JPH03213446A - Shock absorbing bag and its manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is normally stored in the center of the steering wheel of a vehicle, and when a vehicle collides, it senses the impact and momentarily inflates and deploys to protect the driver, etc. The present invention relates to a shock-absorbing bag (so-called airbag) that ensures safety, and a method for manufacturing the same.

(Prior Art) Since airbags are used to instantaneously send gas into the bag by exploding gunpowder, they are required to sufficiently withstand the impact caused by the explosion.

The conventionally provided airbags are:
After forming a polymer coating on one side of a flat woven fabric, the two coated woven fabrics are stacked so that the coated sides face each other, and the periphery is sewn to form a bag.

For example, in the prior art section of Japanese Patent Application Laid-open No. 51-4742 (invention related to a bag for an airbag device and a method for manufacturing the same), it is stated that [a circular piece of cloth is cut out from two square pieces of cloth and the peripheries are sewn together. "Manufacturing a flat airbag" is disclosed.

(Problems to be Solved by the Invention) However, the method of manufacturing airbags by sewing involves many manual steps, making it difficult to automate, making it impossible to manufacture economically, and the strength of the sewing parts may be lower than other methods. In addition, there are problems such as the fact that the sewing area is difficult to inspect for strength and air permeability, and there is also the problem that there is basically no sufficient reliability in the sewing itself.

Therefore, if an excessively strong and thick woven fabric is used to improve reliability, the airbag becomes bulky and cannot be stored compactly in the center of the steering wheel or the like.

The present invention has been made in view of the problems of the prior art, and its purpose is to provide a shock-absorbing bag that is homogeneous, highly reliable, easy to manufacture, can be stored compactly, and is lightweight. The object of the present invention is to provide a manufacturing method thereof.

(Means for Solving the Problems) In order to achieve the above object, the gist of the present invention is to provide a tape-like product in which fiber filaments are arranged in a substantially straight and parallel state, or a tape-like material that is wound into a bag-like shape. The first invention was a shock-absorbing bag, and a tape-like product was obtained in which the fiber filaments were arranged in a substantially linear and parallel state, and this tape-like product was cut into a predetermined size and shape. A second invention provides a method for manufacturing a shock absorbing bag, which is characterized in that the bag is manufactured by winding it around a mandrel having fiber yarns or tows so that the filaments 1- are kept substantially straight and parallel. A third method of manufacturing a shock absorbing bag is characterized in that the fibers are opened to obtain a tape-like material, and the tape-like material is wound around a mandrel having a predetermined size and shape. As an invention,
Manufactured by coating a tape with elastomer on a tape in which the fiber filaments are arranged in a substantially straight and parallel state, and winding this tape around a mandrel having a predetermined size and shape. A fourth invention is a method for producing a shock absorbing bag characterized by A fifth invention provides a method for manufacturing a shock absorbing bag, which comprises wrapping the tape around a mandrel having a predetermined size and shape, and then coating the surface of the tape with an elastomer. Alternatively, a tape is obtained by opening the tow so that the filaments are maintained in a substantially straight and parallel state, and then coating the tape with an elastomer.This tape is then wrapped around a mandrel having a predetermined size and shape. The sixth invention is a method for manufacturing a shock absorbing bag, characterized in that the bag is manufactured by winding the bag around the bag, and the method is such that the fiber yarn or tow is opened into a tape shape by opening the fiber yarn or tow so that the filaments are maintained in a substantially straight and parallel state. manufacturing a shock-absorbing bag, which comprises: obtaining a tape-like material, wrapping the tape-like material around a mandrel having a predetermined size and shape, and then coating the surface of the tape-like material with an elastomer. A method is defined as a seventh invention, and in the fourth, fifth, sixth, or seventh invention, the elastomer is a rubber composition, and a tape coated with the elastomer wrapped around a mandrel is subjected to vulcanization treatment. The first invention is a method for manufacturing a shock absorbing bag, which is characterized in that the bag is subjected to the following steps.

In this specification, the term "tape-like material" refers to "a material in which one or several yarns (multifilament threads) are arranged in a sheet-like manner so that the monofilaments remain substantially straight and parallel." Okay, "tape" means "
"A product in which the monofilaments constituting the above-mentioned tape-like material are mutually bonded and integrated."

