Housing feedthrough with shield contact

Abstract

A housing bushing suitable for contacting the shield (103) of a shielded cable (101) is described, along with a method for contacting the shield. The housing bushing comprises a screw-in sleeve (201) with a through-hole (203). The through-hole (203) in the screw-in sleeve (201) includes a cavity (205) into which a clamping element (112) with a central through-hole (113) can be received. A shielded cable can be received into the through-hole (113) of the clamping element. The housing bushing includes a clamping plunger (111) which interacts with the screw-in sleeve (201) to exert an axial pressure force on the clamping element (112) directed towards the screw-in sleeve (201).

Description

Area

[0001] The invention relates to a housing feedthrough suitable for contacting a shield of a cable, and a method for contacting a shield of a shielded cable in a housing feedthrough. background

[0002] Shielded electrical cables are used, for example, in the automotive sector to connect electrical assemblies and components. To save material and weight, there is a general trend towards increasingly higher operating voltages, which allow for smaller conductor cross-sections. This is particularly true for vehicles with purely electric or hybrid drives. In such vehicles, devices and consumers are increasingly supplied from higher-voltage power sources. These power sources can be designed for voltages of up to 1000 V. Consumers in electric vehicles include, for example, the drive motor and heating units. Due to the high operating voltages, cables with an electrically effective shield are frequently used to connect consumers to a battery.In the area of ​​a cable distribution box, a battery housing, or more generally, a shielded enclosure (not necessarily in motor vehicles), it is therefore necessary to contact the cable shields to achieve continuous shielding of the electric fields generated by the high operating voltages. For this purpose, feedthroughs are provided that are in electrical contact with the respective enclosure on one side and with the cable shield on the other.

[0003] Traditionally, cable shields are contacted using various types of crimp connections, which typically exert tensile and / or torsional forces on the shield. With a shield made of wire braid, there is therefore a risk that individual wires of the shield will break off and, in the worst case, cause a short circuit. Furthermore, conventional shield contacting does not guarantee that the shield is contacted along its entire circumference.

[0004] US Patent 4,854,891 A discloses a housing wall feedthrough with a feedthrough body. The shield of a coaxial cable is placed over a conical ring. A ring is pressed against the other ring by a union nut, so that the shield is compressed between a conical recess in the feedthrough body and the conical ring. Outside the housing wall feedthrough, the shield rests on the outer sheath of the cable. Due to the lack of a seal, environmental influences from the outside can penetrate into the housing in which the housing wall feedthrough is mounted.

[0005] DE 40 02 188 A1 describes a device for inserting a shielded cable into a housing. The shielded cable has a shield that is clamped between a conical surface of an inner cone and a corresponding surface of an outer cone. The outer cone is pressed against the inner cone by means of a nut. The threaded bushing of the cable entry is sealed against the inner wall of the housing by means of an O-ring. The cable is sealed in the threaded bushing by means of a rubber gasket.

[0006] US 10,573,994 B2 concerns a cable gland connected to a connector. The cable gland is mounted in an enclosure wall, with the shield of a cable electrically connected to the enclosure wall. The cable is electrically shielded by wires. The shield is clamped and electrically contacted between a pipe end and a ring. The clamping force is applied by means of a nut. It is further proposed that the cable incorporate additional components to protect it, among other things, against the ingress of moisture.

[0007] DE 10 2014 200 133 A1 discloses a device for fixing an electrical cable in a plug which is provided with retaining elements.

[0008] EP 0 525 216 A1 shows a sealed cable penetration through the wall of an enclosure, in which a metal sleeve is permanently connected to the outer sheath of a cable. The cable penetration is sealed in the wall with a cutting ring, the cutting edge of which cuts into the metal sleeve.

[0009] Starting from this, the present invention has the objective of creating a housing feedthrough with shield contact in order to overcome or at least improve one or more of the problems mentioned above. Description of the invention

[0010] To solve this problem, the invention according to claim 1 proposes a housing bushing suitable for contacting the shield of a shielded cable, comprising a screw-in sleeve with a through-hole. The through-hole in the screw-in sleeve includes a cavity into which a clamping element with a central through-hole can be received. A shielded cable can be received into the through-hole of the clamping element. The housing bushing includes a clamping plunger that interacts with the screw-in sleeve to exert an axial pressure force on the clamping element directed towards the screw-in sleeve. According to the invention, the housing bushing is provided with a sheath that seals the cable against the outside.

