JP2000170625A - Fuel injection nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact fuel injection nozzle capable of obtaining a suitable injection rate shape according to the engine operating conditions while obtaining fine spray for improving mixing. SOLUTION: In this fuel injection nozzle 1, a double needle valve having an inner needle valve 7 slidably inserted in a bottomed outer needle valve 8 is inserted in a nozzle body so that its tip many project from the body tip, a fuel passage 10 is formed between the inner needle valve and the outer needle valve, a fuel passage 21 is formed between the outer needle valve and the nozzle body, a small-diameter nozzle hole 8e to be opened by opening of the inner needle valve is formed on the tip of the outer needle valve a large-diameter nozzle hole 17 formed by opening the end of the fuel passage 21 in the position deviated from the nozzle hole 8e is formed on the tip of the nozzle body, and the suitable fuel injection rate area according to the engine operating conditions is obtained by injection from the nozzle hole 8e, injection from the nozzle hole 17, and switching of the injection from all nozzle holes 8e, 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection nozzle capable of changing a spray pattern so as to perform appropriate combustion.

[0002]

2. Description of the Related Art Automobiles are equipped with a diesel engine employing a common rail system.

[0003] In such a diesel engine, in order to obtain an optimum combustion that provides good exhaust gas characteristics [exhaust particulate matter (PM), NOx: small], it is necessary to match an operating state of the engine according to a change in the operating state. It is said that the fuel should be sprayed from the fuel injection nozzle into the cylinder (combustion chamber) with the optimum combustion injection rate shape.

For this purpose, the shape of the injection rate of the fuel sprayed from the fuel injection nozzle is optimized according to the engine operating condition shown in FIG. 6, specifically, the injection rate shape in FIG. As shown by a to f, an injection rate shape is set such that the injection time is shortened and the injection rate is increased as the engine speed decreases (low vehicle speed) and the engine load increases, and the initial injection rate is increased in the high engine load range. It is desirable to have an injection rate shape that suppresses the injection rate or a high injection rate shape that changes the injection rate after the initial stage of injection according to engine operating conditions.

Therefore, a fuel injection nozzle used in a diesel engine has a nozzle structure as disclosed in Japanese Utility Model Laid-Open No. 4-116668, in which the injection rate can be varied by controlling the lift amount of a needle valve using a piezoelectric element. Attempts have been made to obtain an optimal fuel injection rate shape with a proposed and compact structure.

In order to reduce the injection rate, the fuel injection nozzle with a variable injection rate narrows the passage area on the upstream side from the injection hole by the displacement of the piezoelectric element to suppress the flow of the jet from the injection hole, To increase the efficiency, the previous passage area is returned.

By the way, in order to perform good combustion,
Fine spraying and good mixing are required. In particular, in the case of split (split) injection, pilot injection, and the like, the initial injection performed at a low injection rate requires a fine spray that particularly improves high mixing in order to suppress the generation of exhaust particulates (PM) and NOx. Can be

However, a fuel injection nozzle using a piezoelectric element has a structure in which the shape of an injection rate is changed by suppressing the momentum of a jet by displacement of the piezoelectric element, so that the injection pressure of the fuel decreases as the injection rate decreases. For this reason, as the injection pressure decreases, the mixing deteriorates and the fine particles of the spray increase, so that the injection rate shape according to the operating conditions of the engine is satisfied, but the spray with the spray characteristics that provides optimal combustion is secured. Hateful.

In order to prevent the decrease in the injection pressure, a separate structure and device for increasing the injection pressure are required, so that the cost burden is considerably increased.

Therefore, a fuel injection nozzle (Japanese Patent Laid-Open No. 9-32693) which arranges two needle valves in parallel at a predetermined interval so as not to interfere with the spraying and enables two kinds of spraying is adopted. A double needle valve with the inner needle valve slidably housed inside the bottomed outer needle valve inside a bottomed cylindrical nozzle body, and two types of injection holes formed at the tip of the nozzle body Then, when the inner needle valve is lifted, the fuel is sprayed from one of the injection holes, and when the outer needle valve is lifted, the fuel injection nozzle is sprayed from both the injection holes (JP-A-61-272463). It is conceivable that the injection rate shape can be varied without reducing the injection pressure.

[0011]

However, in the former fuel injection nozzle, since the two needle valves are arranged in parallel, the whole nozzle becomes large and cannot be assembled in a restricted narrow place, so that it is practical. Not.

