JP7326870B2 - equipment and keyboard instruments - Google Patents

Description

The present invention relates to a device having a vibration source such as a speaker and a keyboard instrument.

2. Description of the Related Art Conventionally, in acoustic devices such as electronic musical instruments and speaker boxes, there have been cases where the case of the musical instrument or the acoustic device resonates due to the sound pressure generated by the speaker, which affects the quality of the reproduced sound. As a method for solving such a problem, there is known a case member of a musical instrument or an audio equipment provided with a reinforcing rib having a honeycomb structure. For example, Patent Document 1 describes a speaker box having a honeycomb structure in which cells of uniform or non-uniform sizes are arranged on one surface (outer surface or inner surface) or both surfaces of a speaker mounting plate.

Japanese Utility Model Laid-Open No. 56-116792

The above-mentioned Patent Document 1 describes suppressing the resonance of the case by providing a honeycomb structure around the speaker attached to the speaker mounting plate. Here, regarding the honeycomb structure, only the provision of the honeycomb structure on one side or both sides of the speaker mounting plate and the arrangement of cells of uniform or non-uniform size are disclosed. Therefore, there is room for further improvement in order to better suppress resonance in the case provided with the honeycomb structure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a device having a housing structure capable of satisfactorily suppressing resonance in a device having a vibration source such as a speaker, and a keyboard instrument.

The device according to the invention comprises:
a vibration source speaker;
a case housing the speaker, the case having an area in which a plurality of polygonal ribs for suppressing resonance due to vibration of the speaker are arranged;
with
The regions where the plurality of polygonal ribs are arranged include a first region where a plurality of first polygonal ribs having polygons of a first size are arranged, and the first region outside the first region. a second region in which a plurality of second polygonal ribs having polygons of a second size larger than the size are arranged.

According to the present invention, it is possible to satisfactorily suppress resonance in a device having a vibration source such as a speaker.

1 is an external view showing an embodiment of a keyboard instrument according to the present invention; FIG. 1 is a cross-sectional view showing an example of the internal structure of the keyboard instrument according to the first embodiment; FIG. 1 is a schematic diagram showing an example of an assembly structure of a keyboard instrument according to a first embodiment; FIG. 4 is a schematic diagram showing an example of a speaker panel applied to the upper case of the keyboard instrument according to the first embodiment; FIG. FIG. 4 is a schematic diagram for explaining a resonance suppressor applied to the first embodiment; It is a figure which shows the result of the natural vibration analysis in a speaker panel. FIG. 10 is a plan view showing another example of the resonance suppressor applied to the first embodiment; FIG. 10 is a cross-sectional view showing an example of the internal structure of the keyboard instrument according to the second embodiment; It is a schematic showing an example of the assembly structure of the keyboard instrument according to the second embodiment. FIG. 11 is a schematic diagram showing an example of a resonance suppressor applied to the lower case of the keyboard instrument according to the second embodiment; FIG. 11 is a schematic diagram showing an example of a speaker panel applied to a keyboard instrument according to a third embodiment;

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail, referring drawings. In this embodiment, an electronic keyboard instrument will be described as an example of the device and keyboard instrument according to the present invention.

<First Embodiment>
(electronic keyboard instrument)
FIG. 1 is an external view showing an embodiment of a keyboard instrument according to the present invention, and FIG. 2 is a sectional view showing an example of the internal structure of the keyboard instrument according to the first embodiment. Also, FIG. 3 is a schematic diagram showing an example of the assembly structure of the keyboard instrument according to the present embodiment. FIG. 3A is a schematic diagram showing an example of an assembly structure of an upper case and a lower case of a keyboard instrument, and FIG. 3B is a schematic diagram showing the inner side of the upper case inside the instrument.

An electronic keyboard instrument 100 according to this embodiment, as shown in FIGS. As shown in FIG. 1, the upper case 110 and the lower case 120 have a shape in which the longitudinal direction extends in the arrangement direction of the keys 142 in the keyboard unit 140 (horizontal direction in the drawing), and the keys 142 of the keyboard unit 140 are exposed. have.

Specifically, the upper case 110 includes a center panel 130 arranged behind the keys 142 in the front-rear direction with respect to the keyboard unit 140 (above in the vertical direction in FIG. and a pair of speaker panels 112 arranged on both end sides (that is, on the high tone side and the low tone side) in the arrangement direction.

