JP2578819Y2 - Diesel engine fuel injection system - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for a diesel engine.

[0002]

2. Description of the Related Art A diesel engine has two main and secondary injections in a combustion chamber for the purpose of reducing combustion noise, reducing harmful substances in exhaust gas, and improving combustion efficiency by atomizing fuel and shortening spray time. There is a two-nozzle injection type engine provided with holes. In the two-nozzle injection type diesel engine, for example, pilot injection is performed from the sub injection hole prior to the main fuel injection by the main injection hole, thereby preventing ignition delay to the fuel mixture and reducing combustion noise. , Reduction of harmful substances in exhaust gas,
The aim is to improve combustion efficiency.

In order to provide two injection holes in a combustion chamber, two fuel injection nozzles (fuel injection means) are provided for each cylinder, or a sub-nozzle is provided from one fuel injection nozzle. The fuel injection nozzle branches off, that is, a fuel injection nozzle (fuel injection means) having two nozzles is attached to one fuel injection nozzle to form a sub injection hole.

Further, in order to supply fuel to these two injection holes, one fuel pump is conventionally provided, so-called 1 fuel pump.
The structure of the pump 2 nozzle injection is adopted.

[0005]

As described above, the conventional 2
In a nozzle injection type diesel engine, one fuel pump supplies fuel to two injection holes. However, when the fuel is supplied by one fuel pump, the degree of freedom of the setting of the fuel control is narrow, and the fuel injection is adjusted so that the main fuel injection is appropriately performed, and the pilot injection is optimally performed. There is a problem that it becomes difficult. Further, the main injection hole is configured to always perform the main fuel injection, and the sub injection hole is configured to always perform the pilot injection. For this reason, for example, regarding the main fuel injection, the diameter of the main injection hole is too large in the middle load region of the engine, a high-speed fuel injection flow cannot be obtained, and the mixing of air and fuel cannot be performed optimally. In addition, there is a problem that if soot cannot be reduced, the amount of HC cannot be reduced. On the other hand, when the load is high, the diameter is too small, so that a large amount of fuel cannot be injected within a required time.

As described above, in the conventional one-pump two-nozzle injection, the fuel injection cannot be optimally performed according to the operating state of the engine, and the desired combustion is not necessarily realized in the entire operating range of the engine. There is a problem that can not be. The present invention has been made to solve such a problem, and an object of the present invention is to provide a fuel injection device for a diesel engine designed to achieve optimum combustion in the entire operation range of the engine. I do.

[0007]

To achieve the above object, according to the solution to ## according to the fuel injection device of the present invention of the diesel engine, the first injection hole and this disposed in the combustion chamber of an engine
Has a second injection hole with a smaller opening area than the first injection hole
And into the combustion chamber through these first and second injection holes.
Supply and injectable fuel injection means the fuel into respective independent fuel independently to the first and second injection holes of fuel injection means
A fuel supply means for exerting fuel injection means and, operating condition detecting means for detecting operating conditions of the engine, and control means on the basis of the detected operating state by OPERATION state detecting means, for controlling the fuel supply means And this control means
Indicates that the detected operating state is in the low load region of the engine
Sometimes, pilot fuel is injected through the second injection hole
After that, the main fuel is injected through the first injection hole,
The rolling state is at least in the area of the engine's medium load or higher.
Sometimes, the main injection of fuel is performed only through the second injection hole .

