Airbag unit, in particular head side airbag unit

Abstract

A safety airbag unit having a safety airbag (22) folded or wound into an oblong package and a wrapper (28) holding the package in the folded state, the safety airbag unit having a folded back longitudinal end (36) of the package. In addition to a first tear line (32) by which the safety airbag (22) emerges from the wrapper (28), the wrapper (28) has a second tear line (50) in the region of a bend location (38), which second tear line effects a better flow of gas towards the folded back package section (40).

Description

Technical Field

[0001] The present invention relates to an airbag unit, particularly a head-side airbag unit, which has an airbag that folds or rolls into an elongated package and a sealing element that holds the package in a folded state. Background Technology

[0002] These airbag units are installed in vehicles, specifically as so-called curtain-like side head airbag units. When inflated, these head airbag units cover at least a majority of one or more side windows of the front occupant and the rear occupant seated behind them. The airbags prevent side impacts and are longitudinally folded or rolled up, meaning the package has a longitudinal crease or roll-up axis extending parallel to the longitudinal direction of the airbag. In other words, measured along the vehicle's longitudinal direction (relative to the installed state), the length of the package corresponds to the length of the deployed airbag. Typically, these airbag units are mounted above the side windows along the roof frame and may also be mounted below the trim panel along one or two pillars. The package holds the airbag in its folded or rolled-up state, thereby simplifying assembly. Summary of the Invention

[0003] However, there are specific installation situations where the package is difficult to extend, meaning that installation at its extended length may be difficult, for example due to limited space in the pillar area. Therefore, according to the invention, this longitudinal end of the package, together with the encapsulation surrounding the package (which encapsulates the package like a sausage casing), folds back in a U-shape at the bend. Thus, when the encapsulation tears due to the internal pressure in the airbag during a triggering event, the folded-back airbag section returns to its initial position, i.e., its unbent position, and covers an additional section of the vehicle to provide safety there as well.

[0004] For the airbag to deploy and retract rapidly in the folded-back section, it is crucial that gas flow quickly through the interior of the package into this folded-back section. This is typically difficult because the folded-back section is at least temporarily secured to the rest of the airbag unit by fastening devices. The object of this invention is to provide an airbag unit that can be variably installed.

[0005] This objective is achieved in an airbag unit of the type described at the beginning in the following manner: the longitudinal end of the package, together with the surrounding flexible encapsulation, is folded back at the bending position to form a U-shape, wherein the U-shape is formed by the airbag unit, the folded-back package section and the encapsulation surrounding the folded-back section, and the remainder of the airbag unit, wherein the encapsulation has a predetermined first tear line extending along the length of the airbag unit, and the airbag is exposed from the encapsulation by the first tear line when deployed, wherein the encapsulation has an additional predetermined second tear line in the region of the bending position.

[0006] While current encapsulations for such elongated airbag units typically have only a single tear line extending along the entire length of the airbag package, this invention incorporates an additional pre-designed weakening in the folded area. This weakening allows the airbag to expand more easily in the folded area because the encapsulation is easier to open than in the prior art. The folded area also expands the flow channels formed during gas inflow within the airbag, which is not yet fully deployed or has barely expanded, at the beginning of the inflation process. This allows gas to flow into the folded-back package section more rapidly than in previous methods, resulting in faster deployment of the package section and tearing of the first tear line.

[0007] Preferably, the second tear line extends on the wall sections of the package facing each other. By folding back the longitudinal ends of the package, the two sections of the package are close to or side by side, and the second tear line is subsequently provided in these wall sections facing each other.

[0008] The second tear line should extend in the longitudinal direction of the package, and especially only in the longitudinal direction of the package, i.e., along the fold line or along the winding axis. This achieves faster tear performance.

[0009] The second tear line can also be circumferentially spaced from the first tear line along its entire length. This ensures that the encapsulation opens independently of each other at the first and second tear lines.

[0010] The second tear line should extend for at least 60%, particularly at least 75%, of the length of the folded-back package section to allow gas flow up to the longitudinal end of the airbag.

[0011] Furthermore, it is advantageous that the second tear line extends from the bend position for the same length as the section along the encapsulation starting from the bend position. This should result in the deployed airbag being more visible from the encapsulation on one side of the encapsulation than on the other side in the region of the second tear line.

[0012] To ensure that the airbag protrudes from the airbag along its entire length at the first tear line and deploys downwards toward the bottom of the vehicle, the second tear line should extend only along a portion of the folded-back enclosure, starting from the bend position, and not along the entire enclosure. This ensures that the end of the airbag exits the enclosure at the first tear line, and not entirely only at the second tear line.

[0013] The airbag unit according to the invention may further include a gas generator, which is connected to the airbag in terms of flow at the middle third of the longitudinal extension dimension of the folded airbag unit. The gas generator then produces gas, which preferably diffuses forward and backward in opposite directions from this middle third.

[0014] Fastening devices may be provided, by means of which the folded-back section of the airbag unit is secured to or more generally fixed relative to the rest of the airbag unit. Here, for example, a strap or clip fastened to the vehicle may be provided. An alternative possibility is that the folded-back section of the encapsulation is secured to the rest of the encapsulation. The installation position is determined within a narrow range by the fastening devices.

[0015] The airbag unit according to the invention is particularly a curtain-like head side airbag for covering at least a portion of the side windows of the assigned vehicle, especially a shared airbag for front and rear occupants, i.e., the airbag extends over the side windows assigned to the front and rear occupants.

[0016] Encapsulations are particularly flexible tubes made of, for example, textile materials, which can be manufactured in such a way that the encapsulation is arranged around the package and then sewn together.

[0017] The first tear line and / or the second tear line can be a perforation in the encapsulation or a tear-type seam in the encapsulation.

[0018] In order to predetermine the timing of the opening process of the encapsulation, the encapsulation is preferably more vulnerable at the second tear line than at the first tear line, at least in the section extending alongside the second tear line. Thus, the encapsulation breaks at the second tear line, and subsequently, the section of the first tear line extending alongside the second tear line (i.e., extending in the same longitudinal section as the first tear line) breaks. Attached Figure Description

[0019] Other features and advantages of the invention will become apparent from the following description and accompanying drawings, with reference to the following description and accompanying drawings. In the drawings:

[0020] Figure 1 A schematic side view of the interior space of a vehicle equipped with an airbag unit according to the present invention is shown.

[0021] Figure 2 The side view shows the results according to Figure 1 A schematic view of the airbag unit according to the invention in its extended state.

[0022] Figure 3 It shows that according to Figure 2 An airbag unit with a folded-back longitudinal end.

[0023] Figure 4 The above shows according to Figure 3 The airbag unit according to the present invention, and

[0024] Figure 5 The airbag unit according to the invention is shown from above at the start of the deployment process. Detailed Implementation

[0025] exist Figure 1 The vehicle shown has A-pillar 10, B-pillar 12 and C-pillar 14, roof frame 16, side windows 18 for front occupants and side windows 20 for rear occupants.

[0026] The two side windows 18 and 20 are covered by a curtain-like head airbag 22 in the event of a side impact. The head airbag is marked by a dotted line and a shaded line on its outer edge when deployed.

[0027] Before activation, the airbag 22 is positioned in the vehicle in a folded or rolled manner along the roof frame below the side trim panel and also along the A-pillar 10 and / or along the C-pillar 14 or D-pillar.

[0028] Airbag 22 is Figures 2 to 5 This is a portion of the airbag unit 24 shown. The airbag unit 24 includes an airbag 22, which... Figure 2 As can be seen, it has only longitudinal creases 26, which are parallel to each other and extend along the entire length of the airbag 22. Instead, the airbag is rolled up in the lateral direction, so that its central axis also (i.e., like crease 26) extends in the longitudinal direction.

[0029] Furthermore, the airbag unit includes an encapsulation member 28, which is preferably implemented as, for example, a flexible hose, and is made of, for example, a sheet of fabric material, textile material, or the like. The encapsulation member 28 holds the airbag 22 in its folded or rolled-up state, that is, the encapsulation member holds the airbag in its packaged shape.

[0030] The encapsulation 28 has a first tear line 32 (shown in dashed lines) in the area of ​​its lower edge 30 ("lower" is relative to the installed state of the airbag unit 24).

[0031] Tear line 32 may be formed, for example, by a tear seam or perforation, through which the strip material of the encapsulation is sewn together after the package (folded airbag) is packaged.

[0032] Optionally, the airbag unit 24 also includes a gas generator 34, which generates gas in... Figure 1 It can also be seen that the gas generator is fastened to the roof frame 16, for example, in the area of ​​the B-pillar 12.

[0033] In the installed state, the folded or rolled-up airbag 22, i.e., the package thus formed, is U-shaped folded back in the region of at least one of the longitudinal ends (here, the front longitudinal end 36) and installed in this state, as in Figure 1 , Figure 3 and Figure 4 This can be seen in the image. Therefore, the bending position is 38.

[0034] The so-called returned packaging section 40 (see Figure 4 Extending from the bend 38 to the longitudinal end 36 of the airbag, the folded-back section 42 of the encapsulation 28 surrounding the airbag is also the same. The section of the airbag unit consisting of sections 40 and 42 is referred to as the folded-back section of the airbag unit. The non-folded-back section is referred to as the remainder of the encapsulation, the remainder of the airbag, and the remainder of the airbag unit.

[0035] These remaining sections extend from the bend position 38 to another longitudinal end 44 of the airbag unit.

[0036] The encapsulation 28 has a pre-defined second tear line 50 in the area in front of and behind the bend position 38 and in the area away from the bend position 38. The second tear line preferably extends at the middle in terms of height between the upper edge 52 and the lower edge 30 of the encapsulation 28 (again, relative to the installed state).

[0037] The second tear line 50 may be formed by a perforation or tear seam of the encapsulation 28.

[0038] Furthermore, the second tear line 50 is spaced apart from the first tear line 32 along its entire length, and the second tear line is preferably parallel to the first tear line and extends in the longitudinal extension direction X of the package.

[0039] The tear line is the fold back relative to the airbag unit, at... Figure 3The state shown is only provided on the inner side of the "U-shape" in the encapsulation 28, that is, on the wall sections 60 of the encapsulation 28 facing each other (see...). Figure 4 )superior.

[0040] Therefore, observe Figure 3 and Figure 4 As can be seen, the second tear line 50 extends from the bend position 38 for the same length as the fold-back section 42 along the encapsulation 28 and the remaining sections.

[0041] Further optionally, the second tear line extends for at least 60%, especially at least 75%, of the length L of the fold-back section 42 (measured from the inside of the bend position 38), i.e., does not extend to the longitudinal end 36 and the encapsulation 28.

[0042] The second tear line 50 is more fragile than the first tear line 32 in the region of the second tear line 50, causing the second tear line to break prematurely when gas is applied inside the airbag 22.

[0043] In the installed state, the fastening device 62 (e.g., a belt or retainer) can secure the folded-back section of the airbag unit 24 to the rest of the airbag unit, or both together, to the vehicle. Preferably, this fastening device 62 can also be broken when the airbag is filled with pressurized gas.

[0044] In addition, with the help of Figure 4 It can also be identified that the gas generator 34 is connected to the interior of the airbag in terms of circulation at the middle third of the longitudinal extension dimension of the airbag unit to which it can be installed, that is, pressurized gas is injected into the airbag 22 in this area.

[0045] The working principle of the airbag unit is explained below.

[0046] Under constrained conditions, the gas generator 34 is activated and according to Figure 5 Pressurized gas is injected into the airbag 22 in the opposite longitudinal direction. The gas displaces the airbag, thus creating longitudinally extending channels through which further pressurized gas flows primarily. Simultaneously, the airbag deploys transversely to the longitudinal extension direction X, and at least partially opens the encapsulation 28 at the first tear line 32. Furthermore, gas also flows towards the longitudinal end 36. Because the airbag 22 deploys transversely to the longitudinal extension direction X, the airbag... Figure 5The airbag 22 shortens in the direction shown by the forward movement of the longitudinal end 36. In the region of the bend position 38, the airbag 22 can deploy rapidly due to the rapid rupture of the encapsulation 38, which opens along the second tear line 50 before tearing at the tear line 32. Thus, gas can flow smoothly into the folded-back encapsulation section 40. The encapsulation section 40 can be adjusted according to... Figure 5 Flip forward quickly again in the direction of the arrow and unfold completely downwards.

[0047] It is important to emphasize that, Figure 1 In the side view, the folded-back airbag section can extend below and above the rest of the airbag package, and can also fold back inside the rest of the airbag package, as in... Figure 4 It is displayed in the middle.

[0048] Naturally, airbags can fold back at the front longitudinal end and / or rear longitudinal end, depending on the available structural space and geometry of the vehicle.

Claims

1. An airbag unit having an airbag (22) folded or rolled into an elongated package and a sealing element (28) holding the package in a folded state, wherein the longitudinal end (36) of the package, together with the surrounding flexible sealing element (28), is folded back at a bending position (38) to form a U-shape, wherein the U-shape is formed by the airbag unit having a folded-back package section (40) and the folded-back section of the sealing element surrounding it, and the remainder of the airbag unit, and The encapsulation (28) has a predetermined first tear line (32) that extends along the length of the airbag unit (24) and the airbag (22) is exposed from the encapsulation (28) by the first tear line when deployed. The encapsulation (28) has an additional predetermined second tear line (50) in the region of the bend position (38) that extends on the wall sections (60) of the encapsulation (28) facing each other.

2. The airbag unit according to claim 1, characterized in that, The second tear line (50) extends in the longitudinal extension direction (X) of the package.

3. The airbag unit according to claim 2, characterized in that, The second tear line (50) extends only in the longitudinal extension direction (X) of the package.

4. The airbag unit according to any one of claims 1 to 3, characterized in that, The second tear line (50) is circumferentially spaced from the first tear line (32) along its entire length.

5. The airbag unit according to any one of claims 1 to 3, characterized in that, The second tear line (50) extends for at least 60% of the length of the folded-back section (42) of the encapsulation (28).

6. The airbag unit according to claim 5, characterized in that, The second tear line (50) extends for at least 75% of the length of the fold-back section (42) of the encapsulation (28).

7. The airbag unit according to any one of claims 1 to 3, characterized in that, The second tear line (50) extends from the bend (38) for the same length as the fold-back section (42) along the envelope and the rest of the envelope.

8. The airbag unit according to any one of claims 1 to 3, characterized in that, The second tear line (50) extends from the bend position (38) only along a portion of the length of the folded-back section (42) of the encapsulation.

9. The airbag unit according to any one of claims 1 to 3, characterized in that, A gas generator (34) is provided, which is connected to the airbag (22) in the flow direction at the middle third of the longitudinal extension dimension of the folded airbag unit.

10. The airbag unit according to any one of claims 1 to 3, characterized in that, At least one fastening device (62) is provided, by means of which the folding section of the airbag unit is secured relative to the airbag unit.

11. The airbag unit according to claim 10, characterized in that, The foldback section of the airbag unit is secured to the rest of the airbag unit by means of the fastening device.

12. The airbag unit according to any one of claims 1 to 3, characterized in that, The airbag (22) is a curtain-like head side airbag designed to cover at least a portion of the side windows of the assigned vehicle.

13. The airbag unit according to claim 12, characterized in that, The airbag (22) is a shared airbag (22) for both front and rear occupants.

14. The airbag unit according to any one of claims 1 to 3, characterized in that, The encapsulation (28) is a flexible hose.

15. The airbag unit according to any one of claims 1 to 3, characterized in that, The first tear line (32) and / or the second tear line (50) are perforations or tear seams of the encapsulation (28).

16. The airbag unit according to any one of claims 1 to 3, characterized in that, The encapsulation (28) is designed at the second tear line (50) such that when the airbag (22) is filled with gas, the encapsulation opens, and then the section of the first tear line (32) extending beside the second tear line (50) opens.

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