JP3295351B2 - Electronic fuel injection engine with mechanical governor - 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 Conventionally, various types of working machine engines using a vaporizer and a mechanical governor have been proposed. In this type of work machine engine, the speed fluctuation rate [(no-load maximum rotation speed−full-load maximum rotation speed) ÷ full-load maximum rotation speed] is small, that is, the governor difference (no-load maximum rotation speed− It is required to reduce the full load maximum rotation speed). In particular, in engine generators, it is strongly desired to stabilize the rotation speed, and many mechanical devices for mechanical governors for reducing the governor difference have been proposed.

[0003] In addition, a mechanical governor provided with a torque-up device for increasing the amount of fuel during overload operation has been proposed since the engine speed decreases when the engine shifts to an overload operation range. Further, among working machine engines using a vaporizer, those equipped with an electronic governor are well known.

[0004]

However, an engine with a mechanical governor using the carburetor and an engine with an electronic governor using the carburetor have the following problems. (1) First, in an engine with a mechanical governor using a carburetor, in order to reduce the governor difference and realize the torque-up function, change the mechanical configuration of the governor, for example, providing a torque-up spring. Therefore, there is a problem that the correction must be roughly performed. Further, since the operation form required for the engine differs depending on the use of the engine, there is a problem that the configuration of the mechanical governor must be designed each time according to the use. Furthermore, when simultaneously trying to reduce the governor difference and increase the torque-up function, it is necessary to add a mechanical structure for reducing the governor difference and a mechanical structure for increasing the torque to the mechanical governor. As the number of functions to be performed increases, the configuration of the mechanical governor becomes more complicated.

(2) In an engine with an electronic governor using a carburetor, the electronic governor performs the speed control function, so that it is easy to reduce the governor difference. However, even with an electronic governor, the amount of air taken into the combustion chamber is merely controlled by opening the throttle valve, and the actual air-fuel ratio is determined by the nature of the carburetor, in which the amount of fuel taken in is determined by the negative pressure of the venturi. There is a problem that it is influenced by typical characteristics. For this reason, it is difficult to change the air-fuel ratio significantly outside the characteristics of the carburetor that automatically keeps the air-fuel ratio constant with respect to the fluctuation of the air amount. Also, the configuration of recent vaporizers is when idling,
It has a complicated structure to achieve the optimal air-fuel ratio according to partial load operation, full load operation, and start-up. It is not easy to design a vaporizer configuration that can achieve satisfactory characteristics.

(3) To solve the above problems (1) and (2),
In recent years, it is also conceivable to use an electronic fuel injection device, which is partly used in gasoline vehicles, to perform all the operations electronically. However, since the work machine engine has a sudden load change that is not found in an automobile engine, a configuration that performs all electronic control is a fast control process that can obtain a quick response to a sudden load change. It is necessary to employ a device, and it becomes difficult to provide an engine at low cost. Furthermore, in the case of a working machine engine, the operating environment,
Consideration must also be given to the very harsh operating conditions. For example, when the temperature around the engine becomes high,
It is common for a working machine engine to be below freezing, to be covered with mud or rainwater, or to be continuously operated at full load for a long time (sometimes 2 to 3 days). If all of these severe operating environments and operating conditions are electronically controlled, it is necessary to take sufficient measures for the stability of the engine, which increases the manufacturing cost.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic fuel injection engine which can solve the above problems. An example of a specific purpose is as follows. (a) An inexpensive electronic fuel injection engine that can be optimally controlled according to the use of various working machines such as agricultural machines and construction machines is provided. (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. 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.

[0008]

The present invention will be described below with reference to, for example, FIGS. 1 to 5 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 controlling the opening of the throttle valve 5, and a valve opening for substantially detecting the opening θ of the throttle valve 5.
Injection setting means for setting a steady state fuel injection amount and an injection timing based on the degree sensor 8 and data relating to a substantial air intake amount of the intake pipe 3 determined by the action of the mechanical governor 6 and the engine speed n. 32, operating state detecting means 25 for detecting the operating state of the engine, and correcting the injection amount set by the injection amount setting means 32 based on the detection result of the operating state detecting means 25 to correspond to the operating state. Air-fuel ratio control means 33 for determining the value of the set air-fuel ratio.
The air-fuel ratio control means 33 determines that the throttle opening θ is 10
0%, and it is determined that the rotational speed n is decreasing.
If this happens, increase the injection amount to
Engine at high load
It is characterized by being used for a cutter .

