Method for manufacturing a one-piece woven airbag

Abstract

A method for manufacturing a one-piece woven (OPW) airbag includes providing yarns and beaming the yarns onto at least one beam of a loom. The yarns are simultaneously woven into a fabric airbag structure having two layers of portions defining both an inflatable volume and a non-inflatable portion and a single layer of portions forming a seam that bounds the inflatable volume. The airbag structure is cut to define the OPW airbag and at least one opening extending through only one of the two layers of portions.

Description

[0001] Related Applications

[0002] This application claims the benefit of U.S. Patent Application Serial No. 17 / 479,234, filed September 20, 2021, the entirety of which is hereby incorporated by reference herein. TECHNICAL FIELD

[0003] The present invention relates generally to an apparatus for helping to protect an occupant of a vehicle. More particularly, the present invention relates to a one-piece woven (OPW) inflatable airbag and method of manufacturing the same. BACKGROUND

[0004] It is known to inflate an occupant restraint system in the event of a vehicle collision to help protect the vehicle occupant. Examples of occupant restraint systems include driver and passenger frontal airbags, side airbags, airbags, curtain airbags, inflatable seat belts, inflatable knee bolsters, and inflatable headliner panels.

[0005] Occupant restraint systems can have various constructions. For example, an occupant restraint system can be constructed from stacked woven cloth panels that are interconnected by, for example, stitching or ultrasonic welding to form connections or seams that help define an inflatable volume of the protection device. As another example, an occupant restraint system can have an OPW construction in which the stacked cloth panels are woven together. The cloth panels are woven together to form connections or seams that help define an inflatable volume of the OPW protection device.

[0006] Current manufactured OPWs are first laser cut from a flat sheet. Next, one or more holes or openings are cut in one side of the OPW airbag using a separate operation that are configured to receive, for example, mounting structures, inflators, and the like. SUMMARY

[0007] According to one example, a method for manufacturing a one-piece woven (OPW) airbag includes providing a yarn and beaming the yarn onto at least one beam of a loom. The yarn is simultaneously woven into a fabric airbag structure having two layers of portions that define both an inflatable volume and a non-inflatable portion and a single layer of portions that form a seam that bounds the inflatable volume. The airbag structure is cut to define the OPW airbag and at least one opening that extends through only one of the two layers.

[0008] In another example, a method for manufacturing an OPW airbag includes providing a yarn and beaming the yarn onto at least one beam of a loom. The yarn is simultaneously woven into a woven airbag structure having two layers of portions defining both an inflatable volume and a non-inflatable portion and a single layer of portions forming a seam that bounds the inflatable volume. The airbag is coated. The coated airbag structure is laser cut at a first intensity to define the OPW airbag. At least one opening extending through the coating and only one of the two layers is laser cut at a second intensity that is less than the first intensity.

[0009] In another aspect, alone or in combination with any other aspect, the cutting step includes laser cutting the airbag structure and the at least one opening.

[0010] In another aspect, alone or in combination with any other aspect, the laser is operated at a first intensity to define the OPW airbag and at a second intensity that is less than the first intensity to define the at least one opening.

[0011] In another aspect, alone or in combination with any other aspect, the second intensity is less than about 70% of the first intensity.

[0012] In another aspect, alone or in combination with any other aspect, the laser cuts through the coating disposed on the airbag to define the at least one opening.

[0013] In another aspect, alone or in combination with any other aspect, an inflator is inserted through the at least one opening to place the inflator and the inflatable volume in fluid communication with each other.

[0014] In another aspect, alone or in combination with any other aspect, a mounting tab is inserted through the at least one opening for securing the airbag to a vehicle side structure.

[0015] In another aspect, alone or in combination with any other aspect, a fastener is inserted through the at least one opening for securing the airbag to a vehicle side structure.

[0016] In another aspect, alone or in combination with any other aspect, the airbag structure forms a curtain airbag.

[0017] Other objects and advantages of the application will be more fully understood from the following detailed description when taken in connection with the accompanying drawings, in which: BRIEF DESCRIPTION OF DRAWINGS

[0018] FIG. 1A is a schematic view of an example occupant restraint system including a curtain airbag in a stored state in a vehicle roof.

