Retaining device for a shielding spring

Abstract

Described herein is a retaining device for a shielding spring in an automotive (HV) inlet. The retaining device comprises: a retaining component configured to be positioned radially outside of shielding wings of a shielding spring, wherein the inner diameter of the retaining component is smaller than the distance between tips of two opposing shielding wings of the loaded shielding spring, so that a radially inward force is appliable on the shielding wings by the retaining component. Further described herein are an assembly for an automotive HV inlet, and an automotive HV inlet.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a retaining device for a shielding spring, in particular in the field of automotive high-voltage (HV) inlets. The present disclosure also relates to an assembly for an automotive HV inlet comprising the retaining device and a shielding spring, and to an automotive HV inlet comprising the assembly and an HV cable.BACKGROUND

[0002] In the field of automotive HV inlets, it is common to utilize shielding to protect against electromagnetic interference and ensure the safe transmission of electrical signals and power. Known HV inlets involve the use of shielding springs with multiple shielding wings that extend radially inward around an opening to make contact with the shielding layer of an HV cable. This shielding layer is connected to the ground to provide a path for any stray electrical currents. The connection between the shielding wings and the shielding layer is crucial for maintaining the integrity of the electromagnetic shielding.

[0003] Despite the effectiveness of the known HV inlets, there are challenges associated with maintaining a reliable connection between the shielding wings of the shielding spring and the shielding layer of the HV cable, particularly during temperature cycling. Temperature fluctuations can cause expansion and contraction of the materials involved, leading to potential gaps or misalignments between the shielding wings and the shielding layer. This can result in inconsistent contact pressure, which may compromise the electrical connection and reduce the effectiveness of the electromagnetic shielding. Additionally, repeated temperature cycling can lead to material fatigue, further exacerbating the risk of connection failure over time.

[0004] Moreover, the materials commonly used in these systems, such as copper alloys for the shielding spring and aluminum alloys for the shielding layer, may have different thermal expansion coefficients. This discrepancy can further contribute to the challenges of maintaining a consistent and reliable connection during temperature variations. As a result, the performance of the shielding system may be adversely affected, leading to potential safety risks and reduced efficiency of the HV inlet.

[0005] It is therefore a technical problem underlying the present invention to provide an improved shielding in automotive HV inlets that at least partially overcomes the disadvantages above.SUMMARY

[0006] It is an object of this invention to provide a retaining device that overcomes one or more of the disadvantages of known automotive HV inlets.

[0007] The invention is defined in the independent claims. Preferred embodiments are subject of the dependent claims.

[0008] A first aspect of the invention provides a retaining device for a shielding spring in an automotive (HV) inlet, the retaining device comprising: a retaining component configured to be positioned radially outside of shielding wings of a shielding spring, wherein the inner diameter of the retaining component is smaller than the distance between tips of two opposing shielding wings of the loaded shielding spring, so that a radially inward force is appliable on the shielding wings by the retaining component.

[0009] Because the inner diameter of the retaining component is smaller than the distance between the tips of two opposing shielding wings of the loaded shielding spring, the retaining component can apply a radially inward force on the shielding wings of the shielding spring.

[0010] The "retaining component" is a part of the retaining device that is configured to encircle or be placed around another component, in this case, the shielding wings of the shielding spring. The skilled person would understand that the retaining component can have either a substantially circular cross-section or, alternatively, a non-circular cross-section, wherein the specific cross-sectional shape is selected based on the requirements of the shielding spring and the dimensions of the HV cable to be accommodated. The "shielding wings" are parts of the shielding spring that extend radially inward with respect to an opening of the shielding spring that is configured for receiving an HV cable. The term "loaded" shielding spring refers to a shielding spring whose shielding wings are subjected to a force, resulting in their deformation and the storage of potential energy. The shielding spring may be loaded when an HV cable is accommodated within its opening, causing the shielding wings to be pressed radially outward. The shielding wings are responsible for providing electromagnetic interference protection by maintaining contact with other components, for example the shielding layer of the HV cable. The term "radially inward force" refers to a force directed towards the centre of a body, for example a circle or cylinder. In the present context, this force pertains to the opening of the shielding spring, where it serves to maintain the position of the shielding wings and ensure consistent contact pressure.

[0011] The advantages of a retaining device according to the first aspect include increased and consistent contact force between the shielding spring and the components it interfaces with - in particular the shielding layer of the HV cable. This ensures a stable electrical connection, even during temperature cycling, which can cause expansion and contraction of materials. Additionally, the retaining device according to the first aspect is cost-effective compared to alternatives such as changing the coating material of the shielding spring, which may significantly increase the cost of the HV inlet.

