Case and keyboard musical instrument

Abstract

To provide a case with reduced loss of appearance due to changes in external temperature even when members of different materials are combined, and a keyboard musical instrument equipped with this case.SOLUTION: A case 200 of a keyboard instrument 10 comprises: a lower case 220 made of a first material as a resin material and long in a left-right direction LR as one direction; a plurality of reinforcement members 300 (first reinforcement members 310, second reinforcement members 320) fixed to the lower case 220 and divided and arranged in the left-right direction LR using a steel plate as a second material smaller in linear expansion coefficient than the first material; a front case 250 formed long in one direction and fixed over the plurality of reinforcement members 300; and side cases (left side case 230, right side case 240) arranged adjacent to the front case 250 and fixed to one ends of the reinforcement members 300.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a case and a keyboard instrument. [Background technology]

[0002] Cases made of a combination of different materials have been disclosed. For example, Patent Document 1 discloses a keyboard instrument with a case in which a reinforcing member is attached across a front panel that is an extrusion molded product of aluminum material and a rear panel that is a sheet metal member made of an iron-based material, and an upper case is integrally provided. The front panel and the rear panel are joined together at their folded edges, and the joined surfaces are joined together to provide a continuous panel surface between the front panel and the rear panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-27919 A Summary of the Invention [Problem to be solved by the invention]

[0004] Cases for keyboard instruments and the like can be made more attractive and lighter by combining components made of different materials. However, different materials have different linear expansion coefficients, so that changes in the outside temperature can cause gaps to appear at the joints between components made of different materials, or the joints can be pressed together too hard, causing distortion or cracking of the components. This can damage the appearance of the case.

[0005] An object of the present invention is to provide a case in which damage to the appearance caused by changes in outside temperature is reduced even when components made of different materials are combined, and a keyboard instrument equipped with this case. [Means for solving the problem]

[0006] The case of the present invention comprises a lower case made of a first material and long in one direction, a plurality of reinforcing members fixed to the lower case and made of a second material having a linear expansion coefficient smaller than that of the first material, the reinforcing members being divided and arranged in the one direction, a front case formed long in the one direction and fixed across the plurality of reinforcing members, and a side case arranged adjacent to the front case and fixed to one end of the reinforcing members.

[0007] A keyboard instrument according to the present invention includes the above-mentioned case. Effect of the Invention

[0008] According to the present invention, it is possible to provide a case in which damage to the appearance caused by changes in outside temperature is reduced even when components made of different materials are combined, and a keyboard instrument equipped with this case. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a keyboard instrument according to an embodiment of the present invention; [Diagram 2] 1 is a perspective view of a side case, a lower case, a front case and a reinforcing member of a case according to an embodiment of the present invention, seen from the rear. FIG. [Diagram 3] 4 is a perspective view showing a first reinforcing member of the case according to the embodiment of the present invention. FIG. [Figure 4] 4 is a partially enlarged perspective view of the case according to the embodiment of the present invention, seen from a P1 direction in FIG. 3. [Diagram 5] 4 is a perspective view showing a second reinforcing member of the case according to the embodiment of the present invention. FIG. [Figure 6] 6 is a cross-sectional view of the case according to the embodiment of the present invention taken along line VI-VI in FIG. 2. [Figure 7] 7 is a cross-sectional view of the case according to the embodiment of the present invention taken along line VII-VII in FIG. 2. [Figure 8] 8 is a cross-sectional view of the case according to the embodiment of the present invention taken along line VIII-VIII in FIG. 6. [Figure 9]9 is a cross-sectional view of the case according to the embodiment of the present invention taken along line IX-IX in FIG. 7. [Figure 10] FIG. 2 is a perspective view of the left portion of the case according to the embodiment of the present invention, with the left side case omitted. [Figure 11] FIG. 2 is a perspective view of the right side portion of the case according to the embodiment of the present invention, with the right side case omitted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The keyboard instrument 10 shown in FIG. 1 includes a full-size (88 keys) keyboard 5 having a plurality of white keys 3 and a plurality of black keys 4 as a plurality of keys, and a case 200. In the following description, the front of the keyboard 5 in the front-rear direction FB is the front side F, the rear of the keyboard 5 in the front-rear direction FB is the rear side B, the left side of the keyboard 5 is the left side L, and the right side is the right side R. The keys of the keyboard 5 are arranged in the left-right direction LR. In addition, in the up-down direction UL of the keyboard instrument 10, the top is the upside Up, and the bottom is the downside Lo. In this embodiment, the keyboard instrument 10 is an electronic keyboard instrument, but the keyboard instrument 10 may be of another type. In addition, the case 200 is not limited to the keyboard instrument 10, and may be the case 200 of another device.

