Method for manufacturing a wiring harness with at least one busbar for a vehicle

Abstract

Method for manufacturing a wiring harness with at least one busbar for a vehicle comprising the wiring harness, a substantially non-conductive body and at least one ground point (13), wherein the method for establishing an electrical contact between a group of ground conductors (2) of the wiring harness and the at least one busbar (11) of the wiring harness is provided, comprising the steps: - Provision of a cable harness bundle (1) with the group of ground wires (2), - Provision of a bundle gauge (3) for the cable harness bundle (1) and a first conductor gauge (4) for the group of ground conductors (2), - Inserting each individual grounding conductor (2) of the group of grounding conductors (2) into a conductor guide element of the first conductor guide (4) assigned to the respective grounding conductor (2) and fixing the group of grounding conductors (2) with a second conductor guide (5), - Leading the group of ground wires (2) to the power busbar (11), - electrical connection of the group of ground wires (2) to the busbar (11), - electrical connection of the ground point (13) to the power busbar (11), and - mechanical fixing of the power busbar (11) in the vehicle.

Description

[0001] The invention relates to a method for manufacturing a cable harness with a power busbar for a vehicle.

[0002] The physical electrical system of a modern vehicle has a complex architecture. It consists of a network of wires, designed as a wiring harness. This means that various wires, such as ground wires or power supply lines, are bundled together to form the wiring harness.

[0003] The electrical / electronic system of a modern vehicle with a partially electrified powertrain exhibits an even higher degree of complexity. This also applies to the wiring harness and is explained, for example, in document DE 102010042963 A1.

[0004] The state of the art also includes DE 10 2011 054 432 A1, EP 0 895 306 A1 and DE 103 08 759 A1.

[0005] It is an object of the invention to describe an improved vehicle with a wiring harness which bundles a group of ground wires and with a substantially electrically non-conductive body, as well as a method which relates to the manufacture of the wiring harness.

[0006] This problem is solved by a method according to claim 1. Advantageous embodiments and further developments of the invention are set out in the dependent claims.

[0007] According to the invention, the vehicle has at least one ground point and the wiring harness has at least one busbar which is associated with the at least one ground point, wherein the ground point is electrically connected to the busbar and the busbar is mechanically fixed in the vehicle.

[0008] In this way, parts of the wiring harness are electrically connected to the ground point in the vehicle via the power busbar in order to create an electrical ground connection between the vehicle's components connected to the ground wires.

[0009] In vehicles with a non-conductive body, this is unsuitable for use as a return conductor for electrical components. Ground wires must be routed over longer distances and in bundles with a larger number of wires than in a vehicle with a metallic body, leading to fewer ground points or even a single ground point. Consequently, depending on the vehicle's configuration, a particularly large number of ground wires must be electrically connected to ground at this single ground point. A space-saving and easy-to-install busbar is therefore especially advantageous.

[0010] This applies in particular, for example, to a vehicle with a body that is essentially made of carbon fiber reinforced plastic.

[0011] According to a preferred embodiment of the invention, the cable harness bundles a group of ground wires, which are led through a bundle of the cable harness to the busbar, which is assigned to the group of ground wires and is electrically connected to it.

[0012] This is advantageous because it eliminates the need to equip each individual ground wire with a connector, which would then be connected to a ground busbar or similar connector. Using a busbar saves space, material, and assembly effort.

[0013] Furthermore, a method for manufacturing a wiring harness for a vehicle, in particular for manufacturing an electrical contact between the group of ground conductors of the wiring harness and the at least one busbar of the wiring harness, is proposed, comprising the following steps: • Provision of the cable harness bundle with the group of ground wires • Provision of a bundle gauge for the cable harness bundle and a first conductor gauge for the group of ground conductors • Inserting the cable harness bundle into the bundle jig and inserting each individual ground wire of the group of ground wires into a wire guide element of the first wire jig assigned to the respective ground wire and fixing the group of ground wires with a second wire jig.

