JP2006009227A - Two-layer type shock cushioning safety hat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce twisting shock to a rider neck by a thrown out rider and the road surface or a collision opponent during an accident of a two-wheeled vehicle. <P>SOLUTION: The safety function of a helmet is separated into an inner hat body and an outer covering hat body in order to reduce the twisting of the neck by friction of the helmet with the road surface. The inner hat body mainly absorbs and cushions the shock load vertical to the plane and the outer covering hat body covering the inner hat body without a gap absorbs and cushions the shock of the road surface, etc., and rotation torque with friction by deformation or falling off of the outer covering hat body. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a structure of a riding safety helmet.

To protect the heads of motorcycle occupants and construction site workers from the impact of accidents, wearing helmets is required by law. In particular, motorcycles have a high accident rate, and even after a collision, an occupant thrown out on the road due to inertia due to traveling speed often collides with a road surface or a collision object and suffers fatal injury to the head and neck. For this reason, many helmets protect the head with a strong cap body against impact, and in order to reduce the shock transmission from the rigid cap body to the head, it is necessary to incorporate a cushioning material inside the cap body. It is customary. (For example, Patent Document 1.2.3.4)
JP 2004-76167 A (with one-layer cushioning material) JP 2003-147623 A (with one-layer cushioning material) JP 2001-295129 A (with two-layer divided cushioning material) JP-A-11-172517 (with two-layer cushioning material)
All of the above-mentioned documents and commercial products in Japan and other countries are ones in which a cushioning material is incorporated inside a hard cap body, and there are no ones incorporated in the outside of the cap body.

  The shock absorbing structure of these helmets is acceleration relaxation in the direction of impact input that is substantially perpendicular to the plane. Further, as seen in JIS T1833 “Safety cap for riding”, the shock absorption test also assumes the occurrence of vertical acceleration. In the impact absorption evaluation, the maximum acceleration of the helmet can be measured by a prescribed test method, and the HIC index is used to evaluate the degree of damage to the human brain as a number from the magnitude and duration of acceleration above a certain level. However, both are assumed to input acceleration perpendicular to the surface of the head alone. The combination test with the neck and the body on which the head is placed and the rotational torsion test are not considered.

  However, unlike a construction site, unlike a fallen object accident involving a helmet wearer who has no motion inertia in a stationary state, most serious accidents occur when a motorcycle is running. In many cases, an occupant thrown out of a motorcycle that suddenly decelerates or falls due to a collision falls and crashes on the road surface with an inertial velocity in the traveling direction, and slides on the road surface. The head supported by the neck along with the helmet will clash first on the road surface, but as shown in FIG. 1, the impact acting on the head of the occupant moving forward due to inertia is the reaction from the road surface due to the fall. It is the combined force of the force and the road friction force in the direction of travel, and is input with an angle at an angle, not perpendicular to the helmet. The outer periphery of the helmet in contact with the road surface receives a rotational force due to friction with the road surface. This rotational force acts not on the head but on the neck that supports the head. The conventional helmet structure can mitigate the impact perpendicular to the head, but the horizontal cross section of the human head and helmet has a long head shape, so the rotational force is strong and the road surface collides with speed. Because there is no way to relieve the rotational force on the neck due to friction, and the neck that moves smoothly to the left and right has a very low resistance to external rotational torsional torque. The torsion of the accident makes the seriousness of the accident serious and has fatal consequences. It has been reported that the number of fatal accidents due to cervical injuries has increased dramatically while the number of fatal accidents due to head injuries has decreased since the mandatory wearing of helmets (FMVSS 218), which took effect in January 1967 in the United States. .

  What can't be overlooked is that wearing a helmet increases the degree of injury depending on the situation of the collision. Since the helmet is considerably larger than the human head, the distance to the collision partner decreases, and the collision or contact frequency increases. The head diameter of an adult male is 18-20 cm, whereas the diameter of a helmet is about 28 cm. The distance to the opponent has decreased by 4 cm or more, and the contact frequency has increased. Further, as a result of an increase in the radius from the head central axis to the helmet outer periphery input point, the torsional torque applied to the neck via the head increases by about 45% compared to when not worn by simple calculation. Wearing a helmet alleviates the direct impact that is input vertically to the head, but the torsional impact on the neck is rather increased. There is a trade-off between the reduction of head impact and increased neck impact due to helmet wearing in the United States (eg, “Report on the results of mandatory motorcyclists wearing helmets by Missouri State ABAT”) and other countries. Reported in a motorcycle accident investigation.

  The problem is to reduce the rotational torsional impact applied to the occupant's neck through the helmet without damaging the surface vertical impact mitigation of the helmet in the event of an accident.

  When the first collision of the occupant's head thrown and dropped with the road surface or the collision object is the highest, the velocity of falling and the direction of travel is the greatest, and the rotational torsional energy applied to the neck is the maximum. Influences. The means taken to solve this problem is that a conventional outer cap body, that is, a helmet body made of resin is mounted on the outer side of the helmet without any gap, and when an impact is applied, the outer cap body is caused by a rotational torsional moment. It was to drop out. This mitigates transmission of the applied rotational torsional impact to the neck.

