JP3295350B2 - Electronic fuel injection engine with mechanical governor and control method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic fuel injection engine, and more particularly, to an electronic fuel injection engine suitable for an engine mounted on a working machine.

[0002]

2. Description of the Related Art In recent years, demands for automobile engines include high output, improved fuel efficiency, and purification of exhaust gas. In particular, the requirements for purifying exhaust gas have become stricter year by year. In order to simultaneously respond to such conflicting demands, fuel injection is also performed in gasoline engines. In this fuel injection, in order to obtain an optimum fuel supply over the entire rotation range of the engine, it is necessary to calculate and obtain a fuel injection amount based on many factors, and many types using a small electronic computer have been proposed.

[0003] An electronically controlled fuel injection device plays a central role in an electronic fuel injection engine for an automobile, and the electronically controlled fuel injection device uses the electronically controlled fuel injection device to generate an optimal mixture according to the state of the engine. We supply it to the room. Conventionally, in order to accurately determine the air-fuel ratio of the air-fuel mixture required for combustion in an electronically controlled fuel injection device for a vehicle, the following three methods are known as methods for measuring the intake air amount, which is a prerequisite for the determination. I have.

[0004] The first method is a mass flow equation (MAF) for directly calculating the amount of air per one revolution of an engine based on an air flow meter and the number of revolutions of the engine to determine a fuel injection quantity. The second method is a manifold pressure formula (hereinafter, referred to as MAP) that calculates the amount of intake air per one revolution of the engine based on the intake pipe negative pressure and the engine speed to determine the fuel injection amount. A third method is a throttle angle formula (hereinafter, referred to as TAP) for determining a fuel injection amount by calculating an intake air amount per one rotation of an engine based on an angle of a throttle valve of an intake pipe and an engine speed.
It is.

On the other hand, there is a working machine engine mounted on various working machines separately from an automobile engine. The engine for the working machine is an engine having a completely different operation form from the engine for a vehicle. FIG. 7 is a diagram showing the difference between the operating modes of the working machine engine and the automobile engine. The vertical axis indicates horsepower (PS), and the horizontal axis indicates the engine speed.
Curve 9 for the first speed in the case of an automobile engine indicated by curve 90
The characteristic curve changes according to the curve 90b for the second speed 90a and the curve 90b for the third speed, and the human controls the speed by operating the clutch, the accelerator pedal, and the brake.
The operating range of the vehicle engine is a low-speed low-load range 91.
Is the center. On the other hand, the working machine engine changes in the form of, for example, curves 92a, 92b, and 92c, is speed-controlled by a governor (speed governor), and its operation range is set to a high-speed high-load range 93 in most cases. It is.

[0006]

Here, when the above-mentioned electronically controlled fuel injection device is applied to a working machine engine, the following problems occur. (1) First, the work machine engine has a sudden change in torque that is not present in an automobile engine, and it is necessary to adopt a configuration capable of rapidly responding to this change in torque. For example, taking a cultivator engine as an example, a sudden change in torque that occurs instantaneously, such as when the soil is removed from the ground from a plowed state by a rotary earthmoving machine or when the reverse operation is performed. Therefore, it is essential to cope with such a sudden change in torque. The electronically controlled fuel injection device for an automobile described above hardly has such a sudden load change.

In order to cope with this sudden load change, the load change is detected electronically, the intake air amount is detected, the intake air amount is controlled by adjusting the opening of the throttle valve,
Although it is conceivable that all of the determination of the fuel injection amount is performed by electronic calculation, it is difficult to adjust the opening of the throttle valve in accordance with the above-mentioned rapid load change with an inexpensive control device because the calculation speed is difficult. Responsiveness cannot be obtained.

