WO2025261717A1

WO2025261717A1 - Restraining system, inflatable airbag and method for its manufacturing

Info

Publication number: WO2025261717A1
Application number: PCT/EP2025/064265
Authority: WO
Inventors: Jack Johansson
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 2024-06-19
Filing date: 2025-05-23
Publication date: 2025-12-26
Anticipated expiration: 2026-12-19
Also published as: DE102024117242A1

Abstract

A restraining system for protecting a seated person is described. This restraining system comprises a safety belt having a shoulder portion (62) extending over at least a part of the torso of the to be protected person when the restraining system is in its state of use, an inflatable airbag (5) attached to the shoulder portion (62) of the safety belt, and an inflator for inflating the inflatable airbag (5), such that the inflatable airbag (5) inflates in front of the person when the inflator is activated. In order to improve the restraining performance of the inflatable airbag (5), the inflatable airbag (5) comprises a support sub-structure (S) enclosing a support part (18) of the gas space, and a restraining sub-structure (R) enclosing a restraining part of the gas space. The restraining sub-structure (R) comprises at least a left section (40) enclosing a left chamber (42) of the restraining part of the gas space and a right section (44) enclosing a right chamber (46) of the restraining part of the gas space. The left section (40) and the right section (44) extend from the support sub-structure (S) when the airbag (5) is in its inflated state (Fig. 8).

Description

Restraining system, inflatable airbag and method for its manufacturing

Description

The invention relates to a restraining system according to the preamble of claim 1 , to an airbag adapted for being a part of this restraining system according to claim 12, and to a method for manufacturing the same according to claim 13.

A “classic” restraining system for protecting a seated person in a motor vehicle comprises a safety belt (which is again a part of a safety belt system) and at least one inflatable airbag being positioned in front of the person to be protected, for example in a steering wheel or in an instrument panel. In some configurations, especially if the person to be protected is far away from a suitable support structure of the vehicle, it can be an alternative to attach the inflatable airbag to the safety belt, such that in case of an accident, the inflatable airbag deploys from this safety belt right in front of the head and/ or chest of the person to be protected. In this case, a combined restraining system comprising a safety belt and an inflatable airbag being attached to this safety belt is provided. Of course, the inflatable airbag encloses a gas space and an inflator for inflating the airbag is provided. Such a restraining system is for example disclosed in generic US 2018 281 727 A1 .

The invention sets itself the task to improve a generic restraining system in such a way that its restraining performance is improved.

This task is solved by a restraining system having the features of claim 1 . An airbag adapted for being a part of such a restraining system is defined in claim 12 and a method for manufacturing such an airbag is defined in claim 13.

According to the invention, the airbag comprises a support sub-structure enclosing a support part of the gas space and a restraining sub-structure enclosing a restraining part of the gas space. The restraining sub-structure comprises at least a left section enclosing a left chamber of the restraining part of the gas space and a right section enclosing a right chamber of the restraining part of the gas space. In the inflated state, the left section and the right section extend from the support sub-structure towards the shoulders of person to be protected such that most of the load is applied to the shoulders and more vulnerable body parts are less loaded.

This means that if the person is orientated in such a way that the person looks into the driving direction of the car, the support sub-structure is located (in driving direction) in front of the left section and the right section of the restraining sub-structure. Or in other words: The support sub-structure substitutes the support structure which is classically provided by a structural part of the vehicle, for example the instrument panel or the steering wheel. By this measure, the restraining function of the restraining substructure (which essentially replaces a classic frontal airbag) is enhanced since the restraining sub-structure is supported and hindered from tilting away.

As mentioned, the left and the right sections of the restraining sub-structure are essentially assigned to the shoulders of the person to be protected, such that a good restraining performance for the torso is provided. In some cases, it might be preferred that the head of the person is separately restrained and in this case it can be preferred that the restraining sub-structure additionally comprises a top section enclosing a top chamber of the second part of the gas space.

