EP3388662B1 - Mounting for a fuel injection system to link a fuel-guiding component with a fuel injection valve and a fuel injection system - Google Patents

Description

State of the art

The invention relates to a suspension for fuel injection systems for connecting a fuel injection valve with a fuel-carrying component and a fuel injection system with such a suspension. In particular, the invention relates to the field of fuel injection systems for mixture-compressing, spark-ignited internal combustion engines.

From the DE 10 2005 020 380 A1 a fuel injection device with a sound-decoupling construction is known. The known fuel injection device comprises a fuel injection valve, a receiving bore for the fuel injection valve in a cylinder head and a fuel distribution line with a connection piece. The fuel injector is partially inserted into the connecting piece. In one possible embodiment, the fuel injector has a wire ring inserted in a groove in the area of its inlet connection. Furthermore, a connection body in the form of a locking nut is provided, which is screwed onto an external thread on the circumference of the connecting piece. At one end facing the connecting piece, the connecting body has a section containing an internal thread, to which an annular collar adjoins, which has a curved support surface in the form of a ball socket. With this support surface, the annular collar of the connecting body is supported on the wire ring, which is received with its curvature in the annular collar.

The ones from the DE 10 2005 020 380 A1 The known embodiment of the fuel injection device has the disadvantage that vibrations can be transmitted between the connecting piece and the inlet connecting piece of the fuel injection valve via the wire ring. In particular, vibrations can be transmitted from the fuel injector to the connecting piece.

Especially with electromagnetic high-pressure injection valves, which are used in Otto engines with direct injection, a noticeable and annoying contribution to the overall noise of the engine can be made, which can be described as valve tickers. Such a valve ticking occurs due to the rapid opening and closing of the fuel injector, in which the valve needle is moved into the respective end stops with high dynamics. The impact of the valve needle in the end stops leads to short-term but very high contact forces which are transmitted via a housing of the fuel injector to the cylinder head and a fuel rail in the form of structure-borne noise and vibrations. This leads to a high level of noise on the cylinder head and on the fuel rail.

Disclosure of the invention

The suspension according to the invention with the features of claim 1 and the fuel injection system according to the invention with the features of claim 8 have the advantage that an improved suspension of the fuel injector on the fuel-carrying component is made possible. Here, noise can be reduced through targeted decoupling. In particular, a soft connection of the fuel injection valve to the fuel-carrying component can be achieved, which enables a noise reduction in the overall system with the fuel injection system.

The measures listed in the subclaims allow advantageous developments of the suspension specified in claim 1 and the fuel injection system specified in claim 8.

The suspension and fuel injection system are particularly suitable for gasoline direct injection applications. The fuel-carrying component is preferably designed as a fuel distributor, in particular as a fuel distributor strip. Such a fuel distributor can, on the one hand, serve to distribute the fuel to a plurality of fuel injection valves, in particular high-pressure injection valves. On the other hand, the fuel distributor can serve as a common fuel reservoir for the fuel injection valves. The fuel injection valves are then preferably connected to the fuel distributor via corresponding suspensions. During operation, the fuel injection valves then inject the fuel required for the combustion process under high pressure into the respective combustion chamber. The fuel is compressed by a high pressure pump and pumped into the fuel distributor in a quantity controlled manner via a high pressure line.

The fuel injector, in particular the fuel connector, is not part of the suspension according to the invention. In particular, the suspension according to the invention can also be manufactured and sold separately from the fuel injector. The connection body can be part of a fuel-carrying component. In particular, the connection body can be designed as part of a cup of a fuel distribution rail. In this case, however, the connection body can also be connected at a later point in time to a tubular base body or the like of the fuel distribution rail, for example by welding. Thus, the suspension according to the invention is not necessarily part of the entire fuel-carrying component and can also be manufactured and sold independently of such other components of a fuel-carrying component.

In particular, a soft connection of the fuel injection valve to the fuel-carrying component, in particular a fuel distributor, can be achieved. A significant noise reduction in the overall system with the fuel injection system is possible through a soft design of this interface. The soft connection of the fuel injector to the fuel-carrying component can take place with a target stiffness of not more than 50 kN / mm, whereby the strength requirements can be met over the lifetime. The advantage of the soft suspension is a significant reduction in the structure-borne noise transmitted from the fuel injector to the fuel-carrying component and, associated therewith, a reduction in the noise of the injection system. In addition, this noise-reducing measure can be used in addition to other noise-reducing measures, such as a hydraulic throttle at the valve inlet and a soft rail screw connection. Furthermore, the suspension can be used in an advantageous manner with no or only minor structural changes in existing structures. This results in a wide range of applications.