(2) Second, in the case of a working machine engine,
As described above, the operating environment and operating conditions are extremely severe. For example, it is common for a working machine engine that the temperature around the engine is high, the temperature is below freezing, the mud or rainwater is splashed, and the operation under the full load condition is continuous for a long time (sometimes 2 to 3 days). That is. If all of such severe operating environment and operating conditions are electronically controlled, it is necessary to take sufficient measures for engine stability, and there is a problem that manufacturing costs increase.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and an object of the present invention is to provide an electronic fuel injection engine and a control method therefor, which can solve the above problems. An example of a specific purpose is as follows. (a) To provide an electronic fuel injection engine optimal for various working machines such as agricultural machines and construction machines. (b) To provide an electronic fuel injection engine which can be controlled stably even under severe environmental conditions and operating conditions of a work machine engine, and which can respond to a sudden load change. (c) To provide an electronic fuel injection engine for a working machine capable of operating with both responsiveness and fuel efficiency. The problems of the invention other than those described above and the means for solving the problems will be described in detail in the section of the means for solving the problems, the operation, and the embodiments of the invention described later.

[0010]

The present invention will be described below with reference to, for example, FIGS. 1 to 6 showing an embodiment of the present invention. The first invention is shown in FIG.
As shown in FIG. 2, a fuel ignition means 2 provided facing the combustion chamber 1, a fuel injection device 4 provided in the intake pipe 3, and a throttle valve 5 for controlling the amount of air flowing into the combustion chamber 1
A mechanical governor 6 for adjusting the opening of the throttle valve 5, and a valve opening for substantially detecting the opening θ of the throttle valve 5.
Based on the degree sensor 8, the pressure detection value p and the engine speed n.
That stores data for calculating the first injection amount
Based on the P table 23, the valve opening degree θ and the engine speed n
That stores data for calculating the second injection amount
A fuel injection control method applied to an electronic fuel injection engine equipped with a mechanical governor having a P table 24, the fuel injection control method comprising: a process of obtaining a detected pressure value in the intake pipe 3; The process of substantially obtaining the valve opening degree θ, the process of detecting the engine speed n, the frequency of injection of the fuel injector 4 based on the detected pressure value p and the engine speed n, and the first injection per cycle Always calculate the amount
A process of constantly calculating an injection frequency of the fuel injection device 4 and a second injection amount per cycle based on the valve opening θ and the engine speed n, and a process of detecting an operating state of the engine. A step of weighting a first injection amount based on the pressure detection and a second injection amount based on the valve opening degree detection according to a predetermined rule based on the detection result of the operation state, and the fuel injection device 4 assigns the weighted injection amount to the weighted injection amount. And a step of injecting based on .

The second invention, as shown in FIGS. 1 and 2,
A fuel igniting means 2 provided facing the combustion chamber 1, a fuel injection device 4 provided in the intake pipe 3, a throttle valve 5 for controlling the amount of air flowing into the combustion chamber 1, and a throttle valve 5 A mechanical governor 6 for controlling the opening degree of the throttle valve, a pressure sensor 7 for detecting a pressure in the intake pipe 3,
A valve opening sensor 8 for detecting a substantial opening θ of the engine, a speed sensor 9 for detecting the engine speed n, and a fuel injection device 4 based on the detected pressure value p and the detected engine speed n. injection frequency and normally the first injection amount per cycle
A first injection amount calculating means 21 for calculating the time, to constantly calculate the second injection quantity of frequency and per cycle of the fuel injectors 4 of the injection on the basis of the valve opening θ and the detected engine speed n
That the second injection amount calculating unit 22, the detected pressure value p and the engine
Data for calculating the first injection amount based on the rotation speed n
MAP table 23 storing the valve opening degree θ and the engine
Data for calculating the second injection amount based on the rotation speed n
TAP table 24, which stores the operating state of the engine, operating state detecting means 25 for detecting the operating state of the engine, and the first injection amount and the second injection amount are determined by a predetermined rule based on the detection result of the operating state detecting means 25. and a weighting control unit 26 for weighting, based on the weighted injection amount
And injects the fuel injection device 4.

