JP4352014B2 - Fuel injection system - Google Patents

Description

  The present invention relates to a fuel injection system that performs drive control of a rack that adjusts a fuel injection amount.

  Conventionally, there are fuel injection systems that drive and control a fuel injection pump that injects fuel into a cylinder of a diesel engine, a hydraulic timer unit that changes the phase of fuel injection timing, a governor that adjusts the fuel injection amount, and the like. (For example, refer to Patent Document 1).

In such a fuel injection system, the rack built in the governor is driven and controlled, and the fuel injection amount is adjusted by adjusting the rack position. This is performed according to the rotational speed and the intake pressure of the turbocharger. When the fuel injection amount is adjusted based on the engine speed, for example, a maximum fuel injection amount and a minimum fuel injection amount corresponding to the engine speed are determined in advance, and the fuel injection amount is within these ranges. Adjusted. That is, in this case, the relationship between the engine speed and the maximum fuel injection amount and the minimum fuel injection amount is stored in advance in a control means such as an ECM in the fuel injection system, and fuel injection is performed based on these relationships. The amount is controlled.
JP 2004-218636 A

  By the way, in the fuel injection system as described above, when the engine speed is lower than the preset minimum speed for reasons such as improving engine stall resistance, the engine speed is Some control is performed to increase the fuel injection amount as the value decreases. In other words, when the engine is loaded from the state where the engine speed is at the minimum set speed, such as when idling, for example, due to clutch engagement, the engine speed falls below the minimum set speed and the engine speed is reduced. However, the engine stall is prevented by increasing the fuel injection amount as the engine speed decreases on the lower speed side than the minimum set speed.

  In such a fuel injection system, the relationship between the engine speed and the fuel injection amount for increasing the fuel injection amount as the engine speed decreases on the lower speed side than the minimum setting speed is preset. According to a certain minimum set rotational speed, it is stored in advance in the control means as described above. For this reason, when the setting of the minimum setting rotation speed is changed, the following malfunctions may occur.

That is, the minimum set speed is the minimum engine speed within a range that can be adjusted by the operator's operation of the throttle, and is the engine speed at the time of normal idling. For example, the minimum set speed is high. When the setting is changed to the side, it is conceivable that the operability and the driving feeling are impaired when a load is applied to the engine due to clutch engagement or the like during idling. In other words, the fuel injection amount that increases as the engine speed decreases on the lower speed side than the minimum set speed is based on the relationship between the engine speed and the fuel injection amount determined according to a certain minimum set speed. Therefore, when the minimum setting speed is changed to the high speed side, the range of decrease in engine speed due to load application becomes large, or the decrease in engine speed due to load input decreases the fuel injection amount. There is a phenomenon that does not reach a sufficient increase. When such a phenomenon occurs, it takes a certain amount of time to recover the decrease in the engine speed due to the loading of the load, so that operability and driving feeling are impaired.
Conversely, if the minimum set speed is changed to the low speed side, problems such as excessive injection of unnecessary fuel during idling, etc., and increased discharge of unburned fuel may occur. Conceivable.

  Accordingly, the present invention provides a fuel injection system configured to increase the fuel injection amount as the engine speed decreases on the lower speed side than the minimum setting speed at which the setting can be changed. It is an object of the present invention to provide a fuel injection system capable of preventing a decrease in operability / operating feeling and an increase in discharge of unburned fuel accompanying a change in the set rotational speed.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

  That is, in claim 1, the relationship between the engine speed and the fuel injection amount that increases the fuel injection amount as the engine speed decreases on the lower speed side than the minimum setting speed that can be changed is defined. A fuel injection system comprising control means for controlling a fuel injection amount of a fuel injection pump based on a low-rotation side fuel injection quantity characteristic curve, wherein the control means increases or decreases the minimum set rotational speed by changing the setting. Accordingly, the engine speed corresponding to the fuel injection amount of the low-rotation side fuel injection amount characteristic curve is increased or decreased.

  As effects of the present invention, the following effects can be obtained.

  In claim 1, while maintaining the engine stall resistance, it is possible to prevent a decrease in operability / operation feeling and an increase in the discharge of unburned fuel due to a change in the setting of the minimum set rotational speed.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings for understanding of the present invention. The following best mode for carrying out the present invention is an example embodying the present invention, and is not intended to limit the technical scope of the present invention.
FIG. 1 is a block diagram showing a schematic configuration of a fuel injection system, FIG. 2 is a schematic configuration diagram of a fuel injection pump 40 and related devices, etc., and FIG. 3 is a graph showing the relationship between engine speed and fuel injection amount, FIG. 4 is also a partially enlarged graph.

