OPW pressure responsive air outlet for application to airbag exhaust port, and airbag with said air outlet sewn

Abstract

To provide a one-piece woven pressure-responsive air outlet, for use as a vent, for application to airbag discharge openings.SOLUTION: A one-piece woven pressure-responsive air outlet, for use as a vent, for application to airbag discharge openings, includes a lower fabric layer, a middle fabric layer and an upper fabric layer. The lower fabric layer includes warp and weft threads and an inflow region in which the warp and weft threads float. The middle fabric layer includes warp and weft threads and a flow-through region in which the warp and weft threads float. The lower and middle fabric layers include a first chamber and a second chamber downstream of the first chamber in a flow direction. At least one of the chambers is sealed with a thread breakage zone, in which between the fabric layers, selected (warp) threads of one fabric layer are merely tacked to selected (weft) threads of the other fabric layer and are capable of breaking or rupturing at a predefined internal pressure in the chamber.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This application claims the benefit of the Paris Convention priority of German patent application No. 10 2022 125 347.3, filed on September 30, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a one-piece woven (OPW) pressure responsive or pressure dependent air outlet, particularly for application or attachment to an airbag vent, comprising a lower fabric layer, a middle fabric layer and an upper fabric layer, and further to an airbag having such an air outlet sewn to the airbag. [Background technology]

[0003] Pressure-responsive or pressure-dependent air outlets, so-called vents or exhaust valves, in airbags for vehicle occupant restraint systems are known from the prior art. In this case, the inflated airbag can be vented by means of a targeted "air outlet" which is released if necessary. This applies, inter alia, to passenger airbags and to driver airbags. Known solutions are often based on so-called Cut&Saw airbags, in which several pieces of fabric cut out of a plain woven material are sewn together in a complex stitching process. These Cut&Saw airbags are very time-consuming and therefore expensive to produce. Furthermore, the complexity of the manufacturing process requires high safety measures in the manufacturing process to ensure the proper functioning of the components. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US 2013 / 0334801 A1 [Patent Document 2] US 7,784,828 B2 [Patent Document 3] DE 20 2004 019448 U1 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, US 2013 / 0334801 A1 shows an air outlet sewn together from multiple individual parts, which must be carefully manufactured and sewn together separately during the manufacture of the airbag.

[0006] From US 7,784,828 B2 it is seen that the airbag has very complex active air outlets or vents, which are arranged in various parts of the airbag. These vents are opened in special pressure situations by means of so-called tethers sewn into the airbag wall. The production of such air outlets is complex and expensive. The attachment of the tethers in the airbag wall poses great challenges in terms of their strength.

[0007] From German utility model DE 20 2004 019448 U1 an airbag module is known which has a normally open exhaust port which is covered by a fixed or rigid cover plate, this construction occupies a large amount of space and is unsuitable for pressure-responsive exhaust of the gas bag.

[0008] The object of the present invention is therefore to propose an air outlet which avoids or at least greatly reduces the known drawbacks in the prior art. [Means for solving the problem]

[0009] According to a first aspect of the present invention, there is provided a one-piece woven pressure responsive air outlet for airbag exhaust applications, particularly for use as a vent. The one-piece woven pressure responsive air outlet includes a lower fabric layer, a middle fabric layer and an upper fabric layer, a) the lower fabric layer includes warp and weft yarns and an inflow region in which the warp and weft yarns float; b) the intermediate fabric layer includes warp and weft yarns and a flow-through region in which the warp and weft yarns float; c) the lower fabric layer and the intermediate fabric layer substantially comprise at least one first chamber; d) a second chamber is disposed downstream of the first chamber in the flow direction; e) The first Chamber and the second chamber At least one of the fabric layers is sealed by a yarn cutting zone, in which a selected portion of one of the fabric layers is cut between the fabric layers. Warp thread is the selected layer of the other fabric layer. Weft thread and can be cut or broken at a predetermined internal pressure of the chamber. (Form 1) According to a second aspect of the present invention, there is provided an airbag having an air outlet according to the present invention sewn to the airbag (Feature 5). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A preferred embodiment of the invention is now presented. (Mode 1) See the first aspect of the present invention above. (Mode 2) In the air outlet according to Mode 1, f) the upper fabric layer includes warp and weft yarns and substantially includes the downstream second chamber together with the intermediate fabric layer; g) the second chamber includes a yarn cutting zone, in which selected portions of the intermediate fabric layer are cut between the upper fabric layer and the intermediate fabric layer; Warp thread The selected upper fabric layer Weft thread and is capable of being cut or broken at a predetermined internal pressure of the second chamber. or the selected weft yarns of the intermediate fabric layer are intertwined only with the selected warp yarns of the upper fabric layer and are breakable or rupturable at a predetermined internal pressure of the second chamber. It is preferred. (Mode 3) In the air outlet according to Mode 1, the second chamber downstream of the first chamber is contained between the lower fabric layer and the intermediate fabric layer; The thread cutting zone is preferably located between the first chamber and the downstream second chamber. (Feature 4) In the air outlet according to feature 1, The air outlet is preferably applied to the cut-and-sew airbag by stitching. (Mode 5) See the second aspect of the present invention above.

[0011] The above object is achieved by an air outlet according to claim 1, i.e. a one-piece woven (OPW) pressure-responsive air outlet for application or attachment to an airbag exhaust, in particular for use as a vent, comprising: The one-piece woven pressure responsive air outlet includes a lower fabric layer, a middle fabric layer and an upper fabric layer, a) the lower fabric layer includes warp and weft yarns and an inflow region in which the warp and weft yarns float; b) the intermediate fabric layer includes warp and weft yarns and a flow-through region in which the warp and weft yarns float; c) the lower fabric layer and the intermediate fabric layer substantially include or form at least one first chamber; d) a second chamber is disposed downstream of the first chamber in the flow direction; e) At least one of the chambers is sealed or closed by a yarn cutting zone, also called a yarn cutting zone, in which, between the textile layers, selected (warp) yarns of one textile layer are entangled only with selected (weft) yarns of the other textile layer, and which is solved (achieved) by an air outlet which can be cut or broken at a predetermined internal pressure of the chamber.

[0012] Special Notes: In this document, when "warp yarns" and "weft yarns" are used, the expressions in brackets shall be applied interchangeably as "weft yarns" and "warp yarns", respectively. [The expression "warp yarns" may mean "weft yarns" and the expression "weft yarns" may mean "warp yarns".]

[0013] The air outlet according to the invention with an "internal pressure responsive" or "internal pressure dependent" air outlet mouth can be manufactured as a one-piece woven (OPW) in an automated process, which allows cost savings in both the manufacture of the components and their assembly into cut-and-sew airbags. As is well known, OPW components can be programmed with thread / yarn accuracy, so the precision of the components and their repeatability can be great. This eliminates possible inaccuracies in the placement of individual components and seams for sewn airbags and the applications to which they are attached. According to the invention, the air outlet is pre-programmed and woven in one piece and then conventionally sewn in the area of ​​the intended outlet of a conventionally manufactured sewn airbag.

[0014] In one advantageous embodiment of the air outlet according to the invention, the air outlet is characterized in that the upper textile layer comprises warp and weft threads and together with the intermediate textile layer substantially comprises or forms a downstream second chamber, the second chamber comprising a thread-cutting zone in which selected (warp) threads of the intermediate textile layer are intertwined only with selected (weft) threads of the upper textile layer between the upper and intermediate textile layers and can be broken, i.e. torn off or cut, at a predetermined internal pressure of the second chamber.

[0015] A further advantageous embodiment of the air outlet according to the invention is also characterized in that a second chamber downstream of the first chamber is included between the lower and intermediate textile layers, and the thread-cutting zone is arranged between the first chamber and the downstream second chamber. Both of the above advantageous embodiments of the air outlet according to the invention have the particular advantage of being simple, and therefore inexpensive, and particularly precise with regard to their manufacture.

[0016] In yet another advantageous embodiment of the air outlet according to the invention, the air outlet is applied or attached to the Cut & Sew airbag by sewing or stitching.

[0017] The above object is further solved (achieved) by an airbag having an air outlet according to claim 5, i.e. an airbag having an air outlet according to any of the preceding claims (embodiments described above) sewn thereto, and such an airbag is immediately available for assembly for the manufacture of a module for a motor vehicle occupant restraint system.

[0018] Further features and advantages of the invention are apparent from the subclaims or dependent claims 2 to 4.

[0019] To explain the invention in detail and to show how it can be put into practice, reference is made to the accompanying drawings in which: FIG. [Brief description of the drawings]

[0020] [Figure 1] 1 is a highly schematic side cross-sectional view of a first embodiment of an example air outlet according to the invention; FIG. [Diagram 2] FIG. 2 is a plan view of the air outlet shown in FIG. 1. The air outlet is sewn to the plain weave (fabric) of a conventionally manufactured or sewn airbag. [Diagram 3] 4 is a highly schematic side cross-sectional view of a second embodiment of an example air outlet according to the invention; FIG. [Figure 4] 4 is a highly schematic and enlarged perspective view of a portion of an air outlet having a lower textile layer according to FIG. 3 and an upper textile layer extending thereover (overlying it), seen from the right side of the drawing in the direction of arrow IV in order to show the yarn cutting zone, also called the thread cutting zone. EXAMPLES

[0021] For ease of understanding of the structure, all the parts shown are shown separated or pulled apart from one another, although, of course, in reality, the individual fabric layers will overlap one another intimately.

[0022] The term "float" is known to the person skilled in the art but will be explained briefly. In a woven fabric, the warp threads / yarns and weft threads / yarns present therein are connected to one another via weave bindings. The simplest weave is the so-called plain weave. In this case, the warp threads and the weft threads cross (one another). The term "floating" refers to the fact that the crossing threads do not form a bond (i.e. a weave binding) with one another but simply lie next to one another without being bound. Further details can be found in the relevant technical literature. See also DIN 62050.

[0023] In Figure 1, the observer sees three textile layers of a one-piece woven (OPW) pressure responsive or pressure dependent air outlet LA, namely a lower textile layer UG, a middle textile layer MG and an upper textile layer OG. The three textile layers UG, MG and OG are woven together as one piece at the sites of the woven seams WN, which are formed when at least two textile layers are combined and woven into one textile layer during the weaving process.

[0024] In contrast, the so-called stitching seam or sewn seam has the following characteristics: A stitching / sewn seam is formed by stitching / sewing together at least two fabric layers with at least one thread / yarn.

[0025] As can be seen on the left side of the drawing in FIG. 1, a first chamber K1 is arranged (formed) between the lower fabric layer UG and the middle fabric layer MG. This first chamber K1 is shown on its underside with a dashed line and has an inlet area ESB in which the warp and weft threads / yarns of the lower fabric layer UG float, i.e. do not interweave. The effect of this design is that the air impinging on this inlet area ESB presses against the side of the floating threads / yarns in a transverse direction to the drawing direction of the threads / yarns, thus forming a passageway, which can flow through the lower fabric layer UG and therefore through the corresponding fabric layer. And since this area is normally unaffected, it appears closed and closed. On the right side of the drawing in FIG. 1, a second chamber K2 can be seen downstream of the first chamber K1. A yarn cutting zone FBZ, also called the yarn cutting zone, is arranged between the first chamber K1 and the downstream second chamber K2. This will be explained in more detail below. The second chamber K2 is shown in dashed lines in the intermediate fabric layer MG and has a so-called flow-through region DSB in which the warp and weft threads / yarns of the intermediate fabric layer MG float.

[0026] Figures 1 and 2 show in "cross section and plan view" one embodiment of an example of an OPW air outlet LA according to the invention in a production state. The shape, in this case rectangular (see Figure 2), is used only to explain the present principle. In principle, the component can be manufactured in any shape, as long as the principles of the invention described herein can be implemented.

[0027] In the yarn cutting zone FBZ located between the chambers K1 and K2, the warp threads KF of the lower fabric layer UG are not tightly interwoven with the weft threads SF of the intermediate fabric layer MG, but are only loosely tacked with them. Reference should be made to the fact that the present principle is explained here. Thus, in the same way, the warp threads KF of the intermediate fabric layer MG are not tightly interwoven with the weft threads SF of the lower fabric layer UG, but are only loosely tacked with them. This bond is designed such that it can only withstand these intended defined (predetermined) pressures, i.e. the structure makes it possible for the warp threads KF to tear (break) the bond between the intermediate textile layer MG and the lower textile layer UG in the yarn cutting zone FBZ by causing the weft threads SF to tear off when pressurized air flows according to arrow GF1 through the inflow area ESB, from the first chamber K1 through the yarn cutting zone FBZ into the second chamber K2 and from there upwards through the intermediate textile layer MG in its flow-through area DSB towards the upper textile layer OG.

[0028] Below the plane of the one-piece woven air outlet LA shown in cross section in Fig. 1, a plain-woven fabric blank or fabric cut FGZ of a conventionally manufactured airbag (not shown in detail) is represented by a line FGZ, which FGZ includes an outflow cutout ASA, here exemplarily having an oval shape, located on the left side of the plane of Fig. 1 below the chamber K1 and directly parallel to the inflow area ESB. This outflow cutout ASA represents an opening of a sewn airbag (not shown in detail). The entire air outlet LA described here is conventionally sewn to the plain-woven fabric blank FGZ via stitching seams or sewing seams in the area of ​​the weaving seams WN.

[0029] In FIG. 2, the air outlet LA shown in FIG. 1 is shown in a top view (plan view). For ease of reference, the individual fabric layers are shown in perspective form. What can be seen (from FIG. 2) is the location of the outflow cut-out ASA, here exemplarily round, of the plain weave fabric blank FGZ of a conventionally sewn airbag to which the air outlet LA is sewn. The inflow area ESB of the first chamber K1 is arranged above the outflow cut-out ASA (towards the viewer in the drawing). On the right side of the drawing in FIG. 2, the location of the flow-through area DSB of the second chamber K2 can be seen. The woven seam WN of the air outlet LA is shown by a thick solid line.

[0030] Fig. 3 shows a second alternative embodiment of an example of an air outlet LA according to the invention. What can be seen in this figure, purely by way of example, is a plain weave fabric blank FGZ to which an air outlet LA according to the invention is sewn in a conventional manner by stitching / sewing seams NN, indicated by dashed vertical lines. The plain weave fabric blank FGZ has an outflow cutout ASA, above which the air outlet LA is arranged with an inflow area ESB, indicated by dashed lines, of a first chamber K1. The first chamber K1, between the lower textile layer UG and the intermediate textile layer MG extending above it, which are connected to each other by a woven seam WN, contains a flow-through area DSB, which is located opposite the inflow area ESB and opens into the upper second chamber K2. The warp and weft threads of the inflow area ESB and the flow-through area DSB float in this case as in the previously described embodiment, respectively forming areas for air to pass through. The second chamber K2 is in this case located between the middle textile layer MG and the upper textile layer OG and is sealed (sewn closed) by the yarn cutting zone FBZ. When air under a predetermined (predetermined) pressure flows according to the arrow GF2 through the outflow cut-out ASA of the conventionally sewn plain weave fabric blank FGZ of the airbag, then through the inlet area ESB, the chamber K1 and the flow-through area DSB and outwardly into the second chamber K2, the yarns of the yarn cutting zone FBZ are loaded in such a way that the loosely sewn warp and / or weft threads KFR, SFR are torn off, thus allowing the airbag to be vented. This will be explained in more detail below.