It is advantageous that a contact surface is configured on the inner collar of the connection piece, which is configured conically with respect to a longitudinal axis of the receiving space and faces the receiving space. Advantageous centering is ensured by the conical contact surface, which can have an opening angle from a range of approximately 10 ° to approximately 80 °, in particular of at least approximately 45 °, particularly with respect to the longitudinal axis. In addition, with a suitable design of the angle of the conical contact surface, an angle tolerance compensation for the fuel injector with respect to the longitudinal axis of the receiving space can be ensured. The angle tolerance compensation can also be used here can be realized by elastic deformation of the elastically deformable element. An alignment of the elastically deformable element with respect to the longitudinal axis of the receiving space and thus the alignment of the fuel connector of the fuel injector takes place at least indirectly via the conical contact surface.

It is also advantageous that an annular support element is provided and that the elastically deformable element is supported by means of the annular support element on the inner collar of the connection piece. This is particularly advantageous if the conical contact surface is also provided on the inner collar of the connection piece. An alignment of the annular support element with respect to the longitudinal axis of the receiving space is thereby achieved. The annular support element preferably has a rounded outer contour in relation to the contact surface of the inner collar. This ensures tolerance compensation at the interface between the annular support element and the inner collar, with self-centering occurring during operation.

According to the invention, the annular support element has an annular recess into which the elastically deformable element is at least partially inserted. By inserting the elastically deformable element into the ring-shaped recess of the ring-shaped support element, on the one hand, mechanical protection is ensured, with in particular local overstressing being prevented. Furthermore, a uniform introduction of force and thus a homogeneous loading of the elastically deformable element is guaranteed. Furthermore, the elastically deformable element is thereby reliably positioned. Crushing of the elastically deformable element due to incorrect positioning, improper assembly, pinching in places, kinks or the like are thereby prevented from the outset.

It is particularly advantageous here that the annular recess of the annular support element is designed to be open inward. In this way, on the one hand, elastic deformability of the elastically deformable element is also made possible in the radial direction, since radial support on the annular support element is ensured. On the other hand, direct contact between the annular support element and an outside of the fuel connector can be avoided as a result. However, deformation of the elastically deformable element can still be limited.

In addition, it is advantageous that a support surface is configured on the fuel nozzle or on an element connected to the fuel nozzle, that an annular angle element is provided which has an L-shaped profile into which the elastically deformable element is at least partially inserted, and that the fuel connector is supported at least by means of the annular angle element on the elastically deformable element. The ring-shaped angle element also enables mechanical protection of the elastically deformable element. In particular, a homogeneous introduction of force into the elastically deformable element is made possible. In addition, local overstressing of the elastically deformable element is prevented from the outset. Wear due to friction or the like, which in principle is possible on an outside of the elastically deformable element due to abrasion or shear, is also prevented.

It is also advantageous here that the ring-shaped angle element rests on an outside of the fuel connector. This enables the annular angular element to be reliably fixed on the fuel connector, so that vibrations are transmitted directly to the elastically deformable element. Contact noises between the annular angle element and the fuel connector are thus prevented from the outset.

It is also advantageous that the element connected to the fuel connector is materially connected to the fuel connector. For example, the element connected to the fuel connector can be designed as a disk-shaped element that is welded to the fuel connector.

It is also advantageous that a U-shaped connection bracket is provided, that the connection piece is connected to the connection body via the U-shaped connection bracket, that the connection body has at least one recess on its outside, that the connection piece has at least one recess on its inside which is assigned to the recess of the connection body, that the U-shaped connecting bracket engages inside the at least one recess of the connection body and outside the at least one recess of the connector and that the U-shaped connecting bracket is oriented at least approximately perpendicular to a longitudinal axis of the receiving space . This enables simple assembly. During this assembly, the preferably cup-shaped connection piece can be attached to the fuel nozzle. Then, among other things, the elastically deformable element can be mounted. Then, for example, the disk-shaped element can be connected to the fuel connector by welding. After this pre-assembly, the fuel nozzle can be positioned together with the connector on the fuel-carrying component. In this case, the connection piece is suitably positioned on the connection body, so that the U-shaped connection bracket enters the recess of the connection body and can be inserted into the recess of the connection piece. Furthermore, simple dismantling is also made possible here, which may be necessary, for example, as part of maintenance.