In a third aspect based on the second aspect, the operating state detecting means 25 is configured to determine that a change rate of the engine speed n
a rotational speed change rate calculating unit 27 for calculating dn / dt;
Throttle for calculating the rate of change dθ / dt of the throttle opening θ
An opening change rate calculating unit 28;
But movement of the rate of change dn / dt of the engine speed n and Ro
By monitoring the change in the rate of change dθ / dt of the throttle opening θ, it is possible to determine at which stage the engine operating state varies, and perform the weighting operation in accordance with the determination result. Features.

Next, each component of the first to third inventions will be described. The first to third inventions can be applied to a multipoint injection system in which a fuel injection device is provided for each cylinder and a single point injection system in which a single fuel injection device is provided. In the multipoint injection system, the fuel injection device 4 is preferably provided on the combustion chamber 1 side of the throttle valve 5, and in the single point injection system, the fuel injection device 4 is preferably provided on the upstream side of the throttle valve 5. The position where the valve opening sensor 8 is provided is not limited as long as the valve opening can be substantially detected.

The operating state detected by the operating state detecting means 25 includes a case where it is detected that a certain operating state has been entered,
This includes a case where a change from one operating state to another operating state is determined by detecting a predetermined amount of change.
The operation state detected by the operation state detection unit 25 includes a load state, a rotation speed, an external temperature, an operation of changing a set speed by an operator, and the like. The predetermined rules are defined in the ROM corresponding to the operation mode of each work machine at the stage of shipping the work machine engine.
It is simple and preferable to set by the storage means as described above.

The structure of the mechanical governor 6 is not particularly limited. As an example of the mechanical governor 6, there is a mechanical governor 6 that adjusts the opening degree of a throttle valve by imbalance between a centrifugal force of a flywheel due to engine rotation and a governor spring. The first injection amount, the second injection amount, and the weighted injection amount are preferably set simply by calculating the respective injection times.

[0016]

If [action] is the first or second aspect, and weighted by on the basis of the detection result of the operation with the first injection amount by the pressure detecting the valve opening predetermined rule and a second injection amount by the detection, weighting The fuel injection device based on the
Since 4 is injected, the weight can be changed according to the detection result of the operating state, and the optimal injection can be performed according to the operating state of the engine. For example, when an aggressive transient response is required to cope with a sudden load change, the injection amount is determined by predicting the air amount mainly by detecting the valve opening, and when the aggressive transient response is not required, the fuel consumption is determined. The operation that determines the injection amount by predicting the air amount mainly by detecting the pressure can be performed with emphasis on the pressure.

Further, since the amount of air is mechanically controlled by a mechanical governor 6 for adjusting the opening of the throttle valve 5, the opening of the throttle valve 5 is controlled by an actuator or the like by the electronic control described above. Computing time is not required as compared with the control configuration, and the response is extremely fast. Further, by employing the mechanical governor 6, arithmetic processing for controlling the opening degree of the throttle valve 5,
It eliminates the need for components such as an actuator that operates the. Since the calculation processing for controlling the opening of the throttle valve 5 is not required, the calculation means such as the CPU can concentrate on the processing for calculating the injection amount from the amount of air sucked by the combustion chamber. In addition, since components such as the actuator are not required, the risk of malfunction of the operation system and the control system of the actuator at high temperatures and low temperatures such as below freezing can be reduced, and environmental stability can be improved. . As described above, by using the mechanical governor 6, high responsiveness and high stability can be maintained.

According to the third aspect, the weight control means 26
But movement of the rate of change dn / dt of the engine speed n and Ro
By monitoring the movement of the change rate dθ / dt of the throttle opening θ, it is determined at which stage the engine operating state varies, and the weighting operation is performed according to the determination result. Optimal weighting can also be performed on a load that changes rapidly or slowly according to the stage of the change.

[0019]

As described above, the first or second invention has the following effects (a) and (b). (A) Since the weighting of the fuel injection can be changed according to the detection result of the operating state, it is possible to perform the optimal injection according to the operating state of the engine. (B) The throttle valve can be controlled with good response due to the presence of the mechanical governor, and can be accurately and stably controlled regardless of the engine operating conditions and the surrounding environment. According to the third aspect, since the stage of the change in the operating state of the engine is determined, optimal weighting can be performed according to the stage of the change .

