Sealed bus bar and method for producing the sealed bus bar
Patent Information
- Application Number
- EP2023834050
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-02-08
- Filing Date
- 2023-12-18
- Publication Date
- 2025-09-10
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The existing manufacturing process for sealed busbars is complex and time-consuming due to the need for heating, cooling, and gluing of sealants before overmolding, resulting in high energy expenditure and thermal load, as well as increased production costs and complexity.
A manufacturing method where a metallic busbar with multiple connections is first provided, and separate sealing means are arranged at predetermined positions, followed by immediate encapsulation with a plastic coating using injection molding, which simplifies the process by eliminating pre-heating and cooling steps and utilizing shrink tubes with hot-melt adhesive coatings for enhanced sealing.
This approach reduces production cycle time, minimizes energy consumption, and improves the sealing effect while reducing material costs and complexity, allowing for a more efficient and cost-effective production of sealed busbars with a high sealing performance.
Smart Images
Figure EP2023086327_15082024_PF_FP
Abstract
Description
[0001] Sealed busbar and manufacturing process of the sealed busbar
[0002] Description:
[0003] The invention relates to a sealed busbar and a manufacturing method of the sealed busbar.
[0004] During the production of a sealed busbar, a sealant is applied around certain sections of the busbar and typically overmolded with a plastic. However, before the sealant can be overmolded, it must be properly fixed to the busbar to ensure its sealing function. For this purpose, the sealant is heated, cooled, and / or bonded, for example. However, these sequential process steps are very complex and time-consuming, and therefore costly.
[0005] It is therefore an object of the present invention to provide a sealed busbar and a manufacturing method of a sealed busbar in which the complexity and number of manufacturing steps are reduced and the manufacturing method is optimized.
[0006] This problem is solved by the combination of features according to patent claim 1.
[0007] According to the invention, a manufacturing method for a sealed busbar is proposed, in which a metallic, in particular electrically conductive, busbar having a plurality of busbar terminals is first provided, and then one or more separate sealing means are arranged at predetermined positions on the metallic busbar. Immediately after arrangement, the metallic busbar is overmolded with a plastic overmold around the sealing means regions using an injection molding device, at least in such a way that the sealing means is completely overmolded.
[0008] The advantage of this is that the production cycle time is shortened due to the reduction in the number of process steps required prior to overmolding. In particular, eliminating the need to heat and cool the sealant before it is overmolded with the plastic overmolding results in a reduction in energy consumption and thermal stress on the component. The plastic overmolding is preferably produced using insert molding.
[0009] In a preferred embodiment of the method, the sealing means is a shrink tube and / or a shrink film. During overmolding, the shrink tube is heated by thermal energy from the plastic overmolding, in particular a melt of the plastic overmolding, such that the shrink tube shrinks until it forms a tight seal against the metal busbar. This achieves or improves the sealing effect. Furthermore, unlike a rubber sealing ring, no special requirements are required regarding the geometry or shape of the metal busbar.
[0010] In an advantageous embodiment, the heat-shrink tubing is a double-walled heat-shrink tubing, and a coating of hot-melt adhesive is applied to an inner surface of the heat-shrink tubing. It is advantageous that the hot-melt adhesive can melt during the shrinking process, allowing the tubing to adhere to the metal. Furthermore, the outer layer of the double-walled heat-shrink tubing can bond to and embed itself in the injection-molded parts during the injection-molding process. This results in an improved sealing effect. Furthermore, a design is also conceivable in which an outer surface of the heat-shrink tubing has a coating of adhesive, in particular a hot-melt adhesive. This creates or increases the adhesion between the outer surface of the heat-shrink tubing and the plastic overmolding.
[0011] In one embodiment of the method, it is provided that the heat-shrink tubing is cut to size using a cutting device prior to arrangement according to the predetermined position of the metallic busbar. In this way, the heat-shrink tubing is optimally adapted to the metallic busbar or the predetermined position of the metallic busbar at which the heat-shrink tubing is arranged. This reduces material expenditure and optimizes the sealing effect. Furthermore, an embodiment is advantageous in which, during overmolding, the metallic busbar and the sealant are first preheated using the injection molding device. For this purpose, the injection molding device in particular has a heating device. The advantage of this is that the metallic busbar and the sealant are already brought to an optimal temperature for overmolding, and in this way, the fixing of the sealant is also improved.
