helmet

Abstract

To provide a helmet (helmet for bicycles and motorcycles) capable of reducing air resistance during running.SOLUTION: A helmet 1 of the present invention has a cap body 2 that covers and protects a head, and a shock absorbing member 3 that is attached inside the cap body 2 and absorbs an external shock to protect the head, the helmet including: a front through hole 11 provided on a front side of the cap body 2 and formed so as to pass through the cap body 2 and the shock absorbing member 3 from outside toward inside; a rear through hole 12 provided on a rear side of the cap body 2 and formed so as to pass through the cap body 2 and the impact absorbing member 3 from outside toward inside; and a tunnel portion 13 that connects the front through hole 11 and the rear through hole 12 in a communicating manner.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a technology for helmets that protect the head, and particularly relates to helmets that are suitable for a rider to wear when riding a bicycle or a bike (a two-wheeled vehicle equipped with a motor).

Background Art

[0002] Conventionally, when riding a bicycle, particularly a sports bicycle (road bike or mountain bike, hereinafter collectively referred to as a road bike), a rider often wears a helmet. The reason for this is that compared to a normal bicycle (commonly called a mamachari), a road bike is lightweight and can travel at high speeds, and when falling, the impact and damage to the rider can be significant. In particular, damage to the rider's head can lead to major accidents and should be avoided.

[0003] For the above reasons, when riding a road bike, it has become standard for a rider to wear a helmet. A helmet for a road bike is very lightweight and is a cap body in which an impact-absorbing liner is attached inside a thin-walled shell, and in addition, through holes are opened at multiple locations on the cap body. A rider wears a helmet with such a configuration on the head.

[0004] As described above, in a helmet for a road bike, within a range where the required strength can be maintained, through holes oriented in the thickness direction are provided at multiple locations. These through holes are intended to reduce the weight of the helmet, improve breathability, and have the effect of cooling the rider's head.

[0005] For example, Patent Document 1 discloses a helmet suitable for road bikes, which has an outer shell and an inner layer bonded to the outer shell. The front mounting location is at the front of the helmet and offset inward from the inner surface of the inner layer, and the rear mounting location is at the rear of the helmet and offset inward from the inner surface. A gap is formed between the wearer's head and the inner surface, and an internal ventilation system is provided that allows air to flow through this gap. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2017-150126 [Overview of the project] [Problems that the invention aims to solve]

[0007] In recent years, road cycling competitions, such as the Tour de France, have become extremely popular. In these competitions, riding speeds are very high, with speeds exceeding 60 km / h when descending hills. To enable such high-speed riding, it is urgently necessary to reduce the weight and aerodynamic characteristics of the road bikes themselves, as well as the aerodynamic characteristics of helmets, especially reducing air resistance at high speeds.

[0008] However, technologies for reducing air resistance in helmets have not gone beyond making the helmet shell shape streamlined or conical, and no new technologies have been developed. The technology disclosed in Patent Document 1 also does not contribute to reducing air resistance.

[0009] Therefore, in view of the above problems, the present invention aims to provide a helmet (a helmet for bicycles and motorcycles) that can reduce air resistance while riding. [Means for solving the problem]

[0010] To achieve the above objectives, the present invention employs the following technical means.

[0011] The helmet according to the present invention comprises a helmet shell that covers and protects the head, an impact-absorbing member attached inside the helmet shell to absorb external impacts and protect the head, and through holes provided so as to penetrate the helmet shell and impact-absorbing member from the outside to the inside, characterized in that it comprises a front through hole provided on the front side of the helmet shell and formed so as to penetrate the helmet shell and impact-absorbing member from the outside to the inside, a rear through hole provided on the rear side of the helmet shell and formed so as to penetrate the helmet shell and impact-absorbing member from the outside to the inside, and a tunnel portion connecting the front through hole and the rear through hole in a communication manner.

[0012] Preferably, the front through-hole, the rear through-hole, and the tunnel section form a flow path that allows air flowing from the front to be discharged to the rear.

