Sealing body and needle for a fluid injection valve

Abstract

 The invention relates to a sealing body (110) for a valve needle of a fluid injection valve for opening and closing a fluid outlet side of the fluid injection valve, wherein the sealing body (110) is primarily made from a body of rotation with respect to a longitudinal axis (L), wherein at least one partial outer surface (114, 116) of the sealing body (110) deviates from an outline of the body of rotation partially constituting an outer rotational surface (112) of the sealing body (110).
Further, the invention relates to a valve needle and a valve body assembly of a fluid injection valve, having the sealing body. Furthermore, the invention relates to a fuel injection valve for an intake manifold or an internal combustion engine of a motor vehicle, comprising the sealing body.

Description

[0001] The present invention relates to a sealing body for a valve or nozzle needle of a fluid injection valve for opening and closing a fluid outlet side of the fluid injection valve. Further, the invention relates to a valve needle of a fluid injection valve, and a valve body assembly of a fluid injection valve. Furthermore, the invention relates to an injection valve for an internal combustion engine of a motor vehicle.

[0002] Fluid injection valves are widely used, particularly for internal combustion engines in which they are arranged in order to dose fuel into an intake manifold of the internal combustion engine or directly into a combustion chamber of a cylinder of the internal combustion engine. In order to enhance a combustion process in view of the creation of unwanted emissions, the injection valve is suited to dose the fuel under comparatively high pressures. In case of a gasoline engine, the pressures may for example be in the range of up to over 300 bar, and in the case of diesel engines, for example in the range of up to over 2.500 bar.

[0003] Fuel injection valves are manufactured in various forms in order to satisfy the needs for various combustion engines. Injection valves accommodate an actuator for actuating a valve needle of the fuel injection valve, respectively. Such an actuator is for example an electromagnetic or piezoelectric actuator. - Due to new designs of combustion engines, particularly for downsizing the combustion engine, a cylinder head of the combustion engine has to become smaller as well, and therefore it is more critical to accommodate all required components into the cylinder head. As a consequence, the components which have to be incorporated into the cylinder head have to be reduced in their size.

[0004] The issue of packaging becomes a problem in a comparatively small cylinder head, wherein multiple demands must be considered. The most critical demand is an implementation of a cooling function. The essential cooling channels need a minimum surface or diameter to allow adequate heat exchange to protect the combustion engine and its cylinder head from overheating. This requirement limits an available space for all other components mounted to the cylinder head of the combustion engine.

[0005] It is an object of the invention to provide an improved tip end portion of a fluid injection valve, particularly an improved tip end portion of a valve body assembly of a fuel injection valve. In particular, it is an object of the invention to specify a fluid injection valve having a particularly small tip end portion, thereby for example assuring a reliable and precise function like an injection valve according to the state of the art. Moreover, the improved injection valve should be easy to manufacture and to use, as well as being cost-efficient.

[0006] The object of the invention is achieved by means of a sealing body for a valve needle of a fluid injection valve having the features of claim 1. Preferred embodiments, features and advantages of the sealing body, a valve needle comprising the sealing body, a valve body assembly comprising the valve needle and a fluid injection valve comprising the sealing body, the valve needle and/or the valve body assembly are defined in the dependent claims and the following description.

[0007] According to one aspect, a sealing body is disclosed. The sealing body is provided for opening and closing a fluid outlet side of the fluid injection valve. It is primarily made from a body of rotation with respect to a longitudinal axis. In other words, the body of rotation represents a basic shape of the sealing body. According to the invention, at least one outer partial surface of the sealing body deviates from an outline of the body of rotation now additionally and partially constituting an outer rotational surface of the sealing body. I. e. at least one outer partial surface of the sealing body deviates from an outer rotational surface of the body of rotation which in turn partially constitutes an outline of the sealing body. In other words, the outer surface of the sealing body comprises an outer rotational surface which is congruent with a portion of the surface of the body of rotation and one or more outer partial surfaces which do not coincide with the surface of the body of rotation. The body of rotation which represents the basic shape of the sealing body may be a ball or cylinder, the ball or cylinder preferably being solid, i.e. not hollow.

[0008] The invention is applicable to all kinds of fluid injection valves - which may also be called fluid injectors -, particularly to fuel injectors like gasoline injection valves or diesel injection valves which may also be denoted as diesel injection nozzles. An electromagnetic or piezoelectric actuator is applicable in the respective injection valve.

