DE102009058704A1 - Airbag module i.e. passenger airbag module, for motor vehicle, has support provided for supporting module at guiding cross beam and latch of motor vehicle, and screw nut provided for attachment at dashboard - Google Patents

Abstract

The module (1) has an air cushion (1.3) fillable by a gas producer (1.1), and a flexible covering (1.4) for supporting the air cushion during filling the air cushion. Maximum elastic expansion (epsilon', epsilon'') and maximum deflection (1.4', 1.4'') of the covering are co-ordinated according to a desired support of the air cushion during filling the air cushion. A support (4) is provided for supporting the module at a guiding cross beam (3) and a latch (3.1) of the motor vehicle, and a screw nut (1.2) is provided for attachment at a dashboard (2). An independent claim is also included for a method for producing and/or assembling an airbag module.

Description

The present invention relates to a housing-less airbag module for a motor vehicle, a method for its manufacture and assembly and a motor vehicle with such an airbag module.

From the own German registration DE 10 2006 057 503 A1 a bagless airbag module for a motor vehicle is known, ie an airbag module, in which a shot channel for an airbag, which can be filled by a gas generator, against the weft direction is no longer closed by a rigid housing part, but by a flexible shell, so that the Air bag is supported during filling of this flexible sheath to open the firing channel and catch a vehicle occupant. Due to the flexible shell weight and space can be saved in particular.

In the DE 10 2006 057 503 A1 the gas generator is fastened by means of screws only on a dashboard, whereby only the tensile strength of the flexible sheath is taken into account, but not their elongation characteristics.

Also in the DE 10 2007 060 885 A1 concerning a housing-less Baifahrerairbagmodul the gas generator is attached only to a shutter cross member, ie an element of the interior trim part, which has due to the usual production of plastic only a lower rigidity. Alternatively it is from the DE 10 2007 007 220 A1 and the US 6,189,916 B1 each known to attach the gas generator seat side airbags exclusively to a frame of the seat. The DE 10 2004 058 217 A1 . US 6,447,005 B2 and US 5,221,108 B deal with covers of an airbag module in the weft direction of the airbag.

In the generic DE 10 2006 057 503 A1 It has now been recognized that a deformation of the interior trim panel, which is usually made of plastic, with the gas generator fastened exclusively thereto as well as an expansion of the flexible shell during support can each influence the functionality of the airbag, in particular its deployment kinematics.

The object of the present invention is to improve the functionality of the airbag.

This object is solved by the features of claim 1. Claim 8 represents a method for producing and / or mounting an airbag module according to the invention under protection, claim 10 a motor vehicle with such an airbag module. Advantageous embodiments of the invention are the subject of the dependent claims.

An airbag module according to the invention for a motor vehicle, which can be received in particular as a passenger airbag module behind a dashboard, has a gas generator for supplying a filling fluid, in particular gas, for filling an airbag, which is present folded up in the initial state and by filling by the activated gas generator by a Firing channel unfolded into a vehicle interior into there to catch a vehicle occupant in an accident and support. The firing channel may in particular comprise an opening in a vehicle interior trim part, preferably with lateral guides, preferably integrally formed with the vehicle interior trim part, for the airbag, and in a preferred embodiment be closed by a cover formed integrally with the vehicle interior trim part.

For example, in order to open such a cover when filling and unfolding, for example by tearing and / or unfolding, or in order to be able to support occupants in the filled state, the airbag must, when filled, i. e. during filling and / or in the filled state, in turn against the shot or in the direction of catching on the motor vehicle to dissipate reaction forces.

For this purpose, a flexible sheath is provided in an airbag module according to the invention, as they are known from the above DE 10 2006 057 503 A1 is known, whose disclosure content with respect to constructive embodiments of the airbag module and interior trim part is explicitly included in the present application. In particular, the flexible sheath, which may be made, for example, of fabric, in particular airbag fabric, as used for an airbag knitted fabric, mesh, fleece and / or film, preferably tear-resistant film, a shot channel at least against the weft direction of the airbag or the whole partially close, so that the airbag against the weft direction can be at least partially supported on this case, which thus serves as an abutment for the air bag during filling and / or in the filled state. The airbag can also be in other places, such as the Support interior trim part, an associated or integrally formed firing channel or the gas generator. The flexible sheath may partially or completely envelop the airbag module or the unactivated, folded airbag and, in this case, have corresponding opening regions, for example tear lines, through which the airbag can exit the sheath from the passenger compartment. It may be attached to the firing channel, interior trim part and / or gas generator, preferably positive, force and / or material fit, for example by hanging, screws, buttons or gluing, releasably or permanently.