[0011] The axial force application ensures that no or only negligible torsional forces are exerted on the shield of the high-voltage cable. This prevents a wire from breaking off the braid forming the shield and causing a short circuit. Should a wire break off in exceptional circumstances, it will be trapped inside the screw-in sleeve and cannot cause a short circuit. The sheathing prevents moisture and other environmental influences from penetrating the housing into which the cable gland is mounted. Similarly, the shield contact is protected from environmental influences.

[0012] Advantageously, the screw-in sleeve has an external thread and the clamping plunger has an internal thread, which can be engaged with each other.

[0013] The threads arranged on the screw-in sleeve and the clamping plunger easily generate the required axial force for shield contact.

[0014] It has proven advantageous for the clamping plunger to have a cylindrical tube extension that is in contact with the clamping body. The tube extension ensures that the axial force is transmitted evenly to the clamping body.

[0015] In an advantageous embodiment, the clamping plunger includes an annular space into which the screw-in sleeve can be partially received. The annular space ensures that the clamping plunger does not come into direct contact with the screw-in sleeve, so that the clamping force is transmitted exclusively to the clamping body.

[0016] The casing can advantageously be fitted with a seal to seal the screw-in sleeve against the housing wall into which it is screwed. The seal improves the sealing effect of the casing.

[0017] It is particularly advantageous if the cable is additionally sealed against the sheathing with a cable seal. The cable seal, located on the side of the sheathing furthest from the housing wall, ensures that no environmental influences from the outside can penetrate.

[0018] It has proven useful to use a retaining cap to hold the pipe seal in a recess in the casing. The retaining cap is a simple way to secure the pipe seal.

[0019] The retaining cap can be conveniently connected to the casing with a locking hook, a snap connection or by friction fit.

[0020] In a particularly advantageous embodiment, the cavity of the screw-in sleeve is conical and the clamping body is conical with a central through-hole. The inclination of a lateral surface of the conical clamping body essentially corresponds to the opening angle of the conical cavity of the through-hole. A conical design of the cavity and clamping body, respectively, increases the area on which the shield is pressed between the screw-in sleeve and the clamping body, thus improving the electrical contact.

[0021] According to claim 10, the invention relates to a method for contacting a shield of a shielded cable in a housing feedthrough, the method comprising: - Deposition of an outer sheath, a shield and an inner sheath of the cable; - Sliding a retaining cap, a cable seal and a sheath onto the high-voltage cable; - Sliding a clamping plunger and a clamping body onto the shielded cable; - Crimping the shield and placing the shield on the outside of a clamping body; - Screwing a screw-in sleeve into a housing wall; and - Pressing the clamping body axially into the screw-in sleeve.

[0022] The proposed method for contacting the shield of a shielded high-voltage cable avoids exerting torsional forces on the shield braid. This prevents one or more wires of the shield from being torn off during contacting and, in the worst case, causing a short circuit. The clamping forces for contacting the shield are applied almost exclusively axially.

[0023] The retaining cap, the cable seal and the sheathing contribute to improved sealing when the housing feedthrough is fully assembled. Short description of the drawing

[0024] The invention will be explained in more detail below using an exemplary embodiment with reference to the accompanying figures. All figures are purely schematic and not to scale. They show: Fig. 1 a high-voltage cable with threaded components of a housing feedthrough according to the invention; Fig. 2 an exploded view of the housing feedthrough according to the invention; and Fig. 3 fully assembled housing feedthroughs according to the invention.

[0025] Identical or similar elements are provided with identical or similar reference numerals in the figures. Example

[0026] Fig. Figure 1 shows a high-voltage cable 101 prepared for contact, in which the outer sheath 102 is removed over a length L1. An underlying electrical shield 103 is removed over a length L2. Finally, an inner sheath 104 is removed over a length L3, so that an electrical conductor 106 of length L3 is exposed. The following are connected to the high-voltage cable 101 in the following order: Fig. 1. From right to left, the following components are threaded: a retaining cap 107 for a cable seal 108 and the cable seal 108 itself, a sheath 109, a clamping plunger 111 and a clamping body, which is referred to below as a clamping wedge 112.

[0027] The clamping wedge 112 is designed as a rotationally symmetrical cone with a through-hole 113. The diameter of the through-hole 113 is smaller than the outer diameter of the outer sheath 102, but large enough to allow the exposed shield 103 of the high-voltage cable 101 to pass through with clearance, so that the clamping wedge 112 can move on the exposed shield 103 without significant friction. The angle of a surface 114 of the clamping wedge 112 relative to the central through-hole 113 is, for example, 10° to 20°. In other embodiments, this angle can also be chosen differently. In the extreme case, an angle of 90° is also possible. Then the clamping body would be a cylinder. However, it is true that with decreasing angles, the area on which the shield is pressed between the screw-in sleeve and the clamping wedge increases. A larger area is generally advantageous. The clamping body, or rather...For example, the clamping wedge 112 is made of soft brass.