As has already been mentioned, it is generally preferred that in the state of use and when the inflatable airbag is deployed, the restraining sub-structure is located between the person to be protected and the support sub-structure. This simulates the classic system in which the airbag is located between the support structure of the vehicle (instrument panel or steering wheel) and the person to be protected.

In most cases it is not preferred that the seatbelt carries the necessary inflator and for this reason it can be preferred that the safety belt defines a gas conduit or the safety belt carries a gas conduit and the inflator is in fluid connection with the gas space via this gas conduit.

Although it would at least in principle be possible to fill the support part of the gas space and the restraining part of the gas space separately, it is generally preferred that at least one overflow is provided between the support part of the gas space and the restraining part of the gas space, such that one part of the gas space is filled via the other part of the gas space and especially it is preferred that the support part of the gas space is filled via the restraining part of the gas space, meaning that the restraining sub-structure is deployed first. By this measure, the force applied by the deploying airbag to the person is reduced: The support sub-structure starts deploying away from the at least partially deployed restraining sub-structure which is already in contact to the person to be protected.

In some embodiments it can be preferred that the restraining sub-structure additionally comprises a middle section between the left section and the right section such that this middle section is essentially located in front of the chest of the person when the restraining system is used and the airbag is fully deployed. This middle section can be deployable such that it encloses a middle chamber being a part of the restraining part of the gas space and being in fluid communication with the left chamber and the right chamber. Since it is in most cases preferred that the airbag deploys symmetrically, it can be preferred that this middle chamber is in fluid communication with the gas conduit and the left chamber and the right chamber are filled via the middle chamber.

As has been mentioned, it is in most cases desired that the shoulders of the person take most of the load when this person is restrained by the inflatable airbag. For this reason, it is often preferred that the depth of the fully deployed middle chamber is less than the depth of the fully deployed left chamber and the fully deployed right chamber.

It turned out that very good results can be achieved when the support sub-structure and the restraining sub-structure are made from initially separate panels (usually cuttings made from a typical airbag fabric which usually consist of a plastic material), especially in such a way that the restraining sub-structure comprises a restraining panel and a supported panel being essentially congruent with the restraining panel, or a joint panel having a restraining section and a supported section being congruent with the restraining section, and that the support sub-structure comprises at least one supporting panel, especially only one supporting panel, such that the outer skin of the airbag is (except seams) made from only two or three parts. Of course, it is preferred that an inflatable airbag adapted for being a part of such a restraining system can be manufactured easily and with only a few assembly steps. A preferred method for manufacturing the inflatable airbag from the parts just described comprises the following steps:

(i) providing at least one supporting panel for forming the support substructure, said at least one supporting panel comprising at least one first overflow opening,

(ii) providing a restraining panel and a supported panel being essentially congruent with the restraining panel, or a joint panel having a restraining section and a supported section being congruent with the restraining section, said supported panel or section comprising at least one second overflow opening,

(iii) placing the supported section or panel onto the supporting panel such that the at least one first overflow opening and the at least one second overflow opening at least overlap, and connecting the supporting panel and the supported section or panel via at least one overflow-opening surrounding connection extending around the overlapping overflow openings,

(iv) arranging the restraining section or panel and the supported section or panel on top of one another and applying at least one restraining substructure connection to close the second part of the gas space,

(v) closing the at least one supporting panel to form the support chamber enclosing the support part of the gas space.

Often it will be preferred that step (iv) is performed after step (v), but this is not mandatory, whereas it is essential to perform step (iii) in advance of steps (iv) and (v). This means that despite the fact that the supporting panel with is a part of the support structure (or forms the support structure), it is connected to a part of the restraining sub-structure (namely the supported panel or section) before the restraining panel or section of the support sub-structure is attached to the supported panel or section.