<Outline configuration>
First, the schematic configuration of the fuel injection system 1 of the present invention will be described with reference to FIG.
The fuel injection system 1 described here will be described as a case where the fuel injection system 1 is used as a control system for a fuel injection pump of an engine provided in a ship, for example. However, the same effect can be obtained by using this system. As long as it is adopted, it may be adopted for any kind of thing.
As shown in FIG. 1, the fuel injection system 1 is roughly divided into an operation unit 10 and an engine 20.
The operation unit 10 is provided in the cab of the ship, and is provided with, for example, a display unit 11, a main throttle 12, a sub throttle 13, and the like.
The display unit 11 displays the state of the ship adopting this system, a warning, and the like, and can issue a warning by voice by incorporating a speaker or the like.
The main throttle 12 operates, for example, the throttle valve 29 of the engine 20 and is operated when the ship is in a normal operation state, and is, for example, a lever type.
The sub-throttle 13 operates the throttle valve 29 in the same manner as the main throttle 12, but is different from the main throttle 12 in that it is operated when the ship is not in a normal operation state. The shape of the sub-throttle 13 is, for example, a knob type (volume type) switch.
Each of the display unit 11 and the main throttle 12 has its own control unit, and communicates with an ECM 21 (Engine Control Module), which is a control unit on the engine 20 side, so that the operation unit 10 and the engine 20 as a whole. Control is in progress.
If the communication method such as the protocol is different between the operation unit 10 and the engine 20, a communication repeater 15 is provided for matching the communication method as shown in FIG.
The sub-throttle 13 is directly connected to the ECM 21 on the engine 20 side, and the communication system is the same as that on the engine 20 side.
The engine 20 is, for example, a diesel engine, and is provided with an ECM 21, a crankshaft rotation speed sensor 22, a camshaft rotation speed sensor 23, a retarding electromagnetic valve 24, an advance electromagnetic valve 25, a rack 28, and the like.
The ECM 21 controls an actuator and the like related to the engine 20 based on the state of the operation system such as the sensor related to the engine 20 and the operation unit 10 described above.
The crankshaft rotation speed sensor 22 detects the rotation speed of the crankshaft of the engine 20 and outputs the detection result to the ECM 21 as a crankshaft pulse.
The camshaft rotation speed sensor 23 detects the rotation speed of the camshaft of the engine 20 and outputs the detection result to the ECM 21 as a camshaft pulse.
Further, the crankshaft rotation speed sensor 22 and the camshaft rotation speed sensor 23 can be constituted by optical sensors. For example, a predetermined number of marks are provided on the crankshaft, the camshaft itself or gears at predetermined intervals at the time of manufacture. Thus, the ECM 21 can calculate the rotational speeds of the crankshaft and the camshaft 41 by detecting the mark with the optical sensor.
The delay angle solenoid valve 24 and the advance angle solenoid valve 25 are used to drive the timer piston of the hydraulic timer unit for changing the cam shaft phase of the fuel injection pump 40 as shown in FIG. It is a hydraulic control valve for controlling the hydraulic pressure to slide to the side.
The rack 28 adjusts the amount of fuel injected from the fuel injection pump 40.