[0028] The clamping plunger 111 is designed as a rotationally symmetrical body with an outer wall 116 and a base 117. A pipe stub 118 extends centrally from the base 117 towards the clamping wedge 112. An end face 119 of the pipe stub 118 projects relative to an end face 121 of the outer wall 116. The outer wall 116 and the pipe stub 118 are separated from each other and define an annular space 122. The side of the outer wall 116 facing the annular space 122 is provided with an internal thread 123. A central opening 124 extends through the pipe stub 118, the diameter of which is larger than the diameter of the outer sheath of the high-voltage cable 101, so that the clamping plunger 111 can be moved with play on the high-voltage cable 101. On its outer side, the outer wall 116 is provided with an external thread 126.

[0029] The sheath 109 is designed as a rotationally symmetrical hollow cylinder. The sheath 109 has a circumferential wall 127 and a base 128 on the side opposite the clamping pin 111. The circumferential wall 127 and the base 128 define an interior space 129. The base 128 has a passage 130 whose diameter is larger than the diameter of the outer sheath of the high-voltage cable 101, allowing the clamping pin 111 to slide along the high-voltage cable 101 with some play. An annular seal 133 is arranged on an end face 132 of the circumferential wall 127 opposite the base 128. A sheath pipe extension 134 is arranged on the side of the base 128 opposite the interior space 129, forming a receptacle 136 for the cable seal 108.A protruding rim 137 of the retaining cap 107 has an inner diameter matched to the outer diameter of the sheathing tube extension 134, so that the retaining cap 107 can be fitted onto the sheathing tube extension 134 in a sealing manner. The retaining cap 107 is held on the sheathing tube extension 134 either by friction or by positive locking, for example, with snap-fit ​​elements. The retaining cap 107 has a central opening 139 in a base 138 for the high-voltage cable 101.

[0030] In Fig. 2 shows in addition to Fig. 1 a screw-in sleeve 201 and a contact piece 202, which is connected to the conductor 106. In contrast to Fig. 1 the exposed screen 103 is folded over the outer surface 114 of the clamping wedge 112.

[0031] The screw-in sleeve 201 is a cylindrical body with a central through-opening 203, which is divided into three sections. On the side of the screw-in sleeve 201 facing the contact piece 202, the through-opening 203 is formed as a bore 204 in section A. The diameter of the bore 204 is larger than the outer diameter of the inner sheath 104 of the high-voltage cable 101. Adjoining this, the through-opening 203 widens conically in section B, creating a cavity 205 in the shape of a truncated cone in section B. In section C, the cavity transitions back into a bore 206, the diameter of which is larger than the diameter of the bore 204. The inclination of the outer surface of the cavity 205 corresponds to the inclination of the outer surface of the clamping wedge 112. The screw-in sleeve 201 has a circumferential projecting collar 208 on its outer surface.On both sides of the rim 208, the screw-in sleeve 201 is provided with an external thread 209a or 209b.

