Restraining system and inflatable airbag for motor vehicle for restraining occupant seated on vehicle seat

Abstract

The invention relates to a restraint system of a motor vehicle for restraining an occupant seated on a vehicle seat, comprising: a safety belt device having an inflatable airbag; the invention relates to a safety belt device (2) comprising an airbag (15), which is fluidically connected to an occupant (1), and a gas generator, which is fluidically connected to the airbag (15) and which, when activated, is inflated with gas, the airbag (15) having a holder for holding the airbag (15) on an oblique belt section (6) of a safety belt (18) of the safety belt device (2), which oblique belt section spans a chest (5) of the occupant (1), wherein the airbag (15) has a triangular basic shape with rounded corners, and the airbag (15) in the inflated state has an orientation defined by its mounting on the oblique belt portion (6) wherein the two rounded corners (21, 22) are horizontally arranged adjacent to each other, and wherein the rounded corner (20) extends centrally upward between the horizontally arranged rounded corners (21, 22).

Description

[0001] The present invention relates to a restraint system having the features described in the preamble of claim 1 and to an inflatable airbag as described in the preamble of claim 10.

[0002] Seat belt systems for motor vehicles have long been known in the art for restraining occupants to prevent serious injury in the event of an accident. For this purpose, seat belt systems with a three-point design have proven particularly successful, in which one end of the seat belt is secured to the vehicle structure via an end fitting under the vehicle seat, and the other end can be retracted onto a seat belt retractor on the same side. A buckle is guided to allow displacement on the seat belt, and this buckle can be locked onto a buckle located on the opposite side of the vehicle seat to achieve the three-point geometry of the seat belt. In the locked position, the buckle then divides the seat belt into a diagonal section that crosses the occupant's chest and a lap belt section that crosses the occupant's pelvis.

[0003] Furthermore, airbag systems are well-known in the prior art. These systems can be positioned in various locations within a vehicle and contain airbags that, in the event of an accident, are suddenly inflated to a significantly increased volume via a gas generator. For example, front airbags, side airbags, curtain airbags, knee airbags, and roof airbags are known. Due to their placement, intentionally designed inflation behavior, and inflation geometry, these airbags can restrain occupants in specific accident scenarios, particularly preventing impact on the vehicle's internal structure in the event of an accident. A particularly important type of airbag is the front airbag. The driver's front airbag is located in the steering wheel, and the front passenger's front airbag is located in the dashboard. When front airbags are also provided for rear seat occupants, these airbags are located in the backrests or headrests of the front seats. Front airbags are essentially designed to catch occupants facing the direction of travel in the event of a frontal collision and to prevent their heads or upper bodies from impacting the vehicle's internal structure or the inside of the windshield. If such a collision cannot be prevented in the event of a very serious accident, at least the impact momentum can be reduced.

[0004] In modern vehicles, restraint systems that combine seatbelt and airbag restraint for occupants have proven particularly useful, where occupant restraint is achieved via the seatbelt in the initial phase and via the airbag in the later phase of forward displacement. In this case, the load acting on the occupant can be further reduced by selectively using irreversible or reversible belt tensioners and force limiting devices, thereby controlling forward displacement.

[0005] However, despite the significant reduction in load on the occupants, a drawback of such restraint systems is that restraint requires a specific orientation of the occupant relative to the airbag system, especially when restrained by the airbag system. In such cases, the so-called "out-of-position" (OOP) situation becomes particularly challenging if the occupant, for example, is bent down into the legroom, in an extreme sleeping posture, or turned to the rear seat. Consequently, the effectiveness of the airbag system is significantly reduced. Although the airbag is subsequently inflated, the occupant, due to being in OOP, performs entirely different movements and is not subsequently caught by the airbag system. Furthermore, while the seatbelts and airbags are independently secured to the vehicle, which in itself increases assembly work, they must be matched in terms of their restraint characteristics, even in their individual arrangements, resulting in considerable design complexity.

[0006] A restraint system comprising a combination of a seatbelt device and an airbag disposed on the seatbelt of the seatbelt device is known from US 2014 / 0159350 A1, wherein an occupant is restrained both by the seatbelt and by an airbag that deploys on the seatbelt. In this case, the airbag comprises an inflatable airbag having a chamber held in the pelvic girdle portion or the ramp portion, which deploys in front of the occupant's upper body when activated.

