Plug connection for airbag deployment systems

Abstract

The invention relates to a plug connection for airbag deployment systems, said plug connection comprising an airbag igniter housing and an airbag plug comprising a contact support in which two contact elements and one ductile conductor attached to each contact element are arranged, at least regions of the contact support being enclosed by a casing produced by means of overmoulding, overmoulding material, the casing having a contour for mechanically interlocking with a locking contour of the igniter housing and for simultaneously performing a sealing function, and the contact support having two labyrinths located inside the casing so that the two conductors are held so as to exit in an angled manner relative to the centre line of the contact elements.

Description

[0001] The invention relates to a plug connection for airbag ignition systems, comprising an airbag igniter housing and an airbag plug, comprising a contact carrier in which two contact elements and a deformable conductor attached to each of the contact elements are arranged, wherein the contact carrier is provided at least in regions with an outer housing which is produced by means of an overmolding with overmolding material, wherein the outer housing has a contour for mechanical locking with a latching contour of the igniter housing and simultaneous sealing function.

[0002] Plug connectors in a wide variety of designs and variants are used to make contact or create detachable electrically conductive connections. Plug connector solutions are available in a wide range of configurations, for example, with regard to the number of poles, electrical performance, and conditioning for a wide range of external influences such as humidity, temperature, corrosive media, or mechanical stress.

[0003] Depending on the environmental conditions and the resulting impacts on connectors, it must be ensured that the contacting task is performed permanently, reliably, and without failure. To achieve this goal, protection classes have been defined, which are expressed by IP codes (IP = International Protection) and are based on test procedures for various environmental conditions.

[0004] Connectors, especially those designed to meet various protection levels or IP codes (IP classes), are often enclosed, housed, partially or fully sealed, or even shielded by housings. Other requirements, such as sealing the contact elements, strain relief for the connected electrically conductive cables and wires, multiple contacts in a confined space, etc., may result in further special requirements for contact carriers.

[0005] Electrical connectors must ensure the continuous, flawless transmission of electrical signals and electrical power in automotive applications, as well as in dirty, humid, or chemically aggressive environments. Due to the wide range of connector applications, a large number of specially optimized connectors are available.

[0006] Particularly in safety-critical electrical connections, such as an electrically conductive connection between an igniter, e.g., of 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 function flawlessly and be compactly designed. On the one hand, the airbag connector must transmit a trigger signal to the airbag igniter with absolute reliability, and on the other hand, electrical interference signals, triggered, for example, by voltage spikes in the vehicle's electronics, must not trigger inadvertent airbag deployment.

[0007] To solve the particularly challenging task of contacting airbag ignition systems, various concepts and technical designs of connectors have been developed. Connectors designed for use in airbag ignition systems must be compact and space-saving, as very little space is available in the steering wheel of a vehicle. Furthermore, these connectors must provide internal space for filters designed to prevent electromagnetic interference from accidentally triggering the ignition system, such as ferrite cores, so-called ferrite core chokes. To support reliable and simple installation, connectors for contacting airbag ignition systems should be easy to wire, making the installation of an airbag restraint system as simple as possible.In known connectors for airbag systems, the connector housing consists of two shells, with the plug contact and the filter as well as connection pins for the supply cable being arranged in the lower shell, and the supply cable being soldered or welded with its ends to the connection pins.

[0008] DE 101 46 430 A1 discloses an electrical airbag connector with a four-part housing in which two angled electrical socket contacts and an electrical ground wire are arranged. A single socket contact and the ground wire are each electrically connected within the airbag connector via solder and / or crimp connections, each with a cable. When the airbag connector is assembled, a ferrite core choke is electrically connected to one of the two socket contacts and the ground wire. This electrically conductive connection is established via a solder connection between a respective conductor element of the respective socket contact or the ground wire and a respective conductor end of a coil of the ferrite core choke. The socket contacts are already angled after manufacture, so that they can also be installed in an angled state.

[0009] DE 42 17 205 A1 discloses a connector for airbag applications that is wired with a flat conductor strip. The individual conductor paths are pierced by contact pins, and electrical contact is ensured by the application of solder. The soldering step is not only laborious but also increases the susceptibility to errors in assembly quality and contact reliability, since the soldering must be performed on the partially completed connector.

