DE102021117003A1 - Plug connection for airbag ignition systems - Google Patents

Abstract

The invention relates to a plug-in connection for airbag ignition systems, having an airbag igniter housing and an airbag plug, having a contact carrier in which two contact elements and one deformable conductor attached to the contact elements are arranged, the contact carrier being provided at least in regions with a surrounding housing, that overmoulding material is produced by means of overmoulding, the surrounding housing having a contour for mechanical locking with a latching contour of the igniter housing and simultaneous sealing function, the contact carrier having two labyrinths arranged within the surrounding housing, so that the two conductors are arranged at an angle relative to the center line of the Contact elements are held.

Description

The invention relates to a plug-in connection for airbag ignition systems, having an airbag igniter housing and an airbag plug, having a contact carrier in which two contact elements and one deformable conductor attached to the contact elements are arranged, the contact carrier being provided at least in regions with a surrounding housing, that is produced by means of an overmoulding, overmoulding material, the surrounding housing having a contour for mechanical locking with a latching contour of the igniter housing and simultaneous sealing function.

To make contact or to produce detachable electrically conductive connections, plug connections are used in a wide variety of configurations and variants. Plug connection solutions are available in a large number of different designs, for example with regard to the number of poles, electrical power and the conditioning of a wide variety of external influences such as moisture, temperature, corrosive media or mechanical loads.

Depending on the environmental conditions and the resulting effects on plug connections, it must be ensured that the contacting task is implemented permanently, reliably and without interference. In order to achieve this goal, types of protection have been defined, which are expressed by IP codes (IP = International Protection) and to which test procedures with different environmental conditions are stored.

Connectors, in particular for the realization of different types of protection or IP codes, IP classes are in many cases surrounded by housings, housed, partially or completely sealed or also shielded. Other requirements such as sealing of the contacting elements, strain relief of the attached electrically conductive cables and lines, multiple contacts in a confined space, etc. can result in further special requirements for contact carriers.

In the automotive sector, in dirty, damp or chemically aggressive environments, electrical plug connectors must permanently guarantee flawless transmission of electrical signals and electrical power. Due to the wide range of applications for connectors, a large number of specially optimized connectors are known.

Especially with safety-critical electrical connections, such as an electrically conductive connection between an igniter, z. B. an airbag or a belt tensioning device and an electrical control unit of an occupant restraint system in a motor vehicle, high demands are placed on the detachable electrical contact. An electrical airbag connector used in this function must work correctly and be compact. On the one hand, the airbag connector must transmit a triggering signal to the airbag igniter with absolute reliability and, on the other hand, electrical interference signals, e.g. B. be triggered due to voltage peaks in the vehicle electronics, trigger no unintentional ignition of the airbag.

In order to solve the particularly demanding task of contacting airbag ignition systems, different concepts and technical versions of connectors have been developed. Connectors that are designed for use in airbag ignition systems must be compact and space-saving, since there is very little space when they are used in the steering wheel of a motor vehicle. Furthermore, these plug connectors must provide space inside for filters that are intended to prevent electromagnetic interference from leading to an unintentional triggering of the ignition system, for example ferrite cores, so-called ferrite core chokes. In order to support reliable and simple assembly, connectors for contacting airbag ignition systems should be easy to wire in order to make the installation of an airbag restraint system as easy as possible. In known connectors for airbag systems, the connector housing consists of two shells, the plug contact and the filter as well as connecting pins for the supply cable being arranged in the lower shell and the supply cable having its ends soldered or welded to the connecting pins.

the DE 101 46 430 A1 discloses an airbag electrical connector having a four-piece housing in which are disposed two angled female electrical contacts and an electrical ground lead. A single socket contact and the ground line are each electrically connected to a cable within the airbag connector via soldered and/or crimped connections. In an assembled state of the airbag connector, a ferrite core choke is in an electrically conductive connection with one of the two socket contacts and the ground line. This electrically conductive connection is made via a soldered connection between a respective line element of the relevant socket contact or the ground line and a respective line end of a coil of the ferrite core choke. The socket contacts are according to their Manufacture already angled so that they can also be installed in an angled state.

