WO2014106567A1

WO2014106567A1 - Airbag unit

Info

Publication number: WO2014106567A1
Application number: PCT/EP2013/076379
Authority: WO
Inventors: Jens Hoffmann; Nico Wallat; Raimund Nebel; Roland Peiz; Alexander Rottach; Jürgen Knauss; Andreas FÖRG; Holger Zang; Marcus Weber; Wolfgang DRÖSSLER
Original assignee: Autoliv Development Ab
Priority date: 2013-01-05
Filing date: 2013-12-12
Publication date: 2014-07-10
Also published as: DE102013000142A1; DE102013000142B4

Abstract

The invention relates to an airbag unit, comprising an airbag, an inflator unit, and a device for influencing the geometric shape and/or the ventilation state of the airbag. The influencing device comprises a hollow body (62), which has a predetermined breaking line (63) and extends from a first end to a second end. A pyrotechnic charge (74) is operatively connected to the interior of the hollow body. Upon the ignition of the pyrotechnic charge, the hollow body (62) breaks into a first section (62a) and a second section (62b) along the predetermined breaking line (63). At least part of the second section (62b) is accommodated in a passage opening of the assembly fixed to the vehicle and remains in said passage opening after the ignition of the pyrotechnic charge, while the first section (62a) is no longer rigidly connected to the assembly fixed to the vehicle. At the second end of the hollow body, the hollow body has an opening, through which a component (70) that bears the pyrotechnic charge is inserted into the hollow body (62) at least in some sections.

Description

Airbag unit

description

The invention relates to an airbag unit according to the preamble of claim 1.

Airbag units which have an influencing device for influencing the geometric shape and / or the ventilation state of the airbag are known in large numbers. Such influencing devices often have a drawstring or another tension element whose first end is connected to the airbag cover or a ventilation device, and the second end is connected in an initial state via a holding part with a vehicle-fixed component, such as the housing of the airbag module. The length of the drawstring is in this case selected so that it comes under fully expanded gas bag under tension, so that the shape of the airbag is affected or it brings a ventilation device in a predetermined state (usually the closed state) or holds. The holding part has a pyrotechnic charge or is in operative connection with it, so that upon ignition of the pyrotechnic charge, the holding part breaks or is separated from the vehicle-fixed component, so that the second end of the tension band is released, whereby the tension band loses its tension and Thus, the shape of the airbag or the state of the ventilation opening changes.

A generic airbag unit is described for example in WO 2012/130445 A1. Here, the holding part is designed as a hollow body, in which the pyrotechnic charge is arranged. This hollow body extends from a first end, which is connected to the drawstring, to a second end, which is fixedly connected to a vehicle-fixed component. For this purpose, the vehicle-mounted component has a passage opening into which the retaining element Part extends into it. The hollow body of the holding part has a predetermined breaking line, along which the hollow body breaks into a first and a second section when the pyrotechnic charge is ignited. The first section (which is connected to the drawstring) is thus free and the drawstring can no longer absorb tension.

The system described in the generic document basically works very well, but has the disadvantage that the holding part along with its pyrotechnic charge often quite early, namely together with the gas bag, on the housing or a housing-fixed component, must be mounted. For safety reasons, however, it is often preferable if it is possible to mount pyrotechnic charges only at a very late installation time. On this basis, therefore, the present invention has the object to develop a generic airbag unit to the effect that a late assembly of the pyrotechnic charge is made possible.

This object is achieved by an airbag unit having the features of claim 1.

According to the invention, the holding element is constructed at least in two parts, namely from a hollow body extending from a first end to a second end and from a component carrying the pyrotechnic charge. Here, the hollow body is open at its second end and the component carrying the pyrotechnic charge is at least partially inserted through this opening into the interior of the hollow body. Thus, the hollow body can be mounted together with the gas bag. The component carrying the pyrotechnic charge can then be mounted together with the pyrotechnic charge at any later time. The passage opening, in which the hollow body is received at least in sections, is preferably accessible from the outside, so that the component carrying the pyrotechnic charge can be mounted at the very end of the assembly process. Preferably, according to claim 3, the hollow body at its second end outwardly facing latching hook, so that the hollow body can be easily snapped into its through hole. In this case, the component carrying the pyrotechnic charge can secure the latching connection, so that disengagement after completed assembly is precluded.

To improve the mechanical stability, it may be preferable for the portion of the component carrying the pyrotechnic charge, which protrudes from the hollow body, to be received in a passage opening of a vehicle-fixed component. This may be the same passage opening in which the hollow body is received, or it may be a passage opening in another vehicle-fixed component. In this case, however, these components must generally be arranged rigidly relative to one another.

Further preferred embodiments of the invention will become apparent from the other dependent claims and from the embodiment now shown in more detail with reference to the figures.

The invention will now be explained in more detail using an exemplary embodiment with reference to the figures. Hereby show:

FIG. 1 shows a schematic section through an airbag unit according to the invention in an idle state,

FIG. 2 shows that shown in FIG. 1 after actuation of the gas generator and subsequent expansion of the gas bag, FIG. 3 shows that shown in FIG. 2 after actuation of a pyrotechnic charge and destruction of the holding part;

FIG. 4 the detail D from FIG. 1 in an enlarged view, FIG. 4 a shows a perspective view of a holding part which is very similar to that in FIG. 4, FIG. 5 shows a first step during assembly of the holding part on a housing-fixed component in a representation corresponding to FIG.

FIG. 6 shows that shown in FIG. 5 after completion of a first assembly step,

FIG. 7 shows the component shown in FIG. 6 and a component carrying a pyrotechnic charge,

FIG. 8 shows that shown in FIG. 7 after completion of the assembly,

FIG. 9 shows that shown in FIG. 8 after ignition of the pyrotechnic charge.

10 shows a second embodiment of the invention in a figure 8 corresponding representation,

FIG. 11 shows the state shown in FIG. 10 in a state corresponding to FIG. 9,

12 shows a third embodiment of the invention in a figure 8 corresponding representation and

FIG. 13 shows another application example of the invention in a representation corresponding to FIG. FIG. 1 shows an exemplary embodiment of a gas bag unit according to the invention, namely a driver gas bag module. This is basically constructed as usual, namely, it has a housing 20, a gas bag 10 which is folded into the housing 20 and a gas generator 25 serving as an inflator for filling the housing Airbag 10 on. Furthermore, a deflector-diffuser component 30 is provided, which fulfills a number of functions: Firstly, a bottom section 32 extending parallel to the housing bottom 22 of the housing 20 holds the gas bag 10 on the housing 20. Furthermore, a diffuser section 39 of the deflector-diffuser component 30 covers the gas generator 25 and thus prevents contact between the gas bag 10 and the gas generator 25. In the illustrated embodiment, the deflector-diffuser component 30 on a side wall portion 38, which also protects the gas bag in front of the gas generator 25 exiting hot gases in particular. Finally, the bottom portion of the deflector-diffuser component 30 has a raised portion 34 with a first through-opening 36. Housing 20 and deflector-diffuser component 30 form a vehicle-mounted assembly according to the definitions made herein.

The gas bag 10 has an adaptive ventilation device. This consists of a ventilation opening 12 and a nozzle 14, the first end of which surrounds the ventilation opening 12 and is connected to the gas bag 10. It is a drawstring 16 is provided, the first end of the second end of the spout 16 rotates and the second end is connected to a holding part 60. Such a ventilation device is known, for example, from US 2006/0071461 A1, so that it need not be further described here in detail. The holding part 60 is held in the first through hole 36.

The holding part 60 has a hollow body, in the interior of which a pyrotechnic charge is received. If this pyrotechnic charge ignited, so breaks the holding part 60 and the first end, that is, the end which is connected to the drawstring 16 is released. The basic mode of operation is exactly as in the generic text WO 2012/130445 A1, so that this document is hereby also explicitly referred to. Figure 2 shows the state which occurs when the gas bag 10 is completely filled after ignition of the gas generator 25, the holding member 60, however, is still intact. Here, the drawstring 16 is under tension and thus pulls the spout 14 together, so that the adaptive ventilation device in a closed or at least throttled state. Now, if the pyrotechnic charge ignited, so breaks the holding part 60 and the first portion 62 a of the holding part, which carries the second end of the tension band 16 is free, so that the tension band 16 loses its tension, the spout through the ventilation opening 12 after is slipped outside and thus the unthrottled state of the adaptive ventilation device is present (Figure 3).

With reference to Figure 4, the structure of the holding part 60 will now be explained in more detail. This Halteteii 60 has two elements, namely a hollow body 62 and the pyrotechnic charge 74-bearing member 70. The hollow body 62 has a side wall 68, a subsequent to this side wall 68 roof 64 and 64 carried by this roof bracket 66. By this bracket 66, the second end of the drawstring 16 is looped. The peripheral side wall 68 encloses a cavity H. Adjacent to the roof 64, the side wall 68 has a circumferential predetermined breaking line 63 which divides the hollow body 62 into a first (upper) section 62a and a second (lower) section 62b. In this case, the first section 62a substantially comprises the bracket 66 and the roof 64, while the second section 62b essentially comprises the side wall 68.

