Shielded housing

Abstract

Shield housing (1) made of an electrically conductive material which tends to form an oxide layer under an oxygen-containing atmosphere, in particular made of aluminum or an aluminum alloy, with at least one opening (2) whose inner circumference (3) is to be electrically contacted directly or indirectly with the shield of an electrical conductor, wherein a contact sleeve (10) is pressed into the opening (2), which is made of or coated with a material other than the housing, characterized in that a contact element (12) with several lamellae (13) is held in the contact sleeve (10), wherein the lamellae (13) are electrically contacted on the one hand with the inner circumference of the contact sleeve (10) and on the other hand are to be electrically contacted directly or indirectly with the shield of an electrical conductor.

Description

[0001] The present invention relates to a shielding housing and, in particular, to the interface of such a shielding housing for direct or indirect electrical connection to the shield of an electrical line. An example of such a shielding housing is the power unit housing, which houses the drive of vehicles powered by battery- or accumulator-powered electric motors, either alone or in combination with another, non-electrical energy source, a so-called hybrid drive.

[0002] In the prior art, openings are provided in such housings, the inner circumference of which is contacted with the shield of an electrical cable via interface parts. For this purpose, so-called headers are usually connected to the housing as interfaces. The header usually contains a shielding sleeve, the outer surface of which is in loose electrical contact with the inner circumference of the opening in the housing. When the header is mounted on the housing, the shielding sleeve is inserted axially into the openings. A corresponding counterpart, for example a plug, is inserted into the header and is connected to the cable in order to establish the electrical connection between the cable shield and the housing via the shielding sleeve of the header. A problem, however, is that in the prior art these shielding housings are often made of aluminum or an aluminum alloy.However, aluminum and aluminum alloys tend to spontaneously form an oxide layer in oxygen-containing atmospheres. This oxide layer means that even when using intermediate elements (headers) as a stationary interface, electrical contact between the shielding sleeve or, in the case of a direct connection, the cable shield and the housing cannot be reliably maintained.

[0003] From DE 10 2012 208 207 A1 and from JP H0819157 A, connecting mechanisms for a ground conductor with a housing are known.

[0004] Accordingly, the object of the present invention is to further develop a shielding housing of the type mentioned at the outset in such a way that a more reliable and secure contact between the shield of an electrical line and the shielding housing can be realized in the simplest way.

[0005] This object is achieved by the subject matter of claim 1. Advantageous further developments can be found in the subclaims, the following description of the invention as well as the exemplary embodiment and the drawings.

[0006] The basic idea of ​​the present invention is not to make direct electrical contact between the shield of an electrical line or the contacts (shield sleeve) of any intermediate element (header) and the inner circumference of the opening in the shield housing, but rather to press a contact sleeve made of a different material or coated with a different material than the housing, in particular a material less prone to oxide layer formation, into the opening in the housing. Pressing in this context means a press fit, i.e. an interference fit in which the outer dimension of the sleeve to be pressed in is larger than the inner dimension of the opening. It has surprisingly been found that pressing in enables more reliable contact without the subsequent deterioration of the electrical connection due to oxide formation on the housing.By designing or coating the contact sleeve from a different, less oxidizing material, reliable contact with the cable shield can be maintained, since the electrical contact between the contact sleeve and the shield sleeve or shield of the electrical cable does not cause the problems of oxide formation.

[0007] Copper or a copper alloy is advantageously used as the material for the contact sleeve. However, it is also conceivable to form the contact sleeve from aluminum or an aluminum alloy, in which case, and for example, in the case of a shielded housing made of aluminum or an aluminum alloy, a coating made of a different material is preferably provided.

[0008] To further improve the electrical connection, it may be advantageous to coat the contact sleeve with a precious metal, particularly silver or gold, or with tin or nickel. These materials are even less prone to oxide formation and offer low contact resistance, further improving the electrical contact.