[0010] A media-tight cable exiting the ignition system, igniter, is particularly important for contacting tasks in airbag ignition systems, since moisture exposure must be expected at any time during use in vehicles.

[0011] Connectors with a rigid outer housing, whose cable outlet is to be made media-tight by overmolded sealing material, face the problem of the sealing material, which is applied under pressure in a hot state, penetrating axially beyond the sealing area of the sleeve that encloses the cable inside the coupling element for sealing purposes. The reason for this is that, until now, elastic material has been used for the aforementioned sealing sleeve in order to be able to insert the sleeve as tightly as possible into the corresponding opening of the electrical coupling element under radial elastic tension. 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 of electrical coupling elements, which are sealed with a sealing compound applied in a hot, liquid state under high pressure for particularly high tightness. Such sealing compounds include, 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 sealing material overflows the outer circumference of the sleeve used as a seal, causing the sealing compound to penetrate into the contact zones of the coupling element and thus impairing or preventing the electrical contact from functioning.

[0012] In order to improve the sealing effect of the cable outlet while simultaneously ensuring reliable electrical contacting of connectors with a rigid outer housing, DE 10 2004 061 663 B3 proposes 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 is to have the function of a self-sealing seal. In such cases, the elasticity of the material of such a sleeve ensures that the sleeve, under elastic tension, can be pressed tightly against the cable circumference on the one hand and tightly against the inner surface of the cylindrical receiving bore of the contact carrier on the other. In the case of a cable outlet that is sealed by a sprayed-on sealing compound, the sleeve does not need to have or generate an independent sealing effect.In this case, the sealing of the cable outlet is achieved solely by the sealing material. The sleeve's sole function is to reliably prevent the sealing material, which is applied in liquid form under high pressure, from penetrating the contact areas of the coupling element.

[0013] In other words, the teaching of DE 10 2004 061 663 B3 recognizes that in the case of cable outlets in rigid contact carriers, sealing can be achieved solely by means of 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 an essentially incompressible material. With such an incompressible material, the sleeve can no longer be pressed into the receiving opening with an overlap, as is the case with a design made of elastic material, but rather a type of sliding fit must be provided for the bearing. This fit must be designed such that the sleeve can be pushed into the receiving opening of the coupling element with practically no force and with the smallest possible play.

[0014] This solution for sealing cable outlets is not only complex, but the sealing effect depends solely on the tight injection of the sealing material.

[0015] Strain relief devices for connectors are known from the documents JP 2007-87681 A and DE 38 23 598 A1.

[0016] A further plug-in connection solution recognizes that an arrangement formed from the contact element, the contact carrier, the cable with an overmolding housing for these components, while simultaneously mechanically fixing them within the housing, can create a particularly media-tight connection of the detachable, electrically conductive contact. This means that a contact carrier with the contact element accommodated therein is partially or completely overmolded on the outside of the contact carrier. The contact carrier has a cable outlet sealed with a soft sealing element 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, i.e. a cable outlet with largely no angle to the plug-in element.

[0017] 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 design is improved, an angled cable outlet is supported, production and assembly are simplified, and the disadvantages of the prior art are at least partially reduced. The object of the invention is also to design the angled cable outlet situation with reduced installation space in the axial direction of the contact element.

[0018] By assembling the contact element, the contact carrier, and the cable in an overmolded housing for these components, and simultaneously mechanically securing them within the housing, a particularly media-tight connection of the detachable, electrically conductive contact can be created. This means that a contact carrier with the contact element contained within it is partially or completely overmolded on the outside of the contact carrier, i.e., almost completely overmolded. The contact carrier has a cable outlet sealed with a soft sealing element and an optional ferrite core or ferrite core choke.

[0019] To achieve the angled conductor (cable) exit in a way that reduces installation space, the invention provides that the angled exit is not formed by angled contact elements, but rather by the use of a flexible (deformable) conductor or cable, which is deformed into the desired angular position relative to the extension axis or center line of the contact element. For this purpose, the largely complete overmolding comprises a region with a labyrinth, which both brings the deformable conductor or cable into its angular position and holds it against the deformation-induced elastic deformation components.

[0020] According to the invention, a pre-assembled 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 is constructed by 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 in their design in order to realize production and function cost-effectively 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 height correction and almost any outlet direction of the conductor(s) or cable is possible while maintaining a simple standard overmolding process.The pre-assembled unit also includes the conductor(s), which are deformed according to the angled outlet and fixed and held by the labyrinth(s).

