Keyboard device of keyboard instrument

Abstract

To provide a keyboard device of a keyboard instrument, which can obtain excellent touch feeling at the press of a key and which can enhance responsiveness when the pressed key rotationally returns to its original position so as to be able to obtain appropriate repeated press performance.SOLUTION: A keyboard device of a keyboard instrument includes: a keyboard chassis 4; a key 2 provided at an upper part of the keyboard chassis 4; and a key support mechanism 6 for moving the pressed key 2 rotationally around a virtual supporting point positioned behind a back end of the key 2 as the center at the press of the key 2. The key support mechanism 6 includes: a first arm swingably engaging with a first support shaft 18a; and a second arm 32 swingably engaging with a second support shaft 19a. The second arm 32 has a second arm weight 52 which is made of a material with specific gravity larger than that of the second arm 32.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a keyboard device for a keyboard instrument such as an electronic piano, in which a depressed key rotates around a virtual fulcrum located behind its rear end. [Background technology]

[0002] Conventionally, a keyboard device of this type is known, for example, as described in Patent Document 1, which has already been filed by the applicant. This keyboard device includes a keyboard chassis, a key arranged on the upper part of the keyboard chassis, and a key support mechanism that engages with the keyboard chassis and supports the key from below. The key support mechanism has a first arm and a second arm extending in the front-rear direction, which are rotatably supported by a first support shaft and a second support shaft of the keyboard chassis, respectively. The front end of the first arm is rotatably and slidably connected to the front part of the key, while the front end of the second arm is rotatably and slidably connected to a predetermined part of the first arm and has a rear end rotatably connected to the rear end of the key.

[0003] In a keyboard device configured in this way, when the front end of a key is pressed down, the first arm rotates around the first pivot so that its front end lowers and its rear end weight rises, and the second arm rotates around the second pivot so that its front end rises and its rear end lowers. As a result, the key rotates around a virtual fulcrum located behind its rear end so that its front end lowers.

[0004] When the finger is released from the depressed key, the first arm and the second arm rotate in the opposite direction to the above, rotating the key back to its original position. Specifically, the first arm pushes up the front end of the key while rotating so that the weight at the raised rear end lowers and the front end rises. The front end of the second arm lowers to promote the rotation of the first arm, and the rear end rises to push up the rear of the key. As a result, the front end of the key rises and rotates back to its original position around the virtual fulcrum. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-50758 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the above keyboard device, the weight of the first arm is increased by providing a weight to the first arm, so that a touch feeling with sufficient response (playing response) can be obtained when a key is pressed, and the first arm rotates when the key is released, pushing up the key and rotating it back to its original position. Also, by gradually increasing the weight of the first arm, the response when the key is pressed increases, and it is possible to further improve the touch feeling. However, if the weight of the first arm is increased, the first arm becomes difficult to rotate, and as a result, the responsiveness when the pressed key rotates back to its original position decreases, and appropriate repeated keystrokes may not be obtained. Therefore, there is room for improvement in the above keyboard device.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a keyboard device for a keyboard instrument which can provide a good touch when a key is pressed, can improve responsiveness when a pressed key rotates back to its original position, and can provide appropriate repeated keystrokes. [Means for solving the problem]

[0008] In order to achieve the above object, the invention according to claim 1 comprises a keyboard chassis, a key extending a predetermined length in the front-rear direction and arranged on the upper part of the keyboard chassis, and a key support mechanism that engages with the keyboard chassis and supports the key from below, and that, when a key is pressed, causes the pressed key to rotate about an imaginary fulcrum located behind the rear end of the key, the key support mechanism being configured to extend a predetermined length in the front-rear direction, engaging with a first spindle arranged on the keyboard chassis so as to be able to swing, and having a front end that is able to rotate around a front part of the key. the first arm is slidably connected to the first support shaft and configured to extend a predetermined length in the front-to-rear direction, engages with a second support shaft provided on the keyboard chassis rearward of the first support shaft, and has a rear end rotatably connected to the rear of the key, and a front connecting portion of the second arm forward of the second support shaft is rotatably and slidably connected to a rear connecting portion of the first arm rearward of the first support shaft of the first arm, and the second arm is provided with a second arm weight made of a material having a greater specific gravity than the second arm.

