JPH07229437A - Fuel injection control device of internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the starting performance of an internal combustion engine by sufficiently promoting carburetion and atomization of fuel, and preventing plug blushing. CONSTITUTION:This fuel injection control device is provided with a zone judging means (step 202) judging that the engine is in the condition of ordinary zone 204, starting zone 212, or engine stall 222 according to engine speed detected by an engine speed detecting means, and when it is judged to be the ordinary zone 204 by the zone judging means (step 202), fuel is independently injected to each cylinder (step 204-210). When it is judged to be the starting zone 212 by the zone judging means (step 202), fuel is injected independently to each cylinder, dividing into prescribed times, and in stroke except suction stroke of the engine 8 (step 212-218). When it is judged to be the engine stall 222 by the zone judging means (step 202), fuel injection 224 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for an internal combustion engine, and more particularly to control of fuel injection at the start of the fuel injection device.

[0002]

2. Description of the Related Art Conventionally, as a fuel injection method at the time of starting an internal combustion engine, it is common to use simultaneous injection for each rotation and simultaneous injection for each ignition. For example, Japanese Patent Publication No. 47-10895 is known. The fuel injection method described in this publication is designed to simultaneously inject the cylinders of each cylinder group at injection timings including the intake stroke of the cylinders, so that the injected fuel does not vaporize or atomize. It will be sucked into the combustion chamber as it is, and this insufficiently vaporized and atomized fuel will adhere to the spark plug, causing ignition failure, so-called spark plug fogging is likely to occur, and the internal combustion engine startup failure may occur. I had a problem.

In order to solve such a problem, a fuel injection method as disclosed in JP-A-1-116267 has been proposed. The fuel injection method described in this publication is
The injection is a two-group injection, in which the injection amount sucked in one intake stroke is divided into three injections, and the injection is performed outside the intake stroke. In this way, by injecting the injection amount inhaled in one intake stroke in three times and performing the injection in a period other than the intake stroke, the fuel is sufficiently vaporized and atomized, and the fogging of the plug is prevented. Can be prevented.

[0004]

However, in the fuel injection method as disclosed in Japanese Unexamined Patent Publication No. 1-116267, the injection is divided into two groups, so that the number of divisions for each group is limited, Since the number of divided injections and injections in one cycle is three, there is a problem that the vaporization and atomization of the fuel are not sufficient and the starting performance of the internal combustion engine is not good. Therefore, the present invention has been made in view of the above problems, fuel vaporization of the fuel, sufficiently promote the atomization, and prevent plug fogging, the fuel of the internal combustion engine improved the starting performance of the internal combustion engine An object is to provide an injection control device.

[0005]

According to a first aspect of the present invention, there is provided a fuel injection control device for an internal combustion engine, comprising: a plurality of cylinders; and an engine speed detecting means. When the zone determination means determines whether the zone is a normal zone, a start zone or an engine stall zone according to the engine speed detected by the engine speed detection means, and the zone determination means determines the normal zone. Is a first fuel injection control means for independently injecting fuel into each cylinder, and, if the zone determination means determines that the zone is the start zone, independently injects fuel for each cylinder, and The fuel injection is divided into a predetermined number of times, and a second fuel injection control means for injecting fuel in a stroke other than the intake stroke of the engine; If it is determined is that and a third fuel injection control means for stopping the fuel injection.

Further, in the invention described in claim 2, in the invention described in claim 1, when the zone is judged to be a normal zone after the engine is started in the starting zone, the zone continues for a predetermined time. A fuel injection is independently performed for each cylinder, the fuel injection is divided into a predetermined number of times, and fuel is injected in a stroke other than the intake stroke of the engine. I added it.

According to a third aspect of the present invention, in addition to the first aspect of the invention, first reference signal generating means for issuing a predetermined signal each time the crankshaft of the engine rotates by a predetermined angle, and the engine Second reference signal generating means for generating a predetermined signal every time the crankshaft makes two revolutions, and engine cooling water temperature detecting means for detecting the engine cooling water temperature are added, and the second fuel injection control means is further added. Counting means for counting the number of generations of the predetermined signal by the first reference signal generating means within a period in which the predetermined signal by the second reference signal generating means disappears and the next predetermined signal is generated; Each time the count value by the means reaches a predetermined count value, injection timing determining means for determining the fuel injection start timing in the cylinder corresponding to the count value, and the engine cooling A fuel injection amount determining means for determining the total fuel injection amount for each cylinder based on the engine cooling water temperature by the water temperature detecting means, and a total fuel injection amount for each cylinder by the fuel injection amount determining means is divided into a predetermined number of times. It is configured by a divided injection control means for injecting as a result.

