Keyboard device and key guide method

Abstract

To provide a keyboard device and key guide method that can improve feel of pressing keys down.SOLUTION: A virtual axis Va of each white key 2a aligned in a scale direction is set to a different position for each white key 2a. In other words, because an angle of a guide groove 60 of each white key 2a differs between the white keys 2a, it is possible to make each white key 2a oscillate along a different displacement trajectory without changing dimensions of each white key 2a in the front-back direction. Therefore, unlike a structure that changes the displacement trajectory of each key by changing overall length of each key, it is not necessary to make the overall length of some white keys 2a longer, so it is possible to suppress enlargement of a keyboard device 1.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a keyboard device and a key guiding method, and more particularly to a keyboard device and a key guiding method that can change the displacement trajectory of each key while preventing the keyboard device from becoming large in the front-rear direction. [Background technology]

[0002] Some acoustic grand pianos (hereafter referred to as "acoustic pianos") have a structure in which the pivot point of the keys gradually moves closer to the player from the low to high keys. If the pivot point is in a different position for each key, the displacement trajectory of the key when pressed also changes for each key, so there is technology to simulate the displacement trajectory of each key of such an acoustic piano in an electronic piano.

[0003] For example, Patent Document 1 describes a technique for gradually shortening the front-rear dimensions of the white keys 11w and black keys 11b from the low-pitched keys to the high-pitched keys. This technique allows the position of the pivot point of each key to be gradually moved closer to the player from the low-pitched keys to the high-pitched keys, just like an acoustic piano, so that the keys can be swung along the same displacement trajectory as an acoustic piano. In other words, the player can be given a playing experience similar to that of an acoustic piano. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-034853 A (for example, paragraph 0014, Figure 1) Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned conventional technology, the front-to-rear dimension of the low-pitched keys is larger than that of the high-pitched keys, which causes the keyboard device to become larger in size in the front-to-rear direction.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a keyboard device and a key guiding method that can change the key displacement trajectory for each key while preventing the keyboard device from becoming larger in the front-to-rear direction. [Means for solving the problem]

[0007] In order to achieve this object, the keyboard device of the present invention comprises a support member and a key that is supported by the support member so as to be able to swing, wherein either the support member or the key has a guide groove that guides the swing of the rear part of the key, and the other of the support member or the key has a guide shaft that extends in the scale direction, is inserted into the guide groove, and slides along the guide groove when the key swings, wherein the keys are composed of white keys and black keys, wherein the point where the center of the guide shaft is located before the key is pressed is defined as the start point of the guide groove, and when the point where the center of the guide shaft is located when the key is pressed to its end position is defined as the angle of the guide groove, the angle of the guide groove differs between the white keys or between the black keys.

[0008] The key guiding method of the present invention is a method for guiding a keyboard device comprising a support member and a key supported by the support member to be able to swing, wherein either the support member or the key has a guide groove that guides the swing of a rear part of the key, and the other of the support member or the key has a guide shaft that extends in the scale direction and is inserted into the guide groove, the keys are composed of white keys and black keys, and when the point where the center of the guide shaft is located before the key is pressed is defined as the start point of the guide groove, and the point where the center of the guide shaft is located when the key is pressed to its end position is defined as the end point of the guide groove, and the angle of the guide groove is different between the white keys or between the black keys, the swing of the key when pressed is guided by the sliding between the guide groove and the guide shaft. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view of a keyboard device according to an embodiment; [Diagram 2] FIG. [Diagram 3] 3 is a cross-sectional view of the keyboard device showing a state in which a white key has been pressed to an end position from the state shown in FIG. 2. [Figure 4] 4 is a partially enlarged cross-sectional view of the keyboard device taken along line IV-IV in FIG. 2. [Diagram 5] FIG. 13(a) is a cross-sectional view of a mold showing how the side plates and connecting plate are formed, and (b) is a cross-sectional view showing a white key of a first modified example. [Figure 6] 1A is a cross-sectional view of a white key of a second modified example, FIG. 1B is a cross-sectional view of a mold showing how the side plates and connecting plate are formed using the mold, and FIG. 1C is a cross-sectional view of a white key of a third modified example. [Figure 7] FIG. 2A is a perspective view of the white key with the mounting member removed from the mounting hole, and FIG. 2B is a side view of the mounting member. [Figure 8] FIG. 1A is a side view of a white key showing how the mounting member is inserted into the mounting hole while being elastically deformed, and FIG. 1B is a side view of the white key showing how the mounting member is flipped around its center and inserted into the mounting hole. [Figure 9] 1A is a side view of the white key located at the highest pitch, FIG. 1B is a side view of the white key located at the lowest pitch, and FIG. 1C is a top view of the keys, showing the schematic position of the imaginary axis of each white key. [Figure 10] 3 is a partially enlarged cross-sectional view of the keyboard device 1 at a position corresponding to part X in FIG. 2. [Figure 11] 1A is a top view of a key showing the position of the virtual axis in a first modified example, FIG. 1B is a top view of a key showing the position of the virtual axis in a second modified example, and FIG. 1C is a top view of a key showing the position of the virtual axis in a third modified example. [Figure 12]FIG. 13(a) is a side view of a white key of a fourth modified example, and (b) is a perspective view of the white key with the mounting member removed from the mounting hole. [Figure 13] FIG. 13(a) is a perspective view of a white key of a fifth modified example, and (b) is a perspective view of the white key with the mounting member removed from the protruding portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A preferred embodiment will be described below with reference to the accompanying drawings. First, the overall configuration of a keyboard device 1 will be described with reference to Figures 1 and 2. Figure 1 is a perspective view of the keyboard device 1 in one embodiment, and Figure 2 is a cross-sectional view of the keyboard device 1.

[0011] In addition, Fig. 1 shows a state in which a part of the chassis 4 has been broken away to expose the receiving portion 72 of the hammer 7, and Fig. 2 shows a cross section cut along a plane perpendicular to the scale direction (the direction in which the keys 2 are lined up). In Fig. 2, hatching of the shaft portion 41 has been omitted to make it easier to understand. The arrows UD, FB, and LR in Figs. 1 and 2 respectively indicate the up-down direction, front-rear direction, and scale direction of the keyboard device 1, and the same applies to Figs. 3 and onwards.

[0012] 1 and 2, the keyboard device 1 is a keyboard instrument (electronic piano) equipped with a plurality (88 in this embodiment) of keys 2. The keys 2 are composed of a plurality (52 in this embodiment) of white keys 2a for playing fundamental notes and a plurality (36 in this embodiment) of black keys 2b for playing derived notes, and the plurality of white keys 2a and black keys 2b are arranged in the scale direction (arrow LR direction).

[0013] The keyboard device 1 includes a shelf 3 for supporting the white keys 2a and the black keys 2b. The shelf 3 is formed in a flat plate shape extending in the scale direction using synthetic resin, steel plate, or the like, and a resin chassis 4 is supported on the upper surface of the shelf 3. Both front and rear ends (in the direction of the arrow FB) of the chassis 4 are fixed to the shelf 3 via channel members 5. The support structure of the white keys 2a relative to the chassis 4 and the detailed configuration of the white keys 2a are described below, but the configuration is substantially the same for the black keys 2b.

[0014] A wall 40 rises upward from the upper surface of the rear end side (arrow B side) of the chassis 4, and a substantially cylindrical shaft 41 protrudes in the scale direction from the side surface of the upper end side of the wall 40 (see the enlarged portion in FIG. 1). The wall 40 and shaft 41 are formed integrally with the chassis 4, but may be formed separately from the chassis 4.

[0015] A plurality of wall portions 40 are arranged in the scale direction (see FIG. 1), and the protruding portion 20 of the white key 2a is inserted between the opposing wall portions 40. In the following explanation, the pair of wall portions 40 (shaft portions 41) facing each other with the protruding portion 20 in between will be simply referred to as the "pair of wall portions 40 (shaft portions 41)" or the like.

[0016] The protruding portion 20 is a portion that protrudes rearward from the rear end of the white key 2a, and is formed to have a smaller dimension in the scale direction than the portion (the portion that is pressed) at the front end side (the side of the arrow F) of the white key 2a. A mounting member 6 having a guide groove 60 is attached to the protruding portion 20. The mounting member 6 is a part that is fitted into a mounting hole 21 formed in the protruding portion 20 (see FIG. 7), and the method of mounting the mounting member 6 to the white key 2a (protruding portion 20) will be described later.

[0017] The guide grooves 60 are formed on both side surfaces of the mounting member 6 in the scale direction, and the shafts 41 formed on the pair of walls 40 are fitted into the guide grooves 60. When fitting the shafts 41 into the guide grooves 60, the protrusions 20 of the white key 2a are inserted between the pair of shafts 41 from above.

[0018] The shaft portion 41 has an inclined surface 42 (see enlarged portion in FIG. 1) that is inclined so as to cut out the upper end of the tip surface at an angle, and by inserting the protrusion 20 of the white key 2a between the pair of opposing shaft portions 41 from above, the protrusion 20 slides along the inclined surface 42 of the shaft portion 41. This sliding causes the plate-like wall portion 40 to elastically deform, expanding the gap between the pair of opposing shaft portions 41, so that the shaft portion 41 can be easily fitted into the guide groove 60.

[0019] The shaft portion 41 is fitted into the guide groove 60, so that the white key 2a is slidably (swingably) supported between the pair of opposing walls 40. A hammer 7 that moves in conjunction with the swinging of the white key 2a is provided below the white key 2a.

[0020] A rotation shaft 43 (see FIG. 2) that runs along the scale direction is formed in the approximate center of the chassis 4 in the front-to-rear direction, and a hammer 7 is rotatably supported on this rotation shaft 43. The hammer 7 has a mass section 70 (mass body) that provides a key depression sensation when the white key 2a is depressed, and the mass section 70 is located rearward of the rotation shaft 43 (on the side of the arrow B).