[0009] According to this configuration, the key extending a predetermined length in the front-rear direction and arranged on the upper part of the keyboard chassis is supported from below by the key support mechanism having the first arm and the second arm, and when the key is pressed, it rotates around a virtual fulcrum located behind the rear end of the key. The second arm is provided with a second arm weight made of a material with a higher specific gravity than the second arm, so that by increasing the weight of the second arm, the moment of inertia of the second arm is increased. As a result, it is possible to provide a sufficient response when the key is pressed, and a good touch feeling can be obtained when the key is pressed. In addition, by increasing the weight of the second arm, a good touch feeling can be obtained, and an increase in the weight of the first arm can be suppressed. As a result, the responsiveness when the pressed key rotates back to its original position can be improved compared to when only the weight of the first arm is increased, and appropriate repeated keystrokes can be obtained.

[0010] The invention according to claim 2 is the keyboard device for a keyboard instrument according to claim 1, characterized in that the second arm weight is provided in front of the second support shaft and / or around the second support shaft.

[0011] According to this configuration, the weight of the second arm can be increased relatively easily because the second arm weight is provided in front of or around the second support shaft of the second arm. In particular, when the second arm weight is provided in front of the second support shaft, the front end of the second arm, which rises when the key is pressed, is more likely to rotate in a downward direction when the key is released, which further promotes the first arm, the front end of which is pressed down when the key is pressed, to rotate back to its original position. As a result, the touch feeling and key responsiveness when the key is pressed can be further improved.

[0012] The invention according to claim 3 is the keyboard device for a keyboard instrument according to claim 1, characterized in that the second arm weight is attached to at least one of the left and right side surfaces of the second arm.

[0013] With this configuration, the second arm weight is attached to at least one of the left and right side sides of the second arm, so that the operation of the second arm is not impeded when a key is pressed, and by attaching the second arm weight to the second arm, the weight of the second arm can be adjusted to the desired weight.

[0014] The invention of claim 4 is characterized in that, in the keyboard device of the keyboard instrument described in claim 1, the second arm has a weight housing portion that penetrates in the left-right direction, and the weight for the second arm is attached to the second arm while being housed in the weight housing portion by being inserted into the weight housing portion from the outside.

[0015] According to this configuration, when attaching the second arm weight to the second arm, the second arm weight can be easily attached to the second arm while being accommodated in the weight housing portion by simply inserting the second arm weight into the weight housing portion of the second arm from the outside.

[0016] The invention according to claim 5 is characterized in that, in the keyboard device of the keyboard instrument described in claim 4, the second arm weight is accommodated in the weight accommodating section with its periphery covered with a predetermined synthetic resin.

[0017] According to this configuration, the second arm weight is accommodated in the weight accommodating section of the second arm with the periphery of the second arm weight covered with synthetic resin, so that the second arm weight does not rattle or vibrate in the weight accommodating section when the second arm moves with a key being pressed, thereby preventing noise from being generated by the second arm weight when the second arm moves.

[0018] The invention of claim 6 is characterized in that, in the keyboard device of the keyboard instrument described in claim 1, the second arm is manufactured by molding synthetic resin, and is molded integrally with the second arm weight when the second arm is molded.

