WO2019162262A1

WO2019162262A1 - Dual fuel injector

Info

Publication number: WO2019162262A1
Application number: PCT/EP2019/054068
Authority: WO
Inventors: Michael Nitsche; Hans-Joachim Koch
Original assignee: Woodward L'orange Gmbh
Priority date: 2018-02-23
Filing date: 2019-02-19
Publication date: 2019-08-29
Also published as: DE102018001566A1

Abstract

A dual fuel injector (1) having: - at least one stroke-controllable fuel gas nozzle valve member (5) for selectively controlling the opening and closing of at least one nozzle opening (49) of a nozzle assembly (51) of the dual-fuel fuel injector (1), - a stroke control assembly (13) for each fuel gas nozzle valve member (5), which stroke control assembly (13) works hydraulically by the principle of a dual-acting cylinder, characterised in that - each fuel gas nozzle valve member (5) is loaded in the closing direction (A) via a holding-down assembly (25) with a "machined spring" (63).

Description

DESCRIPTION

Dual-fuel fuel injector

The present invention relates to a dual-fuel fuel injector according to the preamble of claim 1.

In generic dual-fuel fuel injectors according to FIG. 1, s. e.g. also the patent DE 10 2015 016034 B3, which are intended for operation with fuel gas and another fuel, preferably liquid fuel, is a with a particular catchy wire compression spring, designed as a helical or spiral spring, loaded Stelzenelement in a throughput Fuel gas Spie herraum taken up. With the spring and gas pressure-loaded further Stelzenelement a closing force is exerted on a fuel gas nozzle valve member so that in case of failure of the switching system, the fuel gas nozzle valve members can be reliably spent against the combustion chamber pressure in the closed position. Since the spring chamber is also used for fuel gas caching, a barrier fluid seal is arranged on the leadership of Stel ze, which prevents fuel gas unintentionally creeps into the fuel gas nozzle valve member control circuit, which operates with a control fluid. Since, however, the barrier fluid pressure is greater than that of the fuel gas, barrier fluid is inadvertently introduced into the fuel gas to be expelled, thus adversely affecting emissions.

Proceeding from this, the present invention has the object to provide a dual-fuel fuel injector of the aforementioned type, which overcomes the disadvantages of the prior art

This object is achieved by a fuel injector with the features of claim 1.

Advantageous developments and Ausführutigsformen the invention are set forth in the further claims.

Vorgcschlagcn according to the invention is a Zweistoff- or dual-Fucl Kraftstoffmjcktor for a Breimkraftmaschine, preferably for a reciprocating Bretinkraftmaschine. Such an internal combustion engine may be designed as a self-igniter and / or a spark igniter, generally as a dual-purpose igniter. Fuel engine, especially as a large engine. The use of the dual-fuel fuel injector is advantageous eg in the context of an ignition jet operation of an internal combustion engine. The dual fuel injector is preferred for use with a first fuel in the form of fuel gas, eg natural gas. Biogas, landfill gas, hydrogen or the like, and a second fuel provided in a preferred form of liquid fuel, eg diesel fuel, bio-oil, heavy oil or similar.

For example, the internal combustion engine having the dual-fuel fuel injector may be for a motor vehicle such as a ship, a rail vehicle such as a locomotive, a utility or special vehicle, or e.g. for a stationary device, e.g. for a combined heat and power plant, an (emergency) power unit, and also for industrial applications, e.g. off-shore or on-shore. In the context of an internal combustion engine, the dual-fuel fuel injector can be used in particular with a fuel injection system thereof, preferably with a common Rai fuel injection system, for example both for fuel gas and the further fuel, preferably liquid fuel.

The dual-fuel fuel injector Ektor has at least one Hubsteuerbares fuel gas nozzle valve member, preferably in the form of a fuel gas nozzle needle, which in particular for the selective up and Zusteuem provided by at least one Düsenöffhung a (dedicated) nozzle assembly of the dual-fuel Kraftstoffmjektors is. Preferably, the dual-fuel

Fuel injector, a plurality of such Hubsteuerbarer fuel gas nozzle valve members, e.g. three or more, and more particularly in an arrangement in which they provide a centrally located nozzle valve member for the discharge of another fuel - e.g. arranged along a circular line, in particular surrounded by a liquid fuel nozzle valve member of the dual-fuel fuel injector (in the case of three nozzle valves, for example, they are divided into a three-axis system g).

A respective fuel gas nozzle valve member can be received and guided axially displaceably in a correspondence receptacle, in particular embodied as an axial bore, furthermore preferably in each case in a nozzle body of the dual fuel injector. The dual fuel injector further includes a lift control assembly each

Brcnngas-Düscnvcntilglicd. The respective Hubstcucranordnung works hydraulically and in particular according to the principle of a double-acting cylinder. In this case, the respective stroke control arrangement preferably comprises a piston section (acting as a piston) which in particular formed at a nozzle-distal end of the Hubsteueranordnung to be controlled fuel gas nozzle valve member, further comprising a first nozzle nearer control chamber and a second, nozzle-dense control chamber, which are volume variable from each other via the piston section separated (insofar a hydraulic cylinder with therein ( axially) form displaceable piston).

According to the principle of the double-acting cylinder according to a respective control chamber of the Hubsteueranordnung preferably ei ne control line out, further] e led in particular via a switching valve (servo valve or pilot valve) to a respective control room. The switching valve (which is further preferably provided with a hydraulic pressure source (control fluid) and a

Hydraulic pressure sink communicates (leakage)), in particular can be a 4/2-way valve, each one control chamber in the context of the Hubsteueranordnung thus formed - via switching the changeover valve - can be hydraulically relieved while the other is charged and vice versa. Preferably, the fuel gas nozzle valve member from the nozzle near Steuerraurn out towards the nozzle assembly turns out of the control room, so far as denzaufnah preferably in the subsequent Korrespo me.

According to the invention, in the case of the proposed dual-fuel fuel injector, a respective fuel gas nozzle valve member is loaded in the closing direction via a respective hold-down arrangement with a so-called "machined spring", in particular designed as a compression spring the technical term is referred to in the context of the present invention, a spring which, in contrast to conventional (wire-based) coil springs not wound from a wire, but is "worked out of full", preferably machined, eg by milling, eroding, laser cutting or the like The so machined from a solid material or solid metal, such as titanium, stainless steel or high-strength alloys, machined "springs" can be made shorter or more compact compared to conventional coil springs advantageous, besides advantageous as Präzisionsfedem, eg with all linear spring characteristic (so that a bias for such a linear characteristic as in conventional coil springs is not required). Furthermore, seating or contact surfaces or generally special geometries can be integrated as required in the "Machined Spring" or be integrated with.

Within the scope of the holding arrangement provided according to the invention (per fuel gas Nozzle valve member) is provided to accommodate this "Machined Spring" in a spring chamber of the N iederhal tean order, which is preferably formed nozzles remote from the fuel gas nozzle valve member, wherein the spring chamber also preferably a - remote nozzle - control chamber is formed (in particular In this case, the "Machined Spring" directly against the fuel gas nozzle valve member - a closing force on this exercising - urged, in preferred embodiments, for example indirectly via a stilt element. Especially in embodiments in which the "Machined Spring" is directly against the fuel gas nozzle valve member in Appendix, due to the simple feasibility of "Machined Springs" with fully planar and level equal · investment area improved power distribution and support against wire-based spiral springs can be achieved t ,

In embodiments with a stilt element, this may be provided with a e.g. bolt or pin-shaped section in the middle of or within the bound space or within the windings of the "Machined Spring" aufgenom or arranged, in particular guided on the turns (thus reliably avoiding buckling of the "Machined Spring"), wherein the stilt element Close to the nozzle, for example, further comprises a spring plate, against which the "machine spring" is supported at one end, whereby a (short) engagement section or extension of the stilt element on the side of the spring plate can be urged towards the fuel gas nozzle valve member (against a fuel nozzle member) nozzle-remote end face of the same.) Düsenfem is the

"Machined Spring" eg against an end face of the spring chamber in abutment or supported against it, preferably against an adjustment between the spring end and spring chamber end face, with which adjustment element, if necessary, a bias against the fuel gas nozzle valve member is adjustable , For example, a perforated or annular disc, the adjustment can advantageously be made simply by choosing the thickness of the adjustment.

With the invention it is possible, the Mederhalteanordnung compared to prior art hold-down arrangements with wire-based coil spring - especially as discussed above - clearly verkl space from led to be able to lead, along with the front door, the F ederraum ni cht longer than fuel gas passage memory - formerly pronounced lack of space (in the area above the nozzle body) owed - to perform, but the Brcnngas- (high-pressure) supply lines - now correspondingly larger dimensions, so far, for example, also with cache functionality - directly or without specially formed cache in Inj ector housing to be able to lead to the nozzle arrangements or an upstream nozzle chamber. In this way, in turn, the previously required barrier fluid seal on the hold-down arrangement or the stilt element can advantageously be dispensed with, so that the barrier fluid entry into the fuel gas is likewise avoided in the intended manner. In addition, but also accounts for unintentional V vortices in the fuel gas supply path to the nozzle arrangement due to the fact that this no longer needs to be performed on the spring chamber (fuel gas buffer).

Overall, the benefits associated with "machined springs" easily outweigh the significantly higher costs of the same-in itself unexpectedly.) In advantageous embodiments, a particular "machined spring" may be multi-course, e.g. be zweigängige or three-pronged spring, -bei which the spring force can be distributed even more evenly parallel to the central axis of the spring. As a result, the compression or expansion is translated more precisely (axially) in parallel (i.e., as the number of gears increases). This may be e.g. a spring-guided bolt or pin element also eliminated.

In the context of preferred embodiments of the dual-fuel fuel injector, a respective spring chamber is all formed in an intermediate plate of the dual-fuel fuel injector, in particular as a blind hole or bore, furthermore in particular with correspondence dimensions in relation to the "Machined Spring" ever received therein, so that this can be guided radially on the outside and furthermore advantageously any buckling (radially outwards) is also effectively avoided thereby. In particular, in the context of a hold-down arrangement designed as above, it is provided that the respective fuel gas nozzle valve member is all received in a can body of the dual-fuel fuel injector St, and the nozzle body in this case is preferably capped by means of the intermediate plate. In this case, in the nozzle body preferably both the correspondence recording for a respective fuel gas nozzle valve member and the (nozzle-like) cylinder wall section to form the control chambers and receiving the piston section worked (in particular as a bore), in particular depending also from a (nozzle remote) end face (against which the intermediate plate is provided for covering the system). In that regard, the Hubsteueranordnung in a simple manner by Zusammenfugen of intermediate plate and Nozzle body are completed, preferably in such a way that the spring chamber preferably forms a common volume in the course of assembly with a control chamber part of the nozzle-shaped control chamber.

Finally, an internal combustion engine is also proposed, in particular the reciprocating type, which has at least one dual-fuel fuel injector as discussed above.

Other features and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention, with reference to the figures of the drawings, the essential details of the invention show, and from the claims. The individual features may be implemented individually for themselves or for a plurality of different combinations in a variant of the invention.

Preferred embodiments of the invention are explained below with reference to the accompanying drawings. Show it:

Fig. 1 by way of example and schematically a partially sectioned and broken view of a generic dual-fuel fuel injector according to the prior art.

Fig. 2 shows an example and schematically a partially sectioned and broken view of a dual-fuel fuel injector according to a preferred embodiment of the invention.

3 shows by way of example and schematically a detailed view of a detail from FIG. 2, focused on the "Mach in ed Spring".

4 shows an example and schematically a view of an intermediate plate of the dual

Fuel fuel injector according to FIG. 2.

In the following description and drawings, the same reference numerals correspond to elements of like or comparable function. Elements of the prior art are provided with primed reference numerals. Fig. 1 shows a dual-fuel Kraftstoffmjektor G according to the prior art. The dual-fuel fuel injector G has a nozzle body 3 ', in which a number Brenngasdüsenventilglieder 5' (only one fuel gas nozzle valve member 5 'is shown) are received and guided axially displaceable stroke. An end portion of the respective fuel gas nozzle valve member 5 is designed as a piston portion T, the piston portion 7 'two control chambers 9', 1 G of a respective (the fuel gas nozzle valve member 5 'associated) Hubsteueranordnung 13' of the dual-fuel Kraftstoffinj ector G, which operates on the principle of the double-acting cylinder, dividing volume variable from each other. To a respective control chamber 9 ', 1 G is in this case a control line 15', 17 'out, which control lines 15', 17 'further via a switching valve 19' either with a pressure sink 2G or a pressure source 23 'are connectable (the control lines 15th ', 17' of the plurality of

Lift control assemblies 13 'may be e.g. be merged, e.g. to a single switching valve 19 ').

By means of the pressure source 23 '- a fuel injection system - control fluid subjected to high pressure can be supplied to a respective control chamber 9' or 1 G connected to a valve position dependent, control fluid is supplied to the pressure sink 2G (low pressure) from the control chamber 11 'respectively connected to the valve position dependent relieving pressure 9 'deductible. With this Hubsteueranordnung 13 'can - depending on the position of the switching valve 19' - a control chamber 9 'or 1 1' are charged, the other ll 'or 9' this relieved and vice versa, thus the fuel gas nozzle valve member 5 'in open be controlled or closed position,

The dual-fuel fuel injector G according to the prior art further comprises a hold-down assembly 25 '(per fuel gas nozzle valve member 5'), via which the fuel gas nozzle valve member 5 'with a closing force (arrow arrow L') was charged. The hold-down arrangement 25 'is formed by means of a stilt element 27', which is a

Intermediate plate 29 ', nozzle-shaped arranged on the nozzle body 3', with a bolt-shaped portion 3 G passes, which in this case in a correspondence recording (axial bore) of the intermediate plate 29 'is guided.

A spring plate 33 'of the stilt element 27' is accommodated in a spring chamber 35 'which adjoins the intermediate plate 29' in another, nozzle-denser housing element 37 '. of the dual-fuel fuel injector G is formed. The fuel space 35 'in this case acts simultaneously as a fuel gas buffer or transit storage, for which at one end (nozzle) a fuel gas supply line 39' (high pressure) leads to the buffer (spring chamber 35 '), and at the end (near the nozzle) a portion 39a' of the fuel gas Supply line 39 ', starting from the buffer to a nozzle space 4G (in Fig. 1 is not explicitly shown) leads.

In the spring chamber 35 'or fuel gas buffer is further a compression spring 43' is added, by means of which the closing force A '- indirectly via the stilt element 27' - on the fuel gas nozzle valve member 5 'is exercised. In this case, the compression spring 43 'at one end against the nozzle-distant end face 45' of the spring chamber 35 'urged, andemends against the spring plate 33'. The compression spring 43 'is designed as a wire-based spiral spring or wire spring and builds obviously relatively long, i. with a dimension LI (in the present case referred to the closed state of the fuel gas nozzle valve member 5 'shown). Due to the considerable size of the coil spring 43 'whose placement in the intermediate plate 29' made impossible, so that the fuel gas - the thus considerably cramped space owed - forced by the spring chamber 35 'must be performed. As a result, a barrier fluid seal 47 'on Stelzendement 27' in the intermediate plate 29 'is required, but from which an unintentional Sperrfluideintrag (via the Kriechspalt along the Stelzenf leadership) in the fuel gas (in the spring chamber 35') results. Furthermore, it comes with this solution to unintentional turbulence in the fuel gas buffer (spring chamber 35 '), in particular the turns of the coil spring 43' owed, so that the intended homogeneous flow of the downstream nozzle openings 49 '(not explicitly illustrated in Fig. 1) is not guaranteed is.

Fig. 2 now shows in a broken and partially sectional view of a dual-fuel fuel injector 1 according to the invention. As in the prior art discussed above, the dual-fuel fuel injector 1 has a number of lift-controllable fuel gas nozzle valve members 5, generally at least one fuel gas nozzle valve member 5, preferably three or more

Fuel gas nozzle valve members 5, which are each provided in particular as a fuel gas nozzle needle. Each fuel gas nozzle valve member 5 is associated with at least one nozzle opening 49 of a nozzle assembly 51 of the dual-fuel Kraftstoffinj ector 1, which via the respective

Brine gas düscnvctil glicd 5 selectively auf- and is zucucrbar (depending on a Hubstcllung same). Preferably, the nozzle openings 49 of the nozzle arrangement 51 are arranged so that the best possible 360 ° cover can be achieved within the scope of an ejection. Aufgenomrnen and led is a respective fuel gas nozzle valve member 5 in one

Correspondence receptacle 53 in a nozzle body 3 of the dual-fuel fuel injector 1, preferably designed as an axial bore. In the illustrated dual-fuel fuel injector 1, the fuel gas nozzle valve members 5 surround, e.g. further, centrally in the nozzle body 3 to ordered liquid fuel nozzle valve member 55, e.g. in a triangular formation or along a circular line (viewed in the circumferential direction) about the same. The liquid fuel nozzle valve member 55 is hereby controllable independently of the fuel gas nozzle valve members 5,

e.g. indirectly hydraulically via a control arrangement with a pilot valve (not shown), a control chamber 57 (further comprising a needle guide sleeve 59 and a nozzle spring

61).

The dual-fuel fuel injector 1 further comprises a Hubsteueranordnung 13 per fuel gas nozzle valve member 5, which Hubsteueranordnung 13 operates hydraulically on the principle of a double-acting cylinder, in particular as explained above for the prior art. In this case, a nozzle-shaped end section of a respective fuel gas nozzle valve member 5 forms a piston section 7 of the stroke control arrangement 13 (which acts as a piston) which divides a nozzle-far control chamber 9 and a control chamber 11 closer to the nozzle, likewise each of the stroke control arrangement 13, from one another. To each control chamber 9, 11 each carries a control line 15 and 17, which - as in the prior art - to a switching valve according to 19 '(servo or pilot valve), in particular a 4/2-way valve (in FIG. 2), for which alternately loading and unloading with a pressure source 23 '(pressurized control fluid) or a pressure sink 2G (leakage side or Niederdmckseite) is connectable. The switching valve may preferably be part of the dual-fuel fuel injector 1 or else separate therefrom, e.g. be arranged externally.

The dual-fuel fuel injector 1 has, as Fig. 2 illustrates this, as in the prior art also a hold-down assembly 25 per fuel gas nozzle valve member 5, wherein - in contrast to the prior art - the respective hold-down assembly 25 now, however, a "Machincd Spring "63, ie executed as Druckfcdcr, by means of which the respective hold-down assembly 25, a respective fuel gas nozzle valve member 5 in the closing direction (arrow A arrow) loaded in the extent that in the dual-fuel Fuel injector 1 according to the invention, a respective fuel gas nozzle valve member 5 via a NiederhaIteanordnung 25 loaded with a "Machined Spring" 63 in the closing direction A.

The "Machined Springs" 63 used with the proposed dual-fuel fuel injector 1 have in comparison with the previously provided wire-based or wire-wound ones

Coil springs 43'- with equivalent closing force application - advantageously shorter dimension L2 (referred to herein in the illustrated closed state of the fuel gas nozzle valve member 5), i.e. a longitudinal dimension L2, so that - in the closed state of the fuel gas nozzle valve member 5 shown - an aspect ratio L2: L1 of about 0.66, i.e. a reduction by one third of the former spring length can be realized (in general, this ratio can apply approximately to the relaxed state of the springs 43 'and 65).

These thus significantly shorter "Machined Springs" 63 now advantageously make it possible to accommodate the same completely in the intermediate plate 29, so that space for a fuel gas supply line 39 is now so sufficiently available that the fuel gas no longer by a spring chamber 35 ' As in the prior art must be performed, but with generously dimensioned fuel gas supply lines 39 to a nozzle chamber 41 and the nozzle assembly 51 is feasible.As a consequence, the associated disadvantages, see above in the prior art or as explained above , advantageously avoided.

As FIG. 2 also illustrates, a respective spring space 35, in which a "machined spring" 63 is accommodated, can be designed as a correspondence cavity, so that the "machined spring" 63 can be guided on the circumference, at least over a section Buckling is thereby avoided. The respective spring chamber 35 is preferably formed as a blind bore in the intermediate plate 29, wherein the blind bore is arranged so that the blind bore or the spring chamber 35 is aligned coaxially with the receptacle 53 of the fuel gas nozzle valve member 5 with assembly of intermediate plate 29 and nozzle body 3. In this case, the spring chamber 35 and the nozzle-like end of the receptacle 53 can then together form the nozzle-like control chamber 9 of the Hubsteueranordnung 13, i. in the sense of a coherent volume.

The hold-down arrangement 25 according to the embodiment illustrated in FIG. 2 furthermore has a stilt element 27 which has a nozzle-like, bolt-shaped or pin-shaped design Section 65, which on the inside of the turns of the "Machined Spring" 63 radially or peripherally in abutment, so that any Auknicken the "Machined Spring" 63 is effectively avoided inside. A nozzle-near end portion "the machined spring" 63 is urged against a spring plate 33 of the stilt member 27, woneben a from the spring plate 33 toward the fuel gas nozzle valve member 5 projecting engaging portion 67 of the stilt member 27 (in the form of an extremely short extension) by means of "Machined S pring "63 generated closing force on the fuel gas nozzle valve member 5, ie at a nozzle-end portion of the same or the piston member 7, can exercise.

Based on Flg. 3, further details of the proposed dual-fuel Kraftstoffmj ector 1 will now be explained in more detail.

As FIG. 3 illustrates, the spring 63 made of solid, in particular machined out of the solid, ie. the "Machined Spring" 63 are advantageously configured with abutment surfaces 69 on the nozzle-side and the nozzle-near end, ie on their axially opposite abutment ends 69, which extend as a ring surface completely flat and level same, so that so - in contrast to Spiralfeldem 43 A support, and therefore also an introduction of force, can take place homogeneously over the entire circumference of the spring 63. This is advantageous in that the force distribution can thus take place parallel to the central axis, but not a tilting moment is caused by a selective application of force, as with FIG In order to increase the precision of parallelism, the spring 63 in the form of "machined spring" can also be designed with more than one thread, ie more accessible.

As also shown by FIG. 3, an adjusting element 71 can still be accommodated in the spring chamber 35, in particular in the nozzle, for example between the nozzle-end of the machined spring 63 and the adjacent end wall 45 of the spring chamber Adjusting element 71 may be an annular disc, wherein a selection of the thickness of the same a biasing force is set, therefore, the closing force on the fuel gas nozzle valve member 5in the intended manner can be influenced.

Fig. 3 also shows next to the terminal end 73 of the control line 15 at the nozzle remote

Control chamber 9, which can be guided nutformig to the control chamber 9, for example as a groove in the Formed end face of the nozzle body 3 and can be capped by means of the intermediate plate 29 (intermediate plate 29 and nozzle body 3 are in this case clamped with a clamping nut 75, s. Fig. 2). As in the present embodiment shown, in which the control chamber 9 is formed together with the spring chamber 35, the spring chamber 35 is also acted upon with control fluid, the wall of the spring chamber 35 at least a portion above an axially extending (eg groove-shaped) recess 77 by means which bet an opening stroke of the fuel gas nozzle valve member 5 and concomitant reduction in volume of the diisenfemen control chamber 9 including the spring chamber 35, the control fluid from the spring chamber 35 is displaced, ie via the communicatively connected thereto control line 15th

4 illustrates the intermediate plate 29 of the dual-fuel fuel injector 1 in a view of the nozzle-near side or underside, wherein the spring chambers 35 are shown together with the formed in the walls, axially extending recesses 77 for the displacement of control fluid. It is seen in this embodiment, each spring chamber 35, for example, to form two axial recesses 77. In the midst of the triangular formation of the spring chambers 35 sections of liquid fuel supply lines 79 are further shown woneben now also generously dimensioned fuel gas supply lines 39 sections are feasible through the intermediate plate 29, which are now advantageously unobstructed bildbar. Also shown are, for example, control line sections of the control lines 17 and guided through the intermediate plate 29 sections of the fuel gas supply lines 39th

LIST OF REFERENCE NUMBERS

I, G dual fuel fuel injector

3, 3 'nozzle body

5, 5 'fuel gas nozzle valve member

7, 7 'piston section

9, 9 'control room (nozzle-finned)

I I, 1 1 'Control room (closer to the nozzle)

13, 13 'Hubsteueranordnung

15, 15 'control line

17, 17 'control line

19 'diverter valve

2G pressure sink

23 'pressure source

25, 25 'hold-down arrangement

27, 27 'stilts

29, 29 'intermediate plate

31 'Bolt-shaped section

33, 33 'spring plate

35, 35 'spring chamber

37, 37 'further housing element

39, 39 'fuel gas supply line 39a, 39a' section 41, 41 'nozzle space

43 'wire-based compression spring

45, 45 'nozzle-like front side

47 'barrier fluid seal

49, 49 'nozzle opening

51 nozzle arrangement

53 Correspondence admission

55 liquid fuel nozzle valve member

57 control room

59 Needle guide sleeve 61 nozzle spring

63 Machined Spring

65 pin-shaped portion 67 engaging portion

69 contact surface

71 adjustment element

73 connection end

75 clamping nut

77 deepening

79 Liquid fuel supply line

A, A 'closing force direction

Claims

claims

1. Dual Fuel Fuel Injector (1), comprising:

at least one stroke-controllable fuel gas nozzle valve member (5) for the selective opening and closing of at least one nozzle opening (49) of a nozzle arrangement (51) of the dual-fuel fuel injector (1),

a Hubsteueranordnung (13) per fuel gas nozzle valve member (5), which Hubsteueranordnung (13) operates hydraulically according to the principle of a double-acting cylinder,

characterized in that

- A respective fuel gas nozzle valve member (5) via one hold-down assembly (25) with a "Machined Spring" (63) in the closing direction (A) is loaded.

2. dual-fuel fuel injector (1) according to claim 1,

characterized in that

- The dual-fuel Kraftstoffmj ector (1) a plurality of each Hubsteueranordnung (13) hubsteuerbaren fuel gas Düsenventilgliedem (5) for the selective up and Zusteuem of Düsenöffhungen (49) an associated nozzle assembly (51) of the dual-fuel Fuel Injector (1), wherein a respective fuel gas nozzle valve member (5) via a respective hold-down assembly (25) with a "Machined Spring" (63) in the closing direction (A) is loaded.

3. Dual Fuel Fuel Injector (1) according to one of the preceding claims,

characterized in that together with a spring chamber (35) of the hold-down assembly (25), in which the "Machined Spring" (63) is accommodated, a nozzle-rich control chamber (9) of the Hubsteuerandordnung (13) is formed.

4. dual-fuel fuel injector (1) according to claim 3,

characterized in that

- The spring chamber (35) all in an intermediate plate (29) of the dual-fuel fuel injector (1) is formed.

5. dual-fuel fuel injector (1) according to claim 4,

characterized in that

- The respective fuel gas nozzle valve member (5) all in a nozzle body (3) of the dual-fuel fuel injector (1) is accommodated, which by means of the intermediate plate (29) is capped.

6. Dual-fuel fuel injector (1) according to one of the preceding claims,

characterized in that

- The respective hold-down assembly (25) has a Stelzenelement (27), which via the "Machined Spring" (63) a force in the closing direction (A) exercising against a nozzle end portion (7) of the fuel gas nozzle valve member (5) is urged.

7. Dual-fuel fuel injector (1) according to one of claims 2 to 6,

characterized in that

- The plurality of fuel gas nozzle valve members (5) are arranged in the circumferential direction at a distance from each other along a circular line, which surrounds a central nozzle needle (55) for the application of another fuel.

8. Dual-dual fuel injector (1) according to one of the preceding claims,

characterized in that

- A respective "Machined Spring" (63) is a catchy, zweigängige or mehrgängige spring.

9. Dual-fuel fuel injector (1) according to one of the preceding claims,

characterized in that

- The closing force of at least one "Machined Spring" (63) is additionally set with an adjusting element (71), via which the "Machined Spring" (63) is biased.

10. internal combustion engine, in particular with a fuel gas common rail injection system, characterized in that

- The internal combustion engine comprises at least one dual-fuel fuel injector (1) according to one of the preceding claims.