JP3010077B2 - Fuel injection control device for two-cycle multi-cylinder engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an in-cylinder injection two-cycle multi-cylinder engine for injecting fuel into a combustion chamber.
In particular, it relates to a device for controlling the fuel injection amount.

[0002]

2. Description of the Related Art In a so-called in-cylinder injection type two-cycle engine in which fuel is injected into a combustion chamber together with compressed air, atomized fuel is supplied in the vicinity of a spark plug, where a dense mixture layer is formed. Therefore, combustion is locally performed. For this reason, especially in the low load operation including idling, even in an operation region where the scavenging action is insufficient and the residual gas is large, ignition of the air-fuel mixture is reliably performed, and there is an advantage that combustion is stabilized. I have.

In a multi-cylinder engine having a plurality of cylinders, such as an automobile engine, it is difficult to provide independent intake and exhaust pipes for each cylinder in terms of space and weight of an engine room. In many cases, usually, the intake and exhaust ports of several cylinders are connected by an intake manifold or an exhaust manifold to be assembled together. When the intake port and the exhaust port are connected by a common manifold, the flow of intake air and exhaust air of one cylinder is affected by the intake and exhaust of another cylinder, and pressure interference between intake and exhaust may occur. For this reason, in a two-cycle engine in which the burned gas in the combustion chamber is pushed out by the intake air and the blown-in intake air is pushed back into the combustion chamber by using the pressure wave of the exhaust gas, when the above-described pressure interference occurs, the There is often a variation in the charging efficiency of the intake air between the two. The variation in the charging efficiency is higher in a high-speed operation region in which the pressure wave generated in the intake manifold or the exhaust manifold remains without being attenuated, or in a high-load operation region in which the exhaust pressure of the exhaust gas into the exhaust manifold is higher. Remarkable,
In particular, when the maximum output occurs, the charging efficiency between the cylinders may differ by as much as 20%.

[0004]

However, in a conventional in-cylinder injection two-cycle engine, an airflow sensor is provided at an upstream open end of an intake manifold, and the average intake air amount of a plurality of cylinders is obtained through the airflow sensor. Thus, the amount of fuel injection for each cylinder is determined, and the same amount of fuel is injected for each cylinder. From this, if the charging efficiency between the cylinders varies as described above, the A / F of the air-fuel mixture between the cylinders particularly in a high rotation / high load operation range.
Will result in significant differences.

Therefore, in one cylinder, the A /
Even if F is appropriate, in other cylinders, the A / F becomes excessively rich and misfiring may occur, or conversely, the A / F becomes too thin and abnormal combustion may occur, realizing efficient combustion. In addition to the above disadvantages, there is a problem that the rotation of the engine becomes unstable.

The present invention has been made in view of such circumstances, and the A / F of the air-fuel mixture of each cylinder is operated by an engine.
It is possible to accurately control the optimum value according to the driving situation.
Come, I Do not allow efficient combustion in each cylinder, the original sex
It is an object of the present invention to provide a fuel injection control device for a two-cycle multi-cylinder engine capable of fully exerting its performance .

[0007]

[Means for Solving the Problems]To achieve the above purpose
Therefore, the fuel injection control device according to the present invention,For multiple cylinders
ParcelAs well as a primary compression chamber for intake air
With a crankcase Has multiple intake pipes that lead intake air to the crank chamber of each cylinder
The intake manifolds are connected at the upstream end of these intake pipes.
With Hold; All intake air during engine operation via this intake manifold
An airflow sensor for detecting air volume; Multiple injection nozzles that individually inject fuel into the combustion chamber of each cylinder
And a two-cycle multi-cylinder engine.
The fuel injection control device is provided with the air flow sensor.
Based on the total amount of intake air detected by the
And the amount of intake air
By dividing by the displacement per cylinder, the flatness of each cylinder
Means for determining an average supply ratio; Detects the pressure in the crankcase of each cylinder with a pressure sensor
Based on the average value of the pressure and the average air supply ratio.
Means for determining the actual charge ratio of the cylinder; Based on the engine speed and air supply ratio,
Maps to guide optimal filling efficiency to engine operating conditions
And from this map by the engine speed sensor
The actual engine speed detected and the actual
Means for determining the charging efficiency for each cylinder based on the charge ratio; Engine operation status at that time based on engine speed
A map for deriving an A / F of an air-fuel mixture most suitable for the situation,
Mixing corresponding to the actual engine speed from this map
Means for determining the Q / A / F; Relationship between the charging efficiency of each cylinder and the A / F of the air-fuel mixture
For determining the amount of fuel to be injected for each cylinder from the
When; The injection nozzle is controlled based on the data indicating the injection amount.
Controlling means; It is characterized by:

[0008]

According to such a configuration, the most suitable for each cylinder
The filling efficiency and the optimal A / F of the air-fuel mixture were determined and based on these.
Since the fuel injection amount for each cylinder is determined as a standard,
When the intake air volume between cylinders fluctuated during gin operation,
Even so, the fuel injection amount can be corrected for each cylinder,
The A / F of the air-fuel mixture of all cylinders
It can be modified to the corresponding value. Because of this, all
Stable combustion of cylinders, ensuring irregular and abnormal combustion
Can be prevented. According to the above configuration, the intake air
The actual amount of intake air flowing through the manifold is
Through each sensor, and based on the detected data,
The air supply ratio of each cylinder is
It can be determined accurately according to the engine operating conditions.
Therefore, the charging efficiency of each cylinder determined from the intake ratio is also correct.
Fuel injection into the combustion chamber of each cylinder
More precise control of the quantity according to the actual engine operating conditions
can do.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to one embodiment shown in the drawings.

[0010] In FIG.
The cycle three-cylinder engine includes a crankcase 2, a cylinder block 3, and a cylinder head 4. The crankcase 2 is divided into an upper case 2a and a lower case 2b, and a crank chamber 6 for accommodating the crankshaft 5 is formed between the two cases 2a and 2b.

The cylinder block 3 is integrated with the upper case 2a. Inside the cylinder block 3, three cylinders 7 are arranged in the axial direction of the crankshaft 5 as shown in FIGS. Is provided. These cylinders 7 are connected to the crankcase 6 in the crankcase 2. The crank chamber 6 is partitioned for each cylinder 7 by a partition wall 8.
The journal portion 5a of the crankshaft 5 is provided on the partition 8 with a bearing 9a.
Is supported through. And this crankshaft 5
Is a piston 10 in each cylinder 7 via a connecting rod 11.
It is connected to.

A plurality of scavenging ports 12 and exhaust ports 13 opened and closed by a piston 10 are opened on the inner surface of each cylinder 7. The scavenging port 12 is opened to the crank chamber 6 of each cylinder 7 via a scavenging passage (not shown) in the cylinder block 3. In the crankcase 2, three intake ports 15 are provided side by side in the axial direction of the crankshaft 5.
The intake ports 15 are individually opened to the crank chambers 6 of the three cylinders 7, and these intake ports 15 are connected to the intake manifold 1.
6 are connected. The intake manifold 16 includes the intake port 1
5, three intake pipes 17 are provided. Intake pipe 17
Are gathered together, and a throttle body 18 is connected to this gathering portion. The throttle body 18 is provided with a throttle valve 19 and a throttle opening sensor 20 for detecting the opening of the throttle valve 19. An upstream end of the throttle body 18 for detecting an intake air amount is provided at an upstream end. Is provided.

The intake port 15 of the crankcase 2 is provided with a reed valve 22 that allows only the flow of intake air from the intake pipe 17 to the crank chamber 6. For this reason, the crankcase 6 in the crankcase 2 serves as a primary compression chamber for compressing the intake air, and the crankcase 2 is used to individually detect the pressure in the crankcase 6 of each cylinder 7. Pressure sensor 14 is provided.

A transmission case 23 is connected to a rear surface of the crankcase 2. A transmission 24 is accommodated in the transmission case 23. The transmission 24 is connected to the crankshaft 5 via a clutch 25 and a flywheel 26.
A crank angle sensor 27 (engine speed sensor) for detecting the rotation angle of the crankshaft 5 through the engine is provided.

A recess 28 is formed in the cylinder head 4 at a position where the cylinder head 4 meets the cylinder 7. The recess 28 has a wedge-shaped combustion chamber 29 between the recess 10 and the top surface 10 a of the piston 10.
The ignition plug 43 faces the combustion chamber 29.

The cylinder head 4 is provided with a fuel injection device 30 for injecting fuel into the combustion chamber 29 together with compressed air. The fuel injection device 30 includes an elongated housing 31 extending in the axial direction of the crankshaft 5. The housing 31 incorporates three electromagnetic injection nozzles 32 corresponding to the number of cylinders, and three electromagnetic fuel injection valves 33, respectively.