The invention will now be described in detail by means of preferred embodiments in view of the figures. The figures show: Figure 1 a restraining panel of a restraining sub-structure, a supported panel of this restraining sub-structure, and a supporting panel for forming the support sub-structure and thus all parts (except seams) of the inflatable airbag of this embodiment,

Figure 2 the supported panel of Figure 1 and the supporting panel of Figure 1 being sewn to the supported panel via overflow-opening-surrounding seams,

Figure 3 the sub-assembly shown in Figure 2 being turned around with the restraining panel of Figure 1 being sewn to the supported panel,

Figure 4 a sectional view taken along plane A-A in Figure 3,

Figure 5 a view onto the precursor of Figure 4 after a folding step of the supporting panel,

Figure 6 what is shown in Figure 5 after applying a closing seam,

Figure 7 the complete restraining system being used by a person with the airbag being in its fully deployed state in a very schematic representation,

Figure 8 a view from the top onto the person, the safely belt and the airbag shown in Figure 7,

Figure 9 the safety belt and the airbag in a view from the direction of the occupant,

Figure 10 a second embodiment, essentially in a representation according to Figure 3,

Figure 11 a first variation to what is shown in Figure 10 in a not completely finished state, and Figure 12 a second variation to what is shown in Figure 10.

A first embodiment of the inventive airbag will now be described by the way of its manufacture from three panels (cuttings) which are usually comprised of a typical airbag fabric. Those panels are: A supporting panel 10 from which the support substructure is formed, a restraining panel 20 and a supported panel 22 from which the restraining sub-structure is formed. The restraining panel 20 and the supported panel 22 are essentially congruent (they have the same outer shape). Instead of provided two separate panels, it would also be possible to provide a joint panel having a restraining section and a congruent supported section (“butterfly design” as is common for example in the field of side-airbags).

The restraining panel 20 comprises a filling opening 26 being preferably located on the middle axis. The supporting panel 10 comprises two first overflow openings 12 and the supported panel 22 comprises two second overflow openings 24 which match to the first overflow openings 12 in such a way that when the supporting panel 10 is placed on the supported panel 22 (or vice versa), the first overflow openings 12 at least overlap the second overflow openings 24, wherein it is preferred that the first overflow openings 12 and the second overflow openings 24 are congruent and placed to flush, as can directly be seen from Figure 1 .

These three panels are sufficient in order to form an embodiment of the inventive airbag, wherein the restraining panel 20 and the supported panel 22 form the restraining sub-structure R and the supporting panel 10 forms the support substructure S (see for example Figure 8). The manufacturing process is now described:

First, the supporting panel 10 is placed onto the supported panel 22 (or vice versa) and overflow-opening-surrounding connection seams 30 (or more generally: hole surrounding connections which could also be in form of bondings or weldings) are applied around the first overflow openings 12 and second overflow openings 24 respectively (please see Figure 2).

In the next step (Figure 3), the restraining panel 20 is sewn to the supported panel 22 by means of a restraining-sub-structure-connection 32 (usually a seam). This restraining-sub-structure-connection 32 always comprises an edge section 32a such that the restraining sub-structure encloses a restraining part of the gas space of the inflatable airbag. In this embodiment, the restraining-sub-structure-connection 32 additionally comprises a left dividing section 32b and a right dividing section 32c, such that a left section 40 enclosing a left chamber 42 of the restraining part of the gas space, a right section 44 enclosing a right chamber 46 of the restraining part of the gas space, and a middle section 50 enclosing a middle chamber 52 of the restraining part of the gas space are formed. The dividing sections 32b, 32c each comprise an overflow interruption 34b, 34c, such that the middle chamber 52 is in fluid communication with the left chamber 42 and the right chamber 46. Since the supporting panel 10 and the supported panel 22 are only connected via overflow-opening-surrounding connections 30, the restraining-sub-structure-connection 32 can be embodied as a seam (or a plurality of seams) without connecting the first panel 10 to the rear panel 22 (please see Figure 4).

In a next step, the supporting panel 10 is folded substantially along a folding line which extends through the first overflow openings 12/ 24 (please see Figure 5) and a closing seam 14 is applied. The manufacturing process of the airbag as such is now finished. By folding the supporting panel such that it alone (together with the closing seam 14) forms the support sub-structure S can give the support sub-structure S a substantial depth which leads to a good support performance. But it needs to be mentioned that it would also be possible to provide an additional supporting panel which is connected (especially sewn) to the supporting panel 10 in order to form the support sub-structure.