[0021] The portion of the hammer 7 that is forward of the rotating shaft 43 (on the side of the arrow F) is configured as a pressing portion 71 for pressing the switch 80 on the circuit board 8 when the white key 2a is pressed. A downwardly recessed receiving portion 72 is formed on the upper surface of the pressing portion 71, and the protrusion 22 that is inserted into this receiving portion 72 protrudes downward from the underside of the white key 2a.

[0022] Since the protrusion 22 is simply inserted (rests) on the receiving portion 72, when assembling the white key 2a, after placing the protrusion 22 on the receiving portion 72, as described above, it is sufficient to insert the protrusion 20 between the opposing walls 40 and fit the shaft 41 into the guide groove 60. This makes it easy to assemble the white key 2a to the chassis 4.

[0023] On the other hand, when removing the white key 2a from the chassis 4, it is only necessary to elastically deform the wall 40 (by pushing the wall 40 apart) to remove the shaft 41 from the guide groove 60, and then pull out the protrusion 22 from the receiving part 72. This makes it easy to remove the white key 2a, improving the maintainability of the white key 2a.

[0024] The lower surface of the protrusion 22 of the white key 2a is formed in a downwardly convex arc shape, and the bottom surface of the receiving portion 72 of the hammer 7 is also formed in a downwardly convex arc shape. The curvature of the contact area between the lower surface of the protrusion 22 and the bottom surface of the receiving portion 72 is the same, and in the initial state before the white key 2a is pressed (the state in FIG. 2) (hereinafter referred to as the "initial position before key pressing"), the lower surfaces of these protrusions 22 and the bottom surface of the receiving portion 72 are in surface contact.

[0025] Next, the operation when the white key 2a is pressed will be described with reference to Figures 2 and 3. Figure 3 is a cross-sectional view of the keyboard device 1 showing a state in which the white key 2a is pressed to the end position from the state in Figure 2.

[0026] As shown in Figures 2 and 3, when the white key 2a is pressed from the initial position, the lower surface of the protrusion 22 slides along the bottom surface of the receiving portion 72, while the protrusion 22 presses the pressing portion 71 (receiving portion 72) downward, thereby rotating the hammer 7 around the rotation axis 43 (clockwise in Figures 2 and 3) (see Figure 3).

[0027] A switch 80 is provided below the pressing portion 71 of the hammer 7, and as the hammer 7 rotates when the white key 2a is pressed, the switch 80 is pressed by the pressing portion 71. The on / off state of this switch 80 detects key press information (note information) of the white key 2a, and a musical tone signal based on this detection result is output to the outside.

[0028] In this way, the rocking of the front end portion of the white key 2a when pressed is guided by the rotation of the hammer 7 around the rotation shaft 43. On the other hand, the rocking of the rear end portion of the white key 2a (the rear portion behind the center of the white key 2a in the front-to-rear direction) is guided by the sliding of the guide groove 60 along the shaft portion 41 of the chassis 4.

[0029] When the white key 2a swings up and down in this manner, unstable movements of the white key 2a may occur, such as rotation of the white key 2a around an axis in the front-to-rear direction (so-called rolling). Therefore, a front guide 44 is provided on the chassis 4 to stabilize the swinging of the white key 2a.

[0030] The front guide 44 is a plate-shaped metal fitting attached to the chassis 4. The front guide 44 rises upward from the front end of the chassis 4, and is inserted into a recess 23 formed in the underside of the front end of the white key 2a. A rubber cover 45 is attached to the front guide 44, and the inner surface of the recess 23 (the surface facing inward in the scale direction) comes into contact with the cover 45, thereby guiding the oscillation of the front end of the white key 2a.

[0031] The front guide 44 (cover 45) guides the swing of the white key 2a forward of the engagement position between the white key 2a and the hammer 7, but the swing of the rear end of the white key 2a is guided by the rear guide 46 (see the enlarged portion in Figs. 2 and 3). The rear guide 46 has a wall 46a formed rearward of the shaft 41 of the chassis 4 and a guide protrusion 46b protruding from the side of the wall 46a, and the guide protrusion 46b guides the up and down swing of the white key 2a (protrusion 20). The detailed configuration of the rear guide 46 will be described with reference to Fig. 4. Fig. 4 is a partially enlarged cross-sectional view of the keyboard device 1 taken along line IV-IV in Fig. 2. Fig. 4 shows the end face (only the cross-sectional shape) of the white key 2a.

[0032] 4, the wall portion 46a of the rear guide 46 is formed in a wall shape rising upward from the chassis 4, and a guide protrusion 46b protrudes from this wall portion 46a in the scale direction. The wall portion 46a and the guide protrusion 46b are formed integrally with the chassis 4, but may be formed separately from the chassis 4.

[0033] A plurality of wall portions 46a are arranged in the scale direction (arrow LR direction), and the protrusion 20 of the white key 2a is sandwiched between a pair of guide protrusions 46b provided between opposing walls 46a. In the following explanation, the pair of walls 46a (guide protrusions 46b) facing each other with the protrusion 20 in between will be simply referred to as the "pair of walls 46a (guide protrusions 46b)" etc.

[0034] The protrusion 20 is formed in a box shape including a pair of side plates 20a facing each other in the scale direction and a connecting plate 20b connecting the lower ends of the pair of side plates 20a in the scale direction. The tip surface of the guide protrusion 46b (the surface facing the side plate 20a) is a guide surface 46c that guides the up and down rocking of the side plate 20a, and the side surface of the protrusion 20 facing the guide surface 46c in the scale direction (the outer surface of the side plate 20a) is a guided surface 20c.

[0035] The guide surface 46c is a plane perpendicular to the scale direction, and notches 46d are formed at the upper ends of the pair of guide surfaces 46c, sloping upward in a direction away from the opposing gap (the protrusion 20 side). By forming such notches 46d, when the protrusion 20 is inserted from above between the opposing pair of guide protrusions 46b, the insertion can be guided by the notches 46d.

[0036] The guided surface 20c of the white key 2a is composed of an inclined surface 20c1 that slopes so that the distance from the guide surface 46c gradually increases from the upper end to the lower end of the side panel 20a, and a curved surface 20c2 that is connected to the lower end of the inclined surface 20c1.

[0037] The inclined surface 20c1 is a plane inclined at an angle of 0.5° or more and less than 1° with respect to the guide surface 46c (vertical direction), and the curved surface 20c2 is an arc-shaped curved surface connecting the lower end of the inclined surface 20c1 (the outer surface of the side plate 20a) and the lower surface 20d of the connecting plate 20b.

[0038] FIG. 4 shows the initial state before the white key 2a is pressed. When the white key 2a is pressed from this state, the guided surface 20c (the inclined surface 20c1 and the curved surface 20c2) slides downward relative to the guide surface 46c, and when the white key 2a is released from the pressed state, the guided surface 20c slides upward relative to the guide surface 46c.

[0039] As the guided surface 20c slides upward when the key is released, the grease applied to the guide surface 46c and the guided surface 20c is scraped upward; however, in this embodiment, the grease scraped upward is more likely to be retained in the sliding area between the guide surface 46c and the guided surface 20c (hereinafter referred to as the "sliding area of ​​the guided surface 20c").

[0040] Specifically, in the initial position before the key is pressed, the entire guided surface 20c (from the upper end of the inclined surface 20c1 to the lower end of the curved surface 20c2) faces the guide surface 46c in the scale direction. In other words, when the white key 2a is returned to the initial position (the state in FIG. 4) after being pressed, the guided surface 20c (inclined surface 20c1) is configured not to protrude above the guide surface 46c.

[0041] This prevents the grease scraped upward by the swinging of the white key 2a from being pushed out to the notch 46d or the upper surface of the guide protrusion 46b. The grease scraped upward flows downward along the guide surface 46c by its own weight, so the grease is easily retained in the sliding area of ​​the guided surface 20c. This improves the key depression feel of the white key 2a.

[0042] In addition, the distance between the guide surface 46c and the guided surface 20c (the inclined surface 20c1 and the curved surface 20c2) gradually increases from the upper end to the lower end of the guided surface 20c. Thus, a small gap is formed between the guide surface 46c and the lower end of the guided surface 20c, and this gap gradually increases as it approaches the lower end of the guided surface 20c. This prevents the grease from being scraped off downward when the guided surface 20c slides downward relative to the guide surface 46c. This also makes it easier for the grease to be retained in the sliding area of ​​the guided surface 20c, improving the key depression feel of the white key 2a.

[0043] Here, if the objective is to make it difficult for the grease to be scraped off, it is possible to, for example, omit the curved surface 20c2 (by extending and connecting the inclined surface 20c1 and the lower surface 20d of the connecting plate 20b) and form the inclination angle of the inclined surface 20c1 with respect to the guide surface 46c to be relatively large. However, in this configuration, the larger the inclination angle of the inclined surface 20c1 with respect to the guide surface 46c, the more likely it is that the sliding of the guided surface 20c with respect to the guide surface 46c will become unstable, making it difficult to stably guide the swinging of the white key 2a. On the other hand, the closer the inclination angle of the inclined surface 20c1 to the guide surface 46c, the more likely it is that the grease will be scraped off downward when the white key 2a swings.

[0044] In contrast, the guided surface 20c in this embodiment is composed of an inclined surface 20c1, which is a flat surface inclined relative to the guide surface 46c, and a curved surface 20c2 connected to the lower end of the inclined surface 20c1. The curved surface 20c2 is spaced from the guide surface 46c at a greater rate than the inclined surface 20c1, and a relatively wide gap is formed between the curved surface 20c2 and the guide surface 46c, which effectively prevents the grease from being scraped off.

[0045] In other words, by giving the function of suppressing scraping off of grease mainly to the curved surface 20c2, it is possible to make the angle of the inclined surface 20c1 with respect to the guide surface 46c as close to parallel as possible, and to fully exhibit the function of scraping off the grease. Therefore, it is possible to suppress rattling in the sliding of the guided surface 20c with respect to the guide surface 46c, and to suppress the grease from being scraped off due to such sliding.