[0011] As shown in FIG. 1, the case 200 has an upper case 210, a lower case 220, a left side case 230 and a right side case 240 as side cases, and a front case 250. The upper case 210, the lower case 220, and the front case 250 are provided long in the left-right direction LR, which is one direction. The upper case 210 has an upper panel 211 and a rear panel (not shown). The left side case 230 and the right side case 240, which are substantially rectangular and long in the front-rear direction FB, are disposed adjacent to the left and right ends of the upper case 210 and the front case 250, respectively. The lower case 220 is provided on the lower side Lo of the upper case 210 and the side cases (the left side case 230 and the right side case 240).

[0012] A keyboard arrangement section 6 in which a keyboard 5 is arranged is provided on the front side F of the upper case 210, between the left side case 230 and the right side case 240. A substantially plate-shaped front case 250 that is long in the left-right direction is provided between the left side case 230 and the right side case 240 on the front side F of the keyboard 5.

[0013] A rotary knob 12 for adjusting the volume is provided on the top panel 211 of the upper case 210. An operation unit 14 equipped with a pitch bender, push buttons, etc. is provided on the top surface of the left side case 230. In addition, an earphone jack 18 is provided on the front surface of the left side case 230.

[0014] The connection structure between the lower case 220 and the front case 250, and between the front case 250 and the side cases (left side case 230, right side case 240) will be described in detail below. The lower case 220, the side cases (left side case 230, right side case 240), and the front case 250 are connected and assembled by the reinforcing member 300, as viewed from the rear side B, as shown in FIG. 2. The reinforcing member 300 is provided on the rear side B of the front case 250. The reinforcing member 300 is divided into a plurality of parts, and the front case 250 is fixed across the reinforcing member 300. In this embodiment, a first reinforcing member 310 is provided on the left side L, and a second reinforcing member 320 is provided on the right side R, and the reinforcing member 300 is provided in two parts. That is, in this embodiment, the first reinforcing member 310 and the second reinforcing member 320 are reinforcing members 300 that are arranged at the ends in the left and right directions among the plurality of reinforcing members 300. Additionally, the first reinforcing member 310 is provided longer than the second reinforcing member 320, and the reinforcing member 300 is divided asymmetrically.

[0015] The lower case 220 is formed by injection molding of a resin material, which is a first material. The reinforcing members 300 (first reinforcing member 310, second reinforcing member 320) are formed by sheet metal processing of a steel plate, which is a second material. The linear expansion coefficient of the second material is smaller than the linear expansion coefficient of the first material. The front case 250 is made of a wood material.

[0016] 3, the first reinforcing member 310 is provided in a generally L-shape that is long in the left-right direction LR. The first reinforcing member 310 has a front plate 311 that is provided with a width substantially equal to the up-down direction UL (width direction) of the front case 250, and a lower plate 312 that is bent from the lower end edge of the front plate 311 to the rear side B and has a width sufficiently narrower than that of the front plate 311. An engagement piece 311a (first protrusion) is provided at the right end of the front plate 311 and is bent to the front side F in a tongue-like shape with the plate surface in the left-right direction. The right end of the lower plate 312 protrudes further than the right end of the front plate 311.

[0017] As shown in FIG. 4, two tongue-shaped engagement pieces 311b, 311c are provided near the left end L of the front plate 311. The inner (right R) engagement piece 311b (second protrusion) of the two tongue-shaped engagement pieces 311b, 311c is provided by bending the plate surface to the front side F with the plate surface in the up-down direction UL. As shown in the enclosed diagram of P2, the engagement piece 311b is substantially rectangular with an inclined portion 311b1 inclined on the outer side (left side case 230 side of the left side L) so that the tip side is narrow. The outer (left L) engagement piece 311c (first protrusion) of the two tongue-shaped engagement pieces 311b, 311c is provided by bending the plate surface to the front side F with the plate surface in the left-right direction LR. The engagement piece 311c is substantially rectangular.

[0018] Two protrusions 311d (abutment protrusions) arranged vertically are provided at the left end portion of the front plate 311 (see also FIG. 10). A concave groove 311e extending from the end portion of the left side L of the front plate 311 to the right side R is provided between the two protrusions 311d, reinforcing the left end portion of the front plate 311. The concave groove 311e has a concave front side F. In addition, a protrusion piece 311f protruding from the plate surface in the front-rear direction FB is provided at the upper end portion of the left side L of the front plate 311 (the upper side Up of the protrusions 311d).

[0019] The front plate 311 is provided at its left end L with a fixed portion 313 formed by bending it toward the rear side B. The fixed portion 313 includes a vertical plate 313a arranged with its plate surface facing the left-right direction, an upper horizontal plate 313b arranged with its plate surface facing the up-down direction UL by bending it from the upper end of the vertical plate 313a toward the right side R, and a lower horizontal plate 313c arranged with its plate surface facing the up-down direction UL by bending it from the lower end of the vertical plate 313a toward the left side L. The vertical plate 313a is provided with a concave groove portion 313e connected to the concave groove portion 311e of the front plate 311. The rear side B of the vertical plate 313a is provided with a bent portion 313f bent toward the right side R at a substantially right angle. The lower horizontal plate 313c is provided with a protruding piece 313d bent toward the upper side Up at a substantially right angle (see also FIG. 3). The protruding pieces 311f and 313d are end-processed so that their ends are bent.

