JP2024051208A - Keyboard device for keyboard instruments - Google Patents

Abstract

[Problem] To provide a keyboard device for a keyboard instrument that allows a key support mechanism having a first arm and a second arm to be easily attached to a keyboard chassis during assembly, allowing efficient assembly. [Solution] The keyboard device comprises a keyboard chassis 4 having a first support shaft 18a and a second support shaft 19a and a flat plate portion 12a extending left and right between them, a key 2 arranged on the upper portion thereof, and a key support mechanism 6 that engages with the keyboard chassis 4 and supports the key 2 from below, the flat plate portion 12a having clearance portions 12c, 12d to avoid interference with the first arm 31 of the key support mechanism 6 during assembly. [Selected Figure] Figure 2

Description

The present invention relates to a keyboard device for keyboard instruments such as electronic pianos, which is equipped with a rotating member that rotates when a key is pressed.

Conventionally, a keyboard device for this type of keyboard instrument is known, for example, as described in Patent Document 1, which has already been filed by the present applicant. This keyboard device comprises a keyboard chassis made of a resin molded product of a predetermined shape, a number of keys consisting of white keys and black keys rotatably supported on the upper part of the keyboard chassis, and a number of hammers rotatably attached to the keyboard chassis for each key. In this keyboard device, an actuator part protruding downward from the front of the key pushes down the front end of the hammer when the key is pressed, causing the hammer to rotate.

The keyboard chassis of the keyboard device has a nearly horizontal flat plate between the key and the hammer, and a key guide is erected on this flat plate to guide the rotating black key vertically and prevent lateral vibration. A support shaft is provided below the front end of the flat plate to support the hammer so that it can rotate freely. Therefore, when assembling the keyboard device, the hammer is attached to the keyboard chassis by inserting it into the keyboard chassis from the front opening of the flat plate and engaging it with the support shaft.

In recent years, keyboard devices have been developed that, in addition to the hammer, are equipped with an arm that connects the key and hammer and is supported rotatably on the keyboard chassis. In such keyboard devices, the key is supported from below by a key support mechanism that has the hammer and arm (hereinafter referred to as the "first arm" and "second arm" respectively), and when a key is pressed, it rotates around a virtual fulcrum that is located behind the rear end of the key.

JP 2012-189872 A

However, when assembling the key support mechanism having the first and second arms to the keyboard chassis described above, the assembly process can be complicated. Specifically, for example, when the second arm is rotatably attached to the keyboard chassis and then the first arm is connected to the second arm, the connecting portion of both arms is located below the flat plate portion of the keyboard chassis, making it difficult to see the connecting portion of both arms from the outside. Moreover, due to the presence of the flat plate portion of the keyboard chassis, the movable range of the first arm is limited when connecting both arms, and connecting it to the second arm can be time-consuming.

The present invention has been made to solve the above problems, and aims to provide a keyboard device for a keyboard instrument that allows the key support mechanism having a first arm and a second arm to be easily attached to the keyboard chassis during assembly, making assembly efficient.

In order to achieve the above object, the invention according to claim 1 comprises a keyboard chassis having a first support shaft extending in the left-right direction, a second support shaft arranged at a predetermined distance rearward and above the first support shaft and extending in the left-right direction, and a flat plate portion arranged to extend in the left-right direction between the first support shaft and the second support shaft, a key extending a predetermined length in the front-rear direction and arranged at the top of the keyboard chassis, and a key support mechanism arranged to engage with the keyboard chassis and support the key from below, the key support mechanism being configured to extend a predetermined length in the front-rear direction, and including a first arm that rotatably and detachably engages with the first support shaft and has a front end rotatably connected to a front part of the key, and a key extending a predetermined length in the front-rear direction. The keyboard chassis is configured so that the second arm is rotatably and detachably engaged with the second support shaft, and the rear end is rotatably connected to the rear of the key, and the second arm front connecting portion forward of the second support shaft is rotatably and detachably connected to the first arm rear connecting portion rear of the first support shaft of the first arm. The flat plate portion of the keyboard chassis has a clearance portion to avoid interference with the first arm when the first arm rear connecting portion of the first arm is connected to the second arm front connecting portion of the second arm held below the front end of the flat plate portion while the second arm is engaged with the second support shaft when the first arm and the second arm are attached to the keyboard chassis during assembly.