[0021] The pre-assembled unit is then overmolded to ensure that it is almost completely encased in the overmold material. The overmold material is left open on the front side of the contact carrier to ensure the contact element is accessible for the contacting task. The cable(s) and electrical lines on the side and behind the cable outlet of the contact carrier are also overmolded with the overmold material.

[0022] The materials of the contact carrier and the overmolding material are matched to each other in such a way that a media-tight bond is created.

[0023] The surrounding housing essentially represents the outer shell of the airbag connector; the pre-assembled unit is located within the overmolding, i.e., within the surrounding housing produced by the overmolding. In this way, a media-tight composite is formed, consisting of one or more contact elements, a soft element seal, a ferrite core choke or end cap, and a contact carrier, which are encased in the surrounding housing. In addition to the media-tight enclosing of the pre-assembled unit, the surrounding housing also seals off 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 overmolding, in that the overmolding material has elastic and seal-like properties, optionally supplemented by a geometric design of the outer contour of the overmolding.A suitable geometry is, for example, a sealing lip, a sealing collar or a bead.

[0024] In contrast to prior art solutions, the angled design of the contact assembly with overmolding according to the invention is realized by the deformable, i.e., flexible, conductor (or cable, depending on the design), which takes on the function of the otherwise necessary angled contact element. This conductor is arranged and secured in a labyrinth on the contact housing, preferably laterally. This achieves very cost-effective production and minimizes the installation space requirement by angled the conductor itself, without any additional components.

[0025] The labyrinth, which due to its geometry has both clamping and guiding properties, fixes the outgoing conductor(s) to each other 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 against the cable insulation.

[0026] The labyrinth is implemented as an element of the contact carrier. The labyrinth can be attached to the contact carrier as a separate component or manufactured as a single piece with the contact carrier—for example, through an injection molding process. As a functional extension of the contact carrier, the labyrinth holds and / or positions the outgoing conductor(s) in an angled position and ensures their fixation during the overmolding process.

[0027] The labyrinth, which is designed here as a conductor labyrinth fixation, is constructed 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 mold sliders are required for the conductor. In the simplest case, this could convert a 180-degree contact carrier into a 90-degree contact carrier using an interchangeable insert in the injection mold. For the 90-degree version, familiar, identical contact, sealing, and interference suppression elements (e.g., a ferrite core choke) from the 180-degree contact carrier variant are used.

[0028] When using two conductors, a central plastic rib separates the two conductors. This allows for a labyrinth per conductor to be designed with a customized labyrinth clamping geometry, allowing the two conductors to exit the airbag connector independently of each other, optimized for installation space (e.g., with a common vertical offset) or optimized for injection molding (e.g., with individual lateral or vertical offsets for optimal design of the separation plane).

[0029] The overmolding forming the outer housing is made of a durable plastic that must be moldable. Thermoplastic elastomers, for example, are suitable. If the overmolding is to include the direct functional integration of the sealing function in addition to an airbag ignition system housing, the overmolding material must have sealing properties. Silicone materials, for example, are suitable in this case.

[0030] Media in the sense of the invention are understood to mean influences occurring in the environment such as moisture, water, liquids, pourable elements such as dust, dirt, sand, etc., gas and mixtures of the aforementioned media.

[0031] The angled airbag connector according to the invention particularly advantageously allows for the use of geometrically identical contact elements, meaning that angled contact elements are not required for the angled plug connection. The soft element seal(s) and interference suppression element(s), for example in the form of ferrite core chokes, are also identical compared to a 180-degree version, meaning a conductor outlet aligned with the center line of the contact element.

[0032] Furthermore, the invention makes it possible to produce a closed and angled airbag connector in several parts by means of an injection molding, which could not have been assembled using the previously required angled contact elements or contact carriers.

[0033] The contact carrier according to the invention, in its simplest design, remains the same for 180-degree versions and requires only the cable routing clamp labyrinth. This can be formed in an injection molding tool interchangeable insert. It is possible to use a combination injection molding tool for both 90-degree and 180-degree versions. Because the angulation of the connector and the contact elements is achieved via the deformable conductor(s), mechanically guided or held in the labyrinth, the height of the cable outlet relative to the contact point (interface) can be selected almost arbitrarily, thus advantageously designing the installation space.The advantages of the "quasi-axial" design (180-degree exit) of the contact carrier prior to overmolding are retained, including protection of the conductor silicone seal against the ingress of overmolding compound by the interference suppression element, simple housing production, and independence from the cable insulation material thanks to a separate silicone seal. By guiding the conductors through the labyrinth on the contact carrier, the position of the conductors can be determined in their respective positions to ensure optimal positioning for the subsequent overmolding process.

