JP2006169645A - Base fabric for air bag and air bag apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base fabric for an air bag destaticizing static electricity and to provide an air bag apparatus. <P>SOLUTION: A front panel 1 and a rear panel 2 as the base fabric for the air bag used in the automotive air bag apparatus are provided with a static electricity destaticizing earth circuit formed with an electroconductive suture thread 3 having electroconductivity. The electroconductive suture thread 3 comprises fibers obtained by incorporating a microparticulate carbonized material or a fibrous carbonized material into the core and carrying out spinning in a yarn manufacturing stage. Thereby, the maximum friction-charged electrostatic potential measured by a method for measuring the friction-charged electrostatic potential specified by JIS L 1094 can be regulated to <100 V. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an airbag base fabric that is used in an airbag for ensuring the safety of an occupant during a collision of an automobile or the like and is sewn into a bag shape with a suture, and an airbag apparatus including the airbag fabric.

  Conventionally, in order to ensure the safety of passengers and passengers, driver airbags, passenger airbags, side airbags, rear airbags, knee airbags, curtain airbags have been used as automobile airbag devices. Various airbag devices such as bags have already been used.

  The airbag fabric used in the airbag apparatus is formed of a single-layer woven fabric composed of warp yarns (warp yarns) and weft yarns (weft yarns) that extend in directions intersecting each other. When manufacturing an airbag, usually, a pattern is first mechanically drawn on the base fabric in accordance with the shape of the airbag in the drawing step, and then the base fabric is cut along the drawn pattern in the cutting step. Thereafter, the base fabrics cut in the suturing step are combined and stitched to form a bag-like bag (see, for example, Patent Document 1).

Japanese Patent No. 3028524

  Most of the airbag devices are made of synthetic fiber, metal, and synthetic resin, and the synthetic fiber bag is hydrophobic and insulating, and is folded and stored. For this reason, a considerable amount of static electricity is generated between the synthetic fiber fabrics or between the synthetic fibers that are close to each other at the folded or wrapped portion of the bag due to vibration or shaking during driving of the automobile. The static electricity charged in such a bag gradually discharges when the automobile engine is stopped, but the static electricity charged in the bag increases during the operation of the automobile, and unspecified parts in the airbag device. There is a risk of electrostatic discharge occurring at unforeseen times.

  Today, many electronic control devices are mounted on automobiles, and for example, the operating voltage of these electronic control devices is gradually reduced, and is easily affected by weak electromagnetic waves with respect to the elements in the package. For this reason, when static electricity charged in the bag is discharged, the electromagnetic noise causes a malfunction in the CPU of the automatic operation control system, causing a program error, a malfunction in the navigation system and the AV device, or an electrical error in the audio system. Interference, that is, noise and image distortion may occur, which may cause discomfort to the passenger. Moreover, if the electrostatic charge voltage accumulated in the bag is high, there is a risk of discomfort to the passenger due to electrostatic discharge. Moreover, it is not preferable that the spark of electrostatic discharge is generated in the vicinity of the inflator from the viewpoint of ensuring the smooth operation of the airbag. Therefore, it is necessary to prevent static electricity generated in the airbag.

  The objective of this invention is providing the base fabric for airbags which can aim at antistatic of static electricity, and an airbag apparatus using the same.

  In order to achieve the above object, a first invention is an airbag base fabric used in an automobile airbag device, comprising an electrostatically charged earth circuit formed of conductive sutures having conductivity. To do.

  In the first invention of the present application, even if static electricity is generated in the airbag base fabric, it can be continuously reduced to a safe low level by a grounding means or the like from the conductive suture through the electrostatic charging ground circuit. Static electricity generated on the cloth is prevented. In addition, malfunctions of various electronic devices mounted on the vehicle due to electrostatic discharge sparks can be reduced. In addition, a large antistatic effect can be obtained only by using a conductive suture as the suture, and the charge removal operation in the processing step is easy and low cost.

  According to a second aspect, in the first aspect, the electrostatically charged ground circuit includes a connection portion connected to a metal member for attaching an airbag base fabric.

  As a result, the static electricity charged in the airbag base fabric flows to the metal member for attaching the airbag base fabric through the connecting portion of the conductive suture and the electrostatic charging ground circuit. It can be mitigated. This reliably prevents static electricity from being charged.

  A third invention is characterized in that, in the first or second invention, the conductive suture includes fibers obtained by kneading and spinning fine particle carbides or fibrous carbides in the core at the stage of yarn production.