[0008]

[Action] The fuel injection system of the aforementioned diesel engine, the control means controls the fuel supply means based on operating conditions of the engine detected by the operating condition detecting means,
Fuel is independently supplied to two injection holes having different opening areas of the fuel injection means, and the two injection holes are selectively used to independently inject fuel into the combustion chamber. That is, two injection holes having different opening areas of the fuel injection means depending on the operation state of the engine can be properly used to perform the fuel injection, so that compared to the conventional fuel injection device of a diesel engine,
The injection pressure, the injection pattern, the injection time, and the like can be changed extremely variously according to the operating state of the engine.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a specific configuration of the diesel engine fuel injection device of the present invention. In FIG.
Indicates, for example, a four-cylinder diesel engine, and a first fuel injection pump 50 (fuel supply means) and a second fuel injection pump 50a (fuel supply means) are disposed on the left and right sides of the engine 1, respectively. I have. Fuel injection pump 50, 50a
Are connected to fuel pipes 4 and 5 for supplying fuel to the fuel injection pumps 50 and 50a, respectively. A fuel injection nozzle (fuel injection means) 10 is attached to the cylinder head 1a of the engine 1 for each cylinder. The fuel injection nozzle 10 and the first fuel injection pump 50 are connected by the fuel pipe 6, and the fuel injection nozzle The fuel injection pump 10a and the second fuel injection pump 50a are connected by a fuel pipe 7, respectively.

FIG. 2 shows a configuration of a main part of the fuel injection nozzle 10. The fuel injection nozzle 10 is generally provided with the nozzle holder 1.
1, a nozzle 21, and a retaining nut 29. A first fuel injection mechanism 48 for injecting the fuel supplied from the first fuel injection pump 2 via the fuel pipe 4 is disposed on the right side of the fuel injection nozzle 10 in the drawing, and on the left side in the drawing, A second fuel injection mechanism 49 for injecting fuel supplied from the second fuel injection pump 3 via the fuel pipe 5 is provided.

On one side of the nozzle holder 11, a large-diameter spacer accommodating chamber 12, a medium-diameter spring accommodating chamber 13, and a small-diameter rod hole 14 of the first fuel injection mechanism 48 are continuously drilled in this order from above. Has been established. A connection end 15 for connecting the fuel pipe 4 is formed at an upper portion of the nozzle holder 11, and the connection end 15 and a lower end surface 16 of the nozzle holder 11 are formed outside the spacer accommodating chamber 12 in the nozzle holder 11. A feed hole 17 is provided to communicate between the two.
On the other side of the nozzle holder 11, the second fuel injection mechanism 4 formed similarly to that of the first fuel injection mechanism 48
9 and a spring housing 13
a, rod hole 14a, connection end 15a, feed hole 1
7a are provided respectively.

In the rod hole 14 of the first fuel injection mechanism 48, a first push rod 31 formed substantially in a columnar shape and integrally provided with a disk-shaped spring seat 32 on the upper portion thereof is provided.
It is slidably inserted from the spring storage chamber 13 side. On the other hand, a substantially cylindrical spacer 33 is fitted into the spacer accommodating chamber 12 from above in the figure.
It is fixed to the nozzle holder 11 by a substantially cylindrical set screw 34 fitted and screwed into the nozzle holder 11. A first spring 35 is interposed between the spacer 33 and the spring seat 32, and the first push rod 31 is constantly urged downward in the figure. A second push rod 36 integrally provided with a spring seat 37 at an upper portion is slidably inserted into the spacer 33 from the set screw 34 side. An adjusting screw 38 is inserted and screwed into the upper open end of the set screw 34, a second spring 39 is interposed between the adjusting screw 38 and the spring seat 37, and a second push rod 36 is inserted.
Are always urged downward in the figure. The urging force of the second spring 39 can be adjusted by changing the pushing amount of the adjusting screw 38. In addition, a shim 40 is interposed between the spring seat 37 and the spacer 33 to adjust the contact relationship between the first push rod 31 and the second push rod 36.