In the latter fuel injection nozzle, although the entire nozzle is made compact, the switching of the spray is performed in two stages, so that it is insufficient to effectively vary the injection rate shape according to the engine operating conditions. .

[0013] Therefore, there is a demand for a fuel injection nozzle which is excellent also in terms of variable injection rate shape and spray characteristics.

The present invention has been made in view of the above circumstances, and has as its object the purpose of obtaining a fine spray capable of improving the mixing with a compact structure, and at the same time, obtaining an optimal spray according to changes in engine operating conditions. An object of the present invention is to provide a fuel injection nozzle capable of obtaining a desired injection rate shape.

[0015]

According to a first aspect of the present invention, there is provided a fuel injection nozzle comprising a double needle valve slidably fitted to an inner needle valve in a bottomed outer needle valve. A first fuel passage is formed between the inner needle valve and the outer needle valve, and a second fuel passage is formed between the outer needle valve and the nozzle body. A fuel passage is formed, a first injection hole which is opened by opening the inner needle valve is formed at a distal end of the outer needle valve, and a second fuel passage end is formed at the distal end of the nozzle body with the first fuel passage end. Forming a second injection hole different from the injection hole diameter of the first injection hole, which is opened at a position shifted from the hole, and a first spray pattern in which fuel is sprayed from the first injection hole; No. 2 where fuel is sprayed from the 2 nozzle holes
And a third pattern in which fuel is sprayed from both the first injection hole and the second injection hole.

The fuel injection nozzle configured as described above has
Since the double needle valve in which the inner needle valve is inserted into the outer needle valve is incorporated into the nozzle body, the structure is compact. In addition, when the inner needle valve is opened, fuel is injected from the first injection hole at the tip of the outer needle valve, and when the outer needle valve is opened, fuel is injected from the second injection hole at the tip of the nozzle body. Injection of fuel is independent of each other, and the total injection hole area and injection hole arrangement during fuel injection are three stages. Specifically, during fuel injection, the tip of the outer needle valve and the nozzle body By switching between the small orifice located at one of the tips and the large orifice located at the other end, the injection pressure is increased by the combination of the two. Under any engine operating conditions,
An optimum injection rate shape is formed according to the engine operating conditions.

In the fuel injection nozzle according to the second aspect of the present invention, the control means performs the rear high injection in which the fuel injection rate increases as the fuel injection proceeds toward the later stage during the fuel injection. The injection is performed in the order of the injection hole having the large injection hole diameter and all the injection holes, so that it matches any ideal fuel injection rate area.

In the fuel injection nozzle according to the third aspect, the control means controls the initial injection of the split injection and the pilot injection in the injection hole having a small injection hole diameter, thereby particularly affecting the exhaust gas characteristics. The initial injection in pilot injection and split injection, which is easy to apply, is injection with increased injection pressure (by injection from a small injection hole), and it is fine spray that can improve mixing, and exhaust gas characteristics are significantly better [Emitted fine particles (P
M): reduced].

In particular, if the first injection hole and the second injection hole are arranged so that the spray from each injection hole does not interfere, both the first injection hole and the second injection hole are used. Good fuel injection is achieved.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to one embodiment shown in FIGS.

Here, FIG. 1 shows the vicinity of a fuel injection nozzle of a diesel engine employing a common rail system to which the present invention is applied, FIG. 2 shows the structure on the nozzle flat side, and 3 shows the structure around the tip of the nozzle. Is shown.

In FIG. 1, reference numeral 1 denotes a variable injection hole type fuel injection nozzle mounted on a cylinder head 2.

The structure of the fuel injection nozzle 1 will be described. In the figure, reference numeral 3 denotes a nozzle body. Nozzle body 3
Has a large-diameter cylindrical portion 3a on the upper side and a small-diameter cylindrical portion 3 on the lower side.
b. The nozzle body 3 is assembled to the cylinder head 2 such that the lower end (corresponding to the tip of the nozzle body) of the small-diameter cylindrical portion 3b faces the cylinder from the lower surface of the cylinder head 2 (in the case of a four-valve engine, intake / exhaust gas). A small-diameter portion 3c formed at the lower end of the cylindrical portion 3b projects from the cylinder head 2 into the cylinder (not shown).