[0007] Document DE 10 2021 111 522 A1 discloses a restraint system with a seatbelt having a diagonal strap portion, wherein an airbag with a main chamber and an auxiliary chamber is disposed on the diagonal strap portion, wherein the main chamber has a specific geometry having a wider central portion and two narrower edge portions, and the auxiliary chamber is connected to the main chamber at the central portion. The auxiliary chamber can provide additional damping for further forward displacement of the occupant after initial contact. Furthermore, due to the wider central portion of the main chamber, the occupant is restrained over a greater width.

[0008] In this context, the object of the present invention is to provide a restraint system having a seat belt device having a seat belt and an airbag held on the diagonal strap portion of the seat belt, and an inflatable airbag for mounting on the diagonal strap portion, the restraint system having a simplified structural design and at the same time providing good restraint for the occupant in the event of an accident.

[0009] The basic idea of ​​the present invention is to provide a restraint system according to the preamble of claim 1, wherein the airbag has a basic triangular shape with rounded corners, and the airbag in the inflated state has an orientation defined by its mounting on the inclined band portion, wherein two rounded corners are arranged horizontally adjacent to each other, and one of the rounded corners extends upward from the center between these horizontally arranged rounded corners.

[0010] The proposed restraint system has the advantage that the airbag is formed from a single inflatable chamber, resulting in a much simpler structural design. This significantly reduces the manufacturing cost of the restraint system. Furthermore, due to the proposed airbag shape and orientation, the restraint system exhibits improved restraint characteristics because the occupant is restrained in a widened portion of the upper body region, particularly the shoulder region, via horizontally arranged, rounded sections adjacent to each other, while simultaneously restrained in the head region via an upwardly extending area through the center of the airbag's rounded corners. Therefore, the restraint system better adapts to the occupant's body structure through the airbag's shape and orientation defined by its installation. The airbag's shape and orientation are specifically designed so that the occupant's head and shoulders are inserted into the airbag when restrained. Protection of the head and shoulders is particularly important because injuries to these parts of the body are especially severe. Moreover, these parts of the body travel the greatest forward distance and experience the greatest acceleration during an accident, resulting in particularly high loads acting on them in the event of an impact. This means that in the event of an accident, the airbag's specific shape provides special protection to those areas of the body, thus effectively reducing the likelihood of serious injury to the occupant. This specific shape is appropriately oriented due to its fastening to the diagonal strap. The installation on the diagonal strap is particularly important because, due to the geometry of the seatbelt, the diagonal strap is always positioned in front of the occupant's chest when the seatbelt is fastened, and because the airbag is mounted on it, it is also positioned in front of the occupant's chest when the seatbelt is fastened.

[0011] Furthermore, it is proposed that, when the airbags are inflated, the airbags are arranged horizontally with rounded corners adjacent to each other on different sides of the ramp section. Therefore, in addition to the restraint provided by the ramp section, the occupant is also restrained by the inflated airbags on both sides of the ramp section.

[0012] Furthermore, it is proposed that the upward-extending rounded corner of the airbag's center is positioned above the diagonal straps during inflation. This means that above the diagonal straps, the occupant is more effectively restrained in their central body area, particularly in their neck extending from the shoulders and their head extending from the neck.

[0013] Furthermore, it is proposed that the radius of the rounded corners arranged horizontally adjacent to each other be smaller than the radius of the rounded corner of the central bulge. Since the radius of the rounded corner of the central bulge is larger, the restraint can be better adapted to a relatively large head compared to a smaller shoulder by making the airbag larger or wider in the region of the rounded corner of the central bulge due to the larger radius in the middle.

[0014] Furthermore, it is proposed that the airbag has a radially inwardly curved shape on its edge surfaces that connect the rounded corners to each other. This proposed development allows for a reduction in airbag volume without negatively impacting the airbag's restraint function. Conversely, it improves the utilization rate of the gas volume generated by the gas generator for occupant restraint. This reduces the volume of generated gas, thereby allowing for a reduction in the size of the gas generator itself. Additionally, it shortens the time required for the airbag to inflate to full deployment while maintaining the same gas volume generation rate.

