Packaging of electrical equipment for a motor vehicle with electromagnetic shielding.

Abstract

This electromagnetic shielding package (10) for electrical equipment of a motor vehicle comprises a housing (20) formed by walls delimiting a housing for surrounding the electrical equipment and a means for electromagnetic shielding of the package (10). In particular, the shielding means comprises an internal electrically conductive coating extending internally on internal faces of the walls of the housing (20). The housing (20) comprises at least one member, integrated into the housing (20), configured to provide electrical continuity between the internal coating and an electrical ground of the motor vehicle in a mounted configuration of the package (10) in the motor vehicle. SHORT FIGURE: FIGURE 2.

Description

Title of the invention: Packaging of electrical equipment for a motor vehicle with electromagnetic shielding. Technical field.

[0001] The present invention relates to the field of electrical equipment for motor vehicles and more particularly to the electromagnetic shielding of this electrical equipment. The invention applies more particularly but not exclusively to an electric motor vehicle comprising an electric motor powered by a battery unit. Prior art.

[0002] Electrical equipment for vehicle motorization systems is already known from the prior art, comprising in particular electronic cards (control, piloting, filtering), capacitive elements and filtering devices mounted in a housing closed by a cover, hereinafter referred to as "packaging".

[0003] These electrical components in which currents circulate, particularly with high powers, generate magnetic fields likely to disrupt the operation of other components. The operation of each of these components is likely to be affected by such electromagnetic disturbances. It is then desirable to mitigate these disturbances.

[0004] Thus, as is known, such electrical equipment must have good electromagnetic compatibility performance. In other words, it must be ensured on the one hand that the electrical equipment is capable of operating itself without disturbances, in its electromagnetic environment, and on the other hand that it is also capable of operating without introducing electromagnetic disturbances likely to harm the proper functioning of third-party electrical equipment located nearby.

[0005] Furthermore, generally speaking, in the case of electric motorization, the battery is subject to electromagnetic constraints coming from the various electronic equipment of the vehicle such as the ECU (electronic control unit) better known by the English acronym ECU which can cause disturbances and malfunction of the battery, electromagnetic interference (EMI).

[0006] One solution is to enclose electrical equipment in electromagnetic shielding packaging.

[0007] Currently, to give equipment packaging electromagnetic shielding properties, the most frequently adopted solution is to make these packagings from metal. However, this solution is not satisfactory, because it significantly increases the weight considerable the motor vehicle.

[0008] An alternative solution consists of making at least part of the packaging from plastic material, and shielding this part of the packaging by applying an aluminum foil to it or by spraying a conductive material onto said part of the packaging. Making this envelope conductive gives it shielding properties. This solution has an obvious weight advantage over the first solution.

[0009] The invention seeks to propose an optimized and efficient solution for electromagnetic shielding packaging which meets new requirements, particularly in terms of protection against leakage currents.

[0010] The invention aims in particular to propose a high-performance package in terms of electromagnetic shielding with simple and effective protection against leakage currents. Summary of the invention

[0011] To this end, the invention relates to an electromagnetic shielding package for electrical equipment of a motor vehicle, comprising a housing formed by walls delimiting a housing for surrounding the electrical equipment and a means for electromagnetic shielding of the package, characterized in that the shielding means comprises an internal electrically conductive coating extending internally on internal faces of the walls of the housing and in that the housing comprises at least one member, integrated into the housing, configured to place the internal coating in electrical continuity with an electrical ground of the motor vehicle in a mounted configuration of the package in the motor vehicle.

[0012] Thanks to the packaging of the invention, by evacuating the leakage currents from the inner coating to the electrical ground of the motor vehicle, during an electrical fault, the leakage current flows from the inner coating to the electrical ground.

[0013] A package according to the invention may comprise one or more of the following characteristics.

[0014] In a preferred embodiment of the invention, the member for providing electrical continuity to the inner coating comprises a metal part in direct contact with the inner shielding coating.

[0015] In a preferred embodiment of the invention, the member is a first electrical connection end piece for the electrical connection of a second complementary electrical connection end piece, external to the packaging, the first electrical connection end piece comprising a metal part in direct contact with the internal shielding coating.

[0016] In a preferred embodiment of the invention, the first connection tip electrical comprises a metal plate embedded in the wall of the housing, the plate being at least partially covered by the inner coating.