The fibers of the present invention typically include human silk, polyvinyl alcohol fibers, aliphatic and aromatic polyamide fibers,
Examples include polyester fibers, carbon fibers, glass fibers, etc., but they are not particularly limited, and include all fibers conventionally used for bonding with rubber.

The fineness of the yarn of the present invention is not particularly limited, but is generally in the range of 30 to 30,000 De. Of course, these do not necessarily need to be supplied as a single thread; rather, it is easier to spread horizontally if multiple threads are supplied at the same time. The thinner the monofilament fineness is, the easier it is to spread, and a range of, for example, 0.8 to IOD is generally preferred.

Methods for opening these yarns include electrical methods, mechanical methods, and methods using air flow, but any method may be used as long as the purpose can be achieved.
Any method such as that disclosed in Japanese Patent No. 3-69626 may be used.

Note that the tape-like material obtained by the opening must be extremely uniform (with little variation in thickness). In addition, the monofilaments must be completely separated from each other, and their spacing must be close enough that the average spacing is less than the average filament diameter.

The tape may be coated with an elastomer before or after the tape is wound around the mandrel.

The elastomer used in the present invention preferably has flexibility and appropriate elasticity.

The elastomer may be a mixture of natural rubber or synthetic rubber such as acrylic, urethane, polybutadiene, styrene-butadiene, or ethylene-propylene, reinforcing agents, flame retardants, vulcanizing agents, etc. A composition containing the following is preferred. If higher heat resistance than the above elastomer is required, use a heat-resistant elastomer consisting of synthetic rubbers such as chloroprene butyl rubber, halogenated butyl rubber, silicone rubber, and fluorine rubber, either singly or in combination, and use a reinforcing agent as well. A composition containing necessary ingredients such as , flame retardant, and vulcanizing agent is preferred.

Further, the ratio of filament to elastomer may be appropriately selected depending on the purpose and required characteristics, but for example, filament: elastomer - 90-40: 10-6.
A ratio (weight ratio) of 0 is used. In particular, in the present invention, since the filaments are spread apart, when impregnated with the above-mentioned elastomer solution, the monofilaments can penetrate well and the monofilaments can be bonded uniformly with a small amount of elastomer, thus relatively increasing the filament ratio. be able to. In particular, when the content ratio of filaments is 50% or more, it becomes possible to bring out unprecedentedly high strength properties. In order to have a high content ratio of filaments and to allow the elastomer solution to penetrate well between the monofilaments, the filaments must be opened sufficiently to incorporate the elastomer solution into the monofilaments, and then the excess elastomer must be removed using a sharp edge such as a doctor knife. If a method such as removing the elastomer is used, it is possible to increase the filament ratio and obtain a composite structure in which the filament and the elastomer are completely integrated.

The filling rate of the elastomer between the monofilaments is approximately 60% or more of the voids between the monofilaments, especially 70% or more of the voids between the monofilaments.
Preferably, it is 90% or more filled with elastomer. If this filling rate is low, the object of the present invention cannot be achieved.

Methods for coating filaments with elastomer I-mer include, in addition to dip coating, dip coating in a dispersion state, injection of elastomer powder, or passing a heated filament through an atmosphere in which the elastomer is scattered and melting it. There are also ways to put it on.

In the present invention, methods for winding a tape or a tape-like material around a mandrel having a predetermined size and shape include a traverse method, a rotating arm method, and other methods in which the arm or mandrel has a special rotational movement. Any special type of winding can be applied.

Divided into shapes, there are three methods: wrapping closed shapes such as cocoons, spheres, and cones; winding cylindrical and disc shapes; and winding irregular shapes such as prisms and pyramids. It can also be applied by method.

Although there are various winding patterns, a predetermined strength can be imparted by broadly classifying them into parallel winding, helical winding, longitudinal winding, or a combination thereof. In cases where pressure is generated inside the bag, such as in an airbag, by forming the bag with a laminated structure of at least two or more layers with different winding directions, the pressure can be applied uniformly.

