Airbag module with airbag having controllable vent

Abstract

An airbag module (5) having a safety feature is described. The airbag module includes an airbag (10) having an outer skin (12) with a crash wall (14) and a side wall (16) extending from the crash wall (14), and an inflator (42). The airbag (10) further includes a controllable vent (20) located in the side wall (16) and a control tether (30) for controlling the controllable vent (20). The control tether (30) extends from the controllable vent (20) to a connector (34) connecting the control tether (30, 30') to the outer skin (12). The control tether (30) controls the controllable vent (20) such that, in a deployed state of the airbag (10), when the control tether (30) is under tension, the controllable vent (20) is in a first state, and when the control tether (30) is not under tension, the controllable vent (20) is in a second state, the second state being a state with less restriction compared to the first state.

Description

[Technical Field]

[0001] The invention relates to an airbag module according to the preamble of claim 1 and to a motor vehicle equipped with such an airbag module according to claim 11.

[0002] The present invention relates particularly to a passenger front airbag module for a passenger vehicle, also known as a "passenger airbag module." Like many front airbag modules, such a passenger airbag module includes an airbag, a storage unit for the airbag, and an inflator. The storage unit (which typically includes a housing) of such an airbag module is located on the passenger side of the vehicle's instrument panel and serves to protect the occupant in the event of a frontal collision.

[0003] Such passenger airbag modules are widely used in automotive technology and are part of almost all modern passenger cars.

[0004] In some respects, the demands on such an airbag module (and in particular on the airbag) are higher than those on a driver airbag module located in the steering wheel, for the following reasons:

[0005] Typically, the volume of a passenger airbag is substantially larger than that of a driver airbag in the same vehicle because the distance between the containment unit and the person to be protected is greater than in the case of a driver airbag module. This, of course, necessitates the use of a more powerful inflator, which typically results in a very "aggressive" deployment behavior of the airbag, especially during the initial deployment phase. As is known, a deploying airbag can pose a threat to the person to be protected, especially when the person is not in their standard seating position but in a "forward-leaning" position (so-called "out-of-position" OoP) in which the occupant's head is closer to the containment unit than in the standard seating position. To make the situation worse, such out-of-position scenarios occur more frequently for passengers than for drivers (who are practically always in the standard seating position when driving).

[0006] Therefore, in the case of an OoP scenario, measures should be taken to at least reduce the risk of occupants being injured by a deploying airbag, especially if they are leaning forward towards the windshield / instrument panel.

[0007] One measure that is often taken is a purely geometric measure: if the vehicle geometry allows it, the containing unit for the airbag is often positioned so that the airbag initially deploys substantially upwards towards the windshield, so that the chances of the deploying airbag hitting any body part of the occupant very early on are very low.

[0008] Another solution is to provide at least one controllable vent, which is adapted to open in the event of an OoP situation as described above. Such controllable vents are known in the art, and a distinction is usually made between controllable vents which are actively controlled by an actuator triggered by a sensor signal and controllable vents which are passively controlled by the deploying airbag itself. In both cases, it is known to use a control tether which controls the controllable vent in such a way that, in the deployed state of the airbag, when the control tether is under tension, the controllable vent is in a first (normally closed) state, and when the control tether is not under tension, the controllable vent is in a second (normally open) state.

[0009] For passively controlled vents, the following layout of an airbag module is known in the art: the airbag of the airbag module includes an outer skin having a crash wall and a side wall extending from the crash wall; the airbag, in a non-deployed state, is stored in a storage unit, with an inflator attached to the storage unit; the airbag further includes a controllable vent disposed in the side wall and a control tether for controlling the controllable vent; the control tether extends from the controllable vent to a connection connecting the control tether to the outer skin; the control tether controls the controllable vent such that, in a deployed state of the airbag, when the control tether is under tension, the controllable vent is in a first state; and when the control tether is not under tension, the controllable vent is in a second state, the second state being less restrictive than the first state.

[0010] In some modern automobile designs, it is desirable to place a large display between the upper surface of the instrument panel and the windshield. For this reason, it is often not possible to configure the containment unit so that the airbag deploys essentially upwards first. As mentioned above, this is a drawback in terms of protecting the occupants from a deploying airbag in an OOP scenario.

[0011] Starting from this prior art, it is an object of the present invention to provide an airbag module with passively controllable vents that help to protect an occupant in an OoP scenario, particularly where the airbag inflates in a shape that essentially inflates the airbag towards the occupant during the initial deployment phase.

