Keyboard instrument and key

Abstract

To provide a keyboard instrument in which classification work is easily performed while a weight such as a counter weight is securely attached and to provide a key used for the keyboard instrument.SOLUTION: A keyboard instrument includes: a metallic weight 100 which is not elastically deformed; and a key base member 300 including a top board 301, and a plurality of ribs 350, 360 and 370 for fixing the weight 100 by making the ribs abut on a front surface on a front side in a longitudinal direction of the key in a state in which an upper surface of the weight 100 is fixed without using an adhesive on a lower surface of the top board 301, a rear surface on a rear side in the longitudinal direction of the key from the front surface and a lower surface on a lower side in a vertical direction of the key from the upper surface. An area of the upper surface of the weight 100 is larger than an area of the lower surface 101 of the weight.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to keyboard instruments and keys. [Background technology]

[0002] Conventionally, keyboard instruments have been disclosed in which a weight is provided as a counterweight in the key base member to obtain an appropriate weight feeling when the key is struck. For example, Patent Document 1 discloses a key base member in which a weight having a rectangular parallelepiped shape that is long in the front-rear direction of the key is housed, and which has a slit-like opening that is long in the front-rear direction only on the underside. This black key is formed by insert molding. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-268654 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above black keys, the weights are attached to the top, left and right sides, front and back, and bottom of the key base, except for the open areas, with the resin material that forms the key base. Therefore, the weights do not easily come off the key base. However, when disposing of a keyboard instrument, the weights made of metal and the key base made of resin must be separated. This separation process is not easy, since it is necessary to peel off and remove the resin material that is attached around the weights.

[0005] To provide a keyboard instrument in which weights such as counterweights can be securely attached and which is easy to separate, and a key for use with the keyboard instrument. [Means for solving the problem]

[0006] The keyboard instrument of the present invention comprises a key having a metal weight that does not elastically deform, a top plate, and a key base member including a plurality of ribs that secure the weight by abutting against a front surface at the front side of the key in the fore-and-aft direction of the key, a rear surface at the rear side of the key in the fore-and-aft direction from the front surface, and an underside at the lower side of the key in the up-and-down direction from the top surface when the upper surface of the weight is fixed to the underside of the top plate without the use of adhesive, wherein the area of ​​the upper surface of the weight is greater than the area of ​​the underside of the weight.

[0007] The key of the present invention comprises a metal weight that does not elastically deform, a top plate, and a key base member including a front surface at the front side of the key in the fore-and-aft direction when the top surface of the weight is fixed to the underside of the top plate without the use of adhesive, a rear surface at the rear side of the key in the fore-and-aft direction from the front surface, and an underside at the lower side of the key in the up-and-down direction from the top surface, and the area of ​​the top surface of the weight is greater than the area of ​​the underside of the weight. Effect of the Invention

[0008] ADVANTAGE OF THE PRESENT DISCLOSURE According to the present invention, it is possible to provide a keyboard instrument which allows for easy separation whilst ensuring reliable attachment of weights such as counterweights, a method for forming a key base member used in this keyboard instrument, and a mould for forming the key base member. [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] FIG. 2 is an enlarged plan view showing the left side of the keyboard instrument according to the embodiment of the present invention. [Diagram 3] 3 is a cross-sectional view of the keyboard instrument according to the embodiment of the present invention taken along line III-III of FIG. 2. [Figure 4] 4 is a cross-sectional view of the keyboard instrument according to the embodiment of the present invention taken along line IV-IV in FIG. 2. [Diagram 5] FIG. 2 is a perspective view showing a white key of the keyboard instrument according to the embodiment of the present invention. [Figure 6]FIG. 2 is a partially enlarged bottom view of the vicinity of a wide portion of a white key of the keyboard instrument according to the embodiment of the present invention, as viewed from below. [Figure 7] FIG. 7 is a cross-sectional perspective view of a white key of a keyboard instrument according to an embodiment of the present invention, taken along line VII-VII of FIG. 6. [Figure 8] FIG. 2 is a perspective view showing a black key of the keyboard instrument according to the embodiment of the present invention. [Figure 9] FIG. 2 is a bottom view of a black key of the keyboard instrument according to the embodiment of the present invention, viewed from below. [Figure 10] 10 is a cross-sectional view of the black key of the keyboard instrument according to the embodiment of the present invention taken along the line XX in FIG. 9 . [Figure 11] FIG. 11 is a schematic cross-sectional view illustrating a method for molding a key base member using a mold for molding the key base member according to an embodiment of the present invention, showing a state in which a weight is inserted. [Figure 12] FIG. 2 is a schematic cross-sectional view for explaining a method for molding a key base member using a mold for molding a key base member according to an embodiment of the present invention, showing a state in which the mold is clamped and injection molding is performed. [Figure 13] FIG. 2 is a schematic cross-sectional view for explaining a method for molding a key base member using a mold for molding a key base member according to an embodiment of the present invention, showing the state after the mold is opened and the product is removed. 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 50 having a plurality of white keys 30 and a plurality of black keys 40 as a plurality of keys, and a case 20. In the following description, the front of the keyboard 50 in the front-rear direction FB is the front side F, the rear of the keyboard 50 in the front-rear direction FB is the rear side B, the left of the keyboard 50 is the left side L, and the right is the right side R. The arrangement direction LR of the keys on the keyboard 50 is the left-right direction. In addition, the top of the keyboard instrument 10 in the up-down direction UL is the up-side Up, and the bottom is the down-side Lo. The keyboard instrument 10 of this embodiment is an electronic piano, but may be any other keyboard instrument as long as it produces sound in response to a player (user) pressing a key.

