JPH07103025A - Start-time fuel injector for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent rich misfire or degradation in emission in a start-time fuel injector for asynchronous fuel injection at the time of starting. CONSTITUTION:The start-time fuel injector for internal combustion engine is provided with a fuel injection valve A1, an asynchronous fuel injection means A2 for carrying out asynchronous injection for all of the cylinders at the time of starting, an asynchronous fuel injection detection means A3 for detecting the starting time and the finishing time of asynchronous fuel injection at the time of first cylinder judgment after the starting, and a cylinder condition detection means A4 for detecting a cylinder, for which the starting time of detected asynchronous fuel injection is in a suction stroke. A synchronous fuel injection means A5 for carrying out synchronous injection after the second suction stroke after the starting, and an injection fuel reduction means A6 are also provided, by which first synchronous fuel injection quantity after asynchronous injection is reduced corresponding to the asynchronous fuel injection time period from the engine starting to the first suction stroke, when both of the starting time and the finishing time of asynchronous fuel injection are not in the suction stroke of the same cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting fuel injection device for an internal combustion engine, and more particularly to a starting fuel injection device configured to perform asynchronous fuel injection to all cylinders during starting.

[0002]

2. Description of the Related Art In recent years, computerization of internal combustion engine control (engine control) has progressed, and the amount of fuel supplied to the engine is calculated by a microcomputer based on the operating state of the engine to control the valve opening time of the fuel injection valve. As a result, an electronic fuel injection amount control device that drives the engine in an optimal state is widely used.

In the electronic fuel injection amount control device as described above, the intake air amount usually detected by an air flow meter or the like and the engine speed detected from the engine speed signal input from the distributor are used. The fuel injection amount (fuel injection time) is calculated by making various corrections to the basic fuel injection amount (basic fuel injection time) calculated based on the signal corresponding to the engine state input from sensors installed in each part of the engine. Has been decided.

Further, generally, an engine having a plurality of cylinders and a fuel injection valve for each cylinder is known. In an engine having a plurality of cylinders, intake, compression, explosion, and exhaust processes are repeatedly performed for each cylinder, and fuel injection is performed in synchronization with these processes.

The microcomputer discriminates the process of each cylinder based on the engine speed signal and the cylinder discriminating signal sent from the distributor every 30 ° CA or 360 ° CA, for example, before the intake process for each cylinder. Then, the fuel injection valve is opened and fuel injection is performed for the fuel injection time calculated as described above (fuel injection performed in this manner is referred to as synchronous fuel injection).

On the other hand, in addition to the normal synchronous fuel injection described above, there is an engine configured to inject fuel only once to a plurality of cylinders simultaneously after detecting the start time from a starter signal. The fuel injection that is carried out as described above is called asynchronous fuel injection). By performing this asynchronous fuel injection, it is possible to improve the startability of the engine even in a state in which cylinder discrimination cannot be performed immediately after the engine is started. Then, after the asynchronous fuel injection is completed, the synchronous fuel injection is sequentially started from the cylinders in which the synchronization is obtained.

FIG. 8 shows an example of a process diagram of an engine provided with a starting-time fuel injection device configured to perform asynchronous fuel injection. In the drawing, the valve open state of the fuel injection valve (in this example, a 4-cylinder engine is shown, which is shown by # 1 to # 4) arranged in each cylinder, the engine speed signal (NE signal),
And cylinder discrimination signals (G1 signal, G2 signal) are also shown.

As shown in the figure, in an engine configured to perform asynchronous fuel injection, cylinder discrimination is performed and synchronous fuel injection is performed in order to shorten the starting time (that is, to improve the startability). Before the fuel injection is started, the amount of fuel necessary for the start is simultaneously injected into all the cylinders.
However, in the engine of this configuration, like the # 1 cylinder and the # 2 cylinder, there are cylinders in which the asynchronous fuel injection and the synchronous fuel injection are overlapped before the intake stroke at the timing when the asynchronous fuel injection is executed. Rich, there is a risk of misfire and worsening of emulation.

As a starting fuel injection amount control device which takes measures to solve this problem, there is one disclosed in Japanese Patent Laid-Open No. 3-54337. FIG. 6 shows a process chart of the engine disclosed in Japanese Patent Laid-Open No. 3-54337.