[0031] Figure 4 shows the example of Figure 3 in a schematic way, seen in the direction of the arrow IV. Between the middle textile layer MG and the upper textile layer OG, the individual warp threads KFR can be found, which are intertwined with the individual weft threads SFR as OPW tuck threads AH, forming the yarn cutting zone FBZ. These OPW tuck threads AH or their warp threads KFR and weft threads SFR, as already mentioned, are torn off when the air from the airbag reaches a predetermined pressure and is released from the airbag, moving the textile layers of the second chamber K2 further away from each other (pulled apart). The path of the now free escaping air is indicated by the arrow GF2 (Figure 3).

[0032] In Fig. 4, a part of the one-piece woven (OPW) pressure-responsive air outlet LA according to the invention is shown in detail, seen from the right side of the paper in Fig. 3 according to the arrow IV (Fig. 3). What can be seen is the chamber K2, the yarn cutting zone FBZ and its intermediate textile layer MG with (respectively) warp threads KF and weft threads SF and the upper textile layer OG extending above (overlapping) it. The warp threads KF of these two textile layers extend substantially into and out of the paper plane in Fig. 4. The weft threads SF extend substantially transversely to the warp threads in the paper plane in Fig. 4. The situation shown in the second chamber K2 shows the movement after ignition of the gas generator (not shown), but the intermediate textile layer MG and the upper textile layer OG extending above it have already been pulled apart to some extent from each other by the internal pressure of the one-piece woven (OPW) pressure-responsive air outlet LA according to the invention. Although many OPW tack threads are distributed across the width of the air outlet LA, only two OPW tack threads are shown here as an example for better visibility. In FIG. 4, the warp threads KFR coming from the middle fabric layer MG are looped by the weft threads SFR coming from the upper fabric layer OG, and these weft threads SFR are pulled out of these fabric layers a little. Then, when the internal pressure of the pressure-responsive OPW air outlet LA reaches a predetermined level, the distance between these facing fabric layers becomes large, the OPW tack threads AH are torn off, and the warp threads KFR and / or weft threads SFR are not cut but broken. The two facing fabric layers can move away from each other. The air flow can pass through the yarn cutting zone FBZ, now unhindered by the OPW tack threads, and can be diverted (escaped) to the outside. This provides a vent or air outlet function.

[0033] All or part of the above embodiments and examples can be described as follows, but are not limited to these. [Appendix 1] One-piece woven (OPW) pressure responsive air outlet for airbag exhaust applications, particularly for use as a vent. The one-piece woven pressure responsive air outlet includes a lower fabric layer, a middle fabric layer and an upper fabric layer; a) the lower fabric layer includes warp and weft yarns and an inflow region in which the warp and weft yarns float; b) the intermediate fabric layer includes warp and weft yarns and a flow-through region in which the warp and weft yarns float; c) the lower fabric layer and the intermediate fabric layer substantially comprise at least one first chamber; d) a second chamber is disposed downstream of the first chamber in the flow direction; e) At least one of the plurality of chambers is sealed by a yarn-cutting zone in which selected (warp) yarns of one fabric layer are entangled only with selected (weft) yarns of the other fabric layer between the fabric layers and can be cut or broken at a predetermined internal pressure of the chamber. [Appendix 2] In the above air outlet, particularly the air outlet described in appendix 1, f) the upper fabric layer includes warp and weft yarns and together with the intermediate fabric layer substantially includes the downstream second chamber; g) the second chamber includes a yarn cutting zone, in which selected (warp) yarns of the intermediate fabric layer are entangled only with selected (weft) yarns of the upper fabric layer between the upper and intermediate fabric layers and can be cut or broken at a predetermined internal pressure of the second chamber. [Appendix 3] In the above air outlet, particularly the air outlet described in appendix 1, The second chamber downstream of the first chamber is also included between the lower fabric layer and the middle fabric layer; The thread cutting zone is disposed between the first chamber and the downstream second chamber. [Appendix 4] In the above air outlet, particularly in the air outlet according to any one of appendices 1 to 3, The air outlet is applied to the Cut & Sew airbag by sewing. [Appendix 5] An airbag having the air outlet according to any one of appendices 1 to 4 sewn to the airbag.