In a needle valve chamber 5 formed in the space inside the nozzle body 3, a double needle valve 6 in which two types of large and small needle valves are concentrically combined is housed slidably in the vertical direction. I have. The double needle valve 6 has a structure in which a needle-shaped inner needle valve 7 and a bottomed cylindrical outer needle valve 8 slidably fitted on the outer peripheral surface of the inner needle valve 7 are combined. Used.

Specifically, the outer needle valve 8 is provided with the large-diameter cylindrical portion 3.
a large-diameter shaft portion 8a that fits inside the small-diameter cylindrical portion 3b and a small-diameter shaft portion 8b that fits within the small-diameter cylindrical portion 3b. 13 and
The tip has a bottomed cylindrical shape formed in a hemispherical shape.
Also, on the base side of the hemispherical portion 8d serving as the tip, FIG.
As shown in (a) and (b), a plurality of first injection holes, for example, six obliquely downward injection holes 8e are formed at predetermined intervals in the circumferential direction. The hemispherical portion 8d protrudes from the tip of the nozzle body 3, that is, the lower end of the small diameter portion 3c. The outer diameter of the straight portion of the small-diameter shaft portion 8b is
It is larger than the outer diameter of the hemispherical portion 8d. Six slit-shaped grooves 9 extending in the axial direction are formed in parallel on the outer peripheral surface of the small-diameter shaft portion 8b forming the linear portion. These grooves 9 form a linear passage 10 (corresponding to a second fuel passage) along the axial direction between the groove 9 and the inner surface of the small-diameter cylindrical portion 3b, as shown in FIG. The upper end of each of these passages 10 extends to near the conical surface 8c. The upper end of each passage 10 has an outer seat portion 12 formed by combining a conical surface 8c for the seat and a sealing surface 11 formed on the inner surface of the nozzle body so as to be in contact with and separated from the conical surface 8c. Pumping high-pressure fuel through an oil reservoir 14 formed in the inner surface of the nozzle body so as to surround the pressure receiving conical surface 13 and a passage 16 formed in the peripheral wall of the large-diameter cylindrical portion 3a. (Not shown). The lower end of each passage 10 (the end of the groove 9) extends to near the boundary with the hemispherical portion 8d as shown in FIG.
As shown in (b), the small diameter portion 3c at the tip of the nozzle body
A plurality of second injection holes formed on the peripheral wall of the small diameter portion 3c, for example, six injection holes formed at predetermined intervals in the circumferential direction, via a relay annular passage 15 formed on the inner surface of the small diameter portion 3c. Hole 17
(Corresponding to the second injection hole). Each of these injection holes 1
7 is obliquely downwardly directed to a point shifted in the circumferential direction from the injection hole 8e formed in the hemispherical portion 8d as shown in FIG. 3 (b), for example, a point between the adjacent injection holes 8e, 8e. The fuel injected from each of the injection holes 17 is formed by utilizing a positional deviation such as a height difference from the injection hole 8e, a circumferential difference from the injection hole 8e, and a radial difference from the injection hole 8e. The fuel can be sprayed without interfering with the fuel injected from the hole 8e.
In other words, the injection holes 8e and the injection holes 17 are three-dimensionally shifted from each other so that the sprays from the injection holes 8e and 17 do not touch. In addition, between the outer surface of the outer needle valve 8 and the inner surface of the nozzle body 3 opposed thereto, for example, one is formed with a groove along the axial center direction, and the other is formed with a protrusion that fits in the groove. A detent 26 is formed so that the shift angle between each injection hole 8e and each injection hole 17 is kept constant.

The outer needle valve 8 is connected to a valve opening mechanism 18 (for example, a mechanism for opening the valve using fuel pressure) for opening and closing (up and down) the outer needle valve 8. The high-pressure fuel flowing into the oil reservoir 14 is injected from the injection hole 17 at the tip of the nozzle body 3 through the outer seat portion 12 and the passage 10 by the opening of the outer needle valve 8 performed in It is. In FIGS. 1 and 3, X indicates the spray from the injection hole 17.

