JPH0520114B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing split bamboo for bamboo swords used in kendo.

Conventional technology Kei bamboo, which has been used for splitting bamboo for bamboo swords since ancient times, has excellent bast fibers and is highly elastic, but the inherent properties of bamboo, such as cracking and splitting, cannot be avoided. This is becoming a serious problem in terms of safety.

In addition, natural bamboo is not uniform in quality, making it difficult to maintain a constant quality when splitting bamboo for commercialized bamboo swords.

On the other hand, split bamboo for bamboo swords made of plastic containing glass fibers or carbon has excellent mechanical properties, product uniformity, and productivity, but on the other hand, it has a natural texture and taste such as the strange sounds it makes during meetings. It is not even close to bamboo.

Therefore, in order to eliminate the negative impact that bamboo's inherent splitting properties have on safety, without impairing the texture of bamboo or the wonderful sounds it makes during meetings, the applicant has developed A split bamboo bamboo sword coated with synthetic resin was proposed as Utility Model No. 64-19470.

By the way, natural bamboo has many nodes, so
The bamboo material, which is split along the longitudinal direction, has protrusions here and there on its front and back surfaces, and each piece has a different shape.

Therefore, even if a synthetic resin is placed around the bamboo material using an adhesive and pressed from the outside with a roller, etc., the synthetic resin will rise at the boundary between the convex portion and the flat portion, making it difficult to use the material for a long period of time. The synthetic resin tended to peel off during the process.

Problems to be Solved by the Invention An object of the present invention is to be able to tightly cover the uneven surface of natural bamboo material with a synthetic resin sheet, and to prevent the synthetic resin sheet from peeling off even after long-term use. The purpose of the present invention is to provide a method for manufacturing split bamboo for bamboo swords.

Means for Solving the Problems In order to achieve the above-mentioned object, the method for producing split bamboo for a shinai of the present invention is to provide softened synthetic resin at least on the outer periphery of the striking part of the bamboo material split along the longitudinal direction of the stem. After curing, the synthetic resin is cut along the longitudinal direction at the section located on the node side of the bamboo material, and this is peeled off to form a cylindrical synthetic resin sheet having cracks in the longitudinal direction. , the synthetic resin sheet is coated on at least the outer periphery of the batting part of the bamboo material with an adhesive so that the split is on the node side of the bamboo material, and a thread is immediately wrapped around the outer surface of the sheet and tightened. , the thread is removed after the adhesive has dried.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

In FIG. 1, 1 is a split bamboo of a bamboo sword, and the split bamboo 1 extends at least to the outer periphery of the striking part of the bamboo material 2 split along the longitudinal direction of the stem, that is, between the tip leather and the nakakubi. It is formed by covering a synthetic resin sheet 4 with an adhesive 3 interposed therebetween.

As shown in FIGS. 2 to 4, the bamboo material 2 is formed from one long piece of bamboo, and the front surface 2a of the bamboo material 2 has a plurality of joints 5, and the back surface 2b of the bamboo material 2
has a protruding node 6 at a position corresponding to node 5,
The handle side 7 is made thicker than other parts, and the surface 2 of the bamboo material 2
Slopes 9a and 9b are formed along the longitudinal direction on both sides of a and back surface 2b, respectively, and the joints of each slope are chamfered with a curved cross section, and the width of the bamboo material 2 is wider than the handle side 7 to the tip side 8. It gradually gets wider halfway towards the end, and gradually tapers towards the tip of the tip.

As shown in FIG. 5, the joint 6 protrudes at right angles on the handle side 7 and the tip side 8, and engages the engaging portion 1.
0 is formed, and in the intermediate portion 11, a protrusion 12 whose back surface is cut into a flat shape is formed.

To manufacture the split bamboo 1, first, a synthetic resin 4' such as nylon, which is highly abrasion resistant and has a feel similar to natural bamboo, is softened on the outer periphery of at least the striking part of the bamboo material 2 as described above. Cover. At this time,
It is preferable that the front surface of the bamboo material 2 serving as the striking surface be coated with a synthetic resin 4' to a thickness of 4 to 7 mm, and the side and back surfaces to a thickness of 2 to 3 mm. Next, after the synthetic resin 4' has hardened, the part located on the node 6 side of the back side of the bamboo material 2 is cut along the longitudinal direction as shown in FIG. 6, and the synthetic resin 4' is peeled off from the bamboo material 2. As a result, a cylindrical synthetic resin sheet 4 having splits 14 along the longitudinal direction as shown in FIG. 7 is formed. Therefore, the inner peripheral shape of the synthetic resin sheet 4 is exactly the same as the outer surface shape of the bamboo material 2. In addition, the synthetic resin 4' is added to the bamboo material 2.
It is also possible to form a synthetic resin sheet 4 covering the entire length of the bamboo material 2.