An engine equipped with the fuel injection amount control device at start-up disclosed in the above publication stores the NE signal counts at the start and end of asynchronous fuel injection by coefficienting the NE signal from the start. After the cylinder discrimination, this NE signal number is calculated back from the current crank position to calculate the crank positions at the start and end of the asynchronous fuel injection. Then, the cylinder in which the intake process is first ended after the asynchronous fuel injection is started is determined, and when the end of the first intake process is after the end of the asynchronous fuel injection, the cylinder in which the synchronous fuel injection is started is defined as this cylinder. By doing so, it is configured to prevent the asynchronous fuel injection and the synchronous fuel injection from overlapping.

When the end of the first intake stroke is before the end of the asynchronous fuel injection, the asynchronous fuel injection is performed across the strokes in each cylinder (for example, from the intake stroke in one cylinder to the compression stroke, the next cylinder). In this case, the process from the exhaust to the intake process) is performed, and in this case, the starting cylinder of the synchronous fuel injection is performed from the cylinder next to this cylinder.

[0012]

However, in the above-described conventional starting fuel injection device, the crank position at the time of starting is TDC (Top Dead Center) or BTDC (Bef).
ore Top Dead Center), there is a cylinder in which asynchronous fuel injection at startup is performed from the intake stroke to the compression stroke (the cylinder # 1 in FIG. 7 corresponds to this). In this case, the # 1 cylinder is not supplied with the fuel required for the initial explosion, which causes a lean misfire.

Further, since the synchronous fuel injection is started from the # 3 cylinder, the fuel supplied for the second explosion in the # 1 cylinder is only the residual amount of the asynchronous fuel injection, which causes a lean misfire. Even if the control is changed to set the synchronous fuel injection start cylinder to the # 1 cylinder, the supply fuel of the second explosion in the # 1 cylinder is the amount obtained by adding the synchronous fuel injection amount to the residual amount of the asynchronous fuel injection, On the contrary, there was a problem that it caused a rich misfire and worsened emission.

The present invention has been made in view of the above points, and an object of the present invention is to provide a starting-time fuel injection device for an internal combustion engine, which can shorten the starting time and prevent rich misfires and emission deterioration. To do.

[0015]

FIG. 1 shows the principle of the present invention.

As shown in the figure, in order to solve the above problems, in the present invention, a plurality of fuel injection valves (A1) are provided for each cylinder, and at the time of starting when cylinder discrimination cannot be performed, Asynchronous fuel injection means for simultaneously injecting fuel asynchronously to all cylinders (A2), and asynchronous fuel injection detection means for detecting the start time and end time of the asynchronous fuel injection at the time of first cylinder discrimination after engine start ( A3) and a cylinder state detecting means for detecting a cylinder in which the asynchronous fuel injection detected by this asynchronous fuel injection detecting means (A3) is in the intake stroke.
(A4), the synchronous fuel injection means (A5) for injecting fuel by the synchronous fuel injection from the second intake process after the start, and the detection result detected by the asynchronous fuel injection detection means (A3), When both the start and end of injection are not in the intake stroke of the same cylinder, after asynchronous fuel injection depending on the fuel injection time at which asynchronous fuel injection was performed from the time the engine is started until the end of the first intake stroke In the first aspect, the fuel injection amount reducing means (A6) for reducing the fuel injection amount of the first synchronous fuel injection is provided.

[0017]

With the above-described structure of the fuel injection device for starting the internal combustion engine, even if a cylinder in which asynchronous fuel injection is performed from the intake process to the compression process occurs at the time of starting, the compression process of the injected fuel is performed. Since the fuel injection amount of the synchronous fuel injection is reduced according to the amount of fuel to be injected at the time of injection, lean misfire or rich misfire can be prevented from occurring, and the starting time can be shortened and the exhaust gas can be exhausted. Emissions can be improved.

[0018]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 2 shows an internal combustion engine (engine) 1 to which a fuel injection device for starting the internal combustion engine according to an embodiment of the present invention is applied.
It is a principal part block diagram of 0. The engine 10 shown in the figure is a 4-cylinder 4-cycle spark ignition engine mounted on a vehicle, and is controlled by a microcomputer 26 described later.