According to this configuration, the first arm and the second arm of the key support mechanism are rotatably supported on the first and second support shafts of the keyboard chassis, respectively, and the key extending in the front-rear direction is supported from below by both arms. In addition, the keyboard chassis is provided with a flat plate portion extending in the left-right direction between the first and second support shafts.

When assembling the keyboard device, the first arm and the second arm are attached to the keyboard chassis by first attaching the second arm to the second support shaft, and while maintaining this position, rotating the second arm so that the front connecting part of the second arm is positioned below the front end of the flat plate portion. Then, while inserting the first arm between the first support shaft and the flat plate portion, connecting the rear connecting part of the first arm to the front connecting part of the second arm. In this case, since the flat plate portion is provided with a clearance part to avoid interference with the first arm, the first arm can be moved relatively widely, and the clearance part can be used as a guide to connect the first arm to the second arm. This allows the key support mechanism having the first arm and the second arm to be easily attached to the keyboard chassis, and allows efficient assembly.

The invention according to claim 2 is characterized in that in the keyboard device of the keyboard instrument described in claim 1, the escape portion is penetrated in the vertical direction, opens forward, and has a U-shaped planar shape.

With this configuration, when assembling the key support mechanism corresponding to the key to the keyboard chassis, the escape portion is U-shaped in plan view, so that when assembling the keyboard device, the first arm can be easily connected to the second arm while avoiding interference between the first arm and the flat plate portion.

The invention according to claim 3 is characterized in that in the keyboard device of the keyboard instrument described in claim 1, a key guide for guiding the key is erected on the flat plate portion, and the escape portion is provided below the key guide and is formed in a groove shape that is open from the front to the bottom.

According to this configuration, the key guide is erected on the flat plate portion, and when the key support mechanism corresponding to the key is assembled to the keyboard chassis, a groove-shaped escape portion that is open from the front to the rear is provided on the underside of the key guide, so that when assembling the keyboard device, the first arm can be easily connected to the second arm while avoiding interference between the first arm and the flat plate portion.

1A and 1B are perspective views showing a portion (for one octave) of a keyboard device of an electronic piano to which the present invention is applied, in which (a) shows the external appearance of the keyboard device and (b) shows a state in which keys other than the white and black keys on the left end are omitted. 2 is a perspective view showing the keyboard device shown in FIG. 1B in a state where the white keys and the black keys, together with their respective key support mechanisms, have been removed from the keyboard chassis; FIG. 1A is a plan view of the keyboard device with all keys omitted except for the leftmost white key and black key, and FIG. 1B is a cross-sectional view taken along line AA. 1A and 1B are perspective views showing a white key and a key support mechanism, in which FIG. 1A shows the white key and the key support mechanism connected together, and FIG. 1B shows the white key and the key support mechanism disassembled. 1A and 1B are perspective views showing a black key and a key support mechanism, in which FIG. 1A shows the black key and the key support mechanism connected together, and FIG. 1B shows the black key and the key support mechanism disassembled. 5A and 5B are diagrams for explaining the operation of a white key in a keyboard device, in which FIG. 5A shows a released state and FIG. 5B shows a pressed state. 5A and 5B are diagrams for explaining the operation of a black key in a keyboard device, in which FIG. 5A shows a key-released state and FIG. 5B shows a key-depressed state. 1A and 1B are diagrams showing a keyboard chassis, in which FIG. 1A is an external perspective view, and FIG. 10A to 10C are explanatory diagrams for sequentially explaining attachment of a first arm and a second arm to a keyboard chassis during assembly of the keyboard device. FIG. 10 is an explanatory diagram following FIG.

A preferred embodiment of the present invention will now be described in detail with reference to the drawings. FIG. 1(a) shows only one octave of the keyboard device 1 of an electronic piano to which the present invention is applied. In the following explanation, the basic structure and operation of the keyboard device 1 will first be explained, and then the main parts of the present invention will be explained.

Figure 1(b) shows the keyboard device 1 of Figure 1(a) with all keys 2 omitted except for the white key 2a and black key 2b on the left end, and Figure 2 shows the white key 2a and black key 2b removed from the keyboard chassis 4 together with the key support mechanism 6.

This keyboard device 1 is equipped with a keyboard chassis 4, a number of keys 2 consisting of white keys 2a and black keys 2b arranged in a row 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, and a key switch 3 for detecting key press information for each key 2.

