DE102017114581A1 - SEALED ELECTRICAL MODULE FOR A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to an electrical assembly (1) for a motor vehicle. This has a component housing (2), which is made of a first plastic material and has a housing opening (4) into which a between an interior (5) of the component housing (2) and a housing environment (6) extending, the housing breakthrough ( 4) is inserted in a form-fitting manner from a second plastic material, which is different from the first plastic material, by means of a fluid-sealing cable bushing (7). The module (1) also has an electrical line (8) whose electrical conductor is surrounded by an insulating jacket (9) made of a third plastic material and which passes through the cable bushing (7) from the housing environment (6) into the interior (5). guided into and electrically coupled to an electrical component. According to the second plastic material of the cable bushing (7) and the third plastic material of the insulation jacket (9) on the housing environment (6) facing outside of the housing aperture (4) are integrally connected to each other.

Description

Technical area

The present invention relates to a sealed electrical assembly for a motor vehicle according to the preamble of claim 1. Furthermore, the invention relates to a method for producing such an assembly according to the preamble of claim 9. The assembly may be e.g. to act a power distributor, in particular a power distribution for connection to the positive terminal of an energy storage or generator.

State of the art

An arrangement according to the preamble of claim 1 is for example from the DE 10 2010 029 658 B4 known. In this case, in an electrical assembly with a wall or housing breakthrough electrical lines are guided by a cable feedthrough through the wall or housing opening. Such a conduit bushing may also be referred to as a grommet and is used primarily to seal the wall or housing breakthrough from moisture or water ingress and the protection of the line so that it does not rub against edges of the wall or housing breakthrough and is damaged as a result.

In the manufacture of the cable feedthrough, however, very close tolerances must be maintained, the exceeding of which can lead to fluidic leaks between the line and the inner circumference of the line feedthrough. Therefore, the nozzles must often be checked at least randomly for their tightness, which requires a corresponding inspection effort. In addition, however, such strong and thus heavy and rigid lines can be used in particular to a power distributor for connection to the positive terminal of an energy storage device or generator with respect to their conductor cross-section, that by their force fluidic leaks between line bushing and line can arise. In particular, when mounting the module or when laying the line tensile forces or bending moments occur, which can lead to a kind of spreading the cable entry at the outlet of the line to the housing environment, which can penetrate from the housing environment in the interior of the housing moisture or moisture.

To address this problem, e.g. a single wire seal for each guided into the component housing line into consideration, as it is also known from sealed connectors. However, this has proved to be too costly.

Description of the invention

The object of the invention is therefore to provide a reliable seal for an electrical assembly with a component housing using structurally simple means possible.

The object is solved by the subject matters of the independent claims. Advantageous developments of the invention are specified in the dependent claims, the description and the accompanying figures.

An electrical assembly according to the invention is particularly suitable for a motor vehicle, as it meets the requirements for installation in a wet area of the motor vehicle, such as the engine compartment in terms of their impermeability to the ingress of moisture, moisture, etc. The arrangement according to the invention comprises a component housing made of a first plastic material and e.g. a power distribution box for installation in the wet area of the motor vehicle. Accordingly, in the component housing, electrical and electronic components may be arranged, e.g. are arranged for distributing the electric current of a positive terminal of an energy storage device or of a motor vehicle generator. The component housing has at least one housing opening for passing one or more electrical lines to the components in the interior of the component housing. Between the interior of the component housing and a housing environment extends a line bushing, which can also be referred to as a spout, is inserted in a form-fitting manner in the housing breakthrough and fluidly seals the housing opening. The line feedthrough is formed from a second plastic material that is different from the first plastic material of the component housing, possibly also foamed, and, when inserted, has an internal channel for conducting the line. The arrangement further comprises at least one electrical line with an electrical conductor, which is surrounded by an insulating jacket of a third, ideally to the other plastic materials different plastic material. The third plastic material can also be identical to the other plastic materials, in particular to the second plastic material. The conduit is routed through the conduit feedthrough from the housing environment into the interior space where it is electrically coupled to the electrical component, e.g. by means of a welding, screw or plug connection.