First, the structure of the engine 10 will be described. In FIG. 2, reference numeral 11 is a throttle valve, and a surge tank 12 and an intake manifold 13 are arranged on the downstream side thereof. The intake manifold 13 is connected to a combustion chamber 15 of the engine body 14 via an intake port 17 and a fuel injection valve 16 is provided. The fuel injection valve 16 is arranged for each cylinder so that a part of the fuel injection valve 16 projects into the intake manifold 13. The fuel injection valve 16 injects fuel to the air flow flowing in the intake manifold 13.

The combustion chamber 15 is connected to a catalyst device (not shown) via an exhaust port 18 and an exhaust manifold 19. A spark plug 20 is provided so that a part thereof projects into the combustion chamber 15. This spark plug 2
The ignition timing of 0 is controlled by the ignition device described later. Reference numeral 21 is a piston, which reciprocates vertically in the drawing.

Reference numeral 22 denotes a rotation angle sensor for detecting the engine speed, which is the shaft 23 of the distributor 23.
The microcomputer 2 detects the rotation of a and outputs an engine speed signal (NE signal) every 30 ° CA, and a cylinder discrimination signal (G1 signal, G2 signal) every 360 ° CA.
Output to 6.

The distributor 23 is the engine 10
By generating an ignition signal in synchronism with the above process and controlling the ignition signal, the high voltage generated in the ignition coil 24 is distributed to each cylinder. The ignition coil 24 is configured to generate a high voltage for igniting the ignition plug 20 in the secondary coil 24b by appropriately setting the energization time of the primary coil 24a and the timing of current interruption.

The operation of the ignition coil 24 is controlled by an igniter 25. Igniter 2
Reference numeral 5 is connected to the microcomputer 26, and based on a control signal from the microcomputer 26, the current of the primary coil 24a of the ignition coil 24 is turned on and off, and the energization time of the primary coil 24a is changed. It has the function of causing.

The microcomputer 26 includes a central processing unit (MPU) 27, a read only memory (ROM) 28 storing a processing program, a random access memory (RAM) 29 used as a work area, and even after the engine is stopped. Backup RAM (B-
RAM) 30, a clock generator 31 for supplying a master clock to the MPU, and the like. The bidirectional bus line 32 has a function of connecting the respective elements configuring the microcomputer 26 to each other and connecting an input port 33 and an output port 34 having a built-in buffer to the respective components. Although the microcomputer 26 is connected to various sensors and devices, only the connection with the configuration necessary for the present invention is shown in the figure.

The microcomputer 26 having such a hardware configuration realizes the asynchronous fuel injection means, the asynchronous fuel injection detection means, the cylinder state detection means, the synchronous fuel injection means, and the injected fuel reduction means by the software processing operation. The fuel injection device for start-up is configured together with the fuel injection valve 16 and the like.

First, the operating principle of the starting fuel injection device according to the present invention will be described with reference to FIG.

As shown in the figure, in the starting fuel injection device according to the present embodiment, fuel is asynchronously injected into each cylinder at the same time (hereinafter referred to as asynchronous fuel injection) in a state where the cylinder discrimination immediately after starting cannot be performed. Is configured to
By performing this asynchronous fuel injection, the starting time is shortened. This asynchronous fuel injection is carried out, for example, 50 ms after the starter switch is turned on.

Now, it is assumed that the asynchronous fuel injection carried out as described above is carried out over two steps in the process of the engine 10. In the example shown in FIG. 4, the first
In the cylinder (# 1 cylinder), asynchronous fuel injection is performed from the intake process to the compression process. Similarly, in the # 3 cylinder, from the exhaust process to the intake process, in the # 4 cylinder, from the explosion process to the exhaust process, and in the # 2 cylinder, Asynchronous fuel injection is performed from the compression process to the explosion process.

