JP3239894U - Structure to prevent slackness of sanshin winding - Google Patents

Abstract

To provide a structure for preventing slackness of a peg, which enables the peg to be gripped and turned without significantly changing the appearance of the top of the sanshin and the peg, and which can reliably prevent the peg from loosening during a performance. SOLUTION: The slack prevention structure for the bobbin of the sanshin is a bearing in which a core rod made of carbon fiber, which is hard to break and has a constant thickness, is inserted into the center hole of the bobbin and fixed by adhesion, and the free end side is inserted and supported. The hole side consists of a rigid or elastic cylinder or tube, which has a constant diameter and does not fluctuate the frictional force, thus eliminating the drawback of string slack. [Selection drawing] Fig. 2

Description

The present invention eliminates metal parts such as pegs and bolts while maintaining the appearance of the bobbin without significantly changing the appearance of the top and bobbin of a traditional sanshin. That is, in the structure for preventing slackness of the peg of the sanshin, a portion of the peg, that is, the contact portion with the rod is improved, so that breakage of the core rod portion and loosening of the strings can be reliably prevented. In particular, to reliably prevent sudden loosening of the peg during a performance, and realize a structure that allows women, children, and the elderly to easily turn the peg with weak force.

The structure of the bobbin of the sanshin has not changed since the sanshin was invented over 600 years ago. Moreover, the contact part with the sanshin pole is tapered, so it is easy to pull out to the thick outside.
During production, a hole for inserting the spool is made in the rod with a taper reamer to make a bearing hole for inserting and supporting the spool, but the taper reamer itself is not a tool for drilling, so it cannot be opened smoothly. Moreover, when drilling holes for the younger brother 1 string and younger brother 3 strings, it is particularly difficult to drill diagonally on the rod, and the repulsive force may shave off a lot of the soft parts of the wood, and the hole may be oval due to camera shake. become. Some craftsmen use electric tools for drilling, but when using electric tools, the holes are not drilled accurately, and the holes are elliptical.
The work of drilling the bearing holes for the insertion support is very important, and the end of the karakui insertion is the most affected. Furthermore, since the taper reamer is not used for drilling holes, many cross-sectional defects are observed. In the case of scraping the bobbin with a file, it is manually scraped with a file while turning the bobbin itself.

Utility model registration younger brother No. 3141612

The technique of Patent Document 1 realizes a structure that can reliably prevent loosening of the bobbin without significantly changing the structure of the head of the traditional sanshin, and without forcibly providing a reverse taper. For the purpose of doing so, the spindle of the bobbin is inserted into the bearing cylinder glued and fixed in the bearing hole of the bobbin support of the sanshin, and its non-circular outer end is inserted into the non-circular hole on the side of the grip bar. At the same time, since the threaded rod is inserted from the outside into the central cylindrical hole of the grip rod and the male threaded portion at the tip is screwed into the female threaded portion at the outer end of the bobbin, there is friction when gripping the bearing cylinder from both the front and rear sides. It is possible to prevent loosening of the spool by force, and by adjusting the tightening force of the screw rod, loosening can be suppressed by a constant frictional force.

The technique disclosed in Patent Document 1 requires a large number of parts, a complicated structure, and a high cost, which hinders popularization of the sanshin. Moreover, it is not possible to reliably prevent string tuning failure due to a decrease in frictional force.

The tuning for manipulating the bobbin of the existing sanshin is a little special, and some people are frustrated because they cannot practice sanshin at home because they cannot perform this operation. As a result, it hinders the popularization of sanshin enlightenment. Especially for beginners, it can be said that it is the first major barrier to mastering the sanshin. To operate the bobbin of the sanshin, to operate the male and female strings, hold down the rod with your thumb and hold down the head of the karakui (pincushion) with your little finger. The strings are tuned by turning the karakui (pincushion) with the index finger, middle finger, and ring finger. When tuning the sanshin, it is difficult for most beginners to learn how to tune the sanshin, as the strings are turned while checking the scale.

In the sanshin classroom, most of the students are unable to tune the strings, so teachers tend to tune the strings. However, even if the strings are tuned, there are many cases where practice does not proceed smoothly due to the lack of friction between the karakui (thread winding) and the sanshin pole, which loosens the thread winding. This is the bottleneck in the popularization of the sanshin.