[0020] The front plate 311 is provided with a plurality of (12 in this embodiment) screw holes 31-1 to 31-12, through which screw members 81 (see FIG. 2) for fixing to the front case 250 are inserted. The lower plate 312 is provided with a plurality of (10 in this embodiment) screw holes 32-1 to 32-10, through which screw members 82 for fixing to the lower case 220 are inserted. The edges of the rear side B of the lower plate 312 corresponding to the screw holes 32-1 to 32-10 and holes 40-1 to 40-4 (described later) in the lower plate 312 slightly protrude toward the rear side B.

[0021] The front plate 311 has two screw holes 31-1 and 31-2 at the end of the left side L, which are arranged vertically with the concave groove 311e between them. The front plate 311 has two screw holes 31-11 and 31-12 at the end of the right side R, which are arranged vertically. The screw holes 31-3 to 31-10 between the screw holes 31-1, 31-2, 31-11 and 31-12 at both the left and right ends are arranged at substantially equal intervals along the longitudinal direction of the front plate 311, and are arranged vertically in a staggered manner. Of the multiple screw holes 31-1 to 31-12 provided in the front plate 311, the screw holes 31-1 and 31-2 at the end of the left side L are round holes. The other screw holes 31-3 to 31-12 are elongated holes that are long in the left-right direction LR. The screw holes 31-3 to 31-12 all have the same shape.

[0022] All of the screw holes 32-1 to 32-10 provided in the lower plate 312 are elongated holes that are long in the left-right direction LR. The length of the elongated hole of the screw hole 32-6 located approximately in the center of the front case 250 and the lower case 220 in the left-right direction LR is set shorter than the lengths of the elongated holes of the other screw holes 32-1 to 32-5 and 32-7 to 32-10.

[0023] Pins 221 erected from the lower case 220 are inserted into four holes 40-1 to 40-4 provided in the lower plate 312 (see boxed view Q1 in FIG. 2). Hole 40-3 located approximately in the center of the front case 250 and the lower case 220 in the left-right direction LR is a round hole, while the other holes 40-1, 40-2, 40-4 are elongated holes. The engagement between the holes 40-1 to 40-4 and the pins 221 restricts movement of the first reinforcing member 310 in the front-rear direction FB to position it, but allows movement in the left-right direction LR.

[0024] An upper horizontal plate 313b of the fixing part 313 is provided with three screw holes 33-1 to 33-3 aligned in the front-to-rear direction FB. The front and rear screw holes 33-1 and 33-3 are elongated holes that are long in the left-to-right direction LR. The screw hole 33-2 between the front and rear screw holes 33-1 and 33-3 is a circular hole. A lower horizontal plate 313c of the fixing part 313 is provided with a screw hole 33-4 that is a circular hole.

[0025] 5, the second reinforcing member 320 is provided in a generally L-shape that is long in the left-right direction LR. The second reinforcing member 320 is provided so that the length in the left-right direction LR is sufficiently shorter than that of the first reinforcing member 310. The second reinforcing member 320 has a front plate 321 provided with a width substantially equal to the up-down direction UL (width direction) of the front case 250, and a lower plate 322 bent from the lower end edge of the front plate 321 to the rear side B and sufficiently narrower in width than the front plate 321. An engagement piece 321a (first protrusion) is provided at the left end of the front plate 311, the plate surface of which is bent to the front side F in a tongue-like shape in the left-right direction LR.

[0026] A tongue-shaped engagement piece 321b is provided on the left side L of the center of the front plate 321, and a tongue-shaped engagement piece 321c is provided on the right side R of the center of the front plate 321. The engagement piece 321b (second protrusion) is provided by bending the plate surface to the front side F with the plate surface in the up-down direction UL. As shown in the enclosed diagram of P3, the engagement piece 321b has a substantially rectangular shape with an inclined part 321b1 inclined on the outside (the right side case 240 side of the right side R) so that the tip side is narrow with the plate surface in the up-down direction UL. The engagement piece 321c (first protrusion) is provided by bending the plate surface to the front side F with the plate surface in the left-right direction LR. The engagement piece 321c has a substantially rectangular shape.

[0027] The right end portion of the front plate 321 is provided with two protrusions 321d (abutment protrusions) arranged vertically (see also FIG. 11). A concave groove 321e extending in the left-right direction LR is provided between the two protrusions 321d for reinforcement. The concave groove 321e has a concave front side F. In addition, a protrusion piece 321f that protrudes from the plate surface in the front-rear direction FB is provided above the end portion of the right side R of the front plate 321 (the upper side Up of the protrusions 321d).