[0014] An advantage of this method is that the ground wires can be of varying lengths. The bundle gauge can provide guide elements for the bundle, indicating which part of the bundle is to be positioned. These guide elements could also be variably adjustable to adapt the gauge to the bundle diameter, thus enabling the use of a single gauge for different cable harness bundles. The wire guide elements of the first wire gauge are preferably designed as grooves or slots, with one guide element for each ground wire.

[0015] Further steps in the process are: • Trimming, i.e., pruning, the group of mass veins with a trimming element • Strip each ground wire of the group of ground wires using a stripping unit to expose a group of strands from the group of ground wires.

[0016] The ground wires are cut to a defined length, and the strands of the ground wires are exposed. The following steps are then taken: • Provision of an initial busbar element • Inserting each individual strand of the group of strands into a strand guide element of the first busbar element assigned to the respective ground conductor. • Providing a second busbar element and connecting the first busbar element to the second busbar element to create the busbar.

[0017] The busbar allows the group of stranded wires to be connected to it. This describes a cost-effective and easy-to-assemble process for manufacturing a cable harness with at least one busbar for ground wires. A wound or tubular cable harness bundle containing the ground wires serves as the starting point. Using a jig, the group of ground wires, consisting of insulated wires of varying lengths, is cut, stripped, and connected to the busbar.

[0018] According to another variant of the method, the cable harness bundle to be provided has a branching point, wherein the group of ground wires is led out of the cable harness bundle at the branching point and at which the bundle jig to be provided has a separating opening for the cable harness bundle and the group of ground wires.

[0019] In this case, the cable harness bundle is guided through the separating opening of the gauge at the branching point, so that part of the gauge separates the group of ground wires from at least one other branching piece of the cable harness bundle for further processing.

[0020] This allows for the production of a cable harness with any number of branches and, if necessary, multiple power busbars.

[0021] The invention is based on the considerations set out below: In a typical vehicle wiring harness, conductors with the same contact type as, for example, ground wires, are usually crimped with a flat pin connector and then connected in groups to conductor collectors (in the chosen example of ground wires to so-called ground combs) using the end fittings created by the crimping.

[0022] Such ground clamps can be bolted or connected to body-mounted ground studs at any point on a vehicle with a metal body. The ground connection to the vehicle's ground reference potential, typically formed by the battery's negative terminal, is established via the ground studs and the vehicle's conductive metal body. Due to the potentially large number of ground studs in the vehicle, the ground wires usually only need to be routed over a short distance within the vehicle.

[0023] This is not possible with a vehicle that has a plastic body. Due to the body's limited electrical conductivity, all or a large number of ground wires must be routed to a central connection point(s). Using crimped ground wires and ground combs poses a problem, as it requires numerous spade connectors on a single section of the wiring harness, as well as multiple ground combs with secure body-mounted screws. This is complex in terms of weight, space requirements, manufacturing technology, assembly, and ease of maintenance.

[0024] It is a challenge to reduce the material, assembly, integration and therefore cost expenditure for connecting ground wires in cable harnesses in plastic car bodies.

[0025] A solution based on a busbar is proposed. Such a system can be integrated into the vehicle in a space-saving manner and enables efficient assembly of the ground connection of the ground wires based on a jig system.

[0026] A preferred embodiment of the invention is described below with reference to the accompanying drawings. Further details, preferred embodiments, and further developments of the invention will be derived from these drawings. Specifically, the drawings schematically illustrate... Fig. 1. Wiring harness integrated into a vehicle with integrated busbar element Fig. 2 cable harness bundles with freestanding ground wires Fig. 3. Attaching the cable harness bundle to a jig Fig. 3a Attaching a branched cable harness bundle to a jig Fig. 4. Fixing and trimming the ground wires Fig. 5. Stripping the cut ground wires Fig. 6. Installing the first busbar element Fig. 7. Installing a second busbar element

[0027] The same reference symbols describe the same technical characteristics.

[0028] Fig. Figure 1 shows a section of a wiring harness with a branch. A group of ground wires (2) and a branch bundle (1a) branch off from a wiring harness bundle (1). The group of ground wires is electrically connected to a busbar (11). The busbar is integrated into the vehicle and, without restriction of generality, is attached to the vehicle by a screw connection (9). The busbar is also connected to a ground point (13) of the vehicle, which is located in Fig. 1 is exemplified in a hook shape, connected.