  Static electricity generated on the airbag fabric is relieved from the conductive suture whose conductivity has been increased by particulate carbide or fibrous carbide via an electrostatic charging earth circuit, and static electricity generated on the airbag fabric is reduced. Is prevented.

  According to a fourth invention, in any one of the first to third inventions, the maximum frictional band voltage of the airbag fabric measured by the frictional band voltage measurement method defined in JIS L 1094 is less than 100V. It is characterized by being. A fifth invention is characterized in that, in the fourth invention, the maximum frictional band voltage of the airbag fabric measured by the frictional band voltage measurement method defined in JIS L 1094 is less than 50V.

  If the maximum frictional voltage is set to less than 100 V (preferably 50 V or less) by the measurement method according to JIS standard, a good antistatic effect can be surely obtained.

  In order to achieve the above object, the sixth invention provides an airbag base fabric in which an electrostatically charged earth circuit is formed by a conductive suture having conductivity, and a pressure fluid for inflating and deploying the airbag base fabric. A metal that attaches the airbag base fabric to the retainer so as to connect the electrostatic charging ground circuit to the ground wire, an inflator that ejects the inflator, a retainer that supports the inflator, a ground wire connected to a ground, and the electrostatic charging ground circuit And a member.

  In the sixth invention of the present application, even if static electricity is charged to the airbag fabric, the charged static electricity is relaxed and removed by the action of the electrostatic charging ground circuit, and the charged static electricity is electrically conductive suture, electrostatic charging ground circuit, It flows to the ground through the metal member and the ground wire. As a result, the static electricity of the airbag fabric can be prevented, and malfunctions of various electronic devices mounted on the vehicle due to electrostatic discharge under high voltage can be eliminated.

  According to the present invention, even if static electricity is generated in the airbag fabric, the static electricity can be mitigated and removed by the action of the electrostatic charging ground circuit, so that electrostatic charging can be prevented.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment is an embodiment in the case where the present invention is applied to a driver's airbag device provided in the steering of the driver's seat as an example.

  FIG. 1 is a longitudinal sectional view showing a schematic structure of an airbag device including an airbag using the airbag fabric of the present embodiment. FIG. 2 is an exploded perspective view of the main part structure in FIG.

  1 and 2, the airbag apparatus includes a folded airbag 9, an inflator 24 for ejecting a pressure fluid (gas) for inflating and deploying the airbag 9, and the inflator 24. The substantially plate-shaped retainer 20 is provided.

  The airbag 9 is covered with a module cover 32. The module cover 32 is provided with a tear line 34 that is torn when the airbag 9 is inflated, and is connected and fixed to the leg piece 20a of the retainer 20 via a rivet (not shown). Further, the peripheral edge portion of the opening 4 of the airbag 9 is sandwiched between a retainer 20 and a ring-shaped airbag mounting tool (metal member for mounting an airbag base fabric) 26 via a metal washer 35.

  The retainer 20 is provided with an opening 22 for inserting the inflator 24 at the center thereof, and a leading side 24a of the inflator 24 is inserted through the opening 22 and a flange 24b is overlapped with the back side surface of the retainer 20. Are arranged as follows. The flange 24b is penetrated by the bolt 28 together with the airbag fitting 26, the metal washer 35, and the airbag 9, and is connected and fixed to the retainer 20 by screwing a nut 30 into the bolt 28. Yes. And by these connection structures, a part (connection part) of the conductive suture 3 (details will be described later) made of conductive thread provided in the airbag 9 and the airbag attachment 26 are electrically connected. The airbag attachment 26 is grounded by a ground wire (not shown) (in a separate circuit without being connected to the inflator 24 so as not to interfere with the inflator 24).

  The detailed configuration of the airbag base fabric constituting the airbag 9 and the folding method thereof, which are the main parts of this embodiment, will be described below.

  FIGS. 3A and 3B are exploded perspective views showing a method for manufacturing the airbag 9.

  3 (a) and 3 (b), the airbag 9 of the present embodiment is configured so that the base fabric (= rear panel) 2 on one side is bonded to the base fabric (= front panel) 1 on the other side. After that (FIG. 3 (a)), the peripheral edge portions are stitched with the conductive suture thread 3 (FIG. 3 (b)). At this time, the rear panel 2 is provided with the aforementioned opening 4 for inserting the inflator 24. Since the airbag 9 is completed in the reverse state, in the case of a resin coat type airbag, the front panel 1 side (the lower side in FIG. 3A) of the rear panel 2 and the rear panel 2 side of the front panel 1 are used. The resin coating is applied on the upper side in FIG.

  4 is a plan view of the airbag 9 bonded together as described above, and FIG. 5 is a cross-sectional view taken along the line III-III in FIG.