According to a first aspect of the present invention, an expansion characteristic of the flexible sheath is tuned in accordance with a desired support of the air bag upon filling. For the inventors have recognized that stretching the flexible sheath during support of the airbag introduces resilience into the system, which can advantageously be deliberately used, for example to reduce load peaks on the fastening of the sheath, for example on the interior trim part, or around an opening - and unfolding kinematics pretend or vary. If, for example, the sheath expands more under load, a force of the airbag in the weft direction is built up correspondingly slower with the same filling by the gas generator, since the sheath absorbs a portion of the pressure of the unfolding airbag under deformation.

In particular, a measure of an elastic and / or plastic deformation of the casing, for example in the direction of the material thickness, perpendicular to it and / or in the weft or catching direction of the airbag, depending on the forces acting on the casing, pressing or closing, is considered as an expansion characteristic of the flexible casing Tensions understood, in particular the ratio of such a deformation to loads causing them, described for example by a coefficient of elasticity or tensor. For example, an elongation characteristic may be given by a coefficient of elasticity or modulus of the casing material or by a, for example, maximum, average or integral, evasive travel of the casing, preferably opposite to the weft or catch direction, depending on the filling pressure of the airbag resting thereon.

Since the gas generator in the airbag and thus on the flexible shell builds up a pressure according to a specific time profile, an expansion characteristic of the flexible envelope can equally well be given in time, for example as elastic deflection against the weft direction over the filling time of the airbag. Similarly, the elongation characteristic can also be a dependence of the deformation of the shell of a loading or deformation speed, i. e. an attenuation include. Since the flexible sheath opposes its resistance to resistance to deformation, an expansion characteristic can also be indicated, for example, by the course of a resistance force over the filling time. In general, an expansion characteristic in the sense of the present invention thus describes, in particular quantitatively, a deformation of the flexible envelope as a function of its load, in particular by the airbag supported on it.

An elongation characteristic can in turn also be given load-dependent and / or time-dependent. For example, a strain coefficient may change with non-linear strain characteristics with the load. Likewise, due to relaxation behavior, for example, elongation may increase with time.

For example, a strain characteristic may be substantially linear, progressive, and / or degressive, or completely linear, progressive, or degressive. For example, an expansion of the sheath, defined as by a length-area or volume measure in the stretched state relative to a corresponding reference dimension, with disproportionate (progressive), disproportionately (progressively) or proportionally with increasing load on the shell and / or over time (linear) increase or decrease the load or time. For example, a coefficient of elasticity or stiffness of the sheath may increase (progressively) or decrease (degressively) with increasing load.

In addition to or as an alternative to a time or load constraint, the flexible wrapper may have areas of different elongation characteristics, such as areas that stretch more under a load and areas that stretch less under the same load. In this case, for example, different or an average elongation characteristic can be tuned in regions.

In this case, tuning of the elongation characteristic is in particular the selection or adjustment of the elongation characteristic, for example by selecting or specifying corresponding casing material, corresponding material thicknesses) and / or structure, any stiffening and / or compliance and / or by appropriate cut or geometric design of the Shell understood.

In this way, the expansion characteristic of the casing is adjusted in accordance with a desired support of the airbag during filling. The desired support, for example, on the basis of a desired load profile attachment of the shell, for example, maximum or permanent sustainable loads, based on an opening for opening a shot channel for the airbag applied opening load, a structural rigidity of the motor vehicle and / or a desired airbag kinematics are specified.

For example, in a case attached to a weak interior trim panel, the deploying airbag needs only low forces to open a cover of the firing channel, and / or relatively long to deploy, because of a softer body structure Vehicle causes a correspondingly lower delay in an accident, the shell may have a more flexible elongation characteristic, in particular a smaller coefficient of elasticity or modulus as the ratio of load to deformation, so as to absorb the load by the unfolding airbag relatively soft.

Conversely, in the case of a fixed interior trim part, the deploying airbag must apply great force to open the cover, or relatively little time is available for its deployment, since a rigid body structure of the vehicle causes a strong delay with short positioning time for the airbag a stiffer elongation characteristic, in particular a larger coefficient of elasticity or modulus, so as to cause the desired deployment of the airbag.