The same components 31 to 40 of the first fuel injection mechanism 48 are used for the second fuel injection mechanism 4.
It is also arranged on the 9 side. On the other hand, a substantially cylindrical nozzle 21 is mounted below the nozzle holder 11 in a liquid-tight manner by a retaining nut 29. The first fuel injection mechanism 4 of the nozzle holder 11 is
The large-diameter guide hole 2 continues to the rod hole 14 on the 8 side.
2 and a small-diameter valve hole 23 are drilled in this order from above,
A fuel reservoir 24 is provided between the guide hole 22 and the valve hole 23. The fuel reservoir 24 and the feed hole 17 of the nozzle holder 11 are connected by a feed hole 25. On the other hand, the lower end of the valve hole 23 is formed in a conical shape.
A plurality of first injection holes 27 for injecting the fuel supplied through 3 into the combustion chamber of the engine 1 at a required angle are provided. The first injection hole 27 protrudes from the tip of the retaining nut 29, and when the fuel injection nozzle 10 is attached to the cylinder head 1a of the engine 1 as shown in FIG. Protrude into.

The nozzle 21 has a guide hole 22a for the second fuel injection mechanism 49, a valve hole 23a, a fuel reservoir 24a, a feed hole 25a, and a second injection hole 27a similar to those of the first fuel injection mechanism 48. And so on, respectively. However, the diameter of the second injection hole 27a is formed smaller than that of the first injection hole 27.
The injection pressure, the injection pattern, the injection time, and the like different from those described above are obtained. The injection holes 27, 27a are provided as close as possible to each other, and both the injection holes 27, 27a are arranged at the center of the combustion chamber. This is because the fuel injection is uniformly performed in the combustion chamber from both of the two injection holes 27 and 27a, thereby increasing the utilization rate of the air in the combustion chamber to improve the combustion efficiency and reduce soot. This is for planning. The length of the fuel injection by the two injection holes 27 and 27a may be different from each other so as not to interfere with each other.

Next, a nozzle needle 41 is fitted into the guide hole 22 and the valve hole 23 of the first fuel injection mechanism 48. The nozzle needle 41 has a large-diameter guide portion 42.
The guide portion 42 is slidably fitted in the guide hole 22, and the needle portion 43 is fitted in the valve hole 23 through a required gap. The lower end of the needle portion 43 is formed in a conical shape. When the conical portion 44 comes into contact with the conical portion 26 of the valve hole 23, the injection hole 27 and the valve hole 23 are shut off. The injection is stopped. A cylindrical protruding end 45 is formed on the upper end surface of the guide portion 42, and the protruding end 45 is inserted into the rod hole 14 and abuts on the first push rod 31. Thus, the nozzle needle 41 is constantly urged downward by the springs 35 and 39.

In the first fuel injection mechanism 48, the total fuel pressure of the fuel supplied to the fuel reservoir 24 through the feed holes 17 and 25 is applied to the tapered lower end surface 46 of the guide portion 42 of the nozzle needle 41. , Springs 35, 39
When the pressure exceeds the urging force, the nozzle needle 41 is pushed upward, the first injection hole 27 and the valve hole 23 communicate with each other, and fuel is injected from the first injection hole 27. At this time, the fuel is supplied from the fuel reservoir 24 to the first injection hole 27 via a gap between the valve hole 23 and the needle portion 43 of the nozzle needle 41. A nozzle needle 41 a similar to the nozzle needle 41 is also provided on the second fuel injection mechanism 49 side of the nozzle 21.