  As shown in FIGS. 4 and 5, the rear panel 2 is electrically connected with the conductive sutures 3a, 3b, 3c, and 3d from the peripheral portion to the vicinity of the opening 4 in addition to the conductive suture 3 at the peripheral portion. Thus, a ground circuit (electrostatic charging ground circuit) is formed. Further, the conductive suture thread 3 at the peripheral edge is provided so as to penetrate the rear panel 2 and the front panel 1 as shown in FIG. At this time, a slit-like slit 10 is extended from the edge of the opening 4. In addition, as shown with a dashed-two dotted line in FIG.4 and FIG.5, you may use the well-known coating cloth (reinforcement cloth) B for intensity | strength reinforcement.

  FIG. 6 is an explanatory diagram for explaining a method of folding the airbag 9.

  When the airbag 9 is folded, first, the airbag 9 is extended flat (FIG. 6A, the airbag in this state is referred to as 9A). Next, the airbag 9A is folded back from both sides to form an elongated intermediate folded body 9B. 6 (d) is a top view of the intermediate folded body 9B, FIG. 6 (c) is a CC side view in FIG. 6 (d), and FIG. 6 (b) is in FIG. 6 (d). It is a cross-sectional view by a BB cross section.

  Thereafter, the intermediate folded body 9B is folded a plurality of times so that the folding line is in the width direction (in this example, a folded shape), thereby obtaining the final folded body 9C. FIG. 6F is a top view of the final folded body 9C, and FIG. 6E is a cross-sectional view taken along the line EE of FIG. 6F.

  FIG. 7 is a cross-sectional view showing a process of turning the vicinity of the airbag opening upside down. The airbag 9C having the final folded body shape as described above is first folded as indicated by a two-dot chain line arrow so that the edge of the opening 4 is turned over as shown in FIG. Thereby, the completed folded airbag 9 (finished product) 9 shown in FIG. 7B is obtained. In the airbag 9, the vicinity 11 of the opening 4 has a shape surrounding the airbag folding body 12 (see also FIG. 1 described above).

  In the airbag apparatus configured as described above, when the inflator 24 ejects gas due to an automobile collision or the like, the airbag 9 starts to expand, and the module cover 32 is cleaved along the tear line 34. Is inflated in front of the occupant. In this case, a portion 13 (see FIG. 1) opposite to the opening 4 of the airbag 9 is first inflated, and then the folding body 12 surrounded by the neighboring portion 11 passes through the path between the folding bodies 12 and 12. It swells upside down. As a result, as shown in FIG. 8, the completely inflated airbag 9 is inverted inside and outside, and the stitched portion by the conductive suture 3 described above is disposed inside the airbag 9.

  The airbag base fabric of this embodiment used for the airbag 9 configured as described above obtains an antistatic effect by the action of the conductive suture 3. In order to confirm this effect, the inventors of the present invention conducted a chargeability test on the airbag fabric of the present invention and the conventional airbag fabric for comparison. Hereinafter, the test contents will be specifically described.

  This chargeability test was carried out with a rotary static tester (owned by Fukui Industrial Technology Center, manufactured by Koa Shokai Co., Ltd.) based on JIS L 1094 (method for charging the fabric and knitted fabric).

  FIG. 9 is a diagram showing the overall structure of the rotary static tester used in this test. In FIG. 9, this rotary static tester includes a rotating drum (constant speed rotating body) 120 to which a test piece (specimen) 127 is attached, a motor 124 that generates the rotational driving force of the rotating drum 120, and the driving force rotating drum. 120, a V-belt 125 that transmits to 120, a friction cloth (cotton cloth) 122 for generating static electricity with one end fixed and a load 121 applied to the other end, and a power receiving unit (detector) 123 for measuring static electricity. is doing.

  In the test, a test piece (details will be described later) 127 is attached to the rotating drum 120 via the metal holder 126, and the rotating drum 120 is rubbed for 60 seconds by a friction cloth (cotton cloth) 122, and generated on the test piece 127. The electrostatic charge voltage was measured by the power receiving unit 123. And the test piece 127 was left still for 24 hours in a measurement temperature / humidity state.

  The temperature and humidity conditions measured in the test room at this time are, in principle, a temperature of 20 ° C. and a relative humidity (40 ± 2)% RH, and the friction cloth 122 is JIS L 0803 (attached white cloth for dyeing fastness test). The specified cotton cloth was used.

