Fastening arrangement of a fuel distribution element on a housing element of an internal combustion engine for a motor vehicle and method for manufacturing such a fastening arrangement

Abstract

The invention relates to a fastening arrangement (10) of a fuel distribution element (12) on a housing element (14) of an internal combustion engine (16) for a motor vehicle, in which the fuel distribution element (12) is fastened to the housing element (14) by means of screws (18) which penetrate respective through-openings (18) of the fuel distribution element (12) and engage in respective screw bosses (22) of the housing element (14), the respective screw boss (22) of which has a respective first support surface (A1) on which a respective, corresponding second support surface (A2) of the fuel distribution element (12) is supported in the axial direction of the respective screw (18) engaging in the respective screw boss (22).wherein at least one of the screw bosses (22) has a rib (28) projecting beyond the first support surface (A1) of the at least one screw boss (22) in the axial direction of the screw (18) engaging in the at least one screw boss (22).

Description

[0001] The invention relates to a fastening arrangement of a fuel distribution element on a housing element of an internal combustion engine for a motor vehicle according to the preamble of claim 1. The invention further relates to a method for manufacturing such a fastening arrangement.

[0002] Such a fastening arrangement of a fuel distribution element, also referred to as a rail or fuel rail, to a housing element of an internal combustion engine, also referred to as an internal combustion engine or combustion engine, and designed, for example, as a reciprocating piston engine, i.e., a reciprocating piston machine, of a motor vehicle, in particular a motor car, is already well known from the general prior art and especially from series vehicle production. In this fastening arrangement, the fuel distribution element, which is designed separately from the housing element (e.g., the cylinder head), is fastened to the housing element by means of respective screws, i.e., bolted to the housing element, in particular in such a way that relative movement between the housing element and the fuel distribution element is prevented. The screws penetrate respective through-openings of the fuel distribution element, in particular completely.Furthermore, the screws engage corresponding screw bosses, also simply referred to as domes, on the housing element. Each screw boss of the housing element has a first support surface against which a corresponding second support surface of the fuel distribution element is supported in the axial direction of the respective screw engaging in the screw boss.

[0003] The object of the present invention is to further develop a fastening arrangement and a method of the type mentioned at the outset in such a way that the fuel distribution element can be attached to the housing element in a particularly advantageous manner.

[0004] This problem is solved by a fastening arrangement with the features of claim 1 and by a method with the features of claim 5. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0005] To further develop a fastening arrangement of the type specified in the preamble of claim 1 such that the fuel distribution element can be particularly advantageously attached to the housing element, the invention provides that at least one of the screw bosses has a rib, wherein the at least one screw boss is also referred to as the first screw boss. The rib of the first screw boss projects beyond the first support surface of the first screw boss in the axial direction of the screw engaging in the first screw boss towards the fuel distribution element. The screw engaging in the first screw boss, and thus in the at least one screw boss, is also referred to as the first screw. The rib has a third support surface which faces the first screw in the radial direction of the first screw, the axial direction of which coincides with a screw axis.The radial direction of the first screw is perpendicular to the axial direction of the first screw and thus perpendicular to the first screw axis. The first screw is rotated relative to the first screw boss in order to screw the first screw, in particular directly, into the first screw boss and thus, in particular directly, bolt it to the housing element, thereby clamping the fuel distribution element against the housing element and securing it to the housing element, thus bolting it to the housing element.In other words, in a method for manufacturing the fastening arrangement, the first screw is rotated about its axis relative to the housing element, the fuel distribution element, and the first screw boss, thereby screwing the first screw, particularly directly, into the first screw boss and thus, particularly directly, bolting it to the housing element. This clamps the fuel distribution element against the housing element, thus securing it to and bolting it to the housing element. The radial direction of the first screw is perpendicular to its axial direction and to the screw axis.

[0006] At the third support surface, a corresponding fourth support surface of a wall area of ​​the fuel distribution element, facing away from the first screw in the radial direction of the first screw and facing the third support surface in the radial direction of the first screw, can be directly supported or supported in the radial direction of the first screw, wherein the wall area of ​​the fuel distribution element has the through-opening penetrated by the first screw engaging in the first screw boss and is thereby penetrated by the first screw engaging in the first screw boss.

[0007] In particular, it is provided that the first screw boss and the rib are formed as a single unit, that is, from a single piece. In other words, it is preferably provided that the rib and the first screw boss are not formed and connected separately, but rather that the rib and the first screw boss are preferably formed from a single piece and thus constituted by a single-piece, integrally manufactured, and monoblock body. For example, the first screw boss and the rib are manufactured by casting, i.e., by a casting process by which, for example, the housing element is manufactured.

[0008] The invention makes it possible to design the fuel distribution element, also referred to as a fuel rail or simply rail, without guide pins for positioning the fuel distribution element relative to the housing element and for supporting the fuel distribution element against the housing element, thus enabling a space-saving, lightweight, and cost-effective design of the fuel distribution element. Simultaneously, the invention allows the fuel distribution element to be supported during assembly when it is mounted to the housing element to which it is attached. For example, the assembly is carried out using the following method.The support or supportability of the fuel distribution element on the housing element is particularly advantageous when the fuel distribution element is mounted on the housing element in an inclined position, also referred to as a mounting position, of the internal combustion engine, for example, a V8 engine. Inclined mounting positions are conceivable for inline 4-cylinder or inline 6-cylinder engines. An inclined mounting position describes a position of the internal combustion engine relative to a horizontal plane, whereby the internal combustion engine, in particular the cylinders and thus a cylinder head of the internal combustion engine, are inclined from a vertical plane to a horizontal plane.If no appropriate countermeasures are taken, the inclined mounting position of the internal combustion engine can cause the fuel distribution element to shift under its own weight on the screw bosses of the housing element, particularly during automatic or synchronous tightening of the screws. This shift can occur on a downward slope relative to the horizontal of the housing element, for example, towards the intake side of the internal combustion engine. This can lead to leaks, such as leaking valve stem seals. The downward slope is the side of the internal combustion engine that forms a smaller angle than the perpendicular to the horizontal.In the aforementioned screw connection, the screws are screwed into the screw bosses, meaning they are screwed into the screw bosses and thus bolted to the housing element. This ensures that the screws are directly bolted to the housing element, thereby securing the fuel distribution element to it. Specifically, this is a synchronous screw connection. This means that, with synchronous screw connections, the screws are simultaneously screwed into the screw bosses (also simply called bosses) and thus simultaneously bolted to the housing element.For this purpose, for example a multi-screwdriver is used, by means of which the, in particular all, screws are turned simultaneously relative to the fuel distribution element and relative to the housing element, while the screws penetrate the through-holes and engage in the screw bosses, whereby the screws are simultaneously screwed to the screw bosses and thus to the housing element, in particular directly, in order to attach the fuel distribution element to the housing element.

[0009] The aforementioned displacement, particularly towards the downward slope, and the resulting leaks could, in principle, be avoided by additional leading guide and / or holding units to position the fuel distribution element in a central position, thus enabling the screws to be tightened simultaneously, especially via automatic synchronous tightening. However, such guide and / or holding units would entail additional effort and therefore increased costs. Furthermore, a complex programming and adjustment program would have to be developed to account for the different tolerances of the fuel distribution element, which might be a forged part, and the housing element, which might be a cast part, particularly a die-cast part. For example, the housing element could be designed as a cylinder head.

[0010] The aforementioned problems and disadvantages can now be avoided. The rib is an integrated component within the housing element, and thus a component-integrated device. This device, particularly considering the inclined mounting position, absorbs mounting forces because the fuel distribution element can be directly supported or braced against the fourth support surface, i.e., the rib, during its installation. This prevents undesired displacement of the fuel distribution element, especially towards a sloping side relative to the horizontal of the internal combustion engine housing element, thereby avoiding the aforementioned leaks. The invention thus enables the fuel distribution element to be mounted to the housing element in a time- and cost-effective manner.In particular, the invention eliminates the need for additional guide and / or holding units as well as additional programming and adjustment programs, thus enabling the assembly of the internal combustion engine, also known as engine assembly, to be carried out in a time- and cost-effective manner. Specifically, the fuel distribution element can be mounted to the housing element even when the internal combustion engine is in an inclined position. The invention enables a reliable and, for example, simultaneous and / or automatic tightening of the screws, thus forming a synchronous tightening process, particularly using a multi-screwdriver, without leaks such as leaking shaft seals.

[0011] The invention also includes a method for manufacturing a fastening arrangement according to the invention. Advantages and advantageous embodiments of the fastening arrangement according to the invention are to be regarded as advantages and advantageous embodiments of the method according to the invention, and vice versa.

[0012] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0013] The drawing shows in: Fig. 1. Partially a schematic sectional view of a fastening arrangement of a fuel distribution element on a housing element of an internal combustion engine of a motor vehicle; Fig. 2. A schematic perspective view of the fastening arrangement in part; Fig. 3. A further schematic perspective view of the fastening arrangement (in part); and Fig. 4. A schematic side view of the fastening arrangement is shown in part.