According to the second plastic of the cable bushing and the third plastic of the insulation jacket on the Casing environment facing the outside of the housing breakthrough materially connected together. In this case, the cable bushing for sealing the housing aperture also extends beyond the wall of the component housing, at least in the direction of the housing environment. In and / or adjacent to the housing opening then the two plastics are connected to each other, eg welded.

With this configuration, the invention makes it possible to reliably seal the component housing in the region of the housing breakthrough also over the product life cycle, because even heavyweight or rigid cables can no longer deflect or spread the cable bushing so that a leak occurs there. Instead, a preferably fluid-tight cohesive connection running around the circumference of the insulation jacket is formed there. A movement of the line relative to the line feedthrough is then excluded, at least in the connection point.

In the simplest case, it may be sufficient to melt the already existing plastic material of the insulation jacket. However, this can only be done with an extremely precise joining method, since after melting or cohesive bonding enough residual material must remain on the insulating jacket in order to isolate the conductor and protect. A particularly advantageous embodiment of the invention therefore provides that the insulating jacket at its outer periphery at least partially a material addition of the third plastic or a non-alien filler material, so possibly a fourth material. The insulating jacket can therefore have an additional material-dependent thickening on its circumference, which serves mainly for melting and bonding to the second plastic material of the line feedthrough. As a result, the actual insulation jacket remains in its usual form and protects even after connecting the conductor with a sufficient material thickness.

As a joining method for bonding, laser welding, in particular laser transmission welding, has proved to be advantageous. For plastic laser welding, it is favorable in terms of materials, if the insulating jacket is made of a thermoplastic elastomer (TPE). TPE is on the one hand well weldable and on the other hand in terms of its electrical and mechanical properties, such as fire protection or the like, approved for use in motor vehicles.

For the cohesive joining by means of laser welding, it has proved to be advantageous in terms of the material pairing to be welded, if the cable feedthrough made of an ethylene-propylene-diene rubber (EPDM) is made. This has already proven itself for cable bushings and allows good weldability, especially in combination with TPE.

Alternatively, the lead bushing may be made of polymethyl methacrylate (PMMA) or a styrene-acrylonitrile copolymer (SAN) and the insulation sheath may be made of polyvinyl chloride (PVC). Advantageously, electrical cables are often encased with PVC today, so that standard cables can be used here.

Particularly advantageous, the invention has proven with comparatively large cross-section lines. Accordingly, the conductor may have a copper cross section of at least 35 mm ² . There are also wire cross sections of 50 mm ² for copper materials or 85 mm ² for aluminum materials conceivable. These heavy-weight lines cause a high force on the cable bushing and can cause leaks without the cohesive connection.

The cable length also contributes to the stress on the cable bushing. Therefore, the invention can be used particularly advantageously if the line has a length of at least 25 cm, preferably at least 30 cm.

In order to enable a connection between the outer circumferential surface of the insulation jacket with the inner peripheral surface of the cable bushing surrounding the insulation jacket, the cable feedthrough can be laser-transparent and the insulation jacket can be made laser-absorbent. Thus, the arrangement can be pre-assembled and the connection can then be carried out subsequently. Possibly. In some cases additional materials with corresponding properties are necessary to achieve laser absorption.

• - Bereitstellen eines Komponentengehäuses aus einem ersten Kunststoffmaterial mit einem Gehäusedurchbruch zum Einhausen einer elektrischen Baugruppe. Das Komponentengehäuse kann wiederum ein Gehäuse eines Stromverteilers sein.
• - Bereitstellen einer Leitungsdurchführung aus einem zweiten Kunststoffmaterial zum formschlüssigen Einsetzen in den Gehäusedurchbruch .
• - Bereitstellen einer elektrischen Leitung mit einem elektrischen Leiter und einem diesen umgebenden Isolationsmantel aus einem dritten Kunststoffmaterial zum Hindurchführen durch die Leitungsdurchführung. Das dritte Kunststoffmaterial ist idealerweise unterschiedlich zu den anderen beiden Kunststoffmaterial, kann aber auch identisch sein zum zweiten Kunststoffmaterial.

