JPH07197304A - Helmet - Google Patents

Abstract

PURPOSE:To obtain a helmet having a high strength and impact resistance despite of its light weight, by forming at least one layer of reinforcing material from a bag shaped nonwoven fabric, then impregnating a thermosetting resin into the layer and curing to make one piece, and arranging the cured layer at a crown portion of the helmet. CONSTITUTION:At least one layer of reinforcing material is made from bag shaped nonwoven fabric, and a thermosetting resin is impregnated to a whole body of reinforcing material and cured to form one piece product. By using the above material, a crown portion of a helmet is produced. It is possible to settle gaps in arrangement and irregularities in overlapping of the reinforcing materials and to reduce a ratio of an inorganic fiber in a molded product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helmet worn when driving an automobile or a motorcycle.

2. Description of the Related Art Conventionally, as reinforcing materials for helmets of this type, there are inorganic fibers such as glass fibers and carbon fibers, or organic fibers such as poly-para-phenylene terephthalamide.
The shape may be roving, cloth, roving cloth, chopped strand mat, or the like. Unsaturated polyester resin, epoxy resin,
BACKGROUND ART Helmets are manufactured by thermosetting a thermosetting resin such as a phenol resin or a vinyl ester resin in a molding die.

[0002]

Conventionally, flat sheet materials such as rovings, cloths, roving cloths, and chopped strand mats have been used as the shape of this type of helmet reinforcing material. When used, it had the following drawbacks.

A reinforcing material such as roving cloth or chopped strand mat made of glass fiber or carbon fiber is placed in advance in a molding die in a required amount, a bag is inserted into this, and pressure is applied for impregnation and defoaming. However, even if the reinforcements are arranged, even if they are arranged, overlapping unevenness occurs, which causes difficulty in terms of the mechanical characteristics of the helmet.

Further, roving cloths and chopped strand mats made of glass fibers or carbon fibers have a large specific gravity of the constituent fibers, so that unsaturated polyester resin,
When the thermosetting resin such as epoxy resin, phenol resin, vinyl ester resin, etc. is heated and pressed and cured in the mold, the specific gravity of the molded product becomes as large as 1.6 to 1.7 and the weight of the helmet is light. It cannot be realized.

Further, in a woven fabric made of poly-para-phenylene terephthalamide fiber or the like, impregnation with a thermosetting resin is not easy, which causes difficulties in processing and use.
Also, roving cloths and chopped strand mats made of glass fibers or carbon fibers can be easily impregnated with resin, but they are poor in flexibility and are not suitable for the use of cubic curved surfaces. The present invention has been made in view of the above circumstances, and it is possible to supply a helmet that is lightweight but excellent in high strength and impact resistance by easily impregnating a resin.

[0006]

The present invention has the following constitution in order to achieve such an object. At least one layer of the reinforcing material used in the hat body part of the helmet body is a bag-shaped non-woven fabric rather than a sheet, and if the thermosetting resin is impregnated and cured into an integrated structure, the reinforcing material can be arranged. The mechanical properties are stable because misalignment and overlapping unevenness can be eliminated. Further, since the impact resistance is improved by using the non-woven fabric, the proportion of the inorganic fibers in the molded product can be reduced and the weight can be reduced.

Regarding the fiber material of the bag-shaped non-woven fabric used in the present invention, there are synthetic fibers such as polyethylene terephthalate fiber, polyvinyl alcohol fiber, polypropylene fiber, polyacrylonitrile fiber, and aromatic polyamide fiber. Considering solvent resistance, , Polyethylene terephthalate fiber, polyvinyl alcohol fiber, polypropylene fiber, aromatic polyamide fiber are preferable. Further, there is no particular problem even when two or more kinds of the above fibers are mixed. In this specification, fibers made of synthetic polymer compounds artificially obtained by a chemical means called synthesis are collectively referred to as synthetic fibers.

Regarding the shape of the nonwoven fabric made of synthetic fibers used in the present invention, there is no particular limitation as long as it is a bag shape, and compression molding, seamless processing, sewing or the like can be used. Since the bag-shaped non-woven fabric has an integrated shape, it does not cause partial displacement or overlap and has a constant strength. Therefore, when a multilayer reinforcing material is required, at least one layer may be a bag-shaped nonwoven fabric. In the case of a non-woven fabric, since it has a three-dimensional structure, the strength in the thickness direction is high, so the amount of resin required for strength is small and the weight can be reduced.

Regarding the fiber diameter of the bag-shaped non-woven fabric made of synthetic fibers used in the present invention, if the thickness is less than 30 μm, the flow resistance of the thermosetting resin when passing through the non-woven fabric layer during bag molding. If it exceeds 60 μm, the flexibility of the non-woven fabric is impaired, and the liquid holding amount of the thermosetting resin also decreases. Therefore, the fiber diameter of the nonwoven fabric made of synthetic fibers is preferably 30 μm or more and 60 μm or less.

[0010]

It is an object of the present invention that the helmet has excellent mechanical properties such as high strength and impact resistance, and that it is effective for further reducing the weight of the conventional helmet. Therefore, when at least one layer of the reinforcing material used in the hat body portion of the helmet body is a bag-shaped non-woven fabric, the ratio of the reinforcing material made of inorganic fibers can be reduced and the weight can be reduced. In addition, it is lightweight and ensures excellent mechanical properties such as high strength and impact resistance.

[0011]

[Example] As a synthetic fiber, 100% by weight of polyethylene terephthalate fiber (polyester fiber) having a fiber diameter of 15 denier and a fiber length of 76 mm was subjected to a needle punching process to weigh 200 g / m ² , thickness 2 mm, strength 15 kg / 5c.
A m-width bag-shaped non-woven fabric was obtained. Using this nonwoven fabric, a vinyl ester unsaturated polyester resin was used to carry out a bag molding method to prepare a helmet cap body (Sample No. 1). For comparison, a helmet cap body (Sample No. 2) was prepared by using a sheet-shaped non-woven fabric instead of a bag-shaped non-woven fabric in the same molding method.

Table 1 shows sample No. The physical property values of 1 and 2 are shown, but the weight, thickness and strength of the non-woven fabric are JIS-L-109.
According to 6, the bending strength, bending elastic modulus, and Izod impact strength of the helmet cap body were in accordance with JIS-K-6911.

Table 1 shows sample No. 1, sample No. The physical property values of Sample No. 2 are shown. 1, sample No. Since the superiority or inferiority of 2 is hardly seen, sample No. Two
From the sample No. of the present invention, It was found that No. 1 was a molded product which was lighter in weight, but was excellent in high strength and impact resistance.

Claims (1)

[Claims] 1. A helmet characterized in that at least one layer of a reinforcing material used in a hat body portion of a helmet main body is a bag-shaped non-woven fabric, and a thermosetting resin is impregnated and hardened into the non-woven fabric to be integrated.