JPS6021094A - Guitar - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a guitar with improved acoustic characteristics and durability.

[Prior art]

It is well known that the guitar as a stringed instrument is divided into two types: the guitar as a natural musical instrument that amplifies the vibrations of the strings in a resonator body and radiates them into the air; There are two types of electric guitars that emit sound, but they all have one thing in common: they consist of a body, a neck, and multiple strings. Fig. 1 shows a conventional example of a solid-type electric guitar, especially the body 2 that constitutes the guitar body 1. The neck body 3 and the fingerboard 4 are usually made of wood with excellent acoustic properties because they do not have a significant effect on sound quality.

In other words, if the body body 2 is made of wood with a high density and hardness, thick and rounded deep bass sounds will be obtained.On the other hand, if the material is light and soft, deep bass sounds will be produced. You can get a sound that isn't there. For this reason, the body main body 2 and the neck main body 3 are made of maple.

It is made from a single piece of wood such as beech, birch, mahogany, or plywood.

However, wood has the disadvantage that it is easily warped or twisted due to changes in temperature, humidity, etc., and has poor dimensional stability. Furthermore, in the case of wood, even if the wood is of the same type, there are some with dense grains and others with sparse grains, resulting in different densities, resulting in variations in quality.

In addition, wood is expensive, difficult to obtain, and requires extensive nail seasoning.

Therefore, recently carbon fiber reinforced resin (CF) is being used instead of wood.
It is known that the body body 2 or the neck body 3 is made from RP) or the like. These fiber-reinforced resins have better dimensional stability than wood, and have a significantly higher density and hardness, which improves the extension of sound, but they also have the characteristics of being heavy and having a metallic sound. Therefore, the neck body 3 has been made to have a hollow structure, but in this case, unnecessary resonance occurs and the acoustic characteristics are deteriorated.

[Summary of the invention]

This invention was made in view of the above points,
By making at least one of the body body and the neck body from fiber-reinforced foamed resin, it is possible to obtain sound quality and sound extension that are intermediate between those of wood and fiber-reinforced resin, improving acoustic characteristics and also being able to withstand changes in temperature, humidity, etc. To provide a guitar that has good dimensional stability and improved durability.

[Example] Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 2 is an exploded perspective view showing an embodiment in which the present invention is applied to an electric guitar. In the figure, a body body 11 and a neck body 12 of an electric guitar 10 are integrally molded from fiber-reinforced foamed resin, which will be described later.
A fingerboard 13 made of hard wood or the like is adhesively fixed onto the fingerboard 2 . In addition, in the figure, 14 is a microphone, 15 is a bridge, 1
6 is the tailpiece, 17 is the knob, 18 is the fret, 1
Reference numeral 9 indicates strings, and since these are not directly related to the present invention, detailed explanations of their structures and the like will be omitted.

Now, one embodiment of the fiber-reinforced foamed resin constituting the body main body 11 and the neck main body 12 will be explained based on FIG. It is formed into a plate shape by alternately stacking continuous fiber layers 21 of fibers for use and short fiber mat layers 22 of reinforcing fibers. In addition, 23 is a continuous fiber of the reinforcing fiber forming the continuous fiber layer 21, and 24 is a closed cell.

High-strength fibers for reinforcing foamed resin include carbon fiber, glass fiber, aramid fiber, and metal fiber.

Highly elastic fibers are used, and carbon fibers are preferably used. These fibers usually have a diameter of several microns to more than ten microns, and are preferably arranged so that the direction of the fibers coincides with the longitudinal direction of the neck body 12.

Foamed resin is epoxy resin or polyester resin.

Thermosetting resins such as polyurethane resins, acrylic resins,
A thermosetting resin such as polyamide resin foamed using a common foaming agent is used.

Incidentally, azodicarbonamide and dinitropentamethylenetetramine are suitable as blowing agents for epoxy resins.

The short fiber mat layer 22 is made by stacking short fibers made of the above-mentioned reinforcing fibers and having a fiber length of about 1 to 50 fibers, oriented in random directions in a two-dimensional plane, and each fiber is completely resolved. It is preferable that it is made of fiber. This short fiber mat layer ensures free movement of the closed cells 24 in the lamination direction of the continuous fiber layer 21 and the short fiber mat layer 22 during foaming of the resin, which will be described later. Therefore, the volume ratio of the short fiber mat layer 22 to the continuous fiber layer 21 is restricted to 2% or more and 100% or less.