Here, the speaker panel 112 extends from the rear side of the keyboard unit 140 to the front side (lower side in FIG. 1) of the electronic keyboard instrument 100, which is the left side and the right side of the keyboard unit 140. It has a shape that As shown in FIG. 2, a speaker 114 for producing musical tones is attached to the speaker panel 112 on the inner side of the musical instrument (on the side where the lower case 120 is assembled). Further, the speaker panel 112 is provided with a mesh-like speaker grill 116 for protecting the sound emitting surface of the speaker 114 . Also, the center panel 130 is provided with switches 132 for performing operations such as volume adjustment and timbre selection, and a display panel 134 for displaying information about the music being played, various setting information, and the like. there is

As shown in FIG. 2, the upper case 110 is assembled to the lower case 120 to form a space inside the musical instrument housing the speaker 114 and the like. A keyboard unit 140 is connected to the lower case 120 via a keyboard unit connecting portion 144 .

The keyboard unit 140 has a plurality of keys 142 as performance operators on the front side (lower side in FIG. 1) facing the user, and the pitch is designated by the user's key depression. As shown in FIG. 1, the keyboard unit 140 has a plurality of white keys and black keys arranged regularly in the longitudinal direction (horizontal direction in the drawing) of the electronic keyboard instrument 100. As shown in FIG. It is connected to the lower case 120 via 144 . The front keyboard portion of the keyboard unit 140 exposed from the upper case 110 serves as an area for the user to press keys, and the keyboard unit connecting portion 144 on the rear side is the inside of the musical instrument formed by the upper case 110 and the lower case 120. stored in. The left and right sides of the keyboard unit 140 are covered with the speaker panel 112 of the upper case 110 described above.

Such an electronic keyboard instrument 100 is arranged such that each key 142 of the keyboard unit 140 is exposed with respect to the lower case 120 and the keyboard unit 140, which are connected via the keyboard unit connecting portion 144, as shown in FIG. 3A, for example. The upper case 110 is assembled to the . Here, speakers 114, which are vibration sources, are attached to the inside of the musical instrument of the speaker panels 112 arranged on the left side and the right side of the upper case 110, as shown in FIG. 3B, for example. As shown in FIG. 3A, the speaker panel 112 is attached to the lower case 120 and the keyboard unit 140 at the speaker panel connecting portions 124 and 146 provided on the inner side of the musical instrument (upper side in the drawing) by screws or the like. It is attached and fixed to the case 120 and the keyboard unit 140 . In the assembly structure of the electronic keyboard instrument 100 shown in FIG. 3A, panel assembly bosses having screw insertion holes, for example, are provided at a plurality of locations as the speaker panel connection portions 124 and 146, respectively.

FIG. 4 is a schematic diagram showing an example of a speaker panel applied to the keyboard instrument according to this embodiment. FIG. 4A is a schematic diagram showing the inner side of the musical instrument of the speaker panel, and FIG. 4B is a schematic diagram showing an example of the resonance suppressor applied to this embodiment. Also, FIG. 5 is a schematic diagram for explaining a resonance suppressor applied to the present embodiment. FIG. 5A is a plan view showing the basic structure of the resonance suppressor, and FIG. 5B is an enlarged view showing a main part of the resonance suppressor.

On the inner side of the speaker panel 112 of the upper case 110 described above, as shown in FIG. 4A for example, screws are installed at positions corresponding to the speaker panel connectors 124 and 146 provided on the lower case 120 and the keyboard unit 140, respectively. A plurality of panel-side connecting portions 118, which are panel assembly bosses with holes, are provided. These panel-side connecting portions 118 are fastened and fixed to speaker panel connecting portions 124 and 146 of the lower case 120 and the keyboard unit 140 by screws or the like.

In addition, in the present embodiment, for example, as shown in FIGS. 3B and 4, a specific region of the speaker panel 112 is provided with a speaker panel 112 in order to suppress resonance of the speaker panel 112 caused by sound pressure accompanying the sounding operation of the speaker 114. of resonance suppressor 150 is provided. Here, for example, in the speaker panel 112 shown in FIG. 4A, the resonance suppression unit 150 accommodates the area where the speaker 114 (or the speaker grille 116) is attached and the keyboard unit 140 shown in FIGS. It is provided in a region (to be described later in detail) which is a region between the side end portion ED and includes near the approximate center of the extending direction of the end portion ED (horizontal direction in the drawing).

Specifically, as shown in FIGS. 4B and 5A, for example, the resonance suppressing portion 150 has a structure in which a plurality of polygonal ribs formed by connecting ribs in a regular hexagonal shape are arranged in a honeycomb arrangement. . Here, the resonance suppressor 150 has an inner region (the region inside the dotted circle in the figure) Rc and an outer peripheral region Rp around it (the region outside the dotted circle in the figure). A plurality of first cells 152, which are polygonal ribs having polygons of a first size, are arranged in a honeycomb pattern in the internal region Rc. Also, in the outer peripheral region Rp, a plurality of second cells 154, which are polygonal ribs having polygons of a second size larger than the first size, are arranged in a honeycomb arrangement.