[0028] The end of the right side R of the front plate 321 is provided with a fixing part 323 formed by bending it to the rear side B. The fixing part 323 is provided with a vertical plate 323a arranged with a plate surface facing the left-right direction, an upper horizontal plate 323b bent from the upper end of the vertical plate 323a to the left side L and arranged with a plate surface facing the up-down direction UL, and a lower horizontal plate 323c bent from the lower end of the vertical plate 313a to the right side R and arranged with a plate surface facing the up-down direction UL. The vertical plate 323a is provided with a concave groove portion 323e provided in the front-rear direction FB in connection with the concave groove portion 321e of the front plate 321. In addition, the rear side B of the vertical plate 323a is provided with a bent portion 323f bent to the left side L. The lower horizontal plate 323c is provided with a protruding piece 323d bent to the upper side Up and arranged with a plate surface facing the left-right direction LR. The protruding pieces 321f and 323d are end-processed by bending the ends.

[0029] The front plate 321 is provided with a plurality of (four in this embodiment) screw holes 34-1 to 34-4 through which screw members 81 for fixing to the front case 250 are inserted. The lower plate 322 is provided with a plurality of (two in this embodiment) screw holes 35-1 to 35-2 through which screw members 82 for fixing to the lower case 220 are inserted. The edges of the rear side B of the lower plate 322 corresponding to the screw holes 35-1, 35-2 and a hole portion 41-1 (described later) in the lower plate 322 slightly protrude toward the rear side B.

[0030] Two screw holes 34-1, 34-2 are provided at the end of the right side R of the front plate 321, one above the other with a recessed groove portion 321e in between. Meanwhile, two screw holes 34-3, 34-4 are provided at the end of the left side L of the front plate 321, one above the other. Of the multiple screw holes 34-1 to 34-4 provided in the front plate 321, the screw holes 34-1, 34-2 on the right side R are round holes, and the screw holes 34-3, 34-4 on the left side L are elongated holes that are long in the left-right direction LR.

[0031] The screw holes 35-1, 35-2 provided in the lower plate 322 are elongated holes that are long in the left-right direction LR. A pin 221 erected from the lower case 220 is inserted into a hole 41-1 that is elongated in the left-right direction LR and is provided between the screw holes 35-1, 35-2 in the left-right direction LR. The engagement between the hole 41-1 and the pin 221 positions the second reinforcing member 320 by restricting movement in the front-rear direction FB, and allows movement in the left-right direction LR.

[0032] An upper horizontal plate 323b of the fixing part 323 is provided with three screw holes 36-1 to 36-3 aligned in the front-rear direction FB. The front and rear screw holes 36-1, 36-3 are elongated holes that are long in the left-right direction LR. The screw hole 36-2 between the front and rear screw holes 36-1, 36-3 is a circular hole. A lower horizontal plate 323c of the fixing part 323 is provided with a screw hole 36-4 that is a circular hole.

[0033] The mounting relationship between the reinforcing member 300 (first reinforcing member 310, second reinforcing member 320), the front case 250, and the lower case 220 will be described. As shown in Figures 6 and 7, the front case 250 is mounted so that its upper end protrudes to the rear side B in a cross-sectional view, and the front plates 311, 321 of the reinforcing member 300 (first reinforcing member 310, second reinforcing member 320) are surface-joined below the upper end. The lower end of the front case 250 is provided in a stepped shape.

[0034] 2 (particularly, boxed views Q1, Q3, and Q4), screw members 81, which are wood screws, are inserted into the screw holes 31-1 to 31-12 of the front plate 311 of the first reinforcing member 310 and the screw holes 34-1 to 34-4 of the front plate 321 of the second reinforcing member 320 and are fastened to the front case 250. Also, screw members 82, which are screws, are screwed into the screw holes 32-1 to 32-10 of the lower plate 312 of the first reinforcing member 310 and the screw holes 35-1, 35-2 of the lower plate 322 of the second reinforcing member 320 and are attached by being screwed into female threads provided corresponding to the lower case 220.

[0035] As shown in the enclosed view of part Q1 in FIG. 2, the front case 250 is provided with an engaged recess 251 (first recess) that is long in the left-right direction LR and corresponds to the engaging piece 311c of the first reinforcing member 310. The engaged recess 251 has a width (vertical direction UL) that is slightly larger than the width of the engaging piece 311c. Therefore, the engagement between the engaging piece 311c and the engaged recess 251 allows the engaging piece 311c to move in the left-right direction LR, but restricts the engaging piece 311c from moving in the up-down direction UL. Therefore, the front case 250 is positioned relative to the first reinforcing member 310 in the up-down direction UL, and the engaging piece 311c is allowed to move in the left-right direction LR.

[0036] As shown in the enclosed view of part Q2 in FIG. 2, the front case 250 is provided with an engaged recess 252 (second recess) having a substantially rectangular recess shape corresponding to the engaging piece 311b of the first reinforcing member 310. Also, as shown in FIG. 10, the flat surface at the left end of the front case 250 abuts against the protrusion 311d and the protruding piece 311f of the front plate 311. The front case 250 is positioned in the left-right direction LR with respect to the first reinforcing member 310 by the protrusion 311d. When attaching the front case 250 to the first reinforcing member 310, if the left end of the front case 250 abuts against the protrusion 311d and the engaged recess 252 is pressed into the engaging piece 311b, the inclined portion 311b1 of the engaging piece 311b bites into the wall surface of the engaged recess 252 facing the inclined portion 311b1. In this manner, the front case 250 is positioned with respect to the first reinforcing member 310, and is restricted so as not to move easily relative to the first reinforcing member 310.