Further, in the invention described in claim 4, in the invention described in claim 3, the total fuel injection amount for each cylinder is increased as the engine cooling water temperature detected by the engine cooling water temperature detecting means increases. This is because the decision means was added.

[0009]

In the present invention configured as described above, when the zone determination means determines that the engine is in the starting zone, the fuel injection is divided into predetermined times independently for each cylinder and the intake air of the engine is divided. Since the fuel is injected in a stroke other than the stroke, the number of divided injections for each cylinder can be increased. Then, by increasing the number of divided injections for each cylinder, it becomes possible to sufficiently promote the vaporization and atomization of the fuel, and there is a particular effect that the starting performance of the engine is improved. Further, since the fuel is injected in a stroke other than the intake stroke of the engine, plug fogging can be prevented and ignition failure can be prevented, so that the engine starting performance is improved.

Even if the zone determination means determines that the zone is the normal zone, the start-time injection continuation means performs the fuel injection independently and separately for each cylinder continuously for a predetermined time. Even if the fuel injection is switched to only the independent injection, the engine rotation speed increases to some extent and then the fuel injection is switched to only the independent injection. Therefore, a rapid change in the engine rotation speed can be prevented and the engine rotation speed can be smoothly increased. Therefore, the transition from the starting zone to the normal zone becomes smooth, and a special effect that the riding comfort of a vehicle equipped with such an engine is improved is obtained. Further, since the fuel injection amount determining means for increasing the total fuel injection amount for each cylinder by the engine cooling water temperature detecting means as the engine cooling water temperature is lower is provided, the starting performance is always constant regardless of the engine cooling water temperature. There is a special effect that is obtained.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall construction of an embodiment in which the present invention is applied to a V-type 6 cylinder engine. In FIG. 1, a V-type 6-cylinder engine 10 has one bank 10a arranged in a V-type.
And the other bank 10b. One bank 10a is provided with the first cylinder 11, the third cylinder 13 and the fifth cylinder 15, and the other bank 1b.
The second cylinder 12, the fourth cylinder 14, and the sixth cylinder 16 are arranged at 0b. The ignition order of these six cylinders 11 to 16 is the first cylinder, the second cylinder, the third cylinder according to the cylinder number.
The cylinders, the fourth cylinder, the fifth cylinder, and the sixth cylinder are set to be ignited in this order.

The left and right banks 10a of the engine 10,
A surge tank 30 forming a part of the intake passage 20 is provided between the cylinders 10b, and the intake passage 20 in the surge tank 30 has independent intake passages 21 to 21 for the cylinders 11 to 16.
It is connected via 26. Also, surge tank 30
Is communicated with the intake supply passage 50 at its rear end, and the upstream end of the intake supply passage 50 is connected to the air cleaner 60. Intake air supply passage 50 downstream of the air cleaner 60
An air flow meter 70 that detects the amount of intake air and a throttle valve 80 that throttles the intake passage are provided in the. Further, fuel injection valves (injectors) 91 to 96 are arranged in the independent intake passages 21 to 26 that connect the surge tank 30 and the cylinders 11 to 16, respectively, and these fuel injection valves (injectors) 91 are provided. 9 to 96 are controlled by the control device 100 described later.

Further, a magnet is arranged at a predetermined position of a crank shaft of an engine (not shown), and a first element for detecting a rotation angle of the crank shaft including, for example, a hall element and a magnet pickup is provided in the vicinity of the crank shaft. 1
12 magnetic sensors are arranged. Then, with this first magnetic sensor, a reference signal of one pulse every time the crankshaft rotates by 30 degrees, that is, the first reference signal N
The signal (see FIG. 5) is output. In addition, a magnet is arranged at a predetermined location of a cam shaft of an engine (not shown), and a second magnetic field for detecting a rotation angle of the cam shaft including, for example, a hall element and a magnet pickup is provided near the cam shaft. One sensor is arranged. The second magnetic sensor causes the reference signal of one pulse each time the cam shaft makes one revolution (the crank shaft makes two revolutions), that is, the second signal.
The G signal (see FIG. 5), which is the reference signal of the above, is output.