Next, the synthetic resin sheet 4 is first placed on the outer periphery of the bamboo material 1.
Apply adhesive 3 such as epoxy adhesive to the part where you removed the
, and then a synthetic resin sheet 4 on the outer surface.
is covered so that the splits 14 are on the node 6 side on the back side of the bamboo material 2.

Of course, the adhesive 3 may be applied to the back surface of the synthetic resin sheet 4 instead of being applied to the bamboo material 2. Furthermore, if the synthetic resin sheet 4 is made the same color as the natural bamboo, there will be no discomfort, and the joint between the synthetic resin sheet 4 and the exposed portion of the bamboo material 2 will not be noticeable.

Next, as shown in FIG. 8, a strong thread 13 is tightly wound around the outer surface of the synthetic resin sheet 4 and tightly tightened, the adhesive 3 is dried, and the thread 13 is removed after drying.

Note that by using the thermosetting adhesive 3 and drying it by heating, and at the same time shrinking the synthetic resin sheet 4, the synthetic resin sheet 4 is brought into closer contact with the surface of the bamboo material 2.

Effects of the Invention As described above, the method for producing split bamboo for a shinai of the present invention involves coating the outer surface of a bamboo material with a softened synthetic resin, and then peeling it off from the bamboo material after it has softened to form a cylindrical synthetic resin sheet. As a result, the inner circumferential shape of the synthetic resin sheet and the outer surface shape of the bamboo material are exactly the same,
When the synthetic resin sheet was coated on the bamboo material, they were in close contact with each other without any gaps, and since the outer surface of the synthetic resin sheet was tied tightly with threads without any gaps until the adhesive dried, the outer surface of the bamboo material could be coated along the unevenness. The thread is attached and a synthetic resin sheet is pressed onto the surface of the bamboo material. For this reason, even if the bamboo material is a natural bamboo material with a complex cross-section that varies from piece to piece, the synthetic resin sheet will not lift up from its outer surface, and the synthetic resin sheet will not easily peel off even after repeated blows over a long period of time. Since the synthetic resin sheet is cylindrical, it does not lose its shape when the thread is wound around it, making it easy to work with.

In addition, since the splits of the synthetic resin sheet are placed on the node side of the bamboo material, when the split bamboo is assembled, the splits are not visible from the outside, and both ends of the synthetic resin sheet are placed on the tip of the bamboo sword and the middle knot. It is then hidden away.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of split bamboo for a Shinai sword according to an embodiment of the present invention, FIG. 2 is a side view of the bamboo material, and FIG.
Figure 4 is a top view of the same as above, Figure 4 is a bottom view of the same as above, Figure 5 is a perspective view of bamboo material when synthetic resin is applied, Figure 6 is
FIG. 7 is a perspective view of the split bamboo when the synthetic resin is cut, FIG. 7 is a perspective view of the synthetic resin sheet, and FIG. 8 is a perspective view of the split bamboo when it is wound with thread. 1...Split bamboo, 2...Bamboo material, 3...Adhesive, 4...
...Synthetic resin sheet, 4'...Synthetic resin, 6...Section,
3...thread, 14...split.

Claims (1)

[Claims] 1 Coating at least the outer periphery of the striking part of the bamboo material split along the longitudinal direction of the stem with a synthetic resin in a softened state,
After curing, the synthetic resin is cut along the longitudinal direction at the section located on the node side of the bamboo material, and this is peeled off to form a cylindrical synthetic resin sheet having cracks in the longitudinal direction. A sheet is coated on at least the outer periphery of the batting part of the bamboo material with an adhesive so that the split is on the node side of the bamboo material, and then a thread is quickly wrapped around the outer surface of the sheet and tightened. A method for producing split bamboo for a bamboo sword, which comprises removing the threads after the agent has dried.