KR101352327B1 - Airbag cushion and airbag system using the same - Google Patents

Abstract

The present invention relates to an airbag cushion comprising a reinforcement cloth made of aramid fibers and an airbag system including the same. More preferably, the reinforcement cloth has a fineness of 210 to 840 denier, a filament number of 60 to 150, and a tensile strength. 9.5 g / d or more and composed of aramid fibers having an elongation at break of 3% or more.

The airbag cushion of the present invention uses a reinforcement cloth made of aramid fiber having excellent heat resistance and mechanical properties, minimizes the number of reinforcement layers at the inflator, etc., effectively maintains the folding state, and withstands high temperature and high pressure of the injection gas during inflator operation. Enable deployment performance.

Airbag Cushion, Aramid, Reinforcement Cloth, Heat Resistance, Shape Stability, Folding

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an airbag cushion,

The present invention relates to an airbag cushion having excellent heat resistance and folding performance and an airbag system including the same.

In general, an air bag detects a collision shock applied to the vehicle at the speed of about 40 km / h or more at a speed of about 40 km / h, and then explodes a gunpowder to gas into the airbag cushion. By means of supplying and inflating, it refers to a device for protecting the driver and passengers, the structure of a general airbag cushion system is as shown in FIG.

As shown in FIG. 1, a general airbag cushion system includes an inflater 121 that generates gas by ignition of the primer 122, and an airbag cushion 124 that is expanded and deployed toward the driver of the driver's seat by the generated gas. Consists of the airbag cushion module 100 is mounted to the steering wheel 101, the impact sensor 130 for generating a shock signal in the collision, and the electron to ignite the primer 122 of the inflator 121 according to the shock signal It is configured to include a control module (Electronic Control Module) (110). The airbag cushion system configured as described above detects an impact in the impact sensor 130 and transmits a signal to the electronic control module 110 when the vehicle collides at the front. At this time, the electronic control module 110 recognizing this ignites the primer 122 to burn the gas generating agent in the inflator 121. The gas generating agent thus combusted expands the airbag cushion 124 through rapid gas generation. The inflated airbag cushion 124 partially absorbs the impact load caused by a collision while contacting the front or side upper body of the driver, and the inflated airbag cushion as the head and chest of the driver move forward or side by inertia When colliding with 124, the gas of the airbag cushion 124 is rapidly discharged to the discharge hole formed in the airbag cushion 124 and cushions the front part or the side part of the driver. Therefore, by effectively buffering the impact force transmitted to the driver or passenger in the front or side collision, it is possible to reduce secondary injuries.

As described above, the airbag cushion used in an automobile is manufactured in a certain shape and then mounted on a handle of an automobile, a side window of an automobile, a side structure or the like in a folded state in order to minimize its volume. At this time, the airbag cushion is maintained in a folded state so that the airbag cushion is inflated and deployed when the inflator 121 is operated.

In particular, high-pressure gas is injected into the airbag cushion when the airbag is deployed due to rapid gas generation, and a reinforcement cloth that is resistant to high temperatures and serves as a thermal barrier in the vicinity of the inflator 121 that ejects the high-pressure gas is provided. It is often attached. Conventionally, polyamide fibers such as nylon 6, polyethylene terephthalate (PET), and the like have been used as reinforcing cloth materials for airbags.

However, nylon 6 has a melting point as low as 220 ℃ and PET has a low heat capacity, nylon 6 and PET has a problem of poor physical properties at high temperatures, especially when applied as a reinforcement cloth to reinforce strength in the body fastening area, etc. There was a disadvantage in using it to attach. This not only deteriorated the folding performance of the airbag but also did not improve the properties of low heat resistance and poor stability of the properties at high temperatures, so that the reinforcement cloth had high melting point and heat capacity, excellent heat resistance at high temperatures, and excellent mechanical strength. Research on the development of an airbag cushion comprising a.

The present invention is to provide an airbag cushion including a reinforcement cloth having excellent heat resistance and mechanical properties, and an airbag system including the same.

The present invention provides an airbag cushion including a reinforcing cloth made of p-aramid fibers having a repeating unit represented by the following Chemical Formula 1.

[Formula 1]

The present invention also provides an airbag system including the airbag cushion.

Hereinafter, the present invention will be described in more detail.

In the present invention, the reinforcement fabric refers to a fabric or nonwoven fabric that serves to reinforce the inflator portion or tab portion of the airbag, and the airbag cushion is manufactured through a weaving-processing-coating-foundation-sewing process while including a reinforcement cloth. Refers to the old airbag products.