[0012] In a first embodiment of the retaining device according to the first aspect, the retaining component is composed of a polymer.

[0013] In this embodiment, the retaining component may provide further benefits such as reduced weight and improved resistance to corrosion compared to metal alternatives. Examples of polymers that are commonly used for connectors include polybutylene terephthalate, polycarbonate, and polyamide.

[0014] In a further embodiment, the retaining device according to the first aspect comprises multiple retaining components.

[0015] This embodiment may enhance the adaptability of the retaining device to HV inlets that may require multiple connections. Each retaining component may be positioned radially outside of the shielding wings of individual shielding springs, which may be beneficial for ensuring secure and stable connections across multiple HV cables. Thereby, this embodiment may accommodate the complex requirements of high-voltage systems with multiple cables, each necessitating its own shielding spring.

[0016] In a further embodiment of the retaining device according to the first aspect, the inner diameter of the retaining component is between 20mm to 25mm, preferably between 21mm to 23mm, and more preferably 22.4mm.

[0017] This embodiment provides precise measurements for the inner diameter of the retaining component, which may enhance the effectiveness of the radially inward force applied on the shielding wings of the shielding spring. The specific ranges ensure that the retaining component can be optimally positioned to exert the necessary force on the shielding wings, thereby improving the stability and reliability of the retaining device in an automotive HV inlet.

[0018] In a further embodiment, the retaining device according to the first aspect further comprises engagement elements configured for engaging with a housing of an HV inlet.

[0019] This embodiment introduces engagement elements that may be configured to engage with a housing of an HV inlet, which suggests a mechanism of communication between the retaining device and the housing and may enhance the stability and alignment of the retaining device within the HV inlet. The engagement elements may provide a secure fit, ensuring that the retaining device remains in the desired position. This embodiment may offer improved reliability and ease of assembly, as the engagement elements can facilitate proper positioning and retention of the retaining device. The addition of engagement elements may also contribute to the overall robustness of the retaining device, potentially reducing the likelihood of dislodgement or misalignment during operation, thereby enhancing the performance and safety of the automotive HV inlet.

[0020] A second aspect of the invention provides an assembly for an automotive HV inlet, comprising: a retaining device according to the first aspect, and a shielding spring having multiple shielding wings that are circumferentially arranged around an opening adapted for receiving an HV cable, wherein the retaining component of the retaining device is positioned radially outside the shielding wings of the shielding spring so that a radially inward force is applied on the shielding wings by the retaining component.

[0021] The shielding spring is characterized by having multiple shielding wings that are arranged around an opening. This opening is specifically designed to accommodate an HV cable. The opening may be cylindrical such that the multiple shielding wings are arranged in a circular manner around the cylindrical opening. The retaining component of the retaining device is positioned on the radial outside of the shielding wings. This positioning ensures that a force is applied inwardly on the shielding wings by the retaining component.

[0022] The advantages of the assembly according to the second aspect include increased and consistent contact force on the shielding wings - even during thermal cycling. This addresses issues such as fretting corrosion and relaxation of the shielding spring wings, which can occur due to temperature fluctuations and material expansion differences. Further, by using the assembly according to the second aspect, the need for more expensive coatings on the shielding spring is eliminated, offering a cost-effective solution while maintaining stable electrical connections.

[0023] In a first embodiment of the assembly according to the second aspect, the distance between tips of two opposing shielding wings of the shielding spring is 20mm to 25mm, preferably between 21mm to 23mm, and more preferably 22.7mm.

[0024] In this embodiment, the distance between the tips of two opposing shielding wings of the shielding spring can be 20mm to 25mm, preferably between 21mm to 23mm, and more preferably 22.7mm. This specific distance range may enhance the effectiveness of the shielding spring by ensuring optimal contact and pressure distribution on the HV cable, thereby improving the overall stability and electrical performance of the assembly.

[0025] In a further embodiment of the assembly according to the second aspect, the shielding spring is composed of a copper alloy, preferably C19010.

[0026] The assembly according to the second aspect may comprise a shielding spring composed of a copper alloy, such as C19010. This alloy may offer high formability and excellent electrical conductivity. Specifically, a C19010 alloy may exhibit excellent resistance to stress relaxation at elevated temperatures, up to 150°C, ensuring stable performance over time - even during thermal cycling. Furthermore, the shielding spring may have a coating composed of tin or silver, which can enhance the corrosion resistance and electrical contact properties of the shielding spring.

