JP3019577B2 - Starting fuel control method for a multi-cylinder internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting fuel control method for a multi-cylinder internal combustion engine (hereinafter, "internal combustion engine" may be referred to as "engine").

[0002]

2. Description of the Related Art Conventionally, a multi-cylinder internal combustion engine is provided for each cylinder based on a detection signal from a crank position detecting means (crank sensor) for detecting a signal corresponding to a specific crank position of each cylinder. A sequential fuel injection method in which fuel is sequentially supplied from a fuel injection valve (injector) to each cylinder is employed. However, such a sequential fuel injection method is capable of supplying fuel to each cylinder at an optimal timing, and identifies a cylinder on the other hand. There is a need to.

In this case, if only one cylinder (specific cylinder) is identified, the other cylinders can be identified because the ignition order of the cylinders is determined. By the way, when the engine is started, the above-mentioned specific cylinder cannot be identified immediately. Therefore, fuel injection is performed simultaneously on all the cylinders until the specific cylinder is identified (see section a in FIG. 9). When identified, the starting fuel is sequentially supplied to each cylinder (see section b in FIG. 9). At this time, if the engine speed exceeds a predetermined value (for example, about 200 to 300 rpm), the fuel is immediately switched to the normal fuel. (See section c in FIG. 9).

[0004]

However, in the conventional method for controlling the starting fuel of a multi-cylinder internal combustion engine as described above,
Until a specific cylinder is identified, fuel is injected into all cylinders at the same time. Therefore, unnecessary fuel may flow into the exhaust system as it is, thereby causing HC (hydrocarbon) in the exhaust gas.
The components increase.

Further, when a specific cylinder is identified, fuel at the time of starting is sequentially supplied to each cylinder, and when the engine speed exceeds a predetermined value, the fuel is immediately switched to normal fuel. In some cylinders, fuel may not be supplied at the start even once, which may cause a misfire due to a shortage of supplied fuel in the cylinder, and as a result, the HC component also increases in the exhaust gas.

That is, the conventional method of controlling the starting fuel of a multi-cylinder internal combustion engine has a problem that the HC component increases in the exhaust gas. The present invention has been made in view of such a problem, and an object of the present invention is to provide a starting fuel control method for a multi-cylinder internal combustion engine, which is capable of reducing HC components in exhaust gas discharged at the time of engine start. I do.

[0007]

Therefore, a starting fuel control method for a multi-cylinder internal combustion engine according to the present invention is characterized in that the following steps are taken. (1) A first output signal from crank position detecting means for outputting a first pulse signal corresponding to a specific crank position of each cylinder of a multi-cylinder internal combustion engine, and a first output signal having a signal pattern different from the first output signal. The state of the second output signal at the time of rising of the pulse of the first output signal and the state of the falling of the pulse of the first output signal based on the second output signal from the cylinder determining unit that outputs the second pulse signal. If any one of the cylinders is identified at the start of the internal combustion engine by the all-cylinder identification means for detecting which of the cylinders is at the specific crank position from the state of the second output signal, the fuel Starting from the first fuel supply cylinder to be injected, all the cylinders are sequentially supplied with at least one or more predetermined same number of start-up fuels, which is greater than the fuel amount during the normal operation. To go.

[0008] Further, a starting fuel control method for a multi-cylinder internal combustion engine according to the present invention (claim 2) is characterized in that the following steps are taken. (1) A first output signal from crank position detecting means for outputting a first pulse signal corresponding to a specific crank position of each cylinder of a multi-cylinder internal combustion engine, and a first output signal having a signal pattern different from the first output signal. The state of the second output signal at the time of rising of the pulse of the first output signal and the state of the falling of the pulse of the first output signal based on the second output signal from the cylinder determining unit that outputs the second pulse signal. If any one of the cylinders is identified at the start of the internal combustion engine by the all-cylinder identification means for detecting which of the cylinders is at the specific crank position from the state of the second output signal, the fuel Fuel is supplied sequentially from the top fuel supply cylinder to be injected, and during this time,
Even if a complete explosion is determined, at least one or more predetermined same number of times for all cylinders starting from the top fuel supply cylinder
Only the starting fuel which is increased from the fuel amount during normal operation is sequentially supplied.