<Fuel injection pump>
Next, a schematic configuration of the fuel injection pump 40 and related devices will be described with reference to FIG.
The hydraulic timer unit 50 in FIG. 2 is shown in cross section.
In particular, for the sake of convenience, the timer piston 52 is shown in a state where it is vertically divided by a one-dot chain line, the state moved to the retard side position is indicated by the timer piston 52a, while the state moved to the advance side position is shown. This is indicated by the timer piston 52b.
Of course, the actual timer piston 52 is not divided into two parts by a one-dot chain line as described above, but is integrally formed. In FIG. 2, only the movement state of the timer piston 52 is described. It is divided into two by a one-dot chain line.
The fuel injection pump 40 is for pressure-feeding the fuel stored in the fuel tank to an injection nozzle provided in a cylinder of the engine 20, and is driven by a cam shaft 41. A coupling fixing member 42 for fixing the coupling 51 to the cam shaft 41 is fixed.
Further, the fuel injection pump 40 is provided with supply ports 43 for supplying fuel to the cylinders of the engine 20, and the example shown in FIG.
Further, the fuel injection pump 40 is integrally provided with a governor 30 and a hydraulic timer unit 50.
The governor 30 includes the rack 28, and the rack 28 is driven by a proportional solenoid that is driven and controlled by the ECM 21.
The hydraulic timer unit 50 is provided with a timer piston 52 that is straight and spline-fitted to the outer peripheral surface of the camshaft coupling 51, and a pump drive gear 53 that is helically spline-fitted to the outer peripheral surface of the timer piston 52. Is provided.
The pump drive gear 53 is fixed by a receiving gear 55 that receives a rotational force from the crankshaft of the engine 20 and a bolt 56.
Thus, the camshaft 41 can be rotated by the rotation of the crankshaft, and the timer piston 52 is slid in the spline direction of the camshaft coupling 51 (left and right as viewed in FIG. 2). By moving, the phase difference between the camshaft coupling 51 and the pump drive gear 53 can be changed.
Here, as already described above, the helical shape of the spline fitting is configured so that the camshaft is retarded by sliding the timer piston 52 to the 52a side and advanced by sliding the timer piston 52 to the 52b side. ing.
Further, a space formed on the outer peripheral side of the timer piston 52 fitted with the pump drive gear 53 is a retarded angle chamber 57a, and a space formed on the inner peripheral side of the timer piston 52 fitted with the camshaft coupling 51 is an advanced angle chamber 57b. Respectively.
In this case, the timer piston 52 can be slid to the retard side (52a side) by pumping the pressure oil to the retard chamber 57a, while the timer is pumped by pumping the pressure oil to the advance chamber 57b. The piston 52 can be slid to the advance side (52b side).
In addition, the retarding solenoid valve 24 and the advancement solenoid valve 25 described above are arranged in the retarding pressure fluid path 58a that leads to the retarding chamber 57a and the advancement pressure oil path 58b that leads to the advancement chamber 57b, respectively. The retard solenoid valve 24 and the advance solenoid valve 25 are controlled and operated by the ECM 21 to feed the pressure oil and slide the timer piston 52.
With this configuration, the ECM 21 functions as a control unit that hydraulically controls the timer piston 52 in accordance with the state of the engine 20, and freely delays the phase difference between the crankshaft of the engine 20 and the camshaft 41. It is possible to make an angle or advance.

  In the fuel injection system 1 configured as described above, the fuel injection amount of the fuel injection pump 40, that is, the position of the rack 28 in the governor 30 (hereinafter simply referred to as “rack position”) in this embodiment, is the engine. It is adjusted based on the rotational speed of 20 (hereinafter simply referred to as “engine rotational speed”), the intake pressure of the supercharger, and the like. That is, the rack 28 that adjusts the fuel injection amount by adjusting its position is driven and controlled in accordance with the engine speed, the intake pressure of the supercharger, and the like, and these relationships are an ECM 21 that is an example of a control means. Is stored in advance.

Specifically, the relationship between the engine speed and the fuel injection amount (rack position) is as shown in the graph of FIG. That is, in the fuel injection system 1 according to the present invention, the fuel injection amount relative to the engine speed is the maximum fuel injection amount characteristic curve A (hereinafter simply referred to as “maximum characteristic curve A”) that defines the relationship between the engine speed and the maximum fuel injection amount. And the minimum fuel injection amount characteristic curve B (hereinafter simply referred to as “minimum characteristic curve B”) that defines the relationship between the engine speed and the minimum fuel injection amount.
Then, the ECM 21 is on the low speed side lower than the minimum setting speed No that can be changed. The ECM 21 increases the fuel injection amount as the engine speed decreases, and defines the relationship between the engine speed and the fuel injection quantity. On the basis of the side fuel injection amount characteristic curve b (hereinafter simply referred to as “low rotation side characteristic curve”) b, the fuel injection amount of the fuel injection pump on the low rotation side from the minimum set rotation speed No is controlled.