[0015] Furthermore, it is proposed that the radius of curvature of the airbag on its lower edge surface is smaller than that on its lateral edge surfaces, which connect two horizontally arranged rounded corners adjacent to each other. These lateral edge surfaces connect the horizontally arranged rounded corners adjacent to each other with the upper central rounded corner. Due to the proposed solution, the edge surfaces connecting the two horizontally arranged rounded corners adjacent to each other extend deeper into the airbag than the two edge surfaces extending to the upper central rounded corner. This is advantageous because the occupant is restrained at a larger contact surface in the transition area from the head to the shoulders, which is important for occupant restraint, while the airbag's gas volume is intentionally reduced by a larger reduction in the contact surface in the occupant's central chest region, which is in any case restrained by the diagonal band portion.

[0016] Furthermore, it is proposed that the airbag is symmetrical about an axis of symmetry in its vertical orientation, which extends at the center through the upward-extending rounded corners of the airbag. This ensures symmetrical restraint of the occupants.

[0017] Furthermore, it is proposed that the inclined band section has a gas line that connects the gas generator to the airbag in terms of flowability. Therefore, the airbag is filled by an external gas generator via the gas line of the inclined band section, eliminating the need to place the gas generator directly on the airbag. Thus, the airbag can be secured to the inclined band section without a gas generator and with significantly reduced installation space requirements.

[0018] Furthermore, a tension band is provided that connects the airbag to the diagonal strap portion and restricts the deformation of the airbag during inflation. During inflation, especially when fully inflated, the tension band holds the airbag in a specific orientation relative to the diagonal strap portion and relative to the occupant restrained therein, allowing it to be used optimally to restrain the occupant. Moreover, even during forward displacement of the occupant and while the occupant is restrained, the airbag is held in a predetermined position relative to the occupant and the diagonal strap portion via the tension band.

[0019] Furthermore, to achieve this objective, an inflatable airbag for mounting on the bend strap portion of a seatbelt assembly is proposed. The airbag has a basic triangular shape with rounded corners, and the inflated airbag has an orientation defined by its mounting on the bend strap portion, wherein two rounded corners are arranged horizontally adjacent to each other, and one of the rounded corners extends upward from the center between these horizontally arranged rounded corners. The proposed inflatable airbag can be installed as an add-on device on other unchanged seatbelt assemblies, wherein the inflatable airbag only needs to be equipped with a retainer for fastening to the bend strap portion.

[0020] The airbag and its retainer are preferably designed such that the rounded corners of the inflated airbag (arranged horizontally adjacent to each other) are positioned on different sides of the ramp portion. Thus, the airbag provides symmetrical support for the occupant on both sides of the ramp portion and is held in place by the retainer on the ramp portion during inflation and restraint.

[0021] Furthermore, the airbag retainer is designed so that the airbag's center, with its rounded corner extending upwards, is positioned above the diagonal straps when the airbag is inflated. This central angle of the airbag above the diagonal straps provides improved restraint for the occupant, particularly in the upper body and head area.

[0022] Furthermore, it is proposed that the radius of the rounded corners of the horizontally arranged airbags adjacent to each other is smaller than the radius of the rounded corner of the central convex shape. Therefore, the shape of the airbag is specially designed to restrain the occupant in the area of ​​the head and shoulders, so that the occupant's head and shoulders will travel the maximum distance when the occupant moves forward during an accident.

[0023] By giving the airbag a radially inwardly curved shape on its edge surfaces that connect the rounded corners to each other, the volume of gas required to inflate the airbag can be reduced without negatively affecting the airbag's restraining function.

[0024] The gas volume can be further reduced without compromising the restraint function, particularly through an airbag with a radius of curvature on its lower edge surface smaller than that on its lateral edge surface. The lower edge surface is connected to two adjacent rounded corners arranged horizontally, and the lateral edge surfaces are connected to the upper center rounded corner with adjacent rounded corners arranged horizontally.

[0025] Furthermore, it is proposed that the airbag is symmetrical about an axis of symmetry that extends from the center through an upwardly extending rounded corner. Therefore, the airbag can symmetrically restrain the occupant in the event of an accident, while minimizing and uniformly distributing the load on the occupant.