As the test piece 127, a normal airbag base fabric is stitched using a conductive suture 3 selected from nylon 66, nylon 46, nylon 6 (both 1400-940 denier), and a normal airbag is produced. What was cut into 100 × 120 mm at two levels of the warp direction and the weft direction was used. The conductive suture 3 is kneaded to 5% with a carbide (volume resistivity of about 10 ⁻³ Ω · cm or less) pulverized into fine particles (in units of 1 micrometer) in a single yarn polymer molding stage into the fiber core, An artificial fiber (= synthetic fiber that is neither colored nor conductively processed) is entangled with a material artificially mixed and blended exclusively.

  And as the test piece 127 of the present invention, the following (Example 1) to (Example 3) are used, and as the test piece 127 of these comparative examples corresponding to the conventional structure, the following (Comparative Example 1) to Five types (Comparative Example 5) were used.

Example 1
A test piece was prepared from a base fabric that had been sewn using a high-conductive fiber bundle 1400 denier every 25 mm of the base fabric and naturally dried through a normal washing and drying process.

(Example 2)
In the same manner as in Example 1, 900 deniers were sewn and sewn, and then a silicon base emulsion was applied with a comma coater, and a test piece was prepared from a base fabric which was dried and cured at 200 ° C. for 15 seconds.

(Example 3)
After the 900 denier ring stitches described in Example 1 were sewn up, a two-component mixed type silicon base elastomer was applied onto the back roll by a knife coater, and a test piece was prepared from a base fabric that was dry-cured at 200 ° C. for 15 seconds. .

(Comparative Example 1)
After weaving ordinary nylon 66 with a water jet loom and finishing it with ordinary 1400 denier, we applied a knife coater to the two-component mixed silicone base elastomer on the back roll and dried at 200 ° C for 15 seconds. The base fabric was cut to prepare a test piece.

(Comparative Example 2)
A test piece was prepared by cutting a commercially available non-coated airbag base fabric of normal nylon 66 by ring sewing with a 1400 denier suture.

(Comparative Example 3)
A commercially available non-coated airbag base fabric of normal nylon 66 was sewn with 900 denier sutures to produce a test piece.

(Comparative Example 4)
After weaving ordinary nylon 66 by the water jet weaving method, a commercially available base fabric that has been heat-shrink-stabilized at 200 ° C. for 15 seconds after being coated with a silicone elastomer is sewn with 900 denier sutures and then cut into a product. Thus, a test piece was prepared.

(Comparative Example 5)
A commercially available non-coated base fabric obtained by weaving ordinary nylon 66 by a Lapier weaving method was washed three times and naturally dried, and then cut into a test piece. A 900-denier suture was used that was sewn by regular stitching.

  FIG. 10 is a table showing the chargeability test results by the rotary static tester for a total of eight test pieces of (Example 1) to (Example 3) and (Comparative Example 1) to (Comparative Example 5). is there. The chargeability test was carried out five times for each test piece, and the average value of three measurement values excluding the maximum value and the minimum value was adopted as the measurement result. Further, the maximum voltage in the warp direction and the maximum voltage in the weft direction of each test piece were measured. The unit is volts (V). When the measurement result was considerably smaller than 50V, it was indicated by ◎, and when it was 50V or more, it was indicated by ×.

  10, in Example 1, the maximum band voltage in the warp direction of the test piece is 25V, and the maximum band voltage in the weft direction is 15V. In Example 2, the maximum band voltage in the warp direction is 8 V, the maximum band voltage in the weft direction is 5 V, and both the maximum band voltage in the warp direction and the maximum band voltage in the weft direction are smaller than in Example 1. Yes. In Example 3, the maximum band voltage in the warp direction and the maximum band voltage in the weft direction are both lower than 5 V, and the maximum band voltage in the warp direction and the maximum band voltage in the weft direction are both smaller than in Example 1. As described above, it was confirmed that the maximum band voltage in the warp direction and the maximum band voltage in the weft direction of Examples 1 to 3 were significantly lower than 50V.

  On the other hand, in Comparative Example 1, the maximum band voltage in the warp direction of the test piece is 10000 V or more, the maximum band voltage in the weft direction is 8000 V, in Comparative Example 2 is similarly 4000 V and 5000 V, and in Comparative Example 3 is similarly 4900 V, 5500 V, Similarly, in Comparative Example 4, 7240V and 6170V and in Comparative Example 5 are similarly 800V or more and 750V or more, which is significantly higher than the maximum voltage in the warp direction and the weft direction of Examples 1 to 3. It could be confirmed. That is, in any of the comparative examples, the electrostatic charge voltage shows a value that greatly exceeds the satisfactory 50V level, and it is clear that the chargeability is strong.

