Method for producing and assembling a housing with EMC insert for a HV vehicle component to be cooled

Abstract

The present invention relates to a method for producing a housing with an EMC insert for an HV vehicle component to be cooled, in which method the housing (82) is formed by overmolding a preformed sheet metal, which forms the EMC insert (81) and has a sheet thickness of at least 0.2 mm, with a plastic material. The sheet metal is overmolding towards an inner side of the housing (82) at most for support structures and the sheet metal is completely overmolding towards an outer side of the housing (82) except for at least one shield contact and one heat sink connection. An outwardly extending heat sink (83) is welded to the heat sink connection of the sheet metal. A device produced using the method is also presented.

Description

[0001] The present invention relates to a method for producing a housing with an EMC insert for a HV vehicle component to be cooled. Furthermore, a device produced using the method is presented.

[0002] In electric vehicles, for example, the traction battery is designed with several high-voltage (HV) battery modules, which are individually cooled. Due to the wiring technology arranged in each battery module, which converts the battery's direct current into an alternating current to operate an electric motor, the respective battery module must be shielded for EMC reasons. It is therefore usually designed as an aluminum die-cast component, which, however, results in a high component weight and also requires disadvantageous corrosion protection measures such as surface coatings, resulting in a correspondingly high CO2 footprint. It is therefore expedient to form a housing for such a battery module from a plastic and to provide a metallic insert for EMC shielding. However, compared to aluminum, for example, plastic has poorer thermal conductivity for the cooling of the battery module required during operation.Cooling plates known from the state of the art, arranged on the outer walls of the battery module, are therefore limited in their efficiency.

[0003] German patent document DE 198 30 227 A1 discloses a housing for an electronic control unit, in particular an airbag control unit. The housing forms a metal sheet insert for electromagnetic shielding and is overmolded with a plastic. A grounding screw and an electrical plug are provided on the housing. The sheet insert comprises a plurality of openings to provide a positive connection between the plastic overmold and the sheet insert.

[0004] Document DE 10 2017 003 854 A1 discloses a plastic housing for an electrical or electronic device that includes a sheet metal insert for electromagnetic shielding. The sheet metal insert is embedded in the plastic housing. Cooling channels are adjacent to the sheet metal insert.

[0005] Document DE 10 2023 114 745 A1 discloses a plastic housing for a high-voltage component. A metal foil is applied to the plastic housing to provide electromagnetic shielding.

[0006] Against this background, it is an object of the present invention to propose a method for cooling a housing of a HV vehicle component, in which the housing is formed from plastic. An EMC insert is arranged within the housing structure. Furthermore, a device is to be presented with which the method can be carried out.

[0007] To achieve the aforementioned object, a method for producing a housing with an EMC insert for a HV vehicle component to be cooled is proposed. The housing is formed by overmolding a preformed sheet metal, which forms the EMC insert and has a sheet thickness of at least 0.2 mm, with a plastic. The sheet metal is overmolding toward an inner side of the housing, at most for supporting structures. Furthermore, the sheet metal is completely overmolding toward an outer side of the housing, except for at least one shield contact and one heat sink connection. A heat sink extending outward is welded to the heat sink connection of the sheet metal.

[0008] The HV vehicle component is selected, for example, as a high-voltage (HV) battery or as a module, an HV battery.

[0009] In the process according to the invention, plastic is used as the housing material, which is advantageously lighter than a metal known from the prior art. Furthermore, mechanical machining of flange and connection surfaces is advantageously not required, as is the case with, for example, an aluminum housing. Support structures on the side of the EMC insert facing the inside of the housing serve to optimize component strength and rigidity of the housing. It is conceivable to attach additional structures using a welding process.

[0010] Another advantage of the EMC insert is that, like a metal housing, it shields surrounding electronic devices from electromagnetic interference. In particular, to ensure electromagnetic compatibility (EMC) in the required frequency band, which is achieved by high-frequency switching to generate alternating voltage using pulse width modulation (PWM), the sheet metal of the EMC insert should have a minimum thickness of 0.2 mm. In a manufacturing process, it may be advantageous to use a sheet thickness of 0.5 mm.

[0011] In one embodiment of the method according to the invention, the plastic is formed by a thermoplastic and the sheet of the EMC insert is made of aluminum. By overmolding the EMC insert with the plastic, the EMC insert is integrated into the housing. During the manufacturing process, the sheet of the EMC insert is inserted into an injection mold and overmolded, for example as a preformed or deep-drawn sheet or as a perforated sheet or fabric. Accordingly, the EMC insert to be overmolded already replicates the geometry of the finished plastic-encased housing. According to the invention, the EMC insert is partially exposed on the inside of the housing. Since the interior of the housing of the HV vehicle component is not exposed to environmental conditions and represents a sealed chamber and / or a dry chamber, corrosion protection of the sheet not covered by plastic is advantageously unnecessary.