As shown in FIG. 6, the injection nozzle 32 has a cylindrical valve guide housing 34. The valve guide housing 34 is supported on the bottom surface of the housing 31. Then, the valve guide housing 34
Is inserted into a fitting hole 35 opened in the cylinder head 28, and a tip end thereof faces the combustion chamber 29. A mounting hole 36 opening to the combustion chamber 29 is provided on the axis of the valve guide housing 34. Is formed. In the mounting hole 36,
A cylindrical valve guide 37 is housed. A guide hole 38 that opens into the combustion chamber 29 is formed on the axis of the valve guide 37, and a needle valve 39 is inserted into the guide hole 38 so as to be movable in the axial direction.

The needle valve 39 has a stem 39a penetrating the guide hole 38 and a hemispherical or mushroom-shaped head 39b located at one end of the stem 39a. The head portion 39b is connected to the guide hole 38 from the combustion chamber 29 side.
In the opening of the guide hole 38, a seat 40 on which the head 39b is seated is formed. An air introduction passage 41 is formed between the stem 39a and the guide hole 38. Air introduction channel 41
Has an upstream end connected to the air passage 42 in the housing 31 and a downstream end connected to the combustion chamber 29 of the guide hole 38.
The downstream end of the air introduction passage 41 is opened and closed by the head portion 39b of the needle valve 39.

Mounting hole 36 of valve guide housing 34
A fuel introduction path 45 is formed between the valve guide 37 and the valve guide 37. The upstream end of the fuel introduction path 45 is
The fuel injection valve 33 is supplied with fuel via a fuel passage 47 in the housing 31. Fuel introduction path 4
The downstream end of 5 is connected to a plurality of fuel injection ports 48 opening to the seat section 40. The fuel injection port 48 is provided in the guide hole 3
8, and is opened and closed by the head portion 39 b of the needle valve 39 together with the guide hole 38.

The stem 39a of the needle valve 39
It penetrates the upper part of the housing 31 and is led out. An armature 49 is fixed to the leading end of the stem 39a. The armature 49 is urged upward by a pair of spring members 50, and the urging causes the head portion 39 b of the needle valve 39 to move the seat portion 4.
0, and the guide hole 38 and the fuel injection port 48 are pressed.
Is closed. Also, at the top of the housing 31,
An electromagnet 51 for operating the needle valve 39 in the opening direction is provided. Electromagnetic coil 52 of electromagnet 51
Is opposed to the lower surface of the armature 49, and when the electromagnetic coil 52 is excited, the armature 49 is attracted against the urging force of the spring member 50, and the needle valve 39
Is removed from the seat 40.

A fuel passage 47 in the fuel injection device 30 is connected to a fuel tank 56 through a fuel pipe 55 as shown in FIG. There is provided a fuel pump 57 for pressure feeding. Further, a fuel return pipe 58 for returning surplus fuel to the fuel tank 56 is connected to the fuel passage 47.

The air passage 42 of the fuel injection device 30 is connected to an air pump 60 via an air pipe 61. The air pump 60 is driven by power transmission from the crankshaft 5. When the air pump 60 is driven, the air sucked through the air cleaner 62 is supplied to the air passage 42. The pressure of the compressed air supplied to the air passage 42 is set lower than the pressure of the fuel supplied to the fuel passage 47. The air passage 42 is connected to an exhaust pipe 63 that allows excess compressed air to escape, and the exhaust pipe 63 is connected to the exhaust silencer of the engine 1.

The injection nozzle 32 and the fuel injection valve 33 of the fuel injection device 30 are driven by a signal output from a control unit 66 as a central processing unit during operation of the engine. Is controlled.

That is, as shown in FIG. 1, during operation of the engine, various signals indicating the operation state of the engine 1, for example, the throttle opening sensor 2 are provided to the control unit 66.
From 0, a signal indicating the opening of the throttle valve 19, a signal indicating the amount of intake air from the air flow sensor 21, and a signal indicating the crank angle and the engine speed from the crank angle sensor 27 are input. The control unit 66 determines the current engine operating condition from the various input signals, and determines the optimal fuel and compressed air injection timing and the like for the current operating condition from a map stored in advance. The injection amount is read, and a signal for realizing this is sent to the electromagnet 51 of the injection nozzle 32 and the fuel injection valve 33.