The control device 100 includes a CPU, ROM, RA
The control device 100 is composed of a well-known microcomputer (not shown) including an M, A / D converter, and various input / output interfaces. The control device 100 includes an air flow meter, an intake air temperature sensor, a water temperature sensor, an O ₂ sensor, an engine. Various sensor outputs such as a rotation speed sensor are input. In addition, as described above, the control device 100 includes
30 ° C for each cylinder 11 to 16 (Crank angle is 3
0 degree) reference signal, that is, the N signal that is the first reference signal, and the reference signal that outputs a signal once every two revolutions of the crankshaft (not shown) of the engine 10, that is,
Various signals such as the G signal and the starter signal, which are the second reference signals, are input.

Now, a processing procedure for the control device 100 to control the fuel injection valves 91 to 96 will be described with reference to the flowchart of FIG. In FIG. 2, step 200
At, the processing operation for controlling the fuel injection valves 91 to 96 is started. In this step 200, when this processing flow is started, the routine proceeds to step 202, and in this step 202, in which zone the fuel injection is performed, that is, the normal zone, the starting zone, or the engine stall state. Determine the zone. This zone determination is performed based on the zone determination processing flow of FIG. 5 described later.

If it is determined in step 202 that the zone is the normal zone, the processing flow for the normal zone is started in the next step 204. When the processing of the normal zone is started, the routine proceeds to step 206, where the engine speed and the intake air amount are read. Next, in step 208, the fuel injection amount is calculated based on the engine speed and the intake air amount read in step 206, and the injection pulse width is determined. Then, the process proceeds to step 210, and in this step 210, the injection method for the normal zone,
Independent injection is performed by injecting each cylinder independently. Since this independent injection is a known injection method, its detailed description is omitted.

If it is determined in step 202 that the zone is the start zone, the process flow of the start zone is started in step 212. When the processing of the start zone is started, the routine proceeds to step 214, where the injection timing is determined. The method of determining the injection timing will be described based on the processing flow for determining the injection timing in FIGS. 6 and 7 described later. Next, in step 216, the engine cooling water temperature is read. After reading the engine cooling water temperature, step 218
Then, in step 218, the independent injection and the divided injection, which are the injection methods in the starting zone, are performed independently for each cylinder. After performing the independent injection and the divided injection in step 218, the process proceeds to step 220. In step 220, independent injection and divided injection are continued for a predetermined time even if the engine rotation speed becomes the rotation speed in the normal zone.

When it is determined that the engine is in the stalled zone in step 202, the processing flow of the engine stalled zone is started in the next step 222. When the processing of the stalled zone is started, the process proceeds to step 224 and this step 224
Stop fuel injection at. These steps 200-2
26 is repeatedly executed.

FIG. 3 shows the relationship between the engine rotation speed and the zone determination. In this figure, the engine rotation speed is 500 (rpm) or less, the start zone, and the engine rotation speed is higher than the normal zone. Shows. Further, it is schematically shown that the independent injection and the divided injection are performed in the starting zone, and the independent injection is performed in the normal zone. Further, it is schematically shown that the independent injection and the split injection are continuously performed while the startup injection continuation counter is operating even when the engine rotation speed in the normal zone is reached. The zone determination method according to the embodiment of the present invention will be described in detail below with reference to FIG.

FIG. 4 shows a processing flow for zone determination according to the embodiment of the present invention. In step 300, the processing flow for zone determination according to the present embodiment is started. Step 3
When the processing flow starts at 00, the routine proceeds to step 302, where the engine rotation speed Ne is a predetermined rotation speed (for example,
(500 rpm) or higher is determined.