[0019] According to this configuration, the second arm, which is manufactured by molding synthetic resin, is molded integrally with the second arm weight during molding, so there is no need to retrofit the second arm weight to the second arm. This means that the attachment process for the second arm weight can be omitted during manufacturing, and the second arm provided with the second arm weight can be manufactured relatively easily. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a perspective view showing a portion (for one octave) of a keyboard device of an electronic piano to which the present invention is applied, where (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. [Diagram 2] 1(b) is a perspective view showing a state in which the white keys and the black keys, together with their respective key support mechanisms, have been removed from the keyboard chassis in the keyboard device shown in FIG. [Diagram 3] FIG. 2A is a plan view of the keyboard device with all keys omitted except for the white and black keys on the left end, and FIG. 2B is a cross-sectional view taken along line AA. [Figure 4]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. [Diagram 5] 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. [Figure 6] 5A and 5B are diagrams for explaining the operation of a white key in a keyboard device, where FIG. 5A shows a key-released state and FIG. 5B shows a key-depressed state. [Figure 7] 1A and 1B are diagrams for explaining the operation of a black key in a keyboard device, where FIG. 1A shows a key-released state and FIG. [Figure 8] 1A is a perspective view showing a second arm of a first embodiment of the present invention, FIG. 1B is a side view, and FIG. 1C is an exploded perspective view showing a state in which a second-arm weight has been removed from the second arm. [Figure 9] 10A is a perspective view showing a second arm of a second embodiment of the present invention, FIG. 10B is a side view, and FIG. 10C is an exploded perspective view showing a state in which a second-arm weight has been removed from the second arm. [Figure 10] 13A to 13C are diagrams showing a second arm of a third embodiment of the present invention, in which (a) is a perspective view, (b) is a side view, and (c) is an exploded perspective view showing a state in which a second-arm weight has been removed from the second arm. [Figure 11] 11A is a perspective view showing the second arm of the fourth embodiment of the present invention, (a) is a perspective view, (b) is an exploded perspective view showing the second arm weight removed from the second arm, and (c) is a perspective view showing the second arm weight separated into a weight body and a weight cover. [Figure 12] 13A and 13B are views showing a second arm of a fifth embodiment of the present invention, in which (a) is a perspective view and (b) is a side view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] A preferred embodiment of the present invention will be described in detail below 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 be explained first, and then the main parts of the present invention will be explained.

[0022] FIG. 1(b) shows the keyboard device 1 of FIG. 1(a) with all keys 2 omitted except for the white key 2a and black key 2b on the left end, and FIG. 2 shows the white key 2a and black key 2b removed from the keyboard chassis 4 together with the key support mechanism 6.

[0023] 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 which 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 depression information of each key 2.

[0024] The keyboard chassis 4 has a chassis main 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 this chassis main body 4a are all formed to extend in the left-right direction (left-right direction in Fig. 3(a)) as a whole, 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 main 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.

[0025] The chassis front part 11 mainly guides the white key 2a when the key is pressed and regulates 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 stand on the chassis front part 11. Each white key 2a is inserted from below to prevent the white key 2a from swaying sideways. The chassis front part 11 also has engagement holes 11b, 11b that penetrate the white key guide 11a in the vertical direction on both the left and right sides, and two upper limit position regulation parts 21, 21 of the white key 2a, which will be described later, penetrate and engage with the engagement holes 11b, 11b, respectively. Furthermore, the chassis front part 11 has a stopper attachment part 11c at its front end, which protrudes forward and extends left-right over the entire chassis body 4a. 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 left-right. In addition, a stopper mounting portion 11d for the black keys is provided at a specified position behind the white key guide 11a on the front part 11 of the chassis. The stopper mounting portion 11d extends in the left-right direction across the entire chassis body 4a, and an upper key stopper 17 for the black keys is attached to the stopper mounting portion 11d so as to extend in the left-right direction.