[0009]

In the above-described method for controlling the starting fuel of a multi-cylinder internal combustion engine according to the present invention (claim 1), the first output signal output by the crank position detecting means corresponding to the specific crank position of each cylinder; If any one of the cylinders is identified by the all-cylinder identifying means at the start of the internal combustion engine based on the first output signal output from the second output signal having a signal pattern different from that of the first output signal, fuel injection should be performed at this time. Starting at the top fueling cylinder and starting at least once for all cylinders
The starting fuel which is increased by the same predetermined number of times as compared with the fuel amount during the normal operation is sequentially supplied.

[0010] In the fuel control method for a multi-cylinder internal combustion engine according to the present invention (claim 2), the first output signal output by the crank position detecting means corresponding to the specific crank position of each cylinder; If any one of the cylinders is identified by the all-cylinder identifying means at the start of the internal combustion engine based on the first output signal output from the second output signal having a signal pattern different from that of the first output signal, fuel injection should be performed at this time. Fuel is sequentially supplied from the leading fuel supply cylinder, and during this time, even if complete explosion is determined by the complete explosion determining means, at least for all cylinders starting from the leading fuel supply cylinder,
The starting fuel that is increased by one or more predetermined same times from the fuel amount during the normal operation is sequentially supplied.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 6 show a starting fuel control method for a multi-cylinder internal combustion engine as an embodiment of the present invention, and FIG. FIG. 2 is a block diagram showing a control system, FIG. 2 is a hardware block diagram of the control system, FIG. 3 is an overall configuration diagram of an engine system in which the present method is implemented, FIG. 4 is a signal waveform diagram for explaining the cylinder identification logic, 5 to 7 are flowcharts for explaining the control procedure, and FIG. 8 is an explanatory diagram of the operation.

FIG. 3 shows an engine system in which the present method is carried out. In FIG. 3, an engine (internal combustion engine) EG has an intake passage 2 communicating with a combustion chamber 1 of the engine.
And the exhaust passage 3, the intake passage 2 and the combustion chamber 1
Are controlled by an intake valve 4, and the exhaust passage 3 and the combustion chamber 1 are controlled by an exhaust valve 5.

The intake passage 2 is provided with an air cleaner 6, a throttle valve 7, and an electromagnetic fuel injection valve (injector) 8 in this order from the upstream side. A catalytic converter (three-way catalyst) 9 and a muffler (muffler) (not shown) are provided. The intake passage 2 has a surge tank 2
a is provided.

Further, the injectors 8 are provided in the intake manifold portion by the number of cylinders. Now, assuming that the engine EG of this embodiment is an in-line four-cylinder engine, four injectors 8 are provided. That is, it can be said that the engine is a so-called multi-point fuel injection (MPI) type multi-cylinder engine. Also, the throttle valve 7
Is connected to the accelerator pedal via a wire cable, so that the opening changes according to the amount of depression of the accelerator pedal, and is further opened and closed by an idle speed control motor (ISC motor). Thus, the opening of the throttle valve 7 can be changed without depressing the accelerator pedal during idling.

With such a configuration, the air sucked through the air cleaner 6 according to the opening degree of the throttle valve 7 is mixed with the fuel from the injector 8 at the intake manifold so as to have an appropriate air-fuel ratio. By igniting the spark plug at an appropriate timing, the fuel is burned to generate engine torque, and then the air-fuel mixture is discharged to the exhaust passage 3 as exhaust gas, and the CO, HC, After the three harmful components of NOx are purified, they are silenced by a muffler and released to the atmosphere.

Further, various sensors are provided to control the engine EG. First, on the intake passage 2 side, an air flow sensor 11, which detects an intake air amount from Karman vortex information, an intake air temperature sensor 12, which detects an intake air temperature, and an atmospheric pressure sensor 13, which detects an atmospheric pressure, are provided at the portion where the air cleaner is provided. The throttle valve is provided with a potentiometer type throttle sensor 14 for detecting the opening of the throttle valve 7, an idle switch 15 for detecting an idling state, and the like.

