JPH0446838A - Manufacture of shock absorbing bag - 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 housed in the center of the steering wheel of a vehicle, and upon a vehicle collision, it senses the impact and instantly inflates and deploys to protect the driver, etc. The present invention relates to a method of manufacturing a shock absorbing bag (so-called airbag) to ensure safety.

[Conventional technology]

Airbags are used to instantly send gas into the bag by exploding gunpowder, so they must be able to withstand the impact.

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 manufacturing method thereof), it is stated that ``a circular piece of cloth is cut out from two square pieces of cloth and the periphery is sewn together. "Manufacturing a flat airbag" is disclosed.

[Problem to be solved by the invention]

However, the method of manufacturing airbags by sewing involves many manual steps, which makes it difficult to automate and cannot be manufactured economically.The strength of the sewing parts may be lower than other methods, and the strength of the sewing parts There are problems such as the time and effort required to test the air permeability, and in addition, there is the problem that the stitching itself cannot be made with sufficient accuracy.

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 purpose is to provide a manufacturing method.

(Means for Solving the Problems) In order to achieve the above object, the gist of the present invention is to coat fiber yarns or tows with an elastomer and then spread the filaments so that they remain substantially straight and parallel. The first invention is a method for manufacturing a shock absorbing bag, which is characterized by obtaining a tape and manufacturing the tape by winding the tape around a mandrel having a predetermined size and shape, and in the first invention, A second invention provides a method for producing a shock absorbing bag, in which the elastomer is a rubber composition, and the method comprises subjecting a tape wound around a mandrel to a vulcanization treatment.

In the present specification, the term "tape" refers to "a sheet of one or several yarns (multifilament threads) arranged in such a way that the monofilaments remain substantially straight and parallel; each monofilament is "Things that are interconnected 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 D. Of course, these do not necessarily need to be supplied in the form of a single thread; rather, it is easier to spread laterally if a plurality of 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 10D is generally preferred.

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

This 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, and vulcanized rubber. Compositions containing agents and the like are 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. ,Flame retardants,
A composition containing necessary ingredients such as a vulcanizing agent is preferred.

In addition to the dip coating method, methods for coating fiber yarn or tow with an elastomer include dip coating in a dispersion state, or by passing the yarn or tow through an atmosphere in which the elastomer is powder-injected or scattered. A method of attaching the same can also be used.

Methods for opening the elastomer-coated yarn or tow include electrical methods, mechanical methods, and methods using air flow, but any method may be used as long as the purpose can be achieved; for example, mechanical methods include , apply pressure to the yarn or tow from above and below with pressure rollers,
A method of spreading the yarn or tow in the lateral direction and opening it can be adopted. By providing this pressure roller with a temperature control function, it is possible to obtain optimal opening conditions by appropriately selecting a combination of opening pressure, yarn or tow feeding speed, and opening temperature.

In the present invention, methods for winding the tape around a mandrel having a predetermined size and shape include a traverse method, a rotating arm method, and other methods in which an arm or a mandrel performs a special rotational movement to wind the tape. Either format 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.

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.

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 covers the filaments in advance to maintain the demolded shape and protect 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. Considering thermal decomposition of the elastomer, the heating temperature is 2
Harsh conditions such as temperatures above 00°C and heating times of 20 minutes or more should be avoided.

[Effect]

Since the yarn or tow is coated with an elastomer in advance, the sliding between the monofilaments is good and opening is performed smoothly.

Since the tape obtained as a result of this opening is wound around a mandrel to obtain a bag, there is no need for sewing, and since the filaments are bonded with an elastomer, the resulting bag is flexible and can be freely moved. It is foldable and 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 Figure 1, 1 is 66 nylon 1260D.

Five of these yarns were passed through the rubber solution impregnating device 2 in a direction parallel to the plane of the paper, keeping the distance between each other at 9.45 mm, and a rubber composition having the formulation shown in Table 1 was soaked in toluene. After impregnating with the melted rubber solution 3, the adhesion amount was controlled to 20 g/m'' using a doctor knife 4. Arrow A indicates the direction of yarn movement. Note that the above 9.45 mm indicates one yarn. The monofilament 1
This corresponds to the width when the fibers are opened to the size of a book. (One yarn consists of 315 monofilaments) Then, the yarn 1 is passed between opposing rollers 5.6, passed through roller 7, and released paper 1 is supplied via roller 8.9.
After sandwiching the upper and lower parts with 0a and 10b, the pressure roller 11.
12, a pressure of 100 kg/cm" was applied from above and below, and the five yarns 1 were opened by pushing them apart in the lateral direction. As a result, the yarns had a width of 300 kg/cm" in the lateral direction relative to the thickness.
It spread more than twice as thin.