In general, the airbag reinforcement can be divided into two types. Firstly, there is a fabric or nonwoven fabric that serves to support the airbag cushion by reinforcing the body fastening portion such as a tab portion connecting the car's roof rail and the airbag cushion, and secondly, in addition to these strength characteristics, the airbag when inflating the car airbag When hot-high pressure gas is injected into the cushion of the fabric, there is a fabric or nonwoven fabric attached to the gas inlet periphery to withstand the temperature and pressure of the injection gas. As a general air bag reinforcement fabric is used a nylon 6 or nylon 66 woven or non-woven fabric of a rapier loom, the airbag cushion of the present invention is characterized in that it comprises a reinforcement fabric using aramid fibers.

In the airbag cushion according to the present invention, by manufacturing a reinforcement fabric using aramid fibers having excellent mechanical properties and heat resistance, the airbag having high strength and low shrinkage and excellent shape stability compared to conventional reinforcement fabrics using nylon 66 fibers and the like and having excellent heat resistance You can make a cushion.

Aramid (aramid) is one of the nylon-based polymers, phenyl ring is connected to all the main chain except amide group, showing excellent mechanical properties with a modulus of 10 times or more than nylon, has a high melting point of 480 ℃ or more heat resistance and excellent heat resistance Indicates. Aramid is a para-type (p-) containing a meta-type (m-) and the repeating unit of the formula (1) according to the connection state of the phenyl ring, the poly P-phenylene terephthalamide) (poly (phenylene terephthalate)) is preferably used. In the case of para-type (p-) aramid fibers, the phenyl rings are laminated on each other in a plate shape so that the crystallization degree is very high, the heat resistance is excellent, and the air bag of the present invention is due to the high mechanical strength of the high strength, high elastic modulus, low shrinkage rate and the like. Suitable as cushion reinforcement material.

In the reinforcing cloth for airbag cushion of the present invention, aramid fibers may be used as a main component, but may be used in combination with nylon 66 fibers. In this case, the yarn in the oblique direction may use only aramid fibers and the yarn in the weft direction may use only nylon 66 fibers, or the yarn in the oblique direction may use only nylon 66 fibers and the yarn in the weft direction may use only aramid fibers. . In order to use aramid fibers as the reinforcing cloth material for the airbag cushion of the present invention, it is most preferable that the proportion of the entire fabric becomes 100%.

In the present invention, the aramid fibers may have a fineness of 210 to 840 denier, filament number of 60 to 150, tensile strength of 9.5 to 14 g / d, elongation at break of 3% or more, and heat shrinkage of 2% or less. It is not particularly limited thereto.

In the present invention, the woven form of the fabric is not limited to a specific form, but both woven forms of flat fabric and OPW (One Piece Woven) type are preferable.

The reinforcement cloth including the aramid fibers according to the present invention may be manufactured through a process of beaming, weaving, refining, and tentering using the aramid fibers as wefts and warp yarns. The fabric may be manufactured using a conventional weaving machine, and is not limited to the use of any specific loom. However, the plain weave fabric may be manufactured using a rapier loom, an air jet loom, a water jet loom, or the like.

In addition, in order to lower air permeability, a rubber coating layer may be included on one or both sides of the airbag cushion reinforcing fabric including the aramid fiber of the present invention. The rubber component may be one or more selected from the group consisting of powder type silicone, liquid type silicone, polyurethane, chloroprene, neoprene rubber, and emulsion type silicone resin. The coating amount per unit area of the rubber component may be used to 20 to 200 g / m ² , preferably 20 to 130 g / m ² . If the coating amount is less than 20 g / m ^{2 It} is not preferable because the fusion and carbonization by hot gas may occur during air bag deployment, and when the coating amount exceeds 200 g / m ² is not preferable in terms of the folding properties of the air bag cushion not.

The fabric for the air bag of the present invention has a tensile strength of 170 to 400 kgf / inch, preferably 280 to 380 kgf / inch measured by the American Society for Testing and Materials (ASTM D 5034-GRAB method). In addition, the airbag fabric is required to have an excellent tear strength level because it is rapidly inflated by a high-temperature gas, the tear strength indicating the burst strength of the airbag fabric is the American Material Testing Association standard (ASTM D 2261-TONGUE) When measured by the method can be a value of 13 to 90 kgf.

