Vibration plate and musical instrument

Abstract

A vibrating plate capable of suppressing expansion and / or bending deformation is provided. A vibrating plate (1) has: a vibrating plate body (10) that is a plate-shaped body having anisotropy; a first reinforcing member (20) that is a long strip-shaped member provided so as to project from a first face (10a) of the vibrating plate body with respect to the first face, and that extends in a direction in which the vibrating plate body is easily deformed with respect to the first face; and a second reinforcing member (30) that is a long strip-shaped member provided so as to project from a second face (10b) of the vibrating plate body with respect to the second face, and that extends in a direction in which the vibrating plate body is easily deformed with respect to the second face. At least a portion of a width direction of the first reinforcing member and the second reinforcing member overlaps at least a portion of a length direction of the first reinforcing member and the second reinforcing member, as viewed in a thickness direction (Z) of the vibrating plate body.

Description

Technical Field

[0001] The invention relates to a vibration plate and a musical instrument. Background Art

[0002] Conventionally, there are musical instruments that produce sound by vibrating a diaphragm such as a soundboard using a vibrator. The vibrator operates in response to, for example, an audio signal to vibrate the diaphragm, thereby producing sound from the diaphragm.

[0003] Patent Document 1 discloses a structure in which an oscillator having a drive unit and a movable unit is attached to a musical instrument having a vibrating plate (soundboard). The movable unit of the oscillator is electromagnetically connected to a magnetic circuit-forming unit (drive unit) composed of a magnet, an iron core, etc., and current flows through the coil of the movable unit, causing the movable unit to reciprocate linearly relative to the magnetic circuit-forming unit, thereby vibrating. The oscillator's drive unit is fixed to the frame of the musical instrument, for example, while the end of the movable unit in the vibration direction is fixed to the vibrating plate.

[0004] Patent Document 1: International Publication No. 2014 / 115482

[0005] However, diaphragms such as soundboards can experience expansion and contraction deformation or bending deformation (flexure) due to age-related changes in temperature and humidity. This expansion and bending deformation is not desirable in musical instruments that vibrate the diaphragm using an oscillator.

[0006] For example, if bending deformation occurs in the vibration plate, the normal line of a part of the vibration plate is tilted. In this case, the vibration direction of the movable part fixed in a part of the vibration plate is tilted relative to the driving part (magnetic circuit forming part). In this state, sometimes when the movable part vibrates, the movable part rubs against the driving part. If the movable part rubs against the driving part, the vibration based on the friction is transmitted to the vibration plate, and the sound emitted from the vibration plate is distorted. That is, the bending deformation of the vibration plate affects the sound characteristics of the vibration plate obtained based on the vibrator. Summary of the Invention

[0007] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a diaphragm capable of suppressing expansion and contraction deformation and / or bending deformation, and a musical instrument having the diaphragm.

[0008] The first embodiment of the present invention is a vibration plate comprising: a plate-shaped vibration plate main body having anisotropic deformation (telescopic deformation and / or bending deformation); a first elongated reinforcement member, which is arranged to protrude from a first surface relative to a first surface of the vibration plate main body and extend along the first surface in a direction to prevent deformation of the vibration plate main body; and a second elongated reinforcement member, which is arranged to protrude from a second surface relative to a second surface of the vibration plate main body and extend along the second surface in a direction to prevent deformation of the vibration plate main body, and when viewed from the thickness direction of the vibration plate main body, at least a portion of the width direction of the first reinforcement member and the second reinforcement member overlaps with at least a portion of the length direction of the first reinforcement member and the second reinforcement member.

[0009] A second embodiment of the present invention is a vibration plate, which has a plate-shaped vibration plate main body with anisotropic deformation (telescopic deformation and / or bending deformation); a long strip of first reinforcement, which is arranged to protrude from the first surface relative to the first surface of the vibration plate main body and extend along the first surface in a direction to prevent deformation of the vibration plate main body; and a long strip of second reinforcement, which is arranged to protrude from the second surface relative to the second surface of the vibration plate main body and extend along the second surface in a direction to prevent deformation of the vibration plate main body, the first reinforcement and the second reinforcement are arranged to be separated in the width direction when viewed from the thickness direction of the vibration plate main body, and the width direction interval between the first reinforcement and the second reinforcement is less than 3 times the maximum dimension of either the first reinforcement or the second reinforcement at a cross section perpendicular to its length direction.

[0010] A third aspect of the present invention is a musical instrument including the diaphragm described above and a vibrator for vibrating the diaphragm main body.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to suppress expansion and contraction deformation and / or bending deformation of the diaphragm. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a plan view of the musical instrument according to the first embodiment of the present invention.

[0014] Figure 2 yes Figure 1 Front view of the instrument.

[0015] Figure 3 Yes Figure 1 、 2 A sectional view of a vibrator of a musical instrument.

[0016] Figure 4 Yes Figure 1 、 2An oblique view of the main part of the vibrating plate of the musical instrument.

[0017] Figure 5 Yes Figure 1 、 2 A side view of the main part of the vibration plate of the musical instrument.

[0018] Figure 6 yes Figure 5 VI-VI line cross-sectional view.

[0019] Figure 7 It is used to describe the ability to suppress Figures 4-6 Schematic diagram of the bending deformation of the vibration plate shown.

[0020] Figure 8 It is a plan view showing a first modified example of the diaphragm of the first embodiment.

[0021] Figure 9 yes Figure 8 IX-IX line cross-sectional view.

[0022] Figure 10 It is a side view showing a second modified example of the diaphragm of the first embodiment.

[0023] Figure 11 It is a side view showing a third modified example of the diaphragm of the first embodiment.

[0024] Figure 12 It is a side view showing a fourth modified example of the diaphragm of the first embodiment.

[0025] Figure 13 It is a plan view showing a fifth modification of the diaphragm of the first embodiment.

[0026] Figure 14 It is a cross-sectional view showing a sixth modification of the diaphragm of the first embodiment.

[0027] Figure 15 It is a cross-sectional view showing a seventh modification of the diaphragm of the first embodiment.

[0028] Figure 16 It is a cross-sectional view showing an eighth modification of the diaphragm of the first embodiment.

[0029] Figure 17 It is a cross-sectional view showing a ninth modification of the diaphragm of the first embodiment.

[0030] Figure 18 It is a plan view showing a first example of a diaphragm according to the second embodiment of the present invention.

[0031] Figure 19It is a cross-sectional view showing a second example of the diaphragm according to the second embodiment of the present invention.

[0032] Figure 20 It is a perspective view showing a main part of a diaphragm according to another embodiment of the present invention.

[0033] Figure 21 The diagram shows the state changes corresponding to the drying and wetting of a plate material. (a) shows the reference state, (b) shows the dry state, and (c) shows the wet state.

[0034] Figure 22 The figures show the state changes according to the drying and wetting of a structure obtained by stacking two plate materials. (a) shows the reference state, (b) shows the dry state, and (c) shows the wet state. DETAILED DESCRIPTION

[0035] [First embodiment]

[0036] Below, refer to Figures 1 to 7 A first embodiment of the present invention will be described.

[0037] like Figure 1 、 2 As shown, the musical instrument MI of this embodiment includes a diaphragm 1 and a vibrator 2 for vibrating the diaphragm 1. The musical instrument MI of this embodiment also includes a frame 3, legs 4, a keyboard 5, and pedals 6, and is constructed like a grand piano.

[0038] In the musical instrument MI of the present embodiment, the keyboard 5 is arranged on the player side (front side) of the musical instrument MI. The keyboard 5 is composed of a plurality of keys, and the player performs performance operations on the plurality of keys with his fingers.