In a next step, the shoulder portion 62 of a safety belt 60 comprising a gas conduit 62 is attached to the front panel in such a way that the gas conduit 62 ends at the filling opening 26 and at an inflator 64. The safety belt 60 usually additionally comprises a lap section (not shown in detail). The outcome of this is schematically shown in Figures 7 and 8.

Thus, when the safety belt is worn and the inflator 64 is triggered, the inflatable airbag 5 is filled via the middle chamber 52 and from there, gas flows into the right chamber 46 and into the left chamber 42 and from those into the support chamber 18 (the support part of the gas space). This means that the deploying airbag pushes itself away from the person that it protects and so, the force applied by the deploying airbag to the person is low.

Figures 7 to 9 show the safety system in its use state when the inflatable airbag 5 is fully deployed. The left section 40 enclosing the left chamber 42 is located essentially in front of the left shoulder of the person and the right section 44 enclosing the right chamber 46 is located essentially in front of the right shoulder. Those left and right chambers 42, 46 have a larger depth (or thickness) than the middle chamber 52 such that most of the load is applied to the sturdy shoulder region of the person. The restraining sub-structure R is supported by the support sub-structure S such that when the belted person moves forward due to inertia forces, the restraining sub-structure cannot bent away.

In order to give the restraining sub-structure S a certain softness, at least one ventilation hole can be provided (not shown in the Figures), especially in the left section 40 and in the right section 42 and here, especially in the supported panel 22 that faces away from the person.

Figure 10 shows a second embodiment: Here, the restraining sub-structure R additionally comprises a top section 54 extending from the middle section 50 for providing additional protection for the head. The manufacturing process is the same as described above.

One sees that the inflatable airbag of the restraining system is easy to manufacture from only few parts. The restraining sub-structure that corresponds to a traditional frontal airbag has good support without the need of a support structure of the vehicle.

Figure 1 1 shows a first variation to the embodiment shown in Figure 10. In order to provide a better restraint for the top section 54 (meaning to avoid that it bents away when hit by the head of the occupant), the head section 54 is connected to the left section and the right section 40, 44 by means of connections, especially connection seams. The positions P, P’ of those is shown in Figure 11 , but the connections (for example seams) are not applied yet. In the embodiment shown, the positions (and thus the seams or other connections) are located in connections sections 40a, 44b, 54a, 54b) in form of protruding sections of the edge of the inflatable airbag, but this is not mandatory.

One can see in Figure 1 1 that the positions of the connections that are allocated to one another (P-P and P’-P’) are in the not yet connected and un-deployed and flat state of the inflatable airbag 5 remote from one another. This leads to a bending of the top chamber towards the occupant in the deployed state and strongly prevents a bending away of the top section when hit by the head of the occupant.

Figure 12 shows a second variation of the second embodiment. Here, the top section 54 has a larger width and the left and right lower ends of the top section 54 extend from the left and right section 40, 44 respectively. This also helps to avoid a bending- away of the top section 54 when being hit by a body part (especially the head). In order to better conform to the head, contouring seams 58 are provided that give the impact surface of the deployed top section 54 a concave shape.

List of reference numbers

5 inflatable airbag

10 supporting panel

12 first overflow opening

14 closing seam

18 support part of gas space (support chamber)

20 restraining panel

22 supported panel

24 second overflow opening

26 inflation hole

30 overflow-opening-surrounding connection (seam)

32 restraining sub-structure connection (seam)