[0026] The invention will now be explained using preferred embodiments with reference to the accompanying drawings. In the drawings:

[0027] Figure 1A first perspective view and a second perspective view of an occupant having a restraint system according to the invention, the restraint system having an airbag according to the invention in the normal locked position; and

[0028] Figure 2 It shows Figure 1 The restraint system with an inflatable airbag according to the present invention; and

[0029] Figure 3 It shows Figure 1 The restraint system according to the invention includes an inflatable airbag and a steering wheel including an inflatable driver airbag; and

[0030] Figure 4 Cutouts of the oblique band portion with an inflatable airbag are shown in three different embodiments.

[0031] Figure 1 An occupant 1 is shown seated on a vehicle seat 3 having a backrest 9 and a seat surface 10, restrained by a seatbelt 18 applied by a seatbelt device 2. The seatbelt 18 is wound at its first upper end to a first seatbelt retractor 13 and at its second lower end secured to the vehicle structure or vehicle seat 3 via an end fitting 14, or may be wound to a second seatbelt retractor fixedly mounted in the vehicle. The first seatbelt retractor 13 may also be secured to the vehicle seat 3, such as in this case to the area of ​​the upper edge of the backrest 9, or to the vehicle structure, wherein additional deformable portions of the seatbelt 18 may be disposed in the path of the first seatbelt retractor 13. Figure 1 As can be seen in the left-hand diagram, the locking tongue 12 is guided in a displaceable manner on the seat belt 18. This locking tongue can be locked relative to the end fitting 14 and the first seat belt retractor 13 in a buckle 11 located on the other side of the vehicle seat 3. When locked in the buckle 11, the locking tongue 12 divides the seat belt 18 into a diagonal strap portion 6 that crosses the chest 5 of the occupant 1 and a lap belt portion 7 that crosses the pelvis 4 of the occupant 1. Furthermore, additional irreversible or reversible belt tensioners and force limiting devices may be provided on the first seat belt retractor 13, on the end fitting 14, or even on the buckle 11.

[0032] Occupant 1 is restrained by a restraint system designed according to the invention, which has a seatbelt device 2 and an airbag 15 according to the invention arranged on the diagonal strap portion 6, wherein the airbag 15 is visible due to the thickening of the seatbelt 18 in the area of ​​the diagonal strap portion 6. Furthermore, a second seatbelt retractor may be provided, which replaces the end fitting 14 and winds up the seatbelt 18 from the free end of the lap belt portion 7. The lap belt portion 7 and the diagonal strap portion 6 can then preferably be designed as separate strap portions, as they are fixedly connected to the buckle 12 at one end in each case. In this case, the buckle 12 is guided on the seatbelt 18 in a non-displaceable manner, and a separation is formed between the lap belt portion 7 and the diagonal strap portion 6. The airbag 15 is held and arranged on the diagonal strap portion 6 by a retainer, in a position such that the diagonal strap portion 6 can be completely wound to a stop position by the first seatbelt retractor 13 without having to use the first seatbelt retractor 13 to wind the airbag 15. The retainer may be part of the airbag 15, for example, in the form of a ring disposed on the airbag 15, or it may be a retainer separate from the airbag 15, wherein the retainer may also additionally form a cover for the airbag 15. The airbag 15 is equipped with a gas generator (not shown) that, when activated, rapidly generates a large amount of gas, thereby inflating the airbag 15. Figures 2 to 4 The geometry is shown. The gas generator can be arranged and / or secured to the seatbelt retractor 13 or the locking mechanism 12, or it can be externally secured to the vehicle structure by a separate fastening device, provided that the gas generator is connected to the airbag 15 for fluidity.

[0033] When inflated, the airbag 15 has a basic triangular shape, such as Figure 4 As can be seen in the left-hand diagram, it has three rounded corners 20, 21, and 22, and is fastened to the diagonal strap portion 6 via a retainer (not shown). To fasten the airbag 15 to the diagonal strap portion 6, a housing or cover may be provided that surrounds the airbag 15 in a folded or rolled-up state and is fastened to the diagonal strap portion 6. Alternatively, the airbag 15 can also be installed by directly sewing the airbag 15 to the diagonal strap portion 6, wherein a housing or cover for encapsulating the airbag 15 may be additionally provided.