[0039] The diaphragm 1 is arranged behind the keyboard 5. The diaphragm 1 of this embodiment has the same planar shape as the soundboard of a grand piano. The soundboard is arranged with its thickness oriented in the vertical direction. The details of the diaphragm 1 will be described later.

[0040] The vibrator 2 is disposed below the vibration plate 1. In this embodiment, a plurality of vibrators 2 (three in the illustrated example) are mounted on the vibration plate 1. The vibrators 2 are spaced apart in the left-right direction of the arrangement of the keys of the keyboard 5. The details of the vibrators 2 will be described later.

[0041] The frame 3 supports the diaphragm 1 from below. The frame 3 is fixed to the diaphragm 1. The frame 3 is formed into a frame-like shape that substantially follows the peripheral edge of the diaphragm 1 in a plan view. Figure 1 The outer contour of the illustrated frame 3 is slightly smaller than the peripheral edge of the diaphragm 1 and is formed in a shape similar to that of the diaphragm 1 .

[0042] The legs 4 extend downward from the frame 3. The pedals 6 are connected to the lower ends of the legs 4 and are arranged on the player's side (front side). The pedals 6 are operated by the player's feet for playing.

[0043] In the musical instrument MI of this embodiment, the vibrator 2 vibrates (excites) the diaphragm 1 based on performance operations of the keyboard 5 and pedals 6, thereby generating sound (reproducing sound). In addition, the musical instrument MI of this embodiment can also generate sound by vibrating the diaphragm 1 with the vibrator 2 based on pre-prepared performance data, for example.

[0044] like Figure 3 As shown, the vibrator 2 of this embodiment is a voice coil type actuator. Figure 3 The up and down directions correspond to Figure 2 The vibrator 2 includes a magnetic path forming portion 100 (driving portion) and a movable body 200 (movable portion). The movable body 200 includes a rod-shaped portion 201, a cover portion 203, a bobbin 204, and a voice coil 205.

[0045] The annular bobbin 204 is secured to the cover 203 by fitting into the lower portion of the cover 203. The voice coil 205 is composed of a conductive wire wound around the outer circumference of the bobbin 204. The voice coil 205 converts the current flowing through it into vibration within the magnetic field formed by the magnetic path forming section 100. The cover 203, bobbin 204, and voice coil 205 form the electromagnetic engagement section 202 that is electromagnetically engaged with the magnetic path forming section 100.

[0046] The lower end, or first end 201a, of the rod-shaped portion 201 is connected and fixed to the cover portion 203 of the electromagnetic engagement portion 202. The rod-shaped portion 201 extends upward from the cover portion 203. The upper end, or second end 201b, of the rod-shaped portion 201 is fixed to the diaphragm 1 via a connecting portion 210 fixed to the lower surface of the diaphragm 1 (e.g., the second surface 10b of the diaphragm body 10, described later). By securing the second end 201b of the rod-shaped portion 201 to the diaphragm 1, the connecting portion 210 transmits the vibration of the movable body 200 to the diaphragm 1.

[0047] The magnetic circuit forming portion 100 is formed by arranging the top plate 101, the magnet 102 and the yoke 103 in this order from the upper side. The electromagnetic engaging portion 202 is supported by the vibration damper 150 so as not to be in contact with the magnetic circuit forming portion 100 and to be displaceable in the up and down directions (the thickness direction of the vibration plate 1). The vibration damper 150 is formed into a disc shape by, for example, fibers or the like. The disc-shaped portion of the vibration damper 150 is formed into a corrugated shape. The end portion of the outer peripheral side of the vibration damper 150 is mounted on the top plate 101, and the end portion of the inner peripheral side of the vibration damper 150 is mounted on the electromagnetic engaging portion 202. The magnetic circuit forming portion 100 is supported on the frame 3 (see FIG. 1 ) via a support member not shown in the figure. Figure 1 、 2).

[0048] The top plate 101 is made of a soft magnetic material such as soft iron, and is formed into a disk shape with a hole in the center. The yoke 103 is made of a soft magnetic material such as soft iron, and the disk-shaped disc portion 103E and the cylindrical column portion 103F having an outer diameter smaller than that of the disc portion 103E are formed so that the axes of the two coincide and are integrated. The outer diameter of the cylindrical portion 103F is smaller than the inner diameter of the top plate 101. The magnet 102 is a permanent magnet in the form of an annular ring. The inner diameter of the magnet 102 is larger than the inner diameter of the top plate 101. The axes of the top plate 101, the magnet 102 and the yoke 103 are consistent, and become the axis A1 of the magnetic path forming portion 100. By the above configuration, a magnetic circuit forming portion 100 is formed. Figure 3 The electromagnetic engagement portion 202 is arranged so that the voice coil 205 is located in the magnetic path space 105 sandwiched between the top plate 101 and the cylindrical portion 103F. At this time, the electromagnetic engagement portion 202 is horizontally (in the direction of the magnetic path) controlled by the vibration damper 150 so that the axis A2 of the rod-shaped portion 201 is concentric with the axis A1 of the magnetic path forming portion 100. Figure 3 The center is the left and right direction).

[0049] Input to the vibrator 2 is based on the keyboard 5 and pedal 6 (see Figure 1 ) of the playing operation and the driving signal of the playing data. Specifically, the driving signal is input to the voice coil 205. At this time, the voice coil 205 is subjected to the magnetic force of the magnetic circuit space 105, and the driving force in the vertical direction corresponding to the waveform shown by the driving signal acts on the bobbin 204. Therefore, the electromagnetic engaging portion 202 is excited by the magnetic circuit forming portion 100, and the electromagnetic engaging portion 202 and the rod-shaped portion 201 become one and vibrate in the vertical direction. The movable body 200 vibrates in the vertical direction, and the vibration is transmitted to the vibration plate 1 via the connecting portion 210, and the vibration plate 1 is vibrated. The vibration of the vibration plate 1 is emitted into the air and becomes sound.

[0050] Below, refer to Figures 4 to 7 The diaphragm 1 according to this embodiment will be described.

[0051] like Figures 4-6 As shown, the vibration plate 1 includes a vibration plate main body 10 , a first reinforcement member 20 , and a second reinforcement member 30 .

[0052] The vibration plate body 10 is formed into a plate shape by a material having anisotropic linear expansion coefficient and rigidity. The vibration plate body 10 is formed into a flat plate shape in a state without bending deformation. The vibration plate body 10 has a first surface 10a and a second surface 10b facing its thickness direction Z. The first surface 10a and the second surface 10b face opposite sides of each other in the thickness direction Z of the vibration plate body 10. The anisotropic linear expansion coefficient means that the linear expansion coefficient of the first surface 10a and the second surface 10b of the vibration plate body 10 along the first direction Y specified by the first surface 10a and the second surface 10b is greater than the linear expansion coefficient of the second direction X along the first surface 10a and the second surface 10b and perpendicular to the first direction Y. In addition, the anisotropic rigidity means that the rigidity of the vibration plate body 10 in the first direction Y is greater than the rigidity in the second direction X.

[0053] The fact that the linear expansion coefficient and rigidity are anisotropic in the diaphragm body 10 means that the expansion and contraction deformation is anisotropic. The anisotropy of the expansion and contraction deformation of a plate-like member such as the diaphragm body 10 will be described below.

