Keyboard device of a keyboard instrument

Abstract

To provide a keyboard device of a keyboard musical instrument capable of easily attaching and detaching an arm to and from a support shaft in assembly and maintenance.SOLUTION: A keyboard device of a keyboard musical instrument includes: a keyboard chassis 4; a key 2 disposed above the keyboard chassis 4; and a key support mechanism 6 provided so as to support the key 2 from a lower part, and operating the pressed key 2 when the key is pressed so as to be rotated with virtual supports P, Q positioned in the rear as centers. The key support mechanism 6 is configured so as to extend by a predetermined length in a fore-and-aft direction, is swingably engaged with a support shaft 19a provided in the keyboard chassis 4 and extending horizontally, and has an arm 32 in which one end is engaged with the key 2. In assembly or maintenance of the keyboard device 1, the arm 32 is held in a predetermined posture and can be mounted from an upper part of the keyboard chassis 4 when it is attached to or detached from the support shaft 19a, and has a bearing part 41 removable to an upper part of the keyboard chassis 4.SELECTED DRAWING: Figure 10

Description

Technical Field

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

Background Art

[0002] Conventionally, as this type of keyboard device, 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 a predetermined length in the front-rear direction. 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 further, 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.

[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. 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 so as to rotate about a virtual fulcrum located rearward by approximately the same length as the key itself, 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 a grand piano keyboard can be obtained.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the conventional keyboard device described above, each connecting link bar of the link mechanism is rotatably supported with a support pin having a circular cross section inserted through a pin hole provided near the center in the length direction thereof. Further, on the base of the keyboard device, a support portion having an upper portion formed in a bifurcated shape is erected, and both end portions of the support pin are respectively supported by the upper end portions of the bifurcated portions of the support portion.

[0006] In the keyboard device configured as described above, at the time of its assembly, in order to rotatably engage each connecting link bar with the support pin, it is necessary to align the pin hole of the connecting link bar with the upper end portions of the bifurcated portions of the support portion and then insert the support pin through the support portion and the connecting link bar, and the assembly work is complicated. Further, when it is necessary to remove the connecting link bar from the support portion during maintenance of the keyboard device, the support pin has to be pulled out from the connecting link bar, which is time-consuming. Thus, in the above keyboard device, its assembly and maintenance work are complicated and time-consuming, and therefore, there is room for improvement in this keyboard device.

[0007] The present invention has been made to solve the above problems, and an object thereof is to provide a keyboard device for a keyboard musical instrument that can be easily attached to and detached from a support shaft with an arm during assembly and maintenance.

Means for Solving the Problems

[0008] To achieve the above object, the invention according to claim 1 includes a keyboard chassis, keys extending in 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 in a predetermined length in the front-rear direction, engages rotatably with a support shaft provided on the keyboard chassis and extending in the left-right direction, and has an arm with one end engaging with the key. During the assembly or maintenance of the keyboard device, the arm is held in a predetermined posture and is in a state of being engaged with the support shaft attachable from above the keyboard chassis in a state where the engagement with the support shaft is released and has a bearing portion that is detachable above the keyboard chassis. and the outer peripheral surface of the support shaft is formed in an outwardly convex arc shape, and includes a pair of curved surface portions facing each other with a predetermined interval therebetween, and a pair of flat surface portions that are respectively continuous between the ends of the pair of curved surface portions and face each other in parallel with a predetermined interval shorter than the distance between the pair of curved surface portions. The bearing portion has an opening that opens to the front end side of the arm, and the opening dimension of the opening is set to be shorter than the interval between the vertices of the pair of curved surface portions and longer than the interval between the pair of flat surface portions This is the feature.

[0009] According to this configuration, the keys extending in the front-rear direction are supported from below by the key support mechanism and are configured to rotate about a virtual fulcrum at the rear. Also, the key support mechanism has an arm that engages rotatably with a support shaft provided on the keyboard chassis, and this arm is provided with a predetermined bearing portion that engages with the support shaft. During the assembly or maintenance of the keyboard device, when attaching or detaching the arm to / from the support shaft via the bearing portion, the arm can be attached to the support shaft or detached from the support shaft above the keyboard chassis while being held in a predetermined posture. in an engaged state This enables easy attachment and detachment of the arm to / from the support shaft during the assembly or maintenance of the keyboard device. in a state where the engagement with the support shaft is released According to the configuration of - Also, the above , the outer peripheral surface of the support shaft of the keyboard chassis is composed of the pair of curved surface portions and the pair of flat surface portions, so that the cross-section is formed in a so-called oval shape. On the other hand, the bearing portion of the arm has an opening that opens to the front end side of the arm. And the opening dimension of this opening is set to be shorter than the interval between the vertices of the pair of curved surface portions and longer than the interval between the pair of flat surface portions.

[0011] Also, the above

[0012] ​ When attaching the arm to the support shaft, while maintaining the posture of the arm so that the opening of the bearing portion faces the curved surface portion of the support shaft, bring the bearing portion close to the support shaft and engage it therewith. In this way, the arm can be easily attached to the support shaft via the bearing portion. On the other hand, when removing the arm from the support shaft, by maintaining the arm in the same posture as when it was attached, align the opening of the bearing portion with the curved surface portion of the support shaft and pull up the arm. Thereby, the arm can be easily removed from the support shaft. As described above, the arm having the above-described bearing portion can be easily attached to and detached from the support shaft having the above-described outer peripheral surface.

[0013] Claim 2 The invention according to Claim 1 In the keyboard device of the keyboard instrument described in the center of this support shaft the long axis passing through

[0014] and extending along the direction in which a pair of curved surface portions face each other is set to be positioned between a front inclined axis that is inclined forward by a predetermined angle with respect to the vertical line and a rear inclined axis that is inclined rearward by a predetermined angle.

[0015] Claim 3 The invention according to Claim 2 In the keyboard device of the keyboard instrument described in

[0016] According to this configuration, by appropriately setting the above-described front inclined axis and rear inclined axis and setting the long axis of the support shaft to be positioned between the front inclined axis and the rear inclined axis with respect to the vertical line, it is possible to prevent the arm from coming off the support shaft during playing or when transporting the keyboard device while ensuring easy attachment and detachment of the arm to and from the support shaft during assembly or maintenance of the keyboard device. Claim 2 the above-described

[0017] Claim 4The invention according to Claims 1 to 3 In the keyboard device of a keyboard instrument described in any one of

[0018] According to this configuration, when attaching or detaching the arm manually to / from the support shaft of the keyboard chassis, the bearing portion of the arm can be relatively easily visually recognized from above, and thereby, while confirming the position of the opening portion of the bearing portion and the support shaft, the attachment and detachment operations of the arm can be efficiently performed.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

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Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0020] 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 a keyboard device 1 of an 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.

[0021] FIG. 1(b) shows a state where keys 2 other than the leftmost white key 2a and black key 2b in the keyboard device 1 of FIG. 1(a) are omitted, 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.

[0022] This keyboard device 1 includes a keyboard chassis 4, a plurality of keys 2 composed of white keys 2a and black keys 2b and arranged side by side in the left-right direction, a key support mechanism 6 that is rotatably attached to the keyboard chassis 4 for each key 2 and supports the corresponding key 2 from below, a key switch 3 for detecting key pressing information of each key 2, and the like.

[0023] The keyboard chassis 4 includes a chassis body 4a made of a resin molded product having 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 portion 11, middle portion 12, and rear portion 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 that are spaced apart in the left-right direction and each extend in the front-rear direction. In the following description, in the keyboard chassis 4, the front portion 11, middle portion 12, and rear portion 13 of the chassis body 4a are referred to as the "chassis front portion 11", "chassis middle portion 12", and "chassis rear portion 13", respectively.

[0024] The front part 11 of the chassis mainly guides the white key 2a when the key is pressed and restricts the upper and lower limit positions of its front end. A plurality of white key guides 11a for preventing the lateral movement of the white key 2a are erected in a side-by-side state in the left-right direction and inserted from below for each white key 2a into the front part 11 of the chassis. 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 in the front part 11 of the chassis, and two upper limit position restricting parts 21, 21 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 the stopper mounting part 11c, respectively, so as to extend in the left-right direction. 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 in the front part 11 of the chassis, and a key upper limit stopper 17 for the black key is mounted on the stopper mounting part 11d so as to extend in the left-right direction.

[0025] The middle part 12 of the chassis mainly guides the black keys 2b when the keys are 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 standing upright 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 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 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. In addition, 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 main body 4a is provided.

[0026] 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 the key is pressed.

[0027] 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. Each of this first arm upper limit stopper 10a and the first arm lower limit stopper 10b provided in the middle part 12 of the chassis has a function as a hammer for imparting a touch weight to the key 2, and regulates 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. Furthermore, 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 to the upper part of the rear part 13 of the chassis.

[0028] 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.

[0029] 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 via the above-mentioned front rails 7 and rear rails 9.

[0030] 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 (for example, AS resin). At the front end portion 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 end portions bent forward. 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 as described above.

[0031] 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.

[0032] 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 in the left-right direction of the white key 2a 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 this 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.

[0033] 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.

[0034] 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 composed of a resin molded product with 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 at the front end, 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. 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 ends 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.

[0035] 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, 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.

[0036] 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 with 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.

[0037] 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 in the front-rear direction by a predetermined length. Further, the second arm 32 has a C-shaped bearing portion 41 with a side surface shape open forward near the center in the length direction, and this bearing portion 41 is rotatably engaged with the second support shaft 19a in the keyboard chassis 4.

[0038] 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 extending in parallel to each other along the length direction of the second arm 32 by a predetermined length. 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 in 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.

[0039] 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 in the form of a long hole and open 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.

[0040] 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, extends a predetermined length in the front-rear direction shorter than the white key 2a, and is formed in a hollow shape that opens downward. At the front lower end of the black key 2b, a front-side key connecting portion 26 formed substantially the same as the front-side key connecting portion 22 of the white key 2a is provided. This front-side 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-side key connecting portion 26 has an extension 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 extension 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 reference numerals are given to the same components as those of the white key 2a and the key support mechanism 6a described above, and detailed descriptions thereof are omitted.

[0041] 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. Note that 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.

[0042] Next, the operations of the key 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.

[0043] 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, with the rotation of the first arm 31, 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. As a result, the second arm 32 rotates clockwise about the second support shaft 19a. Then, with the rotation of the second arm 32, 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.

[0044] 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. As a result, 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).

[0045] As described above, when the white key 2a is pressed down, with the counterclockwise rotation of the first arm 31, the weight 34 of the first arm 31 inclines rearward and upward as shown in FIG. 6(b), and the rear end abuts against the first arm upper limit stopper 10a from below. As a result, 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.

[0046] The white key 2a that is pressed as described above operates to pivot 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).

[0047] On the other hand, when the finger is released from the depressed white key 2a, due to the weight of the hammer 34, the first arm 31 of the key support mechanism 6a pivots in the reverse direction as described above, and accordingly, the second arm 32 also pivots in the reverse direction. Along with this, the white key 2a pivots upward about the virtual fulcrum P. Then, a predetermined portion behind the first pivot shaft 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 pivoting of the white key 2a and returning it to the original key-off state.

[0048] Also, the operation when the black key 2b is pressed 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 pivots counterclockwise about the first pivot shaft 18a, and the second arm 32 pivots clockwise about the second pivot shaft 19a. As a result, the black key 2b operates to pivot about a virtual fulcrum Q at the rear. Note that the position of this virtual fulcrum Q is set in the same manner as the virtual fulcrum P of the white key 2a described above, for example, such that 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.

[0049] 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.

[0050] 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 form the second support shaft 19a (support shaft) of the keyboard chassis 4 into a predetermined cross-sectional shape, and to form the bearing portion 41 into a predetermined shape and size so that the second arm 32 can be easily attached to and detached from the second support shaft 19a during the assembly or maintenance of the keyboard device 1.

[0051] FIG. 8(a) shows a state in which the second arm 32 is supported by the second support shaft 19a of the keyboard chassis 4, and FIG. 8(b) shows an enlarged view of the second support shaft 19a and its surroundings. The posture of the second arm 32 and the positional relationship between the second support shaft 19a of the bearing portion 41 shown in FIG. 8 are those in a state (key-off state) when the key 2 is not pressed.

[0052] FIG. 9(a) shows an enlarged view of the second support shaft 19a. As shown in the figure, the second support shaft 19a has a so-called oval cross-sectional shape in which two locations of a circle centered on its axis are cut out. The outer peripheral surface of the second support shaft 19a is formed in an outwardly convex arc shape, and is composed of a pair of curved surface portions 19c, 19c facing each other with a predetermined interval, and a pair of flat surface portions 19d, 19d that are respectively connected to the ends of the pair of curved surface portions 19c, 19c and face each other in parallel with a predetermined interval. Further, in this second support shaft 19a, the interval D1 between the vertices of the pair of curved surface portions 19c, 19c is set to a value larger than the interval D2 between the pair of flat surface portions 19d, 19d.

[0053] On the one hand, as shown in FIG. 9(b), the bearing portion 41 of the second arm 32 has an inner peripheral surface 41a with an arcuate side surface shape and an opening 41b that opens to the front end side of the second arm 32. The diameter of the inner peripheral surface 41a is set to be approximately the same value as the distance D1 between the vertices of the pair of curved surface portions 19c, 19c of the second support shaft 19a. That is, the inner peripheral surface 41a of the bearing portion 41 has substantially the same curvature as each curved surface portion 19c of the second support shaft 19a. Further, the opening dimension D3 of the opening 41b of the bearing portion 41 is set to a value slightly larger than the distance D2 between the pair of flat surface portions 19d, 19d of the second support shaft 19a and smaller than the distance D1 between the pair of curved surface portions 19c, 19c (D2 < D3 < D1).

[0054] FIG. 10 shows the state immediately before attaching the second arm 32 to the second support shaft 19a of the keyboard chassis 4 during the assembly of the keyboard device 1 or the like. As shown in the figure, when attaching the second arm 32 to the second support shaft 19a, first, the second arm 32 is held in the downwardly inclined posture shown in FIG. 10(a) so that the opening 41b of the bearing portion 41 faces the upper curved surface portion 19c of the second support shaft 19a. Then, while approaching the bearing portion 41 to the second support shaft 19a, it is engaged therewith. As described above, since the opening dimension D3 of the opening 41b of the bearing portion 41 is larger than the distance D2 between the pair of flat surface portions 19d, 19d of the second support shaft 19a, the second support shaft 19a passes through the opening 41b and fits into the bearing portion 41. In this way, the second arm 32 can be easily attached to the second support shaft 19a from above the keyboard chassis 4 via the bearing portion 41.

[0055] On the other hand, when removing the second arm 32 attached to the second support shaft 19a during maintenance of the keyboard device 1 or the like, first, by holding the second arm 32 in a downward-forward posture similar to that shown in FIG. 10(a) described above, the opening 41b of the bearing portion 41 is aligned with the curved surface portion 19c of the second support shaft 19a. Then, the second arm 32 is pulled upward above the keyboard chassis 4. As a result, the second support shaft 19a passes through the opening 41b and detaches from the bearing portion 41. In this way, the second arm 32 attached to the second support shaft 19a via the bearing portion 41 can be easily removed above the keyboard chassis 4.

[0056] Also, regarding the second support shaft 19a described above, an example was shown in which the major axis passing through its axis and extending along the direction in which the pair of curved surface portions 19c, 19c face each other is inclined rearward with respect to the vertical line. However, the second support shaft 19a can also be set in a state where its major axis is inclined forward with respect to the vertical line. FIG. 11(a) shows the second support shaft 19a described above, and the major axis of this second support shaft 19a extends along an axis K1 inclined rearward (rightward in the figure) with respect to the vertical line G. On the other hand, the second support shaft 19a shown in FIG. 11(b) has its major axis extending along an axis K2 inclined forward with respect to the vertical line G.

[0057] Further, the inclination angle of the major axis of the second support shaft 19a with respect to the vertical line may be within a predetermined range as shown in FIG. 12. The second support shaft 19a shown in FIG. 12(a) is set such that its major axis extends along an axis line L1 (rear inclination axis line) inclined backward by a predetermined angle R1 (for example, 45 degrees) with respect to the vertical line G. On the other hand, the second support shaft 19a shown in FIG. 12(b) is set such that its major axis extends along an axis line L2 (front inclination axis line) inclined forward by a predetermined angle R2 (for example, 45 degrees) with respect to the vertical line G. That is, the inclination angle of the major axis of the second support shaft 19a may be within a range of plus or minus 45 degrees. By setting the inclination angle of the major axis of the second support shaft 19a within the above range, it is possible to prevent the second arm 32 from coming off the second support shaft 19a during performance or transportation of the keyboard device 1 while ensuring easy attachment and detachment of the second arm 32 to and from the second support shaft 19a during assembly or maintenance of the keyboard device 1.

[0058] FIG. 13 shows a modified example of the second arm, where (a) is a perspective view and (b) is a right side view. The second arm 32A shown in the figure has a predetermined shape bent downward at the center in the length direction. Further, on the inner side of the bent portion of the second arm 32A, a bearing portion 41 having an inner peripheral surface 41a and an opening 41b similar to those of the second arm 32 described above is formed. Note that the second arm 32A is provided with a second arm front side connecting portion 45 having a connecting recess 45b at the front end and a second arm rear side connecting portion 42 having a connecting hole 43a at the rear end, similar to the second arm 32 described above.

[0059] In the second arm 32A of the modified example configured as described above, for example, when the vicinity of the center in the length direction of the key 2 is pushed during key pressing, a downward pressing load may act on the second arm front side connecting portion 45 at the front end and the second arm rear side connecting portion 42 at the rear end of the second arm 32A from above. In this case, the second arm 32A is likely to deform in a direction in which the opening 41b of the bearing portion 41 narrows, and as a result, it is possible to reliably prevent the second arm 32A from coming off the second support shaft 19a. Note that the overall strength of the second arm 32A can be increased depending on its shape.

[0060] As described above, according to the keyboard device 1 to which the main part of the present invention is applied, the second arm 32 can be easily attached to and detached from the second support shaft 19a of the keyboard chassis 4 during the assembly or maintenance of the keyboard device 1. Thereby, the assembly and maintenance work of the keyboard device 1 can be efficiently performed.

[0061] Note that the present invention is not limited to the above-described embodiment and can be implemented in various modes. For example, in the embodiment, the arm of the present invention is applied to the second arm 32 of the key support mechanism 6, but the present invention is not limited thereto, and it is also possible to apply it to the first arm 31.

[0062] In addition, the detailed configurations of the second arm 32 and the second support shaft 19a shown in the embodiment are merely examples, and can be appropriately changed within the scope of the gist of the present invention.

Explanation of Reference Numerals

[0063] 1 Keyboard device 2 Key 2a White key 2b Black key 4 Keyboard chassis 4a Chassis main body 6 Key support mechanism 6a Key support mechanism for white keys 6b Key support mechanism for black keys 14 Rib 19 Second arm support portion 19a Second support shaft (support shaft) 19c Curved surface portion 19d Flat surface portion 31 First arm 32 Second arm (arm) 41 Bearing portion 41a Inner peripheral surface 41b Opening P Virtual fulcrum of white key Q Virtual fulcrum of black key D1 Distance between a pair of curved surface portions D2 Distance between a pair of flat surface portions D3 Opening dimension of opening Axis K1 Axis K2 Axis L1 (rear tilt axis) Axis L2 (front tilt axis) Vertical line G Predetermined angle R1 Predetermined angle R2

Claims

1. A keyboard chassis, Keys extending a predetermined length in the front-rear direction and disposed above 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 has an arm that is rotatably engaged with a support shaft provided on the keyboard chassis and extending in the left-right direction, and one end of which is engaged with the key, During the assembly or maintenance of the keyboard device, the arm can be attached to the support shaft in a state of being engaged with the support shaft from above the keyboard chassis while being held in a predetermined posture when attaching and detaching with respect to the support shaft, and has a bearing portion that can be removed from above the keyboard chassis in a state of releasing the engagement with respect to the support shaft, The outer peripheral surface of the support shaft, Is formed in an outwardly convex arc shape, and includes a pair of curved surface portions facing each other with a predetermined interval therebetween, And a pair of flat surface portions that are respectively connected to the ends of the pair of curved surface portions and face each other in parallel with a predetermined interval shorter than the distance between the pair of curved surface portions, The bearing portion has an opening that opens to the front end side of the arm, The opening dimension of the opening is set to be shorter than the interval between the apexes of the pair of curved surface portions and longer than the interval between the pair of flat surface portions. A keyboard device for a keyboard musical instrument, characterized in that.

2. The support shaft is set such that a major axis passing through the center of the support shaft and extending along the direction in which the pair of curved surface portions face is located between a front inclined axis that is inclined forward by a predetermined angle with respect to the vertical line and a rear inclined axis that is inclined rearward by a predetermined angle. The keyboard device for a keyboard musical instrument according to claim 1, characterized in that.

3. The keyboard device for a keyboard musical instrument according to claim 2, characterized in that the predetermined angle is 45 degrees.

4. The bearing portion is provided near the center in the length direction of the arm and above the arm. The keyboard device for a keyboard musical instrument according to any one of claims 1 to 3, characterized in that.

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