On the exhaust passage 3 side, an oxygen concentration sensor (air-fuel ratio sensor) 17 (hereinafter, referred to as an air-fuel ratio sensor) for detecting the oxygen concentration (O ₂ concentration) in the exhaust gas is provided upstream of the catalytic converter 9.
Simply O of ₂ sensor 17) is provided. In addition,
As the O ₂ sensor 17, a sensor with a heater or a sensor without a heater may be used. further,
As other sensors, a water temperature sensor 19 for detecting an engine cooling water temperature and a crank angle sensor 21 as a crank position detecting means for detecting a crank angle from a signal corresponding to a specific crank position of each cylinder as shown in FIG. The crank angle sensor 21 also serves as a rotation speed sensor for detecting the engine rotation speed), and a TDC sensor (cylinder determination sensor) 22 as cylinder determination means for outputting a signal for identifying the cylinder is provided in the distributor. I have. The crank angle sensor 21 and the TDC sensor 22 are configured such that the slit plate 100 is sandwiched between a light emitting element and a light receiving element. Four slits for the crank angle sensor of the slit plate 100 are formed at intervals of 90 °. The slit for the TDC sensor on the plate 100 is 3
One is a form made (see Figure 2).

The detection signals from these sensors are input to an electronic control unit (ECU) 23. The ECU 23 is also supplied with a voltage signal from a battery sensor 25 for detecting the voltage of the battery 24 and a signal from a cranking switch 26 or a vehicle speed sensor 20 for detecting the time of starting.

The hardware configuration of the ECU 23 is as shown in FIG. 2. The ECU 23 has a CPU 27 as its main part. The CPU 27 has an intake air temperature sensor 12, an atmospheric pressure sensor 13, a throttle sensor 14, detection signals from the O ₂ sensor 17, the water temperature sensor 19, and the battery sensor 25 are input through the input interface 28 and the A / D converter 30, and the detection signals from the idle switch 15, the cranking switch 26, and the vehicle speed sensor 20. Is input via the input interface 29. Also,
Air flow sensor 11, crank angle sensor 21, TDC
A detection signal from the sensor 22 is directly input to an input port of the CPU 27.

Further, the CPU 27 has a ROM for storing program data and fixed value data via a bus line.
While the RAM 32 and the battery 24 are updated and sequentially rewritten, data is exchanged with the battery backup RAM 33 which is backed up by holding the stored contents while the battery 24 is connected.

The data in the RAM 32 disappears and is reset when the ignition switch is turned off. Further, a fuel injection control signal based on the calculation result by the CPU 27 is output to the four injectors 8 (more precisely, transistors for injector solenoids) via the injection driver 34.

Focusing on fuel injection control (air-fuel ratio control), a control signal for fuel injection calculated by a method described later is output from the CPU 27 to the injector solenoid via the driver 34, and the four injectors 8 are sequentially operated. Although so Yuku so driven, for such a fuel injection control (injector drive time control), ECU 23, as shown in FIG. 1, first, to determine the basic drive time T _B for the injector 8 basic The basic drive time determination means 51 includes information on the intake air amount A from the air flow sensor 11 and the crank angle sensor 21.
Determine the intake air quantity A / N information per engine revolution from the engine speed N information from, is what determines the basic drive time T _B based on this information.

Also, as a result of comparing the output of the O ₂ sensor 17 with the judgment voltage (reference voltage), the engine speed N, the engine load A / N, the engine coolant temperature detected by the water temperature sensor 19, and the intake air temperature sensor 12 A correction means 52 for setting a correction coefficient K according to the detected intake air temperature, the atmospheric pressure detected by the atmospheric pressure sensor 13 and the like is provided. Further, a dead time for correcting the drive time according to the battery voltage is provided. a dead time compensation means sets a (dead time) T _D 53
Is also provided.

[0024] Thus, the basic drive time T _B of the correction coefficient K, the dead time T _D, the normal-time fuel injection time _{T B × K + T D (} = T inj) is adapted to be set. Further, a start-up injection time setting means 54 for setting a start-up fuel injection time Ts (= T _inj ) according to the engine coolant temperature or the like is provided.

