Fuel rail with a clamping system

Abstract

Fuel rail (100) for a fuel injection system with a tubular body (10) formed by a single-stage or multi-stage forging process and having excess material (14), characterized in that the tubular body (10) comprises at least one clamping formation (15) formed by partially removing the excess material (14) in the extension of the tubular body (10) on a lateral axis (Z).

Description

Technical field of the invention

[0001] The present invention relates to a fuel rail with a tensioning system according to the preamble of claim 1. Background of the invention

[0002] A fuel charge assembly (FCA) includes a high-pressure pump, a common fuel rail, and a number of fuel injectors connected to a common fuel rail. The common fuel rail is a fuel rail that distributes the required amount of fuel (gasoline, diesel, or any other fluid) to the fuel injectors at specified pressures.

[0003] The injection system may, in particular, be designed as a fuel injection system used for injecting a fuel or a mixture with at least one fuel. Furthermore, an injection system may be used not only for liquid fluids but may, if appropriate, also allow the injection of gaseous fluids, in particular combustible gases.

[0004] A preferred solution for the production of a fuel rail is a forging process. An elongated and cylindrical tube is obtained through a forging process.

[0005] One prior art document is disclosed in patent application number US2017159627A1. In this application, a forged fuel rail for a motor vehicle comprises a tubular base body, an inlet integrally formed with the base body and made of the same material as the base body. Furthermore, a plurality of injector mounts and a support member for securing the fuel rail to another motor vehicle component are integrally formed with the base body and made of the same material as the base body. A reinforcing member extends between a corresponding one of the injector mounts and the support member and is integrally formed with the base body and made of the same material as the base body. The reinforcing member is formed from a flash produced during a forging process.

[0006] Another prior art document is disclosed in patent application number JPS63179175A. In this application, one or more fuel inlet chips, one or more fuel injector inlets, and common rail fixing members are fixedly connected to the main pipe. The manufacturing process of the present invention includes the following steps: The aluminum alloy ingot is heated to 440°C to 450°C and, while maintaining this heated state, is placed into the die composed of the two forming tools "6a" and "6b." The ingot is subjected to hot die forging. A second cold working process (finishing) of the tertiary shape and threading at the outer end of the common rail forms the common rail inlet chip, the fuel injector inlet, and the common rail fixing member. Thus, the fixing member is manufactured during the forging process of the fuel rail.It can be formed during the manufacturing of the body tube. As a modification, the functional part serving as the manifold fixing member can be left intact. Brief description of the invention

[0007] One object of the present invention is to find a solution to the lack of clamping surfaces for securing fuel rails during machining processes. Another object of the present invention is also to achieve a stable and reliable position for certain processes, such as machining and transport for the fuel rail.

[0008] The present invention proposes a fuel rail for a fuel injection system comprising a tubular body formed by a single-stage or multi-stage forging process and having excess material. According to the present invention, the tubular body comprises at least one clamping formation formed by partially removing the excess material in the extension of the tubular body along a lateral axis Z. Thus, a stable and reliable position for certain processes, such as machining and transport for the fuel rail, is achieved in a balanced manner.

[0009] In one possible embodiment of the present invention, the clamping formation has a planar and rectangular shape for fixing and clamping the fuel rail blank to a workbench. Thus, the clamping formation conforms to and matches some of the fastening or clamping means on the benches.

[0010] In one possible embodiment of the present invention, the clamping formation is integral with the tubular body. Therefore, additional clamping devices do not need to be removed from or attached to the tubular body.

[0011] In one possible embodiment of the present invention, the clamping formation is configured to begin at the tubular body and extend along a lateral axis of the fuel rail. Thus, a balanced clamping formation for the tubular body is provided.

[0012] In one possible embodiment of the present invention, the clamping formation has a length "l2" that is shorter than a length "l1" of the pipe body. This provides stable and reliable support for the pipe body during a machining process or transport process of the fuel rail.

[0013] In one possible embodiment of the present invention, a length of the clamping formation along the lateral axis Z is greater than or equal to a diameter of the tubular body. Thus, a balanced clamping formation for the tubular body is provided. As a result, the clamping formation extending from the tubular body has dimensions that support the tubular body.

[0014] In one possible embodiment of the present invention, at least one clamping formation located in the first region of the fuel rail is arranged and configured to correspond to at least one clamping formation located in the second region of the fuel rail. Thus, a balanced clamping system for the fuel rail is provided.

[0015] In one possible embodiment of the present invention, at least two clamping formations are formed near two distal ends of the tubular body and extend into the second region of the fuel rail, and at least two further clamping formations are formed near a center of gravity of the tubular body and extend into the first region of the fuel rail. Thus, a balanced clamping system is provided for the fuel rail. This achieves a stable and reliable position for some processes, such as machining and transportation for the fuel rail, in a balanced manner.

[0016] In one possible embodiment of the present invention, the fuel rail is designed with a clamping system comprising corresponding support means, ie, fixing means or clamping means, on a workbench for the fuel rail, which correspond to the at least one clamping formation. Thus, a balanced clamping system for the fuel rail is provided.

[0017] A fuel rail for a fuel injection system is provided, comprising a tubular body with at least one clamping formation according to the above-mentioned embodiments, wherein the clamping formation is used as a semi-finished or finished product during machining or transport of the fuel rail and is severed after use in the aforementioned machining process or transport process.

[0018] Therefore, the workholdings are left on the fuel rail for some operations, such as machining and transportation. There are no additional material costs for the workholdings, as the workholdings are created from scrap materials, which are excess material left over from the forging process. Short description of the characters

[0019] The accompanying drawings are provided solely for the purpose of illustrating the invention, the advantages of which over the prior art have been mentioned above and are explained in more detail below: Fig. Figure 1 shows a fuel rail with clamping formations before some machining processes from a perspective front view according to the present invention. Fig. Figure 2 shows a fuel rail before some machining processes from a perspective front view according to the prior art. Fig. Figure 3 shows a fuel rail after forging with excess material around a parting line from a top perspective view according to the present invention. Fig. 4 shows a first pressing tool for the forging process of the fuel rail from a perspective front view. Fig. 5 shows a second pressing tool for the fuel rail forging process from a perspective front view. Detailed description of the characters

[0020] The present invention relates to a fuel rail (100) with a clamping system having a number of clamping formations (15) for fixing the fuel rail (100) for machining processes. One object of the present invention is therefore to achieve a stable and reliable position for certain processes, such as machining and transport of the fuel rail (100). The clamping system comprises corresponding support means for the clamping formations (15). The corresponding support means can, for example, have fixing means or clamping means on a workbench for the fuel rail (100).

[0021] Specifically, the present invention relates to the field of fuel injection systems, which are preferably used for mixture-compressing, spark-ignition internal combustion engines, wherein the fuel distribution line (100) is located, for example, in an engine compartment of a motor vehicle and is used for the direct injection of fuel into combustion chambers of the internal combustion engine.

[0022] The fuel rail (100), in other words a fuel distribution line, for a fuel injection system is mainly produced by a forging process through two dies to form a tubular body (10). A metal material is arranged in a die having a first pressing tool (21) and a second pressing tool (22) arranged in Fig. 4 and Fig. 5 are shown as examples. Fig. Figure 3 shows a fuel rail (100) after forging with excess material (14) around a parting line (13) from a top view according to the present invention. Forging not only creates a tube body (10), but also a remaining flash, which is excess material (14) on the tube body (10). Strictly speaking, Fig. 3 thus not yet the final product, but instead the material that is machined and shaped by forging to form the tube body (10), and excess material (14). A first part (11) and a second part (12) of the fuel rail (100) are formed during forging by the first pressing tool (21) and the second pressing tool (22), respectively, and together have a uniform cylindrical tube body shape. A parting line (13) shows a line on the tube body (10) at which the excess material (14) from the tube body (10) begins and extends along a lateral axis (Z) of the fuel rail (100) ( Fig. 1, Fig. 3).

[0023] For forging, the desired shape of the fuel rail (100) can be complexly specified. In this exemplary embodiment, the tubular body (10) has a tubular portion that is also provided with a longitudinal bore along a longitudinal axis (X) to form an interior for fuel. This longitudinal bore is provided after machining the tubular body (10). In addition, the tubular body (10) has eccentric formations (16), which can be designed as fasteners, injector receptacles, etc., and which are formed distal to a main axis (A) of the tubular body (10). The eccentric formations (16) extend from the tubular body (10) along a vertical axis (Y). During forging, a locally increased material requirement occurs here and there, for example when viewed along the longitudinal axis (X).Furthermore, the eccentric formations (16) are mainly formed by a forging process and then subjected to associated machining processes.

[0024] The tube body (10) is formed by a single-stage or multi-stage forging process. In principle, the forging process of the fuel rail (100) comprises three main steps: - forging of pre-material for forming a fuel distribution line (100) with structural elements, ie with eccentric formations (16), - Cutting off excess material (14) around the dividing line (13), - Machining structural elements of the fuel rail (100) into desired shapes with associated boundaries.

[0025] Fig. Figure 2 shows a fuel rail (100) prior to some machining processes from a perspective front view according to the prior art. Since the forged fuel rail (100) has irregular shapes, there are no proper clamping surfaces for fixing the fuel rail (100) for machining processes. In the prior art, during the process for manufacturing the fuel rail (100) after forging, excess material (14) around the parting line (13) is removed as process waste, as shown in Fig. 2 can be seen.

[0026] Fig. 1 and Fig. 2 show fuel distribution lines (100) as semi-finished products that are about to undergo machining processes.

[0027] The aim of the present invention is to find a solution to the lack of clamping surfaces for fixing fuel rails (100) for machining processes on a workbench. Thus, the present invention achieves a stable and reliable position for some processes, such as machining and transport of the fuel rail (100), in a balanced manner.

[0028] Fig.1 shows a fuel rail (100) with clamping formations (15) before some machining processes from a perspective front view according to the present invention. As a detailed description of the invention, the excess material (14) obtained from the forging process is cut off in such a geometry that correct clamping formations (15) are obtained on a lateral axis (Z) of the tubular body (10). The position of the clamping formations (15) can be selected taking into account the machining requirements of the fuel rail (100) as a semi-finished product. With respect to the main axis (A) of the tubular body (10), some of the clamping formations (15) are formed in a first region (1) located on one side of the tubular body (10), and some of the clamping formations (15) are formed in a second region (2) located on another side of the tubular body (10).This provides a balanced clamping system for the fuel rail (100).

[0029] In one embodiment of the present invention, a clamping system can be designed with at least one clamping formation (15) on which the tubular body (10) can be reliably held on a workbench.

[0030] In a further embodiment of the present invention, a clamping system can be designed such that it has at least two opposing clamping formations (15) which support each other in terms of number and strength of the fuel rail (100) during the machining process. To this end, at least two clamping formations (15) are formed close to two distal ends of the tubular body (10) and at least two further clamping formations (15) are formed close to a center of gravity of the tubular body (10) (which is in particular the center of the tubular body). Thus, the position of the clamping formations (15) can be selected taking machining requirements into account. These positions are established during the separation of the excess material (14) for shaping and forming the clamping formations (15).Thus, the clamping formations (15) ensure stable and reliable holding of the pipe body (10) during the machining process and also ensure a reduction in machining steps when using the present application according to the present invention.

[0031] In a further use of the present application according to the present invention during packaging of the fuel rail (100) as a semi-finished or finished product of the tubular body (10), the clamping formations (15) can be used during transport and can then be separated from the fuel rail (100).

[0032] All clamping formations (15) correspond to support devices, such as, for example, fixing means or clamping means on a workbench or on a transport unit for the fuel distribution line (100), not shown in the figures.

[0033] In the fuel rail (100) according to the present invention, the clamping protrusions (15) have a length (l2) that is shorter than a length (l1) of the tubular body. Furthermore, the length of the clamping protrusions (l2) on the lateral axis (Z) is greater than or equal to a diameter of the tubular body (R). This provides stable and reliable support for the tubular body (10) during a machining process of the fuel rail (100).