[0027] A third aspect of the invention provides an automotive HV inlet comprising: a housing, an HV cable having a conductive core, a shielding layer and at least one insulation layer, and an assembly according to the second aspect, wherein the assembly is arranged such that the HV cable extends through the opening of the shielding spring, and the retaining component of the retaining device presses the shielding wings of the shielding spring radially inwards against the HV cable.

[0028] The term "housing" generally refers to a protective casing of the HV inlet and its components. An "HV cable" is a high-voltage cable with a conductive core for electrical transmission, a shielding layer for electromagnetic interference protection, and insulation for safety.

[0029] The advantages of an HV inlet according to the third aspect include increased and consistent contact force between the shielding wings and the HV cable. This aspect mitigates issues like fretting corrosion and thermal expansion discrepancies, offering a cost-effective solution compared to alternative methods like changing the spring's coating.

[0030] In a first embodiment of the automotive HV inlet according to the third aspect, the pressure distribution of the pressure the shielding wings apply to the HV cable is uniform over the circumference of the HV cable.

[0031] In this particular embodiment, the pressure distribution applied by the shielding wings to the HV cable may be uniform over the circumference of the HV cable. This can ensure that the pressure exerted by the shielding wings is evenly distributed around the HV cable, potentially enhancing the stability and reliability of the connection, and reducing the risk of damage to the HV cable due to uneven pressure.

[0032] In a further embodiment of the automotive HV inlet according to the third aspect, the core of the cable is composed of an aluminum alloy, preferably EN AW-6101.

[0033] The core of the HV cable may be composed of an aluminum alloy, preferably EN AW-6101. This material choice can enhance the electrical conductivity and mechanical properties of the HV cable. The specific composition of the aluminum alloy may provide improved performance characteristics such as better corrosion resistance, weight reduction, and cost efficiency compared to other materials like copper. The use of EN AW-6101 aluminum alloy in the core can also facilitate easier handling and installation due to its lighter weight. This embodiment may contribute to the overall efficiency and reliability of the automotive HV inlet by optimizing the material properties of the conductive core.

[0034] In a further embodiment of the automotive HV inlet according to the third aspect, the shielding layer of the HV cable is composed of an aluminum alloy, and is preferably EN AW-3103.

[0035] The shielding layer of the HV cable may be composed of an aluminum alloy, preferably EN AW-3103. The use of an aluminum alloy, such as EN AW-3103, may offer benefits like improved conductivity, reduced weight, and enhanced corrosion resistance compared to other materials. This also may facilitate efficient electromagnetic shielding, ensuring that the HV cable maintains its integrity and performance in automotive applications.

[0036] In a further embodiment of the automotive HV inlet according to the third aspect, the retaining component of the retaining device presses the shielding wings of the shielding spring radially inwards against the shielding layer of the HV cable.

[0037] In this embodiment, the retaining component presses the shielding wings radially inwards specifically against the shielding layer of the HV cable. This may ensure a more secure and stable electrical connection by directly engaging the shielding layer, which can enhance the electromagnetic compatibility and reduce potential interference. The direct contact between the shielding wings and the shielding layer may also improve the mechanical stability of the HV cable within the housing, potentially leading to increased durability and reliability of the automotive HV inlet.

[0038] In a further embodiment of the automotive HV inlet according to the third aspect, at a contact point on an axis of the HV cable and along a radial axis, the core of the HV cable is in contact with one of the insulation layers, the one of the insulation layers is in contact with the shielding layer, the shielding layer is in contact with the shielding wings of the shielding spring, and the shielding wings of the shielding spring are in contact with the retaining component of the retaining device.

[0039] In this embodiment, the core of the HV cable may be in contact with one of the insulation layers, which in turn may be in contact with the shielding layer. The shielding layer may then be in contact with the shielding wings of the shielding spring, and these shielding wings may be in contact with the retaining component of the retaining device. This may ensure a continuous and efficient transmission of electrical signals and shielding effectiveness. A technical benefit of this arrangement is to enhance the electromagnetic compatibility (EMC) performance of the HV inlet by ensuring that the shielding layer is effectively grounded through the retaining component. This can reduce electromagnetic interference (EMI) and improve the overall reliability and safety of the automotive HV inlet. The contact between the core and the insulation layer, followed by the insulation layer's contact with the shielding layer, ensures that the high-voltage core is adequately insulated and shielded, thereby preventing potential electrical hazards. The subsequent contact of the shielding layer with the shielding wings and the retaining component ensures that the shielding is securely held in place and properly grounded.

[0040] In a further embodiment of the automotive HV inlet according to the third aspect, at least one of the insulation layers of the HV cable is absent along the radial axis at the contact point on the axis of the HV cable.