[0054] like Figure 21 As shown, one (single) sheet material P1 is dry or wet and is in the thickness direction (in Figure 21 Specifically, if a sheet of plate P1 is stretched and deformed in a direction perpendicular to the vertical direction (in the vertical direction). Figure 21 (a) Drying is carried out from the reference state shown in FIG. Figure 21 (b) in the dry state), then in the direction perpendicular to the thickness direction (in Figure 21 In addition, if a sheet P1 is moistened (becomes Figure 21 (c)) in a wet state, the sheet material P1 stretches in a direction perpendicular to the thickness direction. Furthermore, the anisotropic expansion and contraction deformation of a sheet material P1 means that the length of contraction or expansion of the sheet material P1 relative to the reference state due to drying or wetting differs in a first direction perpendicular to the thickness direction of the sheet material P1 and a second direction perpendicular to both the thickness direction of the sheet material P1 and the first direction.

[0055] The bending deformation of the vibration plate body 10 that is dependent on expansion and contraction deformation refers to deformation of the vibration plate body 10 that is bent so that the first surface 10a and the second surface 10b of the vibration plate body 10 are bent. Since the linear expansion coefficient and rigidity of the vibration plate body 10 are anisotropic, the bending deformation (flexural deformation) is anisotropic. Moreover, the anisotropy of the bending deformation of the vibration plate body 10 that is dependent on expansion and contraction deformation means that the first direction Y is "a direction in which the vibration plate body 10 is easily expanded and contracted" compared to the second direction X, and is also "a direction in which the vibration plate body 10 is easily bent and deformed." The bending deformation of plate-like components such as the vibration plate body 10 is described below.

[0056] The bending deformation of the plate-shaped member such as the vibration plate body 10 is as follows. Figure 22 As shown in FIG, when two sheets P2 and P3 of single body with anisotropic expansion and contraction deformation are overlapped to form a plate-like component PB, bending deformation may occur in the plate-like component PB. Specifically, when the directions of expansion and contraction deformation between the two overlapping sheets P2 and P3 are orthogonal to each other, bending deformation occurs in the plate-like component PB. Figure 22 In the illustrated plate-like member PB, the upper plate member P2 easily expands and contracts in the left-right direction, and the lower plate member P3 easily expands and contracts in the direction perpendicular to the paper surface.

[0057] If the plate-like member PB is Figure 22 (a) Drying is carried out from the reference state shown in FIG. Figure 22 (b) The upper plate P2 actively shrinks in the left-right direction, but the lower plate P3 does not actively shrink in the left-right direction. Therefore, the upper surface of the upper plate P2 shrinks in the left-right direction, and the left-right shrinkage of the lower surface of the upper plate P2 overlapping with the lower plate P3 is suppressed by the lower plate P3. As a result, Figure 22 In the dry state shown in (b), the plate-shaped member PB is bent and deformed so as to be convex downward.

[0058] On the other hand, if the plate-like member PB is Figure 22 (a) Wetting (become Figure 22 (c) shows the wet state), the upper plate P2 actively stretches in the left-right direction, but the lower plate P3 does not actively stretch in the left-right direction. Therefore, the upper surface side of the upper plate P2 stretches in the left-right direction, but the left-right extension of the lower surface side of the upper plate P2 overlapping with the lower plate P3 is suppressed by the lower plate P3. As a result, Figure 22 In the wet state shown in (c), the plate-shaped member PB is bent and deformed so as to convexly face upward.

[0059] In the drawing ( Figures 4-6 In the diagrams 1 and 2, the first direction Y and the second direction X are indicated by straight lines, assuming that the vibration plate body 10 does not undergo bending deformation.

[0060] The vibration plate body 10 of this embodiment has wood grain extending along the first surface 10a and the second surface 10b and is made of wood. The direction of the wood grain of the vibration plate body 10 corresponds to the aforementioned second direction X. The wooden vibration plate body 10 is easily bent and deformed in a direction perpendicular to the wood grain direction (i.e., the first direction Y). Furthermore, the vibration plate body 10 is not limited to wood and may also be made of other materials such as resin and paper.

[0061] The first reinforcement member 20 is provided so as to protrude from the first surface 10a in the thickness direction Z of the vibration plate body 10 relative to the first surface 10a of the vibration plate body 10. The first reinforcement member 20 is formed in an elongated strip shape extending along the first surface 10a of the vibration plate body 10 in the first direction Y. The length dimension L1 of the first reinforcement member 20 is sufficiently greater than the height dimension H1 of the first reinforcement member 20 and the width dimension W1 of the first reinforcement member 20.

[0062] The first reinforcement 20 of this embodiment extends linearly along the first direction Y. That is, the first reinforcement 20 extends in a direction perpendicular to the second direction X, which is the wood grain direction of the vibration plate body 10. In this embodiment, the length dimension L1 of the first reinforcement 20 is the dimension along the first direction Y. The width dimension W1 of the first reinforcement 20 is the dimension in the width direction of the first reinforcement 20 along the first surface 10a and perpendicular to the length direction of the first reinforcement 20. In this embodiment, the width direction of the first reinforcement 20 corresponds to the second direction X. In addition, the height dimension H1 of the first reinforcement 20 corresponds to the thickness direction Z of the vibration plate body 10.

[0063] In the present embodiment, the width dimension W1 of the first reinforcement 20 is constant throughout the entire length direction of the first reinforcement 20 .

[0064] The height dimension H1 of the first reinforcement member 20 may be constant in the entire length direction of the first reinforcement member 20. Figure 5 As shown, the height dimension H1 of the first reinforcement member 20 varies depending on the position of the first reinforcement member 20 in the longitudinal direction. Specifically, the height dimension H1 of the first reinforcement member 20 is largest in the longitudinal middle portion of the first reinforcement member 20. Furthermore, the height dimension H1 of the first reinforcement member 20 decreases as it moves from the longitudinal middle portion toward the ends of the first reinforcement member 20. The height dimension H1 of the first reinforcement member 20 is preferably greater than the thickness dimension H3 of the vibration plate body 10, and more preferably, for example, is three times the thickness dimension H3 of the vibration plate body 10.

[0065] like Figure 6As shown, the cross-sectional shape of the first reinforcement 20 perpendicular to the longitudinal direction of the first reinforcement 20 is a rectangle whose height dimension H1 is longer than the width dimension W1. Therefore, the cross-sectional shape of the first reinforcement 20 is line-symmetrical in the width direction. Figure 6 In FIG. 1 , a dashed line indicated by reference numeral WC1 is a center line WC1 of the first reinforcement 20 in the width direction of the first reinforcement 20. The cross-sectional shape of the first reinforcement 20 is a line-symmetrical shape with the center line WC1 as an axis.

[0066] like Figures 4-6 As shown, the second reinforcement member 30 is arranged to protrude from the second surface 10b of the vibration plate body 10 in the thickness direction Z of the vibration plate body 10. In other words, the second reinforcement member 30 protrudes from the vibration plate body 10 in the direction opposite to the first reinforcement member 20. The second reinforcement member 30 is formed into an elongated strip shape extending along the second surface 10b of the vibration plate body 10 in the first direction Y. The length dimension L2 of the second reinforcement member 30 is sufficiently greater than the height dimension H2 of the second reinforcement member 30 and the width dimension W2 of the second reinforcement member 30.

[0067] The second reinforcement 30 of this embodiment extends linearly along the first direction Y, similar to the first reinforcement 20. That is, the second reinforcement 30 extends in a direction perpendicular to the second direction X, which is the wood grain direction of the vibration plate body 10. In this embodiment, the length dimension L2 of the second reinforcement 30 is the dimension along the first direction Y. The width dimension W2 of the second reinforcement 30 is the dimension in the width direction of the second reinforcement 30 along the second surface 10b and perpendicular to the length direction of the second reinforcement 30. In this embodiment, the width direction of the second reinforcement 30 corresponds to the second direction X. Furthermore, the height dimension H2 of the second reinforcement 30 corresponds to the thickness direction Z of the vibration plate body 10.