[0034] exist Figure 4The orientation of the airbag 15 relative to the inclined band portion 6, as can be seen, is defined by the mounting of the airbag 15 on the inclined band portion 6. The airbag 15 has two of its rounded corners 21 and 22 arranged horizontally adjacent to each other in an orientation. A third rounded corner 20 extends upward from the center between the horizontally arranged rounded corners 21 and 22, thus creating the basic triangular shape of the airbag 15. Due to its mounting on the inclined band portion 6, the airbag 15 is oriented such that the two horizontally arranged rounded corners 21 and 22, adjacent to each other, are arranged on different sides of the inclined band portion 6, and the upper central rounded corner 20 is positioned above the inclined band portion 6.

[0035] The radius RA of the lower fillets 21 and 22, arranged horizontally adjacent to each other, is smaller than the radius of the central upper fillet 20. Therefore, the surface area of ​​the airbag 15 in the region of the upper fillet 20 is larger than the surface area in the region of the lower fillets 21 and 22 arranged adjacent to each other. The edge surfaces 23, 24, and 25 of the airbag 15 have a curvature pointing radially inward relative to the airbag 15, thereby reducing the volume of the airbag 15 while maintaining the dimensions of the fillets 20, 21, and 22. In contrast, the lower edge surface 25 connecting the horizontally arranged fillets 21 and 22 has a smaller radius of curvature R1, while the edge surfaces 23 and 24 connecting the lateral fillets 21 and 22 to the central fillet 20 have a larger radius of curvature R2. Therefore, the lower edge surface 25 extends deeper into the airbag 15 than the lateral edge surfaces 23 and 24. Figure 4 As can be seen in the middle diagram, the tension band 17 can be additionally attached to the inclined band portion 6, and its free end is connected to the airbag 15, holding the airbag 15 in place during inflation and limiting the deformation of the airbag 15 during inflation. Additionally, a gas line 19 can be provided in the inclined band portion 6, such as... Figure 4 As can be seen in the diagram on the right, the gas line connects to both the gas generator and the airbag 15 in terms of fluidity. Therefore, the tension band 17 can also be designed as a gas line.

[0036] like Figure 2As can be seen, due to the fastening of the inclined band portion 6 and the orientation defined thereby, the airbag 15 is inflated, so that the occupant 1 is covered by the airbag 15, specifically the portion of the upper central rounded corner 20 of the airbag 15 covering the area of ​​his head 8, and the portions of the airbag 15 arranged with adjacent rounded corners 21 and 22 covering the area of ​​his shoulders 26. In the normal driving position of the occupant 1, the airbag 15 is supported by the upper arm of the occupant 1 below the portions of the adjacent rounded corners 21 and 22, i.e., on the edge surface 25. Therefore, when the occupant 1 is displaced forward in an accident, his head 8 is inserted into the upper part of the airbag 15 formed by the central upper rounded corner 20, and his shoulders 26 are inserted into the lower part of the airbag 15 arranged horizontally with adjacent rounded corners 21 and 22. Due to its shape, the airbag 15 effectively replicates the geometry of the occupant 1 in the head and shoulder areas. Since the head 8 and shoulders 26 travel the maximum distance and are subjected to particularly large acceleration when displaced forward from the normal driving position in the event of an accident, the restraint of the occupant 1 in these body areas provides particularly effective protection in the event of an accident and particularly effectively reduces the load acting on the occupant.

[0037] Figure 3 It shows Figure 2 The restraint system includes a steering wheel 8 and a driver airbag 16 inflated from the steering wheel 8. An airbag 15 held on the sloping section 6 is positioned and oriented in the inflated state such that it is located between the driver airbag 16 and the occupant 1, thereby covering the chest 5 in the area of ​​the shoulder 26 and the front of the head 8.

Claims

1. A restraint system for a motor vehicle for restraining an occupant (1) seated in a vehicle seat (3), the restraint system having a seat belt device (2) having -Inflatable airbag (15), and - A gas generator, which is connected to the airbag (15) in terms of fluidity and inflates the airbag (15) with gas when activated, wherein - The airbag (15) has a retainer for holding the airbag (15) on the diagonal strap portion (6) of the seat belt (18) of the seat belt device (2), the diagonal strap portion crossing the chest (5) of the occupant (1). Its features are, -The airbag (15) has a basic triangular shape with rounded corners, and - The airbag (15) has an orientation defined by its mounting on the inclined band portion (6) when inflated, wherein two rounded corners (21, 22) are arranged horizontally adjacent to each other, and wherein the rounded corner (20) extends upward at the center between the horizontally arranged rounded corners (21, 22).