[0034] Thanks to the soft element seal, which seals the conductor(s) against the contact carrier and contact element, it is particularly advantageous that the seal is not required to be provided by the overmolding material. This means that there is no need to create a material bond between the overmolding material and the insulation material of the conductor (cable), which is often problematic with regard to the material pairing of insulation and overmolding, and the resulting relative movements of the conductor(s) destroy a material bond - if the sealing function between the overmolding and the conductor insulation material is required.

[0035] By overmolding the preassembled unit, consisting of a contact carrier with a labyrinth that accommodates the contact element(s), the soft element seal, and the optional ferrite choke, the resulting plug-in connection can be brought into contact by simply sliding it onto the contact pins of the airbag igniter system. The prior art contacting method, which involves a direct welding process between the stranded wire and the contact pins, is thus replaced by a simple push-on and push-on process. This is particularly advantageous because the direct welding process is very complex due to the different geometries of the elements to be welded (the contact pin is round, the stranded wire is a strand bundle, or a bunch of strands), and requires accessibility to the welding point.Due to the possibility of using contact elements in the form of one or more plug-in contact boxes for contacting on the plug side, the cables, current-carrying cables and thus the stranded wire(s) are connected by crimping or welding before assembly.

[0036] Last but not least, the invention supports virtually any desired outlet angle in a very flexible manner without requiring the use of angle-adapted contact carriers and / or contact elements within the plug connection, as the deformable conductors are deformed according to the required outlet angle and held by the respective labyrinth.

[0037] The invention is explained in more detail below using an exemplary embodiment in conjunction with the figure. It shows: Fig. 1 shows the plug connection for airbag ignition systems in a sectional front view as well as a side cut-out view and a sectional top view.

[0038] Figure 1 depicts the plug connection for airbag ignition systems in a first embodiment, consisting of an airbag igniter housing 100 and an airbag connector 1. Arranged within the contact carrier 10 are the contact element 2 with the conductor (current-carrying cable) 6 secured thereto via the crimp connection 3, the soft element seal 4, and optionally the ferrite core choke 5. An overmolding, overmolding material 20, is applied to the outside of the contact carrier 10 over the entire circumference and projects beyond it on the cable outlet side, so that the line, current-carrying cable 6 in one cable section, and the labyrinth 30 are also enclosed by the overmolding material 20 and likewise cover the contact carrier 10 and / or the ferrite core choke 5 at the front.

[0039] In the embodiment shown, two conductors 6 are installed with an outgoing angle of approximately 90 degrees; the invention can also be implemented with one conductor 6 or a plurality of conductors 6 and different outgoing angles.

[0040] In Figure 1 Two labyrinths 30 are shown, each of which is assigned to a conductor 6 and is held and separated from one another by the central rib 32. The labyrinths 30 are formed by at least one labyrinth rib 31, in the example shown there are two labyrinth ribs 31. The respective conductor 6 is deformed in an arc shape starting from the ferrite core choke 5 and is both held and fixed by the labyrinth ribs 31 with the shown outlet angle (ie the shown angular outlet relative to the center line ML of the contact elements 2) of approximately 90 degrees. In order to compensate for the offset of the conductors 6 in two planes, as shown in the front view and view Z of the Figure 1As shown, the labyrinth ribs 31 assigned to the respective conductors 6 are geometrically differently designed and separated by the central rib 32.

[0041] No overmolding material 20 is provided at 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. This means that the overmolding 20 completely encloses the contact carrier 10 over its entire surface, with the exception of the front access for the contact element 2.

[0042] The overmolding 20 has a shoulder 21 on the outside, which interacts with a locking lug 22 to seal the airbag connector 1 for airbag ignition systems against the airbag igniter housing 100, which is designed here as an insertion opening for the airbag connector 1. In this way, a separate O-ring or other sealing element is not required; the seal is achieved integrally by the shoulder 21 and the locking lug 22. In this case, the overmolding material 20 can be formed from a silicone material to improve the sealing function.

