EP1630786B1 - Sound board with fibre reinforced composite material for stringed instruments - Google Patents

Sound board with fibre reinforced composite material for stringed instruments Download PDF

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Publication number
EP1630786B1
EP1630786B1 EP05007785A EP05007785A EP1630786B1 EP 1630786 B1 EP1630786 B1 EP 1630786B1 EP 05007785 A EP05007785 A EP 05007785A EP 05007785 A EP05007785 A EP 05007785A EP 1630786 B1 EP1630786 B1 EP 1630786B1
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EP
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Prior art keywords
soundboard
core plate
strip
compression strength
plate
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EP05007785A
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German (de)
French (fr)
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EP1630786A1 (en
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Martin Schleske
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    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10D—STRINGED MUSICAL INSTRUMENTS; WIND MUSICAL INSTRUMENTS; ACCORDIONS OR CONCERTINAS; PERCUSSION MUSICAL INSTRUMENTS; AEOLIAN HARPS; SINGING-FLAME MUSICAL INSTRUMENTS; MUSICAL INSTRUMENTS NOT OTHERWISE PROVIDED FOR
    • G10D3/00—Details of, or accessories for, stringed musical instruments, e.g. slide-bars
    • G10D3/22—Material for manufacturing stringed musical instruments; Treatment of the material
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10D—STRINGED MUSICAL INSTRUMENTS; WIND MUSICAL INSTRUMENTS; ACCORDIONS OR CONCERTINAS; PERCUSSION MUSICAL INSTRUMENTS; AEOLIAN HARPS; SINGING-FLAME MUSICAL INSTRUMENTS; MUSICAL INSTRUMENTS NOT OTHERWISE PROVIDED FOR
    • G10D3/00—Details of, or accessories for, stringed musical instruments, e.g. slide-bars
    • G10D3/02—Resonating means, horns or diaphragms