From the DE 42 17 205 A1 a connector for airbag applications is known, which is wired to a flat conductor strip and in which the individual conductor tracks are pierced by contact pins and the electrical contact is ensured by the application of solder. The work step of applying solder is not only cumbersome, but also makes the assembly quality and contacting reliability more prone to errors, since the solder work has to be done on the half-finished connector.

A medium-tight exit of the cable from the ignition system, igniter, is particularly important when it comes to contacting tasks in airbag ignition systems, since moisture stress is to be expected at all times when used in vehicles.

In the case of connectors with a rigid outer housing, the cable outlet of which is to be designed to be media-tight by means of overmoulded sealing material, there is the problem of the sealing material applied under pressure in a hot state penetrating axially through the sealing area of the sleeve enclosing the cable within the coupling element for sealing purposes. The reason for this is that elastic material has previously been used for the aforementioned sleeve used for sealing purposes in order to be able to insert the sleeve as tightly as possible under radial elastic tension into the associated opening of the electrical coupling element. Such sleeves made of elastic material are well suited for sealing a cable outlet from an electrical coupling element (connector plug). However, such sleeves made of elastic material are not suitable for cable outlets from electrical coupling elements, which are sealed for a particularly high degree of tightness with a sealing compound applied in a hot state and in liquid form under high pressure. Such sealing compounds are, for example, thermoplastics that are sprayed on in a liquid state under high pressure. With such cable outlet closures of electrical coupling elements, it often happens that the liquid applied closure material flows over the sleeve used as a seal on its outer circumference, so that the closure compound penetrates into the contact zones of the coupling element and thus impairs or prevents the function of the electrical contact.

the DE 10 2004 061 663 B3 proposes to improve the sealing effect of the cable outlet while at the same time ensuring reliable electrical contacting of connectors with a rigid outer housing, that a sleeve made of elastic material used as a seal between a cable outlet and the receiving opening for the cable of a contact carrier is only required if this sleeve has the function of a should have an automatic seal. In such cases, the elasticity of the material of such a sleeve serves to ensure that the sleeve can press against the cable circumference on the one hand and on the inner lateral surface of the cylindrical receiving bore of the contact carrier under elastic tension on the other hand. On the other hand, in the case of a cable outlet that is sealed by a sprayed-on sealing compound, the sleeve does not have to have or produce an independent sealing effect. In this case, the tightness of the cable outlet is created exclusively by the sealing material. The only task of the sleeve here is to reliably prevent the sealing material applied in liquid form under high pressure from penetrating into the contact spaces of the coupling element.

In other words, recognizes the teaching of DE 10 2004 061 663 B3 that in the case of cable outlets in rigid contact carriers, the seal can be achieved solely by an injected, elastic sealing material and a rigid sleeve prevents the injected sealing material from spreading into the contacting area. This is achieved by forming the sleeve from a substantially incompressible material. With such an incompressible material, the sleeve can no longer be pushed into the receiving opening while being pressed and overlapped, as is the case with an embodiment made of elastic material, but a type of sliding fit is to be provided for the bearing. This fit is to be designed in such a way that the sleeve can be pushed into the receiving opening of the coupling element with as little play as possible with practically no force.

This solution for sealing the cable outlet is not only complex, but the sealing effect depends solely on the sealing injection of the sealing material.

Another plug-in connection solution recognizes that an arrangement formed from the contact element, the contact carrier, the cable with a surrounding housing produced by overmoulding of these components with simultaneous mechanical fixation within the surrounding housing can create a particularly media-tight combination of the detachable, electrically conductive contact. This means that a contact carrier with the contact element accommodated therein is partially or completely encapsulated on the outside of the contact carrier. The contact carrier has a with a soft sealing element sealed cable outlet and an optional ferrite core, ferrite core choke. This plug-in connection solution, which has been further developed with regard to media-tight properties, is advantageous in particular for a largely axially aligned arrangement of contact element and cable, ie a cable outlet largely without an angle to the plug-in element.