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a first embodiment of a general-purpose electronic fuel injection engine of the present invention. The general-purpose electronic fuel injection engine E includes a fuel spark plug 2 provided facing a combustion chamber 1 of the engine, a fuel injection device 4 provided in an intake pipe 3, and an amount of air flowing into the combustion chamber 1. , A mechanical governor 6 for controlling the opening of the throttle valve 5, a pressure sensor 7 for detecting the pressure p in the intake pipe 3, and substantially detecting the opening θ of the throttle valve 5. Valve opening sensor 8 and engine speed n
And a rotation speed sensor 9 for detecting the rotation speed.

The general-purpose electronic fuel injection engine E includes:
A control unit 10 for performing overall control is provided. The control unit 10 detects the pressure p of the pressure sensor 7, the engine speed n from the speed sensor 9, and the valve opening θ from the valve opening sensor 8.
Is input at least. The output of the control unit 10 is output to an injection unit 11 that performs injection control of the fuel injection device 4, and is configured to inject a predetermined injection amount based on a calculation of the control unit 10. Although the injection unit 11 is often configured as a unit of the fuel injection device 4, the control unit 10 may have a part of the function.

In the configuration shown in FIG. 1, the pressure sensor 7 is provided in the surge tank chamber 12 of the intake pipe 3, but is provided at each predetermined position of the intake pipe 3 corresponding to the configuration of each engine. Further, a temperature sensor for detecting the intake air temperature may be provided in the surge tank chamber 12 as needed, and the detected temperature may be input to the control unit 10 to perform various corrections. In the case of a multi-cylinder engine, it is general that each intake pipe is connected to each cylinder via the surge tank chamber 12, and each fuel injection device 4 is provided for each intake pipe.
The mechanical governor 6 includes, for example, a governor lever 14 swingably supported by a governor shaft 13, a speed control lever 15 for an operator to set an engine rotation speed, and a governor spring 16.
The control rod 17 of the throttle valve 5 is connected to one end of the throttle valve 5, the governor spring 16 is connected to the other end of the governor lever 14, and the governor spring 16 is operatively connected to the speed control lever 15. Then, a governor force (GF) is applied to the governor lever 14 to drive the throttle valve 5 in a direction to close, and the tension of the governor spring 16 drives the throttle valve 5 in a direction to open. That is, the governor force (GF) and the governor spring 16
The degree of opening of the throttle valve 5 is controlled in proportion to the tension of the throttle valve. The valve opening sensor 8 has a governor shaft 13
With this configuration, the valve opening sensor 8 can be stably supported, and the connecting rod 1 between the governor lever 14 and the throttle valve 5 can be detected.
7, the influence of the operation delay can be reduced.

FIG. 2 is a functional block diagram showing a schematic configuration of the control unit. The control unit 10 determines the injection frequency of the fuel injection device 4 and the injection amount per cycle based on the detected pressure value p and the engine speed n.
A second injection amount calculating means 22 for determining an injection frequency of the fuel injection device 4 and a second injection amount per cycle based on the valve opening degree θ and the engine speed n; a detected pressure value p; A MAP table 23 storing data for determining the first injection amount based on the number n, and a TAP table storing data for determining the second injection amount based on the valve opening θ and the engine speed n 24, an operation state detection unit 25, and a weight control unit 26.

In the configuration example shown in FIG.
Reference numeral 5 denotes a rotational speed change rate calculator 27 for calculating a change rate (dn / dt) of the engine speed n, and a throttle opening degree change rate calculator 28 for calculating a change rate (dθ / dt) of the throttle opening θ. And The weight control unit 26 is configured to include at least a determination unit 29 and a weight unit 30. The determination unit 29 receives the output of the rotation speed change rate calculation unit 27 and the output of the throttle opening change rate calculation unit 28,
The weighting unit 30 determines whether the operating state has changed to which state. The weighting unit 30 determines the first injection amount calculated by the first injection amount calculation unit 21 based on the determination result of the determination unit 29 and the second injection amount.
The second injection amount calculated by the injection amount calculation unit 22 is weighted according to a preset rule.