[0014] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0015] Fig. Figure 1 shows a partial schematic sectional view of a mounting arrangement 10 of a fuel distribution element 12, also referred to as a rail or fuel rail, on a housing element 14, in this case designed as, for example, a cylinder head, of an internal combustion engine 16 of a motor vehicle, also referred to simply as a vehicle. The internal combustion engine has several combustion chambers. Each combustion chamber has a corresponding injector by means of which a fuel, in particular liquid, can be introduced, in particular directly, into the respective combustion chamber, to which the respective injector is assigned. The fuel distribution element 12 is a common fuel distribution element for all injectors, in which the fuel can be received, in particular at a pressure also referred to as fuel pressure.The injectors can be supplied with pressurized fuel from the fuel distribution element 12.

[0016] In the fastening arrangement 10, the fuel distribution element 12, which is formed separately from the housing element 14, is fastened to the housing element 14 by means of several screws. Of these screws, one screw, designated 18, is shown in the figures, and screw 18 is also referred to as the first screw. The preceding and following descriptions of screw 18 can readily be applied to the other screws and vice versa. Screw 18 penetrates a corresponding through-opening 20 of the fuel distribution element 12 and engages in a corresponding screw boss 22 of the housing element 14, also referred to simply as a boss. Screw 18 has a first thread 24, which is designed as an external thread. A second thread 26, which is designed as an internal thread, is arranged in the screw boss 22.The thread 24 is screwed, in particular directly, into the thread 26, whereby the screw 18 is screwed, in particular directly, to the screw boss 22 and thus to the housing element 14. This clamps the fuel distribution element 12 against the housing element 14 and thus secures it to the housing element 14.

[0017] Looks especially good Fig. 1 and Fig. Figure 3 shows that the screw boss 22 has a first support surface A1, against which a corresponding second support surface A2 of the fuel distribution element 12 is supported in the axial direction of the screw 18 engaging and screwed into the screw boss 22, in particular directly. The axial direction of the screw 18, whose radial direction is perpendicular to the axial direction of the screw 18, coincides with an imaginary screw axis, not shown in the figures, also referred to as the screw axis. In a method for manufacturing the fastening arrangement 10, the screw 18 is rotated about the screw axis relative to the housing element 14 and relative to the fuel distribution element 12, while the screw 18 penetrates the through-opening 20 and engages in the screw boss 22, thereby screwing the threads 24 and 26 together and thus screwing the screw 18 into the screw boss 22.

[0018] In order to be able to attach the fuel distribution element 12 to the housing element 14 in a particularly advantageous, and especially time- and cost-effective, manner during the assembly of the fuel distribution element 12 to the housing element 14 in the process, the screw boss 22 has a rib 28 that projects beyond the support surface A1 of the screw boss 22 in the axial direction of the screw 18 towards the fuel distribution element 12, which is particularly well suited to Fig. 2 is recognizable.

[0019] Looks especially good Fig. 3 It can be seen that the rib 28 has a third support surface A3 facing radially towards the screw 18, on which a corresponding fourth support surface A4, facing away from the screw 18 in the radial direction and towards the third support surface A3, is attached. Fig.4) a wall region WB of the fuel distribution element 12 is directly supported or can be supported in the radial direction of the screw 18. The wall region WB has the through-opening 20 and is thus penetrated by the through-opening 20 and by the screw. It can be seen that the support surface A4 is at least partially overlapped by the support surface A3 in the radial direction of the screw 18 to the outside, without any component being arranged between the support surfaces A3 and A4 in the radial direction of the screw 18. As a result, the support surface A4 can be directly supported or is supported in the radial direction of the screw 18 to the outside by the support surface A3 and thus by the housing element 14.This prevents, for example, undesirable displacements of the fuel distribution element 12, particularly towards a sloping side of the internal combustion engine 16, during the aforementioned mounting of the fuel distribution element 12 on the housing element 14, without the need for additional holding and / or securing devices. It is evident that the support surfaces A3 and A4 are stop surfaces or function as stop surfaces, by means of which the fuel distribution element 12 can be directly supported or supported on the housing element 14 in the radial direction of the screw outwards.

[0020] For example, the support surface A4 of the fuel distribution element 12 is a flattened area or has a flattened area. Alternatively or additionally, the support surface A4 has a chamfer or is designed as a chamfer. For example, the support surface A4 extends in a plane that is, for instance, inclined to the axial direction of the screw 18. The support surface A3 extends, for example, parallel to the support surface A4 and / or in a plane that is parallel or inclined to the axial direction of the screw 18. Reference symbol list 10 Mounting arrangement 12 Fuel distribution element 14 Housing element 16 Internal combustion engine 18 screw 20 Passage opening 22 screw dome 24 first thread 26 second thread 28th rib A1 first support surface A2 second support surface A3 third support surface A4 fourth support surface WB wall area

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