Seatbelt device having an inflatable airbag

Abstract

The invention relates to a seatbelt device (1) having a seatbelt (2), at least one belt retractor (3, 4), a belt buckle (5) which can be fixedly fastened to the vehicle, a belt tongue (6) which divides the seatbelt (2) into a diagonal belt portion (15), the diagonal belt portion crossing the chest of an occupant in the buckled state, and a lap belt portion (14), the lap belt portion crossing the lap of the occupant in the buckled state, and which can be locked in the belt buckle (5) so as to be tension-resistant; an inflatable airbag (19) which is provided on the diagonal belt portion (15); and a gas generator (7) for inflating the airbag (20), wherein the airbag (20) has a main chamber (21), which is situated in front of the chest and the head of the occupant in the inflated state, and a feed chamber (17), which fluidically connects the main chamber (21) to the gas generator (7), the feed chamber (17) having, in the inflated state, a vertically oriented feed portion (22) which opens into the main chamber (21).

Description

[0001] 2025P00273 WO-PICT-STB - 1 -

[0002] SAFETY BELT DEVICE WITH AN INFLATABLE GASSBAG

[0003] The invention relates to a safety belt device with an inflatable gas bag having the features of the preamble of claim 1.

[0004] Seat belt systems in motor vehicles have long been state of the art and serve to restrain the occupant in an accident to prevent serious injuries. Three-point seat belt systems have proven particularly effective; these feature a seat belt that, at one end, can be attached to the vehicle structure or the seat itself via a vehicle-mounted end fitting on one side of the seat, and at the other end, can be wound up via a belt retractor that is also vehicle-mounted to the seat or the vehicle structure on the same side of the seat.Furthermore, a belt tongue is slidably guided on the seat belt, which can be locked in a belt buckle attached on the other side of the vehicle seat to achieve the 3-point geometry and, in the locked position, divides the seat belt into a diagonal belt section extending from the belt buckle diagonally across the occupant's chest to the belt retractor and a lap belt section extending from the belt buckle to the end fitting across the occupant's pelvis.

[0005] Furthermore, airbags have long been known in the art. These can be positioned at various locations within the vehicle and contain a gas-filled bag which, in the event of an accident, is rapidly inflated to a significantly increased volume by a gas generator. For example, front airbags, side airbags, curtain airbags, knee airbags, and overhead airbags are known. Due to their arrangement and their deliberately designed inflation behavior and geometry, they restrain the occupant in specific accident scenarios and, in particular, prevent the occupant from impacting the vehicle's internal structure. A particularly important airbag is the front airbag, which is located in the steering wheel for the driver and in the instrument panel for the front passenger. If front airbags are also provided for the rear seat occupants, these are located in the backrests or headrests of the front seats.The primary function of a front airbag is to restrain a forward-facing occupant in a frontal collision and protect them from impacting the vehicle's internal structure or the inside of the windshield with their head or upper body. If such an impact cannot be prevented in a very severe accident, the airbag can at least reduce the impact force. In modern vehicles, restraint systems combining seat belts and airbags have proven particularly effective. Initially, the seat belt restrains the occupant, while the airbag provides additional restraint during the forward movement phase. The impact forces on the occupant can be further reduced, and the forward movement controlled, through the targeted use of irreversible or reversible belt pretensioners and force limiters.

[0006] One disadvantage of such restraint systems, despite the significant reduction in occupant impact, is that restraint, particularly with airbags, always requires a specific orientation of the occupants relative to the airbags. So-called "out-of-position" (OOP) positions are especially problematic when the occupant, for example, bends down into the footwell, is in an extreme sleeping position, or is turning towards the rear seats. In these situations, the effectiveness of the airbag is considerably reduced. While the airbag will inflate, the occupant, due to their OOP position, will be performing a completely different movement and will therefore not be restrained by the airbag. Furthermore, the seat belts and airbags are mounted independently of each other on the vehicle, which alone increases the installation effort.However, even in their separate arrangement, their retention characteristics must be coordinated, which results in considerable effort in the design.

[0007] A restraint system combining a seat belt assembly and an airbag mounted on the seat belt assembly is already known from US patent 2014 / 0159350 A1. In this system, the occupant is restrained by both the seat belt and the airbag deploying from the seat belt. The airbag comprises an inflatable gas bag with a chamber, which is attached to the lap belt or diagonal belt section and deploys in front of the occupant's upper body upon activation.

[0008] Against this background, the invention is based on the objective of providing a safety belt device with a gas bag held on a diagonal belt section, with an improved inflation characteristic, particularly with regard to a possible collision with a steering wheel or other parts of the interior.