In the present embodiment, the entire resonance suppressing portion 150 as shown in FIG. 5A, or at least a portion of each of the inner region Rc and the outer peripheral region Rp as shown in FIG. integrally formed. In addition, in the present embodiment, the size and arrangement of the first cell 152 and the second cell 154 applied to the resonance suppression unit 150, and the mutual connection structure are set as follows.

First, the size (length and area of one side) of the first cell 152 and the second cell 154 depends on the shape and dimensions of the speaker panel 112 in which the resonance suppressor 150 is provided, and the mounting and fixing position to the lower case 120 and the keyboard unit 140. , is set according to the specifications of the speaker 114 and the like. Specifically, based on these conditions, a natural vibration analysis (also referred to as a modal analysis) for grasping the natural vibration frequency (resonance frequency) of the speaker panel 112, which is an object, and the shape change during resonance; will be described later). Then, the sizes of the first cell 152 and the second cell 154 are set according to the result of the analysis (degree of resonance including spread and magnitude of vibration).

5B, the resonance suppression unit 150 is in a state in which the first cells 152 in the inner region Rc are rotated, for example, 30° with respect to the second cells 154 in the outer region Rp within the plane of the drawing. are arranged as That is, the vertex direction of the first cell 152 (extending direction of a straight line passing through the opposite vertices of a regular hexagon or the central point and the vertex; indicated by a dashed line in the figure, the same applies hereinafter) Dc is the direction of the second cell 154. is set to have a different direction rotated by 30°, not coinciding with the vertex direction Dp of .

5B, the resonance suppression unit 150 is configured so that the ribs intersect from three directions at all connection points that connect each first cell 152 and each second cell 154. Designed. Specifically, the rib 156 extending from the left side to the right side of the drawing toward a connection point Pc (for example, an intermediate point) in the middle of the rib 154s on one side of a certain second cell 154A from the vertex of a certain first cell 152A. A first direction D1, a second direction D2 from the top to the bottom of the drawing toward the connection point Pc at the rib 154s on one side of the second cell 154A, and a second direction D2 from the top to the bottom of the drawing toward the connection point Pc at the rib 154s on one side of the second cell 154A. The ribs 154s and the ribs 156 are connected so as to intersect from the third direction D3 extending upward from the side. In other words, the resonance suppression unit 150 is such that the rib 156 connected to the vertex of the first cell 152 in the inner region Rc at the connection point Pc is a rib 154s that is one side of the second cell 154 in the outer region Rp. It is formed to connect perpendicularly (90°) to the .

By having such a configuration, the resonance suppressing section 150 has a polygonal side length ratio of, for example, 1:2 between the first cell 152 in the inner region Rc and the second cell 154 in the outer region Rp. (or 1:2n, where n is a positive integer), and in the case of the area ratio, the sizes are set to be 1:4 (or 1:(2n) ² ). As a specific example of the resonance suppression unit 150 in this case, the length of one side of the polygon in the first cell 152 is set to 3 mm, and the length of one side of the polygon in the second cell 154 is set to 6 mm. The thickness and height of the ribs forming the sides of the first cell 152 and the second cell 154 are set to be the same, for example, the thickness is set to 1 mm and the height is set to 5 mm.

Next, the size and arrangement of the first cell 152 and the second cell 154 applied to the resonance suppression unit 150 will be described in detail by showing an example.

In this embodiment, the shape and dimensions of the speaker panel 112 and the mounting and fixing position to the lower case 120 and keyboard unit 140 are set as analysis conditions in a simulation model, and the natural vibration analysis (modal analysis) is performed. Here, as the shape of the speaker panel 112, the overall shape of the panel, the folding back of the panel edge, the shape and arrangement of the reinforcing ribs, and the like are set as analysis conditions. In addition, as the dimensions of the panel, the total length, width, thickness, etc. of the panel, and as the assembly fixing position, the installation position of the panel-side connection portion 118 were set as analysis conditions. As a result, the inventors of the present application can grasp the natural vibration frequency of the upper case 110 and the lower case 120 included in the electronic keyboard instrument 100 and the locations where vibration due to resonance at that frequency is large. and the size and arrangement of the second cell 154 were verified.

FIG. 6 is a diagram showing results of natural vibration analysis in the speaker panel. FIG. 6A is a schematic diagram showing an analysis result of a speaker panel (comparative example) not provided with a resonance suppressor according to this embodiment, and FIG. 6B is an analysis result of a speaker panel provided with a resonance suppressor according to this embodiment. It is a figure which shows. Here, FIGS. 6A and 6B show only the main parts of the speaker panel related to the results of the natural vibration analysis. Moreover, in FIG. 6A, the same reference numerals are given to correspond to the configuration of the resonance suppressor according to the present embodiment.

