DE102017113577B4 - vehicle seat - Google Patents

Abstract

Vehicle seat (7), comprising - a seat structure with a seat cushion (2), - a clamped first fabric layer (3; 9) which is arranged underneath the seat cushion (2), and - a clamped second fabric layer (4) which is underneath the seat cushion (2) and arranged one on top of the other with the first fabric layer (3; 9), wherein- the first fabric layer (3; 9) has a lower failure limit under a load exerted by the seat structure than the second fabric layer (4).

Description

The invention relates to a vehicle seat, having a seat structure with a seat cushion. The invention is particularly applicable to automobile seats, aircraft seats and helicopter seats.

Vehicle seats such as airplane seats or helicopter seats have to withstand high acceleration forces in order to be approved. Suitable measures must therefore be taken to protect the occupants (passengers, pilots, etc.) in order to enable energy dissipation in the event of a crash and to influence movement behavior. For this purpose, vehicle seats have so far been equipped with crash structures made of aluminum or steel, which, in the event of a crash, undergo targeted plastic deformation while absorbing energy, such as in the DE 10 2015 106 993 A1 specified. The crash structures can include crash panels or seat stays, which represent parts of a seat frame, for example. The disadvantage here is that such crash structures are heavy, take up a large amount of space and/or are expensive.

Document US 2011/0 043 008 A1 relates to a vehicle seat. A vehicle seat back comprising a frame and a back support member is described herein. The back support member may be connected to the frame at a first location and at a second location. The back support member may include a frangible link configured to rupture during an impact event to increase an operative length of the back support member.

The pamphlet U.S.A. 4,138,157 relates to an energy absorbing safety belt having a thin, flexible, elongate element, the length of which is substantially greater than its width, suitable for securing a wearer in a vehicle, the element being provided with at least one integral discontinuity along its length, whereby the element is capable of absorbing kinetic energy imparted to it by movement of the wearer.

It is the object of the present invention to at least partially overcome the disadvantages of the prior art and in particular to provide an improved possibility of absorbing energy from a vehicle seat, in particular an aircraft seat or motor vehicle seat, in the event of a crash.

This object is solved according to the features of the independent claim. Preferred embodiments can be found in particular in the dependent claims.

The object is achieved by a vehicle seat, in particular an aircraft seat or motor vehicle seat, having a seat structure with a seat cushion, a clamped first fabric layer which is arranged underneath the seat structure (in particular the associated seat cushion), and a clamped second fabric layer which lies one on top of the other with the first fabric layer is arranged. A superimposed arrangement can be understood to mean an arrangement of the first fabric layer and the second fabric layer, in which the second fabric layer is arranged below the first fabric layer. However, the second fabric layer can in principle also be arranged above the first fabric layer.

The first fabric layer has a lower failure limit under a load exerted by the seat structure (in particular the associated seat cushion) than the second fabric layer.

This vehicle seat has the advantage that the dynamic behavior of the seat cushion and of a person sitting on it can be positively influenced in the event of a crash through the targeted initiation of a failure of textile structures. Crash structures made of aluminum or steel can be dispensed with at least in part, or the crash structures can be made lighter, more space-saving and/or cheaper. Energy that occurs in the event of a crash can be absorbed in the area of the seat surface and does not have to be routed through the seat frame. This allows the seat frame to be built lighter.

Because the first fabric layer has a lower failure limit than the second fabric layer, the first fabric layer can absorb energy in the event of a crash with dissipative absorption, while the second fabric layer holds the seat structure and prevents it from breaking through. The failure limit, when the first layer of fabric begins to be destroyed, can be set in a targeted manner. For this purpose, use is made of the fact that in the event of a crash, the seat structure presses vertically downwards on the first fabric layer (“downward crash”) and thus exerts a distributed load on the first fabric layer. Since layers of fabric can only transmit membrane stresses, their clamping creates a tensile load in the fabric. If the tensile load exceeds a critical value (i.e. the "failure limit"), at least local destruction of the first fabric layer occurs with dissipative energy loss. As a result, a load level and a load curve can be set in a targeted manner.

It is a further development that an underside of the seat structure facing the first fabric layer projects in the direction of the first fabric layer standing convex curvature. Advantageously, this promotes a uniform development of tensile stress in the first fabric layer, which improves a high energy absorption capability.

The failure limit can therefore generally be understood as a mechanical load limit up to at least partial failure of the fabric layer.