FIG. 3 is a flowchart outlining the basic processing performed by the control unit shown in FIG. Step SP
In step 1, the operating state detection unit 25 constantly monitors at least one of the rate of change of the rotational speed (dn / dt) and the rate of change of the throttle opening (dθ / dt) during the operation of the engine. In step SP2, the first injection is performed. The amount calculation unit 21 and the second injection amount calculation unit 22 constantly calculate the first injection amount and the second injection amount, respectively. The exercise state detection unit 25 detects the state of exercise in step SP3, and weights in step SP4. The determining unit 29 of the control unit 26 determines which operating state is based on the engine operating state, for example, (dn / dt) and (dθ / dt), and the weighting unit 30 determines The weighting process is performed with reference to the rules, and in step SP5, the fuel injection device 4 is injected with the injection amount obtained by the weighting process.

The processing of this flowchart will be further described. The rate of change (dn / dt) of the rotational speed is detected because the load increases when the engine is rotating, and the engine rotational speed decreases or increases when the engine speed decreases. It is. As described above, the change in load can be detected from the rate of change in the number of revolutions. Therefore, the operating state detection unit 25 is provided with a configuration for detecting the rate of change in the number of engine revolutions. The rate of change (dθ / dt) of the opening of the throttle valve is detected when the operator changes the speed setting position of the speed control lever 15 of the mechanical governor 6 shown in FIG. It is for detecting. Further, even in the case of a change in the load applied to the engine, the change in the load can be detected quickly by observing the rate of change of the opening θ of the valve opening sensor 8. Generally speaking, the transient response is better in (dθ / dt) than in (dn / dt).

FIG. 4 is a flowchart showing an example of the control performed by the weight control section. FIG. 5 is a diagram showing how the engine follows when there is a load change in the engine. FIG. 5A shows a case where the load torque suddenly increases, and FIG. This shows the case where it has become smaller. In FIG. 5, the dashed line indicates the load torque applied to the engine, and the solid line indicates the generated torque following the load torque.

Hereinafter, referring to FIGS. 4 and 5, (dn /
dt), a method of detecting a load change applied to the engine, and weighting according to the stage of the change will be described. In step SP21 of FIG. 4, (dn /
It is determined whether or not dt) is within a small specified fluctuation range that is not particularly problematic in the load fluctuation. If it is determined that it is within the small specified fluctuation range, M is determined in step SP22.
The injection amount is determined by weighting at a ratio of 100% AP and 0% TAP. In this case, there is no difference from the configuration in which control is performed only by the MAP. In this MAP operating state, fuel economy is good and economical.

If it is determined in step SP21 that the difference exceeds a small specified fluctuation range, the process proceeds to step SP2.
At 3, it is determined whether (dn / dt) has changed more than a predetermined value. The determination as to whether or not the change is larger than the predetermined value is performed by detecting whether or not the slopes of the torque curves that follow in FIGS. 5A and 5B are increased, and the states are as shown in FIGS. Things.

Then, in step SP23, (dn
If / dt) has not changed significantly beyond the predetermined value, the process returns to step SP22, and the operation continues at MAP 100%. On the other hand, when it is determined in step SP23 that (dn / dt) has changed more than the predetermined value, in step SP24, the injection time is determined by weighting with the ratio of MAP 0% and TAP 100%. Since the TAP directly detects the opening degree of the throttle valve, it is possible to predict a change in the air amount due to the throttle valve in advance, and the TAP has excellent responsiveness to air amount fluctuation. The injection amount can be determined.