The second invention controls the fuel igniting means 2 provided facing the combustion chamber 1, the fuel injection device 4 provided in the intake pipe 3, and the amount of air flowing into the combustion chamber 1. The throttle valve 5, the mechanical governor 6 for controlling the opening of the throttle valve 5, and the opening θ of the throttle valve 5 are substantially detected.
The steady state fuel injection amount and injection timing are set based on the data relating to the substantial air intake amount of the intake pipe 3 determined by the action of the valve opening degree sensor 8 and the mechanical governor 6 and the engine speed n. Injection setting means 32, operating state detecting means 25 for detecting an operating state of the engine, and correcting the injection amount set by the injection amount setting means 32 based on the detection result of the operating state detecting means 25, Air-fuel ratio control means 33 for determining the value of the air-fuel ratio corresponding to the state
Possess the door, the operating condition detecting means 25, valve opening sensor
8 has a load detecting means for detecting the load on the engine based on the rate of change dθ / dt of the opening degree θ , so that the air-fuel ratio control means 33 prevents the rotation of the engine from decreasing when the load increases. In addition to controlling the air-fuel ratio, the air-fuel ratio is controlled so that the rotation of the engine does not increase when the load decreases. The third invention is the second invention.
In the present invention, the operating state detecting means (25) may
Degree (θ) change rate (dθ / dt) plus engine speed
Starts the engine based on the change rate (dn / dt) of (n)
It has load detecting means for detecting the load, and this engine
It is characterized by being used as an engine generator .

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.

As data relating to the amount of air sucked into the intake pipe 3, the intake pipe negative pressure p and the opening θ of the throttle valve 5 can be exemplified. The method of detecting the operating state performed by the operating state detecting means 25 includes, for example, detecting when a certain operating state has been entered, or detecting a change amount from a certain operating state to another operating state. In some cases.
The operating state detected by the operating state detecting means 25 includes a small
At least the throttle angle θ is included, and the load state, the number of revolutions, the external temperature, the operation of changing the set speed by the operator, etc. can be exemplified. The air-fuel ratio control means 33 stores a program for controlling the working machine in accordance with the operation mode of each working machine at a shipping stage of the working machine engine in a storage means such as a ROM, and controls the program by a central processing unit (CPU). An operating configuration is preferred. The configuration 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 of a throttle valve by imbalance between a centrifugal force of a flyweight caused by engine rotation and a governor spring.

[0012]

According to the first aspect, when the mechanical governor controls the opening of the throttle valve, the amount of air taken into the combustion chamber from the intake pipe is adjusted. Injection setting means 32
Sets the steady state fuel injection amount and injection timing based on the data related to the substantial air intake amount of the intake pipe 3 determined by the action of the mechanical governor 6 and the engine speed n. On the other hand, the operating state detecting means 25 constantly detects the operating state of the engine, and the air-fuel ratio controlling means 33
Determines the value of the air-fuel ratio corresponding to the operating state by increasing or decreasing the injection amount set by the injection amount setting unit 32 based on the detection result of the operating state detecting unit 25.
Inject from Thus, a step of setting the steady-state fuel injection amount and the injection timing, and a step of setting the value of the air-fuel ratio corresponding to the operating state by increasing or decreasing the set injection amount as necessary. Therefore, in normal operation, it is possible to maintain a stable operation state almost similar to the mechanical governor, and when it reaches a certain predetermined operation state, operate it with the desired air-fuel ratio according to the application and function of the work machine Can be. Therefore, optimal operation control can be performed according to the use and characteristics of the work machine.

Further, since the mechanical governor 6 for adjusting the opening of the throttle valve 5 is configured to mechanically control the air amount, the throttle valve 5 is electronically controlled.
As compared with a configuration in which the opening degree of the actuator is controlled by an actuator or the like, no computation time is required, and the response is extremely fast. Further, the use of the mechanical governor 6 eliminates the need for components such as arithmetic processing for controlling the opening of the throttle valve 5 and an actuator for operating the throttle valve 5. 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 and correcting the injection amount. 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 second aspect , the air-fuel ratio control means 33 controls the air-fuel ratio so that the rotation of the engine does not decrease when the load increases, and increases the rotation of the engine when the load decreases. Since the air-fuel ratio is controlled so as not to be affected, it is possible to perform extremely stable operation regardless of the load fluctuation. Also, the rate of change of the throttle valve opening
(Dθ / dt) is detected by the operator
Change the speed setting position of the governing lever 15 of the
In the event that the
You. In the case of fluctuations in the load on the engine,
Also, by observing the rate of change of the opening degree θ of the valve opening degree sensor 8,
As a result, a change in load can be detected quickly.

[0015]

As described above, the first invention has the following effects (a) to (c) . (A) 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. (B) While maintaining the above-mentioned stability and good response of the mechanical governor, the substantial characteristics of the mechanical governor can be freely changed according to the detection result of the operating state. (C) When the air-fuel ratio control means increases the load,
Because the air-fuel ratio is controlled to increase the rotation of the
The pure mechanical mechanical governor has a higher load
Sometimes the rotation drops, but in the present invention
Unique to high rotation suitable for concrete cutter
Operation can be performed. In the second invention,
In addition to the effects (a) to (b) above, the opening of the valve opening sensor
The change rate of the load to quickly detect the load fluctuation.
Can be issued. If the third invention, it is possible to provide an engine generator which fluctuations in rotational speed Ru can be suppressed with high accuracy due to load fluctuations.

[0016]

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 torque sensor 35 provided as necessary. Torque sensor 35
Are the transmission shaft of the engine and the drive shaft for the work machine (PT
O-axis). In addition, the rotation speed sensor 9,
The pressure sensor 7, the valve opening sensor 8, and the torque sensor 35 constitute an engine state detection sensor 34.

The general-purpose electronic fuel injection engine E includes:
A control unit 10 for performing general control is provided, and the control unit 10 receives an engine speed n and receives a pressure sensor 7.
At least one of the detected pressure p and the valve opening θ from the valve opening sensor 8 is input. 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.

Further, in the configuration shown in FIG.
Are provided in the surge tank chamber 12 of the intake pipe 3, but are provided at predetermined positions of the intake pipe 3 corresponding to the configuration of each engine. In the case of the multipoint injection system, 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. 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.

The mechanical governor 6 includes, for example, a governor lever 14 swingably supported by a governor shaft 13 and a speed control lever 15 for setting an engine rotation speed by an operator.
And a governor spring 16. An operating rod 17 linked to the throttle valve 5 is connected to one end of the governor lever 14, a governor spring 16 is connected to the other end of the governor lever 14, and the governor spring 16 is connected to the speed control lever 15. And governor lever 1
By applying governor force (GF) to the throttle 4, the throttle valve 5 is driven in the closing direction, and the governor spring 1
The throttle valve 5 is driven in the opening direction by the tension of 6. That is, the opening degree of the throttle valve 5 is controlled based on an imbalance between the governor force (GF) and the tension of the governor spring 16.

The valve opening sensor 8 is configured to detect the rotation of the governor shaft 13. With this configuration, the valve opening sensor 8 can be stably supported, and the governor lever 14 and the throttle valve 5 can be stably supported. The effect of the operation delay of the connecting rod 17 and the like can be reduced.

The control section 10 has an injection setting section 32 for setting an injection in a steady state, an operation state detection section 25 for detecting an operation state of the engine, and an air-fuel ratio control section 33.
The processing performed by the injection setting unit 32 includes a process of predicting an air flow rate determined by the action of the mechanical governor 6 and a process of achieving an air-fuel ratio during steady operation based on the predicted air flow rate and the engine speed n. At least the step of calculating the injection amount and the injection frequency is included.

As a method of setting the fuel injection amount and the injection frequency in the injection setting unit 32, the fuel injection amount is determined by calculating the intake amount per one revolution of the engine from the intake pipe negative pressure p and the engine speed n. The fuel injection amount is determined by calculating a manifold pressure formula (hereinafter referred to as MAP), or by calculating an intake air amount per one rotation of the engine based on the opening degree θ of the throttle valve 5 of the intake pipe 3 and the engine speed n. A throttle angle type (hereinafter, referred to as TAP) is employed. Further, the injection amount obtained by the MAP or TAP may be weighted according to a predetermined rule according to the operation state detected by the operation state detection unit 25 to determine the amount of fuel to be actually injected. .

