Safety belt webbing and safety belt system

Abstract

A seat belt webbing for restraint of vehicle occupants, comprising a central webbing area (12) extending along a longitudinal direction of the webbing (10) and two edge areas (14) which have longitudinal edges (16) limiting the width (B) of the webbing (14), wherein the edge areas (14) have a smaller thickness and / or a higher compliance in the thickness direction of the webbing (10) than the central webbing area (12), characterized in that the central webbing area (12) and the edge areas (14) have warp threads (17, 19), wherein at least a part of the warp threads (17) of the central webbing area (12) have a lower elongation than at least a part of the warp threads (19) of the edge areas (14).

Description

[0001] The invention relates to a safety belt webbing for restraint of vehicle occupants and a safety belt system with such a safety belt webbing.

[0002] Seat belt systems are designed to keep vehicle occupants in their seated position in the event of a collision, thus protecting them from injury. The seat belt webbing used in such systems, which is placed around the upper body of the vehicle occupant, is typically made of a woven, thin, tear-resistant yarn. A well-known example of this is the three-point seat belt used in modern passenger cars.

[0003] From generic DE 198 57 517 A1, an inflatable seat belt for restraint of vehicle occupants is known, comprising a central belt section extending along a longitudinal direction of the belt and two edge sections having longitudinal edges limiting the width of the belt, wherein the edge sections have a smaller thickness and / or greater compliance in the thickness direction of the belt than the central belt section. The central belt section is constructed in two layers, with the space between the two layers serving for the passage of gas.

[0004] From DE 40 26 429 A1 a safety belt webbing is further known in which the central webbing area and the edge areas have different weaving structures, wherein the weaving structure of the edge areas is comparatively flexible compared to the stiff weaving structure of the central webbing area.

[0005] The object of the present invention is to provide an improved safety belt webbing for vehicle occupant restraint and a safety belt system.

[0006] This problem is solved by the characterizing features of claim 1.

[0007] The safety webbing according to the invention can therefore be narrower in the edge areas than in the central area of ​​the webbing when viewed in a section transverse to the longitudinal direction of the webbing.

[0008] Alternatively or additionally, the edge regions of the safety webbing according to the invention can exhibit greater compliance or be softer in the thickness direction of the webbing than the central webbing region. In particular, the edge regions are more easily deformed under load in the thickness direction, i.e., perpendicular to the longitudinal and width directions of the webbing. Such a load occurs, for example, when the webbing is wound onto a spool.

[0009] Both variants, which can be implemented separately or in combination, have the advantage of improving the performance of the safety belt webbing.

[0010] In comparison to conventional webbing, a more homogeneous webbing feed can be achieved through a webbing tensioner and improved coupling or layering of the webbing layers in the spool winding of a webbing rewinder.

[0011] Furthermore, test results show that the shoulder belt force is more homogeneous and longer lasting compared to conventional webbing, with the same test setup and tensioner unit, and that the overall efficiency of a safety belt system can be increased.

[0012] To further improve the performance of the seatbelt webbing, a further development of the seatbelt webbing provides that the edge areas taper in cross-section from the central webbing area towards the longitudinal edges, in particular becoming wedge-shaped. A transition, especially one without a break or essentially smooth, can be formed between the central webbing area and the edge areas.

[0013] The edges of the seat belt webbing can be symmetrically tapered. The thickness of the webbing can decrease on both sides towards a longitudinal edge, similar to a chamfer. In other words, the webbing surfaces facing away from each other approach each other at the edges. For example, the webbing surfaces in the central area can run along parallel planes, while at the edges they approach each other at an angle to these planes.

[0014] It is understood that the geometries described above describe the webbing in an unwound or flattened state, and that, microscopically speaking, the webbing surface is not flat, as it is a woven fabric. However, the webbing has a uniform surface structure whose "valleys" and "hills" run almost exactly along planes.

[0015] According to one design of the safety belt webbing, the central belt area is designed to have a constant thickness.

[0016] According to the invention, the central band area and the edge areas of the safety belt webbing have warp threads, wherein at least a part of the warp threads of the central band area, in particular all warp threads of the central band area, have a lower elongation than at least a part of the warp threads of the edge areas, in particular all warp threads of the edge areas.

[0017] When the term "elongation" is used in connection with warp threads, it refers to the elongation at break or the elongation at tensile strength of the individual warp threads (e.g., according to DIN EN ISO 2060, 2062) of the warp threads used. Elongation in this context is therefore a property of the warp threads.

[0018] By using warp threads of different stretch in the edge areas and the central band area, the compliance in the edge areas can be adjusted relative to the central band area.

[0019] In a further embodiment of the safety webbing, at least some of the warp threads in the edge regions, in particular all warp threads in the edge regions, exhibit an elongation of at least 20%, preferably at least 25%, and more preferably at least 30%. In particular, at least some of the warp threads in the edge regions, in particular all warp threads in the edge regions, can exhibit an elongation of 30%.

[0020] At least some of the warp threads of the central webbing area, in particular all warp threads of the central webbing area, can, according to a further development of the safety webbing, exhibit an elongation of at most 15%, preferably at most 12%, more preferably at most 10%. In particular, at least some of the warp threads of the central webbing area, in particular all warp threads of the central webbing area, can exhibit an elongation of 10%.

[0021] Improved performance of the webbing can be achieved in particular by ensuring that at least some of the warp threads in the outer areas, in particular all warp threads in the outer areas, have at least twice, preferably at least three times, the elongation compared to at least some of the warp threads in the central area of ​​the webbing, in particular compared to all warp threads in the central area of ​​the webbing.

[0022] In addition to using warp threads of different elongation, the performance of the safety webbing can be further improved by ensuring that at least some of the warp threads in the edge areas, in particular all warp threads in the edge areas, have a smaller cross-section than at least some of the warp threads in the central webbing area, in particular all warp threads in the central webbing area.

[0023] Thinner warp threads in the edge areas make it easy to create narrower cross-sections in these areas. When this text refers to a cross-section of the warp threads, it means the cross-sectional area of ​​a particular warp thread in a section taken perpendicular to its length, thus indicating the thread thickness of the respective warp thread before weaving.

[0024] In particular, the safety webbing can be designed such that at least some of the warp threads of the edge areas, in particular all warp threads of the edge areas, have a cross-section that is at least 10% smaller, in particular up to 20% smaller, than the cross-section of at least some of the warp threads of the central webbing area, in particular all warp threads of the central webbing area.

[0025] Furthermore, the central band area and the edge areas can have warp threads, whereby at least some of the warp threads of the central band area, in particular all warp threads of the central band area, have a higher breaking load according to (e.g. according to DIN EN ISO 2060, 2062) than at least some of the warp threads of the edge areas, in particular all warp threads of the edge areas.

[0026] The width of the edge areas, measured transversely to the longitudinal extent of the webbing, can be at least 3 mm, preferably at least 5 mm. In particular, the width of the edge areas can be 5 mm.

[0027] The width of the central band area, measured transversely to the longitudinal extent of the webbing, can be at least 35 mm, preferably at least 37 mm. In particular, the width of the central band area is 37 mm.

[0028] For example, the safety belt webbing has a total width of 47 mm, with the edge areas measuring 5 mm each and the central belt area measuring 37 mm in width.

[0029] The problem underlying the invention is also solved by a safety belt system comprising a belt tensioner, a belt retractor, and a safety belt webbing designed as described above. The proposed safety belt webbing improves the efficiency of the safety belt system by increasing the webbing retraction and resulting in a more homogeneous webbing retraction pattern.

[0030] According to an advantageous further development of the seat belt system, the belt tensioner is integrated into the belt retractor. In this way, the seat belt system can be implemented with a smaller design.

[0031] The invention is described in more detail below using an exemplary embodiment. The following are schematic representations: Fig. 1 a safety belt according to the invention shown section by section in a top view, Fig. 2 the seatbelt strap Fig. 1 in a cross-section, and Fig. 3 a cross-section through a safety belt system according to the invention.

[0032] Fig. Figure 1 shows a seat belt webbing 10 for restraint of vehicle occupants, with a central webbing area 12 and two edge areas 14.

[0033] The central band area 12 and the edge areas 14 extend along a longitudinal direction of the safety belt webbing 10, wherein the longitudinal direction is the z-direction of the in Fig. The Cartesian coordinate system shown in Figure 1 corresponds to the boundary regions 14. The boundary regions 14 enclose the central band region 12 on two sides and have longitudinal edges 16 that limit the width B of the webbing.

[0034] The width B1 of the central band area 12 is at least 35 mm, preferably at least 37 mm.

[0035] The width B2 of the edge areas 14 is at least 3 mm, preferably at least 5 mm.

[0036] The width B of the safety belt webbing 10, measured in the x-direction, is 47 mm in the embodiment shown here. The central belt section 12 has a width B1 of 37 mm, while the width B2 of the edge sections 14 is 5 mm each.

[0037] According to a further embodiment of the invention, it is also conceivable to provide a total width B of up to 49 mm or more for the safety belt webbing 10.

[0038] As in Fig. As can be seen from the cross-section shown in Figure 2, the edge regions 14 of the safety belt webbing 10 have a smaller thickness than the central webbing region 12. The thickness of the safety belt webbing 10 is measured in the y-direction.

[0039] The edge regions 14 are symmetrically tapered in cross-section from the central band region 12 towards the longitudinal edges 16 and taper in a wedge shape, while the central band region 12 has a constant thickness.

[0040] The safety webbing 10 is a fabric having a large number of warp threads 17, 19 extending longitudinally along the safety webbing 10 and in Fig. 1 are shown as dashed lines. The warp threads 17, 19 are interwoven with weft threads (not shown) that run in the width direction of the safety webbing 10.

[0041] At least some of the warp threads 17 of the central band area 12, in particular all warp threads 17 of the central band area 12, exhibit less elongation than at least some of the warp threads 19 of the outer areas 14, in particular all warp threads 19 of the outer areas 14.

[0042] Thus, at least some of the warp threads 19 of the edge regions 14, in particular all warp threads 19 of the edge regions 14, can have an elongation of at least 20%, preferably at least 25%, more preferably at least 30%.

[0043] Alternatively or additionally, at least a part of the warp threads 17 of the central band area 12, in particular all warp threads 17 of the central band area 12, has an elongation of at most 15%, preferably at most 12%, more preferably at most 10%.

[0044] A portion of the warp threads 19 of the edge regions 14, in particular all warp threads 19 of the edge regions 14, have at least twice, preferably at least three times, the elongation compared to at least a portion of the warp threads 17 of the central band region 12, in particular compared to all warp threads 17 of the central band region 12.

[0045] In the example shown here, the elongation of the warp threads 17 of the central band area 12 is 10%, whereas the elongation of the warp threads 19 of the outer areas 14 is 30%. It may be provided that at least some of the warp threads 17 of the central band area 12 have a higher breaking load than at least some of the warp threads 19 of the outer areas 14.

[0046] In the example described here, all warp threads 17 of the central band area 12 have a higher breaking load than the warp threads 19 of the outer areas 14.

[0047] At least some of the warp threads 19 of the edge regions 14, in particular all warp threads 19 of the edge regions 14, have a smaller cross-section than at least some of the warp threads 17 of the central band region 12, in particular all warp threads 17 of the central band region 12.

[0048] The warp threads 19 of the edge regions 14 can therefore be thinner than the warp threads 17 of the central band region 12. In the embodiment shown here, the cross-sectional area or thickness of the warp threads 19 of the edge regions 14 is 10% smaller than that of the warp threads 19 of the central band region 12.

[0049] According to further embodiments of the safety webbing 10, it is also conceivable that the warp threads 19 of the edge areas 14 have a cross-sectional area that is up to 20% smaller.

[0050] The selection of warp threads 17, 19 for the edge areas 14 and the central band area 12 results in the safety webbing 10 having a higher compliance in the thickness direction in the edge areas 14 than in the central band area 12.

[0051] A safety belt system 18 equipped with the safety belt webbing 10 according to Fig.3, which has a belt tensioner 20 and a belt retractor 22, has an overall higher efficiency due to the design of the safety belt webbing 10 described above.

[0052] The safety belt webbing 10 improves the belt retraction and force transmission to the occupant in an emergency situation or in the event of a crash, as well as reducing the film reel effect through better coupling of the wound belt layers.

[0053] Preferably, the belt tensioner 20 can be integrated into the belt retractor 22 and form a so-called retractor tensioner.

Claims

[1] Seat belt for vehicle occupant restraint, comprising a central belt area (12) extending along a longitudinal direction of the belt (10) and two edge areas (14) which have longitudinal edges (16) limiting the width (B) of the belt (14), wherein the edge areas (14) have a lesser thickness and / or a higher compliance in the thickness direction of the belt (10) than the central belt area (12), characterized by , that the central band area (12) and the edge areas (14) have warp threads (17, 19), wherein at least some of the warp threads (17) of the central band area (12) have a lower elongation than at least some of the warp threads (19) of the edge areas (14). [2] Safety belt webbing according to claim 1, characterized by , that the edge regions (14) in cross-section taper from the central band region (12) towards the longitudinal edges (16). [3] Safety belt webbing according to claim 2, characterized by, that the boundary regions (14) are symmetrically tapered. [4] Safety belt webbing according to one of the preceding claims, characterized by , that the central band region (12) has a constant thickness. [5] Safety belt webbing according to any of the preceding claims, characterized by , that all warp threads (17) of the central band area (12) exhibit less elongation than all warp threads (19) of the outer areas (14). [6] Safety belt webbing according to any one of the preceding claims, characterized by , that at least some of the warp threads (19) of the edge areas (14) have an elongation of at least 20%. [7] Safety belt webbing according to any one of the preceding claims, characterized by , that at least some of the warp threads (17) of the central band area (12) have an elongation of no more than 15%. [8] Safety belt webbing according to any one of the preceding claims, characterized by, that at least some of the warp threads (19) of the outer regions (14) have at least twice the elongation compared to at least some of the warp threads (17) of the central band region (12). [9] Seat belt webbing according to any one of the preceding claims, characterized by , that the central band area (12) and the edge areas (14) have warp threads (17, 19) and at least some of the warp threads (19) of the edge areas (14) have a smaller cross-section than at least some of the warp threads (17) of the central band area (12). [10] Safety belt webbing according to claim 9, characterized by , that at least some of the warp threads (19) of the edge areas (14) have a cross-section that is at least 10% smaller than the cross-section of at least some of the warp threads (17) of the central band area (12). [11] Safety belt webbing according to one of the preceding claims, characterized by, that the central band area (12) and the edge areas (14) have warp threads (17, 19), wherein at least some of the warp threads (17) of the central band area (12) have a higher breaking load than at least some of the warp threads (19) of the edge areas (14). [12] Safety belt webbing according to one of the preceding claims, characterized by , that the width (B2) of the edge areas (14) measured transversely to the longitudinal extent of the webbing (10) is at least 3 mm. [13] Safety belt webbing according to one of the preceding claims, characterized by , that the width (B1) of the central band area (12) measured transversely to the longitudinal extent of the webbing (10) is at least 35 mm. [14] Seat belt system comprising a belt tensioner (20), a belt retractor (22) and a seat belt webbing (10) according to any of the preceding claims. [15] Safety belt system according to claim 14, characterized by, that the belt tensioner (20) is integrated into the belt retractor (22).

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