Definitions

  • the invention relates to a resonator plate in fiber composite construction for acoustic stringed instruments, in particular for use as at least one of the two resonant plates of the resonator of stringed instruments, consisting of a core plate and provided on at least one of the two outer sides of the core plate fiber coating of long fibers in a carrier material embedded, wherein the core plate has a lower average density than the fiber coating.
  • Structures in fiber composite construction generally consist of long fibers which are oriented in certain directions, and a carrier material, which is usually a thermosetting or thermoplastic plastic, in particular an epoxy resin system.
  • US Pat. No. 4,353,862 A shows a guitar resonance panel in which a glass fiber fabric impregnated with polyester resin is applied to a layer of wood.
  • the weft threads of the glass fiber fabric run approximately parallel and the warp threads of the glass fiber fabric approximately transversely to the grain of the wood layer.
  • EP 0 433 430 A relates to the resonator plate of a stringed instrument in which a number of layers are superimposed, each consisting of long fibers embedded in a substrate.
  • the long fibers run parallel to one another in each layer, while the fiber directions of the individual layers deviate from one another.
  • the top and bottom cover layers of this resonator plate are made of wood to reduce the overall density of the resonator plate and achieve the desired damping characteristics.
  • the subject of EP 1 182 642 A is also a three-layered resonance plate, in which the middle layer forms a lower density core plate, while the two outer layers have a fiber coating of long fibers embedded in a carrier material.
  • the fiber coating is single-layered and at the same time designed to be multidirectional.
  • this resonance plate is stiffened by a correspondingly selected orientation of the multidirectional fiber coating of the central part of the resonance plate in the transverse direction.
  • DE 201 13 495 U1 discloses a resonant plate in fiber composite construction in which the core plate in the region of the two lower and upper jaws has recesses for reducing the oscillating mass.
  • the core plate is provided with recesses in the outer zones adjoining the central zone laterally.
  • the invention has for its object to further develop a resonant plate of the type mentioned that on the one hand compared to excellent, manufactured in traditional construction solid wood resonance panels a significantly improved acoustic quality, especially while maintaining the usual and desirable timbre of a solid wood Resonant plate has a much higher sound power, but on the other hand, in comparison to known resonance panels in fiber composite construction by a particularly pressure-stable construction - with a simple production - is characterized.
  • a resonant plate of the type mentioned fact that the core plate of at least three juxtaposed, extending in the longitudinal direction of the resonant plate strip withunterunterlast Anlagen longitudinal compressive strength, wherein a vertical longitudinal center plane of the resonant plate enclosing zone of the core plate forming strip of a material with a higher longitudinal compressive strength and preferably consists of spruce wood, while the two laterally adjoining the middle zone outer strip made of a material with a lower longitudinal compressive strength and preferably consist of balsa and / or hard foam.
  • the resonance plate only that part of the resonance plate is amplified, which is particularly stressed by the string tension.
  • This part of the core plate is reinforced in such a way that in this case a substantially increased longitudinal compressive strength is provided compared to the other regions of the core plate. This makes it possible using the lowest possible additional mass to achieve the required stability of the resonance plate, in particular an absolute security against the described risk of buckling.
  • the use of a very small additional mass for longitudinal reinforcement of the core plate is of crucial importance for achieving a high sound emission, since the vibration level of the natural oscillations relevant for the sound radiation of the instrument is higher, the smaller the oscillating mass of the resonance plate.
  • the solution according to the invention with the longitudinal reinforcement of the two end regions of the core plate is characterized by a significantly lower mass and thus a significantly higher sound radiation out.
  • the middle zone of the core plate consists of a strip 2 of a material of high compressive strength, preferably of spruce wood.
  • two outer, large-area strips 3 adjoin the side, which consist of a material of low density and correspondingly low compressive strength, preferably on balsa wood or hard foam.
  • the strip 2 which is arranged symmetrically to the vertical longitudinal center plane of the resonance plate, occupies a width of 10 to 25%, preferably 14 to 20%, of the overall width of the outline of the resonance plate.
  • the two end regions 14, 15 of the central zone of the resonance plate receive a longitudinal compressive strength which is increased in comparison with the two lateral strips 3, so that the resonance plate can reliably absorb the longitudinal compressive forces F, -F caused by the string tension and buckling of the resonance plate (as described with reference to FIG. 1b) is excluded with certainty.
  • This considerable increase in the pressure and buckling strength of the resonance plate is achieved with a reasonably small increase in the oscillating mass of the resonance plate.
  • FIGS. 3a to 3c show three variants of the embodiment according to FIGS. 2a and 2b:
  • the central zone of the core plate is reinforced by two segments of a compression-resistant strip 2, which are arranged at a mutual distance and preferably symmetrically to the vertical longitudinal center plane of the resonance plate.
  • the space between the two segments of the strip 2 is as well as the two outer zones filled with low density material (strip 3).
  • the core plate in the region of the central zone on a strip 2 of high longitudinal compressive strength, whose height is only a portion of the thickness d of the core plate.
  • This strip is expediently formed in the core plate in such a way that it can be bent on all sides, i. also on the top and bottom, of low density material (strip 3) is enclosed.
  • Fig. 3c shows an embodiment in which in the middle zone of the core plate at a distance one above the other two segments of a strip 2 are provided with increased longitudinal compressive strength.
  • the overall height of these strip segments is smaller than the thickness d of the core plate.
  • the two segments of the strip 2 are preferably flush with the top or bottom of the core plate on which the fiber coatings 6 are arranged.
  • a resonant plate made in fiber composite construction has as much as possible the same anisotropy of the sound velocity of the longitudinal waves as an excellent wood resonance plate. Since this anisotropy is influenced to some extent already by the above-described inventive measures (increasing the longitudinal compressive strength in the central zone of the resonance plate), it is important to achieve the desired value of the anisotropy by an appropriate design of the two outer fiber coatings 6. Two suitable possibilities for this are shown in FIGS. 4 and 5.
  • FIG. 4 shows (in schematic, exploded illustration) a resonance plate whose middle zone has an increased longitudinal compressive strength (the measures used for this purpose, for example according to FIGS. 2a, 2b, 3a to 3c, are not shown in detail in FIG. 4).
  • the core plate is designated in Fig. 4 with 21, the two outer fiber coatings are designated 22, 23.
  • These Fiber coatings 22, 23 each contain a layer of long fibers embedded in a carrier material, which are arranged parallel to one another within the respective layer. In this case, the long fibers of the two fiber coatings 22, 23 - relative to an imaginary vertical longitudinal center plane 24 of the resonance plate - at different angles 25 and 26, in the illustrated embodiment under opposite and unequal large angles.
  • Fig. 5 illustrates a further possibility, such as a resonant plate, whose central zone has been given increased compressive strength by one of the illustrated measures, can be formed by appropriate design of the two outer fiber coatings to have the desired longitudinal velocity anisotropy of the sound waves.
  • Fig. 5 shows a surface segment of a fiber coating 6, which consists of many individual, separate, patchwork-like layers applied to the core plate zones of long fibers. Each of these zones has a unidirectional fiber profile per se. Overall, however, take the fiber longitudinal directions of all zones different angles. As a result, a multidirectional, single-layer fiber coating is achieved as a whole.
  • the resulting anisotropy of the resonance plate can be set very precisely to the desired value (also taking into account the influence of the pressure stiffening of the central zone of the resonance plate).

Description

Die Erfindung betrifft eine Resonanzplatte in Faserverbund-Bauweise für akustische Saiteninstrumente, insbesondere zur Verwendung als zumindest eine der beiden Resonanzplatten des Resonanzkörpers von Streichinstrumenten, bestehend aus einer Kernplatte und einer auf wenigstens einer der beiden Außenseiten der Kernplatte vorgesehenen Faserbeschichtung aus Langfasern, die in ein Trägermaterial eingebettet sind, wobei die Kernplatte eine geringere mittlere Dichte als die Faserbeschichtung aufweist.The invention relates to a resonator plate in fiber composite construction for acoustic stringed instruments, in particular for use as at least one of the two resonant plates of the resonator of stringed instruments, consisting of a core plate and provided on at least one of the two outer sides of the core plate fiber coating of long fibers in a carrier material embedded, wherein the core plate has a lower average density than the fiber coating.

In neuerer Zeit hat man versucht, die Resonanzplatten akustischer Saiteninstrumente in Faserverbund-Bauweise herzustellen. Strukturen in Faserverbund-Bauweise bestehen im allgemeinen aus Langfasern, die in bestimmten Richtungen orientiert sind, und einem Trägermaterial, das meist ein duroplastischer oder thermoplastischer Kunststoff, insbesondere ein Epoxydharzsystem ist.In recent times, attempts have been made to produce the resonance plates of acoustic stringed instruments in fiber composite construction. Structures in fiber composite construction generally consist of long fibers which are oriented in certain directions, and a carrier material, which is usually a thermosetting or thermoplastic plastic, in particular an epoxy resin system.