This control will be described in detail with reference to FIG.
(A) shows the injection period of the compressed air and the fuel in the low load / low speed operation range. In this rotation range, piston 1
0 is after the bottom dead center (BDC) and the scavenging port 12 and the exhaust port 13
After is closed, an excitation signal is sent to the electromagnet 51, and the electromagnetic coil 52 is excited. Then, the armature 49 of the injection nozzle 32 is attracted by the electromagnet 51, so that the head portion 39b of the needle valve 39 is
Then, the guide hole 38 and the fuel injection port 48 are opened. Therefore, the compressed air supplied from the air pump 60 to the air passage 42 flows through the guide hole 38 to the combustion chamber 2.
9 is injected. When a predetermined time has elapsed from the injection of the compressed air, a drive signal is sent to the fuel injection valve 33, and the pressurized fuel is injected into the combustion chamber 29 through the fuel injection port 48. This fuel mixes with the compressed air injected from the guide hole 38 and is atomized. The fuel is multiplied by the flow of the compressed air and is injected into the combustion chamber 29. To form

The driving of the fuel injection valve 33 and the excitation of the electromagnet 51 are stopped before the mixture is ignited by the ignition plug 43. As a result, the armature 49 is pushed up by the spring member 50, and the head portion 39b of the needle valve 39 is seated on the seat portion 40, so that the guide hole 38 and the fuel injection port 48 are simultaneously closed, and the compressed air to the combustion chamber 29 is compressed. And the fuel injection is stopped. Immediately before the piston 10 reaches the top dead center (TDC), the ignition plug 4
An ignition signal is sent to the engine 3 and the mixture is ignited through the ignition plug 43.

As shown in FIG. 5B, in the high rotation and high load operation range, when the exhaust port 13 starts to open,
The injection of fuel and compressed air is started before and after. And
The fuel injection is stopped when the exhaust port 13 is closed, and the compressed air injection is stopped between the time when the fuel injection is stopped and the time when the mixture is ignited.

On the other hand, in this type of two-cycle three-cylinder engine 1, when the intake port 15 and the exhaust port 13 of each cylinder 7 are connected by a common manifold, as described in the section of the related art, three cylinders are used. 7, the pressure interference of the intake and exhaust occurs. Then, in the two-cycle three-cylinder engine 1 in which the crank chamber 6 is the primary compression chamber of the intake air, the ratio of the intake air remaining in the combustion chamber 29 after scavenging, that is, the charging efficiency of the intake air varies between the cylinders 7. In the present invention, the injection amount of the fuel injected into the combustion chamber 29 is corrected based on the scavenging amount for each cylinder 7. Next, a control method for correcting the fuel injection amount will be described with reference to FIGS.
Will be described.

Since the variation in the amount of intake air accumulated in the combustion chamber 29 after scavenging is large mainly in a high-speed and high-load operation range, the control unit 66 shown in FIG.
As shown in the current engine in the first step S ₁ 1
It is determined whether or not the operation status of the vehicle is in the high-load / high-speed operation range. When the operation state of the engine 1 is out of the high-load / high-speed operation range, the control unit 66 maps the optimal fuel injection amount for the operation state at that time based on various signals indicating the operation state of the engine 1. Searching from above, this determines the fuel injection quantity.

[0030] When the engine 1 is in a high-load and high-speed operating range, the flow proceeds to the next step S _2. Based on a signal sent from the step S ₂ in the air flow sensor 21, the piston 10 is to detect the total amount of intake air per one cycle for one reciprocation. Next, the total intake air amount is divided by the number of cylinders 7 to calculate the intake air amount per cylinder (step S).
Proceed to ₃ . Once determined the intake air amount per cylinder, the process proceeds to step S _4, in step S _4, by dividing the intake air amount per cylinder in the exhaust amount per cylinder, the average air supply of each cylinder 7 Processing for calculating the ratio L _av is performed.

[0031] Subsequently, the flow proceeds to step S ₅ based on the signal sent from the pressure sensor 14 of the crankcase 2, the average value V _1, V _2, V ₃ of the pressure of the crank chamber 6. Then, to evaluate the quality of the suction action of three cylinders 7 in the next step S _6, calculates the actual air supply ratio L of each cylinder 7. In step S _6, the average value V _1, V _2, V ₃ of the pressure of the crank chamber 6, is compared with the overall average value V _av of the pressure of the crank chamber 6, the deviation of these two values , The actual supply ratio L of each cylinder 7 is calculated. That is, the average values of the pressures of the three crank chambers 6 are V ₁ ,
Assuming that V ₂ and V ₃ , the average value V _av of the entire pressure in the crank chamber 6 is V _av = (V ₁ + V ₂ + V ₃ ) / 3 (1)