It is a development that the failure limit or the load limit is a critical tensile stress, since this can be predicted particularly easily. In a further development, the critical tensile stress is expressed as a force applied by the seat structure or as an impulse applied by the seat structure, since a force or an impulse can be applied to the fabric layer in a particularly simple and precisely reproducible manner. A force value applied to the fabric layer and/or an applied pulse value can also be used as the failure limit.

A further development is that the first fabric layer is a continuous, smooth fabric layer. In the event of a crash, the first fabric layer can then tear locally when the failure limit of the textile of the first fabric layer is reached or exceeded.

Another development is that the first fabric layer and/or the second fabric layer are clamped without tensile stress, ie are not placed under tensile stress as such by the clamping. This can favor a high energy intake. It is also a further development that the first fabric layer and/or the second fabric layer are clamped under a tensile stress (pre-tension). This facilitates precise positioning of the respective fabric layer.

The first fabric layer and/or the second fabric layer can, for example, be clamped in on two sides, i.e. on two opposite sides. The first fabric layer and/or the second fabric layer can also be clamped around the edge, for example.

The seat cushion can also be referred to as a seat cushion.

In one configuration, the first fabric layer has at least one undulated area. Compared to a continuous, smooth layer of fabric, this enables particularly high energy absorption and a more precise setting of the failure limit. A wavy area is understood to mean, in particular, an area in which a (single- or multi-layer) fabric or textile is gathered and held together by threads. In the undulated area, the textile is not smooth, but e.g. wavy. In the event of a crash, these threads are advantageously stretched, possibly to the point of tearing, for which deformation energy must be applied.

Another configuration is that the first fabric layer has at least one tear seam. This achieves the advantage that a locally defined failure of the first fabric layer at the at least one tear seam can be adjusted, for example by a length and/or a local course of the tear seam. A particularly precise setting of the failure limit can also be achieved in this way. In addition, if the failure progresses along the tear seam, a particularly large amount of energy can be absorbed, especially in comparison to a crack propagating in a continuous, smooth fabric layer.

In a further embodiment, the first fabric layer has a plurality of tear seams. In this way, a particularly large amount of energy can be absorbed by tearing the tear seams.

In yet another embodiment, the first fabric layer has a plurality of fabric strips that are sewn together by the tear seams. This gives the advantage that the first layer of fabric only fails at the tear seams and a tear does not propagate into the textile. In addition, the tear seams can be designed to be particularly long (namely continuous), which enables particularly high energy absorption. The fabric strips can also be referred to as textile strips.

Another configuration is that at least two tear seams have different failure limits. In this way, the advantage is achieved that a temporal or local sequence of a failure of the tear seams can be set particularly precisely and thus also a particularly targeted setting of a load level and load profile, for example in relation to a high energy absorption. For example, the order in which the tear seams fail can be set, for example from the inside to the outside. The fact that two tear seams have different failure limits can mean in particular that they tear at different rates.

It is also an embodiment that the first fabric layer and the second fabric layer are connected to one another, in particular are sewn together. This enables particularly simple handling of the two layers of fabric.

It is also an embodiment that the second fabric layer hangs down from the first fabric layer in non-sewn areas. The advantage is thus achieved that the second fabric layer only supports the seat structure when a high degree of energy has already been absorbed by the first fabric layer. This exploits the effect that the first fabric layer loses stability in the event of a failure and the seat structure can move further, at least locally, in the direction of the second fabric layer than when the first fabric layer is intact. The fact that the second fabric layer hangs down from the first fabric layer can include, in particular, that the second fabric layer is arranged noticeably below the first fabric layer or noticeably spaced apart from the first fabric layer.

Another configuration is that the at least one tear seam is located in a region of the first fabric layer that is not sewn to the second fabric layer. In this way, the influence of the sewing of the two fabric layers together on the failure behavior of the tear seams of the first fabric layer is kept low or even completely prevented.

It is also an embodiment that the first fabric layer is sewn to an underside of the seat cushion. This advantageously results in a particularly compact structure that is easy to handle. For example, textile areas (e.g. fabric strips or textile strips) can easily be sewn into the seat cushion.

Another configuration is that the first fabric layer and the second fabric layer are clamped together in a clamping device or clamping device. As a result, a particularly compact structure can be achieved. In addition, the layers of fabric can be positioned particularly precisely relative to one another. Furthermore, the fabric layers do not need to be provided with openings or the like in their clamped area. The clamping device can have, for example, one or more clamping jaws.

It is also another embodiment that the first fabric layer and the second fabric layer have eyelets and are clamped together with their eyelets. This enables the fabric layers to be attached particularly easily and precisely to appropriate attachment points, e.g. to hooks or bolts. A common clamping can in particular be understood to mean that the first fabric layer and the second fabric layer are attached with at least one respective eyelet at the same fastening point. In a further development, the first fabric layer and the second fabric layer have eyelets and are clamped together (in pairs) with all of their eyelets, which enables particularly precise positioning relative to one another.

Alternatively, the first fabric layer and the second fabric layer can have eyelets and can be clamped with their eyelets separately or at different fastening points.

In a further development, the seat structure has a seat shell in addition to the seat cushion.

It is also an embodiment that the vehicle seat is a motor vehicle seat. The motor vehicle can be a passenger car, a truck, a bus, a heavy-duty vehicle, a construction machine, and so on.

Another configuration is that the vehicle seat is an aircraft seat such as an airplane seat or a helicopter seat.

• 1 zeigt als Schnittdarstellung in Seitenansicht einen Ausschnitt aus einem Flugzeugsitz gemäß einem ersten Ausführungsbeispiel;
• 2 zeigt als Schnittdarstellung in Seitenansicht einen Ausschnitt aus einem Flugzeugsitz gemäß einem zweiten Ausführungsbeispiel; und
• 3 zeigt als Schnittdarstellung in Seitenansicht ondulierte Bereiche des Flugzeugsitzes gemäß dem zweiten Ausführungsbeispiel.

The characteristics, features and advantages of this invention described above, and the manner in which they are achieved, will become clearer and more clearly understood in connection with the following schematic description of an exemplary embodiment, which will be explained in more detail in connection with the drawings.

• 1 shows a sectional side view of a section of an aircraft seat according to a first exemplary embodiment;
• 2 shows a section of a side view of an aircraft seat according to a second embodiment; and
• 3 shows undulated areas of the aircraft seat according to the second exemplary embodiment as a sectional representation in a side view.

1 FIG. 1 shows a section of an aircraft seat 1 according to a first exemplary embodiment as a sectional side view. The aircraft seat 1 can be an aircraft seat or a helicopter seat, for example.

The aircraft seat 1 has a seat cushion 2 as part of a seat structure. Below the seat cushion 2 there is a first fabric layer 3 which is clamped in a clamping device E at the side. Below the first fabric layer 3, a second fabric layer 4 is arranged, which is also clamped in the clamping device E. The first fabric layer 3 covers the entire underside of the seat cushion 2 so that the underside of the seat cushion 2 can rest completely on the first fabric layer 3 . In the event that the components of the aircraft seat 1 shown require a professional l-like basic structure and the side view shows a cross section thereof, the two fabric layers 3, 4 can be clamped on two sides, e.g. by means of two clamping jaws K1 of the clamping device E. In the event that the components of the aircraft seat 1 shown are constructed rotationally symmetrically, the fabric layers 3 , 4 must be clamped all around, e.g. by means of a ring-shaped clamping jaw K2 of the clamping device E.

In the event of a crash (“downward crash”), a linear surface load (“crash load C”) is exerted on the first fabric layer 3 via the seat cushion 2 . Since the first fabric layer 3 can only transmit membrane stresses, a tensile load is generated in its fabric or textile by its clamping. If the tensile load exceeds a "failure limit", at least local destruction of the first fabric layer 3 occurs with dissipative energy loss. The convex curvature of the underside of the seat cushion 2 advantageously supports a uniform formation of tensile stress in the first fabric layer 3, which increases the ability for high energy absorption in the first fabric layer 3 further supported. The first fabric layer 3 can be sewn to the underside of the seat cushion 2, in particular sewn into it.

If the first fabric layer 3 fails, the seat cushion 2 moves further down until it rests on the second fabric layer 4 . The second fabric layer 4 has a higher failure limit than the first fabric layer 3, so that it does not fail as easily as the first fabric layer 3. In particular, the failure limit of the second fabric layer 4 can be so high that it does not fail under given load conditions. Crash energy not absorbed by the first fabric layer 3 can then, for example - if still necessary - be absorbed by other crash structures of the aircraft seat 1 and/or a floor structure of the aircraft (not shown) to which the aircraft seat 1 is attached. In this sense, the second fabric layer 4 can be regarded as “non-failing”, which prevents the seat cushion 2 from breaking through at the bottom.

The first fabric layer 3 and the second fabric layer 4 are connected to one another via seams 5 . The second layer of fabric 4 hangs down in unstitched areas 6 located between the seams 5 .

2 shows a sectional side view of a section of an aircraft seat according to a second embodiment. The aircraft seat is constructed similarly to the aircraft seat 1, but has modifications 10 in the areas 8 of the first fabric layer 9 that are not sewn to the second fabric layer 4, which influence the failure behavior of the first fabric layer 3.

