JP2017008854A - Fuel injection nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection nozzle capable of dividing an omnidirectional shaft periphery of a nozzle body 3 into an angular range of weak spray penetration force and an angular range of strong spray penetration force.SOLUTION: A fuel injection nozzle includes a nozzle body 3 having a plurality of injection holes having injection hole inlets 31 opened at an inner peripheral face of a sack chamber 8, and a needle 2 separating from and sitting on a seat surface 10 of the nozzle body 3 for opening and closing a fuel flow channel 13 at an upstream side with respect to the plurality of injection holes. In the plurality of injection holes, an upper-stage injection hole 7H having the injection hole inlet 31 positioned at an upper side of an axial direction with respect to the injection hole inlet 32 of a lower-stage injection hole 7L exists. Thus spray penetration force is weakened in the angular range in which the upper-stage injection hole 7H exists in the omnidirectional shaft periphery of the nozzle body 3, in comparison with that in the angular range in which the lower-stage injection hole 7L exists. That is, the omnidirectional shaft periphery of the nozzle body 3 can be divided into the angular range of weak spray penetration force and the angular range of strong spray penetration force.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fuel injection nozzle that injects fuel into a cylinder of an engine.

In an engine, it is known that the optimum value of the spray characteristics of the fuel injected from the fuel injection nozzle varies depending on the shape of the combustion chamber and the target value of the amount of heat.
For example, the penetrating force is taken up from the spray characteristics. When the penetrating force is strong, the fuel spray spreads farther, so that the air utilization rate in the combustion chamber is increased and a good combustion state is obtained. Thereby, the amount of smoke discharged can be reduced, and the engine output and fuel consumption can be improved. On the other hand, when the penetrating force is strong, the fuel spray easily reaches the combustion chamber wall surface, and the amount of heat released from the combustion chamber wall surface to the cooling medium increases, resulting in an increase in engine cooling loss. For this reason, it is necessary to optimally set spray characteristics such as penetration force depending on the combustion chamber shape and the target value of heat.

Incidentally, in recent years, it has been desired to divide the combustion chamber into an intake valve side region and an exhaust valve side region, and to change the spray characteristics of the fuel injected toward both regions.
For example, there is an engine in which the fuel injection nozzle mounting position is offset from the cylinder shaft toward the intake valve side region. In this engine, the distance from the fuel injection nozzle to the combustion chamber wall surface in the intake valve side region is shorter than that in the exhaust valve side region, and fuel spray easily reaches the combustion chamber wall surface in the intake valve side region. For this reason, it is necessary to weaken the penetration force to the intake valve side region and to increase the penetration force to the exhaust valve side region.

  In addition, there is an engine in which the fuel injection nozzle mounting position is offset from the cylinder shaft toward the exhaust valve side region. In this engine, the distance from the fuel injection nozzle to the combustion chamber wall surface in the exhaust valve side region is shorter than that in the intake valve side region, and fuel spray easily reaches the combustion chamber wall surface in the exhaust valve side region. For this reason, it is necessary to increase the penetration force to the intake valve side region and weaken the penetration force to the exhaust valve side region.

Furthermore, since the intake valve side region tends to be cooler than the exhaust valve side region, there is a demand for suppressing the cooling loss in the intake valve side region as compared to the exhaust valve side region. In this case, in order to suppress the fuel spray from reaching the combustion chamber wall surface in the intake valve side region, it is necessary to weaken the penetration force to the intake valve side region and to increase the penetration force to the exhaust valve side region. is there.
Therefore, there is an increasing demand to divide the entire azimuth around the axis of the nozzle body roughly into two, a range where the penetrating force is strong and a range where the penetrating force is weak.

In addition, the fuel injection nozzle of Patent Document 1 includes an upper nozzle hole arranged on the upper side of the sac chamber and a lower nozzle hole arranged on the lower side of the sac chamber, when the axial direction of the nozzle body is the vertical direction. These are alternately arranged in two upper and lower stages.
In the case of this fuel injection nozzle, it is disclosed that the spray penetration force changes depending on whether the needle lift amount is large or small.
However, according to the fuel injection nozzle of Patent Document 1, the above demand cannot be satisfied.

JP 2011-247171 A

  An object of the present invention is to provide a fuel injection nozzle that can divide all directions around the axis of a nozzle body into a range where the spray penetration force is weak and a range where the spray penetration force is strong.

According to the first aspect of the present invention, the needle has an annular seat part that opens and closes the fuel flow path by being seated on and off the seat surface, and a conical tip protrusion located downstream of the seat part. have.
The nozzle body has a cylindrical sac chamber on the downstream side of the fuel flow path.
The plurality of nozzle holes are provided in the circumferential direction and have an inlet on the inner peripheral surface of the sac chamber.
The tip protrusion is in the sack chamber when the seat is seated on the seat surface.
If the side that moves when the seat is separated from the seat surface is the upper side in the axial direction, and the side that moves when the seat is seated on the seat surface is the lower side in the axial direction, In particular, there is a specific nozzle hole whose inlet is axially above the inlet of the other nozzle holes.