As described above, when the asynchronous fuel injection is carried out over two steps, particularly when the asynchronous fuel injection is carried out from the intake step to the compression step, there arises a problem (# in the example shown in FIG. 4). A problem occurs in one cylinder). That is, when the asynchronous fuel injection is performed from the intake stroke to the compression stroke, the fuel injected during the time required for the asynchronous fuel injection intake stroke (indicated by arrow t1 in FIGS. 4 and 5) is in the combustion chamber 15. However, the fuel injected during the compression process of asynchronous fuel injection (indicated by arrow t2 in FIGS. 4 and 5) is not supplied into the combustion chamber 15 but remains in the intake port 17. .

Therefore, in the structure of the conventional starting fuel injection device, when the synchronous fuel injection is started, the residual fuel remaining in the intake port 17 is synchronous fuel injection at the first synchronous fuel injection after the asynchronous fuel injection. The fuel is supplied into the combustion chamber 15 together with the generated fuel, and the air-fuel ratio becomes rich by the amount of residual fuel, resulting in rich misfiring. This is because the amount of fuel to be injected synchronously is determined regardless of the above-mentioned residual fuel, and the amount of fuel to be injected synchronously is set so that complete combustion is possible. When starting,
Various corrections are made to the basic fuel injection amount (for example, an increase at the time of starting), and the injected fuel amount is increased and corrected. Therefore, the influence of the residual fuel is further increased.

Therefore, in this embodiment, when the asynchronous fuel injection is performed from the intake stroke to the compression stroke,
By calculating the residual fuel remaining in the intake port 17, subtracting the residual fuel amount remaining in the intake port 17 from the amount of fuel injected in synchronous fuel injection, and injecting the subtracted fuel amount during synchronous fuel injection, The present invention is characterized in that the residual fuel and the fuel to be synchronously injected are combined so that the fuel injection amount is one time.

Next, a method of calculating the residual fuel amount (TAUB) will be described with reference to FIG. FIG. 5 is an enlarged view of the fuel injection timing and the cylinder process of the # 1 cylinder in FIG.

To calculate the residual fuel amount TAUB, the number of engine speed signals (NE signals) is counted immediately after starting,
The number of NE signals from immediately after the start to the start of asynchronous fuel injection (hereinafter referred to as NES), the number of NE signals from immediately after the start to the end of asynchronous fuel injection (hereinafter referred to as NEE), immediately after the start Until the end of the intake stroke of
The number of E signals (hereinafter referred to as NETT) is obtained.

Of the above-mentioned NE signal numbers, NES and NE
E can be obtained by detecting the start time because the asynchronous fuel injection is started (50 ms after the start) and the asynchronous fuel injection time is predetermined as described above. Further, NETT detects the current crank position after the cylinder discrimination signal (G1 signal in the example shown in FIGS. 4 and 5) is detected, and then the NE signal number (hereinafter referred to as NET) at the time of detecting the current crank position. (Shown) can be divided by the number of NE signals corresponding to one step to obtain a surplus number at the time of the division. In the case of the present embodiment, the crank angle in each step is 180 ° CA, so the number of NE signals corresponding to one step is 6.

As described above, the NE signal number NES immediately after the start until the asynchronous fuel injection starts, the NE signal number NEE immediately after the start until the asynchronous fuel injection ends, and the first intake stroke immediately after the start. When the NE signal number NETT until the end is obtained, the residual fuel amount TAUB can be obtained by the following equation.

TAUB = TAUA × {(NEE-NETT) / (NEE-NES)} ... However, in the formula, TAUA represents the injection amount of the asynchronous fuel injection.

Therefore, in the synchronous fuel injection which is first executed after the end of the asynchronous fuel injection, the residual fuel amount TAUB obtained by the equation from the fuel injection amount (TAU) obtained by the normal fuel injection amount calculation processing is calculated. The subtracted fuel amount is injected into the intake port 17 at the time of synchronous fuel injection. As a result, the residual fuel TAUB remaining in the asynchronous fuel injection and the fuel (TAU-TAUB) injected in the synchronous fuel injection are taken into the intake port 17, and the total intake fuel amount is TAU. be able to. As a result, even if the residual fuel amount TAUB is present, it is possible to reliably prevent the occurrence of rich misfire, and it is possible to shorten the starting time and improve the exhaust emission.

Next, the residual fuel calculation process and the synchronous fuel injection amount calculation process executed by the microcomputer 26 based on the above-mentioned basic principle will be described with reference to FIG.