[0009] After providing the outer partial surface or outer partial surfaces, the sealing body is a partially spherical and/or a partially conical sealing body. Furthermore, the sealing body becomes a partially planar and/or a concave sealing body. The outer rotational surface of the body of rotation partially remains at the sealing body as at least one continuously connected surface. A sealing area of the sealing body further remains at the sealing body as a conical or partially spherical circular ring. Further, the sealing area of the sealing body is part of the partial remaining rotational surface of the body of rotation, i.e. of the outer rotational surface of the sealing body which it shares with the body of rotation that represents its basic shape.

[0010] The outer partial surface of the sealing body deviating from the outline or the outer rotational surface of the body of rotation preferably deviates towards the inside of the outer rotational surface of the body of rotation. In other words, the outer partial surface may be positioned within the body of rotation, the edge or at least one of the edges of the outer partial surface preferably being positioned on the surface of the body of rotation. Particularly, the outer partial surface of the sealing body deviating from the outer rotational surface of the body of rotation is constituted as a fluid or passage at/in the sealing body. Particularly, the outer partial surface of the sealing body is configured as a planar or concave surface.

[0011] To put it in another way, the sealing body has the basic shape of a body of rotation such as a ball or a cylinder. At least one portion of the body of rotation is missing to expose the outer partial surface, in particular for forming a fluid channel in the sealing body by means of the outer partial surface. For example, the surface of the sealing body has a general spherical shape which is flattened or recessed in at least one region by means of the at least one outer partial surface. In one embodiment, the outer surface of the sealing body comprises a spherical region at each of the axial ends of the sealing body, i.e. each of the spherical regions is in the shape of a spherical segment. The longitudinal axis extends through each of the spherical regions, and the at least one outer partial surface is arranged axially between the spherical regions. A shaft of the valve needle is attached to one of the spherical regions in one embodiment.

[0012] In one embodiment, the sealing body has an n-fold rotational symmetry with respect to the longitudinal axis, n being a natural number greater than or equal to 2, and preferably less than or equal to 10, preferably less than or equal to 5. For example, the sealing body has a four-fold rotational symmetry with respect to the longitudinal axis. A body having an "n-fold rotational symmetry with respect to an axis" is understood to be invariant with respect to a rotation around that axis by 360°/n or multiples thereof, but not by other angles, in particular, the body is not rotationally invariant.

[0013] In embodiments of the invention, the outer partial surface of the sealing body is configured as an outer facet-surface, wherein the outer facet-surface may be configured as a bevel, a chamfer, a facet or a facing. The bevel or chamfer, respectively, preferably extends in direction of the longitudinal axis. The chamfer may have a V-shaped or U-shaped cross-section, for example. A surface normal of the facet is perpendicular to the longitudinal axis in one embodiment.

[0014] In preferred embodiments of the invention, the sealing body - in particular a cross-section of the sealing body perpendicular to the longitudinal axis, the cross section preferably comprising the center of gravity of the sealing body - has at least two different diameters in different radial directions of the sealing body itself, and also in different radial directions of the injection valve into which the sealing body will be integrated. In a first radial direction, the sealing body has a maximum diameter which is a diameter of the body of rotation which represents the basic shape of the sealing body, and in a second radial direction, the sealing body has a minimum diameter which is smaller than the maximum diameter. In one embodiment, the second or minimum diameter of the sealing body is at least defined by one, preferably two outer facet-surfaces of the sealing body.

[0015] According to one embodiment, the primary body of rotation of the sealing body is a ball or a cylinder. According to another embodiment, the sealing body is a partially spherical and/or a partially conical sealing body

[0016] According to one embodiment, the sealing body is a partially planar and/or a concave sealing body (110)

[0017] According to one embodiment, the partially outer rotational surface of the sealing body is at least one continuously connected surface of the rotational body. According to another embodiment, a sealing area of the sealing body is a surface which is in the shape of a conical or partially spherical circular ring. In yet another embodiment, the sealing area of the sealing body is a portion of the partially remaining rotational surface of the sealing body.