[0041] This embodiment may facilitate direct contact between the shielding wings of the shielding spring and the shielding layer of the HV cable by omitting at least one insulation layer along the radial axis at the contact point on the cable's axis. This may enhance the electrical connection between the shielding spring and the cable's shielding layer, potentially improving electromagnetic compatibility and reducing interference. By allowing the shielding wings to press directly against the shielding layer, the design may ensure a more efficient and reliable conductive path.

[0042] The skilled person appreciates that features disclosed in connection with one aspect can also be combined with other aspects of the invention. Figure 1:shows an HV cable; Figure 2:illustrates an embodiment of a shielding spring; Figure 3:shows an embodiment of a retaining device; Figure 4:shows two HV cables, each extend through the opening of a shielding spring; Figure 5:shows a cross-sectional view of an automotive HV inlet assembly with a shielding spring and retaining component; Figure 6:illustrates a perspective view of an automotive HV inlet assembly with an HV cable extending through the shielding spring.

[0043] Figure 1 shows an HV cable as known in the prior art, comprising a conductive core 24, a shielding layer 26, and two insulation layers 28. The conductive core 24 is composed of an aluminum alloy. The shielding layer 26 is positioned radially outward of the conductive core 24 and is also composed of an aluminum alloy. The two insulation layers 28 include an inner insulation layer and an outer insulation layer, both of which are positioned radially outward of the shielding layer 26. The inner insulation layer is located between the conductive core 24 and the shielding layer 26, while the outer insulation layer is positioned radially outward of the shielding layer 26.

[0044] Figure 2 illustrates a shielding spring 14, as known in the prior art. The shielding spring 14 comprises multiple shielding wings 16 that are circumferentially arranged around a cylindrical opening. The distance 32 between the tips 34 of two opposing shielding wings 16 is depicted. The opening of the shielding spring 14 is configured to engage with the HV cable such that the shielding wings 16 can apply a radially inward force onto the HV cable, particularly the shielding layer 26.

[0045] When the HV cable is extending through the opening of the shielding spring 14, the shielding wings 16 are flexible enough to slightly bend radially outward and apply a spring force on the HV cable that is directed radially inwards. The shielding wings 16 of the shielding spring 14 can be pressed radially inward by a retaining component 12 of a retaining device 10. The shielding wings 16 are positioned to apply a uniform pressure distribution over the circumference of the HV cable when the retaining component 10 is in place.

[0046] The retaining device 10, further explained below, would be positioned radially outside the shielding wings 16 of the shielding spring 14. The retaining component 12 would have an inner diameter smaller than the distance 32 between the tips 34 of the shielding wings 16, thereby applying a radially inward force on the shielding wings 16 to ensure they press against the HV cable, particularly the shielding layer 26.

[0047] Figure 3 illustrates two views of the retaining device 10, providing both a side view (bottom) and a top view (top). The retaining device 10 comprises two retaining components 12, which are cylindrical in shape. These components are configured to be positioned radially outside of the shielding wings 16 of a shielding spring 14. The top view of the retaining device 10 shows the cylindrical nature of the retaining components 12. The side view details the arrangement of the retaining components 12, showing their circular openings, which are intended to accommodate the shielding wings 16 of a shielding spring 14. The inner diameter 30 of the retaining components 12 is smaller than the distance 32 between the tips 34 of two opposing shielding wings 16, ensuring the application of the necessary force to maintain the shielding wings 16 in position. Additionally, the engagement elements 18 are adapted for engaging with a housing of an HV inlet, providing stability and alignment for the retaining device 10 within the HV inlet.

[0048] Figure 4 depicts two HV cables extending through the openings of two shielding springs 14. The shielding wings 16 of each loaded shielding spring 14 are circumferentially arranged around the cylindrical openings and are in contact with the shielding layer 26 of each HV cable. This contact ensures effective electromagnetic interference EMI shielding by maintaining a continuous conductive path. The shielding wings 16 are shown to exert a radially inward spring force, which may be enhanced by the retaining components 12 of a retaining device 10, ensuring that the shielding layer 26 is securely engaged. The distance 32 between the tips 34 of opposing shielding wings is larger than the inner diameter 30 of the retaining component 12 of the retaining device 10, allowing the wings to be pressed inward effectively.