If it is determined to be "YES" in this step 302, that is, if it is determined that the engine rotation speed Ne is equal to or higher than a predetermined rotation speed (for example, 500 rpm), the routine proceeds to step 304, at the time of starting. The injection continuation counter (A) is decremented, that is, the starting injection continuation counter (A) is decremented by 1, and it is determined in the next step 306 whether the starting injection continuation counter (A) is "0". . If "YES" is determined in this step 306, that is, if A = 0, the process proceeds to step 308, it is determined to be a normal zone, and FLG1 is set. If "NO" is determined in this step 306, that is, if A ≠ 0, the process proceeds to step 314, it is determined to be the starting zone, and FLG2 is set.

On the other hand, if "NO" is determined in the step 302, that is, if the engine rotation speed Ne is less than a predetermined rotation speed (for example, 500 rpm), the routine proceeds to a step 310, and FLG1 is set. Whether or not, that is, whether or not it is determined as the normal zone is determined. When it is determined to be “NO” in this step 310, the starting injection continuation counter (A) is set to n in step 312.
, And go to the next step 314. In this step 314, it is determined that the injection method is in the starting zone, and FLG2 is set.

When it is determined in step 302 that the engine rotation speed Ne is lower than a predetermined rotation speed (for example, 500 rpm) and FLG1 is set,
That is, when the engine rotation speed Ne becomes equal to or lower than a predetermined rotation speed (for example, 500 rpm) in the normal zone, the process proceeds to step 316. In step 316, the engine rotation speed Ne is the predetermined rotation speed (for example, 300 rpm).
If it is determined that the following is true, the routine proceeds to step 318, where it is determined that the engine is stalled, and the FLG3
Set. Further, in step 316, the engine rotation speed Ne is the predetermined rotation speed (for example, 300 rpm).
When it is determined that the above is the case, the routine proceeds to step 312, where the starting injection continuation counter (A) is set to n as described above.
Then, in step 314, it is determined to be the starting zone, and FLG2 is set. As described above, it is determined whether it is the normal zone, the starting zone, or the engine stall state.

Next, the fuel injection method when it is determined to be in the starting zone will be described. FIG. 5 is a diagram schematically showing the intake stroke, compression stroke, explosion stroke, exhaust stroke, and fuel injection timing for each cylinder. First, fuel injection in the starting zone will be described with reference to FIG.

In FIG. 5, each cylinder 11 of the engine 10
16 to 16 (see FIG. 1) independently perform the intake stroke, compression stroke, explosion stroke and exhaust stroke. At this time, the magnets arranged on the crankshaft of the engine and the first magnetic sensor arranged in the vicinity of the crankshaft cause the first reference signal to be generated once every 30 degrees of rotation of the crankshaft of the engine. To generate the N signal. At the same time, the magnet disposed on the cam shaft of the engine and the second magnetic sensor disposed in the vicinity of the cam shaft each time the cam shaft makes one revolution, that is, the crank shaft makes two revolutions (720). The G signal, which is the second reference signal, is generated at a timing of once every one rotation.

Here, each time the G signal switches from "high" to "low", the cylinders 11 to 16 (see FIG. 1) repeat the strokes of suction, compression, explosion and exhaust. Also,
The control device 100 (see FIG. 1) is provided with an injection timing counter (not shown), and the injection timing counter counts up by 1 each time the N signal switches from “high” to “low”. That is, 0 to 11
Up to, and when the count value reaches 11, the injection timing counter is reset.

In FIG. 5, each of the cylinders 11 to 16 (see FIG. 1) is shown to be injected in a stroke other than the intake stroke. For example, focusing on the first cylinder,
The fuel injection is started at the timing when the intake stroke of the first cylinder is completed, that is, at the timing when the injection timing counter is switched from 2 to 3. When you start to inject fuel,
Split injection is performed based on the flowchart of FIG. 8 described later. Similarly, in the second cylinder, the fuel injection is started and the split injection is performed at the timing when the intake stroke of the second cylinder is completed, that is, the timing when the injection timing counter is switched from 4 to 5. Also,
In the third cylinder, the fuel injection is started and the split injection is performed at the timing when the intake stroke of the third cylinder is completed, that is, the timing when the injection timing counter is switched from 6 to 7. Further, in the fourth cylinder, fuel injection is started at the timing when the intake stroke of the fourth cylinder is completed, that is, the timing when the injection timing counter is switched from 8 to 9, and the split injection is performed.
Further, in the fifth cylinder, the timing at which the intake stroke of the fifth cylinder is completed, that is, the injection timing counter is 10
The fuel injection is started at the timing of switching from 11 to 11, and the split injection is performed. Further, in the sixth cylinder, the timing when the intake stroke of the sixth cylinder is completed,
That is, the fuel injection is started at the timing when the injection timing counter switches from 0 to 1, and the split injection is performed.

