EP3388662A1 - Mounting for a fuel injection system to link a fuel-guiding component with a fuel injection valve and a fuel innjection system - Google Patents

Abstract

A suspension (2) for fuel injection systems (1), which is used to connect a fuel injection valve (17) with a fuel-carrying component (3), comprises a connecting body (5) and a connecting piece (9), which are interconnected. Here, a receiving space (15) is formed within the connecting body (5) and the connecting piece (9), in which a fuel nozzle (16) of the fuel injection valve (17) is at least partially arranged. At the connection piece (9) an inner collar (12) is designed. Furthermore, an elastically deformable element (27) is provided. The elastically deformable element (27) is supported at least indirectly on the inner collar (18) of the connecting piece (9). Furthermore, the fuel nozzle (16) is at least indirectly supported on the elastically deformable element (27). In addition, a fuel injection system is given with such a suspension (2).

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. Specifically, the invention relates to the field of fuel injection systems for mixture-compression, spark-ignition internal combustion engines.

From the DE 10 2005 020 380 A1 is a fuel injection device with a sound-decoupling design 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 distributor line with a connecting piece. In the connection piece, the fuel injection valve is partially inserted. In one possible embodiment, the fuel injection valve has a wire ring inserted in a groove in the region of its inlet neck. Further, a connecting body in the form of a lock nut is provided, which is screwed onto an external thread on the circumference of the connecting piece. At an end facing the connecting piece, the connecting body has a section containing an internal thread, to which a ring 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 from the DE 10 2005 020 380 A1 known configuration of the fuel injection device has the disadvantage that vibrations can be transmitted via the wire ring between the connecting piece and the inlet nozzle of the fuel injection valve. Specifically, vibrations from the fuel injector can be transmitted to the port.

Especially in the case of electromagnetic high-pressure injection valves, which are used in Otto engines with direct injection, a conspicuous and disturbing contribution to the overall noise of the engine can be made, which can be described as a valve plug. Such a valve leakage is caused by the rapid opening and closing of the fuel injection valve, in which the valve needle is adjusted with high dynamics in the respective end stops. The impact of the valve needle in the end stops leads to short-acting, but very high contact forces, which are transmitted via a housing of the fuel injection valve to the cylinder head and a fuel rail in the form of structure-borne noise and vibrations. This leads to the cylinder head and the fuel rail to a strong noise.

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 injection valve to the fuel-carrying component is made possible. Here, a noise reduction by targeted decoupling is possible. Specifically, a soft connection of the fuel injection valve to the fuel-carrying component can be achieved, which allows a noise reduction of the entire system with the fuel injection system.

The measures listed in the dependent claims advantageous refinements of the claim 1 suspension and the fuel injection system specified in claim 8 are possible.

Specifically, the suspension and fuel injection system are suitable for gasoline direct injection applications. The fuel-carrying component is in this case 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 storage for the fuel injection valves. The fuel injectors are then preferably connected to the fuel manifold via corresponding hangers. During operation, the fuel injection valves then inject the fuel necessary for the combustion process under high pressure into the respective combustion space. The fuel is in this case compressed via a high-pressure pump and quantity-controlled conveyed via a high-pressure line in the fuel distributor.

The fuel injection valve, in particular the fuel nozzle, 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 injection valve. The connection body may be part of a fuel-carrying component. In particular, the connection body can be designed as part of a cup of a fuel distributor strip. In this case, however, the connection body can also be connected at a later time to a tubular base body or the like of the fuel distributor strip, 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. By a soft design of this interface, a substantial noise reduction of the entire system with the fuel injection system is possible. The soft connection of the fuel injection valve to the fuel-carrying component can in this case take place with a target stiffness of not more than 50 kN / mm, wherein the strength requirements can be met over the lifetime. The advantage of the soft suspension is a significant reduction of the transmitted structure-borne sound from the fuel injection valve to the fuel-carrying component and, associated with this, 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 Railverschraubung. Furthermore, the suspension can advantageously be used without or with only minor structural changes in existing constructions. This results in a broad scope.

It is advantageous that on the inner collar of the connecting piece a contact surface is configured, which is designed conically with respect to a longitudinal axis of the receiving space and facing the receiving space. Due to the conical contact surface, in particular with respect to the longitudinal axis can have an opening angle from a range of about 10 ° to about 80 °, in particular of at least approximately 45 °, an advantageous centering is guaranteed. In addition, with a suitable design of the angle of the conical contact surface, an angular tolerance compensation for the fuel injection valve with respect to the longitudinal axis of the receiving space can be ensured. The angle tolerance compensation can also be used here be realized by an elastic deformation of the elastically deformable element. An orientation of the elastically deformable element with respect to the longitudinal axis of the receiving space and thus the orientation of the fuel nozzle of the fuel injection valve takes place at least indirectly via the conical contact surface.

It is also advantageous that an annular support member is provided and that the elastically deformable element is supported by means of the annular support member on the inner collar of the fitting. This is particularly advantageous if, in addition, the conical contact surface is provided on the inner collar of the connecting piece. As a result, an alignment of the annular support element with respect to the longitudinal axis of the receiving space is achieved. The annular support element in this case preferably has a rounded outer contour with respect to the contact surface of the inner collar. As a result, a tolerance compensation is ensured at the interface between the annular support member and the inner collar, wherein a self-centering occurs during operation.

Here, it is also advantageous that the annular support member has an annular recess into which the elastically deformable element is at least partially inserted. By inserting the elastically deformable element into the annular recess of the annular support element, on the one hand, a mechanical protection is ensured, wherein in particular a local overstress is prevented. Furthermore, a uniform application of force and thus a homogeneous loading of the elastically deformable element is ensured. Furthermore, the elastically deformable element is thereby reliably positioned. Bruising of the elastically deformable element due to incorrect positioning, improper installation, pinching in places, kinks or the like are thereby prevented from the outset.

It is particularly advantageous in this case that the annular recess of the annular support member is designed to be open inwardly. As a result, on the one hand, an elastic deformability of the elastically deformable element also in the radial direction allows, as a radial support is ensured on the annular support member. On the other hand, a direct contact between the annular support member and an outer side of the fuel nozzle can be avoided. However, deformation of the elastically deformable element can still be limited.

Moreover, it is advantageous that on the fuel nozzle or on a connected to the fuel nozzle element, a support surface is configured, that an annular angle element is provided which has an L-shaped profile, in which the elastically deformable element is at least partially inserted, and that the fuel nozzle is supported at least by means of the annular angular element on the elastically deformable element. The annular angle element also allows mechanical protection of the elastically deformable element. In particular, a homogeneous force is introduced into the elastically deformable element. In addition, a local overuse of the elastically deformable element is prevented from the outset. Also wear due to friction or the like, which is in principle possible on an outer side of the elastically deformable element by abrasion or shear, is thereby prevented.

It is also advantageous here that the annular angle element bears against an outer side of the fuel nozzle. As a result, a reliable fixation of the annular angle element is made possible on the fuel nozzle, so that vibrations are transmitted directly to the elastically deformable element. Contact noise between the annular angle element and the fuel nozzle are thus prevented from the outset.

It is also advantageous that the element connected to the fuel nozzle is materially connected to the fuel nozzle. For example, the element connected to the fuel stub may be configured as a disk-shaped element that is welded to the fuel stub.

It is also advantageous that a U-shaped connection bracket is provided, that the connection piece is connected via the U-shaped connection bracket with the connection body, that the connection body has on its outside at least one recess, that the connection piece has on its inside at least one recess , which is associated with the recess of the connection body, that the U-shaped connection bracket engages inside the at least one recess of the connection body and outside in the at least one recess of the connector and that the U-shaped connection bracket is oriented at least approximately perpendicular to a longitudinal axis of the receiving space , As a result, a simple assembly is possible. In this assembly, the preferably pot-shaped connection piece can be applied to the fuel nozzle. Then, among other things, the elastically deformable element can be mounted. Subsequently, for example, the disk-shaped element can be connected by welding to the fuel nozzle. After this pre-assembly, the fuel stub can be positioned with the fitting on the fuel-bearing component. Here, the connector is suitably positioned on the connector body, so that the U-shaped connecting bracket into the recess of the connection body and in the recess of the connector can be inserted. Furthermore, in this case also a simple disassembly is possible, which may be required, for example, in the context of maintenance.

In a modified embodiment, the connecting piece can also be designed in the form of a union nut. In this way, also a releasable connection between the fuel injection valve and the fuel-carrying component can 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 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 identical reference numerals. 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 a partial, schematic sectional view according to a second embodiment of the invention and
• Fig. 3 a connecting bracket of 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 an excerpt, schematic sectional view according to a first embodiment. The fuel injection system 1 can be used in particular for high-pressure injection in internal combustion engines. Specifically, the fuel injection system 1 can be used in mixture-compression, spark-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 is designed in this embodiment as a fuel distributor strip 3. The fuel distributor strip 3 has a tubular main body 4 and a connection body 5. In the tubular base body 4, an elongate fuel chamber 6 is formed, from which a branched through the connection body 5 connecting channel 7 branches off. In this case, further connecting bodies are preferably attached to the tubular base body 4, which are designed in accordance with the connection body 5. The connection body 5 is in this case part of the suspension 2. The connection body 5 can be connected in a suitable manner to the tubular base body 4. However, the tubular base body 4 is not necessarily part of the suspension 2, because the suspension 2 with the connection body 5 can also be manufactured and distributed independently of the tubular base body 4. As part of a pre-assembly of the connection body 5 can be connected together with other appropriately designed connection bodies with the tubular base body 4, which is possible for example by welding. The connection body 5 has an external thread 8 in this exemplary embodiment. Furthermore, the suspension 2 has a connection piece 9 with an internal thread 10. At least in the region of the internal thread 10, the connecting piece 9 is designed tubular. Here, the connecting piece 9 on an end face 11 an inner collar 12. In the assembled state, as in the Fig. 1 is shown, the connector 9 is screwed with its internal thread 10 on the external thread 8 of the connector body 5. The connector 9 is thus configured in this embodiment in the form of a union nut 9. The connection body 5 is configured in this embodiment as a rail cup 5.

Thus, the terminal body 5 and the connector 9 are connected to each other. In the connected state, a receiving space 15 is formed within the connecting body 5 and the connecting piece 9, in which a fuel nozzle 16 of a fuel injection valve 17 of the fuel injection system 1 is partially arranged.

The fuel nozzle 16 has a collar 18, on which an inlet for the fuel is provided to guide the fuel from the connecting channel 7 into a fuel chamber 19 in the interior of the fuel injection valve 17. In the region of the collar 18, a sealing ring 20 is provided, which is located between the fuel nozzle 16 and the connection body 5 to form a seal. The sealing ring 20 is in this case between the collar 18 and a support ring 21. The support ring 21 encloses a tapered portion of the fuel nozzle 16th

At the inner collar 12 of the connecting piece 9, a contact surface 22 is configured. The contact surface 22 in this case faces the receiving space 15. Furthermore, the contact surface 22 is designed conically with respect to a longitudinal axis 23 of the receiving space 15. An opening angle for the contact surface 22 may be, for example, about 45 °.

In addition, an annular support member 24 is provided, on which a rounded edge 25 is configured. The annular support member 24 is disposed in the receiving space 15 and surrounds the fuel nozzle 16. The rounded edge 25 of the annular support member 24 in this case the contact surface 22 of the inner collar 18 faces. About the rounded edge 25, the annular support member 24 is supported on the contact surface 22 of the inner collar 18.

The annular support member 24 also has an annular recess 26. The annular recess 26 is in this case designed to be open inwardly. This means that the annular recess 26 is configured open to the fuel nozzle 16. In the annular recess 26, an elastically deformable element 27 is partially inserted.

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

Further, in this embodiment, an annular member 30 is provided, which is connected via a weld 31 with the fuel nozzle 16. In a modified embodiment, however, the annular element 30 may also be designed as a snap ring 30 or be connected in some other way to the fuel nozzle 16.

On the annular member 30, a support surface 32 is configured. In a modified embodiment, however, the support surface 32 may also be configured directly on the fuel stub 16, in particular a collar of the fuel stub 16.

Further, an annular angle member 33 is provided, which has an L-shaped profile, in 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 of annular design. Thus, the elastically deformable member 27 is disposed between the annular angle member 33 and the annular support member 24.

Therefore, in this embodiment, the elastically deformable member 27 is supported by the annular angle member 33 on the support surface 32 of the annular member 30. Thus, the elastically deformable element 27 is indirectly supported on the support surface 32 of the annular element 30. In a modified embodiment, the elastically deformable element 27 may also be supported directly on the support surface 32 of the annular element 30.

The annular angle element 33 abuts in this embodiment on an outer side 34 of the fuel nozzle 16. As a result, a stationary positioning of the annular angle element 33 is ensured on the fuel nozzle 16.

About the weld 31, a cohesive connection of the annular member 30 is formed with the fuel nozzle 16 in this embodiment. However, it can also be provided a positive connection. Other connection options are conceivable.

Thus, the fuel nozzle 16 is supported at least on the elastically deformable element 27 on the inner collar 18 of the connecting piece 9. Direct contact between the connector 9 and the fuel nozzle 16 is avoided. Thus, vibrations are significantly attenuated. Therefore, an elastic mounting of the fuel injection valve 17 can be realized in an advantageous manner. The elastically deformable element 27 can in this case be realized by a wire mesh, a plate spring, a special spring or in other ways. The elastically deformable element 27 can in this case be designed so that it also acts as an angle tolerance compensation element 27. The power flow between the fuel nozzle 16 and the fuel-carrying component 3 passes over the elastically deformable element 27, whereby a vibration transmission is substantially damped.