[0019] FIG. 1Bis a side view of a curtain airbag in a stored state.

[0020] FIG. 2 is a side view of a curtain airbag in a deployed state.

[0021] FIG. 3 is a side view of a fabric structure for forming a curtain airbag.

[0022] FIG. 4A is a cross-sectional view taken generally along FIG. 3 line 4B-4B in

[0023] FIG. 4B is a schematic illustration of a single layer opening formed in a first side of the fabric structure.

[0024] FIG. 4C is a schematic illustration of a single layer opening formed in a second side of the fabric structure.

[0025] FIG. 4D is an enlarged view of a portion of FIG. 3

[0026] is a side view of a roll of fabric material for forming the fabric structure of FIG. 5 FIG. 3

[0027] FIG. 6 is a schematic illustration of a cutting process for forming a curtain airbag.

[0028] FIG. 7 is a flowchart illustrating a method of forming an airbag of FIG. 3 DETAILED DESCRIPTION

[0029] The present invention relates generally to an apparatus for helping to protect an occupant of a vehicle. More particularly, the present invention relates to an OPW inflatable airbag and a method of manufacturing the same.

[0030] FIGS. 1A-2 An example configuration of an apparatus 10 or occupant restraint system for helping to protect one or more occupants 60 of a vehicle 12 is illustrated. As shown, the vehicle 12 extends along a centerline 22 from a first or front end 24 to a second or rear end 26. The vehicle 12 extends on opposite sides of the centerline 22 to a left / driver side 28 and a right / passenger side 30. Each side 28, 30 includes a side structure 29 including A, B, and C pillars and doors connected to the pillars. FIG. 1A

[0031] Referring to FIG. 1A ​​​​The first end 24 of the vehicle 12 includes an instrument panel 42 facing a passenger cabin or compartment 40. A windshield or windscreen 44 can be located between the instrument panel 42 and the roof 32. The vehicle 12 can be an autonomous vehicle, in which case the passenger compartment 40 can be devoid of operator controls (e.g., steering wheel, pedals, gauges, center console, etc.). Accordingly, the instrument panel 42 can be reduced in size or removed altogether in order to maximize space in the passenger compartment 40. In the illustrated example, a steering wheel 49 extends from the instrument panel 42.

[0032] The seats 50 are positioned in the passenger compartment 40. In this open passenger compartment 40 configuration, the vehicle seats 50 can be configured, positioned, and oriented in various ways, unbound by the need to facilitate a vehicle driver / operator. For example, in FIG. 1B the seats 50 can be arranged in front and rear rows 52, 54, respectively, oriented in a forward-facing manner similar to a conventional automobile. It will be appreciated that the vehicle 12 can alternatively include more or fewer rows of seats 50 (not shown). In any case, a safety belt 56 is associated with each seat 50 for restraining an occupant 60 in that seat.

[0033] Each seat 50 includes a base or bottom 53 for receiving a leg 66 of an occupant 60. A seat back 55 extends from the base 53 toward the roof 32 and receives an upper torso 64 of the occupant 60. A headrest 57 is connected to the seat back 55 and receives a head 62 of the occupant 60.

[0034] The apparatus 10 can be configured to deploy at any known location of the vehicle (e.g., steering wheel, door, front seat, roof, etc.). To this end, the apparatus 10 can include, for example, a center side airbag, a side impact airbag, an inflatable seat belt, an inflatable knee pad, and / or an inflatable headliner panel. Thus, the apparatus 10 can be used to protect a driver and / or any number of passengers in the vehicle 12.

[0035] In the illustrated example, the apparatus 10 includes an inflatable vehicle occupant protection device in the form of an inflatable curtain airbag 80. The airbag 80 has FIG. 1B The illustrated stored state, in which the deflated curtain is rolled up, folded, or rolled up and folded, is positioned on the passenger side 30 of the vehicle 12 near the intersection of the side structure 29 and the roof 32. Alternatively or additionally, the apparatus 10 can include an inflatable curtain airbag 80 on the driver side 28 of the vehicle 12. With this in mind, while the airbags 80 on the respective driver and passenger sides 28, 30 are similar, for the sake of brevity, only the construction and operation of the airbag associated with the passenger seat 50 on the passenger side will be discussed.