[0017] In a preferred embodiment of the invention, the member comprises a metal insert mounted inside a blind bore of a wall of the housing and in electrical contact with the inner coating, configured to secure the electrical equipment to the wall of the housing.

[0018] In a preferred embodiment of the invention, the housing being formed by assembling two parts together having peripheral edges provided with faces facing each other on which the coating extends, the member comprises a releasable or permanent fixing element configured to press the two contact faces against each other.

[0019] In a preferred embodiment of the invention, the fixing element is metallic.

[0020] In a preferred embodiment of the invention, the coating is obtained by spraying a layer of an electrically conductive material onto the inner faces of the walls of the housing.

[0021] In a preferred embodiment of the invention, the material is a metallic material essentially comprising zinc.

[0022] The invention also relates to an electrical system for a motor vehicle comprising an electrical circuit of the vehicle having a phase entry point and a neutral entry point between which a voltage is intended to be applied to electrically supply the electrical circuit, the electrical circuit being electrically connected to the packaging by the member according to the invention.

[0023] In a preferred embodiment of the invention, the system comprises a ground connector having a first end connected to electrical ground and a second end intended to be connected to the ground terminal of a charging station to connect the electrical ground to ground. Brief description of the drawings

[0024] Other characteristics and advantages of the invention will appear in the light of the following description, given with reference to the accompanying drawings in which: Fig.l

[0025] [Fig.l] represents a perspective view of a package according to the invention; Fig.2

[0026] [Fig.2] represents a perspective view of the packaging of [Fig.l] according to another angular point of view; Fig.3

[0027] [Fig.3] represents a sectional view of a connector of the package of [Fig.l]; Fig.4

[0028] [Fig.4] represents an enlarged scale view of the circled part IV-IV of [Fig.3]; Fig.5

[0029] [Fig.5] represents a sectional view of an insert. Fig.6

[0030] [Fig.6] represents an enlarged scale view of the circled part VI-VI of [Fig.5]. Fig.7

[0031] [Fig.7] represents a sectional view and on an enlarged scale of a fixing element of two parts of the packaging case of [Fig.l]. Description of the embodiments

[0032] [Fig. 1] shows an electrical system for a motor vehicle. The system comprises an electromagnetic shielding package which is designated by the general reference 10.

[0033] Generally, a motor vehicle comprises an electrical system for powering a plurality of electrical equipment items of the vehicle. Electrical equipment comprises, for example, electronic cards (control, piloting, filtering), capacitive elements and / or filtering devices.

[0034] The electrical system preferably further comprises an electrical circuit having a phase entry point and a neutral entry point between which an electrical supply voltage is intended to be applied to electrically supply the electrical circuit and consequently the electrical equipment.

[0035] In a preferred embodiment of the invention, the motor vehicle is an electrically powered vehicle and comprises a battery which is electrically connected to an electric motor of the motor vehicle to supply it with electrical energy. The battery is electrically connected in the example described to the electrical circuit of the vehicle's electrical system.

[0036] Conventionally, the electrical system further comprises an electrical ground. The electrical ground comprises, for example, a chassis or a body of the motor vehicle. The electrical ground is preferably connected to the electrical circuit of the vehicle's electrical system.

[0037] In the case of an electrically powered vehicle, the electrical system further comprises a phase conductor and a neutral conductor having first ends connected respectively to the phase and neutral entry points of the electrical circuit and second ends intended to be connected respectively to the phase and neutral terminals of the electrical network of a charging station.

[0038] Generally, such a charging station comprises an electrical network having a phase terminal and a neutral terminal between which the electrical network generates an alternating network voltage. In addition, the charging station has, for example, an earth terminal connected to the earth.

[0039] Thus, preferably, the electrical system further comprises an earth connector having a first end connected to the electrical ground and a second end intended to be connected to the earth terminal of the charging station to connect the electrical ground to the earth.

[0040] More particularly, in order to protect the operation of the electrical equipment of the vehicle's electrical system from electromagnetic disturbances, the system also comprises an electromagnetic shielding package 10 for at least one piece of electrical equipment of the vehicle, for example an electronic card.