The invention also relates to a method for producing an electrical assembly for a motor vehicle. The procedure involves the following steps:

• - Providing a component housing made of a first plastic material with a housing opening for Einhausen an electrical assembly. The component housing may in turn be a housing of a power distributor.
• - Providing a cable bushing of a second plastic material for positive insertion into the housing breakthrough.
• - Providing an electrical line with an electrical conductor and a surrounding insulating jacket of a third Plastic material for passing through the cable feedthrough. The third plastic material is ideally different from the other two plastic material, but may also be identical to the second plastic material.

The components used for the method can be developed according to the assembly described above.

According to the invention, the third plastic material of the insulation jacket of the conductor connected to the electrical assembly and guided through the cable feedthrough line with the overlapping second plastic material of the cable feedthrough is materially connected. This essentially results in the advantages that are achieved with the assembly described above.

A particularly advantageous embodiment of the method provides that the cohesive connection by means of laser welding, preferably laser transmission welding, takes place at an angle to the overlapping region of the two plastic materials from an oblique direction. Since here the second plastic material of the line feedthrough does not have to be penetrated by the laser, both the second and the third plastic material can be designed laser absorbing.

Alternatively, the cohesive connection by means of laser welding, preferably laser transmission welding, can take place from a direction substantially perpendicular to the overlapping region of the two plastic materials. In this case, the cable feedthrough laser-transparent and the insulation jacket can be carried out laser absorbing. Thus, the structure of the laser welding device can be structurally simpler.

list of figures

• 1 eine erfindungsgemäße elektrische Baugruppe, bei der ein Isolationsmantel mit einer Leitungsdurchführung stoffschlüssig verbunden ist, und
• 2 eine weitere Ausführungsform der erfindungsgemäßen elektrischen Baugruppe.

Hereinafter, an advantageous embodiment of the invention will be explained with reference to the accompanying figures. Show it:

• 1 an electrical assembly according to the invention, in which an insulating jacket is materially connected to a line feedthrough, and
• 2 a further embodiment of the electrical assembly according to the invention.

The figures are merely schematic representations and serve only to illustrate the invention. Identical or equivalent elements are consistently provided with the same reference numerals.

Detailed description

1 shows in a rough schematic sectional view of an electrical assembly 1 , which is suitable for installation in a motor vehicle.

The assembly 1 has a component housing 2 , which is shown here only partially for better illustration and in which it is a housing of an electric power distributor for distributing electrical energy of a generator or energy storage of the motor vehicle. The component housing 2 is completely surrounded by a lateral wall 3 completed and has at least on one side a housing breakthrough 4 on to an interior 5 of the component housing 2 with a housing environment 6 connect to. The component housing 2 is injection molded from a first plastic material and is thus provided as a separate component.

In the case breakthrough 4 is a line feedthrough 7 used and is held in a positive fit, the form-fitting is indicated here only by way of example and can be accomplished via a different geometric and / or structural design. Functionally, the cable bushing seals 7 the housing breakthrough 4 against the penetration of foreign bodies or water into the interior 5 from. The cable feedthrough 7 is foamed from a second plastic material, for example, in this embodiment of EPDM / PP.

Through the cable feedthrough 7 is an electrical line 8th guided, which has a (unspecified) electrical conductor, of an insulating jacket 9 is surrounded. The conductor consists of a copper material and has a cross section of at least 35 mm ² , whereby larger cross-sections, such as 50 mm ² and more are possible. This depends on the power of the generator and / or the energy storage. Alternatively, the line can also consist of an aluminum material, in which also cross sections of 85 mm ^{2 are} possible. The insulation jacket 9 is made of a third plastic material, which in this embodiment is TPE.

Outside or adjacent to the wall 3 are an outer circumferential surface 10 of the insulation sheath 9 and an inner surface 11 the line implementation 7 cohesively interconnected by their plastic materials are welded here. The cohesive connection 12 , So the joint between the two plastic materials, is shown here by way of example.

2 shows a further embodiment of the module 1 in which the insulation jacket 9 at a longitudinal portion of the conduit 8th a material allowance 13 having. This is in principle a radial thickening on which the insulation jacket 9 has more sections of the second plastic material, which can then be melted without the material thickness of the insulation sheath 9 to reduce to a radial undersize.

In 2 is also hinted that the cohesive connection 12 by means of a laser welding device 14 is formed, in this embodiment, approximately perpendicular to the longitudinal direction of the line 8th is arranged. So that the laser the cohesive connection 12 can form at the desired location, the second plastic material of the line feedthrough 7 is laser-permeable, while the third plastic material of the insulation sheath 9 is laser absorbent.

