Cable fastening, electrical device and method for producing a cable fastening

Abstract

Cable fastening, with a cable (8, 9) which is guided through a cable fastening element (1) and fastened in the cable fastening element (1), wherein the cable fastening element (1) is fastened to and / or in a housing, wherein the housing comprises a metallic material, wherein the cable fastening element (1) comprises a metallic material, wherein the cable fastening element (1) and / or a fastening element in electrical contact with the cable fastening element (1) has a cutting edge (2) which is cut into the material of the housing, characterized in that the cable fastening element (1) has a wire sealing element (15) for creating a seal between the cable fastening element (1) and one wire (9.1 - 9.4) or a plurality of wires (9.1 - 9.4) of the cable.

Description

The invention relates to a cable mount and a system for providing a cable mount and an electrical device having a cable mount and a method for producing a cable mount.US 2008 / 0 164 059 A1 discloses a method and a system for inserting a cable through an opening while maintaining electromagnetic shielding.U.S. Pat. No. 4,022,262 A discloses a closure body with a seal.U.S. Pat. No. 6,358,069 B2 discloses a shielded line connection structure for a shielded connector.JP 2009 189 098 A discloses a sealed connector for connecting shielded cables.US 2013 / 0 265 808 A1 discloses an inverter.JP H08 78 098 A discloses a shielded connector directly connected to a device.Cable mountings of the type in question are used first of all for the mechanical mounting of a cable in a housing. They absorb the mechanical forces acting on a part of the cable. Cable mountings thus prevent these mechanical forces from being able to affect elements potentially sensitive to mechanical damage, such as electrical connection elements connected to the cable. Cable mountings which serve for purely mechanically fixing the cable in a housing are known in the prior art in a multiplicity of variants. However, the use of known cable mountings usually does not go beyond the mere mechanical mounting of a cable.The object of the invention is therefore to specify a cable fastening and a system for providing a cable fastening and an electrical device having a cable fastening and a method for producing a cable fastening, which enable further functionalities of the cable fastening beyond the purely mechanical fastening.The object is achieved by a cable mount and a system for providing a cable mount and an electrical device having a cable mount and a method for producing a cable mount having the features of the independent claims. The features of the dependent claims relate to advantageous embodiments.The cable fastening according to the invention is characterized by a cable fastening element which comprises a metallic material. The cable fastening element is fastened in a housing which likewise comprises a metallic material. It is essential for the invention that the cable fastening element and / or a fastening element in electrical contact with the cable fastening element have a cutting edge which is cut into the material of the housing.It has been found that the cutting-in of the metallic material of the housing leads to a substantially better thermal and / or electrical connection between the cable fastening element and the housing. This also applies if the cutting edge is not arranged on the cable fastening element itself, but on a separate fastening element, with which the cable fastening element is fastened in the housing. For this purpose, the fastening element preferably likewise comprises a metallic material and is in electrical contact with the cable fastening element.The fastening element can be, for example, a screw which is screwed into the material of the housing in such a way that the thread of the screw cuts into the material of the housing. The thread of the screws in such a case represents the cutting edge.The better electrical contacting, which results from the embodiment of the cable fastening according to the invention, makes it possible, for example, to make electrical contact with a component of the cable advantageously with the metallic material of the housing. A particularly preferred embodiment of the cable fastening provides in this connection that the cable fastening element is in electrical contact with a shield of the cable. By cutting the cutting edge into the material of the housing, a gas-tight connection and thus an excellent electrical contact between the housing and the cable fastening element are produced. This allows a low-inductance connection of the shielding of the cable to the housing. Such a connection of the shield of the cable to the housing has in particular a high degree of damping as an advantage.In addition, a mechanical connection of the cable to the housing is also produced, which is superior to previous fastenings. This applies in particular with regard to vibrations. The mechanical connection via the cutting edge cut into the material of the housing is extremely rigid, for which reason mechanical vibrations which are transmitted to a part of the cable can be absorbed particularly well by the cable fastening. In practice, in the case where the cable is subjected to vibrations, this means that they are initially forwarded as far as the cable fastening. There, the cable is fixed in such a rigid manner that the region of the cable which continues beyond the cable fastening is not impaired, or at least to a much lesser extent, by the vibrations than would be the case without the cable fastening according to the invention.A further advantage of the cable fastening according to the invention lies in the particularly good thermal contact between the cable fastening element and the housing. This