Vehicle seat with a safety belt device

Abstract

The vehicle seat (2) has a safety belt device (8) which is designed to prevent an occupant from slipping beneath a lap belt (10A) (submarining) in the event of a crash. The safety belt device (8) has a first belt system (9) with a first safety belt (10) with at least the lap belt (10A), and a second belt system (15) with a second safety element (16) which is separate from the first safety belt (10) and which has a seat section (22) which runs transversely within the seat part (6). The second safety element (16) is attached, on one side, to an anchor point (18) and, on the other side, to a belt pretensioner (20) which is designed to exert a tensile stress on the second safety element (16), specifically in such a way that, in the event of triggering, the second safety element (16) is automatically tightened with the aid of the belt tensioner (20) in order to prevent an occupant from slipping beneath the lap belt (10A). As a result of the second safety element (16) being formed separately, slipping beneath the lap belt is reliably prevented and, as a result of the integration of the second safety element into the seat part (6), in particular into a cushion (26), this is achieved without loss of comfort.

Description

[0001] Page 1

[0002] Description

[0003] Vehicle seat with a safety belt device

[0004] The invention relates to a vehicle seat with a safety belt device which is designed to prevent an occupant from being pulled through a lap belt in the event of a crash.

[0005] Such a submarining is also known as submarining. Due to the forces occurring in a (frontal) crash, there is a risk that the occupant will be pressed into the seat cushion and thus slide under the lap belt.

[0006] This problem, which is known in itself, is exacerbated in comfort seats that provide a relaxation or reclining position.

[0007] Various measures can be taken to prevent this submersion.

[0008] For example, the seat can be reinforced in the front area of ​​the thigh support, which, however, leads to additional weight and costs. A dedicated edge for pelvic support, made of sheet metal or plastic, can also be integrated. Besides the added weight and increased costs, this also results in reduced comfort, as there is only thin padding / comfort layer in the edge area. An active mechanism can also be integrated, such as a ramp built into the seat that is activated in the event of a crash. The integration of airbags, for example in the side bolsters of the seat cushion or in the seat surface, is also possible. However, the latter solutions lead to...

[0009] Page 2 (2024344) again leads to additional mass, increased costs and an additional installation space requirement in the seat.

[0010] Alternatively, some solutions also propose an optimized belt system. Examples of such solutions can be found in...

[0011] DE 11 2015002402 T5, WO 2023 / 025483 A1, EP 1 968819 B1,

[0012] EP 3 186 112 B1, US 2004 / 0070191 A1 or WO 2012 / 048363 A1.

[0013] In some of these solutions, the seatbelt is redirected multiple times, passing over the chest and / or pelvis and additionally below the thighs. When the belt is tightened, the seat section below the thighs is essentially stiffened or lifted, or the thighs themselves are directly lifted, thus at least reducing the risk of the seatbelt slipping down. These seatbelt systems are often very complex. Furthermore, there is a risk that the tightening of the belt section below the thighs occurs too late. Some solutions involve a separate webbing strap on the seat section, but this results in a loss of comfort.

[0014] Based on this, the invention aims to provide a vehicle seat with a safety belt device that reliably prevents the seat from diving in the event of a crash while simultaneously achieving a high level of comfort.

[0015] The problem is solved according to the invention by a vehicle seat comprising a seat section and a backrest section, as well as a seat belt assembly, wherein the seat belt assembly has a first belt system comprising a first seat belt with at least one lap belt, a buckle, and a buckle tongue for manual insertion into the buckle. Furthermore, the seat belt assembly has a second belt system with a second safety element, which is preferably designed as a second seat belt and is separate from the first seat belt. The second safety element has a seat section that extends transversely and within the seat section and, for example, passes through the seat section or at least through padding of the seat section. The second safety element is equipped with

[0016] Page 3 of page 2024344 is attached at one end to an anchor point and at the other end to a belt tensioner. This tensioner is designed to exert a tensile force on the second safety element. In particular, it is designed such that, in the event of a triggering event, the second safety element is automatically tightened and thus tensioned by the belt tensioner by generating a tensile force, thereby preventing an occupant from slipping through the lap belt. The second safety element is generally designed as a typically flexible and preferably band- or strand-shaped tension element, for example in the form of a band, rope, tension strand, chain, etc.