[0011] The case 20 is a substantially rectangular plate with the left-right direction as the longitudinal direction, and is divided into an upper case 21 and a lower case 22. The upper case 21 and the lower case 22 are each formed from a resin material. Inside the case 20, a circuit board, a battery as a power source, and the like are stored. An operation unit 11 having knobs and dials for volume and various settings is provided on an upper surface 21a on the left side of the upper case 21. In addition, an earphone jack 12 is provided on the front surface on the left side of the upper case 21.

[0012] The top surface 21a of the upper case 21 adjacent to the keyboard 50 on the left side of the upper case 21 and the top surface 21b of the upper case 21 adjacent to the keyboard 50 on the right side are inclined surfaces that slope downward from the rear to the front. In addition, the top surface 21c that is long in the left-right direction and provided at the upper center of the upper case 21 is also inclined. In addition, although not shown, a hole corresponding to a speaker is provided on the rear surface of the upper case 21.

[0013] 2, the white keys 30 are provided in shapes corresponding to the musical scale of A to F. In the following explanation, the white key 30 will be explained by taking the F key (white key 30F) as a representative example, but the present invention can also be applied to white keys 30 of other musical scales. On the other hand, the black keys 40 are all provided in the same shape.

[0014] As shown in FIG. 3 showing a cross section of a white key 30 and FIG. 4 showing a cross section of a black key 40, the case 20 is assembled by combining the upper case 21 and the lower case 22, for example, by screwing a lower boss 23 erected from the lower case 22 and an upper boss 24 erected from the upper case 21 with a bolt. An internal case 25 is provided inside the case 20. The internal case 25 is elongated in the key arrangement direction LR, and has a cross section that is approximately U-shaped with its opening facing the lower side Lo in the cross section of FIG. 3 and FIG. 4. A circuit board 60 is provided on the upper surface of the internal case 25. The circuit board 60 is provided with a plurality of switches 61 for detecting key depression, corresponding to the plurality of white keys 30 and black keys 40.

[0015] As shown in the enclosed diagram, which is a perspective view of the P portion in FIG. 3 from above, the switch 61 is provided in a substantially rectangular parallelepiped shape of a long rectangle with rounded corners that is long in the front-rear direction FB of the key with both ends in a semicircular arc shape. The switch 61 is made of an elastic material such as a rubber material. The switch 61 includes a rear pressing portion 61a with a circular hole on the upper surface and a front pressing portion 61b. The rear pressing portion 61a and the front pressing portion 61b are provided in a bottomed circular recess shape and have bottoms 61a1 and 61b1. The bottom 61b1 of the front pressing portion 61b is provided longer on the lower side Lo than the bottom 61a1 of the rear pressing portion 61a. The lower side Lo of the switch 61 is provided with a ring-shaped deformation portion 61c that is thin and flexible. Two switch contacts (not shown) are provided on the circuit board 60, corresponding to the bottoms 61a1, 61b1 of the rear pressing portion 61a and the front pressing portion 61b. When these two switch contacts are pressed simultaneously, the pressed key is detected and a predetermined note is sounded. The structure of the switch 61 is the same for the white keys 30 and the black keys 40.