[0018] According to another aspect, a valve needle for a fluid injection valve is disclosed. The valve needle is provided for opening and closing a fluid outlet side of the fluid injection valve. It comprises the sealing body according to at least one of the previously described embodiments and developments. Expediently, the sealing body is rigidly coupled, particularly welded or laser welded, to the valve needle, in particular to a shaft of the valve needle. The valve needle preferably shares the longitudinal axis with the sealing body. The shaft in particular extends in longitudinal direction with its main extension direction. In a radial direction of the valve needle, i. e. in particular also in a radial direction of the injection valve in which the valve needle will be integrated, at least one diameter, preferably the minimum diameter, of the sealing body may be equal or at least almost equal to the diameter of the valve needle - in particular of the shaft - in its lower portion, i. e. a portion of the valve needle adjacent to or adjoining the sealing body.

[0019] In one embodiment, the minimum outer diameter of the sealing body does not exceed the outer diameter of the valve needle in its lower portion by more than 10% to 20%. Further, in one embodiment, the maximum outer diameter of the sealing body does not exceed the outer diameter of the valve needle in its lower portion by more than 5% to 35%.

[0020] According to one embodiment, the minimum outer diameter of the sealing body does not exceed the outer diameter of the valve needle by more than 2%, 4%, 6%, 8%, 10%, 15%, or 200 ± 1%, and/or the maximum outer diameter (d₁) of the sealing body (110) does not exceed the outer diameter of the valve needle (100) by more than 5%, 10%, 15%, 20%, 25%, 30%, or 35% ± 2,5%.

[0021] According to another aspect, a valve body assembly is specified. It comprises a base body, wherein the base body comprises a valve needle and/or a sealing body according to at least one of the previously described embodiments and developments. In particular, the base body has a longitudinally extending central cavity in which the valve needle with the sealing body is arranged in axially moveable fashion.

[0022] The valve body assembly may further comprise a guidance element. The guidance element is in particular fixed to the base body or in one piece with the base body. The guidance element may expediently extend circumferentially around the sealing body in top view along the longitudinal axis. The sealing body may be received in a central recess of the guidance element. In this way, the guidance element may be operable to guide the sealing body in axial direction. A fluid passage of the valve body assembly is preferably constituted by the central cavity of the base body, the guidance element and the at least one outer partial surface of the sealing body. In particular, the outer partial surface forms a fluid channel together with the guidance element.

[0023] The guidance element itself is preferably free from a fluid channel in an internal side surface of the guidance. For example, the surface of the central recess is a surface of revolution, in particular a cylindrical surface. In one embodiment, in a radial direction of the valve body assembly, an inner diameter of the guidance element - i.e. in particular a diameter of the central recess - does not exceed the diameter of the valve needle in its lower portion (cf. above) by more than 5% to 35%. For example, it does not exceed the diameter of the valve needle in its lower portion by more than 5%, 10%, 15%, 20%, 25%, 30%, or 35% ± 2,5%.

[0024] According to yet another aspect, a fluid injection valve is specified. It comprises the sealing body, the valve needle and/or the valve body assembly according to at least one of the previously described embodiments and developments.

[0025] According to the invention, it is possible to provide a fluid injection valve, particularly a fuel injection valve, with a smaller tip end portion in comparison to the state of the art. A particularly small diameter of the tip end portion - i.e. particularly small lateral dimensions - is achievable which in turn facilitates packaging within a cylinder head of an internal combustion engine. Due to the smaller tip end portion of the injection valve and the simplification of packaging, the cooling problems in the cylinder head and consequently of the internal combustion engine are reduced. Moreover, the injection valve is particularly easy to manufacture and to use, as well as being as cost-efficient.

[0026] Further advantages, advantageous embodiments and developments of the sealing body, the valve needle, the valve body assembly and the fluid injection valve will become apparent from the exemplary embodiments which are explained below in more detail with reference to schematic figures. Elements of the same design and function that appear in different figures are identified by the same reference numerals.

[0027] In the figures:

Fig. 1

shows an embodiment of an injection valve according to the state of the art in a longitudinal sectional view;

Fig. 2

shows a tip end portion of the injection valve from fig. 1 in an area of a guidance for a sealing body of a valve needle of the injection valve in a cross-sectional view;

Fig. 3A

shows a top view of a sealing body according to a first embodiment,

Fig. 3B

shows a top view of a sealing body according to a second embodiment,

Fig. 3C

shows a top view of a sealing body according to a third embodiment, the sealing body being made from a solid ball;

Fig. 4

shows side view of an armature-needle assembly comprising a valve needle with the sealing body according to the first embodiment; and

Fig. 5

shows the armature-needle assembly of Fig. 4 in a perspective view.