[0009] In order to realize the contact between the contact sleeve and the shielding sleeve or the shield of the electrical line, it is advantageous to provide a contact element with several lamellae in the sleeve, which is held in the contact sleeve, wherein the lamellae are on the one hand electrically contacted with the inner circumference of the contact sleeve (usually loosely resting on the inner circumference of the sleeve) and on the other hand are to be electrically contacted with the shield of an electrical line (preferably by either inserting the shield of the electrical line directly into the lamellae or inserting a shielding sleeve into the lamellae).

[0010] In order to achieve a particularly good electrical transition between the lamellae or the contact element and the contact sleeve, the lamellae are preferably also made of copper, aluminum or an alloy thereof and it is also advantageous to coat the lamellae with a precious metal, in particular silver or gold or with tin or nickel, especially when aluminum or an aluminum alloy is used.

[0011] For this purpose, it has proven particularly advantageous if the blades of the contact element run parallel to the direction of insertion, particularly in the direction along which the shield of an electrical cable or the shield sleeve is inserted into the contact element. Of course, the blades can also run diagonally to the direction of insertion, preferably to ensure a smooth joining process. The insertion direction can be the direction in which the connector and header, or the header and housing, or the shield sleeve and opening are plugged together.

[0012] The contact element can be formed from a base body made of an electrically conductive material in which the lamellae running in the plugging direction, which are separated from one another by slots, are formed.

[0013] The slats are preferably connected to one another via at least one edge web which is formed integrally (in one piece or made of the same material) with the slats and runs perpendicular to the slats.

[0014] At least two groups of several contact points each are arranged adjacent to and / or on the entirety of the slats, wherein the groups of contact points extend substantially parallel to the edge web.

[0015] Essentially parallel is understood here to mean that the groups of contact points can also run at a small angle (less than 45°, preferably less than 15°) to the edge web, or the individual contact points of a group can be arranged around a line that runs essentially parallel to the edge web (for example, meandering, serpentine or zigzag).

[0016] The first group consists of inner contact points, which serve to contact a first part, here the shielding sleeve of a header, and is arranged adjacent to or on the edge web of the contact element.

[0017] The second group consists of external contact points that are intended to contact a second part, for example the contact sleeve.

[0018] The groups of contact points protrude from the plane spanned by the entire lamellae. This allows the contact element to easily create a multi-point electrical contact between the parts to be contacted, with the first group of contact points ensuring electrical contact with the first part and the second group of contact points ensuring electrical contact with the second part. At the same time, the first and second parts are mechanically clamped together by the protruding contact points, compensating for any existing tolerances, so that the first and second parts are positively connected.

[0019] This surprisingly simple measure makes it possible, for example, to dispense with the preforming or interlacing of the lamellae to produce multi-point contacts with the parts, which is frequently encountered in the prior art, and the production and assembly of a contact element according to the invention is consequently considerably simpler.

[0020] It has been found to be advantageous if the contact points of the first group protrude on the opposite side of the plane spanned by the slats compared to the adjacent contact points of the second group.

[0021] In a preferred embodiment, all contact points within the first group protrude from the plane spanned by the lamellae in the same direction, but opposite to the second group of contact points. With this arrangement of the contact points, the groups of contact points act as supports, and the contact element clamps the two parts together, for example, when inserting the shielding sleeve into the contact sleeve, which also ensures very good electrical contact between the parts.

[0022] A further preferred embodiment has a contact element in which an edge web is integrally connected to the slats on both sides. This increases the mechanical robustness of the component and effectively prevents the slats from fanning out due to incorrect insertion of a part. At the same time, the assembly of the contact element according to the invention is simplified.

[0023] In a preferred embodiment, the second group of outer contact points is at a maximum distance from one or both edge webs.

[0024] This has the advantage that the maximized lever arm facilitates the deformation of the lamellae when making the connection and, in particular, simplifies the insertion of the shielding sleeve without the quality of the electrical contact being noticeably impaired.