Can be represented by Therefore, for example, when the pressure V _{1 in} the crank chamber 6 of the first cylinder 7 is higher than the average value V _av of the entire pressure, that is, when the value of V _av −V ₁ is negative, the first cylinder 7 Is calculated as L = L _av + C × (V _av −V ₁ ) (1-1). Conversely, when the value of V _av −V ₁ is plus, L _av −C × (V _av −V ₁ ) (1-2)

Is obtained. Similarly, the other second cylinder 7
When the actual charge air ratio of the three cylinder 7 L also above (1-1) in place of the V ₁ of the formula and (1-2) below is obtained by substituting V ₂ and V _3. In the above formulas (1-1) and (1-2), C is a constant obtained in advance from the relationship between the pressure in the crank chamber 6 and the air supply ratio.

In this manner, the actual supply ratio L of each cylinder 7
If There computed, the process proceeds to step S ₇ for detecting the actual rotational speed of the engine 1 based on a signal input from the crank angle sensor 27. Then, from the relationship between the engine speed and Kyukihi L at a next step S _8, and calculates the charging efficiency eta _c of each cylinder 7 at that time. In calculating the charging efficiency η _c , the control unit 66 stores in advance a map for deriving the optimum charging efficiency η _c for the operating condition at that time based on the engine speed and the air supply ratio L. FIG. 3 shows an example of a map for deriving the filling efficiency η _c , and the control unit 66 _calculates the filling efficiency based on the actual data obtained in steps S ₆ and S ₇ from this map. Search for and read out η _c . In this embodiment, the fuel injection amount is corrected only in the high-load / high-speed operation range, so that the air supply ratio L in the region where the correction is performed is 0.7 to 1.2, The filling efficiency η _c is in the range of 0.4 to 0.7.

[0035] When the filling efficiency eta _c of each cylinder is determined, the process proceeds to the next step S _9, where determining the A / F of the optimum air-fuel mixture to the engine speed at that time. When determining the A / F, the control unit 66 includes the data shown in Table 1.
As shown in the map for guiding the A / F of the optimal mixture at that time based on the engine rotational speed is stored in advance, the control unit 66 detected in step S ₇ from on the map The A / F is retrieved and read based on the actual engine speed.

[0036]

[Table 1]

Next, in step S _10, the charging efficiency eta _c calculated in step S _8, the relationship between the A / F calculated in step S _9, the injection quantity of fuel to be injected into each cylinder 7 to calculate the G _f. This calculation process when the weight of the intake air occupying the stroke volume at ambient conditions was G _ho, is calculated by using the _{G f = G ho × η c} / (A / F) becomes equation.

[0038] If the fuel injection amount G _f for each cylinder 7 is determined, the process proceeds to step S ₁₁ to determine the fuel injection time T _f in accordance with the inherent flow characteristic of the fuel injection valve 33. The fuel injection time T _f (energization time) of the fuel injection valve 33 and the fuel injection amount G
The _f, since a linear relationship as shown in FIG. 4, con
The Control Unit 66, the map for directing the fuel injection time T _f from the fuel injection amount G _f are stored in advance.
Therefore, the control unit 66 reads out and search for the fuel injection time T _f based from on the map to the fuel injection amount G _f determined in step S _10.

[0039] When the fuel injection time T _f is determined, the process proceeds to the next step S _12, where the fuel as injection end timing of the fuel are the same for each cylinder 7 according to the engine speed and engine load Determine the injection timing. The fuel injection valve 33 of each cylinder 7 in the last step S ₁₃
A drive signal is sent to each cylinder 7, and an amount of fuel corresponding to the magnitude of the scavenging amount is injected for each cylinder 7.

Therefore, according to such an embodiment of the present invention, in the high-load and high-speed operation range, the amount of intake air between the cylinders 7 varies, and the ratio of the intake air remaining in the combustion chamber 29 after scavenging is increased. Even if a difference occurs, the fuel injection amount is increased or decreased for each cylinder 7 in accordance with the variation of the scavenging amount, so that the A / F of the air-fuel mixture of each cylinder 7 is
The value can be corrected to an optimum value according to the operating condition of the engine 1 at that time.

Therefore, the A / F of the air-fuel mixture between the cylinders 7 can be adjusted to an appropriate value, and the combustion state of all the cylinders 7 is stabilized, and irregular combustion or abnormal combustion can be prevented. There is an advantage that the rotation of the engine 1 is very stable.