Reinforcing cloth for airbag cushion of the present invention can be manufactured in a suitable form according to the application site, such as near the inflator, which needs to be reinforced with heat resistance and durability due to high temperature and high pressure gas, the application site by adding a reinforcement layer if necessary Durability and the like can be improved. In the present invention, by producing a reinforcement fabric using aramid fibers of excellent physical properties, it is most preferable to use the reinforcement layer number of the applied area to less than one layer, and by minimizing the number of reinforcement layer to two layers or less depending on the application area of the airbag cushion In addition to improving folding performance, manufacturing efficiency can be improved by shortening the process.

In the present invention, the step of weaving, refining, and tendering the reinforcement cloth fabric containing the aramid fibers can be prepared according to a conventional method. However, the tendering step may be heat-treated in a range higher than the heat treatment temperature in the existing tenterization process because the crystallization temperature of the aramid fibers, the heat treatment temperature is 150 to 200 ℃, preferably to be applied to 160 to 190 ℃ Can be. If the heat treatment temperature is less than 150 ℃ in the tenter step, the coating layer may be peeled off or the shape stability may be lowered due to insufficient curing of the silicone, and when the heat treatment is performed in harsh conditions exceeding 200 ℃, the durability of the reinforcing fabric fabric It is not preferable because it may cause a decrease or discoloration phenomenon.

The airbag cushion of the present invention may be processed through an additional process such as silicone rubber coating after manufacturing the airbag cushion fabric through a conventional weaving method, a refining and heat setting process. The airbag cushion fabric thus coated is cut and folded into a certain type of airbag cushion. The airbag cushion is not limited to a particular shape and can be manufactured in a general shape.

The airbag cushion of the present invention can be bonded to the air inflator surrounding the inflator and the airbag cushion tab portion including the aramid fiber reinforcement cloth sewing method using a sewing thread or by using an adhesive, or bonded by heat or ultrasonic treatment. It is not limited to a specific bonding method.

In the present invention, when the reinforcing fabric is bonded to the airbag cushion using a sewing thread, the sewing portion may be sewn to 30 to 50 ea / 100 mm, preferably 30 to 40 ea / 100 mm. At this time, if the number of stitches of the sewing part is less than 30ea / 100mm, the strength of the sewing part is so weak that there is a problem that the sewing part with the cover is torn off when assembling the airbag. Less than%) may occur.

In addition, the present invention provides an airbag system including the above airbag cushion, and the airbag system may be equipped with a conventional device well known to those skilled in the art. The airbag can be broadly divided into a frontal airbag and a side curtain airbag. The frontal airbag includes a driver's seat, a passenger seat, a side protection, a knee protection, ankle protection, a pedestrian protection airbag, and the side curtain type airbag protects the passenger in the event of a vehicle collision or rollover. Thus, the airbag of the present invention includes both frontal and side curtain airbags.

In the present invention, matters other than those described above can be added or subtracted as required, and therefore, the present invention is not particularly limited thereto.

Airbag cushion of the present invention by using a reinforcement cloth using aramid fibers to ensure excellent heat resistance of excellent performance, it is possible to obtain excellent mechanical properties such as tensile strength and tear strength.

In particular, it has excellent heat resistance to sufficiently prevent fusion and tearing of the cushion fabric which may be caused by high-temperature gas by reinforcing the inflator portion or tab portion of the airbag cushion while minimizing the number of reinforcement layers of the reinforcement cloth. In addition, the mechanical strength is very great in the manufacturing process, such as improving the folding performance.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Example  One

Weaving the fabric using a rapier loom with a straight density of 49x49 (bone / inch, warp x weft) using 420 denier nylon 66 fibers, and then using a knife-over air Knife1over1air) was coated using a two-component silicone rubber so that the coating amount of the silicone rubber was 20 g / m ² , and the fabric for the airbag cushion was subjected to a heat-setting process and cut into an airbag cushion using a laser cutting machine.

In addition, using a 840 denier p- aramid fiber having the formula (1, filament number 140, tensile strength 12.0g / d, cut elongation 3.2%) using a weaving density of 25x22 (bone / inch, warp x weft) After weaving the fabric using a piercing loom, the coating (double-side coating) amount of the silicone rubber is 130g / m, using a two-component silicone rubber by the knife1over1air method on the uncoated fabric that has undergone the refining and heat-setting process. Coated to ² to prepare a reinforcing fabric fabric subjected to the heat-setting process, using a laser cutting machine to prepare a reinforcing fabric for air bags to be attached to the inflator of the air bag cushion.

One layer of reinforcement cloth was sewn at 35ea / 100mm of stitching using a sewing thread of 1260 denier to the airbag cushion cut separately.