Die bisherigen Bemühungen zur Herstellung von Resonanzplatten in Faserverbund-Bauweise zielen durchweg darauf ab, die akustischen Eigenschaften des zu ersetzenden Holzes möglichst zu kopieren. So zeigt die US 4 353 862 A eine Gitarren-Resonanzplatte, bei der auf eine Holzschicht ein mit Polyesterharz getränktes Glasfasergewebe aufgebracht ist. Hierbei laufen die Schussfäden des Glasfasergewebes etwa parallel und die Kettfäden des Glasfasergewebes etwa quer zur Maserung der Holzschicht.The previous efforts to produce resonant panels in fiber composite construction consistently aim to copy the acoustic properties of the wood to be replaced as possible. For example, US Pat. No. 4,353,862 A shows a guitar resonance panel in which a glass fiber fabric impregnated with polyester resin is applied to a layer of wood. In this case, the weft threads of the glass fiber fabric run approximately parallel and the warp threads of the glass fiber fabric approximately transversely to the grain of the wood layer.

Die EP 0 433 430 A betrifft die Resonanzplatte eines Streichinstrumentes, bei der eine Anzahl von Schichten übereinander angeordnet sind, die jeweils aus Langfasern bestehen, die in ein Trägermaterial eingebettet sind. Dabei verlaufen in jeder Schicht die Langfasern parallel zueinander, während die Faserrichtungen der einzelnen Schichten voneinander abweichen. Die oberste und unterste Deckschicht dieser Resonanzplatte besteht aus Holz, um die Gesamtdichte der Resonanzplatte zu verringern und die gewünschten Dämpfungseigenschaften zu erreichen.EP 0 433 430 A relates to the resonator plate of a stringed instrument in which a number of layers are superimposed, each consisting of long fibers embedded in a substrate. In this case, the long fibers run parallel to one another in each layer, while the fiber directions of the individual layers deviate from one another. The top and bottom cover layers of this resonator plate are made of wood to reduce the overall density of the resonator plate and achieve the desired damping characteristics.

Gegenstand der EP 1 182 642 A ist ferner eine aus drei Schichten bestehende Resonanzplatte, bei der die mittlere Schicht eine Kernplatte geringerer Dichte bildet, während die beiden äußeren Schichten eine Faserbeschichtung aus Langfasern aufweisen, die in ein Trägermaterial eingebettet sind. Hierbei ist die Faserbeschichtung einlagig und zugleich multidirektional ausgebildet. Bei einer Variante dieser Resonanzplatte ist durch eine entsprechend gewählte Orientierung der multidirektionalen Faserbeschichtung der Mittelteil der Resonanzplatte in Querrichtung versteift.The subject of EP 1 182 642 A is also a three-layered resonance plate, in which the middle layer forms a lower density core plate, while the two outer layers have a fiber coating of long fibers embedded in a carrier material. Here, the fiber coating is single-layered and at the same time designed to be multidirectional. In a variant of this resonance plate is stiffened by a correspondingly selected orientation of the multidirectional fiber coating of the central part of the resonance plate in the transverse direction.

Schließlich ist durch die DE 201 13 495 U1 eine Resonanzplatte in Faserverbund-Bauweise bekannt, bei der die Kernplatte im Bereich der beiden unteren und oberen Backen Aussparungen zur Verringerung der schwingenden Masse aufweist. Bei einer dieser Ausführungsformen (Fig. 1 h) ist die Kernplatte in den seitlich an die mittlere Zone anschließenden äußeren Zonen mit Aussparungen versehen.Finally, DE 201 13 495 U1 discloses a resonant plate in fiber composite construction in which the core plate in the region of the two lower and upper jaws has recesses for reducing the oscillating mass. In one of these embodiments (FIG. 1 h), the core plate is provided with recesses in the outer zones adjoining the central zone laterally.

Ziel all dieser Versuche ist es vor allem, ein günstigeres Verhältnis von Steifigkeit zu Masse zu realisieren, als dies bei den traditionellen Resonanzplatten aus Vollholz gegeben ist. Besonders bei Resonanzplatten für Streichinstrumente ergeben sich allerdings aufgrund der in Längsrichtung wirkenden hohen Saitenspannung (bei der Geige fast 300 Newton) kritische Festigkeitsprobleme, wenn die Resonanzplatte nach dem Sandwichprinzip aus einer Kernplatte geringer Dichte und zwei auf den beiden Außenseiten der Kernplatte vorgesehenen Faserbeschichtungen aufgebaut wird. Diese Probleme seien an Hand der Fig. 1a und 1b näher erläutert:

  • Fig. 1a zeigt ein Streichinstrument (beispielsweise eine Geige) ganz schematisch in einer Seitenansicht. Fig. 1b veranschaulicht den oberen Endbereich 15 der Decke, d.h. der oberen Resonanzplatte 11, in vergrößerter Darstellung. Die Zugspannung der Saiten 10 wirkt einerseits über den Steg 9 vertikal als Druckkraft in Richtung -Z auf die obere Resonanzplatte 11 und andererseits als Druckkraft F in Richtung -Y am Halsfuß 13 und als Gegenkraft -F in Richtung Y am Untersattel 12 des Korpus. Dadurch findet eine Stauchung der oberen Resonanzplatte 11 in Richtung Y statt, wobei die üblichen Kernmaterialien geringer Dichte zur Aufnahme hoher Druckkräfte wenig geeignet sind. Überschreitet die aufgrund der Saitenspannung in Längsrichtung Y auf die Resonanzplatte 11 wirkende Druckkraft ein kritisches Maß, so droht in den ansteigenden Endbereichen 14, 15 ein Ausknicken der Resonanzplatte, wie dies schematisch in Fig.1b für den Endbereich 15 angedeutet ist: Über den Querschnitt der Plattendicke erfolgt eine "S"-kurvenförmige Verschiebung 7 des Plattenlängsschnittes sowie eine Faserablösung 16 auf der Druckseite, d.h. auf der Unterseite der Resonanzplatte. Im Bereich des Ausknickens wird die Verklebung zwischen der Faserbeschichtung 6 und dem Kernmaterial aufgebrochen, und es entstehen Hohlräume 8.
The aim of all these attempts is above all to realize a more favorable ratio of stiffness to mass than is the case with traditional solid wood panels. However, especially with resonant plates for stringed instruments, due to the high string tension acting in the longitudinal direction (almost 300 newton in the violin), critical strength problems arise when the resonant plate is constructed on the sandwich principle from a low density core plate and two fiber coatings provided on both outer sides of the core plate. These problems are explained in more detail with reference to FIGS. 1a and 1b:
  • Fig. 1a shows a stringed instrument (for example a violin) very schematically in a side view. Fig. 1b illustrates the upper end portion 15 of the ceiling, ie the upper resonance plate 11, in an enlarged view. The tension of the strings 10 acts on the one hand via the web 9 vertically as a compressive force in the direction -Z on the upper resonating plate 11 and on the other hand as a compressive force F in the direction -Y on the neck foot 13 and as a counter force -F in the direction Y on the lower saddle 12 of the body. As a result, a compression of the upper resonance plate 11 takes place in the direction Y, the usual low-density core materials being poorly suited to accommodate high compressive forces. Exceeds the compressive force acting on the resonance plate 11 due to the string tension in the longitudinal direction Y, a critical extent, so threatening in the rising end portions 14, 15 buckling of the resonant plate, as is schematically indicated in Figure 1 b for the end portion 15: About the cross section of Plate thickness takes place an "S" -curve shift 7 of the longitudinal plate section and a fiber separation 16 on the pressure side, ie on the underside of the resonance plate. In the region of the buckling, the bond between the fiber coating 6 and the core material is broken, and cavities 8 are created.

Der Erfindung liegt die Aufgabe zugrunde, eine Resonanzplatte der eingangs genannten Art dahin weiter zu entwickeln, dass sie einerseits im Vergleich zu ausgezeichneten, in traditioneller Bauweise gefertigten Vollholz-Resonanzplatten eine deutlich verbesserte akustische Qualität, insbesondere unter Beibehaltung der gewohnten und erwünschten Klangfarbe einer Vollholz-Resonanzplatte eine wesentlich höhere Schalleistung aufweist, dass sie sich jedoch andererseits im Vergleich zu bekannten Resonanzplatten in Faserverbund-Bauweise durch eine besonders druckstabile Bauweise - bei gleichzeitig einfacher Fertigung - auszeichnet.The invention has for its object to further develop a resonant plate of the type mentioned that on the one hand compared to excellent, manufactured in traditional construction solid wood resonance panels a significantly improved acoustic quality, especially while maintaining the usual and desirable timbre of a solid wood Resonant plate has a much higher sound power, but on the other hand, in comparison to known resonance panels in fiber composite construction by a particularly pressure-stable construction - with a simple production - is characterized.

Diese Aufgabe wird erfindungsgemäß bei einer Resonanzplatte der eingangs genannten Art dadurch gelöst, dass die Kernplatte aus wenigstens drei nebeneinander angeordneten, in Längsrichtung der Resonanzplatte verlaufenden Streifen mitunterschiedlicher Längsdruckfestigkeit besteht, wobei ein die vertikale Längsmittelebene der Resonanzplatte einschließende Zone der Kernplatte bildender Streifen aus einem Material mit einer höheren Längsdruckfestigkeit besteht und vorzugsweise aus Fichtenholz besteht, während die beiden seitlich an die mittlere Zone anschließenden äußeren Streifen aus einem Material mit einer geringeren Längsdruckfestigkeit bestehen und vorzugsweise aus Balsaholz und/oder Hartschaum bestehen.This object is achieved in a resonant plate of the type mentioned fact that the core plate of at least three juxtaposed, extending in the longitudinal direction of the resonant plate strip withunterunterlastlicher longitudinal compressive strength, wherein a vertical longitudinal center plane of the resonant plate enclosing zone of the core plate forming strip of a material with a higher longitudinal compressive strength and preferably consists of spruce wood, while the two laterally adjoining the middle zone outer strip made of a material with a lower longitudinal compressive strength and preferably consist of balsa and / or hard foam.

Erfindungsgemäß wird somit nur derjenige Teil der Resonanzplatte verstärkt, der durch die Saitenspannung besonders beansprucht ist. Dies ist die mittlere Zone der Kernplatte (die die vertikale Längsmittelebene der Resonanzplatte einschließt), insbesondere die beiden Endbereiche dieser mittleren Zone. Dieser Teil der Kernplatte wird derart verstärkt, dass hier eine im Vergleich zu den übrigen Bereichen der Kernplatte wesentlich erhöhte Längsdruckfestigkeit gegeben ist. Dadurch gelingt es unter Einsatz der geringstmöglichen zusätzlichen Masse die erforderliche Stabilität der Resonanzplatte, insbesondere eine absolute Sicherheit gegen die geschilderte Gefahr eines Ausknickens, zu erreichen. Die Verwendung einer ganz kleinen zusätzlichen Masse zur Längsversteifung der Kernplatte ist für die Erzielung einer hohen Schallabstrahlung von ausschlaggebender Bedeutung, da die für die Schallabstrahlung des Instrumentes maßgeblichen Schwingungspegel der Eigenschwingungen umso höher sind, je kleiner die schwingende Masse der Resonanzplatte ist. Im Vergleich zu einer Ausführung, bei der über die Gesamtfläche der Resonanzplatte ein ausreichend knickfestes Kernplattenmaterial (mit entsprechend hoher Dichte) gewählt wird, zeichnet sich die erfindungsgemäße Lösung mit der Längsversteifung der beiden Endbereiche der Kernplatte durch eine wesentlich geringere Masse und damit eine deutlich höhere Schallabstrahlung aus.According to the invention, only that part of the resonance plate is amplified, which is particularly stressed by the string tension. This is the central zone of the core plate (which includes the longitudinal vertical median plane of the resonator plate), particularly the two end regions of this central zone. This part of the core plate is reinforced in such a way that in this case a substantially increased longitudinal compressive strength is provided compared to the other regions of the core plate. This makes it possible using the lowest possible additional mass to achieve the required stability of the resonance plate, in particular an absolute security against the described risk of buckling. The use of a very small additional mass for longitudinal reinforcement of the core plate is of crucial importance for achieving a high sound emission, since the vibration level of the natural oscillations relevant for the sound radiation of the instrument is higher, the smaller the oscillating mass of the resonance plate. Compared to an embodiment in which a sufficiently kink-resistant core plate material (with a correspondingly high density) is selected over the entire surface of the resonance plate, the solution according to the invention with the longitudinal reinforcement of the two end regions of the core plate is characterized by a significantly lower mass and thus a significantly higher sound radiation out.

Die Erhöhung der Längsdruckfestigkeit des durch die Saitenspannung besonders beanspruchten Teiles der Kernplatte kann erfindungsgemäß in verschiedenen Varianten erfolgen, die Gegenstand der Ansprüche 2 bis 6 sind und an Hand der Fig. 2a, 2b und 3a bis 3c näher erläutert werden.The increase in the compressive strength of the stressed by the string tension part of the core plate according to the invention can be made in various variants, which are the subject of claims 2 to 6 and are explained in more detail with reference to FIGS. 2a, 2b and 3a to 3c.

Nun sollen Resonanzplatten in Faserverbund-Bauweise nicht nur eine hohe Schallabstrahlung, sondern möglichst auch die gewohnte Klangfarbe einer ausgezeichneten Vollholz-Resonanzplatte aufweisen. Die Klangfarbe wird wesentlich durch die Frequenzen und Schwingungsformen der Eigenschwingungen bestimmt, die ihrerseits von der Anisotropie der Schallgeschwindigkeit der Longitudinalwellen abhängen (bei Fichtenholz beträgt das Verhältnis von Schallgeschwindigkeit in Längsrichtung zu Schallgeschwindigkeit in Querrichtung des Faserverlaufs etwa 4:1). Um bei einer Resonanzplatte in Faserverbund-Bauweise die gleiche Klangfarbe wie bei einer guten Holz-Resonanzplatte zu erzielen, kommt es daher darauf an, die genannte Anisotropie herzustellen.Now resonance boards in fiber composite construction should have not only a high sound radiation, but possibly also the usual timbre of an excellent solid wood resonance panel. The tone color is essentially determined by the frequencies and modes of the natural vibrations, which in turn depend on the anisotropy of the sound velocity of the longitudinal waves (in spruce wood, the ratio of sound velocity in the longitudinal direction to sound velocity in the transverse direction the fiber profile about 4: 1). In order to achieve the same timbre on a resonant panel in fiber composite construction as in a good wood resonance panel, it is therefore important to produce the said anisotropy.

Dieses Ziel wird erfindungsgemäß durch eine besondere Ausbildung der beiden auf den Außenseiten der Kernplatte vorgesehenen Faserbeschichtungen erreicht, wobei auch die Längsdruckversteifung der mittleren Zone der Kernplatte bzw. der beiden Endbereiche dieser mittleren Zone die genannte Anisotropie mit beeinflusst. Zwei Lösungen sind Gegenstand der Ansprüche 7 und 8 und werden an Hand der Fig. 4 und 5 im einzelnen erläutert.This object is inventively achieved by a special design of the two provided on the outer sides of the core plate fiber coatings, wherein the longitudinal pressure stiffening of the central zone of the core plate or the two end portions of this central zone influences the said anisotropy. Two solutions are the subject matter of claims 7 and 8 and will be explained with reference to FIGS. 4 and 5 in detail.