A switching means 55 for selectively outputting the normal fuel injection time or the starting fuel injection time is provided, and a control means 61 for controlling the switching of the switching means 55 is also provided. I have. Here, the switching control of the switching unit 55 by the control unit 61 will be described. That is, when all the cylinders are identified by the all-cylinder identifying unit 63 after the engine EG is started, the control unit 61 starts the first fuel supply cylinder (in this case, the first fuel supply cylinder to be subjected to fuel injection at this time). The cylinder that is in the exhaust stroke when the cylinder is identified becomes the first fuel supply cylinder, and therefore the first cylinder that is identified first is the first cylinder. Is that the first fuel supply cylinder is the second cylinder, the first cylinder identified is the third cylinder, the first fuel supply cylinder is the first cylinder, and the first identified cylinder is the fourth cylinder, The first fuel supply cylinder is the third cylinder, and if the first identified cylinder is the second cylinder, the first fuel supply cylinder is the fourth cylinder.
The fuel is supplied sequentially from the first cylinder to the first fuel supply cylinder, and even if the complete explosion is determined by the complete explosion determining means 62 during this time, the fuel is supplied to all the cylinders starting from the top fuel supply cylinder. The switching means 55 is controlled so that the starting fuel is supplied sequentially at least once, and thereafter the normal fuel is supplied sequentially to each cylinder.

The all-cylinder identifying means 63 receives signals from the crank angle sensor 21 and the TDC sensor 22 and detects that each cylinder is at a specific crank position. Sensor 21, TDC
A description will be given of the fact that each cylinder can be identified as being at a specific crank position based on a signal from the sensor 22.

That is, by forming slits for each sensor of the slit plate 100 as shown in FIG. 2, a signal from the TDC sensor 22 [ cylinder identification signal (second
Output signal)] , a signal [ TD from the crank angle sensor 21 ]
C signal (first output signal)] is shown in FIGS. 4 (a) and 4 (b) .
Table 1 shows the signal level of the cylinder identification signal when the TDC signal rises and falls, and the pulse signal becomes as shown in the following Table 1. From the relationship shown in Table 1, each cylinder can be identified. Because That is, since the combination of the signal levels of the cylinder identification signal at the time of the rise and fall of the TDC signal differs for each cylinder, it is possible to identify which cylinder it is.

[0028]

[Table 1]

The complete explosion judging means 62 determines whether the engine speed detected by the engine speed sensor 21 is a predetermined value (2
If it exceeds about 00 to 300 rpm), it is determined that the explosion is complete. Hereinafter, such fuel injection control will be described with reference to flowcharts shown in FIGS.

First, the main routine shown in FIG. 5 will be described. This main routine is started by key-on, but in step A1, the 5 ° confirmation flag is reset.
This means that the control is started after passing through BTDC 5 °. Then, thereafter, in step A2, a counter value (described later) is set to 0, and in step A3, a start mode flag is set.

Thereafter, in step A4, it is determined whether or not the engine speed is equal to or higher than a start completion determination rotational speed. If not, it is determined that the explosion has not yet been completed, and in step A5, a start mode flag is set. Thereafter, in step A4, when the engine speed becomes equal to or higher than the start completion determination rotation speed, it is determined that the explosion has been completed, and
At step A6, it is determined whether or not the cranking switch 26 is on. If the cranking switch 26 is still on, it is determined that the starter motor is in operation. A5 startup processing is performed.

When the cranking switch 26 is turned off, it is determined in step A7 whether or not the starting mode flag has been reset. In A8, it is determined whether the counter value is 4.
Here, it is assumed that the counter value is incremented by one each time the top dead center position of each cylinder is detected by the crank angle sensor 21. A signal indicating that the top dead center position of each cylinder is detected by the crank angle sensor 21 is called a TOP signal.

In this case, if the counter value is not 4, the NO route is taken in step A8, and the start-up process in step A5 is still performed. Thereafter, when the counter value becomes 4, this time at step A9,
Reset the start mode flag. Then, after that, in step A10, the correction coefficient K and the like are calculated from various parameters, and then the processing in step A4 and thereafter is performed.

That is, normally, thereafter, the engine speed is equal to or higher than the start completion determination speed, and the cranking switch 26 is also in the OFF state. Therefore, the YES route is performed in step A4, and the NO route is performed in step A6. Further, in step A7, since the starting mode flag is in the reset state, the process of step A10 is performed by taking the YES route.