[0046] In this embodiment, the curved surface 20c2 is formed at the lower end of the inclined surface 20c1 to increase the degree of the gap between the lower end of the guided surface 20c and the guide surface 46c, but this is not necessarily limited to this. For example, the curved surface 20c2 may be an inclined surface (flat surface) inclined relative to the guide surface 46c, and the inclination angle of the inclined surface (angle relative to the guide surface 46c) may be larger than that of the inclined surface 20c1. Even with this configuration, it is possible to suppress rattling in the sliding of the guided surface 20c relative to the guide surface 46c, while suppressing grease from being scraped off due to such sliding.

[0047] Next, with reference to Fig. 5(a), a method for forming the side plate 20a and the connecting plate 20b (the protruding portion 20 of the white key 2a) using a die 100 will be described. Fig. 5(a) is a cross-sectional view of the die 100 showing how the side plate 20a and the connecting plate 20b are formed.

[0048] As shown in Fig. 5(a), a mold 100 for molding the side plates 20a and the connecting plate 20b includes a lower mold 101 and an upper mold 102. A recess 101a is formed in the lower mold 101, and a protrusion 102a to be inserted into this recess 101a is formed in the upper mold 102. When the protrusion 102a is inserted into the recess 101a, a cavity having a shape corresponding to the pair of side plates 20a and connecting plate 20b is formed in the mold 100. After a heated and melted resin material is injected into this cavity from an injection port (not shown), the resin material is cooled (solidified) to mold the side plates 20a and the connecting plate 20b.

[0049] After molding, the side plate 20a and the connecting plate 20b are released from the mold 100. As described above, the inclined surface 20c1 constituting the side surface of the side plate 20a has an angle of 0.5° or more and less than 1°, and this inclination also functions as a draft gradient for releasing the side plate 20a from the recess 101a of the lower mold 101.

[0050] In addition, the inner surface 20e of the side plate 20a facing each other between a pair of side plates 20a is also inclined at an angle parallel to the inclined surface 20c1, and this inclination also serves as a draft angle for releasing the side plate 20a from the convex portion 102a of the upper mold 102.

[0051] When molding the white key 2a from such a resin material, the plate thickness of each part of the white key 2a needs to be 2 to 3 mm to prevent deterioration of the moldability. In this case, if the protruding part 220 is formed as a single plate like the white key 202a of the first modification shown in Fig. 5 (b), it becomes difficult to ensure the rigidity of the protruding part 220. If the rigidity of the protruding part 220 is low, the protruding part 220 sandwiched between the guide protrusions 46b is easily deformed when the white key 202a swings, which may cause problems such as the protrusion 220 being unable to stably guide the swing of the white key 202a and the protruding part 220 being easily damaged.

[0052] In contrast, the protruding portion 20 of this embodiment is formed in a box shape with a pair of side plates 20a whose outer surfaces facing the scale direction are configured as guided surfaces 20c, and a connecting plate 20b that connects the pair of side plates 20a in the scale direction. This ensures the rigidity of the protruding portion 20 even when the white key 2a is molded using a resin material, that is, when the thickness of each plate 20a, 20b of the protruding portion 20 is limited to 2 to 3 mm. By ensuring the rigidity of the protruding portion 20, the oscillation of the white key 2a can be stably guided and the protruding portion 20 can be prevented from being damaged.

[0053] Here, when the purpose is to form the protrusion 20 of the white key 2a into a box shape, it is possible to connect the upper ends of the side plates 20a of the protrusion 320 with a connecting plate 320b, as in the white key 302a of the second modified example shown in Fig. 6(a). A method for forming such a protrusion 320 using a mold 200 will be described later with reference to Fig. 6(b). However, if the protrusion 320 is provided with a draft angle during molding using the mold 200, it is necessary to form the side plates 20a so as to have a tapered thickness. This causes problems such as poor moldability of the protrusion 320 and reduced rigidity of the protrusion 320.

[0054] In contrast, in this embodiment, as shown in Fig. 5(a), the lower ends of a pair of side plates 20a are connected to each other by a connecting plate 20b to form the protrusion 20 in a box shape, and the distance between the inner surfaces 20e of the pair of side plates 20a is gradually narrowed toward the lower ends of the side plates 20a. This allows the thickness of the side plate 20a to be made substantially constant (the inclined surface 20c1 and the inner surface 20e of the side plate 20a can be made substantially parallel) while forming a draft angle in the side plate 20a relative to the lower mold 101 and the upper mold 102, improving the formability of the protrusion 20. Furthermore, by forming the side plate 20a to have a constant thickness, the rigidity of the protrusion 20 can be ensured, and the rocking movement of the white key 2a can be stably guided.

[0055] Thus, in this embodiment, the pair of side plates 20a and the connecting plate 20b form the rear end of the protruding portion 20 in a box shape, and the rear end of the space surrounded by these plates 20a, 20b is closed by a closing plate 20f (see the enlarged portion in FIG. 3). The lower end of the closing plate 20f is connected to the connecting plate 20b, and both ends of the closing plate 20f in the scale direction (the direction of the arrows LR in FIG. 3) are connected to the pair of side plates 20a. By providing such a closing plate 20f, the rigidity of the protruding portion 20 can be improved, so that the rocking movement of the white key 2a can be stably guided.

[0056] Next, the white key 202a of the first modified example will be described with reference to Fig. 5(b). The same parts as those in the above embodiment are given the same reference numerals and their description will be omitted. Fig. 5(b) is a cross-sectional view of the white key 202a of the first modified example. Fig. 5(b) shows a cross-section of the keyboard device 1 (see Fig. 2) cut at a position corresponding to Fig. 4.

[0057] As shown in FIG. 5(b), the white key 202a of the first modified example has a protrusion 220 formed in the shape of a single plate, and the guided surface 20c (inclined surface 20c1 and curved surface 20c2) described in the above embodiment is formed on the side of the plate-shaped protrusion 220.

[0058] A pair of guide protrusions 246b sandwiching the protrusion 220 from both sides in the scale direction has the same configuration as the guide protrusions 46b (see FIG. 4) described in the above embodiment, except that the length of protrusion from the wall 46a is increased. In other words, the guide surface 46c similar to that of the above embodiment is formed on the tip surface of the guide protrusions 246b.

[0059] In the white key 202a of this first modification, the entire guided surface 20c (the inclined surface 20c1 and the curved surface 20c2) faces the guide surface 46c in the initial position before the key is pressed. This prevents the grease scraped up by the white key 202a from being pushed out to the notch 46d or the upper surface of the guide protrusion 246b when the white key 202a returns to the initial position (the state of FIG. 5(b)) after pressing. This makes it easier for the grease to be retained in the sliding area of ​​the guided surface 20c.

[0060] In addition, the distance between the guide surface 46c and the guided surface 20c (the inclined surface 20c1 and the curved surface 20c2) gradually increases from the upper end to the lower end of the guided surface 20c, so that even if the guided surface 20c slides downward relative to the guide surface 46c when the white key 202a is pressed, the grease applied to the surfaces 20c, 46c is not easily scraped off downward. This also makes it easier for the grease to be retained in the sliding area of ​​the guided surface 20c.

[0061] Next, the white key 302a of the second modified example will be described with reference to Fig. 6(a) and Fig. 6(b). Fig. 6(a) is a cross-sectional view of the white key 302a of the second modified example, and Fig. 6(b) is a cross-sectional view of the die 200 showing how the side plate 20a and the connecting plate 320b are formed using the die 200. Fig. 6(a) shows a cross-section of the keyboard device 1 (see Fig. 2) cut at a position corresponding to Fig. 4.

[0062] The white key 302a of the second modified example has the same configuration as the white key 2a (see FIG. 4) described in the above embodiment, except that the connecting plate 320b of the protrusion 320 connects the upper ends of the side plates 20a to each other in the scale direction.

[0063] That is, the protruding portion 320 is formed in a box shape having an opening on the lower surface side, and the guided surface 20c is formed on the side surface of this box-shaped protruding portion 320 (side plate 20a). An end portion on the inner side in the scale direction of the curved surface 20c2 of the guided surface 20c is connected to the lower end of the inner surface 20e of the side plate 20a.

[0064] In the white key 302a of this second modification, the entire guided surface 20c (the inclined surface 20c1 and the curved surface 20c2) faces the guide surface 46c in the initial position before the key is pressed. This prevents the grease scraped up by the white key 302a from being pushed out to the notch 46d or the upper surface of the guide protrusion 46b when the white key 302a returns to the initial position (the state of FIG. 6(a)) after pressing. This makes it easier for the grease to be retained in the sliding area of ​​the guided surface 20c.

[0065] In addition, the distance between the guide surface 46c and the guided surface 20c (the inclined surface 20c1 and the curved surface 20c2) gradually increases from the upper end to the lower end of the guided surface 20c, so that even if the guided surface 20c slides downward relative to the guide surface 46c when the white key 302a is pressed, the grease applied to the surfaces 20c, 46c is not easily scraped off downward. This also makes it easier for the grease to be retained in the sliding area of ​​the guided surface 20c.

[0066] As shown in Figure 6(b), the mold 200 for molding the side plate 20a and the connecting plate 320b is obtained by omitting the convex portion 102a (see Figure 5(a)) described in the above embodiment from the upper mold 202, and forming the convex portion 102a on the bottom surface of the concave portion 101a of the lower mold 201 (upside down).

[0067] When such a protrusion 102a is formed on the lower die 201, in order to form a draft angle on the side plate 20a relative to the lower die 201, it is necessary to incline the inner surface 20e of the side plate 20a in a direction approaching the inclined surface 20c1 from its upper end to its lower end. In other words, the lower end side of the side plate 20a has a tapered shape. Therefore, when it is desired to further ensure the rigidity of the protrusion 320 or to improve the formability of the protrusion 320, it is preferable to connect the lower ends of the side plates 20a with the connecting plate 20b as in the above embodiment (see FIG. 5(a)).

[0068] Next, a third modified white key 402a will be described with reference to Fig. 6(c). Fig. 6(c) is a cross-sectional view of the third modified white key 402a. Fig. 6(c) shows a cross-section of the keyboard device 1 (see Fig. 2) cut at a position corresponding to Fig. 4.