According to the second aspect of the present invention, the needle has an annular seat portion that opens and closes the fuel flow path by being seated on the seat surface, and a conical tip protrusion located downstream of the seat portion. Have
The nozzle body has a cylindrical sac chamber on the downstream side of the fuel flow path.
The plurality of nozzle holes are provided in the circumferential direction and have an inlet on the inner peripheral surface of the sac chamber.
The tip protrusion is in the sack chamber when the seat is seated on the seat surface.
When the side that moves when the seat portion is separated from the seat surface is the upper side in the axial direction, and the side that moves when the seat portion is seated on the seat surface is the lower side in the axial direction, 2 adjacent in the circumferential direction Among the combinations of two or more nozzle holes, the inlets of the nozzle holes belonging to the combination are at the same height with respect to the axial direction, and are specified to be higher in the axial direction than the inlets of the nozzle holes other than the nozzle holes belonging to the combination A combination exists.

According to the first or second aspect of the invention, in all the directions around the axis of the nozzle body, the spray penetration force is weaker in the range where the specific injection hole or the specific combination exists than in the other ranges.
For this reason, all directions around the axis of the nozzle body can be divided into a range where the spray penetration force is weak and a range where the spray penetration force is strong.

It is sectional drawing which showed the fuel-injection nozzle (Embodiment 1). It is sectional drawing which showed the principal part of the fuel-injection nozzle (Embodiment 1). (A) is a half cross-sectional view showing a range where an upper nozzle hole is present, and (b) is a half cross-sectional view showing a range where a lower nozzle hole is present (Embodiment 1). It is the expanded view which showed the example of arrangement | positioning of a nozzle hole entrance (embodiment 1). It is explanatory drawing which showed the mode of the fuel flow in a sac chamber (Embodiment 1). (A) is explanatory drawing which showed typically an example of the spray form of fuel, (b) is explanatory drawing which showed the injection direction of the fuel spray with the arrow (embodiment 1). (A) is explanatory drawing which showed typically the modification of the spray form of fuel, (b) is explanatory drawing which showed the injection direction of the fuel spray with the arrow (embodiment 1). (A) is explanatory drawing which showed typically the modification of the spray form of fuel, (b) is explanatory drawing which showed the injection direction of the fuel spray with the arrow (embodiment 1). It is sectional drawing which showed the principal part of the fuel-injection nozzle (Embodiment 2). (A) is the expanded view which showed the example of arrangement | positioning of a nozzle hole inlet, (b) is explanatory drawing which showed the injection direction of the fuel spray with the arrow (Embodiment 2). It is sectional drawing which showed the principal part of the fuel-injection nozzle (Embodiment 3). (A) is the expanded view which showed the example of arrangement | positioning of a nozzle hole inlet, (b) is explanatory drawing which showed the injection direction of the fuel spray with the arrow (Embodiment 3). It is the expanded view which showed the example of arrangement | positioning of a nozzle hole entrance (embodiment 4). FIG. 10 is a development view showing an arrangement example of nozzle hole inlets (Embodiment 5). It is the expanded view which showed the example of arrangement | positioning of a nozzle hole entrance (embodiment 6). FIG. 10 is a development view showing an example of arrangement of nozzle holes (seventh embodiment). (A)-(c) is explanatory drawing which showed the height relationship of the nozzle hole inlet of an upper stage nozzle hole, and the nozzle hole inlet of a lower nozzle hole (Embodiment 8).

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings.

[Configuration of Embodiment 1]
1 to 8 show Embodiment 1 to which the present invention is applied.
The fuel injection valve of this embodiment is mounted corresponding to each cylinder of a vehicle running engine such as an automobile.

The fuel injection valve includes a fuel injection nozzle 1 that directly injects fuel into the combustion chamber of the engine. The fuel injection nozzle 1 includes a needle 2 that reciprocates in its axial direction, and a cylindrical nozzle body 3 that accommodates the needle 2.
The needle 2 includes a cylindrical main body portion 4, an annular seat portion 5, and a conical tip protrusion 6. The urging force of the return spring acts on the needle 2.
The nozzle body 3 has a plurality of nozzle holes 7 and a suck chamber 8. The plurality of nozzle holes 7 and the sack chamber 8 are provided in the sack portion 9 on the tip side of the nozzle body 3. The nozzle body 3 is provided with a seat surface 10 on which the seat portion 5 can be seated. In addition, the nozzle body 3 is provided with a fuel reservoir chamber 12 into which high-pressure fuel is introduced from a high-pressure generator such as a supply pump or a common rail via a fuel hole 11.
Details of the plurality of nozzle holes 7 will be described later.

The sac chamber 8 is located downstream of the fuel flow path 13. The sac chamber 8 is a distribution chamber in which fuel that flows in an annular shape in the fuel flow path 13 is collected and temporarily stored, and then distributed to the nozzle holes 7 evenly.
The sheet surface 10 has a conical shape in which the inner diameter gradually decreases toward the distal end side.
The nozzle body 3 is connected to an actuator that drives the needle 2 to open. As the actuator, a solenoid actuator or a piezo actuator is employed.
The return spring and the actuator are not shown.