[0043] The soft element seal 4 seals the conductor(s) 6 against the contact carrier 10, rests axially against a shoulder or ledge of the contact carrier, and abuts the ferrite core choke 5. If the variant of the inventive design is implemented without a ferrite core choke 5, an end cap (not shown) is provided instead. The ferrite core choke 5 or the end cap provides the axial contact surfaces for the soft element seal 4, so that the overmolding material 20 cannot penetrate into the contact box 2 during the overmolding process. List of reference symbols

[0044] 1Airbag connector 2Contact element 2Locking lance 3Crimp connection 4Soft element seal 5Ferrite core choke 6Conductor (deformable conductor, current-carrying cable) 10Contact carriers 20Overmolding, overmolding material 21Step, concentric ring shoulder 22Locking lug 30Labyrinth 31Labyrinth rib 32Middle rib 100Airbag igniter housing 101Airbag igniter contact pin MLCenter line of the contact element

Claims

1. Plug-in connection for airbag deployment systems, having an airbag igniter housing (100) and an airbag plug (1), having a contact carrier (10), in which two contact elements (2) and a deformable conductor (6) which is attached to the contact elements (2) are arranged, wherein the contact carrier (10) is provided at least in regions with an enclosure, which is produced by means of an encapsulation comprising encapsulation material (20), wherein the enclosure has a contour for mechanically locking with a latching contour of the igniter housing (100) and a simultaneous sealing function, characterized in that the contact carrier (10) has two labyrinths (30) arranged within the enclosure, so that the two conductors (6) are held so as to exit in an angled manner relative to the centre line (ML) of the contact elements (2).

2. Plug-in connection for airbag deployment systems according to Claim 1, characterized in that the labyrinths (30) are both held on the contact carrier (10) and separated from one another by a central rib (32).

3. Plug-in connection for airbag deployment systems according to Claim 1, characterized in that the labyrinths (30) are formed by in each case at least one first labyrinth rib (31).

4. Plug-in connection for airbag deployment systems according to Claim 3, characterized in that the labyrinths (30) are formed by in each case at least one second labyrinth rib (31) having a geometry which differs from the respectively first labyrinth rib (31).

5. Plug-in connection for airbag deployment systems according to Claim 1, characterized in that the conductors (6) exit at an angle of 90 degrees relative to the centre line (ML) of the contact elements (2).

6. Plug-in connection for airbag deployment systems according to Claim 1, characterized in that the conductors (6) are arranged eccentrically with respect to the centre line (ML) and offset with respect to one another in the projection plane normal to the exit direction.

7. Plug-in connection for airbag deployment systems according to Claim 1, characterized in that the largely complete sheathing of the contact carrier (10) by encapsulation material (20) is omitted at the end side of the contact side in order to keep the contact element (2) accessible for the contact-making task.

8. Plug-in connection for airbag deployment systems according to Claim 1, characterized in that a soft element seal (4) for sealing off the conductors (6) is arranged within the contact carrier (10).

9. Plug-in connection for airbag deployment systems according to Claim 8, characterized in that the conductors (6) are sealed off from the housing of the contact carrier (10).

10. Plug-in connection for airbag deployment systems according to Claim 1, characterized in that a ferrite core choke (5) for shielding the conductors (6) is arranged within the contact carrier (10).

11. Plug-in connection for airbag deployment systems according to Claims 8 and 10, characterized in that the ferrite core choke (5) and the soft element seal (4) are arranged around the conductors (6) within the contact carrier (10).

12. Plug-in connection for airbag deployment systems according to Claim 1, characterized in that the encapsulation has a latching lug (22), which engages in a sealing manner into an annular gap on the airbag igniter housing (100), so that the airbag plug (1) is sealed off with respect to the airbag igniter housing (100).

13. Plug-in connection for airbag deployment systems according to Claim 12, characterized in that the encapsulation has an oblique ramp and an undercut adjacent to the latching lug (22), wherein the undercut is formed as an encircling groove.

14. Plug-in connection for airbag deployment systems according to Claim 1, characterized in that the two contact elements (2) each have a latching lance (2'), which latching lances, in the end position of the contact element (2) within the contact carrier (10), are latched in a form-fitting manner with respect to a shoulder in the contact carrier (10) in a latching position.

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