[0069] As shown in FIG. 6(c), the white key 402a of the third modified example has an insertion hole 420g that extends vertically in the protrusion 420, and a column-shaped rear guide 447 that stands up from the chassis 4 is inserted into this insertion hole 420g.

[0070] Guide surfaces 447a facing both sides in the scale direction of the rear guide 447 are flat surfaces perpendicular to the scale direction. A pair of inner surfaces facing the inside in the scale direction of the insertion hole 420g are guided surfaces 420h facing the guide surfaces 447a, respectively.

[0071] The guided surface 420h is composed of an inclined surface 420h1 that is inclined so that the distance between the guide surface 447a and the guide surface 447a gradually increases from its upper end to its lower end, and a curved surface 420h2 that is connected to the lower end of the inclined surface 420h1.

[0072] The inclined surface 420h1 is a flat surface inclined at an angle of 0.5° or more and less than 1° with respect to the guide surface 447a (vertical direction), and the curved surface 420h2 is an arc-shaped curved surface connecting the lower end of the inclined surface 420h1 and the side surface of the protruding portion 420.

[0073] In the white key 402a of this third modified example, the entire guided surface 420h (the inclined surface 420h1 and the curved surface 420h2) faces the guide surface 447a in the initial position before the key is pressed. This prevents the grease scraped up by the protrusion 420 from being pushed out to the upper surface side of the rear guide 447 when the white key 402a returns to the initial position (the state of FIG. 6(c)) after being pressed. This makes it easier for the grease to be retained in the sliding area of ​​the guided surface 420h.

[0074] In addition, the distance between the guide surface 447a and the guided surface 420h (the inclined surface 420h1 and the curved surface 420h2) gradually widens from the upper end side to the lower end of the guided surface 420h. Therefore, a small gap is formed between the guide surface 447a and the lower end of the guided surface 420h, and this gap gradually becomes larger as it approaches the lower end of the guided surface 420h. As a result, even if the guided surface 420h slides downward relative to the guide surface 447a when the white key 402a is pressed, the grease applied to each of these surfaces 420h, 447a is not easily scraped off downward. This also makes it easier for the grease to be held in the sliding area of ​​the guided surface 420h.

[0075] Returning to Figs. 2 and 3, the following description will be given. As described above, the rocking of the rear end of the white key 2a is guided by the sliding of the guide groove 60 along the shaft portion 41 of the chassis 4. The mounting member 6 in which this guide groove 60 is formed is made of a flexible resin material (e.g., elastomer or rubber). That is, the mounting member 6 is made of a soft material that is less hard than the resin (e.g., ABS resin) that is the material of the white key 2a and the chassis 4. This makes it possible to suppress noise generated when the guide groove 60 slides along the shaft portion 41 of the chassis 4, compared to when the mounting member 6 is made of the same (relatively hard) material as the white key 2a and the chassis 4. This provides the player with a good playing experience.

[0076] Here, the point where the center of the shaft portion 41 is located at the initial position before the key is pressed is described as the starting point P1 of the guide groove 60 (see the enlarged portion in Figure 2), and the point where the center of the shaft portion 41 is located at the end position of the key being pressed is described as the end point P2 of the guide groove 60 (see the enlarged portion in Figure 3).

[0077] The guide groove 60 extends linearly and inclines downward toward the front in a side view, with its starting point P1 located forward and below the end point P2. The starting point P1 and the end point P2 of the guide groove 60 are both located on a virtual circle Vb centered on a virtual rotation axis of the white key 2a (hereinafter referred to as the "virtual axis Va").

[0078] The imaginary axis Va is a point located rearward and below the shaft portion 41 in a side view, and indicates the same position as the rocking fulcrum (rotation axis) of a key of an acoustic piano. Therefore, when the white key 2a is pressed, the white key 2a can be rocked along a displacement trajectory similar to that of an acoustic piano key by sliding the guide groove 60 along the shaft portion 41. This gives the player a feeling of playing similar to that of an acoustic piano.

[0079] When the shaft portion 41 is located at the starting point P1 of the guide groove 60 (see the enlarged portion in FIG. 2), a gap is formed between the shaft portion 41 and the inner circumferential surface on the starting end (lower end) side of the guide groove 60. On the other hand, when the shaft portion 41 is located at the ending point P2 of the guide groove 60 (see the enlarged portion in FIG. 3), a gap is also formed between the shaft portion 41 and the inner circumferential surface on the terminal end (upper end) side of the guide groove 60.

[0080] In other words, if the region of the inner circumferential surface of the guide groove 60 where the shaft portion 41 slides from the starting point P1 to the ending point P2 is taken as the sliding surface of the guide groove 60, the outer circumferential surface of the shaft portion 41 contacts only the sliding surface of the guide groove 60 at both the initial position before the key is pressed and the end position of the key being pressed. This makes it possible to prevent the shaft portion 41 from contacting (colliding) with the inner circumferential surface at the start end or end end of the guide groove 60 when the white key 2a is pressed to the end position or when the white key 2a returns from the end position to the initial position. This makes it possible to suppress noise caused by such contact, providing the player with a good playing feel.

[0081] Next, the detailed configuration of the mounting member 6 will be described with reference to Fig. 7 and Fig. 8. Fig. 7(a) is a perspective view of the white key 2a showing the state in which the mounting member 6 has been removed from the mounting hole 21, and Fig. 7(b) is a side view of the mounting member 6. Fig. 8(a) is a side view of the white key 2a showing how the mounting member 6 is being inserted into the mounting hole 21 while being elastically deformed, and Fig. 8(b) is a side view of the white key 2a showing how the mounting member 6 is being turned over around its center C and inserted into the mounting hole 21.

[0082] 7, the protruding portion 20 of the white key 2a is formed with a mounting hole 21 with a circular cross section into which the mounting member 6 is fitted, and the outer shape of the mounting member 6 is formed into a cylindrical shape (a shape corresponding to the mounting hole 21) with a central axis along the scale direction. In the following explanation, the direction around the outer circumferential surface of the mounting member 6 and the direction around the inner circumferential surface of the mounting hole 21 are referred to as the circumferential direction.

[0083] A rectangular parallelepiped first protrusion 61 and second protrusions 62, 63 are integrally formed on the outer circumferential surface of the mounting member 6. The first protrusion 61 is a protrusion for restricting rotation of the mounting member 6 relative to the mounting hole 21, and the second protrusions 62, 63 are protrusions for restricting the mounting member 6 from falling off from the mounting hole 21.

[0084] The first protrusion 61 is formed at one location in the circumferential direction of the mounting member 6, and the second protrusions 62, 63 are formed at two locations in the circumferential direction of the mounting member 6. Of the pair of second protrusions 62, 63, one second protrusion 62 protrudes from a central portion in the scale direction of the outer circumferential surface (tip surface) of the first protrusion 61, and the other second protrusion 63 protrudes from the central portion in the scale direction of the outer circumferential surface of the mounting member 6 in the opposite direction to the second protrusion 62 (first protrusion 61).

[0085] The first projection 61 extends in the scale direction so as to be connected to each of a pair of side surfaces of the mounting member 6, while the second projections 62, 63 are formed so that the dimension in the scale direction is smaller than that of the first projection 61 (mounting member 6).

[0086] On the inner circumferential surface of the mounting hole 21, a fitting hole 24 is formed at a position corresponding to the first projection 61, and fitting holes 25, 26 are formed at positions corresponding to the second projections 62, 63 (see FIG. 8 for fitting hole 26).

[0087] The fitting holes 24 are formed in a pair (side by side in the scale direction) on either side of the fitting hole 25 into which the second projection 62 is inserted, and the pair of fitting holes 24 are connected to the side of the protruding portion 20 of the white key 2a (exposed on the side of the protruding portion 20). The inner diameter of the mounting hole 21 of the white key 2a is formed slightly larger than the outer diameter of the mounting member 6 (the diameter in the area where the projections 61-63 are not formed). Therefore, for example, if the mounting member 6 does not have the second projections 62, 63, it is possible to insert the mounting member 6 into the mounting hole 21 (insert the first projection 61 into the fitting hole 24) without elastically deforming the mounting member 6.

[0088] On the other hand, in this embodiment, the second protrusions 62, 63 are formed on the mounting member 6, so that when an attempt is made to insert the mounting member 6 into the mounting hole 21 without elastically deforming it, the second protrusions 62, 63 will catch on the side of the white key 2a (protrusion 20).

[0089] Therefore, when fitting each of the protrusions 61-63 of the mounting member 6 into the fitting holes 24-26 of the mounting hole 21, as shown in Fig. 8(a), the mounting member 6 is elastically deformed (compressed) so as to recess the area where the second protrusions 62, 63 are formed by at least the total protrusion dimension L1+L2 (see Fig. 7(b)) of the second protrusions 62, 63, while being inserted into the mounting hole 21. Then, by inserting the mounting member 6 to a position where the second protrusions 62, 63 reach the fitting holes 25, 26, the shape of the elastically deformed mounting member 6 is restored, and each of the protrusions 61-63 is fitted into the fitting holes 24-26. This completes the mounting of the mounting member 6 into the mounting hole 21.

[0090] The dimension of the fitting hole 24 in the circumferential direction of the mounting hole 21 is formed to be the same as (or slightly larger than) the dimension of the first protrusion 61 in the same direction, while the dimension of the fitting holes 25, 26 in the circumferential direction of the mounting hole 21 is formed to be larger than the dimension of the second protrusions 62, 63 in the same direction. Therefore, when the mounting member 6 is inserted into the mounting hole 21 while being elastically deformed, the second protrusions 62, 63 can be fitted into the fitting holes 25, 26 even if the relative positions of the fitting hole 24 and the first protrusion 61 in the circumferential direction are slightly misaligned.