[0025] A very advantageous embodiment of the invention has, as described above, two distal edge webs, between which the slats are arranged. Two first groups of contact points are arranged on the edge webs or immediately adjacent to the edge webs. A second group of contact points is arranged in the middle of the slats, i.e. at the maximum distance from the edge webs. The first group of contact points and the second group of contact points protrude from the plane spanned by the slats on opposite sides of the slats. Such an arrangement enables the first part to be easily inserted into the second part until the second group of contact points is reached. In order to be able to insert the first part further into the second part, the pressure which is necessary for deforming or rebounding the slat must be overcome. After deformation or reboundWhen the lamella rebounds, the first part can pass through the first groups of contact points and—if desired—be completely absorbed by the second part. The rebounded or deformed lamella clamps the two parts together, and a favorable electrical multipoint contact is achieved between the two parts via the contact element's groups of contact points.

[0026] It has proven advantageous that the individual contact points of the first group of contact points and the individual contact points of the second group of contact points are arranged on the slats in alignment with one another in the plugging direction.

[0027] The contact points protruding from the plane spanned by the lamellae can be created in a variety of ways. For example, it is conceivable to apply an electrically conductive material to the material of the lamella at the positions where contact points are provided using an application or build-up process known to those skilled in the art. The material is preferably the same material as the lamellae. However, it can also be advantageous to use a material with no tendency to surface corrosion under normal operating conditions, such as a precious metal, but with good electrical conductivity. However, the material can be provided with a coating, preferably tin, silver, or gold, to reduce the tendency to surface corrosion and to provide a contact with low contact resistance.This ensures particularly good and long-lasting electrical contact.

[0028] In a preferred embodiment, the contact points are embossed into the material of the slat. In the simplest case, a pin-like stamping die is used, which displaces the slat material at the position where a contact point is to be created, such that the deformed area protrudes as a contact point from the plane spanned by the slats.

[0029] It is obvious to a person skilled in the art that the geometry of the contact points is not limited, and that other locally limited contact areas protruding from the plane spanned by the lamellae are also understood as contact points in the sense of the invention. For example, lines, circles, pyramids, and a wide variety of other shapes are conceivable. It is also obvious that several locally limited and closely adjacent contact areas can be understood as a single contact point. The crucial point is that only a fraction of the lamellae surface is used as a contact point, and that this serves as a support point when the parts of the plug-in connection are joined together, so that the previously almost undeformed lamellae are subsequently mechanically clamped between the parts of the plug-in connection.

[0030] Particularly preferred is a cross-section of the contact points that features a smooth transition from the lamella. Smooth means that there are no sharp edges that could impede the connection of the connector parts.

[0031] It is particularly advantageous if the embossing of the contact points is coupled with the punching process for producing the semi-finished product, from which the contact elements are manufactured in a subsequent step. Ideally, this is a combined punching and embossing process that takes place in one tool. A strip and / or the lamellar structure can be punched out of a sheet metal or a sheet metal strip or band (for example, in an endless process), and the contact points can be embossed simultaneously or immediately thereafter. In a subsequent step, the contact element is manufactured by cutting off a length from the semi-finished product, depending on the geometry of the plug connection.

[0032] In one embodiment, it is advantageous if the slats are additionally bent. This creates a cambered slat structure that can compensate for larger tolerances between the elements of the plug-in connection.

[0033] Advantageously, the contact element is formed into an annular component.

[0034] It is preferred that the contact element be made of a conductive, resilient material. Suitable materials include metals such as copper or copper alloys, which may be fully or partially coated with another material, such as tin, silver, or gold, for example, in the area of ​​the contact points.

[0035] Particularly preferably, the contact element made of resilient material is a slotted annular component, i.e., part of the circumference consists of a slot running perpendicularly or at an angle to the edge webs, so that the contact part can be temporarily compressed or expanded and can thus be mounted on a part prepared for this purpose, in particular a recess of the contact sleeve.