[0012] This problem is solved by an airbag module having the features of claim 1. A motor vehicle equipped with such an airbag module is defined in claim 11.

[0013] It has been found that, in particular for the above-mentioned shapes, very good results can be obtained when the connection of the control tether is located at the impact wall and the control tether does not extend directly in a straight line from there to the controllable vent, but rather the tensioned control tether is deflected by the deflection mechanism so as to at least partially form a V-shape, which means that the control tether exhibits a first section extending between the controllable vent and the deflection mechanism and a second section extending between the deflection mechanism and the connection to the impact wall.

[0014] Because of this geometry, the controllable vent remains tightly closed during unimpeded deployment of the airbag, but opens very quickly when the impact wall of the deploying airbag strikes an obstacle, such as the occupant's head.

[0015] Furthermore, it has been found that best results are often obtained when the angle between the first and second sections of the control tether is an acute angle, preferably between 10° and 60°. To achieve this, it may be preferable for the first deflection mechanism to be located on the opposite side of the impact wall.

[0016] In one embodiment, the first deflection mechanism is a first deflection element attached to the inner surface of the outer skin. This deflection element is preferably made of a flexible material, such as a typical airbag material. This has the advantage that the airbag can be fully manufactured before being attached to its containment unit and / or inflator.

[0017] In an alternative embodiment, the first deflection mechanism is a deflection element attached to one of the inflator, the housing, and the mounting element that attaches the inflator to the housing, which has the advantage that the deflection mechanism has a very well-defined position that does not change at all during deployment of the airbag.

[0018] In some applications, it may be advantageous to provide two controllable vents, for example for redundancy or to achieve stronger ventilation. In this case, the airbag module includes an additional controllable vent, and the control tether defines a shared control tether for controlling both controllable vents, or an additional tether is provided for controlling the additional controllable vent. Furthermore, the airbag module includes a second deflection mechanism for deflecting a portion of the additional control tether or the shared control tether that controls the additional controllable vent. In this manner, a symmetrical layout can be achieved.

[0019] To avoid the control tether exerting two high forces on the controllable vents in the event of an unimpeded airbag deployment, it may be preferable to provide an additional tether connecting the impact wall to the inner surface of the outer skin. Alternatively, the control tether may include a third section connecting the impact wall to the inner surface of the outer skin, which third section does not transmit force to the controllable vents.

[0020] In a preferred embodiment, the controllable vent comprises a blocking element located at least partially between the first layer and the second layer when the controllable vent is in its first state, the first layer comprising a first hole and the second layer comprising a second hole, the first hole and the second hole at least partially overlapping. The blocking element is connected to a first section of the control tether. The blocking element remains in its original blocking position as long as the outer skin is free to deploy and when the outer skin is fully deployed, but is pushed through the hole in the outer layer when the impact wall impacts an obstacle so that the control tether cannot reach its tensioned state.

[0021] Particularly good results can be achieved if the blocking element is substantially triangular and the first section of the control tether is connected to one vertex of the triangular blocking element.

[0022] To improve the tightness in the first state of the controllable vent, it may be preferable that at least the end of the tether attached to the blocking element has two legs that are both attached to the blocking element. By this measure, the blocking element is stabilized and kept in a flat shape at least in the first state of the controllable vent, which may help to improve the tightness. [Brief explanation of the drawings]