The fuel injection in the starting zone of the embodiment of the present invention will be described in detail below with reference to the flow charts of FIGS. 6, 7 and 8. In FIG. 6 and FIG. 7, first, in step 400, the processing flow of the starting zone is started. Then, in step 402, F
It is determined whether LG2 is set, that is, whether the injection method is in the starting zone. If “YES” is determined in step 402, it means that the injection method is at the time of starting, so the process proceeds to the next step 404. Step 40
If it is determined to be "NO" in 2, it is not the injection method at the time of starting, so the routine proceeds to step 460, and this processing flow is repeated. In step 404, it is determined whether or not the level of the G signal (reference signal that outputs a signal once every two revolutions of the engine crankshaft (see FIG. 5)) has switched from "high" to "low". To do. If "YES" is determined in this step 404, that is, it is determined that the level of the G signal is switched from "high" to "low", the process proceeds to the next step 406. If it is determined to be “NO” in step 404, step 4
Go to 08.

Proceeding to step 406, this step 4
At 06, the count value B of the injection timing counter (B) is set to 0 (B ← 0). After setting the count value of the injection timing counter (B) to 0, the process proceeds to the next step 408. In this step 408, N
It is determined whether or not the level of the signal (reference signal for each crank angle of 30 degrees (see FIG. 5)) has switched from “high” to “low”. In this step 408,
When it is determined to be "YES", that is, it is determined that the level of the N signal is switched from "high" to "low", and the process proceeds to the next step 410. In this step 408,
If "NO" is determined, the process proceeds to step 460 and this processing flow is repeated.

In step 410, the count value B of the injection timing counter (B) is set up as (B ← B + 1). Here, if the count value B of the injection timing counter (B) is 0 in step 406 described above,
In this step 410, the count value B becomes 1. Next, in steps 412 to 422, the count value of the injection timing counter (B) is determined. When it is determined to be “YES” in step 412, that is, the count value B of the injection timing counter (B) is 0 to 1 (1 ←
If it is determined that the value has changed to 0), the process proceeds to step 424, and in this step 424, FLG for starting the injection of the sixth cylinder is set (FLG (j) = 6). When FLG is set (FLG (j) = 6), the flow advances to the next step 426 to read the engine cooling water temperature. After reading the engine cooling water temperature, the process proceeds to the next step 428, and the fuel injection amount is calculated based on the engine cooling water temperature and fuel injection amount map of FIG.

When the fuel injection amount is calculated, the next step 4
Proceed to step 60, repeat the above steps, step 4
At 06, the count value B of the injection timing counter (B)
Is set to 1 (B ← 1), and in step 410, the count value B of the injection timing counter (B) is set up, and the count value B is set to 2. Then step 4
12 to 422, but since the count value B of the injection timing counter (B) is 2 here, step 41
It is determined to be "NO" in all steps of 2 to 422, the process proceeds to the next step 460, and the above-mentioned steps are repeated. Next, in step 406, the count value B of the injection timing counter (B) is set to 2 (B ← 2), and in step 410, the count value B of the injection timing counter (B) is set up and the count value B is set. Is 3.

Then, the process proceeds to step 412, where
Since the count value B of the injection timing counter (B) is 3, it is determined to be "NO" in step 412, and the process proceeds to step 414. In this step 414, the count value B of the injection timing counter (B) is 2 to 3
It is determined that the state has changed to (3 ← 2), the determination is “YES”, and the process proceeds to the next step 430. This step 430
In, the FLG for starting the injection of the first cylinder is set (FLG (j) = 1). Set FLG (FL
When G (j) = 1), the process proceeds to the next step 432 and the engine cooling water temperature is read. After reading the engine cooling water temperature, the process proceeds to the next step 434, and the fuel injection amount is calculated based on the engine cooling water temperature and fuel injection amount map of FIG. When the fuel injection amount is calculated, the process proceeds to the next step 460 and the above steps are repeated.