Next, at step SP25, (dn / d
t) It is determined whether or not the value has dropped below a certain value. This determination is to detect whether or not the slope of the torque curve that follows in FIGS. 5A and 5B is reduced to be in the states (c) and (g), respectively. And step SP2
If it is determined in (5) that (dn / dt) is not lower than a certain value (in (b) and (f) in FIG. 5), T
The operation is continued by setting the injection time by AP 100%,
When it is determined in step SP25 that (dn / dt) is lower than a certain value ((c) and (g) in FIG. 5).
In step SP26, the fuel injection time of the MAP is weighted by 50% and the fuel injection time of the TAP is weighted by 50% to determine the injection time. With this setting, it is possible to perform the operation in a state where both the responsiveness and the fuel efficiency are compatible.

Next, at step SP27, MAP
50% fuel injection time and TAP fuel injection time 50%
% Or not (dn / dt). If it is determined that it is better to continue driving, the process proceeds to step S
Returning to P26, if it is determined that it is better not to continue, the process returns to step SP21. Note that this step SP
The determination of 27 is also performed by setting a predetermined determination value. In this way, when the load on the engine fluctuates suddenly, it is possible to determine the fuel injection amount that is responsive to the fluctuation of the air amount determined by the mechanical governor that quickly responds to the fluctuation. Further, even when the load changes smoothly, the stage of the change is detected, so that the optimum fuel injection amount can be set in consideration of the fuel efficiency of the engine and the like.

FIG. 6 is a schematic time chart showing the outline of the weighting process. FIG. 6 assumes a case in which a four-cylinder gasoline engine employs an all-cylinder simultaneous injection system. First, in FIG. 6A, an ignition signal from an ignition coil is received, and the number of this ignition signal is directly connected to the engine speed. Therefore, the engine speed at that time is obtained as shown in FIG. 6B. Next, the injection time t (FIG. 6C) corresponding to the first injection amount is constantly calculated by MAP, and the injection time s (FIG. 6D) corresponding to the second injection amount is constantly calculated by TAP. You. Then, by adding weights, a value obtained by adding the injection time t and the injection time s at a predetermined ratio is output as a corrected injection time.
For example, as in step SP26 of FIG.
In the case of weighting with% and TAP 50%, the injection time may be the time obtained by adding t / 2 and s / 2, as shown in FIG.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the present invention. Hereinafter, such an embodiment will be described. (1) In the present invention, the weighted injection amount is not always the injection amount finally determined. For example, a new correction means for finely adjusting the weighted injection amount by various measurements such as an O ₂ sensor for detecting the oxygen concentration in the exhaust gas is newly provided, and the injection amount after the fine adjustment is used as a final injection amount. Is also good. (2) In the above embodiment, the operating state detection unit 25
Although (dn / dt) and (dθ / dt) are used, the transmission shaft of the engine, the drive shaft for the working machine (PT
It is also possible to adopt a mode in which a torque sensor is provided on the (O-axis) and the operation state is detected based on the output.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a general-purpose electronic fuel injection engine of the present invention.

FIG. 2 is a functional block diagram of a control unit.

FIG. 3 is a flowchart showing an outline of a basic process performed by a control unit.

FIG. 4 is a flowchart illustrating an example of control performed by a weight control unit.

FIGS. 5 (A) and 5 (B) are diagrams each showing a state in which the engine follows a change in load on the engine.

FIG. 6 is a schematic time chart showing an outline of the weighting process.

FIG. 7 is a diagram for explaining a difference in operation between an automobile engine and a working machine engine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Combustion chamber, 2 ... Fuel spark plug, 3 ... Intake pipe, 4 ... Fuel injection device, 5 ... Throttle valve, 6 ... Mechanical governor, 8 ... Valve opening sensor, 21 ... First injection amount calculation unit, 22
... Second injection amount calculator, 23 ... MAP table, 24 ... T
AP table, 25: operation state detection unit, 26: weight control unit, 27: rotation speed change rate calculation unit, 28: throttle
Opening degree change rate calculation unit, θ: valve opening degree , n: engine speed,
p: pressure , dθ / dt: change rate of throttle opening θ, d
n / dt: change rate of the engine speed n .