[0036] That is, the airbag 80 is inflatable from the stored state in a direction away from the roof 32 to an inflated state in which the airbag 80FIG. 2 The illustrated deployed state. In the deployed state, the inflatable curtain 80 extends along the side structure 29 and is positioned between the side structure of the vehicle 12 and any passenger-side 30 occupant 60. The deployed inflatable curtain 80 extends from an upper end 34 positioned near the roof 18 to a lower end 38 positioned near the occupant's 60 torso.

[0037] An inflator 82 is fluidly connected to the airbag 80 and is disposed in the cover or housing / module 68 positioned in the roof 32 along with the airbag 80. The inflator 82 can have a known construction suitable for inflating the airbag 80. For example, the inflator 82 can house a quantity of pressurized inflation fluid (not shown) stored in gaseous form for inflating the airbag 80. Alternatively, the inflator 82 can house a combination of pressurized inflation fluid and a combustible material for heating the inflation fluid, or can be a pyrotechnic inflator that uses combustion of a gas-generating material to generate the inflation fluid. As another alternative, the inflator 82 can be of any suitable type or construction for supplying a medium for inflating the airbag 80. In any case, the inflator 82 includes openings (not shown) through which the inflation fluid is directed into the airbag 80.

[0038] The vehicle 12 includes one or more sensors 86 for sensing the occurrence of an event for which the airbag 80 is intended to inflate. Examples of such events include a vehicle collision (e.g., a frontal collision, a rear collision, a side collision, an offset collision, or an angled collision), a vehicle rollover, or both. Upon sensing the event, the sensor provides an electrical signal through a wire 88 to the inflator 82 (or to a controller 89 connected thereto) so that the inflator actuates and discharges fluid under pressure into the airbag 80 in a known manner.

[0039] The airbag 80, when inflated, helps to protect the passenger-side 30 occupant 60 in the event of a vehicle 12 collision, a vehicle rollover, or both. The airbag 80, when inflated, also helps to absorb impact energy of the airbag and helps to distribute the impact energy over a large area of the airbag.

[0040] Reference FIG. 3In this example configuration, the airbag 80 includes integrally formed panels 90 that cooperate to define an inflatable volume 92. Seams 94 extending along the panels 90 help define inflatable chambers 96 within the inflatable volume 92 and non-inflatable portions 98. The airbag 80 has an OPW construction in which the airbag is a single, unitary woven article having portions (i.e., the panels 90) that are woven as separate, spaced-apart layers of material and portions (i.e., the seams 94) that are woven as a single layer (i.e., not spaced-apart layers from one another). The OPW construction can be particularly beneficial in airbag constructions because it can provide long duration inflation and high pressurization capability, which can be desirable for curtain airbags and other types of airbags.

[0041] The particular OPW construction of the airbag 80 is by way of example only. The present invention is suitable for implementation in OPW airbag structures having any construction (e.g., multiple inflatable portions, a single inflatable portion, no inflatable portions, and any number (including zero) of seams). That is, the airbag 80 has an OPW construction that facilitates seam integrity, makes packaging easier and more compact, and allows for uniform shrinkage in the weft direction. To achieve this, the OPW construction of the airbag 80 is configured such that certain portions of the airbag are woven in different weave patterns. In describing the airbag 80, reference is made to its length measured in the warp direction (as shown, left to right) and its width measured perpendicular to this length and in the weft direction (as shown, top to bottom). That is, the weave direction of the airbag 80 yarns is indicated by W. FIG. 3 FIG. 3

[0042] Referring to FIG. 4A , the panels 90 each include a plurality of warp yarns or “ends” indicated at 110. The panels 90 also each include a plurality of weft yarns or “picks” indicated at 112. The warp yarns 110 and weft yarns 112 are oriented perpendicular to one another. The warp yarns 110 are interlaced with the weft yarns 112 in an alternating or “over-under” manner.

[0043] ​​In the inflatable regions 96, 200, each panel 90 is woven in a one-by-one (1 x 1) weave pattern (referred to in the art as a "plain weave" pattern). Every other warp yarn is used to form an upper layer, with its adjacent warp yarns always in the lower position as a single weft yarn is inserted (e.g., 1 upper and 2, 3, 4 lower). A second weft yarn is then inserted to form a lower layer. In this case, the warp yarns used for the upper layer are always in the upper position, and their adjacent yarns form the lower layer (e.g., 1, 2, 3 upper and 4 lower). A third weft yarn is then inserted to form an upper layer in this case (e.g., 3 upper and 1, 2, 4 lower), and a fourth weft yarn is inserted back to a lower layer in this case (e.g., 4 upper and 1, 2, 3 lower). This combination is then repeated. In this example, all odd warp and weft yarns form the upper panel, and all even warp and weft yarns form the lower panel. This is referred to in the art as double layer plain weave.

[0044] The weave pattern includes what is referred to in the art as "floats." A "float" refers to the number of adjacent warp 110 or weft 112 yarns over or under, respectively, a weft or warp yarn. The number of floats in a woven fabric varies depending on the particular weave type in which the fabric is woven. For example, a plain weave fabric includes a single float because the warp and weft yarns pass over and under a single weft and warp yarn, respectively. As another example, a 2 x 2 weave fabric includes two floats because the warp and weft yarns pass over and under two adjacent weft and warp yarns, respectively.

[0045] The seams 94 have a construction that varies according to the plain weave pattern in order to provide the desired functionality for a particular seam. In the portion illustrated in FIG. 4, the seam 94 has a non-plain two-by-two (2 x 2) followed by three-by-three (3 x 3) weave pattern (referred to hereinafter as a low float weave pattern). The low float weave pattern is shown and described in U.S. Patent Publication No. 2006 / 0236403, which is incorporated herein by reference in its entirety. However, it should be appreciated that the seam 94 can have alternative non-plain weave patterns, examples of which are noted below.

[0046] In addition to those floats that normally occur in a weave pattern, floats can also occur in areas where different weave patterns of the fabric meet one another. This is particularly important in OPW airbag designs where double layer plain weave meets a non-plain weave pattern, for example, at the transition between the inflatable chamber 96 and the seam 94. The number and location of these extra floats is determined by the weave patterns of the fabric at the junction. Although it can not be possible to avoid extra floats at the junction, the weave patterns can be configured to a large extent to help place a desired number of floats in a desired location at the junction between weave patterns.

[0047] In the example configuration, the airbag 80 includes a plain weave portion and a non-plain weave portion. The portion 200 of the airbag 80, indicated as being free of hatch lines, represents portions of the cloth panel 90 that are woven with layers of the weave component separated by plain weaving. The portion of the airbag 80, indicated at 202 with hatch lines, represents portions of the cloth panel 90 that are woven together with a low float weave pattern to help form the seam 94 of the airbag 80. The portion 202 forming the seam 94 can have an alternative weave pattern, one or more of: a 3x3 panama weave pattern, an alternative basket weave pattern, and / or a weave repeat pattern.

[0048] The portion, indicated at 206 with hatch lines, extends around the entire perimeter 208 of the airbag 80 and represents portions of the cloth panel 90 that are woven together with the BST 99 weave pattern. One or more portions 206 can also be provided inside the perimeter 208. The portions 206 are single layer / non-inflated portions.

[0049] Returning to FIG. 3 , along the top of the perimeter 208 are provided portions of the airbag 80, indicated at 212 with hatch lines. Each portion 212 includes one or more openings 214 that receive fasteners (not shown) to help secure the airbag 80 to, for example, the roof 32 and / or side structure 29, such as to an A-pillar. The portions 212 represent portions of the cloth panel 90 that are woven with a panama weave pattern, such as a 4x3x4x3 panama weave pattern. The portions 212 are single layer non-inflated portions.

