JPH0431089Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a shinai, and in particular, a core hole whose cross section is long in the circumferential direction is formed inside the blade of a wariko that constitutes a shinai. This invention relates to a bamboo sword in which a reinforcing core material made of glass fiber reinforced plastic is press-fitted into the hole.

[Conventional technology and its problems]

The shinai used in kendo usually consists of four warikos, and these warikos were traditionally made from high-quality bamboo. Traditionally, domestically produced bamboo materials have been used, but recently, due to the lack of high quality domestically produced bamboo materials, imported bamboo materials have come to be used. However, imported bamboo materials are often of inferior quality, and as a result, they are prone to breakage, cracking, and splitting. Therefore, as an alternative to bamboo as a natural material, plastic materials and composite materials made by combining thin plastic plates and reinforcing materials have been developed and put into use (for example, Japanese Patent Application Laid-Open No. 106474/1983). , see Japanese Patent Application Laid-Open No. 61-8070).

However, these earlier shinai had a problem in that they were much heavier than regular bamboo shinai, and the actual feeling of use was completely different from that of bamboo shinai. . Therefore, there has been a demand for the development of a shinai that feels almost the same in actual use as a shinai made of natural bamboo, and that is lightweight and has excellent impact resistance.

In addition, in the case of Shinai whose wariko is made of a laminate made of thin plastic plates and reinforcing materials, the reinforcing fibers are exposed when they are struck against each other, making the Shinai more likely to break and causing fiber fragments to scatter around the surrounding area. It was not environmentally friendly.

[Purpose of invention]

Therefore, the purpose of the present invention is to solve the problems of the conventional plastic shinai mentioned above,
To provide a shinai that gives a sense of use extremely similar to a shinai made of natural bamboo, has high bending elasticity, rigidity, and impact resistance, is excellent in durability, and prevents fibers from scattering to the outside.

[Means for solving problems]

In order to achieve the above object, the shinai of the present invention is a shinai constructed by bundling a plurality of wariko, each of the wariko is molded from a plastic material, and the wariko has a handle part and a blade part. A core hole is formed that runs longitudinally through the blade and the tip, and the cross section of the core hole in the blade excluding the handle and tip is formed into a long hole shape that is elongated in the circumferential direction. A reinforcing core material made of reinforced plastic is inserted into the hole, and the reinforcing core material is press-fitted into the core hole without a gap in the handle and tip portion, and is located approximately at the center of the core hole in the blade portion, It is characterized in that a gap is formed between the reinforcing core material and the inner wall on both sides of the core hole in the circumferential direction.

[Effect]

According to the present invention, the weight of the Shinai can be reduced by forming a core hole that runs vertically in the longitudinal direction inside the splitter made of plastic material, and by inserting a reinforcing core material made of reinforced plastic inside the core hole. Durability can be improved.

Further, the reinforcing core material of the present invention is press-fitted into the core hole in the tip and handle portion without any gap, and the structure is such that a gap exists between the reinforcing core material and the inner wall of the core hole in the blade portion. Therefore, when the shinai are struck together with more force than a predetermined impact strength, the central portion of the reinforcing core material collides with the inner wall of the core hole, producing a sound similar to that produced by natural bamboo.

Furthermore, since all of the warikos that make up a shinai have equal strength and weight, each wariko can equally support the compressive force caused by thrusting techniques in kendo competitions, and the shinai can Since the bamboo sword does not bend in any direction, damage to the bamboo sword and accidents caused by this can be prevented.

〔Example〕

Embodiments of the bamboo sword according to the present invention will be described below with reference to the drawings.

Fig. 1 shows a shinai constructed according to the present invention, and the shinai, which is designated as a whole by reference numeral 1, consists of a handle 2, a tsuba 3, a blade 4, and a tip 5.The shinai 1 has four parts. It is constructed by bundling splitters 6, 6, 6, 6. According to the present invention, each of these splitters 6 can be molded from ultra-high molecular weight plastic, vinyl chloride resin, polystyrene, nylon, polycarbonate, phenolic resin, polyester resin, or the like.

2 shows a cross section of the handle 2 of the bamboo sword, FIG. 3 shows a cross section of the blade 4, and FIG. 4 shows a cross section of the tip 5. As is clear from these cross-sectional views, when the four splitters 6 are bundled, the handle 2
A center hole 7 is formed in the center of the blade portion 4, and the size of the center hole 7 is determined such that the inner diameter increases from the handle portion 2 toward the blade portion 4. Further, the cross section of the tip portion 5 is as shown in FIG.
a, 6 butt against each other, and the remaining pair of splitters 6, 6's round protrusions 6b, 6b abut against each other.