Thereafter, similarly, in step 416,
If it is determined to be "YES", that is, if it is determined that the count value B of the injection timing counter (B) has changed from 4 to 5 (5 ← 4), the process proceeds to the next step 436. In this step 436, FLG for starting the injection of the second cylinder is set (FLG (j) = 2). FLG
Is set (FLG (j) = 2), the next step 4
Proceed to 38 to read the engine cooling water temperature. After reading the engine cooling water temperature, the process proceeds to the next step 440, and the fuel injection amount is calculated based on the engine cooling water temperature and fuel injection amount map of FIG.

If it is determined in step 418 that "YES", that is, if the count value B of the injection timing counter (B) has changed from 6 to 7 (7 ← 6), Go to step 442. This step 44
In 2, the FLG for starting the injection of the third cylinder is set (FLG (j) = 3). Set FLG (F
LG (j) = 3), go to the next step 444,
Read engine cooling water temperature. After reading the engine cooling water temperature, the routine proceeds to the next step 446, and the fuel injection amount is calculated based on the engine cooling water temperature and fuel injection amount map of FIG.

Further, if it is determined in step 420 that "YES", that is, if the count value B of the injection timing counter (B) has changed from 8 to 9 (9 ← 8), Go to step 448 of. This step 44
In 8, the FLG for starting the injection of the fourth cylinder is set (FLG (j) = 4). Set FLG (F
LG (j) = 4), go to the next step 450,
Read engine cooling water temperature. After reading the engine cooling water temperature, the routine proceeds to the next step 452, and the fuel injection amount is calculated based on the engine cooling water temperature and fuel injection amount map of FIG.

If it is determined in step 422 that "YES", that is, that the count value B of the injection timing counter (B) has changed from 10 to 11 (11 ← 10), Go to step 454 of. In this step 454, FLG for starting the injection of the fifth cylinder is set (FLG (j) = 5). When FLG is set (FLG (j) = 5), the next step 456
Proceed to and read the engine cooling water temperature. After reading the engine cooling water temperature, the routine proceeds to the next step 458, and the fuel injection amount is calculated based on the engine cooling water temperature and fuel injection amount map of FIG.

Next, the split injection will be described with reference to the flowchart of FIG. First, in step 500, when the split injection process is started, the process proceeds to step 502. In step 502, the injection valve ON process is performed. Here, the injection valve ON process is performed by the steps 424, 430, 436, 442, 448 and 454 of FIG.
In the condition that FLG (j) = j is set, the injection valve of the cylinder set to FLG (j) = j is turned on for a predetermined time (Ta time (see FIG. 9), for example, 8 ms). It means a process (opening the injection valve). Next, in step 504, injection valve off processing is performed. Here, in the injection valve off process, the injection valve turned on in step 502, that is, the injection valve of the cylinder set to FLG (j) = j is set for a predetermined time (Tc time (see FIG. 9), for example, 4 ms. ) Means turning off (closing the injection valve).

Then, the process proceeds to step 506, where
The fuel injection amount is integrated based on the calculation formula.

[0039]

## EQU1 ## Tb (i) = Tb (i-1) + Ta where Tb (i) is the cumulative amount of fuel injected up to this time (i times), and Tb (i-1) F last time (( i-1)
Is the cumulative amount of fuel injected up to. Further, Ta is the injection amount of this time (i times).

Then, the routine proceeds to step 508, where it is judged whether or not there is a fuel remaining amount. That is, step 42 of FIG.
8, 434, 440, 446, 452, and 458, the difference (Ts-Tb) between the total fuel injection amount Ts obtained in 8 times (i times) and the total fuel injection amount Tb at this time (i times) is the fuel injection amount Ta per time. It is determined whether or not it is larger. If “Yes” is determined in this step 508, that is,
The difference (Ts-Tb) between the total fuel injection amount Ts and the integrated amount Tb of the fuel injected up to this time (i times) is the fuel injection amount T of one time.
When it is smaller than a (Ts-Tb <Ta), it is determined that there is a fuel remaining amount, and the process proceeds to the next step 510.

