JPH10298817A - Impact resistant helmet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the breakage of a ceramic part even by the application of a strong impact force and improve the impact resistance of a helmet by fixing a ceramic part to the whole surface, etc., of the outer face of a specific helmet main body. SOLUTION: A ceramic part 3 made of alumina, etc., is fixed to the whole surface or a part of the surface of the outer face of a helmet main body 1 made of a fiber-reinforced thermoplastic resin such as phenolic resin having a specific tensile strength of >=10×10<6> cm and a specific elastic modulus of >=2.5×10<8> cm, produced by using a high-strength fiber such as high-strength glass fiber as the base material and having a resin content of 5-25%. The ceramic part 3 preferably has a monolithic form which can closely cover the outer face of the helmet main body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a helmet made of high-strength fiber-reinforced thermosetting plastic (hereinafter referred to as "ACM"). When a high-speed flying object is received from the outside by fixing a part of the helmet-shaped ceramic with an adhesive or a mechanical method, the energy of the flying object is almost absorbed by the partial destruction of the ceramic, and the helmet body is damaged. Also, the present invention relates to a helmet having an extremely small inner surface depression and having excellent impact resistance against high-speed flying objects.

[0002]

2. Description of the Related Art It is a well-known fact today that the bonding of a ceramic and an ACM plate can be an impact-resistant body against objects falling from a high place or objects flying at high speed. Bonding a ceramic curved plate and an ACM curved plate is also used in Japan and overseas in bulletproof vests for bulletproof vests and the like. The present applicant has also applied for a patent relating to this (Japanese Patent Application Laid-Open No. 8-192497).
However, helmets are being studied using new materials to improve the impact resistance.However, there is still no helmet that satisfies the high impact resistance at short distances, and it is necessary to improve this point. I came.

[0003]

A conventional helmet made of ACM has excellent impact resistance, but as a result of various investigations to improve the impact resistance when a stronger impact force is applied to the helmet, it has been found that The invention is to fix the ceramic on the entire surface or a part of the outer surface of the helmet to the surface of the helmet, thereby suppressing the destruction of the ceramic even under a strong impact force, reducing the separation between the ceramic and the ACM, and reducing the inner surface of the ACM. This led to the completion of a helmet with extremely low swelling and excellent impact resistance.

[0004]

According to the present invention, a specific tensile strength is 10 × 10 ⁶ cm or more and a specific elastic modulus is 2.5 × 10 6
^A ceramic is fixed to the whole or a part of the outer surface of a helmet made of a thermosetting resin fiber reinforced plastic having a high strength fiber of ⁸ cm or more and a resin content of 5 to 25%. The present invention relates to an impact-resistant helmet, and is further characterized in that the shape of the ceramic is an integral shape or a divided shape composed of a plurality of individual pieces. And a shock-resistant helmet. Further, the present invention relates to an impact-resistant helmet, wherein a predetermined number of ceramics after being arranged are symmetrical.

The ceramics used here are preferably mainly called fine ceramics, and include alumina (purity 90 to 99.9), silicon nitride, silicon carbide, zirconia and the like. Not done. Further, one or more of such ceramics may be used in combination. The physical properties of ceramics include Vickers hardness of 1000 kg / mm ² or more and bending strength of 30.
kgf / mm ² or more, elastic modulus 2.8 × 104 kg / mm
^Two or more are preferred. The ceramic shape is an integrated helmet shape that almost exactly covers the outside of the helmet (Fig. 1), or it is divided into two or more pieces (Fig. 2), or the divided shape is a triangle , Polygons (squares, rectangles, trapezoids), hexagons, etc., and combinations of these polygons (FIGS. 3, 4, 5, and 6)
It may be.

On the other hand, as a high-strength fiber used for ACM, specific tensile strength obtained by dividing tensile strength by density is 10 × 10 ⁸ c
m or more, and the specific elastic modulus obtained by dividing the elastic modulus by the density is 2.5
× 10 ⁸ cm or more. Specifically, high-strength glass fiber, aramid fiber, aromatic polyester fiber, high-strength polyethylene fiber, high-strength nylon fiber, and the like.
General glass fiber, nylon fiber, polyester fiber, etc. are not applicable. When fibers having a specific tensile strength or a specific elastic modulus of not more than the above values are used, the impact resistance of the composite molded product is not always sufficient. On the other hand, as a resin to be impregnated or applied to these high-strength fibers, a phenol resin,
Thermosetting resins such as epoxy resins, polyurethane resins, unsaturated polyester resins, vinyl ester resins, and polyimide resins.