A desired support may also be provided indirectly, for example, by empirically setting an opening, deployment, catching or occupant support characteristic of an airbag module attached to an interior trim panel while varying the expansion characteristic of the shell. Correspondingly, casings can, for example, be matched to different gas generators with different powers, different opening loads for firing channel covers and / or different deployment characteristics.

According to a second aspect of the present invention, which may be combined in a preferred embodiment with the first aspect, the airbag module on the one hand, as from the aforementioned DE 10 2006 057 503 A1 known, with at least one fastening means to an interior trim part, such as a dashboard, attached, for example, clipped, latched, screwed or glued with this. According to the invention at least one support is additionally provided, with which the airbag module is supported in the mounted state on a structural element of the motor vehicle, for example, a body or steering cross member, a traverse or a subframe. As a result, the airbag module can also be supported on the preferably stiffer vehicle structural element, in particular when the airbag is filled, and thus experiences a better, in particular stiffer, support.

Conversely, in the case of a fixed interior trim part, the deploying airbag must apply great force to open the cover, or relatively little time is available for its deployment, since a rigid body structure of the vehicle causes a strong delay with short positioning time for the airbag a stiffer elongation characteristic, in particular a larger coefficient of elasticity or modulus, so as to cause the desired deployment of the airbag.

A desired support may also be provided indirectly, for example, by empirically setting an opening, deployment, catching or occupant support characteristic of an airbag module attached to an interior trim panel while varying the expansion characteristic of the shell. Correspondingly, casings can, for example, be matched to different gas generators with different powers, different opening loads for firing channel covers and / or different deployment characteristics.

According to a second aspect of the present invention, which may be combined in a preferred embodiment with the first aspect, the airbag module on the one hand, as from the aforementioned DE 10 2006 057 503 A1 known, with at least one fastening means to an interior trim part, such as a dashboard, attached, for example, clipped, latched, screwed or glued with this. According to the invention at least one support is additionally provided, with which the airbag module is supported in the mounted state on a structural element of the motor vehicle, for example, a body or steering cross member, a traverse or a subframe. As a result, the airbag module can also be supported on the preferably stiffer vehicle structural element, in particular when the airbag is filled, and thus experiences a better, in particular stiffer, support.

Also according to the second aspect, the airbag module can be advantageously adapted to different inflators different performance, airbag modules with different weights or interior trim parts with different stiffnesses or strengths by one or more supports for support on one or more structural elements of the motor vehicle are provided only optional or optional For example, only with heavier, stronger gas generators or weaker interior trim parts.

In a preferred embodiment, a support for support on a structural element of the motor vehicle is releasably connected thereto on the one hand to the structural element and on the other hand to the gas generator and / or an interior trim part, for example positive and / or non-positive, for example by screwing, clipping or latching, so that it is provided only when needed. In this way, for example, the same airbag modules with different thickness interior trim parts or the same interior trim parts are used with different gravity gas generators.

Likewise, a support may also be fixedly connected to one of the structural member, the inflator, and an interior trim member, for example, adhesively bonded, or integrally formed, while being releasably secured to another of the structural member, the inflator, and an interior trim panel. In particular, a fastening strip of an interior trim part for fastening the airbag module can be further developed thereon as a support or support part, which is supported on the structural element, in particular a fastening section of the structural element such as a clamp.

Preferably, the support is attached to the structural element. In this way, vibrations of the airbag module can additionally be damped or reduced. In a preferred embodiment, at least one attachment means and at least one support are disposed on the same side of the airbag module to facilitate access during assembly, maintenance and inspection.

Further advantageous developments of the present invention will become apparent from the dependent claims and the following description of preferred embodiments. This shows, partially schematized:

1 an airbag module according to a first embodiment of the present invention in section;

2 an airbag module according to a second embodiment of the present invention in 1 corresponding representation; and

3 a supporting force of the airbag of the airbag module after 1 respectively. 2 at filling.

