JP2014221616A - Air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bag that is manufactured by a simple method appropriate for mass production and that is excellent in pressure resisting characteristics.SOLUTION: An air bag is configured by coupling outer peripheries of panels 2 and 3 together by sewing. The air bag is configured by being sewn in a coil shape with a sewing thread 4 in such a manner as to wind up ends of all the panels 2 and 3 to be coupled. The air bag enables an improvement in productivity, eliminates the risk of stitch skipping caused by poor tension, and enables the expectation of an improvement in the effect of suppressing gas leakage.

Description

  The present invention relates to an airbag that is mounted on a vehicle and instantly inflates to protect an occupant in the event of a vehicle collision, and more particularly to an airbag that is excellent in productivity and pressure resistance characteristics.

2. Description of the Related Art In recent years, an airbag device has been widely used as a safety device for protecting an occupant from an impact when a vehicle collides. The airbag device instantly inflates into the space between the occupant and the interior structure at the time of collision, and has a function of absorbing the impact when the occupant directly collides with the instrument panel, side door, handle, etc. .
Therefore, as an airbag device, a sensor that detects rapid deceleration when receiving an impact such as a vehicle collision, an inflator that generates a high-pressure gas for inflation by receiving a signal from the sensor, and an inflation from the inflator An air bag body that is inflated and deployed by the high-pressure gas for reducing the impact of the occupant and a diagnostic circuit that determines whether or not the air bag system is functioning normally are provided.

The airbag is usually formed by joining a plurality of panels by sewing. The sewing portion is required to have pressure resistance that can withstand the pressure inside the airbag and heat resistance that can withstand the high-pressure gas from the inflator.
For example, Patent Document 1 discloses that a panel of a sewing portion is folded and that portion is sewn with a multi-stitch staggered seam, and Patent Document 2 discloses that a part is sewn by flat stitching. ing.

  These sewing operations are performed using a normal sewing machine, that is, sewing using an upper thread and a lower thread. In sewing using an upper thread and a lower thread, skipping may occur due to the tension of each thread being different. Since this skip causes gas leakage, it affects the pressure resistance characteristics.

JP-A-4-257746 Japanese Patent Laid-Open No. 11-245750

  The present invention solves the above-described problems, and an object thereof is to provide an airbag manufactured by a simple method suitable for mass production and having excellent pressure resistance.

  That is, the present invention relates to an airbag in which outer peripheries of panels are joined by sewing, and the locus of sewing threads is sewn in a coil shape so as to wind the ends of all the panels to be joined.

  ADVANTAGE OF THE INVENTION According to this invention, the air bag excellent in the pressure | voltage resistant characteristic can be provided by the simple method suitable for mass production.

It is the schematic sectional drawing which showed an example in the sewing part 1 of the airbag of this invention. It is a schematic plan view showing a part of the airbag of the present invention sewn in a coil shape with a sewing thread (sewing).

  The present invention is an airbag formed by sewing the outer periphery of a panel, which is sewn in a coil shape with a sewing thread so as to wind the ends of all the panels to be joined.

  FIG. 1 shows a schematic cross-sectional view of a sewing part 1 of an airbag which is an example of an embodiment of the present invention. As shown in FIG. 1, in the present invention, the panel 2 and the panel 3 constituting the airbag are folded together (or rolled into a roll shape) at the sewing portion 1 so that the ends thereof are wound inside. As shown in the schematic plan view of FIG. 2, only the sewing (sewing) thread 4 is sewn in a coil shape.

  Since the airbag of the present invention has the outer periphery sewn only with the sewing thread 4, the conventional troublesome work such as checking the condition of the upper thread and the lower thread and adjusting the tension is not required. Can be improved. In addition, there is no fear of skipping due to a tension failure, and it is easy to secure a pressure resistance characteristic. Furthermore, the effect of suppressing gas leak can be expected by bending the ends of all the panels to be joined together and sewing them so that the sewing thread is coiled. In addition, it has been confirmed that the seam strength is the same as compared with the sewing by a conventional sewing machine (see the examples).

  For the base fabric used for the airbag cutting fabric of the present invention, use a material that has been subjected to air-impermeable processing by laminating and applying rubber or resin, etc., depending on the performance of the inflator, the bag capacity, the use site, etc. Also good.

  A fiber fabric is used as the base fabric. Here, the fiber fabric means a woven fabric woven using fiber yarns, a knitted fabric and a non-woven fabric knitted using fiber yarns.

  The fibers constituting the fiber fabric are not particularly limited, such as natural fibers, chemical fibers, and inorganic fibers. For example, Nylon 6, Nylon 66, Nylon 46, Nylon 610, Nylon 612 and the like, or aliphatic polyamide fibers obtained by copolymerization and mixing thereof, Nylon 6T, Nylon 6I, Nylon 9T and aliphatic amines represented by Copolymerized polyamide fiber of aromatic carboxylic acid, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate alone or a copolymer thereof, polyester fiber obtained by mixing, ultrahigh molecular weight polyolefin fiber, vinylidene, Chlorine-containing fibers such as polyvinyl chloride, fluorine-containing fibers containing polytetrafluoroethylene, polyacetal fibers, polysulfone fibers, polyphenylene sulfide fibers (PPS), polyethers -Terketone fiber (PEEK), wholly aromatic polyamide fiber, wholly aromatic polyester fiber, polyimide fiber, polyetherimide fiber, polyparaphenylene benzbisoxazole fiber (PBO), vinylon fiber, acrylic fiber One type or two or more types may be appropriately selected from cellulose fibers, silicon carbide fibers, alumina fibers, glass fibers, carbon fibers, steel fibers, and the like. Of these, synthetic fiber filaments are preferred from the viewpoints of versatility and the production process of the base fabric and physical properties of the base fabric. In particular, nylon 66 fiber is preferable from the viewpoints of physical properties, durability, heat resistance, and the like. From the viewpoint of recycling, polyester fibers and nylon 6 fibers are also preferable.

  These fibers include various additives that are usually used to improve spinnability, processability, durability, etc., such as heat stabilizers, antioxidants, light stabilizers, anti-aging agents, and lubricants. One or more of a smoothing agent, a pigment, a water repellent, an oil repellent, a concealing agent such as titanium oxide, a gloss imparting agent, a flame retardant, and a plasticizer may be used. In addition, when it is desirable to weave the calami weave, processing such as twisting, bulking, crimping, winding, or gluing may be performed. Further, as the form of the yarn, in addition to the long fiber filament, a spun yarn of short fibers, a composite yarn of these, or the like may be used.

  For example, when the fiber fabric is a woven fabric, it may be a plain weave, an oblique weave (basket weave), a lattice weave (ripstop weave), a twill weave, a knot weave, an entangled weave, an imitation weave, or a composite structure thereof. If necessary, in addition to the two axes of warp and weft, a multi-axis design including 60 degrees obliquely may be used, and the arrangement of the threads in this case may be the same as that of the warp or weft. Of these, plain weaving is preferable in that the denseness of the structure, the uniformity of physical properties and performance can be ensured.

  Fabric production may be selected as appropriate from various looms used for weaving ordinary industrial fabrics, for example, shuttle looms, water jet looms, air jet looms, rapier looms, and projectile looms. Good.

  When the fiber fabric is a knitted fabric, a single knitting structure such as a single knitting such as a single tricot knitting, a single cord knitting, a single atlas knitting, a weft knitting such as a flat knitting, a rubber knitting or a pearl knitting, or a combination thereof And those composed of double tissues. Moreover, when the said fiber fabric is a nonwoven fabric, what is manufactured by a chemical bond, a thermal bond, a needle punch, a spunlace, a stitch bond, a spun bond, a melt blow, wet, etc. is mention | raise | lifted.

  The single yarn thickness of the yarn constituting the base fabric may be the same or different, and is preferably in the range of 0.5 to 8 dtex, for example. Further, the strength of the single yarn is also preferably 5.4 cN / dtex or more, and more preferably 8 cN / dtex or more. Further, the cross-sectional shape of the single yarn of these fibers may be appropriately selected within a range that does not hinder the production of the fabric and the physical properties of the obtained fabric, such as a circle, an ellipse, a flat, a polygon, a hollow, and other irregular shapes. Moreover, you may use what integrated several thread | yarns from which thickness, cross-sectional shape, etc. differ by a combined yarn, twisting.

  The total fineness of the fibers is preferably 150 to 1000 dtex, and more preferably 235 to 700 dtex. If it is less than 150 dtex, the strength required for the airbag tends to be difficult to obtain. If it exceeds 1000 dtex, the weight becomes too large, and the thickness of the base fabric may increase, resulting in poor bag storage.

The base fabric preferably has a basis weight of 190 g / m ² or less and a tensile strength of 600 N / cm or more. If the basis weight and tensile strength are within this range, it can be said that it is light and excellent in physical properties. Here, the basis weight refers to the weight of the base fabric in an unprocessed state before applying a non-aeration treatment agent to be described later.

The cover factor when the base fabric is a woven fabric is preferably 1500 to 2500. If the cover factor is less than 1500, the opening of the fabric will be large and it will be difficult to obtain the airtightness of the bag. If the cover factor is greater than 2500, the thickness of the fabric will increase and the bag will not be easily stored. There is a fear. Here, the cover factor means that the warp yarn total fineness is D ₁ (dtex), the warp yarn density is N ₁ (lines / 2.54 cm), the weft total yarn fineness is D ₂ (dtex), and the weft yarn density Is N ₂ (lines / 2.54 cm), (D ₁ × 0.9) ^1/2 × N ₁ + (D ₂ × 0.9) ^1/2 × N ₂ .

  The base fabric may be subjected to scouring and heat treatment.

  As described above, the base fabric may have a resin layer for the purpose of improving heat resistance and reducing air permeability. Further, for that purpose, the resin layer is attached to at least the entire surface of one side of the base fabric, but on the surface of the base fabric, the gap portion of the yarn bundle constituting the base fabric, or the gap portion of the single fiber yarn, etc. It may be interposed. It is preferable to fabricate the airbag so that the coated surfaces are inside by joining the surfaces having the resin layer, because of the heat resistance and that the damage to the coating can be suppressed even when an external force is applied to the base fabric. .

  Examples of the resin include halogen-containing rubbers such as chloroprene rubber, hyperon rubber, and fluorine rubber, silicone rubber, ethylene propylene rubber, ethylene propylene terpolymer rubber, nitrile butadiene rubber, styrene butadiene rubber, isobutylene isoprene rubber, and urethane rubber. And rubbers such as acrylic rubber, and halogen-containing resins such as vinyl chloride resin, vinylidene chloride resin, chlorinated polyolefin resin and fluorine resin, urethane resin, acrylic resin, ester resin, amide resin, olefin resin and silicone resin Examples thereof include resins, and these are used alone or in combination. Of these, silicone rubber and silicone resin are preferable in terms of excellent flexibility, heat resistance, and weather resistance.

  As coating methods, 1) coating method (knife, kiss, reverse, comma, slot die, lip, etc.), 2) dipping method, 3) printing method (screen, roll, rotary, gravure, etc.), 4) transfer method, etc. (Transfer), 5) Laminating method, and 6) Spraying method. Among these, the coating method is preferable because the range of the application amount that can be set is large.

Moreover, as an application quantity, 5-60 g / m < ² > is preferable. If the coating amount is less than 5 g / m ² , the air permeability of the base fabric is increased, which may cause a problem in the airtightness of the bag. If the coating amount is more than 60 g / m ² , the thickness of the base fabric is increased. This may increase the thickness of the bag and cause problems with the bag storage.

  The occupant side cloth and the inflator side cloth may be joined by any method such as sewing, adhesion, welding, weaving, knitting, or a combination thereof, and robustness as an airbag. As long as it satisfies the impact resistance at the time of deployment and the impact resistance performance of the occupant.

  The thickness of the sewing thread used for sewing may be 235 dtex (corresponding to 50th hand) to 2800 dtex (corresponding to 0 hand), and the number of stitches may be 2 to 10 needles / cm.

  Furthermore, if necessary, seal material, adhesive or adhesive material is applied to the upper and / or lower parts of the seam, between the seams, the seam allowances, etc., in order to prevent gas leakage from the seams such as the outer periphery seam. It may be spread or laminated.

  What is necessary is just to select suitably the sewing thread | yarn used for a sewing from what is generally called as a synthetic fiber sewing thread | yarn, and what is used as an industrial sewing thread | yarn. For example, nylon 6, nylon 66, nylon 46, polyester, polymer polyolefin, fluorine-containing, vinylon, aramid, carbon, glass, steel and the like may be used, and any of spun yarn, filament twisted yarn or filament resin processed yarn may be used.

  In addition, as described above, a heat-resistant protective cloth or a mechanical reinforcing cloth for protecting from the hot gas may be provided around the inflator attachment port according to the characteristics of the inflator to be used. These protective cloths and reinforcing cloths are made of heat-resistant materials such as heat-resistant fiber materials such as wholly aromatic polyamide fibers, wholly aromatic polyester fibers, PBO fibers, polyimide fibers, and fluorine-containing fibers. Alternatively, it is also possible to use a woven fabric that is separately prepared using a thread that is the same as the airbag body or thicker than the base fabric. Moreover, you may use what gave the heat resistant coating | covering material to the textile fabric.

  Hereinafter, based on an Example, this invention is demonstrated further more concretely. In addition, the method of performance evaluation of the airbag fabric and airbag characteristics performed in the examples is shown below.

Measurement method of seam strength According to the evaluation method of seam strength specified in 6.1 of JIS-L1093, the seam strength is measured in the warp direction and the weft direction of the base fabric (N = 3). And the total average of the latitudes.
The thickness of the sewing thread and the sewing specifications were those described in Examples and Comparative Examples, and the number of stitches was 3.5 stitches / cm. For the base fabric, nylon 66 fibers (470 dtex / 72f) were used, and an uncoated plain weave made with a weaving density of 46 / inch was used.

Example 1
1400 dtex sewing (sewing) thread was used as shown in FIG.

Comparative Example 1
The upper thread / lower thread were sewn using a sewing thread of 1400 dtex / 1400 dtex.

Comparative Example 2
Double chain stitching was performed using 1400 dtex / 1400 dtex sewing thread as the upper thread / lower thread.

  Also in the sewing of the present invention, it is possible to achieve a seam strength comparable to that of a conventionally used sewing method.

1 Sewing part
2 panels
3 panels
4 Sewing thread

Claims (1)

An airbag formed by joining the outer periphery of a panel by sewing, wherein the airbag is sewn in a coil shape with a sewing thread so as to wind up the end portions of all the panels to be joined.