Airbag module with airbags having controllable vents

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 present invention relates to an airbag module according to the preamble of claim 1, and to a motor vehicle comprising such an airbag module according to claim 11.

[0002] The present invention particularly relates to a front passenger airbag module for a passenger car, which is also called a "passenger airbag module". Like many front airbag modules, such a passenger airbag module comprises an airbag, a storage unit for the airbag, and an inflator. The storage unit of such an airbag module (usually comprising a housing) is arranged on the passenger side of the vehicle instrument panel and serves to protect occupants 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 several respects, the requirements for such an airbag module, especially for the airbag thereof, are higher than those for a driver airbag module arranged on a steering wheel. The reasons are as follows.

[0005] Typically, the volume of a passenger-side airbag is substantially larger than that of a driver-side airbag in the same car. This is because the distance between the containment unit and the person to be protected is greater than in the case of the driver-side airbag module. This, of course, requires the use of a stronger inflator, which usually results in a very "aggressive" deployment behavior of the airbag, especially in the initial stages of deployment. As is well known, a deploying airbag can be a threat to the person to be protected, especially if this person is not in their standard seating position, but rather in a "forward-leaning position" (so-called "out-of-position" OoP) where the occupant's head is closer to the containment unit than in a standard seating position. To make matters worse, such out-of-position scenarios occur more frequently for passengers than for drivers (when driving, the driver is substantially always in a standard seating position).

[0006] Therefore, in OoP scenarios, measures should be taken to at least reduce the risk of occupant injury from deploying airbags, especially if the occupant is leaning forward towards the windshield / instrument panel.

[0007] One common approach is a purely geometric one. Where the vehicle's geometry allows, the airbag containment unit is often positioned so that the airbag initially deploys substantially upward towards the windshield, making it very unlikely that the deploying airbag will hit any part of the occupant's body at a very early stage.

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

[0009] For passively controlled vents, the following layout of an airbag module is known in the art: The airbag of the airbag module comprises an outer skin having a collision wall and side walls extending from the collision wall. In the undeployed state, the airbag is housed in a storage unit, the storage unit having an inflator attached to it. The airbag further comprises a controllable vent located in the side wall and a control tether for controlling the controllable vent. The control tether extends from the controllable vent to a connection that connects the control tether to the outer skin. The control tether controls the controllable vent such that, in the deployed state of the airbag, the controllable vent is in a first state when the control tether is under tension, and the controllable vent is in a second state when the control tether is not under tension, the second state being a state in which the throttling is smaller than that of the first state.

[0010] Some modern car designs favor placing a large display between the upper surface of the instrument panel and the windshield. For this reason, it is often impossible to configure the containment unit so that the airbags deploy primarily upwards. As mentioned above, this is a drawback in terms of protecting occupants from airbag deployment in out-of-place (OoP) scenarios.

[0011] Starting from this prior art, the object of the present invention is to provide an airbag module having a passively controllable vent that helps protect the occupant, in an OoP scenario, in particular, in a shape that the airbag essentially inflates toward the occupant in the initial deployment phase.

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

[0013] In particular, in the above-described configuration, it was found that very good results could be obtained when the control tether connection point is located at the impact wall, the control tether does not extend directly in a straight line from there to the controllable vent, and the tensioned control tether is deflected by the deflection mechanism so that it forms at least partially a V-shape. This means that the control tether has a first section extending between the controllable vent and the deflection mechanism, and a second section extending between the deflection mechanism and the connection point to the impact wall.

[0014] Due to its geometric shape, the controllable vent remains tightly closed while the airbag deploys unimpeded, but releases extremely 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 the best results are often obtained when the angle between the first and second sections of the control tether is acute, preferably between 10° and 60°. To achieve this, it may be preferable that the first deflection mechanism 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 common airbag material. This has the advantage that the airbag can be manufactured entirely before it is attached to its housing unit and / or inflator.

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

[0018] In some applications, it may be advantageous to have 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 to control both controllable vents, or an additional tether is provided to control the additional controllable vent. Furthermore, the airbag module includes a second deflection mechanism for deflecting the additional control tether or a portion of the shared control tether that controls the additional controllable vent. In this way, a symmetrical layout can be achieved.