In this way, a tape 13 (see FIG. 2) having a width W of about 50 mm is obtained, and while the release paper is wound up by rollers 15 and 16, the tape 13 is passed through roller 17 and rotated by disk-shaped mandrel 20. Through the delivery eye 18 that reciprocates in a direction parallel to the shaft 19, a disassembleable metal disc-shaped mandrel 20 coated with a release agent in advance is uniformly filled with no gaps at a tape feed rate of 10 m/lIIin. I rolled it up. In the above-mentioned FIG. 2, 14 is a monofilament.

Thereafter, the monofilaments were vulcanized under heating and pressure conditions of 180°C and 0.5 kg/cm'' to firmly bond the monofilaments with rubber.Then, the disk-shaped mandrel 20 was disassembled and formed on the mandrel. The shock absorbing bag 21 was taken out.The inflated and deployed state of the shock absorbing bag 21 is shown in FIG.

(Example 2) FIG. 4 shows another example, in which there is no impregnating device, and 40 g/ml of the same rubber solution 3 as above was mixed with the lower release paper 10b using an attached mixing device (not shown). +w” coating, and then five yarns 1 were placed on top of it in a direction parallel to the paper surface while maintaining a distance of 9.45 cm from each other, and then a release paper 10a was layered on top of it, and the following steps were carried out. Example 1
A shock absorbing bag was obtained through the same process and under the same conditions.

Note that drying of the coating liquid can be accelerated by attaching a drying facility to an appropriate location on the rear surface of the pressure roller.

Table 1 (Comparative Example) As a comparative example, a plain woven fabric with a warp density and a weft density of 24 threads/hand' was produced using 840 denier yarn. Next, a rubber solution prepared by dissolving a rubber composition having the composition shown in Table 1 in toluene was applied to one side of this plain woven fabric. The coating amount was 65 g/va'' in terms of solid content. Then, two woven fabrics were obtained by vulcanizing at 150°C for 14 minutes and coated with rubber solution on one side, and the two woven fabrics were sewn. A bag having the same external shape as the shock absorbing hang 20 was manufactured.The weight of this hang was 360 g.

(Performance Comparison Test) Next, a comparative test was conducted on the hang according to Example 1 and the bag according to the comparative example in terms of pressure resistance, storability, and expandability according to the following method.

■Pressure resistance 100 for each of 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 into a 20 cm square and stacked was measured and expressed as an index with the height of the comparative example as 100. The lower this index is, the more flexible and excellent the storage property is.

■ Deployability When an internal pressure of 1 kg/cmz was applied to the bag, the time required for the tip of the bag to completely reach the deployed position was measured and expressed as an index with the comparative example being 100. The lower the index, the better the speed and developability.

The above test results are shown in Table 2 below.

Table 2 As is clear from Table 2, the bag according to this example has 2 k
g/cm'' pressure test, none of the 1,000 bags burst, but nine of the bags in the comparative example burst, and the rupture location was at the seam. is also significantly superior to the comparative example in terms of storage and expandability.

〔Effect of the invention〕

■Unlike bags made from woven or knitted fabrics, the shock-absorbing bag of the present invention has a structure in which ultra-thin tape is wrapped around a mandrel, so it is easy to wrap, compact, and highly reliable. Moreover, since no sewing is required, the production process can be streamlined, and a strong impact-absorbing bag with an integrated structure can be manufactured at low cost.

(2) In the present invention, since the filament is bonded to an 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 bag according to the present invention has an exhaust port, a mounting port, etc., and is particularly useful for automobiles that require high strength. Ideal for airbags. In addition, by changing the ratio of filament and elastomer using the technology of the present invention, hot air balloons, atto balloons,
Balloons such as airships, shock-absorbing bags for collisions with high-speed moving objects, gas bags to block blasts caused by mine explosions, flexible containers for powder, fuel tanks, water storage tanks, etc. for liquids, etc. It can also be applied to heat-resistant insulation materials for civil engineering construction work.

[Brief explanation of the drawing]

Fig. 1 is a side view of each step showing an embodiment of the present invention, Fig. 2 is a perspective view of the tape, Fig. 3 is a perspective view of the shock absorbing bag in an inflated and deployed state, and Fig. 4 is a side view of each process showing an embodiment of the present invention. Side views of each process showing an example are shown. 1. Yarn, 13. Tape, 20. Disc-shaped mandrel, 21. Shock absorption bag.

Claims (1)

[Claims] 1) A tape is obtained by coating a fiber yarn or tow with an elastomer and then opening the filaments so that they remain substantially straight and parallel, and this tape is shaped into a predetermined size and shape. 2) A method for manufacturing a shock absorbing bag, characterized in that the elastomer is a rubber composition, and the elastomer is manufactured by wrapping the tape around a mandrel, and the tape is vulcanized. The method for manufacturing a shock absorbing bag according to claim 1, wherein