[0012] In a further embodiment of the method according to the invention, the at least one shield contact is formed with a component from the following list: screw sleeve, welding flange for LV connection, welding flange for HV connection, equipotential bonding contact, connection bolt for electrical contacts: B+, PE, PA. In the area of ​​a respective contact of the EMC insert with a component from the above list, the at least one shield contact is designed as a clean flange contact, i.e., manufactured in a dry room during the manufacturing process, with a bare metal contact surface and a cross-sectional area sufficient for equipotential bonding. In order to arrange a respective connection bolt such as B+, PE or PA on the housing, it is conceivable to design the EMC insert in such a way that the EMC insert is connected directly to the respective connection bolt - e.g. by welding.Furthermore, it is conceivable to integrate an LV connection and / or an HV connection directly into the housing or to attach it to the housing by ultrasonic welding, which advantageously eliminates the need for a seal or even a screw flange.

[0013] In yet another embodiment of the method according to the invention, a predetermined mass is selected for the heat sink in the case of passive cooling, for example, in the range of a proportional weight, e.g., 10%, of a housing constructed entirely of aluminum. Alternatively, a cooling structure in the form of a cooling plate connected to an active cooling system is arranged on the heat sink.

[0014] In a further embodiment of the method according to the invention, openings are provided in the EMC insert to reduce thermal material stresses between the plastic and the sheet metal. Through such openings, the plastic can be directed to a different side of the EMC insert during the manufacturing process, thus, for example, increasing component rigidity. However, air and creepage distances are also advantageously increased by providing openings. Furthermore, it is conceivable that the openings could be advantageously used for arranging busbars and / or cable guides.

[0015] Such a plastic, guided through openings, mechanically and positively secures the EMC insert in the housing, eliminating the need for a chemical bond between the sheet metal and the plastic. A material bond between the plastic and the EMC insert is also not required, but may be intended during the manufacturing process. The EMC insert's fixings are selected so that relative movement between them, for example due to thermal expansion, can be compensated. This is advantageous over a purely material bond, in which the EMC insert would eventually detach from the plastic.

[0016] The plastic passing through the openings can also be arranged to fulfill additional functions, such as: • Formation of rib structures for better manufacturability, strength or rigidity of the housing; • Improvement of clearance and creepage distances with regard to the electrical insulation requirements in narrow areas to (internal) components enclosed by the housing, whereby live components are shielded from the EMC insert; • Component guidance, positioning or alignment for internal components; • Busbar guide or cable guide or cable duct for internal components.

[0017] Furthermore, a device is claimed which comprises a housing of an HV vehicle component, an EMC insert enclosed by the housing, and a heat sink. The housing is formed by overmolding a preformed sheet metal, which forms the EMC insert and has a sheet thickness of at least 0.2 mm, with a plastic. The sheet metal is overmolding towards an inner side of the housing, at most for supporting structures. Towards an outer side of the housing, the sheet metal is completely overmolding except for at least one shield contact and one heat sink connection. A heat sink extending outwards is welded to the heat sink connection of the sheet metal.

[0018] In one embodiment of the device according to the invention, the plastic is formed by a thermoplastic and the sheet is formed by aluminum.

[0019] In a further embodiment of the device according to the invention, the at least one shielding contact is formed with a component from the following list: screw sleeve, welding flange for LV connection, welding flange for HV connection, potential equalization contact, connection bolt for electrical contacts: B+, PE, PA.

[0020] In yet another embodiment of the device according to the invention, in the case of passive cooling, a predetermined mass is selected for the heat sink. Alternatively, in the case of active cooling, a cooling structure in the form of a cooling plate is arranged on the heat sink.

[0021] In a further embodiment of the device according to the invention, openings are provided in the EMC insert. The openings are designed to relieve thermal material stresses between the plastic and the sheet metal.

[0022] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

[0023] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0024] The characters are described coherently and comprehensively. Fig. 1 shows a sectional view of a housing with an EMC insert in an embodiment of the device according to the invention. Fig. 2 shows a sectional view of shield contacts of the EMC insert in a further embodiment of the device according to the invention. Fig. 3 shows a sectional view of openings of an EMC insert in a further embodiment of the device according to the invention. Fig. 4 shows a perspective sectional view of a housing with EMC insert in a further embodiment of the device according to the invention. Fig. 5 shows a perspective sectional view 50 of an EMC insert 51 in the further embodiment of the device according to the invention from Fig. 4. Fig. 6 shows a sectional view of an upper housing part with EMC insert in a further embodiment of the device according to the invention. Fig. 7 shows a sectional view of an upper housing part with EMC insert and inserted connection bolt in a continued embodiment of the device according to the invention. Fig. 8 shows a sectional view of an upper housing part with EMC insert and arranged heat sink in a further embodiment of the device according to the invention. Fig. 9 shows a sectional view of a bulge between openings of the EMC insert in a further developed embodiment of the device according to the invention.