[0023] The invention will now be described by way of preferred embodiments in view of the drawings, which show: [Figure 1] FIG. 1 is a schematic representation of the front of a vehicle on the passenger side with the airbag of the airbag module in a non-deployed state. [Figure 2] FIG. 2 illustrates the article shown in FIG. 1 with the airbag of the airbag module in a deployed position. [Figure 3] FIG. 3 is a schematic cross-sectional view of the airbag module of FIG. 2 taken along plane AA of FIG. [Figure 4] FIG. 4 shows detail D of FIG. [Figure 5]5 is a side view of the controllable vent shown in FIG. 4, taken in direction R of FIG. [Figure 6] FIG. 6 shows an alternative embodiment of a controllable vent in a representation substantially in accordance with FIG. [Figure 7] FIG. 7 shows an alternative embodiment of a controllable vent shutoff element. [Figure 8] FIG. 8 illustrates an alternative embodiment of the second layer. [Figure 9] FIG. 9 illustrates a further alternative embodiment of a blocking element and a control tether attached to the blocking element. [Figure 10] FIG. 10 illustrates an OoP event substantially as shown in FIG. 2, with the occupant leaning forward as the airbag deploys. [Figure 11] FIG. 11 is a representation according to FIG. 3, showing the passengers of the event shown in FIG. [Figure 12] FIG. 12 shows a second embodiment of the airbag module in a representation according to FIG. [Figure 13] FIG. 13 shows a third embodiment of the airbag module of the invention in a representation according to FIGS. [Figure 14] FIG. 14 shows a fourth embodiment of the airbag module of the invention in a representation according to FIG. [Figure 15] FIG. 15 shows a fifth embodiment of the airbag module of the invention in a representation according to FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] FIG. 1 schematically illustrates the passenger side of a passenger vehicle. An occupant P is seated in a passenger-side vehicle seat 50, facing a windshield 56 and an instrument panel 52. A monitor 54 is located between the upper edge of the instrument panel 52 and the windshield 56. An airbag module 5, including an airbag 10 and an inflator 42, is concealed behind the surface of the instrument panel 52, as is commonly known in the art. The airbag module also includes a containment unit, which is not shown in detail in FIG. 1. Due to the position of the monitor 54, the deployment opening of the airbag module faces substantially toward the occupant P (rather than toward the windshield, as is often the case with prior art occupant airbag modules). This, of course, means that the airbag 10 will deploy directly toward the occupant P.

[0025] FIG. 2 shows the article shown in FIG. 1 with the airbag 10 fully deployed. The occupant P (as in FIG. 1) is in a standard seating position (before the occupant begins to move substantially toward the airbag due to inertial forces) so that the airbag 10 can deploy unimpeded. FIG. 3 also shows the airbag in a fully deployed state in a cross-sectional view along plane AA of FIG. 1. The housing 40, which is part of the containment unit, is also visible in this view. The cover of the containment unit (which may be integral with the instrument panel) is not shown. The inflator 42 is attached to the housing 40 by a flange, as is known in the art, which also attaches the airbag 10 to the housing 40.

[0026] The airbag 10, of course, comprises an outer skin 12 having geometrically an impact wall 14, a support wall 18, and a side wall 16 connecting the impact wall 14 and the support wall 18. Often, the impact wall, the support wall 18, and the side wall 16 are made from separate cuts, and in particular, the side wall 16 is made from at least one cut that is connected to both the impact wall and the support wall 18.

[0027] A controllable vent 20 is provided in the sidewall 16 , and the airbag 10 further includes a control tether 30 for controlling the controllable vent 20 .

[0028] The structure of the controllable vent 20 is best shown in Figures 4 and 5. The controllable vent 20 comprises a hole 20a in a first layer (which in this embodiment is the sidewall of the airbag's outer skin 12), a second layer 26 located inside the outer skin 12 in this embodiment and including a hole 26a that at least overlaps the hole 20a in the first layer, and a shielding element 24 located between the first layer (outer skin 12) and the second layer 26 and covering the two holes 20a and 26a. The second layer 26 and the shielding element 24 are typically made of a flat material, particularly a standard airbag material (the same material as the outer skin 12). As can be seen in Figure 5, the second layer 26 and the shielding element 24 are triangular in shape and connected via a connecting seam 29. The connecting seam 29 extends along substantially all edges of the second layer 26 but only one edge of the shielding element 24. The apex of the blocking element 24 away from the connected edge via a connecting seam 29 is connected to one end of a control tether 30. The second layer 26 includes a control tether hole 28 through which the control tether 30 passes.

[0029] 4, the blocking element 24, when held in place by the control tether 30, blocks the hole in the first layer 20a and the hole 26a in the second layer 26, such that the controllable vent 20 is in a blocked first state when the control tether 30 is under tension. It is easy to see that when the airbag is deployed (meaning that the gas pressure inside the airbag outer skin 12 exceeds the pressure outside the airbag 10) and the control tether 30 is no longer under tension, the blocking element 24 is pushed through the hole 20a in the outer skin such that the controllable vent 20 transitions to an open second state.

