DE102021110681B3 - 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 line each 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 overmoulding, the surrounding housing having a contour for mechanical locking with a latching contour of the igniter housing and at the same time a sealing function, a soft element seal for sealing the lines being arranged inside the contact carrier, a ferrite core choke for shielding the lines being arranged inside the contact carrier , wherein the ferrite core choke and the soft element seal are arranged inside the contact carrier around the lines.

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 line each 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 overmoulding, the surrounding housing having a contour for mechanical locking with a latching contour of the igniter housing and at the same time a sealing function, a soft element seal for sealing the lines being arranged inside the contact carrier, a ferrite core choke for shielding the lines being arranged inside the contact carrier .

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 for 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 that are triggered due to voltage peaks in the vehicle electronics, for example, must not trigger 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 already angled after they have been manufactured, 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 outlet of the cable, outgoing from the ignition system, igniter has a particularly high value for contacting tasks of airbag ignition systems, since moisture loads are 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, which is 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.

the DE 199 45 303 A1 discloses a trigger unit for initiating pyrotechnic elements, which is composed of two sleeves. The first sleeve encloses a switching and control unit, for example the so-called hybrid in the case of a raw igniter. The hybrid includes, among other things, the electronic circuits for addressing an igniter and, if necessary, for determining the ignition point. With this first sleeve, a second sleeve is connected, ent the charge body holds. In the case of a detonator, for example, this is the detonator charged with the primer or, in the case of a belt tensioner, the propellant charge for gas generation. The ignition means, which is connected to the switching and control unit and is not surrounded by the first sleeve, dips into this second sleeve. The switching and control unit can consist of a printed circuit board on which sensitive electronic components are arranged. Because the switching and control unit is surrounded by a stable sleeve, it can also be used for mechanical assembly of a triggering unit using automatic handling and loading machines without endangering the electronic components. The switching and control unit is arranged in a sleeve and can be overmoulded with a plastic.

The technical teaching of DE 198 59 417 A1 comprises a plug-in connection, referred to as a coupling, for two-pole electrical couplings consisting of a coupling plug and a coupling socket for connecting a sensor coupled to a functional unit to be activated to its power supply, the plug pins of the coupling plug being overmoulded with thermoplastic material in such a way that a grip body has plug pins protruding at the end arises, and wherein the grip body has an annular groove for receiving a sealing ring, which reliably seals the transition between the coupling plug and the coupling socket to the outside. It is provided that the coupling plug has a hard-elastic insert and that this insert is overmoulded together with the pre-assembled pins.

In the pamphlet DE 60 2004 000 539 T2 an electrical connector is presented which has an electrical contact housing, at least one electrical contact, an outer housing and an elastic retaining ring. The electrical contact is held within the electrical contact housing. The outer housing includes a tubular portion radially spaced from the electrical contact housing to form an annular space between an inner surface of the tubular portion and the electrical contact housing. The resilient retaining ring is coupled to the tubular portion to restrict radial expansion of the tubular portion, the resilient retaining ring being a split ring.

the WO 2018/206601 A1 presents a method for mounting a connector on a multi-core sheathed cable that extends in a longitudinal direction and has a plurality of cores surrounded by a cable sheath, wherein a sealing element made of a sealing material is applied to the plurality of cores, the sealing element for each of the cores individually Having passage through the sealing material. The wires are then mounted in a connector housing, the connector housing having a receptacle at its rear end and the sealing element being pushed into the receptacle and for this purpose preferably being pushed along the wires so that the sealing element rests sealingly in the receptacle. A sealing sheath is then applied, which extends from the rear end of the connector housing to the cable sheath.

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, production and assembly are simplified and the disadvantages occurring in the prior art are at least partially reduced.

The invention recognizes that by means of 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, a particularly media-tight composite of the detachable; electrically conductive contact can be created. 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 invention understands this to be largely completely encapsulated. The contact carrier has a cable outlet sealed with a soft sealing element and an optional ferrite core, ferrite core choke.

The invention supports the mechanical, form-fitting and/or cohesive connection of the contact element(s) within the contact carrier and optionally the soft element seal and/or the ferrite core choke by means of a mechanical undercut, groove on the inside of the contact carrier, into which the encapsulation material can flow. As a result, the encapsulation material can create a form-fitting and/or material-locking connection within the mechanical undercut, groove, and bring about the mechanical fixation.