[0016] As shown in Fig. 3, the white key 30 is provided with a switch pressing portion 33 at a position corresponding to the switch 61 for the white key 30. A support shaft 25a that rotatably supports the white key 30 is provided at the rear of the internal case 25. A plurality of support shafts 25a are provided corresponding to each of the white keys 30 and black keys 40. A plurality of hammer members 70 are provided inside the internal case 25. Each hammer member 70 is provided with a weight portion 71 on the rear side B. An arm portion 72 extending from the weight portion 71 to the front side F is rotatably supported by a support shaft 25b provided in the internal case 25.

[0017] The tip of the arm 72 is provided with a hammer cap 73 that engages with the hammer pressing part 31 that extends from the white key 30 to the lower side Lo. The hammer pressing part 31 is provided with a hole 31a with which the hammer cap 73 engages. The white key 30 is also provided with a hook-shaped restricting protrusion 32 at the front end, which extends to the lower side Lo and has a tip protruding backward. The restricting protrusion 32 has a plate-shaped left restricting protrusion 32a and a plate-shaped right restricting protrusion 32b, as described later. Between the left restricting protrusion 32a and the right restricting protrusion 32b, a white key guide part 120 is provided at the front end of the inner case 25. The white key guide part 120 slides on the inner surfaces of the left restricting protrusion 32a and the right restricting protrusion 32b, and guides the movement of the restricting protrusion 32 in the up-down direction UL. Therefore, the white key 30 is reduced in lateral vibration in the key arrangement direction LR when the key is struck.

[0018] As shown in FIG. 4, the black key 40 is provided with a switch pressing portion 43 corresponding to the switch 61 for the black key 40. The black key 40 is also provided with a hammer member 80. The hammer member 80 for the black key 40 also includes a weight portion 81, an arm portion 82, and a hammer cap 83. The hammer cap 83 engages with a hole portion 41a of the hammer pressing portion 41 provided on the black key 40. The hammer pressing portion 41 of the black key 40 includes left and right side plates 403 that extend downward, as described later. Between the left and right side plates 403, a black key guide portion 220 provided on the inner case 25 is provided. The black key guide portion 220 slides on the inner surfaces of the left and right side plates 403, and guides the movement of the black key 40 in the up-down direction UL. Therefore, the black key guide portion 220 reduces the lateral vibration of the black key 40 in the key arrangement direction LR when the key is struck.

[0019] When a white key 30 is pressed, the hammer pressing portion 31 of the white key 30 presses down the hammer cap 73. Then, the weight portion 71 of the hammer member 70, which is provided facing the hammer cap 73 across the support shaft 25b, rises. In this way, the white key 30 can be struck while feeling the same weight as on a real piano. Then, the raised weight portion 71 comes into contact with the upper cushion 26 for the hammer provided on the inner case 25.

[0020] On the other hand, when a white key 30 is pressed, the restricting protrusion 32 is pressed down and comes into contact with the lower cushion 29 provided corresponding to the restricting protrusion 32. When a white key 30 is pressed, the switch 61 is pressed by the switch pressing portion 33 provided on the white key 30, and a sound corresponding to the pressed white key 30 is generated. Then, when the white key 30 is released, the weight portion 71 of the hammer member 70 moves down and comes into contact with the lower cushion 27, and the jaw portion of the restricting protrusion 32 comes into contact with the upper cushion 28, resulting in the state shown in FIG. 3.

[0021] Similarly, when a black key 40 is pressed, the hammer member 80 rotates, allowing the player to feel the same weight as on a real piano when striking the key. Similar to the weight portion 71 for the white key 30, the weight portion 81 for the black key 40 also comes into contact with the upper cushion 26 and the lower cushion 27 at the upper and lower limits.

[0022] When a white key 30 or a black key 40 is pressed, the switch pressing parts 33 and 43 press the upper surface of the switch 61, and a sound corresponding to the pressed white key 30 or black key 40 is generated. When a white key 30 or a black key 40 is pressed, the switch pressing parts 33 and 43 initially contact the upper surface of the rear side of the switch 61. Then, the deformation part 61c bends, and the bottom part 61a1 of the rear pressing part 61a descends first. When the pressed white key 30 or black key 40 becomes approximately horizontal, the switch pressing parts 33 and 43 contact the upper surface of the switch 61 over the front-rear direction FB of the key. Then, the lower surface positions of the bottom parts 61a1 and 61b1 of the rear pressing part 61a and the front pressing part 61b become approximately the same, and the lower surfaces of the bottom parts 61a1 and 61b1 press two switch contacts simultaneously, and a sound corresponding to the pressed key is generated.