advantage is useful, for example, in cases where a portion of the cable leading to the cable attachment according to the invention is exposed to high temperatures. As a result of the thermal contact, the thermal energy introduced into the cable can be dissipated into the housing via the cable fastening element. As a result, the thermal energy is not passed on, or at least to a significantly reduced extent, to a region of the cable lying beyond the cable fastening element. As a result, for example, fastening elements which are located behind the cable fastening according to the invention as viewed in the heat flow direction can be protected from thermal influences.This advantage is particularly useful when the housing is cooled by cooling. In a particularly advantageous manner, the housing has a water cooling system. By means of water cooling, large amounts of thermal energy can be dissipated from the housing. This makes it possible to keep the temperature of the casing at a comparatively low level. A low temperature level of the housing in this connection brings about a particularly good dissipation of the heat from the cable into the housing via the cable fastening element.Advantageously, the cable fastening element can have a tunnel-like region for the cable to pass through. A tunnel-like region is to be understood in particular as a region of the cable fastening element which surrounds a specific section of the cable around the entire circumference thereof. Such a tunnel-like region has the advantage that it enables good mechanical fixing of the cable which is passed through the tunnel-like region. In addition, such a tunnel-like region for the passage of the cable enables good, in particular also large-area, contact with a shield of the cable or, as a result of the large-area contact with the cable, good dissipation of thermal energy from the cable.The cable fastening element preferably has a clamping region. In the clamping region, the cross section of the opening in the cable fastening element, through which the cable is guided, is reduced for fastening the cable. This results in a force-locking fixing of the cable. At the same time, good contact is produced between cable and cable fastening element, since the cable fastening element is pressed against the cable, at least in the region of the clamping region. In this context, it is particularly advantageous if the clamping region is arranged in the region of a tunnel-like region for the cable to pass through.The reduction of the cross section is based in particular on the clamping region being plastically deformed in order to reduce the cross section. This can be made possible, for example, by a circular region being brought into a shape deviating from a circular shape for clamping the cable. In this case, the circumference of the clamping region remains-at least approximately-constant. The deformation brings about a deviation from the previously present circular shape. A circular shape has the largest possible cross-section compared to other shapes of the same circumference. The deformation therefore brings about an obligatory reduction in the cross section and thus a jamming of the cable in the cable fastening element. Depending on the type of tool used for deforming the clamping region, the deformed region can have a polygonal shape, for example.Preferably, the cable fixing element is fixed to the inner side of a wall of the housing. The inner side can have an integrally formed fastening region for this purpose. This preferably protrudes from the wall. Preferably, the cutting edge is cut into this fastening region. Such a protruding fastening region enables the secure fastening of a fastening element according to the invention, also for example on a thin-walled housing.Preferably, the cutting edge has a curvature. Curved cutters are particularly well suited for cutting into the regularly tough metallic material of a housing of the type in question.It is particularly preferably a cable which is suitable and / or intended for conducting high electrical powers. Particularly preferably, this is a cable through which, when used as intended, an electrical power of at least 1000 watts, particularly preferably of at least 10000 watts, is conducted-at least temporarily, i.e. for example at load peaks. At such high powers, the advantages of the cable fastening according to the invention are particularly important.The cable fastening element can be divided into a first region and a second region by a releasable connection. The releasable connection can be in particular a screw connection. This can be designed such that one of the regions is screwed into the other region, in particular parallel to the feed-through direction of the cable. In the region of the releasable connection, a sealing element, for example an O-ring, can be arranged.One of the regions may comprise the clamping region. Alternatively and / or additionally, a region can be fastened to the housing. This region has in particular the cutting edge. In particular, it is possible for one region to have the clamping region and for the other region to be fastened to the housing.The cable fastening element can have a core sealing element for producing a seal between the cable fastening element and one or a plurality of cores of the cable. Such a core sealing element makes it possible to lead the cores out of the cable fastening element, so that a seal is produced between the individual cores and the cable fastening element. In this case, the core sealing element can have an opening for each core, through which the respective core is guided through the core sealing element. The number and / or dimensions of the openings are matched in particular to the number and / or dimensions of the wires.To produce the seal, it is