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

The chassis front 11 is mainly for guiding the white key 2a when the key is pressed, and for regulating the upper and lower limit positions of the front end of the white key 2a. A plurality of white key guides 11a are arranged in a left-right direction and are inserted from below into the chassis front 11 for each white key 2a to prevent the white key 2a from swaying sideways. The chassis front 11 also has engagement holes 11b, 11b that penetrate in the vertical direction on both the left and right sides of each white key guide 11a, and the two upper limit position regulating parts 21, 21 of the white key 2a, which will be described later, engage with the engagement holes 11b, 11b, respectively. Furthermore, the chassis front 11 has a stopper attachment part 11c at its front end that protrudes forward and extends in the left-right direction over the entire chassis body 4a, and a key upper limit stopper 16a and a key lower limit stopper 16b for the white key are attached to the lower and upper surfaces of the stopper attachment part 11c, respectively, so as to extend in the left-right direction. In addition, a black key stopper attachment section 11d is provided on the chassis front section 11 at a specified position behind the white key guide 11a, and extends left and right across the entire chassis body 4a. An upper key limit stopper 17 for the black keys is attached to this stopper attachment section 11d so as to extend left and right.

The chassis intermediate section 12 mainly guides the black key 2b when the key is pressed, and also supports the first arm 31 and the second arm 32 of the key support mechanism 6a, 6b for the white and black keys so that they can swing freely. The chassis intermediate section 12 has a flat plate-like flat section 12a extending in the left-right direction, and a plurality of black key guides 12b standing on the flat section 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 the black key 2b from swinging sideways. In addition, a first arm support section 18 that supports the first arm 31 of the key support mechanism 6 is provided at the front of the chassis intermediate section 12. The first arm support section 18 has a plurality of first support shafts 18a that are provided between adjacent ribs 14, 14 so as to extend in the left-right direction, and the first arm 31 is supported by these first support shafts 18a so that it can swing freely. Furthermore, a second arm support 19 is provided at the rear of the chassis intermediate section 12 to support the second arm 32 of the key support mechanism 6. The second arm support 19 has a plurality of second support shafts 19a provided between adjacent ribs 14, 14 to extend in the left-right direction. The second support shafts 19a are arranged on the same axis extending in the left-right direction at a position rearward and higher than the first support shaft 18a, and the second arm 32 is supported by these second support shafts 19a so as to be able to swing freely. In addition, a first arm lower limit stopper 10b extending in the left-right direction over the entire chassis main body 4a is provided at a predetermined position of the middle rail 8 (described later) provided on the lower side of the chassis intermediate section 12.

The key switch 3 is attached to the bottom of the keyboard chassis 4, between the chassis front part 11 and the chassis middle part 12. The key switch 3 is composed of a horizontally elongated printed circuit board 3a extending in the left-right direction, and multiple switch bodies 3b made of rubber switches attached to the printed circuit board 3a for each key 2 and pressed by the first arm 31 when the key is pressed.

The chassis rear part 13 mainly guides the key 2 in the vertical direction while preventing lateral vibration at its rear end, and regulates the upper limit position of the rear end of the first arm 31. As shown in Figures 2 and 3(a), the chassis rear part 13 has a plurality of partition walls 13a spaced apart from each other at a predetermined interval in the left-right direction to separate adjacent keys 2, 2. Also, as shown in Figure 3(b), a first arm upper limit stopper 10a extending in the left-right direction over the entire chassis main body 4a is provided at a predetermined position on the upper part of the chassis rear part 13. This first arm upper limit stopper 10a and the first arm lower limit stopper 10b provided on the chassis intermediate part 12 are intended to regulate the upper limit position of the first arm 31, which functions as a hammer for applying touch weight to the key 2, when the first arm 31 rotates upward and the lower limit position when the first arm 31 rotates downward. In addition, a metal cover plate 15 is attached to the top of the rear part 13 of the chassis, extending left and right across the entire chassis body 4a and positioned to cover the rear end of the key 2.

As shown in Figs. 2 and 3(a), the chassis body 4a of the keyboard chassis 4 configured as described above has a plurality of first openings 5a that open upward and forward, and a plurality of second openings 5b that open upward. Through each of the first openings 5a, the first arm 31 of the key support mechanism 6 engages with the first support shaft 18a from the outside, and through each of the second openings 5b, the second arm 32 engages with the second support shaft 19a from the outside.