[0068] The second reinforcement 30 can be formed into a shape different from that of the first reinforcement 20, for example. The second reinforcement 30 of this embodiment has the same shape as the first reinforcement 20. Specifically, the width W2 of the second reinforcement 30 is constant throughout the entire length of the second reinforcement 30. Furthermore, the height H2 of the second reinforcement 30 varies depending on the position of the second reinforcement 30 in the lengthwise direction. Similar to the first reinforcement 20, the height H2 of the second reinforcement 30 is preferably greater than the thickness H3 of the vibration plate body 10, and more preferably, for example, is three times the thickness H3 of the vibration plate body 10.

[0069] In addition, if Figure 6 As shown, the cross-sectional shape of the second reinforcement 30 perpendicular to the longitudinal direction of the second reinforcement 30 is a rectangle whose height dimension H2 is longer than the width dimension W2. Therefore, the cross-sectional shape of the second reinforcement 30 becomes line symmetric in the width direction. Figure 6The dashed line indicated by the symbol WC2 in FIG. 3 is the center line WC2 of the second reinforcement 30 in the width direction of the second reinforcement 30. The cross-sectional shape of the second reinforcement 30 is a line-symmetrical shape with the center line WC2 as an axis.

[0070] In this embodiment, the rigidity of the first reinforcement 20 and the second reinforcement 30 are equal to each other. In addition, the specific gravity of the first reinforcement 20 and the second reinforcement 30 is less than the specific gravity of the vibration plate body 10. In addition, the first reinforcement 20 and the second reinforcement 30 are made of the same material.

[0071] In this embodiment, the first reinforcement 20 and the second reinforcement 30 are both made of wood. The wood grain direction of the first reinforcement 20 and the second reinforcement 30 is the same. The wood grain direction of the first reinforcement 20 and the second reinforcement 30 can be completely aligned or slightly tilted. Furthermore, the first reinforcement 20 and the second reinforcement 30 are not limited to wood and can also be made of other materials such as resin (e.g., CFRP).

[0072] like Figure 6 As shown, the cross-sectional shapes of the first reinforcement 20 and the second reinforcement 30 are equal (i.e., rectangular). Furthermore, the cross-sectional area of ​​the first reinforcement 20 perpendicular to the longitudinal direction of the first reinforcement 20 and the cross-sectional area of ​​the second reinforcement 30 perpendicular to the longitudinal direction of the second reinforcement 30 are equal. Furthermore, the cross-sectional shapes of the first reinforcement 20 and the second reinforcement 30 are identical, including their size.

[0073] Thus, the cross-sectional shape of the first reinforcement 20 and the cross-sectional shape of the second reinforcement 30 are line-symmetrical with each other in the thickness direction Z of the vibration plate body 10. Figure 6 , the dashed line HC3 is the center line HC3 of the vibration plate body 10 in the thickness direction Z of the vibration plate body 10 . The cross-sectional shapes of the first reinforcement 20 and the second reinforcement 30 are formed to be line-symmetrical with respect to the center line HC3 .

[0074] In addition, in this embodiment, Figure 5 As shown, the shapes of the first reinforcement 20 and the second reinforcement 30 as viewed in their width direction (second direction X) are also line-symmetrical with respect to the center line HC3 of the diaphragm body 10 .

[0075] The first reinforcement 20 and the second reinforcement 30 overlap each other when viewed in the thickness direction Z of the vibration plate body 10. Figure 5As shown, the length dimension L1 of the first reinforcement 20 and the length dimension L2 of the second reinforcement 30 are equal. Furthermore, the positions of the first reinforcement 20 and the second reinforcement 30 in their longitudinal directions (first direction Y) are aligned. Furthermore, the longitudinal directions of the first reinforcement 20 and the second reinforcement 30 are parallel to each other. Therefore, the first reinforcement 20 and the second reinforcement 30 overlap along their entire lengths. Furthermore, the first reinforcement 20 and the second reinforcement 30 are arranged to be line-symmetrical with each other in their longitudinal directions.

[0076] exist Figure 5 In FIG, the dot-dash line indicated by reference numeral LC1 is the center line LC1 of the first reinforcement 20 in the longitudinal direction of the first reinforcement 20. In addition, the dot-dash line indicated by reference numeral LC2 is the center line LC2 of the second reinforcement 30 in the longitudinal direction of the second reinforcement 30. Figure 5 In the embodiment, the center lines LC1 and LC2 of the first reinforcement 20 and the second reinforcement 30 coincide with each other. Thus, the first reinforcement 20 and the second reinforcement 30 are arranged to be line-symmetrical with each other in the longitudinal direction.

[0077] In addition, in this embodiment, Figure 6 As shown, the position of the first reinforcement 20 and the position of the second reinforcement 30 in the width direction coincide with each other. That is, the center lines WC1 and WC2 of the first reinforcement 20 and the second reinforcement 30 in the width direction coincide with each other. Furthermore, the width dimensions W1 and W2 of the first reinforcement 20 and the second reinforcement 30 are equal. Therefore, the first reinforcement 20 and the second reinforcement 30 overlap with each other throughout the width direction.

[0078] Furthermore, in this embodiment, in a cross section perpendicular to the longitudinal direction (first direction Y) of the first reinforcement 20 and the second reinforcement 30, the cross-sectional shape including both the first reinforcement 20 and the second reinforcement 30 is line-symmetrical in the width direction. In other words, the cross-sectional shape including both the first reinforcement 20 and the second reinforcement 30 is line-symmetrical about the center lines WC1 and WC2 in the width directions of the first reinforcement 20 and the second reinforcement 30 as axes.

[0079] Furthermore, in this embodiment, the length TH (total length TH) from the protruding front end of the first reinforcement 20 to the protruding front end of the second reinforcement 30 in the thickness direction Z of the vibration plate body 10 is preferably at least five times the thickness dimension H3 of the vibration plate body 10. The above-mentioned total length TH corresponds to the sum of the height dimensions H1 and H2 of the first reinforcement 20 and the second reinforcement 30 and the thickness dimension H3 of the vibration plate body 10.

[0080] In the present embodiment, in each of the reinforcements 20 and 30 (the reinforcements constituting the first reinforcement 20 and the second reinforcement 30), when the maximum height dimension of the reinforcements 20 and 30 is HMAX and the maximum width dimension of the reinforcements 20 and 30 is WMAX, it is preferable that 0.5 ≤ HMAX / WMAX ≤ 4.0. For example, HMAX / WMAX is more preferably approximately 2.0.

[0081] The reinforcement members 20 and 30 of the vibration plate 1 are Figure 1 In the musical instrument MI shown in FIG. 1 , the arrangement can be such that the vibrator 2 does not interfere with the mounting position of the vibration plate body 10. Figure 1 As shown in the example, the first reinforcement 20 and the second reinforcement 30 may be arranged inside the frame 3 as viewed from the thickness direction Z of the vibration plate body 10. Figure 1 As shown in the example, a plurality of the reinforcement members 20 and 30 are arranged at intervals in the width direction. The plurality of sets of the first reinforcement member 20 and the second reinforcement member 30 can be as follows. Figure 1 Although they are parallel to each other as shown in the example, they may not be parallel to each other.

[0082] As described above, in the vibration plate 1 of this embodiment, a first, elongated reinforcement 20 is provided on the first surface 10a of the vibration plate main body 10. The reinforcement 20 extends in the direction (first direction Y) in which the vibration plate main body 10 is easily deformed (expanded and / or bent). Furthermore, a second, elongated reinforcement 30 is provided on the second surface 10b of the vibration plate main body 10. The reinforcement 30 extends in the direction in which the vibration plate main body 10 is easily deformed (expanded and / or bent). Furthermore, when viewed in the thickness direction Z of the vibration plate main body 10, the first reinforcement 20 and the second reinforcement 30 overlap. Thus, the first and second reinforcements 20 and 30 can effectively suppress the vibration plate main body 10 from attempting to expand or contract in the direction in which it is easily deformed, or from attempting to bend in the direction in which it is easily bent.

[0083] This point will be described below.

[0084] For example, Figure 7 As shown, when a stress (a force indicated by arrow F1) acts on the vibration plate body 10 in a direction prone to expansion and contraction (first direction Y) due to drying or the like, the first reinforcement 20 clamps the stress generated on the first surface 10a of the vibration plate body 10, thereby suppressing the contraction of the portion on the first surface 10a of the vibration plate body 10. Furthermore, the second reinforcement 30 clamps the stress generated on the second surface 10b of the vibration plate body 10, thereby suppressing the contraction of the portion on the second surface 10b of the vibration plate body 10.

[0085] Furthermore, although not shown, when stress is applied to the vibration plate body 10, such as by moisture, which tends to cause the vibration plate body 10 to extend in the direction in which it is prone to expansion and contraction (first direction Y), the first reinforcement 20 clamps the stress generated on the first surface 10a of the vibration plate body 10, thereby suppressing the extension of the portion on the first surface 10a of the vibration plate body 10. Furthermore, the second reinforcement 30 clamps the stress generated on the second surface 10b of the vibration plate body 10, thereby suppressing the extension of the portion on the second surface 10b of the vibration plate body 10.

[0086] As described above, the expansion and contraction deformation of the diaphragm body 10 in the first direction Y caused by drying or wetting of the diaphragm body 10 can be effectively suppressed. In addition, the diaphragm body 10 can be effectively prevented from bending in a direction prone to bending deformation due to the expansion and contraction deformation.

[0087] In addition, in the vibration plate 1 of this embodiment, the vibration plate body 10 has wood grain extending along the first surface 10a and the second surface 10b, and is made of wood. Therefore, the vibration plate body 10 is easily deformed in the direction perpendicular to the wood grain direction (first direction Y). In contrast, the first reinforcement 20 and the second reinforcement 30 extend in directions intersecting the wood grain direction in such a way that they overlap with each other. As a result, the first reinforcement 20 and the second reinforcement 30 can effectively suppress the vibration plate body 10 from attempting to deform in the direction perpendicular to the wood grain direction.

[0088] Furthermore, in the vibration plate 1 of this embodiment, the rigidity of the first reinforcement 20 and the second reinforcement 30 are equal. Therefore, the forces used to suppress the expansion and contraction deformation of the vibration plate body 10 and the bending deformation dependent on expansion and contraction can be made uniform (or equal) in the first reinforcement 20 and the second reinforcement 30. This allows for more effective suppression of the expansion and contraction deformation of the vibration plate body 10 and the bending deformation dependent on expansion and contraction.

[0089] Furthermore, in the vibration plate 1 of this embodiment, the first reinforcement 20 and the second reinforcement 30 are made of the same material. Therefore, simply by forming the first reinforcement 20 and the second reinforcement 30 into the same shape and size, the forces that suppress the expansion and contraction deformation of the vibration plate body 10 and the bending deformation that depends on the expansion and contraction deformation can be easily made uniform (or equal) in the first reinforcement 20 and the second reinforcement 30.

[0090] Furthermore, in the vibration plate 1 of this embodiment, the first and second reinforcements 20, 30 have the same rigidity and material, and the cross-sectional areas of the first and second reinforcements 20, 30 perpendicular to their longitudinal directions are equal. Therefore, even if the cross-sectional shapes of the first and second reinforcements 20, 30 differ, the characteristics of the reinforcements 20, 30 expanding and contracting along their longitudinal directions in response to changes in temperature and humidity are the same in the first and second reinforcements 20, 30. This prevents any differences in the effects of suppressing expansion and contraction deformation of the vibration plate body 10 and the resulting bending deformation between the first and second surfaces 10a, 10b of the vibration plate body 10. As a result, expansion and contraction deformation of the vibration plate body 10 and the resulting bending deformation can be appropriately suppressed.

[0091] Furthermore, in the diaphragm 1 of this embodiment, the first reinforcement 20 and the second reinforcement 30 are arranged so as to be line-symmetrical with each other in the longitudinal direction of the first reinforcement 20 and the second reinforcement 30. Thus, even if the length L1 of the first reinforcement 20 and the second reinforcement 30 differ, or the arrangement of the first reinforcement 20 and the second reinforcement 30 differs, expansion and contraction deformation of the diaphragm body 10 and bending deformation associated with expansion and contraction deformation can be effectively suppressed.

[0092] In the diaphragm 1 of this embodiment, when the total length TH from the protruding front end of the first reinforcement 20 to the protruding front end of the second reinforcement 30 is five times or more the thickness dimension H3 of the diaphragm body 10, the second moment of area of ​​the two reinforcements 20 and 30 in the thickness direction Z of the diaphragm body 10 relative to the diaphragm body 10 becomes large. As a result, the two reinforcements 20 and 30 can effectively suppress expansion and contraction deformation of the diaphragm body 10 and bending deformation dependent on expansion and contraction deformation.

[0093] Furthermore, in the vibration plate 1 of this embodiment, when the ratio HMAX / WMAX of the maximum height dimension HMAX to the maximum width dimension WMAX of the reinforcements 20 and 30 (reinforcements serving as the first reinforcement 20 and the second reinforcement 30) is 0.5 or greater, warping (vertical warping) of the reinforcements 20 and 30 in the thickness direction Z of the vibration plate body 10 (vertical warping) can be suppressed. Furthermore, when HMAX / WMAX is 4.0 or less, warping (lateral warping) of the reinforcements 20 and 30 in the width direction 20 and 30 can be suppressed. In other words, good balance of the second moment of area of ​​the reinforcements 20 and 30 in each of the thickness direction Z of the vibration plate body 10 and the width direction of the reinforcements 20 and 30 can be ensured. Thus, vertical warping and lateral warping of the reinforcements 20 and 30 can be effectively suppressed. Consequently, expansion and contraction deformation of the reinforcements 20 and 30, as well as bending deformation dependent on expansion and contraction deformation, can be effectively suppressed.

[0094] Furthermore, when HMAX / WMAX is approximately 2 (the height dimensions H1 and H2 of the reinforcements 20 and 30 are approximately twice the width dimensions W1 and W2), the rigidity of the reinforcements 20 and 30 (the specific rigidity of the reinforcements 20 and 30) relative to the rigidity of the vibration plate body 10 can be effectively increased. This effectively suppresses expansion and contraction deformation of the vibration plate body 10. Furthermore, attempts by the vibration plate body 10 to bend in a direction prone to bending due to expansion and contraction deformation can be more effectively suppressed.

[0095] Furthermore, in the diaphragm 1 of this embodiment, even when the specific gravity of the reinforcements 20 and 30 is less than that of the diaphragm body 10, the specific rigidity of the reinforcements 20 and 30 can be increased. This can more effectively suppress the expansion and contraction deformation of the diaphragm body 10. Furthermore, it can more effectively suppress the diaphragm body 10 from attempting to bend in a direction prone to bending deformation due to its expansion and contraction deformation.