[0036] Further features and advantages of the present invention, which can be implemented alone or in combination with one or more of the above-mentioned features, will become apparent from the following description of an exemplary embodiment. This description is made with reference to the accompanying drawings, in which Fig. 1 schematically shows a section of a shielding housing according to the present invention as an exploded view; and Fig. 2 the excerpt from Fig. 1 shows an exploded view with the high-voltage header inserted into the openings of the shielding housing.

[0037] Fig. Figure 1 shows a schematic section of a shielding housing 1. In the exemplary embodiment, the shielding housing 1 is the unit housing that houses the electric drive of an electric or hybrid vehicle. The housing 1 is made of aluminum or an aluminum alloy. Fig. The section shown in Figure 1 represents a part of the housing wall. In the embodiment shown, two openings 2, here circular openings, are provided in this wall, wherein the edge 3, which defines the inner circumference of the openings 2, is to be electrically contacted with the shield (not shown) of an electrical line.

[0038] For this purpose, as it is Fig. 2, a high-voltage header 4 is used as the interface. This comprises a plastic housing 5 in which electrical contacts are accommodated. On the one hand, the housing accommodates the load conductor bolt 6, which is located within the housing 1, which is Fig. 2 on the left side, is to be connected to the load side. Furthermore, the header 5 accommodates a shielding sleeve 7, which on the one hand (in Fig. 2 on the right) is electrically connected to the shield of an electrical cable by connecting an associated plug with a plug housing (neither shown) to the housing 5 of the header 4. Such a plug is described, for example, in DE 10 2012 201 123 B. In the illustrated embodiment, the header 4 is fastened to the housing 1 via four bores using corresponding fastening means, preferably screws here, and corresponding threads 9 in the housing 1.

[0039] In the prior art, the shielding sleeve 7 was only brought into contact with the inner edge 3 or the inner circumference of the openings 2 to establish electrical contact. The outer circumference of the shielding sleeve 7 rested loosely against the inner circumference 3 of the openings 2. However, due to the tendency of aluminum or the aluminum alloy to form an oxide layer, this electrical contact could not be maintained permanently. This is where the present invention comes in.

[0040] According to the invention, a contact sleeve 10 is therefore provided. The sleeve 10 is made of copper or a copper alloy and coated with silver. The outer circumference 11 of the sleeve is dimensioned, at least in a partial area, to be oversized relative to the inner circumference or diameter (inner dimension) of the openings 2, so that the sleeve 10 can be pressed into the openings 2 in this partial area.

[0041] First, however, two contact elements 12, which are designed as a slotted, annular component and have several lamellae 13 running parallel in the plugging direction, are positioned in the sleeves 10. In the illustrated embodiment, the contact elements 12 are also made of copper or a copper alloy and are coated with silver.

[0042] The contact elements 12 each have an edge web 14 at their axially opposite ends, between which the lamellae 13 extend. Furthermore, three groups of contact points 15 and 16 are provided, which are embossed into the sheet material of the contact elements 12. A first group of contact points 16 is usually spaced apart from or centrally located between the two edge webs 14. The embossing is carried out in such a way that the contact points 16 are in Fig. 1 protrude outwards.

[0043] The other two groups of contact points 15 are formed in the respective edge webs 14 or close to them on the slats. The embossing is such that these contact points protrude inward.

[0044] The contact elements 12 can be inserted into the sleeves 10 in such a way that they are compressed in the area of ​​the slot 18, thereby reducing their diameter so that they can be inserted into the openings of the contact sleeves 10. Since the contact elements are made of a resilient material, they spring back after being inserted into the openings and are secured in the axial direction by the flange 17 at the ends of the sleeve. The flanges 17 create an annular recess 19 in the sleeve 10.

[0045] After inserting the contact elements 12 into the contact sleeves 10, the contact sleeves 10 are pressed into the respective openings 2 in the aforementioned partial area where the contact sleeves 10 have an oversize. This creates an interference fit and a close, sealed contact between the outer circumference 11 of the contact sleeves 10 and the inner circumference 3 of the openings 2. This breaks up the existing oxide layer on the inner circumference 3. Due to the close contact, renewed oxide formation is not to be expected.