[0026] The chassis intermediate section 12 mainly guides the black key 2b when the key is pressed, and also supports a first arm 31 and a second arm 32 of the key support mechanism 6a, 6b for the white and black keys so that they can swing. The chassis intermediate section 12 has a flat section 12a extending in the left-right direction and a plurality of black key guides 12b standing on the flat section 12a and spaced apart appropriately in the left-right direction. Each black key guide 12b is inserted from below for each black key 2b, preventing the black key 2b from swinging sideways. A first arm support section 18 is provided at the front of the chassis intermediate section 12 to support the first arm 31 of the key support mechanism 6. The first arm support section 18 has a plurality of first support shafts 18a extending in the left-right direction between adjacent ribs 14, and the first arm 31 is supported by the first support shafts 18a so that it can swing. Furthermore, a second arm support section 19 that supports a second arm 32 of the key support mechanism 6 is provided at the rear of the chassis intermediate section 12. The second arm support section 19 has a plurality of second support shafts 19a that are provided between adjacent ribs 14, 14 so as to extend in the left-right direction. The plurality of 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. A first arm lower limit stopper 10b that extends in the left-right direction over the entire chassis main body 4a is provided at a predetermined position of a middle rail 8 (described later) provided on the lower side of the chassis intermediate section 12.

[0027] The key switch 3 is attached to the lower part 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 long printed circuit board 3a extending in the left-right direction, and a plurality of switch bodies 3b made of rubber switches attached to the printed circuit board 3a for each key 2 and pressed by a first arm 31 when the key is pressed.

[0028] The chassis rear part 13 mainly guides the key 2 in the up-down direction while preventing lateral vibration at the rear end of the key 2, and regulates the upper limit position of the rear end of the first arm 31. As shown in Fig. 2 and Fig. 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 Fig. 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, respectively. Furthermore, a metal cover plate 15 is attached to the upper part of the chassis rear part 13 so as to extend in the left-right direction across the entire chassis body 4a and to cover the rear end of the key 2.

[0029] 2 and 3(a), the chassis body 4a of the keyboard chassis 4 configured as above is provided with a plurality of first openings 5a that open upward and forward, and a plurality of second openings 5b that open upward. The first arm 31 of the key support mechanism 6 engages with the first spindle 18a from the outside through each of the first openings 5a, and the second arm 32 engages with the second spindle 19a from the outside through each of the second openings 5b.

[0030] In the keyboard chassis 4, multiple chassis bodies 4a are connected to each other in a line up 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-rear direction. The keyboard chassis 4 is then fixed onto a shelf board (not shown) of the electronic piano via the front rails 7 and rear rails 9.

[0031] 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 are engaged with the left and right engagement holes 11b, 11b of the chassis front part 11 while penetrating therethrough.

[0032] In addition, a front-key connecting part 22 is provided at a predetermined position behind the upper limit position restricting part 21 at the front of the white key 2a, which is connected to the first arm 31 of the key support mechanism 6a. The front-key connecting part 22 has a connecting recess 22a formed in a U-shape with an elongated hole-like side and opening forward. A buffer member 20 is attached to the connecting recess 22a so as to cover the entire inner circumferential surface thereof, and serves to suppress noise generation when a connecting shaft 35b of the first arm 31, which will be described later, slides within the connecting recess 22a. A keyboard weight 30 (see FIG. 3) is attached to the front of the white key 2a between the upper limit position restricting part 21 and the front-key connecting part 22, for imparting a desired touch weight when the key is pressed.

[0033] Furthermore, a key rear connector 23 is provided at the rear of the white key 2a, which is connected to the second arm 32 of the key support mechanism 6a. The key rear connector 23 has a plate-shaped connector body 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 connector body 23a. A tool insertion hole 24 is formed at 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, for example.

[0034] On the other hand, the key support mechanism 6a includes a first arm 31 and a second arm 32 which 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.

[0035] 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 made of a resin molded product of a predetermined shape by injection molding a predetermined resin material (e.g., polyacetal). The arm body 33 extends a predetermined length in the front-rear direction, and a first arm front connector 35 is provided at its front end to connect to the front-key connector 22 of the white key 2a. The first arm front connector 35 has a box section 35a formed in a box shape that opens upward and forward, and a connector 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 section 35a. The connector shaft 35b is connected to the connector recess 22a of the front-key connector 22 of the white key 2a so as to be rotatable and slidable in the front-rear direction.