[0023] Furthermore, the white and black keys 30 and 40 are provided with weights 100 and 200 as counterweights, respectively. The weights 100 and 200 improve the feel when striking the keys. That is, when striking the keys lightly, a reaction force against the hammer members 70 and 80 is applied to the fingertips, making the force of pressing the key feel lighter. On the other hand, when striking the keys hard, the force of pressing the key feels heavier due to the inertial force generated by the weights 100 and 200. The weights 100 and 200 are both frustum-shaped. The white key 30 is provided with the weight 100 in a truncated cone shape. The black key 40 is provided with the weight 200 in a truncated pyramid shape that is long in the front-to-rear direction FB of the key.

[0024] The attachment locations of the weight 100 on the white key 30 will be described with reference to Figs. 5 to 7. Figs. 5 to 7 show the F white key 30F as an example. As shown in Fig. 5, the white key 30 is equipped with wooden members 310 and 320 as attachment members provided on the left side L and right side R, respectively, and a key base member 300 (see Figs. 6 and 7 for the wooden member 320). The key base member 300 includes a top plate 301 whose top surface 301p is the keying surface. The top plate 301 of the key base member 300 is provided with a step portion 305 on the right side R. The step portion 305 corresponds to the black key 40 of the white key 30 arranged on the keyboard 50. The top plate 301 on the front side F of the step portion 305 is a wide portion 301a, and the rear side B is a narrow portion 301b.

[0025] A front plate 302 is provided extending downward from the lower surface 301q of the front end portion of the top plate 301 toward the lower side Lo. The front plate 302 is disposed with its plate surface facing the front-rear direction FB, and is provided with approximately the same width as the wide portion 301a of the top plate 301. The restricting protrusions 32 are provided on the rear surface of the front plate 302 in a plate-like shape, and include a left restricting protrusion 32a and a right restricting protrusion 32b.

[0026] 6 and 7, the key base member 300 has side plates 303 (left side plate 303a, right side plate 303b) that are attached to the left and right sides and hang down from the underside of the top plate 301. The side plates 303 are provided to correspond to the wide portion 301a of the top plate 301. The left side plate 303a of the side plate 303 provided on the left side L and the right side plate 303b of the side plate 303 provided on the right side R are provided opposite each other.

[0027] The key base member 300 is provided with a vertical plate 306 on the rear side B of the step 305, corresponding to the narrow width portion 301b. The side surface 303a1 of the left side plate 303a and the left side surface 306a of the vertical plate 306 are substantially continuous surfaces. The integrally formed wooden member 310 is provided across the side surface 303a1 of the left side plate 303a and the left side surface 306a of the vertical plate 306. On the other hand, the right side plate 303b is connected to the vertical plate 306 at the step 305 via a connecting plate 305a that is perpendicular to the right side plate 303b. A front wooden member 321 of the wooden member 320 is provided on the side surface 303b1 of the front right side plate 303b, and a rear wooden member 322 of the wooden member 320 is provided on the right side surface 306b of the rear vertical plate 306.

[0028] As shown in Fig. 7, the left and right plates 303a and 303b each have two grooves 110 at the top and bottom. The grooves 110 are used to store excess adhesive that is generated when the wooden members 310 and 320 are attached to the side surface 303a1 of the left plate 303a and the side surface 303b1 of the right plate 303b with adhesive. The protruding plates 307 protrude horizontally outward from the bottom end of the right plate 303b and the bottom end of the rear side B of the vertical plate 306. These protruding plates 307 are used to support the wooden members 310 and 320 and prevent them from falling into the keyboard instrument 10 in the event that they should fall off. The rear end of the key base member 300 is provided with a rotation hole 308 that is pivotally supported by the support shaft 25a.

[0029] 6 and 7, the key base member 300 has a weight 100 and a rib 500 for fixing the weight 100 on the underside 301q of the top plate 301. The rib 500 includes a first rib 350 and a second rib 360. The key base member 300 also has auxiliary ribs 370 (a left auxiliary rib 371 and a right auxiliary rib 372).

