EP2948675B1 - Fuel injection system comprising a fuel-guiding component, a fuel injection valve and a mounting - 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. 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 connecting piece, the fuel injection valve is partially overlapping introduced. A connecting body is arranged such that the fuel injection valve is held therein in such a way that the fuel injection valve and the connecting body are introduced system-free to all not axially parallel to the fuel injection valve extending surfaces or walls of the receiving bore of the cylinder head. In one possible embodiment, the connecting body is only a slotted snap ring. The snap ring engages in a tapered portion of the inlet nozzle of the fuel injection valve. In the connecting piece a groove is provided, in which the snap ring is locked securely and firmly. To engage under the fuel injection valve, the snap ring has a conical or curved spherical contact surface. A hold-down is clamped between the end face of the spud and a shoulder on the fuel injector.

The from the DE 10 2005 020 380 A1 known configuration of the fuel injection device has the disadvantage that between the connecting piece, the Snap ring and the intake manifold vibrations can be transmitted. Specifically, vibrations from the fuel injector can be transmitted to the port. Another suspension for connecting a fuel injection valve with a fuel-carrying component is out US 7 334 571 B known. Especially in the case of electromagnetic high-pressure injection valves, which can be 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 to 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 is made possible at the fuel component. 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. In operation, the fuel injectors inject the necessary for the combustion process Fuel then under high pressure in the respective combustion chamber. 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 nozzle of the fuel injection valve is part of the suspension according to the invention. In contrast, the fuel-carrying component is not necessarily part of the suspension according to the invention. Furthermore, the connection body of the suspension can also be produced and distributed separately from a tubular base body of a component designed as a fuel distributor strip fuel or other components of the fuel-carrying component. Here, a pre-assembly of the connecting body to one or more further components of the fuel-carrying component take place and, for example, a compound can be produced by welding.

It is advantageous that the elastically deformable element is arranged so that the connecting body allows at least substantially along the longitudinal axis an elastic support of the fuel nozzle to the connector body. Thus, the elastic support is mainly or completely given in the axial direction and not in the radial direction.

It is also advantageous that the connecting body has a fuel nozzle-side retaining element and that the fuel nozzle acts on the fuel nozzle-side retaining element on the elastically deformable element of the connecting body. Furthermore, it is advantageous that the elastically deformable element with the fuel nozzle-side retaining element is elastic. When deformable element is connected to the fuel nozzle-side retaining element. In this embodiment, the position of the elastically deformable element is held in an advantageous manner by the fuel nozzle-side retaining element.

It is also advantageous that the connecting body has a connection body-side holding element, that the connection body-side holding element is at least partially partially disposed in the recess of the connection body and that the elastically deformable element is supported on the connection body-side holding member to the connection body. By the connection body-side holding element, the elastically deformable element is also held in position. Specifically, the elastically deformable member may be connected to the terminal body-side holding member. Thus, the connecting body can be designed as a three-component or three-layer connecting body. Each element, namely the fuel nozzle-side retaining element, the elastically deformable element and the connector body-side retaining element, assumes different functions here. The fuel nozzle-side retaining element of the connecting body holds the elastically deformable element in position and forwards the forces from the fuel injection valve to the elastically deformable element. Integrated here is also a tolerance compensation between the longitudinal axes of the fuel nozzle and the longitudinal axis of the receiving space of the connection body. The elastically deformable element dampens the forces transmitted by the fuel injection valve to the fuel component. The elastically deformable element can thus be configured as a damping element. The elastically deformable element is preferably configured with a rigidity of not more than 50 kN / mm. The stiffness of the elastically deformable element can be adjusted by a choice of material and by a geometry of the elastically deformable element.

Specifically, the elastically deformable element can be configured as a disk-shaped and / or annular disk-shaped and / or perforated element. Due to the design of the elastically deformable element in the form of a disc or perforated disc, a geometric influence on the rigidity is possible.

Furthermore, a material with a high internal damping can be selected. For example, the elastically deformable element may be made of a plastic, in particular PEEK (polyether ether ketone).

Furthermore, the connection body-side holding element has its own function. The connector body-side retaining member holds the elastically deformable member in position and passes the forces from the elastically deformable member on the fuel-carrying component on. In addition, a frictional connection between the fuel injection valve and the fuel-carrying component is achieved.

The connecting body may be configured as an annular or partially annular connecting body. Specifically, the connecting body can be designed in this case according to a snap ring. In a partially annular design of the Connecting body, the connecting body is partially arranged partially in the receiving space facing recess of the connecting body. Here, the connecting body is arranged in sections in the recess, since the connecting body is designed partially ring-shaped. Further, the connecting body is partially disposed in the recess, since the connecting body is partially disposed outside of the recess to cooperate with the fuel nozzle accordingly.

In one embodiment of the connecting body as an annular connecting body and a complete partial arrangement in the recess of the connector body is possible. In both cases, an at least partial arrangement is thus provided in the recess.

Brief description of the drawings

• Fig. 1 eine Brennstoffeinspritzanlage mit einer Aufhängung entsprechend einem ersten Ausführungsbeispiel der Erfindung und eine Brennkraftmaschine in einer auszugsweisen, schematischen Schnittdarstellung;
• Fig. 2 eine Aufhängung entsprechend einer nicht beanspruchten Konfiguration der in Fig. 1 dargestellten Brennstoffeinspritzanlage in einer schematischen Schnittdarstellung entlang der mit II bezeichneten Schnittlinie;
• Fig. 3 einen Querschnitt eines Verbindungskörpers der in Fig. 2 dargestellten Aufhängung in einer schematischen Darstellung entlang der mit III bezeichneten Schnittlinie;
• Fig. 4 den in Fig. 3 dargestellten Querschnitt entsprechend einem weiteren Beispiel;
• Fig. 5 den in Fig. 1 mit V bezeichneten Ausschnitt der Brennstoffeinspritzanlage entsprechend einem weiteren Ausführungsbeispiel der Erfindung in einer schematischen Schnittdarstellung und
• Fig. 6 den in Fig. 5 dargestellten Ausschnitt der Brennstoffeinspritzanlage entsprechend einer nicht beanspruchten Konfiguration.

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 according to a first embodiment of the invention and an internal combustion engine in a partial, schematic sectional view;
• Fig. 2 a suspension according to an unclaimed configuration of the in Fig. 1 shown fuel injection system in a schematic sectional view along the section line designated II;
• Fig. 3 a cross section of a connecting body of in Fig. 2 illustrated suspension in a schematic representation along the section line designated III;
• Fig. 4 the in Fig. 3 illustrated cross-section according to another example;
• Fig. 5 the in Fig. 1 with V designated section of the fuel injection system according to a further embodiment of the invention in a schematic sectional view and
• Fig. 6 the in Fig. 5 illustrated section of the fuel injection system according to a not claimed configuration.

Embodiments of the invention

Fig. 1 shows a fuel injection system 1 with a suspension 2 according to a first embodiment and an internal combustion engine 3 in a partial, schematic sectional view. The fuel injection system 1 can be used in particular for high-pressure injection in internal combustion engines 3. Specifically, the fuel injection system 1 can be used in mixture-compressing, spark-ignited internal combustion engines 3. The suspension 2 is particularly suitable for such a fuel injection system. 1

The fuel injection system 1 has a component 4 carrying fuel. The fuel-carrying component 4 is configured in this embodiment as a fuel distributor 4, in particular fuel distributor strip 4. The fuel distributor 4 has an elongated fuel chamber 5, is conveyed in the high-pressure fuel from a high-pressure pump, not shown. The fuel distributor 4 has a plurality of outputs 6, of which in the Fig. 1 For simplicity of illustration only the output 6 is shown. At each of these outputs 6, a fuel injection valve 7 is arranged. The fuel injection valve 7 is connected via the suspension 2 to the output 6 of the fuel distributor 4. The connection of the suspension 2 with the fuel distributor 4 takes place in a suitable manner, which is shown only schematically.

The suspension 2 has a connection body 8 with a receiving space 9. Here, the receiving space 9 is configured in this embodiment symmetrical to a longitudinal axis 10 of the receiving space 9 of the connecting body 8. The longitudinal axis 10 coincides in this embodiment with a longitudinal axis 10 of the fuel injection valve 7.

The fuel injection valve 7 has a housing 11 with a conical shoulder 12. The conical shoulder 12 is in this case designed on a fuel nozzle 13 of the fuel injection valve 7.

In the assembled state, the fuel nozzle 13 is at least partially disposed in the receiving space 9. Here, a sealing ring 14 and a support ring 15 are arranged in a circumferential groove 16 of the fuel nozzle 13. The sealing ring 14 is in this case on the inside of the fuel nozzle 13 and on the outside of an inner wall 17 of the connecting body 8. The circumferential groove 16 is located in the region of an inlet-side end 18 of the fuel nozzle 13, via which fuel is fed into the fuel injection valve 7 during operation.