[0009] According to the invention, a safety belt device with the features of claim 1 is proposed to solve the problem. Further preferred developments can be found in the dependent claims, the figures, and the accompanying description. According to the basic idea of ​​the invention, it is proposed that the gas bag has a main chamber arranged in front of the occupant's chest and head when inflated, and a feed chamber connecting the main chamber to the gas generator in a flow-technical manner, and that the feed chamber has a vertically oriented feed section opening into the main chamber when inflated.

[0010] The proposed design of the airbag within the seatbelt assembly allows the airbag to be inflated at a very high speed within its holder on the diagonal belt section, thus aligning it vertically (in the Z-direction). This reduces the likelihood of a collision with the steering wheel or other interior components in front of the occupant's chest. It is crucial that the airbag is held by the diagonal belt section so that it inflates into the interior space in front of the occupant. The feed chamber with its vertically oriented feed section significantly reduces the inflation time required, ensuring the airbag is inflated as fully as possible before the occupant's forward movement begins.Due to its orientation within the feed section, the feed chamber serves to pre-position the gas bag and create a more stable base for inflating the main chamber. The vertical orientation of the feed section allows the feed chamber to be shorter, thus reducing the gas volume required to inflate the feed chamber and enabling significantly faster inflation of the gas bag within the feed chamber area.

[0011] It is further proposed that, when inflated, the feed chamber has an inlet section at its end facing the gas generator, directed towards the diagonal belt section. This proposed orientation of the feed chamber's inlet section simplifies the introduction of the gas flow into the feed chamber via a gas lance located on the diagonal belt section. Furthermore, this orientation of the inlet section reduces the lateral forces exerted by the gas bag on the diagonal belt section during inflation, thus improving the gas bag's position on the diagonal belt section.

[0012] It is further proposed that the gas bag be formed as a double layer of two interconnected fabric layers, and that the feed chamber be formed by a section between two spaced-apart joints of the fabric layers. This allows for very cost-effective production of the feed chamber, as the spacing of the joints can be easily used as a parameter for determining the chamber's volume. The joints can be made using seams, woven connections of the fabric layers in a one-piece woven process, welded joints, or similar methods.

[0013] It is further proposed that the width of the feed chamber in its uninflated state be less than 0.5 times the width of the tissue layers perpendicular to the longitudinal direction of the feed chamber. Due to the proposed dimensioning of the feed chamber's width, its cross-section and thus its volume in the inflated state are reduced to such an extent that, particularly in conjunction with the vertically oriented feed section, it inflates much more quickly to a stable vertical orientation, from which the inflation of the main chamber then takes place.

[0014] It is further proposed that the gas bag have at least two retaining sections, and that these retaining sections are located in the area of ​​the feed chamber. The advantage of this improvement lies in the fact that the feed chamber itself, and consequently the gas bag as a whole, is better stabilized, thereby providing improved support and holding of the gas bag in position, particularly during the initial phase, i.e., during the inflation of the feed chamber.

[0015] It is further proposed that the retaining sections be arranged sequentially with respect to the direction of gas flow in the feed chamber. This proposed arrangement of the retaining sections provides improved support for the gas bag in the feed chamber during the various inflation phases. The retaining sections are thus used more effectively to fix the gas bag, with only the first retaining section acting for fixation in the initial phase, and subsequently both retaining sections working together to secure the gas bag in its position.

[0016] It is further proposed that the feed chamber be arranged between two secondary chambers, with each secondary chamber being fluidically connected to the feed section of the feed chamber at one inlet side. The gas bag is thus laterally extended in the area of ​​the feed chamber by the two secondary chambers, creating a wider surface. The secondary chambers are only inflated once the feed chamber is already inflated and the gas flow exits the feed chamber via the vertical feed section and enters the secondary chambers via the inlet side. Since the feed chamber is arranged between the secondary chambers, each secondary chamber is inflated by a portion of the gas flow that is deflected by 180 degrees. It is further proposed that the feed chamber and its feed section open into a central section of the gas bag.The feed chamber, which is inflated more quickly by the solution according to the invention, thus forms a central section that stabilizes the entire gas bag during inflation, from which the gas bag is inflated.

[0017] The invention is explained below with reference to a preferred embodiment and the accompanying figures.

[0018] Fig. 1 a safety belt device according to the invention; and

[0019] Fig. 2 shows an enlarged section of the safety belt assembly with an deployed gas bag; and

[0020] Fig. 3 shows an enlarged section of the gas bag with the feed chamber. Figure 1 shows a safety belt assembly 1 according to the invention, comprising a safety belt 2, two belt retractors 3 and 4, a belt buckle 5, a gas generator 7, a belt tongue 6, a deflection device 11, and a belt guide 12. The deflection device 11 and the belt guide 12 each have a belt slot or a belt guide opening through which the safety belt 2 is guided and / or deflected to achieve a predetermined path. For this purpose, the deflection device 11 and the belt guide 12 are fixedly attached to the vehicle, to a vehicle seat, a B-pillar, a C-pillar, or another location in the vehicle structure.