The inner needle valve 7 has a large-diameter shaft portion 7a that fits in the large-diameter shaft portion 8a and a fine-shaft portion 7b smaller than the inner diameter of the small-diameter shaft portion 8b that fits in the small-diameter shaft portion 8b [(FIG. b) and FIG.
In the shape of a needle. As shown in FIG. 3 (a), the tip of the small shaft portion 7b has a sheet cone which is combined with a conical sealing surface 19 formed on the inner surface of the small diameter shaft portion 8b on the upstream side of the injection hole 8e. The surface 7c is formed, and constitutes the inner seat portion 20 in the same portion. The inner sheet portion 20 has a passage 21 formed by a gap between the outer peripheral surface of the small shaft portion 7b and the inner peripheral surface of the small diameter shaft portion 8b.
(Corresponding to a first fuel passage), an oil reservoir 23 formed on the inner surface of the large-diameter shaft portion 8a so as to surround a pressure-receiving conical surface 22 formed immediately above the passage end, and a large-diameter shaft portion 8a. Is communicated with the fuel pumping section (not shown) through a relay annular groove 24 formed on the outer peripheral surface of the first cylinder section and a passage 25 formed on the peripheral wall of the large-diameter cylindrical section 3a.

The inner needle valve 7 is also connected to the valve opening mechanism 18.
When the inner needle valve 7 is opened by the mechanism 18, the high-pressure fuel flowing into the oil reservoir 23 flows through the passage 2.
1. Through the inner seat portion 20, the fuel is injected from the injection hole 8e at the tip of the outer needle valve 8. In FIGS. 1 and 3, Y indicates the spray from the injection hole 8e.

The injection holes 8e and 17 have different injection hole diameters. For example, the diameter of the injection hole 8e is determined to be smaller than the diameter of the injection hole 17; if the inner needle valve 7 is opened, high-pressure fuel is sprayed from the injection hole 8e having a small diameter. Spray depending on the injection hole area of the hole 8e), the outer needle valve 8
Is opened, high-pressure fuel is sprayed from the injection hole 17 having a large injection hole diameter (spray depending on the injection hole area of the injection hole 17), and both the inner needle valve 7 and the outer needle valve 8 are opened. For example, high-pressure fuel is sprayed from both the small orifice 8e and the large orifice 17 (spray depending on the total orifice area of the orifices 8e and 17).

That is, the fuel injection nozzle 1 has a spray pattern (corresponding to the first spray pattern) sprayed from the small orifice 8e, and a spray pattern (second spray pattern) sprayed from the large orifice 17. ), And a spray pattern (corresponding to a third spray pattern) sprayed from both the small orifice 8 e and the large orifice 17. I have.

The valve opening mechanism 18 includes the valve opening mechanism 1.
A controller 28 (for example, composed of a microcomputer) for controlling the fuel injection nozzle 8 is connected.
e, eruption from injection hole 17, injection hole 8e and injection hole 1
7, the fuel injection nozzle 1 can freely change the shape of the injection rate of the fuel sprayed from the fuel injection nozzle 1 without lowering the injection pressure. . That is, by the combination of the switchings, the injection rate shape according to the optimized engine operating condition, specifically, low engine speed (low vehicle speed) and high engine load as shown by a to f in FIG. Injection rate shape that shortens the injection time and increases the injection rate as it becomes, injection rate shape that suppresses the initial injection rate in high engine load areas, and rear height where the injection rate after the initial stage of injection varies according to engine operating conditions The injection rate shape of the above is obtained.
Further, according to a command from the controller 28, under engine operating conditions requiring split (split) injection and pilot injection, high-pressure fuel is injected from the injection hole 8e having a small injection hole diameter only during the initial injection, or the small injection hole diameter is used when the engine is started. The high pressure fuel is injected from the injection hole 8e.

FIG. 5 is a flow chart showing an example of the control of the injection hole switching.

The variable control of the fuel injection rate shape according to this flowchart will now be described.
Is the engine speed, fuel injection amount,
The operating state of the engine is detected from the intake air temperature, the intake pressure, the EGR rate, and the like.

At this time, if the operation of the engine is at the time of starting, the process proceeds from step S2 to determine whether it is at the time of starting, to step S3, the inner needle valve 7 is opened for a predetermined time, and The inflowing high-pressure fuel is injected into the cylinder (combustion chamber) from the injection hole 8e at the tip of the outer needle valve 8.

At this time, since the injection hole 8e has a small injection hole diameter, the injection pressure of the fuel is increased by an amount corresponding to the small injection hole diameter, and the high-pressure fuel is sprayed from the injection hole 8e in a state where it is easily combusted, that is, the fuel is injected into the cylinder air. Fine spray Y having excellent mixing properties is performed. As a result, fuel spray suitable for starting is performed.

Pilot injection, split (split)
If the operating state of the engine requires injection, it is determined whether pilot injection or split injection is performed in step S.
4 to step S5, for example, in FIG. 5 (a), the initial injection of the split injection represented by the hatched area α, that is, only the first small injection, the high-pressure fuel is injected from the injection hole 8e having the small injection hole diameter described above. It is finely sprayed inside (combustion chamber). By this fine spraying, a high effect of reducing the discharged fine particles (PM) that is higher than the effect of reducing the discharged fine particles (PM) caused by the initial injection of the pilot injection and the split injection can be obtained.
The following fuel injection is performed, for example, according to the engine load.
The spray is performed in any pattern such as only the injection hole 8e, only the injection hole 17, and both the injection hole 8e and the injection hole 17.

On the other hand, as shown by a to f in FIG. 6, a fuel injection, which is optimized under the engine operating conditions, in which the initial injection rate is suppressed and the subsequent middle to late injection rates are increased, so-called rear injection When high injection is performed, the process proceeds from step S6 to determine whether to perform rear high injection or not, to step S7. Then, in the early stage of the injection, the injection hole 8e having the small injection hole diameter is used, and thereafter, the injection hole 17 having the large injection hole diameter is used.
5 and the injection hole 17).
The rear high injection as shown in (b) is performed.

At this time, by changing the injection time in accordance with the engine operating conditions or changing the rate of increase of the injection rate during injection, the three-stage switching can be performed without reducing the injection pressure. Even under engine operating conditions, FIG.
For example, a fuel injection rate profile that is excellent in exhaust gas characteristics and exhibits optimal combustion as shown by a to f in FIG.

If the normal injection is to be performed instead of the rear high injection, the process proceeds from step S6 to step S8, where the required injection time differs (light load: long, high load: short, medium load: middle). Accordingly, when the required injection time is long (at a light load), injection is performed only through the injection hole 8e having a small injection hole diameter,
When the required injection time is short (at high load), injection is performed at both the small injection hole 8e and the large injection hole 17; at an intermediate required injection time (at medium load), the large injection hole is used. What is necessary is just to inject by the injection hole 17 of an injection hole diameter.

As described above, when the inner needle valve 7 is opened, high-pressure fuel is injected into the fuel injection nozzle 1 from the small injection hole 8e at the tip of the outer needle valve 8, and the outer needle valve 8 is opened. The large orifice 1 at the tip of the nozzle body 3
Independent fuel injection systems that inject high-pressure fuel from No. 7 have three stages of total injection hole area and injection hole arrangement during fuel injection, specifically, during fuel injection,
The mode can be switched between “injection hole 8e (injection hole area: small)”, “injection hole 17 (injection hole area: large)”, and “injection hole 8e and injection hole 17 (injection hole area: maximum)”. Moreover, since this switching does not involve a decrease in the injection pressure, mixing can be performed under any engine operating conditions without reducing the injection pressure by using the switching of the total injection hole area and the injection hole arrangement. With the fine spray that can be improved, it is possible to obtain an optimum injection rate shape according to the engine operating conditions. In addition, during the fuel injection, the rear high injection in which the fuel injection rate is increased toward the later stage of the injection is performed by the injection hole 8e having the small injection hole diameter in the initial stage, and thereafter, the injection hole 17 having the large injection hole diameter, and all the injection holes ( Since the injection is performed in the order of 8e and 17), an ideal fuel injection rate area can be matched according to various engine operating conditions.

In addition, since the initial injection of the split injection and the pilot injection is performed in the injection hole 8e having a small injection hole diameter, the initial injection particularly in the pilot injection and the split injection, which easily affects the exhaust gas characteristics, has a small hole diameter. As a result, the injection pressure is increased, and the fine spray that can further improve the mixing is obtained, so that it is possible to further reduce the discharged fine particles (PM). Needless to say, when the fuel is injected through the injection hole 8e having a small injection hole diameter at the time of starting, the discharged fine particles (PM)
Can be reduced.

In addition, the small orifice 8e and the large orifice 17 are arranged so that the small orifice 8e and the large orifice 17 are offset from each other so that the spray from each of the orifices does not interfere with each other. A good spray can be ensured even when fuel is injected from both sides.

In addition, since the detent 26 is provided between the outer needle valve 8 and the nozzle body 3, the fuel distribution in the combustion chamber can always be kept constant.

Further, since the fuel injection nozzle 1 having such an effect has a concentric structure in which the double needle valve 6 is assembled to the nozzle body 3 so as to protrude from the tip, the fuel injection nozzle 1 can be compactly installed in a restricted narrow place (such as a cylinder head of a 4-valve engine). It can be attached to any engine.

In one embodiment, the nozzle hole at the tip of the outer needle valve has a small nozzle hole diameter, and the nozzle hole at the tip of the nozzle body has a large nozzle hole diameter. A certain injection hole may have a large injection hole diameter, and an injection hole at the tip of the nozzle body may have a small injection hole diameter.

In one embodiment, the present invention is applied to an engine that injects fuel directly into a cylinder. However, the present invention may be applied to other engines, for example, an engine that injects fuel into an intake pipe.

[0047]

As described above, according to the first aspect of the present invention, the fuel injection nozzle has a compact structure by adopting a concentric structure, and also has a structure in which the inner needle valve is opened and the fuel injection nozzle is opened. Independent fuel injection systems in which fuel is injected from a first injection hole at the tip of the needle valve, and fuel is injected from a second injection hole at the tip of the nozzle body when the outer needle valve is opened. By adopting, the total injection hole area and the injection hole arrangement at the time of fuel injection can be switched in three stages, and it is possible to form an injection rate shape under any engine operating conditions without lowering the injection pressure.

Therefore, it is possible to obtain an optimal injection rate shape corresponding to a change in engine operating conditions while obtaining a fine spray capable of improving mixing with a compact structure.

According to the second aspect of the present invention, in addition to the above-described effects, an effect is provided that any ideal fuel injection rate area can be matched.

According to the third aspect of the present invention, in addition to the above-described effects, the injection pressure of the initial injection in the pilot injection and the split injection, which easily affects the exhaust gas characteristics, can be increased. Thereby, the effect that the exhaust gas characteristics can be further improved is exhibited.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a fuel injection nozzle according to one embodiment of the present invention.

FIG. 2 is a plan view of the fuel injection nozzle along AA in FIG. 1;

FIG. 3A is a cross-sectional view illustrating the structure of an injection nozzle shown in an enlarged manner around a tip end of the fuel injection nozzle. (B) is a bottom view of the injection nozzle.

FIG. 4 is a plan cross-sectional view of the fuel injection nozzle along BB in FIG.

FIG. 5 is a flowchart for explaining switching between a small nozzle hole and a large nozzle hole.

FIG. 6 is a diagram for explaining an optimal fuel rate shape according to engine operating conditions.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fuel injection nozzle 3 ... Nozzle body 6 ... Double needle valve 7 ... Inner needle valve 8 ... Outer needle valve 8e ... Injection hole (1st injection hole) 9 ... Groove 10 ... Passage (2nd fuel passage) 12 ... Outer seat portion 17 ... Injection hole (second injection hole) 18,20 ... Valve opening mechanism, controller (control means) 20 ... Inner seat portion 21 ... Path (first fuel passage). 26 ... detent.

Claims (3)

[Claims] 1. A nozzle body comprising: an outer needle valve having a tip formed with a bottom; and an inner needle valve slidably fitted in the outer needle valve, and a tip portion of the nozzle body. A double fuel valve inserted into the nozzle body so as to protrude from the tip of the fuel cell, and a first fuel passage is formed between the inner needle valve and the outer needle valve; A second fuel passage is formed between the needle valve and the nozzle body, and fuel is injected from the first fuel passage to the tip of the outer needle valve in accordance with the opening of the inner needle valve. A first injection hole is provided, and a tip of the second fuel passage is opened at a position shifted from the first injection hole at a tip portion of the nozzle body, and the outer needle valve is opened. A fuel injection hole for injecting the fuel from the second fuel passage according to the first injection hole, and having a diameter different from the injection hole diameter of the first injection hole; A second spray hole in which fuel is sprayed from the first spray hole; a second spray pattern in which fuel is sprayed from the second spray hole; A fuel injection nozzle configured to be switchable to a third pattern in which fuel is sprayed from both the injection hole and the second injection hole. 2. The fuel injection system according to claim 1, further comprising control means for switching the first to third patterns, the control means comprising:
2. The fuel injection nozzle according to claim 1, wherein the injection is performed in the order of an injection hole having a small injection hole diameter at an initial stage, and thereafter, an injection hole having a large injection hole diameter and then all the injection holes. 3. A control means for switching the first to third patterns, wherein the control means performs initial injection of split injection and pilot injection in an injection hole having a small injection hole diameter. The fuel injection nozzle according to claim 1, wherein: