Keyboard device of a keyboard instrument

Abstract

To provide a keyboard device of a keyboard musical instrument capable of preventing occurrence of noise in a connection part between a first arm and a second arm of a key support mechanism when pressing keys and capable of obtaining excellent touch feeling by ensuring smooth operation of the connection part.SOLUTION: A keyboard device of a keyboard musical instrument includes a keyboard chassis 4, a key 2 disposed above it, and a key support mechanism 6 for supporting the key 2 from a lower part and rotating it with virtual supports P, Q as centers. One of a first arm rear side connection part 37 and a second arm front side connection part 45 has an engagement shaft 50 extending horizontally, and the other of the first arm rear side connection part 37 and the second arm front side connection part 45 has a side face shape formed in a U shape open to one of longitudinal directions, and has an engagement recess 45b engaged with the engagement shaft 50, and a cushioning member 51 in slide contact with an inner surface of the engagement recess 45b is mounted to the engagement shaft 50 while its outer peripheral surface is covered.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a keyboard device applied to a keyboard instrument such as an electronic piano, in which a pressed key operates to rotate about a virtual fulcrum located behind the rear end thereof.

Background Art

[0002] Conventionally, as a keyboard device of this type, for example, the keyboard device of Patent Document 1 already filed by the applicant is known. This keyboard device includes a key extending in the front-rear direction and a link mechanism that supports the key from below. The link mechanism has a front connecting link bar and a rear connecting link bar that each extend in the front-rear direction by a predetermined length. The front end portion of the front connecting link bar is rotatably connected to the front portion of the key, while the rear end portion of the rear connecting link bar is rotatably connected to the rear end portion of the key. Further, each of the above connecting link bars is rotatably supported via a support pin provided near the center in the length direction, and the rear end portion of the front connecting link bar and the front end portion of the rear connecting link bar are rotatably and slidably connected to each other. More specifically, a long hole is formed in the rear end portion of the front connecting link bar, while a central connecting pin that is inserted into the long hole protrudes from the front end portion of the rear connecting link bar.

[0003] In the keyboard device configured as described above, when the front end portion of the key is pushed down, each connecting link bar of the link mechanism rotates in a predetermined direction about the support pin. In this case, the central connecting pin of the rear connecting link bar slides along the length direction of the long hole in the front connecting link bar while rotating. When the front end portion of the key is pushed down to the lowest position, the rear end portion of the key is positioned downward by a distance approximately half that of the front end portion. As a result, the key operates to rotate about a virtual fulcrum located behind by approximately the same length as its own length, and as a result, while the length of the key is configured to be shorter than that of an acoustic grand piano, a key operation similar to that of the grand piano keyboard can be obtained.

Prior Art Documents

Patent Documents

[0004] Japanese Patent Document 1 Japanese Unexamined Patent Application Publication No. 2020-52391 (Figs. 3 to 5) Summary of the Invention Problems to be Solved by the Invention

[0005] In the above-described conventional keyboard device, since each connecting link bar of the link mechanism is made of a hard material such as metal, depending on the relationship between the diameter of the central connecting pin of the rear connecting link bar and the width dimension of the long hole of the front connecting link bar, there is a risk that key operations cannot be performed appropriately. That is, when the diameter of the central connecting pin is smaller than the width dimension of the long hole and a relatively large gap is generated between the central connecting pin and the side surface in the width direction of the long hole, noise may occur when the key is pressed because the central connecting pin hits the side surface of the long hole. Conversely, when there is almost no such gap, the central connecting pin cannot slide smoothly with respect to the long hole, and as a result, the touch feeling when pressing the key may become heavy. Therefore, there is room for improvement in this keyboard device.

[0006] The present invention has been made to solve the above problems, and an object of the present invention is to provide a keyboard device for a keyboard musical instrument that can prevent the generation of noise at the connecting portion between the first arm and the second arm of the key support mechanism during key pressing and can ensure smooth operation of the connecting portion, thereby obtaining a good touch feeling. Means for Solving the Problems

[0007] To achieve the above object, the invention according to claim 1 includes a keyboard chassis, keys extending a predetermined length in the front-rear direction and disposed on the upper part of the keyboard chassis, and a key support mechanism that engages with the keyboard chassis and is provided to support the keys from below. When a key is pressed, the pressed key is operated to rotate about a virtual fulcrum located behind the rear end of the key. The key support mechanism is configured to extend a predetermined length in the front-rear direction and is provided on the keyboard chassis Extending in the left - right direction to a first support shaft through a first bearing portion provided at a predetermined position and a first arm that is swingably engaged therewith and has a front end portion rotatably and slidably connected to the front portion of the key. The first arm is configured to extend a predetermined length in the front-rear direction and is provided on the keyboard chassis behind the first support shaft Extending in the left - right direction to a second support shaft through a second bearing portion provided at a predetermined position and a second arm that is swingably engaged therewith and has a rear end portion rotatably connected to the rear portion of the key. A front-side connecting portion of the second arm in front of the second support shaft is rotatably and slidably connected to a rear-side connecting portion of the first arm behind the first support shaft of the first arm. One of the rear-side connecting portion of the first arm and the front-side connecting portion of the second arm has an engaging shaft extending in the left-right direction, and the other of the rear-side connecting portion of the first arm and the front-side connecting portion of the second arm has an engaging recess that engages with the engaging shaft. A buffer member that slidably contacts the inner surface of the engaging recess is attached to the engaging shaft in a state of covering the outer peripheral surface thereof.

[0008] According to this configuration, the keys that extend a predetermined length in the front-rear direction and are arranged on the upper part of the keyboard chassis are supported from below by the key support mechanism having the first arm and the second arm described above, and when a key is pressed, it operates so as to rotate about a virtual fulcrum located behind the rear end of the key. Further, in the key support mechanism, the first arm rear side connecting portion of the first arm and the second arm front side connecting portion of the second arm are connected so as to be rotatable and slidable. One of these first arm rear side connecting portion and second arm front side connecting portion has an engaging shaft, and the other has an engaging recess. And, a buffer member that slidably contacts the inner surface of the engaging recess is attached to the engaging shaft in a state of covering the outer peripheral surface thereof. In this way, by attaching the buffer member to the engaging shaft, the engaging shaft does not directly hit the inner surface of the engaging recess, and therefore, it is possible to prevent the generation of noise at the connecting portion between the first arm and the second arm of the key support mechanism when a key is pressed. Further, since the buffer member attached to the engaging shaft slidably contacts the engaging recess, smooth operation at the connecting portion between the first arm and the second arm can be ensured, and thereby, a good touch feeling can be obtained when a key is pressed.

[0009] The invention according to claim 2 is the keyboard device of the keyboard instrument according to claim 1, wherein the engaging shaft is composed of a left protruding portion and a right protruding portion that respectively protrude leftward and rightward, and the buffer member is composed of a molded product made of an elastic synthetic resin, is formed in a cylindrical shape, has a left cylindrical portion into which the left protruding portion fits, a right cylindrical portion formed in a cylindrical shape into which the right protruding portion fits, and a connecting portion provided so as to connect the right end face of the left cylindrical portion and the left end face of the right cylindrical portion.

[0010] According to this configuration, since the buffer member is composed of a molded product made of an elastic synthetic resin, it is relatively inexpensive and can be easily manufactured. Further, when attaching the buffer member to the engaging shaft, one of the left and right cylindrical portions of the buffer member is fitted to one of the left and right protruding portions of the engaging shaft, and while pulling the other cylindrical portion through the connecting portion, it is fitted to the other protruding portion. In this way, the buffer member can be attached to the engaging shaft relatively easily.

[0011] The invention according to claim 3 is characterized in that, in the keyboard device of the keyboard instrument according to claim 2, on the outer peripheral surfaces of the left cylinder portion and the right cylinder portion, there are formed recessed portions that are open outward and serve as lubricant holding portions for holding a lubricant.

[0012] According to this configuration, since the outer peripheral surfaces of the left cylinder portion and the right cylinder portion of the buffer member are provided with recessed lubricant holding portions, by applying a lubricant to the buffer member attached to the engagement shaft, the lubricant can be held on the outer peripheral surfaces of the left cylinder portion and the right cylinder portion for a long period of time. As a result, smooth operation at the connecting portion between the first arm and the second arm by the engagement shaft and the engagement recess can be ensured over a long period of time.

[0013] The invention according to claim 4 is characterized in that, in the keyboard device of the keyboard instrument according to claim 2 or 3, at least one of the left cylinder portion and the right cylinder portion has a cut portion cut along its length direction.

[0014] According to this configuration, since at least one of the left cylinder portion and the right cylinder portion of the buffer member has a cut portion cut along its length direction, the buffer member is attached to the engagement shaft as follows. For example, when only one of the left cylinder portion and the right cylinder portion has a cut portion, after fitting one of the non-cut left or right cylinder portions to one of the left or right protruding portions of the engagement shaft, the other cut cylinder portion is fitted to the other protruding portion through the cut portion. As a result, compared to the buffer member without the above-described cut portion, when attaching the buffer member having the cut portion to the engagement shaft, it can be easily attached to the engagement shaft without pulling the buffer member. Further, when both the left cylinder portion and the right cylinder portion have cut portions, the buffer member can be attached to the engagement shaft even more easily by fitting each cylinder portion to the engagement shaft through these cut portions.

[0015] The invention according to claim 5 is, in the keyboard device of the keyboard instrument according to any one of claims 1 to 4, on at least one of the inner surface of the engagement recess and the outer surface of the buffer member, projecting from the inner surface of the engagement recess and / or the outer surface of the buffer memberIt is characterized in that a letoff convex portion is provided for imparting a letoff touch feeling to a key to be pressed by being formed in a convex shape and temporarily inhibiting the slide when the engagement shaft slides in the engagement concave portion when the key is pressed.

[0016] According to this configuration, at least one of the inner surface of the engagement concave portion and the outer surface of the buffer member is provided with projecting from the inner surface of the engagement recess and / or the outer surface of the buffer member a letoff convex portion formed in a convex shape. When the engagement shaft slides in the engagement concave portion when the key is pressed, the slide is temporarily inhibited by the letoff convex portion. As a result, a click feeling due to temporary resistance is generated in the key to be pressed, and a touch feeling approximated to the letoff of an acoustic piano can be obtained.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

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Figure 4

Figure 5

Figure 6

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Figure 8

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Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0018] Hereinafter, with reference to the drawings, preferred embodiments of the present invention will be described in detail. FIG. 1(a) shows only one octave of the keyboard device 1 of the electronic piano to which the present invention is applied. In the following description, first, the basic configuration and operation of the keyboard device 1 will be described, and then the main part of the present invention will be described.

[0019] FIG. 1(b) shows a state where keys 2 other than the leftmost white key 2a and black key 2b are omitted in the keyboard device 1 of FIG. 1(a), and FIG. 2 shows a state where the white key 2a and black key 2b are removed from the keyboard chassis 4 together with the key support mechanism 6.

[0020] This keyboard device 1 includes a keyboard chassis 4, a plurality of keys 2 composed of white keys 2a and black keys 2b arranged side by side in the left - right direction, a key support mechanism 6 rotatably attached to the keyboard chassis 4 for each key 2 to support the corresponding key 2 from below, a key switch 3 for detecting key - pressing information of each key 2, and the like.

[0021] The keyboard chassis 4 includes a chassis body 4a made of a resin molded product of a predetermined shape by injection - molding a predetermined resin material (for example, ABS resin). As shown in FIG. 3, in this chassis body 4a, its front part 11, middle part 12, and rear part 13 are all formed so as to extend in the left - right direction (the left - right direction in FIG. 3(a)) as a whole, and these are integrally molded by a plurality of ribs 14 spaced apart in the left - right direction and each extending in the front - rear direction. In the following description, in the keyboard chassis 4, the front part 11, middle part 12, and rear part 13 of the chassis body 4a are respectively referred to as the "chassis front part 11", the "chassis middle part 12", and the "chassis rear part 13".

[0022] The front part 11 of the chassis mainly guides the white key 2a when the key is pressed and regulates the upper limit position and the lower limit position of the front end thereof. In this front part 11 of the chassis, a plurality of white key guides 11a for preventing the lateral movement of the white key 2a are erected in a state of being arranged side by side in the left-right direction, and are inserted from below for each white key 2a. Further, engagement holes 11b, 11b penetrating in the vertical direction are provided on both the left and right sides of each white key guide 11a of the front part 11 of the chassis, and two upper limit position regulating parts 21, 21 on the left and right of the white key 2a described later penetrate through and engage with both the engagement holes 11b, 11b, respectively. Furthermore, a stopper mounting part 11c protruding forward and extending in the left-right direction over the entire chassis main body 4a is provided at the front end of the front part 11 of the chassis, and a key upper limit stopper 16a and a key lower limit stopper 16b for the white key are mounted on the lower surface and the upper surface of this stopper mounting part 11c so as to extend in the left-right direction, respectively. Note that a stopper mounting part 11d for the black key extending in the left-right direction over the entire chassis main body 4a is provided at a predetermined position behind the white key guide 11a of the front part 11 of the chassis, and a key upper limit stopper 17 for the black key is mounted on this stopper mounting part 11d so as to extend in the left-right direction.

[0023] The middle part 12 of the chassis mainly guides the black keys 2b when a key is pressed, and swingably supports the first arm 31 and the second arm 32 of the key support mechanisms 6a and 6b for the white keys and black keys, which will be described later. This middle part 12 of the chassis has a flat part 12a in the shape of a flat plate extending in the left - right direction, and a plurality of black - key guides 12b erected on this flat part 12a and arranged at appropriate intervals in the left - right direction. Each black - key guide 12b is inserted from below for each black key 2b to prevent lateral movement of the black key 2b. Further, at the front part of the middle part 12 of the chassis, a first - arm support part 18 for supporting the first arm 31 of the key support mechanism 6 is provided. This first - arm support part 18 has a plurality of first support shafts 18a provided so as to extend in the left - right direction between adjacent ribs 14, 14, and the first arm 31 is swingably supported by these first support shafts 18a. Furthermore, at the rear part of the middle part 12 of the chassis, a second - arm support part 19 for supporting the second arm 32 of the key support mechanism 6 is provided. This second - arm support part 19 has a plurality of second support shafts 19a provided so as to extend in the left - right direction between adjacent ribs 14, 14. The plurality of second support shafts 19a are arranged on the same axis extending in the left - right direction at a position behind and higher than the above - mentioned first support shafts 18a, and the second arm 32 is swingably supported by these second support shafts 19a. Incidentally, at a predetermined position of a middle rail 8, which will be described later, provided below the middle part 12 of the chassis, a first - arm lower - limit stopper 10b extending in the left - right direction over the entire chassis body 4a is provided.

[0024] Also, below the keyboard chassis 4, between the front part 11 of the chassis and the middle part 12 of the chassis, the key switch 3 is attached. This key switch 3 is composed of a horizontally long printed circuit board 3a extending in the left - right direction, and a plurality of switch bodies 3b each composed of a rubber switch attached to this printed circuit board 3a for each key 2 and pressed by the first arm 31 when a key is pressed.

[0025] The rear part 13 of the chassis mainly serves to guide the key 2 in the vertical direction while preventing lateral movement at its rear end, and to regulate the upper limit position of the rear end of the first arm 31. As shown in FIGS. 2 and 3(a), the rear part 13 of the chassis has a plurality of partition walls 13a spaced apart from each other at a predetermined interval in the left-right direction so as to partition adjacent keys 2 from each other. Further, as shown in FIG. 3(b), at a predetermined position in the upper part of the rear part 13 of the chassis, a first arm upper limit stopper 10a extending in the left-right direction over the entire chassis body 4a is provided. The first arm upper limit stopper 10a and the first arm lower limit stopper 10b provided in the middle part 12 of the chassis each have a function as a hammer for imparting a touch weight to the key 2, and regulate the upper limit position and the lower limit position when the first arm 31 rotates upward and downward with respect to the first arm 31. Further, on the upper part of the rear part 13 of the chassis, a metal cover plate 15 extending in the left-right direction over the entire chassis body 4a and arranged to cover the rear end of the key 2 is attached.

[0026] As shown in FIGS. 2 and 3(a), the chassis body 4a of the keyboard chassis 4 configured as described above is provided with a plurality of first openings 5a opening upward and forward and a plurality of second openings 5b opening upward. Through each of the above-mentioned first openings 5a, the first arm 31 of the key support mechanism 6 is engaged with the first support shaft 18a from the outside, and through each of the above-mentioned second openings 5b, the second arm 32 is engaged with the second support shaft 19a from the outside.

[0027] In the above-mentioned keyboard chassis 4, a plurality of chassis bodies 4a are connected in a state of being arranged side by side in the left-right direction, and are all screwed in a state of being placed on metal front rails 7, middle rails 8, and rear rails 9 that extend in the left-right direction and are arranged at a predetermined interval in the front-rear direction. Then, the keyboard chassis 4 is fixed on a shelf board (not shown) of the electronic piano through the above-mentioned front rails 7 and rear rails 9.

[0028] Next, the key 2 and the key support mechanism 6 will be described. Fig. 4(a) shows an enlarged view of the white key 2a and its key support mechanism 6a, and Fig. 4(b) shows an exploded view thereof. As shown in the figure, the white key 2a is formed in a hollow shape that extends a predetermined length in the front-rear direction and is open downward by injection molding a predetermined resin material (e.g., AS resin). At the front end of the white key 2a, a pair of left and right upper limit position regulating portions 21, 21 are provided, which are formed to extend downward from the left and right side walls and have their lower ends bent forward. As described above, these upper limit position regulating portions 21, 21 engage with the left and right engaging holes 11b, 11b of the front portion of the chassis 11 in a penetrating state, respectively.

[0029] Also, at a predetermined position behind the upper limit position regulating portion 21 in the front portion of the white key 2a, a key front side connecting portion 22 connected to the first arm 31 of the key support mechanism 6a is provided. This key front side connecting portion 22 has a connecting recess 22a formed in a U shape with a long hole-shaped side surface and open forward. Further, in this connecting recess 22a, a key side noise suppressing member 20 is attached so as to cover the entire inner peripheral surface, and when the connecting shaft 35b (described later) of the first arm 31 slides within the connecting recess 22a, the generation of noise is suppressed.

[0030] Furthermore, at the rear portion of the white key 2a, a key rear side connecting portion 23 connected to the second arm 32 of the key support mechanism 6a is provided. This key rear side connecting portion 23 has a plate-shaped connecting main body portion 23a that hangs downward from the central portion of the white key 2a in the left-right direction and has a predetermined thickness in the left-right direction, and a pair of left and right engaging convex portions 23b, 23b that project coaxially from the left and right side surfaces of the connecting main body portion 23a, respectively. Also, at the rear portion of the white key 2a, a tool insertion hole 24 is formed that penetrates in the vertical direction and is for inserting a predetermined tool from above when disconnecting the connection between the white key 2a and the second arm 32 of the key support mechanism 6a during maintenance of the keyboard device 1 or the like.

[0031] On the other hand, the key support mechanism 6a includes a first arm 31 and a second arm 32 that engage with each other and are respectively connected to the key front side connecting portion 22 and the key rear side connecting portion 23 of the white key 2a.

[0032] As shown in FIG. 4(b), the first arm 31 is composed of an arm main body 33 and two weights 34, 34 attached to the arm main body 33. The arm main body 33 is formed of a resin molded product having a predetermined shape, such as by injection molding a predetermined resin material (e.g., polyacetal). The arm main body 33 extends a predetermined length in the front-rear direction, and a first arm front-side connecting portion 35 for connecting to the key front-side connecting portion 22 of the white key 2a is provided at the front end portion. The first arm front-side connecting portion 35 has a box portion 35a formed in a box shape that is open upward and forward, and a connecting shaft 35b provided so as to extend in the left-right direction while connecting the front upper end portions of the left and right side walls of the box portion 35a. And this connecting shaft 35b is connected to the connecting recess 22a of the key front-side connecting portion 22 of the white key 2a so as to be rotatable and slidable in the front-rear direction.

[0033] Also, the arm main body 33 has a U-shaped bearing portion 36 with a downwardly open side surface shape at a predetermined position immediately behind the first arm front-side connecting portion 35 (First bearing portion) and this bearing portion 36 is rotatably engaged with the first support shaft 18a in the keyboard chassis 4. Further, the arm main body 33 is provided with a first arm rear-side connecting portion 37 for connecting to the second arm 32 at a predetermined position behind the bearing portion 36. Specifically, the first arm rear-side connecting portion 37 has a connecting shaft 37a that extends in the left-right direction and both ends of which protrude outward from the left and right side surfaces of the arm main body 33, respectively. And both ends of this connecting shaft 37a are engaged with the connecting recesses 45b, 45b of the second arm front-side connecting portion 45, which will be described later, of the second arm 32.

[0034] Two elongated plate-shaped weights 34, 34 are attached to the weight attachment portion 38, which is the rear portion of the arm main body 33, in a state of sandwiching the weight attachment portion 38 from both sides. Each weight 34 is made of a material having a specific gravity greater than that of the arm main body 33 (e.g., a metal such as iron), and is formed into a predetermined shape, such as by pressing a metal plate.

[0035] The second arm 32 is formed of a resin molded product having a predetermined shape by injection molding a resin material similar to the arm body 33 of the first arm 31. This second arm 32 is shorter than the first arm 31 and extends a predetermined length in the front-rear direction. Further, the second arm 32 has a C-shaped bearing portion 41 with a side surface shape that opens forward near the center in the length direction. (Second bearing portion) This bearing portion 41 is rotatably engaged with the second support shaft 19a in the keyboard chassis 4.

[0036] Also, a second arm rear side connecting portion 42 connected to the key rear side connecting portion 23 of the white key 2a is provided at the rear portion of the second arm 32. This second arm rear side connecting portion 42 is formed in a bifurcated shape and has two left and right connecting arm portions 43, 43 that extend a predetermined length in parallel with each other along the length direction of the second arm 32. A connecting hole 43a penetrating in the left-right direction is formed at the rear end portion of each connecting arm portion 43. Then, both connecting arm portions 43, 43 sandwich the connecting main body portion 23a of the key rear side connecting portion 23 of the white key 2a from both the left and right sides between their rear end portions, and each connecting hole 43a is rotatably fitted to the corresponding engaging convex portion 23b of the key rear side connecting portion 23.

[0037] Furthermore, a second arm front side connecting portion 45 connected to the first arm rear side connecting portion 37 of the first arm 31 is provided at the front portion of the second arm 32. This second arm front side connecting portion 45 has a pair of left and right connecting pieces 45a, 45a spaced apart from each other by a predetermined interval in the left-right direction, and a U-shaped connecting recess 45b having a side surface shape that is a long hole and opens forward is formed in each connecting piece 45a. Then, the left and right connecting pieces 45a, 45a of the second arm front side connecting portion 45 are rotatably and slidably engaged with both end portions of the connecting shaft 37a of the first arm 31 via their connecting recesses 45b, 45b, respectively.

[0038] Fig. 5(a) shows an enlarged view of the black key 2b and its key support mechanism 6b, and Fig. 5(b) shows an exploded view thereof. The black key 2b is formed of the same resin material as the white key 2a by injection molding or the like. It is shorter than the white key 2a and extends a predetermined length in the front-rear direction, and is formed in a hollow shape that opens downward. At the front lower end of the black key 2b, a front key connecting portion 26 formed substantially the same as the front key connecting portion 22 of the white key 2a is provided. This front key connecting portion 26 has a connecting recess 26a formed in a U-shape with a long hole-shaped side surface and opening forward. Further, the front key connecting portion 26 has an extended portion 26b that extends a predetermined length forward from the front surface of the main body of the black key 2b at the lower front end of the connecting recess 26a, and this extended portion 26b functions as an upper limit position regulating portion of the black key 2b. In the following description, for the black key 2b and the key support mechanism 6b, the same components as those of the white key 2a and the key support mechanism 6a described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0039] The key support mechanism 6b that supports the black key 2b is configured substantially the same as the key support mechanism 6a for the white key described above. Specifically, the arm body 33 of the first arm 31 and the second arm 32 of the key support mechanism 6b are configured to have exactly the same shape and size as the arm body 33 and the second arm 32 of the key support mechanism 6a for the white key. The two left and right weights 34, 34 of the key support mechanism 6b for the black key have different shapes at the rear from the weight 34 of the key support mechanism 6a for the white key.

[0040] Next, the operation of the keys 2 and the key support mechanism 6 in the keyboard device 1 configured as described above will be described. Fig. 6 shows the operation of the white key 2a and its key support mechanism 6a, and Fig. 7 shows the operation of the black key 2b and its key support mechanism 6b.

[0041] In the key-off state shown in Fig. 6(a), when the front end of the white key 2a is pressed down by a finger of the player, the front-side connecting portion 22 of the white key 2a moves downward, whereby the first arm 31 rotates counterclockwise about the first support shaft 18a. Further, as the first arm 31 rotates, the front-side connecting portion 45 of the second arm that engages with the connecting shaft 37a of the first arm 31 via the connecting recess 45b moves upward. Thereby, the second arm 32 rotates clockwise about the second support shaft 19a. Then, as the second arm 32 rotates, the rear-side connecting portion 23 connected via the rear-side connecting portion 42 of the second arm at the rear end thereof is pulled down, and the rear end of the white key 2a moves downward.

[0042] Incidentally, when the first arm 31 rotates as described above, as the box portion 35a of the front-side connecting portion 35 of the first arm 31 moves downward, the switch body 3b of the key switch 3 corresponding to the key 2 that has been keyed is pressed from above by the bottom wall of the box portion 35a. Thereby, in the electronic piano, the keying information of the key 2 that has been keyed is detected, and based on the detected keying information, a sound is generated from a speaker (not shown).

[0043] As described above, when the white key 2a is pressed down, as the first arm 31 rotates counterclockwise, the weight 34 of the first arm 31 inclines rearward upward as shown in Fig. 6(b), and the rear end abuts against the first arm upper limit stopper 10a from below. Thereby, further rotation of the first arm 31 is blocked. Then, when the front end of the white key 2a is pressed down to the lowest position, the front end of the white key 2a abuts against the key lower limit stopper 16b, and further pressing down of the white key 2a is blocked.

[0044] The white key 2a pressed as described above operates to rotate about a virtual fulcrum P located behind its rear end. The position of this virtual fulcrum P is set such that, for example, the distance from the front end of the white key 2a is approximately twice the length of the white key 2a itself. As a result, when the front end portion of the white key 2a is pushed down to the lowest position, compared to the key-off state shown in Fig. 6(a), the front end portion of the white key 2a is positioned downward by a predetermined key stroke (e.g., 10 mm), and the rear end portion is positioned downward by a distance approximately half of the key stroke (e.g., 5 mm).

[0045] On the other hand, when the finger is released from the pressed white key 2a, due to the weight of the hammer 34, the first arm 31 of the key support mechanism 6a rotates in the reverse direction as described above, and accordingly, the second arm 32 also rotates in the reverse direction. Along with this, the white key 2a rotates upward about the virtual fulcrum P. Then, a predetermined portion behind the first pivot 18a in the first arm 31 abuts against the first arm lower limit stopper 10b from above, and both upper position regulating portions 21, 21 of the white key 2a abut against the key upper limit stopper 16a from below, preventing further rotation of the white key 2a and returning it to the original key-off state.

[0046] Also, the operation when pressing the black key 2b is performed in the same manner as the above-described white key 2a and key support mechanism 6a. That is, in the key-off state shown in Fig. 7(a), when the front end portion of the black key 2b is pushed down, the first arm 31 rotates counterclockwise about the first pivot 18a, and the second arm 32 rotates clockwise about the second pivot 19a. As a result, the black key 2b operates to rotate about a virtual fulcrum Q at the rear. The position of this virtual fulcrum Q is set such that, similar to the virtual fulcrum P of the white key 2a described above, for example, the distance from the front end of the black key 2b is approximately twice the length of the black key 2 itself. Therefore, when the front end portion of the black key 2b is pushed down to the lowest position, compared to the key-off state shown in Fig. 7(a), the front end portion of the black key 2b is positioned downward by a predetermined key stroke, and the rear end portion is positioned downward by a distance approximately half of the key stroke.

[0047] On the other hand, when the finger is released from the depressed black key 2b, the first arm 31 and the second arm 32 of the key support mechanism 6b rotate in the opposite direction to the above, and accordingly, the black key 2b rotates upward about the virtual fulcrum Q. Then, the extended portion 26b of the key front side connecting portion 26 of the black key 2b abuts against the key upper limit stopper 17 from below, and further rotation of the black key 2b is blocked, returning to the original key-off state.

[0048] Next, with reference to FIGS. 8 to 13, the main part of the present invention will be described. The main part of the present invention is to provide a buffer member 51 on the outer peripheral surface side of the connecting shaft 37a of the first arm rear side connecting portion 37, which is the connecting portion with the second arm 32, in the first arm 31 of the key support mechanism 6. In the following description, the connecting shaft integrally formed with the arm main body 33 of the first arm 31 on the connecting shaft 37a will be referred to as the "connecting shaft 50".

[0049] FIG. 8(a) shows the white key 2a and its key support mechanism 6a, and FIG. 8(b) shows a state in which the connecting portion between the first arm 31 and the second arm 32 is separated and the buffer member 51 is removed from the connecting shaft 50 of the first arm 31 in the key support mechanism 6a. As shown in FIG. 8(b), the connecting shaft 50 (engagement shaft) is composed of a left protruding portion 50L and a right protruding portion 50R that protrude from the arm main body 33 by the same predetermined length to the left and right, respectively. These protruding portions 50R and 50L are arranged on the same straight line extending in the left-right direction and are formed in a circular shape with a predetermined diameter in cross section.

[0050] FIG. 9 shows an enlarged view of the buffer member 51. This buffer member 51 is composed of a molded product made of a predetermined synthetic resin (for example, thermoplastic elastomer) having elasticity. All of them are formed in a cylindrical shape, arranged at a predetermined interval in the left - right direction with respect to each other, and have a left cylindrical portion 52 and a right cylindrical portion 53 having the same shape, and a connecting portion 54 provided so as to connect these cylindrical portions 52 and 53. The left cylindrical portion 52 and the right cylindrical portion 53 have substantially the same length and inner diameter as the protruding lengths and diameters of the respective protruding portions 50L and 50R of the connecting shaft 50, and are formed in a thick - walled cylindrical shape having a predetermined thickness. Further, on the outer peripheral surfaces of the left cylindrical portion 52 and the right cylindrical portion 53, lubricant holding portions 52a and 53a are respectively provided, which are formed in a concave shape opening outward.

[0051] On the other hand, the connecting portion 54 is formed in an arc - shaped cross - section so as to connect approximately 1 / 4 of the circumferential direction at the right - hand end face of the left cylindrical portion 52 and the left - hand end face of the right cylindrical portion 53.

