METHOD FOR PRODUCING A CONNECTOR FOR ELECTRICAL SYSTEMS, CONNECTOR AND CONNECTION OF A CONNECTOR TO A CABLE

Description

[0001] The subject matter relates to a method for producing a connector for electrical systems, in particular for a motor vehicle electrical system. The subject matter further relates to a connector for electrical systems and the connection of a connector to a cable formed from multiple wires or strands.

[0002] The documents DE 22 49 707 A1, RO 126 513 A0, EP 2 662 934 A2 and JP 2013 105648 A disclose connection parts of the prior art.

[0003] Due to the increasing electrification of vehicles, today's vehicles have an increasing number of electrical devices. Connectors are typically used to electrically connect electrical systems to the power lines or cables of a vehicle. Due to the increasing use of connectors and enormous cost pressure, connectors are subject to ever-increasing demands.

[0004] The connectors must not only be particularly easy to connect to the power lines or cables of a vehicle, but must also exhibit good electrical conductivity and be as lightweight as possible. Furthermore, the manufacturing process for the connectors must be cost-effective and reliable.

[0005] Due to the increasing number of electrical consumers and the resulting increase in the number of current-carrying lines and cables, small cable cross-sections are preferred and therefore connection parts with a small cross-section and a resulting small size are required.

[0006] It is known from the prior art to stretch sheet metal and then bend it to produce a connector. However, this manufacturing process is disadvantageous in that the stretching process—especially for small connectors—does not provide a sufficiently thick wall thickness for the connector, making it impossible to reliably weld a connection to an electrical conductor or cable.

[0007] It is also known to design a connector in multiple parts. However, this is disadvantageous in terms of the mechanical strength of the connector and results in a resource-intensive assembly process.

[0008] Based on this, the object of the invention was to provide a method for producing a connecting part, a connecting part and a connection of a connecting part to a cable formed from several wires or strands, with which small geometries can be produced in a process-reliable and cost-effective manner and a reliable connection to a cable is made possible.

[0009] This object is achieved by a method for producing a connecting part, which comprises the following steps: Deep drawing of a sheet metal blank to produce a sleeve having a first end region and a second end region, wherein the first end region has a bottom and wherein the second end region is open, forming, in particular pressing, the second end region to create a tab and introducing a through hole into the tab.

[0010] The deep-drawing process allows for the reliable production of a sleeve with only tight tolerances. This is particularly advantageous for the production of connecting parts with small dimensions. Furthermore, the base of the first end area of ​​the sleeve has a small outer radii due to the deep-drawing process.

[0011] This allows the base of the first end region to be advantageously connected both mechanically and electrically to an electrical cable by means of a weld seam. It is particularly advantageous if the weld seam is a friction weld, i.e., a weld seam created by friction welding.

[0012] It is also possible to carry out the aforementioned deep-drawing process with high volumes and short cycle times, allowing the connecting parts to be produced cost-effectively. Forming, in particular pressing, the second end area to create a tab and inserting a through hole into the tab is also possible cost-effectively with high process reliability.

[0013] Furthermore, the connecting part is preferably designed as a single piece. This increases the stability of the connecting part and also reduces production costs, as complex assembly work can be eliminated.

[0014] According to one exemplary embodiment, the second end region of the sleeve is deformed, preferably pressed, in such a way that the inner walls of the tab at least partially abut one another and the cross section of the tab is essentially elliptical, with a wide plane defining the maximum cross-sectional width of the tab. The wide plane is preferably formed by the at least partially abutting inner walls of the tab. By pressing the second end region of the sleeve, a uniformly stable electrical contact can be ensured, for example in the case of a clamp contact on an electrically conductive component. By pressing, the size of the second end region of the connection part can also be reduced, which is advantageous in terms of the required installation space.

