JPH068971Y2 - Helmet - Google Patents

Description

[Detailed description of the device] (Industrial application field) This device is used when riding a motorcycle or a bicycle.
A helmet used to protect the head of a human body from impact.

(Prior Art) As a helmet to be used when riding a motorcycle or the like, conventionally, a shock absorber is arranged inside a shell of fiber reinforced plastic (FRP) made by reinforcing resin with a reinforcing fiber material. Is known. As the reinforcing fiber material, for example, as described in JP-A-53-104346, a very ordinary bidirectional woven fabric in which woven yarns extend only in two directions orthogonal to each other is used. However, such a helmet has the following problems.

That is, since such a conventional helmet uses a bidirectional woven fabric for the shell, the shell has relatively large anisotropy, and the strength and rigidity in the bias direction are low, so that an impact force is exerted in that direction. When it works, it will be destroyed relatively easily.
In order to solve this, a so-called pseudo-isotropic lamination in which a large number of bidirectional woven fabrics are laminated so that their warp or weft directions are slightly shifted may be considered, but this increases the weight of the shell body. However, since the in-plane anisotropy can be reduced as a whole, but the in-plane anisotropy of each layer cannot be reduced, delamination is likely to occur when an impact force is applied. Further, it is troublesome to stack a large number of bidirectional fabrics along the curved surface, while shifting the warp or weft directions little by little, which causes a problem that the number of processes increases and the manufacturing cost increases.

Further, the conventional helmet described above has a large anisotropy of the shell with respect to bending rigidity, and if a force is applied to the shell to deform it in a direction in which the bending rigidity is small, the shell may or may not be destroyed. The impact on the part is large.
In order to solve this, it is sufficient to increase the wall thickness in the direction in which the bending rigidity becomes smaller, but if so, the weight also increases, the number of steps also increases, and the manufacturing cost increases.

(Problems to be Solved by the Invention) An object of the present invention is to solve the above-mentioned problems of the conventional helmet, and to provide a helmet that is thin, lightweight, excellent in isotropy, and strong against impact.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention relates to a FRP shell body obtained by reinforcing a resin with a reinforcing fiber material, and an impact absorber arranged inside the shell body. And a reinforcing fiber material comprising a multi-axial woven fabric or a multi-axial knitted fabric made of carbon fibers, and a reinforcing fiber mat located at the outermost layer.

In the helmet of the present invention, the shell is made of FRP made by reinforcing resin with a reinforcing fiber material. Then, the reinforcing fiber material includes at least one multiaxial woven fabric or multiaxial knitted fabric made of carbon fibers. However, in addition to carbon fibers, it may further include a multiaxial woven fabric or a multiaxial knitted fabric made of high strength, high elastic modulus reinforcing fibers such as glass fibers, polyaramid fibers, and vinylon fibers.

Here, in the multiaxial woven fabric, as shown in FIG. 2, three woven yarns, namely, a woven yarn 5 (weft yarn), a woven yarn 6 (bias yarn), and a woven yarn 7 (bias yarn) are 60 ° to each other. Although the weaving yarn 6 and the weaving yarn 7 are arranged so as to form an angle, and the weaving yarn 5 intersects with the weaving yarn 6 and the weaving yarn 7, they are integrated into a triaxial woven fabric. It is a thing.

As shown in FIG. 3, the polyaxial woven fabric also includes woven yarns each including two yarns, that is, woven yarns 5a and 5b (weft yarns), woven yarns 6a and 6b (bias yarns), and woven yarn 7a. And 7b (bias yarns) are arranged so as to form an angle of 60 ° with each other, and the weaving yarns 6a, 6b and the weaving yarns 7a, 7b are not crossed, but the weaving yarns 5a and 5b are the weaving yarns 6a, 6b and the weaving yarns 6a, 6b. It may be a triaxial woven fabric in which the yarns 7a and 7b are crossed and integrated.

The multiaxial knitted fabric has a layered structure as shown in FIG.
Four knitting yarns which are arranged so as to form an angle of 45 ° with each other and have no bend, that is, a knitting yarn 8 (weft yarn), a knitting yarn 9
(Warp yarn), knitting yarn 10 (diagonal yarn), knitting yarn 11 (diagonal yarn)
Is a triaxial knitted fabric having a tricot structure with auxiliary yarns 12 thinner than the knitting yarns.

The polyaxial knitted fabric may also be a tetraaxial knitted fabric having a chain knitting structure instead of the tricot structure, as shown in FIG.

The polyaxial knitted fabric may be a triaxial knitted fabric without the knitting yarn 8 in the 4-axial knitted fabric shown in FIGS. 4 and 5. In this case, the knitting yarns form an angle of 60 ° with each other. However, the angle formed by the knitting yarns is preferably 60 ° in the triaxial knitted fabric and 45 ° in the tetraaxial knitted fabric, but can be set to other angles.

In the above-mentioned multiaxial woven fabric and multiaxial knit, the woven yarn and the knitted yarn are
It is composed of multifilaments having a single yarn diameter of about 4 to 40 μm, a number of single yarns of about 500 to 6,000, and a cross-sectional area of about 0.006 to 1.0 mm ² .

The auxiliary yarn in the multiaxial knitted fabric is composed of multifilaments such as carbon fiber, glass fiber, polyaramid fiber, polyester fiber, polyamide fiber, vinylon fiber and rayon fiber. Then, the auxiliary yarn is 100 ° C. so as not to contract during the molding of the shell and disturb the arrangement of the knitting yarn.
It is preferable that the dry heat shrinkage ratio in 5 is 5% or less.
Further, the thickness is preferably sufficiently thin as compared with the knitting yarn so that the unevenness of the resin distribution does not become large when molded.