First, in the speaker panel (comparative example) in which the resonance suppressing section according to the present embodiment is not provided, the natural vibration analysis based on the above analysis conditions shows that the keyboard unit connection section 144 of the keyboard unit 140 is as shown in FIG. 6A. It has been found that intense resonance occurs around the approximate center RS (position where the distance L1≈L2) of the end EDp on the side where the is housed.

Specifically, the speaker panel 112p has a panel-side connection portion 118 provided on the peripheral edge portion (upper and left and right sides in the drawing) excluding the end EDp on the side (lower side in the drawing) where the keyboard unit 140 is housed. It is attached and fixed to the case 120 and the keyboard unit 140 . In addition, the speaker panel 112p is provided with a bent portion 112s of a panel member and reinforcing ribs 112r for reinforcing the strength of the panel at the peripheral portion excluding the end portion EDp. On the other hand, the end portion EDp of the speaker panel 112p accommodates the keyboard unit 140, and is made up of a thin panel member that does not have a tall bent portion 112s or reinforcing ribs 112r like the peripheral portion.

As a result, the speaker panel 112p is fixed at the panel-side connecting portion 118, the bent portion 112s of the panel member, and the reinforcing rib 112r. . Here, as shown in FIG. 6A, the degree of resonance is defined as a semicircular region in which the vibration propagates and attenuates approximately concentrically with the region including the central region RS as the center of resonance (maximum resonance). is distributed. In the result of the natural vibration analysis shown in FIG. 6A, for convenience of illustration, the region where the maximum resonance of RS near the center of the end EDp is indicated by the darkest monotone, and the lower the degree of resonance, the lighter the monotone. indicated by

Therefore, in the present embodiment, based on the above analysis results, as shown in FIGS. 4B and 6B, the internal region Rc shown in FIG. A fine honeycomb structure is applied to arrange a plurality of small size (first size) first cells 152 in a honeycomb arrangement. In addition, by applying the rough honeycomb structure of the outer peripheral region Rp shown in FIG. Two cells 154 are arranged in a honeycomb pattern. Further, the first cells 152 arranged in the resonance central region and the second cells 154 arranged around the resonance central region are set in a rotated state so that the vertex directions do not match.

In the speaker panel 112 provided with such a resonance suppressor 150, the natural vibration analysis based on the above analysis conditions shows that the maximum natural vibration is as shown in FIG. 6B compared to the case shown in FIG. 6A. It has been found that as the degree of resonance is reduced, the area over which vibration spreads is reduced, thereby suppressing resonance.

Specifically, similar to the speaker panel 112p shown in FIG. 6A, the peripheral edge of the speaker panel 112 includes a panel-side connector (fixed end) 118 for assembly and fixing to the lower case 120 and the keyboard unit 140, A bent portion 112s of the panel member and reinforcing ribs 112r are provided to reinforce the strength of the panel. In addition, the area between the area where the speaker 114 (or the speaker grill 116) of the speaker panel 112 is attached and the end ED on the side where the keyboard unit 140 is housed (lower side in the drawing), A resonance suppressor 150 is provided in a region including RS near the approximate center of the ED. Here, based on the results of the natural vibration analysis shown in FIG. 6A, the resonance suppression unit 150 has ribs having a fine honeycomb structure arranged in the central region of resonance (the region where the maximum resonance occurs), and vibrates around the ribs. Ribs with a coarse honeycomb structure are arranged in the region where the .DELTA.

As a result, the speaker panel 112 is reinforced with honeycomb-structured ribs having rigidity corresponding to the degree of resonance in the center region of resonance at the end ED and in the surrounding region. Therefore, when the panel-side connecting portion 118 provided on the speaker panel 112, the bent portion 112s of the panel member, and the reinforcing rib 112r are used as fixed ends, resonance in natural vibration occurs at the end portion ED located between them. However, the degree of resonance is reduced and the vibrating region is reduced, thereby suppressing resonance.

As described above, in the present embodiment, the housing of the electronic keyboard instrument 100 to which the vibration source such as the speaker is attached is subjected to the eigen-vibration analysis in advance to identify the resonance position and region in the eigen-vibration, and the degree of resonance is determined. Ribs having a honeycomb structure with different rigidity are arranged according to the requirements. That is, in a region (central region) where vibration due to resonance of the housing is large, the rigidity of the housing is further increased by arranging small-sized polygonal ribs (first cells) in a honeycomb arrangement. In addition, the rigidity of the housing is moderately increased by arranging large-sized polygonal ribs (second cells) in a honeycomb arrangement in a region where vibration due to resonance is relatively small (around the central region). As a result, it is possible to arrange a honeycomb structure having a rigidity corresponding to the degree of resonance. It is possible to increase the rigidity of the entire housing while reducing the manufacturing cost by reducing the amount of use and the number of parts, and it is possible to satisfactorily suppress resonance.