[0036] 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 side surfaces of the arm body 33. Both ends of this connecting shaft 37a engage with connecting recesses 45b, 45b of a second arm front connecting portion 45 of the second arm 32, which will be described later.

[0037] Two elongated plate-like weights 34, 34 are attached to weight attachment part 38, which is the rear part of arm body 33, sandwiching weight attachment part 38 from both sides. Each weight 34 is made of a material (e.g., a metal such as iron) having a higher specific gravity than arm body 33, and is formed into a predetermined shape by pressing a metal plate, for example.

[0038] 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. The second arm 32 is shorter than the first arm 31 and extends a predetermined length in the front-rear direction. The second arm 32 has a bearing portion 41 near the center in the longitudinal direction, the bearing portion 41 having a C-shaped side shape that opens forward, and the bearing portion 41 rotatably engages with the second support shaft 19a of the keyboard chassis 4.

[0039] A second arm rear connecting part 42 that is connected to the key rear connecting part 23 of the white key 2a is provided at the rear of the second arm 32. The second arm rear connecting part 42 is bifurcated and has two left and right 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 rotatably fits into the corresponding engaging protrusion 23b of the key rear connecting part 23.

[0040] 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 apart from each other in the left-right direction by a predetermined distance, and each connecting piece 45a has a U-shaped connecting recess 45b whose side shape is an elongated hole and which 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, respectively, via the connecting recesses 45b, 45b.

[0041] FIG. 5(a) shows the black key 2b and its key support mechanism 6b in an enlarged manner, and FIG. 5(b) shows them in an exploded manner. 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. The front-side connecting part 26 has a connecting recess 26a formed in a U-shape with a long hole-like side shape and an open frontward. 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 the extension part 26b functions as an upper limit position regulating part for the black key 2b. In the following description, the same components of the black key 2b and the key support mechanism 6b as those of the white key 2a and the key support mechanism 6a described above are designated by the same reference numerals, and detailed description thereof will be omitted.

[0042] The key support mechanism 6b supporting 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 in 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 6a for white keys, but the shape and length can be changed as appropriate depending on the touch weight required for the key 2.

[0043] Next, a description will be given of the operation of the key 2 and the key support mechanism 6 in the keyboard device 1 configured as above. 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.

[0044] In the key-released state shown in Fig. 6(a), when the player presses down the front end of the white key 2a with his / her finger, the front-key connector 22 of the white key 2a moves downward, causing the first arm 31 to rotate counterclockwise around the first support shaft 18a. As the first arm 31 rotates, the second-arm front connector 45, which engages with the connector shaft 37a of the first arm 31 via the connector recess 45b, moves upward. As a result, the second arm 32 rotates clockwise around the second support shaft 19a. As the second arm 32 rotates, the rear-key connector 23 connected via the second-arm rear connector 42 at its rear end is pulled down, causing the rear end of the white key 2a to move downward.

[0045] During the above-mentioned rotation of the first arm 31, as the box portion 35a of the first arm front connecting portion 35 moves downward, the bottom wall of the box portion 35a presses from above the switch body 3b of the key switch 3 corresponding to the pressed key 2. As a result, the electronic piano detects 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.

[0046] As described above, when the white key 2a is pressed down, the weight 34 of the first arm 31 tilts upward toward the rear as the first arm 31 rotates counterclockwise, and the rear end abuts against the first arm upper limit stopper 10a from below, as shown in Fig. 6(b). 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.

[0047] The white key 2a depressed as described above moves so as to rotate around an imaginary fulcrum P located behind its rear end. The position of this imaginary 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 depressed 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 key stroke (e.g., 5 mm) lower, compared to when the key is released as shown in Fig. 6(a).