In this invention, as described above, it is essential to use a polyaxial woven fabric or a polyaxial knitted fabric made of carbon fiber as the reinforcing fiber material. Polyaxial woven fabrics and knitted fabrics have much higher isotropy than bidirectional woven fabrics, so even if only one piece is used,
The isotropy of the shell can be greatly improved in terms of strength and rigidity. However, in order to further improve these characteristics, in the present invention, a mat such as a chopped strand mat, a surface mat, and a swirl mat, which is made of carbon fiber or the above-mentioned reinforcing fiber, which is more isotropic, is used in a multiaxial manner. It is used in combination with a woven fabric or a multiaxial knitted fabric, for example, by alternately laminating them. At this time, the mat is always positioned in the outermost layer so as to improve the smoothness of the surface and to easily disperse the stress when an impact is applied.

Examples of the resin forming the matrix of the shell body include thermosetting resins such as epoxy resin, unsaturated polyester resin, vinyl ester resin, and phenol resin, polyamide resin, polybutylene terephthalate resin, ABS resin, polyether ether ketone resin, Thermoplastic resins such as polyphenylene sulfide resin, poly-4-methylpentene-1 resin, and polypropylene resin can be used.

The shell body is manufactured by, for example, applying a reinforcing fiber material to a mold,
It can be carried out by impregnating with a resin, heating and pressurizing and molding. At this time, when the drapeability is insufficient, the reinforcing fiber material may be cut.

Inside the shell, a shock absorber is arranged with or without being joined to the shell. This shock absorber is made of expanded polystyrene, expanded polyethylene, expanded polystyrene,
It is made of foamed plastic such as foamed polyurethane.

(Embodiment) In FIG. 1, helmets are arranged in layers, and 1
A FRP shell body 4 is obtained by reinforcing a resin with a sheet of reinforcing fiber mat 1 and a sheet of multiaxial woven fabric or multiaxial knitted fabric 2 made of carbon fiber. The mat 1 is located outside the polyaxial woven fabric or the polyaxial knitted fabric 2 and forms the outermost layer. Further, inside the shell body 4, a shock absorber 3 formed by molding foamed plastic is arranged without being joined to the shell body 4.

(Example) A glass chopped strand mat having a basis weight of 300 g / m ² was placed inside a helmet mold, and a carbon fiber triaxial woven fabric TWC2140 manufactured by Toray Industries, Inc. (unit weight: 140) was placed on the glass chopped strand mat.
g / m ² ), and further a mat, a triaxial woven fabric, and a mat are placed in this order and impregnated with a vinyl ester resin, and then 130 °
After heating for 5 minutes under pressure, molding was performed, the mold was removed, and unnecessary portions were cut off to obtain a shell. The weight of this shell was 650 g. Furthermore, a shock absorber made of rigid expanded polystyrene was placed inside the shell to obtain a helmet.

Next, the shock absorption of this helmet was tested based on SNELL M85, which is a test method for riding helmets. The test examines the impact acceleration when the helmet is allowed to fall freely from the top of a flat iron anvil and collide with it. The first time it drops from a height of 306 cm, and the second time it drops from a height of 225 cm. Let In this test, the maximum acceleration G is required to be 285 G or less on the average of the impact peak value, and it is said that the peak value at one time should not exceed 314 G. The first was 198G and the second was 213G, both of which were far below the standard values.

(Effect of the Invention) The helmet of the present invention is a multi-axial woven fabric made of carbon fiber, which has a large reinforcing effect on the FRP shell body and is much more isotropic than ordinary bidirectional woven fabrics. Alternatively, since the polyaxial knitted fabric is used, the shell has a high in-plane isotropic property with respect to strength and rigidity and does not need pseudo isotropic lamination as in the case of using a bidirectional woven fabric.
Thinner and lighter with the same strength and rigidity. Further, the shell is highly isotropic and therefore has excellent impact resistance and is tough. Furthermore, the shell body exhibits rigidity due to the high elastic modulus of the carbon fiber even if it is thin, and when it receives an impact, it deforms itself and absorbs impact energy, and the impact force that acts is the reinforcing fiber mat of the outermost layer. Since it is dispersed, the shock absorption capacity is increased.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional view showing an embodiment of the helmet of the present invention, and FIGS. 2 and 3 are schematic plan views showing multiaxial fabrics of different aspects used in the present invention,
4 and 5 are schematic plan views showing the polyaxial knitted fabrics of different modes used in the present invention. 1: Reinforcing fiber mat 2: Multiaxial woven fabric or multiaxial knitted product 3: Impact absorber 4: Shell 5, 5a, 5b: Woven yarn 6, 6a, 6b: Woven yarn 7, 7a, 7b: Woven yarn 8: Knit Thread 9: Knitting thread 10: Knitting thread 11: Knitting thread 12: Auxiliary thread

Claims (1)

[Scope of utility model registration request] 1. A fiber reinforced plastic shell made by reinforcing a resin with a reinforcing fiber material, and a shock absorber disposed inside the shell body, wherein the reinforcing fiber material is made of carbon fiber. A helmet comprising: a multiaxial woven fabric or a multiaxial knitted fabric and a reinforcing fiber mat located in the outermost layer.