[0017] Tensioning and tightening the second safety element reliably prevents the wearer from slipping through the lap belt. It is important to emphasize that this safety element is independent of the first seat belt. This means that the second safety element is not connected to the first seat belt. Specifically, the belt tensioner allows the second safety element to be controlled and, in particular, tensioned independently of the first seat belt. Typically, the first seat belt also has its own tensioner, which automatically tightens the first seat belt in the event of a triggering event. Therefore, these are two separate safety devices.This measure also ensures that the tensioning of the second safety element, and thus in particular the tensioning of the seat section of this second safety element, occurs in a timely and reliable manner, and especially independently of the first safety belt. The separate design also makes the entire belt routing less complex.

[0018] Furthermore, it should be emphasized that the seat section of the second safety element runs inside the seat cushion and not on top of it. The seat section is therefore embedded within the seat cushion. It runs at least beneath a seat cover, so that the seat section is not visible from the outside. This increases overall comfort compared to a seat belt that runs above the seat cushion.

[0019] 2024344 Page 4 In this context, a triggering situation or triggering event is understood to be a situation in which the safety systems installed in the vehicle have detected the risk of an accident or an accident, in particular a head-on collision. A triggering event is therefore understood to be both a so-called "pre-crash situation" and a "crash situation".

[0020] The upholstery is usually a single piece, particularly a foam element. Depending on the design, the seat may have several upholstery elements. Preferably, the seat section extends entirely within or beneath a single upholstery element.

[0021] In a preferred embodiment, the seat section runs within or beneath the upholstery of the seat. This achieves a particularly high level of comfort, as the seat section of the second safety element is imperceptible to the occupant during normal operation. Furthermore, in the event of activation, the upholstery located between the seat section and the thighs prevents the seat section from cutting into the thighs.

[0022] When the seat section is guided within the upholstery, it is located inside the upholstery, for example, between two layers of padding. When the seat section is guided beneath the upholstery, it is positioned below the seat cushion. This design is particularly advantageous for seat constructions where a foam blank is provided for the seat component, and where, in comfort zones, one or more upholstery elements are attached to this foam blank—especially only in defined local areas—made, for example, of cut foam. In this case, the seat section therefore runs beneath such an upholstery element.

[0023] In a preferred embodiment, the seat section extends in an area between 5 mm and 10 mm below a seat surface of the seat part, and in particular

[0024] 2024344 PPage 5 within the padding. This ensures a high level of comfort while maintaining good effectiveness in the event of activation.

[0025] Preferably, a groove is cut into the upholstery in which the seat section runs. For this purpose, for example, a suitable piece of the upholstery is cut out so that the groove is formed, into which the seat section can then simply be inserted.

[0026] The groove is preferably still filled with a strip of upholstery. After the seat section is inserted, a strip of upholstery is again placed in the groove, thus completing the upholstery and restoring its comfort function. In this design variant, the groove can be made from either the top or the bottom.

[0027] Alternatively, the upholstery may be slit and have a slot through which the seat section can be inserted into the upholstery.

[0028] In a preferred embodiment, the seat section sits in a particularly shallow groove and is covered over its entire surface by a padding layer, e.g., a foam element. The padding layer therefore covers the groove extensively and extends beyond it laterally. In particular, the padding layer covers the entire seat surface. The depth of the groove is, for example, adapted to the thickness of the seat section, so that the seat section is flush with the upper edge of the groove and thus with the top surface of the padding. Preferably, the padding layer is connected to a cover of the seat section, in particular by a fabric bond, e.g., by lamination. Alternatively, when using such a padding layer, the groove is omitted entirely, so that the seat section rests directly on the padding. The thickness of the padding layer is, for example, in the range of 5 mm to 10 mm.

[0029] According to another preferred variant, the seat section is located entirely beneath the upholstery. Specifically in this variant, the

[0030] Page 6 of page 2024344 shows that the belt tensioner has a particularly large stroke range to prevent the seat from sagging. The seat section, for example, runs on a support for the cushion, especially on a seat pan.

[0031] In a preferred embodiment, the seatbelt tensioner is designed as a pyrotechnic tensioner, as is generally known from conventional seatbelt systems. The tensioner therefore has a pyrotechnic explosive unit that is triggered in the event of a crash, resulting in rapid tightening of the seat section.

[0032] Alternatively, and especially as a supplement, the seatbelt tensioner is designed as a reversible electromechanical tensioner. For this purpose, the tensioner features a suitably designed electromechanical system with an electric drive and a mechanical actuator for applying the tension. A reversible seatbelt tensioner is understood to be a system that can be used to repeatedly tension and release the second safety element, in contrast to a non-reversible system, such as a pyrotechnic explosive device. This reversible system is triggered, in particular, in a pre-crash situation to generate pre-tension.

[0033] In the combined design, in which the belt tensioner is designed both as a non-reversible and in particular pyrotechnic as well as as a reversible and in particular electromechanical belt tensioner, different units for exerting the tensile tension are therefore integrated within the belt tensioner, namely in particular on the one hand the pyrotechnic explosive unit and on the other hand the electromechanics.

[0034] The belt tensioner is preferably designed as a mechanical belt tensioner and therefore includes a suitable mechanical unit for exerting the tensile tension in the event of triggering. For this purpose, the belt tensioner particularly includes a mechanical energy storage device, specifically in the form of a pre-tensioned spring. In the event of triggering, for example, a locking element is released, so that the mechanically stored energy is released and the tension of the second

[0035] Page 7 of page 2024344 states that the safety element is activated purely mechanically. Such a mechanical unit is used in particular as an alternative to, and instead of, a pyrotechnic explosive unit.

[0036] In a preferred further development, a belt force limiter is also integrated into the belt tensioner. This limits the tensile tension to a maximum value.

[0037] The second safety element is preferably designed as a second safety belt, i.e., as a strap. Alternatively, it is designed as another flexible traction element such as a rope or chain.

[0038] Within the seat section, at least one seat segment is generally guided. If required, several seat segments can also be guided, preferably connected to each other at opposite ends and, in particular, jointly attached to the anchor point or the belt tensioner.

[0039] In a preferred embodiment, a support element is integrated into the seat section – in addition to padding – which extends particularly within or even beneath the padding and is particularly plate-shaped. The seat section extends beneath this support element, so that in the event of activation, the support element is effectively lifted by the tightening of the seat section; at the very least, the seat section is stiffened in the area of ​​the support element to such an extent that it cannot sink downwards into the padding. This raises or stiffens a comparatively large area of ​​the seat section, thus effectively preventing it from sinking inwards. The support element has a higher degree of hardness and stiffness compared to the padding and is, for example, made of a plastic and specifically designed as an injection-molded part.

[0040] An embodiment of the invention is explained in more detail below with reference to the figures. These show, in some cases in simplified form:

[0041] FIG 1 shows a vehicle seat with a safety belt device,

[0042] 2024344 Page 8 FIG 2 a sectional view through a partial area of ​​a seat part of the vehicle seat according to a first embodiment in which a seat section lies in a groove,

[0043] FIG 3 shows a sectional view through a partial area of ​​a seat part of the vehicle seat according to a second embodiment with a support element,

[0044] FIG 4 shows a sectional view through a partial area of ​​a seat part of the vehicle seat according to a third embodiment with a flat cover in the form of a padding layer, as well as

[0045] FIG 5 shows a sectional view through a part of a seat section of the vehicle seat according to a fourth embodiment in which the seat section runs below the upholstery.

[0046] A vehicle seat 2 shown in FIG. 1 has, as usual, a backrest section 4 and a seat section 6. The backrest section 4 is adjustable in its inclination and can, in particular, also be moved into a relaxed position or a reclining position.

[0047] A seat belt device 8 is assigned to the vehicle seat 2, which in the exemplary embodiment has two separate safety systems. These are, firstly, a first belt system 9 with a first seat belt 10, which is designed as a conventional belt, for example, a so-called three-point belt. One section of this first seat belt 10 is designed as a lap belt 10A and another section of the seat belt 10 as a chest belt 10B, with these sections, when fastened, being guided over the occupant's chest and pelvis, respectively. The first belt system 9 also has a buckle 12 and a buckle tongue 14 for manual insertion into the buckle 12.

[0048] The first belt system 9 is designed in a manner known per se and includes, for example, suitable safety devices such as belt tensioners, etc.

[0049] 2024344 Page 9 As a second safety system, a second belt system 15 is attached in the exemplary embodiment, which has a second flexible safety element in the form of a second seat belt 16, as well as an anchor point 18 and a belt tensioner 20. The second seat belt 16 is attached at one end to the anchor point 18 and at the other end to the belt tensioner 20. The second seat belt 16 has a section, in particular a central section, which is referred to as the seat section 22. This runs below a seat surface 24, which forms the upper surface of the seat part 6 oriented towards the occupant. In particular, the seat section 22 runs within a padding 26. The seat section 22 and also, additionally, the anchor point 18 are shown with dashed lines in FIG. 1.

[0050] The anchor point 18 is designed in particular as a retaining tab. It is preferably attached to a side bolster of the vehicle seat 2. Preferably, it is integrated within the vehicle seat 2 so that it is not visible from the outside.

[0051] The belt tensioner 20 is preferably attached laterally, and in particular to a side bolster. As an alternative to the illustrated embodiment, it is preferably arranged within the seat section 6 and thus not visible from the outside. The entire second belt system 15 is preferably installed within the seat section 6 and thus not visible from the outside.

[0052] The belt tensioner 20 has at least one unit, not shown in detail here, for tightening the second seat belt 16, so that a tensile stress is exerted on it. For this purpose, the belt tensioner 20 has, in particular, a pyrotechnic unit or a mechanical unit, the latter, for example, in the form of a pre-tensioned spring. Additionally, the belt tensioner preferably has a further, reversible unit, in particular an electromechanical unit.

[0053] The one end of the second safety belt 16, which is attached to the belt tensioner 20, is moved by means of the belt tensioner 20 to exert the tensile tension, preferably in the direction of arrow 28 shown in FIG 1.

[0054] 2024344 Page 10 Figure 2 shows a first preferred embodiment. Figure 2 shows a partial cross-sectional view through the seat part 6. In addition to the padding 26, a cover 30, for example made of fabric, leather, etc., is also shown, the outer surface of which also defines the seat surface 24.

[0055] In the padding 26, a section is first cut out, creating a transverse groove 32 into which the seat section 22 is inserted, so that it runs within the groove 32. The groove 32 is then filled with a strip of padding 34, so that the second seat belt 16 is not noticeable to the occupant. The distance between the seat section 22 and the seat surface 24 is, for example, between 3 cm and 12 cm, and particularly between 5 cm and 10 cm.

[0056] In the embodiment shown in FIG. 3, a support element 36, in particular a plate-shaped one, is integrated into the padding 26. Below this support element, at least one seat section 22 and, for example, as shown, two seat sections 22 of the second belt system 15 are attached. These are connected to each other, for example, at opposite ends and then jointly fastened to the anchor point 18 or to the belt tensioner 20. FIG. 3 also shows slots 38 provided in the padding 26, through which, for example, the seat sections 22 can be inserted.

[0057] In the event of activation, the seat sections 22 are tightened, so that the support element 36 is supported from below or even slightly raised. In any case, this results in a stiffening effect, thus preventing the occupant from sinking through.

[0058] In a third embodiment according to FIG. 4, the seat section 22 is inserted into a shallow groove 32 of the upholstery 26 or even rests on top of it. The seat section 22 is completely covered by a padding layer 40, which is formed in particular by a foam element. The padding layer 40 is therefore located between the cover 30 and the upholstery. Preferably, it is connected to the

[0059] 2024344 PPage 11 Cover 30 firmly connected, for example fabric-bonded and in particular laminated with the cover.

[0060] In a fourth embodiment according to FIG. 5, the seat section 22 is arranged below the upholstery 26 and extends, in particular, on a seat frame, especially a seat pan 42, on which the upholstery 26 is mounted. In this embodiment, the belt tensioner 20 is designed for a particularly large stroke, so that the seat section 22 is raised significantly when triggered.

[0061] 2024344 Page 12

[0062] Reference symbol list

[0063] 2 vehicle seats

[0064] 4 Backrest section

[0065] 6 Seat section

[0066] 8 Seat belt device 9 First belt system

[0067] 10 first seat belt 10A lap belt

[0068] 10B Chest strap

[0069] 12 Seatbelt buckle

[0070] 14 Lock tongue

[0071] 15 second belt system

[0072] 16 second safety belt 18 anchor point

[0073] 20 seatbelt pretensioners

[0074] 22 Seating section

[0075] 24 seats

[0076] 26 Padding

[0077] 28 Arrow

[0078] 30 reference

[0079] 32 Nut

[0080] 34 upholstery strips

[0081] 36 Support element

[0082] 38 slots

[0083] 40 layers of padding

[0084] 42 Seat tub

[0085] 2024344 P

Claims

Page 13 Claims 1. Vehicle seat (2) comprising a seat section (6) and a backrest section (4) and a seat belt assembly (8), wherein the seat belt assembly (8) comprises a first belt system (9) comprising a first seat belt (10) with at least one lap belt (10A), a buckle (12) and a buckle tongue (14) for manual insertion into the buckle (12), wherein the seat belt assembly (8) comprises a second belt system (15) with a second safety element (16) which is separate from the first seat belt (10) and which has a seat section (22) which extends transversely within the seat section (6), wherein the second safety element (16) is attached on one side to an anchor point (18) and on the other side to a belt tensioner (20) which is designed to exert a tensile force on the second safety element (16), such thatthat in the event of a triggering event, the second safety element (16) is automatically tightened by means of the belt tensioner (20) to prevent an occupant from passing through the lap belt (10A).

2. Vehicle seat (2) according to the preceding claim, wherein the seat part (6) has padding (26) and the seat section (22) extends within or below the padding (26).

3. Vehicle seat (2) according to one of the preceding claims, wherein the seat part (6) has a seat surface (24) and the seat section (22) extends in a range between 5 mm and 10 mm below the seat surface (24).

4. Vehicle seat (2) according to one of the preceding claims, in which a groove (32) is formed in the upholstery (26) in which the seat section (22) runs 5. Vehicle seat (2) according to the preceding claim, wherein the groove (32) is filled with a cushion strip (34). 2024344 Page 14 6. Vehicle seat (2) according to one of the two preceding claims, wherein the groove (32) is covered with a layer of padding.

7. Vehicle seat (2) according to one of the preceding claims, wherein the belt tensioner (20) is designed as a pyrotechnic belt tensioner (20).

8. Vehicle seat (2) according to one of the preceding claims, wherein the belt tensioner (20) is designed as a reversible electromechanical belt tensioner (20).

9. Vehicle seat (2) according to one of the preceding claims, wherein the belt tensioner (20) is designed as a mechanical belt tensioner (20).

10. Vehicle seat (2) according to one of the preceding claims, wherein the second safety element (16) is designed as a second safety belt or other flexible traction element such as rope, chain, etc.

11. Vehicle seat (2) according to one of the preceding claims, in which a support element (36) is integrated into the seat part (6), under which the seat section (22) runs, so that in the event of triggering the support element (36) is lifted with the aid of the second safety element (16). 2024344 P

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