[0037] As shown in the enclosed view of part Q4 in FIG. 2, the front case 250 is provided with an engaged recess 253 (first recess) that is long in the left-right direction LR and corresponds to the engaging piece 321c of the second reinforcing member 320. The engaged recess 253 has a width (vertical direction UL) that is slightly larger than the width of the engaging piece 321c. The engagement between the engaging piece 321c and the engaged recess 253 allows the engaging piece 321c to move in the left-right direction LR and restricts movement in the vertical direction UL. Therefore, the front case 250 is positioned in the vertical direction UL with respect to the second reinforcing member 320.

[0038] As shown in the enclosed view of part Q3 in FIG. 2, the front case 250 is provided with an engaged recess 254 (second recess) having a substantially rectangular recess shape corresponding to the engaging piece 321b of the second reinforcing member 320. Also, as shown in FIG. 11, the flat surface at the right end of the front case 250 abuts against the protrusion 321d and the protruding piece 321f of the front plate 321. The front case 250 is positioned in the left-right direction LR with respect to the second reinforcing member 320 by the protrusion 321d. When attaching the front case 250 to the first reinforcing member 310, if the right end of the front case 250 abuts against the protrusion 321d and the engaged recess 254 is pressed into the engaging piece 321b, the inclined portion 321b1 of the engaging piece 321b bites into the wall surface of the engaged recess 254 facing the inclined portion 321b1. In this manner, the front case 250 is positioned with respect to the second reinforcing member 320, and is restricted so as not to move easily relative to the second reinforcing member 320.

[0039] 2, the engaging pieces 311a, 321a of the first reinforcing member 310 and the second reinforcing member 320 are engaged with engaged recesses 255 (first recesses) that are long in the left-right direction LR and are provided in the front case 250 in correspondence with the engaging pieces 311a, 321a. The vertical direction UL of the engaged recesses 255 is slightly larger than the vertical direction UL (width) of the engaging pieces 311a, 321a. As a result, the front case 250 is positioned in the vertical direction UL with respect to the first reinforcing member 310 and the second reinforcing member 320.

[0040] The right end of the first reinforcing member 310 and the left end of the second reinforcing member 320 are set as division positions for the reinforcing member 300, and a predetermined gap is provided between the right end of the first reinforcing member 310 and the left end of the second reinforcing member 320. The gap S1 between the front plates 311, 321 and the gap S2 between the lower plates 312, 322 are provided offset in the left-right direction.

[0041] As shown in FIG. 6, the upper horizontal plate 313b of the fixing portion 313 in the first reinforcing member 310 is fixed by inserting the screw member 83 into the front and rear screw holes 33-1, 33-3 (see FIG. 4) and screwing into the female screw portion provided in the boss 222 erected from the lower case 220. Meanwhile, as shown in FIG. 8, the screw member 84 is inserted from the lower side Lo into the screw hole 33-2 sandwiched between the front and rear screw holes 33-1, 33-3 in the upper horizontal plate 313b, and screwed into the member constituting the left side case 230 and fixed. Also, the screw member 85 is inserted from the lower side Lo into the screw hole 33-4 of the lower horizontal plate 313c via the lower case 220, and screwed into the member constituting the left side case 230 and fixed. In this way, the left side case 230 is fixed to one end of the first reinforcing member 310. The hole 224 of the lower case 220 through which the screw member 85 is inserted is an elongated hole that is long in the left-right direction LR. The inner surface (right side R) of the protruding piece 313d of the lower horizontal plate 313c is in close proximity to or in contact with the protrusion 231 protruding to the lower side Lo of the left side case 230, thereby positioning the first reinforcing member 310 relative to the left side case 230 in the left-right direction LR.

[0042] As shown in FIG. 7, the upper horizontal plate 323b of the fixing portion 323 in the second reinforcing member 320 is fixed by inserting the screw member 83 into the front and rear screw holes 36-1, 36-3 (see FIG. 4) and screwing into the female screw portion provided in the boss 223 erected from the lower case 220. Meanwhile, as shown in FIG. 9, the screw member 84 is inserted from the lower side Lo into the screw hole 36-2 sandwiched between the front and rear screw holes 36-1, 36-3 in the upper horizontal plate 323b, and screwed into the member constituting the right side case 240 and fixed. Also, the screw member 85 is inserted from the lower side Lo into the screw hole 36-4 of the lower horizontal plate 323c, and screwed into the member constituting the right side case 240 and fixed. In this way, the right side case 240 is fixed to one end of the second reinforcing member 320. The hole 224 of the lower case 220 through which the screw member 85 is inserted is an elongated hole that is long in the left-right direction LR. The inner surface (left side L) of the protruding piece 323d of the lower horizontal plate 323c is in close proximity to or in contact with a protrusion 241 protruding to the lower side Lo of the right side case 240, thereby positioning the second reinforcing member 320 relative to the right side case 240 in the left-right direction LR.