The suspension 2 also has a connecting body 20, which is formed from a plurality of elements, namely a fuel nozzle-side retaining element 21, a connecting-body-side retaining element 22 and an elastically deformable element 23.

The connecting body 8 has a receiving space 9 facing recess 24, which is configured in this embodiment as a circumferential annular groove. The connecting body 20 is partially arranged in the recess 24 of the connecting body 8. In this exemplary embodiment, the connection-body-side holding element 22 is partially arranged in the recess 24 of the connection body 8.

In addition, the fuel nozzle in the region of the conical shoulder 12 has a recess 25. Along the longitudinal axis 10, the recess 25 is bounded on the one hand by the conical shoulder 12 of the fuel nozzle 13 and on the other hand by a shoulder 26. The shoulder 26 is oriented perpendicular to the longitudinal axis 10 in this embodiment.

The elastically deformable member 23 is disposed between the fuel nozzle side holding member 21 and the connector body side holding member 22. The elastically deformable element 23 essentially allows an elastic deformation of the connecting body 20 along the longitudinal axis 10. Thus, an elastic support of the fuel nozzle 13 on the connecting body 8 along the longitudinal axis 10 is made possible. Here, the elastically deformable element 23 is arranged so that the connecting body 20 substantially along the longitudinal axis 10 allows an elastic support.

In this case, the elastically deformable element 23 is preferably configured as a disk-shaped and / or annular disk-shaped and / or perforated element 23. The holding element 21 holds the elastically deformable element 23 in position and directs the forces from the fuel stub 13 on the elastically deformable element 23 on. Accordingly, the holding element 22 holds the elastically deformable element 23 in position and passes the forces from the elastically deformable element 23 on the connection body 8 and thus on the fuel-carrying component 4 on. Thus, the transmitted from the fuel injection valve 7 leading to the component 4 components are damped. This leads to a vibration damping and noise reduction.

In this embodiment, the connection-body-side holding element 22 and the elastically deformable element 23 of the connecting body 20 are located outside the recess 24. In a modified embodiment, the connection-body-side holding element 22 and / or the elastically deformable element 23 may also be partially in the recess 24 of the connection body 8 are located.

Fig. 2 shows a suspension according to an unclaimed configuration of the in Fig. 1 shown fuel injection system 1 in a sectional view along the section line designated II. The connecting body 20 is configured in this embodiment as a U-shaped bracket 20. Here, the connecting body 20 has a first arm 30, a second arm 31 and a connecting sheet 32. Via the connecting bow 32, the first arm 30 is connected to the second arm 31. In the assembled state, the arms 30, 31 of the connecting body 20 extend through the receiving space 9 of the connecting body 8. The fuel injection valve 7 with the fuel nozzle 13 is not shown here for simplicity of illustration. In this embodiment, a plurality of recesses 24, 24 A, 24 B, 24 C are arranged in the connecting body 8, which are connected to the receiving space 9. In the assembled state, the arms 30, 31 of the connecting body 20 are guided through the recesses 24, 24A, 24B, 24C. The connecting bend 32 of the connecting body 20 strikes against an outer side 33 of the connecting body 8.

Fig. 3 shows a cross section of the connecting body 20 of FIG Fig. 2 shown suspension 2 in a schematic view along the designated III cutting line. The holding elements 21, 22 each have a semicircular cross section 34, 35. When viewed in cross-section, this results in straight edges 36, 37. The straight edges 36, 37 in this exemplary embodiment are thus chords of the cross sections 34, 35 on the basis of circular diameters running along the diameter. In a modified embodiment, the straight edges 36, 37 may also extend along other chords of the underlying circle. The Cross-sections 34, 35 can also generally be configured as circle segments 34, 35 in such an embodiment.

The elastically deformable element 23 is viewed in cross section between the straight edges 36, 37 of the cross sections 34, 35 are arranged. The outer holding elements 21, 22 are used for positioning and chambering of the elastically deformable element 23. In this case, the fuel nozzle-side holding element 21 directs the force from the fuel injection valve 7 to the elastically deformable element 23. The connecting body-side holding element 22 ensures a support of the elastically deformable element 23 on the connecting body 8. By the cross sections 34, 35, the resulting outer contour of the connecting body 20 is designed so that the fuel injection valve 7 in the connecting body 20 can be slightly tilted. As a result, a tolerance compensation between the longitudinal axes of the fuel injection valve 7 and the receiving space 9 of the connection body 8 allows, these two longitudinal axes in the Fig. 1 coincide and are both denoted by the reference numeral 10 for simplicity of illustration.

Furthermore, a tolerance compensation with respect to a longitudinal axis 40 of a cylinder head bore 41 is made possible.

Thus, a decoupling of the fuel injection valve 7 of the connector body 8 is made possible by the elastically deformable element 23. The elastically deformable element 23 may in this case also be formed from a wire mesh, which is joined between the holding elements 21, 22. The joining can be done for example by pressing and / or welding. Such a knitted fabric for designing the elastically deformable element 23 can be designed so that a rigidity of the entire connecting body 20 of not more than 50 kN / mm is achieved. The design can be influenced by a weight, a density and a wire thickness of a wire knit serving for the elastically deformable element 23. Possible movements between the fuel injection valve 7 and the connection body 8 are thereby decoupled so that the transmitted from the fuel injection valve 7 leading to the fuel component 4 structure-borne noise is reduced. Due to the friction between the individual wires of the wire mesh, the elastically deformable element 23 then additionally dampens the movement transmitted by the fuel injection valve 7 to the connecting body 8 and thus the transmitted structure-borne noise, resulting in less noise. However, other embodiments of the elastically deformable element 23 are also possible.

Fig. 4 shows the in Fig. 3 illustrated cross-section of the connecting body 20 according to another example not claimed. In this example, the cross sections 34, 35 of the holding elements 21, 22 as U-shaped cross-sections 34, 35 configured. In cross-section therefore results in an embodiment of the arms 30, 31 corresponding to two facing U-shaped shells. The elastically deformable element 23 is in each case partially inserted into the two inner spaces 42, 43 of the holding elements 21, 22. This joining can be done for example by pressing or welding.

Thus, the elastically deformable element 23 can be connected, on the one hand, to the fuel nozzle-side retaining element 21 and, on the other hand, to the connector-body-side retaining element 22.

Fig. 5 shows the in Fig. 1 with V designated section of the fuel injection system 1 according to a further embodiment in a schematic sectional view. In this embodiment, the connecting body 20, the fuel nozzle-side holding member 21 and the elastically deformable member 23. Thus, an embodiment of the connecting body 20 of two elements, namely the holding element 21 and the elastically deformable element 23, possible. The fuel nozzle-side retaining element 21 essentially ensures the holding function. The elastically deformable element 23 essentially ensures the elastic deformability along the longitudinal axis 10. In this case, a low rigidity, in particular a rigidity of not more than 50 kN / mm, can be achieved. The geometry of the connecting body 20 may in this case be predetermined annular or partially annular. Specifically, the connecting body 20 may be configured according to a snap ring.

The advantage of in the Fig. 5 illustrated embodiment is that a spring travel can be limited. Thus, this embodiment is particularly suitable for fuel injection systems 1, in which a high or very high fuel pressure is effective during operation. Because with a very wide range of system pressures, there is the problem that the fuel injection valve 7 otherwise could perform too great a movement along the longitudinal axis 10 with respect to the internal combustion engine 3. Such an excessive movement is limited, for example, by an embodiment of the elastically deformable element 23 as a plate spring 23. Because of this, the movement along the longitudinal axis 10 is limited by a maximum spring travel 44. After going through the Spring travel 44, the elastically deformable element 23 is then pressed block and thus, so to speak, flat.

In a modified embodiment, however, the elastically deformable element 23 may also be configured in another way. Here, the elastically deformable element 23 may also be designed so that there is no path limitation. This is possible in particular by an embodiment of the elastically deformable element 23 made of an elastically deformable plastic.

Fig. 6 shows the in Fig. 5 shown section of the fuel injection system 1 according to another example not claimed. In this example, the connecting body 20 is formed of only one element 23, namely the elastically deformable element 23. Thus, all functions for holding the fuel injection valve 7, in particular a tolerance compensation and a noise damping, are integrated into a component 23. The elastically deformable element 23 may in this case be configured annular or partially annular. Specifically, the elastically deformable element 23 may be configured according to a snap ring. However, the elastically deformable element 23 may also be designed as a U-shaped headband, as shown in the Fig. 2 is illustrated.

