DE102015005482B4 - Gas bag with an adaptive ventilation device - Google Patents

Abstract

Gas bag (10) with at least one adaptive ventilation device, with: a gas bag skin (12) which has an impact surface (P) and at least one ventilation opening (16, 16'), a tension element ( 30, 30'), a cover element (20, 20') arranged outside the airbag skin (12) and assigned to the ventilation opening (16, 16'), a first end of the tension element (30, 30') being permanently connected to the airbag skin (12 ) or is detachably or separably connected to a holding element and a second end of the pull element (30, 30') is permanently connected to the cover element (20, 20') and wherein when the pull element (30, 30') is tensioned, the cover element (20, 20 ') the ventilation opening (16, 16') throttles more than when the tension element (30, 30') is not tensioned, the covering element (20, 20') around the ventilation opening (16, 16') being connected to the airbag skin (12) with a fully closed connection is connected, so that by d The geometric surface of the airbag skin (12) enclosed by the connection has a first surface area, and the cover element (20, 20') has at least one flow opening (23), characterized in that the cover element (20, 20') is a cone which consists of a slotted , circular blank (22, 22') is produced in that the slit of the blank (22, 22') is closed by means of a conical seam (40), so that the geometric surface of the cover element (20, 20') enclosed by the connection has a second surface area which is greater than the first surface area.

Description

The invention relates to a gas bag with an adaptive ventilation device according to the preamble of claim 1.

Almost every front airbag assigned to the upper body of an occupant (usually referred to as a driver airbag or passenger airbag) has a ventilation device through which gas can flow out when the upper body of the occupant to be protected hits the airbag cover of the airbag. In the simplest case, this ventilation device consists of a ventilation opening in the airbag skin. The disadvantage of this is that gas is already lost during inflation and before the occupant hits the ground, which necessitates the use of correspondingly more powerful gas generators.

the FR 2 757 465 A1 therefore proposes a passively controlled ventilation device which at least throttles the outflow of gas from the airbag skin before it hits the occupant to be protected and which goes into an unthrottled state when the occupant hits the impact surface of the airbag skin. In addition to the ventilation opening in the airbag skin, this passively controlled ventilation device has a tension element assigned to this ventilation opening and a covering element. A first end of the tension element is connected to the inside of the impact wall (the outside of which forms the impact surface) of the airbag skin and the second end of the tension element is connected to the cover element. The cover element is located outside of the airbag skin and the diameter of this cover element is larger than the diameter of the ventilation opening. The tension element thus extends through the ventilation opening and its length is dimensioned such that it is under tension when the airbag skin is fully expanded and free from external forces and thus pulls the cover element from the outside onto the region of the airbag skin bordering the ventilation opening, so that the ventilation opening is closed accordingly. If the occupant then dives into the airbag skin, the distance between the impact surface and the ventilation opening is reduced, as a result of which the tension element is no longer under tensile stress and the cover element loses contact with the airbag skin. In this state, gas can then flow out through the ventilation opening.

The generic DE 10 2005 046 623 A1 proposes a gas bag with two opposing ventilation openings. The shell of the airbag is designed in two layers in the area of the ventilation openings, with the respective inner layer having a ventilation opening and the respective outer layer having a flow-through opening. The two outer layers are connected to each other by means of a tether.

In the DE 10 2012 105 959 A1 an airbag is proposed in which a cover element is placed on the outside of the airbag skin and spans a ventilation opening in the airbag skin. The cover element is only partially connected to the airbag skin, so that the gas escaping from the ventilation opening can flow out between the airbag skin and the cover element.

The following invention sets itself the task of improving a generic gas bag in such a way that its suitability for practical use is improved. In particular, the reproducibility of the behavior of the airbag when inflated and when the occupant hits it should be improved.

This problem is solved by an airbag with the features of claim 1 .

The cover element is connected to the airbag skin in any state, ie permanently, with a peripheral connecting line, in particular a peripheral connecting seam, serving as the connection. This peripheral connecting line is completely closed and can be designed as a circular line, which is preferable. In order to nevertheless allow gas to flow out, on the one hand the surface area of the geometric surface of the gas bag envelope enclosed by the connection is smaller than the surface area of the geometric surface of the cover element enclosed by the connection. On the other hand, the cover element has at least one through-flow opening. The following definition applies here: In this application, the content of the geometric area is understood to mean the total area, including ventilation or through-flow openings.

The improvement according to the invention ensures in particular that the gas bag behaves in a very reproducible manner.