By the way, the rising timing of the TDC signal is BTDC 5 °, and the falling timing is
TDC 75 ° and the fuel injection timing is B
Since the TDC is set to 75 °, the cylinder identification signal level at the rise of the TDC signal is determined in a routine executed every 5 ° of the BTDC, and the fall of the TDC signal is executed in the routine executed every 75 ° of the BTDC. The cylinder identification signal level at the time is determined, and the fuel injection control is performed.

First, a description will be given of a routine (BTDC 5 ° interrupt routine) executed by interruption every 5 ° of BTDC. This BTDC 5 ° interrupt routine is as shown in FIG. 6. In step B1, it is determined whether or not the 5 ° confirmation flag is set. If 5 °
If the confirmation flag is not set, step B2
After the 5 ° confirmation flag is set, if it is set, then it is determined in step B3 whether the cylinder identification signal is H. At this time, if the cylinder identification signal is H, the flag CD is set to 1 (step B4), and if the cylinder identification signal is L, the flag CD is set to 0.
(Step B5). After that, the process is called BT
Repeat every 5 ° DC.

Next, a description will be given of a routine (BTDC 75 ° interrupt routine) executed by interruption every 75 ° of BTDC. This BTDC 75 ° interrupt routine is as shown in FIG. 7, and at step C1, 5 °
It is determined whether the confirmation flag is set.
If the 5 ° confirmation flag is not set, return processing is performed. If the 5 ° confirmation flag is set, the counter value (described above) for counting the number of input TOP signals is 4 in step C2. It is determined whether or not the counter value is not 4, and in step C4, the counter value is set to 1
Only increment. If the counter value is 4, the counter value is cleared to 0 in step C3, and then the counter value increment processing in step C4 is performed.

Thereafter, in step C5, the start mode mode is set.
Determine if the lag is set, and if
If the start flag is set,
Then, in step C6, the start according to the engine cooling water temperature or the like is started.
Dynamic fuel injection time Ts (= T _inj) Is set. on the other hand,
If the start mode flag is not set, start
Rather than normal, per engine revolution
(A / N) is calculated (step C7).
A / N to basic drive time T_B(Step C
8), and the above basic drive time T_BBesides the correction factor
K, dead time T_DThe normal fuel injection time T
_B× K + T_D(= T_inj) (Step C)
9).

Thereafter, at step C10, it is determined whether or not the cylinder identification signal is H. That is, it is determined whether or not the cylinder identification signal level at BTDC 75 ° (the cylinder identification signal level at the time of falling of the TDC signal) is H. If T
If the cylinder identification signal level at the fall of the DC signal is H, it is determined in step C11 whether the flag CD is 1 or not. If the cylinder identification signal level at the fall of the TDC signal is L, step C12 is performed. And the flag CD is 1
Is determined.

If YES in step C11, that is, if the cylinder identification signal level at the rise of the TDC signal is H and the cylinder identification signal level at the fall of the TDC signal is H, the identification cylinder is determined from Table 1 above. Is the first cylinder, the data of T _inj is set in the injector driving driver D2 of the leading fuel supply cylinder (second cylinder) to be _subjected to fuel injection at this time, and then the driver D2 is triggered in step C13. (Step C14).

If NO in step C11, that is, if the cylinder identification signal level at the rise of the TDC signal is L
And the cylinder identification signal level at the falling of the TDC signal is H
In the case of (1), since the discriminating cylinder is the fourth cylinder from Table 1, in step C15, the driver D3 for driving the injector of the first fuel supply cylinder (third cylinder) at which fuel injection is to be performed at this time is provided with T _inj . After setting the data, the driver D3 is triggered (step C16).

Further, in the case of YES in step C12, that is, when the cylinder identification signal level at the rise of the TDC signal is H and the cylinder identification signal level at the fall of the TDC signal is L, the identification cylinder is determined from Table 1 above. Is the third cylinder, the data of T _inj is set in the injector driving driver D1 of the leading fuel supply cylinder (first cylinder) in which fuel injection is to be performed at this time, and then the driver D1 is triggered in step C17. (Step C18).