[0019] To avoid the control tether applying two high forces to the controllable vent when the airbag deploys without obstruction, 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 have a third section connecting the impact wall to the inner surface of the outer skin, which does not transmit force to the controllable vent.

[0020] In a preferred embodiment, the controllable vent comprises a debarring element located at least partially between a first layer and a second layer when the controllable vent is in its first state, wherein the first layer comprises a first hole, and the second layer comprises a second hole, and the first and second holes at least partially overlap. The debarring element is connected to a first section of the control tether. The debarring element remains in its original debarring position as long as the outer skin is freely deployed 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 as to prevent the control tether from reaching its tensile state.

[0021] Particularly good results can be obtained when 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 airtightness in the first state of a controllable vent, it may be preferable that at least the ends of the tether attached to the venting element have two legs, both of which are attached to the venting element. This measure stabilizes the venting element and keeps it flat, at least in the first state of the controllable vent. This can help improve airtightness. [Brief explanation of the drawing]

[0023] Herein, the present invention will be described by preferred embodiments in view of the drawings. The figures are as follows: [Figure 1] Figure 1 is a schematic representation of the front of the vehicle on the passenger side, with the airbag module's airbag in a non-deployed state. [Figure 2] Figure 2 shows the item shown in Figure 1 with the airbag module's airbag deployed. [Figure 3] Figure 3 is a schematic cross-sectional view of the airbag module in Figure 2 along plan AA in Figure 2. [Figure 4] Figure 4 is a detailed view of Figure 3, part D. [Figure 5]Figure 5 is a side view of the controllable vent shown in Figure 4, as viewed from direction R in Figure 4. [Figure 6] Figure 6 is a diagram showing an alternative embodiment of the controllable vent in a representation substantially conforming to Figure 5. [Figure 7] Figure 7 is a diagram showing an alternative embodiment of a shut-off element for a controllable vent. [Figure 8] Figure 8 is a diagram showing an alternative embodiment of a second layer. [Figure 9] Figure 9 is a diagram showing a further alternative embodiment of a shut-off element and a control tether attached to the shut-off element. [Figure 10] Figure 10 is a diagram showing the out-of-position (OoP) event substantially as illustrated in Figure 2, where an occupant is leaning forward when the airbag deploys. [Figure 11] Figure 11 is a diagram in accordance with the representation of Figure 3, which also shows the occupant in the event illustrated in Figure 10. [Figure 12] Figure 12 is a diagram showing a second embodiment of an airbag module in a representation conforming to Figure 3. [Figure 13] Figure 13 is a diagram showing a third embodiment of the airbag module of the present invention in a representation conforming to Figure 3 and Figure 12. [Figure 14] Figure 14 is a diagram showing a fourth embodiment of the airbag module of the present invention in a representation conforming to Figure 13. [Figure 15] Figure 15 is a diagram showing a fifth embodiment of the airbag module of the present invention in a representation conforming to Figure 14. DESCRIPTION OF EMBODIMENTS

[0024] Figure 1 schematically shows the passenger side of a passenger car. Occupant P is seated in the passenger-side vehicle seat 50, facing the windshield 56 and the instrument panel 52. The monitor 54 is located between the upper edge of the instrument panel 52 and the windshield 56. The airbag module 5, comprising the airbag 10 and the inflator 42, is concealed behind the surface of the instrument panel 52, as is commonly known in the prior art. The airbag module further comprises a housing unit, which is not shown in detail in Figure 1. Due to the position of the monitor 54, the deployment opening of the airbag module faces substantially towards occupant P (rather than towards the windshield, as is common with occupant airbag modules in the prior art). This, of course, means that the airbag 10 deploys directly toward occupant P.

[0025] Figure 2 shows the item shown in Figure 1 with the airbag 10 fully deployed. The occupant P is in a standard seated position (as in Figure 1) so that the airbag 10 can deploy without obstruction (before the occupant begins to move substantially toward the airbag due to inertia). Figure 3 also shows the airbag in a fully deployed state in a cross-sectional view along plan AA of Figure 1. In this figure, the housing 40, which is part of the containment unit, can also be seen. The cover of the containment unit (which may be integrated with the instrument panel) is not shown. The inflator 42 is mounted to the housing 40 by a flange, as is known in the art, and this flange also mounts the airbag 10 to the housing 40.