The maximum characteristic curve A indicates the maximum fuel injection amount calculated based on each engine speed in the relationship between the engine speed and the fuel injection amount, and is, so to speak, an upper limit line of the fuel injection amount.
The minimum characteristic curve B shows the minimum fuel injection amount calculated based on each engine speed in the relationship between the engine speed and the fuel injection amount, which is a lower limit line of the fuel injection amount.
The minimum set speed No is a minimum engine speed within a range that can be adjusted by an operation of the main throttle 12 by the operator, and is an engine speed at the time of normal idling, and is preset by the ECM 21. In the graph shown in FIG. 3, Nm represents the maximum set speed, and the maximum set speed Nm is the maximum engine speed within a range that can be adjusted by operating the main throttle 12, etc. Are preset.

In addition, as described above, the ECM 21 controls the fuel injection amount based on the low-rotation-side characteristic curve b when the engine rotation speed is lower than the minimum set rotation speed No. This low speed characteristic curve b is a part of the low speed side of the minimum characteristic curve B. When the engine speed is lower than the minimum set speed No, the engine speed is It shows the fuel injection amount characteristic for increasing the fuel injection amount with the decrease.
As shown in the graph of FIG. 3, the low-rotation side characteristic curve b has a point (intersection X) that intersects the maximum characteristic curve A at an engine speed that is lower than the minimum set speed No. The fuel injection amount is increased beyond the value determined by the maximum characteristic curve A on the lower rotation side than the intersection X.

  That is, the ECM 21 basically controls the rack position according to the load or the like within the range indicated between the maximum characteristic curve A and the minimum characteristic curve B including the low rotation side characteristic curve b. Control the injection amount. Then, on the low speed side of the engine speed, the fuel injection amount is increased as the engine speed decreases by performing control so as to follow the low speed side characteristic curve b. At this time, the fuel injection amount along the low-rotation-side characteristic curve b on the lower-rotation side than the engine rotation-speed (engine rotation speed at the intersection point X) lower than the minimum set rotation-number No. Increase.

  As described above, the fuel injection system 1 according to the present invention increases the fuel injection amount as the engine speed decreases on the lower speed side than the preset minimum rotational speed No. We are trying to improve. That is, when the engine speed is reduced when the load is applied, for example, when the clutch is engaged, during operation at the minimum set speed No, such as when idling, the fuel injection amount is increased as the engine speed decreases. To prevent engine stalls.

In addition, the fuel injection system 1 according to the present invention is configured such that the minimum set rotational speed No can be set and changed from the viewpoint of improving the versatility of the engine 20 and preventing noise due to resonance. That is, by making it possible to change the setting of the minimum set rotational speed No, it is possible to change the engine rotational speed during idling, and to cope with a desired driving situation by the operator. Further, since the engine speed during idling can be changed, resonance during idling of a ship or the like can be avoided, and noise due to resonance associated with the operation of the engine 20 can be prevented.
This minimum set rotational speed No is basically set at the time of delivery of a ship or the like in which the fuel injection system 1 is adopted, but can be changed by the operator using an operation panel or the like provided in the operation unit 10. Is done. Specifically, for example, the minimum set rotational speed No is configured to be changeable in increments of 20 [rpm] in the range of 700 to 800 [rpm].

In this way, in the fuel injection system 1 configured so that the minimum set rotational speed No can be changed, the ECM 21 as the control means has the low rotational speed characteristic according to the increase / decrease in the minimum set rotational speed No caused by the setting change. Increase or decrease the engine speed corresponding to the fuel injection amount of the curve b.
That is, for example, when the setting is changed to the high speed side so that the minimum set speed increases from No to No1, the ECM 21 corresponds to the engine speed corresponding to the low speed side characteristic curve b as the minimum set speed increases. Increase the number. In this case, on the graph of FIG. 3, the portion b of the low-rotation side characteristic curve of the minimum characteristic curve B is substantially translated to the high rotation side (right side) (see b1). Conversely, when the setting is changed to the low speed side so that the minimum set speed decreases from No to No2, the ECM 21 corresponds to the engine speed corresponding to the low speed side characteristic curve b according to the decrease in the minimum set speed. Decrease. In this case, on the same graph, the portion b of the low-rotation side characteristic curve of the minimum characteristic curve B is substantially translated to the low-rotation side (left side) (see b2).