The modifications 10 can be, for example, tear seams 11 which hold adjacent textile or fabric strips 12 together. The fabric strips 12 sewn together in this way consequently form the first fabric layer 9 . The second fabric layer 4 is connected to the fabric strips 12 of the first fabric layer 9 via the seams 5 . For example, the seams 5 can be located centrally on the fabric strips 12 . By adjusting the strength of the tear seams 11 and/or their shape, the failure limit and the local failure progression can be set precisely, and thus also the load absorption in the event of a crash. A particularly precise adjustment of the failure limit and the failure progression can be achieved in that at least two tear seams 11 have different failure limits, ie tear with different ease. As a result, it can be achieved, for example, that the tear seams 11 tear in a sequence from the inside to the outside, which enables particularly uniform and high energy absorption.

The modifications 10 can also be undulated areas 13, which in cross section 3 are indicated. In the undulating area 13, the first fabric layer 9 is gathered, for example in a wavy or meandering shape. Threads 14 hold this form together. In the event of a crash, the areal crash load C applied to the undulated area 13 together with the lateral restraint causes a tensile stress or tensile force F to be exerted on the undulated area 13, which stretches these threads 14, possibly up to the point of tearing, for which purpose deformation energy is applied must become.

Of course, the present invention is not limited to the embodiment shown.

More than two fabric layers can also be arranged one above the other, of which, for example, two fabric layers can be designed similarly to the first fabric layer 3 in order to absorb even higher crash loads.

In general, "a", "an" etc. can be understood as a singular or a plural number, in particular in the sense of "at least one" or "one or more" etc., as long as this is not explicitly excluded, e.g. by the expression "exactly a" etc.

The above exemplary embodiment can also be a helicopter seat or a motor vehicle seat or can be applied thereto in an analogous manner.

A numerical specification can also include exactly the specified number as well as a usual tolerance range, as long as this is not explicitly excluded.

Reference List

1

aircraft seat

2

seat pad

3

First layer of fabric

4

Second layer of fabric

5

seam

6

Area not stitched to the first layer of fabric

7

vehicle seat

8th

Area not sewn to the second layer of fabric

9

First layer of fabric

10

modification

11

tear seam

12

tissue strips

13

undulated area

14

Thread of the undulated area

C

crash load

E

clamping device

f

traction

K1

jaw

K2

Ring-shaped jaw

Claims (14)

Vehicle seat (7) comprising - a seat structure with a seat cushion (2), - A clamped first fabric layer (3; 9) which is arranged underneath the seat cushion (2), and - A clamped second fabric layer (4), which is arranged below the seat cushion (2) and superimposed with the first fabric layer (3; 9), wherein - the first fabric layer (3; 9) has a lower failure limit under a load exerted by the seat structure than the second fabric layer (4). Vehicle seat (7) after claim 1 , wherein the first fabric layer (9) has at least one undulated area (13). Vehicle seat (7) according to one of the preceding claims, wherein the first fabric layer (9) has at least one tear seam (11). Vehicle seat (7) after claim 3 , wherein the first fabric layer (9) has a plurality of tear seams (11). Vehicle seat (7) after claim 4 , wherein the first fabric layer (9) has a plurality of fabric strips (12) which are sewn together by the tear seams (11). Vehicle seat (7) according to one of Claims 4 or 5 , wherein at least two tear seams (11) have different failure limits. Vehicle seat (7) according to one of the preceding claims, wherein the first fabric layer (3; 9) and the second fabric layer (4) are connected to one another. Vehicle seat (7) according to one of the preceding claims, wherein the second fabric layer (4) hangs down from the first fabric layer (3) in areas (6) not sewn to the first fabric layer (3; 9). Vehicle seat (7) according to one of claims 3 until 6 in combination with claim 8 , wherein the at least one tear seam (11) is located in a region (8) of the first fabric layer (9) that is not sewn to the second fabric layer (4). Vehicle seat (7) according to one of the preceding claims, wherein the first fabric layer (3; 9) is sewn to an underside of the seat cushion (2). Vehicle seat (7) according to one of the preceding claims, wherein the first fabric layer (3; 9) and the second fabric layer (4) are clamped together in a clamping device (E). Vehicle seat (7) after claim 11 , wherein the first fabric layer (3; 9) and the second fabric layer (4) have eyelets and are clamped together with their eyelets. Vehicle seat (7) according to one of the preceding claims, wherein the vehicle seat (7) is an aircraft seat (1). Vehicle seat (7) according to one of Claims 1 until 12 , wherein the vehicle seat (7) is a motor vehicle seat.

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