Ground wire for a motor vehicle

Abstract

The invention relates to a ground cable (1) for connecting a component to a body part or chassis part of a motor vehicle, wherein the ground cable (1) consists of at least two ground cable strands (2, 3, 4) and at least one ground cable sheath (5) is provided, wherein the ground cable (1) is provided at each of its two ends with an individual connection terminal (6, 7), characterized in that each of the ground cable strands (2, 3, 4) has a different length.

Description

[0001] The invention relates to a ground wire for connecting a component to a body part or chassis part of a motor vehicle.

[0002] For safety reasons, various electrical and other metallic components in a motor vehicle must be grounded to prevent short circuits. This is typically achieved via ground wires, which form an electrical connection between the corresponding component and the body or chassis of the vehicle, for example, between a metallic transmission housing and the chassis.

[0003] Such ground cables usually consist of sheathed round conductors with a single ground wire strand with, for example, a cross-section of 25 mm 2However, with such state-of-the-art ground cables, the problem repeatedly arises that, due to the rigidity of such ground cables, additional disruptive structure-borne noise is transmitted from the corresponding component to the body or chassis of the vehicle and, in the worst case, into the interior, causing disturbance for the passengers. For example, this was observed in the past in connection with the grounding of transfer cases in motor vehicles. While thinner and therefore less rigid individual ground cable strands might reduce the problem of structure-borne noise transmission under certain circumstances, secure electrical grounding and thus grounding might no longer be reliably ensured.

[0004] It is an object of the invention to provide a ground line of a motor vehicle which reduces or, at best, prevents the transmission of structure-borne noise in a structurally simple, cost-effective and safe manner, while at the same time not impairing the grounding effect.

[0005] Furthermore, CN 2 19 106 532 U discloses a secondary earth wire of a power voltage transformer, which comprises a main earth wire, a ground terminal, a plurality of ground branch wires and a plurality of ground wire actuating heads, wherein one end of the main earth wire is connected to the ground terminal, the other end of the main earth wire is connected to one end of a plurality of ground branch wires and the other end of each ground branch wires is connected to the ground terminal.

[0006] In addition, CN 2 18 549 479 U discloses a cable connection shielding earthing tape with corrosion protection function, which comprises a shielding layer connection section, a central corrosion- and wear-resistant section and an earthing section.

[0007] Furthermore, US 2022 / 0 208 418 A1 discloses a composite cable for a vehicle, comprising a communication unit, a power unit, a cable shielding layer and a cable sheath layer.

[0008] Furthermore, from CN 1 16 951 054 A, a two-stage vibration-isolating compressor suspension bracket is known, which comprises a lower sheet metal bracket, wherein a two-stage suspension assembly is symmetrically connected to the lower surface of both ends of the lower sheet metal bracket.

[0009] This object is achieved according to the invention by a ground wire of a motor vehicle, in which at least two ground wire strands and at least one ground wire sheath are provided, wherein the ground wire is provided with a single connection terminal at each end and wherein each of the ground wire strands has a different length. Advantageous embodiments of the invention are the subject of the dependent patent claims and the description.

[0010] A ground wire according to the invention for connecting a component to a body part or chassis part of a motor vehicle consists of at least two ground wire strands and at least one ground wire sheath is provided, wherein the ground wire is provided with a single connection terminal at each end. Thus, according to the invention, at least two ground wire strands are provided for electrical connection, each of which ensures a secure electrical connection via a common connection terminal.

[0011] On the one hand, this is relatively easy to achieve structurally, and on the other hand, the use of at least two grounding conductor strands results in relatively greater flexibility of the grounding conductor strands compared to a single round conductor used in the prior art, which is thus more susceptible to structure-borne sound transmission. The flexibility of the grounding conductor according to the invention results in reduced rigidity and a reduction in vibration transmission.

[0012] According to the invention, vibration damping and stiffness adaptation or reduction are achieved due to a plurality of ground line strands together with respective individual connection terminals and the at least one electrically and vibration-insulating ground line sheath.

[0013] This can be further increased by preferably having three or more ground line strands according to the invention.