[0032] Fig.Figure 3 shows the housing bushing mounted in a housing wall 301, which as a whole is designated by reference numeral 302. To mount the housing bushing 302, the retaining cap 107, the conductor seal 108, the sheath 109, and the clamping plunger 111 are first threaded onto the high-voltage conductor 101. Then, the outer sheath 102, the shield 103, and the inner sheath 104 are stripped to lengths L1, L2, and L3, respectively. Next, the clamping wedge 112 is slid over the exposed shield 103 until it abuts the outer sheath 102. The exposed shield 103 is flared and placed onto the clamping wedge 112. Then the screw-in sleeve 201, with bore 206 and cavity 205 leading, is slid over the clamping wedge 112, and the contact piece 202 is mounted on the conductor 106. The external thread 209a is screwed into a corresponding threaded hole 303. Then the clamping plunger 111, with internal thread 123, is screwed onto the external thread 209b.The clamping plunger 111 presses the clamping wedge 112 and the shield 103 resting on it axially against an inner wall of the cavity 205 of the screw-in sleeve 201, thus establishing an electrical contact between the shield 103 and the housing wall 301. The torque exerted on the clamping wedge 112 due to frictional force when the clamping plunger 111 is screwed onto the screw-in sleeve 201 is transmitted completely or almost completely directly to the screw-in sleeve 201. Consequently, essentially no torsion is exerted on the shield 103. Should a wire of the shield 103 nevertheless break off in exceptional cases, the broken wire piece remains trapped inside the screw-in sleeve 201 and cannot cause a short circuit elsewhere.After the clamping pin 111 is screwed firmly in place, the sheathing 109 is screwed onto the clamping pin 111 until the seal 133 rests firmly against the housing wall 301 and the sheathing 109 seals against the housing wall 301. Then, the cable seal 108 is pushed into the receptacle 136 in the sheathing 109, sealing the high-voltage cable 101 against the sheathing 109. The cable seal 108 is held in the receptacle 136 by means of the retaining cap 107, which is placed on the sheathing tube extension 134. Reference symbol list 101 Management 102 outer mantle 103 umbrella 104 inner mantle 106 leaders 107 Retaining cap 108 Pipe seal 109 Sheathing 111 clamping stamps 112 Wedge clamp 113 Through hole 114 Surface area 116 Exterior wall 117 Floor 118 pipe fittings 119 End face (pipe stub) 121 Front surface (outer wall) 122 annular space 123 internal threads 124 Passage (Clamping die) 126 external threads 127 Perimeter wall 128 Floor 129 Passage 132 Front surface (perimeter wall) 133 Seal 134 Sheathing pipe attachment 136 recording 137 Edge (retaining cap) 138 Base (retaining cap) 139 Passage (retaining cap) 201 Screw-in sleeve 202 Contact piece 203 Passage opening 204 bore 205 cavity 206 bore 208 Circumferential collar 209a,b external thread 301 Housing wall 302 Housing feedthrough 303 Threaded hole

Claims

[1] Housing feedthrough suitable for contacting a shield (103) of a shielded cable (101), comprising a screw-in sleeve (201) having a through-opening (203), wherein the through-opening (203) in the screw-in sleeve (201) comprises a cavity (205) in which a clamping body (112) having a central through-bore (113) can be received, such that a cable (101) can be received in the through-bore (113) of the clamping body (112), wherein the housing feedthrough (302) comprises a clamping plunger (111) which cooperates with the screw-in sleeve (201) in order to exert an axial compressive force on the clamping body (112) directed towards the screw-in sleeve (201), characterized by that the housing feedthrough (302) comprises a sheath (109) which seals the line (101) from an external space. [2] Housing feedthrough according to claim 1, characterized bythat the screw-in sleeve (201) is provided with an external thread (209a,b) and the clamping stamp (111) is provided with an internal thread (123), which can be brought into engagement with one another. [3] Housing feedthrough according to claim 1 or 2, characterized by that the clamping punch (111) has a cylindrical pipe socket (118) which is in contact with the clamping body (112). [4] Housing feedthrough according to one of the preceding claims, characterized by that the clamping stamp (111) comprises an annular space (122) in which the screw-in sleeve (201) can be partially received. [5] Housing feedthrough according to claim 1, characterized by that the casing (109) is provided with a seal (133) in order to seal the screw-in sleeve (201) against a housing wall (301) into which the screw-in sleeve is screwed. [6] Housing feedthrough according to one of the preceding claims, characterized bythat the line (101) is sealed against the sheath (109) with a line seal (108). [7] Housing feedthrough according to one of the preceding claims, characterized by that a retaining cap (107) holds the cable seal (108) in a receptacle (136) of the sheath (109). [8] Housing feedthrough according to one of the preceding claims, characterized by that the retaining cap (107) is connected to the casing with locking hooks, with a snap connection or with frictional engagement. [9] Housing feedthrough according to one of the preceding claims, characterized by that the cavity (205) of the screw-in sleeve (201) is conical and that the clamping body (112) is conical with a central through-bore (113), wherein the inclination of a lateral surface of the conical clamping body (112) substantially corresponds to the opening angle of the conical cavity (205) of the through-opening (203). [10] A method for contacting a shield (103) of a shielded cable (101) in a housing feedthrough (302), the method comprising: - depositing an outer sheath (102), a shield (103) and an inner sheath (104) of the cable; - Pushing a retaining cap (107), a cable seal (108) and a sheath (109) onto the cable (101) - sliding a clamping stamp (111) and a clamping body (112) onto the shielded cable; - flanging the shield (103) and placing the shield on an outer side of a clamping body (112); - screwing a screw-in sleeve (201) into a housing wall (301); - Press the clamping body (112) in the axial direction into the screw-in sleeve (201).

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