[0043] The relationship between the reinforcing member 300 and the front case 250, the lower case 220, and the side case, which corresponds to the expansion and contraction of the front case 250 and the lower case 220 when the outside temperature changes, will be described. For example, when the outside temperature rises, the lower case 220 made of a resin material expands, and the front case 250 made of a wooden material contracts. When the outside temperature drops, the lower case 220 contracts, and the front case 250 expands. On the other hand, since the reinforcing member 300 (first reinforcing member 310, second reinforcing member 320) is a sheet metal member, its expansion and contraction due to normal changes in the outside temperature is sufficiently smaller than that of the lower case 220 and the front case 250.

[0044] Fixing portions 313, 323 of the reinforcing member 300 (first reinforcing member 310, second reinforcing member 320) are fixed to the side cases (left side case 230, right side case 240) via round screw holes 33-2, 33-4, 36-2, 36-4. Therefore, the first reinforcing member 310 and the second reinforcing member 320 are fixed so that relative movement with the side cases (left side case 230, right side case 240) is restricted.

[0045] Also, the engagement piece 311b having the inclined portion 311b1 in the first reinforcing member 310 is disposed closer to the left side case 230 than the long screw hole 31-3 closest to the left side case 230. Furthermore, on the left side case 230 side of the engagement piece 311b, the first reinforcing member 310 and the front case 250 are fixed via the round screw holes 331-1 and 31-2. Therefore, the first reinforcing member 310 and the front case 250 are fixed in a portion near the left end of the front case 250 so that relative movement between them is restricted. That is, the gap between the front case 250 and the left side case 230 does not change even if the front case 250 expands or contracts. On the other hand, in the portion (right side R) more inward than the engagement piece 311b, the first reinforcing member 310 and the front case 250 are fixed via the long screw holes 31-3 to 31-12, so that the first reinforcing member 310 and the front case 250 are fixed so as to be movable relative to each other, as will be described later.

[0046] Similarly, in the second reinforcing member 320, the engagement piece 321b having the inclined portion 321b1 is disposed closer to the right side case 240 than the long screw holes 34-3, 34-4 that are closest to the right side case 240. Therefore, the gap between the right side case 240 and the front case 250 does not change. That is, the second reinforcing member 320 and the front case 250 are fixed to each other in a portion near the right end of the front case 250 so that relative movement is restricted, and the second reinforcing member 320 and the front case 250 are fixed to each other in a portion (left side L) more inward than the engagement piece 321b so as to be capable of relative movement.

[0047] On the other hand, the reinforcing member 300 (first reinforcing member 310, second reinforcing member 320) is fixed to the lower case 220 via elongated screw holes 32-1 to 32-10, 35-1, and 35-2. The fixing parts 313 and 323 are also fixed to the lower case 220 via elongated screw holes 33-1, 33-3, 36-1, and 36-3. Thus, the reinforcing member 300 (first reinforcing member 310, second reinforcing member 320) is movable relative to the lower case 220. In other words, when lower case 220 expands and contracts due to changes in the outside temperature, the underside of the head of screw member 82 attached to long screw holes 32-1 to 32-10, 35-1, 35-2, 33-1, 33-3, 36-1, 36-3 slides between the surfaces of lower plates 312, 322, upper horizontal plates 313b, 323b, and lower horizontal plates 313c, 323c, allowing movement of reinforcing member 300 (first reinforcing member 310, second reinforcing member 320) relative to lower case 220.

[0048] Similarly, at the locations where the reinforcing member 300 (first reinforcing member 310, second reinforcing member 320) is fixed to the front case 250 via the long screw holes 31-3 to 31-12, 34-3, 34-4 in the front plates 311, 321, slippage occurs between the jaw portion of the head of the screw member 81 and the front plates 311, 321.

[0049] Therefore, for example, when the outside temperature rises, the left side case 230 and the first reinforcing member 310 move to the right side R in response to the contraction of the front case 250, and the right side case 240 and the second reinforcing member 320 move to the left side L. Then, the predetermined gaps S1, S2 at the portion where the first reinforcing member 310 and the second reinforcing member 320 are separated are reduced. At this time, the lower case 220 expands in the left-right direction LR, but since the first reinforcing member 310, the second reinforcing member 320 and the lower case 220 are movable relative to each other, no excessive distortion is generated in the lower case 220. When the outside temperature drops, each member expands and contracts in the opposite direction and moves.

[0050] Therefore, the distance between the left and right ends of the front case 250 and the side cases (left case 230, right case 240) is always constant even if the outside temperature changes. Therefore, the gap between the front case 250 and the side cases, which are visible to the player, does not change, ensuring high design quality.