According to the invention, the covering element has the shape of a cone, which is produced from a slit, circular blank, in that the slit of the blank is closed by means of a cone-shell seam.

The at least one ventilation opening is preferably arranged centrally and a plurality of through-flow openings are provided, which are arranged around the at least one ventilation opening with respect to a vertical projection.

In order to avoid gas accumulation between the airbag skin and the cover element, the total area of the through-flow openings is preferably larger than the total area of the ventilation opening or ventilation openings.

Because of the higher level of operational safety and because it is easier to manufacture, the connection with which the cover element is connected to the airbag skin is preferably completely closed and more preferably has the shape of a circle.

A further goal is to further develop the ventilation device in such a way that the ventilation opening can be arranged in a lateral area of the airbag skin. In order to be able to achieve this, it is preferable for the tension element to be configured in a T-shape with three ends, with the third end also being permanently connected at least indirectly to the airbag skin. It is preferable here for the first end of the tension element to be connected to the inside of the impact wall of the airbag skin and for the third end to be connected to the airbag skin opposite the first end, in particular in the area of a gas generator opening.

In order to prevent one-sided and thus asymmetrical ventilation, it is preferable for two ventilation devices to be provided, which are arranged and designed symmetrically with respect to the airbag skin.

In one embodiment, the gas bag according to the invention is assigned to two adjacent seats, which means that in this case its impact surface is designed to be very wide, in particular with a width of more than one meter. In this case in particular, it is preferred that two ventilation devices are provided, which more preferably are independent of one another. In this way, it can be achieved that the ventilation capacity is greater (essentially twice as large) when there are two occupants immersed than when there is only one occupant immersed, so that the airbag behaves essentially the same for each occupant to be protected, regardless of whether he is a next-seat passenger has or not.

The ventilation device according to the invention is particularly suitable for being designed to be passive. In this case, the first end of the tension element is permanently connected to the airbag skin. However, it is also possible to design the ventilation device to be active. In this case, either a separating device is available, which cuts through the tension element (usually a tension strap) as required (such as from the U.S. 2009/0 302 588 A1 known), or the second end of the pulling element is detachably connected to a holding device (such as from DE 10 2012 003 344 A1 known).

Further preferred embodiments of the invention result from the further dependent claims.

• 1 sämtliche für die Erfindung wesentlichen Zuschnitte eines Gassacks eines ersten Ausführungsbeispiels der Erfindung,
• 2 einen Zuschnitt eines Abdeckelementes aus 1 in einer vergrößerten Darstellung,
• 3 ein aus dem Zuschnitt der 2 erhaltenes Abdeckelement und einen ersten Zuschnitt eines Zugelementes, welches mit dem Abdeckelement verbunden ist,
• 4 das in 3 Gezeigte nach dem Aufnähen des Abdeckelementes auf die Gassackhülle,
• 5 einen Schnitt entlang der Ebene A-A in 4 in einem Zustand, in welchem das Zugelement nicht unter Zugspannung steht, insbesondere wenn Gas durch die Ventilationsöffnung abströmt,
• 6 das in 5 Gezeigte, wenn das Zugelement unter Zugspannung steht und somit die Ventilationsöffnung verschlossen ist,
• 7 eine schematisierte perspektivische Darstellung des aus den Zuschnitten der 1 hergestellten Gassackes,
• 8 einen Schnitt entlang der Ebene B-B in 7,
• 9 das in 8 Gezeigte nach Auftreffen eines Insassen auf die Prallfläche der Gassackhülle,
• 10 ein zweites Ausführungsbeispiel der Erfindung in einer der 8 entsprechenden Darstellung,
• 11 ein drittes Ausführungsbeispiel der Erfindung in einer der 8 entsprechenden Darstellung,
• 12 einen Gassack mit einer alternativen Ausgestaltung der Ventilationseinrichtung in einer der 7 entsprechenden Darstellung,
• 13 einen Gassack, welcher grundsätzlich wie der Gassack der 8 ausgestaltet ist, jedoch eine Prallfläche mit großer Breite aufweist, so dass er zwei nebeneinander sitzenden Insassen zugeordnet ist,
• 14 den Gassack aus 13 in einem Zustand, wenn zwei Insassen in die Prallfläche eintauchen,
• 15 den Gassack aus 13 in einem Zustand, wenn ein Insasse in die Prallfläche eintaucht,
• 16 eine Ausführungsform der Erfindung mit einer aktiv gesteuerten Ventilationseinrichtung in einem Zustand, in welchem das Zugelement unter Zugspannung steht, sodass die Ventilationsöffnung durch das Abdeckelement verschlossen ist und
• 17 das in 16 Gezeigte bei durchtrenntem Zugelement, so dass Gas durch die Ventilationsöffnung und durch das Abdeckelement abströmt.