FIG. 3A is a flow chart showing the residual fuel calculation process when asynchronous fuel injection is performed. When the processing shown in the figure is started, first, in step 10 (in the figure, step is abbreviated as S), each count is initialized. Incidentally, NEC in step 10 indicates the NE signal count number, and NET indicates the NE signal count number at the time of cylinder discrimination. In the following step 12, it is judged whether the NE signal (engine speed signal) is coming from the speed sensor 22. NE
If no signal comes in, the engine 10 has not been started, and the processes in and after step 14 are not performed.

If it is determined in step 12 that the NE signal is coming in, that is, if the engine 10 is started, the NE signal counter number (NEC) is incremented in step 14. In other words, NEC is defined as a counter value whose starting time is counting.

Steps 16 to 20 are the processes for obtaining the NE signal number NES from immediately after the start to the start of the asynchronous fuel injection.

In step 16, it is judged whether NES is 0, and if NES = 0, step 18 is executed.
At, it is determined whether asynchronous fuel injection has started. When it is determined in step 18 that the asynchronous fuel injection has not yet started, the process returns to step 12 and the processes of steps 12 to 18 are repeatedly executed until the asynchronous fuel injection is started. At this time, NEC is incremented by 1 in step 14 by repeating the above process once.

If it is determined in step 18 that asynchronous fuel injection has been performed, the process proceeds to step 20, and the NEC value (the number of NE signal counters) at the time of the affirmative determination in step 18 is NES (asynchronous after start). The number of NE signals until the fuel injection is started) is set. NES is obtained by the above series of processing. When NES is set in step 20, since negative determination is always made in step 16 in the subsequent processing, steps 18 and 20 are bypassed so that NES is not changed.

From step 22 to step 26, N from the start of the engine until the asynchronous fuel injection is completed.
This is a process for obtaining the number of E signals NEE.

At step 22, it is judged whether NEE is 0, and if NEE = 0, step 24 is executed.
At, it is determined whether the asynchronous fuel injection has ended. When it is determined in step 24 that the asynchronous fuel injection has not ended, the process bypasses step 26 and executes the processes of step 28 and subsequent steps.

On the other hand, if it is determined in step 24 that the asynchronous fuel injection has ended, the process proceeds to step 2
N when the determination in step 24 is affirmative
The EC value (the number of NE signal counters) is set as NEE (the number of NE signals from immediately after the start until the end of asynchronous fuel injection). NEE is obtained by the above series of processing.

When NEE is set in step 26, a negative determination is always made in step 22 in the subsequent processing, so that steps 24 and 26 are performed.
The NEC is not changed because it is bypassed. If a negative determination is made in step 24, since NEE is NEE = 0, a negative determination is made in step 34 and the process returns to step 12, and thereafter steps 12 to 24 are performed until the asynchronous fuel injection is completed. The process of is repeatedly performed.

The following steps 28 to 32 are processes for detecting the number of NE signals at the time of cylinder discrimination and the cylinder for which the intake process has been completed at the time of cylinder discrimination.

In step 28, it is judged whether or not NET is 0, and if NET = 0, step 3 is executed.
At 0, it is judged whether or not the cylinder discrimination signal (G1 signal or G2 signal, whichever is earlier) comes in. When it is determined in step 30 that the cylinder discrimination signal does not come in, the process bypasses step 32 and the processes of step 34 and the subsequent steps are executed.

On the other hand, if it is determined in step 30 that the cylinder discrimination signal has arrived, the process proceeds to step 32.
To the NE when the affirmative judgment is made in step 28.
The C value (the number of NE signal counters) is set as NET (the number of NE signals at the time of cylinder discrimination). In step 32, the compression TDC (Top Dead Cent
er) was added to the cylinder number (C), and this is the cylinder number (CS) at which the intake process was completed when the cylinder was determined.
(CS = C + 1). NET and CS are obtained by the above series of processing.

If NET is set in step 32, a negative determination is always made in step 28 in the subsequent processing, so that steps 30 and 32 are performed.
The NET is not changed because it is bypassed. If a negative determination is made in step 30, NET is NET = 0. Therefore, a negative determination is made in step 34 and the process returns to step 12, and from step 12 to step 30 until the asynchronous fuel injection ends thereafter. The process of is repeatedly performed. As described above, by the process of step 34, the processes of steps 12 to 32 are repeatedly executed until NES, NEE, and NET are set.