[0014] A flexible adaptation to an installation situation in a motor vehicle and the associated inhomogeneous vibration propagation and thus vibration damping against structure-borne noise is provided by a proposed design of the ground line according to the invention, in which each of the ground line strands has a different length.

[0015] Thus, a contour of the ground wire can also be specified by means of the different lengths of the ground wire strands, which allows flexible adaptation to different installation situations in a motor vehicle.

[0016] Different lengths of the multiple ground line strands as well as the selection of the ground line sheath or the individual ground line strand sheaths also allow, according to the invention, a damping of vibration propagation of structure-borne sound at different frequencies and thus a particularly effective prevention of structure-borne sound transmission by means of a corresponding ground line design according to the invention.

[0017] Physical damping of vibration propagation in the ground line according to the invention can be further achieved by twisting the ground line strands, for example. This results in a certain longitudinal inhomogeneity in the area of the ground line strands, which further inhibits the propagation of structure-borne sound.

[0018] The effect of inhomogeneous and thus dampening structure-borne sound vibration propagation described above can be particularly pronounced if the ground wire strands are interwoven, for example in the form of a braided pattern.

[0019] A further damping effect can be achieved if each of the ground wire strands preferably has an individual ground wire strand sheath.

[0020] Each individual ground wire harness sheath can also form the ground wire sheath itself. This means that the multiple ground wire harnesses run between the shared connection terminals in separate, individual ground wire harness sheaths, forming the actual ground wire sheath of the preferred ground wire design. This results in a further inhomogeneous ground wire design that counteracts the propagation of structure-borne noise.

[0021] An embodiment of the ground cable according to the invention is particularly shielded and dampened in vibration propagation, in which the ground cable sheath additionally surrounds each individual ground cable strand sheath.

[0022] If each of the ground line strands is formed from stranded wires, a special internal damping characteristic results from the inhomogeneity and flexibility of the line strands thus formed according to a preferred embodiment of the invention.

[0023] Further features of the invention emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combination, but also in other combinations or on their own.

[0024] The invention will now be explained in more detail using preferred embodiments and with reference to the drawings. They show: Fig. 1 is a schematic, partially cutaway view of a ground line according to a first embodiment of the invention; Fig. 2 a schematic sectional view along the section A - A in Fig. 1; Fig. 3 a schematic sectional view corresponding to section A - A of Fig. 1 but according to a further embodiment of the invention; Fig. 4 a schematic, partially cutaway view of a ground line according to another embodiment of the invention; Fig. 5 a schematic, partially cutaway view of a ground line according to another embodiment of the invention; Fig. 6 is a schematic, partially cutaway view of a ground line according to a further embodiment of the invention; and Fig. 7 is a schematic view of a ground line according to yet another embodiment of the invention.

[0025] Fig. Figure 1 shows a schematic, partially cutaway view of a ground wire 1 according to a first exemplary embodiment of the invention. The ground wire 1 is used to connect a component to a body part or chassis part of a motor vehicle. The ground wire 1 consists of two ground wire strands, a first ground wire strand 2 and a second ground wire strand 3, and a common ground wire sheath 5, wherein the ground wire 1 is connected at both ends to a single first connection terminal 6, in the Fig. 1 left, and a single second connection terminal 7, in Fig. 1 on the right.

[0026] The ground wire sheath 5 consists of an electrically insulating and flexible material, such as silicone, PVC (polyvinyl chloride) or XPE (cross-linked polyethylene).

[0027] The ground wire strands 2, 3 are preferably made of copper or aluminum or an alloy thereof.

[0028] The connection terminals 6, 7 are each designed as metallic eyelets that are electrically connected to the ground wire harnesses 2, 3. This connection is preferably a crimp connection, for example, but a soldered connection or cold welding would also be conceivable. The connection terminals 6, 7 each establish an electrical ground connection to a component of the motor vehicle, such as a transmission housing body and a body or chassis part of the motor vehicle.

[0029] The particularly flexible design of the ground line 1 according to the invention ensures that the transmission of structure-borne sound between the elements of the motor vehicle connected to the ground line 1 is as low as possible in a structurally simple manner. At the same time, a good electrical connection is ensured by the at least two ground line strands 2, 3 according to the invention. Because the at least two ground line strands 2, 3 can be connected to components or the body or chassis of the motor vehicle via respective common connection terminals 6, 7, the design remains simple and cost-effective according to the invention.

