between an elapsed time from the start of purge and a pulse width correction request.

FIG. 4 is a diagram showing a correlation between an engine temperature (water temperature) and a pulse width correction request.

FIG. 5 is a diagram showing linearity characteristics of a fuel injection valve.

FIG. 6 is a time chart showing a correlation among a target air-fuel ratio, a canister purge, and an injection pulse width.

FIG. 7 is a flowchart showing an embodiment of target air-fuel ratio control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Fuel injection valve 3 Intake passage 4 Throttle valve 5 Ignition plug 6 Exhaust passage 9 Fuel tank 10 Evaporation fuel processor 11 Canister 12 Purge passage 13 Check valve 14 Evaporation fuel passage 15 Purge valve 16 Control unit 17 Air flow meter 18 Crank angle Sensor 19 Water temperature sensor 20 Air-fuel ratio sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location F02M 25/08 F02M 25/08 E 301 301U 301J

Claims (6)

[Claims] 1. A basic injection pulse width calculating means for calculating a basic injection pulse width corresponding to a target air-fuel ratio on the basis of engine operating conditions, and said calculation for maintaining an air-fuel ratio of a combustion mixture at a target air-fuel ratio. Pulse width correction means for correcting a basic injection pulse width to set a final injection pulse width; injection control means for controlling a fuel injection valve based on the final injection pulse width; and the final injection pulse Target air-fuel ratio correction means for forcibly correcting the target air-fuel ratio to a richer side when the width falls below a preset minimum pulse width. Electronically controlled fuel injection device for internal combustion engines. 2. An air-fuel ratio detecting means for detecting an air-fuel ratio of a combustion air-fuel mixture of an engine on the basis of an exhaust gas component concentration, and an actual air-fuel ratio detected by the air-fuel ratio detecting means being a target. 2. The electronically controlled fuel injection system for an internal combustion engine according to claim 1, further comprising: air-fuel ratio feedback means for feedback-correcting the basic injection pulse width so as to approach the air-fuel ratio. 3. An evaporative fuel processing device for adsorbing and collecting evaporative fuel generated from a fuel tank in a canister, and purging the evaporative fuel adsorbed and collected in the canister into an intake passage, wherein the pulse width correction means includes: 2. The electronically controlled fuel injection device for an internal combustion engine according to claim 1, wherein the basic injection pulse width is corrected based on purge control of the evaporated fuel by the evaporated fuel processing device. 4. The apparatus according to claim 1, wherein the pulse width correction means is configured to determine whether or not the evaporative fuel processing device is in a purge state based on at least one of an engine temperature and an elapsed time from the start of the purge.
4. The electronically controlled fuel injection device for an internal combustion engine according to claim 3, wherein a correction degree of the basic injection pulse width is changed. 5. The fuel injection valve according to claim 1, wherein said fuel injection valve directly injects and supplies fuel into a combustion chamber, while said target air-fuel ratio is set for each engine operating region, and said fuel is injected during an intake stroke. The target air-fuel ratio to be injected is divided into a target air-fuel ratio and a target air-fuel ratio that is leaner than the target air-fuel ratio and is used to perform fuel injection in a compression stroke.The target air-fuel ratio correction unit performs fuel injection in the compression stroke. The target air-fuel ratio is forcibly corrected to a richer side by forcibly changing the target air-fuel ratio to be performed to a target air-fuel ratio for performing fuel injection in the intake stroke. An electronically controlled fuel injection device for an internal combustion engine according to one of the preceding claims. 6. An evaporative fuel processing device which adsorbs and collects evaporative fuel generated from a fuel tank in a canister and purges the evaporative fuel adsorbed and collected in the canister into an intake passage. 6. A purge air amount correcting means for increasing and correcting a purge air amount in said evaporative fuel treatment device when a target air-fuel ratio is forcibly corrected to a rich side. An electronically controlled fuel injection device for an internal combustion engine according to claim 1.