[0013] Preferably, when H is the height from the bottom to the top of the helmet body as viewed from the front, and h is the height from the bottom of the helmet body to the center of the front through hole, the ratio h / H should be between 0.54 and 0.6.

[0014] Preferably, when the frontal projected area of ​​the front through-hole is SF and the frontal projected area of ​​the helmet body is ST, the ratio SF / ST should be 0.022 or less (excluding SF / ST=0).

[0015] Preferably, when the front projection area of ​​the front through-hole is SF and the rear projection area of ​​the rear through-hole is SR, the ratio SR / SF should be 0.6 or greater.

[0016] Preferably, a groove is formed on the inner wall surface of the impact-absorbing member at the top of the helmet body, with a downward opening along the front-rear direction, and the tunnel is formed by covering the downward opening of this groove with a plate-like member. [Effects of the Invention]

[0017] According to the helmet of the present invention, it is possible to surely reduce the air resistance during running.

Brief Description of the Drawings

[0018] [Figure 1] It is an external perspective view of the helmet of the present invention. [Figure 2] It is a front perspective view of the helmet of the present invention. [Figure 3] It is a rear perspective view of the helmet of the present invention. [Figure 4] It is a view of the inside of the helmet of the present invention as seen from below. [Figure 5] It is a cross-sectional perspective view of the helmet of the present invention cut by a vertical plane. [Figure 6] It is a cross-sectional perspective view of the helmet of the present invention cut by a vertical plane and shows the flow of air in the usage mode. [Figure 7] It is an example diagram showing the situation of analyzing the air flow in the helmet of the present invention. [Figure 8] It is a graph showing the change in the air resistance Fx of the helmet when the vertical position of the front through-hole is changed. [Figure 9] It is a graph showing the change in the air resistance Fx of the helmet when the area SF of the front through-hole is changed. [Figure 10] It is a graph showing the change in the air resistance of the helmet when "the area SR of the rear through-hole / the area SF of the front through-hole" is changed.

Mode for Carrying Out the Invention

[0019] Hereinafter, embodiments of the helmet according to the present invention will be described with reference to the drawings.

[0020] In the embodiments described below, we will illustrate a helmet 1 used when riding a sports bicycle (road bike or mountain bike, hereinafter collectively referred to as a road bike). This helmet 1 can also be used when riding a motorized two-wheeled vehicle (bike) without any problems. The front-to-back direction of the helmet 1 is illustrated in Figure 2, etc., and this corresponds to the direction as seen from the perspective of the user wearing the helmet 1.

[0021] As shown in Figure 1, the helmet 1 of the present invention is sized to fit snugly on the head without shifting. Specifically, the helmet 1 of the present invention comprises a shell 2 that covers and protects the head, an impact-absorbing member 3 attached inside the shell 2 to absorb external impacts and protect the head, and a strap 4 that fastens around the chin to securely wear the shell 2 (helmet 1) with the impact-absorbing member 3 attached on the head.

[0022] The helmet shell 2 has a bowl-shaped housing that is slightly larger than the size of the head. The helmet shell 2 is streamlined or conical in shape, taking aerodynamic characteristics into consideration, and is a component that covers at least the front and back of the rider's head. The helmet shell 2 is made of a hard material called a shell, which is made of plastic such as PC resin. Through holes 5 are provided in the front, sides, and top of the helmet shell 2. These through holes 5 allow air flowing from the front to enter the helmet 1, improving ventilation and achieving head cooling and preventing stuffiness.

[0023] A string 4 is attached to the inner wall surface at the lower end of the helmet shell 2. There are attachment points for the string 4 on the left inner wall surface of the helmet shell 2, on the right inner wall surface of the helmet shell 2, and on the rear inner wall surface of the helmet shell 2.