The object of the invention is to further develop detachable electrically conductive connections for airbag applications and airbag ignition system contacts in vehicles in such a way that their media-tight structure is improved and an angled cable outlet is supported, production and assembly are simplified and the disadvantages occurring in the prior art are at least partially reduced. The object of the invention is also to design the angled cable outlet situation in the axial direction of extension of the contact element in a space-reduced manner.

An arrangement formed from the contact element, the contact carrier, the cable with a surrounding housing produced by injection molding of these components with simultaneous mechanical fixation within the surrounding housing can create a particularly media-tight combination of the detachable, electrically conductive contact. This means that a contact carrier with the contact element accommodated therein is partially or completely overmoulded on the outside of the contact carrier, d. H. largely completely encapsulated. The contact carrier has a cable outlet sealed with a soft sealing element and an optional ferrite core, ferrite core choke.

In order to achieve the angled conductor outlet (cable outlet) in a space-reducing manner, the invention provides that the angled outlet is not formed by angled contact elements, but by using a flexible (deformable) conductor or cable, which is achieved by deformation into the desired angular position is brought relative to the axis of extension or center line of the contact element. For this purpose, the largely complete encapsulation comprises an area with a labyrinth, which both brings the deformable conductor or the deformable cable into its angular position and holds it against the elastic deformation components caused by the deformation.

According to the invention, a preassembled unit is provided by forming a contact assembly with an angled or lateral conductor outlet, which is suitable for further processing by overmolding. The contact assembly consists of contact elements, the soft element seal and the optional ferrite core choke inserted into the contact carrier. The elements of the contact assembly are kept as simple as possible in terms of their structural design in order to implement production and function in a cost-effective manner and similar to a straight design, ideally using identical parts such as straight contact elements. In this way, the economical production of a media-tight, angled contact assembly is possible, in which a height offset or a height correction and almost any outlet direction of the conductor or cable is possible while maintaining a simple standard overmolding process. The preassembled unit also includes the ladder or ladders, which are deformed according to the angle departure and are fixed and held by the labyrinth or labyrinths.

The preassembled unit is then overmoulded in such a way that the largely complete encapsulation with the overmoulding material is realized, with the overmoulding material being left open on the end face of the contact carrier in order to have the contact element accessible for the contacting task. The cable or cables, electrical lines on the side and behind the cable outlet of the contact carrier are also encapsulated with the encapsulation material.

The materials of the contact carrier and the encapsulation material are matched to one another in such a way that a media-tight bond results.

The surrounding housing represents the outer shell of the airbag connector, within the overmoulding, i. H. The preassembled unit is located within the casing produced by the overmoulding. In this way, a medium-tight composite is formed, consisting of one or more contact elements, soft element seal, ferrite core choke or end cap and contact carrier, which are encased by the surrounding housing. In addition to the media-tight enclosure of the pre-assembled unit, the surrounding housing also seals various media from the housing of airbag ignition systems (the so-called igniter). For this purpose, the invention provides for the direct functional integration of the sealing function into the encapsulation, in that the encapsulation material has elastic and seal-like properties, optionally supplemented by the geometric design of the outer contour of the encapsulation. A suitable geometry is, for example, a sealing lip, a sealing collar or a bead.

Deviating from solutions of the prior art, the inventive, angled design of the contact assembly with encapsulation is ver Really by the deformable, ie flexible conductor (or cable depending on the design), which takes over the task of the otherwise necessary, angled contact element and this conductor is preferably arranged and fixed laterally in a labyrinth on the contact housing. As a result, a very cost-effective production as well as the minimization of the installation space requirement is achieved in that the conductor itself is angled without any additional component.