[0012] In a further advantageous variant, the invention provides that, prior to placement on the metal busbar, a marking for the predetermined position of the sealant is created on the metal busbar using a marking device. Furthermore, the sealant is positioned according to the marking during placement. This advantageously simplifies the placement of the sealant at the predetermined position.
[0013] In a further preferred embodiment of the method, the sealing means is arranged at the predetermined position of the metal busbar by means of a handling device or manually. This allows for automation, particularly when using a handling device.
[0014] In one embodiment, the method according to the invention is carried out by cleaning the metal busbar using a cleaning device before positioning. This has the advantage of optimizing the sealing effect and adhesion of the sealant at the predetermined position.
[0015] It is further advantageous if, after overmolding, a leakage test is carried out using an appropriate testing device. This ensures that the sealed busbar achieves the desired sealing effect. In one advantageous embodiment, the metallic busbar is made of copper or aluminum and / or alloys of copper or aluminum. In a further advantageous variant, the invention provides for the plastic overmolding to be made of polyolefin, polyvinylidene fluoride, Viton, polyvinyl chloride, polyamide (PA), polybutylene terephthalate (PBT), liquid crystalline polymers (LCP), polyphthalamides (PPA), polyphenylene sulfide (PPS) and / or polytetrafluoroethylene. These materials are particularly suitable for a sealed busbar or have mutually complementary positive properties with regard to the sealing effect.
[0016] According to the invention, a sealed busbar is further proposed, produced by a method according to the above disclosure. The sealed busbar comprises a sealing means arranged at a predetermined position on the metallic busbar, and a plastic overmolding arranged around the regions of the sealing means, at least such that the sealing means is completely overmolded.
[0017] The features disclosed above can be combined as desired, as long as this is technically possible and they do not contradict each other.
[0018] Other advantageous developments of the invention are characterized in the subclaims or are presented in more detail below, together with the description of the preferred embodiment of the invention, with reference to the figures. They show:
[0019] Fig. 1 is a sectional view of a sealed busbar and
[0020] Fig. 2 is a schematic view of a manufacturing process of the sealed busbar.
[0021] The figures are schematic examples. Identical reference numerals in the figures indicate identical functional and / or structural features. Figure 1 shows a sealed busbar 10 with a sealing means 3 arranged at a predetermined position P of a metallic busbar 1 and a plastic overmolding 2 around the areas of the sealing means 3, such that the sealing means 3 is completely overmolding. The metallic busbar 1 has a plurality of busbar connections 1a, 1b, 1c, 1d. Furthermore, the metallic busbar 1 is made of copper or aluminum and / or alloys of copper or aluminum. In addition, the sealing means 3 is a double-walled shrink tube, on the inner surface of which a coating of a hot-melt adhesive is arranged. In addition, an outer surface of the shrink tube has a coating of an adhesive.Furthermore, the sealant 3 lies sealingly against the metallic busbar 1. Furthermore, a marking 6 for the predetermined position P of the sealant 3 on the metallic busbar 1 is formed on the metallic busbar 1. Furthermore, the plastic overmolding 2 is made of polyolefin, polyvinylidene fluoride, Viton, polyvinyl chloride, and / or polytetrafluoroethylene.
[0022] The sealed busbar 10 shown in Figure 1 is manufactured by means of the manufacturing process described below and shown schematically in Figure 2.
[0023] The manufacturing method for the sealed busbar 10 first comprises providing a metallic busbar 1 having a plurality of busbar terminals 1a, 1b, 1c, 1d (step a). This is followed by arranging one or more separate sealing means 3 at predetermined positions P of the metallic busbar 1 (step b). Immediately after arranging, the metallic busbar 1 is overmolded with a plastic overmold 2 around the areas of the sealing means 3 by means of an injection molding device, at least such that the sealing means 3 is completely overmolded (step c). The sealing means 3 is a double-walled shrink tube, in which a coating of a hot-melt adhesive is arranged on an inner surface of the shrink tube.Furthermore, during overmolding, the shrink tube is heated by thermal energy from the plastic overmolding 2, in particular a melt of the plastic overmolding 2, such that the shrink tube shrinks until it forms a sealing contact with the metallic busbar 1. For this purpose, during overmolding, the metallic busbar 1 and the sealant 3 are optionally preheated by means of a heating device of the injection molding device.