  From the above results, it was confirmed that the maximum band voltage in the warp direction and the maximum band voltage in the weft direction were reduced when the conductive suture was used for the airbag fabric as described above.

  As is clear from the above description, according to the airbag base fabric (front panel 1 and rear panel 2) using the conductive suture 3 of the present embodiment and the airbag apparatus using the airbag fabric, it is assumed that the driving of the automobile is temporarily performed. Even if the air bag 9 is rubbed due to vibration or vibration at the time, static electricity is generated, the static electricity is passed from the ground circuit by the conductive suture 3 through the air bag attachment 26, and further via the bolt 28, the retainer 20, and the ground wire. In addition, since it can be continuously reduced to a safe low level, static electricity generated in the airbag fabric is prevented. For this reason, it is possible to reduce influential factors that affect the malfunction of the CPU of the automatic operation control system, navigation system, and AV equipment due to electromagnetic waves generated by electrostatic discharge under high voltage. In addition, generation of noise in the in-vehicle TV audio system is also prevented. Further, the occurrence of a spark under a high voltage in the vicinity of the inflator 24 is also prevented. Furthermore, even if the airbag 9 is inflated and deployed at the time of a car collision and comes into contact with the occupant, an electric shock is not given to the occupant due to static electricity charged in the bag. Further, a large antistatic effect can be obtained only by using the conductive suture 3 as the suture, and the charge removal work in the processing process is easy and low cost.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention.

For example, in the present embodiment, the conductive fiber is made by spinning a polymer in which fine carbide particles are dispersed in the polymer molding stage and blending with a normal synthetic fiber. Instead, the volume resistivity (volume resistivity) is used instead. ) Is less than about 10 ⁷ Ω-cm, for example, carbon fibers can be blended and blended with ordinary synthetic fibers.

  In the above-described embodiment, the present invention is applied to a driver's seat airbag. However, the present invention is not limited to this, and a curtain airbag, a passenger airbag, a side airbag, a knee airbag, and a rear seat airbag. The present invention can be applied to various airbag fabrics such as bags and methods for manufacturing airbags. Moreover, it is applicable also to the base fabric for airbags other than a motor vehicle, and the manufacturing method of an airbag. Further, the present invention can be applied to any weaving machine, and can be applied to attached members (for example, a tether, a wrapping material, a protector, a diffuser, etc.).

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view illustrating a schematic structure of an airbag apparatus including an airbag using an airbag base fabric according to an embodiment of the present invention. It is a disassembled perspective view of the principal part structure in FIG. 1 which shows the attachment structure of an airbag. It is a disassembled perspective view which shows the manufacturing method of an airbag. It is a top view of an airbag. It is a cross-sectional view by the III-III cross section in FIG. It is explanatory drawing for demonstrating the folding method of an airbag. It is sectional drawing showing the process of turning over the vicinity part of an airbag opening. It is sectional drawing which shows the state which the airbag expanded fully. It is a figure showing the whole rotary static tester structure used by JIS L 1094. It is a figure which shows the electrification test result of the base fabric for airbags of this embodiment in contrast with a comparative example.

Explanation of symbols

1 Front panel (airbag base fabric)
2 Rear panel (airbag base fabric)
3 Conductive suture 9 Air bag 26 Bag fitting (metal member)

Claims (6)

An airbag base fabric used in an automobile airbag device,
An airbag base fabric comprising an electrostatically charged grounding circuit formed of a conductive suture having conductivity. In the air bag base fabric according to claim 1,
The static electricity grounding circuit includes a connecting portion connected to a metal member for attaching an air bag base fabric. In the airbag fabric according to claim 1 or 2,
The base fabric for an airbag according to claim 1, wherein the conductive suture includes fibers obtained by kneading and spinning fine particle carbide or fibrous carbide in the core at the stage of yarn production. In the base fabric for airbags of any one of Claims 1 thru | or 3,
An airbag base fabric, wherein the maximum frictional band voltage of the airbag base fabric measured by the frictional band voltage measurement method defined in JIS L 1094 is less than 100V. In the air bag base fabric according to claim 4,
An airbag base fabric, wherein the maximum frictional band voltage of the airbag fabric measured by the frictional band voltage measurement method defined in JIS L 1094 is less than 50V. An airbag base fabric in which an electrostatically charged ground circuit is formed by a conductive suture having conductivity; and
An inflator that ejects a pressure fluid for inflating and deploying the airbag fabric;
A retainer for supporting the inflator;
An earth wire connected to ground,
An airbag device comprising: a metal member that attaches the airbag fabric to the retainer so as to connect the electrostatically charged ground circuit to the ground wire.

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