[0028] In the following, the invention is explained as an application for an injection valve 1 configured as a gasoline injection valve 1 (cf. fig. 1) for an intake manifold or an internal combustion engine of a motor vehicle. However, the invention is not restricted to such injection valves 1; the invention is also applicable to a diesel injection nozzle (not shown) of a common-rail injection system or to other injection valves. An injectable fluid may be a fuel, but it can also be any other kind of fluid such as water, oil or any process liquid; i. e. the invention is not limited to the automotive industry.

[0029] Fig. 1 shows an injection valve 1 suitable for dosing fuel, in particular gasoline. The injection valve 1 comprises a valve base body 200 and an inlet tube 400. A pole piece 320 is inserted in the valve base body 200 in the injection valve 1 of Fig. 1. Alternatively, the inlet tube 400 may be in one piece with a pole piece 320.

[0030] An outer housing 300 arranged around the valve base body 200. In the present embodiment, the outer housing 300 is partially arranged at the valve base body 200 and at the inlet tube 400.

[0031] The valve base body 200 has a central longitudinal axis L. Further, a radial direction R, perpendicular to the longitudinal axis L is shown in Fig. 1. Furthermore, the valve base body 200 has a circumferential side wall 210 defining a central cavity 212 extending from a fluid inlet side 41 to a fluid outlet side 11 of the fluid injection valve 1. The outlet side 11 is in fluid communication with the fuel inlet 41 of the injection valve 1.

[0032] The outer housing 300 accommodates an electrical connector of the injection valve 1, houses a bobbin 302 which is provided with an electromagnetic coil of an electromagnetic actuator assembly 30 of the injection valve 1. The electromagnetic actuator assembly 30 further comprises the pole piece 320 and an armature 330. It may further comprise an armature spring 332.

[0033] In the central cavity 212, an armature-needle assembly 10 for opening and closing the fuel outlet side 11 of the injection valve 1 is accommodated. The armature-needle assembly 10 comprises the armature 330. It further comprises a valve needle 120. The armature 330 is operable to displace the valve needle 100 in longitudinal direction. It may be in one piece with the valve needle or fixed to the valve needle 100. In the present embodiment, however, the armature 339 is axially displaceable with respect to the valve needle 120. Axial displacement of the armature 330 with respect to the needle is limited by means of a collar or sleeve 120 of the valve needle 120. The collar or sleeve 120 may also function as a guide for the valve needle 120 for axially guiding the valve needle 100 by means of interaction with the pole piece 320. Therefore, the collar or sleeve is referenced as a "guide" 120 in the following. The guide 120 may be in one piece with a shaft 105 of the valve needle 100. Alternatively, as in the embodiment of Fig. 1, the guide 120 may be fixed to the shaft 105. The armature 330 may be operable to displace the valve needle 100 by means of mechanical interaction with the guide 120.

[0034] A main spring 310 is arranged in a recess provided in the inlet tube 400 (not shown) or the pole piece 320, wherein the recess is preferably in fluid communication with the central cavity 212. The recess expediently extends completely through the pole piece 320 in longitudinal direction L. The main spring 310 is mechanically coupled to the sleeve 120 which in turn is mechanically in contact with an inner side of the recess of the pole piece 320 and guides the needle 120 in the longitudinal direction L. A filter element 390 is received in the recess of the pole piece 320 and fixedly coupled to the pole piece 320. The filter element 390 forms a further seat for the main spring 310. The main spring 310 is preloaded by means of the filter element 390 so that it is operable to bias the valve needle 100 towards a closed position in the longitudinal direction L.

[0035] The valve needle comprises a sealing body 110. In the closed position of the valve needle 100, a sealing area 118 of the sealing body 110 abuts a sealing edge 202 of the valve base body 200 of the injection valve 1 in a sealing manner, thereby preventing fuel from being injected through the fuel outlet 11 of the fluid injection valve 1.