Bei dem in den Fig. 2a und 2b dargestellten ersten Ausführungsbeispiel der Erfindung besteht die mittlere Zone der Kernplatte aus einem Streifen 2 aus einem Material hoher Längsdruckfestigkeit, vorzugsweise aus Fichtenholz. An die mittlere Zone schließen sich seitlich zwei äußere, großflächige Streifen 3 an, die aus einem Material geringer Dichte und entsprechend niedriger Druckbelastbarkeit bestehen, vorzugsweise auf Balsaholz oder Hartschaum. Der Streifen 2, der symmetrisch zur vertikalen Längsmittelebene der Resonanzplatte angeordnet ist, nimmt eine Breite von 10 bis 25 %, vorzugsweise von 14 bis 20 %, der Gesamtbreite des Umrisses der Resonanzplatte ein. Durch diesen Streifen 2 erhalten die beiden Endbereiche 14, 15 der mittleren Zone der Resonanzplatte eine im Vergleich zu den beiden seitlichen Streifen 3 erhöhte Längsdruckfestigkeit, so dass die Resonanzplatte die von der Saitenspannung hervorgerufenen Längsdruckkräfte F, -F zuverlässig aufnehmen kann und ein Ausknicken der Resonanzplatte (wie an Hand von Fig. 1b geschildert) mit Sicherheit ausgeschlossen ist. Diese erhebliche Vergrößerung der Druck- und Knickfestigkeit der Resonanzplatte wird dabei mit einer vertretbar geringen Erhöhung der schwingenden Masse der Resonanzplatte erreicht.In the first embodiment of the invention shown in FIGS. 2a and 2b, the middle zone of the core plate consists of a strip 2 of a material of high compressive strength, preferably of spruce wood. To the middle zone, two outer, large-area strips 3 adjoin the side, which consist of a material of low density and correspondingly low compressive strength, preferably on balsa wood or hard foam. The strip 2, which is arranged symmetrically to the vertical longitudinal center plane of the resonance plate, occupies a width of 10 to 25%, preferably 14 to 20%, of the overall width of the outline of the resonance plate. By means of this strip 2, the two end regions 14, 15 of the central zone of the resonance plate receive a longitudinal compressive strength which is increased in comparison with the two lateral strips 3, so that the resonance plate can reliably absorb the longitudinal compressive forces F, -F caused by the string tension and buckling of the resonance plate (as described with reference to FIG. 1b) is excluded with certainty. This considerable increase in the pressure and buckling strength of the resonance plate is achieved with a reasonably small increase in the oscillating mass of the resonance plate.

Die Fig. 3a bis 3c zeigen drei Varianten der Ausführung entsprechend den Fig. 2a und 2b:FIGS. 3a to 3c show three variants of the embodiment according to FIGS. 2a and 2b:

Gemäß Fig. 3a wird die mittlere Zone der Kernplatte durch zwei Segmente eines kompressionsfesten Streifens 2 verstärkt, die mit gegenseitigem Abstand und vorzugsweise symmetrisch zur vertikalen Längsmittelebene der Resonanzplatte angeordnet sind. Der Raum zwischen den beiden Segmenten des Streifens 2 ist ebenso wie die beiden äußeren Zonen mit Material geringer Dichte ausgefüllt (Streifen 3).According to Fig. 3a, the central zone of the core plate is reinforced by two segments of a compression-resistant strip 2, which are arranged at a mutual distance and preferably symmetrically to the vertical longitudinal center plane of the resonance plate. The space between the two segments of the strip 2 is as well as the two outer zones filled with low density material (strip 3).

Bei der in Fig. 3b dargestellten Ausführung weist die Kernplatte im Bereich der mittleren Zone einen Streifen 2 hoher Längsdruckfestigkeit auf, dessen Höhe nur einen Teil der Dicke d der Kernplatte beträgt. Dieser Streifen ist zweckmäßig derart in die Kernplatte eingeformt, dass er allseitig, d.h. auch auf der Ober- und Unterseite, von Material geringer Dichte (Streifen 3) umschlossen ist.In the embodiment shown in Fig. 3b, the core plate in the region of the central zone on a strip 2 of high longitudinal compressive strength, whose height is only a portion of the thickness d of the core plate. This strip is expediently formed in the core plate in such a way that it can be bent on all sides, i. also on the top and bottom, of low density material (strip 3) is enclosed.

Fig. 3c zeigt ein Ausführungsbeispiel, bei dem in der mittleren Zone der Kernplatte mit Abstand übereinander zwei Segmente eines Streifens 2 mit erhöhter Längsdruckfestigkeit vorgesehen sind. Auch die Gesamthöhe dieser Streifensegmente ist kleiner als die Dicke d der Kernplatte. Die beiden Segmente des Streifens 2 sind vorzugsweise bündig mit der Ober- bzw. Unterseite der Kernplatte, auf denen die Faserbeschichtungen 6 angeordnet sind.Fig. 3c shows an embodiment in which in the middle zone of the core plate at a distance one above the other two segments of a strip 2 are provided with increased longitudinal compressive strength. The overall height of these strip segments is smaller than the thickness d of the core plate. The two segments of the strip 2 are preferably flush with the top or bottom of the core plate on which the fiber coatings 6 are arranged.

Wie oben bereits erwähnt, muss dafür gesorgt werden, dass eine in Faserverbund-Bauweise hergestellte Resonanzplatte möglichst die gleiche Anisotropie der Schallgeschwindigkeit der Longitudinalwellen wie eine ausgezeichnete Holz-Resonanzplatte aufweist. Da diese Anisotropie in gewissem Umfang bereits durch die vorstehend beschriebenen erfindungsgemäßen Maßnahmen (Erhöhung der Längsdruckfestigkeit in der mittleren Zone der Resonanzplatte) beeinflusst wird, kommt es darauf an, durch eine zweckmäßige Gestaltung der beiden äußeren Faserbeschichtungen 6 den gewünschten Wert der Anisotropie zu erreichen. Zwei geeignete Möglichkeiten hierfür sind in den Fig. 4 und 5 dargestellt.As mentioned above, it must be ensured that a resonant plate made in fiber composite construction has as much as possible the same anisotropy of the sound velocity of the longitudinal waves as an excellent wood resonance plate. Since this anisotropy is influenced to some extent already by the above-described inventive measures (increasing the longitudinal compressive strength in the central zone of the resonance plate), it is important to achieve the desired value of the anisotropy by an appropriate design of the two outer fiber coatings 6. Two suitable possibilities for this are shown in FIGS. 4 and 5.

Fig. 4 zeigt (in schematischer, auseinandergezogener Darstellung) eine Resonanzplatte, deren mittlere Zone eine erhöhte Längsdruckfestigkeit aufweist (die hierzu eingesetzten Maßnahmen, etwa gemäß den Fig. 2a, 2b, 3a bis 3c, sind in Fig. 4 nicht im einzelnen dargestellt). Die Kernplatte ist in Fig. 4 mit 21 bezeichnet, die beiden äußeren Faserbeschichtungen sind mit 22, 23 bezeichnet. Diese Faserbeschichtungen 22, 23 enthalten jeweils eine Lage von in ein Trägermaterial eingebetteten Langfasern, die innerhalb der jeweiligen Schicht parallel zueinander angeordnet sind. Dabei verlaufen die Langfasern der beiden Faserbeschichtungen 22, 23 - bezogen auf eine gedachte vertikale Längsmittelebene 24 der Resonanzplatte - unter unterschiedlichen Winkeln 25 bzw. 26, und zwar beim dargestellten Ausführungsbeispiel unter gegensinnigen sowie ungleich großen Winkeln. Durch geeignete Wahl der Winkel lässt sich auf diese Weise auch bei Verwendung einer einzigen Lage von Langfasern pro Faserbeschichtung (und dadurch mit der für die Erzielung der gewünschten hohen Schallabstrahlung notwendigen geringen Masse der Resonanzplatte) die geforderte Anisotropie der Schallgeschwindigkeit der Longitudinalwellen erreichen.4 shows (in schematic, exploded illustration) a resonance plate whose middle zone has an increased longitudinal compressive strength (the measures used for this purpose, for example according to FIGS. 2a, 2b, 3a to 3c, are not shown in detail in FIG. 4). , The core plate is designated in Fig. 4 with 21, the two outer fiber coatings are designated 22, 23. These Fiber coatings 22, 23 each contain a layer of long fibers embedded in a carrier material, which are arranged parallel to one another within the respective layer. In this case, the long fibers of the two fiber coatings 22, 23 - relative to an imaginary vertical longitudinal center plane 24 of the resonance plate - at different angles 25 and 26, in the illustrated embodiment under opposite and unequal large angles. By suitable choice of the angle can be achieved in this way even when using a single layer of long fibers per fiber coating (and thus with the necessary for achieving the desired high sound radiation low mass of the resonance plate) the required anisotropy of the speed of sound of the longitudinal waves.

Fig. 5 veranschaulicht eine weitere Möglichkeit, wie eine Resonanzplatte, deren mittlere Zone durch eine der erläuterten Maßnahmen eine erhöhte Längsdruckfestigkeit erhalten hat, durch eine entsprechende Gestaltung der beiden äußeren Faserbeschichtungen so ausgebildet werden kann, dass sie die gewünschte Anisotropie der Schallgeschwindigkeit der Longitudinalwellen aufweist. Fig. 5 zeigt ein Flächensegment einer Faserbeschichtung 6, die aus vielen einzelnen, voneinander getrennten, nach Art eines Patchwork einlagig auf die Kernplatte aufgetragenen Zonen von Langfasern besteht. Jede dieser Zonen weist für sich genommen einen unidirektionalen Faserverlauf auf. Insgesamt nehmen die Faserlängsrichtungen aller Zonen aber unterschiedliche Winkel ein. Dadurch wird in der Gesamtheit eine multidirektionale, einlagige Faserbeschichtung erzielt. Durch geeignete Wahl der Faserrichtung in den einzelnen Zonen lässt sich die resultierende Anisotropie der Resonanzplatte (auch unter Berücksichtigung des Einflusses der Druckversteifung der mittleren Zone der Resonanzplatte) sehr genau auf den gewünschten Wert einstellen.Fig. 5 illustrates a further possibility, such as a resonant plate, whose central zone has been given increased compressive strength by one of the illustrated measures, can be formed by appropriate design of the two outer fiber coatings to have the desired longitudinal velocity anisotropy of the sound waves. Fig. 5 shows a surface segment of a fiber coating 6, which consists of many individual, separate, patchwork-like layers applied to the core plate zones of long fibers. Each of these zones has a unidirectional fiber profile per se. Overall, however, take the fiber longitudinal directions of all zones different angles. As a result, a multidirectional, single-layer fiber coating is achieved as a whole. By suitable choice of the fiber direction in the individual zones, the resulting anisotropy of the resonance plate can be set very precisely to the desired value (also taking into account the influence of the pressure stiffening of the central zone of the resonance plate).

Claims (8)