Thus, inside each splitter 6, a core hole 8 is formed which extends longitudinally from the handle portion 2 toward the tip portion 5. The shape and size of the cross section of this core hole 8 differ depending on the part of the bamboo sword, and the handle part 2 and the tip part 5 have circular holes 8a and 8c.
The cross-sectional shape of the core hole 8b of the blade portion 4 is formed in the shape of a long hole elongated in the circumferential direction. As described above, the cross section of the core hole 8 differs depending on the part of the shinai, but it is preferable to set the dimension so that it changes continuously along the longitudinal direction.

Furthermore, according to the present invention, a reinforcing core material 10 made of reinforced plastic is press-fitted into the core hole 8 of each splitter 6 over substantially the entire length thereof. The reinforcing core material 10 in the illustrated embodiment is a bar with a circular cross section, and its material is made of glass fiber reinforced plastic, carbon fiber reinforced plastic, plastic reinforced with carbon and glass fiber, etc. ing. In addition, this reinforcing core material 10 is inserted into the circular hole without any gap in the parts of the handle part 2 and the tip part 5, but in the blade part 4, the reinforcing core material 10 is inserted almost in the center of the core hole 8b. Press-fitted with 1 air gap on both sides
1 and 11 are formed. Note that the reinforcing core material 10 described above is usually press-fitted from the tip 5 toward the handle 2 side.

Further, in order to prevent the entire bundled split pieces 6 from shifting in the radial direction, a dowel protrusion 12 is formed on one of the boundary surfaces of the adjacent split pieces 6, and the dowel protrusion 12 is formed on the other side. A receiving hole 13 into which the holder fits is formed (see Fig. 2).

Further, a handle leather 14 is attached to the handle part 2 of the bamboo sword, and a tip leather 15 is attached to the tip 5 of the sword.

As mentioned above, since the splitter 6 is molded from a plastic material, there are no knots like in natural bamboo material. Therefore, in order to simulate bamboo material in appearance,
It is preferable to form an artificial joint 16 as shown in FIG.

[Effect of idea]

As is clear from the above description, according to the present invention, a longitudinal core hole is formed inside the splitter that makes up the blade, and a reinforcing core material made of reinforced plastic is inserted into the core hole, leaving a gap. Because the shinai was press-fitted with a shinai made of natural bamboo, it can be made lightweight, and when struck, it emits a sound similar to that of a bamboo shinai. It can provide a feeling of use that is very similar to that of a bamboo sword. Furthermore, since the reinforcing core material is housed inside the splitter, the fibers will not scatter to the outside. Further, by adding a reinforcing core material, bending rigidity can be improved and a bamboo sword with excellent durability can be provided.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a bamboo sword manufactured according to the present invention, Fig. 2 is a cross-sectional view showing a cross-section of the handle, and Fig. 3 is a cross-sectional view showing a cross-section of the blade. ,
Figure 4 is a cross-sectional view showing the cross section of the tip of the sword, Figure 5
The figure is a side view showing nodes formed on the surface of the splitter. 1...Bamboo sword, 2...Handle, 4...Blade, 5...
... Sword tip, 6... Split, 7... Center hole, 8... Core hole, 10... Reinforcement core material, 11... Void.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a bamboo sword constructed by bundling a plurality of warikos, each of the warikos is molded from a plastic material, and within the wariko are a handle, a blade, and a tip. A core hole is formed that runs vertically through the blade in the longitudinal direction. A reinforcing core material made of aluminum is inserted, and the reinforcing core material is press-fitted into the core hole in the handle and tip portions without any gaps, and in the blade portion, it is located approximately in the center of the core hole, and the reinforcing core material is press-fitted into the core hole in the sword tip portion, and is located approximately in the center of the core hole in the blade portion. A bamboo sword characterized by a gap being formed between the inner walls on both sides in the circumferential direction and the reinforcing core material. 2. The bamboo sword according to claim 1, wherein the reinforcing core material is made of glass fiber reinforced plastic. 3. The bamboo sword according to claim 1, wherein the reinforcing core material is made of carbon fiber reinforced plastic.