[0029] The ground point is electrically connected to the vehicle's ground potential. The electrical connection of the ground point to the busbar and the busbar to the group of ground wires ensures that each individual ground wire is connected to the ground potential.

[0030] Ground wires connect electrical consumers in the vehicle to ground potential. In a vehicle with a carbon fiber reinforced body, as described in this embodiment, a multitude of ground wires, each assigned to a specific electrical consumer, are routed to the ground point. This is necessary because, unlike a vehicle with a sheet metal body, the body panels cannot serve as return conductors for the electrical consumers. Therefore, unlike a vehicle with a sheet metal body, an electrical consumer attached to a body panel requires not only a supply wire for the electrical potential but also a return wire, i.e., a ground wire, for ground potential.

[0031] The electrical components are integrated decentrally within the vehicle. In a vehicle with a non-conductive body, the ground point is centrally located, meaning that numerous ground wires must converge at this point. Therefore, it is necessary to connect a large number of bundled ground wires, referred to as the ground wire group, to the electrical potential of the ground point within the smallest possible installation space.

[0032] The busbar receives the group of ground wires and connects them to the same electrical potential. This has the advantage that each individual ground wire does not need to be fitted with a connector, e.g., a spade connector, which in turn needs to be connected to a mating part of the spade connector connected to the ground point.

[0033] In other words, this means that centrally connected ground wires with similar potential and conductivity characteristics are directly connected to the busbar during wiring harness manufacturing, without any intermediate elements. During subsequent vehicle assembly, this busbar then only needs to be connected to a ground point in the vehicle via a screw connection. This saves installation space in the vehicle around the ground point and minimizes the assembly effort required for the ground connection. This saves assembly time during vehicle production and significantly reduces the potential for errors compared to the effort required to connect two flat-leaf elements for each individual ground wire.

[0034] In addition to its advantageous space efficiency, the busbar also offers the potential for weight and cost savings, especially compared to a technical solution using plugs. The system's low complexity also increases the reliability and durability of the ground connection.

[0035] Process steps for manufacturing a cable harness according to Fig. 1 go out of the Fig. 2 to 7 or from Fig. 3a.

[0036] After Fig. 2. First, a bundle (1) of a cable harness is provided. The bundle includes ground wires (2) that are assigned to electrical consumers in the vehicle and that emerge from the bundle, which may be wrapped, bandaged or encased in tubing, at different lengths.

[0037] It is also possible that the group of ground wires emerges at a branch point or junction of the cable harness. In this case, the bundle (1) branches into the group of ground wires (2) and into another bundle (1a), which is located in Fig. 2 is shown with a dashed line. Both the case of a single bundle and the case of a branching bundle are still considered.

[0038] In the case of a single bundle, this is according to... Fig. 3 is applied to a bundle diagram (3). The bundle diagram also includes a diagram for the individual veins of the group of mass veins. Fig. Figure 3a shows a bundle gauge (3') for a branching bundle, this bundle gauge having a separating opening (12) in contrast to the bundle gauge (3). When the branching bundle is placed against the bundle gauge, the further bundle (1a) is guided through the separating opening in such a way that the bundle gauge separates the group of mass conductors from the further bundle (dashed line).

[0039] It is also possible to form a single bundle according to... Fig. 2 on a gauge with a separating opening acc. Fig. 3a. It is assumed that the gauge (3) or (3') is assigned to the cable harness bundle to be processed and is adapted to it, e.g. with regard to the bundle diameter.

[0040] In Fig. 3 and Fig. 3a The ground conductors are individually fitted into a conductor guide element of a conductor gauge (4) assigned to the respective ground conductor. This is preferably done by inserting the conductor in question into a notch provided for this purpose.

[0041] The Fig. 4-7, in favor of a simpler presentation without limiting generality, assume a single bundle according to Fig. 3 out.