In order to obtain ACM, a high-strength fiber is impregnated or coated with a thermosetting resin to prepare a prepreg, a plurality of the prepregs are stacked, and a compression molding method in which heat and pressure are applied, or a hand lay-up in which a prepreg is not formed There are laws. The resin content can be in the range of 5 to 80% (% by weight, hereinafter the same), but in the present invention, 5 to 25%,
It is.

As a method of fixing ceramics on the surface of the helmet body made of ACM obtained by the above-mentioned method, the back surface of the ceramics and the surface of the ACM may be fixed to the resin itself used for the ACM or a synthetic rubber or epoxy resin. Or an adhesive such as double-sided tape, or a method of attaching a magic tape to the outside of the helmet body and the back of the ceramic to fix them together, but in some cases, a machine using bolts, rivets, etc. A typical joining method is also possible. When a plurality of ceramics are arranged by bonding, the gap between one piece and an adjacent piece is preferably small, and is preferably 0.3 mm or less to improve impact resistance. It is better not to apply the adhesive on the contact surface between one piece and the adjacent piece. The reason for this is that when a shock is applied from the outside, that piece of ceramic is considerably destroyed,
This is because the fracture does not propagate to the next ceramic.

In the impact-resistant helmet obtained in this way, for example, when an object having a large impact force or a high-speed flying object collides, the crushed object, which firstly breaks down the ceramic and rapidly loses energy, reaches the helmet. Even so, the impact is small, the impact hardly bulges into the inner surface of the helmet, and it is possible to hardly damage the head. Further, making the ceramic shape bilaterally symmetrical is also important in terms of function and operability, because the balance when a helmet is worn is good.

The present invention will be described below with reference to the drawings. FIG.
The figure shows a case where a helmet-shaped integral ceramic is fixed to the outside of the helmet body. (1) is the helmet body, and (2) is the integral ceramic. FIG. 2 shows a case where ceramics divided into four parts are combined and fixed to the entire surface of the helmet main body. (1) is a helmet main body, and (3) is a combination body of divided ceramics. 3 and 4 show a case where the trapezoidal ceramics are combined and fixed to the side surface of the helmet body.
(4) and (5) are combinations of divided ceramics. FIG. 5 shows a case in which triangular ceramics are combined and fixed to the entire surface of the helmet main body. FIG.
Is a case in which hexagonal ceramics are combined and fixed on the entire helmet body, (1) is a helmet body,
(7) is a combination of divided ceramics.

[0011]

As is apparent from the above description, the helmet of the present invention has excellent impact resistance against an object falling from a high place or an object flying at a high speed.

[Brief description of the drawings]

Fig. 1 Helmet with integrated ceramic fixed
(A) is a side sectional view, (b) is an AA sectional view of (a).

FIGS. 2A and 2B are helmets fixed by combining four-divided ceramics, wherein FIG. 2A is a side view and FIG.

3A and 3B are helmets fixed by combining trapezoidal six-piece ceramics, wherein FIG. 3A is a side view and FIG. 3B is a plan view.

FIG. 4 is a helmet fixed by combining trapezoidal ceramics, (a) is a side view, and (b) is a plan view.

FIG. 5 is a helmet fixed by combining triangular ceramics, (a) is a side view, and (b) is a plan view.

FIG. 6 is a perspective view of a helmet fixed by combining hexagonal ceramics;

[Explanation of symbols]

 1 Helmet body 2 Integrated ceramic 3,4,5,6,7 Split ceramic pieces

Claims (4)

[Claims] 1. A high-strength fiber having a specific tensile strength of 10 × 10 ⁶ cm or more and a specific elastic modulus of 2.5 × 10 ⁸ cm or more as a base material, and a resin content of 5 to 25%. An impact-resistant helmet comprising a ceramic fixed to the entire surface or a part of an outer surface of a helmet body made of thermosetting resin fiber reinforced plastic. 2. The impact-resistant helmet according to claim 1, wherein the shape of the ceramic is an integral shape capable of covering the outer surface of the helmet body. 3. The impact-resistant helmet according to claim 1, wherein the ceramic comprises a plurality of pieces and is arranged in a predetermined number on the outer surface of the helmet body. 4. The impact-resistant helmet according to claim 3, wherein the shape of the predetermined number of ceramics after the arrangement is symmetrical.