JP5749759B2 - Weaving with weaving markers - Google Patents

Description

  The present invention relates to the manufacture of vehicle safety airbags, and more specifically to the manufacture of such airbag fabrics. The present invention relates to, but is not limited to, the utility relating to the manufacture of an airbag fabric of the OPW type (one-piece-woven type).

  In order to efficiently manufacture an airbag, it is required to automatically cut the airbag fabric into a desired shape and size. In some of these automatic cutting devices, the cutting device reads the markings on the fabric using an automatic optical reading system (also referred to herein as an automatic viewing system) so that the cutting device can cut the fabric. Can be determined. The apparatus may cut the fabric using, for example, laser cutting. Such markings may include, for example, various woven patterns using different color yarns. U.S. Pat. No. 6,932,120 describes a marking method that produces a patch in which warp and weft groups are colored and intersect. These patches can be read by an optical guidance system that controls the cutting of the woven fabric, such patches form a fiducial mark or reference position, on which the automatic cutting device is to cut the fabric. Confirm.

  Such a known method for utilizing the intersection between colored (for example black) warp and weft groups to provide the cutting device with a reference mark for recognition by optical reading and guiding means The colored warp yarns can then be combined with other warp yarns in the warp beam of the loom. Alternatively, the colored yarn can be supplied from a separate small creel. However, there is a problem in using warps colored in this way. Thus, each airbag design requires the colored warp to be in a separate position specific to the airbag geometry, and therefore, where the colored weft intersects the colored warp. A reference mark is required at a different desired position to be formed.

  Therefore, it is necessary to change the position of the colored warp yarn every time the design is changed, resulting in production stop time.

  Further, on the other hand, an automatic visual recognition system distinguishes between areas where the dark warp group intersects with the dark weft group and between areas where the dark warp group or weft group intersects the white warp group or weft group. That is not completely reliable, and as a result, production is reduced.

  A number of specific weave patterns have been developed to date to place reference or reference points to cut without the use of contrasting colored yarns. These particular weave patterns utilize different light reflecting properties of different weaves to assist the viewing system. However, it has become clear that such an arrangement is not suitable for an automatic cutting system. Existing optical detection systems cannot reliably recognize such woven patterns.

  Over the selected area of the fabric, the fabric is woven in two layers, where the warp and weft of each layer are separated from the warp and weft of the other layers (however, the warp of both layers is folded with the same group of weft) It is known to produce vehicle airbags by weaving the fabric so that the area, conversely, the weft yarns of both layers are folded together with the same group of warp yarns). The fabrics woven in this way are manufactured as continuous woven fabrics, as in any other commercial weaving process, and individual airbags are mostly areas where the warp and weft yarns of both layers are combined. It is later formed from the woven fabric by cutting the woven fabric along a predetermined line inside. In the present specification, such an airbag is referred to as an OPW airbag for convenience.

  It is an object of the present invention to provide an improved fabric for an airbag, such as an OPW airbag, that avoids or reduces the above disadvantages.

  In accordance with the present invention, the markings visible by the automatic cutting device are provided by yarns of a color that is in contrast to the color of most of the yarns that make up the fabric (referred to herein as the primary color). A woven fabric is provided, and the marking is provided by the marker weft of the contrasting color without depending on the warp of a color other than the main color, and the marker weft or the group of marker wefts of the main color Provided at a predetermined position spaced in the warp direction by the weft, the marker weft can be viewed from one side of the fabric in a predetermined marker region of the fabric and substantially visible in the rest of the fabric The marker area provides optically identifiable markings spaced along the warp and weft directions so that they cannot be or are difficult to see. On the basis of the number of warp yarns and weft yarns, the size of each optically identifiable marking is calculated in the warp yarn direction, the number of warp yarns crossing the woven fabric, the one marking and the next marking. The number of weft yarns between each of the marker weft yarn groups is spaced through the entire woven fabric at the same location through each of the marker regions or along the woven fabric. It extends through the marker area.

  Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings.

Figure 3 schematically shows a portion of a woven fabric that implements the present invention using optically detectable markers that form a reference point for a guided light cutting device. It is the figure corresponding to FIG. 1A which showed the opposite surface of the woven fabric shown by FIG. 1A. FIG. 2 is an enlarged view of a portion of the fabric of FIG. 1 in the area of such a marker. FIG. 3 is a schematic view in a section taken along line AA in FIG. 2. FIG. 3 is a schematic view in a cross section taken along line BB in FIG. 2.

