JPH0141997B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sound hole device for a plastic whistle,
This invention aims to facilitate the shaping of a flute and to optimize pitch, sound quality, and volume.

As shown in Fig. 2, the sound hole A of the flute has the same diameter as the inner wall surface B and the outer wall surface C of the pipe body D, or the diameter of the outer wall surface C is smaller than the diameter of the inner wall surface B. Ideally, however, if the whistle is made of plastic, the diameter of the outer wall surface C of the tone hole A should be smaller than the diameter of the inner wall surface B of the tone hole A, as shown in Figure 3, in order to make it easier for the mold pin that forms the tone hole to come out. The mold pin cannot be removed unless it is formed into a wide taper with a large diameter that is so small that it cannot be seen visually. If the diameter of the outer wall surface C is made larger than the diameter of the inner wall surface B, the standing wave flowing inside the pipe will be cut by the inner wall surface B of the sound hole A, and sound will be generated on the inner wall surface B. Therefore, the sound waves that generated the sound will be transmitted to the outer wall surface. The part of wall thickness E before reaching point C becomes turbulent, making it impossible to generate a clean, beautiful, unmuffled sound. This is the fate of plastic whistles and has not been studied deeply, and the fact is that there are whistles on the market that have sound holes that have a larger diameter on the outer wall surface C than the diameter on the inner wall surface B, although the diameter is extremely small in reality. Such flutes cannot produce the beautiful, clear sound quality unique to flutes.

In order to create an ideal standing wave inside the pipe,
As mentioned above, in contrast to the sound hole A in which the diameter of the outer wall surface C is larger than the diameter of the inner wall surface B, the diameter of the inner wall surface B needs to be larger than the diameter of the outer wall surface C. In the past, a whistle such as the one shown in JP-A-54-48218 is already known as a so-called tapered sound hole in which the diameter of the outer wall is small and the diameter of the inner wall is large. There is. However, in such a sound hole with a tapered cross section, the internal volume as a sound hole chamber is actually limited, so the air pressure inside the tube through the sound hole cannot be released sufficiently, and therefore the tube Since the formation of standing waves within the body cannot be completely achieved, there is a problem in that even with such structural improvements, it is not possible to substantially generate a distinctive and beautiful tone.

The present invention solves the above-mentioned problems with conventional whistles, and aims to provide more beautiful tone, volume, and sound quality. In order to sufficiently perform the release action, the sound hole type is fitted with a sound hole shape having a dome shape with a small diameter on the outer wall surface and a large diameter on the inner wall surface and a large internal volume. It is something to do.

Embodiments of the present invention will be described in detail with reference to the accompanying drawings. As shown in FIG. An insertion hole 7 is formed into an outwardly expanding taper and has a shape corresponding to the external shape of the tone hole type, such as circular, square, or circular. If there is no tsuba in the tone hole shape, step 8
does not form. 9 is a sound hole type when a flange 10 is formed around the periphery, and the flange 10 has a shape and size that allows it to fit tightly into the step 8 of the insertion hole 7, and the leg portion 11 can fit tightly into the insertion hole 7. A dome-shaped sound hole chamber 14 having a large inner wall surface 12 and a small outer wall surface 13 is provided in the center of the sound hole shape 9. The sound hole chamber 14 may have an arc shape as shown in FIG. 5, as long as the inner circumferential surface bulges out and the internal space volume is substantially expanded, or it may have a plurality of shapes as shown in FIG. 6. It may have a stepped portion 17. This sound hole type 9 has a leg 11 inserted into the insertion hole 7 of the tube body 2, and a collar 10 inserted into the step 8.
The sound hole device is tightly fitted and fixed with adhesive or other means so that no space is created between the inner wall of the insertion hole 7 and the leg portion 11 and between the step 8 and the collar 10. form. In the figure, 1 indicates the mouthpiece, and 4 indicates the tail tube.

In the sound hole device of the present invention, the sound hole chamber 14 in the sound hole type 9 is formed into a dome shape with a small diameter on the outer wall surface and a large diameter on the inner wall surface, as described above, compared to conventional sound holes of this type. This allows the spatial volume of the sound hole chamber to be set much larger, and as a result, the movement of air molecules within the expanded sound hole chamber approaches the outside air outside the tube, causing the tube to flow through the sound hole chamber. It is possible to release the internal air pressure extremely efficiently,
This has the effect of being able to obtain a clear and beautiful tone with so-called clear sound.

[Brief explanation of drawings]

Fig. 1 is a side view of a whistle embodying the present invention, Figs. 2 and 3 are partial sectional views of the whistle showing the shape of the conventional tone hole, and Fig. 4 is a side view of a whistle implementing the tone hole device of the present invention. FIGS. 5 and 6 are partial cross-sectional views of the whistle, FIGS. 5 and 6 are cross-sectional views of the sound hole type in the sound hole device of the present invention, and FIG. 7 is a plan view of the sound hole type. In the figure, A, 3: sound hole, B, 5: inner wall surface, C, 6: outer wall surface, D, 2: pipe body, 1: mouthpiece, 4: tail pipe, 7: insertion hole, 8: step. , 9: Sound hole type, 10: Tsuba, 11: Leg, 12: Inner wall surface, 13: Outer wall surface, 14: Sound hole chamber, 17: Step part.

Claims (1)

[Scope of Claims] 1. An insertion hole with a large diameter on the outer wall surface and a small diameter on the inner wall surface, which is formed at each sound hole position of the plastic flute pipe body, has a small diameter on the outer wall surface and a large diameter on the inner wall surface. A sound hole device for a plastic whistle made by tightly fitting and fixing a sound hole with a dome-shaped sound hole. 2. The tone hole device for a plastic whistle according to claim 1, wherein the dome-shaped inner circumferential surface of the tone hole is formed by a plurality of steps. 3. A tone hole device for a plastic whistle according to claim 1 or 2, which has a flange on the upper edge of the outer peripheral surface of the tone hole type.