The appearance of the grip portion where the bobbin is gripped by hand does not change, but a hard-to-break cylindrical core rod made of carbon fiber or the like is inserted into the circular hole in the center of the bobbin and fixed by adhesion. The side of the bearing hole where the free end side of the core rod rotates and slides is a tight hole with high frictional force. Since the cylindrical core rod is inserted into and supported by the bearing hole provided in the rod of the sanshin, frictional force is ensured, and even if the grip portion of the bobbin winding body is gripped and pulled, it will not come off even if it is pulled. There is no thread wound structure.

Since the pincushion structure with strong frictional force can be created in this way, it is possible to prevent the strings from loosening while the sanshin is being played. Also, even if the string is tuned, the friction between the karakui (thread winding) and the sanshin pole is insufficient, and the thread winding loosens, preventing practice from progressing.
The appearance of holding the bobbin by hand does not change, but a cylindrical core rod made of carbon fiber that is hard to break is inserted into the circular hole in the center of the bobbin and fixed by adhesion. The bearing hole side where the free end side of the core rod rotates and slides should be a precise insertion hole or cylinder with high frictional force. A hard material or an elastic material such as rubber or soft synthetic resin may be used. Since a cylindrical core rod is inserted into the bearing hole on the rod side and supported, a frictional force is ensured, and a "non-loosing" bobbin structure is obtained so that even if the bobbin body is pulled, it does not come off.
The core rod insertion support hole may be formed by mixing ebony powder and adhesive. At this time, the inner surface of the insertion support hole is compressed and hardened so that the cylindrical core rod can be tightly inserted thereinto.

FIG. 5 is a cross-sectional view showing a conventional tapered friction portion; FIG. 3 is a cross-sectional view showing a friction portion according to the present invention;

Next, a detailed description will be given of a configuration for implementing the structure for preventing slackness of the sanshin winding according to the present invention. As shown in FIG. 1, conventionally, the tapered portion 3 that inserts and supports the spool 1 on the rod 2 by frictional force consists of a tapered axial surface 31 of the spool 1 and a tapered hole 32 on the rod 2 side. When pushed to the 2 side, the tapered portion 3 becomes thicker and the frictional force becomes stronger, and when pulled conversely, the tapered portion 3 becomes thinner and the frictional force becomes weaker. Since the frictional force changes due to the taper, the string may become loose during performance, causing a problem.

On the other hand, in the present invention, as shown in FIG. 2, a core rod 4 made of carbon fiber and made of carbon fiber and having a constant thickness is inserted into a circular hole 5 at the center of the spool 1 and fixed by adhesion. . An insertion hole 6 for the core rod 4 is formed by mixing ebony powder and an adhesive on the side of the bearing hole 6 where the free end of the core rod 4 rotates and slides. At this time, it is preferable to compress and harden the insertion hole 6 side so that the cylindrical core rod 4 can be properly inserted. Note that the inner diameter is constant and does not change.
As a result, since the columnar core rod 4 is inserted and supported in the insertion hole 6 with high frictional force, a constant frictional force is ensured, and even if the bobbin main body 1 is pulled, it does not come off. structure.

In this way, a strong frictional force and a constant winding structure can be achieved, preventing the strings from loosening while the sanshin is being played. In addition, even if the strings are tuned, the lack of friction between the karakui (thread winding) and the sanshin pole will loosen the thread winding, preventing practice from progressing.
It should be noted that the cylindrical core rod 4 made of carbon fiber, which is hard to break, can be made into a rubber-like insertion support hole 6 of the same diameter, or the diameter of the core rod 4 side can be made larger and press-fitted. However, instead of the insertion support hole 6, a cylinder or tube 7 made of elastic rubber or soft synthetic resin may be used as a substitute for the hard insertion support hole 6. FIG.

As described above, conventional sanshin pegs use the frictional force of the tapered part, so there is a drawback that the strings loosen after tuning. The core rod is inserted into the center hole of the bobbin and fixed by adhesive, and the bearing hole side where the free end side is inserted and supported consists of a hard or elastic cylinder or tube. This eliminates the drawback of loosening.

1 spool 2 sanshin rod 3 tapered part
31 Tapered shaft surface
32 Tapered hole 4 Carbon fiber core rod 5 Circle hole in the center of spool 6 Bearing hole (insertion support hole)
(7) Rubber cylinders or tubes

Claims (1)

A core rod with a uniform thickness and made of a material that does not easily break is inserted into the center hole of the bobbin and fixed by adhesion. A slack prevention structure for a three-wire bobbin with a fixed diameter of the core rod or the bearing hole.

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