[0091] When the mounting member 6 is restored to its original shape with the relative positions of the fitting hole 24 and the first protrusion 61 misaligned, the first protrusion 61 is pressed (caught) against the inner circumferential surface of the mounting hole 21, but by rotating the mounting member 6 about its center C until the relative positions of the fitting hole 24 and the first protrusion 61 match, the first protrusion 61 can be fitted into the fitting hole 24 by the restoring force of the mounting member 6. Therefore, compared to a case where the dimensions of the fitting holes 25, 26 and the second protrusions 62, 63 match in the circumferential direction, for example, the protrusions 61-63 can be easily fitted into the fitting holes 24-26, improving the workability of the mounting operation of the mounting member 6.

[0092] In this manner, in this embodiment, the mounting member 6 having the guide groove 60 formed on the side surface is attached to the white key 2a (protrusion 20). This simplifies the mold for molding the white key 2a compared to a configuration in which the flexible guide groove 60 is integrally formed with the white key 2a by two-color molding, and therefore reduces the manufacturing cost of the white key 2a.

[0093] In addition, when the mounting member 6 having the guide groove 60 is formed separately from the white key 2a, it is possible to adopt a configuration in which the mounting member 606 formed in a ring shape is fitted into the protruding portion 620 of the white key 602a, as in the white key 602a of the fifth modified example described later (see FIG. 13). In such a configuration, the mounting member 606 needs to be pushed into the protruding portion 620 so as to overcome the protruding second restricting portion 628, which will be described in detail later, and this pushing requires a relatively large amount of force. Since the mounting member 606 is a small part that can be handled by the fingertips of an operator, the mounting work is laborious if the ring-shaped mounting member 606 is pushed into the protruding portion 620.

[0094] In contrast, in this embodiment, as shown in Fig. 7, a mounting hole 21 configured so that the mounting member 6 can be inserted is formed in the white key 2a, and the mounting member 6 is fitted into this mounting hole 21. When fitting the mounting member 6, it is necessary to elastically deform the mounting member 6 as shown in Fig. 8(a), but this elastic deformation can be achieved relatively easily by an operator compressing the mounting member 6 while gripping it with his / her fingertips. This improves the workability of fitting the mounting member 6 into the mounting hole 21.

[0095] In addition, although the present embodiment is structured such that the mounting member 6 is attached to the white key 2a, it is also possible to adopt a configuration in which, for example, a mounting hole for mounting the mounting member 6 is formed in the wall portion 40 (see FIG. 1) of the chassis 4, and a guide shaft (a portion corresponding to the shaft portion 41) that can be inserted into the guide groove 60 of the mounting member 6 is provided in the protruding portion 20 of the white key 2a. However, since the wall portions 40 of the chassis 4 are formed integrally in a plurality of rows in the scale direction, a structure in which the mounting member 6 is attached to each of these wall portions 40 requires a laborious installation work.

[0096] In contrast, in this embodiment, the mounting holes 21 for attaching the mounting members 6 are formed in the white keys 2a, and each of the white keys 2a arranged in the scale direction can be removed from the chassis 4. Therefore, the work of attaching the mounting members 6 to the mounting holes 21 can be performed individually for each white key 2a with the white keys 2a removed from the chassis 4, improving the workability of attaching the mounting members 6.

[0097] When the mounting member 6 is attached to the mounting hole 21, the first protrusions 61 are caught in the fitting holes 24, thereby restricting the change in the mounting angle of the mounting member 6 in the circumferential direction of the mounting hole 21. In addition, the second protrusions 62, 63 are caught in the fitting holes 25, 26, thereby restricting the mounting member 6 from falling off from the mounting hole 21.

[0098] As another configuration for preventing such changes in the mounting angle of the mounting member 6 or for preventing it from falling off, a configuration in which the protrusions 61-63 (fitting holes 24-26) are omitted and the mounting member 6 is glued to the mounting hole 21 is exemplified. However, with this configuration, the work of attaching the mounting member 6 to each white key 2a is time-consuming.

[0099] In contrast, in this embodiment, the first projection 61 and fitting hole 24 (positioning portion), and the second projections 62, 63 and fitting holes 25, 26 (regulating portion), which are made of interlocking projections and recesses, are formed on the inner peripheral surface of the mounting hole 21 and the outer peripheral surface of the mounting member 6. The fitting of these projections and recesses regulates the change in the mounting angle of the mounting member 6 and its falling off, eliminating the need to glue the mounting member 6 to each white key 2a. This improves the workability of the mounting work of the mounting member 6.

[0100] Another example of a configuration for preventing the mounting member 6 from changing in the mounting angle or falling off is a configuration in which a wall is formed on the outer edge of the fitting hole 24 in the scale direction, and the first protrusion 61 is caught on this wall to prevent the mounting member 6 from falling off. In such a configuration, the second protrusions 62, 63 (fitting holes 25, 26) can be omitted because the first protrusion 61 can prevent both the mounting angle of the mounting member 6 from changing and the mounting member 6 from falling off. However, if a wall is formed on the outer edge of the fitting hole 24 in the scale direction, it becomes difficult to grasp the position of the fitting hole 24 when viewing the white key 2a from the side, and therefore the task of fitting the first protrusion 61 into the fitting hole 24 is time-consuming.

[0101] In contrast, in this embodiment, the fitting hole 24 is formed along the edge of the opening side (outer side in the scale direction) of the mounting hole 21. That is, since the fitting hole 24 is exposed on the side surface of the white key 2a (protruding portion 20), it is easy to grasp the position of the fitting hole 24 when viewing the white key 2a from the side. This allows the first projection 61 to be easily fitted into the fitting hole 24, improving the workability of the installation work of the mounting member 6.

[0102] Here, a straight line connecting the centers of the second protrusions 62, 63 in the circumferential direction of the mounting member 6 is defined as an imaginary line Vc. Since the guide groove 60 extends to intersect (be perpendicular to) the imaginary line Vc in a side view of the mounting member 6, when the mounting member 6 is compressed as described above (see FIG. 8(a)), the mounting member 6 elastically deforms so as to narrow the groove width of the guide groove 60. Compressing the mounting member 6 in the direction narrowing the groove width of the guide groove 60 makes the mounting member 6 more likely to elastically deform than compressing the mounting member 6 in the longitudinal direction of the guide groove 60. This improves the workability of mounting the mounting member 6.

[0103] In this embodiment, the first projection 61 is disposed on the imaginary line Vc (the second projection 62 is formed overlapping the first projection 61), but it is also possible to form the first projection 61 at a position different from the second projection 62 in the circumferential direction of the mounting member 6, for example. In this case, the position of the fitting hole 24 may be changed according to the arrangement of the first projection 61.

[0104] However, if the first projection 61 is formed at a different position from the second projection 62, when the mounting member 6 is elastically deformed to fit the second projections 62, 63 into the fitting holes 25, 26, the orientation of the first projection 61 (relative orientation to the fitting hole 24) is likely to change due to the distortion of the mounting member 6. Therefore, when the mounting member 6 is inserted into the mounting hole 21, the first projection 61 is likely to get caught on the side of the white key 2a (protruding portion 20) without fitting into the fitting hole 24.

[0105] In contrast, in this embodiment, the first protrusion 61 is disposed on the imaginary line Vc, and the second protrusion 62 is formed by overlapping the first protrusion 61. As a result, when the mounting member 6 is elastically deformed to fit the second protrusions 62, 63 into the fitting holes 25, 26, the relative orientation of the first protrusion 61 with respect to the fitting hole 24 is unlikely to change. Therefore, when the mounting member 6 is inserted into the mounting hole 21 while being elastically deformed, the first protrusion 61 can easily fit into the fitting hole 24 without getting caught on the side surface of the white key 2a (protruding portion 20), improving the workability of the mounting member 6 installation work.

[0106] Moreover, the virtual line Vc is a straight line passing through the center C of the mounting member 6, which is circular in side view. That is, the second projections 62, 63 project in opposite directions from each other with the center C of the mounting member 6 in between. Therefore, for example, if the first projection 61 is omitted and the second projection 62 is directly formed on the outer circumferential surface of the mounting member 6, the outer shape of the mounting member 6 including the second projections 62, 63 will have a shape that has rotational symmetry around the center C (axis along the scale direction). If the mounting member 6 has a shape that has rotational symmetry, it becomes difficult for the worker to recognize which of the second projections 62, 63 should be inserted into the fitting holes 25, 26, that is, in what orientation the mounting member 6 should be attached to the mounting hole 21.

[0107] In contrast, in this embodiment, the outer shape of the mounting member 6 including the protrusions 61-63 does not have rotational symmetry around the center C (axis along the scale direction). That is, the second protrusion 62 is formed overlapping the first protrusion 61, while the second protrusion 63 is formed directly on the outer circumferential surface of the mounting member 6. Therefore, by comparing the shape of the mounting member 6 (the protrusions 61-63) with the shape of the mounting hole 21 (the fitting holes 24-26), it is easy to recognize in what direction the mounting member 6 should be attached to the mounting hole 21.

[0108] In addition, the height of the second projection 62 from the outer circumferential surface of the mounting member 6 is increased by the amount of the second projection 62 formed overlapping the first projection 61. Therefore, for example, as shown in Fig. 8(b), even if the mounting member 6 is elastically deformed to the extent of the total protruding dimension L1+L2 of the second projections 62, 63 (to the extent shown in Fig. 8(a)) and inserted into the mounting hole 21 in a state where the mounting member 6 is inverted 180° around the center C from the state shown in Fig. 8(a), the second projection 62 is likely to get caught on the side surface of the white key 2a (protruding portion 20). This makes it possible to prevent the mounting member 6 from being inserted into the mounting hole 21 in the wrong orientation.

[0109] On the other hand, if the mounting member 6 is elastically deformed to approximately the dimension L1+L2+L3, which is the sum of the protrusion dimension L1+L2 of the second protrusions 62, 63 and the protrusion dimension L3 of the first protrusion 61 (see FIG. 7(b)), in other words, if the mounting member 6 is excessively elastically deformed, there is a risk that the second protrusion 62 will not get caught on the side surface of the white key 2a (protrusion 20), and the mounting member 6 may be able to be inserted into the mounting hole 21. Such excessive elastic deformation of the mounting member 6 is regulated by the partition wall 64 of the mounting member 6.