[0050] The plain weave portions and the non-plain weave portions of the cloth panel 90 can have different gas permeability. For example, the non-plain weave portions can have a higher gas permeability than the plain weave portions due to the tendency for the weave to be looser and for the yarns to shift in non-plain weaving. To this end, an outer coating and / or laminate 230 can be applied to the cloth panel 90 to help control and maintain the gas permeability of the cloth panel at a desired level.

[0051] The coating 230 can be any coating suitable for providing the desired permeability characteristics. For example, the coating 230 can include a urethane or silicone material that is gas impermeable or substantially gas impermeable. In any case, the airbag 80 can thus maintain the improved seam integrity and packaging provided by the above-described plain weave portions and non-plain weave portions without sacrificing gas permeability.

[0052] Referring to FIGS. 4B-4COne or more openings 210 can be formed in the airbag 80 for receiving various structures needed to secure the airbag to the vehicle 20 and to inflate / deploy the airbag, such as fasteners, mounting brackets or tabs, inflators 82, etc. More specifically, openings 210 can be formed in the first panel 90 (as shown on the right side) FIG. 4B FIG. 4C and the second panel 90 (as shown on the left side) to enable the brackets, tabs, inflators, etc. to extend between the panels. The openings 210 are cut in each panel 90 in a manner that does not also cut the other, opposing panel.

[0053] In one example, shown in FIG. 4D , an opening (indicated at cut line 230) is formed in one of the panels 90 along the top of the perimeter 208 on one of the sections 212. The opening 230 allows a mounting tab 240 having an opening 242 to be inserted into a space 224 between the panels 90 in manner A. When this occurs, the opening 242 is aligned with the opening 214 in the section 212. Thus, an operator / installer can simply insert the mounting tab 240 through the opening 242 into the space 224, after which a fastener (not shown) is extended through the aligned openings 214, 242 to help secure the airbag 80 to the vehicle 12. This process can be repeated for any and all sections 212 intended to receive a bracket or tab.

[0054] In another example, shown in FIG. 3 , an opening (indicated at cut line 232) is formed in one of the panels 90 in a section 234 of the airbag 80 that is in fluid communication with the inflatable volume 92. In other words, the opening 232 can be formed in the section 234 to enable the inflator 82 to extend through one of the panels 90 into the inflatable volume 92.

[0055] The panels 90 used to construct the airbag 80 are formed from a continuous roll 250 of fabric material, shown (rolled up) in FIG. 5 . The weave pattern used to weave the panels 90 is selected to facilitate the processing of the roll 250 of woven material. Once the roll 250 is produced and any coating 230 is applied, the panels 90 are cut from the roll to define the airbag 80. More specifically, the (boundary) is cut completely through to completely separate each airbag 80 from the deployed roll 250. This cutting can be performed by a cutting machine, such as a laser 270, shown in FIG. 6 , using a vision system to help improve cutting accuracy.

[0056] ​Advantageously, at the same time, any openings 230, 232 in the airbag 80 are also cut through only one of the two pieces of cloth 90 in the portions where the pieces are present / spaced apart. With this in mind, the laser 270 can operate at a first intensity sufficient to cut through both pieces of cloth 90 when cutting the airbag 80 from the roll 250, thereby separating the airbag from the roll. The laser 270 can then operate at a second intensity less than the first intensity (e.g., about 80% of the first intensity) in order to cut through only one of the pieces of cloth 90 and cut the openings 230, 232 as needed. It should also be appreciated that the laser 270 can operate at different speeds, e.g., about 1.5 m / s during normal (2-ply) cutting and about 0.9 m / s during (single-ply) hole cutting. In one example, the laser is a CO2laser with an output of up to about 2000 W.

[0057] In FIG. 7 In one example method 350 shown for forming the airbag 80, at step 360, yarn is provided. At step 362, the yarn is beaming onto at least one beam of a loom (e.g., air-jet loom or rapier loom). At step 364, the beamed yarn is woven on the loom to form the roll 250 having the OPW construction. At step 366, the coated roll 250 is cut into FIG. 3 FIG. 3 The pattern shown, to define the airbag 80, while also correspondingly adjusting (reducing) the intensity of the laser 270 to cut single-ply openings 230, 232 in the airbag.