According to the definitions made here, the upper end of the bracket 66 forms the first end of the hollow body, while the end of the side wall 68 facing away from the roof 64 forms the second end of the hollow body 62. The hollow body 62 is not closed at its second end, ie the side wall 68 surrounds an opening. In the preferred embodiment shown, the side wall carries on the second end of the hollow body outwardly facing latching hooks 69. With these latching hooks 69 of the hollow body 62 is locked in the mounted state in the first passage opening 36 of the bottom portion 32 of the deflector-diffuser component 30. Since it is necessary for this that the bottom portion 32 of the deflector diffuser component 30 is slightly spaced from the housing bottom 22, the bottom portion 32 around the first passage opening 36 around a raised portion 34, as in Figures 1 to 3 also good to see and has already been described. As can be seen from FIG. 4a, which shows a holding part 60 which is very similar to the holding part of FIG. 4, axial slots 68a can be provided which extend from the second end of the hollow body 62 into the side wall 68 in order to provide the necessary elasticity so that the hollow body 62 can be snapped into the first through hole 36.

The housing bottom 22 also has a through opening opposite the first through opening 36, which is referred to here as the second through opening 27. Through this second passage opening 26, a component 70 carrying the pyrotechnic charge 74 extends into the cavity H of the hollow body 62 in such a way that the pyrotechnic charge 74 is arranged in the cavity H. The component 70 carrying the pyrotechnic charge preferably has a shoulder which rests against the second end of the hollow body 62 so that the hollow body 62 and the component 70 have a defined position relative to one another. Hollow body 62 and the pyrotechnic charge-carrying component 70 form the holding part 60. Both the hollow body 62 and the component 70 are each one-piece plastic injection molded parts.

With reference to FIGS. 5 to 8, the assembly of the holding part 60 on the vehicle-fixed assembly formed by the housing 20 and deflector-diffuser component 30 will now be explained. First, the hollow body 62 is latched by means of the latching hooks 69 in the first through-opening 36, as a result Hollow body 62 is partially held in this first passage opening 36. The second end of the drawstring 16 can already be looped through the bracket 66 at this time. FIG. 6 shows this state.

Once the hollow body is latched in the first passage opening 36, the gas bag module can be mounted almost almost finished, in particular, then the gas bag can be folded into the housing, etc. At any later time, now the pyrotechnic charge 72-bearing member 70 by the second Passage opening 26 is pushed until the front portion of the component 70 enters the cavity H of the hollow body 62. This closes the Component 70, the opening of the hollow body 62. To connect the hollow body 62 and component 70 may be applied to the component 70 previously adhesive, or it may be provided a second, inner latching connection. Alternatively, it would be possible for the component 70 to be held in position solely by a connection to the housing bottom 22. Combinations of the just listed possibilities as well as further connection possibilities are possible. Hereby, the connection is completed and it is the corresponding state in Figure 8 (corresponds to Figure 4) before. Characterized in that a portion of the component 70 is located within the hollow body 62 and in this case preferably at least partially abuts the inside of the side wall 68, a unlatching of the hollow body is excluded even at high tensile load by the tension band 16, since the side wall 68 not after can dodge inside.

If the pyrotechnic charge 74 is ignited by means of the ignition cable 76 assigned to it, the overpressure prevailing in the cavity destroys the hollow body 62 along its predetermined breaking line 63, as a result of which the first section 62a is separated from the second section 62b, so that the second end of the tension band 16 no longer exists firmly connected to the vehicle-mounted assembly. The second section 62 b of the hollow body 62 remains in the first through-opening 36 and remains connected to the component 70.

FIGS. 10 and 11 show a second embodiment of the invention in a representation corresponding to FIGS. 8 and 9. The basic structure is as in the first embodiment. The difference from the first embodiment is that the pyrotechnic charge 74 is surrounded by a deformable cap 78 connected to the component 70 carrying the pyrotechnic charge. This deformable cap 78 may in particular be made of sheet metal. In the initial state (FIG. 10), this deformable cap 78 is turned inside out and is pushed outwards by the pressure which arises when the pyrotechnic charge is ignited, so that it tears off the first section 62a from the second section 62b of the hollow body 62 (FIG 1 ). Here, the deformable cap 78 remains connected to the component 70 and intact, so that no explosive gases of the pyrotechnic charge 74 from the Can escape from the cap 78 and component 70 enclosed cavity and no open flames occur.