In a modified embodiment, the connection piece can also be designed in the form of a union nut. As a result, a detachable connection between the fuel injector and the fuel-carrying component can also be achieved.

Brief description of the drawings

• Fig. 1 eine Brennstoffeinspritzanlage mit einer Aufhängung in einer auszugsweisen, schematischen Schnittdarstellung entsprechend einem ersten Ausführungsbeispiel der Erfindung;
• Fig. 2 eine Brennstoffeinspritzanlage mit einer Aufhängung in einer auszugsweisen, schematischen Schnittdarstellung entsprechend einem zweiten Ausführungsbeispiel der Erfindung und
• Fig. 3 einen Verbindungsbügel der in Fig. 2 dargestellten Aufhängung entsprechend dem zweiten Ausführungsbeispiel der Erfindung.

Preferred exemplary embodiments of the invention are explained in more detail in the following description with reference to the accompanying drawings, in which corresponding elements are provided with corresponding reference symbols. Show it:

• Fig. 1 a fuel injection system with a suspension in a partial, schematic sectional view according to a first embodiment of the invention;
• Fig. 2 a fuel injection system with a suspension in an excerpt, schematic sectional view according to a second embodiment of the invention and
• Fig. 3 a connection bracket of the in Fig. 2 shown suspension according to the second embodiment of the invention.

Embodiments of the invention

Fig. 1 shows a fuel injection system 1 with a suspension 2 in a partial, schematic sectional view corresponding to a first embodiment. The fuel injection system 1 can be used in particular for high pressure injection in internal combustion engines. In particular, the fuel injection system 1 can be used in mixture-compressing, externally ignited internal combustion engines. The suspension 2 is particularly suitable for such a fuel injection system 1.

The fuel injection system 1 has a fuel-carrying component 3 which, in this exemplary embodiment, is designed as a fuel rail 3. The fuel rail 3 has a tubular base body 4 and a connection body 5. An elongated fuel chamber 6 is formed in the tubular base body 4, from which a connecting channel 7, which is guided through the connecting body 5, branches off. In this case, further connection bodies, which are configured in accordance with the connection body 5, are preferably attached to the tubular base body 4. The connection body 5 is part of the suspension 2. The connection body 5 can be connected to the tubular base body 4 in a suitable manner. However, the tubular base body 4 is not necessarily a component of the suspension 2, because the suspension 2 with the connection body 5 can also be manufactured and sold independently of the tubular base body 4. In the context of a pre-assembly, the connection body 5 can then be connected to the tubular base body 4 together with further correspondingly configured connection bodies, which is possible, for example, by welding. In this exemplary embodiment, the connection body 5 has an external thread 8. Furthermore, the suspension 2 has a connection piece 9 with an internal thread 10. At least in the area of the internal thread 10, the connection piece 9 is tubular. In this case, the connection piece 9 has an inner collar 12 on an end face 11. In the assembled state, as shown in the Fig. 1 is shown, the connection piece 9 is screwed with its internal thread 10 onto the external thread 8 of the connection body 5. In this exemplary embodiment, the connection piece 9 is thus designed in the form of a union nut 9. The connection body 5 is designed as a rail cup 5 in this exemplary embodiment.

The connection body 5 and the connection piece 9 are thus connected to one another. In the connected state, a receiving space 15 is formed inside the connection body 5 and the connection piece 9, in which a fuel connector 16 of a fuel injection valve 17 of the fuel injection system 1 is partially arranged.

The fuel connector 16 has a collar 18 on which an inlet for the fuel is provided in order to guide the fuel from the connecting channel 7 into a fuel chamber 19 in the interior of the fuel injector 17. In the area of the collar 18, a sealing ring 20 is provided, which is located between the fuel nozzle 16 and the connection body 5 in order to form a seal. The sealing ring 20 is located between the collar 18 and a support ring 21. The support ring 21 encloses a tapered section of the fuel nozzle 16.