[0096] Furthermore, in the diaphragm 1 of this embodiment, even when the height dimension of the reinforcement members 20 and 30 is three times the thickness dimension H3 of the diaphragm body 10, the specific rigidity of the reinforcement members 20 and 30 can be increased. This can more effectively suppress the expansion and contraction deformation of the diaphragm body 10. Furthermore, it can more effectively suppress the diaphragm body 10 from attempting to bend in a direction prone to bending deformation due to its expansion and contraction deformation.

[0097] According to the musical instrument MI of this embodiment, the vibrator 2 is attached to the diaphragm 1 whose expansion and contraction deformation is effectively suppressed as described above. Therefore, the change in the sound generation characteristics of the diaphragm 1 obtained by the vibrator 2 due to the expansion and contraction deformation of the diaphragm 1 can be suppressed.

[0098] In the first embodiment, for example, Figure 8 、 9 As shown, when viewed from the thickness direction Z of the vibration plate body 10, only a portion of the first reinforcement 20 and the second reinforcement 30 in the width direction overlap. Figure 8 、 9 In the illustrated structure, the center lines WC1 and WC2 of the first and second reinforcement members 20 and 30 in the width direction are located at positions offset from each other, so that only a portion of the first and second reinforcement members 20 and 30 in the width direction overlap. Figure 8 In FIG. 1 , the area where the first reinforcement 20 and the second reinforcement 30 overlap is indicated by linear hatching.

[0099] In addition, for example, a portion of the first reinforcement 20 and the second reinforcement 30 in the width direction may overlap the entire length of one of the first reinforcement 20 and the second reinforcement 30. Figure 8 In the illustrated structure, the length L1 of the first reinforcement 20 is shorter than the length L2 of the second reinforcement 30 , so that the first reinforcement 20 and the second reinforcement 30 partially overlap in the width direction over the entire length of the first reinforcement 20 .

[0100] Even if Figure 8 、 9 The illustrated structure can also effectively suppress the expansion and contraction deformation of the diaphragm body 10 and the bending deformation caused by the expansion and contraction deformation, similarly to the above-described embodiment.

[0101] However, the ratio of the size of the portion where the first reinforcement 20 and the second reinforcement 30 overlap with each other in the width direction to the width dimension of one of the reinforcements 20 and 30 is preferably larger. The larger the ratio of the size of the portion where the first reinforcement 20 and the second reinforcement 30 overlap with each other in the width direction to the width dimension of one of the reinforcements 20 and 30, the more effectively the expansion and contraction deformation of the vibration plate body 10 and the bending deformation that depends on the expansion and contraction deformation can be suppressed. That is, as Figure 6 As illustrated, it is most preferable that the first reinforcement 20 and the second reinforcement 30 overlap over the entire width direction of one of the reinforcement members.

[0102] In the first embodiment, for example, Figure 10 As shown, the length dimensions L1 and L2 of the first reinforcement 20 and the second reinforcement 30 are different from each other. Figure 10 In the embodiment, the length L1 of the first reinforcement 20 is shorter than the length L2 of the second reinforcement 30. Figure 10In the illustrated structure, the longitudinal centerline LC1 of the first reinforcement 20 and the longitudinal centerline LC2 of the second reinforcement 30 coincide with each other. That is, the first reinforcement 20 and the second reinforcement 30 are arranged to be line-symmetrical with each other in their longitudinal directions. Therefore, the same effects as those of the first embodiment described above can be achieved.

[0103] In the first embodiment, for example, Figure 11 As shown, the first reinforcement 20 and the second reinforcement 30 are configured differently. Figure 11 In the embodiment, one first reinforcement 20 is arranged on the first surface 10a of the vibration plate body 10, and the second reinforcement 30 is divided into a plurality of parts along the length direction (in Figure 11 3 in the configuration. Figure 11 In the illustrated structure, the longitudinal centerline LC1 of the first reinforcement 20 and the longitudinal centerline LC2 of the second reinforcement 30 coincide with each other. That is, the first reinforcement 20 and the second reinforcement 30 are arranged to be line-symmetrical with each other in their longitudinal directions. Therefore, the same effects as those of the first embodiment described above can be achieved.

[0104] exist Figure 11 In the embodiment, the total length L2 of the second reinforcement 30 divided into a plurality of parts is equal to the length L1 of the first reinforcement 20 , but may be different from each other, for example.

[0105] In the first embodiment, the first reinforcement 20 and the second reinforcement 30 may be, for example, Figure 12 As shown, the reinforcements 20 and 30 are located at positions offset from each other in the longitudinal direction (first direction Y). In this case, it is preferred that the distance D1 (first distance D1) between the first end 21 of the first reinforcement 20 and the first end 31 of the second reinforcement 30 located on one side in the longitudinal direction, and the distance D2 (second distance D2) between the second end 22 of the first reinforcement 20 and the second end 32 of the second reinforcement 30 located on the other side in the longitudinal direction are both less than 20% of the length dimension of the longer reinforcement of the first reinforcement 20 and the second reinforcement 30. Figure 12 In the illustrated structure, the length L1 of the first reinforcement 20 is longer than the length L2 of the second reinforcement 30. Therefore, the first distance D1 and the second distance D2 are preferably less than 20% of the length L1 of the first reinforcement 20.

[0106] In the first embodiment, for example, Figure 13 As shown in FIG. 1 , when viewed from the thickness direction Z of the vibration plate body 10 , the first reinforcement 20 and the second reinforcement 30 overlap at a portion of their lengthwise directions. Figure 13In the embodiment, the first reinforcement 20 and the second reinforcement 30 intersect each other, so that the middle portions of the first reinforcement 20 and the second reinforcement 30 in the longitudinal direction overlap each other. Figure 13 In FIG, the area where the first reinforcement 20 and the second reinforcement 30 overlap is shown by a linear hatching. Figure 13 In the embodiment, the first reinforcement 20 and the second reinforcement 30 overlap over their entire width directions, but for example, only a portion of the width directions of the first reinforcement 20 and the second reinforcement 30 may overlap. In addition, the first reinforcement 20 and the second reinforcement 30 may overlap at their longitudinal ends, for example.

[0107] Even in a structure where the first reinforcement 20 and the second reinforcement 30 overlap at a portion of their length directions, the first reinforcement 20 and the second reinforcement 30 can suppress the expansion and contraction deformation of the vibration plate body 10 in the first direction Y (the direction in which the vibration plate body 10 is prone to expansion and contraction deformation) and the attempt to bend along the first direction Y (the direction in which the vibration plate body 10 is prone to bending deformation) in the same manner as in the first embodiment.

[0108] However, the ratio of the length of the portion where the first reinforcement 20 and the second reinforcement 30 overlap with each other to the total length of one of the reinforcements 20 and 30 is preferably large, more preferably 50% or more. The larger the ratio of the length of the portion where the first reinforcement 20 and the second reinforcement 30 overlap with each other to the total length of one of the reinforcements 20 and 30, the more effectively the expansion and contraction deformation and bending deformation of the vibration plate body 10 can be suppressed. That is, if Figure 6 、 8 As illustrated, it is most preferable that the first reinforcement 20 and the second reinforcement 30 overlap over the entire length of at least one of them.

