Connector for airbag ignition systems

Abstract

A connector for airbag ignition systems, comprising an airbag igniter housing (100) and an airbag connector (1), comprising a contact carrier (10) in which two contact elements (2) and a deformable conductor (6) attached to each of the contact elements (2) are arranged, wherein the contact carrier (10) is provided at least partially with an over-housing that is manufactured by means of overmolding, overmolding material (20), wherein the over-housing has a contour for mechanical locking with a detent contour of the igniter housing (100) and simultaneous sealing function, characterized in that the two contact elements (2) are designed as non-angled contact elements (2) extending in the plug-in direction and the conductors (6) are deformed into a specific,for this purpose the contact elements (2) are brought into an angled position relative to the axis of extension and the contact carrier (10) has two labyrinths (30) arranged within the housing, so that the two conductors (6) are held in an angled exit relative to the center line (ML) of the contact elements (2).

Description

[0001] The invention relates to a plug connection for airbag ignition systems, comprising an airbag igniter housing and an airbag connector, 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 partially with an outer housing that is produced by means of overmolding, an overmolding material, wherein the outer housing has a contour for mechanical locking with a detent contour of the igniter housing and simultaneous sealing function.

[0002] Connectors in a wide variety of designs and configurations are used to establish or create detachable electrically conductive connections. Connector solutions are available in numerous variations, for example, in terms of the number of poles, electrical power ratings, and resistance to various external influences such as humidity, temperature, corrosive media, or mechanical stresses.

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

[0004] Connectors, especially those used to implement different protection ratings or IP codes, are often enclosed, housed, partially or fully sealed, or shielded. Other requirements, such as sealing of the contact elements, strain relief for the attached electrically conductive cables and wires, and a large number of contacts in a confined space, can impose further specific requirements on the contact carriers.

[0005] Electrical connectors must reliably transmit electrical signals and power over the long term in automotive applications and in dirty, humid, or chemically aggressive environments. Due to the wide range of applications for connectors, 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., an airbag or seatbelt pretensioner) 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 operate flawlessly and be compact. On the one hand, the airbag connector must transmit a trigger signal to the airbag igniter with absolute reliability; on the other hand, electrical interference signals, such as those caused by voltage spikes in the vehicle electronics, must not trigger unintentional airbag deployment.

[0007] To solve the particularly demanding task of connecting airbag ignition systems, various connector concepts and technical designs have been developed. Connectors designed for use with airbag ignition systems must be compact and space-saving, as space is very limited when they are installed in the steering wheel of a vehicle. Furthermore, these connectors must provide internal space for filters to prevent electromagnetic interference from causing unintentional triggering of the ignition system; these filters include ferrite cores, also known as ferrite core chokes. To facilitate reliable and easy installation, connectors for airbag ignition systems should be easy to wire, thus simplifying the installation of an airbag restraint system.In known connectors for airbag systems, the connector housing consists of two shells, with the plug contact and filter as well as connection pins for the supply cable arranged in the lower shell, and with the supply cable being soldered or welded to the connection pins at its ends.

[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 electrically connected within the airbag connector to a cable 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 wire. This electrically conductive connection is made via a soldered connection between a conductor element of the respective socket contact or the ground wire and a conductor end of a coil of the ferrite core choke. The socket contacts are already angled after their manufacture, so that they can also be installed in an angled position.

[0009] German patent DE 42 17 205 A1 discloses a connector for airbag applications which is wired with a flat conductor strip and in which the individual conductor tracks are pierced by contact pins and the electrical contact is ensured by applying solder. The soldering step is not only cumbersome but also results in a higher susceptibility to errors in assembly quality and contact reliability, since the soldering must be done on the partially assembled connector.

[0010] Of particular importance for contacting airbag ignition systems is a media-tight cable exit from the ignition system, i.e., the igniter, since moisture exposure is always to be expected when used in vehicles.

