JPH07167593A - Bulletproof helmet - Google Patents

Abstract

PURPOSE:To enhance impact absorption against bullets or the like, and further reduce the weight of a bulletproof helmet and enhance its sitting features by placing expanded polystyrene having a specific foam magnifying power inside the helmet body as an impact absorption material against bullets or the like. CONSTITUTION:Expanded polystyrene is placed inside a helmet body 1 which is a bulletproof member and joined with a double face tape or an adhesive. The optimum expanded magnifying power is specified to be from 30 to 50 times, which makes it possible to provide excellent impact absorption. When the expansion magnification power is lower than 30 times, the impact absorption will be reduced accordingly, and it will be necessary to increase the thickness of the helmet body, which will result in the increase in the weight. It is difficult to manufacture helmet provided with foams of 50 times of expansion, and the impact absorption will be accordingly reduced, which is unfavorable to the helmets. It is advisable that the thickness of expanded polystyrene be set within the range from 15 to 30mm, which are usually adopted. This construction makes it possible to enhance elastic performance, and reduce the weight of the helmets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bulletproof helmet structure for bulletproofing with a firearm or the like.

[0002]

2. Description of the Related Art Generally, in a bulletproof helmet, many shock absorbing materials such as polyethylene foam, urethane sponge, rubber sponge and gel are used. Unlike the bullet impact, the impact force is concentrated at a high speed and partly.
Therefore, the part that receives bullets etc. must instantly absorb the deformation of the cap body that is a bulletproof member, and in the case of a helmet,
Insufficient absorption of impact force will have a serious impact on the human body, such as a skull fracture.

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The present invention has been made as a result of various studies on a structure for a bulletproof helmet that sufficiently absorbs impact force of bullets and the like and does not affect the skull. And a lightweight bulletproof helmet.

[0004]

According to the present invention, in a bulletproof helmet, a foaming ratio of 30 is used as a shock absorbing material for bullets and the like.
The present invention relates to a bulletproof helmet, which is characterized by arranging expanded polystyrene of about 50 times inside the cap body, and absorbs a momentary strong impact force such as bullets exerted on the cap body, and has no influence on the skull. It has features that it does not give. Further, the antiballistic helmet of the present invention is lightweight because the expansion ratio of expanded polystyrene is high, and at the same time, its purpose can be achieved at a lower cost than other impact absorbing materials.

The contents of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a bulletproof helmet of the present invention, in which expanded polystyrene (2) is arranged inside a cap body (1) which is a bulletproof member. Expanded polystyrene (2)
Is usually joined to the inside of the cap body (1) with a double-sided tape or an adhesive.

The optimum expansion ratio of expanded polystyrene varies depending on the kinetic energy of the fired bullet or the like, but when the expansion ratio is in the range of 30 to 50, excellent shock absorption is obtained. If the expansion ratio is less than 30 times, the impact absorption becomes small, the thickness needs to be increased, and the weight becomes heavy. If it is more than 50 times, it is difficult to manufacture and impact absorption becomes small, which is not preferable in any case.

The thickness (t) of the expanded polystyrene also varies depending on the kinetic energy of a bullet or the like, but is usually set to 15 to 30 mm. If the thickness is 15 mm or less, the shock absorption is not sufficient, and if it is 30 mm or more, the shock absorption is excellent, but the larger the thickness, the larger the cap body needs to be, resulting in an increase in the overall weight.

The reason why expanded polystyrene has a large impact absorption property is considered as follows. Expanded polystyrene is 10
It is a collection of innumerable bubbles composed of more than one face,
This is because the instantaneous kinetic energy applied to the cap body is dispersed in the bubble film of innumerable bubbles and is absorbed in the form of deformation and destruction of the bubbles.

[0009]

[Examples] The impact absorbing power of the examples of the bulletproof helmet of the present invention and the comparative examples using other impact absorbing materials were measured. (Elastic resistance test) As a test piece, 30 cm square and 8 mm thick
Thickness of phenolic aramid fiber woven fabric
The one to which the shock absorbing material of mm was joined was used. This test piece was attached vertically to an oil-clay wall, shot with a carbine from a distance of 10 m, and a pressure-sensitive paper was sandwiched between the shock absorber and the clay wall to measure the impact force. (Test result) The following are the results of measurement of the impact absorbing material used and the impact force. Impact absorbing material Impact force Example 1 Expanded polystyrene (expansion ratio 40 times) Comparative Example 1 Expanded polystyrene (expansion ratio 20 times) Δ Comparative Example 2 Expanded polystyrene (expansion ratio 80 times) × Comparative Example 3 Urethane foam (expansion ratio 40 times) ×) Comparative Example 4 Expanded polyethylene (expansion ratio 40 times) Δ (Note) Impact force ○: 25 kgf / cm or less Δ: 30 to 50 kgf / cm ×: 50 kgf / cm or more

[0007]

The bulletproof helmet of the present invention is extremely excellent in shock absorption of bullets and the like due to expanded polystyrene,
It is lightweight and easy to wear.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an antiballistic helmet of the present invention.

[Explanation of symbols]

 1 Hat body 2 Expanded polystyrene

Claims (1)

[Claims] 1. A bulletproof helmet, characterized in that expanded polystyrene having a foaming ratio of 30 to 50 times is arranged inside a cap body as a shock absorbing material for bullets and the like.