EP1435453B1 - Inward opening dual mode nozzle - Google Patents

Description

State of the art

The invention relates to a fuel injection nozzle for an internal combustion engine according to the preamble of claim 1.

From DE 40 23 223 A1 a fuel injection nozzle with two coaxially arranged nozzle needles is known. In the valve body surrounding the nozzle needles, a common nozzle needle seat is provided for both nozzle needles. As a result, both when the first nozzle needle is opened and when the second nozzle needle is opened, fuel is injected at an angle of, for example, 60 ° to the longitudinal axis of the fuel injector into the combustion chamber. These injection angles are required in the so-called heterogeneous operation of the internal combustion engine.

In some load states of the internal combustion engine, however, it is advantageous if the fuel is injected in the direction of the longitudinal axis of the fuel injection nozzle in the combustion chamber (homogeneous operation).

From WO 02/18775 A1, US Pat. No. 5,458,292 and EP 1 035 322 A2, coaxial injection nozzles are known in which the control spaces are spatially separated from the nozzle needles.

From DE 415 417 C a coaxial injection nozzle is known in which the two nozzle needles can not be controlled independently of each other.

In some load states of the internal combustion engine, however, it is advantageous if the fuel is injected in the direction of the longitudinal axis of the fuel injection nozzle in the combustion chamber (homogeneous operation).

In WO 02/18775 the difference between the so-called homogeneous operation and the heterogeneous operation of an internal combustion engine is explained in detail. These explanations are hereby incorporated by reference.

Advantages of the invention

In a fuel injector with the features of claim 1 according to the preamble A, it can be achieved that injections can take place both in the direction of the longitudinal axis of the fuel injector and at almost any angle to this longitudinal axis in the combustion chamber. As a result, the operating behavior of the internal combustion engine can be further optimized, which has a particularly advantageous effect on the noise and emission development of the internal combustion engine. Furthermore, a manufacturing technology simple construction of the fuel injection nozzle according to the invention is made possible.

In a variant of the fuel injection nozzle according to the invention it is provided that in the outer nozzle needle cooperating with a pressure shoulder of the inner nozzle needle first pressure chamber is formed, and that the first pressure chamber via a supply bore in the outer nozzle needle at least indirectly with the pressure of a common rail is charged.

Alternatively, the diameter of the inner nozzle needle at its end facing away from the combustion chamber may be greater than the diameter of the pressure shoulder of the inner nozzle needle or in the first control chamber a closing spring may be present, which is supported at one end on the inner nozzle needle and the other end on the closure piece. By said alternatives, which can also be combined with each other, is once hydraulically and the other time ensured by the bias of the closing spring closing the inner nozzle needle.

Other variants of the fuel injection nozzle according to the invention provide that the first control chamber is supplied with fuel from the common rail via a first inlet throttle, that the first control chamber via a first outlet throttle and a first directional control valve, in particular a 2/2-way valve, is hydraulically in communication with a fuel return, wherein the first inlet throttle may be arranged in the closure piece or in the outer nozzle needle and the first outlet throttle is arranged in the closure piece. Common to all these embodiments is the ease of manufacture and because of the resulting high manufacturing accuracy a favorable performance of the Fuel injection nozzle.

In a further feature of the invention, it is provided that the outer nozzle needle, with its end facing away from the combustion chamber, at one end defines a second control space present in the nozzle body, and that the closure piece limits the second control space at the other end. As a result, the number of required components is kept small and allows easy production of the fuel injection nozzle according to the invention.

In a further supplement to this variant of the invention, it is provided that the second control chamber is supplied with fuel from the common rail via a second inlet throttle, and that the second control chamber is connected via a second outlet throttle and via a second directional control valve, in particular a 2/2-way valve. is hydraulically in communication with the fuel return.

Alternatively, the second control chamber can be supplied via the supply bore, the first control chamber and the second inlet throttle with fuel from the common rail, in which case the second control chamber via a second outlet throttle and a second directional control valve, in particular a 2/2-way valve is in communication with the fuel return and the first pressure chamber is acted upon by a pressure which is greater than the pressure in the common rail. This configuration of the fuel injection nozzle according to the invention ensures that the pressure required in the common rail does not have to be as high as the desired maximum injection pressure and, moreover, the injection pressure is not continuous, but only during the injection, in the fuel injection nozzle ,

In order to increase the pressure in the common rail to the desired injection pressure, a hydraulic pressure booster can be provided between the common rail and the first pressure chamber whose low-pressure connection is hydraulically connected to the common rail whose high-pressure connection is hydraulically connected to the first pressure chamber and the pressure in a Absteuerraum via a 3/2-way valve is connected to either the common rail or the fuel return. By this pressure booster can be raised in a simple and proven way, the pressure, the control of injection start and duration is effected by a suitable control of the 3/2-way valve.

In order to supply the high-pressure side of the pressure booster and thus also the fuel injection nozzle according to the invention with fuel, a hydraulic connection with a check valve can be provided between the common rail and high pressure port of the pressure booster.

A further advantageous embodiment of the invention provides that the second inlet throttle is arranged in the closure piece, so that the vote of inlet throttles and outlet throttles of the fuel injection nozzle according to the invention can be made directly in the production of the closure piece. This also makes it possible to improve the production of the fuel injection nozzle according to the invention and their operating behavior in a simple manner. Also, the variations in the performance of the fuel injectors in mass production can be reduced.

According to the way valves can be actuated by an electromagnet or a piezoelectric actuator.

Further advantages and advantageous embodiments of the invention are the following drawings, the description and the claims removable.

drawing

Figur 1

ein erstes Ausführungsbeispiel einer erfindungsgemäßen Kraftstoff-Einspritzdüse im Längsschnitt,

Figur 2

ein zweites Ausführungsbeispiel einer erfindungsgemäßen Kraftstoff-Einspritzdüse mit Druckübersetzer,

Figur 3

ein drittes Ausführungsbeispiel einer erfindungsgemäßen Kraftstoff-Einspritzdüse,

Figur 4

Vergrößerte Darstellungen der Spritzlöcher von Ausführungsbeispielen erfindungsgemäßer Kraftstoff-Einspritzdüsen und

Figur 5

eine schematische Darstellung einer Kraftstoffeinspritzanlage mit erfindungsgemäßen Kraftstoff-Einspritzdüsen.

Show it:

FIG. 1

a first embodiment of a fuel injection nozzle according to the invention in longitudinal section,

FIG. 2

A second embodiment of a fuel injection nozzle according to the invention with pressure booster,

FIG. 3

A third embodiment of a fuel injection nozzle according to the invention,

FIG. 4

Enlarged illustrations of the injection holes of embodiments of inventive fuel injectors and

FIG. 5

a schematic representation of a fuel injection system with fuel injection nozzles according to the invention.

Description of the embodiments

1 shows a first embodiment of a fuel injection nozzle 1 according to the invention is shown in longitudinal section. The fuel injection nozzle 1 consists essentially of a nozzle body 3, in which an outer nozzle needle 5 is sealingly guided. In the outer nozzle needle 5, an inner nozzle needle 7 is also guided sealingly. With a combustion chamber end 9, the fuel injection nozzle 1 protrudes into a combustion chamber, not shown, of an internal combustion engine. At the end of the nozzle body 3 facing away from the combustion chamber, not shown, the latter is closed with a closure piece 11.

The fuel injector 1 is supplied by a common rail 114 via a high-pressure fuel line 13 with fuel under high pressure. The control and leakage quantities are discharged via a fuel return 15.

As can be seen from FIG. 1, the outer nozzle needle 5 has a stepped central bore 17, in which the inner nozzle needle 7 is guided. The inner nozzle needle 7 has substantially three different diameters, which are designated in Figure 1 with D ₁ , D ₂ and D ₃ . Unless otherwise stated, the following relations apply: $${\mathrm{<figure-callout\; id="3"\; label="D"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">D</figure-callout>}}_{\mathrm{3}}\mathrm{\ge }{\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="imgf0002.png"\; state="\{\{state\}\}">D</figure-callout>}}_{\mathrm{2}}{\mathrm{and\; <figure-callout\; id="1"\; label="D"\; filenames="imgf0002.png,imgf0006.png"\; state="\{\{state\}\}">D</figure-callout>}}_{\mathrm{1}}\mathrm{\le }{\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="imgf0002.png"\; state="\{\{state\}\}">D</figure-callout>}}_{\mathrm{2}}$$

If D ₃ = D ₂ , a closing spring is needed.

At its combustion chamber end, the inner nozzle needle 7 has a first diameter D ₁ , which merges into a tip 19. The tip 19 of the inner nozzle needle 7 is in the closed state on a first nozzle needle seat 21, which is provided at the end of the stepped center hole 17 of the outer nozzle needle 5 on.

Between first diameter D ₁ and second diameter D ₂ a pressure shoulder 23 is formed on the inner nozzle needle 7. This first pressure shoulder 23 delimits a first pressure chamber 25 formed by the stepped central bore 17 of the outer nozzle needle 5. The first pressure chamber 25 is supplied with fuel from the common rail 114 via a supply bore 27 in the outer nozzle needle 5 and the high-pressure line 13.

The inner nozzle needle 7 is sealingly guided with its second diameter D ₂ in the stepped central bore 17 of the outer nozzle needle 5.

At its end 29 facing away from the combustion chamber, the inner nozzle needle 7 has a third diameter D ₃ which is larger than the second diameter D ₂ and defines a first control chamber 31. The inner nozzle needle 7 is guided with its third diameter D ₃ sealingly in the stepped center bore 17 of the outer nozzle needle 5.

At the end 29 of the inner nozzle needle 7 opposite end of the first control chamber 31 is limited by the closure piece 11. The closure piece 11 is also sealingly introduced into the stepped center bore 17 of the outer nozzle needle 5. The inner nozzle needle 7 can move relative to the closure piece 11 and to the outer nozzle needle 5.

The first control chamber 31 is hydraulically connected via the high-pressure line 13, in which a first inlet throttle 33 is located, to the common rail 114. Via a first outlet throttle 35 and a first 2/2-way valve 37, the first control chamber 31 with the fuel return 15 is hydraulically connected.

The operation of the inner nozzle needle 7 is done by driving the first 2/2-way valve 37 in the following manner: If the inner nozzle needle 7 should lift off the first nozzle needle seat 21 to initiate an injection, the first 2/2-way valve 37 is opened, so that the pressure in the first control chamber 31 drops and lifts the inner nozzle needle 7 from the first nozzle needle seat 21 by the hydraulic force acting essentially on the first pressure shoulder 25. As a result, fuel is injected into the combustion chamber through the first injection holes 39 arranged in the outer nozzle needle 5. As soon as the first 2/2-way valve 37 is closed again, the pressure in the first control chamber 31 rises again and the hydraulic force acting on the end 29 of the inner nozzle needle 7 facing away from the combustion chamber moves the inner nozzle needle 7 counter to that acting on the pressure shoulder 25 hydraulic force back to the first nozzle needle seat 21.

The outer nozzle needle 5 is sealingly guided in a stepped central bore 41 of the nozzle body 3 with their diameters D ₄ and D ₅ . The stepped center bore 41, together with a second pressure shoulder 43 of the outer nozzle needle 5, delimits a second pressure chamber 45.

With its end 47 facing away from the combustion chamber, the outer nozzle needle 5 together with the closure piece 11 and the stepped central bore 41 defines a second control chamber 49. The second control chamber 49 is hydraulically connected to the common rail 114 via a second inlet throttle 51.

Via a second outlet throttle 53 and a second 2/2-way valve 55, the second control chamber 49 with the fuel return 15 is connected. The second inlet throttle 51 and the second discharge throttle 53 are arranged in the closure piece 11.

When the outer nozzle needle 5 is to lift off its seat in the nozzle body 3, the second 2/2-way valve 55 is opened, so that the pressure in the second control chamber 49 drops and acting on the second pressure shoulder 43 hydraulic force, the outer nozzle needle 5 of her not shown seat in the nozzle body 3 lifts. When the outer nozzle needle 5 has lifted from its seat, not shown, in the nozzle body 3, fuel can be injected through the second injection holes 40 shown in Fig. 4 in the combustion chamber. In this case, the fuel is injected in a first approximation in the direction of the longitudinal axis of the fuel injection nozzle 1.

As soon as the second 2/2-way valve 55 is closed again, there is an increase in pressure in the second control chamber 49, so that the outer nozzle needle 5 is again pressed onto its nozzle needle seat.

When dimensioning the fuel nozzle 1 according to the invention, care must be taken that the annular area at the end 47 of the outer nozzle needle 5, which is bounded by the diameters D ₅ and D ₃ , is larger than the area of the second pressure shoulder 43, thus at the same pressure in the second pressure chamber 45 and in the second control chamber 49, a resulting hydraulic force is created, which presses the outer nozzle needle 5 on its sealing seat in the nozzle body 3.

The second injection holes 40, not shown in FIG. 1, of the outer nozzle needle 5 are arranged so that the fuel is directed in the direction of the longitudinal axis of the fuel injection nozzle 1 in the combustion chamber (not shown) is injected (see also Figure 4). Slight deviations between the direction of the injected fuel jet and the longitudinal axis of the fuel injector are also possible and in part desirable. As a result, an improved combustion and emission behavior of the same can be achieved in some operating states of the internal combustion engine.

If the fuel is to be injected laterally into the combustion chamber, not shown, the inner nozzle needle 7 is opened. It is also possible to first open the inner nozzle needle 7 and additionally lift the outer nozzle needle 5 from its nozzle needle seat when the inner nozzle needle 7 is open, so that a large amount of fuel is injected into the combustion chamber in a very short time.

FIG. 2 likewise shows a longitudinal section of a second exemplary embodiment of a fuel injection nozzle 1 according to the invention. The same components are provided with the same reference numerals, and the same applies with regard to FIG. 1.

Between the high pressure line 13 and the first pressure chamber 25, a hydraulic pressure booster 57 is provided in this embodiment. The pressure booster 57 essentially consists of a stepped piston 59, which limits on the one hand a low-pressure chamber 61 and on the other hand a high-pressure chamber 63. The low-pressure chamber 61 is hydraulically connected via the high-pressure line 13 to the common rail 114. The high-pressure chamber 63 is connected to the first pressure chamber 25 via a line 65, which runs through the connecting piece 11, the nozzle body 3 and the outer nozzle needle 5. The high-pressure chamber 63 is filled via a Check valve 67, which is arranged between the high pressure line 13 and the high pressure chamber 63. A Absteuerraum 69 of the pressure booster 57 is hydraulically connected via a 3/2-way valve 71 either with the common rail 114 or the fuel return 15. In the Absteuerraum 69, a closing spring 74 is provided, which moves the stepped piston 59 in the switching position of the 3/2-way valve 71 shown in Figure 2 upward, causing a reduction of the low-pressure space 61 and an enlargement of the high-pressure chamber 63. Once the 3/2-way valve 71 is switched so that the Absteuerraum 69 is hydraulically connected to the fuel return 15, the stepped piston 59, because the force acting in the high pressure chamber 61 hydraulic forces are greater than the forces acting in the high pressure chamber 63 hydraulic forces, according to Fig. 2 moves down. As a result, the pressure in the first pressure chamber 25 increases, so that the force acting on the first pressure shoulder 23 hydraulic force is greater than the force exerted by the first control chamber 31 hydraulic force and the force exerted by a located in the first control chamber 31 closing spring 73 on the inner nozzle needle 7 force is. As a result, the inner nozzle needle 7 lifts off from its first nozzle needle seat 21. When the inner nozzle needle 7 lifts from its sealing seat, the volume of the first control chamber 31 decreases. The fuel displaced thereby flows back into the high-pressure line 13 via the supply bore 27. Because of the simultaneous increase in volume of the low-pressure chamber 61 of the pressure booster 57, the high-pressure line 13 can absorb the amount of fuel displaced from the first control chamber 31.

In the illustrated in Figure 2 second embodiment of a fuel injection nozzle 1 according to the invention opens the inner nozzle needle. 7 pressure-controlled, so that a first inlet throttle and a first outlet throttle are not necessary.

In this embodiment, the inner nozzle needle 7 only two diameters (D ₁ and D ₂ ). The closing force is, as already mentioned, applied by the closing spring 73. This conception can also be used in the embodiment according to FIG.

The second control chamber 49 is supplied in this embodiment via a second inlet throttle 51 with fuel, wherein the second inlet throttle 51 establishes a hydraulic connection between the first control chamber 31 and the second control chamber 49. In this embodiment, the closure piece 11 is made in two parts. This is indicated by the reference numerals 11a and 11b in FIG. By the two-part design of the closure piece 11, a slight eccentricity of the stepped center hole 17 can be compensated relative to the stepped center hole 41. In addition, the production of the closure piece 11 is simplified.

The outer nozzle needle 5 is opened by the second 2/2-way valve 55 is opened and thus takes place via the second outlet throttle 53, a pressure reduction in the second control chamber 49. As soon as the hydraulic force acting on the second pressure shoulder 43 is greater than the hydraulic force exerted by the second control chamber 49 on the outer nozzle needle 5, the outer nozzle needle 5 lifts from its nozzle needle seat in the nozzle body 3 and allows injection.

In the high pressure line 13 is a combined check valve with a parallel throttle, which are designated in their entirety by the reference numeral 75, provided to reduce pressure oscillations in the common rail 114 and in the fuel injection nozzle 1, respectively.

FIG. 3 shows a further exemplary embodiment of a fuel injection nozzle 1 according to the invention with a pressure booster 57. In the following, only the essential differences will be described and otherwise referred to the above.

Unlike in the exemplary embodiment according to FIG. 2, the first control chamber 31 is supplied with fuel via a first inlet throttle 33 arranged in the outer nozzle needle 5. The first inlet throttle 33 communicates with the line 65, which connects the high-pressure chamber 63 of the pressure booster 57 with the first pressure chamber 25.

The first outlet throttle 35 is connected via a line 77 to the discharge chamber 69 of the pressure booster 57. This means that as soon as the 3/2-way valve 71 establishes a hydraulic connection of the fuel return 15 and the discharge chamber 69, the pressure in the first control chamber 31 also drops and thus the inner nozzle needle 7 can open. The second inlet throttle 51 is arranged in this embodiment between the high pressure line 13 and the second control chamber 49 in the closure piece 11a. The second outlet throttle 43 is also arranged in the closure piece 11a.

Various embodiments of fuel injection nozzles according to the invention are simplified and enlarged in FIG. With the enlargements shown in Figure 4a to Figure 4b, especially different possible arrangements of second spray holes 40 are explained and illustrated in the fuel injection nozzle 1 according to the invention. All of the embodiments according to FIGS. 4 a to 4 b can be used in any of the embodiments explained in detail above according to FIGS. 1 to 3.

In the embodiment according to FIG. A, a second nozzle needle seat 79 can be seen. The second nozzle needle seat 79 indicates the contact line between the outer nozzle needle 5 and the nozzle body 3 in the closed state of the fuel injection nozzle 1. The second injection holes 40 are formed in this embodiment by a cylindrical annular gap between the nozzle body 3 and the outer nozzle needle 5. The second injection hole 40 is released only when the outer nozzle needle 5 lifts off from the nozzle body 3 and thus releases the second nozzle needle seat 79.

In the embodiment according to FIG. 4b, grooves distributed over the circumference are formed in the outer nozzle needle 5, which grooves together with the nozzle body 3 form the second injection holes 40.

In the embodiment according to FIG. 4 c, the second injection holes 40, just like the first injection holes 39, are arranged in the outer nozzle needle 5.

In the embodiment according to FIG. 4 d, the second spray holes 40 are the nozzle bodies 3 between the second nozzle needle seat 79 and the guide 81 of the outer nozzle needle 5 in the nozzle body 3.

Reference to the figure 5 will be explained below, as the fuel injection nozzle 1 according to the invention in a Fuel injection system 102 of an internal combustion engine is integrated. The fuel injection system 102 includes a fuel tank 104 from which fuel 106 is conveyed by an electric or mechanical fuel pump 108. Via a low-pressure fuel line 110, the fuel 106 is conveyed to a high-pressure fuel pump 111. Of the high-pressure fuel pump 111 of the fuel 106 passes through a high-pressure fuel line 112 to a common rail 114. On the common rail a plurality of fuel injection nozzles 1 according to the invention are connected, which inject the fuel 106 directly into combustion chambers 118 of an internal combustion engine, not shown ,

Claims (15)

1. Fuel injection nozzle for an internal combustion engine having a nozzle body (3) which projects into the combustion chamber, having two coaxial nozzle needles (5, 7), the outer nozzle needle (5) being guided in the nozzle body (3), having a second nozzle needle seat in the nozzle body (3) for the outer nozzle needle (5) and having a first nozzle needle seat for the inner nozzle needle (7), the inner nozzle needle (7) being guided in the outer nozzle needle (5), and the first nozzle needle seat (21) being arranged in the outer nozzle needle (5), characterized in that the inner nozzle needle (7) bounds at one end, with its end (29) facing away from the combustion chamber, the first control space (31) present in the outer nozzle needle (5), and a closure element (11, 11a, 11b) which interacts with the outer nozzle needle (5) bounds the first control space (31) at the other end.
2. Fuel injection nozzle according to Claim 1, characterized in that a first pressure space (25) which interacts with the first pressure shoulder (23) of the inner nozzle needle (7) is formed in the outer nozzle needle (5), and in that the pressure of a common rail (114) can be applied at least indirectly to the first pressure space (25) via a supply bore (27) in the outer nozzle needle (5).
3. Fuel injection nozzle according to Claim 1 or 2, characterized in that the diameter (D₃) of the inner nozzle needle (7) is greater at its end (29) facing away from the combustion chamber than the diameter (D₂) of the first pressure shoulder (23) of the inner nozzle needle (7).
4. Fuel injection nozzle according to Claim 1 or 2, characterized in that the diameter (D₃) of the inner nozzle needle (7) is equal at its end (29) facing away from the combustion chamber to the diameter (D₂) of the first pressure shoulder (23) of the inner nozzle needle (7).
5. Fuel injection nozzle according to one of the preceding claims, characterized in that a closing spring (73) which is supported at one end on the inner nozzle needle (7) and at the other end on the closure element (11) is provided in the first control space (31).
6. Fuel injection nozzle according to one of the preceding claims, characterized in that the first control space (31) is supplied with fuel from the common rail (114) via a first inflow throttle (33), and in that the first control space (31) is connected hydraulically to a fuel return line (15) via a first outflow throttle (35) and via a first directional control valve, in particular a 2/2 way directional control valve (37).
7. Fuel injection nozzle according to Claim 6, characterized in that the first inflow throttle (33) is arranged in the closure element (11) or in the outer nozzle needle (5).
8. Fuel injection nozzle according to Claim 6 and 7, characterized in that the first outflow throttle (35) is arranged in the closure element (11).
9. Fuel injection nozzle according to one of the preceding claims, characterized in that the outer nozzle needle (5) bounds at one end, with its end (47) facing away from the combustion chamber, a second control space (49) which is present in the nozzle body (3) and in that the closure element (11) bounds the second control space (49) at the other end.
10. Fuel injection nozzle according to Claim 9, characterized in that the second control space (49) is supplied with fuel from the common rail (114) via a second inflow throttle (51), and in that the second control space (49) is connected hydraulically to the fuel return line (15) via a second outflow throttle (53) and via a second directional control valve, in particular a 2/2 way directional control valve (55).
11. Fuel injection nozzle according to Claim 9, characterized in that the second control space (49) can be supplied with fuel from a common rail (114) via the supply bore (27), the first control space (31) and the second inflow throttle (51), in that the second control space (49) is connected hydraulically to the fuel return line (15) via the second output throttle (53) and via the second directional control valve, in particular 2/2 way directional control valve (55), and in that a pressure which is greater than the pressure in the common rail (114) can be applied to the first pressure space (25).
12. Fuel injection nozzle according to Claim 11, characterized in that the fuel injection nozzle (1) comprises a hydraulic pressure intensifier (57), in that the hydraulic pressure intensifier (57) is arranged between the common rail (114) and the first pressure space (25), in that a low pressure space (61) of the pressure intensifier (57) can be hydraulically connected to the common rail (114), in that a high pressure space (63) of the pressure intensifier (57) is hydraulically connected to the first pressure space (25), and in that the pressure in a discharge space (69) of the pressure intensifier (57) can be connected either to the common rail (114) or to the fuel return line (15) via a 3/2 way directional control valve (71).
13. Fuel injection nozzle according to Claim 12, characterized in that a hydraulic connection to a non return valve (67) is provided between the common rail (114) and a high pressure space (63) of the pressure intensifier (57), and said connection is associated with the injection nozzle.
14. Fuel injection nozzle according to one of Claims 11 to 13, characterized in that the first outflow throttle (35), the second outflow throttle (53) and/or the second inflow throttle (51) are arranged in the closure element (11).
15. Fuel injection nozzle according to one of the preceding claims, characterized in that the directional control valves (37, 55, 71) are activated by an electromagnet or a piezo actuator.

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