Example  2

Weaving the fabric at a weaving density of 41x41 (bone / inch, warp x weft) using 630 denier p-aramid fibers (105 filaments, tensile strength of 11.8 g / d, elongation at 3.3%) having Formula 1 After the refining, coating (coating weight 20g / m ² ) and heat-reinforcing airbag reinforcing fabric was prepared through the process of the first step except that the airbag cushion was prepared in the same manner as in Example 1.

Example  3

Weaving the fabric at a weaving density of 49x49 (bone / inch, warp x weft) using 420 denier p-aramid fibers (68 filaments, 11.1 g / d tensile strength, 3.7% cut elongation) having Formula 1 After the refining, coating (coating weight 40g / m ² ) and the heat-treated reinforcing fabric for the air bag through the process of the heat setting was prepared except that the air bag cushion was prepared in the same manner as in Example 1.

Example  4

Weaving fabrics using a jacquard loom with a density of 60x60 (bone / inch, warp x weft) using 315 denier nylon 66 fibers, and then knives over air (knife1over1air) By using two-component silicone rubber, the coating amount of silicone rubber was 95g / m ² , and the airbag cushion fabric was manufactured by heat-setting and cut into airbag cushion form using a laser cutting machine.

In addition, using a 630 denier p- aramid fiber having the formula (1), filament number 105, tensile strength of 11.8g / d, cut elongation 3.3%) weaving at a weaving density of 41x41 (bone / inch, warp x weft) After weaving, a non-coated reinforcing fabric fabric was subjected to the refining and heat-setting process, and a reinforcing fabric for airbags to be attached to the vicinity of the tab of the airbag cushion using a laser cutter.

A separate reinforcement cloth was sewn at 30ea / 100mm of stitching using a 1260 denier sewing thread to the airbag cushion cut separately.

Example  5

Reinforcement for airbags with a weaving density of 49x49 (bone / inch, warp x weft) using 420 denier p-aramid fibers (formula filament number 68, tensile strength 11.1 g / d, cut elongation 3.7%) having Formula 1 An airbag cushion was manufactured in the same manner as in Example 4, except that the fabric was prepared and attached in one layer.

Example  6

Reinforcement for airbags with a weaving density of 60x60 (bone / inch, warp x weft) using 315 denier p-aramid fibers (105 filaments, tensile strength of 10.8 g / d, elongation 4.0%) having the formula (2) An airbag cushion was manufactured in the same manner as in Example 4, except that the fabric was prepared and attached in one layer.

Comparative Example  One

An airbag cushion was manufactured in the same manner as in Example 1, except that a reinforcing cloth prepared using 840 denier nylon 66 fibers was used.

Comparative Example  2

An airbag cushion was manufactured in the same manner as in Example 2, except that a reinforcing cloth (coating weight 20 g / m ² ) prepared using 630 denier nylon 66 fibers was used.

Comparative Example  3

An airbag cushion was manufactured in the same manner as in Example 3, except that a reinforcement fabric made of 420 denier nylon 66 fibers was used.

Comparative Example  4

An airbag cushion was manufactured in the same manner as in Example 4, except that an uncoated reinforcement fabric made of 630 denier nylon 66 fibers was used.

Comparative Example  5

An airbag cushion was manufactured in the same manner as in Example 5, except that an uncoated reinforcement fabric prepared using 420 denier nylon 66 fibers was used.

Comparative Example  6

An airbag cushion was manufactured in the same manner as in Example 6, except that an uncoated reinforcing cloth prepared using 315 denier nylon 66 fibers was used.

The physical property evaluation was performed about the airbag cushion containing the reinforcement cloth which concerns on the said Examples 1-6 and Comparative Examples 1-6.

 (a) Tensile strength: ASTM D 5034

The specimens were cut from the fabric for airbags and fixed to the lower clamp of a tensile strength measuring device according to American Society for Testing and Materials (ASTM) D 5034, and the strength of the airbag cushion specimen fracture was measured while moving the upper clamp upward.

(b) Tear Strength: American Society for Testing and Materials Standards (ASTM) D 2261

After the specimens were cut from the airbag fabric, they were cut 7 cm in the warp or oblique direction, and the left and right fabrics of the incision were attached to the grommet of the tear tester. The fabric was ruptured while crossing the clamps up and down while the fabric was mounted, and the strength was measured.