Further, in this embodiment, the polygonal ribs (first cells and second cells) honeycomb-arranged in the central region and its surroundings according to the degree of resonance of the housing have mutually different vertex directions. set as That is, the small-sized polygonal ribs (first cells) honeycomb-arranged in the region where vibration due to resonance is large, and the large-sized polygonal ribs (second cells) honeycomb-arranged in the region where vibration due to resonance is relatively small. , the vertex direction is rotated by 30°, for example. In a case reinforcement structure using a structure in which multiple polygonal ribs are arranged in a honeycomb structure, there is inevitably a difference in rigidity between the vertex direction from the center point of the polygon and the side direction (perpendicular to the side) (direction-dependent sex) occurs. Therefore, in the present embodiment, by setting the apex directions of the central region and the polygonal ribs arranged around it in different directions, the directional dependence of the rigidity of the housing can be suppressed, and the housing can be made substantially whole. Rigidity can be increased in a direction, and resonance can be suppressed satisfactorily.

In addition, in this embodiment, each of the multi-layered ribs (the first cell and the second cell) of different sizes arranged in the center region and its surroundings according to the degree of resonance of the housing is connected to each other. The vertices and one side of the polygon are connected so as to intersect from three directions at the connection point. That is, the apexes of the small-sized polygonal ribs arranged in a honeycomb arrangement in the region where vibration due to resonance is large are located in the middle of one side of the large-sized polygonal ribs arranged in a honeycomb structure (for example, the midpoint ), connected vertically. In a resin molded article having a connection point where a plurality of sides (for example, four sides or more) converge and intersect, molding defects such as sink marks may occur due to shrinkage of the surface during molding. Therefore, in this embodiment, polygonal ribs of different sizes are formed by intersecting ribs from three directions, and by setting the intersecting angle of the connected ribs as large as possible, the occurrence of molding defects is prevented. It is possible to suppress and reduce the manufacturing cost.

In addition, in the above-described characteristic vibration analysis of the speaker panels 112p and 112, as shown in FIGS. A model is shown in which reinforcing ribs 116r are provided between the portions EDp and ED and extend in the horizontal direction of the drawing to prevent the panel from bending. As a result of further verification, the inventors of the present application found that when such panel reinforcement ribs 116r are not provided, the degree of maximum resonance increases compared to the results of the natural vibration analysis shown in FIG. It was also confirmed that the vibrating region expands as the vibration increases. Also in this case, it was confirmed that the resonance of the speaker panel 112 was satisfactorily suppressed by providing the resonance suppressor 150 according to the present embodiment.

Further, in the above-described embodiment, the case where the natural vibration analysis is performed by setting the simulation model as the analysis conditions such as the shape and dimensions of the speaker panel 112, the mounting and fixing position to the lower case 120 and the keyboard unit 140, etc. will be described. did. The present invention is not limited to this, and in addition to the above conditions, the specifications of the speaker 114 include, for example, the size and mounting position of the speaker 114, the output during sounding, and the interior of the musical instrument in which the speaker 114 is housed. The size of the space, etc. may be set as analysis conditions.

(Modification)
Next, a modified example of the resonance suppressor applied to this embodiment will be described.
FIG. 7 is a plan view showing another example of the resonance suppressor applied to this embodiment.

In the above-described embodiment, as the resonance suppressing portion 150, as shown in FIG. A case where the connection point with one side of is formed by intersection of ribs from three directions has been described. The modified example of this embodiment has a form in which the connection structure between the first cell 152 and the second cell 154 is changed.

As shown in FIG. 7A, in the resonance suppressor 150 applied to the first modification of the present embodiment, only some of the vertices of the first cells 152 in the inner region Rc are the second cells 154 in the outer region Rp. has a structure connected to one side of That is, it has a configuration in which the number of connection points between the first cell 152 and the second cell 154 is reduced compared to the connection structure shown in the above-described embodiment (FIG. 5). As a result, it is possible to suppress the occurrence of molding defects due to a connection structure in which a plurality of sides are concentrated, and to reduce the amount of molding material (resin material, etc.) used, thereby reducing the manufacturing cost.