[0011] In connectors with a rigid outer housing, where the cable exit is to be sealed by overmolded sealing material, the problem arises of the sealing material, applied under pressure and while hot, penetrating axially across the sealing area of ​​the sleeve that encloses the cable within the coupling element for sealing purposes. This is because, until now, elastic material has been used for the aforementioned sealing sleeve to allow it to be inserted 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 exit from an electrical coupling element (connector plug).However, such sleeves made of elastic material are unsuitable for cable exits of electrical coupling elements that are sealed for a particularly high degree of tightness with a sealing compound applied in a hot, liquid state under high pressure. Such sealing compounds are, for example, thermoplastics that are injected in a liquid state under high pressure. With such cable exit seals of electrical coupling elements, it frequently occurs that the liquid sealing material flows over the outer circumference of the sleeve used as a seal, allowing the sealing compound to penetrate into the contact zones of the coupling element and thus impairing or preventing the function of the electrical contact.

[0012] DE 10 2004 061 663 B3 proposes a method for improving the sealing effect of cable exits while simultaneously ensuring reliable electrical contact in connectors with rigid outer housings. This method involves using a sleeve made of elastic material as a seal between the cable exit and the cable receiving opening of a contact carrier only if the sleeve is intended to function as a self-sealing element. In such cases, the elasticity of the sleeve material allows it to press tightly against the cable circumference and the inner surface of the cylindrical receiving bore of the contact carrier under elastic tension. However, in the case of a cable exit sealed by an injection-molded sealing compound, the sleeve does not need to provide or generate an independent sealing effect.In this case, the tightness of the cable exit is ensured solely by the sealing material. The sleeve's only function is to reliably prevent the liquid sealing material, applied under high pressure, from penetrating the contact spaces of the coupling element.

[0013] In other words, the teaching of DE 10 2004 061 663 B3 recognizes that, in the case of cable exits in rigid contact carriers, sealing can be achieved solely by an injected, elastic sealing material, and that a rigid sleeve prevents the injected sealing material from spreading into the contact area. This is achieved by making the sleeve from a substantially incompressible material. With such an incompressible material, the sleeve can no longer be pressed into the receiving opening with overlap, as would be the case with a sleeve made of elastic material; instead, a sliding fit must be provided for its support. This fit must be designed such that the sleeve can be inserted into the receiving opening of the coupling element practically without force and with minimal play.

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

[0015] Another connector solution recognizes that an arrangement consisting of the contact element, the contact carrier, and the cable, within an overmolded housing, and simultaneous mechanical fixation within the housing, creates a particularly media-tight connection for the detachable, electrically conductive contact. This means that a contact carrier with the integrated contact element is partially or completely overmolded on the outside of the carrier. The contact carrier features a cable exit sealed with a soft sealing element and an optional ferrite core or ferrite core choke. This connector solution, further developed with regard to media-tight properties, is particularly advantageous for a largely axially aligned arrangement of the contact element and cable, i.e., a cable exit largely without an angle to the connector element.

[0016] 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 construction is improved, an angled cable exit is supported, manufacturing 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 exit in a space-saving manner in the axial direction of the contact element.

[0017] By means of an arrangement consisting of the contact element, the contact carrier, the cable, and an overmolded housing of these components, with simultaneous mechanical fixation 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., largely completely encapsulated. The contact carrier has a cable exit sealed with a soft sealing element and an optional ferrite core or ferrite core choke.

[0018] To achieve the angled conductor exit (cable exit) in a space-saving manner, the invention provides that the angled exit is not formed by angled contact elements, but rather by using a flexible (deformable) conductor or cable, which is deformed into the desired angular position relative to the axis of extension or centerline of the contact element. For this purpose, the largely complete overmolding includes a labyrinthine area that both positions the deformable conductor or cable at its angular angle and secures it against the elastic deformation components caused by the deformation.

[0019] According to the invention, a pre-assembled unit is provided by forming a contact assembly with an angled or lateral conductor exit, which is suitable for further processing by overmolding. The contact assembly consists of contact elements, a soft element seal, and an optional ferrite core choke inserted into the contact carrier. The design of the contact assembly elements is kept as simple as possible to ensure cost-effective manufacturing and functionality, similar to a straight version, ideally using identical parts such as straight contact elements. This enables the economical production of a media-tight, angled contact assembly, allowing for height offsets or corrections and virtually any exit direction of the conductor(s) or cable, while maintaining a simple, standard overmolding process.The pre-assembled unit also includes the ladder(s), which are deformed according to the angle of the exit and fixed and held by the labyrinth(s).