FIG. 3 shows a configuration of a main part of the first fuel injection pump 50. That is, the first fuel injection pump 50 is constituted by a so-called row-type displacement pump,
A camshaft 52 interlocking with the crank angle θ of a crankshaft (not shown) is rotatably supported via a bearing 53 at a lower portion of the camshaft 52, and a cam 54 is formed integrally with the camshaft 52. Above the cam 54,
Data pets bets 55 fitted freely sliding in the pump housing 51 is disposed, this data pets DOO 55, freely motor Bae Ttorora 56 rotates rolling on the cam surface of the cam 54 the shaft Supported. The upper end portion of the motor pets preparative 55 is fixed plunger 57, the plunger 57 reciprocates up and down integrally with the motor Bae <br/> Tsu preparative 55 by the rotation of the cam 54. Plunger 57
Spring seat 58 formed at the lower part of the upper part and upper spring seat 5 fixed to pump housing 51
9, a plunger spring 60 is interposed, and the plunger 57 is constantly urged downward by the plunger spring 60. The upper part of the plunger 57
Slidably inserted and rotatably fitted vertically into a substantially cylindrical control sleeve 61, also the upper portion of the control sleeve 61 is fitted rotatably in the pump housing 51. A pinion gear 62 is formed on the outer peripheral surface of the control sleeve 61.
Meshes with a rack 63 which slidably inserted through the pump housing 51. For this reason, the control sleeve 61 is driven by the rack 63 so that the pump housing 5
1 and the plunger 57 are freely rotatable. The space above the plunger 57 in the control sleeve 61 forms a cylinder chamber 76 of the first fuel injection pump 50.

A spiral groove, that is, a control groove 64, is formed on the outer peripheral surface of the upper end of the plunger 57, while feed holes 65, 65 are formed in the side wall of the control sleeve 61, and these feed holes are formed. The inner open ends of the plungers 65 are substantially flush with the upper end surface of the plunger 57 when the plunger 57 is at the bottom dead center. The pump housing 51 includes a control sleeve 6.
1, a fuel reservoir 66 is formed, and the fuel reservoir 66 has open outer ends of feed holes 65, 65, and the fuel reservoir 66 communicates with a fuel supply port 78. That is,
The fuel supply port 78 and the feed holes 65 are always in communication via the fuel reservoir 66 regardless of the rotational position of the control sleeve 61.

Next, a delivery valve holder 67 is fixed to the upper end of the pump housing 51 in a liquid-tight manner, and a valve accommodating chamber 68 is provided inside the delivery valve holder 67. The valve housing chamber 68 houses a delivery valve 70 and a delivery valve spring 69. The valve chamber 68 and the cylinder chamber 76 communicate with each other through a valve guide hole 77, and a guide portion 71 of a delivery valve 70 is slidably fitted in the valve guide hole 77. The conical valve portion 7 of the delivery valve 70 is provided at the open end of the valve guide hole 77 on the valve housing chamber 68 side.
2 is urged by the delivery valve spring 69 to abut, and the delivery valve 70 is closed. Further, the valve housing chamber 68 and the cylinder chamber 76 are also communicated by a bypass passage 73, and a check valve 74 that allows only fuel flow from the valve housing chamber 68 to the cylinder chamber 76 is interposed in the bypass passage 73. I have. The valve housing chamber 68 communicates with the discharge port 75, and when the delivery valve 70 is opened, the cylinder chamber 76 communicates with the discharge port 75.

Further, the first fuel injection pump 50 has a structure shown in FIG.
, A first rack actuator (fuel supply means) 80 is mounted. The first rack actuator 80 is connected to a controller (control means) 90 and is controlled by an electric signal of the controller 90 to move the rack 63 of the first fuel injection pump 50 to a required position. That is, the first rack actuator 80 is controlled by the controller 90, and the rack 63,
The control sleeve 61 is rotated via the pinion gear 62. As a result, the positional relationship between the control sleeve 61 and the plunger 57 changes, and the stroke amount of the plunger 57 until the inner open ends of the feed holes 65, 65 of the control sleeve 61 communicate with the grooves of the control groove 64 changes. For this reason, the cam 5
Even if the amount of plunger 57 thrust by 4 is constant, the discharge amount of the first fuel injection pump 50 can be continuously changed from zero to the maximum injection amount.

Next, the second fuel injection pump 50a is
As shown in FIG. 7, the first fuel injection pump 50 is constituted by an in-line positive displacement pump. However, the maximum discharge amount of the second fuel injection pump 50a is equal to the first fuel injection pump 5a.
Since the diameter of the plunger 57a is smaller than that of the plunger 57, the diameter of the plunger 57a is smaller than that of the plunger 57. Further, since the operation of the fuel injection pumps 50 and 50a is different, the cam 44
a is formed in a shape different from that of the cam 44.