possible for the cable fastening element to have a compression element for exerting a compressive force on the core sealing element. In this context, the core sealing element is made in particular of an elastic material, in particular of a rubber-elastic material. The compressive force applied by the compression element to the core sealing element results in an, in particular elastic, deformation of the core sealing element, which in turn leads to sealing. For this purpose, the compression element can generate, in particular, a compressive force parallel to the feed-through direction of the cable. This generates a three-dimensional deformation and stress state in the core sealing element, which ultimately leads to a sealing in the radial direction when the material of the core sealing element yields to the compressive force. Since a radial expansion of the core sealing element towards the outside is prevented, in particular by the cable fastening element which surrounds the core sealing element, the material of the core sealing element is pressed against the individual cores guided through the core sealing element and the sealing effect is thus achieved.For this purpose, the compression element can be screwed in particular into the cable fastening element, and in particular the compression element can be screwed into the cable fastening element in a direction parallel to the feed-through direction of the cable. For this purpose, the compression element can have an external thread and the cable fastening element can have an internal thread complementary to this external thread.The system for providing cable attachment includes at least one portion for attaching the cable attachment member to the housing and a plurality of clamping portions. The clamping regions have different dimensions for receiving different cables. Each clamping region can now be connectable to the region for fastening the cable fastening element to the housing by the releasable connection. This allows the system to be used to provide different cable fastening elements, by means of which differently dimensioned cables can be fastened to a housing. It is understood in this connection that the system can also have a plurality of regions for fastening the cable fastening element to the housing. In this case, it is also possible to provide differently configured fastening elements which can be fastened to differently configured housings or to differently configured regions of a housing.The electrical device is particularly preferably a DC / DC converter and / or an inverter. Such electrical devices are used in particular when electrical loads are to be supplied from a direct voltage source, such as a battery or an accumulator. This is particularly often the case in motor vehicles.It is particularly advantageous for the use of an electrical device according to the invention in a motor vehicle, since the advantages of the present invention are particularly important in this case. In a motor vehicle, an electrical device is regularly subjected to vibrations and vibrations. This applies in particular to cables which lead into the electrical device. In addition, for example in the region of the engine compartment of a motor vehicle, high temperatures occur which act on the cables laid there. An advantage results in particular from the combination of cooling the housing with the cooling of the motor vehicle, which usually is present anyway. Motor vehicles have a cooling system, usually a water cooling system, in particular for cooling the engine of the motor vehicle. This can be used to also cool the housing of the electrical device according to the invention.In addition, loads with comparatively high electrical powers are regularly supplied with electrical energy in motor vehicles. These can be in particular electric drives supplied with alternating current. It is understood that these can be electric drives which serve the purpose of moving the motor vehicle. However, there are often also other electric drives in motor vehicles, in particular in commercial vehicles such as trucks or buses. These can serve, for example, to operate the compressor of an air-conditioning system. Furthermore, they can be used for actuating doors and / or for operating further electrically or electrically driven devices, such as loading tailboards, crane superstructures, a pump of a power steering system, fans, for example as a component of a motor vehicle cooling system, pumps for generating compressed air for operating pneumatic devices, pumps for generating an oil pressure for operating hydraulic devices and / or electrical connection elements for operating external electrical devices. Such external electrical devices can then be connected to the motor vehicle, for example, via sockets provided on the motor vehicle as electrical connection elements. This can enable, in particular, the operation of electrical devices normally operated on a mains socket, which operation is powered by the energy supply of a motor vehicle. For example, conventional household sockets can be provided in recreational vehicles and / or travel buses. In the case of commercial vehicles which are used, for example, by hand-held installations on construction sites, such an energy supply, for example for the operation of electrically operated tools, also has a high practical utility value.The method according to the invention for producing a cable fastening provides for first guiding the cable through the cable fastening element and then fastening it in the cable fastening element to produce the cable fastening. The cable fastening element is then fastened-together with the cable guided through-in-the housing. This procedure allows simpler handling. Thus, the cable can be prefabricated, for example, already with the cable fastening