[0110] Specifically, a plate-shaped partition wall 64 is formed at approximately the center of the inner circumferential surface of the guide groove 60 in the scale direction (direction of arrows LR) so as to protrude from the inner circumferential surface of the guide groove 60. In other words, a pair of guide grooves 60 are formed on both side surfaces of the mounting member 6 in the scale direction with the partition wall 64 in between, and the pair of guide grooves 60 are partitioned by the partition wall 64.

[0111] Since the partition wall 64 is formed with an opening 65 extending along the guide groove 60, when the mounting member 6 is compressed by depressing the second protrusions 62 and 63 as described above (see Fig. 8(a)), elastic deformation of the mounting member 6 that would narrow the groove width of the guide groove 60 can be tolerated.

[0112] The opening width L4 of the opening 65 in the direction along the virtual line Vc (see Fig. 7(b)) is formed to be larger than the total protruding dimension L1 + L2 of the second protrusions 62 and 63 (L4 > L1 + L2). Due to this opening width L4 of the opening 65, attachment to the attachment hole 21 in the correct posture of the mounting member 6 (the state in Fig. 8(a)) becomes possible.

[0113] On the other hand, the opening width L4 of the opening 65 is formed to be smaller than the total protruding dimension L1 + L2 + L3 of the first protrusion 61 and the second protrusions 62 and 63 (L4 < L1 + L2 + L3). Thereby, even when attempting to insert the mounting member 6 into the attachment hole 21 in a state where the mounting member 6 is inverted 180° about the center C (the state in Fig. 8(b)), excessive elastic deformation of the mounting member 6 that would enable insertion of the second protrusion 62 into the fitting hole 26 can be restricted by contact between the edges of the opening 65 (partition wall 64). Thus, it is possible to prevent the mounting member 6 from being attached to the attachment hole 21 in an incorrect posture.

[0114] Here, as described above, the starting point P1 (see the enlarged portion in Fig. 2) and the ending point P2 (see the enlarged portion in Fig. 3) of the guide groove 60 of the white key 2a are located on a virtual circle Vb centered on the virtual axis Va, but the position of the virtual axis Va is set to different positions for the key 2 on the bass side and the key 2 on the treble side. This configuration will be described with reference to Fig. 9.

[0115] Fig. 9(a) is a side view of the white key 2a located on the highest treble side, Fig. 9(b) is a side view of the white key 2a located on the lowest bass side, and Fig. 9(c) is a top view of the key 2 schematically showing the positions of the virtual axes Va of the respective white keys 2a.

[0116] As shown in Figures 9(a) and 9(c), for the white key 2a with the note name C8 located at the highest pitch side, a start point P1 and an end point P2 of the guide groove 60 are formed around a virtual circle VbH centered on a virtual axis VaH that is relatively close to the white key 2a.

[0117] On the other hand, as shown in Figures 9(b) and 9(c), the white key 2a with the note name A0 located at the lowest pitch side has a start point P1 and an end point P2 of the guide groove 60 formed around a virtual circle VbL centered on a virtual axis VaL, which is farther away from the white key 2a than the white key 2a with the note name C8.

[0118] 9(c), the virtual axis Va of each white key 2a aligned in the scale direction is set at a different position for each white key 2a. That is, the angle of the guide groove 60 of each key 2 is different for each white key 2a and for each black key 2b, so that each key 2 can be swung along a different displacement trajectory without changing the dimensions of each white key 2a or black key 2b in the front-rear direction. Therefore, unlike the structure of the prior art (e.g., JP 2015-034853 A) in which the displacement trajectory of each key is changed by changing the overall length of each key, it is not necessary to increase the overall length of some of the keys 2, and therefore the keyboard device 1 can be prevented from becoming large.

[0119] In this embodiment, the position of the virtual axis Va of each white key 2a aligned in the scale direction is gradually (proportionally) brought closer to the white key 2a from the low-pitched to the high-pitched white key 2a. In other words, the angle of the guide groove 60 with respect to the vertical direction gradually increases from the low-pitched to the high-pitched white key 2a. This allows each white key 2a to oscillate along a displacement trajectory similar to that of an acoustic grand piano.

[0120] In this way, the guide grooves 60 can be configured to have different angles between the white keys 2a or between the black keys 2b, even when the guide grooves 60 are formed integrally with the white keys 2a. However, if the angle of the guide grooves 60 formed integrally with the white keys 2a is changed, the mold for forming each white key 2a becomes complicated, and the manufacturing cost of the white keys 2a increases.

[0121] In contrast, in this embodiment, the mounting member 6 with the guide groove 60 formed on the side is attached to the white key 2a (protrusion 20). This simplifies the mold for molding the white key 2a compared to the case where the angle of the guide groove 60 formed integrally with the white key 2a is changed as described above, and therefore reduces the manufacturing cost of the white key 2a.

[0122] In addition, since the mounting members 6 having the same external shape (the projections 61-63) are attached to the white keys 2a, the shape of the mounting holes 21 can be made common to all the white keys 2a. This reduces the number of types of molds required to mold the white keys 2a, thereby reducing the manufacturing cost of the white keys 2a.

[0123] The mounting members attached to each black key 2b may have the same or different external shape as the mounting members 6 attached to the white keys 2a. In either case, it is preferable to attach mounting members having a common external shape, except for the shape (angle) of the guide groove, to each black key 2b. This allows the shape of the mounting holes to which the mounting members are attached to be standardized for each black key 2b, thereby reducing the number of types of molds required to mold each black key 2b.

[0124] As described above, the outer shape of the mounting member 6 including the first protrusion 61 does not have rotational symmetry around the center C of the mounting member 6. This prevents the mounting member 6 from being attached to the mounting hole 21 in an incorrect orientation (angle), making it possible to reliably set the angle of the guide groove 60 of each white key 2a to the desired angle.

[0125] Here, when the virtual axis Va is set at different positions for the low-pitched white key 2a and the high-pitched white key 2a, a difference occurs in the stroke amount of the front end of each white key 2a. This difference in stroke amount will be explained with reference to Figs. 2 and 9.

[0126] 2, the rocking of the portion of the white key 2a on the front side (arrow F side) of the guide groove 60 is guided by the rotation of the hammer 7 about the rotation axis 43 as described above. The end position of this rocking is determined by the contact between the hammer 7 and the stopper 48. The stopper 48 is a cushioning material made of felt or urethane foam that is fixed to the chassis 4 above the mass portion 70 of the hammer 7.

[0127] The position of the rotation shaft 43 of the hammer 7 and the engagement position between the hammer 7 and the white key 2a (the lower end of the protrusion 22) are the same for each of the white keys 2a aligned in the scale direction (for example, the rotation shafts 43 of the hammers 7 are aligned along the scale direction). Therefore, if the rotation angle of the hammer 7 until it comes into contact with the stopper 48 is constant for each of the white keys 2a, the stroke amount of the white key 2a (the lower end of the protrusion 22) at the engagement position with the hammer 7 will be the same for each of the white keys 2a.

[0128] On the other hand, as described above, the oscillation of the rear end of each white key 2a is guided by the guide groove 60, and as shown in FIG. 9(b), in the white key 2a on the low note side, the angle of the guide groove 60 with respect to the vertical direction is relatively small (the virtual axis Va is relatively far away), while as shown in FIG. 9(c), in the white key 2a on the high note side, the angle of the guide groove 60 with respect to the vertical direction is relatively large (the virtual axis Va is relatively close).

[0129] 2 is constant for each white key 2a, the stroke amount (the amount of sliding of the guide groove 60 against the shaft 41) of the rear end of each white key 2a from the initial position before the key is pressed to the final position of the key being pressed is smaller for the white key 2a on the treble side than for the white key 2a on the bass side. If the stroke amount of the rear end of the white key 2a is relatively small, the stroke amount of the front end of the white key 2a (the part forward of the engagement position with the hammer 7) is large (the angle of the white key 2a at the final position of the key being pressed is relatively large with respect to the horizontal).

[0130] In other words, if the rotation angle of the hammer 7 up to the end position of the key depression is set constant for each white key 2a, and the distance to the virtual axis Va is set closer for the white keys 2a on the higher note side than for the white keys 2a on the lower note side, the stroke amount of the front end of the white keys 2a on the higher note side will be larger than that of the white keys 2a on the lower note side. If there is a difference in the stroke amount of the front end of each white key 2a, the player will not be able to feel good when playing.

[0131] A configuration that solves this problem will be described with reference to Fig. 10. Fig. 10 is a partially enlarged cross-sectional view of the keyboard device 1 at a position corresponding to part X in Fig. 2. Note that Fig. 10 illustrates a cross-section including a stopper 48H located on the highest pitch side (corresponding to the white key 2a with the note name C8), but the hatching of the stopper 48H has been omitted to simplify the drawing.

[0132] 10, among the stoppers 48, the one located on the lowest pitch side (corresponding to the white key 2a with the note A0) is designated as stopper 48L, and the one located on the highest pitch side (corresponding to the white key 2a with the note C8) is designated as stopper 48H. The thickness of stopper 48H is formed to be thicker than the thickness of stopper 48L. Although not shown in the figure, the thickness of stoppers 48 is configured to gradually (proportionally) increase from stopper 48L of the white key 2a on the lowest pitch side to stopper 48H of the white key 2a on the highest pitch side.

[0133] In other words, the distance between the mass portion 70 (the portion that comes into contact with the stopper 48 when the white key 2a is pressed) and the stopper 48 in the rotation direction of the hammer 7 becomes gradually narrower from the lower white key 2a to the higher white key 2a. This makes it possible to make the rotation angle of the hammer 7 until it comes into contact with the stopper 48 when the white key 2a is pressed smaller for the higher white key 2a than for the lower white key 2a. Therefore, even if the distance to the virtual axis Va is set closer for the higher white key 2a than for the lower white key 2a as described above, the stroke amount of the front end of each white key 2a can be made uniform. This provides the player with a good playing feel.