  The woven woven fabric related to the drawing is of the type used for the production of one-piece-woven vehicle safety airbags, the woven fabric being woven as a continuous woven fabric, The method of weaving is determined so that over a selected region of the fabric, at least a portion of the selected region provides both sides of each airbag, and the fabric has two layers (the warp and weft yarns of each layer). In the other region, the warp yarns of both layers are folded into a single layer using the same group of weft yarns, and conversely both layers Are woven so that the weft yarns are folded with the warp yarns of the same group. The fabrics woven in this way are manufactured as continuous woven fabrics, as in any other commercial weaving process, and individual airbags are mostly areas where the warp and weft yarns of both layers are combined. It is later formed from the woven fabric by cutting the woven fabric along a predetermined line inside. In the present specification, such a fabric is referred to as an OPW type fabric for convenience. In FIG. 1A, FIG. 1B, and FIG. 2, the warp yarns extend vertically up and down in the figure, and the weft yarns extend horizontally left and right.

  Referring to FIG. 1A, a woven woven fabric according to the present invention is provided on one side of the woven fabric (usually optical detection for guiding, for example, a digital camera, cutting means for cutting an airbag from the woven fabric In the rest of the lighter colored fabric, the upper surface used as means) has a plurality of relatively widely spaced dark rectangles or “buoys” 10. On the back side of the woven fabric, as shown in FIG. 1B, there is a lateral dark band 12 running in the weft direction along the woven fabric at the opposite dark floating position.

  The illustrated fabric is cut into parts for airbags using an automatic cutting device of the type referred to above (which incorporates a viewing system with a camera that detects the contrast between white and black threads). Is intended to be. Software in the computer that controls the device determines how the cutter moves (eg, along the contour of the airbag part or cell) and how the camera is used to fine tune. The cutting machine may cut straight through the area where the black thread appears to be exposed or through the float, or, if the device is programmed to do so, slightly off the black thread float. The fabric may be cut away. The cuts should preferably be made in a single layer region of the fabric (of course not in the airbag cell).

  The area or “float” where the black thread appears to be exposed is preferably square or rectangular, but may have other shapes. A square or rectangular shape has proven to be the most readable for a typical viewing system camera.

  FIG. 2 is an enlarged view schematically showing a region of the fabric including one of the dark colored floats 10. A black marker weft group 16 is interwoven with a white warp group 18 throughout the central region of the figure, and each black weft 16 is disposed between the white wefts 20 in this central region. Between the adjacent upper and lower white wefts, each black weft 16 passes through the path between the same warps. The black threads 16 are directed to the left and right outer sides of the central area (left and right edges of FIG. 2, as shown in FIG. 3), below the all white threads 18, 20 in the upper layer of the fabric, Part of the weft is formed in the adjacent lower layer. Of course, half of the white weft 20 outside the region shown in FIG. 2 also forms the white weft below it. Similarly, the warp yarn 18 woven into the single layer portion in the central region of FIG. 2 may be branched into an upper layer and a lower layer away from the single layer region in both directions in which the warp yarn extends.

  From the above, assuming that the fabric is tightly woven (in FIGS. 2, 3 and 4, the warp and weft are shown relatively widely spaced for clarity of illustration only), the black yarn 2 is visible only from the upper surface of the fabric in a region such as the central region of FIG. 2 where the black yarn is exposed on the upper surface of the fabric, and the dark “floating portion” illustrated in FIG. It is understood that these areas are provided. In the fabric described with reference to FIGS. 2 to 4, the “floating portion” is a region where the black weft 16 extends through a region where the fabric is in a single layer. It is in these areas that “floating” occurs.

  Each band of black weft yarns may have more (or fewer) black yarns than the three shown, and the areas forming each dark colored “float” are shown in FIG. It will be appreciated that more or fewer warps may be incorporated. In a particularly preferred arrangement, there are five black wefts in each band of black wefts, where each white weft is again placed between each black weft and the adjacent black weft. You may be. In the latter case, each marking may include nine warps to secure a generally square marking or float (each said marking is five black black with four intervening white wefts Including thread). Less (or more) warp threads may be used for each marking to secure the rectangular marking.

  In the arrangement described with reference to FIGS. 2 to 4, the black yarn is woven into the fabric independently of the regular white yarn. This means that the regular white yarn weaving does not change in the area of the dark float despite the appearance of black weft. In a preferred embodiment, the weave includes one float in the warp and weft directions, as shown in FIGS. In other embodiments, the weave may be different.

  Thus, those skilled in the art will appreciate that the weave may be more complex (of course closer) than the illustrated weave if the isolated float can be easily located by the optical viewing system. Is done. Thus, in FIG. 2, each black weft passes the warp through the same path as the adjacent white weft, but any weaving that is clearly convenient to obtain a dark marker patch is employed. For example, a pair of black warps may be arranged, and the pair of warps may be above and below each warp in the path. However, it is preferable not to make all the weft yarns in the “floating area” black (although improving visibility). This is because the black yarn is actually weaker and more expensive than the white yarn. It is preferable that the black thread is as few as possible.

  In one embodiment tested by the Applicant, each square area or float is 2 mm × 2 mm wide and each area contains weft yarns in the order black-white-black-white-black. Therefore, each area or floating portion is as large as five wefts. In order to form a 2 mm (warp) x 3 mm (weft) rectangle, the threads may be arranged in the lateral direction as black-white-white-white-black-white-white-white-black, with respect to the square area May be arranged in the vertical direction. A rectangular area (floating part) is preferred.