By the processing from step 10 to step 34, N from immediately after the start until the asynchronous fuel injection is started
The number of E signals NES, the number of NE signals NEE immediately after the start until the end of asynchronous fuel injection, the number of NE signals NET at the time of detecting the current crank position, and the cylinder number CS at which the intake process is completed at the time of cylinder discrimination are obtained. Then the process proceeds to step 36.

Step 36 is a process for obtaining the number of NE signals (NETT) immediately after the start-up until the end of the first intake stroke. As described above, the NE signal number NETT from immediately after the start until the end of the first intake stroke is the current crank when the cylinder discrimination signal (the first pulse of the G1 signal in the example shown in FIGS. 4 and 5) is detected. After the position is detected, the NE signal number NET (see FIG. 5) at the time of detecting the present crank position is divided by the NE signal number (6 in this embodiment) corresponding to one step, and when the division is performed, It can be obtained as a surplus number. A specific calculation formula is shown below.

NETT = {(NET / 6)-(| NET / 6 |)} × 6 However, in the equation, | NET / 6 | corresponds to one step of the NE signal number NET when the current crank position is detected. Shows the quotient when divided by the number of NE signals (6).

When NETT is obtained in step 36, the process proceeds to step 38, and the cylinder number CT at which the intake stroke is first completed after the start of asynchronous fuel injection is calculated (this CT is the starting cylinder of synchronous fuel injection). ).
Specifically, the cylinder number CT at which the intake stroke is first completed after the start of asynchronous fuel injection is obtained by the following equation.

CT = CS- (| NET / 6 |) ... The NE signal number NET from immediately after the start to the end of the first intake stroke by the above steps 36 and 38.
When T and the cylinder number CT at which the intake stroke is first completed after the start of asynchronous fuel injection are obtained, the following step 4
At 0, the NE signal number NEE from immediately after the start to the end of the asynchronous fuel injection is equal to the NE signal number N from immediately after the start obtained in step 36 to the end of the first intake stroke.
It is determined whether it is larger than ETT.

If an affirmative decision is made in step 40,
This is the case where the asynchronous fuel injection is performed across two steps. Therefore, if an affirmative decision is made in step 40, the processing advances to step 42, the residual fuel amount TAUB is calculated based on the above-mentioned equation, and the present processing is ended thereby. On the other hand, if the negative determination is made in step 40, it means that the asynchronous fuel injection is not performed across two steps, and no residual fuel is generated. Therefore, if a negative determination is made in step 40, the residual fuel amount TA
The processing is terminated by setting UB to TAUB = 0. Through the series of processes described above, the residual fuel TAUB and the cylinder CT for which correction for this residual fuel amount TAUB is required
Is required.

FIG. 3B is a flow chart showing a process for reflecting the residual fuel amount TAUB obtained as described above on the synchronous fuel injection. The process shown in FIG.
This is the process performed on the start cylinder CT of the synchronous fuel injection determined in (A).

When the processing shown in the figure is started, first, in step 50, the synchronous fuel injection amount TAU that is normally performed is calculated. In the following step 52, it is determined whether the synchronous fuel injection to be performed this time is the first synchronous fuel injection after the asynchronous fuel injection is performed.

When it is determined in step 52 that the synchronous fuel injection to be performed this time is the first synchronous fuel injection after the asynchronous fuel injection has been performed, the process proceeds to step 54 and is determined in step 50. The residual fuel amount TAUB obtained by the process of FIG. 3A is subtracted from the normal synchronous fuel injection amount TAU, and this is newly set as the first synchronous fuel injection TAUC after the asynchronous fuel injection is performed. On the other hand, if a negative determination is made in step 52, there is no need to make a correction based on the residual fuel amount TAUB, so the process of step 54 is bypassed.