[0051] As shown in Figures 8 and 9, the screw holes (e.g., hole 224) connecting lower case 220 and the side case (left side case 230, right side case 240) are elongated holes that are long in the left-right direction LR, and predetermined gaps S3, S4 are provided between lower case 220 and the side cases (left side case 230, right side case 240) on the underside of case 200, so that movement of the side cases (left side case 230, right side case 240) is not restricted by lower case 220, and since gaps S3, S4 are located on the underside, they are not visible to the player.

[0052] In addition, since the approximate center portion of the case 200 in the left-right direction LR is less affected by expansion and contraction, the screw hole 32-6 in this portion (disposed in the lower plate 312 of the first reinforcing member 310) has a shorter length in the left-right direction LR than other portions. Similarly, the hole portion 40-3 is a circular hole.

[0053] Moreover, the dividing position of reinforcing member 300 (part Q3 in FIG. 2) is set to the right, avoiding the approximate center portion of case 200 in the left-right direction LR, thereby increasing the rigidity of the approximate center portion of case 200 in the left-right direction LR. Also, left side case 230 on which operation unit 14 is arranged is heavier than right side case 240 on which no operation unit, etc. are arranged, so by setting the dividing position of reinforcing member 300 to the right, the rigidity of the heavier left side case 230 side of case 200 can be increased.

[0054] Although not shown, the lower case 220 and the rear panel do not affect the behavior of the front case 250, the side cases (left side case 230, right side case 240), and the lower case 220, as the rear panel is appropriately divided in the left-right direction LR.

[0055] As described above, in the embodiment of the present invention, the case 200 is made of a first material, which is a resin material, and comprises a lower case 220 that is long in one direction, the left-right direction LR, a plurality of reinforcing members 300 (first reinforcing member 310, second reinforcing member 320) that are fixed to the lower case 220 and arranged separately in the left-right direction LR using a steel plate (sheet metal material) that is a second material that has a smaller linear expansion coefficient than the first material (resin material), a front case 250 that is formed long in one direction and fixed across the plurality of reinforcing members 300, and side cases (left side case 230, right side case 240) that are arranged adjacent to the front case 250 and fixed to one end of the reinforcing member 300.

[0056] As a result, even if the front case 250 and the lower case 220 have different linear expansion coefficients and thus expand and contract differently due to changes in the outside air temperature, the divided reinforcing member 300 moves in unison with the side case and the front case 250, and the gap between the side case and the front case 250 is kept constant. Therefore, even if parts made of different materials, such as the front case 250 and the lower case 220, are combined, the appearance is not marred and no damage to the parts occurs.

[0057] Furthermore, the reinforcing members 300 are divided asymmetrically, which makes it possible to set the division positions according to the locations to be reinforced.

[0058] Further, the reinforcing member 300 arranged at the end in one direction among the multiple reinforcing members 300, i.e., the first reinforcing member 310 and the second reinforcing member 320 in this embodiment divided into two, are fixed to the front case 250 and the side case so that their relative movement is restricted, and are fixed to the lower case 220 so as to be relatively movable. Specifically, a round screw hole is provided at the location where the relative movement is restricted, and a long hole is provided at the location where the reinforcing member 300 is fixed so as to be relatively movable. This allows the side case and the reinforcing member 300 arranged at the end to move in synchronization with the expansion and contraction of the front case 250.

[0059] Further, the reinforcing member 300 disposed at the end in one direction includes round screw holes 31-1, 31-2, 34-1, 34-2, 33-2, 33-4, 36-2, 36-4 through which screw members are inserted to fix the front case 250 and the side case, elongated screw holes 31-3 to 31-12, 34-3, 34-4 through which screw members are inserted to fix the front case 250, and elongated screw holes 32-1 to 32-10, 35-1, 35-2 through which screw members are inserted to fix the lower case 220. This makes it possible to restrict or enable relative movement with a simple configuration.

[0060] Further, the reinforcing member 300 has a tongue-shaped first protrusion (engaging pieces 311a, 311c, 321a, 321c), the front case 250 has a first recess (engaged recess 251, 255, 253) that engages with the first protrusion, and the engagement between the first protrusion and the first recess restricts movement of the first protrusion in a direction (up-down direction UL) perpendicular to one direction (left-right direction LR) while allowing movement of the first protrusion in the other direction (left-right direction LR). This allows the reinforcing member 300 and the front case 250 to be positioned in the up-down direction UL while responding to expansion and contraction in the left-right direction LR due to changes in outside air temperature.

[0061] Further, the reinforcing member 300 has a tongue-shaped second protrusion (engagement pieces 311b, 321b) with inclined portions 311b1, 321b1 provided on the side case side to which the reinforcing member 300 is fixed, and the front case 250 has a second recess (engaged recess 252, 254) that engages with the second protrusion. This allows the reinforcing member 300 to be positioned in the left-right direction LR near both ends of the front case 250 together with the round screw holes 31-1, 31-2, 34-1, 34-2.