  If the fabric is an OPW fabric, the black yarn is preferably a single layer fabric region (OPW fabric is woven together with airbag cells, between airbag cells, or outside airbag cells. Woven area). For example, black yarn can be woven into the upper layer within the two-layer region of the fabric, where the black warp yarn is in the region between the “floats” and between the layers (ie, in the airbag cell). It is in a state of hanging loosely.

  For simplicity of explanation, the contrasting weft bands have been shown as black in the above and the remaining weft and warp as white, but for the purpose of optical detection, on the other hand, this color scheme is reversed. And / or the main yarn on the one hand and the marker weft on the other hand may be of any color that provides the necessary optical contrast between the marker weft and the remaining yarn. Understood. However, dyed or colored yarns are costly and reduce strength, so it is preferable to minimize the proportion of dark yarn used as described above.

  The present invention may also be applied to single layer fabrics adapted to cut into a predetermined shape with an automatic guided light cutting device. In the case of such a woven fabric, it is necessary that the black warp thread hangs loosely on the back side of the woven fabric between the dark colored floating portions.

  Although the present invention has been described as applied to the manufacture of airbags, it is understood that the present invention may also be applied to a method of producing other articles from a fabric where the appearance of the fabric is not the most important factor. Is done.

  As used herein and in the claims, the terms “comprising” and “comprising” and their conjugations mean that the particular feature, process or completeness is included. Yes. These terms should not be construed to exclude the presence of other features, processes or components.

  Features disclosed in the above description or in the following claims or the accompanying drawings or means disclosed in relation to means for performing the functions represented in the specific form or disclosed The methods or processes may be utilized to implement the present invention in various forms, individually or in any combination as required.

Claims (14)

A color (hereinafter referred to as “marker color”) in which the marking (10) optically recognizable by the automatic cutting device produces a large contrast difference with respect to the color of the yarn constituting the entire fabric (hereinafter referred to as “main color”). Woven fabric provided by a thread of
The marking (10) is formed at a plurality of locations on the surface of the fabric by the marker weft yarn (16) without depending on the warp yarn ,
The marker weft (16) is woven with a gap in the warp direction across the main color weft (20),
The marker weft thread (16) extends beyond each marker area where the marking (10) is formed, and the marker weft thread (16) includes a portion that does not entangle with the warp thread at a portion beyond the marker area. Thus, the marking (10) is woven so that the outline is clear from one side of the fabric and can be optically recognized, but the outline is ambiguous from the other side and cannot be optically recognized. fabric, characterized by that. The number of marker wefts in the marker region is smaller than the number of main color wefts to other marker regions adjacent in the longitudinal direction , and is smaller than the number of warp yarns in the marker region. The woven fabric according to claim 1.   3. In each of the marker wefts (16), at least one weft (20) of the main color is arranged between two adjacent marker wefts (16). The woven fabric described in 1. The woven fabric according to claim 3 , wherein the marker weft (16) follows the same path as the adjacent main color weft (20) with respect to the warp (18) in the marker region. .   In the marker region, three marker wefts are arranged, and each main color weft (20) is arranged between two adjacent marker wefts (16). The woven fabric according to claim 3 or 4.   In the marker area, three marker wefts are arranged for two main color wefts (20), and each main color weft (20) is arranged between two adjacent marker wefts. The woven fabric according to claim 3 or 4, wherein:   5. Each of the marker wefts is arranged in the marker region, and each of the main color wefts (20) is arranged between two adjacent marker wefts. Or the woven fabric of 4.   In the marker area, five marker wefts are arranged, each having five marker wefts, and two main color wefts (20) are arranged between two adjacent marker wefts. The woven fabric according to claim 3 or 4, wherein The woven fabric according to any one of claims 1 to 4, wherein nine marker wefts and thirteen or less warps are arranged in the marker region. The woven fabric according to any one of claims 1 to 4, wherein five or less marker wefts and nine or less warp yarns are arranged in the marker region. 5. The woven fabric according to claim 1, wherein three marker weft yarns and five warp yarns are arranged in each of the marker regions. The woven fabric is a fabric for an OPW airbag having a single layer region and a two layer region ,
12. The marker weft (16) is woven into a woven fabric only in the single layer region, and the marker weft (16) extends loosely between two layers in the two layer region. The woven fabric according to any one of the above. The woven fabric is a fabric for an OPW airbag having a single layer region and a two layer region ,
Said marker weft (16), as can be viewed by the one side of the fabric, woven only in the upper layer of the two layers area of the fabric, said marker weft (16) 2 in the portion other than the marker area 12. A woven fabric according to any one of the preceding claims, which extends loosely between the layers . The woven fabric according to any one of claims 1 to 13, wherein the marker weft (16) is black and the main color is white.

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