The invention will now be explained in more detail using exemplary embodiments with reference to the figures. Here show:

• 1 all cuts of a gas bag of a first exemplary embodiment of the invention that are essential for the invention,
• 2 a blank of a cover element 1 in an enlarged view,
• 3 one from the cut of the 2 obtained cover element and a first blank of a tension element, which is connected to the cover element,
• 4 this in 3 Shown after the covering element has been sewn onto the gas bag cover,
• 5 a section along the plane AA in 4 in a state in which the tension element is not under tension, in particular when gas is escaping through the ventilation opening,
• 6 this in 5 Shown when the tension element is under tension and thus the ventilation opening is closed,
• 7 a schematic perspective view of the blanks of 1 manufactured gas bag,
• 8th a section along the plane BB in 7 ,
• 9 this in 8th Shown after an occupant hits the impact surface of the airbag cover,
• 10 a second embodiment of the invention in one of 8th corresponding representation,
• 11 a third embodiment of the invention in one of 8th corresponding representation,
• 12 a gas bag with an alternative embodiment of the ventilation device in one of 7 corresponding representation,
• 13 a gas bag, which basically like the gas bag 8th is designed, but has an impact surface with a large width, so that it is assigned to two occupants sitting next to each other,
• 14 off the gas bag 13 in a condition when two occupants are immersed in the impact surface,
• 15 off the gas bag 13 in a condition when an occupant plunges into the impact surface,
• 16 an embodiment of the invention with an actively controlled ventilation device in a state in which the tension element is under tension, so that the ventilation opening is closed by the cover element and
• 17 this in 16 Shown with the tension member severed so that gas escapes through the ventilation opening and through the cover member.

the 1 shows all the cut-outs of a first exemplary embodiment of a gas bag according to the invention that are essential for explaining the invention. In practice, of course, there can be more cuts, such as for reinforcement layers or for additional tethers, but these are not shown here.

Three blanks are provided for the outer shell of the gas bag, namely two lateral blanks 14, 14' of the same shape, which form the side walls S, S' when the gas bag is sewn, and a middle blank 18. The lateral blanks 14, 14' each have a ventilation opening 16, 16' for the passively controlled ventilation device. In principle, further ventilation openings could also be provided, but these are not shown. A gas generator opening 19 is provided in the middle section 18 .

For each ventilation opening 16, 16' there is a blank 22, 22' for a cover element. These two blanks 22, 22' are also of the same shape. On the blanks for the cover later with reference to 2 until 6 in more detail. Each of the passively controlled ventilation devices also has a traction element. In the exemplary embodiment shown, these are T-shaped and are each composed of a first blank 32, 32' and a second blank 34, 34'. Of course, it would also be possible to produce corresponding T-shaped tension elements in one piece, but this is generally not preferred for production reasons (waste).

the 2 shows a blank 22 of a cover element 20 in an enlarged view. This blank 22 is in the shape of a circle with a cut out "pie-shaped" segment. Furthermore, 22 through-flow openings 23 are in the blank 23 - in the embodiment shown, four - provided. These through-flow openings 23 are arranged at the edge; there is no through-flow opening in the middle of the blank.

the 3 shows the cut 2 after two work steps, which can also coincide, have been carried out: On the one hand, the slit of the blank was closed by means of a conical jacket seam 40, so that a conical covering element 20 was formed from the blank 22. Furthermore, the first blank 32 of the tension element associated with the cover element was connected to the cover element 22, for which purpose a connecting seam 42 is used. In principle, the cone shell seam 40 and the connecting seam 42 can be sections of a continuous seam. The first blank 32 of the pull element is preferably connected to the cover element 20 in the middle.

In a next step, the now conical cover element 20 is connected to the outer shell 12 in such a way that the ventilation opening 16 is located below the tip of the conical cover element 20 and (in a vertical projection) the flow openings 23 are arranged around the ventilation opening 16. At this point it should be noted that instead of one ventilation opening 16 there could also be several ventilation openings, with the provision of a central ventilation opening 16 being preferred. the 5 shows the section along the plane AA 4 . It is easy to see here that the total area of the cover element 20 (including the through-flow openings 23) enclosed by the circumferential seam 44 is larger than the surface of the outer shell 12 enclosed by the circumferential seam 44 (likewise including the ventilation opening 16). This also means that gas can easily flow from the ventilation opening 16 to the through-flow openings 23 when the first blank 32 of the tension element is not under tension, since the conical shape of the cover element 20 is formed in this case. It can also be seen that the pulling element, namely its first blank 32, extends through the ventilation opening 16.

If the first blank 32 of the tension element 30 is under tension, as is shown in 6 is shown, the covering element 20 is pressed onto the outer shell 12 (ie the lateral blank 14 here), with the covering element 20 even being able to bulge slightly in the region of the ventilation opening 16 . This results in a good seal and little or no gas can flow out through the ventilation opening 16 .

7 shows the airbag 10 with a fully expanded outer shell 12 before the impact of the to protective occupants. It can be seen that the exemplary embodiment shown is a front passenger airbag. The cover elements (only the cover element 20 can be seen) are each in a state as shown in 6 is shown.

the 8th shows a section along the plane BB in 7 , in which one can also see the arrangement of the tension elements 30, 30'. It can be seen that the two tension elements 30, 30' are essentially T-shaped, such that the first blanks 32, 32` each form one bar of the T and the second blanks 34, 34' form the other bar of the T. In principle, as already mentioned, it would also be possible to produce the tension elements in one piece, so that the blanks could then be referred to as sections. However, from a production point of view, a one-piece production is generally not to be preferred.

How to in particular 8th removes, the first end of a tension element 30, 30' is connected to the inside of the baffle wall of the outer shell 12, in particular sewn. The opposite third end of the tension element 30, 30' is connected to the outer shell 12 in a region of the outer shell 12 opposite the impact surface P, for example in the region of the gas generator opening 19, in particular also sewn. As already mentioned, the second ends of the tension elements are connected to the cover elements 20, 20'. In this case, the first and second blanks connected to one another preferably extend essentially perpendicularly to one another. The geometry is chosen so that when the airbag skin 12 is fully expanded and free from external forces, the tension elements—and in this case both the first and the second blanks—are under tension, so that the 6 and 8th shown state, in which the cover elements 20 close the ventilation openings 16, 16'.

If the occupant I now dives into the impact surface P ( 9 ) the tension elements 30, 30` lose their tension and the cover elements 20, 20' are deformed into their cone shape by the gas pressure (see also 5 ) pressed, in which gas can flow through the ventilation openings and the flow openings. In this case, the cover elements 20, 20' remain connected to the airbag skin 12 of the airbag via their circumferential seam 44, so that a defined, free cross-section is established.

10 shows an alternative embodiment in one of 8th corresponding representation. Here the second blanks 34, 34' of the tension elements 30, 30' are connected by means of a connecting blank 36. Alternatively (although not shown), it would also be possible, starting from the connection blank 36, to provide a common blank for the baffle wall. It is also possible, for example, for the second blanks 34, 34' to be as in 11 shown cross in an X-shape or that they (not shown) are arranged in a V-shape.

By configuring the tension elements with three ends each, in particular as shown and illustrated, it is easily possible to arrange the ventilation openings in a lateral area of the airbag skin.

As in 12 shown, the through-flow openings 23 can also be arranged asymmetrically in the cover elements, in particular in such a way that the exiting gas flow is deflected away from the impact surface P and thus from the occupant, in particular in the direction of the dashboard, windshield or headliner.

the 13 shows an airbag 10, which is basically like the airbag 8th is constructed. It therefore has two ventilation devices which are independent of one another and whose ventilation openings are arranged in the side walls S, S'. The airbag 10 is intended to be assigned to two seats, so that its impact surface P has a large width (that is, when installed, it extends in the transverse direction of the vehicle) of more than one meter.

If both seats assigned to the gas bag (here it can be two individual seats or areas of a seat bench) are occupied, in the event of a frontal crash both occupants I, I' dive into the impact surface P, so that both tension elements 30, 30' lose tensile stress and gas can flow out through both ventilation openings 16, 16` as described above. The maximum ventilation is thus set automatically ( 14 ). If there is only one occupant (in 15 the right-hand seated occupant I'), he actuates only the ventilation device assigned to him when he hits the impact surface, while the other ventilation device remains inactive. This also reduces the ventilation compared to the case that two occupants fall into the impact surface. In this way, essentially the same softness of the airbag is produced in each case, regardless of whether one or two occupants are to be cushioned. In order to achieve an ideal decoupling of the two ventilation devices, it is preferred (as shown) if the first ends of the tension elements are connected to the inside of the baffle wall (the outer surface of which forms the baffle surface P) in such a way that the respective connection point is symmetrical with respect to the occupants is positioned. A permanently open airbag can also be used in such a two-person airbag Ventilation opening can be provided in the airbag skin.