[0025] In Fig. 1 shows a sectional view 10 of a housing 12 with an EMC insert 11 in one embodiment of the device according to the invention. Openings 13 in the EMC insert 11 allow a plastic to reach a respective other side of the EMC insert 11 during overmolding during the manufacturing process. For example, an HV vehicle component is arranged in an interior space 14 of the housing 12. Since such an HV component generates waste heat during operation (both charging at a charging station and discharging during driving), cooling is provided. In the area of ​​a flange connection of the housing, e.g. on a metallic base plate, a partial surface of the sheet metal of the EMC insert is exposed for a shield contact 15 with the base plate to establish potential equalization. Since the interior space 14 is intended to represent a sealing chamber, a sealing groove 16 for the insertion of a seal is located in the area of ​​the flange connection.In addition, a screw sleeve 17 is provided for firmly screwing the housing to the base plate.

[0026] In Fig. Figure 2 shows a sectional view 20 of shield contacts 21, 22 of the EMC insert 11 in a further embodiment of the device according to the invention. A first shield contact 21 of the EMC insert 11 is formed by the screw sleeve 17. A second shield contact 22 of the EMC insert 11 is formed by the connection opening 23. Potential equalization is implemented on the EMC insert 11 through the respective shield contacts 21, 22.

[0027] In Fig. 3 shows a sectional view 30 of openings 33 of an EMC insert 31 in a further embodiment of the device according to the invention. Through the openings 33, the plastic can reach a respective other side of the EMC insert 31 during the manufacturing process and thus, for example, increase component rigidity, for example by forming support structures on an inner side of the EMC insert 31 starting from the openings 33. In a respective intermediate region 32 between the openings 33, which lead to a fixation of the plastic to the EMC insert 31 in the housing 12, a relative movement can advantageously take place between the overmolded plastic and the EMC insert 31 to reduce material stresses.

[0028] In Fig. Figure 4 shows a perspective sectional view 40 of a housing 42 with an EMC insert 41 in a further embodiment of the device according to the invention. Support structures 44 in the form of plastic ribs are arranged on the inside of the housing 42 on the EMC insert 41. A connection bolt for an electrical contact, for example, can be arranged at a connection opening 43.

[0029] In Fig. 5 shows a perspective sectional view 50 of an EMC insert 51 in the further embodiment of the device according to the invention from Fig. 4. Through the openings in the EMC insert 51, the plastic can pass from the outside to the inside or vice versa during overmolding, thus creating a material-locking connection between the plastic-coated outside of the housing and the Fig. 4 with reference numeral 44 shown support structures.

[0030] In Fig. Figure 6 shows a sectional view 60 of an upper part of the housing 62 with an EMC insert 61 in a further embodiment of the device according to the invention. A welding flange 64 for a respective connection, e.g., for an LV (low-voltage) connection or an HV (high-voltage) connection, is provided on the upper part of the housing 62 in the area of ​​the shield contact 63.

[0031] In Fig. Figure 7 shows a sectional view 70 of an upper part of the housing 72 with an EMC insert 71 and an inserted connecting bolt 73, for example a B+ bolt with an outward-facing contact surface 75, in a further embodiment of the device according to the invention. The connecting bolt 73, connected to a HV vehicle component 74, is connected 76 to the plastic of the housing 72 and 77 to the EMC insert 71, for example, by a welding process.

[0032] In Fig. Figure 8 shows a sectional view 80 of an upper part of the housing 82 with EMC insert 81 and arranged heat sink 83 in a further developed embodiment of the device according to the invention. The heat sink 83 is positively connected 86 to the plastic of the housing 82. In addition, the heat sink 83 is tapered 85 to increase fixation in the plastic of the housing. The heat sink 83 and the EMC insert 81 are connected to one another in an area 87, e.g., by a welding process. Within an inner area 88 of the EMC insert 81, a gap pad or gap filler is arranged for heat transfer from an HV vehicle component 84. The size of the heat sink 83 is designed to absorb heat generated in the HV vehicle component 84 during driving and to radiate it from its surface to such an extent that the HV vehicle component 84 can be operated within its operating temperature limits.However, it is also conceivable to connect the heat sink 83 to a cooling system outside the housing 82.