Moreover, as shown in FIG. 7B, the resonance suppressing portion 150 applied to the second modification of the present embodiment has an inner region Rc in which a plurality of first cells 152 are arranged in a honeycomb arrangement, and an outer region Rp. It is set in a substantially triangular region surrounded by a plurality of second cells 154 that are connected to each other. Each vertex of the first cell 152 in the internal region Rc and one side of the second cell 154 in the outer region Rp, or a connection point with a side 158 that serves as a boundary between the inner region Rc and the outer region Rp are connected in three directions. formed by the intersection of ribs from That is, compared to the resonance suppression unit 150 shown in the above-described embodiment (FIG. 5), it has a configuration in which the number of small-sized first cells 152 is reduced and the area of the internal region Rc is reduced. . As a result, when the central region of resonance (the region of maximum resonance) is relatively narrow, a plurality of small-sized first cells 152 can be arranged intensively in this region to further increase the rigidity of the housing. , resonance can be suppressed well.

In addition, as shown in FIG. 7C, the resonance suppressing portion 150 applied to the third modification of the present embodiment has an inner region Rc in which a plurality of first cells 152 are arranged in a honeycomb arrangement, and an outer region Rp. It is set in a substantially hexagonal region surrounded by a plurality of second cells 154 that are arranged in parallel with each other. Connection points between each vertex of the first cell 152 in the internal region Rc and the side 158 serving as a boundary between the internal region Rc and the outer peripheral region Rp are formed by intersections of ribs from three directions. That is, compared to the resonance suppression unit 150 shown in the second modification (FIG. 7B), the number of small-sized first cells 152 is further reduced, and the area of the internal region Rc is further reduced. have. As a result, when the central region of resonance (the region of maximum resonance) is very narrow, it is possible to further increase the rigidity of the housing by arranging a plurality of small-sized first cells 152 more concentratedly in this region. It is possible to satisfactorily suppress resonance.

In the above-described embodiment, as the resonance suppressing portion 150, as shown in FIGS. 5 and 7, a plurality of small-sized first cells 152 are arranged in a honeycomb arrangement in the internal region Rc, and the outer peripheral region surrounding the first cells 152 is arranged. Rp shows a configuration in which a plurality of second cells 154 of large size are arranged in a honeycomb arrangement. In the present embodiment, as shown in the results of the natural vibration analysis in FIG. 6, the regions in which the vibration due to resonance is attenuated are distributed substantially concentrically around the region including the position where the resonance is maximized. Although the case where the honeycomb arrangement of each cell is arranged in a substantially concentric shape corresponding to the distribution has been described, the present invention is not limited to this. That is, according to the degree of resonance of the housing, a plurality of small first cells 152 are arranged in a honeycomb arrangement by applying a fine honeycomb structure to a region where it is necessary to suppress resonance by increasing the rigidity of the housing. However, in a region where it is necessary to moderately increase the rigidity of the housing to suppress resonance, if a coarse honeycomb structure is applied and a plurality of large-sized second cells 154 are arranged in a honeycomb pattern, concentric circles can be used. However, it may have other planar patterns such as continuous stripes or islands.

<Second embodiment>
Next, a second embodiment of the electronic musical instrument according to the invention will be described.
FIG. 8 is a cross-sectional view showing an example of the internal structure of the keyboard instrument according to the second embodiment, FIG. 9 is a schematic view showing an example of the assembly structure of the keyboard instrument according to the present embodiment, and FIG. 1] is a schematic diagram showing an example of a resonance suppressor applied to a lower case of a keyboard instrument according to the present embodiment. [FIG. Here, the same reference numerals are assigned to the same configurations as those of the first embodiment described above.

In the first embodiment described above, the case where ribs having a honeycomb structure are arranged on the speaker panel 112 of the upper case 110 as the resonance suppressor 150 has been described. In the second embodiment, ribs having a honeycomb structure are arranged in specific regions of the lower case 120 to which the upper case 110 is assembled.

The electronic keyboard instrument 100 according to the second embodiment has an external appearance as shown in FIG. 1, and an internal structure as shown in, for example, FIG. It has an assembly structure as shown in . That is, in the electronic keyboard instrument 100, the keyboard unit 140 is connected to the lower case 120 via the keyboard unit connecting portion 144, and the keys 142 of the keyboard unit 140 are exposed to the lower case 120 and the keyboard unit 140. The upper case 110 is assembled as follows.

In the electronic keyboard instrument 100 according to the present embodiment, as shown in FIGS. 8 and 9, a speaker 114 attached to the speaker panel 112 of the upper case 110 is placed in a specific area of the lower case 120 to generate sound. A resonance suppressor 150 is provided to suppress resonance of the lower case 120 caused by the accompanying sound pressure. Here, for example, in the lower case 120 shown in FIG. 9, the resonance suppression section 150 is a region along the end EDb on the attachment side of the keyboard unit connection section 144, and is located between the center panel 130 and the speaker panel shown in FIG. 112 in a region facing the boundary.