The needle 2 is separated from the seat surface 10 of the nozzle body 3 and opens and closes the fuel flow path 13 upstream of the plurality of nozzle holes 7.
The main body 4 is supported in the guide hole 14 of the nozzle body 3 so as to be slidable back and forth. The main body 4 has an outer peripheral surface that forms a fuel flow path 13 with the nozzle body 3. In addition, two inclined surfaces 15 and 16 having different inclination angles are formed at the distal end portion of the main body 4.
The seat portion 5 is formed between the inclined surface 16 of the main body portion 4 and the conical surface 17 of the tip protrusion 6. In addition, you may use the annular ridgeline 18 formed between the inclined surfaces 15 and 16 of the main-body part 4 as a sheet | seat part. The tip protrusion 6 has a conical shape centered on the axis. The tip protrusion 6 enters the sack chamber 8 when the seat portion 5 is seated on the seat surface 10. The tip protrusion 6 protrudes from the seat portion 5 toward the tip of the needle 2.

The fuel flow path 13 is formed between the needle 2 and the seat surface 10. Further, the fuel flow path 13 is located on the upstream side of the sack chamber 8. Further, the fuel flow path 13 is located on the downstream side of the fuel reservoir chamber 12.
In the fuel injection nozzle 1, the fuel flow path 13 is blocked when the seat portion 5 is seated on the seat surface 10. Thereby, fuel injection from the plurality of nozzle holes 7 into the combustion chamber is not performed.
Further, in the fuel injection nozzle 1, when the seat portion 5 is lifted from the seat surface 10, the fuel flow path 13 is opened. As a result, fuel is introduced from the fuel flow path 13 to the sac chamber 8 communicating with the plurality of nozzle holes 7. For this reason, fuel is injected from the plurality of nozzle holes 7 into the combustion chamber.

Here, a direct injection diesel engine is employed as the engine. This engine includes a cylinder head 21. The cylinder head 21 forms a combustion chamber together with the cylinder 22 and the piston 23.
An intake port 24 and an exhaust port 25 are formed in the cylinder head 21. The cylinder head 21 is provided with an intake valve 26 and an exhaust valve 27.

The combustion chamber is divided into an intake valve side region extending toward the intake valve side and an exhaust valve side region extending toward the exhaust valve side.
Here, the intake valve side region is referred to as a region Tin. The exhaust valve side region is referred to as a region Tex.
The region Tin is formed between the piston 23 and the intake valve 26.
The region Tex is formed between the piston 23 and the exhaust valve 27.

Next, an example of the fixed position of the fuel injection nozzle 1 with respect to the cylinder head 21 will be described.
Here, the axis of the nozzle body 3 is referred to as a nozzle axis Y. The axis of the cylinder 22 is called a cylinder axis CL.
In the example of FIG. 6, the fuel injection nozzle 1 is attached to the center of the cylinder head 21 so that the nozzle axis Y and the cylinder axis CL coincide with each other.
In the example of FIG. 7, the fuel injection nozzle 1 is attached to the cylinder head 21 in a state where the nozzle axis Y is offset toward the region Tin by a predetermined amount α with respect to the cylinder axis CL.
In the example of FIG. 8, the fuel injection nozzle 1 is attached to the cylinder head 21 in a state where the nozzle axis Y is offset toward the region Tex by a predetermined amount β with respect to the cylinder axis CL.

[Features of Embodiment 1]
The opening on the inlet side of the sac chamber 8 is formed at the downstream end of the seat surface 10 and at the upstream end of the sac chamber 8. An annular ridge line extending continuously in the circumferential direction is formed in the entrance-side opening of the sack chamber 8. The position of this ridge line is called the upper end 37 of the sack chamber 8.
The sac chamber 8 has a cylindrical peripheral wall surface P centered on the nozzle axis Y and a spherical bottom wall surface Q centered on the sack center on the nozzle axis Y as inner peripheral surfaces.
The space volume in the sac chamber 8 changes according to the lift amount of the needle 2. That is, as the needle 2 is lifted, the space volume in the sac chamber 8 is increased.

The plurality of nozzle holes 7 communicate with the inside and outside of the bottomed cylindrical sack portion 9.
For example, 6 to 12 nozzle holes 7 are provided. In this example, ten nozzle holes 7 are provided.
Here, the axis of each nozzle hole 7 is referred to as a nozzle hole axis HL. In this case, the nozzle hole axis HL is inclined downward by a predetermined angle with respect to the radial direction perpendicular to the nozzle axis Y.
All the nozzle holes 7 have the same angles θH and θL formed by the nozzle hole axis HL and the nozzle axis Y. Further, all the nozzle holes 7 have the same nozzle hole diameter and the same nozzle hole flow path length.

Here, the side that moves when the seat portion 5 moves away from the seat surface 10 is referred to as the upper side in the axial direction. The side that moves when the seat portion 5 is seated on the seat surface 10 is referred to as the lower side in the axial direction.
In this case, among the combinations of two or more nozzle holes 7 adjacent to each other in the circumferential direction, the nozzle hole inlets 31 of the nozzle holes 7 belonging to the combination are at the same height in the axial direction and belong to the combination. There is a specific combination on the upper side in the axial direction from the nozzle hole inlet 32 of the nozzle hole 7 other than the hole 7.

Here, the nozzle hole 7 belonging to the combination is referred to as an upper nozzle hole 7H. The inlet of the upper nozzle hole 7H is referred to as a nozzle hole inlet 31.
Further, the nozzle holes 7 other than the nozzle holes 7 belonging to the combination are referred to as a lower nozzle hole 7L. The inlet of the lower injection hole 7L is referred to as an injection hole 32.
In this case, each nozzle hole inlet 31 is disposed above the nozzle hole inlet 32 in the axial direction.
Specifically, the lower end of the injection hole inlet 31 is located higher than the upper end of the injection hole inlet 32 by a predetermined axial height.