In the vulcanization process of an elastomer made of a rubber composition, adjacent filaments that are crossed or parallel are fused together using an elastomer that has previously covered the filaments, thereby maintaining the shape after demolding and protecting the filaments. This is an important step in the present invention. The temperature condition is preferably a temperature at which the elastomer covering the filament exhibits a predetermined adhesive force, that is, 120 to 190°C, and in consideration of thermal decomposition of the elastomer, the heating temperature is 200°C, heating time is 20 minutes or more, and the harsh conditions are as follows. conditions should be avoided.

When molding into a removable shape, use a deformable hollow mandrel, such as a metal mandrel (which can be disassembled if necessary) or a rubber mandrel, and mold it into a closed shape. If so, use a consumable mandrel made of gypsum, rock salt, easily fused metal, etc. In order to easily remove the mandrel after molding, it is desirable to apply a mold release agent to the mandrel in advance.

(Function) Since the bag is obtained by winding a tape-shaped spread thread around a mandrel, there is no need for sewing, and since the filament is bonded with an elastomer, the resulting bag is flexible and can be folded freely. It is strong because it is reinforced with filaments.

As described above, according to the present invention, a strong impact-absorbing bag having an integral structure can be obtained easily and inexpensively.

(Example) Examples 1 and 2 of the present invention will be described below.

[Example 1] In Fig. 1, 1 is 15000, /1 of polyvara phenylene 34 diphenyl ether terephthalamide.
000 F yarns, five of which are arranged in one to one formation, pass through rollers 2.3 and between gears 4.5 at a speed of 10 m/min. Gear 4.5ba 90r
The yarn 1 rotates in the traveling direction (arrow direction) at an outer circumferential speed of n/min.
Due to this, it is overtaken many times in the direction of travel. Moreover, the tooth tip 4' of the gear 4 is finished sharply as shown in FIG. 2, and the tooth tip 5' of the gear 5 is finished rounded as shown in FIG. Therefore, when yarn 1 passes between these tooth tips,
At the sharp tooth tip 4' of the gear 4, the filament is bent at an angle, so one side of the filament is always stretched beyond its elastic limit, as shown in Figure 2 (a).
On the other hand, since the filament is gradually bent at the round tooth tip 5' of the gear 5, the filament is not subjected to much strain as shown in the second time (C1). As a result, the filament that has passed between these gears 4 and 5 will always have a strain due to being strongly stretched on only one side, so when the tension on the filament I- is relaxed, this strain will be removed as shown in Figure 3. The difference causes the filament to curl.

That is, in FIG. 1, there is a 3% overfeed between roller 2.3 and roller 6.7, so the yarn pulled out by gear 4.5 is transferred between gear 4.5 and roller 6.7. By relaxing the tension between
As shown in Figure (C), curls occur in each monofilament that makes up the yarn, and the force generated by this curl pushes other monofilaments away, and as a result, the yarn is approximately 200 times as thick in the transverse direction as compared to its thickness. spread thinly.

However, as it is, the filament is curled and elastic in the yarn length direction, so if it is stretched again by 3% between roller 6.7 and roller 8.9 in Figure 1 while maintaining this expanded state, , as shown in FIG. 4(d), in a slate state 6 and laterally spread J+- it always becomes a thin tape-like object 10.

Next, this tape-like material 10 is passed through a comb solution impregnating device 11.
After impregnating the rubber solution 12 in which a rubber composition having the formulation shown in Table 1 on page 18 was dissolved in toluene through the process, the amount of adhesion was controlled to 20 g/m2 using a doctor knife 13. In this way, an extremely thin tape 10' coated with the rubber solution and having a thickness of 40 μm and a width of 8 mm was obtained.

An enlarged cross-section of this tape 10' is shown in FIG.

In FIG. 7, 1a is a monofilament.

This tape 10' is passed through rollers 14 and 15, and delivered through a delivery eye 16 that reciprocates in a direction parallel to the rotating shaft 17 of a disc-shaped mandrel 18 to a decomposable metal disc coated with a release agent in advance. The winding angle was 14.5° on the shaped mandrel 18-1-, and the tape feeding speed was 0.45 m/sec.
I rolled it up evenly until there were no gaps. The aforementioned FIG. 7 is an enlarged view of the cross section of the tape 10' and the edge of the disc-shaped mandrel 18.

