JP2001071847A - Bag body for side collision air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bag body for a side collision air bag reducible in the thickness difference of cloth at a joint part of the bag body formed by jointing two pieces of cloth, uniform with a small quantity of coat and expanded between an occupant and a body side window part when impact is applied to the side face of a vehicle, to mainly protect the occupant's head. SOLUTION: This bag body for a side collision air bag is formed by jointing two pieces of cloth. The single yarn size of rewound raw yarn constituting the cloth is 4 denier (hereinafter abbreviated to d) or less, and the strength is 7.5 gram/denier (hereinafter abbreviated to g/d) or more. The total size of the rewound raw yarn is 100 d-700 d, and the cover factor(CF) value, defined by the following expression, of either of two pieces of cloth is 2000-2500. The dry heat contraction coefficient of raw yarn in use before weaving, which forms the cloth, is 5-150% (180 deg.C×30 min. treatment).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag which is one of safety devices for automobiles, and more particularly, to an airbag which is deployed between an occupant and a side window of a vehicle body when an impact is applied to the side surface of the vehicle. The present invention relates to an airbag mainly intended to protect the head of an occupant.

[0002]

2. Description of the Related Art In recent years, the mounting rate of airbags as one of safety components for automobiles has been rapidly increasing with the increase in occupant safety awareness. In the event of a car crash, airbags
The impact is detected by a sensor, and high-temperature, high-pressure gas is generated from the inflator, and the gas rapidly deploys the airbag to help protect occupants.

Conventionally, airbags for the driver's seat and passenger's seat that protect the occupant in the event of a collision from the front have been installed. Recently, airbags that can cope with a collision from the side have been developed. Was.

[0004] As an already proposed side collision airbag, as disclosed in WO96 / 26087, a gas generating device connected to a sensor that senses at the time of side collision or rollover, and a gas generating device for the same are disclosed. Connecting airbags, which are tightly joined on the front and back, and consist of a number of substantially parallel elongated cells that, when deployed, form a cylindrical shape to protect the occupant's head It is possible.

[0005] Further, as proposed in Japanese Patent Application Laid-Open No. 10-109607, when joining the outer peripheral portions of two woven fabrics, the woven fabric is woven into a common woven structure, and the entire bag portion is impermeable. It is stated that sealing with a temper coating material can increase the occupant restraint effect when the vehicle falls.

[0006] Unlike the conventional driver and passenger seats, the side collision airbag is stored in a place where the storage space is not large, such as a front pillar, a roof side rail, a center pillar, and a quarter pillar. Therefore, the volume of the airbag bag at the time of folding cannot be increased, and the airbag bag needs to be more excellent in storage. Regarding this point,
Japanese Patent Laid-Open No. 0-109607 proposes that the thickness can be reduced by weaving the woven yarn constituting the woven fabric into a common woven structure without using a sewing thread, which is advantageous in storage stability.

[0007] Also, a coating is often required in the case of this side impact airbag. That is,
Assuming that the vehicle rolls over, unlike the airbags for the driver's seat and the passenger's seat, it is necessary to secure the internal pressure holding time for several seconds to 10 seconds after the airbag is deployed. Even in high-density woven fabric, misalignment occurs at the intersection between the yarn and yarn of the base fabric, or in the case of sack weaving, at the intersection between the yarn and yarn at the joint between the single and double parts.
As a result, gas leakage occurs, and the internal pressure holding capacity is not sufficient.

