JP3106273U - Two-piece shock relief safety cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a torsional impact on an occupant's neck caused by a thrown occupant and a road surface or a collision object in a motorcycle accident.
SOLUTION: The safety function of the helmet is separated into an inner cap body and an outer cap body in order to alleviate the torsion of the neck due to friction between the helmet and the road surface, and the inner cap body absorbs and reduces mainly an impact load perpendicular to the plane. However, the outer cap that covers the inner cap without any gap absorbs and reduces the rotational torque due to the impact and friction of the road surface or the like by deforming or falling off the outer cap.
[Selection] Figure 2

Description

  This invention relates to the structure of a riding safety helmet.

To protect the heads of motorcycle occupants and construction site workers from the impact of accidents, helmets are required by law. In particular, motorcycles have a high accident rate. Even after a collision, an occupant thrown onto the road due to inertia due to the traveling speed often hits the road surface or a collision object and suffers fatal injury to the head and neck. For this reason, most helmets protect the head with a hard hat against impact, and incorporate cushioning inside the hat to reduce the transmission of shock from this hard hat to the head. It is customary. (For example, Patent Document 1.2.3.4)
JP-A-2004-76167 (with one-layer cushioning material) JP-A-2003-147623 (with one-layer cushioning material) JP 2001-295129 A (with two-layer split cushioning material) JP-A-11-172517 (with two-layer cushioning material)
The above-mentioned literature and the commercially available products in Japan and other countries all incorporate the cushioning material inside the hard cap body, and there is no article that incorporates the cushioning material outside the cap body.

  The shock absorbing structure of these helmets is to reduce acceleration in the direction of a shock input substantially perpendicular to the plane. Further, as seen in JIS T 1833 "Safety cap for riding", the shock absorption test also assumes generation of acceleration perpendicular to the plane. In the evaluation of shock absorption, the maximum acceleration of the helmet can be measured by the prescribed test method, and the HIC index that evaluates the degree of damage to the human brain as a number from the magnitude and duration of acceleration above a certain level is used. However, in each case, it is assumed that an acceleration perpendicular to the plane is input to the head alone. The combination test with the neck and torso on which the head is mounted and the rotation torsion test are not considered.

  However, unlike a helmet wearer who is stationary and has no motor inertia, as in a construction site, most serious accidents occur during motorcycle operation. In many cases, an occupant thrown from a two-wheeled vehicle that has suddenly decelerated or fallen due to a collision falls and crashes on a road surface with an inertial speed in the traveling direction, and slides on the road surface. The head supported by the neck with the helmet collides with the road surface first, but as shown in Fig. 1, the impact acting on the occupant's head moving forward due to inertia, This is the combined force of the force and the road surface friction force in the direction of travel, and is input not obliquely to the helmet but at an angle. 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 supporting the head. With the conventional helmet structure, the impact on the head perpendicular to the plane can be mitigated, but the human head and the helmet have a long head-shaped horizontal cross section, so that the restraining force in the rotational direction is strong, and a road collision with speed To the unprotected neck because there is no way to reduce the rotational force on the neck due to friction and friction, and the neck that moves smoothly to the left and right has very little resistance to external torsional torque. Torsion has seriously affected the accident and has led to catastrophic consequences. Since the mandatory helmet wearing law (FMVSS218), which came into effect in the United States in January 1967, it has been reported that deaths due to head injuries have decreased while deaths due to neck injuries have increased sharply. .

  What cannot be overlooked is that wearing a helmet actually increases the degree of injury in some crash situations. Since the helmet is much larger than the human head, the distance between the helmet and the colliding object is reduced, and the frequency of collision or contact is increased. The head diameter of an adult male is 18-20 cm, while 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. As a result, the radius from the central axis of the head to the input point of the outer periphery of the helmet is increased. As a result, the torsional torque applied to the neck via the head is increased by about 45% in comparison with the non-wearing state. Wearing a helmet mitigates the direct impact that enters the head vertically, but increases the torsional impact on the neck. There is a trade-off between mitigation of head impact and cervical impact by wearing a helmet, which has been reported in the United States (eg, “A motorbike helmet mandatory survey report by ABATE, Missouri”) and other countries. It was reported in a motorcycle accident investigation.

  The problem is to alleviate the rotational torsional impact applied to the occupant's neck via the helmet without impairing the helmet's ability to mitigate the surface vertical impact in the event of an accident.

  At the time of the first collision between the occupant's head that has been thrown and dropped and the road surface or the collision object, the falling speed and the traveling direction speed are the largest, the rotational torsional energy applied to the neck is the largest, and it is critical to alleviate this. Influences. Means taken to solve this problem is to attach a resin-made outer cap without any gap to the outside of the conventional safety hat, that is, the helmet, and when an impact is applied, the outer cap is rotated by a rotating torsional moment. That is to drop. This alleviates the transmission of the applied rotational torsional impact to the neck.