[0033] In Fig. 9 shows a sectional view 90 of a bulge 92 between openings of the EMC insert in a further developed embodiment of the device according to the invention. At least a part of the inner side of the EMC insert is not overmolded with plastic, so that the sheet metal can bulge, for example, to compensate for material stresses, which is shown in the figure for a sheet metal section 92 between two openings. In this case, a break in contact with the injected plastic is possible in the intermediate area between the EMC insert and the plastic. In principle, however, as shown in the Fig. As shown in Figure 9, the form fit between the sheet metal and the plastic is maintained. A bulge is also conceivable for the plastic, for example, in the area of ​​an opening. List of reference symbols 10 Sectional view 11 EMC inserts 12 housings 13 openings in the EMC insert 14 Interior 15 Free partial area for shield contact with base plate 16 Sealing groove 17 screw sleeve 20 Sectional view of shield contact with screw sleeve 21 Shield contact with screw sleeve 22 Shield contact with connection opening 23 Connection opening 30 Sectional view of openings in the EMC insert 31 EMC inserts 32 Intermediate range for relative movement 33 openings in the EMC insert 40 Perspective view 41 EMC inserts 42 housings 43 Connection opening 44 Support structure on the inside 50 Perspective view of EMC insert 51 EMC inserts 60 Sectional view of upper housing section with welding flange 61 EMC inserts 62 housings 63 Shield contact 64 Welding flange for connections 70 Sectional view with inserted connecting bolt 71 EMC inserts 72 housings 73 connecting bolts 74 HV vehicle components 75 Contact surface connecting bolt 76 Connection with plastic of the housing 77 Connection with EMC insert 80 Sectional view of housing with heat sink 81 EMC inserts 82 housings 83 heat sinks 84 HV vehicle components 85 Contour fixation 86 Heat sink connection with plastic of the housing 87 Heat sink connection with EMC insert 88 Heat sink / interior component connection surface 90 sectional view with bulge 92 Sheet metal section with bulge

Claims

[1] Method for producing a housing (12, 42, 62, 72, 82) with EMC insert (11, 31, 41, 51, 61, 71, 81) for a HV vehicle component (74, 84) to be cooled, in which the housing (12, 42, 62, 72, 82) is formed by a pre-formed sheet, which forms the EMC insert (11, 31, 41, 51, 61, 71, 81) and has a sheet thickness of at least 0.2 mm, being over-molded with a plastic, wherein the sheet is over-molded towards an inner side of the housing (12, 42, 62, 72, 82) at most for support structures (44) and the sheet is over-molded towards an outer side of the housing (12, 42, 62, 72, 82) is completely overmolded except for at least one shield contact (21, 22, 63) and a heat sink connection, and in which an outwardly extending heat sink (83) is welded to the heat sink connection of the sheet. [2] A method according to claim 1, wherein the plastic is formed by a thermoplastic and wherein the sheet is formed from aluminum. [3] Method according to one of the preceding claims, in which the at least one shielding contact (21, 22, 63) is formed with a component from the following list: screw sleeve (17), welding flange for LV connection, welding flange for HV connection, potential equalization contact, connection bolt (73) for electrical contacts: B+, PE, PA. [4] Method according to one of the preceding claims, in which, in the case of passive cooling, a predetermined mass is selected for the heat sink (83) or a cooling structure in the form of a cooling plate is arranged on the heat sink (83). [5] Method according to one of the preceding claims, in which openings are provided in the EMC insert (11, 31, 41, 51, 61, 71, 81) to reduce thermal material stresses between plastic and sheet metal. [6] Device comprising a housing (12, 42, 62, 72, 82) of a HV vehicle component (74, 84), an EMC insert (11, 31, 41, 51, 61, 71, 81) encompassed by the housing (12, 42, 62, 72, 82) and a heat sink (83), wherein the housing (12, 42, 62, 72, 82) is formed by a preformed sheet metal forming the EMC insert (11, 31, 41, 51, 61, 71, 81) and having a sheet thickness of at least 0.2 mm, being overmolded with a plastic, wherein the sheet metal is designed to be used towards an inner side of the housing (12, 42, 62, 72, 82) at most for support structures (44) is overmolded and the sheet is completely overmolded towards an outer side of the housing (12, 42, 62, 72, 82) except for at least one shield contact (21, 22, 63) and a heat sink connection, and wherein an outwardly extending heat sink (83) is welded to the heat sink connection of the sheet. [7] Device according to claim 6, wherein the plastic is formed by a thermoplastic and wherein the sheet is formed of aluminum. [8] Device according to one of claims 6 or 7, wherein the at least one shielding contact (21, 22, 63) is formed with a component from the following list: screw sleeve (17), welding flange for LV connection, welding flange for HV connection, potential equalization contact, connection bolt (73) for electrical contacts: B+, PE, PA. [9] Device according to one of claims 6 to 8, wherein in the case of passive cooling a predetermined mass is selected for the heat sink (83) or in the case of active cooling a cooling structure in the form of a cooling plate is arranged on the heat sink (83). [10] Device according to one of claims 6 to 9, wherein openings are provided in the EMC insert (11, 31, 41, 51, 61, 71, 81) which are designed to reduce thermal material stresses between plastic and sheet metal.

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