FIG. 12 shows a third exemplary embodiment. The difference from the first two embodiments is that the component 70 carrying the pyrotechnic charge is constructed in two parts, namely a first element 70a and a second element 70b. Here, the first element 70a directly carries the pyrotechnic charge 74 and the second element 70b acts as a connecting element, which is essentially a hollow tube with a flange. In the geometry, as shown in FIG. 12, it is possible for the second element to be held between the first element 70a and the hollow body 62 without a material connection, in particular in a clamping manner. Due to the two-part construction of the component carrying the pyrotechnic charge, a simplification of the assembly may result in some applications. In a two-part construction of the component 70, the pyrotechnic charge (74) will generally be located outside the hollow body 62 and be in operative connection with the interior of the hollow body 62 via the second element 70b. It should also be noted that even with a one-piece construction of the component 70 (first embodiment) it would be possible to arrange the pyrotechnic charge outside the hollow body 62. In cases in which the pyrotechnic charge (74) is arranged outside the hollow body 62, the component carrying the pyrotechnic charge must also be designed, at least in sections, as a hollow body. Of course, the use of a deformable cap 78 is also possible with a two-part component 70.

In the example of application described above, the holding part which can be destroyed by the pyrotechnic charge is used to control an adaptive valve. Of course, this is not the only possible use, in particular, this holding element is also very well suited for controlling the deployment depth of a gas bag. This is shown in FIG. In particular, it is also possible that the two ends of the drawstring 16 are firmly connected to the airbag 10 and the drawstring 16 through the eyelet formed by the bracket 66 It would, however, be possible that one end of the drawstring is connected to the airbag cover and one end of the drawstring is connected to the retainer.

LIST OF REFERENCE NUMBERS

10 airbag

12 ventilation opening

14 grommet

16 drawstring

20 housing

22 caseback

23 opening in the housing bottom

25 gas generator

27 second passage opening

30 deflector diffuser component

32 floor section

34 increased range

36 first passage opening

38 side wall section

39 Diffuser section

60 holding part

62 hollow body

62a first (upper) section

62b second (lower) section

63 predetermined breaking line

64 roof

66 straps

68 side wall

68a axial slot

69 locking hooks

70 carrying pyrotechnic charge

70a first element

70b second element

72 bore

74 pyrotechnic charge

76 ignition cable

78 deformable cap

Claims

claims

1. Airbag unit with

an airbag (10),

an inflator unit for filling the gas bag (10),

a vehicle-mounted assembly to which the gas bag (10) is connected, and

an influencing device for influencing the geometric shape and / or the ventilation state of the airbag, the influencing device having a predetermined breaking line (63) extending from a first to a second end hollow body (62), with its interior a pyrotechnic charge ( 74) is operatively connected to the ignition of the hollow body (62) along the predetermined breaking line (63) in at least one first end having the first portion (62 a) and in a second end having second portion (62 b) breaks, said

at least a part of the second portion (62b) is received in a passage opening (36) of the vehicle-fixed assembly and remains in this after ignition of the pyrotechnic charge and

the first section (62a) after ignition of the pyrotechnic charge is no longer rigidly connected to the vehicle-mounted assembly,

characterized in that the hollow body (62) has at its second end an opening through which a pyrotechnic charge-carrying component (70) at least partially inserted into the hollow body (62) is inserted.

2. Airbag unit according to claim 1, characterized in that the pyrotechnic charge-carrying component (70) closes the opening of the hollow body (62).

3. Airbag unit according to one of the preceding claims, characterized in that the side wall (68) of the hollow body (62), preferably adjacent to the opening, outwardly facing latching hooks (69) has, by means of which the hollow body (62) is latched in the passage opening (36).

4. Airbag unit according to claim 3, characterized in that the side wall (68) extending from the opening axial slots (68 a).

5. Airbag unit according to one of claims 3 or 4, characterized in that the pyrotechnic charge-carrying component (70) secures the latching hooks (69) against unlatching.

6. Airbag unit according to one of the preceding claims, characterized in that the pyrotechnic charge-carrying component (70) extends through a further passage opening (23) of the vehicle-fixed assembly.

7. Airbag unit according to one of the preceding claims, characterized in that at least the hollow body is an injection molded part made of plastic.

8. Airbag unit according to one of the preceding claims, characterized in that the pyrotechnic charge-carrying component (70) is integrally formed.

9. Airbag unit according to one of claims 1 to 7, characterized in that the pyrotechnic charge-carrying component (70) is formed at least in two parts.

10. Airbag unit according to one of the preceding claims, characterized in that the pyrotechnic charge (74) is located within the hollow body (62).

1 1. The gas bag unit according to one of claims 1 to 10, characterized in that the pyrotechnic charge (74) is located outside the hollow body (62).

12. Airbag unit according to one of the preceding claims, characterized in that the pyrotechnic charge (74) is surrounded by a deformable cap (78) connected to the component (70) carrying the pyrotechnic charge.