[0015] A further embodiment is characterized in that the through-hole is introduced into the tab substantially orthogonally to the wide plane. The axis of the through-hole is thus orthogonal to the wide plane of the tab. By means of such a through-hole, the connecting part can be conveniently connected, for example, to an electrical cable or to an electrical load, in particular by means of a screw. It is preferred that the through-hole be introduced substantially centrally in the wide plane of the tab and that the through-hole is preferably substantially circular.

[0016] According to a further embodiment, the tab is deformed, preferably bent, once or multiple times, particularly after the through-hole has been created. It is also preferred that the creation of the through-hole and the deformation of the tab be performed simultaneously in a combined bending / punching process. By deforming, particularly by bending, the tab, the connecting part can be adapted to various installation scenarios or the available installation space.

[0017] According to a further embodiment, it is preferred that the tab be deformed, in particular bent, about an axis lying in the wide plane and extending substantially in the transverse direction of the connecting part. This ensures that the through hole is provided in the structurally planned position.

[0018] It is also preferred that the tab be bent several times, wherein the respective bending axes, i.e., the axes around which the tab is bent, are formed substantially parallel or transverse to the axis lying in the wide plane and extending substantially in the transverse direction of the connecting part. Such bending processes make it possible to provide variable fastening options for the connecting part, since the position of the through hole can be adapted to various installation scenarios.

[0019] According to a further embodiment, it is preferred that the sleeve has a wall thickness of at least 1 mm after deep-drawing. This ensures that the wall thickness of the base after further processing of the sleeve is sufficient so that it can be reliably connected to a cable by means of a welded joint, in particular a friction welded joint.

[0020] A further aspect relates to a connection part for electrical systems, in particular for an on-board network of a motor vehicle, having a first end region and a second end region, wherein the connection part is formed in one piece, wherein the first end region is formed as a closed, U-shaped tube section, wherein the second end region is formed as a tab with a substantially elliptical cross-section and wherein the tab has a through-hole.

[0021] It is preferred that the closed, U-shaped pipe section preferably consists of a substantially circular wall and a substantially circular base that borders the wall on the underside. The advantages of a connecting part configured in this way have already been explained in connection with the method for producing the connecting part.

[0022] In terms of saving installation space, it is advantageous for the outer diameter of the first end region to be larger than the outer diameter of the second end region. This is because the outer diameter of the first end region usually corresponds to the outer diameter of a cable to be connected. Thus, a smaller outer diameter of the second end region can both save installation space and increase the connection options of the connector.

[0023] According to one embodiment, it is proposed that a transition region be arranged between the first end region and the second end region, and that the transition region tapers substantially from the first end region toward the second end region. It is preferred that the transition region tapers conically from the first end region toward the second end region. However, other types of taper are also conceivable, for example, a curved taper.

[0024] With regard to simple and process-reliable production of the connecting part, it is preferred that the first end region, the transition region, and at least a portion of the second end region are configured substantially mirror-symmetrically along the longitudinal axis of the connecting part. It is preferred that the entire second end region, with the exception of the deformed portion of the tab, is also configured mirror-symmetrically.

[0025] According to a further embodiment, it is preferred that the first end region has an outer diameter of a maximum of 25 mm, in particular a maximum of 8 mm. Such outer diameters can be achieved, in particular, by deep-drawing a sheet metal blank with only small tolerances, so that small connecting parts can be manufactured that correspond to small cable diameters. Small connecting parts are also advantageous in terms of material costs and space consumption.

[0026] With regard to the welding properties and the forming properties of the connecting part, it is advantageous if it is made of aluminum, copper, an aluminum alloy or a copper alloy.

[0027] The connecting component can be manufactured particularly cost-effectively if it is a tubular cable lug. Tubular cable lugs are particularly in demand as mass-produced items.

[0028] A further aspect relates to a connection of an aforementioned connecting part to a cable formed from a plurality of wires or strands, wherein the cable is enclosed by a support sleeve for receiving an end face of the cable in such a way that the wires or strands of the cable are held in the support sleeve and wherein the face of the first end region of the connecting part is welded to the face of the cable and / or the face of the support sleeve by means of a weld seam.