[0026] The airbag 10, of course, comprises an outer skin 12 having a geometric 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 fabricated from separate cuts, and in particular, the side wall 16 is fabricated 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 side wall 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 illustrated in Figures 4 and 5. This controllable vent 20 comprises a hole 20a in a first layer (in this embodiment, the side wall of the outer skin 12 of the airbag), a second layer 26 located inside the outer skin 12 and having a hole 26a that at least overlaps with the hole 20a in the first layer, and a sealing element 24 located between the first layer (outer skin 12) and the second layer 26, covering the two holes 20a and 26a. The second layer 26 and the sealing element 24 are typically made of a flat material, in particular standard airbag material (the same material as the outer skin 12). As can be seen in Figure 5, the second layer 26 and the sealing element 24 are triangular and connected via a connecting seam 29. This connecting seam 29 extends substantially along all edges of the second layer 26, but along only one edge of the sealing element 24. The vertices of the isolation element 24, which are separated from the edge connected via the connecting seam 29, are connected to one end of the control tether 30. The second layer 26 is provided with a hole 28 for the control tether through which the control tether 30 passes.

[0029] As is best seen in Figure 4, the blocking element 24 blocks the holes in the first layer 20a and the second layer 26a when held in place by the control tether 30, so that the controllable vent 20 is in a first state of being blocked when the control tether 30 is under tension. When the airbag is deployed (meaning the gas pressure inside the outer skin 12 of the airbag exceeds the pressure outside the airbag 10) and the control tether 30 is not under tension, it is easy to understand that the blocking element 24 is pushed through the hole 20a in the outer skin so that the controllable vent 20 is opened, transitioning to a second state.

[0030] According to the present invention, as best seen in Figure 3, the control tether 30 extends from the controllable vent 20, i.e., its blocking element 24, to the impact wall 14 to which 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 guided through a deflection mechanism 36, which is in the form of a deflection flap 36 connected to a support wall 18. Due to 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 so that it slides. The effect of the deflection of the control tether 30 will be described later with reference to Figures 10 and 11 in particular, but first it is necessary to mention that alternative embodiments of the controllable vent 20 are described with reference to Figures 6-9, and that the operating principle of the controllable vent is maintained.

[0031] Figure 6 shows one embodiment of the controllable vent 20 as represented in Figure 5. Here, the sealing element 24 and the second layer 26 are sections of a single piece of fabric, and the sealing element 24 and the second layer 26 are connected to each other by a connecting section 25. Similar to the first embodiment, the sealing element 24 and the second layer 26 are triangular, but in contrast to the embodiment in Figure 5, these triangles are substantially the same size but are offset from each other. Similar to 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 sealing element 24 and the second layer 26. This may have advantages with respect to the force contribution and airtightness of the controllable vent when in the first state. Similar to the first embodiment, a hole 28 for a tether is provided in the second layer 26.

[0032] Figure 7 shows a slitting element 24 which is also substantially triangular in shape, in the sense that it has two edges defining an acute angle α. The two legs 33a, 33b of the control tether 30 are attached to the slitting element 24 along the aforementioned 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 slitting elements 24 as shown in Figures 5 and 6. In the embodiment of Figure 7, the control tether 30 comprises two strands 31a, 33b, and the legs 33a, 33b are the end sections of those strands 31a, 31b. Figure 8 shows a modification of the embodiment of Figure 7, where the control tether 30 consists of a main part 32 and a mounting part 33 which is basically V-shaped and therefore has two legs 33a, 33b. Similar to the embodiment in Figure 7, these legs 33a and 33b are attached to the shut-off element 24 along the edge of the shut-off element. The attachment between the shut-off element 24, the control tether attachment portion 33, and the main portion of the control tether can be done by a single seam.

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

[0034] The operating principle of the present invention will be explained with reference to Figures 10 and 11.

[0035] If the occupant is seated in a hunched-over position when the airbag deploys, the impact wall 14 will naturally make contact with the occupant at a very early stage. As a result, the control tether 30 is never subjected to tension, and the pressure rising very rapidly inside the outer skin 12 because the outer skin 12 of the airbag cannot deploy freely causes the sealing element 24 to be pushed out of the hole 20a very early, releasing the gas from inside the outer skin 12, and preventing further deployment of the airbag 10 from being too violent. Thus, a safe vent that reacts quickly to an OoP situation is provided.