[0041] In the example described, the packaging 10 comprises a housing 20 formed by walls 200 delimiting a housing for surrounding the electrical equipment (not shown in the figures). In the example illustrated in the figures, the housing 20 comprises peripheral walls 202, a bottom wall 204 and is closed by a cover wall 206. In the example described, the housing 20 is made of plastic, for example made by injection molding a plastic such as a thermoplastic. The plastic has the advantage of being a lightweight and economical material to manufacture, for example by injection molding the plastic.

[0042] The package 10 further comprises a means 30 for electromagnetically shielding the package 10 comprising an internal electrically conductive coating 300. Preferably, the internal electrically conductive coating 300 extends internally on internal faces of the walls 200 of the housing 20. Preferably, the coating 300 is obtained by spraying a layer of a molten electrically conductive material. For example, the coating 300 is made of a material essentially comprising zinc. The coating 300 is preferably made by a technique called “shooping” metallization.

[0043] Generally speaking, leakage currents are likely to be generated by all of the electrical components housed in the packaging 10. It is thus known that leakage currents can be transmitted by electrical coupling (for example capacitive) which can be linked for example to a parasitic capacitance inside an electrical device or an electrical component housed in the packaging 10. An electrical coupling (without contact, without propagation of the current), which can be for example inductive and / or capacitive, between the devices and the coating 300 is also possible and can induce a leakage current whose intensity depends on the coupling of all of the elements together.

[0044] The invention proposes to minimize leakage currents by means of relays 40 for evacuating leakage currents towards the electrical circuit connected to the ground of the motor vehicle.

[0045] For this purpose, in accordance with the invention, the housing 20 comprises at least one member 40, integrated into the housing 20, configured to provide electrical continuity between the inner lining 300 and the electrical ground of the motor vehicle in a mounted configuration of the packaging 10 in the motor vehicle. In particular, the electrical circuit of the electrical system is electrically connected to the packaging 10 by the member 40 and therefore to the electrical ground of the vehicle.

[0046] In the example described, the housing 20 comprises three types of members designated distinctively and respectively by the references 40A, 40B, 40C. These members 40 allow the electrical continuity of the interior covering 300 with the electrical ground of the motor vehicle when the packaging 10 is mounted in an operational configuration.

[0047] Preferably, in the three types of members described, the member 40 comprises a metal part in direct electrical contact with the inner shielding coating 300. This metal part is for example overmolded in a plastic material forming the housing 20 but it can also be attached by screwing, riveting, crimping or welding.

[0048] Figures 3 and 4 show a type of member referenced 40A. As illustrated in [Fig.3] and [Fig.4], the member 40A comprises a first electrical connection end piece for the electrical connection of a second complementary electrical connection end piece 414, external to the packaging 10. As illustrated in [Fig.3], the first electrical connection end piece 40A comprises a metal part 410A in direct electrical contact with the inner shielding coating 300.

[0049] Preferably, as illustrated in Figures 3 and 4, the metal part 410A comprises a metal plate 412A embedded in the wall 200 of the housing 20 and the second end piece comprises a metal pin 414 extending in projection towards the outside of the housing 20. Preferably, the plate 412A is at least partially covered by the inner coating 300.

[0050] Figures 5 and 6 show a second type of electrical continuity member referenced 40B. This member 40B is configured to secure the electrical equipment to a wall 200 of the housing 20. In this example, the member 40B comprises a metal insert 410B mounted inside a blind bore 420B of an inner face of a wall 200 of the housing 20. The blind bore 420B is preferably formed in a projecting relief 220B of the wall of the housing 20 towards the outside. The projecting relief 220B has for example a general shape of a closed frustoconical stud.

[0051] For example, this metal insert 410B has a generally truncated cone shape. Preferably, this metal insert 410B is for example in electrical contact with the inner coating 300. Generally, this metal insert 410B is in the form of the shape of a socket inside which a fixing element (not shown) of the electrical equipment can be inserted to the wall 200 of the housing 20.

[0052] As illustrated in detail in [Fig. 6], the metal insert 410B comprises a main body 412B of generally frustoconical shape around an axis X and is provided with a peripheral end rim 414B forming a mounting collar. For this purpose, the bore 420B comprises a support shoulder 422B on which the collar 414B of the metal insert 410B rests. In the example illustrated, the support shoulder 222B comprises a radial face on which the collar rests and an axial face. Preferably, the inner liner 300 extends over the rim 414B and inside the bore 420B, for example in a residual gap 416B formed between the shoulder 222B of the bore 420B and the rim 414B of the metal insert 410B.