[0049] Figure 5 illustrates a cross-sectional view of an automotive HV inlet. The HV cable comprises a conductive core 24, a shielding layer 26, and insulation layers 28. The shielding spring 14, with its shielding wings 16, is positioned radially outside the shielding layer 26. The retaining component 12 of the retaining device 10 exerts a radially inward force on the shielding wings 16, pressing them against the shielding layer 26. The housing 20 encloses these components. At a contact point 101 on the axis 100 of the HV cable, along the radial axis 200, the core 24 is in contact with the inner insulation layer, which is in contact with the shielding layer 26, which is in contact with the shielding wings 16, which are in contact with the retaining component 12.

[0050] Figure 6 provides a perspective view of the HV inlet. The HV cable extends through the openings of both the shielding spring 14 and the retaining device 10. The outer insulation layer ends before the HV cable extends through the housing 20 -axially before the contact point 101 - exposing the shielding layer 26. This allows the shielding wings 16 of the shielding spring 14 to make direct contact with the shielding layer 26. The retaining component 12 of the retaining device 10 presses the shielding wings 16 against the shielding layer 26, ensuring a secure connection and grounding. The assembly 22, including the retaining device 10 and shielding spring 14, is positioned within the housing 20.

Claims

1. A retaining device (10) for a shielding spring (14) in an automotive high-voltage, HV, inlet, the retaining device comprising: a retaining component (12) configured to be positioned radially outside of shielding wings (16) of a shielding spring (14), wherein the inner diameter (30) of the retaining component (12) is smaller than the distance (32) between tips (34) of two opposing shielding wings (16) of the loaded shielding spring (14), so that a radially inward force is appliable on the shielding wings (16) by the retaining component (12).

2. The retaining device (10) of claim 1, wherein the retaining component (12) is composed of a polymer.

3. The retaining device (10) of claim 1 or 2, further comprising multiple cylindrical retaining components (12).

4. The retaining device (10) of any one of claims 1 to 3, wherein the diameter (30) of the retaining component (12) is between 20mm to 25mm, preferably between 21mm to 23mm, and more preferably 22.4mm.

5. The retaining device (10) of any one of claims 1 to 4, further comprising engagement elements (18) configured for engaging with a housing (20) of an HV inlet.

6. An assembly (22) for an automotive HV inlet, comprising: a retaining device (10) according to any one of claims 1 to 5, and a shielding spring (14) having multiple shielding wings (16) that are arranged around an opening adapted for receiving an HV cable, wherein the retaining component (12) of the retaining device (10) is positioned radially outside the shielding wings (16) of the shielding spring (14) so that a radially inward force is applied on the shielding wings (16) by the retaining component (12).

7. The assembly (22) of claim 6, wherein the distance (32) between tips (34) of two opposing shielding wings (16) of the shielding spring (14) is 20mm to 25mm, preferably between 21mm to 23mm, and more preferably 22.7mm.

8. The assembly (22) of claim 6 or 7, wherein the shielding spring (14) is composed of a copper alloy, preferably C19010, and / or wherein a coating of the shielding spring (14) is composed of tin or silver.

9. An automotive HV inlet comprising: a housing (20), an HV cable having a conductive core (24), a shielding layer (26) and at least one insulation layer (28), and an assembly (22) according to any one of claims 6 to 8, wherein the assembly (22) is arranged such that the HV cable extends through the opening of the shielding spring (14), and the retaining component (12) of the retaining device (10) presses the shielding wings (16) of the shielding spring (14) radially inwards against the HV cable.

10. The automotive HV inlet of claim 9, wherein the pressure distribution of the pressure the shielding wings (16) apply to the HV cable is uniform over the circumference of the HV cable.

11. The automotive HV inlet of claim 9 or 10, wherein the core (24) is composed of an aluminum alloy, and is preferably EN AW-6101.

12. The automotive HV inlet of any one of claims 9 to 11, wherein the shielding layer (26) of the HV cable is composed of an aluminum alloy, and is preferably EN AW-3103.

13. The automotive HV inlet of any one of claims 9 to 12, wherein the retaining component (12) of the retaining device (10) presses the shielding wings (16) of the shielding spring (14) radially inwards against the shielding layer (26) of the HV cable.

14. The automotive HV inlet of any one of claims 9 to 13, wherein, at a contact point (101) on an axis (100) of the HV cable and along a radial axis (200), the core (24) of the HV cable is in contact with one of the insulation layers (28), the one of the insulation layers (28) is in contact with the shielding layer (26), the shielding layer is in contact with the shielding wings (16) of the shielding spring (14), and the shielding wings (16) of the shielding spring (14) are in contact with the retaining component (12) of the retaining device (10).

15. The automotive HV inlet of claim 14, wherein at least one of the insulation layers (28) of the HV cable is absent along the radial axis (200) at the contact point (101) on the axis (100) of the HV cable.

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