[0020] The pre-assembled unit is then overmolded in such a way that it is almost completely encased in the overmolding material, leaving the end face of the contact carrier uncovered to allow access to the contact element for contacting. The cable(s) and electrical conductors on the side and behind the cable exit of the contact carrier are also overmolded with the overmolding material.

[0021] 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.

[0022] The housing essentially forms the outer shell of the airbag connector. The pre-assembled unit is located within the overmolding, i.e., within the housing produced by the overmolding process. This creates a media-tight assembly consisting of one or more contact elements, a soft element seal, a ferrite core choke or end cap, and a contact carrier, all encased by the housing. In addition to providing a media-tight enclosure for the pre-assembled unit, the housing also seals against various media from the housing of airbag ignition systems (the so-called igniter). The invention achieves this by directly integrating the sealing function into the overmolding material. This is accomplished by ensuring that the overmolding material possesses elastic and seal-like properties, optionally supplemented by the geometric design of the outer contour of the overmolding.A suitable geometry is, for example, a sealing lip, a sealing collar or a bead.

[0023] In contrast to prior art solutions, the angled design of the contact assembly according to the invention with overmolding is achieved by a deformable, i.e., flexible, conductor (or cable, depending on the design), which takes over the function of the otherwise necessary angled contact element. This conductor is preferably arranged and fixed laterally in a labyrinth on the contact housing. This results in very cost-effective manufacturing and minimizes the installation space requirement, as the conductor itself is angled without the need for an additional component.

[0024] The labyrinth, which due to its geometry functionally possesses 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 results for the overmolding process and the injection molding tool, among other things with regard to the sealing surfaces against the cable insulation.

[0025] The labyrinth is structurally implemented as an element of the contact carrier. It can be a separate component attached to the contact carrier or manufactured as a single piece with it – for example, through an injection molding process. As a functional addition to the contact carrier, the labyrinth holds and / or positions the outgoing conductor(s) at an angle and ensures their fixation during the overmolding process.

[0026] The labyrinth, designed here as a conductor labyrinth fixation, is constructed so that the injection mold opening direction is identical for both 90-degree and 180-degree contact carrier housings due to offset labyrinth clamping and guide ribs, thus eliminating the need for mold slides for the conductor. In the simplest case, this would allow a 90-degree contact carrier to be created from a 180-degree contact carrier using an interchangeable insert in the injection mold. For the 90-degree version, identical contact, sealing, and interference suppression elements (such as a ferrite core choke) known from the 180-degree contact carrier variant are used.

[0027] When using two conductors, a central plastic rib separates them. This allows for a labyrinth for each conductor with an individually designed labyrinth clamping geometry, so that the two conductors exit the airbag connector independently, optimized for installation space (e.g., with a common height offset) or for the injection molding tool (e.g., with an individual lateral or height offset for optimal design of the separation plane).

[0028] The overmolding, which forms the outer housing, is made of a durable plastic that must be suitable for injection molding. Thermoplastic elastomers are one example of suitable materials. If the overmolding is intended to provide direct functional integration of the sealing function in addition to that of an airbag ignition system housing, the overmolding material must possess sealing properties. Silicone materials are a suitable example in this case.

[0029] Media within the meaning of the invention are understood to be environmental influences such as moisture, water, liquids, free-flowing elements such as dust, dirt, sand, etc., gas and mixtures of the aforementioned media.

[0030] The angled airbag connector according to the invention offers the particularly advantageous advantage of using geometrically identical contact elements; that is, angled contact elements are not required for the angled connector. 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, i.e., a conductor exit aligned with the center line of the contact element.

[0031] Furthermore, the invention makes it possible to produce a closed and angled airbag connector in multiple parts by injection molding overmolding, which could not have been assembled using the previously required angled contact elements or contact carriers.