In addition, in the keyboard chassis 4, multiple chassis bodies 4a are connected to each other in a line in the left-right direction, and are screwed in a state in which they are placed on metal front rails 7, middle rails 8, and rear rails 9 that all extend in the left-right direction and are arranged at a predetermined distance from each other in the front-to-rear direction. The keyboard chassis 4 is then fixed to a shelf board (not shown) of the electronic piano via the front rails 7 and rear rails 9.

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 them exploded. As shown in the figure, the white key 2a is formed by injection molding a specific resin material (e.g., AS resin) to extend a specific length in the front-rear direction and to be hollow and open downward. The front end of the white key 2a is provided with a pair of left and right upper limit position restricting parts 21, 21 that extend downward from the left and right side walls and are formed so that their lower ends are bent forward. As described above, these upper limit position restricting parts 21, 21 engage with the left and right engagement holes 11b, 11b of the chassis front part 11 while penetrating them, respectively.

The front of the white key 2a is provided with a key front side connecting part 22, which is connected to the first arm 31 of the key support mechanism 6a, at a predetermined position behind the upper limit position restricting part 21. The key front side connecting part 22 has a connecting recess 22a formed in a U-shape with an elongated hole-like side and an open front. The connecting recess 22a is provided with a buffer member 20 that covers the entire inner circumferential surface and suppresses noise generation when the connecting shaft 35b of the first arm 31 described later slides within the connecting recess 22a. The front of the white key 2a is provided with a keyboard weight 30 (see FIG. 3) between the upper limit position restricting part 21 and the key front side connecting part 22 to provide a desired touch weight when the key is pressed.

Furthermore, the rear of the white key 2a is provided with a key rear connecting part 23 that is connected to the second arm 32 of the key support mechanism 6a. This key rear connecting part 23 has a plate-shaped connecting body part 23a that hangs down from the center 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 engagement protrusions 23b, 23b that protrude coaxially from the left and right side surfaces of the connecting body part 23a. In addition, a tool insertion hole 24 is formed in the rear of the white key 2a, which penetrates in the up-down direction and is used to insert a specific tool from above when releasing 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, etc.

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

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

The arm body 33 also has a U-shaped bearing 36 with a downwardly open side at a predetermined position immediately behind the first arm front connecting portion 35, and this bearing 36 rotatably engages with the first support shaft 18a of the keyboard chassis 4. Furthermore, the arm body 33 has a first arm rear connecting portion 37 that connects to the second arm 32 at a predetermined position behind the bearing 36. Specifically, the first arm rear connecting portion 37 has a connecting shaft 37a that extends in the left-right direction and has both ends that protrude outward from the left and right sides of the arm body 33. Both ends of this connecting shaft 37a engage with connecting recesses 45b, 45b of the second arm front connecting portion 45 of the second arm 32, which will be described later.

Two elongated plate-like weights 34, 34 are attached to the weight attachment section 38 at the rear of the arm body 33, sandwiching the weight attachment section 38 from both sides. Each weight 34 is made of a material (e.g., a metal such as iron) with a higher specific gravity than the arm body 33, and is formed into a predetermined shape by pressing a metal plate, etc.

The second arm 32 is made of a resin molded product of a predetermined shape by injection molding the same resin material as 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-to-rear direction. In addition, the second arm 32 has a C-shaped bearing portion 41 near the center in the longitudinal direction, with the side shape opening forward, and this bearing portion 41 rotatably engages with the second support shaft 19a in the keyboard chassis 4.

The rear of the second arm 32 is provided with a second arm rear connecting part 42 that is connected to the key rear connecting part 23 of the white key 2a. This second arm rear connecting part 42 is bifurcated and has two connecting arms 43, 43 that extend parallel to each other for a predetermined length along the length of the second arm 32. A connecting hole 43a that penetrates in the left-right direction is formed at the rear end of each connecting arm 43. Between their rear ends, the connecting arms 43, 43 hold the connecting body part 23a of the key rear connecting part 23 of the white key 2a from both the left and right sides, and each connecting hole 43a fits rotatably into the corresponding engaging protrusion 23b of the key rear connecting part 23.

Furthermore, a second arm front connecting part 45 is provided at the front of the second arm 32, which is connected to the first arm rear connecting part 37 of the first arm 31. This second arm front connecting part 45 has a pair of left and right connecting pieces 45a, 45a spaced a predetermined distance from each other in the left-right direction, and each connecting piece 45a has a U-shaped connecting recess 45b whose side shape is an elongated hole and opens forward. The left and right connecting pieces 45a, 45a of the second arm front connecting part 45 are rotatably and slidably engaged with both ends of the connecting shaft 37a of the first arm 31 via the connecting recesses 45b, 45b.