Before the encapsulation, a preassembled unit is provided in which the contact element or elements, the soft element seal and the optional ferrite core choke are inserted into the contact carrier. In addition to the shielding function against high-frequency influences, the ferrite core choke closes the contact carrier on the cable entry side of the contact carrier at the front, so that the on penetration of overmolding material into the contact chamber is prevented. As an alternative or in addition to the ferrite core choke, an end cap can take on this function.

Since the forces acting during the overmoulding process are considerable, it is necessary for the pre-assembled unit to be mechanically fixed. For this purpose, the invention provides that a mechanical stop in the form of a mechanical undercut formed, for example, by a groove, a concentric annular shoulder or an axial stop for the contact elements ensures fixation during overmolding.

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 annular gap between the contact carrier and the ferrite core choke or end cap is selected to be large enough for the overmolding material to penetrate at least partially.

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 assembly 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 the housing of airbag ignition systems (the so-called igniter) with regard to various media. 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.

An alternative, non-integrated sealing function in the encapsulation is also possible in an advantageous development of the invention, for example by a separate O-ring, a sealing cord or a seal, for which the encapsulation can then have a suitable geometry on its outer surface, for example a Groove, a concentric annular shoulder or shoulder.

The soft sealing element can have compressible properties, which materials from the silicone group offer, for example. The contact element can be formed from a contact box with a latching lance.

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.

By overmoulding the pre-assembled unit consisting of a contact carrier, the contact element or elements, 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 igniter system, the form practiced in the prior art the contacting by a direct welding process of the stranded wire and the contact pins is replaced by a simple plugging, 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.

• 1 die Darstellung der Steckverbindung für Airbag-Zündsysteme in einer ersten Ausführungsform;
• 2 die Vorder- und Seitansicht-Schnittdarstellung der Steckverbindung für Airbag-Zündsysteme in einer zweiten Ausführungsform;
• 3 die 3D-Darstellung der Steckverbindung für Airbag-Zündsysteme in der zweiten Ausführungsform;
• 4 die 3D-Teildarstellung der Steckverbindung für Airbag-Zündsysteme in der zweiten Ausführungsform;
• 5 die perspektivische Ansicht auf die Anordnung innerhalb des Kontaktträgers;
• 6 die 3D-Darstellung des Kontaktträgers aus zwei Blickrichtungen.

The invention is explained in more detail below using two exemplary embodiments in conjunction with the figures. show:

• 1 the representation of the connector for airbag ignition systems in a first embodiment;
• 2 the front and side view sectional view of the connector for airbag ignition systems in a second embodiment;
• 3 the 3D representation of the connector for airbag ignition systems in the second embodiment;
• 4 the 3D partial representation of the plug connection for airbag ignition systems in the second embodiment;
• 5 the perspective view of the arrangement within the contact carrier;
• 6 the 3D representation of the contact carrier from two perspectives.

1 shows the plug-in 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 line fixed to it via the crimp connection 3, live cable 6, the soft element seal 4 and optional 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 also protrudes on the cable outlet side, so that the line, current-carrying cable 6 is also surrounded by the overmold material 20 in a cable section, as is the contact carrier 10 and/or the ferrite core choke 5 covered at the front. The annular gap between the contact carrier 10 and the ferrite core choke 5 is selected to be large enough for the encapsulation material 23 to penetrate at least partially. In this way, a mechanical, positive and material connection of the contact carrier 10 with the elements preassembled as an assembly, consisting of at least one contact box 2 with a cable attached to the contact box 2 via a crimp connection 3, current-carrying cable 6 and a soft element seal 4 and a Ferrite core choke 5 realized.

No encapsulation material 20 is provided on the end of the contact carrier 10 opposite the cable outlet, so that the contact carrier 10 and the contact element 2 are accessible and the plug contact pin(s) 102 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 at least one shoulder 21, so that a contact shoulder for an O-ring 101 for sealing the airbag connector 1 with respect to the airbag igniter housing 100 is formed.

2 shows the front and side sectional view of the airbag connector 1 for airbag ignition systems in a second embodiment. In this exemplary embodiment, there is no shoulder on the outside as a contact shoulder for an O-ring, but a shoulder 21 works together with a locking lug 22 to seal airbag connector 1 for airbag ignition systems with respect to airbag igniter housing 100, which is used here as an insertion opening for the Airbag connector 1 is designed to seal. In this way, a separate O-ring or other sealing element is not required, the sealing takes place in an integrated manner by the shoulder 21 and the locking lug 22. In this case, the encapsulation material 20 can be formed from a silicone material to improve the sealing function.