[0021] The safety belt 2 comprises two separate webbing sections, the first ends of which can each be wound onto one of the belt retractors 3 or 4. The belt retractors 3 and 4 are themselves fixedly attached to the vehicle structure or to the vehicle seat on one side and, in a locked position, form a fixed connection between the ends of the webbing sections and the vehicle structure in a known manner.

[0022] The other ends of the webbing sections are attached to the belt tongue 6, which, to achieve the 3-point geometry, can be locked in the belt buckle 5, which is attached to the vehicle structure or to the vehicle seat itself on the other side of the vehicle seat. The belt buckle 5 is connected via a flexible pull cord 9 to a vehicle-mounted retaining element 8. Furthermore, a vehicle-mounted gas generator 7 is provided, which is fluidically connected to a connection port of the belt buckle 5 via a flexible filling hose 10.

[0023] In the locked position of the belt tongue 6, the safety belt 2 has a 3-point geometry. One webbing section forms a lap belt section 14 that crosses the occupant's pelvis, and the other webbing section forms a diagonal belt section 15. This diagonal section runs from the belt tongue 6 to the deflection device 11 and transitions into a vertical section 13 from the deflection device 11, via the belt guide 12, to the belt retractor 3. A gas bag 20, visible in Figures 2 and 3, is attached to the diagonal belt section 15. The gas bag 20 has a supply chamber 17 with an inlet section 23. This inlet section is fluidically connected to the connection port of the belt tongue 6 and, via this port, to a gas lance in the buckle 5. The gas lance in the buckle 5 is connected to the gas generator 7 via a filling hose 10.The fluidic connection between the connecting piece of the belt tongue 6 and the gas lance in the belt buckle 5 can be established before the gas generator 7 is activated, or it can be established only by the activation of the gas generator 7. The gas bag 20 has two retaining sections 26 and 27 with which it is held to the diagonal belt section 15. The retaining sections 26 and 27 are arranged on the gas bag 20 such that, in its deployed position (which would be the inflated position upon activation of the gas generator 7), the gas bag 20 is positioned with a main chamber 21 in front of the occupant's head and chest, the positioning of the gas bag 20 being defined by the course and arrangement of the diagonal belt section 15.Since the diagonal belt section 15, when the safety belt device 1 is in its applied state, generally runs in a fixed spatial relationship to the buckled occupant over the shoulder and diagonally across the occupant's chest, this also results in a fixed spatial relationship of the unfolded gas bag 20 to the occupant.

[0024] The gasbag 20 is formed from two layers of fabric, which are connected in certain zones and not in others. The fabric layers are generally manufactured as separate layers, and the connections can be made, for example, by seams. Furthermore, the gasbag 20 can also be manufactured using a one-piece woven (OPW) process, in which the layers are produced in a single weaving operation and the connections are created within the weaving process itself.

[0025] The gasbag 20 has a main chamber 21, which is shaped and arranged so that, when the gasbag 20 is inflated, it is positioned in front of the occupant's chest and head. Furthermore, the gasbag 20 has a supply chamber 17 and two secondary chambers 18 and 19 located next to the supply chamber 17, which, when inflated, are situated below the main chamber 21. The supply chamber 17 is formed by the space between two connections 24 and 25, such as seams, between the fabric layers. The supply chamber 17 has a supply section 22 opening centrally into a middle section 16 of the main chamber 21 and an inlet section 23 located at its lower end. The inlet section 23 is shaped by the course of the connections 24 and 25 such that the incoming gas flow is directed approximately in the direction of the adjacent diagonal belt section 15.This ensures that the gas is introduced into the feed chamber 17 through the inlet section 23 with the lowest possible transverse forces exerted on the diagonal belt section 15. Further along, the connections 24 and 25 are arranged and aligned such that the gas flow from the feed section 22 is introduced into the main chamber 21 as vertically and centrally as possible. As a result, the gas flow from the inlet section 23 through the feed chamber 17 to the feed section 22 in the main chamber 21 is as short and direct as possible.The connections are arranged at least in the middle of the feed chamber 17 and in the area of ​​the feed section 22 at a distance from each other that is less than half the total width of the gas bag 20 in this area, i.e. less than the sum of the widths of the auxiliary chambers 18 and 19 in this area perpendicular to the longitudinal direction of the guide chamber 17, i.e. perpendicular to the longitudinal direction of the flow direction of the gas stream in the feed chamber 17.