[0109] In the first embodiment, the first reinforcement 20 and the second reinforcement 30 may be, for example, Figure 13 As shown, the first and second reinforcement members 20 and 30 intersect with the first direction Y (the direction in which the vibration plate body 10 is easily deformed (telescopic deformation and / or bending deformation)). However, it is preferred that the inclination angle of the length direction of the first reinforcement member 20 and the second reinforcement member 30 relative to the first direction Y is smaller than the inclination angle of the length direction of the first reinforcement member 20 and the second reinforcement member 30 relative to the second direction X. In other words, the first reinforcement member 20 and the second reinforcement member 30 preferably extend mainly along the first direction Y.

[0110] In addition, the first reinforcement 20 and the second reinforcement 30 are not limited to extending linearly mainly in the first direction Y, and may be formed into a strip shape that bends (snaps) along the second direction X while extending mainly in the first direction Y. Figure 13In the embodiment, the first reinforcement 20 extends linearly, and the second reinforcement 30 extends mainly in the first direction Y while being curved (meandering) in the second direction X.

[0111] In the first embodiment, the width dimensions of the reinforcements 20, 30 (first reinforcement 20, second reinforcement 30) may vary, for example, in the longitudinal direction of the reinforcements 20, 30. Figure 13 In the embodiment, the width dimension of the first reinforcement member 20 increases as it moves from one side of the length direction toward the other side (in Figure 13 In addition, Figure 13 In the embodiment, the width dimension of the second reinforcement member 30 which snakes along the second direction X is constant throughout the entire length direction of the second reinforcement member 30 .

[0112] In the first embodiment, the cross-sectional shape of the reinforcement members 20, 30 perpendicular to the longitudinal direction of the reinforcement members 20, 30 is not limited to a rectangle, but may be any. Figure 14 As shown, the base end portions of the reinforcement members 20 and 30 in the height direction (thickness direction Z) are formed to have a constricted shape. Figure 14 The cross-sectional shape of the reinforcement members 20 and 30 shown in the example is similar to the first embodiment described above and is line-symmetrical in the width direction. Figure 14 In the embodiment, similarly to the first embodiment, the cross-sectional shape of the first reinforcement 20 and the cross-sectional shape of the second reinforcement 30 are formed to be line-symmetrical with each other in the thickness direction Z of the diaphragm body 10 .

[0113] In the first embodiment, for example, Figure 15 、 16 As shown, the cross-sectional shapes of the reinforcement members 20 and 30 perpendicular to the longitudinal direction of the reinforcement members 20 and 30 are different between the first reinforcement member 20 and the second reinforcement member 30. Figure 15 In the embodiment, the cross-sectional shape of the first reinforcement member 20 is a rectangle, and the cross-sectional shape of the second reinforcement member 30 is the same as Figure 14 Similarly, the base end portion of the second reinforcement 30 in the height direction has a constricted shape. Figure 16 In the embodiment, the cross-sectional shape of the first reinforcement 20 is rectangular, and the cross-sectional shape of the second reinforcement 30 is triangular. Even with such a structure, the same effects as those of the first embodiment can be obtained if the cross-sectional areas of the first reinforcement 20 and the second reinforcement 30 perpendicular to the longitudinal direction are equal.

[0114] In the first embodiment, for example, Figure 17As shown, in the cross section of the reinforcements 20, 30 perpendicular to the longitudinal direction of the reinforcements 20, 30, the height dimension H1 of the first reinforcement 20 and the height dimension H2 of the second reinforcement 30 are different from each other. Figure 17 In the embodiment, the height dimension H2 of the second reinforcement member 30 is smaller than the height dimension H1 of the first reinforcement member 20. In this structure, when the vibrator 2 is attached to the second surface 10b of the vibration plate body 10, interference between the vibrator 2 and the second reinforcement member 30 with a smaller height dimension can be effectively suppressed.

[0115] In addition, if Figure 17 As shown in the example, the height dimension H1 of the first reinforcement 20 and the height dimension H2 of the second reinforcement 30 can be different from each other. When the cross-sectional areas of the first reinforcement 20 and the second reinforcement 30 perpendicular to the longitudinal direction are equal to each other, the same effect as the aforementioned first embodiment can be obtained.

[0116] [Second embodiment]

[0117] Next, the main reference Figure 18 、 19 In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and the like, and their descriptions are omitted.

[0118] Figure 18 A diaphragm 1C according to a first example of the second embodiment is shown. Figure 19 The second embodiment shows a second example of a vibration plate 1D. The vibration plates 1C and 1D of the second embodiment can be used in the same manner as the vibration plate 1 of the first embodiment. Figure 1 、 2 The instrument MI shown.

[0119] Figure 18 、 19 The diaphragms 1C and 1D shown in the figure have a diaphragm main body 10, a first reinforcement 20, and a second reinforcement 30, similarly to the first embodiment. The diaphragm main body 10 is similar to that of the first embodiment.

[0120] exist Figure 18 The vibration plate 1C shown, the first reinforcement 20 and Figure 13 The first reinforcement 20 shown in the example is formed in the same manner. That is, the first reinforcement 20 mainly extends in a straight line along the first direction Y, and its width dimension increases from one side toward the other side in the longitudinal direction (in Figure 13 In addition, the second reinforcement 30 and the Figure 13The illustrated second reinforcement 30 is formed identically. That is, the second reinforcement 30 extends primarily in the first direction Y while curving (snaking) in the second direction X. The width of the second reinforcement 30 is constant throughout the entire length of the second reinforcement 30. The maximum width dimension W1MAX (maximum width dimension W1MAX) of the first reinforcement 20 is greater than the width dimension of the second reinforcement 30.

[0121] exist Figure 19 The vibration plate 1D shown in FIG. 1D has the first reinforcement 20 and the second reinforcement 30 having the same Figure 15 The first reinforcement 20 and the second reinforcement 30 shown in the example have the same cross-sectional shape. The maximum dimension W2MAX (maximum width dimension W2MAX) in the width direction of the second reinforcement 30 is larger than the width dimension W1 of the first reinforcement 20 .

[0122] exist Figure 18 、 19 In the vibration plates 1C and 1D of the second embodiment shown, the first reinforcement 20 and the second reinforcement 30 are arranged with a gap in their width direction (main second direction X). Therefore, the first reinforcement 20 and the second reinforcement 30 do not overlap in the thickness direction Z of the vibration plate body 10. The gap I in the width direction between the first reinforcement 20 and the second reinforcement 30 is less than 3 times the maximum dimension of either the first reinforcement 20 or the second reinforcement 30 in a cross section perpendicular to its longitudinal direction. Here, the gap I in the width direction between the first reinforcement 20 and the second reinforcement 30 is the distance between the centroid C1 of the first reinforcement 20 and the centroid C2 of the second reinforcement 30 in a cross section perpendicular to the longitudinal direction. The maximum dimension of a cross section of a reinforcement can be, for example, the maximum dimension in the width direction of a reinforcement (maximum width dimension), or the maximum dimension in the height direction of a reinforcement (maximum height dimension).

[0123] exist Figure 18 In the diaphragm 1C shown, the interval I in the width direction between the first reinforcement 20 and the second reinforcement 30 is equal to or less than three times the maximum width W1MAX of the first reinforcement 20 . Figure 18 The symbol R shows an example of a range of three times the maximum width dimension W1MAX of the first reinforcement member 20 starting from the centroid C1 of the first reinforcement member 20. Figure 18 , it is shown that the interval I in the width direction between the first reinforcement 20 and the second reinforcement 30 is equal to or less than three times the maximum width dimension W1MAX of the first reinforcement 20 .