A contact surface 22 is configured on the inner collar 12 of the connection piece 9. The contact surface 22 here faces the receiving space 15. Furthermore, the contact surface 22 is configured conically with respect to a longitudinal axis 23 of the receiving space 15. An opening angle for the contact surface 22 can be approximately 45 °, for example.

In addition, an annular support element 24 is provided on which a rounded edge 25 is configured. The annular support element 24 is arranged in the receiving space 15 and encloses the fuel connector 16. The rounded edge 25 of the annular support element 24 faces the contact surface 22 of the inner collar 18. The annular support element 24 is supported on the contact surface 22 of the inner collar 18 via the rounded edge 25.

The annular support element 24 also has an annular recess 26. The annular recess 26 is designed to be open inwards. This means that the annular recess 26 is designed to be open towards the fuel connector 16. An elastically deformable element 27 is partially inserted into the annular recess 26.

The elastically deformable element 27, which is partially inserted into the annular recess 26 of the annular support element 24, is thus supported via the annular support element 24 on the inner collar 18 of the connection piece 9. In this exemplary embodiment, the elastically deformable element 27 is thus indirectly supported on the inner collar 18. In a modified embodiment, the elastically deformable element 27 can, however, also be supported directly on the inner collar 12 of the connection piece 9.

Furthermore, in this exemplary embodiment, an annular element 30 is provided which is connected to the fuel connection 16 via a weld 31. In a modified embodiment, however, the annular element 30 can also be designed as a snap ring 30 or be connected to the fuel connector 16 in some other way.

A support surface 32 is configured on the annular element 30. In a modified embodiment, however, the support surface 32 can also be configured directly on the fuel connection 16, in particular a collar of the fuel connection 16.

Furthermore, an annular angle element 33 is provided that has an L-shaped profile into which the elastically deformable element 27 is partially inserted. In this exemplary embodiment, the elastically deformable element 27 has a rectangular, in particular square, profile and is configured in the shape of a ring. The elastically deformable element 27 is thus arranged between the annular angle element 33 and the annular support element 24.

In this exemplary embodiment, the elastically deformable element 27 is therefore supported by means of the annular angle element 33 on the support surface 32 of the annular element 30. The elastically deformable element 27 is thus indirectly supported on the support surface 32 of the ring-shaped element 30. In a modified embodiment, the elastically deformable element 27 can also be supported directly on the support surface 32 of the annular element 30.

In this exemplary embodiment, the annular angle element 33 rests against an outer side 34 of the fuel connector 16. This ensures that the annular angular element 33 is positioned in a fixed position on the fuel connector 16.

In this exemplary embodiment, a material connection between the annular element 30 and the fuel connector 16 is formed via the weld seam 31. However, a positive connection can also be provided. Other connection options are also conceivable.

The fuel connector 16 is thus supported on the inner collar 18 of the connection piece 9 at least via the elastically deformable element 27. A direct contact between the connection piece 9 and the fuel nozzle 16 is avoided here. This significantly dampens vibrations. An elastic mounting of the fuel injector 17 can therefore be realized in an advantageous manner. The elastically deformable element 27 can be realized here by a wire mesh, a plate spring, a special spring or in some other way. The elastically deformable element 27 can be designed in such a way that it also acts as an angle tolerance compensation element 27. The flow of force between the fuel connector 16 and the fuel-carrying component 3 leads via the elastically deformable element 27, whereby the transmission of vibrations is substantially dampened.

Fig. 2 shows a fuel injection system 1 with a suspension 2 in an excerpt, schematic sectional view corresponding to a second embodiment. In this exemplary embodiment, the connection body 5 has on its Outside 40 cutouts 41, 42. Furthermore, the connection piece 9 has recesses 44, 45 on its inside 43. The recess 44 of the connection piece 9 is assigned to the recess 41 of the connection body 5. Furthermore, the recess 45 of the connection piece 9 is assigned to the recess 42 of the connection body 5. In the assembled state, the recess 41 of the connecting body 5 and the recess 44 of the connecting piece 9 form a cylindrical free space into which an arm 46 of a U-shaped connecting bracket 47 is inserted. Furthermore, the recess 45 of the connecting piece 9 and the recess 42 of the connecting body 5 form a cylindrical free space into which a further arm 48 of the U-shaped connecting bracket 47 is inserted. The U-shaped connecting bracket 47 is oriented perpendicular to the longitudinal axis 23 of the receiving space 15. This means that the two arms 46, 48 lie in a plane which is oriented perpendicular to the longitudinal axis 23.