[0036] The sealing edge 202 of the valve base body 200 is preferably comprised by a guidance element 220. The guidance element 220 is provided for axially guiding the sealing element 110. Thus, the valve needle 100 is axially guided by means of the guidance element 110 interacting with the sealing body 110 and by the guide 120 interacting with the pole piece 320.

[0037] The guidance element 220 is in particular positioned at the fuel outlet 11 of the valve base body 200 and fixed to the latter. It is also conceivable that the guidance element is in one piece with the valve base body 200. The guidance element 220 preferably comprises at least one orifice for injecting fuel, in particular directly into a combustion chamber of the internal combustion engine.

[0038] The valve needle 100 is axially displaceable away from the closed position towards an open position of the valve needle 100 for injecting fuel through the orifice at the outlet side 11. Movement of the valve needle 100 away from the closed position is effected by the electromagnetic actuator assembly 30 via the armature 330 against the bias of the main spring 310.

[0039] For actuating the injection valve 1, the armature 330 and the valve needle 100 are moveable in a reciprocating manner inside the central cavity 212. The guide 120 is arranged longitudinally adjacent to the armature 330 and is rigidly coupled to the valve needle 100. Also, the guide 122 and needle 120 may be integrally formed. The armature 330 is longitudinally movable relative to the valve needle 100. A kinetic energy of the armature 330 may be absorbed by the armature spring 332 downside of the armature 330, i.e. on the side of the armature 330 remote from the guide 120, in particular when the armature moves towards the fluid outlet side 120. Here, the armature spring 332 is preferably accommodated in the central cavity 212, as well.

[0040] The sealing body 110 of the valve needle 100 of the injection valve 1 of Fig. 1 is a body of rotation, specifically a ball. As shown in Fig. 2, the sealing body 110 is designed as a smooth ball having essentially identical diameters, everywhere. All diameters of the ball 110 are approximately more than 20% larger than the diameter of the valve needle 100 in radial direction R of its lower portion, i. e. the shaft 105 of the valve needle 100 at its side adjacent to the sealing body 110.

[0041] Further, as mentioned above, the sealing body 110 is guided and supported in the guidance element 220. For the passing of fuel between the sealing body 110 and the guidance element 220 to the fuel outlet side 11, the guidance 220 according to the state of the art comprises a plurality of fluid channels 150 at/in an inner side of the guidance element 220, cf. Fig. 2. The provision of the fluid channels 150 in the guidance element 220 increases a necessary outer diameter of the guidance element 220 and consequently an outer diameter of a tip end portion of the injection valve 1 in radial direction R.

[0042] A fluid injection valve 1 according to the present invention may be of the same basic construction as previously described in connection with the fluid injection valve of Fig. 1.

[0043] However, a guidance element 220 according to the present invention is preferably free from fluid channels 150. Instead, fluid channels 150 are incorporated into the sealing body 110. To this end, the sealing body 110 deviates from the shape of a rotational invariant body. It is only partially constituted by a body of rotation, cf. a partial outer rotational surface 112 of the sealing body 110 which is constituted by a partial outline of the body of rotation now only partially constituting the sealing body 110.

[0044] One embodiment of a sealing body 110 is shown in a top view along the longitudinal axis L in Fig. 3A.

[0045] Here, the sealing body 110 is preferably a solid sealing body 110. In the present embodiment, it has the basic shape of a ball. Alternatively, it may have the basic shape of a cylinder or cone.

[0046] The sealing body 110 is received in a recess of the guidance element 220. The side surface of the recess follows the contour of basic shape of the sealing body 110 in top view along the longitudinal axis L. In particular, the basic shape of the sealing body 110 and the recess of the guidance element 220 are congruent, apart from a small radial gap to enable sliding contact between the sealing body 110 and the guidance element 220.

[0047] The outer surface of the sealing body 110 deviates from the spherical surface of its basic ball-shape. Rather, the sealing body 110 comprises a plurality of partial outer facet-surfaces 114 in addition to an outer rotational surface 112, which is congruent with a portion of the spherical surface of the basic ball-shape. Axially extending fluid channels 150 are established between the sealing body 110 and the guidance element 220 by means of the outer facet-surfaces 114.