  Here, when the minimum set speed No is increased or decreased by the setting change described above, the engine speed corresponding to the fuel injection amount of the low speed side characteristic curve b is increased or decreased according to the increase or decrease of the minimum set speed No. However, this is not limited to merely increasing or decreasing the engine speed corresponding to the fuel injection amount of the low-rotation side characteristic curve b. For example, the fuel injection amount is set according to the set minimum rotational speed No. This includes cases where characteristics are changed. That is, it is not limited to the case where the low-rotation side characteristic curve b is substantially translated while maintaining its shape on the graph, and the shape of the curve may be changed according to the setting change of the minimum set rotational speed No. Furthermore, a plurality of low-rotation-side characteristic curves b corresponding to the minimum set rotational speeds No that can be set within a predetermined range of the engine rotational speed are stored in the ECM 21 in advance and set by the operator or the like. A configuration in which the fuel injection amount is controlled based on the low rotation-side characteristic curve b corresponding to the minimum set rotation speed No may be used.

Thus, in accordance with the setting change of the minimum set speed No, the engine speed corresponding to the fuel injection amount of the low speed side characteristic curve b is increased or decreased to maintain the engine stall resistance and the minimum set speed. It is possible to prevent a decrease in operability / operation feeling and an increase in the discharge of unburned fuel due to a change in the No setting.
That is, when the minimum set rotational speed No is changed to the high rotational speed side, the fuel injection amount is appropriately increased as the engine rotational speed decreases when a load is applied during idling or the like. Therefore, it is possible to prevent an increase in the range of decrease in engine speed, and it is possible to prevent a decrease in operability and driving feeling. Further, when the minimum set rotational speed No is changed to the low speed side, unnecessary fuel is not excessively injected at the time of idling or the like, and an increase in discharge of unburned fuel can be prevented. .

  Hereinafter, using the partially enlarged graph shown in FIG. 4, a specific example of changes in the engine speed and the fuel injection amount will be shown, and the above-described effects will be described. Here, the lowest set speed before the setting is changed is No, and the low speed characteristic curve corresponding to the lowest set speed No is b.

First, a description will be given of a case where the minimum setting rotational speed No is set and changed to No1 on the high rotational side.
First, it is assumed that the engine speed corresponding to the fuel injection amount of the low speed characteristic curve b is not increased (the low speed characteristic curve b is not moved) due to the increase in the minimum set speed from No to No1 due to the setting change. It is assumed that the idling operation is performed in a state where the engine speed is the lowest set speed No1. That is, on the graph, a state corresponding to the point p1 at which the engine speed on the low-rotation side characteristic curve b is No1 is obtained. From this state, when a load is applied to the engine 20 by clutch engagement or the like, the injection amount is increased to the maximum fuel injection amount at the engine speed (No. 1) in that state. That is, on the graph, the point p1 moves to the point p2 on the maximum characteristic curve A. Further, since the engine speed decreases due to the applied load, the engine speed moves from the point p2 to the low speed side along the maximum characteristic curve A on the graph.
When the engine speed decreases to a certain value, the fuel injection amount is increased from the value on the low rotation side based on the low rotation side characteristic curve b. That is, on the graph, when the intersection point X between the maximum characteristic curve A and the low rotation side characteristic curve b is reached from the point p2, the low rotation side characteristic curve b follows the engine rotation speed at the intersection X. As a result, the fuel injection amount is increased. Thereafter, when the load is released, the engine speed increases, returns to the lowest set speed No1, and corresponds to the point p1.
In other words, even if the minimum setting speed is increased from No to No1 due to the setting change, the engine speed corresponding to the fuel injection amount of the low speed characteristic curve b is not increased (the low speed characteristic curve b is not moved). Then, the engine speed decreases from No1 until the fuel injection amount is increased based on the low-rotation side characteristic curve b beyond the injection amount based on the maximum characteristic curve A due to a decrease in the engine speed from the idling time. The engine speed at the intersection X is reduced.