In 1 is a section of an interior trim panel, such as a dashboard 2 shown. It points to its the passenger compartment (top in 1 ) facing away from a planar guide 2.2 on, at the a gas generator 1.1 a caseless airbag module 1 by means of a mother 1.2 screwed on and the one shot channel for an airbag 1.3 the airbag module defined by a cover 2.1 the instrument panel is closed to the passenger compartment. The mother 1.2 , the part of the gas generator screwed into it 1.1 form in cooperation with the guiding surface 2.2 a fastening means for fastening the airbag module 1 on the interior trim part 2 ,

On the opposite side closes a flexible shell 1.4 of the airbag module 1 the firing channel. The leadership 2.2 is for stiffening by means of a ribbing 2.4 supported on the dashboard.

In addition to the screw connection 1.2 the airbag module is supported 1 in weft direction (vertically from bottom to top in 1 ) on the same side as the fastener 1.2 (left in 1 ) on a steering cross member 3 from. This is a support 4 on a tab 3.1 of the carrier 3 screwed. In the execution after 1 is this prop 4 integral with the planar guide 2.2 the dashboard 2 educated. In the otherwise matching execution of the 2 is instead a separate prop 4 ' provided with the airbag module 1 at the lead 2.2 screwed on. This offers the advantage of having the prop 4 ' optionally only on demand, such as heavier gas generators, higher generator outputs and / or weaker dashboards can be mounted.

When activated, the gas generator fills 1.1 the airbag 1.3 which then unfolds, while the cover 2.1 the firing channel on by material weakening 2.3 predetermined tear and Hinge lines tears open and exits into the passenger compartment to catch and support a vehicle occupant.

In this case, the deployed or unfolded airbag is supported 1.3 against him by the leadership 2.2 defined firing direction, ie vertically down to the flexible shell 1.4 to do this at the guide 2.2 and the gas generator 1.1 hooked by hooks (not shown) and as an abutment for the airbag 1.3 serves.

The elongation characteristic of the flexible sheath 1.4 is tuned according to the invention to the desired support. Exemplary is this in 1 . 2 dot-dashed lines a maximum elastic elongation ε 'of the flexible sheath with a first, more rigid elongation characteristic 1.4 and dash-duplexes a maximum elastic strain ε "of the flexible sheath with a second, softer, elongation characteristic 1.4 '' located.

The elongation characteristic is, for example, by the maximum elastic strain ε ', ε''or the deflection 1.4 ' . 1.4 '' the flexible shell 1.4 under the weight of the airbag resting on it 1.3 described. It can be seen that, due to the smaller coefficient of elasticity of the flexible sheath with the second expansion characteristic, this undergoes a greater deflection counter to the weft direction, ie it yields more strongly to the deploying airbag. Accordingly, a support force F '', which builds up from the shell 1.4 directly or via the gas generator attached to it 1.1 in the lead 2.2 on and in this is forwarded to the vehicle structure, slower and only to a lower maximum than a supporting force F ', which results in the first elongation characteristic, such as 3 shows, in which the time course of these supporting forces F ', F''over the time t is shown.

In this way, for example, by the vote of the shell 1.4 with the first elongation characteristic in a stiff vehicle body and cover 2.1 ensure that the airbag opens the latter quickly enough and positioned quickly enough despite the high deceleration of the impacting vehicle, with higher load peaks in the correspondingly stiffer dashboard 2 be impressed (see F 'in 3 ). On the other hand, is due to a softer vehicle body more deployment time available and the air bag 1.3 to open the cover 2.1 apply only a lesser force, so can vote by the second strain characteristics, for example, choosing a more elastic material for the flexible shell 1.4 , the peak load in the dashboard 2 be reduced (see F '' in 3 ). The vote on a desired support, for example, a desired force curve F (t) (see. 3 ), a desired opening or unfolding kinematics or the like can be done empirically and / or mathematically, in particular by simulations, with variation of elongation parameters such as a coefficient of elasticity 1.3 supported on the shell as described above 1.4 in turn, on the gas generator 1.1 is attached. This burdened therefore the leadership 2.2 the dashboard 2 not only with the weight of the airbag module 1 but in its activation also with the reaction forces of the gas generator 1.1 and supporting forces of the shell 1.3 , However, these forces are according to the invention at least partially on the support 4 respectively. 4 ' on the steering cross member 3 derived. LIST OF REFERENCE NUMBERS 1 airbag module 1.1 inflator 1.2 mother 1.3 air bag 1.4 flexible shell 1.4 ', 1.4'' by supporting airbag stretched sleeve 2 Dashboard (interior fitting) 2.1 cover 2.2 guide 2.3 material dilution 2.4 rib 3 Steering cross member (structural element) 3.1 flap 4; 4 ' support ε '; ε '' maximum elongation against weft direction

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102006057503 A1 [0002, 0003, 0005, 0010, 0022, 0025]
• DE 102007060885 A1 [0004]
• DE 102007007220 A1 [0004]
• US 6189916 B1 [0004]
• DE 102004058217 A1 [0004]
• US 6447005 B2 [0004]
• US 5221108 B [0004]

Claims (10)

Airbag module ( 1 ) for a motor vehicle, with a gas generator ( 1.1 ), a through this inflatable air bag ( 1.3 ), and a flexible envelope ( 1.4 ) for supporting the airbag ( 1.3 when filling; characterized in that a strain characteristic (ε ', 1.4 '; ε '', 1.4 '' ) of the flexible envelope ( 1.4 ) corresponding to a desired support (F ', F'') of the airbag ( 1.3 ) is tuned during filling; and / or the airbag module ( 1 ) in addition to a fastener ( 1.2 ) for attachment to an interior trim part ( 2 ) a support ( 4 ; 4 ' ) for supporting on a structural element ( 3 . 3.1 ) of the motor vehicle. Airbag module ( 1 ) according to claim 1, characterized in that the flexible envelope ( 1.3 ) a predetermined load- and / or time-dependent, in particular linear, progressive and / or degressive strain characteristic (ε ', 1.4 '; ε '', 1.4 '' ) having. Airbag module ( 1 ) according to one of the preceding claims, characterized in that the flexible envelope ( 1.3 ) Regions with different elongation characteristics (ε ', 1.4 '; ε '', 1.4 '' ) having. Airbag module ( 1 ) according to one of the preceding claims, characterized in that a desired support of the airbag ( 1.3 ) when filling on the basis of an opening load for opening a shot channel for the airbag ( 1.3 ), a structural rigidity of the motor vehicle, a load (F ';F'') of an interior trim part ( 2 ) and / or a desired airbag kinematics is predetermined. Airbag module ( 1 ) according to one of the preceding claims, characterized in that a support ( 4 ; 4 ' ) for supporting on a structural element ( 3 . 3.1 ) of the motor vehicle with the gas generator ( 1.1 ), an interior trim part ( 2 ) and / or the structural element ( 3 . 3.1 ) is respectively fixed or detachably connected or integrally formed. Airbag module ( 1 ) according to one of the preceding claims, characterized in that a fastening means ( 1.2 ) for attachment to an interior trim part ( 2 ) and a support ( 4 ; 4 ' ) for supporting on a structural element ( 3 . 3.1 ) of the motor vehicle are arranged on the same side of the airbag module. Airbag module ( 1 ) according to one of the preceding claims, characterized in that the flexible envelope ( 1.4 ) Airbag fabric, knitted fabric, mesh material, nonwoven and / or foil. Method for producing and / or assembling an airbag module ( 1 ) according to one of the preceding claims, characterized in that a strain characteristic (ε ', 1.4 '; ε '', 1.4 '' ) of the flexible envelope ( 1.4 ) corresponding to a desired support (F ', F'') of the airbag ( 1.3 ) is adjusted during filling and / or that the airbag module ( 1 ) by means of the fastening means ( 1.2 ) on an interior trim part ( 2 ) of a motor vehicle and by means of the support ( 4 ; 4 ' ) on a structural element ( 3 . 3.1 ) of the motor vehicle is supported. Method according to claim 8, characterized in that optionally different flexible envelopes ( 1.4 ) with different elongation characteristics (ε ', 1.4 '; ε '', 1.4 '' ) and / or a support ( 4 ; 4 ' ) for supporting on a structural element ( 3 ) of the motor vehicle is optionally provided. Motor vehicle with an airbag module ( 1 ) according to one of the preceding claims 1 to 7, characterized in that a strain characteristic (ε ', 1.4 '; ε '', 1.4 '' ) of the flexible envelope ( 1.4 ) of the airbag module in accordance with a desired support (F ', F'') of the airbag is matched during filling and / or the airbag module ( 1 ) by means of the fastening means ( 1.2 ) on an interior trim part ( 2 ) of a motor vehicle and by means of the support ( 4 ; 4 ' ) on a structural element ( 3 . 3.1 ) of the motor vehicle is supported.

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