(c) Airbag Cushion Deployment Test

The airbag cushions prepared according to Examples 1 to 6 and Comparative Examples 1 to 6 were folded and mounted to the airbag module. Electrical signals are applied to the inflator composed of ignition agent, gunpowder, gas generator, and diffuser screen to cause electrical ignition of the ignition agent, and the hot heat generated by the gunpowder immediately burns the gas generator, generating nitrogen gas and finally inflating the airbag. When airbag deployment test is performed within 30/1000 seconds and the cushion is removed from the airbag module and inspected for appearance, when there is no abnormality such as fusion or tear on the reinforcement cloth, it is evaluated as "PASS" and the reinforcement cloth In the case of abnormality such as fusion or tearing, the evaluation was "FAIL".

The measurement results for the airbag reinforcement of Examples 1 to 6 and Comparative Examples 1 to 6 are shown in Table 1 below.

division fiber Fineness (d) Tensile strength (kgf / inch) Tear strength (Kgf) Airbag cushion
Deployment test slope
direction Weft
direction slope
direction Weft
direction Example 1 p-aramid 840 352 353 88 87 Pass Comparative Example 1 Nylon66 840 275 265 63 60 Fail Example 2 p-aramid 630 336 331 65 63 Pass Comparative Example 2 Nylon66 630 260 253 55 56 Fail (partial carbonization) Example 3 p-aramid 420 283 278 59 61 Pass Comparative Example 3 Nylon66 420 233 227 48 47 Fail Example 4 p-aramid 630 338 330 42 40 Pass Comparative Example 4 Nylon66 630 259 252 29 30 Fail (Tap break) Example 5 p-aramid 420 286 276 38 37 Pass Comparative Example 5 Nylon66 420 235 225 21 20 Fail (Tap break) Example 6 p-aramid 315 265 262 33 29 Pass Comparative Example 6 Nylon66 315 215 219 13 14 Fail (Tap Part Breaks)

As shown in Table 1, the airbag reinforcement fabric of Examples 1 to 6 using aramid fibers is superior in the evaluation of tensile strength and tear strength compared to the airbag reinforcement fabric using nylon 66 fibers of Comparative Examples 1 to 6 It can be seen that having.

Accordingly, reinforcement for reinforcing strength to support the airbag cushion by reinforcing a heat shield reinforcement cloth attached to the gas inlet periphery when the airbag is deployed to withstand the temperature and pressure of the injection gas and the airbag tab portion connecting the car roof rail and the airbag cushion. In the case of fabrics in general, unlike 3 or more layers of nylon 66 fiber reinforcement fabric, two or less layers of p-aramid fiber reinforcement fabric have excellent mechanical properties and excellent heat resistance in the vicinity of the inflator to improve folding performance. Etc. There are advantages in the manufacturing process.

In the present invention, by manufacturing an airbag cushion using a reinforcement cloth containing aramid fibers, heat resistance is significantly improved, shrinkage phenomenon at high temperature and high pressure is low, form stability is excellent, tensile strength or tear strength, etc., while minimizing the number of layers of reinforcement It is possible to provide an excellent airbag system with improved mechanical properties.

1 shows a typical airbag system.

Claims (10)

Including a reinforcing cloth made of p- aramid fibers having a repeating unit of formula 1, wherein the aramid fibers have a fineness of 210 to 840 denier, the number of filaments 60 to 150, the tensile strength of 9.5 g / d or more, and cut Airbag cushion with more than 3% elongation. [Formula 1]

The method of claim 1, The aramid fiber is an airbag cushion having a heat shrinkage of 2% or less. The method of claim 1, The reinforcing cloth is an airbag cushion coated with at least one rubber component selected from the group consisting of powder type silicone, liquid type silicone, polyurethane, chloroprene, neoprene rubber, and emulsion type silicone resin. The method of claim 3, An airbag cushion having a coating amount of 20 to 200 g / m ² per unit area of the rubber component. The method of claim 1, The reinforcing fabric is airbag cushion that is bonded by a sewing method by a sewing thread, bonded using an adhesive, or bonded by fusion by heat or ultrasonic treatment. The method of claim 1, The reinforcement cloth is an airbag cushion having a reinforcement layer number of two or less. An airbag system comprising the airbag cushion according to claim 1. The method of claim 7, wherein Wherein the airbag is a frontal airbag or a side curtain airbag. The method of claim 1, The aramid fiber is an airbag cushion having a melting point of 480 ℃ or more. The method of claim 1, The reinforcing fabric has a tensile strength of 170 to 400 kgf / inch measured by the American Society for Testing and Materials, ASTM D 5034-GRAB method, and a tear strength of 13 to 90, measured by the American Society for Testing and Materials, ASTM D 2261-TONGUE method. kgf airbag cushion.

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