The labyrinth, which functionally has both clamping and guiding properties due to its geometry, fixes the outgoing conductor(s) to one another and/or at an angle to the contact housing, so that an optimal shape is achieved for the overmolding process and the injection molding tool, among other things with regard to the sealing surfaces of the cable insulation.

The labyrinth is designed as an element of the contact carrier. The labyrinth can be fixed to the contact carrier as a separate component or can be manufactured in one piece with the contact carrier—for example by an injection molding manufacturing process. The labyrinth as a functional supplement to the contact carrier holds and/or positions the outgoing conductor or conductors in an angled position and ensures that they are fixed during the overmolding process.

The labyrinth, which is designed here as a conductor labyrinth fixation, is designed in such a way that the injection mold opening direction is identical for a 90 degree and a 180 degree contact carrier housing due to offset labyrinth clamping and guide ribs and no tool slides are required for the conductor. In the simplest case, a 90-degree contact carrier could be created from a 180-degree contact carrier via an exchangeable insert in the injection molding tool. For the 90 degree version, identical contact, sealing and interference suppression elements (e.g. a ferrite core choke) known from the 180 degree contact carrier variant are used.

When using two conductors, a central plastic rib separates both conductors from each other. As a result, one labyrinth per conductor can be designed with an individually designed labyrinth clamping geometry, so that the two conductors are independently space-optimized (e.g. with a common height offset) or injection molding tool-optimized (e.g. with an individual lateral or height offset for the optimal design of the parting line). out of the airbag connector.

The encapsulation, which forms the housing, is made of a durable plastic that must be processable in the injection molding process. Thermoplastic elastomers, for example, are suitable. If the encapsulation is to include the direct functional integration of the sealing function in addition to an airbag ignition system housing, the encapsulation material must have sealing properties. Silicone materials, for example, are then suitable.

Media in the context of the invention are understood to mean influences occurring in the environment such as moisture, water, liquids, loose elements such as dust, dirt, sand, etc., gas and mixtures of the aforementioned media.

The angled airbag connector according to the invention results in the use of geometrically identical contact elements, i. H. no angled contact elements have to be used for the angled plug connection. Also with regard to the soft element seal(s) and interference suppression element(s), for example in the form of ferrite core chokes, these are identical in comparison to a 180 degree version, i. H. a conductor outlet aligned with the center line of the contact element.

Furthermore, the invention makes it possible to produce a closed and angled airbag connector in multiple parts by injection molding, which could not have been assembled due to the angled contact elements or contact carriers required up to now.

The contact carrier according to the invention is retained in its simplest form for 180 degree versions and only requires the cable routing clamp labyrinth. This can be formed in an injection mold replacement insert. It is possible that a combination injection molding tool can be used for 90 degree and 180 degree versions. Because the bending of the plug connection and the contact elements is achieved via the deformable conductor or conductors, mechanically guided or held in the labyrinth, the height of the cable outlet relative to the contacting point (interface) can be chosen almost at will and the installation space can thus be advantageously designed. The advantages of the "quasi-axial" design (180 degrees outlet) of the contact carrier before the overmoulding in the form of protection of the conductor silicone seal against incoming overmoulding compound by the interference suppression element, simple manufacture of the housing, independence from the material of the cable insulation thanks to a separate silicone seal are retained. By guiding the conductors through the labyrinth on the contact carrier, the conductors can be fixed in their respective positions be placed so that an optimal position for the following overmolding process is ensured.

Due to the soft element seal, which brings about the sealing of the conductor or conductors with respect to the contact carrier and contact element, it is particularly advantageously not necessary for the sealing to be provided by the encapsulation material. This means that there is no need to create a cohesive bond between the overmoulding material and the insulation material of the conductor (cable), which is often problematic with regard to the material pairing of insulation and overmoulding and the relative movements that occur in the conductor or conductors create a cohesive bond - if the sealing function between overmolding and conductor insulation material is required - destroyed.