32a edge section

32b left dividing section

32c right dividing section

34b left overflow interruption

34c right overflow interruption

40 left section

40a connection section

42 left chamber

44 right section

44b connection section

46 right chamber

50 middle section

52 middle chamber

54 top section

54a, 54b connection section

56 top chamber

58 contouring seam

60 safety belt

62 shoulder portion

63 gas conduit

64 inflator R restraining sub-structure

P, P’ position of connection seam

S support sub-structure

Claims

1 . A restraining system for protecting a seated person, comprising: a safety belt (60) having a shoulder portion (62) extending over at least a part of the torso of the to be protected person when the restraining system is in its state of use, an inflatable airbag (5) attached to the shoulder portion (62) of the safety belt (60), said inflatable airbag (5) enclosing a gas space, and an inflator (64) for inflating the inflatable airbag (5), such that the inflatable airbag (5) inflates in front of the person when the inflator (64) is activated, characterized in that the inflatable airbag (5) comprises: a support sub-structure (S) enclosing a support part (18) of the gas space, and a restraining sub-structure (R) enclosing a restraining part of the gas space, said restraining sub-structure (R) comprising at least a left section (40) enclosing a left chamber (42) of the restraining part of the gas space and a right section (44) enclosing a right chamber (46) of the restraining part of the gas space, wherein in the inflated state the left section (40) and the right section (44) extend from the support sub-structure (S).

2. The restraining system according to claim 1 , wherein the restraining substructure (R) additionally comprises a top section (54) enclosing a top chamber (56) of the support part of the gas space.

3. The restraining system according to any one of the claims 1 or 2, wherein when the restraining system is in its state of use and when the inflatable airbag (5) is deployed, the restraining sub-structure (R) is located between the person to be protected and the support sub-structure (S).

4. The restraining system according to any one of the claims 1 to 3, wherein in the deployed state, the left section (40) and the right section (44) are spaced from one another, preferably by a distance between 2 and 20 cm.

5. The restraining system according to any one of the claims 1 to 4, wherein the safety belt (60) defines a gas conduit (63) or the safety belt carries a gas conduit (63) and the inflator (64) is in fluid communication with the gas space via the gas conduit (63).

6. The restraining system according to any one of the preceding claims, wherein at least one overflow is provided between the support part (18) of the gas space and the restraining part of the gas space.

7. The restraining system according to claim 6 and 7, wherein the support part (18) of the gas space is filled via the restraining part of the gas space, preferably via the left chamber (42) and the right chamber (46).

8. The restraining system of any one of the preceding claims, wherein the restraining sub-structure (R) additionally comprises a middle section (50) between the left section (40) and the right section (44).

9. The restraining system according to claim 8, wherein the middle section (50) encloses a middle chamber (52) being a part of the supporting part of the gas space and being in fluid communication with left chamber (42) and the right chamber (46).

10. The restraining system according to claim 9, wherein the middle chamber (32) is in fluid communication with the gas conduit (52) and the left chamber (22) and the right chamber (26) are filled via the middle chamber (32).

1 1. The restraining system according to claim 10, wherein the depth of the fully deployed middle chamber (52) is less than the depth of the fully deployed right chamber (46) and the depth of the fully deployed left chamber (42).

12. Inflatable (5) airbag adapted for being a part of the restraining system of any one of the preceding claims.

3. Method for manufacturing the inflatable airbag of claim 12, comprising the following steps:

(i) providing at least one supporting panel (10) for forming the support substructure (S), said at least one supporting panel (10) comprising at least one first overflow opening (12),

(ii) providing a restraining panel (20) and a supported panel (22) being essentially congruent with the restraining panel (20), or a joint panel having a restraining section and a supported section being congruent with the restraining section, said supported panel (22) or section comprising at least one second overflow opening (24),

(iii) placing the supported section or panel (22) onto the supporting panel (10) such that the at least one first overflow opening (12) and the at least one second overflow opening (24) at least overlap, and connecting the supporting panel (10) and the supported section or panel (22) via at least one overflow-opening surrounding connection (30) extending around the overlapping overflow openings (12, 24),

(iv) arranging the restraining section or panel (20) and the supported section or panel (22) on top of one another and applying at least one restraining sub-structure connection (32) to close the second part of the gas space,

(v) closing the at least one supporting panel to form the support chamber enclosing the support part (18) of the gas space.