If NO in step C12, that is, if the cylinder identification signal level at the rise of the TDC signal is L
And the level of the cylinder identification signal at the time of the fall of the TDC signal is L
In the case of (1), since the discriminating cylinder is the second cylinder from Table 1, in step C19, the driver D4 for driving the injector of the leading fuel supply cylinder (fourth cylinder) at which fuel injection is to be performed at this time is supplied with T _inj . After setting the data, the driver D4 is triggered (step C20).

Thus, when any one of the first to fourth cylinders is identified by the all-cylinder identifying means 63 at the time of starting the engine, fuel is sequentially supplied from the leading fuel supply cylinder to be injected at this time. Will be supplied. During this period, even if a complete explosion is determined, the starting fuel is supplied at least once to all the cylinders starting from the head fuel supply cylinder by the processing from step A8 to step A5 in FIG. They are supplied sequentially (see section A in FIG. 8).

Thus, when a specific cylinder such as the first cylinder is identified, the starting fuel is sequentially supplied to each cylinder.
On the way, when the engine speed exceeds a predetermined value, compared to the conventional means for immediately switching to the normal fuel, the starting fuel is not supplied even once in some cylinders. There is no danger of misfiring due to a shortage of supplied fuel. As a result, it is also possible to prevent the HC component from increasing in the exhaust gas.

Further, fuel injection is not performed until a specific cylinder such as the first cylinder is identified. When this specific cylinder is identified, the fuel is sequentially injected from the leading fuel supply cylinder to be injected at this time. According to the present embodiment, any cylinder can be identified even when compared with a means for supplying the engine, so that the start is not delayed by up to four strokes.
Thus, there is no delay required for starting.

Even if a complete explosion is determined as described above, starting fuel is sequentially supplied at least once to all cylinders starting from the corresponding leading fuel supply cylinder, and then is returned to normal fuel. Switching is performed (FIG. 8).
Section B). Note that the starting fuel is set as a fuel having a sufficiently rich air-fuel ratio as compared with the normal fuel.

In the above-described embodiment, even if a complete explosion is determined, starting fuel is sequentially supplied to all the cylinders two or more times a predetermined number of times, starting from the corresponding top fuel supply cylinder. The fuel may be switched to the normal fuel. Further, in the above-described embodiment, regardless of the presence or absence of the complete combustion determination, if any cylinder is identified by the all-cylinder identifying means 63, all the cylinders are started from the top fuel supply cylinder at which fuel injection is to be performed at this time. At least one time (including a predetermined number of times or more) may be sequentially supplied to the cylinder at least once, and then switched to the normal fuel.

It is needless to say that the present invention is not limited to a four-cylinder engine, but can be applied to a multi-cylinder engine having an arbitrary number of cylinders provided that a sensor capable of identifying each cylinder is provided.

[0050]

As described above in detail, according to the starting fuel control method for the multi-cylinder internal combustion engine of the present invention, the first pulse signal is output in accordance with the specific crank position of each cylinder of the multi-cylinder internal combustion engine. The first output signal from the crank position detecting means, and the second output signal from the cylinder determining means outputting a second pulse signal having a signal pattern different from the first output signal. From the state of the second output signal at the time of the rising edge of the pulse and the state of the second output signal at the time of the falling edge of the pulse of the first output signal. If any one of the cylinders is identified by the all-cylinder identification means when the internal combustion engine is started, at this time, starting from the leading fuel supply cylinder where fuel injection is to be performed, at least for all cylinders,
One or more predetermined same number of times of the start-up fuel which is increased more than the fuel amount during the normal operation is sequentially supplied (claim 1). When the cylinder is identified, the fuel is sequentially supplied from the leading fuel supply cylinder at which fuel injection is to be performed at this time. Starting at the cylinder, at least once for all cylinders
Since the start-up fuel which is increased from the fuel amount during the normal operation is sequentially supplied (Claim 2), there is no delay in the start-up. Time fuel is sequentially supplied to each cylinder, and when the engine speed exceeds a predetermined value on the way, the fuel at start-up is once at least in some cylinders as compared with the conventional means of immediately switching to normal fuel. Is not supplied, there is no risk of misfiring due to a shortage of supplied fuel in the cylinder, and as a result, there is an advantage that the HC component can be prevented from increasing in the exhaust gas.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a control system of a starting fuel control method for a multi-cylinder internal combustion engine as one embodiment of the present invention.