Thereafter, the monofilaments were vulcanized under heating and pressure conditions of 180° C. and 10.5 kg/cm 2 to firmly adhere the monofilaments with rubber. Thereafter, the disc-shaped mandrel 18 was disassembled and the shock absorbing bag formed on the mandrel was taken out.

Table 1 [Example 2] As a mandrel, a disk-shaped mandrel 1 shown in FIG.
8 in place of diameter 5 made of butyl rubber as shown in Figure 5.
The structure is the same as in Example 1 except that a hollow spherical mandrel 19 with a diameter of 0.00 mm is used.

In FIG. 5, 20 is eight valves for injecting air, 21 is an air supply pipe, and 22 is a small hole bored in the air supply pipe. The diameter of the mirror plate 23 installed on the air supply pipe 21 was 50 mm.

In the state shown in the figure, the valve 20 is opened and air is blown into the spherical mandrel 19 through the small hole 22 of the air supply pipe 21.
A state in which the internal pressure of the spherical mandrel 19 is 0.3 kg/cm2 is shown.

After applying a mold release agent for rubber molds to the spherical mandrel 19 using a spray gun, the tape 10' is wound onto the spherical mandrel 19 through the delivery eye 16 at an angle of 14.5°. Tape feed speed 0.45m/
sec until there were no gaps left. After that, further air is injected into the spherical mandrel 9 through the valve 20 to reduce the internal pressure of the spherical mandrel 19 to 0.5 kg/cm.
2, and the mandrel was left in a 180"C oven (not shown) for 10 minutes to complete vulcanization, and the monofilaments were firmly bonded with rubber. After this, the mandrel was removed from the oven. After cooling for 30 minutes at room temperature, the valve 20 is opened to evacuate the air inside the mandrel, and the butyl rubber mandrel is pulled out together with the air supply pipe 21 to form a spherical shock absorbing bag 24 as shown in FIG. I got it.The weight of this bag is 27
It was 0g.

[Comparative example]

As a comparative example, a plain woven fabric with warp density and weft density of 24 wood/2 hands was produced using yarn of 840 denier. Next, a rubber solution prepared by dissolving a rubber composition shown in Table 1 on page 18 in Toluyune was applied to one side of this plain woven fabric. The coating amount was 65 g/m2 in terms of solid content.

Then, two pieces of woven fabric were obtained by vulcanizing at 150° C. for 14 minutes and coated with a rubber solution on one side, and a spherical bag was made from the two pieces of woven fabric by sewing. The weight of this spherical bag was 360 g.

[Comparative Test of Comparison of Comparison of Comparison of Comparative Examples] Next, a comparison test was conducted on the spherical bag according to Example 2 and the spherical bag according to the comparative example in terms of pressure resistance, storability, and expandability according to the following method.

0 ■Pressure resistance 100 for each of the examples and comparative examples
No bags were made, and an internal pressure of 2 kg/cm'' was applied to each bag, and the number of bags that did not burst was counted.

■Storability The height when the bags were folded to a 20C11 angle and stacked was measured and expressed as an index obtained by subtracting the height of the comparative example by 100. The lower this index is, the more flexible and excellent the storage property is.

■ Deployability When an internal pressure of 2 kg/cm2 was applied to the bag, the time required for the tip of the bag to completely reach the deployed position was measured, and the time was expressed as an index with the comparative example set as 100. The lower the index, the better the speed and developability.

The above test results are shown in Table 2 on the next page.

As is clear from Table 2, the bag according to this example has a weight of 2k
In the g/cm2 pressure test, none of the 1,000 pieces burst, but nine of the ones in the comparative example burst, and the rupture location was the sewn part. The bag according to this example is also significantly superior to the comparative example in terms of storage and unfolding properties.