[0032] The contact carrier according to the invention remains unchanged in its simplest form for 180-degree versions and requires only the cable guide clamp labyrinth. This can be formed in an interchangeable injection mold insert. It is possible to use a combination injection mold for both 90-degree and 180-degree versions. Because the angulation of the connector and the contact elements is achieved mechanically guided or held in the labyrinth by the deformable conductor(s), the height of the cable exit relative to the contact point (interface) can be selected almost arbitrarily, thus advantageously optimizing the installation space.The advantages of the "quasi-axial" design (180-degree exit) of the contact carrier prior to overmolding are retained, namely the protection of the conductor silicone seal against ingress of overmolding material by the interference suppression element, the simple manufacturing of the housing, and the independence from the conductor insulation material due to a separate silicone seal. The conductor guidance through the labyrinth on the contact carrier allows the conductor position to be precisely determined, ensuring optimal positioning for the subsequent overmolding process.

[0033] The soft element seal, which seals the conductor(s) against the contact carrier and contact element, eliminates the need for the overmolding material to provide the seal. This means that a material-bonded connection between the overmolding material and the conductor's (cable's) insulation material is not required. This is often problematic with regard to the material pairing of insulation and overmolding, and the relative movements of the conductor(s) can destroy a material-bonded connection when a seal between the overmolding and the conductor's insulation material is required.

[0034] By overmolding the pre-assembled unit, consisting of a labyrinth contact carrier that accommodates the contact element(s), the soft element seal, and the optional ferrite choke, this resulting plug connection can be brought into contact by simply sliding it onto the contact pins of the airbag igniter system. The prior art method of contacting the wire and contact pins through direct welding is thus replaced by a simple push-fit connection. 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 wire is a bundle of strands) and requires access to the welding point.The possibility created to use contact elements in the form of one or more plug-in contact boxes for the contacting of the plug side allows the wires, current-carrying cables and thus the strands to be crimped or welded before assembly.

[0035] Last but not least, the invention supports virtually any exit angle with great flexibility without requiring the use of angle-adapted contact carriers or contact elements within the plug connection, by deforming and holding the deformable conductors according to the required exit angles through the respective labyrinth.

[0036] The invention is explained in more detail below with reference to an exemplary embodiment in conjunction with the figure. The figure shows: Fig. 1. The illustration of the plug connection for airbag ignition systems in a sectional front view, a side view, and a sectional top view.

[0037] Fig. Figure 1 represents the connector for airbag ignition systems in a first embodiment, consisting of an airbag igniter housing 100 and an airbag connector 1. Within the contact carrier 10 are arranged the contact element 2 with the conductor (current-carrying cable) 6 attached to it via the crimp connection 3, the soft element seal 4, and optionally the ferrite core choke 5. An overmolding material 20 is applied to the entire circumference of the contact carrier 10 and extends beyond it on the cable exit side, so that the conductor (current-carrying cable 6 in a cable section) and the labyrinth 30 are also enclosed by the overmolding material 20, and the contact carrier 10 and / or the ferrite core choke 5 are likewise covered at their end faces.

[0038] In the illustrated embodiment, 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.

[0039] In Fig. Figure 1 shows two labyrinths 30, each associated with a conductor 6 and held and separated from each other 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 exit angle (i.e., the shown angled exit relative to the center line ML of the contact elements 2) of approximately 90 degrees. To accommodate the offset of the conductor 6 in two planes, as shown in the front view and view Z of the Fig.As shown in Figure 1, the labyrinth ribs 31 assigned to the respective ladders 6 are geometrically different and separated by the central rib 32.

[0040] No overmolding material 20 is provided at the end of the contact carrier 10 facing the insertion direction, so that the contact carrier 10 and the contact element 2 are accessible and the plug contact pin(s) 101 of the airbag igniter can be inserted. That is, the overmolding 20 completely and fully encloses the contact carrier 10 except for the end-face access for the contact element 2.