[0048] 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 that described above, and the second arm 32 also rotates in the opposite direction to that described above. As a result, the white key 2a rotates upward around the imaginary fulcrum P. Then, a predetermined portion of the first arm 31 behind the first spindle 18a abuts against the first arm lower limit stopper 10b from above, and both upper limit position restriction 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.

[0049] The operation of the black key 2b when pressed is similar to 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 pivot 18a, and the second arm 32 rotates clockwise around the second pivot 19a, so that the black key 2b rotates around the virtual pivot Q at the rear. The position of the virtual pivot Q is set so that the distance from the front end of the black key 2b is approximately twice the length of the black key 2 itself, for example, as with the virtual pivot 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 approximately half the distance of the key stroke, compared to the key-released state shown in FIG. 7(a).

[0050] 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, and the black key 2b rotates 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.

[0051] Next, the main part of the present invention will be described with reference to Figures 8 to 12. The main part of the present invention is that in the keyboard device 1, the second arm 32 of the key support mechanism 6 is provided with a second arm weight made of a material having a greater specific gravity than the second arm 32 (for example, a metal such as iron).

[0052] 8 shows the second arm 32A of the first embodiment of the present invention, where (a) is a perspective view, (b) is a side view, and (c) is an exploded perspective view. As shown in these figures, the second arm 32A has two second arm weights 52, 52 attached to a connecting portion 51 provided to connect between the bearing portion 41 near the center and the second arm front connecting portion 45 at the front end. The connecting portion 51 has a partition wall 51a in the center in the left-right direction, and two left and right weight mounting portions 51b, 51b (only one is shown in FIG. 8) formed in a concave shape opening to the left and right are provided on both the left and right sides of the partition wall 51a. A through hole 51c is formed in the partition portion 51a to pass a rivet 53 described later through.

[0053] The two second arm weights 52, 52 are both made of a material (e.g., a metal such as iron; the same applies below) having a greater specific gravity than the second arm 32A, and are formed as elongated plates extending in the front-rear direction, and have the same shape as each other. Each second arm weight 52 has an attachment hole 52a that penetrates through the center. Both second arm weights 52, 52 are inserted from the outside into the left and right weight attachment parts 51b, 51b of the second arm 32A, respectively, and are fixed in place with rivets 53 inserted through both attachment holes 52a, 52a and through hole 51c of the partition wall 51a.

[0054] According to the second arm 32A of this embodiment, the second arm weights 52, 52 made of a material having a higher specific gravity than the second arm 32A are attached, so that by increasing the weight of the second arm 32A, the moment of inertia of the second arm 32A is increased. As a result, it is possible to provide a sufficient response when a key is pressed, and a good touch feeling can be obtained when the key is pressed. In addition, since a good touch feeling can be obtained by increasing the weight of the second arm 32A, an increase in the weight of the first arm 31 can be suppressed. As a result, compared to the case where only the weight of the first arm 31 is increased, the responsiveness when the pressed key 2 rotates back to its original position can be improved, and appropriate repeated keystrokes can be obtained.

[0055] In addition, since the second arm weight 52 is provided in front of the bearing 41, i.e., in front of the second support shaft 19a with which the bearing 41 engages, the second arm 32A is more likely to rotate in the direction in which the second arm front connector 45 at the front end, which rises when a key is pressed, descends when the key is released. As a result, the first arm 31, whose front end, the first arm front connector 35, is pressed down when a key is pressed, is more likely to rotate back to its original position. As a result, the touch feeling and responsiveness of the key 2 when the key is pressed can be further improved.

[0056] 9 shows a second arm 32B of a second embodiment of the present invention, where (a) is a perspective view, (b) is a side view, and (c) is an exploded perspective view. In the second arm 32B of this embodiment, in addition to the second arm weight 52 of the first embodiment described above, an L-shaped weight 54 (second arm weight) is attached near the bearing portion 41 of the second arm 32B. The second arm 32B is provided with two L-shaped weight attachment portions 41a, 41a (only one is shown in FIG. 9) on the left and right sides, which are connected downward from the rear of the bearing portion 41 and formed in a concave shape opening to the left and right, respectively.