element. The unit formed in this way from cable and cable fastening element can then be handled as a prefabricated assembly during the assembly of the electrical device. When fastening the cable fastening element in the housing, according to the invention, a cutting edge of the cable fastening element and / or a cutting edge of a fastening element electrically connected to the cable fastening element then cuts into the material of the housing.The invention is explained in greater detail schematically below with reference to FIGS. 1 to 3 FIG. 1 shows an exemplary cable fastening element according to the invention. FIG. 2 shows an exemplary cable fastening element according to the invention according to a further embodiment. FIG. 3 shows a cable fastened in an exemplary cable fastening element according to the invention. FIG. 4 shows an exemplary cable fastening element according to the invention in a further embodiment.The cable fastening element 1 according to the invention shown by way of example in FIG. 1 has a plurality of arcuate cutting edges 2. These are designed and provided for cutting into the material of a housing of an electrical device according to the invention when fastening the cable fastening element 1. The fastening can be effected, for example, in such a way that the cable fastening element is clamped between two fastening regions projecting from a wall of the housing in such a way that the cutters 2 formed on the cable fastening element 1 in pairs in the example shown cut into one of the fastening regions in each case. A flattened region 4 comes to rest against the wall of the housing. Advantageously, a further flattened region 4 is available, which can be used, for example, to fix the cable fastening element 1 by a component which spans the cable fastening element and is connected to the housing.In FIG. 2 an alternative embodiment of a cable fastening element 1 according to the invention is shown. This cable fastening element 1 itself has no cutting edges 2. It is designed to be fastened to the housing by fastening elements which have corresponding cutting edges. For this purpose, it has connecting regions 5, with which the fastening elements can cooperate. In the example shown, this is made possible by the fact that openings 6 are available through which the fastening elements, which can be screws, for example, can be guided.The exemplary cable fastening elements 1 illustrated in FIGS. 1 and 2 each have a tunnel-like region 7 for passing a cable through. In order to fix the cable in the tunnel-like region, a region of the tunnel-like region as a clamping region can be plastically deformed. This can be done, for example, by acting on the tunnel-like region from the outside with a corresponding tool in such a way that the latter experiences a plastic deformation. By deforming the initially circular cross section of the tunnel-like region in the clamping region, the latter receives a cross section deviating from a circular shape. The cross-sectional area is thereby reduced. This leads to the cable being clamped in.FIG. 3 shows a cable fastening element 1 fixed to a cable in a cable fastening element according to the invention. A first region of the cable 8 can be led, for example, into the housing in which the cable fastening element 1 is fastened within the scope of a cable fastening according to the invention. This region of the cable has a sheathing and can be laid, for example, in the engine compartment of a motor vehicle. A further region 9 of the cable protrudes from the fastening element in the form of individual wires 9.1, 9.2, 9.3 and 9.4. This part of the cable no longer has a sheathing in the example shown. The sheathing ends in the cable fastening element 1 according to the invention, where a shield arranged between the sheathing of the cable and the wires is electrically connected to the cable fastening element 1. This can be done, for example, by removing the jacket around a part of the shield and bending the part of the shield thus exposed outwards and placing it over the remaining jacket, so that this part of the shield is located between the cable fastening element 1 and the jacket of the cable.The region 9 of the cable ends in an electrical connecting element 10, and if the region 8 of the cable is now exposed to adverse environmental conditions, such as vibrations and / or high temperatures, these can be accommodated-at least largely-by the cable fastening element 1. In this case, in particular, the vibrations and / or the thermal energy are prevented from being transmitted to the electrical connecting element 10-at least largely. The electrical connecting element 10, in particular its components which produce the electrical contact, such as metallic contact tongues, are effectively protected from such influences in this way.The cable fastening element 1 can be divided into a first region 12 and a second region 13 by a detachable connection 11, as shown in FIG. 4. The releasable connection 11 can be a screw connection, as in the example shown. This can be designed such that one of the regions is screwed into the other region, in particular parallel to the feed-through direction of the cable. In the region of the releasable connection, a sealing element 14 can be arranged. In the example shown, this is designed as an O-ring. The first region 12 and / or the second region 13 can be configured tunnel-like as in the example shown.As illustrated, the first portion 12 may include the clamping portion. Alternatively and / or additionally, the second region 13 can be designed as illustrated for fastening to the housing. This second region 13 then has in particular the cutting edge 2.The cable fastening element 1 can have a core sealing element 15 for producing a seal between the cable fastening element 