[0042] After the veins are inserted, they are arranged according to... Fig. 4 is fixed in the wire gauge (4) with a fixing jig (5). Like the wire gauge, the fixing jig is also adapted to the group of ground wires. After Fig. 4. The ground wires of varying lengths are cut to a defined length using a trimming tool (6), e.g., an automated cutting blade. This process step offers the advantage that, when the wires of the cable harness are bundled earlier in the manufacturing process, the length of these bundles only needs to be adhered to within a rough length specification. A defined length is achieved through the trimming step.

[0043] Joint Fig. 5. The trimmed ground wires are stripped using a wire stripping tool (7). In this step, the individual strands of the group of ground wires are exposed.

[0044] The exposed group of strands (8) is according to Fig.6 is fitted into a metallic support piece (9) of a busbar. For this purpose, each strand of the group of strands is assigned a guide element (9a), such as a groove. As a final step, the support piece of the busbar is connected to a fixing piece so that the strands are permanently in conductive contact with the metallic guide element. The connection can be made by soldering, pressing, or crimping. The wire fixing jig is then released to separate the cable harness bundle and the busbar from the jigs (3) and (4).

[0045] Optionally, the busbar can be completely surrounded with insulating material in the area where it connects to the strands.

[0046] According to another variant, the busbar can have a greater number of grooves than the number of strands to be connected. This allows, for example, additional strands to be connected to the busbar for retrofitting or repair purposes.

[0047] The advantage of this process is that assembly effort is shifted from vehicle manufacturing to component production. Furthermore, quality assurance measures can be incorporated during component manufacturing. Component delivery is hardly affected, however, because the busbar can be designed to fit snugly against the wiring harness bundle, meaning that there are no disadvantages in terms of transportability, packaging, and logistical handling between a component supplier and a vehicle manufacturer compared to a conventional wiring harness.

[0048] Furthermore, the manufacturing process is efficient, as each process step affects an entire group of ground wires, minimizing the need to separate the process steps for individual ground wires.

[0049] The busbar can also be geometrically varied in its design and construction to meet the integration requirements within the vehicle. For example, anti-rotation elements can be incorporated for connection within the vehicle. A plug connection can be an effective alternative to a permanent screw connection. With a screw connection, the number of screws required for a linear assembly can be significantly reduced if the busbar is attached to the ground point using a single screw connection.

Claims

[1] Method for producing a wiring harness with at least one bus bar for a vehicle having the wiring harness, a substantially electrically non-conductive body and at least one ground point (13), wherein the method is designed to produce an electrical contact between a group of ground wires (2) of the wiring harness and the at least one bus bar (11) of the wiring harness, comprising the steps: - Provision of a cable harness bundle (1) with the group of ground wires (2), - providing a bundle gauge (3) for the cable harness bundle (1) and a first wire gauge (4) for the group of ground wires (2), - inserting each individual ground wire (2) of the group of ground wires (2) into a wire guide element of the first wire gauge (4) assigned to the respective ground wire (2) and fixing the group of ground wires (2) with a second wire gauge (5), - Leading the group of ground wires (2) to the current busbar (11), - electrically connecting the group of ground wires (2) to the current busbar (11), - electrically connecting the ground point (13) to the busbar (11), and - mechanical fixing of the busbar (11) in the vehicle. [2] Method according to claim 1, wherein the vehicle is provided with a body substantially made of carbon fiber reinforced plastic. [3] Method according to one of the preceding claims, comprising the steps of - trimming the group of ground wires (2) with a trimming element (6), - Stripping each individual ground wire (2) of the group of ground wires (2) with a stripping unit (7) to expose a group of strands (8) of the group of ground wires (2). [4] Method according to claim 3, comprising the steps of - providing a first busbar element (9), - inserting each individual strand (8) of the group of strands (8) into a strand guide element (9a) assigned to the respective ground wire (2), - Providing a second busbar element (10) and connecting the first busbar element (9) to the second busbar element (10) to produce the busbar (11). [5] Method according to one of claims 2 to 4, in which - the cable harness bundle (1) to be provided has a branching point and at the branching point the group of ground wires (2) is led out of the cable harness bundle (1), and - the bundle gauge (3) to be provided has a separation opening (12) for the cable harness bundle (1) and the group of ground wires (2).

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