[0024] Furthermore, during the manufacturing process, the metallic busbar 1 is cleaned using a cleaning device before placement (step ao). Subsequently, before placement on the metallic busbar 1, a marking 6 for the predetermined position P of the sealing means 3 is created on the metallic busbar 1 using a marking device (step ai). The sealing means 3 is then positioned according to the marking 6 during placement. Furthermore, the positioning of the sealing means 3 at the predetermined position P of the metallic busbar 1 is carried out using a handling device.
[0025] Furthermore, after overmolding, a leakage test is carried out using an appropriate testing device (step co).
[0026] The invention is not limited to the preferred embodiments described above. Rather, a number of variants are conceivable that utilize the presented solution even in fundamentally different embodiments.
Claims
Patent claims 1 . Manufacturing method of a sealed busbar (10), comprising the following steps: a. Providing a metallic busbar (1) having a plurality of busbar connections (1 a, 1 b, 1 c, 1 d) b. Arranging one or more separate sealing means (3) at predetermined positions (P) of the metallic busbar (1); wherein immediately after the arrangement, the following step is carried out: c. Overmolding the metallic busbar with a plastic overmolding (2) around the areas of the sealing means (3) by means of an injection molding device at least in such a way that the sealing means (3) is completely overmolding.
2. Manufacturing method according to claim 1, wherein the sealing means (3) is a shrink tube, wherein during the overmolding the shrink tube is heated by a thermal energy of the plastic overmolding (2), in particular a melt of the plastic overmolding (2), such that the shrink tube shrinks until it lies sealingly against the metallic busbar (1).
3. Manufacturing method according to claim 2, wherein the shrink tube is a double-walled shrink tube, wherein a coating of a hot melt adhesive is arranged on an inner surface of the shrink tube.
4. Manufacturing process according to claim 2 or 3, wherein the Heat shrink tubing is cut to size by means of a cutting device (10) prior to placement according to the predetermined position (P) of the metallic busbar (1).
5. Manufacturing method according to one of the preceding claims, wherein during the overmolding, the metallic busbar (1) and the sealing means (3) are first preheated by means of the injection molding device.
6. Manufacturing method according to one of the preceding claims, wherein, before arranging on the metallic busbar (1), a marking (6) for the predetermined position (P) of the sealing means (3) is produced on the metallic busbar (1) by means of a marking device, wherein the sealing means (3) is arranged according to the marking (6) during arranging.
7. Manufacturing method according to one of the preceding claims, wherein the arrangement of the sealing means (3) at the predetermined position (P) of the metallic busbar (1) is carried out by means of a handling device or manually.
8. Manufacturing method according to one of the preceding claims, wherein the metallic busbar (1) is cleaned by means of a cleaning device before being arranged.
9. Manufacturing method according to one of the preceding claims, wherein after the overmolding a leakage test is carried out by means of an appropriate testing device.
10. Manufacturing method according to one of the preceding claims, wherein the metallic busbar (1) is made of copper or aluminum and / or alloys of copper or aluminum.
11. Manufacturing method according to one of the preceding claims, wherein the plastic overmolding (2) is made of polyolefin, polyvinylidene fluoride, Viton, polyvinyl chloride, polyamide, polybutylene terephthalate, liquid crystalline polymers, polyphthalamides, polyphenylene sulfide and / or polytetrafluoroethylene.
12. Sealed busbar (10) produced by a method according to one of the preceding claims, with a sealing means (3) arranged at a predetermined position of a metallic busbar (1) and a plastic overmolding (2) around the areas of the sealing means (3), at least in such a way that the sealing means (3) is completely overmolding.