  1. Soundboard of composite fibre material construction for acoustic stringed instruments, in particular for use as at least one of the two soundboards of the resonant body of bowed stringed instruments, comprising a core plate and a fibre laminate (6) which is provided on at least one of the two outer faces of the core plate and is composed of long fibres embedded in a carrier material, the core plate having a lower average density than the fibre laminate, characterised in that the core plate comprises at least three strips with differing longitudinal compression strength disposed adjacent to one another and extending in the longitudinal direction of the soundboard, wherein a strip forming the zone of the core plate including the vertical longitudinal central plane of the soundboard is made from a material with a higher longitudinal compression strength and is preferably made from spruce, whilst the two outer strips laterally adjoining the central zone are made from a material with a lower longitudinal compression strength and are preferably made from balsa wood and/or hard foam.
  2. Soundboard as claimed in Claim 1, in which the strip (2) which forms the central zone of the core plate including the vertical longitudinal central plane of the soundboard occupies a width of 10 to 25%, preferably 14 to 20%, of the total width of the outline of the soundboard.
  3. Soundboard as claimed in Claim 1, in which the strip (2) made from the material with higher longitudinal compression strength is composed of two reciprocally spaced segments, the space between the two segments being filled with a low-density material.
  4. Soundboard as claimed in Claim 3, in which the two segments of the strip (2) made from the material with higher longitudinal compression strength are disposed spaced alongside one another, symmetrically with respect to the vertical longitudinal central plane of the soundboard.
  5. Soundboard as claimed in Claim 3, in which the two segments of the strip (2) made from the material with higher longitudinal compression strength are disposed spaced one above the other in the central zone of the core plate.
  6. Soundboard as claimed in Claim 1, in which the core plate has in the region of the central zone including the vertical longitudinal central plane of the soundboard at least one strip (2) made from the material with higher longitudinal compression strength which extends only over a part of the thickness (d) of the core plate.
  7. Soundboard as claimed in Claim 1, in which the two fibre laminates (22, 23) provided on the outer faces of the core plate each contain a layer of long fibres which are embedded in a carrier material and are disposed parallel to one another within the respective layer, whereby the long fibres of the two layers extend at different angles (25, 26) - relative to the vertical longitudinal central plane (24) of the soundboard - preferably at opposing and unequal angles.
  8. Soundboard as claimed in Claim 1, in which the two fibre laminates provided on the outer faces of the core plate each contain a layer of long fibres which are embedded in a carrier material and are disposed multidirectionally within the respective layer.
EP05007785A 2004-08-24 2005-04-08 Sound board with fibre reinforced composite material for stringed instruments Expired - Fee Related EP1630786B1 (en)

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DE102004041010A DE102004041010A1 (en) 2004-08-24 2004-08-24 Resonance plate in fiber composite construction for acoustic string instruments

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103413541A (en) * 2013-08-31 2013-11-27 连云港神鹰碳纤维自行车有限责任公司 Method of making guitar with carbon fiber reinforced composite materials

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7276868B2 (en) * 2004-03-29 2007-10-02 Allred Iii Jimmie B Carbon-fiber laminate musical instrument sound board
US7687696B2 (en) * 2005-08-05 2010-03-30 Charles Edward Fox Tonally improved hollow body stringed instrument
US20080202309A1 (en) * 2007-02-22 2008-08-28 Wiswell John R Musical instrument and method of construction therefor
UA93064C2 (en) * 2008-06-05 2011-01-10 Флориан Ильич Юрьев Artificial laminating material for musical instrument soundboards
US8450587B2 (en) 2011-08-16 2013-05-28 Mcp Ip, Llc Bracing system for stringed instrument
US10074348B2 (en) 2013-10-16 2018-09-11 Mcp Ip, Llc Laminate faced honeycomb bracing structure for stringed instrument
JP6146258B2 (en) * 2013-10-22 2017-06-14 ヤマハ株式会社 Manufacturing method of stringed instrument board
JP6606543B2 (en) 2014-04-23 2019-11-13 オイ オール−プラスト アーベー Acoustic products made of composite materials
US10657931B2 (en) 2018-03-16 2020-05-19 Fender Musical Instruments Corporation Lightweight body construction for stringed musical instruments

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2150736A (en) * 1937-10-20 1939-03-14 Harry S Braman Stringed instrument body
US2674912A (en) * 1951-10-09 1954-04-13 Joseph E Petek Violin sounding board construction
US3427915A (en) * 1964-08-19 1969-02-18 Melvin Mooney Acoustic panels
US3477330A (en) * 1967-09-29 1969-11-11 Conn Ltd C G Laminated soundboard for a string instrument
JPS54119910A (en) * 1978-03-10 1979-09-18 Nippon Gakki Seizo Kk Sound plate for stringed instrument such as guitar
US4353862A (en) * 1980-05-12 1982-10-12 Kaman Aerospace Corporation Method for making sound board
US4408516A (en) * 1981-08-24 1983-10-11 John Leonard K Graphite fibre violin
FR2598843B1 (en) * 1986-05-15 1989-02-10 Centre Nat Rech Scient COMPOSITE STRUCTURE FOR STRINGED INSTRUMENT HARMONY TABLE AND MANUFACTURING METHOD THEREOF
DE3890284T1 (en) * 1987-03-07 1989-04-13 Joseph Harold Stephens VIOLIN
FR2649525B1 (en) * 1989-07-05 1991-10-11 Centre Nat Rech Scient MUSICAL INSTRUMENT WITH A BOW OF COMPOSITE MATERIAL
JPH0631942B2 (en) * 1989-07-28 1994-04-27 ヤマハ株式会社 Soundboard for musical instruments
AUPP361698A0 (en) * 1998-05-21 1998-06-11 Gondwana Musical Instrument Company Pty Ltd Stringed musical instrument
FI106485B (en) * 2000-03-24 2001-02-15 Liikanen Musical Instr Ky Support structure for string instrument
DE20113495U1 (en) * 2000-08-23 2001-10-31 Schleske Martin Soundboard in fiber composite construction

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103413541A (en) * 2013-08-31 2013-11-27 连云港神鹰碳纤维自行车有限责任公司 Method of making guitar with carbon fiber reinforced composite materials
CN103413541B (en) * 2013-08-31 2015-12-23 连云港神鹰碳纤维自行车有限责任公司 A kind of carbon fibre reinforced composite makes the method for guitar

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DE502005000447D1 (en) 2007-04-19
US7208665B2 (en) 2007-04-24
US20060042447A1 (en) 2006-03-02
DE102004041010A1 (en) 2006-03-02

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