On the other hand, as in the present invention, the engine speed corresponding to the fuel injection amount of the low speed characteristic curve b is increased by increasing the minimum set speed from No to No1 due to the setting change. Suppose that the idling operation is performed in the state of the minimum set rotational speed No1. That is, as the minimum setting rotational speed is increased from No to No1 due to the setting change, the low rotational speed characteristic curve b is moved to b1, and the engine rotational speed on the low rotational speed characteristic curve b1 after the movement is No1. It becomes a state corresponding to the point p3. From this state, when a load is applied to the engine 20 due to clutch engagement or the like, the injection amount is increased as described above, moving from the point p3 to the point p2 on the maximum characteristic curve A on the graph and being applied. The engine speed decreases due to the load, and the graph moves from the point p2 to the low speed side along the maximum characteristic curve A on the graph.
When the engine speed decreases to a certain value, the fuel injection amount is increased on the low rotation side based on the low rotation side characteristic curve b1. That is, on the graph, when the intersection point X1 between the maximum characteristic curve A and the low rotation side characteristic curve b1 is reached from the point p2, it follows the low rotation side characteristic curve b1 on the lower rotation side than the engine speed at the intersection point X1. As a result, the fuel injection amount is increased. Thereafter, when the load is released, the engine speed increases, returns to the lowest set speed No1, and corresponds to the point p3.
That is, when the minimum setting speed is increased from No to No1 by changing the setting, the engine speed corresponding to the fuel injection amount of the low speed characteristic curve b is increased and moved to the low speed characteristic curve b1. Therefore, the engine speed decreases from the idling time until the fuel injection quantity is increased based on the low speed characteristic curve b1 beyond the injection quantity based on the maximum characteristic curve A, so that the engine speed is No1. To the engine speed at the intersection X1.

  Comparing these, the fuel injection amount is based on the low-rotation-side characteristic curve b (or b1) when the engine speed is reduced by applying a load since idling at the minimum set speed No1 after the setting change. The range of decrease in the engine speed from No1 until the engine speed is increased up to the engine speed at the intersection point X is that the low speed side characteristic curve b is moved to b1 until the engine speed at the intersection point X1. It will be suppressed. That is, the amount of decrease in the engine speed can be reduced by the difference ΔN between the engine speed at the intersection X1 and the engine speed at the intersection X. In other words, it is possible to speed up the recovery of the engine speed, which is reduced by loading the load, by the difference ΔN. Thereby, it is possible to prevent a decrease in operability and driving feeling when a load is applied during idling or the like.

Next, a description will be given of a case where the minimum set rotation speed No is changed to No2 on the low rotation side.
In this case, the engine speed corresponding to the fuel injection amount of the low-rotation characteristic curve b is not decreased (the low-rotation characteristic curve b is not moved) due to the decrease in the minimum set rotational speed from No to No2 due to the setting change. Then, the idling in the state where the engine speed is the minimum set speed No2 corresponds to the point p4 where the engine speed on the low speed characteristic curve b is No2 on the graph, and the fuel in that state Let the injection amount be F0.
On the other hand, as in the present invention, the engine speed corresponding to the fuel injection amount of the low speed characteristic curve b is reduced by reducing the minimum set speed from No to No2 due to the setting change. When the characteristic curve b is moved to b2, the engine speed on the low-speed characteristic curve b2 after movement on the graph corresponds to idling when the engine speed is the minimum set speed No2. Becomes point p5 at which No2 is obtained, and the fuel injection amount in this state is F2.

  That is, when these are compared, the engine speed corresponding to the fuel injection amount of the low speed characteristic curve b is decreased with the decrease in the minimum set speed No due to the setting change, and the low speed characteristic curve b becomes b2. By being moved, the fuel injection amount at the time of idling at the minimum set rotational speed No2 after the setting change is reduced from F0 to F2. Thereby, unnecessary fuel is not excessively injected, and an increase in discharge of unburned fuel can be prevented.

The block diagram which showed schematic structure of the fuel-injection system. The schematic block diagram of the fuel-injection pump 40 and its related apparatus. The graph which shows the relationship between an engine speed and fuel injection quantity. Also a partially enlarged graph.

Explanation of symbols

1 Fuel injection system 20 Engine 21 ECM
40 Fuel injection pump A Maximum fuel injection amount characteristic curve B Minimum fuel injection amount characteristic curve b Low rotation side fuel injection amount characteristic curve

Claims (1)

Low-rotation-side fuel injection amount characteristic curve that defines the relationship between the engine speed and the fuel injection amount, which increases the fuel injection amount as the engine speed decreases, on the low-rotation side of the minimum setting speed that can be changed. A fuel injection system comprising a control means for controlling the fuel injection amount of the fuel injection pump based on
The control means increases / decreases an engine speed corresponding to a fuel injection amount of the low-rotation side fuel injection amount characteristic curve according to an increase / decrease of the minimum set rotation speed by the setting change. .

Images