[0134] In this embodiment, the stroke amount of the front end of each white key 2a is made uniform by changing the thickness of the stopper 48, but this is not necessarily limited to this. For example, the thickness of the stopper 48 of each white key 2a may be made uniform for each white key 2a, while the thickness of the mass part 70 of the hammer 7 in the vertical direction may be gradually (proportionally) thicker from the low note side to the high note side. Even in this configuration, the distance between the mass part 70 and the stopper 48 in the rotation direction of the hammer 7 can be gradually narrowed from the low note white key 2a to the high note white key 2a.

[0135] Next, modified examples of the arrangement of the virtual axis Va will be described with reference to Fig. 11. Fig. 11(a) is a top view of the key 2 that shows the position of the virtual axis Va in a first modified example, Fig. 11(b) is a top view of the key 2 that shows the position of the virtual axis Va in a second modified example, and Fig. 11(c) is a top view of the key 2 that shows the position of the virtual axis Va in a third modified example.

[0136] As shown in FIG. 11(a), in the first modification of the virtual axis Va, the virtual axis VaH of the white key 2a on the highest note side (note name C8) is set farther away from the white key 2a than the virtual axis VaL of the white key 2a on the lowest note side (note name A0). The virtual axis Va is configured to gradually (proportionally) move away from the white key 2a from the low note side to the high note side. This allows the displacement trajectory of the white key 2a to gradually change from the low note side white key 2a to the high note side white key 2a. The distance from the white key 2a to the virtual axis Va can be adjusted by changing the angle of the guide groove 60 (see FIG. 9) as described above. The same applies to the other modifications described below.

[0137] As shown in FIG. 11(b), in the second modification of the virtual axis Va, the virtual axis VaL of the lowest white key 2a and the virtual axis VaH of the highest white key 2a are the same distance from the white key 2a. On the other hand, the virtual axis VaM of the white key 2a in the midrange (for example, note name E4) is set closer to the white key 2a than the virtual axes VaL and VaH. The virtual axis Va is configured to gradually (quadratically) approach the white key 2a from the low and high white keys 2a to the white key 2a in the midrange. This allows the displacement locus of the white key 2a to gradually change from the low and high white keys 2a to the white key 2a in the midrange.

[0138] As shown in FIG. 11(c), in the third modified example of the virtual axis Va, the virtual axis Va is configured to gradually (in stages) approach the white key 2a from the virtual axis VaL of the lowest white key 2a to the virtual axis VaH of the highest white key 2a.

[0139] More specifically, the range of each white key 2a is divided (equally) into four ranges, and compared to the white keys 2a in the lowest range (e.g., note names A0 to E2), the white keys 2a in the middle range (e.g., note names F2 to E4) are set closer to the virtual axis Va. On the other hand, the white keys 2a that make up the same divided area (e.g., note names A0 to E2) are the same distance from the virtual axis Va.

[0140] Similarly, compared to the white keys 2a on the relatively higher side of the midrange (for example, with note names F4 to E6), the white keys 2a on the highest range (for example, with note names F6 to C8) are set at positions closer to the virtual axis Va, but the white keys 2a (for example, with note names F4 to E6) that make up the same divided area are the same distance to the virtual axis Va.

[0141] In this way, by gradually moving the virtual axis Va closer to the white keys 2a from the low pitch side to the high pitch side, each white key 2a can be oscillated along a displacement trajectory similar to that of an acoustic grand piano, as in the above embodiment (see FIG. 9(c)). Furthermore, since the position of the virtual axis Va gradually moves closer to the white keys 2a from the low pitch side to the high pitch side, the angle of the guide groove 60 with respect to the vertical direction can also be gradually increased from the low pitch side to the high pitch side. As a result, for white keys 2a with the same position of the virtual axis Va (for example, note names A0 to E2), the angle of the guide groove 60 can be set to the same, so that the mounting member 6 attached to each of those white keys 2a can be made common. This allows the number of types of mounting members 6 to be reduced, thereby reducing the manufacturing cost of the mounting members 6.

[0142] Next, a fourth modified white key 502a will be described with reference to Fig. 12. The same parts as those in the above embodiment are given the same reference numerals and their description will be omitted. Fig. 12(a) is a side view of the fourth modified white key 502a, and Fig. 12(b) is a perspective view of the white key 502a with the mounting member 506 removed from the mounting hole 521.

[0143] As shown in Fig. 12, the white key 502a of the fourth modified example has the same configuration as the white key 2a (see Fig. 9) described in the above embodiment, except that the shape of the inner peripheral surface of the mounting hole 521 is elliptical. That is, the mounting hole 521 of the white key 502a has fitting holes 24 to 26 similar to those of the white key 2a.

[0144] The mounting member 506 attached to the mounting hole 521 has the same configuration as the mounting member 6 described in the above embodiment, except that its outer shape is an ellipse (a shape corresponding to the mounting hole 521) that follows the shape of the guide groove 60. That is, the mounting member 506 is formed with a first projection 61 and second projections 62, 63, and a partition wall 64 (opening 65).

[0145] The mounting member 506 is formed using a soft material that is less hard than the resin used to make the white key 502a, thereby preventing noise from being generated when the guide groove 60 slides along the shaft portion 41 (see FIG. 3).

[0146] In the above embodiment, the angle of the guide groove 60 is set to a different angle for each white key 2a (or each black key 2b), but in the modified example shown in Fig. 12, the angle of the guide groove 60 is set to the same angle for all white keys 502a lined up in the scale direction. In other words, each white key 502a is formed with a mounting hole 521 of a common shape, and a common mounting member 506 is attached to the mounting hole 521.

[0147] If the straight line connecting the centers of the second projections 62, 63 in the direction around the outer circumferential surface of the mounting member 506 is taken as a virtual line Vc, the outer shape of the mounting member 506 is a shape that is symmetrical about the virtual line Vc in a side view. The shape of the guide groove 60 is also a shape that is symmetrical about the virtual line Vc in a side view. In other words, the mounting member 506 is a shape that is rotationally symmetrical (two-fold symmetrical) about the virtual line Vc, and even if the front and back of the mounting member 506 are inverted 180° around the virtual line Vc, it can be attached to the mounting hole 521. This allows the mounting member 506 to be attached to all the white keys 502a arranged in the scale direction without considering the front and back of the mounting member 506 around the virtual line Vc. This improves the workability of the mounting operation of the mounting member 506.

[0148] Such a shape with rotational symmetry (two-fold symmetry) about the imaginary line Vc may be applied to each mounting member 6 of the above embodiment (see Figs. 9(a) and 9(b)). In this case, by gradually changing the shape of the mounting hole 21 (the position of each fitting hole 24-26), i.e., the mounting angle of the mounting member 6, from the bass side to the treble side white key 2a, the angle of the guide groove 60 (the position of the imaginary axis Va) can be changed in a similar manner.

[0149] Next, a white key 602a of the fifth modified example will be described with reference to Fig. 13. Fig. 13(a) is a perspective view of the white key 602a of the fifth modified example, and Fig. 13(b) is a perspective view of the white key 602a with the mounting member 606 removed from the protruding portion 620.

[0150] 13, protrusion 620 of white key 602a of the fifth modified example is formed in a plate shape (rectangular parallelepiped shape) extending in the front-rear direction (arrow FB direction), and mounting member 606 is attached to this protrusion 620. Mounting member 606 is formed in a square tube shape with an insertion hole 666 extending in the front-rear direction, and guide groove 60 penetrates the side surface of mounting member 606 in the scale direction (arrow LR direction).

[0151] The dimensions of the protrusion 620 in the vertical and scale directions are formed to be the same as (or slightly smaller than) the dimensions of the insertion hole 666 in the same directions, and the mounting member 606 is attached to the white key 602a by inserting the protrusion 620 into the insertion hole 666 of the mounting member 606. This makes it unnecessary to form a hole in the protrusion 620 for attaching the mounting member 606, thereby ensuring the rigidity of the protrusion 620.

[0152] The mounting member 606 is formed using a soft material that is less hard than the resin that is used to make the white key 602a, which helps to reduce noise generated when the guide groove 60 slides along the shaft portion 41 (see FIG. 3).

[0153] The white key 602a is formed with a first restricting portion 627 and a second restricting portion 628 that restrict the forward and backward displacement of the mounting member 606 attached to the protruding portion 620. The first restricting portion 627 is a portion that is formed so that its dimensions in the scale direction and the up-down direction are larger than those of the protruding portion 620. Since the protruding portion 620 protrudes rearward from the rear surface of the first restricting portion 627, when the mounting member 606 is attached to the protruding portion 620, the first restricting portion 627 restricts the mounting member 606 from being displaced forward.

[0154] On the other hand, a second restricting portion 628 is formed on the rear end side of the protruding portion 620. The second restricting portion 628 is a protrusion extending up and down, and protrudes from the side surfaces on both sides in the scale direction of the protruding portion 620. The rear surface of the second restricting portion 628 is an inclined surface that inclines forward as it moves outward in the scale direction. Therefore, when the protruding portion 620 is inserted into the insertion hole 666 of the mounting member 606, the mounting member 606 (insertion hole 666) is pushed and spread along the inclined rear surface of the second restricting portion 628, and the mounting member 606 gets over the second restricting portion 628, whereby the mounting member 606 is attached to the protruding portion 620.

[0155] The dimension from the rear surface of the first restricting portion 627 to the second restricting portion 628 is approximately the same as the front-rear direction of the mounting member 606, and the front-rear displacement of the mounting member 606 is restricted by sandwiching the mounting member 606 between these restricting portions 627, 628. This makes it possible to prevent the mounting member 606 from falling off the protruding portion 620 while eliminating the need to glue the mounting member 606 to the white key 602a.

[0156] The above has been explained based on the above embodiment, however, the present invention is in no way limited to the above embodiment, and it can be easily inferred that various improvements and modifications are possible within the scope that does not deviate from the spirit of the present invention.

[0157] In the above embodiment, the mounting member 6, 506, 606 having the guide groove 60 is attached to the white key 2a, 202a, 302a, 402a, 502a, 602a, but this is not necessarily limited to the above. For example, the guide groove 60 may be formed integrally with the white key 2a, 202a, 302a, 402a, 502a, 602a.