Each nozzle hole 7 is a straight nozzle hole whose flow path area does not change from the nozzle hole inlets 31 and 32 toward the nozzle hole outlets 33 and 34.
Further, each nozzle hole inlet 31 opens at the peripheral wall surface P of the sack chamber 8. Further, each nozzle hole inlet 32 is opened at the bottom wall surface Q of the sack chamber 8.
Further, each nozzle hole outlet 33, 34 is opened at the outer peripheral surface of the sack portion 9.
Here, in the nozzle hole inlet 31, the uppermost end position in the direction of the nozzle axis Y is referred to as the upper end 35 of the nozzle hole inlet 31. In the nozzle hole inlet 32, the uppermost end position in the direction of the nozzle axis Y is referred to as the upper end 36 of the nozzle hole inlet 32.

As shown in FIG. 2, FIG. 3A and FIG. 4, five upper nozzle holes 7H are provided in an angular range θWP of 0 to 180 ° in the circumferential direction around the nozzle axis Y. . These upper nozzle holes 7H are formed at equal intervals in the circumferential direction. Moreover, the arrow WP shown to FIG. 2 and FIG. 5 has shown the azimuth | direction with a weak spray penetration force.
As shown in FIG. 2, FIG. 3B and FIG. 4, five lower nozzle holes 7L are provided in an angular range θSP of 180 to 360 ° in the circumferential direction around the nozzle axis Y. . These lower injection holes 7L are formed at equal intervals in the circumferential direction. Moreover, arrow SP shown in FIG. 2 and FIG. 5 has shown the azimuth | direction with strong spray penetration force.

Further, between the adjacent upper nozzle holes 7H and the lower nozzle holes 7L, the circumferential angle is the same as the angle between the upper nozzle holes 7H and the angle between the lower nozzle holes 7L.
Further, the axial distance from the upper end 35 of each injection hole inlet 31 to the upper end 37 of the sac chamber 8 is shorter than the axial distance from the upper end 36 of each injection hole inlet 32 to the upper end 37 of the sac chamber 8. .
Here, FIGS. 6B to 8B show the injection direction of the fuel spray FW injected from the upper injection hole 7H and the injection direction of the fuel spray FS injected from the lower injection hole 7L. In addition, the length of the arrow in a figure shows an example of the magnitude | size of spray penetration force.

Next, the state of the fuel flow in the sac chamber 8 when the needle 2 is low lifted will be described with reference to FIGS.
Here, the sack chamber 8 has a space 8H extending in a region where each upper nozzle hole 7H is arranged with a virtual plane including the nozzle axis Y as a boundary, and each lower nozzle hole 7L with the virtual plane as a boundary. It is divided into a space 8L extending in a region.
The space 8H is formed in an angle range θWP with the nozzle axis Y as the center. The space 8L is formed in an angle range θSP with the nozzle axis Y as the center.

When the needle 2 is lifted low, the flow rate of the fuel flowing into the sac chamber 8 from the fuel flow path 13 is faster than when the needle 2 is lifted high.
At this time, most of the fuel that has flowed into the space 8 </ b> H from the upstream fuel flow path 13 flows along the surface of the tip protrusion 6. The fuel peeled off from the tip of the tip protrusion 6 flows along the nozzle axis Y to the bottom surface of the space 8H, and bends greatly to the outer peripheral side of the space 8H at the bottom surface of the space 8H.
Then, the fuel swirled on the bottom surface of the space 8H flows from the lower side to the upper side of the space 8H, bends to the outer peripheral side of the space 8H, and flows into the plurality of upper injection holes 7H from the respective injection hole inlets 31.

Further, a part of the fuel that has flowed into the space 8H from the fuel flow path 13 flows to the lower side of the space 8H along the inner peripheral surface of the space 8H.
Here, the axial distance from the upper end 35 of the injection hole inlet 31 to the upper end 37 of the sack chamber 8 is such that the upper injection hole 7H is shorter than the lower injection hole 7L. For this reason, the fuel that flows into the lower side of the space 8H is bent slightly toward the outer peripheral side of the space 8H, and flows into the plurality of upper injection holes 7H from the injection hole inlets 31.
As a result, fuel flowing from the lower side to the upper side of the space 8H collides with fuel moving from the upper side to the lower side of the space 8H at each nozzle hole 31. Therefore, the fuel passing through the upper nozzle holes 7H is disturbed. Will occur.
Therefore, when the fuel passing through each upper nozzle hole 7H is disturbed, the spray angle of the fuel spray FW is larger than the fuel spray FS as the spray characteristics injected into the region Tin from each upper nozzle hole 7H. Large spray characteristics with small spray penetration can be obtained.