Therefore, it is necessary to apply a coating material to the surface in order to make the air permeability of the cloth as close to zero as possible, and the proposal of JP-A-10-109607 mentioned above can reduce the thickness of the base cloth. However, there is no mention of a measure that can reduce the coating amount. This is because, when a bag weave is proposed in Japanese Patent Application Laid-Open No. 10-109607, a difference in the thickness of the cloth occurs particularly at the boundary between the single and double portions of the peripheral portion forming the bag portion. On the other hand, in order to eliminate gas leakage from the inflator in the entire woven fabric, it is necessary that a certain amount of coating material be laminated in any part. In other words, if you try to make a coat layer in the thickest part of the base cloth, the coat thickness will be large in other parts where the base cloth thickness is small,
The overall coating amount increases, resulting in an airbag bag with increased weight and reduced flexibility of the bag fabric, which is not preferable in terms of storability.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and in particular, forms a joint between two fabrics.
The misalignment is less likely to occur at the joint between the heavy and double parts, the gas leakage is small, the difference in the thickness of the fabric at the joint can be reduced, and the coating amount is small and uniform. ,
A lightweight, compact and highly reliable airbag that expands between the occupant and the vehicle body side window when an impact is applied to the side of the vehicle, and mainly protects the occupant's head It is an object to provide a bag for an airbag.

[0010]

Means for solving the above-mentioned problem, that is, a first aspect of the present invention is a bag for a side impact airbag formed by joining two pieces of cloth. The single yarn fineness of the deboiled yarn constituting the yarn is 4 denier (hereinafter abbreviated as d) or less, and the strength is 7.5 g / denier (hereinafter g / d).
A bag body for a side collision airbag, wherein the total weave degree of the defibrated yarn is 100 to 7;
2. The side impact airbag bag according to claim 1, wherein the value of the cover factor (CF) defined by the following formula is 2000 to 2500 for each of the two fabrics:
The third aspect is the side-impact airbag bag according to claim 1, wherein the dry heat shrinkage ratio of the raw yarns constituting the fabric before weaving is 5 to 15% (processing at 180 ° C for 30 minutes). ^2. The side impact air according to claim 1, wherein the entire outer surface of the bag is coated and / or laminated, and the total weight of the applied and applied amount is 80 g / m ² or less per outer surface area of the bag. The fifth aspect is the bag for a side impact airbag according to claim 1, wherein the surface of the fabric is calendered.

Here, if the single yarn fineness of the unwound yarn is larger than 4d, the single yarn diameter of the original yarn becomes large, the bulk becomes a bulky fabric, the thickness becomes large, and there is a problem in the storability. If the strength of the unwound yarn is less than 7.5 g / d, the strength of the airbag for protecting the occupant is not sufficient.

[0012] Further, each of the two woven cloths has a CF of 2
It needs to be between 000 and 2500. That is, if it is less than 2,000, coating leakage at the time of coating occurs, and misalignment is apt to occur at the joint, and there is a problem in the performance of the obtained coated cloth. . Also 25
If it is more than 00, problems such as weaving and warp fluff occur, which is a problem in industrial production. Further, it is desirable that the raw yarn forming the fabric has a length of 100d to 700d. 1
When it is less than 00d, the fabric strength and tear strength are insufficient, and when it is more than 700d, the fabric becomes rigid and there is a problem in storage.

It is a very important factor that the raw yarn (before forming a woven fabric) used at that time has a dry heat shrinkage of 5 to 15% (processed at 180 ° C. for 30 minutes). because,
In the state of the woven fabric in which the fabric is woven, the binding force between the yarns is not very large, but the yarns having a dry heat shrinkage of 5 to 15% are used, and then the shrinkage of the yarns is performed during the boiling water treatment and the dry heat treatment. It has been found that by causing the expression, the force of restraining the yarns from each other acts, the frictional resistance between the yarns increases, and the misalignment hardly occurs. If the dry heat shrinkage is less than 5%, the shrinkage force after shrinkage processing is not sufficient, and the yarn-to-yarn friction is not sufficiently increased, and misalignment of the fabric is likely to occur. If misalignment at the joint occurs when the airbag is deployed, gas leaks from that portion and does not serve as an occupant restraint. In addition, if an attempt is made to produce a yarn larger than 15%, productivity will be degraded in the yarn manufacturing process, which is not economically preferable.

The dry heat shrinkage of the raw yarn (before forming a woven fabric) used for warp and weft is 5 to 15% (180 ° C.).
X 30 minutes), the warp and the weft may be different.

Here, the total amount of coating and lamination is preferably 70 g / m ² or less. Because, in order to improve storage, the thickness of the bag fabric itself,
Flexibility and the like are most important, but the smaller the amount of coating and lamination, the better. However, as described above, in order to prevent gas leakage, a certain amount of coat and laminate thickness is required at any part, but at most 7 parts.
It is necessary to make it 0 g / m ² or less. More preferably, it is 50 g / m ² or less. If the amount is exceeded, the entire woven fabric becomes bulky, which is not preferable in terms of storability.

The loom used here is not particularly limited. For example, a water jet loom,
An air jet room, a rapier room, a projector room, and the like are used. However, water jet looms and air jet looms are particularly preferred and used in view of weaving productivity, damage to warp yarns, yarn contamination, and the like. A Jacquard device or a Dobby device is used to determine the pattern of the weaving. In particular, a jacquard device (electronic or mechanical) is required to perform complicated patterning, and an electronic jacquard device is preferred and used because of productivity and ease of pattern change.

The synthetic fibers constituting the airbag according to the present invention are not particularly limited in the material, but are preferably those such as aliphatic polyamide fibers such as nylon 66, nylon 6, nylon 46 and nylon 12, and aramid fibers. A homopolyester such as an aromatic polyamide fiber or polyethylene terephthalate or polybutylene terephthalate is used. Other examples include wholly aromatic polyesters, ultrahigh molecular weight polyethylene fibers, PPS fibers, and polyetherketone fibers. However, in consideration of economy, polyester fibers and polyamide fibers (nylon 66, nylon 46, nylon 6) are particularly preferable. In addition, there is no problem even if these synthetic fibers contain various additives in order to improve the processability in the yarn production process and the post-processing process. For example, antioxidants, heat stabilizers, leveling agents, antistatic agents, thickeners, flame retardants and the like.

The coating material is not particularly limited, and a synthetic rubber such as chloroprene, chlorosulfonated olefin, or silicone may be applied or a rubber-like material may be laminated via an adhesive. Even in the case of lamination, the difference in woven fabric thickness at the joint is small, and it is necessary to prevent voids between the rubber and the woven fabric at the joint, and the effect of the present invention makes it possible to adhere without voids. .

[0019]

Next, the present invention will be described in more detail by way of examples. In addition, the physical property in an Example and a comparative example was measured by the following method.

Air permeability: JISL10966.27.1.
Method A (Fragile method)

Weight: JISL10966.4.2

Bending degree: JISL10966.9.1.1.
Method A (45 ° cantilever method)

Thickness: JIS L109966 (240 g
/ Cm ² under pressure)

Woven density: JISL109966.

Misalignment performance: A sample having a width of 3 cm is cut in the bias direction between the meridional direction and the weft direction (45 °), which is representative of the strong bias (the direction in which misalignment is difficult due to increased bias), and the distance between the chucks is 5 cm. At a pulling speed of 5 cm / min. To prevent sample slip in the chuck during measurement of the sample. And measure the maximum strength at that time.

Coating thickness of the joining portion: The process of the joining portion of the single portion and the double portion and the weft SEM cross-sectional photograph are taken, and the thickness of the coating material is set to the single portion (the binding portion) and the double portion (the woven portion). The thick part was measured and represented by the average value of its course and weft.

Example 1 A warp and a weft have a cutting strength of 9.6 g / 315d / 108f.
d, Using a nylon 66 filament raw yarn having a dry heat shrinkage of 8.0%, using an air jet loom and an electronic jacquard device, in a plain weave in a bag section at a warp of 62 yarns / in and a weft of 53 yarns / i.
After weaving in a bag weave so as to obtain n, a boiling water shrinking step was passed, followed by drying and setting steps to prepare a processed fabric. The measured strength of the unwound base yarn (total weave degree: 330 d) of the base fabric was 7.9 g / d. Conversely, 45 g / m2 of silicone resin was applied to one side using a knife coater.
^Two coats were applied on both sides and finished. Table 1 shows the physical properties of the woven fabric.