[0158] In the above embodiment, the guide groove 60 of the mounting member 6, 506, 606 attached to the white key 2a, 202a, 302a, 402a, 502a, 602a is slidably engaged with the shaft portion 41 of the chassis 4, but this is not necessarily limited to the above. For example, the guide groove 60 may be formed in the chassis 4, and a guide shaft that can slide in the guide groove 60 may be formed in the white key 2a, 202a, 302a, 402a, 502a, 602a. In this case, a mounting hole that can mount a member equivalent to the mounting member 6, 506, 606 may be formed on the chassis 4 (wall portion 40) side, or the guide groove 60 may be formed directly on the wall portion 40.

[0159] In the above embodiment, a case where a gap is formed between each of the inclined surface 20c1, 420h1 and the curved surface 20c2, 420h2 of the guided surface 20c, 420h and the guide surface 46c, 447a has been described, but this is not necessarily limited to this. For example, the entire inclined surface 20c1, 420h1 (or a part of the upper end side) may be formed parallel to the guide surface 46c, 420h and brought into surface contact with the guide surface 46c, 420h, and a gap may be formed only between the curved surface 20c2, 420h2 and the guide surface 46c, 420h. Also, the curved surface 20c2, 420h2 may be omitted, and the guided surface 20c, 420h may be formed only from the inclined surface 20c1, 420h1. That is, if a gap is formed between the guided surfaces 20c, 420h and the guide surfaces 46c, 447a in at least an area including the lower ends of the guided surfaces 20c, 420h, it is possible to prevent the grease from being scraped off.

[0160] In the above embodiment, the mounting member 6, 506, 606 (guide groove 60) is formed using a material having a lower hardness than the white key 2a, but this is not necessarily limited to the above. For example, the shaft portion 41 (guide shaft) of the chassis 4 may be formed using a material having a lower hardness than the white key 2a. In this case, the mounting member 6, 506, 606 (guide groove 60) may also be formed using a material having a lower hardness than the white key 2a, or the hardness of the mounting member 6, 506, 606 (guide groove 60) may be the same as (or higher than) that of the white key 2a. In addition, the hardness of the mounting member 6, 506, 606 (guide groove 60) and the shaft portion 41 (guide shaft) may be the same, or one of them may have a higher hardness than the other.

[0161] In the above embodiment, the mounting member 6, 506 has a circular or elliptical outer shape, but the mounting member 6, 506 may have a polygonal outer shape or a shape that combines circles and polygons. In other words, the shape of the mounting member 6, 506 can be set appropriately as long as it has the guide groove 60.

[0162] In the above embodiment, the mounting member 6,506 is attached to the mounting hole 21,521 by fitting each of the protrusions 61-63 of the mounting member 6,506 into the fitting holes 24-26 of the mounting hole 21,521, but this is not necessarily limited to this. For example, any or all of the protrusions 61-63 (fitting holes 24-26) may be omitted and the mounting member 6,506 may be bonded to the mounting hole 21,521. Also, convex portions corresponding to each of the protrusions 61-63 may be provided on the mounting hole 21,521 side, while concave portions corresponding to the fitting holes 24-26 may be provided on the mounting member 6,506.

[0163] In the above embodiment, a case has been described in which the change in the mounting angle of the mounting member 6 relative to the mounting hole 21 is restricted by the engagement of the fitting hole 24 and the first protrusion 61, but this is not necessarily limited to this. For example, the fitting hole 24 and the first protrusion 61 may be omitted, and the change in the mounting angle of the mounting member 6 may be restricted by the engagement of one or both of the second protrusions 62, 63 with the fitting holes 25, 26. In this case, the dimensions of the fitting holes 25, 26 in the circumferential direction of the mounting hole 21 may be formed to be the same as (or slightly larger than) the dimensions of the second protrusions 62, 63 in the same direction.

[0164] In the above embodiment, the case where the imaginary line Vc connecting the second projections 62, 63 (first projection 61) in a side view intersects with the guide groove 60, or the first projection 61 is formed on the imaginary line Vc has been described, but this is not necessarily limited to this. For example, the imaginary line Vc may not intersect with the guide groove 60, or the first projection 61 may be formed at a position that does not overlap with the imaginary line Vc. In other words, the positions at which the projections 61 to 63 are formed on the outer circumferential surface of the mounting member 6, 506 can be set as appropriate.

[0165] In the above embodiment, the fitting hole 24 is formed along the edge of the opening side (outer side in the scale direction) of the mounting hole 21, but this is not necessarily limited to this. For example, a wall may be formed on the edge of the fitting hole 24 on the outer side in the scale direction, and the first protrusion 61 may be caught on this wall to prevent the mounting member 6 from falling off. In this case, the second protrusions 62, 63 (fitting holes 25, 26) may be omitted.

[0166] In the above embodiment, the guide groove 60 is formed linearly from the starting point P1 to the ending point P2. However, the guide groove 60 may be formed in an arc shape from the starting point P1 to the ending point P2.

[0167] In the above embodiment, the outer circumferential surface of the shaft portion 41 contacts only the sliding surface of the guide groove 60 at both the initial position before the key is pressed and the terminal position of the key being pressed, but this is not necessarily limited to this. For example, the outer circumferential surface of the shaft portion 41 may contact the inner circumferential surface of the lower end side or the upper end side of the guide groove 60 at either or both of the initial position before the key is pressed and the terminal position of the key being pressed.

[0168] In the above embodiment, the case where the opening 65 is formed in the partition 64 that defines the guide groove 60 has been described, but the partition 64 or the opening 65 may be omitted. In addition, the case where the opening width L4 of the opening 65 is formed smaller than the total protruding dimension L1+L2+L3 of the first protrusion 61 and the second protrusions 62, 63 has been described, but the opening width L4 of the opening 65 may be formed to be the same as (or smaller than) the total protruding dimension L1+L2+L3 of the first protrusion 61 and the second protrusions 62, 63 (it is sufficient that the opening width L4 is at least larger than the protruding dimension L1+L2 of the second protrusions 62, 63).

[0169] In the above embodiment, the outer shape of the mounting member 506 (the shape of the guide groove 60) is described as being symmetrical about the imaginary line Vc when viewed from the side, but the outer shape of the mounting member 506 (the shape of the guide groove 60) may also be asymmetrical about the imaginary line Vc.

[0170] In the above embodiment, the distance between the mass portion 70 (the portion that comes into contact with the stopper 48 when the white key 2a is pressed) and the stopper 48 in the rotation direction of the hammer 7 is gradually narrowed from the low-pitched white key 2a to the high-pitched white key 2a, but this is not necessarily limited to the above. For example, the distance between the mass portion 70 and the stopper 48 in the rotation direction of the hammer 7 may be constant from the low-pitched white key 2a to the high-pitched white key 2a. [Explanation of symbols]

[0171] 1 Keyboard device 2 keys 2a,202a,302a,402a,502a,602a White key (key) 2b Black key (key) 21,521 Mounting holes 4,404 Chassis (support member) 41 Shaft (guide shaft) 43 Rotational Axis 48 Stopper 6,506,606 Mounting material 60 Guide groove 7. Hammer P1 Guide groove start point P2 End point of guide groove

Claims

1. A locking device comprising: a support member; and a key supported by the support member so as to be pivotable; Either the support member or the key has a guide groove for guiding the swing of a rear portion of the key, The other of the support member and the key includes a guide shaft that extends in a scale direction, is inserted into the guide groove, and slides along the guide groove when the key is swung; The keys are composed of white keys and black keys, When the point where the center of the guide shaft is located before the key is pressed is defined as the start point of the guide groove, when the key is pressed to the end position is defined as the end point of the guide groove, and when the point where the center of the guide shaft is located is defined as the end point of the guide groove, the straight line connecting the start point and the end point is defined as the angle of the guide groove. A keyboard device, characterized in that the angles of the guide grooves are different between the white keys or between the black keys.

2. 2. The keyboard device according to claim 1, further comprising a mounting member in which the guide groove is formed and which is attached to the support member or the key.

3. The support member or the key is configured to allow the mounting member to be inserted in a scale direction and includes a mounting hole into which the mounting member is attached, 3. The keyboard device according to claim 2, wherein the outer shape of the mounting member that fits along the inner circumferential surface of the mounting hole is common to the white keys or common to the black keys.

4. 4. The keyboard device according to claim 3, wherein the outer shape of the mounting member has a shape that does not have rotational symmetry around an axis along the scale direction.

5. 4. The keyboard device according to claim 3, wherein the mounting member is made of a material softer than that of the keys.

6. 2. The keyboard device according to claim 1, wherein an angle of said guide groove with respect to a vertical direction gradually increases from the lower key to the higher key.

7. a hammer that engages with the key forward of the pivot point of the key and rotates around a predetermined rotation axis; and a stopper that contacts the hammer at the end position to restrict the rotation of the hammer, 7. The keyboard device according to claim 6, wherein the distance between said hammer and said stopper becomes gradually narrower from the lower key to the higher key.

8. a mounting member in which the guide groove is formed and which is attached to the support member or the key; 7. The keyboard device according to claim 6, wherein an angle of said guide groove with respect to a vertical direction increases stepwise from the lower key to the higher key.

9. A locking device comprising: a support member; and a key supported by the support member so as to be pivotable; Either the support member or the key has a guide groove for guiding the swing of a rear portion of the key, The other of the support member and the key includes a guide shaft extending in a scale direction and inserted into the guide groove, The keys are composed of white keys and black keys, When the point where the center of the guide shaft is located before the key is pressed is defined as the start point of the guide groove, when the key is pressed to the end position is defined as the end point of the guide groove, and when the point where the center of the guide shaft is located is defined as the end point of the guide groove, the straight line connecting the start point and the end point is defined as the angle of the guide groove. A method for guiding the keys in a keyboard apparatus, the angles of the guide grooves being different between the white keys or between the black keys, comprising: A key guiding method, characterized in that the rocking movement of the key when it is pressed is guided by the sliding of the guide shaft on the guide groove.

Images