[0042]

[0043]

[0044]

[0045] It should be noted that the operation range for correcting the injection quantity of fuel,
It is not limited only to the high-load / high-speed operation range,
The fuel injection amount may be corrected in other operation regions.

[0046]

According to the present invention described in detail above, the engine
If the intake air volume between cylinders fluctuates during operation
To the optimal filling efficiency and A / F determined from the map
The fuel injection amount can be corrected for each cylinder based on the
You. For this reason, the A / F of the air-fuel mixture of all cylinders is
The value can be corrected to a value corresponding to the engine operating condition, and the A / F of the air-fuel mixture between the cylinders can be adjusted to an appropriate value.
Therefore, the combustion state of all cylinders is stable, and irregular combustion or abnormal combustion can be reliably prevented , and the effect is correspondingly reduced.
High-efficiency combustion is possible, and the original performance of the engine is
Can be demonstrated in minutes. In the present invention,
Based on the actual amount of intake air flowing through the manifold,
Since the air ratio is determined, this intake ratio is used for actual engine operation.
It can be determined accurately according to the turning situation. Therefore,
The charging efficiency of each cylinder determined from this intake ratio is also accurately determined.
In other words, the fuel injection amount is
More accurate control can be performed according to the situation.

[Brief description of the drawings]

FIG. 1 is a diagram showing a supply path of fuel and compressed air and a signal transmission path between an engine and a control unit in one embodiment of the present invention.

FIG. 2 is a flowchart showing correction contents of a fuel injection amount.

FIG. 3 is a characteristic diagram showing a relationship between an intake air charging efficiency and an air supply ratio with respect to an engine speed.

FIG. 4 is a characteristic diagram showing a relationship between a fuel injection amount of a fuel injection valve and an injection time.

FIG. 5A is a diagram showing a fuel and compressed air injection period in a low-load / low-speed operation range. FIG. 4B is a diagram illustrating a fuel and compressed air injection period in a high-load / high-speed operation range.

FIG. 6 is a sectional view of a fuel injection device.

FIG. 7 is a cross-sectional view of a two-cycle multi-cylinder engine.

FIG. 8 is a cross-sectional view of the two-cycle multi-cylinder engine cut in an axial direction of a crankshaft.

[Explanation of symbols]

 6 ... Crank chamber 7 ... Cylinder14. Pressure sensor 16 ... intake manifold 17 ... intake pipe 21 ... Air flow sensor 29: Combustion chamber 32 ... injection nozzle  66 means (control unit)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-298632 (JP, A) JP-A-2-271070 (JP, A) JP-A-63-208644 (JP, A) (58) Investigation Field (Int. Cl. ⁷ , DB name) F02D 41/02 F02D 45/00

Claims (1)

(57) [Claims] 1. Division into a plurality of cylindersAs well as sucking
A crankcase that functions as a primary compression chamber for incoming air; Has multiple intake pipes that lead intake air to the crank chamber of each cylinder
The intake manifolds are connected at the upstream end of these intake pipes.
With Hold; All intake air during engine operation via this intake manifold
An airflow sensor for detecting air volume; Multiple injection nozzles that individually inject fuel into the combustion chamber of each cylinder
Two-stroke multi-cylinder engine with
hand, Total intake air amount detected by the above airflow sensor
The amount of intake air per cylinder is calculated based on
Divide this intake air amount by the displacement per cylinder
Means for determining the average charge ratio of each cylinder by: Detects the pressure in the crankcase of each cylinder with a pressure sensor
Based on the average value of the pressure and the average air supply ratio.
Means for determining the actual charge ratio of the cylinder; Based on the engine speed and air supply ratio,
Maps to guide optimal filling efficiency to engine operating conditions
And from this map by the engine speed sensor
The actual engine speed detected and the actual
Means for determining the charging efficiency for each cylinder based on the charge ratio; Engine operation status at that time based on engine speed
A map for deriving an A / F of an air-fuel mixture most suitable for the situation,
Mixing corresponding to the actual engine speed from this map
Means for determining the Q / A / F; Relationship between the charging efficiency of each cylinder and the A / F of the air-fuel mixture
For determining the amount of fuel to be injected for each cylinder from the
When; The injection nozzle is controlled based on the data indicating the injection amount.
Means to control; Two cycles characterized by having
Fuel injection control device for multi-cylinder engine.