Specifically, for example, as shown in FIG. 10, the resonance suppression unit 150 includes a plurality of small-sized (first size) small-sized (first-sized) vibration suppressors similar to the configuration shown in FIG. It has an inner region Rc in which the first cells 152 are arranged in a honeycomb arrangement, and an outer region Rp in which a plurality of second cells 154 of large size (second size) are arranged in a honeycomb arrangement.

Also in this embodiment, the size and arrangement of the first cells 152 in the inner region Rc and the second cells 154 in the outer region Rp, and the mutual connection structure are set in the same manner as in the above-described embodiment. That is, a natural vibration analysis (modal analysis) is performed on the lower case 120, and a plurality of first cells 152 of a small size (first size) are arranged in a honeycomb pattern in a region of maximum resonance, and vibration due to resonance around the first cells 152 is arranged in a honeycomb arrangement. A plurality of large size (second size) second cells 154 are arranged in a honeycomb pattern in the attenuation region. As a result, the rigidity of the lower case 120 can be increased according to the degree of resonance, and resonance can be satisfactorily suppressed.

In the present embodiment, as shown in FIG. 9, a resonance suppressor 150 is provided in a region near the speaker on the right side of the lower case 120 in the drawing (high-pitched sound side in the arrangement direction of the keys 142 in the keyboard unit 140). showed that. This is because the battery box 128 is provided in an area near the speaker on the left side of the lower case 120 in the drawing (the bass side in the arrangement direction of the keys 142 in the keyboard unit 140). Since the rigidity on the left side of the drawing is increased, there is no need to provide the resonance suppressor 150 . That is, it is not limited to the battery box 128 shown in the present embodiment, and as a result of the natural vibration analysis, it is necessary to provide the resonance suppression unit 150 for a region in which a structure having a rigidity that suppresses resonance is provided. Instead, the resonance suppressor 150 is provided only for a region with low rigidity and large vibration due to resonance.

<Third Embodiment>
Next, an electronic musical instrument according to a third embodiment of the present invention will be described.
FIG. 11 is a schematic diagram showing an example of a speaker panel applied to a keyboard instrument according to the third embodiment. FIG. 11A is a schematic diagram showing the inner side of the musical instrument of the speaker panel, and FIG. 11B is a schematic diagram showing an example of a resonance suppressor applied to this embodiment. Here, the same reference numerals are assigned to the same configurations as those of the above-described embodiments.

In each of the above-described embodiments, the resonance suppressing portion 150 has cells made up of polygonal ribs of two different sizes, large and small, and a plurality of small-sized first cells 152 are arranged in a honeycomb arrangement in the central region of resonance. A structure in which a plurality of large-sized second cells 154 are arranged in a honeycomb structure has been described. In the third embodiment, the resonance suppression unit 150 has cells made of polygonal ribs of three or more sizes, and has a structure in which the size and arrangement of the cells are set according to the degree of resonance. .

The resonance suppressor 150 applied to the electronic keyboard instrument 100 according to the third embodiment is, for example, in the speaker panel 112 shown in FIG. Cells of three different sizes, large, medium and small, are placed in the area between the end ED on the side where the is housed and including near the approximate center in the extending direction of the end ED (horizontal direction in the drawing) are arranged in a honeycomb arrangement.

Specifically, for example, as shown in FIG. 11B, the resonance suppression unit 150 includes an internal region (the region inside the dotted line circle in the figure) Rc, an outer peripheral region Rp around the inner region Rc, and an outer peripheral region Rp. Furthermore, it has an outer edge region Rx on the outer peripheral side. As in the above-described embodiments, a plurality of first cells 152 having a small size (first size) are arranged in a honeycomb arrangement in the internal region Rc, and a size larger than the first cells 152 (first cell 152) is arranged in the outer peripheral region Rp. A plurality of second cells 154 of two sizes) are arranged in a honeycomb pattern. Further, in the outer edge region Rx, a plurality of third cells 160 having a size (third size) larger than that of the second cells 154 are arranged in a honeycomb pattern.

Also in this embodiment, the size and arrangement of the first cell 152 in the inner region Rc, the second cell 154 in the outer region Rp, and the third cell 160 in the outer region Rx, and the mutual connection structure are the same as in the above-described embodiment. is set in the same way. That is, the speaker panel 112 is subjected to a natural vibration analysis as shown in FIG. , and a plurality of second cells 154 having a larger size (second size) than the first cells 152 are arranged in a honeycomb manner in a region where vibration due to resonance is damped. A plurality of third cells 160 having a larger size (third size) than the second cells 154 are arranged in a honeycomb arrangement in a region adjacent to the outer peripheral side of the region and further damping vibration due to resonance. As a result, the rigidity of the speaker panel 112 can be appropriately increased according to the degree of resonance, and resonance can be satisfactorily suppressed.