[0030] The first rib 350 and the second rib 360 of the rib 500 are respectively arranged in the front-to-back direction FB of the key on the lower surface 301q of the top plate 301. The rib 500 (the first rib 350 and the second rib 360) fixes at least one of the front and rear of the weight 100 in the front-to-back direction FB of the key. Specifically, the first rib 350 is provided on the front side F of the weight 100, and the second rib 360 is provided on the rear side B of the weight 100. The first rib 350 and the second rib 360 have holding portions 351, 361 that are substantially hook-shaped and are provided along the outer shape of the weight 100. The retaining portions 351, 361 have outer peripheral wall portions 351a, 361a provided along the outer peripheral surface 102 of the weight 100, and bottom wall portions 351b, 361b provided on the bottom surface 101 side of the weight 100 and having approximately the same width as the outer peripheral wall portions 351a, 361a. The rear surface of the outer peripheral wall portion 351a and the front surface (surface on the weight 100 side) of the outer peripheral wall portion 361a abut against the outer peripheral surface 102 of the weight 100. The upper surfaces (surface on the weight 100 side) of the bottom wall portions 351b, 361b abut against the bottom surface 101 of the weight 100.

[0031] The weight 100 may be in contact with the lower surface 101 and the outer circumferential surface 102 by at least one of the first rib 350 and the second rib 360. The retaining portions 351, 361 may be provided on at least one of the first rib 350 and the second rib 360.

[0032] Ribs 352, 362 are provided on the front surface of the outer peripheral wall 351a of the holding portion 351 and on the rear surface of the outer peripheral wall 361a of the holding portion 361 (the surfaces opposite to the weight 100, respectively). The ribs 352, 362 are arranged on the center line of the key in the front-rear direction FB of the weight 100, and are provided in a plate shape with the plate surface arranged parallel to the front-rear direction FB of the key, standing upright from the lower surface 301q of the top plate 301. In other words, the rib 500 (rib portions 352, 362) is arranged on a vertical plane parallel to the center line of the key in the front-rear direction FB of the weight 100. The front end of the rib portion 352 of the first rib 350 is connected to the rear surface of a reinforcing rib 304 that connects the left and right side plates 303. The reinforcing rib 304 reinforces the key arrangement direction LR of the side plate 303. In this way, the first rib 350 is connected to the reinforcing rib 304 that connects the left and right side plates 303 of the key base member 300. The rear end of the rib portion 362 of the second rib 360 is connected to the front surface of the connecting plate 305a. As shown in Fig. 7, the opposing corners of the rib portions 352, 362 are C-chamfered portions 352a, 362a.

[0033] The key base member 300 has auxiliary ribs 370 (left auxiliary rib 371, right auxiliary rib 372) that fix the weight 100 in the key arrangement direction LR. The auxiliary rib 370 is provided in the form of a hook-shaped plate. The auxiliary rib 370 is provided so that the plate surface is perpendicular to the rib portions 352 and 362 (parallel to the key arrangement direction LR). The rear side (opposite side from the weight 100) of the left auxiliary rib 371 of the auxiliary rib 370 is connected to the inner surface (right side) of the left side plate 303a. The rear side (opposite side from the weight 100) of the right auxiliary rib 372 of the auxiliary rib 370 is connected to the inner surface (left side) of the side surface 303b1. The auxiliary rib 370 holds the weight 100 from the lower surface 101 with the hook-shaped tip portion and fixes it to the key base member 300. The weight 100 is fixed with its upper surface 103 (see FIG. 3) in contact with a lower surface 301q of the top plate 301.

[0034] Additionally, a space 380 is provided on the front side F of the reinforcing rib 304 (first rib 350) which is surrounded by the reinforcing rib 304, the top plate 301, the left and right side plates 303, and the front plate 302. The space 380 is a space which is used during assembly of the keyboard instrument 10, for example, for inserting an application nozzle for applying grease to the inner surfaces of the left and right restriction protrusions 32a and 32b which come into sliding contact with the white key guide portion 120.