[0048] The facet-surfaces 114are planar in the present embodiment. The surface normals of the planar facet-surfaces 114 extend perpendicular to the longitudinal axis. In the present embodiment, the sealing body 110 has four planar facet-surfaces 114 which are spaced apart from each other and alternate with portions of the outer rotational surface 112 in angular direction around the longitudinal axis. The sealing body 110 according to the present embodiment has a four-fold rotational symmetry.

[0049] Between two diametrically opposite positions at the rotational surface 112 of the sealing body 110, a maximum outer diameter d₁ of the sealing body 110 is located in radial direction R. Further, between two diametrical opposite positions of two planar surfaces 114 of the sealing body 110, a minimum outer diameter d₂ of the sealing body 110 is located in radial direction R.

[0050] A sealing area 118 of the sealing body 110 is fully constituted by the residual rotational surface 112, i. e. a conical or partial spherical circular ring of the sealing area 118 is not affected by a planar facet-surfaces 114.

[0051] A second exemplary embodiment of a sealing body 110 is shown in a top view along the longitudinal axis L in Fig. 3B.

[0052] The sealing body 110 of the second exemplary embodiment corresponds in general with the design of the sealing body 110 of the first exemplary embodiment. In contrast to the first embodiment, the axially extending fluid channels 150 are formed by means of outer partial surfaces 114 which are not planar facet-surfaces but by means of concavely curved outer partial surfaces 116. In this way, the fluid channels 150 "cut-out" from the basic ball-shape are in the shape of cylinder portions, the cylinder axes extending parallel to the longitudinal axis L.

[0053] In this way, the portions of the remaining rotational surface 112 which are in sliding contact with the guide element 220 for axially guiding the sealing body 110 can be particularly large for a given cross-sectional area of the fluid channels 150. In this way, a particularly precise guidance is achievable.

[0054] The guidance element 220 is omitted in Fig. 3B. Instead, the contour of the spherical basic shape of the outer surface of the sealing body 110 is indicated with dash-dotted lines.

[0055] A sealing body 110 according to a third exemplary embodiment is shown in Fig. 3C.

[0056] According to the third embodiment, planar surfaces 114 and concave surfaces 116 alternate regularly at the sealing body 110. Between two adjacent planar surfaces 114 and/or between two adjacent concave surfaces 116, the residual rotational surface 112 of the sealing body 110, i. e. a portion of the surface of the body of rotation which represents the basic shape of the sealing element 110, is provided. At an equator 111 of the sealing body 110, a plurality of planar surfaces 114, preferably three, four (cf. fig. 3) or five planar surfaces 114, are particularly equidistantly arranged. Further, directly adjoining to a single planar surface 114, at least one concave surface 116 is arranged. Here, the single planar surface 114 and the adjoining concave surface 116 or surfaces 116 share a boundary.

[0057] In one development, a concave surface 116 extends from the planar surface 114 to a pole of the sealing body 110. The poles of the sealing body 110 may be comprised by the outer rotational surface 112 of the sealing body 110 in this or any other embodiment of the sealing body 110.Alternatively, the sealing body 110 may comprise a planar 114 or concave surface 116 at one or both poles in this or any other embodiment of the sealing body 110. The poles are in particular the intersections of the sealing body 110 with the longitudinal axis L. The equator 111 is in particular the contour of the sealing body 110 in a plane perpendicular to the longitudinal axis L through the center of gravity of the sealing body 110. Furthermore, the concave surfaces 116 may be replaced by planar surfaces, as well as the planar surfaces 114 may be replaced by concave surfaces.

[0058] Figures 4 and 5 each show an armature-needle assembly 10 comprising the valve needle 100 with the sealing body 110 according to the first embodiment, the armature 330 and the guide 120.

[0059] As can be seen in Fig. 4, a diameter of the valve needle 100 may comply with the minimum outer diameter d₂ of the sealing body 110, in radial direction R. Further, as can be seen from Fig. 5, the maximum outer diameter d₁ of the sealing body 110 is larger than the diameter of the valve needle 100. This maximum outer diameter d₁ mates with an inner diameter of the guidance 220 (see also Fig. 3A).

[0060] In order to allow fuel flow between through the fluid channels 150, the sealing body 110 is preferably fixed to the shaft 105 of the valve needle 100 only at certain regions of its outer surface at which the tip end of the valve needle 100 abuts at the rotational surface 112 of the sealing body 110. The outer partial surfaces 114, 116 which form the fluid channels 150 are preferably exposed, in particular they are preferably neither covered by the shaft 105 of the valve needle 100 nor by a bonding material - e.g. braze metal, adhesive, or the like - which is used for fixing the sealing body 110 to the shaft 105.