The operating state detecting section 25 detects the operating state of the engine by opening the throttle valve θ, the number of revolutions n, the torque sensor 3
5 and the like. As another method of detecting the operating state, the change rate dθ / d of the opening degree θ is
t, the rate of change of the rotational speed dn / dt, and the like. Here, the rate of change of the rotational speed (dn / dt) is detected when the load is increased when the engine is rotating, or when the engine speed is reduced, the engine rotational speed is decreased or increased, respectively. Because you do. The operator detects the rate of change of the opening degree of the throttle valve (dθ / dt) by the operator using the speed control lever 15 of the mechanical governor 6 shown in FIG.
When the speed setting position is changed, the change is detected as soon as possible. Further, even when the load applied to the engine fluctuates, the opening θ of the valve opening sensor 8
The change in load can be detected quickly by observing the change rate of the load. Generally speaking, the transient response (dθ / dt) has a better response than (dn / dt).

The air-fuel ratio controller 33 determines an unsteady state requiring special correction based on the output of the operating state detector 25, and determines the value of the air-fuel ratio in accordance with the operating state. It is. FIG. 2 is a flowchart showing an example of processing performed by the control unit in the engine applied to the concrete cutter. FIGS. 3A and 3B are diagrams in which horsepower is plotted on the vertical axis and rotation speed is plotted on the horizontal axis. Hereinafter, FIGS. 1 to 3
The operation will be described with reference to FIG.

In step SP1 of FIG. 2, the injection setting unit 32 sets the fuel injection amount and the injection frequency based on the air amount determined by the operation of the mechanical governor 6. With this setting, a governor curve 36 for realizing a predetermined governor characteristic as shown in FIG. 3A is set, and the engine operates on the governor curve 36 in a steady state. Next, at step SP2, the throttle opening .theta.
0% and whether the rotational speed n is decreasing is determined based on the opening degree θ and dn / dt. If it is determined that the condition is not satisfied, the steady operation in step SP1 is continued. . On the other hand, if it is determined in step SP2 that the throttle opening is 100% and the rotational speed n is decreasing, the injection amount is increased in step SP3 to increase the injection amount as shown in FIG. to rpm n ₂ greater high load than the rotational speed n _1. By increasing the injection amount as shown in FIG.
When the rotational speed is about to decrease at a high load of 0%, the normal governor curve 36 is changed to the governor curve 3 when the fuel is increased.
7 can be changed. The range in which this characteristic can be changed can be set freely within the flammable range of the air-fuel ratio.

With this setting, it is possible to easily increase the number of revolutions in a working machine such as a concrete cutter that wants to increase the number of revolutions as the load increases. Therefore, the operation in the steady state enjoys the advantage that the mechanical governor 6 can operate stably by the action of the mechanical governor 6, and the operation according to the working characteristics of the working machine can be performed when the state cannot be handled by the simple mechanical governor 6. The governor curve 38 in FIG. 3B is a governor curve when the amount of fuel is reduced.
This is to show that the governor characteristics can be freely changed by reducing the amount of fuel or the like.

FIG. 4 is a flowchart showing an example of a process performed by the control unit in the engine applied to the engine generator. In step SP11 shown in FIG. 4, the injection setting unit 32 sets the fuel injection amount and the injection frequency based on the air amount determined by the action of the mechanical governor 6. By this setting, a governor curve 36 for realizing a predetermined governor characteristic as shown in FIG. 3A is set in the same manner as described above. Next, in step SP12, it is determined whether or not the engine load has changed in a practically problematic manner, for example, by using dn / dt (or the torque sensor 35) including dθ / dt. If it is determined that the load has increased, the load state such as whether the load has increased or decreased has been grasped in step SP13, and in step SP14, a table set in advance according to the magnitude, direction, and the like of the change in the load. For example, the amount of fuel injection is increased or decreased to keep the change in engine speed within an extremely small range. If the engine load has not changed to a problem in step SP12, the operation in the steady state determined by the mechanical governor 6 and the injection setting unit 32 is continued.

Note that the determination process in step SP12 is not limited to the case of setting based on one threshold value, but may include a plurality of determination branches according to the manner of change in load. According to this embodiment, it is possible to predict in advance that the rotational speed of the engine will increase or decrease from the fluctuation of the engine load, and to increase or decrease the fuel in advance so as to cancel the fluctuation. Numerical control can be performed.

