JPH0549994B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a soundboard for a stringed musical instrument that is easy to manufacture and is capable of sufficiently and favorably producing sounds from the low range to the high range. [Prior Art] The soundboard of a stringed instrument, such as a piano, transmits and amplifies the vibrations of the strings to the entire soundboard, and produces good sound to the outside.The quality of the piano's sound depends on the quality of its materials, structure, etc. It is no exaggeration to say that this primarily determines the volume and duration of the sound. Therefore, the soundboard is required to be light in specific gravity, highly elastic, absorb little vibration energy, and vibrate evenly and well, especially from the bass to the treble. For this reason, soundboards have traditionally been made of Japanese pine, spruce, etc., but constructing them only from such natural materials is extremely expensive and requires processes such as material selection, wood removal, and chiseling. Not only is it complicated, but the specific elastic modulus E/ρ (E: Young's modulus, ρ: density) is limited by the value specific to the wood, so it is impossible to achieve a higher sounding efficiency than a certain level. For these reasons, a sandwich structure soundboard has recently been proposed in which a core material of low specific gravity such as foam is used and wood veneers are laminated and bonded on both sides of the core material. However, in such soundboards, the shear modulus of the core material is small and the shear loss is large, so
In particular, the high frequency response, volume, and sound extension were lacking, and the overall sound balance was poor. [Summary of the Invention] This invention has been made in view of the above-mentioned points, and its purpose is to produce well-produced sounds from the low range to the high range, and to obtain a well-balanced sound. The object of the present invention is to provide a soundboard for a stringed instrument, which is composed of a core material, a front plate made of wood and a back plate made of wood, which are respectively bonded to the front and back surfaces of the core material. is made of a material such as wood, metal, or composite material that has a higher shear modulus or a lower shear loss tangent than the front plate and the back plate. [Example] Hereinafter, the present invention will be described in detail based on an example shown in the drawings. FIG. 1 is a perspective view of essential parts showing an embodiment of a soundboard for a stringed musical instrument according to the present invention. In the figure, a soundboard 1 is constructed by laminating and bonding a front plate 2 and a back plate 3 made of wood veneer to the front and back surfaces of a core material 4, respectively. The surface plate 2 is formed by arranging a plurality of spruce veneers 2a to 2j in the lateral direction with their grain directions (arrow A direction) aligned. Similarly, the back plate 3 is formed by arranging a plurality of spruce veneers in the lateral direction with their grain directions aligned. Surface plate 2
and the back plate 3 are joined to the front and back surfaces of the core material 4 with their grain directions aligned, and have the same plate thickness (for example, 4 mm). As the core material 4, a pad with a plate thickness of 2 mm is used, but in addition to this, the core material 4 may have a higher shear modulus G than the front plate 2 and the back plate 3, or
A material with low shear loss, preferably a material with both properties, is preferred. For example, in the case of wood, materials such as Japanese cedar and oreono are used; in the case of metals, materials such as aluminum, magnesium, and titanium are used; and in the case of composite materials, materials such as carbon fiber reinforced resin (CFRP) and glass fiber reinforced resin (GFRP) are used. In addition, when the core material 4 is formed of the above-mentioned wood, it is arranged so that the grain direction of the wood grain direction is parallel to the grain direction of the front board 2 (back board 3). Next, the shear modulus G and shear loss tangent of spruce, padock, rice cedar, aluminum, and CFRP are
Tan〓 is shown in a table.

〔Effect of the invention〕

As explained above, the soundboard for a stringed instrument according to the present invention includes a core material, and a front plate and a back plate that are laminated and bonded to the front and back surfaces of the core material, and the core material is bonded to the front and back surfaces of the core material. Since it is made of wood, metal, or a composite material that has a higher shear modulus or a lower shear loss tangent than the back plate, the sound quality, volume, and sound extension of each range are improved, and the overall sound quality is improved. You can get a well-balanced sound. Therefore,
This can have a very large effect on improving the performance of musical instruments.

[Brief explanation of drawings]

Fig. 1 is a perspective view of essential parts showing an embodiment of a soundboard for a stringed musical instrument according to the present invention, and Fig. 2 is a graph showing the relationship between shear loss tangent tan〓 and frequency (Hz) of various soundboards. be. 1...Soundboard, 2...Front board, 3...Back board, 4
...core material.

Claims (1)

[Scope of Claims] 1. A core material 4, a front plate 2 made of wood and a back plate 3 made of wood, respectively bonded to the front and back surfaces of this core material 4.
The core material 4 is made of wood, metal, or a composite material that has a higher shear modulus or a lower shear loss tangent than the front plate 2 and the back plate 3. Soundboard for stringed instruments.