[0035] The black key 40 will be described with reference to Figs. 8 to 10 and Fig. 4. As shown in Fig. 8, the black key 40 has a key base member 400 and a weight 200 (see Fig. 4). The black key 40 is open on the lower side Lo and has a generally rectangular parallelepiped shape that is long in the front-rear direction FB of the key, and has a rotation hole 408 supported by the support shaft 25a at the rear end. The key base member 400 includes a top plate 401 whose upper surface 401p is a keying surface, a front plate 402 provided on the front side F of the top plate 401, and left and right side plates 403 (left plate 403a, right plate 403b) that are provided hanging down from the left and right edges of the top plate 401. The upper part of the front plate 402 is an inclined front plate 402a. The front side F parts of the front plate 402 and the side plates 403 extend toward the lower side Lo and define the hammer pressing part 41.

[0036] As shown in Figures 9 and 10, the key base member 400 has a weight 200 and ribs 510 (first rib 450, second rib 460) arranged at the front and rear of the underside 401q of the top plate 401 in the front-to-rear direction FB of the key to secure the weight 200.

[0037] As shown in FIG. 4, the plate-shaped first rib 450 arranged on the front side F is arranged with its plate surface parallel to the front-rear direction FB of the key, and its tip (lower end) is hook-shaped. The weight 200 side of the first rib 450 abuts against the lower surface 201 and the outer circumferential surface 202 of the weight 200. On the other hand, the plate-shaped second rib 460 arranged on the rear side B is arranged with its plate surface parallel to the front-rear direction FB of the key, and includes a hook-shaped weight 200 side (front side F) part, and abuts against the lower surface 201 and the outer circumferential surface 202 of the weight 200 (see FIG. 9). The upper surface 203 of the weight 200 abuts against the lower surface 401q of the top plate 401. In this way, the weight 200 is fixed to the key base member 400 associated with the black key 40. The weight 200 only needs to be in contact with the underside 201 and the outer circumferential surface 202 via at least one of the first rib 450 and the second rib 460. That is, even in the black key 40, the rib 510 (first rib 450, second rib 460) secures at least either the front or the rear of the weight 200 in the front-to-back direction FB of the key. The rib 510 (first rib 450, second rib 460) is disposed on a vertical plane parallel to the center line of the weight 200 in the front-to-back direction of the key.

[0038] As shown in FIG. 9, the second rib 460 is provided with switch pressing ribs 461, which are two plate-shaped ribs that intersect at right angles. The switch pressing ribs 461 are connected to the left and right side plates 403. The distance between the two switch pressing ribs 461 is arranged so as to match the distance between the centers of the rear pressing portion 61a and the front pressing portion 61b of the switch 61. That is, as shown in FIG. 9, the switch pressing rib 461 is arranged at the center of the rear pressing portion 61a and the front pressing portion 61b, and as shown in FIG. 10, the center of the plate thickness direction of the second rib 460 is arranged so as to match the center line CL (which is also the center line of the weight 200) in the left-right direction of the switch 61. Therefore, the points (two points) where the two switch pressing ribs 461 and the second rib 460 intersect at right angles are arranged on the central axes of the circular holes of the rear pressing portion 61a and the front pressing portion 61b. In this way, the second rib 460 (the switch pressing rib 461) is provided corresponding to the switch 61. The length of the second rib 460 in the front-to-rear direction FB of the key is set sufficiently longer than the length of the upper surface of the switch 61 with which it comes into contact in the front-to-rear direction FB of the key.

[0039] Further, a reinforcing rib 404 is provided between the first rib 450 and the second rib 460 to reinforce the key arrangement direction LR of the side plate 403. The reinforcing rib 404 is a plate-shaped rib that connects the left side plate 403a and the right side plate 403b and is provided so as to be perpendicular to the first rib 450 and the second rib 460. The reinforcing rib 404 abuts against the outer peripheral surface 202 and the lower surface 201 of the weight 200 and is provided across the weight 200.

[0040] Additionally, a space 480 is provided on the front side F of the first rib 450. The space 480 can be used during assembly of the keyboard instrument 10, for example, to insert a nozzle for applying grease between the black key guide portion 220 and the left and right side plates 403 extending toward the hammer pressing portion 41, which are in sliding contact with each other.

[0041] Next, a method for molding the key base member 400 of the black key 40 using a mold 800 will be described with reference to Figures 11 to 13. The mold 800 includes a core mold 600 and a cavity mold 700. The key base member 400 is molded by injection molding of a resin material using the mold 800. The core mold 600 includes a substantially plate-shaped core block 650. The core block 650 includes a hammer pressing portion molding section 601 for molding the hammer pressing portion 41, a rotation hole molding section 608 for molding the rotation hole 408, a weight insertion section 630, etc.