[0062] Furthermore, the reinforcing member 300 includes contact protrusions (protrusions 311d, 321d) that come into contact with an end face on one side of the front case 250. This makes it possible to easily position the front case 250 relative to the reinforcing member 300.

[0063] The keyboard instrument 10 is provided with a case 200. This makes it possible to provide a keyboard instrument 10 that reduces the deterioration of its appearance and the damage to its components caused by changes in outside temperature, even when components made of different materials are combined.

[0064] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims.

[0065] The invention described in the first claim of this application is set forth below. [1] A lower case made of the first material and elongated in one direction; A plurality of reinforcing members fixed to the lower case, made of a second material having a linear expansion coefficient smaller than that of the first material, and arranged separately in the one direction; a front case that is elongated in the one direction and fixed across the plurality of reinforcing members; a side case disposed adjacent to the front case and fixed to one end of the reinforcing member; A case equipped with: [2] The case described in [1], wherein the multiple reinforcing members are divided asymmetrically. [3] The case described in [1] or [2], wherein the reinforcing member arranged at the end in one direction among the plurality of reinforcing members includes a portion fixed to the front case so as to be movable relative to the front case and a portion fixed so as to restrict relative movement, and is fixed to the side case so as to restrict relative movement, and is fixed to the lower case so as to be movable relative to the side case. [4] A case described in any of [1] to [3], wherein the reinforcing member arranged at the end in the one direction includes a round screw hole through which a screw member is inserted to fix the case to the front case and the side case, a long screw hole through which a screw member is inserted to fix the case to the front case, and a long screw hole through which a screw member is inserted to fix the case to the lower case. [5] The reinforcing member has a tongue-shaped first protrusion, the front case has a first recess that engages with the first protrusion, The case described in any one of [1] to [4], wherein engagement between the first protrusion and the first recess restricts movement of the first protrusion in a direction perpendicular to the one direction, while allowing movement of the first protrusion in the one direction. [6] The reinforcing member has a tongue-shaped second protrusion having an inclined portion on the side case side to which the reinforcing member is fixed, The case according to any one of [1] to [5], wherein the front case has a second recess that engages with the second protrusion. [7] A case described in any one of [1] to [6], wherein the reinforcing member has a contact protrusion that contacts an end face of the front case in the one direction. [8] A keyboard instrument comprising a case according to any one of [1] to [7]. [Explanation of symbols]

[0066] 3 White keys 4 Black keys 5 Keyboard 6 Keyboard layout area 10 Keyboard Instruments 12 Knobs 14 Operation unit 18 Earphone jack 31-1~31-12, 32-1~32-10, 33-1~33-4 Screw holes 34-1~34-4, 35-1~35-2, 36-1~36-4 Screw holes 40-1~40-4,41-1 Hole 81~85 Screw members 200 Case 210 Upper Case 211 Top panel 220 Lower case 221 Pin 222 Boss 223 Boss 224 Hole 230 Left side case 231 Protrusion 240 Right side case 241 Protrusion 250 Front case 251~255 Engaged recess 300 Reinforcing member 310 First reinforcing member 311 Front plate 311a Engagement piece 311b Engagement piece 311b1 Inclined part 311c Engagement piece 311d Projection 311e Concave groove 311f Projection piece 312 Lower plate 313 Fixed part 313a Vertical board 313b Upper horizontal board 313c Lower horizontal plate 313d Projection piece 313e Concave groove portion 313f Bent portion 320 Second reinforcing member 321 Front plate 321a Engagement piece 321b Engagement piece 321b1 Inclined part 321c Engagement piece 321d Protrusion 321e Concave groove 321f Projection piece 322 Lower plate 323 Fixed part 323a Vertical plate 323b Upper horizontal plate 323c Lower horizontal plate 323d Projection piece 323e Concave groove 323f Bending section S1~S4 gap

Claims

1. a first case made of a first material and extending in one direction; A plurality of reinforcing members fixed to the first case, made of a second material having a linear expansion coefficient smaller than that of the first material, and arranged separately in the one direction; a second case extending in the one direction and fixed across the plurality of reinforcing members, the second case being made of a third material having a linear expansion coefficient different from that of the first material and larger than that of the second material; A case equipped with:

2. A case as described in claim 1, wherein the first material is a resin material, the second material is a metal material, and the third material is a wood material.

3. A case as described in claim 1 or claim 2, comprising a third case arranged adjacent to the second case and fixed to one end of the reinforcing member.

4. A case described in any of claims 1 to 3, wherein the reinforcing member includes a portion that is fixed to be movable relative to the second case and a portion that is fixed so that relative movement is restricted.

5. The case according to claim 3 , wherein the reinforcing member is fixed to the third case so that movement thereof relative to the third case is restricted.

6. The case according to claim 1 , wherein the reinforcing member is fixed to the first case so as to be movable relative to the first case.

7. 7. The case according to claim 1, wherein the reinforcing member includes a contact protrusion that contacts an end face of the second case in the one direction.

8. A keyboard instrument comprising the case according to any one of claims 1 to 7.

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