1 and one or a plurality of cores 9.X of the cable. In this case, the core sealing element 15 can have an opening 16 for each core 9.X, through which the respective core 9.X is guided through the core sealing element 15. The number and / or dimensions of the openings 16 are matched in particular to the number and / or dimensions of the cores 9.X.To produce the seal, the cable fastening element 1 has, in particular, a compression element 17 for exerting a compressive force on the core sealing element 15.As illustrated, the compression element 17 acts in particular by means of a screw connection 18 on the core sealing element 15, and as in the example shown, one or a plurality of support rings 19 can be present for stabilizing the core sealing element 15.Reference Number:1 Cable fastening element 2 Cutting edge 3 Tunnel-like region 4 Flattened region 5 Connecting region 6 Opening 7 Tunnel-like region 8 First region of the cable 9 Further region of the cable 9.1-9.4 Wires of the cable 10 Electrical connecting element 11 Releasable connection 12 First region 13 Second region 14 Sealing element 15 Wire sealing element 16 Opening 17 Compression element 18 Screw connection 19 Supporting ring

Claims

Cable fastening, having a cable (8, 9) which is guided through a cable fastening element (1) and fastened in the cable fastening element (1), wherein the cable fastening element (1) is fastened to and / or in a housing, wherein the housing has a metallic material, wherein the cable fastening element (1) has a metallic material, wherein the cable fastening element (1) and / or a fastening element which is in electrical contact with the cable fastening element (1) has a cutting edge (2) which is cut into the material of the housing, characterized in that the cable fastening element (1) has a core sealing element (15) for producing a seal between the cable fastening element (1) and a core (9.1-9.4) or a plurality of cores (9.1-9.4) of the cable.Cable fastening according to claim 1, characterised in that the cable fastening element (1) is in electrical contact with a shield of the cable (8, 9).Cable fastening according to Claim 1 or 2, characterized in that the housing is cooled, in particular water-cooled.Cable fastening according to one of the preceding claims, characterized in that the cable fastening element (1) has a tunnel-like region (7) for the cable (8, 9) to pass through.Cable fastening according to one of the preceding claims, characterized in that the cable fastening element (1), in particular the tunnel-like region (7), has a clamping region in which, in the cable fastening element (1), the cross section of the opening in the cable fastening element (1), through which the cable (8, 9) is guided, is reduced for fastening the cable (8, 9).Cable fastening according to one of the preceding claims, characterized in that the cable fastening element (1) is fastened to the inside of a wall of the housing, in particular wherein a fastening region formed onto the housing from the inside of the wall projects from the wall of the housing and the cutting edge (7) is cut into the fastening region.Cable fastening according to one of the preceding claims, characterized in that it is a cable (8, 9) for passing an electrical power of at least 1000 W, preferably of at least 10,000 W, through when the cable fastening is used as intended.Cable fastening according to one of the preceding claims, characterized in that the cable fastening element (1) is divided into a first region (12) and a second region (13) by a releasable connection (11), in particular a screw connection, in particular wherein one region has the clamping region and the other region is fastened to the housing.Cable fastening according to one of the preceding claims, characterized in that the core sealing element (15) has an opening (16) for each core (9.1-9.4), through which the respective core (9.1-9.4) is guided through the core sealing element (15).Cable fastening according to one of the preceding claims, characterized in that the cable fastening element (1) has a compression element (17) for exerting a compressive force on the core sealing element (15), in particular wherein the compression element (17) can be screwed into the cable fastening element (1) in order to generate the compressive force parallel to the direction of passage of the cable.A system for providing cable attachment according to any of claims 8 to 10, characterized in that the system comprises at least one portion (13) for attaching the cable attachment element (1) to the housing and a plurality of portions (12) having clamping portions, the portions (12) having clamping portions having different dimensions for receiving different cables, each of the portions (12) having clamping portions being connectable to the portion (13) for attaching the cable attachment element (1) to the housing by the releasable connection (11).The electrical device with a cable mount according to any one of claims 1 to 10, characterized in that the electrical device is a DC / DC converter and / or an inverter.Electrical device according to Claim 12, characterized in that the electrical device is part of a motor vehicle when used as intended.Method for producing a cable fastening according to one of Claims 1 to 10, wherein a cable (8, 9) is initially guided through a cable fastening element (1) and fastened in the cable fastening element (1), whereupon the cable fastening element (1) is fastened to and / or in a housing, wherein, during the fastening of the cable fastening element (1) in the housing, a cutting edge (2) of the cable fastening element (1) and / or of a fastening element which is in electrical contact with the cable fastening element (1) cuts into the material of the housing.

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