The connection piece 9 is thus connected to the connection body 5 via the U-shaped connecting bracket 47. In this exemplary embodiment, the connection piece 9 is designed as a cup-shaped connection piece 9.

Fig. 3 shows the in Fig. 2 U-shaped connecting bracket 47 shown in a schematic representation. The arm 46 is connected to the further arm 48 via a curved connecting section 49. An inside 50 of the curved connecting section 49 can form a stop for the assembly.

The invention is not restricted to the exemplary embodiments described.

Claims (8)

1. Mounting (2) for fuel injection systems (1) for connecting a fuel injection valve (17) to a fuel-conducting component (3), wherein a connection piece (9) is provided, wherein, within the connection piece (9), there is provided a receiving space (15) in which a fuel connector (16) of the fuel injection valve (17) can be at least partially arranged, and wherein an internal collar (12) is formed on the connection piece (9), wherein an elastically deformable element (27) is provided, wherein the elastically deformable element (27) is supported at least indirectly against the internal collar (12) of the connection piece (9), and wherein the fuel connector (16) can be supported at least indirectly on the elastically deformable element (27), and wherein the fuel connector (16) can be supported at least indirectly on the elastically deformable element (27) at its upper side which is situated upstream as viewed in a flow direction through the fuel connector (16), wherein a noise reduction can be achieved by means of a decoupling between the fuel injection valve (17) and the fuel-conducting component (3), wherein a ring-shaped support element (24) is provided, and wherein the elastically deformable element (27) is supported by means of the ring-shaped support element (24) on the internal collar (12) of the connection piece (9),
   characterized
   in that the ring-shaped support element (24) has a ring-shaped recess (26) into which the elastically deformable element (27) is at least partially inserted.
2. Mounting according to Claim 1,
   characterized
   in that, on the internal collar (12) of the connection piece (9), there is formed an abutment surface (22) which, in relation to a longitudinal axis (23) of the receiving space (15), is of conical form and faces towards the receiving space (15).
3. Mounting according to Claim 1,
   characterized
   in that the ring-shaped recess (26) of the ring-shaped support element (24) is of inwardly open form.
4. Mounting according to any of Claims 1 to 3,
   characterized
   in that, in the case of the mounting in conjunction with the fuel injection valve (17), a support surface (32) is formed on the fuel connector (16) or on an element (30) connected to the fuel connector (16), in that a ring-shaped angled element (33) is provided which has a L-shaped profile into which the elastically deformable element (27) is at least partially inserted, and in that the fuel connector (16) is supported at least by means of the ring-shaped angled element (33) on the elastically deformable element (27).
5. Mounting according to Claim 4,
   characterized
   in that the ring-shaped angled element (33) bears against an outer side (34) of the fuel connector (16).
6. Mounting according to Claim 4 or 5,
   characterized
   in that the element (30) connected to the fuel connector (16) is cohesively connected to the fuel connector (16).
7. Mounting according to any of Claims 1 to 6,
   characterized
   in that a U-shaped connecting clip (47) is provided, in that, in the case of the mounting in conjunction with the fuel injection valve (17), the connection piece (9) is connected by means of the U-shaped connecting clip (47) to a connection body (5) of the fuel-conducting component (3), in that the connection body (5) has at least one cutout (41, 42) on its outer side (40), in that the connection piece (9) has, on its inner side (43), at least one cutout (44, 45) which is assigned to the cutout (41, 42) of the connection body (5), in that the U-shaped connecting clip (47) engages into the at least one cutout (41, 42) of the connection body (5) and into the at least one cutout (44, 45) of the connection piece (9), and in that the U-shaped connecting clip (47) is oriented at least approximately perpendicular to a longitudinal axis (23) of the receiving space (15).
8. Fuel injection system (1), in particular for mixed-compressing, applied-ignition internal combustion engines, having at least one fuel-conducting component (3), at least one fuel injection valve (17), and at least one mounting (2) according to any of Claims 1 to 7, wherein the fuel injection (17) is mounted, by means of the mounting (2), on the fuel-conducting component (3).

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