On the other hand, most of the fuel that has flowed into the space 8L from the fuel flow path 13 is separated from the surface of the tip protrusion 6 and the upper end 37 of the sack chamber 8 in the vicinity of the entrance of the space 8L.
Here, the axial distance from the upper end 36 of the injection hole inlet 32 to the upper end 37 of the sack chamber 8 is such that the lower injection hole 7L is longer than the upper injection hole 7H. For this reason, the fuel peeled off from the surface of the tip protrusion 6 and the upper end 37 of the sac chamber 8 bends greatly to the outer peripheral side of the space 8L and flows into each lower injection hole 7L from each injection hole inlet 32.
Therefore, the fuel passing through each lower injection hole 7L is not disturbed, and the spray angle of the fuel spray FW is smaller than the fuel spray FS as the spray characteristics injected from each lower injection hole 7L into the region Tex. A spray characteristic with a large spray penetration force can be obtained.
In the case of the fuel injection nozzle 1 of this example, the injection direction of the fuel spray injected from the upper injection hole 7H is an angle range θWP. Further, the injection direction of the fuel spray injected from the lower injection hole 7L is an angle range θSP.

[Effect of Embodiment 1]
As described above, in the fuel injection nozzle 1 of the present embodiment, there is the upper injection hole 7H in which the injection hole inlet 31 is on the upper side in the axial direction with respect to the injection hole inlet 32 of the lower injection hole 7L.
Accordingly, in all the directions around the axis of the nozzle body 3, in the angle range θWP in which the upper nozzle hole 7H exists, as shown in FIG. 6, the spray penetration force is larger than the angle range θSP in which the lower nozzle hole 7L exists. Becomes weaker.
For this reason, all directions around the axis of the nozzle body 3 can be divided into an angle range where the spray penetration force is weak and an angle range where the spray penetration force is strong.
The angle range where the spray penetration force is weak corresponds to the angle range θWP. Further, the angle range where the spray penetration force is strong corresponds to the angle range θSP.

Here, in the example of FIG. 6, the fuel injection nozzle 1 is attached to the cylinder head 21 so that the angle range where the spray penetration force is weak and the region Tin match, and the angle range where the spray penetration force is strong and the region Tex match. It is fixed. In this case, the combustion forms in the region Tin and the region Tex are changed, and the combustion heat transmitted to the intake valve 26 can be reduced. Thereby, the cooling loss of area | region Tin can be suppressed rather than area | region Tex.
Further, in the example of FIG. 7, the fuel injection nozzle 1 is fixed to the cylinder head 21 so that the angle range where the spray penetration force is weak matches the region Tin, and the angle range where the spray penetration force is strong matches the region Tex. doing. In this case, it is possible to reduce the cooling loss in the region Tin where the distance from the fuel injection nozzle 1 to the combustion chamber wall surface is short.
In the example of FIG. 8, the fuel injection nozzle 1 is fixed to the cylinder head 21 so that the angle range where the spray penetration force is weak and the region Tex coincide, and the angle range where the spray penetration force is strong and the region Tin coincide. doing. In this case, it is possible to reduce the cooling loss in the region Tex where the distance from the fuel injection nozzle 1 to the combustion chamber wall surface is short.
In any case, since the cooling loss can be reduced, an effect such as improvement in fuel consumption can be obtained.

[Configuration of Embodiment 2]
FIG. 9 and FIG. 10 show Embodiment 2 to which the present invention is applied. Here, the same reference numerals as those in the first embodiment indicate the same configuration or function, and a description thereof will be omitted.

The combustion chamber is divided into a region Tin, a region Tex, a region Tfr, and a region Tre.
Here, the region Tin extends from the cylinder axis CL to the intake valve side. Further, the region Tex extends from the cylinder axis CL to the exhaust valve side. The region Tfr is a front side region formed between the region Tin and the region Tex. The region Tre is a rear side region formed between the region Tin and the region Tex.
The plurality of nozzle holes 7 includes three upper nozzle holes 7H, four intermediate nozzle holes 7M, and three lower nozzle holes 7L. In this example, the height in the axial direction increases in the order of the lower injection hole 7L, the intermediate injection hole 7M, and the upper injection hole 7H.

The upper injection hole 7H corresponds to the injection hole 7 belonging to the combination, and has injection hole inlets 31 adjacent in the circumferential direction. The upper nozzle hole 7H is arranged in an angle range θWP of 0 to 108 °. Further, the angle range θWP corresponds to the region Tin.
The intermediate injection hole 7M corresponds to the injection holes 7 other than the injection holes 7 belonging to the combination, and has injection hole inlets 41 and 42 adjacent in the circumferential direction. The intermediate nozzle hole 7M is an intermediate angle range between the angle range θWP and the angle range θSP. Further, the intermediate injection hole 7M is arranged in an angle range θMP of 108 to 180 ° and an angle range θMP of 288 to 360 °. The intermediate angle range θMP has an intermediate spray penetration force. The angle range θMP corresponds to a region where the intake valve 26 and the exhaust valve 27 are not provided. That is, the angle range θMP corresponds to the region Tfr and the region Tre.

The lower injection hole 7L corresponds to the injection holes 7 other than the injection holes 7 belonging to the combination, and has injection hole inlets 32 adjacent in the circumferential direction. The lower injection hole 7L is arranged in an angle range θSP of 180 to 288 °. The angle range θSP corresponds to the region Tex.
Accordingly, the plurality of upper injection holes 7H have a specific combination in which each injection hole inlet 31 is at the same height with respect to the axial direction and is above the injection hole inlet 32 and the injection hole inlets 41 and 42 in the axial direction. .
Further, each nozzle hole inlet 41, 42 is opened at the bottom wall surface Q of the sack chamber 8.