Example 2 The warp and the weft have a cutting strength of 350 g / 90f of 9.2 g / d,
Using a polyester filament yarn having a dry heat shrinkage of 8.0%, a plain weave in a bag portion using a water jet loom and an electronic jacquard device, a warp length of 62 / in and a weft of 53 / i.
After weaving in a bag weave so as to obtain n, a boiling water shrinking step was passed, followed by drying and setting steps to prepare a processed fabric. The measured strength of the unwound base yarn (total weave degree: 365 d) of the base fabric was 7.6 g / d. Next, double-sided calendering was performed at a linear pressure of 30 kg / cm between metal rolls heated to 150 ° C. Thereafter, a silicone resin was coated on both sides with a knife coater at a rate of 45 g / m ² on each side to finish. Table 1 shows the physical properties of the woven fabric.

Example 3 The warp and the weft have a cutting strength of 210d / 72f of 9.6 g / d,
Using a nylon 66 filament raw yarn with a dry heat shrinkage of 8.0%, using an air jet loom and an electronic jacquard device, a plain weave is used to form a woven bag so that the warp becomes 76 / in and 65 / in in the bag. After weaving, the fabric was passed through a boiling water shrinking step, followed by drying and setting steps to produce a processed fabric. The measured strength of the unwound base yarn (total weave degree: 221d) of the base fabric was 7.9 g / d. The base fabric was finished by applying a coat of 45 g / m ² on each side with a silicone resin using a knife coater. Table 1 shows the physical properties of the woven fabric.

Example 4 The warp and the weft have a cutting strength of 420d / 144f of 9.6g /
d, Using a nylon 66 filament raw yarn having a dry heat shrinkage of 8.0%, using an air jet loom and an electronic jacquard device, in a plain weave at a bag section of 54 yarns / in and 45 wefts / i.
After weaving in a bag weave so as to obtain n, a boiling water shrinking step was passed, followed by drying and setting steps to prepare a processed fabric. The measured strength of the unwound base yarn (total weave degree: 442 d) of the base fabric was 7.8 g / d. A chloroprene rubber sheet (0.05 mm thick) was adhered to both sides of the base cloth via an adhesive to finish. Table 1 shows the physical properties of the woven fabric.

[0031]

[Table 1]

Comparative Example 1 A warp and a weft have a cutting strength of 315 g / 108 f of 9.6 g /
d, using a nylon 66 filament raw yarn having a dry heat shrinkage of 4.0%, using an air jet loom and an electronic jacquard device in a plain weave at a bag portion of 64 yarns / in and a weft of 55 yarns / i.
After weaving in a bag weave so as to obtain n, a boiling water shrinking step was passed, followed by drying and setting steps to prepare a processed fabric. When the strength of the unwound raw yarn (total weave degree: 318 d) of the base fabric was measured, it was 7.9 g / d. Using a knife coater, apply 45 g / m ² per side of silicone resin to the base cloth.
Was applied to both sides and finished. Table 2 shows the physical properties of the woven fabric.

Comparative Example 2 The warp and weft had a 420 d / 72f cut strength of 9.6 g / d.
Using a nylon 66 filament raw yarn with a dry heat shrinkage of 8.0%, a plain weave using an air jet loom and an electronic jacquard device is used to form a woven bag so that the wrap portion becomes 54 ply / in and weft 45 ply / in. After weaving, the fabric was passed through a boiling water shrinking step, followed by drying and setting steps to produce a processed fabric. When the strength of the unwound base yarn (total weave degree: 443 d) of the base fabric was measured, it was 7.8 g / d. The base cloth was coated with a silicone resin using a knife coater at a rate of 45 g / m ² on each side to finish. Table 2 shows the physical properties of the woven fabric.