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI F02D 45/00 358 F02D 45/00 358Z 362 362H 364 364D 364G (56) Reference JP-A-2-136531 (JP, A) JP-A-57-143135 (JP, A) JP-A-1-138336 (JP, A) JP-A-63-1734 (JP, A) JP-A-4-219436 (JP JP, A) JP-A-4-321739 (JP, A) Japanese Utility Model Application Sho 55-25612 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 9/00-45/00

Claims (3)

(57) [Claims] 1. A fuel ignition device (2) provided facing a combustion chamber (1), and a fuel injection device provided in an intake pipe (3).
(4), a throttle valve (5) for controlling the amount of air flowing into the combustion chamber (1), a mechanical governor (6) for adjusting the opening of the throttle valve (5), and a stottle valve (5) Opening (θ)
A valve opening sensor (8) for substantially detecting a pressure detection value (p);
And calculating the first injection amount based on the engine speed (n)
Table (23) that stores data for
The second injection amount is calculated based on the degree (θ) and the engine speed (n).
TAP table storing data to be output (24)
A fuel injection control method applied to an electronic fuel injection engine with a mechanical governor , comprising: a step of obtaining a detected pressure value in an intake pipe (3); and a throttle valve (5). , The process of detecting the engine speed (n), the process of detecting the engine speed (n), and the process of detecting the fuel injection device (4) based on the detected pressure value (p) and the engine speed (n). The process of constantly calculating the injection frequency and the first injection amount per cycle, the valve opening (θ) and the engine speed
(n) calculating the injection frequency of the fuel injection device (4) and the second injection amount per cycle at all times ; detecting the operating state of the engine; Weighting the first injection amount based on the pressure detection and the second injection amount based on the valve opening degree detection according to a predetermined rule, and injecting the fuel injection device (4) based on the weighted injection amount. Characterized by including
Fuel injection control method. 2. A fuel ignition device (2) provided facing a combustion chamber (1), and a fuel injection device provided in an intake pipe (3).
(4), a throttle valve (5) for controlling the amount of air flowing into the combustion chamber (1), a mechanical governor (6) for controlling the opening of the throttle valve (5), and an intake pipe (3). A pressure sensor (7) for detecting the internal pressure, a valve opening sensor (8) for detecting a substantial opening (θ) of the throttle valve (5), and a rotation speed (n) of the engine. Rotation speed sensor (9) and pressure detection value (p)
And the first injection amount per cycle based on the detected engine speed (n).
A first injection amount calculating means (21) for constantly calculating, and a valve opening (θ)
And the second injection amount per cycle based on the detected engine speed (n).
A second injection amount calculating means (22) for constantly calculating, and a pressure detection value
Calculate the first injection quantity based on (p) and engine speed (n)
A MAP table (23) storing data for performing
The second injection amount based on the valve opening (θ) and the engine speed (n)
TAP table (2) that stores data for calculating
4), operating state detecting means (25) for detecting the operating state of the engine, and the first injection amount and the second injection amount are determined by a predetermined rule based on the detection result of the operating state detecting means (25). and a weighting control means for weighting (26), said fuel injection device on the basis of the weighted injection amount
An electronic fuel injection engine with a mechanical governor, wherein (4) is injected. 3. The electronic fuel injection engine with a mechanical governor according to claim 2, wherein the operating state detecting means (25) is configured to control the engine speed (n).
Speed change rate calculating unit for calculating the change rate (dn / dt) of the engine
(27) and the rate of change of throttle opening (θ) (dθ / dt)
And a throttle opening change rate calculation unit (28) for calculating
The weighting control means (26) detects the change in the rate of change (dn / dt) of the engine speed (n) and the change in the throttle opening (θ).
Monitoring the movement of the rate (dθ / dt) to determine in which stage the engine operating state varies, and performing the weighting operation according to the determination result. Electronic fuel injection engine with mechanical governor.