[0124] exist Figure 19 In the diaphragm 1D shown, the interval I in the width direction between the first reinforcement 20 and the second reinforcement 30 is equal to or less than three times the maximum width W2MAX of the second reinforcement 30 . Figure 19 The symbol R shows an example of a range of three times the maximum width dimension W2MAX of the second reinforcement 30 with the centroid C2 of the second reinforcement 30 as the starting point. Figure 19 , it is shown that the interval I in the width direction between the first reinforcement 20 and the second reinforcement 30 is equal to or less than three times the maximum width dimension W2MAX of the second reinforcement 30 .

[0125] As described above, in the diaphragms 1C and 1D of the second embodiment, similar to the first embodiment, a first, elongated reinforcement 20 is provided on the first surface 10a of the diaphragm body 10. The reinforcement 20 extends in the direction (first direction Y) in which the diaphragm body 10 easily deforms (expands and / or bends). Furthermore, a second, elongated reinforcement 30 is provided on the second surface 10b of the diaphragm body 10. The reinforcement 30 extends in the direction in which the diaphragm body 10 easily deforms (expands and / or bends). Furthermore, the first and second reinforcements 20 and 30 are spaced apart in the width direction of the reinforcements 20 and 30, as viewed in the thickness direction Z of the diaphragm body 10. The spacing between the first and second reinforcements 20 and 30 in the width direction is no greater than three times the maximum dimension of either reinforcement 20 or 30 in a cross-section perpendicular to the longitudinal direction. Thus, similar to the first embodiment, the first reinforcement 20 and the second reinforcement 30 can effectively suppress the diaphragm body 10 from attempting to expand or contract in a direction in which it is easily deformed or to bend in a direction in which it is easily deformed.

[0126] In addition, the vibration plates 1C and 1D of the second embodiment can achieve the same effects as those of the first embodiment. Figure 1 、 2 ), achieving the same effect as the first embodiment.

[0127] The second embodiment of the reinforcement can be configured in a manner similar to the first embodiment (e.g., Figures 4-6 ), its modified examples (such as Figures 8 to 17 )same.

[0128] As mentioned above, although the present invention was described in detail, the present invention is not limited to the above-mentioned embodiment, and various modifications can be added without departing from the scope of the present invention.

[0129] In the present invention, the vibration plate body 10 is not limited to a single plate, and may be Figure 20The composite board shown is a composite board made of a plurality of (three in the figure) stacked sheets 11. Figure 20 The vibration plate body 10 shown in the example has a plate 11 that is a wooden plate 11. The plurality of wooden plates 11 each have wood grain extending along the first surface 10a and the second surface 10b of the vibration plate body 10. The directions of the wood grain of the plurality of wooden plates 11 may be, for example, consistent with each other, or may cross each other. For example, the wood grain direction of a given wooden plate 11 may cross the wood grain directions of the other two wooden plates 11 sandwiching the given wooden plate 11, and the wood grain directions of the other two wooden plates 11 may be consistent with each other. The vibration plate body 10 having three overlapping plates 11 has anisotropy in bending deformation. Specifically, the first direction Y is easier to bend and deform than the second direction X.

[0130] When the vibration plate body 10 is the composite plate described above, the first reinforcement 20 provided on the first surface 10a and the second reinforcement 30 provided on the second surface 10b can extend along the first surface 10a and the second surface 10b in a direction (e.g., orthogonal direction) that intersects the wood grain direction of at least one wooden board 11. In other words, the first reinforcement 20 and the second reinforcement 30 can extend along a direction in which at least one wooden board 11 is easily deformed. Figure 20 In the embodiment, the first reinforcement 20 and the second reinforcement 30 extend in a direction perpendicular to the wood grain direction of the wooden board 11 forming the first surface 10a of the vibration plate body 10. Even if the vibration plate body 10 is a composite board, by arranging the first reinforcement 20 and the second reinforcement 30 in the above manner, it is possible to effectively suppress the vibration plate body 10 from attempting to bend in a direction that is prone to bending deformation (bending deformation of the vibration plate body 10) by the first reinforcement 20 and the second reinforcement 30, as in the first and second embodiments.

[0131] The vibration plate of the present invention is not limited to Figure 1 、 2 The keyboard musical instrument such as the piano described as an example can also be applied to other musical instruments having a vibration plate, such as string instruments and percussion instruments (such as a cajon).

[0132] Description of the label

[0133] 1, 1C, 1D…vibration plate, 2…vibrator, 10…vibration plate body, 10a…first surface, 10b…second surface, 11…wooden board (plate material), 20…first reinforcement, 30…second reinforcement, X…second direction (direction of wood grain), Y…first direction (direction in which the vibration plate body 10 is easily deformed), Z…thickness direction.

Claims

1. A vibration plate comprising: A plate-shaped vibration plate body having anisotropic deformation; a first elongated reinforcement member, which is arranged to protrude from the first surface relative to the first surface of the vibration plate body and extends along the first surface in a direction to prevent deformation of the vibration plate body; and a second elongated reinforcing member, which is arranged to protrude from the second surface relative to the second surface of the vibration plate body and extends along the second surface in a direction to prevent deformation of the vibration plate body; When viewed in the thickness direction of the vibration plate body, at least a portion of the first reinforcement and the second reinforcement in the width direction overlaps at least a portion of the first reinforcement and the second reinforcement in the length direction.

2. The vibration plate according to claim 1, wherein At least a portion of the first reinforcement and the second reinforcement in the width direction overlaps over the entire length of at least one of the first reinforcement and the second reinforcement.

3. A vibration plate comprising: A plate-shaped vibration plate body having anisotropic deformation; a first elongated reinforcement member, which is arranged to protrude from the first surface relative to the first surface of the vibration plate body and extends along the first surface in a direction to prevent deformation of the vibration plate body; and a second elongated reinforcing member, which is arranged to protrude from the second surface relative to the second surface of the vibration plate body and extends along the second surface in a direction to prevent deformation of the vibration plate body; The first reinforcement and the second reinforcement are arranged at intervals in the width direction when viewed from the thickness direction of the vibration plate body. The distance between the first and second reinforcement members in the width direction is not more than three times the maximum dimension of either the first reinforcement member or the second reinforcement member in a cross section perpendicular to the longitudinal direction thereof.

4. The vibration plate according to any one of claims 1 to 3, wherein The vibration plate body has wood grain extending along the first surface and the second surface and is made of wood. The first reinforcement and the second reinforcement extend in a direction intersecting with a grain direction of the vibration plate body.

5. The vibration plate according to any one of claims 1 to 3, wherein The vibration plate body is a composite plate formed by stacking a plurality of wooden plates. The plurality of wooden boards each have wood grain extending along the first surface and the second surface. The first reinforcement member and the second reinforcement member extend in a direction intersecting with a wood grain direction of at least one of the wooden boards.

6. The vibration plate according to any one of claims 1 to 3, wherein The first reinforcement member and the second reinforcement member have the same rigidity.

7. The vibration plate according to any one of claims 1 to 3, wherein The first reinforcement member and the second reinforcement member are made of the same material.

8. The vibration plate according to claim 6, wherein A cross-sectional area of ​​the first reinforcement perpendicular to the longitudinal direction and a cross-sectional area of ​​the second reinforcement perpendicular to the longitudinal direction are equal to each other.

9. The vibration plate according to any one of claims 1 to 3, wherein The first reinforcement member and the second reinforcement member are arranged to be line-symmetrical with each other in the longitudinal direction of the first reinforcement member and the second reinforcement member.

10. A musical instrument comprising: The vibration plate according to any one of claims 1 to 9; and A vibrator vibrates the vibration plate body.

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