JPH0425159Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shinai (shinai), and in particular to a composite shinai in which the wariko that constitutes the shinai is made of various composite materials having excellent lightness, bending rigidity, and impact resistance.

As the name suggests, shinai are usually made of natural bamboo, but they have low durability against severe repeated impact loads, and after a certain amount of use, they can crack or break, and in some cases, they can cause injuries due to breakage. It has been pointed out that the problem of causing

For this reason, composite shinai made from various composite materials have been developed, but none of these composite shinai have been able to satisfy both strength and lightness, so they are rarely used in practice. The reality is that there is not.

In order to satisfy both strength and lightness, the applicant has made each wariko that makes up a shinai (usually a shinai is made up of four warikos tied together).
A composite shinai that is composed of a lightweight core material, a reinforcing member arranged to surround the lightweight core material, and a protective member arranged to further surround the reinforcing member, and has received a great response among users. (For example, Patent Application No. 182256 of 1982).

The purpose of the present invention is to provide a composite shinai, which is an improved version of the composite shinai developed by the applicant, and which can further increase strength without sacrificing lightness.

This objective is achieved by adding innovation to the lightweight core material of the splitter to make it difficult for the reinforcing member, which has the most important function in terms of the strength of the splitter, to deform.

In other words, when an impact load is applied to the shinai (most of the impact load is applied from the surface direction of the wariko), a reinforcing member with an almost rectangular cross section (the reinforcing member is made of FRP thin plate) This method focuses on the fact that the corners of the reinforcing member are particularly susceptible to deformation, and damage to the shinai is likely to be accelerated by deformation of the corners of the reinforcing member. In order to It is made of a material with high compressive strength.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a cross section of a shinai, and a shinai is usually constructed by bundling four warizi 1a, 1b, 1c, and 1d. When considering each wariko (for example, the wariko indicated by 1a), the impact load that acts on the shinai is divided into the impact load _P1 that acts from the surface direction of the wariko and the impact load that acts from the side direction of the wariko. The impact load P ₂ is roughly divided into the impact load P _{2 that acts from the diagonal direction, and the impact load P 3 that} acts from the diagonal direction. ₂ is rather infrequent, and most of them can be said to be impact loads P ₃ acting from an oblique direction. In addition, the impact load P ₃ acting from an oblique direction is a component force in the surface direction of the splitter as shown in the figure.
P _3a and the lateral component force P _3b can be considered separately, but the angle θ at which the diagonal impact load P ₃ acts is:
Actually, most of the cases are within the range of 0≦θ≦45°, and there are few cases where θ≧45°. Therefore, P _3a > P _3b
This can be said to be the case in most cases. For this reason,
In improving the strength of the splitter, it can be said that it is effective to focus on the component force P _3a in the P ₃ direction, which acts frequently.

Figure 2 shows the wariko 1 constituting the composite shinai of the present invention.
0 is a cross-sectional view showing the basic structure of the splitter 10.
includes a lightweight core material 12, a reinforcing member 14 arranged to surround the lightweight core material 12, and a reinforcing member 1
4 and a protective member 16 arranged so as to surround 4. The point that the splitter 10 is constructed of the lightweight core material 12, the reinforcing member 14, and the protection member 16 in this way is the same as the splitter disclosed in Japanese Patent Application No. 182256 of 1982 filed by the applicant of the present application.

The reinforcing member 14 includes a front side reinforcing member 14a, a back side reinforcing member 14b, and two side side reinforcing members 1.
It consists of 4c. Each reinforcing member 14a, 14b, 1
4c is a fiber-reinforced plastic (FRP) thin plate made by impregnating carbon fiber, glass fiber, Kepler fiber, etc. with reinforcing resin such as epoxy and curing it. In this case, the reinforcing fibers are aligned in the longitudinal direction of the splitter,
It is better to impregnate this with resin. In the illustrated embodiment, the reinforcing member 14 is composed of four flat FRP thin plates, and the thin plates are arranged so as to be in close contact with each other at the abutting portions (corners) between the thin plates. However, the FRP thin plate does not necessarily have to be a flat plate, and a slightly curved thin plate can be used. It may be arranged as follows.

The protection member 16 arranged to surround the reinforcing member 14 includes a front side protection member 16a, a back side protection member 16b, and two side side protection members 16c. The back side protection member 16b can also be omitted. Since the front side protection member 16a and the side side protection member 16c are members to which the impact from the opponent's Shinai directly acts, it is recommended to use materials with excellent impact resistance and abrasion resistance, such as high-density polyethylene or nylon. Good. Since impact does not directly act on the backside protection member 16b, it is preferable to make it from lightweight polyethylene foam or the like.

Lightweight core material 12, reinforcing member 14 and protective member 1
Step 6 is to apply an adhesive (e.g. epoxy adhesive) to the joining surfaces of each member, place them in the positional relationship as shown in Figure 2 in a mold (not shown), and heat and pressurize them. integrated by. After integral molding, one splitter is completed by cutting out squares along cutting lines 18a and 18b as shown in the figure.

A feature of the composite shinai of the present invention lies in the structure of the lightweight core material 12 arranged in an area surrounded by the reinforcing member 14. As shown in FIG. 2, the lightweight core material 12 has a portion 12a that occupies the central region of the swarm, and portions 12b that occupy areas close to both side surfaces of the swarm. In the composite shinai of the present invention, the member to which the impact load directly acts is the protective member 16, but the most important member having the function of resisting the bending force due to the impact load is the reinforcing member 14. Therefore, if the reinforcing member 14 is distorted during use of the shinai, the bending resistance of the reinforcing member 14 will be significantly reduced, leading to breakage of the shinai. On the other hand, as a result of repeated impact tests, it was found that distortion of the reinforcing member 14 was particularly likely to occur at its corners. This is because, as mentioned above, most of the impact force that acts on the wariko of the shinai comes from the first
This impact force is indicated by P _3a in the figure, and it is thought that the corner portions of the reinforcing member 14 are likely to be distorted by this impact force.