So far, only exemplary embodiments of an embodiment have been described in which the ventilation device or the ventilation devices are passively controlled. According to a second embodiment of the invention, however, it is also possible to apply the invention to gas bag units with an active ventilation device for the gas bag. An embodiment of this second embodiment of the invention is in the 16 and 17 shown. Here the first end of the tension element 30 designed as a tension band is connected to the bottom of a gas bag housing 52, which also serves as a holding element for this first end. Adjacent to its first end, the drawstring passes through a separator such as that shown in US Pat US2009/0302588 A1 is described. If the airbag skin is fully expanded and the tension element 30 is not severed, it is under tension so that the cover element 20 closes the ventilation opening 16 . In response to an external signal, the separating device 54 severs the tension band (tension element 30) so that it loses its tension and gas can thus flow out through the ventilation opening 16 as described above. Alternatively, the second end of the pulling element 30 can also be detachably connected to a holding element, as is the case, for example, in FIG DE 10 2012 003 344 A1 is described.

reference list

10

gas bag

12

airbag cover

14, 14'

side crop

16, 16'

ventilation opening

18

medium cut

19

gas generator opening

20, 20'

cover element

22, 22'

Cutting the cover element

23,

flow opening

30, 30'

tension element

32, 32'

first cut

34, 34'

second cut

36

connection cutting

40

conical seam

42

connecting seam

44

circumferential seam

50

gas generator

52

gas bag housing

54

separator

P

baffle

S, S'

Side wall

I, I'

inmate

Claims (11)

Gas bag (10) with at least one adaptive ventilation device, with: a gas bag skin (12) which has an impact surface (P) and at least one ventilation opening (16, 16'), one of the at least one ventilation opening (16, 16') assigned tension element ( 30, 30'), a cover element (20, 20') arranged outside the airbag skin (12) and assigned to the ventilation opening (16, 16'), a first end of the tension element (30, 30') being permanently connected to the airbag skin (12 ) or is detachably or separably connected to a holding element and a second end of the pulling element (30, 30') is permanently connected to the covering element (20, 20') and wherein when the pulling element (30, 30') is tensioned, the covering element (20, 20') throttles the ventilation opening (16, 16') more than when the tension element (30, 30') is not tensioned, the cover element (20, 20') being connected to the airbag skin (12) around the ventilation opening (16, 16') is connected with a fully closed connection, so that the The geometric surface of the airbag skin (12) enclosed by the connection has a first surface area, and the cover element (20, 20') has at least one flow opening (23), characterized in that the cover element (20, 20') is a cone which consists of a slit, circular blank (22, 22'), in that the slit of the blank (22, 22') is closed by means of a cone-shaped seam (40), so that the geometric surface of the covering element (20, 20 ') has a second surface area which is larger than the first surface area. gas bag after claim 1 , characterized in that the adaptive ventilation device is passively controlled, so that the first end of the tension element (30, 30 ') is permanently connected to the airbag skin (12). The gas bag according to one of the preceding claims, characterized in that the cover element (20, 20') has a plurality of flow openings (23) which are arranged around the ventilation opening (16) in relation to the vertical projection onto the area defined by the ventilation opening (16). are. gas bag after claim 3 , characterized in that the total area of the flow openings (23) is larger than the total area of all ventilation openings (16) surrounded by the connection. The gas bag according to one of the preceding claims, characterized in that the tension element (30, 30') is T-shaped with three ends, the third end also being at least indirectly permanently connected to the gas bag skin (12). gas bag after claim 5 , characterized in that the first end of the tension element (30, 30') is connected to the airbag skin (12) on the inside of the impact wall of the airbag skin (12) having the impact surface (P) and in that the third end is connected opposite the first end is. Gas bag according to one of the preceding claims, characterized in that two ventilation devices arranged symmetrically with respect to the gas bag skin (12) are provided. gas bag after claim 7 , characterized in that the two ventilation openings (16, 16') are arranged in opposing side walls (S, S') of the gas bag (10). gas bag after claim 7 or claim 8 , characterized in that the two ventilation devices are independent of each other. gas bag after claim 9 , characterized in that the gas bag is a gas bag to protect at least two people, the impact surface (P) has a width of at least one meter. Gas bag according to one of the preceding claims, characterized in that the through-flow opening (23) or the through-flow openings (23) is/are arranged in such a way that the gas flow is deflected away from the impact surface (P) of the airbag skin.

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