CN103502623B - Fuel distributor and system with fuel injection valve - Google Patents

Abstract

A fuel distributor (2), in particular for a fuel injection system of a mixture-compressing, spark-ignition internal combustion engine, comprises a distributor body (10) and a support element (4), a fuel chamber (14) being formed in the distributor body (10). At least one cup (12) is provided on the distributor body (10), on which the support structure (4) is arranged. The support element (4) forms a support surface (17) at least partially on one end (18) of the cup-shaped part (12). In this way, the dispenser body (10) and the cup (12) can be formed of plastic, while the preferably metallic support element (4) forms a support surface (17) for the compression spring (5). The invention further relates to a system (1) having a fuel injection valve (3), a compression spring (5) and a support element (4).

Description

Fuel distributor and system with fuel injection valve

technical field

The invention relates to a fuel distributor, in particular for a fuel injection system of a hybrid compression external ignition internal combustion engine. The invention relates in particular to the field of fuel injection systems designed as medium-pressure systems.

Background technique

In the case of fuel injection systems suitable for automobiles, it is conceivable to use a fuel distributor plate made of steel or aluminium, suitable for high pressure applications. Thereby, a compressive strength of, for example, a pressure of 20 MPa (200 bar) is achieved. A fuel distributor plate suitable for low pressure applications is also available at 0.5MPa (5bar). The range of application of such fuel distributor pressure plates suitable for low-pressure applications is of course limited to this low-pressure range.

For mounting the fuel injection valve, it is conceivable to use a compression spring which is seated between the fuel distributor pressure plate and the fuel injection valve. Here, the fuel injection valve is pressed into the cylinder head of the internal combustion engine, for example, with a holding force of 500 N. As a result, the fuel injection valve is reliably positioned on the cylinder head, wherein the combustion chamber pressure passing through the combustion chamber also displaces the fuel injection valve from the desired position via vibration acceleration. In order to be able to support the compression spring on the fuel distributor pressure plate with a desired prestressing force of, for example, 500 N, the fuel distributor pressure plate needs to be molded in metal.

Contents of the invention

The fuel distributor according to the invention and the system according to the invention have the advantage that the use of compression springs or the like reduces the need for at least one material from which the fuel distributor is constructed. In particular, low-cost but limited applied surface stress materials can be used.

Advantageously, said dispenser body and cup are made of plastic. It is also advantageous here that the dispenser body comprises the cup, so that the cup is an integral component of the dispenser body. For example, the dispenser body of the particular plurality of cups may be embodied as a die-cast part. Inexpensive production is possible through the use of designs made of plastic. Of course, the problem with using plastics is that plastics undergo plastic rheology at high surface stresses and the required tolerances can no longer be maintained. In order to avoid this, a support surface is formed by a support element arranged on the cup, which can support a compression spring or the like. The surface stresses acting on the plastic are thus considerably reduced, so that plastic rheology of the plastic is avoided and the required tolerances can be maintained.

Advantageously, the support element is designed as a ring-shaped or partially ring-shaped support element, wherein the support element is connected to the end of the cup. In particular, the annular configuration of the support element enables an even distribution of the force of the compression spring onto the end of the cup and at the same time a good connection of the support element to the end of the cup.

Advantageously, the support element is connected to the end of the cup with a form fit. The positive fit can here be produced by ramps, steps, by dovetail joints or the like. Additionally or alternatively, the support element is also connected to the end of the cup by being sprayed at least partially into the end of the cup. The form-fit can here be produced during spraying.

It is also advantageous if the support element has at least one arm, with which the support element is held on the end of the cup. Preferably, two or more arms are provided here, which securely fix the support element on the end of the cup by, for example, exerting a force relative to each other by the arms. Retention of action.

It is advantageous here if the straight arms are each pressed against the outside of the cup with a prestressing force. The legs can here be arc-shaped and possibly engage in recesses on the outside of the cup.

It is also advantageous if the legs each have a barb, wherein each barb engages from behind a step arranged on the outside of the cup. As a result, a snap-in connection can be formed which enables a simple assembly of the support element on the cup and, in particular, also ensures transport safety.

Advantageously also, the support element also has at least one tongue that fits at least partially in a recess provided on the outside of the cup. For example, the support element can first be placed on the cup, and then the tongue is pressed into a recess provided on the cup. It is also possible that the support element has at least one tongue which is placed elastically inwards, is acutely angled and grips in the outside of the cup. Thus, a certain form-fit is obtained. As a result, transport safety can likewise be achieved.