5(a) shows the black key 2b and its key support mechanism 6b in an enlarged view, and FIG. 5(b) shows them in an exploded view. The black key 2b is formed by injection molding the same resin material as the white key 2a, and is shorter than the white key 2a, extends a predetermined length in the front-rear direction, and is hollow and open downward. The front lower end of the black key 2b is provided with a front-side connecting part 26 formed in a manner similar to the front-side connecting part 22 of the white key 2a. This front-side connecting part 26 has a connecting recess 26a whose side shape is an elongated hole and is formed in a U-shape that opens forward. In addition, the front-side connecting part 26 has an extension part 26b at the lower front end of the connecting recess 26a, which extends a predetermined length forward from the front surface of the main body of the black key 2b, and this extension part 26b functions as an upper limit position regulating part for the black key 2b. In the following explanation, the same components of the black key 2b and key support mechanism 6b as those of the white key 2a and key support mechanism 6a described above will be given the same reference numerals, and detailed explanations will be omitted.

The key support mechanism 6b that supports the black key 2b is constructed in a manner similar to the key support mechanism 6a for white keys described above. Specifically, the arm body 33 of the first arm 31 and the second arm 32 of the key support mechanism 6b are constructed to be exactly the same shape and size as the arm body 33 and the second arm 32 of the key support mechanism 6a for white keys. Note that the two weights 34, 34 on the left and right of the key support mechanism 6b for black keys are illustrated as being the same as the weights 34, 34 of the key support mechanism 6b for white keys, but the shape and length are appropriately changed depending on the touch weight required for the key 2, etc.

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. Figure 6 shows the operation of the white key 2a and its key support mechanism 6a, and Figure 7 shows the operation of the black key 2b and its key support mechanism 6b.

When the front end of the white key 2a is pressed down by the player's finger in the released key state shown in FIG. 6(a), the front key connection part 22 of the white key 2a moves downward, causing the first arm 31 to rotate counterclockwise around the first support shaft 18a. In addition, with the rotation of the first arm 31, the front second arm connection part 45, which engages with the connection shaft 37a of the first arm 31 via the connection recess 45b, moves upward. As a result, the second arm 32 rotates clockwise around the second support shaft 19a. With the rotation of the second arm 32, the rear key connection part 23 connected via the rear second arm connection part 42 at the rear end is pulled down, and the rear end of the white key 2a moves downward.

When the first arm 31 rotates as described above, the box portion 35a of the first arm front connecting portion 35 moves downward, and the bottom wall of the box portion 35a presses the switch body 3b of the key switch 3 corresponding to the pressed key 2 from above. As a result, the electronic piano detects the key press information of the pressed key 2, and a sound is generated from a speaker (not shown) based on the detected key press information.

When the white key 2a is pressed down as described above, as the first arm 31 rotates counterclockwise, the weight 34 of the first arm 31 tilts upward at the rear as shown in FIG. 6(b), and the rear end abuts against the first arm upper limit stopper 10a from below. This prevents the first arm 31 from rotating any further. 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, preventing the white key 2a from being pressed down any further.

When the white key 2a is pressed as described above, it rotates around the virtual fulcrum P, which is located behind its rear end. The position of this virtual fulcrum P is set, for example, so that 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 of the white key 2a is pressed down to the lowest position, the front end of the white key 2a is located a predetermined key stroke (e.g., 10 mm) lower, and the rear end is located approximately half the distance of the key stroke (e.g., 5 mm) lower, compared to when the key is released as shown in FIG. 6(a).

On the other hand, when the pressed white key 2a is released, the weight of the weight 34 causes the first arm 31 of the key support mechanism 6a to rotate in the opposite direction to the above, and the second arm 32 also rotates in the opposite direction to the above. As a result, the white key 2a rotates upward around the virtual fulcrum P. Then, a specific portion of the first arm 31 behind the first support shaft 18a abuts against the first arm lower limit stopper 10b from above, and both upper limit position regulating parts 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 its original released state.