[0029] By deep-drawing the aforementioned connector, a sufficient base thickness can be provided for a reliable welded connection. The closed design of the connector's base ensures a longitudinally sealed connection to the cable, reliably preventing the ingress of liquid into the cable, for example, due to capillary forces.

[0030] From a production-technical perspective, it is also advantageous if the weld seam is a friction weld, i.e., it is created by means of a friction weld connection between the end face of the first end region of the connecting part and the end face of the cable and / or the end face of the support sleeve. Preferably, the connecting part is rotated during the welding process. In particular, it is preferred that the friction weld connection between the end face of the first end region exists with both the end face of the cable and the end face of the support sleeve. The friction weld can be a rotational friction weld.

[0031] A further embodiment is characterized in that the end face of the cable is essentially flush with the end face of the support sleeve. The end face of the cable is preferably formed by the ends of the wires or strands. This enables the reliable creation of a friction welded connection with both the cable and the support sleeve.

[0032] According to a further embodiment, it is advantageous for the cable to be stripped in the area of ​​the support sleeve. This enables a reliable electrical connection between the cable and the support sleeve.

[0033] The subject matter is explained in more detail below using a drawing showing exemplary embodiments. The drawing shows: Fig. 1a a side view of an embodiment of a sleeve during a subject process after deep drawing in section, Fig. 1b the in Fig. 1a illustrated embodiment of the sleeve after deep drawing in a front view, Fig. 2a a side view of the Fig. 1a und 1b illustrated embodiment of the sleeve after pressing in section, Fig. 2b, which in Fig. 2a illustrated embodiment of the sleeve after pressing in a front view, Fig.3a a top view of the previously illustrated embodiment of the sleeve after the introduction of a through hole, Fig. 3b the in Fig. 3a illustrated embodiment of the sleeve after the introduction of the through hole in a rotated front view, Fig. 4a a first process step of joining an embodiment of the subject connection part with a cable by means of a rotation friction welding process in a side view, Fig. 4b a second process step of the in Fig. 4a joining shown, Fig. 4c a third process step of the Fig. 4a und 4b shown joining, Fig. 5a an embodiment of the subject connection part in a side view, Fig. 5b the in Fig. 5a illustrated embodiment of the connecting part in a plan view, Fig. 6a another embodiment of the subject connecting part in a side view, Fig. 6b the in Fig. 6a illustrated embodiment of the connecting part in a plan view, Fig. 7a another embodiment of the subject connecting part in a side view, Fig. 7b the in Fig. 7a illustrated embodiment of the connecting part in a plan view, Fig. 8a another embodiment of the subject connecting part in a side view and Fig. 8b the Fig. 8a illustrated embodiment of the connecting part in a top view.

[0034] In the following description of the various embodiments, components and elements with the same function and the same mode of operation are provided with the same reference numerals, even if the components and elements in the various embodiments may have differences in their dimensions or shape.

[0035] Fig. 1a shows a side view of an embodiment of a sleeve 2 during a specific process after deep drawing. The sleeve 2 is tubular and has a substantially circular wall 4. This is shown in the Fig. 1b The sleeve 2 can be seen in the front view shown. Furthermore, the sleeve comprises a first end region 6, which has a bottom 8, and a second end region 10, which is open. The sleeve 2 has a substantially U-shaped cross-sectional profile and is preferably made of copper, aluminum, or alloys thereof. The wall thickness of the sleeve 2 is preferably at least 1 mm.