[0052] The buffer member 51 configured as described above is attached to the connecting shaft 50 in a state where the left cylindrical portion 52 is fitted to the left protruding portion 50L of the connecting shaft 50 and the right cylindrical portion 53 is fitted to the right protruding portion 50R of the connecting shaft 50. When attaching this buffer member 51 to the connecting shaft 50, one of the left and right cylindrical portions 52 and 53 is fitted to one of the left and right protruding portions 50L and 50R of the connecting shaft 50, and while pulling the other of the cylindrical portions 52 and 53 through the connecting portion 54, it is fitted to the other of the protruding portions 50L and 50R. In this way, the buffer member 51 can be attached to the connecting shaft 50 relatively easily.

[0053] As described above, according to the keyboard device 1 to which the main part of the present invention is applied, a buffer member 51 is attached to the connecting shaft 50 of the first arm 31 in a state of covering its outer peripheral surface, and the left cylindrical portion 52 and the right cylindrical portion 53 of this buffer member 51 are in sliding contact with the inner surfaces of the connecting recesses 45b, 45b (engagement recesses) of the left and right connecting pieces 45a, 45a of the second arm 32. Thereby, the connecting shaft 50 of the first arm does not directly hit the inner surface of each connecting recess 45b of the second arm. Therefore, at the time of key pressing, it is possible to prevent the generation of noise at the connecting portion between the first arm 31 and the second arm 32 of the key support mechanism 6. In addition, smooth operation at the connecting portion between the first arm 31 and the second arm 32 can be ensured, and thereby a good touch feeling can be obtained at the time of key pressing.

[0054] Further, since concave lubricant holding portions 52a, 53a are provided on the outer peripheral surfaces of the left cylindrical portion 52 and the right cylindrical portion 53 of the buffer member 51, by applying a lubricant to the buffer member 51 attached to the connecting shaft 50, the lubricant can be held on the outer peripheral surfaces of the left cylindrical portion 52 and the right cylindrical portion 53 over a long period of time. Thereby, smooth operation at the connecting portion between the first arm 31 and the second arm 32 by the connecting shaft 50 and the connecting recess 45b can be ensured over a long period of time.

[0055] FIG. 10 shows a modified example of the buffer member 51. As shown in the figure, in this buffer member 51A, it is only different from the above-described buffer member 51 in that a cut portion 53b is provided in the right cylinder portion 53. This cut portion 53b is cut along the length direction of the right cylinder portion 53. When attaching the buffer member 51 having such a cut portion 53b to the connecting shaft 50, after fitting the non-cut left cylinder portion 52 to the left protruding portion 50L of the connecting shaft 50, the cut right cylinder portion 53 is passed through its cut portion 53a, specifically, while expanding the cut portion 53a, it is fitted to the right protruding portion 50R. Thereby, compared with the above-described buffer member 51, when attaching the buffer member 51A having a cut portion to the connecting shaft 50, it can be easily attached to the connecting shaft 50 without pulling the buffer member 51. In FIG. 10, the cut portion 53b is provided only in the right cylinder portion 53, but a similar cut portion may also be provided in the left cylinder portion 52. In this case, by fitting the left and right cylinder portions 52 and 53 to the left and right protruding portions 50L and 50R of the connecting shaft 50 through these cut portions, the buffer member 51 can be attached to the connecting shaft 50 even more easily.

[0056] FIG. 11 shows another modified example of the buffer member 51, where (a) is a perspective view and (b) is a right side view. This buffer member 51B cooperates with the connecting recess 45b of the second arm 32 to impart a letoff touch feeling to the key 2 that is pressed.

[0057] Specifically, as shown in FIG. 11, on the outer peripheral surface of the left cylinder portion 52 of the buffer member 51B, two letoff convex portions 52c, 52c are provided at predetermined positions symmetric to each other. Similarly, on the outer peripheral surface of the right cylinder portion 53 of the buffer member 51B, two letoff convex portions 53c, 53c are provided. Each letoff convex portion 52c, 53c extends over the entire length direction of the corresponding cylinder portion 52, 53 and is formed to protrude outward (radial direction). Note that each letoff convex portion 52c, 53c is formed so that its surroundings are recessed, thereby being formed to protrude relatively.

[0058] Figure 12 shows the connection state between the connection shaft 50 of the first arm 31 to which the above-described buffer member 51B is attached and the connection recess 45b of the second arm 32. As shown in this figure, in the connection recess 45b of each connection piece 45 of the second arm 32, two release convex portions 45c, 45c are provided at predetermined upper and lower positions on the inner surface thereof. Each release convex portion 45c is formed so as to protrude a predetermined length from the inner surface of the connection recess 45b.

[0059] Figure 13 is a view similar to Fig. 12 described above, where (a) shows the unlocked state and (b) shows the key-pressed state. As shown in Fig. (a) of this figure, in the unlocked state, the release convex portions 53c, 53c of the buffer member 51B are located in front of the release convex portions 45c, 45c of the engagement recess 45b in the second arm 32. When the key 2 is pressed from this state, as described above, the first arm 31 rotates counterclockwise and the second arm 32 rotates clockwise, so that the buffer member 51B integrated with the connection shaft 50 slides to the back side (the right side in Fig. 13) of the engagement recess 45b. In this case, each release convex portion 53c of the buffer member 51B abuts against each release convex portion 45c of the engagement recess 45b from the front and then immediately moves backward (see Fig. 13(b)).

[0060] As described above, when each release convex portion 53c of the buffer member 51B temporarily abuts against each release convex portion 45c of the engagement recess 45b, when the connection shaft 50 of the first arm 31 slides in the engagement recess 45b of the second arm during key pressing, the sliding is temporarily inhibited. As a result, a click feeling due to temporary resistance is generated in the key 2 being pressed, and a touch feeling approximated to the release of an acoustic piano can be obtained.