[0041] The overmolding 20 has an external shoulder 21 which interacts with a locking lug 22 to seal the airbag connector 1 for airbag ignition systems against the airbag igniter housing 100, which here serves 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. To improve the sealing function, the overmolding material 20 can be made of a silicone material.

[0042] The soft element seal 4 seals the conductor(s) 6 against the contact carrier 10, is axially supported against a shoulder or step of the contact carrier, and rests against the ferrite core choke 5. If the variant of the inventive design is implemented without the 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. Reference symbol list 1 Airbag connector 2 Contact element 2' Rastlance 3 crimp connection 4 Soft element seal 5 Ferrite core choke 6 conductors (deformable conductor, current-carrying cable) 10 contact carriers 20 Overmolding, overmolding material 21st paragraph, concentric ring shoulder 22 Rastnase 30 Labyrinth 31 Labyrinth rib 32 Midrib 100 airbag igniter housings 101 Plug contact pin of the airbag igniter ML center line of the contact element QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10146430 A1

[0008] DE 4217205 A1

[0009] DE 102004061663 B3 [0012, 0013]

Claims

[1] Plug connector for airbag ignition systems, comprising an airbag igniter housing (100) and an airbag connector (1), comprising a contact carrier (10) in which two contact elements (2) and a deformable conductor (6) attached to each of the contact elements (2) are arranged, wherein the contact carrier (10) is provided at least partially with an outer housing which is produced by means of overmolding, overmolding material (20), wherein the outer housing has a contour for mechanical locking with a detent contour of the igniter housing (100) and simultaneous sealing function, characterized by , that the contact carrier (10) has two labyrinths (30) arranged within the housing, such that the two conductors (6) are held in an angled exit relative to the center line (ML) of the contact elements (2). [2] Connector for airbag ignition systems according to claim 1, characterized by, that the labyrinths (30) are both held to the contact carrier (10) and separated from each other by a central rib (32). [3] Plug connector for airbag ignition systems according to claim 1, characterized by , that the labyrinths (30) are each formed by at least one first labyrinth rib (31). [4] Plug connector for airbag ignition systems according to claim 3, characterized by , that the labyrinths (30) are formed by at least one second labyrinth rib (31) with a geometry different from that of the first labyrinth rib (31). [5] Plug connector for airbag ignition systems according to claim 1, characterized by , that the conductors (6) extend at an angle of 90 degrees relative to the center line (ML) of the contact elements (2). [6] Plug connector for airbag ignition systems according to claim 1, characterized by, that the conductors (6) are arranged in the projection plane normal to the exit direction off-center to the center line (ML) and offset from each other. [7] Plug connector for airbag ignition systems according to claim 1, characterized by , that the largely complete covering of the contact carrier (10) by overmolding material (20) is recessed on the contact side in order to keep the contact element (2) accessible for the contacting task. [8] Plug connector for airbag ignition systems according to claim 1, characterized by , that a soft element seal (4) is arranged within the contact carrier (10) for sealing the conductors (6). [9] Connector for airbag ignition systems according to claim 8, characterized by , that the conductor (6) is sealed to the housing of the contact carrier (10). [10] Plug connector for airbag ignition systems according to claim 1, characterized by, that a ferrite core choke (5) is arranged within the contact carrier (10) for shielding the conductors (6). [11] Plug connector for airbag ignition systems according to claims 8 and 10, characterized by , that the ferrite core choke (5) and the soft element seal (4) are arranged inside the contact carrier (10) around the conductors (6). [12] Plug connector for airbag ignition systems according to claim 1, characterized by , that the overmolding has a locking lug (22) which engages in a sealing manner in an annular gap on the airbag igniter housing (100), so that a seal of the airbag connector (1) against the airbag igniter housing (100) is achieved. [13] Plug connector for airbag ignition systems according to claim 12, characterized by , that the overmolding adjacent to the locking lug (22) has a sloping ramp and an undercut, the undercut being formed as a circumferential groove. [14] Plug connector for airbag ignition systems according to claim 1, characterized by, that the two contact elements (2) each have a locking lance (2') which, in the end position of the contact element (2) within the contact carrier (10), are positively locked against a shoulder in the contact carrier (10).

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