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

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

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

[0039] As shown in Figure 14, of course, instead of slidably holding one control tether to the collision wall 14, two completely separate control tethers 30, 30' can also be used.

[0040] Finally, the layouts described in Figures 1-3 can be combined with an additional tether 38 that serves purely to limit the expansion 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 Holes in the first layer 22 First hole 24 Blocking elements 25 Connection between the blocking element and the second layer 26. The second layer 26a Holes in the second layer 26B Tunnel Section 28 holes for tether 30, 30' control tether 30a, 30b, 30c, 30d control section 31a, 31b Strand 32 Main part of the control tether 33 Mounting section for control tether 33a, 33b Legs 34 Connection part / connection seam connection flap 36. Deflection Elements / Declining Flaps 38 Additional Tether 40 Housing 42 Inflators 50 seats per vehicle 52 Instrument Panel 54 monitors 56 Windshield

Claims

1. Airbag module (5), An airbag (10) having an outer skin (12) having a collision wall (14) and a side wall (16) extending from the collision wall (14), A storage unit for housing the airbag (10) when the airbag (10) is in a non-deployed state, The storage unit is equipped with an inflator (42) attached to it, The aforementioned airbag (10) A controllable vent (20) located on the side wall (16), A control tether (30) for controlling the controllable vent (20), further comprising: a control tether (30) extending from the controllable vent (20) to a connection portion (34) that connects the control tether (30) to the outer skin (12), In the airbag module (5), the control tether (30) controls the controllable vent (20) such that, when the airbag (10) is deployed, 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 in which the throttling is smaller than that of the first state. The connection part (34) connects the control tethers (30, 30') to the collision wall (14), The control tether (30) is guided through a first deflection mechanism (36), and so the control tether (30) is deflected by the deflection mechanism (36) at least when the control tether (30) is under tension, and as a result the control tether (30) includes 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), The airbag module (5) is characterized in that the first section (30a) and the second section (30b) of the control tether (30) are configured at an acute angle.

2. The airbag module according to claim 1, characterized in that the first deflection mechanism (36) is located on the opposite side of the collision wall (14).

3. The airbag module according to claim 1 or 2, characterized in that the acute angle is between 10° and 60°.

4. The airbag module according to claim 1 or 2, characterized in that the first deflection mechanism (36) is a first deflection element (36) attached to the inner surface of the outer skin (12), and the first deflection element (36) is made of a flexible material to form a flap.

5. The airbag module according to claim 1 or 2, characterized in that the first deflection mechanism (36) is a deflection element (36) attached to one of the inflator (42), the housing unit, and the mounting element for attaching the inflator to the housing unit.

6. The airbag module includes an additional controllable vent (20'), The control tether defines 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'). The airbag module according to claim 1 or 2, further comprising an additional control tether (30') for controlling the additional controllable vent (20') or an additional deflection mechanism (36') for deflecting a portion of the shared control tether (30).

7. The airbag module according to claim 1 or 2, wherein the impact wall (14) is provided with an additional tether (38) that connects the impact wall (14) to the inner surface of the outer skin, the inflator (42), the housing unit, and one of the mounting elements that attach the inflator to the housing unit, in particular to the housing (40) which is part of the housing unit, or the control tether comprises a third section that connects the impact wall to the inner surface of the outer skin, the inflator (42), the housing unit, and one of the mounting elements that attach the inflator to the housing unit, in particular to the housing (40) which is part of the housing unit.

8. The airbag module according to claim 1 or 2, wherein the controllable vent (20) comprises a blocking element (24) that is at least partially located between a first layer (12) and a second layer (26) when the controllable vent (20) is in its first state, the first layer (12) comprises a first hole (20a), the second layer (26) comprises a second hole (26a), and the first hole (20a) and the second hole (26a) at least partially overlap.

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

10. The airbag module according to claim 9, characterized in that at least one end of the control tether (30) attached to the blocking element (24) is provided with two legs (33a, 33b) attached to the blocking element (24).

11. An automobile comprising a windshield (56), an instrument panel (52), an airbag module (5) according to claim 1 or 2, and a monitor (54) disposed between the instrument panel (52) and the windshield (56).

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