In step 510, since it is determined in step 508 that there is a remaining fuel amount, the fuel remaining amount injection process is performed, so the flag for starting divided injection is cleared (FLG (j) = 0), and proceeds to the next step 512. In this step 512, a preliminary flag for performing the processing for the remaining fuel amount injection is set (YFLG (j) =
j) Set spare flag (YFLG (j) = j)
After that, the process proceeds to the next step 514, and this step 51
In 4, the injection valve ON process for remaining fuel amount injection is performed. Here, the injection valve ON processing of the remaining fuel amount injection in step 514 is performed by the preliminary flag (YFL) in step 512 described above.
YF is set on condition that G (j) = j) is set.
The injection valve of the cylinder set to LG (j) = j is set to (T
s-Tb) means a process of turning on (opening the injection valve) for a time (fractional number in FIG. 9).

Next, the routine proceeds to step 516, where the injection valve off process for remaining fuel amount injection is performed. Here, in the injection valve off process of the remaining fuel amount injection, the injection valve turned on in step 514, that is, the injection valve of the cylinder set to YFLG (j) = j is turned off (the injection valve is closed). ), The spare flag is erased (YFLG (j) = 0), and the data of the integrated fuel amount Tb is erased. Then, the process proceeds to step 518 and the above-mentioned step 5
Repeat 00 to 516.

If it is determined to be "NO" in step 508, that is, the difference (Ts-Tb) between the total fuel injection amount Ts and the integrated amount Tb of the fuel injected up to this time (i times) is one fuel. When it is larger than the injection amount Ta (Ts-Tb> Ta), it is determined that there is no remaining fuel amount processing, the process jumps to step 518, and steps 500 to 508 described above are repeated.

As described above, in the present embodiment, when it is determined that the starting zone is based on the engine rotation speed, as shown in FIG. 5, in each stroke other than the intake stroke of each cylinder 11-16. Since the fuel is separately injected into the cylinders 11 to 16 by dividing the fuel into a predetermined number of times, it is possible to increase the number of divided injections to the cylinders 11 to 16. Then, by increasing the number of divided injections for each of the cylinders 11 to 16, it becomes possible to sufficiently promote the vaporization and atomization of the fuel, and there is a particular effect that the starting performance of the engine is improved. . Further, since the fuel is injected in a stroke other than the intake stroke of the engine, plug fogging can be prevented and ignition failure can be prevented, so that the engine starting performance is improved.

Even if it is determined that the zone is the normal zone on the basis of the engine rotation speed, as shown in FIG. 3, each of the cylinders 11 to 16 is continuously maintained for a predetermined time during which the start-time injection continuation cower is operating. Since the fuel injection is performed independently and separately, even if the fuel injection is switched from independent and split injection to only independent injection, the engine rotation speed increases to some extent and then only independent injection is performed, resulting in a sudden change in engine rotation speed. Can be prevented and the engine speed can be smoothly increased. Therefore, the transition from the starting zone to the normal zone becomes smooth, and a special effect that the riding comfort of a vehicle equipped with such an engine is improved is obtained. Further, as shown in the map of FIG. 10, the lower the engine cooling water temperature is, the larger the total fuel injection amount for each of the cylinders 11 to 16 is, so that a constant starting performance is always obtained regardless of the engine cooling water temperature. A special effect of being able to be obtained is obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of an engine according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between an engine rotation behavior and an injection method according to the embodiment of the present invention.

FIG. 4 is a flowchart showing an operation of zone determination according to the embodiment of the present invention.

FIG. 5 is an intake of each cylinder of the engine of the embodiment of the present invention,
It is a figure which shows each process of compression, explosion, and exhaust, and the relationship of injection timing.

FIG. 6 is the first half of a flowchart showing the operation of fuel injection in the starting zone according to the embodiment of the present invention.

FIG. 7 is a second half of a flowchart showing the operation of fuel injection in the starting zone according to the embodiment of the present invention.

FIG. 8 is a flowchart showing the operation of divided injection amount calculation for each cylinder according to the embodiment of the present invention.

FIG. 9 is a diagram showing a relationship between an on time and an off time of the injection valve according to the embodiment of the present invention.

FIG. 10 is a map showing the relationship between engine cooling water temperature and fuel injection amount.