[0042] The weight insertion portion 630 is provided in a concave shape on which the weight 200 can be placed, with the bottom side (upper surface 203) having a larger area among the bottom surfaces of the weight 200 having a truncated pyramid shape being the outer side (upper side). The weight insertion portion 630 includes a first rib molding portion 610 and a second rib molding portion 620 as a rib molding portion 651. The first rib molding portion 610 and the second rib molding portion 620 are arranged opposite each other in the front-to-rear direction FB of the key, with the first rib molding portion 610 being arranged on the front side and the second rib molding portion 620 being arranged on the rear side B.

[0043] The first rib molding portion 610 and the second rib molding portion 620 are each provided in a groove shape extending from the outer peripheral surface 202 of the weight 200 to the bottom surface (lower surface 201) having a small area. Molten resin is poured into the first rib molding portion 610 and the second rib molding portion 620 to mold the first rib 450 and the second rib 460.

[0044] The cavity mold 700 also includes a cavity 710 that is recessed in the outer shape of the black key 40 .

[0045] The method of molding the key base member 400 by injection molding using a mold 800 first involves inserting and positioning the weight 200 in the weight insertion portion 630 provided in the core mold 600 of the mold 800, as shown in Fig. 12. The weight 200 is inserted from the lower surface 201 side (the bottom surface side with the smaller area in the frustum shape). Therefore, even if the positions of the weight 200 and the weight insertion portion 630 are slightly misaligned, they are automatically aligned by the inclined outer peripheral surface 202, and the weight 200 is properly positioned in the weight insertion portion 630.

[0046] Then, a process is performed in which the core mold 600 and the cavity mold 700 are clamped together. At this time, the core block 650 is inserted into the cavity 710. Next, a process is performed in which molten resin is injected into the clamped mold 800 to mold the key base member 400, which includes the first rib 450 and the second rib 460 that are respectively disposed at the front and rear in the front-rear direction FB of the key and that fix the weight 200.

[0047] 13, the cavity mold 700 and the core mold 600 are opened to perform a product removal process to remove the molded key base member 400. In this way, the weight 200 is attached to the key base member 400 by insert molding. The white key 30 with the weight 100 can also be molded by insert molding.

[0048] When disposing of the white keys 30 and black keys 40, the resin key base members 300, 400 and the metal weights 100, 200 can be separated as follows. For the white key 30, for example, the weight 100 can be removed by cutting the reinforcing rib 304 in about two places with nippers and tilting it forward F. Alternatively, the weight 100 can be removed by cutting and removing the rib portions 352, 362 of the first rib 350 and the second rib 360 and the auxiliary rib 370 with nippers, or by tilting and shifting the holding portion 351 left and right.

[0049] Similarly, in the case of the black key 40, the weight 200 can be removed by cutting and removing the first rib 450 or the second rib 460 near the weight 200 with pliers, or by tilting it left or right and shifting it.

[0050] As described above, according to the embodiment of the present invention, the keyboard instrument 10 has the weights 100, 200 and the key base members 300, 400 including the ribs 500, 510 to which the weights 100, 200 are fixed.

[0051] This allows the weights 100, 200 to be securely attached to the key base members 300, 400, and allows the weights 100, 200 to be easily removed simply by cutting the ribs 500, 510 (the first ribs 350, 450 or the second ribs 360, 460). This makes it possible to provide a keyboard instrument 10 equipped with a keyboard 50 that is easy to separate when discarded.

[0052] Furthermore, the ribs 500, 510 fix at least one of the front and rear ends of the weights 100, 200 in the front-rear direction FB of the key. This makes it possible to attach the weights 100, 200 to the key base members 300, 400 more reliably.

[0053] Furthermore, the ribs 500, 510 are disposed on a vertical plane parallel to the center line of the weights 100, 200 in the front-rear direction FB of the key. This allows the weights 100, 200 to be fixed in a well-balanced manner, making them suitable for use as counterweights.

[0054] The key base member 300 also has an auxiliary rib 370 that fixes the weight 100 in the key arrangement direction LR. This makes it possible to attach the weight 100 to the key base member 300 more reliably.