[0046] The pressed-in state is in Fig. 2 shown.

[0047] During assembly of the header 4, the shielding sleeve 7 initially only partially penetrates the contact element 12 in the contact sleeve. The contact points 16 protrude outwards from the contact element 12 and define a support for the lamellae made of a resilient material. The shielding sleeve is initially prevented from fully penetrating the contact sleeve 10 by the contact points 15. Depending on the nature of the lamellae 13, slight pressure is required to deform the lamellae 13 and overcome the contact points 15 arranged on the input side. By further pushing the shielding sleeve 7 into the contact sleeve 10, the lamellae 13, on which the contact points 16 are arranged in the center, are deformed in the direction of the contact sleeve 10 until the shielding sleeve 7 reaches the contact points 15 on the output side.This creates both an intimate multi-point contact between the contact points 16 and the contact sleeve 10 and an intimate multi-point contact between the contact points 15 and the shielding sleeve, thereby mechanically clamping the shielding sleeve 7 in the contact sleeve and also creating a very good electrical contact, which ensures permanent contact, particularly in high-voltage connections, which can be ensured even under adverse operating conditions, for example when used in motor vehicles and the shocks and vibrations as well as temperature fluctuations that occur there.

Claims

[1] Shielding housing (1) made of an electrically conductive material which tends to form an oxide layer in an oxygen-containing atmosphere, in particular made of aluminium or an aluminium alloy, with at least one opening (2) whose inner circumference (3) is to be electrically contacted directly or indirectly with the shield of an electrical line, wherein a contact sleeve (10) is pressed into the opening (2) and is made of a different material than the housing or is coated with a different material than the housing, characterized by that a contact element (12) with a plurality of lamellae (13) is held in the contact sleeve (10), wherein the lamellae (13) are on the one hand electrically contacted with the inner circumference of the contact sleeve (10) and on the other hand are to be electrically contacted directly or indirectly with the shield of an electrical line. [2] Shield housing (1) according to claim 1, wherein the contact sleeve (10) is formed from copper, aluminum or an alloy thereof. [3] Shielding housing (1) according to claim 1 or 2, wherein the contact sleeve (10) is coated with a precious metal, in particular silver, gold or with tin or nickel. [4] Shield housing (1) according to one of the preceding claims, wherein the contact element (12) is formed from copper, aluminum or an alloy thereof. [5] Shield housing (1) according to one of the preceding claims, in which the contact element (12) is coated with a precious metal, in particular silver, gold or with tin or nickel. [6] Shield housing (1) according to one of the preceding claims, in which the lamellae (13) of the contact element (12) run parallel to, in particular in the plug-in direction along which a counterpart for contacting the shield of an electrical line can be plugged into the contact element (12). [7] Shielding housing (1) according to claim 6, in which the slats (13) are separated from one another by slots and are connected to one another at their two ends by an integrally formed edge web (14) running perpendicular to them, wherein at least two groups, each formed from a plurality of, preferably embossed, contact points (15, 16), are arranged adjacent to and / or on the entirety of the slats (13), wherein the groups of contact points extend substantially parallel to the edge webs (14), two first groups consist of inner contact points (15) which are arranged adjacent to or on the respective edge webs (14), and a second group consists of outer contact points (16) which are arranged at a distance from the edge webs (14), wherein all contact points (15) of the first groups protrude from the plane spanned by the entirety of the slats (13) in the same direction as one another but in the opposite direction to the second group of contact points (16). [8] Shield housing (1) according to claim 7, wherein the second group of outer contact points (16) is maximally spaced from the edge webs (14). [9] Shield housing (1) according to one of the preceding claims, in which the contact element (12) consists of a resilient material and is preferably designed as a slotted (18), annular component. [10] Shield housing (1) according to one of the preceding claims, in which the contact sleeve (10) has an annular recess (19) in which the contact element (12) is held fixed in the axial direction.

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