The operation of the black key 2b when it is pressed is the same as that of the white key 2a and the key support mechanism 6a described above. That is, when the front end of the black key 2b is pressed down in the key-released state shown in FIG. 7(a), the first arm 31 rotates counterclockwise around the first support shaft 18a, and the second arm 32 rotates clockwise around the second support shaft 19a, so that the black key 2b rotates around the virtual fulcrum Q at the rear. The position of this virtual fulcrum Q is set so that the distance from the front end of the black key 2b is about twice the length of the black key 2 itself, for example, like the virtual fulcrum P of the white key 2a described above. Therefore, when the front end of the black key 2b is pressed down to the lowest position, the front end of the black key 2b is located lower by a predetermined key stroke, and the rear end is located lower by about 1/2 the distance of the key stroke, compared to when the key is released as shown in FIG. 7(a).

On the other hand, when the pressed black key 2b is released, the first arm 31 and the second arm 32 of the key support mechanism 6b rotate in the opposite direction, causing the black key 2b to rotate upward around the virtual fulcrum Q. Then, the extension 26b of the front-key connecting part 26 of the black key 2b abuts against the upper key stopper 17 from below, preventing further rotation of the black key 2b and returning it to its original released state.

Next, the main part of the present invention will be described with reference to Figures 8 to 10. The main part of the present invention is to configure the keyboard chassis 4 so that the key support mechanism 6 having the first arm 31 and the second arm 32 can be easily attached when assembling the keyboard device 1.

Figure 8 shows the keyboard chassis 4, where (a) is an external perspective view and (b) is a plan view. As shown in this figure and the above-mentioned Figure 3(b), in the keyboard chassis 4, a flat portion 12a (flat plate portion) on which multiple (five in Figure 8) black key guides 12b are erected is provided to extend in the left-right direction between a first support shaft 18a on which a first arm 31 is rotatably supported and a second support shaft 19a on which a second arm 32 is rotatably supported.

The flat portion 12a has a number of clearances 12c, 12d formed in correspondence with each key support mechanism 6 to prevent interference between the first arm 31 and the flat portion 12a when attaching the key support mechanism 6 to the keyboard chassis 4 during assembly of the keyboard device 1.

Specifically, the recesses corresponding to the key support mechanism 6a for the white keys (hereinafter referred to as "white key recesses 12c") penetrate vertically and open forward, and have a U-shaped planar shape. As shown in Figure 8, in this keyboard chassis 4, seven white key recesses 12c are formed in the flat portion 12a along the left-right direction.

On the other hand, the recesses corresponding to the key support mechanism 6b for the black keys (hereinafter referred to as "black key recesses 12d") are provided on the underside of the black key guide 12b and are formed as concave grooves that open from the front to the bottom. As shown in Figure 8, in this keyboard chassis 4, five black key recesses 12d are formed in the flat portion 12a along the left-right direction.

The above-mentioned white key recesses 12c and black key recesses 12d are formed when the chassis body 4a is molded.

Now, with reference to Figures 9 and 10, we will explain how to attach the first arm 31 and the second arm 32 of the key support mechanism 6a for the white keys to the keyboard chassis 4 when assembling the keyboard device 1.

As shown in FIG. 9(a), first, the second arm 32 is inserted from above into the second opening 5b of the keyboard chassis 4 with the second arm 32 tilted slightly backward from the vertical. In this case, the opening of the bearing portion 41 of the second arm 32 is aligned with the second support shaft 19a of the keyboard chassis 4, and the second support shaft 19a is inserted into the bearing portion 41. As a result, as shown in FIG. 9(b), the second arm 32 is attached to the second support shaft 19a in a freely rotatable state.

Next, as shown in FIG. 9(c), the second arm 32 is rotated clockwise around the second support shaft 19a and held in a substantially horizontal position. In this case, the connecting recess 45b of the second arm front connecting part 45 is located below the front end of the flat part 12a and faces slightly upward relative to the horizontal.

Next, as shown in FIG. 10(a), the first arm 31 is inserted from the front into the first opening 5a of the keyboard chassis 4 while being tilted slightly downward from the horizontal. Then, while pushing the first arm 31 backward, the connecting shaft 37a of the first arm 31 is inserted from the front into the connecting recess 45b of the second arm 32 as shown in FIG. 10(b). In this case, as shown in FIG. 10(b), the diagonally upper part of the connecting shaft 37a of the first arm 31 is inserted into the white key escape 12c. This prevents the first arm 31 from interfering with the front end of the flat portion 12a, and allows the connecting portion 37a of the first arm 31 to be easily inserted into the connecting recess 45b of the second arm 32 while the white key escape 12c functions as a guide. In this way, the first arm 31 is connected to the second arm 32 via the connecting shaft 37a in a rotatable and slidable manner.