By overmoulding the pre-assembled unit consisting of a contact carrier with a labyrinth, which accommodates the contact element(s), the soft element seal and the optional ferrite choke, this plug-in connection formed in this way can be brought into contact by simply sliding it onto the contact pins of the airbag ignition system, which are located when the vehicle is stationary The form of contacting practiced in technology by means of a direct welding process of the stranded wire and the contact pins is thus replaced by simply slipping on and sliding on. This is particularly advantageous because the direct welding process is very complex due to the different geometries of the elements to be welded (contact pin is round, stranded wire is a stranded bundle, stranded bundle) and requires accessibility to the welding point. Due to the possibility created of using contact elements in the form of one or more plug-in contact boxes on the connector side for contacting, the lines, current-carrying cables and thus the stranded wires are attached by crimping or welding before assembly.

Last but not least, the invention supports almost any exit angle very flexibly without the need to use angle-adapted contact carriers and/or contact elements within the plug-in connection because the deformable conductors are deformed according to the required exit angle and held by the respective labyrinth.

• 1 die Darstellung der Steckverbindung für Airbag-Zündsysteme in einer Schnitt-Vorderansicht sowie einer Seiten-Ausschnittansicht und einer Schnitt-Draufsicht.

The invention is explained in more detail below using an exemplary embodiment in conjunction with the figure. It shows:

• 1 the representation of the connector for airbag ignition systems in a sectional front view and a side detail view and a sectional plan view.

1 shows the plug connection for airbag ignition systems in a first embodiment, consisting of airbag igniter housing 100 and an airbag plug 1. Inside the contact carrier 10 are the contact element 2 with the conductor (current-carrying cable) 6 fixed to it via the crimp connection 3, the soft element seal 4 and optionally the ferrite core choke 5 arranged. On the outside of the contact carrier 10, an overmold, overmold material 20 is applied over the entire circumference and protrudes beyond it on the cable outlet side, so that the line, current-carrying cable 6 in a cable section and the labyrinth 30 are also surrounded by the overmold material 20 and likewise the contact carrier 10 and/or the Ferrite core choke 5 covered at the front.

In the exemplary embodiment shown, two conductors 6 with an exit angle of approximately 90 degrees are installed; the invention can also be implemented with one conductor 6 or a plurality of conductors 6 and different exit angles.

In 1 two labyrinths 30 are shown, each associated with a conductor 6 and supported by the center rib 32 and separated from one another. The labyrinths 30 are formed by at least one labyrinth rib 31, in the example shown there are two labyrinth ribs 31 each. The respective conductor 6 is deformed in an arc, starting from the ferrite core choke 5, and through the labyrinth ribs 31 with the exit angle shown (i.e. the angled exit shown relative to the Center line ML of the contact elements 2) of about 90 degrees both supported and fixed. To offset the conductor 6 in two planes, such as in the front view and the Z view 1 shown, the labyrinth ribs 31 assigned to the respective conductors 6 have different geometric designs and are separated by the central rib 32.

No encapsulation material 20 is provided on the front end of the contact carrier 10 in the plug-in direction, so that the contact carrier 10 and the contact element 2 are accessible and the plug-in contact pin(s) 101 of the airbag igniter can be inserted. i.e. the encapsulation 20 encloses the contact carrier 10 completely and over the entire surface with the exception of the front access for the contact element 2.

The encapsulation 20 has a shoulder 21 on the outside, which interacts with a locking lug 22 in order to seal the airbag connector 1 for airbag ignition systems with respect to the airbag igniter housing 100, which is designed here as an insertion opening for the airbag connector 1. In this way a separate O- A ring or other sealing element is not required, the sealing takes place in an integrated manner by the shoulder 21 and the latching lug 22. In this case, the encapsulation material 20 can be formed from a silicone material to improve the sealing function.

The soft element seal 4 seals the conductor or conductors 6 against the contact carrier 10, is supported axially against a shoulder, paragraph of the contact carrier and rests on the ferrite core choke 5. If the variant of the structure according to the invention is realized without a ferrite core choke 5, an end cap (not shown) is arranged instead. The ferrite core choke 5 or the end cap provide the axial contact surfaces for the soft element seal 4, so that the encapsulation material 20 cannot penetrate into the contact box 2 during the encapsulation process.