Claims

1. Sealing body for a valve needle (100) of a fluid injection valve (1) for opening and closing a fluid outlet (11) of the fluid injection valve (1), wherein the sealing body (110) is primarily made from a body of rotation with respect to a longitudinal axis (L), characterised in that
at least one outer partial surface (114, 116) of the sealing body (110) deviates from an outline of the body of rotation partially constituting an outer rotational surface (112) of the sealing body (110).

2. Sealing body according to the preceding claim, characterised in that the outer partial surface (114, 116) of the sealing body (110) deviates towards an inside of the outline of the body of rotation.

3. Sealing body according to any of the preceding claims, wherein the outer rotational surface (112) of the sealing body (110) comprises a spherical region at each of the axial ends of the sealing body, the longitudinal axis (L) extending through each of the spherical regions, and the at least one outer partial surface (114, 116) is arranged axially between the spherical regions.

4. Sealing body according to any of the preceding claims, characterised in that the outer partial surface (114) of the sealing body (110) is configured as a planar surface (114), and/or the outer partial surface (116) of the sealing body (110) is configured as a concave surface (116).

5. Sealing body according to any of the preceding claims, characterised in that the sealing body (110), in different radial directions (R) of the sealing body (110) which are perpendicular to the longitudinal axis (L), has a maximum diameter (d₁) in a first radial direction (R) which is a diameter of the body of rotation from which the sealing body (110) is primarily made, and, a minimum diameter (d₂) in a second radial direction (R) which is smaller than the maximum diameter (d₁) and is defined by the partial outer surface (114, 116) of the sealing body (110).

6. Sealing body according to any of the preceding claims, characterised in that the primary body of rotation of the sealing body (110) is a ball or a cylinder.

7. Valve needle for a fluid injection valve (1) for opening and closing a fluid outlet (11) of the fluid injection valve (1), wherein the valve needle (100) comprises a sealing body (110) according to any of claims 1 to 6 and having a shaft (105) with a main extension direction along the longitudinal axis (L).

8. Valve needle according to the preceding claim, characterised in that in a radial direction (R) of the valve needle (100), at least one diameter (d₂) of the sealing body (110) is almost equal to the diameter of the shaft (105).

9. Valve body assembly of a fluid injection valve (1), comprising a base body (200) with a central cavity (212) and a valve needle (100) according to any of claims 7 to 8, wherein the central cavity extends along the longitudinal axis (L) and the valve needle (100) is received in the central cavity (212).

10. Valve body assembly according to the preceding claim, further comprising a guidance element (220) which is operable to guide the sealing body (110) in axial direction and which extends circumferentially around the sealing body (110) in top view along the longitudinal axis, wherein an axially extending fluid passage (150) is shaped between the guidance element(220) and the sealing body (110) by means of the at least one partial outer surface (114, 116) of the sealing body (110).

11. Valve body assembly according to the preceding claim, wherein the guidance element (220) has a central opening in which the sealing body (110) is received, the contour of the central opening being rotationally invariant with respect to the longitudinal axis (L) and basically congruent to the contour of the body of rotation in top view along the longitudinal axis (L).

12. Valve body assembly according to claim 10 or 11 further comprising a sealing edge (202) mechanically interacting with a sealing area (118) of the sealing body (110) to seal and unseal a fluid outlet (11) of the valve body assembly, wherein the at least one outer surface (114, 116) is laterally offset with respect to the sealing area (118) in radially (R) outward direction.

13. Valve body assembly according to the preceding claim, wherein the sealing area (118) of the sealing body (110) is a in the shape of a conical or partially spherical circular ring.

14. Valve body according to one of claims 12 or 13, wherein the sealing area (118) of the sealing body (110) is part of the partially remaining rotational surface (112) of the sealing body (110).

15. Fuel injection valve (1) for an internal combustion engine of a motor vehicle, comprising a sealing body (110) according to any of claims 1 to 6, a valve needle (100) according to any of claims 7 to 8, and/or a valve body assembly (10) according to any of claims 9 to 14.

Drawing