SAFETY ARRANGEMENT FOR A VEHICLE AND METHOD FOR CONTROLLING A SAFETY ARRANGEMENT

• US 20110042926A1
• Filed: 01/13/2009
• Published: 02/24/2011
• Est. Priority Date: 01/19/2008
• Status: Active Grant

• Current Assignee: Autoliv Development AB (Autoliv Incorporated)
• Original Assignee: Autoliv Development AB (Autoliv Incorporated)
• Inventors: Schmidbauer, Thomas, Mayer, Johann, Gonter, Mark, Wohllebe, Thomas
• Granted Patent: US 8,157,291 B2
• Time in Patent Office: Days
• US Class Current: 280/735
• CPC Class Codes: B60R 2021/01225 control of expansion volume
• CPC Class Codes: B60R 2021/23384 having ends which are movable or detachable during deployment
• CPC Class Codes: B60R 21/0134 responsive to imminent contact with an obstacle , e.g. using radar systems
• CPC Class Codes: B60R 21/0136 responsive to actual contact with an obstacle , e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle monitoring crash strength in combination with passenger seat detection B60R21/01558
• CPC Class Codes: B60R 21/2338 Tethers
• CPC Class Codes: B60R 21/276 with means to vent the inflation fluid source, e.g. in case of overpressure B60R21/30 takes precedence; venting means on inflatable member walls B60R21/239

Abstract

The invention relates to a safety arrangement for a vehicle, in particular for a motor vehicle with an airbag (2), folded together in the non-activated basic state, which on a triggering of the safety arrangement (1) by an activation signal is able to be inflated with different volumes in the direction of the interior of the vehicle by means of a gas generator (3), and with a crash sensor system which detects a vehicle impact and emits the activation signal for this. According to the invention, the crash sensor system comprises both a pre-crash sensor system and also an in-crash sensor system, wherein the pre-crash sensor system generally already detects an impending collision before an actual impact, and for this circumstance emits a pre-crash activation signal as activation signal. The in-crash sensor system detects an actual impact and for this circumstance emits an in-crash activation signal (backup) if the pre-crash sensor system has previously not detected the impending collision and has not emitted a pre-crash activation signal. The airbag is able to be inflated to a larger airbag volume (FIG. 1; Volume A+B) and to a relatively smaller airbag volume (FIG. 2; Volume A) by comparison, wherein by a pre-crash activation signal in a pre-crash mode the inflation process is activated for the larger airbag volume (FIG. 1; Volume A+B), and by an in-crash activation signal in an in-crash mode the inflation process is activated for the relatively smaller airbag volume (FIG. 2; Volume A).

Claims

1-12. -12. (canceled)

13. A safety arrangement for a motor vehicle comprising:

an airbag folded together in a non-activated basic state, the airbag operable to be inflated with different volumes in a direction of an interior of the vehicle by a gas generator on triggering of the safety arrangement by an activation signal; and

a crash sensor system, which detects a vehicle impact and emits the activation signal, the crash sensor system including a pre-crash sensor system and an in-crash sensor system, the pre-crash sensor system operable for detecting an impending collision before an actual impact and for this circumstance emitting a pre-crash activation signal as the activation signal, and the in-crash sensor system operable for detecting an actual impact and for this circumstance emits an in-crash activation signal if the pre-crash sensor system has previously not detected the impending collision and has not emitted a pre-crash activation signal;

wherein the airbag is able to be inflated to a larger airbag volume and to a relatively smaller airbag volume compared thereto, wherein an inflation process for the larger airbag volume is activated by the pre-crash activation signal in a pre-crash mode, and the inflation process for the relatively smaller airbag volume is activated by the in-crash activation signal in an in-crash mode.

14. The safety arrangement according to claim 13, wherein the relatively smaller airbag volume corresponds to the airbag volume of a hitherto standard airbag and the larger airbag volume is substantially greater by comparison, in particular is greater by a factor 1.3 to 2.0.

15. The safety arrangement according to claim 13, wherein the airbag volume is variable in a controlled manner between a minimum volume and a maximum volume and also for intermediate sizes.

16. The safety arrangement according to claim 13, further comprising a gas outlet valve defining a controllable vent and wherein the inflation process in the pre-crash activation is controlled with a longer inflation time compared with an in-crash triggering.

17. The safety arrangement according to claim 13, wherein the volume variability of the airbag is realized by limiting straps, which on the one hand are fastened on the inner side of an unfolding airbag wall and which on the other hand, through the unfolding of the airbag, are respectively able to be drawn out from a fixed guide opening and are able to be clamped there with a correspondingly variable limiting strap length determining the airbag volume, and that for airbag internal pressure adaptation, a controllable vent is integrated in the airbag module housing.

18. The safety arrangement according to claim 17, wherein the vent opening takes place by displacement of a vent part freeing at least one gas outlet opening, preferably by pyrotechnics, and a clamping device for limiting strap clamping is coupled directly or indirectly therewith and able to be actuated.

19. The safety arrangement according to claim 18, wherein the controllable vent is formed by a valve slider, adjustable in a pytotechnically controlled manner, on a module housing, which on displacement frees gas outlet openings on the module housing and at the same time clamps at least one limiting strap in a clamping plate, and/or

that the controllable vent is formed by a housing wall region, displaceable in a pyrotechnically controlled manner, of a module housing, in particular a displaceable or pivotable housing wall region, on which the gas generator is preferably arranged, such that with a displacement a partial region of the module housing is opened, in particular by means of a tilting lever and/or on a linear guide, and at the same time at least one limiting strap is able to be clamped by the housing wall region or an actuating lever.

20. The safety arrangement according to claim 13, wherein the volume variability of the airbag is realized by tucked-in folds with tear seams and/or tear seam fields, wherein the tear seams and/or tear seam fields do not tear open or only partially tear open for a relatively small airbag volume, and on reaching a particular airbag internal pressure or on reaching particular airbag internal pressure stages, tear open in succession in stages for an unfolding of a larger airbag volume, and

that for airbag internal pressure adaptation, a gas outlet valve is provided as controllable vent, which is preferably integrated in the module housing.

21. The safety arrangement according to claim 13, wherein the gas generator is a single-stage gas generator.

22. The safety arrangement according to claim 13, further comprising a first vent integrated in the module housing and able to be activated for controlling the gas mass flow for filling the airbag in the pre-crash mode with a large airbag volume or in the in-crash mode with a smaller airbag volume;

and

a second vent is integrated in the airbag and able to be triggered pyrotechnically, which is able to be activated for an adaptivity of the airbag, in particular an adaptation of the airbag volume to the severity of the accident and/or to occupant parameters.

23. A method for controlling a safety arrangement according to claim 17, the method comprising:

in the pre-crash mode with the presence of a pre-crash activation signal, the limiting straps are freely unclamped and by activation of the gas generator the airbag is filled with a large airbag volume, wherein the vent remains closed during the inflation process and wherein in addition or alternatively the vent is at least partially opened if applicable after or during the inflation process for adaptation of the airbag characteristics to the severity of the accident and/or occupant parameters, or this adaptation takes place by controlled opening of a second vent, and

that in the in-crash mode with the presence of an in-crash activation signal as backup for filling a relatively smaller airbag volume during the inflation process the vent is opened early and at the same time, for volume limiting, the limiting straps are clamped, wherein by means of the time of activation of the vent and hence of the limiting strap clamping an adaptivity, in particular an adapting of the airbag volume to the severity of the accident and/or to occupant parameters is able to be carried out, or this adaptation takes place by controlled opening of the second vent.

24. A method for controlling a safety arrangement according to claim 20, wherein in the pre-crash mode with the presence of a pre-crash activation signal, by activation of the gas generator with closed vent, the small airbag volume is filled and then, on reaching a particular internal pressure of the airbag, the tear seams or tear seam fields tear open, whereby the large airbag volume is filled and wherein in addition or alternatively the vent is at least partially opened, if applicable after or during the inflation process for adapting the airbag characteristic to the severity of the accident and/or to occupant parameters, or this adaptation takes place by controlled opening of a second vent, and that in the in-crash mode the vent is opened early for filling a relatively smaller airbag volume during the inflation process, wherein if applicable by a controlling of the vent opening in line with specific objectives, an adaptivity is achieved or this adaptivity takes place by controlled opening of the second vent.