[0034] A manufacturing method of the fuel rail (100) of the present invention comprises the following main steps: - forging of pre-material for forming a fuel distribution line (100) with structural elements, ie with eccentric formations (16) by means of a first pressing tool (21) and a second pressing tool (22), - partially cutting off the excess material (14) around the parting line (13) to form at least one clamping formation (15), - Machining structural elements of the fuel rail (100) into desired shapes with associated boundaries.

[0035] Here, before the machining process of the structural elements of the fuel distribution line (100), the fuel distribution line (100) is fixed via the clamping system by the clamping formations (15) or by the at least one clamping formation (15).

[0036] Thereafter, after completion of the machining process of the structural elements of the fuel distribution line (100), the clamping formation(s) (15) is / are also separated from the tubular body (10) of the fuel distribution line (100).

[0037] Therefore, the clamping formation(s) (15) are left on the fuel rail (100) for the operation or use of the fuel rail (100). There are no additional material costs for the clamping formation(s) (15) because the clamping formation(s) (15) are created from waste materials, which are excess material (14) remaining from the forging process.

[0038] Furthermore, the clamping formation (15) is unified with the tubular body (10). Therefore, no clamping devices need to be removed from or attached to the tubular body (10). List of reference symbols 100 fuel rail 10 pipe bodies 11 first part 12 second part 13 dividing line 14 excess material 15 Clamping formation 16 eccentric shapes 21 first pressing tool 22 second pressing tool R Diameter of the pipe body X Longitudinal axis Y vertical axis Z Lateral Axis A main axis 1 first area 2 second area 11 Length of the pipe body 12 Length of the clamping formation QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2017159627A1

[0005] JPS63179175A

[0006]

Claims

[1] Fuel rail (100) for a fuel injection system comprising a tubular body (10) formed by a single-stage or multi-stage forging process and having excess material (14), characterized by that the tubular body (10) comprises at least one clamping formation (15) which is formed by partially removing the excess material (14) in the extension of the tubular body (10) on a lateral axis (Z). [2] Fuel distribution line (100) according to claim 1, wherein the clamping formation (15) has a planar and rectangular shape for fixing and clamping the fuel distribution line (100) as a semi-finished product to a workbench. [3] Fuel distribution line (100) according to claim 1 or 2, wherein the clamping formation (15) is unitary with the tubular body (10). [4] Fuel distribution line (100) according to one of the preceding claims, wherein the clamping formation (15) is designed such that it begins at a parting line (13) of the tubular body (10) and extends on a lateral axis (Z) of the fuel distribution line (100). [5] Fuel distribution line (100) according to one of the preceding claims, wherein the clamping formation (15) has a length (l2) which is shorter than a length (l1) of the tubular body. [6] Fuel distribution line (100) according to one of the preceding claims, wherein a length (l2) of the clamping formation on the lateral axis (Z) is greater than or equal to a diameter of the tubular body (R). [7] Fuel distribution line (100) according to one of the preceding claims, wherein at least one clamping formation (15) located in the first region (1) of the fuel distribution line (100) is arranged and designed such that it corresponds to at least one clamping formation (15) located in the second region (2) of the fuel distribution line (100). [8] Fuel distribution line (100) according to one of the preceding claims, wherein at least two clamping formations (15) are formed close to two distal ends of the tubular body (10) and extend in the second region (2) of the fuel distribution line (100) and at least two further clamping formations (15) are formed close to a center of gravity of the tubular body (10) and extend in the first region (1) of the fuel distribution line (100). [9] Fuel distribution line (100) according to one of the preceding claims, wherein the fuel distribution line (100) is designed with a clamping system which comprises corresponding support means, ie fixing means or clamping means, on a workbench for the fuel distribution line (100), which correspond to the at least one clamping formation (15). [10] Fuel rail (100) for a fuel injection system comprising a tubular body (10) with at least one clamping formation (15) according to claims 1-9, wherein the clamping formation (15) is used as a semi-finished product during the machining of the fuel rail (100) and is separated after use in the aforementioned machining processes. [11] Fuel distribution line (100) for a fuel injection system with a tubular body (10) with at least one clamping formation (15) according to claims 1-9, wherein the clamping formation (15) is used as a semi-finished product or finished product during the transport of the fuel distribution line (100) and is separated after use in the aforementioned transport processes.

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