[0024] The impact-absorbing member 3 is fixed securely inside the helmet shell 2. The impact-absorbing member 3 is sized to completely cover the head without shifting. The inner wall surface of the impact-absorbing member 3 is covered with a cushion or the like, either entirely or partially, to facilitate easy contact with the head. The impact-absorbing member 3 is made of a material that absorbs external impacts and protects the head, such as expanded polystyrene.

[0025] The impact-absorbing member 3 protects the head by deforming when, for example, a road bike falls and the helmet shell 2 is subjected to an impact from the road surface. The impact-absorbing member 3 and the helmet shell 2 together ensure that the head is reliably protected.

[0026] The strap 4 is a component that securely fastens the helmet 1 (impact-absorbing member 3 and helmet shell 2) to the rider's head by being placed over the chin. In other words, the strap 4 is a component that prevents the helmet 1 from falling off the rider's head when worn by placing it over the chin.

[0027] The strap 4 is made of a flexible material so that it can be worn over the chin. The strap 4 is often made of nylon or polyester, for example. The strap 4 is attached to the inner wall surface of the cap 2 in a suspended state at three points.

[0028] More specifically, the strap 4 is attached to the right front and right rear sides of the inner wall surface of the helmet shell 2, suspended from each other. The chin strap 4a on the right front side and the chin strap 4b on the right rear side are bundled together, and one side of the fastening member (buckle 6) is attached to the end of them.

[0029] Furthermore, the straps 4 are attached to the left front and left rear sides of the inner wall surface of the helmet shell 2, respectively, in a suspended state. The chin strap 4c on the left front side and the chin strap 4d on the left rear side are bundled together, and the other end of the buckle 6 is attached to their ends. The buckle 6 allows the length of the straps 4 to be adjusted, so that the length of the straps 4 can be adjusted to fit the wearer's head.

[0030] Now, a key feature of the helmet 1 of the present invention is that a front through-hole 11 formed at the front of the helmet 1 and a rear through-hole 12 formed at the rear of the helmet 1 are in communication inside the helmet 1. The tunnel section 13 formed by the communication between the front through-hole 11 and the rear through-hole 12 allows air entering from the front through-hole 11 to flow smoothly to the rear through-hole 12, reducing air resistance to the helmet 1 and significantly improving the aerodynamic characteristics of the helmet 1.

[0031] Specifically, as shown in Figure 2, a front through-hole 11 is provided on the front of the helmet 1, near the top of the head, which is formed to penetrate from the outside to the inside of the helmet 1. Various shapes are possible for this front through-hole 11, but in this embodiment, it is a through-hole that has a roughly pentagonal shape when viewed from the front, with the opening facing roughly forward.

[0032] Similarly, as shown in Figure 3, a rear through-hole 12 is provided at the rear of the helmet 1, on the side closer to the top of the head, formed to penetrate from the outside to the inside of the helmet 1. Various shapes are possible for this rear through-hole 12, but in this embodiment, it is a through-hole that has a roughly elliptical shape when viewed from the rear, with the opening facing roughly backward.

[0033] On the other hand, as shown in Figure 5, a concave groove 7 (downward-opening groove 7) facing in the front-rear direction is formed on the inner wall of the top of the helmet 1 (impact-absorbing member 3). This groove 7 is a ridge extending in the front-rear direction, and its width is approximately the same as or smaller than the width of the front through-hole 11 and the rear through-hole 12. The width is said to decrease from the front through-hole 11 to the rear through-hole 12, but it may be the same width, or conversely, the width may increase from the front through-hole 11 to the rear through-hole 12. This groove 7 allows the front through-hole 11 and the rear through-hole 12 to communicate with each other.

[0034] To prevent contact between the groove 7 and the rider's head, and to make the groove 7 tunnel-shaped, a bulkhead (inner shell 14) is fitted to cover the groove 7 from below. This inner shell 14 is a thin plate made of plastic or the like, and after being fitted, it becomes flush with the inner wall surface of the impact absorbing member 3. This inner shell 14 gives the groove 7 a culvert-like shape, and together with the groove 7, the front through hole 11 and the rear through hole 12, a tunnel section 13 is formed that connects the front and rear of the helmet 1.