Since the lightweight core material 12 is a member that occupies a considerable portion of the total area of the splitter, it is necessary to make it from a material that is highly lightweight. In other words, the specific gravity of the reinforcing member 14 and the protective member 16 is considerably higher than that of natural bamboo material (approximately 0.7), so in order to make the overall weight of the composite shinai almost equal to the overall weight of the bamboo shinai, it is necessary to This is because the weight of the core material 12 must be reduced. On the other hand, the lightweight core material 12
is not only lightweight, but also has the function of supporting the reinforcing member 14 from inside and preventing distortion of the reinforcing member 14 due to impact. From this point of view, resin-impregnated materials such as wood, hard plastics, plastics containing microscopic hollow bodies such as glass balloons, and felts have been developed as materials that have both lightness and compressive strength against impact forces. It has been found that lightweight metals such as aluminum are preferable.

Therefore, in the composite shinai of the present invention, at least a portion occupying an area close to both sides of the wariko (i.e., a portion directly supporting the corner of the reinforcing member 14 from the inside)
As for 12b, any of the above-mentioned materials having high compressive strength against the compressive force acting from the surface direction of the splitter is arranged. When, for example, wood is used as the lightweight core material of this portion 12b, it is arranged so that the wood fibers are oriented vertically (from the front surface to the back surface of the splitter) as shown in FIG.

On the other hand, for the portion 12a of the lightweight core material 12 that occupies the central area of the splitter, any of the above-mentioned materials may be used, but in order to particularly reduce the weight, foam such as plastic may be used. , a pipe or a honeycomb structure made of lightweight metal such as aluminum can be used. When using wood for this part 12a, as shown in Figure 2, arrange the wood fibers so that they are oriented horizontally (direction facing both sides of the splitter). (impact force shown as P ₂ in Figure 1). Alternatively, the wood fibers can be arranged so that they are oriented in the longitudinal direction of the splitter.

In any case, the lightweight core material disposed at least in the area 12b that occupies areas close to both sides of the wart is made of a material that has a high compressive strength against the compressive force acting from the surface direction of the wart, so that it is particularly effective against distortion. It is important to be able to reliably reinforce the corners of the reinforcing member 14, which are likely to be damaged. It should be noted that the lightweight core material placed in the portions 12b occupying areas close to both sides of the splitter does not necessarily need to be placed over the entire length of the splitter; It may be placed only at a portion approximately 1/3 of the total length from the tip of the child.

Next, another embodiment of the composite shinai wariko of the present invention will be described based on FIG. 3. The splitter 10' according to this embodiment has the following features compared to the splitter 10 shown in FIG.
The difference is that a linear object 20 is provided and a buffer member 22 is provided between the side reinforcement member 14c and the side protection member 16c, but the lightweight core material is a feature of the present invention. It is shown in Fig. 2 that the lightweight core material of the portion 12b, which occupies at least an area close to both sides of the splitter, is made of a material with high compressive strength against the compressive force acting from the surface direction of the splitter. It is the same as Wariko. The linear object 20 is
It is preferably made of nylon or Kepler fiber, etc., and it is preferable to use a core covered with a net fabric. This linear object 20 is made to extend in the longitudinal direction of the splitter, so that even if the splitter should break,
This is to prevent the fragments of the warizhi from scattering. Therefore, when the linear object 20 is impregnated with wax emulsion and integrally molded in a mold, the linear object 20 and its adjacent objects (in the case of the example shown in FIG. 3, the lightweight core material 12a and Surface side reinforcing member 14
a) Make sure that the linear object 2 and
It is necessary to maintain the original flexibility of 0 so as not to lose it. The buffer member 22 has the function of alleviating the impact force acting from the side direction of the splitter (the impact force in the direction indicated by _P2 in FIG. 1), and is preferably made of polyethylene foam or the like.

As described above, in the composite shinai of the present invention, of the lightweight core material 12 constituting the wariko, the lightweight core material of the portion 12b that occupies at least an area close to both sides of the wariko is
Since it is made of a material with high compressive strength against the compressive force acting from the surface direction of the splitter, the corners of the reinforcing member 14 where distortion is most likely to occur can be effectively reinforced, and the breakage resistance of the splitter is greatly improved. It is something that can be done.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating the cross-sectional shape of a shinai and the direction of impact force acting on the shinai. Second
The figure shows the cross-sectional structure of a wariko based on the first embodiment of the composite shinai according to the present invention. FIG. 3 shows a cross-sectional structure of a wariko based on a second embodiment of the composite shinai according to the present invention. 10... Warizo, 12... Lightweight core material, 12a...
A lightweight core material that occupies the central area of the warizo, 12b... A lightweight core material that occupies areas close to both sides of the warizo, 14...
...Reinforcement member, 16...Protection member.

Claims (1)

[Claims for Utility Model Registration] The wariko that constitutes the bamboo sword includes a lightweight core material 12 and a reinforcing member 14 arranged so as to surround the lightweight core material 12.
and a protective member 16 disposed so as to further surround the reinforcing member 14, the lightweight core material 12 has a central portion 12a occupying its central region, and a wariko. and a side portion 12b occupying an area close to both side surfaces of the side portion 12b.
is characterized in that it is made of a material arranged in such a direction that it resists the compressive force acting from the surface direction of the splitter with a compressive strength greater than that of the material forming the central portion. A composite bamboo sword.