To explain an example of a method for manufacturing the body body 11 and neck body 12 made of the fiber-reinforced foamed resin 20 as described above, first, carbon fibers arranged in a sheet shape parallel to each other in one direction are foamed with 100 parts of epoxy resin. Agent 9
A prepreg sheet of continuous fibers is made by impregnating the mixed foamed resin and pre-curing it. Further, a short fiber mat made of carbon fiber is prepared, and the aforementioned foamed resin is impregnated into the mat and precured to prepare a short fiber mat prepreg sheet.

Next, continuous fiber prepreg sheets and short fiber prepreg sheets are alternately laminated, and this laminate is placed in a predetermined mold and heated and pressurized to simultaneously foam and cure the epoxy resin. , a body main body 11 and a neck main body 12 having a desired shape and thickness are integrally formed.

Here, the physical properties of the fiber-reinforced foamed resin, 1R fiber-reinforced resin, and wood (maple) are shown in the table.

〔table〕

As is clear from the table above, fiber-reinforced foamed resin has physical properties that are intermediate between fiber-reinforced resin and maple wood, so it has better sound extension and has a heavier feel than wood. Compared to resin, it is lighter and has less sound elongation, so it does not produce a metallic sound, yet still provides a gorgeous sound quality.

In addition, like fiber-reinforced resin, fiber-reinforced foam resin has good dimensional stability because it does not distort due to temperature and humidity, and has a higher Young's modulus than wood, so the neck body can be bent by 120 degrees due to the tension of the strings. This can be prevented, and since the specific gravity is smaller than that of fiber-reinforced resin, there is no need for the neck body 12 to have a hollow structure.

In addition, in the case where the body body and the neck body are formed separately and are combined into a single body, vibration transmission loss occurs at the joint part, but the above-mentioned through body body 1
1 and the neck body 12 are integrally formed from the same material, transmission loss is reduced, vibration damping characteristics are improved, and the structure is strong enough to withstand the tension of the strings.It is also easy to manufacture and improve productivity. It has the following advantages:

Note that the specific gravity of the fiber-reinforced foamed resin can be freely changed from about 0.6 to 1.5 by changing the expansion ratio. Similarly, Young's modulus and shear modulus are also determined by the continuous fiber layer 21.
It can be freely changed by changing the specific gravity by changing the blending ratio of the short fiber mat layer 22 and the short fiber mat layer 22. Therefore, compared to fiber-reinforced resin, fiber-reinforced foamed resin can be manufactured with desired physical properties, and the sound quality can be easily improved.

In addition, although the above embodiment describes the case where the body main body 11 and the neck main body 12 of a solid electric guitar are integrally formed with fiber-reinforced foamed resin, the present invention is not limited to this in any way, and the body main body 11 and neck body 1
It goes without saying that the present invention can also be applied to a guitar in which only one of the above two is made of fiber-reinforced foamed resin, an acoustic electric guitar, or a guitar as a natural musical instrument.

〔Effect of the invention〕

As described above, the guitar according to the present invention has at least one of the body and the neck made of fiber-reinforced foamed resin. Although there is no typical sound, a gorgeous sound can be obtained, and a guitar with excellent acoustic characteristics can be provided.

In addition, the physical properties can be easily controlled, the desired sound quality can be obtained, there is little variation in quality, and there is little influence from temperature, humidity, etc., resulting in good dimensional stability and improved durability.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing an example of a conventional solid electric guitar, Fig. 2 is an exploded perspective view showing an embodiment of the present invention applied to a solid electric guitar, and Fig. 3 is a fiber-reinforced foam. FIG. 3 is a perspective view showing a model of a resin cut away in the thickness direction. 11...Body body, 12...Neck body, 1
3... Fingerboard, 20... Fiber-reinforced foamed resin, 21
... Continuous fiber layer, 22 ... Short fiber mat layer, 2
3: Continuous fiber, 24: Closed cell. Patent applicant: Nippon Musical Instruments Manufacturing Co., Ltd. Agent: Masaki Yamakawa (and one other person)

Claims (1)

[Claims] A guitar characterized in that at least one of the body and the neck is made of fiber-reinforced foamed resin.