Reference List

1

airbag connector

2

contact element

2'

Rest Lance

3

crimp connection

4

soft element seal

5

ferrite core choke

6

conductor (deformable conductor, live cable)

10

contact carrier

20

overmolding, overmolding material

21

Heel, concentric ring shoulder

22

detent

30

labyrinth

31

labyrinth rib

32

center rib

100

Airbag igniter housing

101

Plug contact pin of the airbag igniter

ML

Centerline of the contact element

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was 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.

Patent Literature Cited

• DE 10146430 A1 [0008]
• DE 4217205 A1 [0009]
• DE 102004061663 B3 [0012, 0013]

Claims (14)

Plug-in connection for airbag ignition systems, having an airbag igniter housing (100) and an airbag plug (1), having a contact carrier (10) in which two contact elements (2) and one deformable conductor (6) each attached to the contact elements (2) are arranged, wherein the contact carrier (10) is provided at least in regions with a surrounding housing that is produced by means of an overmoulding, overmoulding material (20), the surrounding housing having a contour for mechanical locking with a latching contour of the igniter housing (100) and simultaneous sealing function, characterized in that the contact carrier (10) has two labyrinths (30) arranged within the surrounding housing, so that the two conductors (6) are held at an angle relative to the center line (ML) of the contact elements (2). Plug connection for airbag ignition systems according to claim 1 , characterized in that the labyrinths (30) are both supported on the contact carrier (10) and separated from one another by a central rib (32). Plug connection for airbag ignition systems according to claim 1 , characterized in that the labyrinths (30) are each formed by at least one first labyrinth rib (31). Plug connection for airbag ignition systems according to claim 3 , characterized in that the labyrinths (30) are each formed by at least one second labyrinth rib (31) with a geometry that differs from the respective first labyrinth rib (31). Plug connection for airbag ignition systems according to claim 1 , characterized in that the conductors (6) depart at an angle of 90 degrees relative to the center line (ML) of the contact elements (2). Plug connection for airbag ignition systems according to claim 1 , characterized in that the conductors (6) are arranged in the projection plane normal to the outlet direction off-centre to the center line (ML) and offset from one another. Plug connection for airbag ignition systems according to claim 1 , characterized in that the largely complete encapsulation of the contact carrier (10) by encapsulation material (20) on the contact side is cut out in order to keep the contact element (2) accessible for the contacting task. Plug connection for airbag ignition systems according to claim 1 , characterized in that a soft element seal (4) for sealing the conductor (6) is arranged inside the contact carrier (10). Plug connection for airbag ignition systems according to claim 8 , characterized in that the sealing of the conductor (6) to the housing of the contact carrier (10) takes place. Plug connection for airbag ignition systems according to claim 1 , characterized in that a ferrite core choke (5) for shielding the conductor (6) is arranged inside the contact carrier (10). Plug connection for airbag ignition systems according to claim 8 and 10 , characterized in that the ferrite core choke (5) and the soft element seal (4) are arranged inside the contact carrier (10) around the conductor (6). Plug connection for airbag ignition systems according to claim 1 , characterized in that the encapsulation has a locking lug (22) which engages in an annular gap on the airbag igniter housing (100) in a sealing manner, so that the airbag plug (1) is sealed with respect to the airbag igniter housing (100). Plug connection for airbag ignition systems according to claim 12 , characterized in that the encapsulation adjacent to the locking lug (22) has an inclined ramp and an undercut, the undercut being designed as a circumferential groove. Plug connection for airbag ignition systems according to claim 1 , characterized in that the two contact elements (2) each have a latching lance (2'), which in the end position of the contact element (2) within the contact carrier (10) is positively latched in a latching position opposite a shoulder in the contact carrier (10).

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