Fig. 2 shows a fuel injection system 1 with a suspension 2 in an excerpt, schematic sectional view according to a second embodiment. In this embodiment, the connection body 5 at its Outside 40 recesses 41, 42 on. Furthermore, the connection piece 9 has recesses 44, 45 on its inside 43. The recess 44 of the connection piece 9 is in this case associated with the recess 41 of the connection body 5. Furthermore, the recess 45 of the connection piece 9 is associated with 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 space in which an arm 46 of a U-shaped connecting bracket 47 is inserted. Further, the recess 45 of the connecting piece 9 and the recess 42 of the connecting body 5 form a cylindrical space in which a further arm 48 of the U-shaped connecting bracket 47 is inserted. The U-shaped connecting bracket 47 is in this case 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.

Thus, the connector 9 is connected via the U-shaped connecting bracket 47 to the connector body 5. The connector 9 is configured in this embodiment as a cup-shaped connector 9.

Fig. 3 shows the in Fig. 2 illustrated U-shaped connecting bracket 47 in a schematic representation. The arm 46 is in this case connected via a curved connecting portion 49 with the further arm 48. An inner side 50 of the bent connecting portion 49 may in this case form a stop for the assembly.

The invention is not limited to the described embodiments.

Claims (8)

Suspension (2) for fuel injection systems (1) for connecting a fuel injection valve (17) with a fuel-carrying component (3), wherein a connecting piece (9) is provided, wherein within the connecting piece (9) a receiving space (15) is provided in in that a fuel stub (16) of the fuel injection valve (17) is at least partly arranged, and wherein an inner collar (12) is configured on the connecting piece (9), wherein an elastically deformable element (27) is provided, that the elastically deformable element (27) 27) is supported at least indirectly on the inner collar (12) of the connecting piece (9) and that the fuel nozzle (16) is at least indirectly supported on the elastically deformable element (27) and
in that the fuel stub (16) can be supported at least indirectly on the elastically deformable element (27) at its upstream upper side viewed in the flow direction through the fuel stub (16), a noise reduction being achieved by decoupling between the fuel injector (17) and the fuel Component (3) can be achieved
characterized,
in that an annular support element (24) is provided, and in that the elastically deformable element (27) is supported on the inner collar (12) of the connection piece (9) by means of the annular support element (24), and in that the annular support element (24) has an annular recess (26) into which the elastically deformable element (27) is at least partially inserted. Suspension according to claim 1,
characterized,
in that on the inner collar (12) of the connecting piece (9) a bearing surface (22) is configured which is conical in relation to a longitudinal axis (23) of the receiving space (15) and faces the receiving space (15). Suspension according to claim 1,
characterized,
in that the annular recess (26) of the annular support element (24) is designed to be open inwards. Suspension according to one of claims 1 to 3,
characterized,
in that a support surface (32) is configured on the fuel stub (16) or on an element (30) connected to the fuel stub (16) in such a way that an annular angle element (33) is provided which has an L-shaped profile into which elastically deformable element (27) is at least partially inserted, and that the fuel stub (16) at least by means of the annular angular element (33) is supported on the elastically deformable element (27). Suspension according to claim 4,
characterized,
in that the annular angle element (33) bears against an outer side (34) of the fuel nozzle (16). Suspension according to claim 4 or 5,
characterized,
in that the element (30) connected to the fuel stub (16) is connected to the fuel stub (16) by a material fit. Suspension according to one of claims 1 to 6,
characterized,
that a U-shaped connecting bracket (47) is provided, that the connecting piece (9) over the U-shaped connecting bracket (47) with a connecting body (5) of the fuel-carrying component (3) is connected, that the connecting body (5) at its outer side (40) has at least one recess (41, 42) that the connecting piece (9) on its inner side (43) at least one recess (44, 45) which the recess (41, 42) of the connecting body (5) is assigned, that the U-shaped connecting bracket (47) in the at least one recess (41, 42) of the connecting body (5) and in the at least one recess (44, 45) of the connecting piece (9) engages and that the U-shaped Connecting bracket (47) is oriented at least approximately perpendicular to a longitudinal axis (23) of the receiving space (15). Fuel injection system (1), in particular for mixture-compression, spark-ignition internal combustion engine, with at least one fuel component (3), at least one fuel injection valve (17) and at least one suspension (2) according to one of claims 1 to 7, wherein the fuel injection valve (17) via the suspension (2) is suspended from the fuel-carrying component (3).

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