[0057] The two L-shaped weights 54, 54 are both made of a material with a higher specific gravity than the second arm 32B, and are formed in a substantially L-shape and have the same shape as each other. The two L-shaped weights 54, 54 are fitted from the outside into the left and right L-shaped weight mounting portions 41a, 41a of the second arm 32B, respectively, and fixed thereto by adhesion.

[0058] According to the second arm 32B of the present embodiment, it is possible to obtain the same actions and effects as the second arm 32A of the first embodiment described above, and in addition, the weight of the second arm 32B can be increased relatively easily.

[0059] 10 shows a second arm 32C according to a third embodiment of the present invention, with (a) being a perspective view, (b) being a side view, and (c) being an exploded perspective view. This second arm 32C is provided with a weight housing 56 that penetrates the connecting portion 51 in the left-right direction and is used to mount a single second-arm weight 55 in a housed state. This weight housing 56 is provided with four locking claws 57, two on the top and two on the bottom, at its right opening, and two locking claws 58, one on the top and one on the bottom, at its left opening.

[0060] The second arm weight 55 of this embodiment is made of a material with a larger specific gravity than the second arm 32C and is formed in a block shape extending in the front-rear direction. The second arm weight 55 is accommodated in the weight accommodating section 56 by being inserted into the weight accommodating section 56 from the left. In this case, the second arm weight 55 in the weight accommodating section 56 is fixed in the weight accommodating section 56 in a state where it is locked from the left and right directions by locking claws 57, 58 on both the left and right sides.

[0061] According to the second arm 32C of the present embodiment, it is possible to obtain the same action and effect as the second arm 32A of the first embodiment, and in addition, it is possible to easily attach the second arm weight 55 to the second arm 32C by simply inserting it into the weight storage portion 56.

[0062] 11 shows a second arm 32D of the fourth embodiment of the present invention, where (a) is a perspective view, (b) is an exploded perspective view, and (c) is an exploded perspective view of the second arm weight. The second arm 32D is different from the second arm 32C of the third embodiment described above only in the second arm weight 59. That is, the second arm weight 59 is made of the same material as the second arm weight 55 of the third embodiment, and is made of a block-shaped weight body 59a extending in the front-rear direction, and a cylindrical weight cover 59b attached so as to cover the periphery of the weight body 59a, specifically, the weight body 59a except for the front end and the rear end. The weight cover 59b is made of, for example, a soft synthetic resin or a synthetic resin having elasticity.

[0063] According to the second arm 32D of the present embodiment, when the second arm 32D moves in response to a key press, the second-arm weight 59 (weight main body 59a) does not rattle or vibrate in the weight accommodating portion 56. This makes it possible to prevent noise caused by the second-arm weight 59 when the second arm 32D moves.

[0064] 12 shows a second arm 32E of a fifth embodiment of the present invention, with (a) being a perspective view and (b) being a side view. Most of this second arm 32E is made of synthetic resin, with a portion being made of a second arm weight. Specifically, at the connection portion 51, a second arm weight 61 is provided so as to hang down from the underside of a top plate portion 60 that extends flatly in the front-rear direction. This second arm weight 61 is formed in a plate shape having a predetermined thickness, and is provided so as to extend in the front-rear direction at the center of the underside of the top plate portion 60.

[0065] When manufacturing this second arm 32E, the second arm weight 61 is set in a mold and the second arm 32E can be obtained by insert molding, in which molten synthetic resin is injected into the mold, to be molded integrally with the second arm weight 61.

[0066] According to the second arm 32E of the present embodiment, it is possible to obtain the same action and effect as the second arm 32A of the first embodiment described above, and in addition, during manufacture, the process of attaching the second arm weight 61 can be omitted, and the second arm 32E provided with the second arm weight 61 can be manufactured relatively easily.