[0030] According to the present invention, as can be best seen in FIG. 3 , the control tether 30 extends from the controllable vent 20, i.e., its blocking element 24, to the impact wall 14, where the control tether 30 is connected by a connection in the form of a connecting seam 34. However, the control tether does not extend directly from the controllable vent 20 to the impact wall 14, but is instead guided through a deflection mechanism 36, here in the form of a deflection flap 36 connected to the support wall 18. Due to its guidance through the deflection element 36, the control tether is divided into a first section 30a and a second section 30b. It is important to note that the deflection flap 36 deflects the control tether 30 in a sliding manner. The effect of the deflection of the control tether 30 will be explained later, with particular reference to FIGS. 10 and 11 , but it should first be mentioned that an alternative embodiment of the controllable vent 20 will be explained with reference to FIGS. 6 to 9, where the operating principle of the controllable vent is maintained.

[0031] FIG. 6 shows an embodiment of the controllable vent 20 in the representation shown in FIG. 5. Here, the blocking element 24 and the second layer 26 are sections of a single piece of fabric, and the blocking element 24 and the second layer 26 are connected to each other by a connecting section 25. Like the first embodiment, the blocking element 24 and the second layer 26 are triangular, but in contrast to the embodiment of FIG. 5, these triangles have substantially the same size but are offset from each other. Like the first embodiment, a connecting seam 29 is provided, but in contrast to the first embodiment, this connecting seam 29 does not have a section that passes through both the blocking element 24 and the second layer 26. This can have advantages regarding the force contribution and airtightness of the controllable vent when in the first state. Like the first embodiment, a hole 28 for a tether is provided in the second layer 26.

[0032] FIG. 7 shows a blocking element 24 that is also substantially triangular in shape, in the sense that it has two edges that define an acute angle α. Two legs 33a, 33b of the control tether 30 are attached to the blocking element 24 along the just-mentioned edges so that these legs 33a, 33b also surround the acute angle α. This measure can also contribute to better force transmission and better airtightness of the controllable vent when the controllable vent is in the first state. This geometric shape can also be applied to blocking elements 24 as shown in FIGS. 5 and 6. In the embodiment of FIG. 7, the control tether 30 comprises two strands 31a, 33b, and the legs 33a, 33b are the end sections of the strands 31a, 31b. FIG. 8 shows a variation of the embodiment of FIG. 7. Here, the control tether 30 is composed of a main portion 32 and an attachment portion 33 that is essentially V-shaped and thus has two legs 33a, 33b. 7, the legs 33a, 33b are attached to the isolation element 24 along the edges of the isolation element. The attachment between the isolation element 24, the control tether attachment portion 33, and the main portion of the control tether may be by a single seam.

[0033] Figure 9 shows an embodiment of second layer 26 that is particularly suitable for blocking element and tether combinations such as those shown in Figures 7 and 8. Here, second layer 26 has a tunnel section 26B that guides a portion of control tether 30.

[0034] The operating principle of the present invention will be explained with reference to FIGS.

[0035] If the occupant is seated in a leaned-over position when the airbag deploys, the crash wall 14 will naturally come into contact with the occupant very early on. As a result, the control tether 30 is never under tension, and the pressure that builds up very quickly inside the airbag outer skin 12, because the outer skin 12 is not free to deploy, will force the blocking element 24 out of the hole 20a very early on, releasing gas from inside the outer skin 12 and preventing further deployment of the airbag 10. Thus, a safety vent that responds quickly to an OoP situation is provided.

[0036] In contrast, when the airbag is free to deploy (see, for example, FIG. 2), the blocking element 24 remains in its pinched position until the airbag is fully deployed and then held in place by the control tether.

[0037] It is of course also possible to provide two controllable vents 20, 20', preferably symmetrically, as shown in Figure 12. Here, a single control tether 30 can be used, slidably connected to the impact wall 14 by a connecting flap 34. In this case, the control tether has four sections 30a-30d. Providing two controllable vents 20, 20' symmetrically, particularly as shown in Figure 12, essentially has two advantages. First, the amount of gas released in an OoP situation is naturally increased, and second, the forces transmitted to the impact wall 14 are symmetrical.

[0038] FIG. 13 shows a variation of the embodiment of FIG. 12, which also utilizes symmetrical force transmission to the support wall 18, but which uses only one controllable vent.

[0039] Of course, instead of one control tether slidably held to the impact wall 14, two completely separate control tethers 30, 30' could be used, as shown in FIG.