[0034] Within the framework of the entire disclosure of the present invention (including the claims and drawings), modifications and adjustments of the embodiments are possible based on the basic technical ideas. Furthermore, within the framework of the entire disclosure of the present invention, various combinations or selections (including "non-selection") of the various disclosed elements (including each element of each claim, each element of each example, each element of each drawing, etc.) are possible. In other words, the present invention naturally includes various modifications and alterations that a person skilled in the art would be able to make in accordance with the entire disclosure including the claims and drawings, and the technical ideas of the present invention.

[0035] Furthermore, the reference numerals in the drawings attached in the claims are intended solely to aid in the understanding of the invention, and are not intended to limit the invention to the embodiments and examples shown.

[0036] Furthermore, the entire contents of each of the above references are hereby incorporated by reference. [Explanation of symbols]

[0037] AH OPW (One-piece woven) tack thread ASA spill cutout DSB flow-through region ESB inflow area FBZ Yarn / Thread Cutting Zone FGZ Plain Woven Fabric Blank / Cut to G F1 Arrows showing gas flow GF2 Gas flow arrows K1 First Chamber K2 Second Chamber KF Warp / Yarn KFR Warp / Yarn KFR Warp / Yarn LA Air Outlet MG intermediate woven layer NN stitching seam / sewing seam OG upper textile layer SF Weft / Yarn SFR Weft / Yarn SFR Weft / Yarn UG lower textile layer WN Woven seam

Claims

1. 1. A one-piece woven (OPW) pressure responsive air outlet for airbag vent applications, comprising: The one-piece woven (OPW) pressure responsive air outlet comprises a lower fabric layer (UG), a middle fabric layer (MG) and an upper fabric layer (OG); a) the lower fabric layer (UG) comprises warp and weft yarns and an inflow zone (ESB) in which the warp and weft yarns float; b) the intermediate fabric layer (MG) includes warp and weft yarns and a flow-through region (DSB) in which the warp and weft yarns are floating; c) said lower textile layer (UG) and said intermediate textile layer (MG) substantially comprise at least one first chamber (K1); d) a second chamber (K2) is arranged downstream of the first chamber (K1) in the flow direction; e) at least one of the first chamber (K1) and the second chamber (K2) is sealed by a thread-cutting zone (FBZ), in which selected warp threads of one fabric layer are only intertwined with selected weft threads of the other fabric layer between the fabric layers and can be cut or broken at a predetermined internal pressure of the chamber; Featuring an air outlet.

2. The air outlet according to claim 1, f) said upper textile layer (OG) comprises warp and weft threads and substantially comprises said second chamber (K2) downstream together with said intermediate textile layer (MG); g) the second chamber (K2) includes a thread cutting zone (FBZ), in which, between the upper fabric layer (OG) and the intermediate fabric layer (MG), selected warp threads of the intermediate fabric layer (MG) are intertwined only with selected weft threads of the upper fabric layer (OG) and can be cut or broken at a predetermined internal pressure of the second chamber (K2), or selected weft threads of the intermediate fabric layer (MG) are intertwined only with selected warp threads of the upper fabric layer (OG) and can be cut or broken at a predetermined internal pressure of the second chamber (K2). Featuring an air outlet.

3. The air outlet according to claim 1, the second chamber (K2) downstream of the first chamber (K1) is comprised between the lower fabric layer (UG) and the intermediate fabric layer (MG); the yarn cutting zone (FBZ) is arranged between the first chamber (K1) and the downstream second chamber (K2); Featuring an air outlet.

4. The air outlet according to claim 1, The air outlet is applied to the cut-and-sew airbag by sewing. Featuring an air outlet.

5. An airbag having the air outlet according to any one of claims 1 to 4 sewn to the airbag.

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