[0026] This results in a feed chamber 17 with a reduced volume and the shortest possible length in the direction of gas flow, so that when the gas generator 7 is activated, the feed chamber 17 is inflated to a stable structure with a corresponding internal pressure in the shortest possible time before the occupant begins to move forward. This reduces the probability of the gas bag 20 colliding with a steering wheel or another part of the vehicle's interior structure in front of the occupant. Starting from this already filled feed chamber 17, the main chamber 21 is then inflated.

[0027] The retaining sections 26 and 27 are arranged on one of the fabric layers in the area of ​​the feed chamber 17, so that the gas bag 20 is supported as stably as possible in the initial phase of its deployment in the area of ​​the feed chamber 17. The retaining sections 27 and 26 are arranged one behind the other in the direction of flow, so that the feed chamber 17 is supported over as large a portion of its length as possible. The secondary chambers 18 and 19 each have an inlet adjacent to the feed section 22 of the feed chamber 17, through which a portion of the gas flow exiting the feed section 22 enters the secondary chambers 18 and 19 via a 180-degree deflection, as can be seen in Fig. 3. This causes the gas bag 20 to inflate into a wider structure in its lower section as well, which is formed by the combination of the two secondary chambers 18 and 19 with the supply chamber 17 arranged between them. Reference numeral list

[0028] 1 Seat belt device 2 Seat belt

[0029] 3 First seatbelt retractor

[0030] 4 Second belt retractor

[0031] 5 Seatbelt buckle

[0032] 6. Belt tongue

[0033] 7 Gas generator

[0034] 8 retaining element

[0035] 9 tow rope

[0036] 10 Filling hose

[0037] 11 Deflection device

[0038] 12 Belt guide part

[0039] 13 Vertical section

[0040] 14 Pelvic belt section 15 Diagonal belt section 16 Midsection

[0041] 17 Feed chamber

[0042] 18 Side chamber

[0043] 19 Side chamber

[0044] 20 gasbag

[0045] 21 Main Chamber

[0046] 22 Feed section

[0047] 23 Inlet section

[0048] 24 connections

[0049] 25 connections

[0050] 26 Stop section

[0051] 27 Stop section

Claims

2025P00273 WO-PICT-STB - 9 - Claims 1. Seat belt assembly (1) with -a seat belt (2), -at least one seatbelt retractor (3,4), -a vehicle-mountable seat belt buckle (5), -a belt tongue (6) dividing the safety belt (2) into a diagonal belt section (15) crossing the chest of an occupant when fastened and a lap belt section (14) crossing the occupant's pelvis when fastened, which can be locked in the belt buckle (5) in a tensile-resistant manner, and -an inflatable gas bag (20) arranged on the diagonal belt section (15), and -a gas generator (7) for inflating the gas bag (20), characterized in that -the gasbag (20) has a main chamber (21) arranged in the inflated state in front of the chest and head of the occupant and a feed chamber (17) which fluidically connects the main chamber (21) with the gas generator (7), and -the feed chamber (17) in the inflated state has a vertically oriented feed section (22) opening into the main chamber (21).

2. Safety belt device (1) according to claim 1, characterized in that - the feed chamber (17) in the inflated state has at its end facing the gas generator (7) an inflow section (23) directed towards the diagonal belt section (15).

3. Safety belt device (1) according to one of claims 1 or 2, characterized in that -the gas bag (20) is formed in two layers from two interlocked layers of fabric, and -the feed chamber (17) is formed by a section between two connections (24, 25) of the fabric layers arranged at a distance from each other.

4. Safety belt device (1) according to claim 3, characterized in that -the width of the feed chamber (17) is less than 0.5 times the width of the fabric layers in the direction perpendicular to the longitudinal direction of the feed chamber (17).

5. Safety belt device (1) according to any one of claims 1 to 4, characterized in that -the gas bag (20) has at least two holding sections (26,27), and-the holding sections (26,27) are arranged in the area of ​​the feed chamber (17).

6. Safety belt device (1) according to claim 5, characterized in that the retaining sections (26, 27) are arranged one behind the other in relation to the direction of flow of the gas stream in the feed chamber (17).

7. Safety belt device (1) according to one of claims 1 to 6, characterized in that -the feed chamber (17) is arranged between two auxiliary chambers (18,19), and -the side chambers (18,19) are each fluidically connected at an inlet side to the feed section (22) of the feed chamber (17).

8. Safety belt device (1) according to one of claims 1 to 7, characterized in that -the feed chamber (17) with the feed section (22) opens into a central middle section (16) of the gas bag (20).

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