As shown in FIG. 1, a second rack actuator (fuel supply means) 80a is mounted on the second fuel injection pump 50a. The second rack actuator 80a is also connected to the controller 90, and is controlled by an electric signal of the controller 90, as in the case of the first rack actuator 80 of the first fuel injection pump 50.
The discharge amount of the second fuel injection pump 50a can be continuously changed from zero to the maximum injection amount.

The operation of the cams 54, 54a of the fuel injection pumps 50, 50a is controlled by timers (not shown), and the fuel injection timing of the fuel injection pumps 50, 50a is controlled. The controller 90 further includes an engine speed sensor 91 for detecting the engine speed,
An engine load sensor 92 for detecting an engine load is connected, and an engine speed Ne detected by the engine speed sensor 91, an engine load L detected by the engine load sensor 92, and the like are input to the controller 90. That is, the engine speed sensor 91 and the engine load sensor 92 constitute an engine operating state detecting means, and the controller 90 controls the rack actuators 80, 80a based on the operating state of the engine detected by these sensors.
Are independently controlled, and the discharge amounts of the fuel injection pumps 50 and 50a, that is, the fuel injection amounts from the injection holes 27 and 27a of the fuel injection nozzle 1 are independently changed. Here, the engine load sensor 92 includes, for example, an accelerator opening sensor that detects the amount of depression of the accelerator.

Next, the procedure of the fuel injection control executed by the controller 90 will be described with reference to FIGS. First, the controller 90 is connected to the engine load sensor 9.
The engine load L detected by the engine speed sensor 2 and the engine speed Ne detected by the engine speed sensor 91 are read (step S10).

Then, it is determined whether the engine load L detected by the engine load sensor 92 is less than the first predetermined load L1 (step S20). The first predetermined set load L1 is set to, for example, a value of 5 to 10% of the maximum engine load Lmax. Of the present engine 1. More specifically, the engine load L is set to the first predetermined set load. L1
When it is less than, it means that the engine 1 is in idle or low load operation.

If the determination result of step S20 is affirmative (Ye
In the case of s), the A-mode injection is executed irrespective of the engine speed Ne as shown in FIG. 6 (step S30). Here, FIG. 6 is a characteristic diagram showing a relationship between the engine speed Ne, the engine load L, and the fuel injection modes A, B, and C described later. Also, the A-mode injection is:
This is fuel injection in which pilot injection is first performed from the small-diameter second injection hole 27a described above, and immediately thereafter, main fuel injection is performed from the large-diameter first injection hole 27. FIG. 7 shows the relationship between the crank angle θ of the engine 1 and the push-up amounts of the nozzle needles 41 and 41a of the fuel injection nozzle 10 in the A-mode injection. According to FIG. 7, when the crank angle reaches θ1, the second
Controller 90 via rack actuator 80a
From the second fuel injection pump 50a fuel-controlled by
A required amount of fuel is discharged, whereby the nozzle needle 41a on the second fuel injection mechanism 49 side of the fuel injection nozzle 10 is discharged.
Is pushed up, and fuel is injected from the small diameter second injection hole 27a. In this way, pilot injection is performed as pre-injection prior to main fuel injection. The pilot injection has a shorter injection time and a smaller injection amount than the main fuel injection.

[0027] After the fuel injection by the second injection holes 27a is completed, the crank angle reaches .theta.2, first fuel injection pump 5 0 to which is fuel controlled by the controller 90 via the first rack actuator 80, the required An amount of fuel is discharged, whereby the nozzle needle 41 of the first fuel injection mechanism 48 is pushed up, and fuel is injected from the large diameter first injection hole 27. Thus, the main fuel injection is performed. This main fuel injection has a longer injection time and a larger injection amount than the pilot injection. As described above, in the A-mode injection, prior to the main fuel injection by the first injection hole 27, the pilot injection as the pre-injection is appropriately performed from the second injection hole 27a. Combustion noise is effectively reduced.