Then, while maintaining the connection between the first arm 31 and the second arm 32, the front part of the first arm 31 is moved downward as shown in FIG. 10(c) and the first support shaft 18a of the keyboard chassis 4 is inserted into the bearing part 36 of the first arm 31. This allows the first arm 31 to be attached to the first support shaft 18a in a freely rotatable state. This completes the attachment of the first arm 31 and the second arm 32 to the keyboard chassis 4.

The method of attaching the first arm 31 and the second arm 32 of the black key support mechanism 6b to the keyboard chassis 4 is almost the same as that of the white key support mechanism 6a described above, so a description thereof will be omitted. The only difference between the method of attaching the first arm 31 and the second arm 32 of the black key support mechanism 6b to the keyboard chassis 4 is that, in FIG. 10(b) above, when the connecting shaft 37a of the first arm 31 is connected to the connecting recess 45b of the second arm 32, the diagonally upper portion of the connecting shaft 37a of the first arm 31 enters the black key recess 12d.

As described above in detail, in this embodiment, the flat portion 12a of the keyboard chassis 4 is provided with the white key recess 12c and the black key recess 12d in accordance with the key support mechanisms 6a and 6b for the white and black keys, so that the first arm 31 can be moved relatively widely, and the first arm 31 can be connected to the second arm 32 while the recesses 12c and 12d function as guides. This allows the key support mechanism 6 having the first arm 31 and the second arm 32 to be easily attached to the keyboard chassis 4, allowing efficient assembly.

The present invention is not limited to the above-described embodiment, but can be implemented in various forms. The detailed configurations of the white key recess 12c and black key recess 12d shown in the embodiment are merely examples, and can be modified as appropriate within the scope of the present invention.

REFERENCE SIGNS LIST 1 Keyboard device 2 Key 2a White key 2b Black key 4 Keyboard chassis 5a First opening 5b Second opening 6 Key support mechanism 6a Key support mechanism for white keys 6b Key support mechanism for black keys 12a Flat portion 12b Black key guide (key guide)
12c Recess for white keys (recess)
12d Recess for black keys (recess)
18 First arm support portion 18a First support shaft 19 Second arm support portion 19a Second support shaft 31 First arm 32 Second arm 36 Bearing portion 37 First arm rear connecting portion 37a Connecting shaft 45 Second arm front connecting portion 45b Connecting recess P Virtual fulcrum of white key Q Virtual fulcrum of black key

Claims (3)

a keyboard chassis having a first support shaft extending in the left-right direction, a second support shaft disposed a predetermined distance rearward and above the first support shaft and extending in the left-right direction, and a flat plate portion provided between the first support shaft and the second support shaft and extending in the left-right direction;
A key extending a predetermined length in the front-rear direction and disposed on the upper part of the keyboard chassis;
a key support mechanism that is engaged with the keyboard chassis and supports the key from below;
Equipped with
The key support mechanism includes:
a first arm configured to extend a predetermined length in the front-rear direction, rotatably and detachably engaged with the first support shaft, and a front end portion of the first arm rotatably connected to a front portion of the key;
a second arm configured to extend a predetermined length in the front-rear direction, rotatably and detachably engaged with the second support shaft, with a rear end rotatably connected to a rear part of the key, and a second arm front connecting part forward of the second support shaft rotatably and detachably connected to a first arm rear connecting part rearward of the first support shaft of the first arm;
It has
A keyboard device for a keyboard instrument, characterized in that when the first arm and the second arm are attached to the keyboard chassis during assembly, the flat portion of the keyboard chassis has a recess to avoid interference with the first arm when the first arm rear connecting portion of the first arm is connected to the second arm front connecting portion of the second arm held below the front end of the flat portion while the second arm remains engaged with the second support shaft. The keyboard device of a keyboard instrument according to claim 1, characterized in that the recess is formed in a U-shape in plan view, with a vertical penetration and an open front. A key guide for guiding the key is provided on the flat plate portion,
2. The keyboard device for a keyboard instrument according to claim 1, wherein the recess is provided below the key guide and is formed in a groove shape that is open from the front to the bottom.

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