[0035] The front through-hole 11 and the rear through-hole 12 may be connected by an inner shell 14 that has a trough shape with an opening at the top. The opening portion of the inner shell 14 is attached to the inner wall of the top of the impact absorbing member 3 so that it faces the inner wall of the top of the helmet 1. This inner shell 14 forms a tunnel (tunnel section 13) through which the front through-hole 11 and the rear through-hole 12 communicate.

[0036] When riding a road bike, the rider assumes a forward-leaning posture, so as shown in Figure 6, the helmet 1 is tilted forward, and the front through-hole 11 faces approximately forward. Under these conditions, air flowing from the front of the helmet 1 flows into the inner shell 14 through the front through-hole 11, in other words, into the groove 7, and is discharged from the rear through-hole 12. As air flows through this short-circuited channel, the air resistance of the helmet 1 is reduced, and the aerodynamic characteristics are improved (airflow F in Figure 6). Various cross-sectional shapes and cross-sectional areas are possible for the inner shell 14 from the inlet to the outlet. One possible configuration is one in which the cross-sectional area of ​​the inlet is wide, the cross-sectional area of ​​the middle part of the inner shell 14 is small, and the cross-sectional area of ​​the outlet of the inner shell 14 is narrower than that of the inlet, but this configuration is not the only possible configuration.

[0037] With this configuration (especially the change in the width of the groove 7), the airflow that enters the inner shell 14 is accelerated by the Venturi effect and rectification effect, and is discharged at high speed from the rear through-hole 12, which is thought to significantly reduce the air resistance to the helmet 1.

[0038] The applicant has confirmed through wind tunnel experiments using a full-scale model and computer simulations that forming a tunnel (shortcut airflow channel) in helmet 1 improves the aerodynamic characteristics of helmet 1.

[0039] Furthermore, if you want to more actively introduce outside air into the helmet 1 to prevent stuffiness and heat inside the helmet 1, it is also effective to remove the inner shell 14 from the helmet 1. For this reason, it is preferable that the inner shell 14 be detachable from the helmet 1. In addition, by forming slit holes in one or more places on the inner shell 14, it is possible to introduce air into the helmet 1 through the slit holes while creating an air passage through tunnels, thereby preventing the rider's head from getting hot and stuffy.

[0040] As described above, the helmet 1 of the present invention comprises a helmet shell 2 that covers and protects the head, an impact-absorbing member 3 attached inside the helmet shell 2 to absorb external impacts and protect the head, and through holes 5 provided so as to penetrate the helmet shell 2 and the impact-absorbing member 3 from the outside to the inside. The helmet has a configuration in which a tunnel section 13 is provided that connects a front through hole 11 provided on the front side and a rear through hole 12 provided on the rear side in a communication manner. As a result, wind from the front passes through this tunnel section 13, it is possible to reliably reduce the air resistance of the helmet 1 when riding. [Examples]

[0041] Regarding the helmet 1 described above, the applicant has demonstrated through computer simulations that it can reliably reduce the air resistance Fx during riding. The results of the computer simulations are described in detail below.

[0042] Figure 7 is an example diagram showing the analysis of airflow in the helmet 1 of the present invention. The software used for this computer simulation was MSC Software scFLOW, and the analysis method used was Detached Eddy Simulation (DES). The example analysis result shown in the right panel of Figure 7 shows the distribution of the resistance value Fx(N) applied to the helmet 1, and the contour plot shows the situation after the variation in flow velocity has converged after the start of the calculation. The left panel of Figure 7 shows the analysis model (helmet cross-section) used in this computer simulation. Specifically, it shows the helmet 1 of the present invention placed on a model that mimics the head of a person riding a bicycle.