(Effects of the Invention) Unlike bags formed from woven or knitted fabrics, the shock-absorbing bag according to the present invention has a structure in which an ultra-thin tape or tape-like material is wound around a mandrel. It is easy to use, can be assembled easily, is highly reliable, and does not require sewing, which makes it possible to streamline the production process and make it possible to manufacture a strong shock-absorbing bag with a one-piece structure at a low cost.

(2) In the present invention, since the filament is bonded with elastomer, the resulting shock absorbing bag is flexible and can be folded freely.

(2) In the present invention, the filaments are fused to each other by an elastomer during the vulcanization process, and remain in that state to maintain the strength of the molded product.

As described above, according to the present invention, a strong impact-absorbing bag reinforced with filaments can be obtained extremely easily.

Furthermore, by changing the shape of the mandrel, bags of complex shapes can be obtained as desired.

■Since the present invention allows a strong bag of any shape to be integrally molded, the shock-absorbing hack bag according to the present invention has an exhaust L", a mounting opening, etc. 3, and is required to have high strength. Ideal for automotive airbags. In addition, by changing the ratio of filament and elastomer using the technology related to the present invention, it can be used for gases such as hot air balloons, atto balloons, balloons such as airships, shock-absorbing bags during collisions of high-speed moving objects, and mines. Gas bags to block explosions, flexible containers for powder, fuel tanks, water storage tanks, etc. for liquids, etc.
Furthermore, it can also be applied to heat-resistant insulation +A for civil engineering construction work.

[Brief explanation of drawings]

Fig. 1 is a side view of each process showing an embodiment of the present invention, Fig. 2 is a model diagram showing the strain that the filament undergoes, Fig. 3 is a drawing explaining the curling state of the filament, and Fig. 4 is a diagram showing the yarn. Figure 5 is a cross-sectional view of the spherical mandrel and air supply pipe, Figure 6 is a plan view of the shock absorbing bag, and Figure 7 is a cross-section of the tape coated with rubber solution and the edge of the mandrel. This is an enlarged view of 4. 1. Yarn, 1a.. Monofilament, 10. Tape-like material, 10'... Tape, 18.. Disc-shaped mandrel, 19.. Spherical mandrel, 24. Shock absorption bag.

Claims (1)

[Claims] 1) A tape-like item in which fiber filaments are arranged in a substantially straight and parallel state, or a shock-absorbing bag in which the tape is wound into a bag shape. 2) A shock-absorbing bag in which the fiber filaments are arranged in substantially straight lines. A shock-absorbing bag characterized in that it is manufactured by obtaining a tape-like product arranged so as to maintain a parallel state and wrapping the tape-like product around a mandrel having a predetermined size and shape. 3) A tape-like product is obtained by opening fiber yarns or tows so that the filaments remain substantially straight and parallel, and the tape-like material is then passed through a mandrel having a predetermined size and shape. 4) A method for producing a shock absorbing bag, characterized in that it is produced by wrapping it around a tape.4) A tape-like material in which the fiber filaments are arranged in a substantially straight and parallel state is coated with an elastomer to produce a tape. A method for manufacturing a shock absorbing bag, characterized in that the tape is wound around a mandrel having a predetermined size and shape. 5) The fiber filaments are maintained in a substantially straight and parallel state. The method is characterized in that a tape-shaped article arranged in the following manner is obtained, the tape-shaped article is wound around a mandrel having a predetermined size and shape, and then the surface of this tape-shaped article is coated with an elastomer. Method for manufacturing a shock absorbing bag 6) A tape is obtained by opening a fiber yarn or tow so that the filaments are maintained in a substantially straight and parallel state, and coating the tape with an elastomer to obtain a tape. 7) A method for manufacturing a shock absorbing bag, characterized in that it is manufactured by winding the fiber yarn or tow around a mandrel having a predetermined size and shape. The method is characterized in that the fibers are opened to obtain a tape-like material, and after this tape-like material is wrapped around a mandrel having a predetermined size and shape, the surface of this tape-like material is coated with an elastomer. 8) A method for producing a shock absorbing bag according to claim 4 or 5, characterized in that the elastomer is a rubber composition, and a tape coated with the elastomer wrapped around a mandrel is subjected to a vulcanization treatment.
, 6 or 7, the method for producing a shock absorbing bag