[0036] In Fig. 2a is a side view of the Fig. 1a und 1b 1 shows the embodiment of the sleeve 2 after pressing. It can be seen that the inner walls 12 or the inner surface of the wall 4 essentially abut one another in the second end region 10. As a result of the pressing, a tab 14 with a substantially elliptical cross-section has formed in the second end region 10 (cf. Fig. 2b ). The first end region 6 tapers essentially conically by means of a transition region 16 and then merges into the second end region 10 or the tab 14. The transition region 16 and the first end region 6 enclose an internal cavity 18. In Fig. 2b It can further be seen that the outer diameter d 1 of the first end region 6 is larger than the outer diameter d 2 of the second end region 10 or the tab 14. Preferably, the outer diameter d 1 is a maximum of 10 mm, in particular a maximum of 8 mm.

[0037] In Fig. 3a is a plan view of the previously illustrated embodiment of the sleeve 2 after the introduction of a through hole 20. After the introduction of the through hole 20, all process steps are completed, so that a connecting part 22 has now been produced. The through hole 20 is introduced centrally in a wide plane E of the tab 14. The wide plane E of the tab 14 is in Fig. 3b and runs along the maximum cross-sectional width of the tab 14. The longitudinal axis X of the connecting part 22 preferably runs centrally through the through hole 20.

[0038] The Fig. 4a bis 4c show the connection of a physical connector 22 to a cable 24 by means of a rotational friction welding process. The cable 24 is preferably a battery cable of a motor vehicle, in particular for connecting a battery to a starter, a generator, or another electrical line of a motor vehicle. The cable 24 is composed of several strands or wires 26 that are sheathed by insulation 28. In the end region of the cable 24, the insulation 26 is removed so that the wires 26 are exposed and enclosed by a support sleeve 30. The support sleeve 30 is preferably round and made of aluminum, copper, or alloys thereof. It can be seen that the end face 30a of the support sleeve 30 is flush with the end face 24a of the cable 24.

[0039] The support sleeve 30 is preferably pressed together so that the wires 26 lie closely against one another within the support sleeve 30. In a first process step of the rotational friction welding process, the connecting part 22 is set in rotation, while the cable 24 is arranged in a holder (not shown) in a rotationally fixed manner.

[0040] In the Fig. 4b In the process step shown, the connecting part 22 is brought into contact with the cable 24 such that the end face 22a of the connecting part 22 comes into contact with the end face 30a of the support sleeve 30 and the end face 24a of the cable 24. For this purpose, the cable 24 is moved toward the connecting part 22 in the direction of arrow Y.

[0041] Due to the rotation of the connecting part 22, friction develops between the connecting part 22 and the cable 24 or the support sleeve 30, which leads to heating and plasticization of the materials in contact. As a result, the connecting part 22 is welded to the cable 24 and the support sleeve 30 by means of a friction weld 32. Fig. 4c a correspondingly created friction weld seam 32 is shown.

[0042] In the Fig. 5a bis 8b Various embodiments of a specific connecting part 22 are shown. The connecting parts 22 differ only in the bending processes to which they were subjected. The bending processes can be performed simultaneously with the creation of the through-hole 20 or after the creation of the through-hole 20.

[0043] The Fig. 5a und 5b The connecting part 22 shown has not been subjected to any bending process. It therefore essentially corresponds to the Fig. 3a, 3b as well as Fig. 4a bis 4c shown connection part 22.

[0044] The Fig. 6a und 6b The connecting part 22 shown or the tab 14 of the connecting part 22 was bent about two bending axes B 1 and B 2. It can be seen that the bending axes B 1 and B 2 run in the transverse direction of the connecting part 22, with the bending axis B 1 in the Fig. 3b shown plane E and the bending axis B 2 extends parallel to the bending axis B 1. The double bending of the tab 14 enables an offset screwing surface for the through hole 20, wherein the axis running through the through hole 20 continues to run in the transverse direction of the connecting part 22.

[0045] This is the Fig. 7a und 7b The embodiment of the connecting part 22 shown has been bent substantially by 90° about a bending axis B 3 , so that the axis running through the through hole 20 extends substantially parallel to the longitudinal axis X of the connecting part 22.