If the result of the determination in step S20 is negative (No)
Then, it is determined whether the engine load L is equal to or more than the first predetermined load L1 and less than the second predetermined load L2 (step S4).
0). Here, the second predetermined load L2 is, for example, 50 to 70 of the maximum engine load Lmax.
%, Which is a determination value set to determine whether or not the engine load L is high.

If the result of the determination in step S40 is affirmative, B-mode injection is executed irrespective of the engine speed Ne as shown in FIG. 6 (step S5).
0). Here, the B-mode injection is to perform main fuel injection through the second injection holes 27a, and at this time, no fuel is injected from the first injection holes 27. As described above, since the second injection hole 27a is formed to have a smaller diameter than the first injection hole 27, the second fuel injection pump 5 that is fuel-controlled by the controller 90 via the second rack actuator 80a.
0a, when a required amount of fuel is discharged, high-speed and high-pressure fuel injection can be performed into the combustion chamber, thereby promoting the mixing of fuel and air, and effectively reducing HC when soot is discharged. .

If the result of the determination in step S40 is negative,
That is, when the engine load L is high, it is next determined whether or not the engine speed Ne detected in step S10 exceeds a predetermined set speed Ne1 (step S60). Here, the predetermined rotation speed Ne1 is, for example, 60 to the maximum rotation speed degree Ne max. Of the engine 1.
This is set as a 90% rotation speed, and is a determination value set to determine whether the engine rotation speed Ne is in a high rotation range.

If the decision result in the step S60 is negative, the B-mode injection in the above-mentioned step S50 is executed. In other words, even if the engine load L is in the high load region, if the engine speed Ne is not in the high rotation region, the fuel injected from the second fuel injection pump 50a is sufficiently supplied by the small-diameter second injection hole 27a for a sufficient time. It is because it can finish injecting into. Thereby, soot and HC can be reduced. The engine operating state in which the B-mode injection is performed is hereinafter referred to as a normal operation.

If the result of the determination in step S60 is affirmative, C-mode injection is performed (step S70). Here, the C-mode injection is to perform main fuel injection through the first injection hole 27, and at this time, no fuel is injected from the second injection hole 27a. That is, when the determination result of step S60 is affirmative, the engine load L is in the high load range and the engine speed Ne is in the high rotation range, so that the fuel injection amount becomes large, and the small-diameter second Since the injection of the fuel cannot be completed within the required time in the injection hole 27a, the fuel is injected from the large-diameter first injection hole 27. As a result, the fuel desired at the time of high load and high rotation is injected into the combustion chamber within the required time, and the horsepower at the output point is sufficiently secured. Thus, the routine ends,
The program returns.

As described above, in the fuel injection device of the present diesel engine, the diameter of the injection hole is appropriately switched according to the operating state of the engine, and the fuel injection pumps 50, 50a corresponding to the injection holes 27, 27a are respectively provided. Since these are controlled by the controller 90 via the rack actuators 80 and 80a, respectively, the combustion noise is reduced at the time of idling and a low load, and the soot and HC are effectively reduced at the time of normal operation. At a high load and a high rotation speed, a desired horsepower can be secured, and thus, optimal combustion is realized in the entire operation range of the engine.

The fuel injection device for a diesel engine according to the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the engine load L
The fuel injection control executed based on the engine speed Ne and the engine speed Ne is not limited to the fuel injection control in the A, B, and C modes shown in FIGS.
Further, the switching between the injection holes 27 and 27a, that is, the proper use may be performed based on e.

In the above-described embodiment, the engine speed sensor 91 and the engine load sensor 92 constitute operating state detecting means, and the engine operating state detected by these sensors, that is, L and Ne, is used. Thus, the fuel injection from the injection holes 27 and 27a is controlled respectively. However, the operating state detecting means is not limited to this. For example, as shown by a two-dot chain line in FIG. 1, an atmospheric temperature sensor 93 for detecting an atmospheric temperature, a cooling water temperature for detecting an engine cooling water temperature. A sensor 94 and the like may be provided to control the fuel injection from the injection holes 27 and 27a, respectively, based on the engine operating state detected by these sensors. Further, the engine load sensor 92 is not limited to the accelerator opening sensor, and may be constituted by another sensor that detects the engine load L.

In the embodiment described above, the two injection holes 27 and 27a to which fuel is independently supplied are provided in one fuel injection nozzle 10, but the invention is not limited to this. For example, two fuel injection nozzles (fuel injection means) having one injection hole and mutually different injection hole diameters may be arranged in each combustion chamber of the engine 1.

[0037]

As described above in detail, in the fuel injection device for a diesel engine according to the present invention, the control means controls the opening of the fuel injection means according to the operating state of the engine.
Fuel injection is performed by appropriately using two injection holes having different products . As a result, the injection pressure, the injection pattern, the injection time, and the like can be varied in various ways according to the operating state of the engine, so that optimal combustion can be achieved in the entire operating range of the engine. an effect called that.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a specific configuration of a fuel injection device for a diesel engine according to the present invention.

FIG. 2 is a side sectional view showing a configuration of a main part of a fuel injection nozzle 10 in FIG.

FIG. 3 is a front sectional view showing a configuration of a main part of a first fuel injection pump 50 in FIG. 1;

FIG. 4 is a front sectional view showing a configuration of a main part of a second fuel injection pump 50a in FIG. 1;

FIG. 5 is a flowchart showing a procedure of fuel injection control executed by a controller 90 in FIG. 1;

FIG. 6 is a characteristic diagram showing a relationship among an engine speed Ne, an engine load L, and fuel injection modes A, B, and C.

FIG. 7 shows the crank angle θ of the engine 1 and the fuel injection nozzle 1
FIG. 7 is a characteristic diagram showing a relationship between the nozzle needles 41 and 41a and the pushing amount of the nozzle needles 41a.

[Explanation of symbols]

 Reference Signs List 1 diesel engine (engine) 10 fuel injection nozzle (fuel injection means) 27 first injection hole 27a second injection hole 50 first fuel injection pump (fuel supply means) 50a second fuel injection pump (fuel supply means) 80 first Pump actuator (fuel supply means) 80a Second pump actuator (fuel supply means) 90 Controller (control means) 91 Engine speed sensor (operating state detecting means) 92 Engine load sensor (operating state detecting means)

Continuation of the front page (56) References JP-A-62-135637 (JP, A) JP-A-62-26562 (JP, U) JP-A-3-51165 (JP, U) (58) Fields investigated (Int) .Cl. ⁶ , DB name) F02M 45/08 F02M 45/00 F02D 41/38

Claims (1)

(57) [Scope of request for utility model registration] 1. A first injector disposed in a combustion chamber of an engine.
Hole and a second injection nozzle having an opening area smaller than that of the first injection hole.
A hole through which the combustion takes place through the first and second injection holes.
Fuel supply to work and independent injectable fuel injection means the fuel into the chamber, said fuel injection means to supply fuel to each <br/> independently to the first and second injection holes of the fuel injection means means, operating condition detecting means for detecting operating conditions of said engine, based on the detected operating state by said operating condition detecting means, and control means for controlling the pre-Symbol fuel supply means, said control means The detected operating state is
When the engine is in the low load region, fuel is supplied through the second injection hole.
After the pilot injection, the fuel is injected through the first injection hole.
Fuel, while the operating condition is at least
When the gin is in the area above the medium load, the second injection hole
A fuel injection device for a diesel engine, characterized in that the main fuel is injected only through the fuel injection device.