2. The constraint system according to claim 1, characterized in that, - The airbags (15) are arranged horizontally with rounded corners (21, 22) adjacent to each other when inflated, and are arranged on different sides of the inclined band portion (6).

3. The constraint system according to any one of claims 1 or 2, characterized in that, The upward-extending rounded corner (20) of the center of the airbag (15) is positioned above the inclined band portion (6) when inflated.

4. The constraint system according to any one of claims 1 to 3, characterized in that, - The radius (RA) of the rounded corners (21, 22) arranged horizontally to be adjacent to each other is smaller than the radius of the central raised rounded corner (20).

5. The constraint system according to any one of claims 1 to 4, characterized in that, - The airbag (15) has a radially inwardly curved shape on its edge surfaces (23, 24, 25) that connect the rounded corners (20, 21, 22) to each other.

6. The constraint system according to claim 5, characterized in that, - The radius of curvature (R1) of the airbag (15) on the lower edge surface (25) is smaller than the radius of curvature on the lateral edge surfaces (23, 24), the lower edge surface being connected to the two rounded corners (21, 22) that are horizontally arranged to be adjacent to each other, and the lateral edge surfaces being connected to the upper center rounded corner (20) that are horizontally arranged to be adjacent to each other.

7. The constraint system according to any one of claims 1 to 6, characterized in that, - The airbag (15) is symmetrical about a vertically oriented axis of symmetry (S), which extends at the center through the upwardly extending fillet (20) of the airbag (15).

8. The constraint system according to any one of claims 1 to 7, characterized in that, - The inclined band portion (6) has a gas line (19) that connects the gas generator to the airbag (15) in terms of fluidity.

9. The constraint system according to any one of claims 1 to 8, characterized in that, - A tension band (17) is provided, which connects the airbag (15) to the inclined band portion (6) when inflated and restricts the deformation of the airbag (15) when inflated.

10. An inflatable airbag (15) for installation on the diagonal strap portion (6) of a seatbelt device (2). Its features are, - The airbag (15) has a basic triangular shape with rounded corners (20, 21, 22), and - The airbag (15) has an orientation defined by its mounting on the inclined band portion (6) when inflated, wherein two rounded corners (21, 22) are arranged horizontally adjacent to each other, and wherein the rounded corner (20) extends upward at the center between the horizontally arranged rounded corners (21, 22).

11. The inflatable airbag (15) according to claim 10, characterized in that, - The rounded corners (21, 22) of the airbag (15) are arranged horizontally adjacent to each other when the airbag is inflated, and are arranged on different sides of the inclined band portion (6).

12. The inflatable airbag (15) according to any one of claims 10 or 11, characterized in that, - The upward-extending rounded corner (20) of the center of the airbag is positioned above the inclined band portion (6) when inflated.

13. The inflatable airbag (15) according to any one of claims 10 to 12, characterized in that, - The radius (RA) of the rounded corners (21, 22) arranged horizontally to be adjacent to each other is smaller than the radius of the central raised rounded corner (20).

14. The inflatable airbag (15) according to any one of claims 10 to 13, characterized in that, - The airbag (20) has a radially inwardly curved shape on its edge surfaces (23, 24, 25) that connect the rounded corners (20, 21, 22) to each other.

15. The inflatable airbag (15) according to claim 14, characterized in that, - The radius of curvature (R1) of the airbag (15) on the lower edge surface (25) is smaller than the radius of curvature on the lateral edge surfaces (23, 24), the lower edge surface being connected to the two rounded corners (21, 22) that are horizontally arranged to be adjacent to each other, and the lateral edge surfaces being connected to the upper center rounded corner (20) that are horizontally arranged to be adjacent to each other.

16. The inflatable airbag (15) according to any one of claims 10 to 15, characterized in that, - The airbag (15) is symmetrical about an axis of symmetry (S), which extends at the center through the upwardly extending rounded corner (20).

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