[0055] Additionally, the rib 500 (first rib 350) is connected to a reinforcing rib 304 that connects the left and right side plates 303 of the key base member 300. This allows the weight 100 to be easily removed even by cutting the reinforcing rib 304.

[0056] The ribs 500, 510 include a rib 510 provided on the black key 40, and the rib 510 provided on the black key 40 includes a second rib 460 (a rib 461 for pressing a switch), which is a rib arranged corresponding to a switch 61 for detecting a key press. This ensures that the switch 61 can be pressed reliably.

[0057] In addition, the molding method of the key base member 300, 400 includes the steps of inserting and positioning the weight 100, 200 in the weight insertion portion 630 provided in the core mold 600 of the mold 800, clamping the core mold 600 and the cavity mold 700 of the mold 800 together, and injecting molten resin into the clamped mold 800 to mold the key base member 300, 400 including the ribs 500, 510 that fix the weight 100, 200.

[0058] This provides a molding method for the key base members 300, 400 that allows the weights 100, 200 to be easily removed and separated by simply cutting the ribs 500, 510 (first ribs 350, 450 and second ribs 360, 460) while reliably fixing the weights 100, 200.

[0059] Furthermore, the mold 800 for molding the key base members 300, 400 has a cavity 710 provided in the cavity mold 700 and a core block 650 provided in the core mold 600. The core block 650 has a weight insertion portion 630 including a rib molding portion 651. The weight insertion portion 630 is provided in a truncated cone-shaped concave shape with the larger-area bottom side on the outer side, and the rib molding portion 651 is provided in a groove shape extending from the outer peripheral surface of the truncated cone-shaped weight insertion portion 630 to the smaller-area bottom side.

[0060] This makes it possible to provide a mold 800 for molding the key base members 300, 400 which allows the weights 100, 200 to be securely fixed while allowing the weights 100, 200 to be easily removed and separated by simply cutting the ribs 500, 510 (first ribs 350, 450 and second ribs 360, 460).

[0061] 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. [Explanation of symbols]

[0062] 10 Keyboard instrument 11 Operation section 20 Case 21 Upper case 22 Lower case 30 White key 30F White key 31 Hammer pressing section 40 Black key 50 Key 100 Weight 101 Underside 102 Outer periphery 110 Groove section 300 Key base member 301 Top plate 303 Side plate 303a Left side plate 303a1 Side surface 303b Right side plate 303b1 Side surface 305 Step section 305a Connection plate 307 Projection plate 310 Wood member 320 Wood member 321 Front wood member 322 Rear wood member 350 First rib 351 Holding section 351a Outer periphery wall section 351b Lower wall section 352 Rib section 352a Chamfered section 360: second rib; 361: retaining portion; 361a: outer peripheral wall portion; 361b: lower wall portion; 362: rib portion; 362a: chamfered portion; 370: auxiliary rib; 371: left auxiliary rib; 372: right auxiliary rib

Claims

1. A metal weight that does not elastically deform, a key base member including a top plate and a rib for holding the weight on a second surface of the weight located below the first surface in the vertical direction of the key when the first surface of the weight is in contact with the underside of the top plate; a key having a The area of ​​the first surface of the weight is greater than the area of ​​the second surface of the weight. Keyboard instrument.

2. The ribs are provided in plurality, The plurality of ribs are arranged on the same line in the front-rear direction of the key.

2. A keyboard instrument as claimed in claim 1.

3. The key base member has an auxiliary rib that fixes the weight in the key arrangement direction.

2. A keyboard instrument as claimed in claim 1.

4. The rib is connected to a reinforcing rib that connects the left and right side plates of the key base member.

2. A keyboard instrument as claimed in claim 1.

5. At least one rib abutting against the second surface of the weight provided on the key base member corresponding to a black key presses a switch for detecting the key press in response to the key press.

5. A keyboard instrument according to claim 1.

6. A metal weight that does not elastically deform, a key base member including a top plate and a rib for holding the weight on a second surface of the weight located below the first surface in the vertical direction of the key when the first surface of the weight is in contact with the underside of the top plate; having The area of ​​the first surface of the weight is greater than the area of ​​the second surface of the weight. key.

7. The ribs are provided in plurality, The plurality of ribs are arranged on the same line in the front-rear direction of the key. The key according to claim 6.

8. The key base member has an auxiliary rib that fixes the weight in the key arrangement direction. The key according to claim 6.

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