In each of the above-described embodiments, the case where the resonance suppressor is applied to an electronic keyboard instrument has been described, but the present invention is not limited to this. That is, the present invention can be applied to a device to which a vibration source is attached when it is necessary to suppress the influence of the resonance of the housing on the function of the device. Therefore, it can be applied favorably to electronic musical instruments other than keyboard instruments, and to acoustic equipment such as speaker boxes.

Although several embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and includes the invention described in the claims and their equivalents.
The invention described in the original claims of the present application is appended below.

(Appendix)
[1]
a vibration source speaker;
a case housing the speaker, the case having an area in which a plurality of polygonal ribs for suppressing resonance due to vibration of the speaker are arranged;
with
The regions where the plurality of polygonal ribs are arranged include a first region where a plurality of first polygonal ribs having polygons of a first size are arranged, and the first region outside the first region. a second region disposed with a second plurality of polygonal ribs having polygons of a second size greater than the size.

[2]
The case has, inside, a plurality of connecting ribs that connect the plurality of first polygonal ribs and the plurality of second polygonal ribs, respectively.
The device according to [1].

[3]
The plurality of connecting ribs extend from the vertices of the polygon of a first polygonal rib toward the midpoint of one side of the polygon of a second polygonal rib.
The device according to [2].

[4]
The plurality of polygonal ribs include ribs that are joined in a regular hexagonal shape,
The device according to any one of [1] to [3].

[5]
a keyboard;
a speaker as a vibration source arranged behind the keys on the keyboard in the front-rear direction;
a case housing the speaker, the case having an area in which a plurality of polygonal ribs for suppressing resonance due to vibration of the speaker are arranged;
with
The regions where the plurality of polygonal ribs are arranged include a first region where a plurality of first polygonal ribs having polygons of a first size are arranged, and the first region outside the first region. a second region arranged with a plurality of second polygonal ribs having polygons of a second size larger than the size.

[6]
The case has an upper case and a lower case,
The speaker is fixed to the upper case side,
The plurality of polygonal ribs are arranged in a region between the speaker and the keyboard, which is part of the outer periphery of the upper case.
The keyboard instrument according to [5].

[7]
A battery box for housing a battery is provided on either one of the high-pitched sound side and the low-pitched sound side in the key arrangement direction of the lower case, and the plurality of polygonal ribs are provided on the other.
The keyboard instrument according to [5] or [6].

100 Electronic keyboard instruments (devices, keyboard instruments)
110 upper case 112 speaker panel 114 speaker (vibration source)
116 speaker grille 118 panel side connection part 120 lower case 124 speaker panel connection part 128 battery box 130 center panel 140 keyboard unit 142 key 144 keyboard unit connection part 146 speaker panel connection part 150 resonance suppression part 152 first cell (first polygon rib)
154 second cell (second polygonal rib)
156 ribs (connecting ribs)
Pc Connection point Rc Internal region (first region)
Rp outer region (second region)
Rx outer edge region

Claims (7)

a vibration source speaker;
a case housing the speaker, the case having an area in which a plurality of polygonal ribs for suppressing resonance due to vibration of the speaker are arranged;
with
The regions where the plurality of polygonal ribs are arranged include a first region where a plurality of first polygonal ribs having polygons of a first size are arranged, and the first region outside the first region. a second region disposed with a second plurality of polygonal ribs having polygons of a second size greater than the size. The case has, inside, a plurality of connecting ribs that connect the plurality of first polygonal ribs and the plurality of second polygonal ribs, respectively.
The device of claim 1. The plurality of connecting ribs extend from the vertices of the polygon of a first polygonal rib toward the midpoint of one side of the polygon of a second polygonal rib.
3. The device of claim 2. The plurality of polygonal ribs include ribs that are joined in a regular hexagonal shape,
4. A device according to any one of claims 1-3. a keyboard;
a speaker as a vibration source arranged behind the keys on the keyboard in the front-rear direction;
a case housing the speaker, the case having an area in which a plurality of polygonal ribs for suppressing resonance due to vibration of the speaker are arranged;
with
The regions where the plurality of polygonal ribs are arranged include a first region where a plurality of first polygonal ribs having polygons of a first size are arranged, and the first region outside the first region. a second region arranged with a plurality of second polygonal ribs having polygons of a second size larger than the size. The case has an upper case and a lower case,
The speaker is fixed to the upper case side,
The plurality of polygonal ribs are arranged in a region between the speaker and the keyboard, which is part of the outer periphery of the upper case.
A keyboard instrument according to claim 5. A battery box for housing a battery is provided on either one of the high-pitched sound side and the low-pitched sound side in the key arrangement direction of the lower case, and the plurality of polygonal ribs are provided on the other.
A keyboard instrument according to claim 6 .

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