[0043] As shown in the left diagram of Figure 7, it can be seen that air enters through the front through-hole 11, passes through the tunnel section 13, and exits from the rear through-hole 12 in a nearly horizontal position towards the rear of the helmet 1. It is well known that users of sports-type bicycles such as road bikes adopt a more "forward-leaning posture" than those of regular bicycles, and therefore the user's head (in other words, the helmet 1) is tilted forward.

[0044] The riding posture of a road cyclist varies depending on the situation (sometimes leaning more deeply forward, sometimes in an upright position), but it has been shown that in most cases, the line passing through the center of the rider's head is tilted 25° forward relative to the vertical. Therefore, in computer simulations, the rider's head is assumed to be tilted 25° forward.

[0045] The applicant conducted computer simulations under various conditions and obtained the results shown in Figures 8 to 10.

[0046] Figure 8 is a graph showing the results of a simulation to determine the optimal position for installing the front through-hole 11 to achieve the best results (reduction of air resistance Fx during riding). The right side of Figure 8 schematically shows the position where the front through-hole 11 is formed. In the right side of Figure 8, H represents the height from the bottom to the top of the helmet shell 2 (in other words, helmet 1) as viewed from the front, and h represents the position from the bottom of the helmet shell 2 to the center of the front through-hole 11. The opening area (rectangular area) of the front through-hole 11 is set to 1.57% of the front projected area of ​​the helmet shell 2.

[0047] The graph in Figure 8 (left) shows the ratio h / H on the horizontal axis and the air resistance Fx (hereinafter sometimes referred to as air resistance Fx) acting on the helmet 1 during riding on the vertical axis. As is clear from this figure, the air resistance Fx graph has a convex shape downwards, and it can be seen that the minimum Fx value is obtained when h / H is around 0.57. The helmet 1 of the present invention has a configuration having a front through hole 11, a rear through hole 12, and a tunnel section 13 connecting the two holes, and due to this configuration, it has the effect of significantly reducing air resistance Fx. For this reason, as a comparative example, we decided to use the air resistance Fx of a conventional helmet that does not have a front through hole 11, a rear through hole 12, and a tunnel section 13 connecting the two holes (sometimes referred to as a helmet without holes) as the reference.

[0048] The applicant has confirmed that, as seen from the graph in the left diagram of Figure 8, a value of h / H between 0.54 and 0.6 is sufficient to achieve an air resistance smaller than that of a helmet without holes. When h / H is between 0.54 and 0.6, air coming from the front of the helmet 1 enters the tunnel section 13 through the front through-hole 11 and exits almost horizontally through the rear through-hole 12, reducing the air resistance Fx acting on the helmet 1 itself.

[0049] Next, Figure 9 shows the results of an investigation into what value of the front through-hole 11 minimizes the air resistance Fx acting on the helmet 1. When the frontal projected area of ​​the helmet shell 2 viewed from the front is ST, and the frontal projected area of ​​the front through-hole 11 is SF, the relationship between SF / ST and Fx is shown in the left diagram of Figure 9.

[0050] As shown in Figure 9 (left), it can be seen that the air resistance Fx increases when SF / ST is around 0.025.

[0051] The applicant has confirmed that, as seen from the graph in the left diagram of Figure 9, the value at which the air resistance Fx is smaller than that of a helmet without holes is sufficient if SF / ST is 0.022 or less (excluding SF / ST=0). If SF / ST is 0.022 or less, air coming from the front of the helmet 1 enters the tunnel section 13 through the front through-hole 11 and exits almost horizontally through the rear through-hole 12, reducing the air resistance Fx acting on the helmet 1 itself.

[0052] Next, let's explain Figure 10. Figure 10 shows the results of simulations under various conditions to see how the air resistance Fx acting on the helmet 1 changes when the ratio of the size (area SF) of the front through-hole 11 to the size (area SR) of the rear through-hole 12 is changed. As can be seen from the left side of Figure 10, it is found that when SR / SF exceeds approximately 0.5, the air resistance Fx decreases sharply. When considering a helmet without holes as a comparative example, it has become clear that the effects of the present invention can be fully demonstrated if the helmet 1 has a rear through-hole 12 with an SR / SF of 0.6 or higher, that is, an SR area of ​​0.6 times or more than the area SF of the front through-hole 11. Based on the results of the computer simulation, this trend continues up to an SR / SF of approximately 1.7.