It is also advantageous to provide a compression spring which is connected to the support element. For example, the support element can be pressed onto the compression spring.

Description of drawings

Preferred embodiments of the invention are explained in detail in the following description with reference to the accompanying drawings, in which identical elements are provided with the same reference numerals. Shown in the accompanying drawings:

FIG. 1 schematically shows a system with fuel distributors and fuel injection valves corresponding to a first embodiment of the invention;

Figure 2 schematically shows a support element corresponding to a system according to a second embodiment of the invention;

Fig. 3 shows the support element shown in Fig. 2 corresponding to a possible configuration of the present invention with a schematic cross-sectional view taken along the section line marked with III;

FIG. 4 shows the support element shown in FIG. 2 corresponding to another possible configuration of the present invention in a schematic cross-sectional view taken along the section line marked with III;

Fig. 5 shows the supporting element corresponding to the third configuration of the present invention in a schematic cross-sectional view;

Fig. 6 shows a schematic cross-sectional view of the fuel distributor shown in Fig. 1 corresponding to a fourth embodiment of the present invention; and

FIG. 7 shows a schematic cross-sectional view of the fuel distributor shown schematically in FIG. 6 corresponding to a fifth embodiment of the invention.

detailed description

FIG. 1 shows a system 1 with a fuel distributor 2 , a fuel injection valve 3 and a support element 4 . The system 1 here includes a compression spring 5 . The fuel distributor 2 is not an essential component of the system 1 . In particular, the system 1 can comprise the fuel injection valve 3 , the support element 4 and the compression spring 5 , but not the fuel distributor 2 , and can be manufactured and driven in this way as the system 1 . On the other hand, the fuel distributor 2 can also comprise the support element and optionally also the compression spring 5 and be produced and driven on this circumference. The system 1 can also be designed as a fuel injection system 1 comprising the fuel distributor 2 , the fuel injection valve 3 , the support element 4 , the compression spring 5 and possibly further components.

The fuel distributor 2 and the system 1 are especially suitable for fuel injection systems operating at medium pressure. Here, the fuel is preferably fed into the fuel distributor 2 in the range of 3 MPa to 10 MPa or 30 bar to 100 bar. In particular, the medium pressure may be in the range of 5 MPa to 7 MPa, or in other words, 50 bar to 70 bar. The fuel distributor 2 according to the invention and the system 1 according to the invention are of course also suitable for other applications.

The fuel distributor 2 of the first exemplary embodiment has a distributor body 10 comprising a distributor tube 11 and a plurality of cups 12 arranged side by side on the distributor tube 11 . The cup 12 is only shown here in FIG. 1 . Medium-pressure fuel can be conducted via a connection 13 into a fuel chamber 14 arranged in the distributor pipe 11 , wherein the connection 13 can correspondingly form a high-pressure connection. Fuel is conducted from the fuel chamber 14 via channels to the fuel injector 3 which is fixed in the cup 12 . In this case, inlet-side end 15 of fuel injector 3 engages at least partially in cup 12 . During operation, the fuel is injected into the combustion chamber of the internal combustion engine at the combustion chamber-side end 16 of the fuel injector 3 via one or more nozzle openings.

In the assembled state, the fuel distributor 2 is present at a fixed distance from a fixed position relative to the internal combustion engine (not shown). The fuel injector 3 is fastened here between the cup 12 of the fuel distributor 2 and the cylinder bore of the internal combustion engine. The compression spring 5 is prestressed in the assembled state, so that the prestress acts on the fuel injector 3 and holds the injector 3 against the cylinder head. For example, fuel injector 3 can be pressed into the cylinder head with a prestress of approximately 500N.

The distributor body 10 and the cup 12 of the fuel distributor 2 are made of plastic. The cup 12 is here an integral component of the dispenser body 10 . For example, in particular the dispenser body 10 of the cup 12 can be embodied as a die-cast part. The support element 4 is arranged on the cup 12 . Here, the support element 4 forms a support surface 17 on the end 18 of the cup 12 .

In the case of the fuel distributor 2 of the first embodiment, the support element 4 is designed as an annular or partially annular support element 4 and is connected to the end 18 of the cup 12 . The support element 4 is thus a component of the fuel distributor 2 of the first embodiment.

In the system 1 of the first exemplary embodiment, the base body 20 is arranged on the inlet-side end 15 of the fuel injector 3 , which receives the compression spring 15 . Here, the base body 20 can be placed by the inlet-side end 15 onto the remaining fuel injector 3 . Base body 20 is here releasably or non-releasably connected to the remaining components of fuel injector 3 .

The compression spring 5 has an arcuate section 21 which, in this exemplary embodiment, serves as an arcuate contact section 21 . Here, contact is formed between the arc segment 21 and the support surface 17 of the support element 4 . During assembly, the arcuate contact section 21 is moved here relative to the support surface 17 in order to enable a preloading of the compression spring 5 .

In the assembled state, the compression spring 5 exerts a compression force on the fuel injector 3 , causing a considerable counterforce on the support element 4 . The support element 4 distributes this force evenly over the end 18 of the cup 12 . This prevents the surface stress on the end 18 of the cup 12 from exceeding the permissible range, thus preventing plastic flow of the plastic and ensuring that the required tolerances are maintained. Creeping of the plastic in the region of the contact points is thus prevented.

As a result, the prestressing force of the compression spring 5 can be distributed over a large surface and the surface stresses can be drastically reduced. Plastic rheology of the plastic is thus prevented and the cup 12 retains the predetermined shape and the predetermined tolerances, especially at its end 18 .

In other configurations of the fuel distributor 2 the compression spring 5 can be connected to the support element 4 . For example, the annular disk-shaped support element 4 is pressed directly against the compression spring 5 . Before assembly, the annular disk-shaped support element 4 is placed on the base body 20 by means of a compression spring 5 . In particular, the support element 4 can be fixed here on the fuel injector 3 and, when mounted on the fuel distributor 2 , come into position on the end 18 of the cup 12 . The freedom of movement required for the prestressing of the compression spring 5 can be achieved here by a suitable configuration of the support element 4 and/or of the base body 20 .

In another possible configuration, the support element 4 is connected to the compression spring 5 and is simultaneously fastened to the fuel distributor 2 . In this case, the compression spring 5 is prestressed against the fuel injector 3 during assembly.

FIG. 2 shows a schematic diagram of the support element 4 of the system 1 or of the fuel distributor 2 corresponding to a second embodiment of the invention. The support element 4 here comprises a support ring 23 and a plurality of arms 23 , 24 , 25 , 26 . Via the arms 23 to 26 the support element 4 can be fastened to the outer side 27 ( FIG. 1 ) of the cup 12 .

Possible configurations of the support arms 23 to 26 are explained in detail with reference to FIGS. 3 and 4 .

FIG. 3 shows the support element 4 shown in FIG. 2 according to a possible embodiment of the invention in a schematic cross-sectional view along the section line indicated by III. Shown here are arcuate sections 28 , 29 , 30 of arms 23 , 24 , 26 which are bent inwardly towards outer side 27 of cup 12 . When the support element 4 is mounted on the cup 12 , the arcuate sections 28 , 29 , 30 of the arms 23 , 24 , 26 are prestressed radially outward. Correspondingly, a support arm 25 is also arranged, which likewise has an arcuate section, which is prestressed. In the assembled state, the support element 4 is thus held on the end 18 of the cup 12 . If necessary, recesses, ribs etc. are provided on the outer side 27 of the cup 12 to improve the fixation.

FIG. 4 shows a schematic cross-sectional view of the support element 4 shown in FIG. 2 according to a further possible embodiment of the invention in a schematic cross-sectional view along the section line indicated by III. In the exemplary embodiment here, barbs 31 , 32 , 33 are provided at the ends of the arms 23 to 26 , which engage from behind the step provided on the outer side 27 of the cup 12 . During assembly, the arms 23 to 26 are spread slightly until the barbs 31 , 32 , 33 and the barbs provided on the arm 25 hook behind the provided step. Thus, the support element 4 is fixed on the fuel distributor 2 .

FIG. 5 shows, in a schematic cross-sectional view, the support element 4 and the cup 12 of the fuel distributor 2 corresponding to a third embodiment of the invention. In this embodiment, the support element 4 has a support ring 22 on which the support surface 17 is formed. A plurality of tongues 40 , 41 are also provided on the support element 4 , each tongue 40 , 41 engaging a step 42 , 43 arranged on the outer side 27 of the cup 12 from behind. The steps 42 , 43 are formed in this exemplary embodiment by recesses 44 , 45 provided on the outside 27 of the cup 12 . For example, during assembly, the support element 4 is first placed onto the end 18 of the cup 12 . The tongues 40 , 41 are then pressed radially inwards into the recesses 44 , 45 , so that the steps 42 , 43 are backed up. The tongues 40 , 41 engage in recesses 44 , 45 provided on the outer side 27 of the cup 12 .