The contact element 2 of this exemplary embodiment has a square outer geometry. Round, polygon-like or multi-edged external geometries are also possible. A latching lance 2' is provided for holding, fixing the contact element 2 within the contact carrier 10 for fixing against the insertion forces of the plug contact pin 102 and/or forces occurring when the contact carrier 10 is overmolded with overmolding material 20, which in the end position of the contact element 2 within the contact carrier 10 in a detent position in a form-fitting manner relative to a shoulder in the contact carrier 10 prevents axial displacement. Alternatively, instead of the latching lance 2', a bead or wart can also bring about a form-fitting fixation.

The soft element seal 4 seals the line, current-carrying cable 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.

3 illustrates in a 3D representation the airbag connector 1 for airbag ignition systems in the second embodiment. The outer geometry is cylindrical, rotationally symmetrical and has a conical area. Only one end face of the airbag connector 1 is not covered by encapsulation material 20 so that the contact element 2 (there are two contact elements in this exemplary embodiment) is accessible for the plug contact pin 102 . The two lines, live cable 6 can like shown can be realized as separate lines. Alternatively, a twin line can also be used, in which the current conductors, cores have a first insulating jacket and are then again surrounded by a common insulating jacket.

4 shows the 3D partial representation of the airbag connector 1 for airbag ignition systems in the second embodiment with the encapsulation 20 shown partially transparent.

5 shows the perspective view of the arrangement within the contact carrier 10, which in this exemplary embodiment is formed from two contact boxes 2, each with a line attached to the contact box 2 via a crimp connection 3, live cable 6 and a soft element seal 4 and a ferrite core choke 5. This The module is first pre-assembled and then inserted into the contact carrier 10. The contact carrier 10 is designed in two or more parts, so that the pre-assembled module is first inserted into a part of the contact carrier 10, then the contact carrier 10 is completed and closed by the second and possibly further housing elements.

In this exemplary embodiment, the two contact boxes 2 are gold-plated, so that improved electrical contacting with reduced resistance takes place.

6 shows the 3D representation of the contact carrier 10 from two viewing directions. The contact carrier area with the square outer geometry essentially encloses the contact elements 2 with the crimp connection 3, the contact carrier area with the oval outer geometry essentially encloses the soft element seal 4 and the ferrite core choke 5. The transition area between square outer geometry and oval outer geometry forms an axial one on the inside Contact shoulder for the soft element seal 4.

Reference List

1

airbag connector

2

contact element

2'

Rest Lance

3

crimp connection

4

soft element seal

5

ferrite core choke

6

wire, live wire

10

contact carrier

20

overmolding, overmolding material

21

Heel, concentric ring shoulder

22

detent

23

overmolding material channel

100

Airbag igniter housing

101

o ring

102

Plug contact pin airbag igniter

Claims (10)

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 line (6) each attached to the contact elements (2) are arranged the contact carrier (10) is provided at least in regions with a surrounding housing that is produced by means of an overmolding (20), the surrounding housing having a contour for mechanical locking with a latching contour of the igniter housing (100) and at the same time having a sealing function, with inside of the contact carrier (10) a soft element seal (4) for sealing the lines (6) is arranged, a ferrite core choke (5) for shielding the lines (6) being arranged inside the contact carrier (10), characterized in that the ferrite core choke (5 ) and the soft element seal (4) are arranged within the contact carrier (10) around the lines (6). Plug connection for airbag ignition systems according to claim 1 , characterized in that the encapsulation (20) of the surrounding housing brings about a mechanical connection of the contact carrier (10) to the two contact elements (2) by a mechanical undercut on the contact carrier (10). Plug connection for airbag ignition systems according to claim 2 , characterized in that the encapsulation (20) of the surrounding housing brings about a seal and fixation with respect to the lines (6). Plug connection for airbag ignition systems according to claim 1 , characterized in that the largely complete encapsulation of the contact carrier (10) by the encapsulation (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 the lines (6) is designed as a twin line. Plug connection for airbag ignition systems according to claim 1 , characterized in that the annular gap between the contact carrier (10) and ferrite core choke (5) with encapsulation material (20, 23) is at least partially filled. Plug connection for airbag ignition systems according to claim 1 , characterized in that the encapsulation has a shoulder (21), so that a contact shoulder for an O-ring (101) for sealing the airbag connector (1) relative to an airbag igniter housing (100) is formed. 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 8 , 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 is positively latched in the end position of the contact element (2) within the contact carrier (10) in a latching position opposite a shoulder in the contact carrier (10).

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