JP7497787B2 - Violins - Google Patents

Description

To provide a violin having good volume, tone and sound produced by effectively utilizing wood for the top and back plates during production.

Non-Patent Document 1. As shown in "Making a Violin" by Shoichiro Kawakami, violins are made by cutting a pair of thick logs (spruce or maple logs cut, dried, and cut to the required size, referred to as logs in this patent) into halves, with the top and back made of spruce (Western pine) and maple (maple), respectively, and gluing them together in the center, then shaving them to cut out the desired curved top and back. Only about 10% of the logs are effectively used, as the thick boards are shaved and the back center is hollowed out to adjust the thickness of each part and finished, and the rest becomes sawdust and is not used.

There have been attempts to make effective use of the top and back plates, for example, instruments made by compressing flat boards with high-pressure steam to make curved boards for the top and back plates, but these are used for beginners or practice, and are not highly regarded as instruments for skilled players. Pressurization can cause unevenness in the wood, such as high and low density and distortion, which affects the sound. In Patent Document 2, the top and back plates are flat and there is no waste of wood, but they are inexpensive for practice and not for skilled players.

As shown in Non-Patent Document 1, the top plate of a conventional violin is cut from 2.5 mm at its thinnest part to 3.5 mm at the center of the thickest part, an f-hole is drilled, and a straight brace 18 with a width of 5.5 mm is attached to the back side (see Figure 4). The top plate transmits vibrations from the bridge to the whole instrument and amplifies the sound by resonating with the back plate, but the braces are installed above and below the center of the top plate, and they also help transmit vibrations and strengthen the top plate. The brace is located slightly toward the bass side from the center, and a sound post is installed on the treble side. This system has been considered optimal. However, there is also a demand for an instrument with a louder volume that can withstand performance in a large hall.
In an attempt to meet the demand for instruments with a louder sound, Patent Document 3 proposes the installation of a sound post shaped to improve the contact area, but the basic structure of the top plate, braces, and transmission of vibrations to the back plate remains the same as in Non-Patent Document 1.

The back board is also carved out of a thick log in the same way as the front board, so a pair of halved boards are glued together in the middle, and the back board is cut to the required shape and thickness from a board that is about 30 mm thick and has the length and width.However, the thickness in the middle is only 4.5 mm, less than one-sixth the original, so wood efficiency is low.

In the reference document, Patent 2566703, Patent Document 1, a proposal is made to place the stiffeners on the G and E strings parallel to the strings, so that they are almost vertical along the grain, in order to improve the volume. However, a top plate with two stiffeners parallel to the strings coincides with the grain, making it vulnerable to cracking. Also, the sound post is said to be in contact with the stiffener on the E string side, but it seems that it is difficult to obtain good results. There is an improvement in the treble range, but the bass range is not satisfactory. There is no mention of the inefficiency of the wood.

Patent 2566703 Patent Publication 2018-205675 Patent 3307674

"Making a Violin" by Shoichiro Kawakami, Kinokuniya Bookstore

The manufacturing method for violins was established about 300 years ago and has not changed much since then. Now that performances are held in large halls, there is a trend toward a louder sound. On the other hand, from the viewpoint of environmental protection, excessive felling of wood must be avoided, and the supply of materials is getting worse, and the situation is expected to become even more serious in the future. In other words, materials will become precious from now on, and it will be necessary to manufacture better instruments using less materials.

The shape of a violin is complex and three-dimensional, and it is difficult to efficiently obtain more than two tops or backs from a log for one violin. However, it seems possible to do this by first cutting the log to a certain width, making several pieces of wood with trapezoidal cross sections and long, rectangular shapes (hereafter referred to as trapezoidal pillars), and then cutting out the desired number of thin, bow-shaped boards (hereafter referred to as arc-shaped boards) from each trapezoidal pillar and gluing them together to create a curved, three-dimensional object. This is because it is possible to efficiently cut out pieces of the same shape from thick wood. What should be noted here is that it is not enough to use any wood as long as the shape matches, but rather it is important to combine it to match the log. This maintains a quality that is roughly equivalent to that obtained when carved based on the grain, specific gravity, etc.

Specifically, the log is not split in two, but is first cut vertically along the grain into several trapezoidal columns. First, as an example of the top plate for a violin, as shown in [Figure 1], it is cut into six trapezoidal columns, each one 1/5 to 1/10 of the width of the central narrow part of the instrument (approximately 110 mm), for example 20 mm wide, and multiple arc-shaped pieces of the same shape with the required curves are cut out from each trapezoidal column (A3, B4, C5, D6, E7, F8). These arc-shaped pieces (a9, b10, c11, d12, e13, f14) are combined one by one to make multiple sets. By gluing each set together, multiple sets of three-dimensional shapes including curves can be obtained.

Violins are three-dimensionally symmetrical, so a pair of arcuate pieces is required, one for each side. Either an equal number of symmetrical pieces are made separately, or pieces with a little extra thickness are made and used upside down.

The bonding surfaces of the arc-shaped materials are smoothed, glued together with adhesive to create a rough-cut surface, which is then processed to create the surface. A strong adhesive is used, such as a two-part epoxy resin adhesive with bisphenol A as the main ingredient. Since the surface and back panels do not need to be disassembled and the adhesive removed later, a heat-curing type is fine. It is convenient to use as it has a curing time similar to that of animal glue. If you mix a small amount of paint of the same color as the raw wood, with a small amount of yellow and brown added to white oil paint, the adhesive will be less noticeable.

The maple logs for the back panel are processed in the same way as the front panel to produce the back panel.

To solve this problem, it is not enough to increase the effective use of raw wood; the performance of the instrument must be sufficient. The performance is improved by improving the back side of the top plate as follows.
1) A bass bass bar (hereafter simply referred to as a bass bar) with a width of 3 mm to 5 mm, preferably about 4 mm, is attached to the bass side, and a treble soprano bar (hereafter simply referred to as a soprano bar) is attached to the treble side, and the top and bottom are curved outward. 2) A connecting bar (hereafter simply referred to as a connecting bar) is attached to connect the bass bar, soprano bar, and top plate. These three bars (hereafter referred to as trio bars) are fixed to each other and to the top plate to support each other. The curved bar and the crossover with the grain of the top plate make the top plate less likely to crack, and each bar is less likely to fall over. The width of the brace in Non-Patent Document 1 is 5.5 mm, but in the case of the trio bar, the width can be narrower. By integrating the top plate, sufficient strength can be obtained. Since the strength of the top plate can be increased, the thickness of the top plate can be made slightly thinner. The thickness of the central part can be made thinner than the thickness shown in Non-Patent Document 1, 3.3 mm or less. For example, it can be made thinner, about 3 mm.

The analysis related to the sound of the center of the top plate is shown in "Table 1". Although the Triobar is strong, the plate between the two f-holes is thin and the volume is small, so the present invention is considered to be suitable for good sound production in comparison with the brace in Non-Patent Document 1.

本発明の体積計算は実施例１に基づく；巾ｘ長さｘ厚み、力木／トリオバーは長さｘ巾ｘ平均高さ。強度は表板を裏側に間隔７５ｍｍの２つの支えの間に置き、表側より荷重をかけて割れの有無を見た。特許文献１によるバイオリンはより低い荷重で割れを見た。

The volume calculation of the present invention is based on Example 1; width x length x thickness, and the brace/trio bar is length x width x average height. The strength was measured by placing the top plate between two supports spaced 75 mm apart on the back side and applying a load from the top side to check for cracks. The violin according to Patent Document 1 cracked at a lower load.

The length of the bass bar of the present invention is slightly shorter than that of the brace in Non-Patent Document 1, preferably 190mm to 230mm, and the length of the soprano bar is preferably 170mm to 210mm. The mounting positions of the bass bar and the soprano bar are such that the center of the bass bar and the soprano bar are spaced approximately the width of the bridge, and they extend and curve in the vertical direction, and both the top and bottom pass through the middle between the center line of the violin and the upper and lower ends of the f-holes. The connecting bar is bonded to the bass bar, the soprano bar, and the top plate, and is preferably installed within a range of 15mm above and below the position of the bridge. Good sound is often obtained by being slightly away from the bridge. Also, a height of 3mm or more will function sufficiently. The trio bar can usually be made of spruce, which has a dense vertical grain, but the soprano bar in particular can be made of harder wood, such as maple. The sound quality of the high notes can be changed.

The soprano bar where the sound post is to be installed should be widened from 5 to 8 mm, but it is best to widen it towards the center. Make sure that the point where the sound post touches the back plate is not too far from the center line. You can either use a partly wider material from the beginning, or install the soprano bar on the top plate and then glue a flat piece of wood to it at the end. Make the surface of the soprano bar smooth so that the sound post does not fall over. This makes it easier to set up the sound post.

The Trio Bar works effectively even on violins that do not use wood efficiently, as in Non-Patent Document 1. It can also be attached to those made according to Non-Patent Document 1.

The steps other than the steps for the front and back panels may be carried out in accordance with Non-Patent Document 1.

The sound post is an important part that transmits vibrations from the bridge to the back plate. We compared the following methods: placing it between the top plate and the back plate near the trio bar; gluing a 2mm thick, 5mm wide board on the trio bar and placing it between the back plate; and shaving the soprano bar a little to make it flat and placing it directly between the back plate. The best method was to place it directly between the soprano bar and the back plate. You can also shave the soprano bar a little deeper at the part where the sound post is to be placed and set the sound post up. In the case of a violin, this improves the volume of the E string.

The completed violin was fitted with fittings and strings, and after a sufficient stabilization period, it was played and found to have excellent volume and sound quality. It was also found to have a strong vibration from the G string, as well as excellent volume and ease of pronunciation of the high notes.

Effective use of wood reduces the felling of valuable large trees, prevents environmental degradation, and provides a wide range of musical instruments with excellent sound quality.

Logs and cutting positions in Example 1 How to take arc-shaped members from trapezoidal columns Arc-shaped material combination diagram Back side of the top plate of Non-Patent Document 1 The back side of the tabletop and the trio bar of this invention

1 Log 2 Cutting point 3 Trapezoidal column A 4 Trapezoidal column B 5 Trapezoidal column C 6 Trapezoidal column D
7 Trapezoidal column E 8 Trapezoidal column F 9 Arc-shaped material a 10 Arc-shaped material b
11 arc-shaped material c 12 arc-shaped material d 13 arc-shaped material e 14 arc-shaped material f
15 Combination of arc-shaped members 16 Position of arc-shaped member e 17 Position of arc-shaped member f 18 Strengthening bar 19 Position of sound post installation 20 Bass bar 21 Soprano bar 22 Sound post installation portion 23 Connecting bar

Processing of the top plate - Left side arc-shaped material: Italian spruce, Ciresa company spruce, violin, top, 1st/quality, length 380 mm, width 120 mm, thickness 55 mm/30 mm Cut the cut part of the raw wood 1 vertically to a width of 20 mm, and cut five trapezoidal pillars A3,
The trapezoidal columns B4, C5, D6, and E7 were cut into 6 arc-shaped pieces each for the trapezoidal columns A, B, C, and D along the cut lines shown in Figure 2, resulting in 24 arc-shaped pieces a9 (6 pieces), b10 (6 pieces), c11 (6 pieces), and d12 (6 pieces). In this case, the trapezoidal column A was cut by drawing cut line A on one side and cut line B on the other side, and the arc-shaped piece of the correct shape was obtained by cutting along these two lines. Similarly, cut lines B and C were drawn on trapezoidal column B, and cut lines C and D were drawn on trapezoidal column C. Some of the cuts were diagonal, so a jigsaw was used.
Right-side arcuate timber: Nearly identical spruce timber was placed upside down and treated in exactly the same way to obtain 24 right-side arcuate timber that were symmetrical to the left.
The pair of arc-shaped pieces on the left and right sides were assembled and glued together correctly, with the top and bottom held in place by a mold, using a two-part epoxy resin adhesive. The adhesive was lightly colored with Sekaido white and brown oil paints.
The left and right EFs were treated in the same way as ABCD, and each was obtained as an arc-shaped piece, but only a portion of the length was needed. Both were glued with the same adhesive. The rough surface was lightly shaped and cut, and then finished for use. The thickness of the center was 3.3 mm, and the thinnest part was 2.3 mm.
To attach the trio bar to the top, a 4mm thick spruce was bent with steam, but for the soprano bar, a 2mm board was bent at the center 20mm long and glued to fit the soprano bar. The bass bar is 205mm long, the soprano bar 180mm long, and glue was used to glue it to the top. The bass bar is 11mm high, the soprano bar 8mm high, the connecting bar is 5mm, the soprano bar contact part is 5mm high, and the tips of the bass bar and soprano bar are both 3mm. Finally, an f-hole was drilled and used as the top.
The procedure for making the back is almost the same as for the top, except for the Trio bar. The back was made using Tonewood's Slovakian maple, violin, back, best/quality. The glue position was adjusted to match the grain of the maple board, and the glue was adjusted to match the wood color. For coloring, a very small amount of Sekaido Extra-Fine-Artists oil paints, zinc white, cadmium yellow, and sepia were mixed.
According to Non-Patent Document 1, a violin was made using the above back and top plates by the internal mold method, and then it was varnished, a sound post was installed, and the fittings Guardelli/violin-set were installed to complete the violin.
The violin manufactured in this way was a playable violin, using a bridge made by Auber/Deluxe, France, and strings made by Bilastro Obligato. Three months after the instrument had stabilized, including the varnish, it was played and found to be satisfactory in terms of tone, volume, ease of playing, etc. (See Table 2).

Claims (2)

In the manufacture of violins, which are made of a violin, small fractional violin, viola, and violin cello (hereinafter referred to as violins), which are made of a body that connects the top and back of the instrument, and which have a neck for stringing four strings, a fingerboard, and accessories including a bridge, the first step in the manufacture of the top and back of the instrument is to cut a raw wood into several pieces of wood (hereinafter referred to as trapezoids) whose cross section is a trapezoid along the grain and whose width is one-fifth to one-tenth of the width of the narrow part of the body of the finished instrument, and then cut each of these into curved boards (hereinafter referred to as arc-shaped boards) for the parts that correspond to the finished instrument. The violin is then efficiently cut into multiple pieces, and corresponding arc-shaped pieces are combined and glued together to approximate the shape of the finished instrument, to form a rough top and rough back. The top and back are then finished, and a bass bar and a treble soprano bar, which are arch-shaped and curved outward at the top and bottom and are 5 mm or less in width, are installed on the back of the top, and a connecting bar is attached to connect these to the top to form the top. At this time, the part of the treble soprano bar that comes into contact with the sound post is ground parallel to the top to make it smooth, and finally a sound post is attached between the treble soprano bar and the back. A violin in which a bass bar and a treble soprano bar, each of which is bow-shaped and curved outward at the top and bottom and 5 mm or less in width, are installed on the back of the top plate, a connecting bar is attached to connect these to the top plate, and the part of the treble soprano bar that comes into contact with the sound post is cut parallel to the top plate and smoothed in order to install the sound post, and finally, the sound post is installed between the treble soprano bar and the back plate.

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