Comparative Example 3 The warp and weft had a 420 d / 72f cut strength of 9.6 g / d.
Using a nylon 66 filament raw yarn with a dry heat shrinkage of 8.0%, a plain weave using an air jet loom and an electronic jacquard device is used to form a woven bag so that the wrap portion becomes 54 ply / in and weft 45 ply / in. After weaving, the fabric was passed through a boiling water shrinking step, followed by drying and setting steps to produce a processed fabric. The yarn strength of the base cloth (total weave degree: 441 d) was measured to be 7.9 g / d. The base cloth was coated with a silicone resin using a knife coater at a rate of 90 g / m ² on each side to finish. Table 2 shows the physical properties of the woven fabric.

[0035]

[Table 2]

As can be seen from Tables 1 and 2, in Examples 1 and 2, although the coat amount was as small as 45 g / m ² , the bag portion (double portion) and the binding portion (single portion) The thickness difference after coating in step (1) is small and the coating is uniform, so that the air permeability of the bag portion is almost equal to 0 and a lightweight airbag body with excellent performance without gas leakage when the airbag is deployed is obtained. succeeded in. In the case of Example 4, since there was no difference in rubber thickness at the joint due to lamination and the thickness of the base cloth was uniform, an airbag bag having no void at the joint even after rubber was attached was successfully obtained.

On the other hand, in Comparative Example 1, the bias strength was low, and misalignment in the woven structure was apt to occur. This was apt to cause misalignment in the joint portion of the woven fabric, which caused gas leakage from the portion and sufficient internal pressure holding performance. It turned out that it was not. Also, the difference in coat thickness at the joint was large, and gas leakage was likely to occur from the bag around the joint. In Comparative Example 2, there was no problem in misalignment, but the difference in coat thickness at the joint was large, and gas leakage was likely to occur from the bag around the joint. In Comparative Example 3, although there was a large difference in the coating thickness at the joint, the coating amount was increased, and there was no gas leakage problem.
However, as a result, the thickness and weight of the entire airbag body increased, resulting in unsatisfactory storability.

[0038]

According to the present invention, it is possible to provide a side airbag fabric which is excellent in storability and excellent in safety because it can be coated with a necessary low air permeability and flexibility.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a bag joint portion of the present invention.

[Explanation of symbols]

 1 bag part 2 single part 3 coat and / or laminate

Continued on the front page F term (reference) 3D054 AA02 AA03 AA07 AA16 AA18 CC25 CC33 CC45 EE20 FF03 FF11 FF14 FF17 FF18 4L048 AA24 AA34 AA48 AB07 AC09 AC11 BA01 BA02 CA01 CA15 DA25 EA01 EB00 EB02 EB05

Claims (5)

[Claims] 1. A bag for a side impact airbag formed by joining two fabrics, wherein the denier yarn constituting the fabric has a single yarn fineness of 4 denier (hereinafter abbreviated as d) or less. A bag for a side collision airbag, having a strength of not less than 7.5 g / denier (hereinafter abbreviated as g / d). 2. The woven yarn has a total weave of 100 to 700 d, and the cover factor (CF) of each of the two fabrics is 2,000 to 2,500 as defined by the following equation. For side impact airbags. 3. The bag for a side impact airbag according to claim 1, wherein the dry heat shrinkage ratio of the raw yarns constituting the fabric before weaving is 5 to 15% (processing at 180 ° C. for 30 minutes). 4. The bag according to claim 1, wherein the entire outer surface of the bag is coated and / or laminated, and the total weight of the applied and applied amount is 80 g / m ² or less per outer surface area of the bag. For side impact airbags. 5. The bag for a side impact airbag according to claim 1, wherein the surface of the fabric is calendered.