[0030] The Fig. Figure 2 shows a schematic sectional view along section A - A in Fig. 1. It is clearly visible that each of the ground wire strands 2, 3 is made of stranded wires 10. These are particularly flexible and thus reduce the stiffness compared to round conductors and thus the tendency to transmit structure-borne noise without impairing the electrical conduction.

[0031] The Fig. 3 shows a schematic sectional view corresponding to section A - A of the Fig. 1 but according to a further embodiment of the invention.

[0032] The ground line 1, the first ground line strand 2 of the ground line 1, individually has a first ground line strand sheath 8, and the second ground line strand 3 of the ground line 1 individually has a second ground line strand sheath 9. The ground line sheath 5 additionally surrounds the ground line 1.

[0033] In contrast to the first embodiment according to Fig. 1 run in the further embodiment according to Fig. 4 the first ground wire strand 2 and the second ground wire strand 3 twisted in the common ground wire sheath 5.

[0034] It is also possible to have three or more ground wire strands, in the case of the embodiment according to Fig. 5, three ground wire strands are provided, namely a first ground wire strand 2, a second ground wire strand 3, and a third ground wire strand 4. The ground wire strands 2, 3, and 4 are braided together.

[0035] The Fig. Figure 6 shows a schematic, partially cutaway view of a ground line 1 according to another embodiment of the invention. Both the first ground line strand 2 and the second ground line strand 3 each have a single first ground line strand sheath 8 and a second ground line strand sheath 9, respectively, which thus form the ground line sheath 5.

[0036] The Fig. Figure 7 shows a schematic view of a ground wire 1 according to yet another embodiment of the invention. The first ground wire strand 2 and the second ground wire strand 3 are shown in dashed lines in the illustration, as they are not actually visible in the ground wire sheath 5.

[0037] The first ground wire strand 2 is longer than the second ground wire strand 3, whereby by means of the different lengths of the ground wire strands 2, 3 a contour of the ground wire 1 with a bend in the Fig. 7 is predefined downwards by way of example. Such a predefined shape or contour of the ground line 1 according to the invention can, for example, easily predetermine an installation position for certain predefined installation situations in a motor vehicle. List of reference symbols 1 ground wire 2 first ground wire harness 3 second ground wire harness 4 third ground wire strand 5 Ground wire sheath 6 first connection terminal 7 second connection terminal 8 first ground wire harness sheath 9 second ground wire harness sheath 10 strands

Claims

[1] Ground cable (1) for connecting a component to a body part or chassis part of a motor vehicle, wherein the ground cable (1) consists of at least two ground cable strands (2, 3, 4) and at least one ground cable sheath (5) is provided, and wherein the ground cable (1) is provided at each end with a single connection terminal (6, 7), characterized by that each of the ground wire strands (2, 3, 4) has a different length. [2] Ground line (1) according to claim 1, characterized by that three or more ground wire strands (2, 3, 4) are present. [3] Ground line (1) according to claim 1 or 2, characterized by that the ground wire strands (2, 3, 4) are twisted. [4] Ground line (1) according to one of the preceding claims, characterized by that the ground wire strands (2, 3, 4) are intertwined. [5] Ground line (1) according to one of the preceding claims, characterized bythat each of the ground line strands (2, 3, 4) individually has a ground line strand sheath (8, 9). [6] Ground line (1) according to claim 5, characterized by that each individual ground wire harness sheath (8, 9) forms the ground wire sheath (5). [7] Ground line (1) according to claim 5, characterized by that the ground cable sheath (5) additionally surrounds each individual ground cable strand sheath (8, 9). [8] Ground line (1) according to one of the preceding claims, characterized by that a contour of the ground line (1) is predetermined by means of the different lengths of the ground line strands (2, 3, 4). [9] Ground line (1) according to one of the preceding claims, characterized by that each of the ground line strands (2, 3, 4) is formed from stranded wires (10).

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