FIG. 5 is a schematic time chart showing the air-fuel ratio correction processing according to this embodiment. FIG. 5 assumes a case in which a four-cylinder gasoline engine employs an all-cylinder simultaneous injection system. First, FIG.
Receives an ignition signal from an ignition coil. Since the number of the ignition signals is directly connected to the engine speed, the engine speed at that time is obtained as shown in FIG. Next, the injection timing and the injection time t are set by the injection setting unit 32 by the calculation processing of at least one of MAP and TAP.
(FIG. 5C) is calculated. In addition, in an unsteady operation state, for example, when the load becomes large as described in FIG. 4, an injection time s (FIG. 6D) for correction is calculated in accordance with the operation state. Is done. Then, the air-fuel ratio control unit 33 outputs the corrected injection time obtained by adding the injection time s to the injection time t. When the amount of injected fuel is reduced, it goes without saying that the injection time s is subtracted from the injection time t.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the spirit of the present invention. Hereinafter, such an embodiment will be described. (1) In the present invention, the injection amount corrected by the air-fuel ratio controller 33 is not always the injection amount finally determined. For example, a correction means for finely adjusting the corrected injection amount again 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 finalized. It may be an amount. (2) In the above-described embodiment, the working machine has been described by taking the concrete cutter and the generator as examples.
It is clear that the control program can be changed.

[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 flowchart illustrating an example of a process performed by a control unit.

FIG. 3A is a diagram showing governor characteristics in a steady state;
FIG. 3B is a diagram showing how the governor characteristics are changed by changing the fuel injection amount.

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

FIG. 5 is a schematic time chart schematically showing a process of changing the governor characteristics.

[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, 25 ... Operating state detection unit, 32 ...
Injection setting unit, 33: air-fuel ratio control unit, dθ / dt: valve opening
Change rate of sensor opening, dn / dt ... engine speed
Rate of change.

────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI F02D 45/00 364 F02D 45/00 364A 376 376C (56) References JP-A-4-219436 (JP, A) JP-A-8 JP-A-42380 (JP, A) JP-A-7-158475 (JP, A) JP-A-2-176135 (JP, A) JP-A 9-133034 (JP, A) JP-A-2-199240 (JP, A) JP-A-1-116264 (JP, A) JP-A-5-202782 (JP, A) JP-A-6-193473 (JP, A) JP-A-57-97035 (JP, A) JP-A-2- 241945 (JP, A) JP-A-49-58232 (JP, A) JP-A-1-203640 (JP, A) (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 controlling the opening of the throttle valve (5); and a stottle valve (5). Opening (θ)
Based on the valve opening sensor (8) which is substantially detected, data relating to the actual air intake amount of the intake pipe (3) determined by the action of the mechanical governor (6), and the engine speed (n). Injection setting means (32) for setting the steady-state fuel injection amount and injection timing, and operating state detecting means (25) for detecting the operating state of the engine
Air-fuel ratio control for correcting the injection amount set by the injection amount setting means (32) based on the detection result of the operation state detection means (25) to determine the value of the air-fuel ratio corresponding to the operation state have a means (33), the air-fuel ratio control means (33) is a throttle opening (theta) is 10
0%, and it is determined that the rotational speed (n) is decreasing.
If the engine speed is higher than the normal rotation speed, increase the injection amount.
Engine speed at high load.
An electronic fuel injection engine with a mechanical governor, which is used for a cutter . 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 a stottle valve (5). Opening (θ)
Based on the valve opening sensor (8) which is substantially detected, data relating to the actual air intake amount of the intake pipe (3) determined by the action of the mechanical governor (6), and the engine speed (n). Injection setting means (32) for setting the steady-state fuel injection amount and injection timing, and operating state detecting means (25) for detecting the operating state of the engine
Air-fuel ratio control for correcting the injection amount set by the injection amount setting means (32) based on the detection result of the operation state detection means (25) to determine the value of the air-fuel ratio corresponding to the operation state have a means (33), wherein the operating condition detecting means (25), the opening degree of the valve opening sensor 8
a load detecting means for detecting a load applied to the engine based on the rate of change dθ / dt of (θ) , so that the air-fuel ratio control means (33) does not reduce the rotation of the engine when the load increases. An electronic fuel injection engine with a mechanical governor, which controls the air-fuel ratio and controls the air-fuel ratio so that the rotation of the engine does not increase when the load decreases. 3. The electronic fuel injection engine with a mechanical governor according to claim 2 , wherein the operating state is detected.
Means (25) adds to the rate of change (dθ / dt) of the opening (θ).
Based on the rate of change of engine speed (n) (dn / dt)
And has load detection means to detect the load on the engine.
Use this engine as an engine generator
And wherein, electronic fuel injection engine with a mechanical governor.