[0061] Note that the present invention is not limited to the above-described embodiments and can be implemented in various modes. For example, in the embodiment, while the connecting shaft 50 is provided at the rear connecting portion 37 of the first arm 31 of the first arm 31, the engaging concave portion 45b is provided at the front connecting portion 45 of the second arm 32 of the second arm 32. However, the positional relationship between the connecting shaft 50 and the engaging concave portion 45b that engage with each other can be reversed, that is, it is also possible to provide the connecting shaft on the second arm 32 and the engaging concave portion on the first arm 31. In this case, the engaging concave portion provided on the first arm 31 is configured to open rearward.

[0062] In addition, in the embodiment, the letoff convex portions 52c, 53c, and 45c are provided on the buffer member 51B and the engaging concave portion 45b of the second arm 32. However, the shapes of these and the number of letoff convex portions are not particularly limited, and as long as the letoff touch feeling can be imparted to the key to be pressed, the letoff convex portion may be provided only on either the buffer member 51B or the engaging concave portion 45b of the second arm 32.

[0063] Furthermore, in the embodiment described above using the key support mechanism 6a that supports the white key 2a, the present invention can of course be applied to the key support mechanism 6b for the black key 2b. In addition, the detailed configuration of the buffer member 51 shown in the embodiment is merely an example and can be appropriately changed within the scope of the gist of the present invention.

Explanation of Reference Numerals

[0064] 1 Keyboard device 2 Key 2a White key 2b Black key 4 Keyboard chassis 6 Key support mechanism 6a Key support mechanism for white keys 6b Key support mechanism for black keys 18 First arm support portion 18a First support shaft 19 Second arm support portion 19a Second support shaft 31 First arm 32 Second arm 37 First arm rear connecting part 37a Connecting shaft 45 Second arm front connecting part 45b Connecting recess (engagement recess) 45c Let-off convex part 50 Connecting shaft (engagement shaft) 50L Left protruding part 50R Right protruding part 51 Buffer member 51A Modified example of buffer member 51B Modified example of buffer member 52 Left cylinder part 52a Lubricant holding part 52c Let-off convex part 53 Right cylinder part 53a Lubricant holding part 53b Cutting part 53c Let-off convex part 54 Connecting part P Virtual fulcrum of white key Q Virtual fulcrum of black key

Claims

1. A keyboard chassis, Keys extending a predetermined length in the front-rear direction and arranged on the upper part of the keyboard chassis, A key support mechanism that engages with the keyboard chassis and is provided to support the keys from below, and when a key is pressed, the pressed key is operated to rotate about a virtual fulcrum located behind the rear end of the key, Comprising, The key support mechanism, Is configured to extend a predetermined length in the front-rear direction, and is swingably engaged with a first support shaft extending in the left-right direction provided on the keyboard chassis via a first bearing portion provided at a predetermined position, and a front end portion is rotatably and slidably connected to the front portion of the key. A first arm, Is configured to extend a predetermined length in the front-rear direction, and is swingably engaged with a second support shaft extending in the left-right direction provided behind the first support shaft on the keyboard chassis via a second bearing portion provided at a predetermined position, and a rear end portion is rotatably connected to the rear portion of the key. A second arm, wherein a front-side connecting portion of the second arm in front of the second support shaft is rotatably and slidably connected to a rear-side connecting portion of the first arm behind the first support shaft of the first arm, Having, One of the rear-side connecting portion of the first arm and the front-side connecting portion of the second arm has an engaging shaft extending in the left-right direction, The other of the rear-side connecting portion of the first arm and the front-side connecting portion of the second arm has an engaging recess that engages with the engaging shaft, A keyboard device for a keyboard musical instrument, characterized in that a buffer member that slidably contacts the inner surface of the engaging recess is attached to the engaging shaft in a state of covering its outer peripheral surface.

2. The engaging shaft is composed of a left protruding portion and a right protruding portion that respectively protrude leftward and rightward, The buffer member, Is composed of a molded product made of an elastic synthetic resin, Formed in a cylindrical shape, a left cylindrical portion into which the left protruding portion fits, Formed in a cylindrical shape, a right cylindrical portion into which the right protruding portion fits, A connecting portion provided to connect the right end surface of the left cylindrical portion and the left end surface of the right cylindrical portion, The keyboard device for a keyboard musical instrument according to claim 1, characterized by having.

3. The keyboard device for a keyboard musical instrument according to claim 2, characterized in that lubricant holding portions are formed on the outer peripheral surfaces of the left cylindrical portion and the right cylindrical portion in a concave shape that opens outward to hold a lubricant.

4. The keyboard device of a keyboard musical instrument according to claim 2 or 3, wherein at least one of the left cylinder portion and the right cylinder portion has a cut portion cut along its longitudinal direction.

5. On at least one of the inner surface of the engagement recess and the outer surface of the buffer member, a convex portion protruding from the inner surface of the engagement recess and / or the outer surface of the buffer member is formed, and when the engagement shaft slides in the engagement recess during key pressing, a letoff convex portion for imparting a letoff touch feeling to the key being pressed is provided by temporarily inhibiting the slide. The keyboard device of a keyboard musical instrument according to any one of claims 1 to 4, characterized in that.

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