In this example, the recess 25 is limited on the one hand by the conical shoulder 12 and on the other hand by a further conical shoulder 45. An opening angle 46 for the conically shaped shoulder 45 is selected in this case in combination with a geometry of the elastically deformable element 23 so that an advantageous degressive spring characteristic for the elastic suspension of the fuel injection valve 7 is achieved on the connection body 8. In a modified embodiment, however, a linear spring characteristic or a progressive spring characteristic can also be achieved. This can be achieved by a suitable choice of the opening angle 46 and a suitable geometric configuration of the elastically deformable element 23.

Thus, a soft suspension 2 for attaching the fuel injection valve 7 to the fuel-carrying component 4 can be realized. As a result, a significant reduction of noise is possible. This can be achieved by a significant reduction of the transmitted structure-borne noise from the fuel injection valve 7 to the fuel-carrying component 4. In addition, this noise reducing measure can be used in addition to other noise reducing measures, such as a hydraulic throttle at the upstream end 18 of the fuel nozzle 13 and a soft Railverschaubung.

The elastically deformable element 23 may in this case consist of one or more suitable materials. In this case, the elastically deformable element 23 can obtain its elasticity by a suitable choice of the material and / or by a suitable geometric configuration. For example, in the case of the Fig. 6 described example, the elastically deformable element 23 are also made of a bent piece of sheet metal, wherein the elasticity is predetermined by a sheet thickness and a suitable bend. The sheet thickness can also vary locally.

Furthermore, the rigidity can also be influenced by additional geometrical elements in the case of a disk-shaped, elastically deformable element 23. For example, a disk-shaped ausgestaltetes element 23 may be configured as a perforated disc 23 in order to influence the elasticity accordingly.

The invention is not limited to the described embodiments.

Claims (8)

1. Mounting (2) for fuel injection systems (1) for connecting a fuel injection valve (7) to a fuel-conducting component (4), wherein an attachment body (8) with a receiving space (9) is provided, wherein a fuel connector (13) of the fuel injection valve (7) is provided and can be arranged at least partially in the receiving space (9), and wherein a connecting body (20) is provided which, at least in sections, is arranged partially in at least one recess (24), which is connected to the receiving space (9), of the attachment body (8), on which connecting body the fuel connector (13) can be supported along a longitudinal axis (10) of the receiving space (9),
   wherein the connecting body (20) has an elastically deformable element (23) and in that the elastically deformable element (23) is arranged such that the connecting body (20) permits elastic support of the fuel connector (13) on the attachment body (8) at least partially along the longitudinal axis (10), characterized
   in that the connecting body (20) has a fuel-connector-side holding element (21), and in that the fuel connector (13) acts via the fuel-connector-side holding element (21) on the elastically deformable element (23) of the connecting body (20), wherein the fuel-connector-side holding element (21) and the elastically deformable element (23) are separate parts and are inserted together into a cutout (25) of the fuel connector (13).
2. Mounting according to Claim 1,
   characterized
   in that the elastically deformable element (23) is arranged such that the connecting body (20) permits elastic support of the fuel connector (13) on the attachment body (8) at least substantially along the longitudinal axis (10).
3. Mounting according to Claim 1,
   characterized
   in that the elastically deformable element (23) is connected to the fuel-connector-side holding element (21).
4. Mounting according to one of Claims 1 to 3,
   characterized
   in that the connecting body (20) has an attachment-body-side holding element (22), in that the attachment-body-side holding element (22) is, at least in sections, arranged partially in the recess (24) of the attachment body (8), and in that the elastically deformable element (23) is supported on the attachment body (8) via the attachment-body-side holding element (22).
5. Mounting according to Claim 4,
   characterized
   in that the elastically deformable element (23) is connected to the attachment-body-side holding element (22).
6. Mounting according to one of Claims 1 to 5,
   characterized
   in that the elastically deformable element (23) is in the form of a disc-shaped and/or annular-disc-shaped and/or holed element (23).
7. Mounting according to one of Claims 1 to 6,
   characterized
   in that the connecting body is in the form of a ring-shaped or partially ring-shaped connecting body (20).
8. Fuel injection system (1), in particular for mixture-compressing, auto-ignition internal combustion engines, having at least one fuel-conducting component (4), at least one fuel injection valve (7), and at least one mounting according to one of Claims 1 to 7, wherein the fuel injection valve (7) is mounted by means of the mounting (2) on the fuel-conducting component (4).

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