[0058] The cutting process used herein can be used to cut openings anywhere in an OPW airbag where separation of pieces / ply is needed in order to insert another object between the plies / pieces, e.g., openings for inflators, hanging tabs, mounting brackets, and / or anti-kink splines for the length of the airbag to be deployed. The cutting process can also be advantageous where an object (e.g., a steel clip or a one-piece bracket) is to be inserted between two fused plies of the airbag. Laser cutting of stud holes can also be used.

[0059] It should be appreciated that the cutting process shown and described herein helps to avoid the coating around the cut openings from fusing itself when the airbag is coated, since the intensity used to form these openings is reduced, i.e., not high enough to melt / reflow the coating.

[0060] The hole / opening cutting process of the present invention has the advantage of reducing the number of steps and cost associated with forming OPW airbags that include structure-receiving openings. More specifically, the present invention combines the step of cutting airbags from a roll with the step of forming desired structure-receiving openings in the cut airbags. That is, by simply adjusting the laser intensity and / or speed, the same laser used to cut individual airbags from a roll can also be used to cut any single layer openings in the airbags. Thus, the process is more efficient, less costly and more accurate than using one separate, different process to cut the airbags and another separate, different process to form openings for mounting tabs, inflators, etc.

[0061] What has been described above are examples of the present invention. Of course, it is not possible to describe every conceivable combination of components or methodologies for purposes of describing the present invention, but one of ordinary skill in the art will recognize that many other combinations and permutations are possible. Accordingly, the present invention is intended to embrace all such alterations, modifications and variations.

Claims

1. A method for manufacturing a one-piece woven airbag, the method comprising: providing yarn; beaming the yarn onto at least one beam of a loom; simultaneously weaving the yarn into a woven airbag structure having two-layer portions defining both an inflatable volume and a non-inflatable portion and single-layer portions forming seams that bound the inflatable volume; and cutting the airbag structure to define the one-piece woven airbag and at least one opening extending through only one of the two-layer portions, wherein the cutting step comprises laser cutting the airbag structure and the at least one opening, and wherein the laser is operated at a first intensity to define the one-piece woven airbag and at a second intensity less than the first intensity to define the at least one opening.

2. The method of claim 1, wherein, The second intensity is less than 70% of the first intensity.

3. The method of claim 1 or 2, wherein, The laser cuts through a coating disposed on the airbag to define the at least one opening.

4. The method of claim 1 or 2, further comprising inserting an inflator through the at least one opening to place the inflator and the inflatable volume in fluid communication with one another.

5. The method of claim 1 or 2, further comprising inserting a mounting tab through the at least one opening for securing the airbag to a vehicle side structure.

6. The method of claim 1 or 2, further comprising inserting a fastener through the at least one opening for securing the airbag to a vehicle side structure.

7. The method of claim 1, wherein, The airbag structure forms a curtain airbag.

8. A method for manufacturing a one-piece woven airbag, the method comprising: providing yarn; beaming the yarn onto at least one beam of a loom; simultaneously weaving the yarn into a woven airbag structure having two-layer portions defining both an inflatable volume and a non-inflatable portion and single-layer portions forming seams that bound the inflatable volume; coating the airbag; laser cutting the coated airbag structure at a first intensity to define the one-piece woven airbag; and laser cutting at least one opening extending through the coating and only one of the two-layer portions at a second intensity less than the first intensity.

9. The method of claim 8, wherein, The second intensity is less than 70% of the first intensity.

10. The method of claim 8, further comprising inserting an inflator through the at least one opening to place the inflator and the inflatable volume in fluid communication with one another.

11. The method of claim 8, further comprising inserting a mounting tab through the at least one opening for securing the airbag to a vehicle side structure.

12. The method of claim 8, further comprising inserting a fastener through the at least one opening for securing the airbag to a vehicle side structure.

13. The method of claim 8, wherein, The airbag structure forms a curtain airbag.

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