In the case of the fuel injection nozzle 1 of this example, the injection direction of the fuel spray injected from the upper injection hole 7H is an angle range θWP. Further, the injection direction of the fuel spray injected from the intermediate injection hole 7M is an intermediate angle range θMP. Further, the injection direction of the fuel spray injected from the lower injection hole 7L is an angle range θSP.
Here, FIG. 10B shows the injection direction of the fuel spray FW injected from the upper injection hole 7H, the injection direction of the fuel spray FM injected from the intermediate injection hole 7M, and the fuel spray injected from the lower injection hole 7L. The injection direction of FS is shown. In addition, the length of the arrow in a figure shows an example of the magnitude | size of spray penetration force.
As described above, the fuel injection nozzle 1 of the present embodiment has the same effects as those of the first embodiment.

[Configuration of Embodiment 3]
11 and 12 show Embodiment 3 to which the present invention is applied. Here, the same reference numerals as those in Embodiments 1 and 2 indicate the same configuration or function, and the description thereof will be omitted.

The plurality of nozzle holes 7 includes three upper nozzle holes 7H, four intermediate nozzle holes 7M, and three lower nozzle holes 7L. In this example, the height in the axial direction increases in the order of the lower injection hole 7L, the intermediate injection hole 7M, and the upper injection hole 7H.
The intermediate injection hole 7M has injection hole inlets 51-54.
The axial height of the intermediate nozzle hole 7M gradually changes between the nozzle hole inlet 51 and the nozzle hole inlet 52. Further, the nozzle hole inlet 51 exists on the upper side in the axial direction from the nozzle hole inlet 52. Further, the nozzle hole inlet 51 is provided closer to the nozzle hole inlet 31 than the nozzle hole inlet 52.
The axial height of the intermediate injection hole 7M gradually changes between the injection hole inlet 53 and the injection hole inlet 54. Further, the injection hole inlet 53 exists on the lower side in the axial direction than the injection hole inlet 54. Further, the nozzle hole inlet 53 is provided closer to the nozzle hole inlet 32 than the nozzle hole inlet 54.
Further, each nozzle hole 51 to 54 is opened at the bottom wall surface Q of the sack chamber 8.
Here, FIG. 12B shows the injection direction of the fuel spray FW injected from the upper injection hole 7H, the injection direction of the fuel spray FM injected from the intermediate injection hole 7M, and the fuel spray injected from the lower injection hole 7L. The injection direction of FS is shown. In addition, the length of the arrow in a figure shows an example of the magnitude | size of spray penetration force.
As described above, the fuel injection nozzle 1 of the present embodiment has the same effects as those of the first and second embodiments.

[Configuration of Embodiment 4]
FIG. 13 shows a fourth embodiment to which the present invention is applied. Here, the same reference numerals as those in the first to third embodiments indicate the same configuration or function, and a description thereof will be omitted.

The plurality of nozzle holes 7 includes three upper nozzle holes 7H and seven lower nozzle holes 7L.
The upper injection hole 7H corresponds to the injection hole 7 belonging to the combination, and has injection hole inlets 31 adjacent in the circumferential direction. The upper nozzle hole 7H is arranged in an angle range θWP of 0 to 108 °.
The lower injection hole 7L corresponds to the injection holes 7 other than the injection holes 7 belonging to the combination, and has injection hole inlets 32 adjacent in the circumferential direction. The lower injection hole 7L is arranged in an angle range θSP of 108 to 288 °.
Therefore, the plurality of upper nozzle holes 7H are in a specific combination in which the nozzle hole inlet 31 is at the same height in the axial direction and is above the nozzle hole inlet 32 in the axial direction.
As described above, the fuel injection nozzle 1 of the present embodiment has the same effects as those of the first to third embodiments.

[Configuration of Embodiment 5]
FIG. 14 shows a fifth embodiment to which the present invention is applied. Here, the same reference numerals as those in the first to fourth embodiments indicate the same configuration or function, and a description thereof will be omitted.

Among the plurality of nozzle holes 7, there is a specific nozzle hole 7 in which the nozzle hole inlet 31 is located above the nozzle hole inlets 32 of the other nozzle holes 7 in the axial direction.
Here, the specific nozzle hole 7 is referred to as an upper nozzle hole 7H. The inlet of the upper nozzle hole 7H is referred to as a nozzle hole inlet 31.
Moreover, the other nozzle hole 7 is called the lower nozzle hole 7L. The inlet of the lower injection hole 7L is referred to as an injection hole 32.
That is, one upper nozzle hole 7H and nine lower nozzle holes 7L are formed in the sack portion 9.

The upper injection hole 7H corresponds to the injection hole 7 belonging to the combination, and has injection hole inlets 31 adjacent in the circumferential direction. The upper nozzle hole 7H is arranged in an angle range θWP of 0 to 108 °.
The lower injection hole 7L corresponds to the injection holes 7 other than the injection holes 7 belonging to the combination, and has injection hole inlets 32 adjacent in the circumferential direction. The lower injection hole 7L is arranged in an angle range θSP of 108 to 288 °.
As described above, the fuel injection nozzle 1 of the present embodiment has the same effects as those of the first to fourth embodiments.