FIG. 2 is a hardware block diagram showing a control system of a multi-cylinder internal combustion engine starting fuel control method as one embodiment of the present invention.

FIG. 3 is an overall configuration diagram of an engine system for implementing the method.

FIG. 4 is a signal waveform diagram for explaining cylinder identification logic according to the present method.

FIG. 5 is a flowchart illustrating a control procedure according to an embodiment of the present invention.

FIG. 6 is a flowchart illustrating a control procedure according to an embodiment of the present invention.

FIG. 7 is a flowchart illustrating a control procedure according to an embodiment of the present invention.

FIG. 8 is an operation explanatory view of one embodiment of the present invention.

FIG. 9 is an operation explanatory view of a conventional example.

[Explanation of symbols]

1 the combustion chamber 2 the intake passage 2a surge tank 3 exhaust passage 4 intake valve 5 an exhaust valve 6 an air cleaner 7 throttle valve 8 injectors 9 catalytic converter 11 an air flow sensor 12 intake air temperature sensor 13 atmospheric pressure sensor 14 throttle sensor 15 idle switch 17 O ₂ sensor 19 Water temperature sensor 20 Vehicle speed sensor 26 Cranking switch 21 Crank angle sensor (engine speed sensor) as crank position detecting means 22 TDC sensor as cylinder discriminating means 23 Electronic control unit (ECU) 24 Battery 25 Battery sensor 27 CPU 28, 29 Input interface 30 A / D converter 31 ROM 32 RAM 33 Battery backup RAM 34 Injection driver 51 Basic drive time determination means 52 Correction means 53 Dead time compensation Means 54 starting injection time setting means 55 the switching means 61 control means 62 complete explosion determining means 63 all cylinder identifying means 100 slit plate

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-142347 (JP, A) JP-A-59-229026 (JP, A) JP-A-63-314333 (JP, A) 185239 (JP, A) JP-A-3-121237 (JP, A) JP-A-3-63740 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 41/00-41 / 40 F02D 45/00 F02P 5/15

Claims (2)

(57) [Claims] 1. A first output signal from a crank position detecting means for outputting a first pulse signal corresponding to a specific crank position of each cylinder of a multi-cylinder internal combustion engine, and a signal pattern different from the first output signal. The state of the second output signal at the time of rising of the pulse of the first output signal, and the falling of the pulse of the first output signal, based on the second output signal from the cylinder discriminating means for outputting the second pulse signal. When any one of the cylinders is identified at the start of the internal combustion engine by the all-cylinder identifying means for detecting which of the cylinders is at the specific crank position from the state of the second output signal at the time, When starting from the top fuel supply cylinder where fuel injection is to be performed, at least one or more predetermined same times for all cylinders
Usually than the fuel amount at the time of operation it is characterized by sequentially supplying increased amount of starting fuel, starting fuel control method for a multi-cylinder internal combustion engine by a few. 2. A first output signal from a crank position detecting means for outputting a first pulse signal corresponding to a specific crank position of each cylinder of a multi-cylinder internal combustion engine, and a signal pattern different from the first output signal. The state of the second output signal at the time of rising of the pulse of the first output signal, and the falling of the pulse of the first output signal, based on the second output signal from the cylinder discriminating means for outputting the second pulse signal. When any one of the cylinders is identified at the start of the internal combustion engine by the all-cylinder identifying means for detecting which of the cylinders is at the specific crank position from the state of the second output signal at the time, When fuel is sequentially supplied from the leading fuel supply cylinder to be subjected to fuel injection, and during this time, even if complete explosion is determined by the complete explosion determining means, starting from the top fuel supply cylinder and starting with the first fuel supply cylinder, all cylinders are supplied. In contrast, at least one or more predetermined
A start-up fuel control method for a multi-cylinder internal combustion engine, comprising sequentially supplying start-up fuel whose amount has been increased by an equal number of times from the fuel amount during normal operation.