JPH0463713B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a wariko of a bamboo sword (shinai), and in particular,
This invention relates to a splitter having excellent lightness, bending strength, and impact resistance.

As the name suggests, shinai are made from natural bamboo material, but the drawback of bamboo shinai is that they are particularly weak against impact. As a result, hangnails, cracks, splits, etc. may occur on the wariko of the shinai during use.
In some cases, breakage has caused bodily injury accidents.

In order to solve these problems, Shinai warikos made of various composite materials have been developed. Some bamboo swords made of composite materials can almost solve the problem of durability against impact, but unfortunately they are hardly ever used. The biggest reason for this is that the weight of a shinai made from composite materials is much greater than that of a regular bamboo shinai, and the actual feeling of use is completely different from that of a bamboo shinai. be.

Therefore, there is a need for the development of a composite shinai that is lightweight, bending resistant, and impact resistant so that the feeling in actual use is almost the same as that of a natural bamboo shinai.

When practicing or playing kendo with a shinai, the wariko of each shinai receives impact loads from the opponent's shinai on the surface and sides of the wariko. In general, if you compare the curved shape of the side surface of the warts with the curved shape of the surface of the warts, the curvature of the curved shape of the side is larger, so the impact load is smaller when it is applied to the side of the warts. It can be accepted by area. Therefore, between the surface and side surfaces of the wart, the side of the wart is more easily damaged, and dents, cracks, and tears are more likely to occur on the side of the wart.

The present inventor has found that in order to obtain excellent bending rigidity while maintaining lightness with a composite Shinai, it is best to configure the reinforcing member to have a box-like shape when viewed from the cross-sectional direction of the wariko. However, at the same time, it was also found that by providing appropriate reinforcing ribs to prevent the box-like reinforcing member from being distorted by impact, dents, cracks, and tears that occur on the surface and sides of the splitter can be greatly reduced. I found it.

Therefore, an object of the present invention is to provide a wariko for a shinai that is equipped with a box-shaped reinforcing member and a reinforcing rib that prevents the reinforcing member itself from being distorted, and is also lightweight. That's true.

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the term "box-like" used in this specification refers not only to a shape that forms a completely closed rectangle as shown in the figure, but also to a shape that has a slight gap at any of the four corners or any part of each side. thing,
Also included are shapes in which each arbitrary side is slightly curved.

FIG. 1 is a perspective view of a shinai 10, and normally the shinai 10 is composed of four splits 12.

FIG. 2 is a cross-sectional view showing a schematic structure of the warp 12 of the shinai of the present invention. A front surface protection material 16, a side surface protection material 18, and a back surface material 20 are provided. The box-shaped reinforcing member has a substantially rectangular cross-sectional shape on both its inner and outer surfaces. In addition, the area 2 surrounded by the reinforcing member 14
2 is provided with reinforcing ribs arranged as described below. Although the surface protection material 16, side protection material 18, and back surface material 20 are not directly related to the present invention, they can be made of various types of plastics, wood, rubber, etc. from the viewpoint of strength and lightness.

FIG. 3 shows a box-shaped reinforcing member 14, which is a feature of the present invention, and reinforcing ribs 2 provided in a region 22 (FIG. 2) surrounded by this reinforcing member 14.
6 shows various configuration examples. Reinforcement member 14
can be made from a material with excellent tensile strength, such as fiber reinforced plastic (FRP), lightweight metal sheet, etc., but there are some issues such as adhesion with the protective material 16, 18, 20, ease of molding, etc. For this reason, it is best to make it from FRP such as carbon fiber or glass fiber. The reinforcing ribs 26 are preferably made of the same hard material as the reinforcing member 14 for reasons such as ease of molding.
The reinforcing member 14 can also be made of a different hard material.

In FIG. 3a, the reinforcing ribs 26 are arranged so as to extend in the width direction (horizontal direction) of the splitter within the region 22, and the box-shaped reinforcement is particularly achieved by the impact load acting on the side surface of the splitter. This is highly effective in preventing the member 14 from being distorted. In FIG. 3b, reinforcing ribs 26 are arranged in the area 22 so as to extend in the height direction (vertical direction) of the splitter, and the box is particularly damaged by impact loads acting on the surface of the splitter. This is highly effective in preventing the shaped reinforcing member 14 from being distorted. In FIG. 3c, reinforcing ribs 26 extending in the width direction (horizontal direction) and height direction (vertical direction) of the splitter are arranged within the region 22, and on both the surface and side surfaces of the splitter. This has the effect of preventing distortion of the reinforcing member 14 from the applied impact load. FIG. 3d shows that in the area 22 surrounded by the box-shaped reinforcing member 14, not only the reinforcing rib 26 but also
It is filled with an arbitrary lightweight material (for example, foamed plastic) 28, which can more effectively prevent deformation of the reinforcing member 14. In the illustrated example, the number of reinforcing ribs 26 is one, but any number can be used.

The box-shaped reinforcing member 14 is preferably provided over the entire length of the splitter in order to increase the bending rigidity of the splitter. It may be provided only in a certain length portion near the tip of the child. Further, it is not necessary to form a box shape except for necessary parts. Furthermore, even if the box-shaped reinforcing member 14 is provided over the entire length of the splitter, the reinforcing rib 26 can be provided only at a certain length near the tip of the splitter. The overall weight of the child can be further reduced. In addition, reinforcing members 1 are placed at several locations along the longitudinal direction of the splitter.
4 and the surface protection material 16, etc. (for example, foamed plastic) may be used. With the configuration of the present invention described above, it is possible to increase the thickness of the protective material in the central portion where the impact is particularly large, and the impact resistance strength can be improved, and since the reinforcing member has a large specific gravity, Since there is room to place a protective material with a smaller specific gravity, weight reduction and impact resistance can be achieved at the same time. In addition, when the box-shaped reinforcing member is deformed by impact, its impact resistance strength decreases, so in order to prevent this deformation, a lightweight core is placed within the area of the box-shaped reinforcing member to improve impact resistance and light weight. At the same time, by providing appropriate reinforcing ribs to prevent the box-shaped reinforcing member from being distorted by impact, dents, cracks, and tears occurring on the surface and side surfaces of the splitter can be significantly reduced. Therefore, it is possible to provide a composite shinai that is light in weight, has bending resistance, and impact resistance so that the feeling in actual use is almost the same as that of a natural bamboo shinai.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the outline of a shinai. Second
The figure is a cross-sectional view of the splitter of the present invention. FIG. 3 shows various configurations of a box-shaped reinforcing member and reinforcing ribs provided within the reinforcing member. 14... Box-shaped reinforcing member, 26... Reinforcing rib.

Claims (1)

[Claims] 1. The wariko that constitutes the shinai is made of a composite material that includes at least a reinforcing member, and the shape of the reinforcing member is box-like when viewed from the cross-sectional direction of the wariko, and the box-like reinforcement A splitter for a bamboo sword, characterized in that a reinforcing rib extending in the width direction and/or height direction of the splitter is provided in a region surrounded by the member.