[0053] Finally, [Fig. 7] shows a third type of member referenced 40C. For example, this third member 40C has the function of ensuring electrical continuity between two parts 204 and 206 of the housing 20 which are assembled with each other, for example in a releasable or permanent manner. Preferably, the two parts 204 and 206 assembled with each other comprise peripheral rims which have contact faces facing each other on which the coating 300 extends. In the example illustrated, the housing 20 comprises a main body 202, 204 and a cover 206 mounted on the main body which are each provided with a peripheral rim around an open end each delimiting the contact faces.The third member 40C comprises a fixing element, preferably metallic, configured to press the two contact faces together in order to ensure electrical continuity of the internal shielding coating 300 of each of the two parts of the housing 20.

[0054] The main aspects of the operation of a package according to the invention will now be described with reference to Figures 1 to 7.

[0055] Once the packaging 10 is mounted in the motor vehicle, the leakage currents, for example generated by electrical devices housed in the packaging 10, are evacuated by the inner coating 300 which forms an electrical transmission layer. In addition, the members 40 form an electrical bridge between the inner coating 300 and the local mass of the electric vehicle. In this way, the leakage currents are minimized.

[0056] Of course, the invention is not limited to the embodiments previously described. Other embodiments within the reach of those skilled in the art may also be envisaged without departing from the scope of the invention defined by the claims below.

Claims

Claims

1. Electromagnetic shielding packaging (10) for electrical equipment of a motor vehicle, comprising a housing (20) formed by walls (200) delimiting a housing for surrounding the electrical equipment and a means (30) for electromagnetic shielding of the packaging (10) characterized in that the shielding means (30) comprises an internal electrically conductive coating (300) extending internally on internal faces of the walls (200) of the housing (20) and in that the housing (20) comprises at least one member (40; 40A, 40B, 40C), integrated in the housing (20), configured to provide electrical continuity between the internal coating (300) and an electrical ground of the motor vehicle in a mounted configuration of the packaging (10) in the motor vehicle, the member (40;40A) being a first electrical connection tip for the electrical connection of a second complementary electrical connection tip (410, external to the packaging (10), the first electrical connection tip (40A) comprising a metal part (410A) in direct contact with the inner shielding coating (300).;

2. Packaging (10) according to the preceding claim, in which the electrical continuity member (40; 40A, 40B, 40C) of the inner coating (300) comprises a metal part in direct contact with the inner shielding coating (300).

3. Packaging (10) according to any one of the preceding claims, in which the first electrical connection tip (410A) comprises a metal plate embedded (412A) in the wall (200) of the housing (20), the plate (412A) being at least partially covered by the inner coating (300).

4. Packaging (10) according to any one of the preceding claims, in which the member (40; 40B) comprises a metal insert (410B) mounted inside a blind bore (420B) of a wall (200) of the housing (20) and in electrical contact with the inner coating (300), configured to secure the electrical equipment to the wall (200) of the housing (20).

5. Packaging (10) according to any one of the preceding claims, in which the housing (20) is formed by assembling two parts (202, 204, 206) together having peripheral edges provided with faces facing each other on which the re- garment (300), the member (40C) comprises a releasable or permanent fixing element (410C) configured to press the two contact faces against each other.

6. Packaging (10) according to the preceding claim, in which the fixing element (41 OC) is metallic.

7. Packaging (10) according to any one of the preceding claims, wherein the coating (300) is obtained by spraying a layer of an electrically conductive material onto the inner faces of the walls (200) of the housing (10).

8. A package (10) according to any preceding claim, wherein the material is a metallic material comprising essentially zinc.

9. Electrical system for a motor vehicle comprising an electrical circuit of the vehicle having a phase input point and a neutral input point between which a voltage is intended to be applied to electrically supply the electrical circuit, the electrical circuit being electrically connected to the packaging (10) by the member (40; 40A, 40B, 40C) according to any one of the preceding claims.

10. A system according to the preceding claim, wherein the electrical ground of the motor vehicle comprises the chassis of the motor vehicle which is electrically connected to the electrical circuit.

11. A system according to claim 9 or 10, comprising an earth connector having a first end connected to electrical ground and a second end intended to be connected to the earth terminal of a charging station to connect the electrical ground to earth.

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