[0040] And finally, the layout described with respect to Figures 1 to 3 can be combined with an additional tether 38 that serves purely to limit inflation depth (Figure 15). [Explanation of symbols]

[0041] 5 Airbag Module 10 Airbags 12 outer skin 14 Collision Wall 16 side wall 18 Supporting wall 20, 20' Controllable Vent 20a First layer hole 22 First Hole 24 Blocking Elements 25 Connection between the blocking element and the second layer 26 Second Layer 26a Second layer hole 26B Tunnel Section 28 Tether hole 30, 30' control tether 30a, 30b, 30c, 30d Control Section 31a, 31b strands 32 Main parts of the control tether 33 Control tether attachment point 33a, 33b Legs 34 Connection / Connection seam connection flap 36 Deflector element / deflector flap 38 additional tethers 40 Housing 42 Inflator 50 vehicle seats 52 Instrument panel 54 monitors 56 Windshield

Claims

1. An airbag module (5), an airbag (10) comprising an outer skin (12) having a crash wall (14) and a side wall (16) extending from the crash wall (14); a storage unit that stores the airbag (10) when the airbag (10) is in a non-deployed state; an inflator (42) attached to the storage unit; The airbag (10) a controllable vent (20) located in said sidewall (16); a control tether (30) for controlling the controllable vent (20), the control tether (30) extending from the controllable vent (20) to a connection (34) connecting the control tether (30) to the outer skin (12); an airbag module (5) wherein the control tether (30) controls the controllable vent (20) such that, in a deployed state of the airbag (10), the controllable vent (20) is in a first state when the control tether (30) is under tension and the controllable vent (20) is in a second state when the control tether (30) is not under tension, the second state being a state with less restriction than the first state; the connection portion (34) connects the control tether (30, 30') to the impact wall (14); 1. An airbag module (5) comprising: an airbag module (5) including: a control tether (30) guided through a first deflection mechanism (36) such that the control tether (30) is deflected by the deflection mechanism (36) at least when the control tether (30) is under tension; and a control tether (30) exhibiting a first section (30a) extending between the controllable vent (20) and the deflection mechanism (36), and a second section (30b) extending between the deflection mechanism (36) and the connection (34) to the impact wall (14).

2. 2. The airbag module of claim 1, wherein said first deflection mechanism (36) is located opposite said crash wall (14).

3. 3. The airbag module according to claim 1 or 2, characterized in that the first section (30a) and the second section (30b) of the control tether (30) form an acute angle, preferably an angle between 10° and 60°.

4. 4. The airbag module according to claim 1, wherein the first deflection mechanism (36) is a first deflection element (36) attached to the inner surface of the outer skin (12), the first deflection element (36) being preferably made of a flexible material so as to form a flap.

5. 4. The airbag module according to claim 1, wherein the first deflection mechanism is a deflection element attached to one of the inflator, the containment unit, and a mounting element that attaches the inflator to the containment unit.

6. the airbag module comprises an additional controllable vent (20'); the control tethers define a shared control tether (30) for controlling both controllable vents (20, 20'), or an additional control tether (30') is provided for controlling the additional controllable vent (20'); 6. The airbag module of claim 1, further comprising an additional deflection mechanism (36') for deflecting the portion of the additional control tether (30') or the shared control tether (30) that controls the additional controllable vent (20').

7. 7. The airbag module according to claim 1, wherein an additional tether (38) is provided connecting the impact wall (14) to one of the inner surface of the outer skin, the inflator (42), the containment unit and attachment elements attaching the inflator to the containment unit, in particular to a housing (40) that is part of the containment unit, or wherein the control tether comprises a third section connecting the impact wall to one of the inner surface of the outer skin, the inflator (42), the containment unit and attachment elements attaching the inflator to the containment unit, in particular to a housing (40) that is part of the containment unit.

8. 8. The airbag module of claim 1, wherein the controllable vent (20) comprises a blocking element (24) located at least partially between a first layer (12) and a second layer (26) when the controllable vent (20) is in its first state, the first layer (12) comprising a first hole (20a) and the second layer (26) comprising a second hole (26a), the first hole (20a) and the second hole (26a) at least partially overlapping.

9. 9. An airbag module according to claim 8, characterized in that the blocking element (24) is substantially triangular in shape.

10. 10. The airbag module of claim 9, wherein at least the end of the control tether (30) attached to the blocking element (24) comprises two legs (33a, 33b) both attached to the blocking element (24).

11. 11. A motor vehicle comprising: a windshield; an instrument panel; an airbag module (10) according to at least one of claims 1 to 10; and a monitor (54) arranged between the instrument panel (52) and the windshield (56).

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