[0067] The second arm 32 in the keyboard device 1 of the present invention is not limited to the first to fifth embodiments described above, but can be implemented in various ways. For example, in the second arms 32A and 32B of the first and second embodiments, the second arm weight 52 and the L-shaped weight 54 are attached to both the left and right sides of the second arms 32A and 32B, but it is also possible to attach them to either the left or right side as necessary. In addition, although a metal such as iron is exemplified as the second arm weight, the present invention is not limited to this, and various materials can be used as long as they have a higher specific gravity than the second arm 32, such as metals other than iron and composite materials of metal and synthetic resin.

[0068] Furthermore, the detailed configurations of the second arms 32A to 32E shown in the first to fifth embodiments are merely examples and can be modified as appropriate within the scope of the invention. [Explanation of symbols]

[0069] 1 Keyboard device 2 keys 4 Key Chassis 6 Key support mechanism 18 First arm support part 18a 1st spindle 19 Second arm support part 19a 2nd spindle 31 First Arm 32 Second Arm 32A Second arm of the first embodiment 32B Second arm of the second embodiment 32C Second arm of the third embodiment 32D Second arm of the fourth embodiment 32E Second arm of the fifth embodiment 35 First arm front connection part 37 First arm rear connection part 41a L-shaped weight attachment part (weight for second arm) 42 Rear connection part of second arm 45 Second arm front connection part 51 Connection part 51a Partition 51b Weight attachment part 51c through hole 52 Second arm weight 52a (Second arm weight) mounting hole 53 Rivet 54 L-shaped weight (for second arm) 55 Second arm weight 56 Weight holder 57 Locking claw 58 Locking claw 59 Second arm weight 59a Weight body 59b Weight cover 60 Top plate 61 Second arm weight

Claims

1. A keyboard chassis and A key extending a predetermined length in the front-rear direction and disposed on the upper portion of the keyboard chassis; a key support mechanism that is engaged with the keyboard chassis and supports the key from below, and that, when a key is pressed, causes the pressed key to rotate about a virtual fulcrum that is located behind the rear end of the key; Equipped with The key support mechanism includes: a first arm configured to extend a predetermined length in the front-rear direction, pivotably engaged with a first support shaft provided on the keyboard chassis, and a front end of which is rotatably and slidably connected to a front portion of the key; a second arm configured to extend a predetermined length in the front-rear direction, pivotally engaging with a second support shaft provided on the keyboard chassis rearward of the first support shaft, with a rear end rotatably connected to the rear of the key, and a second arm front connector located forward of the second support shaft rotatably and slidably connected to a first arm rear connector located rearward of the first support shaft of the first arm; It has 1. A keyboard device for a keyboard instrument, wherein the second arm is provided with a second arm weight made of a material having a specific gravity greater than that of the second arm.

2. 2. The keyboard device for a keyboard instrument according to claim 1, wherein the second arm weight is provided in front of the second support shaft and / or around the second support shaft.

3. 2. The keyboard device for a keyboard instrument according to claim 1, wherein the second arm weight is attached to at least one of the left and right side surfaces of the second arm.

4. The second arm has a weight receiving portion penetrating therethrough in the left-right direction, 2. The keyboard device of a keyboard instrument according to claim 1, wherein the second arm weight is attached to the second arm while being accommodated in the weight accommodating portion by being inserted into the weight accommodating portion from the outside.

5. 5. The keyboard device for a keyboard instrument according to claim 4, wherein the second arm weight is accommodated in the weight accommodating portion with its periphery covered with a predetermined synthetic resin.

6. 2. The keyboard device of a keyboard instrument according to claim 1, wherein the second arm is manufactured by molding synthetic resin, and the second arm weight is molded integrally with the second arm weight when the second arm is molded.

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