The production of the assembly 1 can be done in particular by the method described below.

First, the component housing 2 injection molded from the first plastic material, the line feedthrough 7 made of the second plastic material and the electrical line 8th together with the insulation jacket 9 provided.

Then the wiring is 7 in the housing breakthrough 4 positively inserted, wherein the line 8th already at this time by the wiring 7 may be passed through or later passed through.

Then by means of the laser welding device 14 the third plastic material of the insulation jacket 9 with the second plastic material of the cable feedthrough so that it overlaps radially in sections 7 Laser welded, so that in sections the cohesive connection 12 is trained. In this case, a circumferential weld seam is preferably formed as a longitudinal water seal.

Finally, for example, in an automobile manufacturer, the assembly 1 Installed in a wet area of the motor vehicle, wherein the cohesive connection 12 can serve as a strain relief, but in any case forms a fluid-tight joint, so that no longitudinal water in the line bushing 7 can occur.

LIST OF REFERENCE NUMBERS

1

Electrical assembly

2

component housing

3

wall

4

Case breaking

5

inner space

6

housing environment

7

Cable bushing

8th

Electrical line

9

insulation jacket

10

Outer casing surface

11

Interior (coat) area

12

cohesive connection / joint

13

addition of material

14

Laser welding device

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010029658 B4 [0002]

Claims (11)

An electrical assembly (1) for a motor vehicle, comprising a component housing (2) made of a first plastic material and having a housing aperture (4) into which an inner space (5) of the component housing (2) and housing environment (FIG. 6) extending, the housing breakthrough (4) fluidly sealing cable bushing (7) from a different plastic material to the first plastic material is positively inserted, and with an electrical line (8), the electrical conductor of an insulating jacket (9) from a third Plastic material is surrounded and which is guided by the line bushing (7) of the housing environment (6) into the interior (5) and electrically coupled to an electrical component, characterized in that the second plastic material of the line feedthrough (7) and the third plastic material of the insulation jacket (9) on the housing environment (6) z facing outer side of the housing breakthrough (4) are materially interconnected. Assembly (1) after Claim 1 , characterized in that the insulating jacket (9) has on its outer periphery (10) at least in sections a material addition (13) of the third plastic material or a foreign material filler. Assembly (1) after Claim 1 or 2 , characterized in that the insulating jacket (9) is made of a thermoplastic elastomer, TPE. Assembly (1) according to one of the preceding claims, characterized in that the line bushing (7) is made of an ethylene-propylene-diene rubber, EPDM. Assembly (1) after Claim 1 or 2 , characterized in that the line feedthrough (7) made of polymethyl methacrylate, PMMA, or a styrene-acrylonitrile copolymer, SAN, and the insulating jacket (9) made of polyvinyl chloride, PVC, are made. Assembly (1) according to one of the preceding claims, characterized in that the conductor has a copper cross-section of at least 35 mm ² . Assembly (1) according to one of the preceding claims, characterized in that the line (8) has a length of at least 25 cm. Assembly (1) according to any one of the preceding claims, characterized in that the cable feedthrough (7) laser-transparent and the insulation jacket (9) are laser-absorbing. Method for producing an electrical assembly for a motor vehicle, comprising the steps of: providing a component housing (2) of a first plastic material with a housing opening (4) for housing an electrical component, providing a line leadthrough (7) of a second plastic material for positive locking Inserting into the housing opening (4), - Providing an electrical line (8) with an electrical conductor and a surrounding insulating jacket (9) of a third plastic material for passing through the cable feedthrough (7), characterized in that the third plastic material of the insulating jacket (9) connected via the conductor to the electrical assembly and through the cable feedthrough (7) guided through line (8) is materially connected to the overlapping second plastic material of the cable feedthrough (7). Method according to Claim 9 , characterized in that the cohesive connection by means of laser welding at an angle to the overlapping region of the two plastic materials takes place from an oblique direction. Method according to Claim 9 , characterized in that the cohesive connection by means of laser welding from a to the overlapping region of the two plastic materials substantially perpendicular direction.

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