In a corresponding manner, in the configuration according to FIG. 4 , the barbs 32 , 33 of the arms 24 , 26 can engage from behind the steps 42 , 43 provided on the outside of the cup 12 to secure them.

The support element 4 can thus be held securely on the cup 12 of the dispenser body 10 by means of a positive fit. The positive fit can be achieved, for example, by tongues 40 , 41 or by barbs 31 , 32 , 33 .

However, it is also possible to fix the support element 4 on the cup 12 of the dispenser body 10 without a positive fit by corresponding prestressing, as described with reference to FIG. 3 .

The tongues 40 , 41 of the support element 4 can be formed, for example, by perforations 40 , 41 . Of course, the use of other jaws or the like is also conceivable.

FIG. 6 shows a schematic cross-sectional view of the fuel distributor 2 shown in FIG. 1 corresponding to a fourth embodiment of the invention. In this embodiment, the support element 4 is designed as an annular or partially annular support element 4 . A bearing surface 17 for the compression spring 5 is provided on the supporting element 4 . The cup 12 has a shoulder 50 at its end 18, with radially outwardly directed projections 51, 52 in the cutout. The shoulder 50 forms a positive fit here with a correspondingly shaped support element 4 . Additionally, the support element 4 can be sprayed into the end 18 of the cup 12 . For example, the shoulder 50 can be molded by an injection method, wherein the support element 4 is positioned on the end 18 during injection.

FIG. 7 shows a schematic cross-sectional view of the fuel distributor 2 shown in FIG. 6 corresponding to a fifth embodiment of the present invention. In this embodiment, the annular or partially annular support element 4 has an at least approximately right-angled cross-section. Here, the support element 4 engages into a right-angled receptacle 53 on the end 18 of the cup 12 . The shoulder 50 engages here from the inside into the support element 4 . The fastening between the support element 4 and the cup 12 takes place here, for example, by spraying the support element 4 into the end 18 of the cup 12 . In this embodiment, the connection is realized without a positive fit.

The formation of sharp edges is prevented by the sinking of the annular or partially annular support element 4 into the end 18 of the cup 12 . A sealing ring, possibly arranged at inlet-side end 15 of fuel injector 3 and introduced into cup 12 , can thus not be damaged. The shoulder 50 formed here from the plastic material of the cup 12 provides a guide area through which the sealing ring is introduced into the cup 12 .

The support element 4 is preferably formed from a metallic material. In this way, substantial deformations can also be avoided at high surface stresses compared to typical plastics.

Thus, in particular, the metal support element 4 can be fixed on the dispenser body 10 formed from plastic.

The invention is not limited to the described embodiments.

Claims (7)

1. A fuel distributor (2) having a distributor body (10) and at least one support element (4), in which a fuel chamber (14) is formed, wherein at least one cup (12 ) is arranged on the dispenser body (10), the support element (4) is arranged on the cup, and wherein the support element (4) is at least partially at the end of the cup (12) A support surface (17) is formed on the portion (18), It is characterized in that, The support element (4) has a planar support ring (22), which bears against the end (18) of the cup (12), wherein a plurality of supports protrude from the support ring (22). arms (23, 24, 25, 26) provided with flexurally elastic arcuate segments (28, 29, 30) and bent inwardly towards the circumferential outer side (27) of the cup (12), Fixing of the support element ( 4 ) on the circumferential outer side ( 27 ) of the cup ( 12 ) is thereby enabled via the legs ( 23 , 24 , 25 , 26 ). 2. Fuel distributor according to claim 1, characterized in that the distributor body (10) and the cup (12) are made of plastic and that the support element (4) is formed of metallic material . 3. The fuel dispenser according to claim 1, characterized in that the support element (4) is connected with the end of the cup (12) with a form fit and/or the support element ( 4) Attaching to the end (18) of the cup (12) by spraying at least partially onto the end (18) of the cup (12). 4. The fuel distributor according to claim 1, characterized in that the support arms (23-26) are pressed onto the circumferential outer side (27) of the cup (12) with prestressing. 5. Fuel distributor according to claim 4, characterized in that the support arm (23-26) has a barb (31-33) which acts from behind on the Steps (42, 43) on the circumferential outer side (27) of the cup (12). 6 . The fuel distributor as claimed in claim 1 , characterized in that a compression spring ( 5 ) is provided, which is connected to the support element ( 4 ). 7. The fuel distributor according to claim 1, characterized in that said fuel distributor is suitable for a fuel injection system of a hybrid compression external ignition internal combustion engine.