  In other words, the impact absorption direction of the inner cap body and the outer cap body is separated, the inner cap body absorbs and moderates the impact acceleration mainly perpendicular to the plane with the conventional structure, and the outer cap body absorbs the impact acceleration in the outer peripheral direction and The peak value of the rotational torsional impact applied to the neck is reduced by deforming or falling off due to the impact or frictional force due to road surface abrasion.

  The maximum impact value on the thrown occupant's head and neck is generated when the falling speed and the traveling speed are the highest, that is, 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 recollision speed between the road surface and the cap body is also greatly reduced, so after the second collision after being hit in the first collision, the neck The torsional torque has been greatly reduced. Therefore, it is important to effectively absorb and mitigate the impact during the first collision. In addition, if the outer cap itself is made of a soft plastic, it is effective, and has an effect of reducing a shock input perpendicular to the plane. When transmitting the impact acceleration to the inner cap, there is energy absorption due to compression and deformation of the thickness of the outer cap itself, and the impact load is dispersed by the structure that covers the outer shape of the inner cap without gaps, so it is applied to the head To reduce the acceleration. Although there is a concern about an increase in the weight of the outer cap itself, since the thickness is about several mm and a lightweight material such as foam molding can be used, the influence of this is small.

  The use of the dual-structured cap according to the present invention can greatly reduce the torsion of the cervix due to a road collision which has been difficult to protect in the past, and can mitigate fatal cervical and spinal damage. In particular, it has a great safety effect for growing young people and women with a delicate physique. In addition, it can be used for a helmet used for intense movement such as for bicycles and sports, and safety can be improved.

  In addition, in the case of encountering a sudden illness or a person who has difficulty walking, it is conceivable to remove the outer cap and lend it to these people for emergency evacuation and use it for short-distance transportation to the hospital . However, it is necessary to satisfy safety requirements such as wearing a chin strap.

The present invention effectively separates the accelerations in the direction perpendicular to the surface and in the direction of the outer circumference, and reduces the impact. However, the inner cap body can use a conventional safety structure helmet. The outer cap body is a slightly soft resin molded product, has a shape that covers the inner cap body without any gap, and has a structure in which the outer cap body is pushed in from the outside and mounted. It is necessary that it does not loosen due to wind contact or vibration, and the dimensional relationship is a slight interference fit. It can be detached by spreading it to the left and right with both hands on the lower end of the opening.
An embodiment of the present invention will be described with reference to the side view of FIG. 2 and the 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, and chin strap, may be any conventional safety type. The inner cap body is a hard resin cap, which is the inner cap 1 in the present invention. An elastic resin cap 2 is attached to the outside of the inner cap 1 without any gap. Since the outer cap body 2 is formed using the outer shape of the inner cap body 1 as a basic shape, it can be mounted without a gap by giving a slight tightening margin. A buffer liner 3 is incorporated inside the inner cap body 1. On the left and right side surfaces of the outer cap 2, fastening holes 2 a are respectively opened for holding and mooring the inner cap. On the corresponding inside, a projecting fastener 1a of the inner cap body 1 is formed so as to fit into the fastening hole 2a, and serves as a detachment anchor. The degree of the fitting between the projection-like fastener 1a and the retaining hole 2a and the degree of the holding force due to the inward tightening of the outer cap body 2 are determined by 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 the energy absorption amount, and the material characteristics of each cap body. The structure of the fasteners and fastening holes for mooring the inner and outer caps can be any as long as they can prevent falling off due to wind pressure during traveling, such as tight fitting of the caps, nylon fasteners, hooking by steps, etc. But it can achieve its purpose. The visor fastening pin hole 1c and the chin strap fastening pin hole 1b may have a normal structure. The slit 2b provided on the outer periphery of the outer cap body, when a gap is formed between the outer cap body and the inner cap body, discharges the air in the gap by the negative pressure of the outer peripheral airflow to bring the two into close contact. Let it.

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

Explanation of reference numerals

1. Helmet inner cap 1a. Protruding fasteners 1b. Hole in chin strap pin 1c. 1. Hole for visor fastening pin Helmet outer cap 2a. Retaining holes 2b. 2. air vent slit Buffer liner

Claims (1)

  A plastic outer cap is attached to the outer surface of the riding safety cap, and the outer cap is moored to the safety cap by fasteners provided on the left and right sides. A two-layer shock-absorbing safety cap that deforms or comes off the anchor and falls off the safety cap.

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