[Explanation of symbols]

10 ... Engine, 10a, 10b ... Bank, 11-16
... cylinder, 20 ... intake passage 21-26 ... independent intake passage, 30 ... surge tank, 50
... intake air supply passage, 60 ... air cleaner, 70 ... air flow meter, 80 ... throttle valve, 91-96 ... fuel injection valve (injector), 100 ... control device

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location F02D 41/36 B 45/00 312 Q

Claims (4)

[Claims] 1. A fuel injection control device for an internal combustion engine, comprising: a plurality of cylinders and an engine speed detecting means; a normal zone, a starting zone, and an engine stall depending on the engine speed detected by the engine speed detecting means. Zone determining means for determining which of the zones is a zone, and a first fuel injection control means for independently injecting fuel for each cylinder when the zone determining means determines the normal zone, When it is determined by the zone determination means that the zone is the start zone, the fuel is independently injected into each cylinder, the fuel injection is divided into predetermined times, and the fuel is injected in a stroke other than the intake stroke of the engine. A second fuel injection control means, and a third fuel injection control means for stopping the fuel injection when the zone determination means determines that the engine is in the stalled zone. The fuel injection control device for an internal combustion engine, characterized in that there was e. 2. A fuel injection control device for an internal combustion engine, comprising: a plurality of cylinders; and an engine speed detecting means, wherein a normal zone, a starting zone, and an engine stop are set according to the engine speed detected by the engine speed detecting means. Zone determining means for determining which of the zones is a zone, and a first fuel injection control means for independently injecting fuel for each cylinder when the zone determining means determines the normal zone, When the zone determination means determines that the zone is the start zone, the fuel is independently injected into each cylinder, the fuel injection is divided into predetermined times, and the fuel is injected in a stroke other than the intake stroke of the engine. A second fuel injection control means, and a third fuel injection control means for stopping the fuel injection when the zone determination means determines that the engine is in the stalled zone. After the fuel injection is divided into a predetermined number of times by the second fuel injection control means and the engine is started, and when the zone determination means determines that the zone is a normal zone, the zone continues for a predetermined time, It is characterized by further comprising start-time injection continuation control means for independently injecting fuel into each cylinder, dividing the fuel injection into predetermined times, and injecting fuel in a stroke other than the intake stroke of the engine. Fuel injection control device for internal combustion engine. 3. A fuel injection control device for an internal combustion engine having a plurality of cylinders and an engine speed detecting means, wherein a normal zone, a starting zone and an engine zone are set according to the engine speed detected by the engine speed detecting means. Zone determining means for determining which of the zones, first fuel injection control means for independently injecting fuel into each cylinder when the zone determining means determines a normal zone, When it is determined by the zone determination means that the zone is the start zone, the fuel is independently injected into each cylinder, the fuel injection is divided into predetermined times, and the fuel is injected in a stroke other than the intake stroke of the engine. A second fuel injection control means, a third fuel injection control means for stopping the fuel injection when the zone determination means determines that the engine is in the engine stall zone, A first reference signal generating means for generating a predetermined signal each time the crankshaft of the engine rotates a predetermined angle, and a second reference signal generating means for generating a predetermined signal each time the crankshaft of the engine rotates two times. An engine cooling water temperature detecting means for detecting an engine cooling water temperature, wherein the second fuel injection control means is a period during which a predetermined signal by the second reference signal generating means disappears and a next predetermined signal is generated. Counting means for counting the number of times a predetermined signal is generated by the first reference signal generating means, and start of fuel injection into a cylinder corresponding to the count value each time the count value by the counting means reaches a predetermined count value. Injection timing determining means for determining timing, and fuel for determining the total fuel injection amount for each cylinder based on the engine cooling water temperature by the engine cooling water temperature detecting means And injection amount determining means, and split injection control means for injecting by dividing the total fuel injection quantity for each cylinder by the fuel injection quantity determining means a predetermined number of times,
A fuel injection control device for an internal combustion engine, comprising: 4. The fuel injection control device for an internal combustion engine according to claim 3, wherein the total fuel injection amount for each cylinder is increased as the engine cooling water temperature detected by the engine cooling water temperature detecting means is increased. A fuel injection control device for an internal combustion engine, comprising: