Injector for injecting a gaseous medium

Abstract

The present invention relates to an injector (1) for injecting a gaseous medium, in particular a gaseous fuel, preferably hydrogen, into a combustion chamber (20) of an internal combustion engine. The injector (1) comprises, among other things, an axially movable valve closing element (5) for opening and closing at least one opening on a sealing seat (7), an actuator (21) for actuating the valve closing element (5), and a flow-influencing geometry (10) arranged downstream of the sealing seat (7).According to the invention, the flow influencing geometry (10) is characterized by three successive flow sections, wherein downstream of the valve closing element (5) there is a section (12) tapering in the flow direction for a strong jet deflection radially inwards, which opens into an axial region (13) representing a central bore, from which in turn at least two radially outwardly directed oblique bores (25) branch off, the ends of which define an outlet (19) of the flow influencing geometry (10).

Description

State of the art

[0001] The present invention relates to an injector for injecting a gaseous medium, in particular a gaseous fuel, into a combustion chamber of an internal combustion engine. Specifically, the invention relates to an injector with which hydrogen can be injected directly into the combustion chamber of a mixture-compressing, spark-ignition internal combustion engine.

[0002] Gas injectors are known from the state of the art in various designs. Due to cost advantages and improved environmental compatibility, gaseous fuels have recently become increasingly popular. Compared to injectors for liquid fuels, the injected gas volume occupies a much larger volume than an equivalent amount of liquid fuel. This results in an increased stroke requirement for a closing element, which is usually actuated by a magnetic actuator. Designing a magnetic circuit using standard materials is very difficult or sometimes impossible due to the limited installation space. Materials with higher magnetic force are very expensive and sometimes harmful to health (e.g., FeCo).

[0003] DE 10 2021 206 438 A1 already discloses a gas nozzle for a gas valve, which comprises a nozzle body that is at least partially hollow-cylindrical in shape and forms a sealing seat over which a gas flow path leads. Furthermore, the gas valve has a valve-closing element that is partially accommodated in the nozzle body and has an end section that is arranged outside the nozzle body and has a sealing contour that interacts with the sealing seat. Furthermore, the gas valve has a sleeve that surrounds the nozzle body and the end section of the valve-closing element and delimits the gas flow path downstream of the sealing seat. The gas flow path downstream of the sealing seat has a cross-sectional constriction to achieve the Venturi effect, in the region of which at least one intake channel opens. The sleeve is designed in the form of a blow cap that can be applied to the nozzle body.

[0004] Another injector for injecting a gaseous medium is also known from WO 2023 / 001384 A1. The blow cap, which can be placed on a nozzle body, has a sleeve-shaped base body with a circumferential surface that merges into a base region at the downstream end. The base region is designed such that at least one obliquely or asymmetrically discharging outlet opening is provided. Furthermore, a flow guide section directed inward toward the valve closing element, counter to the flow direction, is formed in the base region, which deflects the gas to be discharged. Disclosure of the invention

[0005] The injector according to the invention for injecting a gaseous medium, in particular a gaseous fuel, into a combustion chamber of an internal combustion engine, with the features of claim 1 has the advantage that an optimized gas flow in the injector is made possible by the geometric design of a flow-influencing geometry arranged downstream of the sealing seat, so that the internal flow of the gaseous medium is designed to be as loss-free as possible via the inner contour of the cap-shaped attachment body, so that the back pressure below, i.e. downstream of the valve closing element, is reduced and at the same time the jet can be introduced into the combustion chamber in a targeted manner.

[0006] In addition, the forces acting on the valve closing element are reduced to a minimum in a special way. This reduces the magnetic force of an actuator that must be selected to keep the injector open, thus enabling the use of cost-effective materials in the actuator's magnetic circuit.

[0007] This is achieved according to the invention in that the injector has a valve closing element for opening and closing at least one opening on a sealing seat. The valve closing element is preferably an axially movable valve needle with a plate-shaped end section. Furthermore, an actuator is provided for actuating the valve closing element. The actuator is preferably a magnetic actuator, but can also be, for example, a mechanically or (piezo-) electrically operated actuator. Further preferably, the actuator is configured to actively open the valve closing element by means of a lifting movement and to keep it open, while the valve closing element is closed by a spring force.

[0008] The flow influencing geometry, which is accommodated in particular in a cap-shaped attachment body, in short a blow cap, is characterized according to the invention in that three flow sections follow one another in a particular way in terms of flow technology, wherein downstream of the valve closing element there is a section tapering in the flow direction for a strong jet deflection radially inwards, which opens into an axial region representing a central bore, from which in turn at least two radially outwardly directed oblique bores branch off, the ends of which define an outlet of the flow influencing geometry.

[0009] The interaction of the three flow sections allows for optimized blow-off behavior. Overall, this results in low-loss redirection of the gas flow. Furthermore, desired spray angles can be easily and cost-effectively achieved in any way. Furthermore, a particularly homogeneous mixture formation is possible. By keeping the angled bores as small as possible in diameter, high flow velocities can be achieved for greater penetration.

[0010] The subclaims describe preferred developments of the invention.

[0011] A geometry design for the tapered first section is particularly advantageous if, at maximum needle stroke I h of the valve closing element the following relation applies: 5 × I n ≥ s ≥ 1.5 × I h, where s is the distance between the radially outer contour of the valve closing element at its downstream edge region and the ring line lying axially below it in a projection on a section of the flow influencing geometry tapering in the flow direction in order to generate a virtually loss-free flow downstream of the valve closing element.

[0012] It is particularly advantageous that the section of the flow-influencing geometry that tapers in the direction of flow downstream of the valve closing element is largely conical. It is advantageous that the inclination angle α of the inner contour in the region of the tapered section is 85° ≥ α ≥ 30°, preferably > 45°.

[0013] This inner contour defined according to the invention, with its special features in shape and design, can be advantageously accommodated in attachment bodies with reducible external dimensions. This, in turn, enables a very flexible use of sleeves or attachment bodies on injectors in various combustion chamber geometries of internal combustion engines.

[0014] The present invention is preferably used in injection systems that inject hydrogen directly into a combustion chamber. In particular, the injector is suitable for directly injecting hydrogen into a combustion chamber of an internal combustion engine. drawing

[0015] Preferred embodiments of the invention will now be described in detail with reference to the accompanying drawings. Fig. 1 is a schematic sectional view of an injector for injecting a gaseous medium according to the prior art, Fig. 2 a sectional view of a known cap-shaped attachment body for an injector according to Fig. 1, Fig. 3 a schematic sectional view of a cap-shaped attachment body for an injector for injecting a gaseous medium according to a first embodiment, Fig. 4 a schematic sectional view of a cap-shaped attachment body for an injector for injecting a gaseous medium according to a second embodiment, Fig. 5 a schematic sectional view of a cap-shaped attachment body for an injector for injecting a gaseous medium according to a third embodiment, Fig. 6 a schematic sectional view of a cap-shaped attachment body for an injector for injecting a gaseous medium according to a fourth embodiment, Fig. 7 a schematic sectional view of a cap-shaped attachment body for an injector for injecting a gaseous medium according to a fifth embodiment and Fig. 8 a schematic sectional view of a cap-shaped attachment body for an injector for blowing in a gaseous medium according to a sixth embodiment. Preferred embodiments of the invention

[0016] For a better understanding of the invention, the following is based on the Fig. 1 and Fig. 2 describes the basic structure of an injector for injecting a gaseous medium as well as a known structure of a flow influencing geometry arranged downstream of the valve seat.

[0017] In the Fig. Figure 1 shows a schematic cross-sectional view of the known injector 1 for injecting a gaseous medium. Since the invention is directed to the flow-influencing geometry 10, which is arranged downstream of the valve seat 3 in terms of flow technology, only this assembly will be described in more detail here for the known injector 1. For example, a magnetic actuator 21 is provided to actuate the injector 1, so that the injector 1 can be controlled in a targeted manner.

[0018] The injector 1 also has a nozzle body 2, which on the injection side forms a conically shaped valve seat 3 at its end for a valve closing element 5 that opens outwards, i.e., opens in the direction of a combustion chamber 20. The valve closing element 5 is guided axially movably within the nozzle body 2 via a guide 18. In addition, the valve closing element 5 has an end section 6 in the form of a valve disk, which forms a sealing seat 7 corresponding to the valve seat 3. The two sealing seat partners, valve seat 3 and valve closing element 5, are each made of metal. The geometric and material design is such that sufficient tightness is guaranteed during operation of a hydrogen engine.In the event of a fault, a shut-off system (not shown here) installed upstream of the injector 1 for safety reasons would interrupt the supply of the gaseous medium, particularly the highly volatile hydrogen. The sealing contour of the end section 6 of the valve closing element 5 is, for example, rounded, while the valve seat 3 on the nozzle body 2 has a conical shape. However, other contours are also conceivable.

[0019] The nozzle body 2 and the end section 6 of the valve closing element 5 are surrounded by a sleeve 8 for jet shaping. In the following, in particular also with reference to the invention, reference is generally made to a flow-influencing geometry 10 arranged downstream of the sealing seat 7. This can either be formed directly as a single piece on the nozzle body 2, which, however, requires a high manufacturing outlay, or it can be integrated into an additional component, wherein this component, with reference to the embodiments according to the prior art, is Fig. 1 and Fig. 2 is generally referred to as a sleeve 8. The sleeve 8 has a large overlap length with the nozzle body 2 in order to be able to securely and reliably fasten the sleeve 8. In principle, however, it can also be referred to as a cap-shaped attachment body 8, which, with reference to the exemplary embodiments according to the invention, is also defined as a blow cap 8.

[0020] The sleeve 8 and the end portion 6 of the valve closure element 5 jointly define a gas flow path 4, into which at least one intake channel 15 formed in the sleeve 8 opens. Air from the environment can be sucked into the gas flow path 4 via the one or more intake channels 15.

[0021] If the valve closing element 5 is in an open position lifted from the valve seat 3, the gas flow path 4 then leads via the valve seat 3 into an interior of the sleeve 8, which is characterized by a special shape with an inner contour 9. Starting from a cylindrical section 11 of the sleeve 8 and following the valve closing element 5 in the flow direction, a cross-sectional reduction occurs at a large axial distance from the valve closing element 5 in a central cylindrical axial region 13 of the flow-influencing geometry 10 of the sleeve 8, with the taper being achieved via a conically extending section 12 in the inner contour 9 of the sleeve 8. The intake channels 15 open into the inner contour 9 of the sleeve 8 precisely in the central axial region 13.

[0022] The reduction in cross-section within the gas flow path 4 ensures that, as the gas flows out through the gas flow path 4 toward an outlet 19, air is drawn from the environment into the gas flow path 4 via the intake channels 15 ("Venturi effect"). This means that air is mixed with the gas before it reaches the outlet 19, thus improving the mixture preparation.

[0023] The cross-sectional reduction is offset by the fact that the central axial region 13 is again followed by a conically extending section 14, but in this case widening conically in the direction of flow, with this section 14 extending to the outlet 19. The cross-sectional reduction in the inner contour 9 of the sleeve 8 is intended to achieve the Venturi effect, which is optimized together with the air admixture. Experience has shown that such a solution or other known geometries or inner contours of cap-shaped attachment bodies do not achieve sufficiently good results with regard to the introduction of the jets into the combustion chamber 20 or their jet guidance and jet shaping for optimal combustion.

[0024] Therefore, the object of the invention is to provide an inner contour 9 of a cap-shaped attachment body 8 with a flow-influencing geometry 10 arranged downstream of the sealing seat 7, with which optimal combustion results are achieved due to the flow guidance according to the invention.

[0025] Injection systems for the direct injection of a gaseous medium, in particular hydrogen, but also CNG, methane, ammonia, or mixtures of the aforementioned gases, have the task of specifically controlling the dosage and injection direction of the gas jet(s) into the combustion chamber 20 via injection valves or, more generally, injectors 1. For this purpose, appropriate sleeves or blow caps 8 can be used on the injector 1, as already explained above. Furthermore, injection systems for direct (hydrogen) injection require a large lift of the valve needle with the valve closing element 5. The magnetic circuit design (magnetic actuator 21) with the known standard materials is very difficult or sometimes impossible due to the limited installation space. Materials with higher magnetic force and thus better B / H characteristics are very expensive and sometimes even harmful to health (e.g., FeCo).In this respect, a reduction in magnetic force should also be achieved through improved beam guidance.

[0026] The core of the invention is to design the internal flow of the gaseous medium with as little loss as possible via the inventive inner contour 9 of the cap-shaped attachment body 8, so that the back pressure located below, i.e. downstream of the plate-shaped end section 6 of the valve closing element 5 is reduced and, at the same time, the jet can be introduced into the combustion chamber 20 in a targeted manner. This defined inner contour 9, with its special features in shape and design, can advantageously be accommodated in attachment bodies 8 with reducible external dimensions. This, in turn, enables a very flexible use of sleeves or attachment bodies 8 on injectors 1 in various combustion chamber geometries of internal combustion engines.

[0027] The following are based on the Fig. 3 to 8 injectors 1 with flow influencing geometries 10 according to the invention, arranged downstream of the valve seat 3 in terms of flow technology, according to preferred embodiments of the invention are described in detail. As already mentioned, these flow influencing geometries 10 can be formed directly as one piece on the nozzle body 2 or, as shown in all figures, can be integrated into an additional component, which can be referred to as a cap-shaped attachment body 8 (in short, blow cap 8). The attachment body 8 will usually have a significantly smaller overlap length with the nozzle body 2 than in Fig. 1. The only essential requirement is a secure and reliable attachment to the nozzle body 2, which enables perfect and axially parallel alignment to the injector 1. Conventional joining methods such as pressing, welding, soldering, gluing, or combinations thereof can be used.

[0028] In the Fig. Figure 3 shows a first embodiment of a flow-influencing geometry 10 arranged downstream of the valve seat 3 in a cap-shaped attachment body 8 and created via an inventive inner contour 9. The valve closing element 5 with its plate-shaped end section 6 is shown only schematically and in a simplified manner. However, the end section 6 can also have chamfers or rounded portions on its outer contour.

[0029] The flow influencing geometry 10 produced with the inner contour 9 according to the invention has several essential aspects and geometric specifications, whereby the ratio of two surfaces to each other is considered to be an essential criterion of the invention, namely the two surfaces A S and A1, which occur at maximum valve needle lift I h , i.e. maximally opened sealing seat 7 and thus maximally lifted valve closing element 5. The area A Srepresents the annular seat cross-sectional area that results between the valve seat 3 and the contact line of the end section 6 of the valve closing element 5, while the area A1 is determined by the distance that results from the shortest distance between the outer contour of the valve closing element 5 at its downstream edge region and the opposite wall of the inner contour 9. In other words, the area A1 represents the narrowest cross-section below the valve closing element 5 when the sealing seat 7 is maximally open. This area A1 is also annular and, as an imaginary surface, here at an approximately right angle, is located on a tapered, in particular conically extending section 12 in the inner contour 9 of the attachment body 8, which ensures a significant taper of the inner contour 9 over a short axial extent, which also advantageously contributes to the desired optimized flow result. For the ratio of the areas A Sand A1 shall apply: A1 ≥ 2.5 x A S .

[0030] The jet guidance from the sealing seat 7 is achieved via the inner contour 9 in the conical section 12, which is designed with an inclination angle α of 85° ≥ α ≥ 30°, preferably with an inclination angle α of > 45°. This relatively large angle α of the conical section 12 generates a strong radially inward flow component over a very short axial length. The lines of the flow path 4 illustrate this.

[0031] Another characteristic of the formation of the inner contour 9 is the distance s, which occurs at maximum needle stroke I h between the radially outer contour of the valve closing element 5 at its downstream edge region and the annular line axially projected below it on the conically extending section 12. The following applies: 5 × I h ≥ s ≥ 1.5 × I hto generate a nearly loss-free flow around the end section 6 of the valve closing element 5. In particular, for an optimized flow result 4 × I h ≥ s ≥ 2.5 × I h . The maximum needle stroke I h runs over an axial extension length of 100 µm to 2 mm, whereby the maximum needle stroke I h ideally between 0.15 mm and 0.5 mm.

[0032] As a result of these geometric specifications, a flow redirection occurs over a short axial distance in the area of ​​the valve closing element 5 from a large diameter in the area of ​​the sealing seat 7 to a significantly smaller diameter with an inner surface A2 at the end of the tapered, in particular conically extending section 12, so that in this area immediately downstream of the valve closing element 5, flow redirection advantageously takes place in the form of an "S-bend". Instead of the conical shape of section 12, this section 12 can also be slightly convex or slightly concave. In addition to the ratio of the flow cross-sections corresponding to A1 ≥ 2.5 x A S Therefore, the following should be added for the flow cross sections of the areas A S and A2 apply: 5 x A S ≥ A2 ≥ 2 x A S, so that a supercritical flow is ensured and a limitation of back pressures below the valve closing element 5 is achieved.

[0033] This is also associated with the acceleration of the flow into the actual outlet bore, which is characterized by the axial region 13 following the conical section 12 in the flow direction, thereby reducing losses and turbulence in the wall region and bringing the effective flow cross-section closer to the geometric cross-sectional area A2. The axial region 13 is ideally a cylindrical hole section with an axial length L. While the first conical section 12 immediately downstream of the valve closing element 5 ensures a strong flow deflection, the axial region 13, as the second downstream section, is responsible for generating high jet stability. In addition, a reduction in losses and turbulence in the wall region is achieved, whereby an overall almost effective filling of the flow cross-section in the cylindrical axial region 13 is made possible.A bore diameter as small as possible in the axial area 13 contributes to reducing the dead volume.

[0034] In the axial region 13, the gas flow is guided through a central bore. The ratio of the axial length L to the diameter of the central bore D should preferably be 0.3 < L / D < 1 to stabilize the flow after deflection into the central bore of the axial region 13 and to approximate the effective flow cross-section to the geometric cross-sectional area of ​​the central bore.

[0035] In a third axial section with the axial length H, at least two radially outwardly directed oblique bores 25 are provided, which, in terms of flow, directly adjoin the axial region 13. Typically, two to six such oblique bores 25 are provided, which ultimately open at or define the outlet 19 of the flow-influencing geometry 10.

[0036] The inclined bores 25 have a circular or elliptical cross-section. The flow-related beginning of the inclined bores 25 does not necessarily have to coincide with an inner jet splitter region 26, which forms the upstream end of a jet splitter 27, with respect to the axial arrangement. Fig. 3, this jet splitter region 26, which could also be referred to as a flow rocker, is provided further downstream than the end of the axial region 13 or the beginning of the inclined bores 25. The axial length of the jet splitter 27 is indicated by s2, so that here the following applies: s2 < H. The true length of the inclined bores 25, starting with the end of the axial region 13 and ending at the outlet 19, is marked with K. With regard to the axial length of the jet splitter 27, here the following applies: s2 < K. The jet splitter 27 should generally be understood to be the radially inner material between the inclined bores 25.

[0037] The third section of the flow control geometry 10, the inclined holes 25, are intended to achieve objectives such as low-loss redirection of the gas flow, the realization of specific desired spray angles, and particularly homogeneous mixture formation. With the smallest possible diameters of the inclined holes 25, high flow velocities can be achieved for greater penetration.

[0038] The jet splitter region 26, which serves as a flow rocker, can, as shown, be largely tapered or can also be formed with a small plateau. Alternatively, the jet splitter region 26 can also be rounded (see, for example, Fig. 6).

[0039] In the Fig. 4 to 8 show five further exemplary embodiments of flow-influencing geometries 10 arranged fluidically downstream of the valve seat 3 in a cap-shaped attachment body 8 and generated via an inner contour 9 according to the invention. In particular, modifications in the area of ​​the axial region 13 and the inclined bores 25 of the cap-shaped attachment body 8 are proposed, which achieve the advantageous effects described above.

[0040] In the Fig. 4, the jet splitter 27 is designed with a large axial length s2, so that s2 > H, which is why the jet splitter region 26 lies within the axial extent of the axial region 13 with the axial length L and the distribution of the gas flow to the individual inclined bores 25 via the jet splitter region 26 takes place very early. This design variant has the advantage that the flow can be deflected more specifically in the direction of the inclined bores 25. The flow can be stabilized even with a significantly smaller bore length K and the gas flow can be introduced into the combustion chamber 20 with low losses and at the desired jet angle. With this variant, the dead volume and the length of the attachment body 8 can be reduced. Better mixture formation, particularly in the partial load and very small quantity range, can be advantageously expected.

[0041] In the Fig. 5 and Fig. 6 shows schematic sectional views of a cap-shaped attachment body 8 for an injector 1 for injecting a gaseous medium according to a third and fourth embodiment. Both solutions are characterized by a very short beam splitter 27. In both cases, s2 < H applies. Accordingly, the above-mentioned embodiments according to Fig. 4 regarding the advantages of a short cap solution also applies here. The beam splitter area 26 is either flattened like a plateau ( Fig. 5) or rounded ( Fig. 6) is carried out.

[0042] In terms of geometry, the fifth and sixth embodiments are similar according to Fig. 7 and Fig. 8 the embodiments of the Fig. 5 and Fig. 6. However, these Fig. 7 and Fig. 8 attention should be drawn to an alternative manufacturing option for the attachment body 8.

[0043] In a modular concept, a multi-part attachment body 8 with two sections 28 and 29 should be manufactured. The upper section 28 of the attachment body 8 contains section 12 and the axial area 13 and can be provided, for example, as a turned initial part. This upper section 28 serves, for example, as the basic geometry for all customer variants. For different customer-specific mass flow requirements, only the diameter D of the central bore in the axial area 13 is varied as an adjustment parameter.

[0044] The extensive customer variations (including beam angle, number of holes, projection of the attachment body 8 on the cylinder block, etc.) can be accommodated by a customized geometry of the attachment body 8. This allows all customer-specific design variants to be manufactured cost-effectively and with less effort by creating the second section 29 with the angled holes 25 separately and individually. The multi-part attachment body 8 can preferably be joined by welding. Optionally, more complex geometry variants can be manufactured using an MIM process or 3D printing.

[0045] Furthermore, the proposed solutions enable more flexible hole designs, which may be necessary, for example, in limited installation space. This provides increased freedom for various dimensions of cap-shaped attachment bodies 8, with the outer diameters of the attachment bodies 8 in the area of ​​attachment to the nozzle body 2 being, for example, in the range from 8 mm to 15 mm, while the outer diameters of the attachment bodies 8 in the area of ​​the outlet 19 are, for example, in the range from 6 mm to 12 mm. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2021 206 438 A1

[0003] WO 2023 / 001384 A1

[0004]

Claims

[1] Injector (1) for injecting a gaseous medium, in particular a gaseous fuel, preferably hydrogen, into a combustion chamber (20) of an internal combustion engine, comprising an axially movable valve closing element (5) for opening and closing at least one opening on a sealing seat (7), an actuator (21) for actuating the valve closing element (5), and a flow influencing geometry (10) arranged downstream of the sealing seat (7), characterized by , that the flow influencing geometry (10) is characterized by three successive flow sections, wherein downstream of the valve closing element (5) there follows a section (12) tapering in the flow direction for a strong jet deflection radially inwards, which opens into an axial region (13) representing a central bore, from which in turn at least two radially outwardly directed oblique bores (25) branch off, the ends of which define an outlet (19) of the flow influencing geometry (10). [2] Injector according to claim 1, characterized by that at maximum needle stroke (I h ) of the valve closing element (5) the following relation applies: 5 × I h ≥ s ≥ 1.5 × I h, wherein (s) is the distance between the radially outer contour of the valve closing element (5) at its downstream edge region and the ring line lying axially below it in a projection on the section (12) of the flow influencing geometry (10) tapering in the flow direction in order to generate a virtually loss-free flow downstream of the valve closing element (5). [3] Injector according to claim 2, characterized by that at maximum valve needle lift (I h ) an annular seat cross-sectional area (A S) between a valve seat (3) and the contact line of the valve closing element (5) and a further annular surface (A1) is determined by the distance which results as the shortest distance between the outer contour of the valve closing element (5) at its downstream end and the opposite wall of the section (12) of the flow influencing geometry (10) tapering in the direction of flow, wherein for the ratio of the surfaces (A S and A1) the following applies: A1 ≥ 2.5 x A S . [4] Injector according to claim 3, characterized by that at the end of the section (12) tapering in the direction of flow, the axial region (13) follows, wherein at the beginning of the axial region (13) an inner surface (A2) is defined and in relation to the annular seat cross-sectional area (A S ) The following applies: 5 × A S ≥ A2 ≥ 2 × A S . [5] Injector according to one of the preceding claims, characterized bythat the axial region (13) is largely cylindrical and has an axial length (L), wherein the ratio of axial length (L) and diameter (D) is preferably 0.3 < L / D < 1. [6] Injector according to claim 5, characterized by that the flow-related start of the inclined bores (25) coincides with the end of the axial region (13), the axial length of the inclined bores (25) up to the outlet (19) being marked with (H). [7] Injector according to claim 6, characterized by that the radially inner material between the inclined bores (25) acts as a beam splitter (27), wherein the axial length (s2) of the beam splitter (27) is equal to or unequal to the axial length (H) of the inclined bores (25), wherein in the case of inequality both s2 > H and s2 < H can apply. [8] Injector according to claim 7, characterized bythat the jet splitter (27) has an upstream jet splitter region (26) serving as a flow rocker, which either tapers to a largely conical point or is flattened with a plateau or is rounded. [9] Injector according to one of the preceding claims, characterized by that the section (12) of the flow influencing geometry (10) tapering in the direction of flow downstream of the valve closing element (5) is designed with an angle of inclination α of 85° ≥ α ≥ 30°, preferably with an angle of inclination α of > 45°. [10] Injector according to one of the preceding claims, characterized by that the flow influencing geometry (10) arranged downstream of the sealing seat (7) is realized in a cap-shaped attachment body (8), in particular a blow cap. [11] Injector according to claim 10, characterized bythat the cap-shaped attachment body (8) can be attached to a spray-side end of the injector (1), in particular to a nozzle body (2). [12] Injector according to claim 10 or 11, characterized by that the attachment body (8) can be manufactured in several parts, wherein the section (12) deflecting the flow radially inwards and the subsequent axial region (13) form a first section (28) of the attachment body (8) which can be formed independently of a second section (29) having the inclined bores (25), wherein both sections (28, 29) can be firmly connected to one another. [13] Injector according to one of the preceding claims, characterized by that the valve closing element (5) is part of an axially movable valve needle, wherein the valve closing element (5) has an end section (6) which is largely plate-shaped.

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