[Configuration of Embodiment 6]
FIG. 15 shows a sixth embodiment to which the present invention is applied. Here, the same reference numerals as those in the first to fifth embodiments indicate the same configuration or function, and a description thereof will be omitted.

The plurality of nozzle holes 7 includes one upper nozzle hole 7H, six intermediate nozzle holes 7M, and three lower nozzle holes 7L. In this example, the height in the axial direction increases in the order of the lower injection hole 7L, the intermediate injection hole 7M, and the upper injection hole 7H.
The upper injection hole 7H corresponds to the specific injection hole 7 and has an injection hole inlet 31. The upper nozzle hole 7H is disposed in an angle range θWP of 0 to 36 °.
The intermediate injection hole 7M corresponds to the other injection hole 7 and has injection hole inlets 61 and 62 adjacent in the circumferential direction. The intermediate nozzle hole 7M is disposed in an angle range θMP of 36 to 144 ° and an angle range θMP of 252 to 360 °.
The lower injection hole 7L corresponds to the other injection hole 7 and has the injection hole inlet 32 adjacent in the circumferential direction. The lower injection hole 7L is arranged in an angle range θSP of 144 to 252 °.
Each nozzle hole inlet 61, 62 is opened at the bottom wall surface Q of the sack chamber 8.
As described above, the fuel injection nozzle 1 of the present embodiment has the same effects as those of the first to fifth embodiments.

[Configuration of Embodiment 7]
FIG. 16 shows a seventh embodiment to which the present invention is applied. Here, the same reference numerals as those in the first to sixth embodiments indicate the same configuration or function, and a description thereof will be omitted.

The plurality of nozzle holes 7 includes one upper nozzle hole 7H, eight intermediate nozzle holes 7M, and one lower nozzle hole 7L. In this example, the height in the axial direction increases in the order of the lower injection hole 7L, the intermediate injection hole 7M, and the upper injection hole 7H.
The upper injection hole 7H corresponds to the specific injection hole 7 and has an injection hole inlet 31. The upper nozzle hole 7H is disposed in an angle range θWP of 0 to 36 °.
The intermediate injection hole 7M corresponds to the other injection hole 7, and has injection hole inlets 71 to 74 adjacent in the circumferential direction. The intermediate nozzle hole 7M is arranged in an angle range θMP of 36 to 180 ° and an angle range θMP of 216 to 360 °.
The lower injection hole 7 </ b> L corresponds to the other injection hole 7 and has an injection hole inlet 32. The lower injection hole 7L is arranged in an angle range θSP of 180 to 216 °.
In addition, each nozzle hole 71 to 74 is opened at the bottom wall surface Q of the sack chamber 8.
As described above, the fuel injection nozzle 1 of the present embodiment has the same effects as those of the first to sixth embodiments.

[Configuration of Embodiment 8]
FIG. 17 shows an eighth embodiment to which the present invention is applied. Here, the same reference numerals as those in the first to seventh embodiments indicate the same configuration or function, and a description thereof will be omitted.

Here, the specific injection hole 7 or the injection hole 7 belonging to the combination is referred to as an upper injection hole 7H. The inlet of the upper nozzle hole 7H is referred to as a nozzle hole inlet 81.
Moreover, the nozzle holes 7 other than the nozzle holes 7 belonging to another nozzle hole 7 or the combination are referred to as a lower nozzle hole 7L. The inlet of the lower nozzle hole 7L is referred to as a nozzle hole inlet 82.
First, the lower end of the injection hole inlet 81 is at the same axial height as the upper end of the injection hole inlet 82, as shown in FIG. This nozzle hole inlet 81 is at a position higher than the nozzle hole inlet 82 by a predetermined axial height h1.

Next, the center of the injection hole inlet 81 is at the same axial height as the upper end of the injection hole inlet 82, as shown in FIG. This nozzle hole inlet 81 is at a position higher than the nozzle hole inlet 82 by a predetermined axial height h2.
Next, the upper end of the injection hole inlet 82 is located between the center and the upper end of the injection hole inlet 81 as shown in FIG. The nozzle hole inlet 81 is at a position higher than the nozzle hole inlet 82 by a predetermined axial height h3.
Note that h1, h2, and h3 satisfy the relationship of h1>h2> h3.
In the present embodiment, the nozzle holes 7 other than the nozzle holes 7 belonging to the combination are the lower nozzle holes 7L, but the nozzle holes 7 other than the nozzle holes 7 belonging to the combination may be the intermediate nozzle holes 7M.
As described above, the fuel injection nozzle of the present embodiment has the same effects as those of the first to seventh embodiments.

[Modification]
In the present embodiment, an example in which the present invention is applied to the fuel injection nozzle 1 that directly injects high-pressure fuel introduced from a supply pump or a common rail into the combustion chamber of the engine has been described. The fuel is directly pumped from the fuel injection pump such as a distribution type fuel pump into the fuel reservoir chamber. When the fuel pressure in the fuel reservoir chamber exceeds the urging force of the spring, the needle 2 opens and the direct injection engine The present invention may be applied to a fuel injection nozzle that directly injects into the combustion chamber.

In this embodiment, the needle 2 of the fuel injection nozzle 1 is configured to be directly opened by a driving force of a solenoid actuator or a piezoelectric actuator and closed by a biasing force of a spring. As an actuator to be used, a solenoid valve or a piezo actuator for adjusting the fuel pressure in a control chamber provided immediately above the needle 2 and controlling the opening / closing operation of the needle 2 may be employed.
In this embodiment, a direct injection diesel engine is employed as the direct injection engine, but a direct injection gasoline engine may be employed as the direct injection engine.
When the intake port 24 is branched into two intake ports for one combustion chamber, two intake valves 26 are required. Further, when the exhaust port 25 is branched into two exhaust ports for one combustion chamber, two exhaust valves 27 are required.

In the present embodiment, the specific nozzle holes 7H or the nozzle holes 7H belonging to the combination are provided at equal intervals over an angular range of 36 to 180 ° in the circumferential direction around the axis of the nozzle body 3. The nozzle holes 7H or the nozzle holes 7H belonging to the combination may be provided at equal intervals over an angular range of 90 to 270 ° in the circumferential direction around the axis of the nozzle body 3.
Further, the shape of the nozzle hole inlet may be formed not only in a circular shape but also in an elliptical shape or an oval shape. Further, the shape of the nozzle hole outlet may be formed not only in a circular shape but also in an elliptical shape or an oval shape.
Moreover, you may employ | adopt the taper nozzle hole from which a flow path area becomes large gradually toward a nozzle hole exit from a nozzle hole inlet.
Moreover, you may employ | adopt the taper nozzle hole from which a flow path area becomes small gradually toward a nozzle hole exit from a nozzle hole entrance.
The present invention is not limited to the above-described embodiment, and can be implemented with various modifications.

DESCRIPTION OF SYMBOLS 1 Fuel injection nozzle 2 Needle 3 Nozzle body 8 Suck chamber 7 Injection hole 7H Upper injection hole (specific injection hole, specific combination, injection hole belonging to combination)
7L Lower nozzle hole (other nozzle holes, nozzle holes other than those belonging to the combination)
10 Sheet surface 31 Injection hole entrance 32 Injection hole entrance

Claims (5)

(A) A plurality of injection holes (7, 7H, 7L) for injecting fuel into the combustion chamber of the engine, and a conical seat surface (13) that forms a fuel flow path (13) upstream of the plurality of injection holes. A cylindrical nozzle body (3) having 10);
(B) a needle (2) accommodated in the nozzle body so as to be reciprocally movable in the axial direction;
The needle has an annular seat portion (5) that opens and closes the fuel flow path by being seated and separated with respect to the seat surface, and a conical tip protrusion (6) located on the downstream side of the seat portion. The nozzle body has a cylindrical sack chamber (8) on the downstream side of the fuel flow path,
The plurality of nozzle holes are provided in a circumferential direction and have inlets (31, 32, 61, 62, 71 to 74, 81, 82) on an inner peripheral surface of the sac chamber,
The tip protrusion enters the sack chamber when the seat portion is seated on the seat surface,
When the side that moves when the seat portion is separated from the seat surface is the upper side in the axial direction, and the side that moves when the seat portion is seated on the seat surface is the lower side in the axial direction,
Among the plurality of nozzle holes, the inlet (31, 81) is located above the inlets (32, 61, 62, 71-74, 82) of the other nozzle holes (7L) in the axial direction. A fuel injection nozzle (1) characterized by the presence of a nozzle hole (7H). (A) A plurality of injection holes (7, 7H, 7L, 7M) for injecting fuel into the combustion chamber of the engine, and a conical seat that forms a fuel flow path (13) upstream of the plurality of injection holes A cylindrical nozzle body (3) having a face (10);
(B) a needle (2) accommodated in the nozzle body so as to be reciprocally movable in the axial direction;
The needle has an annular seat portion (5) that opens and closes the fuel flow path by being seated and separated with respect to the seat surface, and a conical tip protrusion (6) located on the downstream side of the seat portion. The nozzle body has a cylindrical sack chamber (8) on the downstream side of the fuel flow path,
The plurality of nozzle holes are provided in a circumferential direction, and have inlets (31, 32, 41, 42, 51-54, 81, 82) on an inner peripheral surface of the sac chamber,
The tip protrusion enters the sack chamber when the seat portion is seated on the seat surface,
When the side that moves when the seat portion is separated from the seat surface is the upper side in the axial direction, and the side that moves when the seat portion is seated on the seat surface is the lower side in the axial direction,
Among the combinations of two or more nozzle holes adjacent in the circumferential direction, the inlets (31, 81) of the nozzle holes (7H) belonging to the combination are at the same height in the axial direction and belong to the combination. A fuel injection nozzle, characterized in that there is a specific combination on the upper side in the axial direction from the inlets (32, 41, 42, 51 to 54, 82) of the injection holes (7L, 7M) other than the holes. The fuel injection nozzle according to claim 1 or 2,
The plurality of nozzle holes have the same angle formed by the nozzle axis (HL) of all the nozzle holes and the axis (Y) of the nozzle body. The fuel injection nozzle according to any one of claims 1 to 3,
The fuel injection nozzle according to claim 1, wherein an axis of the nozzle body coincides with a cylinder axis (CL) of the engine. The fuel injection nozzle according to any one of claims 1 to 3,
The nozzle of the nozzle body is offset from a cylinder axis of the engine.

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