[0046] Fig. 8a 8b and 8b show a connecting part 22 whose tab 14 has been bent around a total of three bending axes B 4 , B 5 , and B 6 . This allows the tab 14 to be adapted to specific structural conditions. It can be seen that the axis running through the through hole 20 runs obliquely to the longitudinal and transverse axes of the connecting part 22.

Claims

1. Method of manufacturing a connection part for electrical installations, in particular for an on-board network of a motor vehicle, comprising: - deep-drawing a sheet metal blank for producing a sleeve having a first end region and a second end region, wherein the first end region has a bottom and wherein the second end region is open, - forming, in particular pressing, the second end region to produce a tab, and - making a through hole in the tab.

2. Method according to the preceding claim, characterized in that - the second end region of the sleeve is formed in such a way that inner wall sides of the tab at least partially abut one another and the cross-section of the tab is formed substantially elliptically, wherein a wide plane defines the maximum cross-sectional width of the tab.

3. A method according to any one of the preceding claims, characterised in that - the through hole is made in the tab substantially orthogonal to the wide plane.

4. Method according to any one of the preceding claims, characterized in that - the tab is deformed, preferably bent, one or more times, in particular after the through hole has been introduced and / or - the tab is deformed, in particular bent, about an axis lying in the broad plane and running essentially in the transverse direction of the connecting part.

5. Method according to one of the preceding claims, characterized in that - the sleeve after deep drawing has a wall thickness of at least 1 mm after deep-drawing.

6. Connection part for electrical installations, in particular for an on-board network of a motor vehicle, - having a first end region (6) and - with a second end region (10), - wherein the connection part (22) is provided as one piece, characterized in that - the first and the second end region (6, 10) are manufactured from a deep-drawn sheet metal blank, wherein after the deep-drawing the first end region comprises a bottom and the second end region is open, in a way that - the first end region (5) is provided as a closed, U-shaped tube section, - that the second end region (10) is formed, after the deep drawing, as a tab (14), and - that the tab (14) has a through hole (20).

7. Connection part according to claim 6, characterized in that - the tab (14) has a substantially elliptical cross-section.

8. Connection part according to one of claims 6 or 7, characterized in that - the outer diameter (d1) of the first end portion (6) is larger than the outer diameter (d2) of the second end portion (10).

9. Connection part according to one of claims 6 or 8, characterized in that - a transition region (16) is arranged between the first end region (6) and the second end region (10), and - that the transition region (16) essentially tapers from the first end region (6) towards the second end region (10).

10. Connection part according to one of claims 6 to 9, characterized in that - the first end region (6), the transition region (16) and at least a part of the second end region (10) are substantially mirror-symmetrical along the longitudinal axis (X) of the connection part (22) and / or - that the first end region (6) has an outer diameter (d1) of at most 25 mm, in particular of at most 8 mm.

11. Connection part according to one of claims 6 to 10, characterized in that - the connection part (22) is made of aluminium, copper, an aluminium alloy or a copper alloy.

12. Connection part according to one of claims 6 to 11, characterised in that - the connection part (22) is formed as a preferably closed tubular cable lug.

13. Connection of a connection part (22) according to claim 7 to a cable (24) made of a plurality of wires (26) or strands, - wherein the cable (24) is enclosed by a support sleeve (30) for receiving an end face (24a) of the cable (24) in such a way that the wires (26) or strands of the cable (24) are held in the support sleeve (30), characterized in that - the end face (22a) of the first end region (10) of the connection part (22) is welded by means of a weld seam (32) to the end face (24a) of the cable (24) and / or the end face (30a) of the support sleeve (30).

14. Connection according to the preceding claim, characterized in that - the weld is a friction weld (32).

15. Joint according to any one of claims 13 or 14, characterized in that - the end face (24a) of the cable (24) is substantially flush with the end face (30a) of the support sleeve (30) and / or - that the cable (24) is stripped in the region of the support sleeve (30).