With the above configuration, even if a cylinder (# 1 cylinder in this embodiment) in which asynchronous fuel injection is performed from the intake stroke to the compression stroke occurs at the time of start-up, the fuel amount TAUC for synchronous fuel injection is Asynchronous fuel injection The fuel is injected in the internal compression process, and the fuel injection amount TAU of the synchronous injection is injected according to the residual fuel amount NETT remaining in the intake port 17.
Is reduced by the residual fuel amount NETT. Therefore, the fuel supplied to the fuel chamber 15 at the time of the synchronous fuel injection amount is the sum of the residual fuel amount NETT remaining in the intake port 17 and the fuel amount TAUC for the synchronous fuel injection (that is, TA
U). That is, in the case of this embodiment, the fuel amount (T) corresponding to the hatched portion shown in the compression process in FIG.
AUB) is supplied into the combustion chamber 15 together with the synchronous fuel injection amount TAUC at the time of synchronous fuel injection performed in the exhaust process, and the total fuel amount supplied into the combustion chamber 15 is (TAUB + TAUC = TAU). Become. Therefore, the occurrence of rich misfire can be prevented, the startability can be improved and the exhaust emission can be prevented from being deteriorated.

[0063]

As described above, according to the present invention, even if the cylinder in which the asynchronous fuel injection is performed from the intake stroke to the compression stroke at the time of starting occurs, the injected fuel is injected in the compression stroke. Since the fuel injection amount of the synchronous injection is reduced according to the fuel amount and the fuel is injected, it is possible to prevent the occurrence of lean misfire or rich misfire.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of an engine in which a fuel injection device for start-up according to an embodiment of the present invention is mounted.

FIG. 3 is a flowchart showing a process executed by a starting fuel injection device which is an embodiment of the present invention.

FIG. 4 is a process diagram of an engine in which a startup fuel injection device according to an embodiment of the present invention is mounted.

FIG. 5 is a diagram for explaining a residual fuel calculation method when asynchronous injection is performed in two steps.

FIG. 6 is a diagram showing an example of steps in a conventional engine.

FIG. 7 is a diagram showing an example of steps in a conventional engine.

FIG. 8 is a diagram showing an example of steps in a conventional engine.

[Explanation of symbols]

10 Engine 15 Combustion Chamber 16 Fuel Injection Valve 17 Intake Port 20 Spark Plug 23 Distributor 24 Ignition Coil 25 Igniter 26 Microcomputer TAU: Fuel Injection Amount at Synchronous Fuel Injection TAUA: Fuel Injection Amount at Asynchronous Fuel Injection TAUB: Residual Fuel Amount NES: Number of NE signals from immediately after start to start of asynchronous fuel injection NEE: Number of NE signals from immediately after start to end of asynchronous fuel injection NET: Number of NE signals when the current crank position is detected NETT: Start Number of NE signals immediately after completion of the first intake stroke C: Cylinder number that was compression TDC at the time of cylinder discrimination (0 → # 1 cylinder, 1 → # 2 cylinder, 2 → # 3 cylinder, 3 →
# 4 cylinder) CS: Cylinder number at which the intake process is completed at the time of cylinder discrimination CT: Cylinder number at which the intake process is first completed after the asynchronous fuel injection is started (that is, the cylinder at which synchronous fuel injection is started)

Claims (1)

[Claims] 1. A fuel injection valve provided for each of a plurality of cylinders, an asynchronous fuel injection means for simultaneously and asynchronously injecting fuel into all cylinders at the time of starting when cylinder discrimination cannot be performed, and an engine. The asynchronous fuel injection detection means for detecting the start time and the end time of the asynchronous fuel injection at the time of the first cylinder discrimination after the start, and the start time of the asynchronous fuel injection detected by the asynchronous fuel injection detection means are the intake process. Cylinder state detection means for detecting a cylinder that is present, synchronous fuel injection means for injecting fuel by synchronous fuel injection after the second intake stroke after starting, and the asynchronous fuel based on the detection result detected by the asynchronous fuel injection detection means. When the start and end of injection are not in the intake stroke of the same cylinder, depending on the fuel injection time during which asynchronous fuel injection is performed from the start of the engine until the end of the first intake stroke , Start timing fuel injection system for an internal combustion engine, characterized in that a and injected fuel reduction means to lose weight the fuel injection amount of the initially performed synchronously fuel injection after the asynchronous fuel injection.