[0053] In summary, the helmet 1 of the present invention comprises a helmet shell 2 that covers and protects the head, an impact-absorbing member 3 installed inside the helmet shell 2 to absorb external impacts and protect the head, and through holes 5 provided so as to penetrate the helmet shell 2 and the impact-absorbing member 3 from the outside to the inside. The helmet has a configuration in which a tunnel section 13 is provided that connects a front through hole 11 provided on the front side and a rear through hole 12 provided on the rear side, so that wind from the front passes through this tunnel section 13, thereby reliably reducing the air resistance of the helmet 1 when riding.

[0054] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. In particular, matters not explicitly stated in the embodiments disclosed herein, such as operating conditions, handling conditions, dimensions of components, and weight, do not deviate from what is normally practiced by those skilled in the art, and are matters that can be easily anticipated by those skilled in the art. [Explanation of symbols]

[0055] 1 Helmet 2. Helmet shell 3. Impact absorbing member 4 String 4a Chin strap (front right side) 4b Chin strap (right rear side) 4c Chin strap (left front side) 4D chin strap (left rear side) 5 Through hole 6 Fastening members 7 Groove 11 Front through hole 12 Rear through hole 13 Tunnel section 14 Inner Shell F Airflow

Claims

1. It comprises a helmet shell that covers and protects the head, and an impact-absorbing member installed inside the helmet shell to absorb external impacts and protect the head. A front through-hole is provided on the front side of the helmet body and is formed to penetrate the helmet body and the impact-absorbing member from the outside to the inside, A rear through-hole is provided on the rear side of the helmet body and is formed to penetrate the helmet body and the impact-absorbing member from the outside to the inside, It has a tunnel section that connects the aforementioned front through hole and rear through hole in a communication manner, The top of the helmet body, on the inner wall surface of the impact-absorbing member, has a downward-opening groove formed along the front-rear direction, and the tunnel portion is formed by covering the downward opening of this groove. A helmet having a flow path formed by the aforementioned front through-hole, rear through-hole and tunnel section, which allows air flowing from the front of the helmet to be discharged to the rear of the helmet, The lower opening of the groove is covered with a thin plastic sheet member. The aforementioned front through-hole is formed so that the vertical width of the hole gradually narrows from the outside to the inside of the helmet body. The aforementioned rear through-hole is formed so that its vertical width gradually widens from the inside to the outside of the helmet body. The grooved section within the tunnel has a wider vertical width at the connection side with the front through-hole and the connection side with the rear through-hole, and a narrower vertical width in the middle section. A helmet characterized by the following features.

2. The front through hole is formed in a substantially pentagonal shape when viewed from the front, The aforementioned rear through-hole is formed in a substantially elliptical shape when viewed from the rear. The groove portion is formed to be approximately the same size as or smaller than the width of the front through hole and the rear through hole. The helmet according to feature 1.

3. The helmet according to Claim 1, characterized in that, in a forward-leaning posture, when H is the height from the bottom to the top of the helmet body as seen from the front, and h is the height from the bottom of the helmet body to the center of the front through hole, h / H is 0.54 or more and 0.6 or less.

4. In a forward-leaning posture, the frontal projected area of ​​the front through hole is SF, and the frontal projected area of ​​the helmet body is The helmet according to claim 1, characterized in that when ST is set, SF / ST is 0.022 or less (excluding SF / ST = 0).

5. The helmet according to Claim 1, characterized in that, in a forward-leaning posture, when the front projected area of ​​the front through-hole is SF and the rear projected area of ​​the rear through-hole is SR, SR / SF is 0.6 or more.

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