  That is, the shock absorption direction of the inner cap body and the outer cap body is separated, and the inner cap body absorbs and relaxes mainly the vertical surface impact acceleration by the conventional structure, and the outer cap body absorbs and reduces the impact acceleration in the outer circumferential direction. The peak value of the rotational torsional impact applied to the neck is relieved by receiving deformation or dropping upon receiving impact or frictional force due to road surface abrasion.

  The maximum impact value on the head and neck of the occupant thrown out is generated when the fall speed and the traveling direction speed are the highest, that is, by the first collision with the road surface. After that, the inertial velocity energy is absorbed by the road friction of the whole body, and the re-collision speed between the road surface and the cap body is also greatly reduced. Therefore, after the second collision after the first collision, the neck The torsional torque is greatly reduced. Therefore, it is important to perform effective shock absorption and mitigation during the first collision. In addition, it is effective if the jacket itself is made of a slightly soft plastic, and has an effect of relaxing the impact input perpendicular to the surface. When transmitting the impact acceleration to the inner cap body, there is energy absorption due to thickness compression and deformation of the outer cap body itself, and the impact load is distributed by the structure that covers the outer shape of the inner cap body without gaps, so to the head Reduce the acceleration of Although there is a concern about an increase in the weight of the outer cap body itself, the thickness is about several millimeters, and a lightweight material such as foam molding can be used, so the influence of this is small.

  By using the double-structured cap body according to the present invention, it is possible to greatly reduce the torsion of the neck due to a road surface collision, which has been difficult to protect in the past, and to alleviate fatal cervical vertebra and spine damage. It has great safety benefits, especially for growing youth and delicate women. In addition, it can be used for helmets used for intense exercise such as bicycles and sports, and safety can be improved.

  In addition, when encountering a suddenly ill person or a person who has difficulty walking, it may be possible to remove the outer cap body for the purpose of emergency evacuation and lend it to these persons for short-distance transportation to a hospital. . However, it is necessary to satisfy safety requirements such as wearing a chin strap.

Although the present invention effectively separates the acceleration in the direction perpendicular to the surface and the outer peripheral direction and reduces the impact, a conventional safety structure helmet can be used for the inner cap body. The outer cap body is a slightly soft resin molded product that has a shape that covers the inner cap body without any gaps, and is pushed in from the outside. It is necessary not to loosen due to wind or vibration, and the dimensional relationship is a slight interference fit. If both hands are applied to the lower end of the opening and spread to the left and right, it can be detached.
An embodiment of the present invention will be described with reference to a side view of FIG. 2 and a cross-sectional view of FIG. The basic structure of the helmet shown in FIG. 2 such as the cap body and the internal buffer liner, visor, chin strap, etc. may be a conventional safety type. The inner cap body is a hard resin cap body, which is the inner cap body 1 in the present invention. An elastic resin cap body 2 is mounted outside the inner cap body 1 without a gap. Since the outer cap body 2 is formed with the outer shape of the inner cap body 1 as a basic shape, the outer cap body 2 can be mounted without a gap by giving a slight tightening allowance. A buffer liner 3 is incorporated in the inner cap body 1. On the left and right side surfaces of the outer cap body 2, fastening holes 2 a are opened to hold and anchor the inner cap body. On the corresponding inner side, the projecting fastener 1a of the inner cap body 1 is formed so as to be fitted into the retaining hole 2a, and plays the role of a removal anchor. The degree of the fitting force of the protruding fastener 1a and the fastening hole 2a and the holding force due to the inward tightening of the outer cap body 2 are the deformation of each cap body due to the impact force at the time of collision, and the falling off of the outer cap body. It is determined in consideration of the degree, the optimum value of energy absorption, and the material characteristics of each cap body. The structure of the fasteners and the fastening holes that moor the inner and outer cap bodies can be used as long as they can be prevented from falling off due to wind pressure during running, such as tight side fitting of the cap bodies, nylon fasteners, hooking by steps, etc. But it can achieve its purpose. The fastening pin hole 1c of the visor and the fastening pin hole 1b of the chin strap may have a normal structure. The slit 2b provided on the outer periphery of the outer cap body, when a gap is generated between the outer cap body and the inner cap body, exhausts the air in the gap with the negative pressure of the outer peripheral airflow to bring them into close contact with each other Let

It is a conceptual diagram which shows the force added to a helmet. It is a side view of an Example. It is sectional drawing of an Example.

Explanation of symbols

1. Inner cap body 1a. Protruding fasteners 1b. Chin strap pin hole 1c. 1. Visor retaining pin hole Helmet cover 2a. Retaining holes 2b. 2. Air vent slit Buffer liner

Claims (1)

  A plastic outer cap body is attached to the outer surface of the riding safety cap body, and the outer cap body is moored to the safety cap body by fasteners provided on the left and right side surfaces. A double-layered shock relief safety cap that deforms or becomes detached from the safety cap.

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