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; keys 51, 71, 81 provided at an upper part of the keyboard chassis; and hammers 31, 72, 82 rotating in association with the keys 51, 71, 81 below the keyboard chassis. The keys 51, 71, 81 are configured in a manner to rotate around a virtual supporting point P positioned behind a back end of the key 51 or rotational supporting points 71a, 81a which are provided at back ends of the keys 71, 81 and which are rotatably supported by the keyboard chassis 4 as the center, and are set to have the inertia moment larger than that of the hammers 31, 72, 82.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, which is equipped with hammers that rotate in conjunction with a pressed key. [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 by rotating so that the weight at the raised rear end lowers and the front end rises. Meanwhile, 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] Patent Publication No. 2023-50758 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 of claim 1 comprises a keyboard chassis, a key extending a predetermined length in the front-to-rear direction and arranged on the upper part of the keyboard chassis, and a hammer extending in the front-to-rear direction and rotatably supported on the keyboard chassis below the key via a hammer spindle, which engages with the key forward of the hammer spindle and rotates in conjunction with the key being pressed, wherein when the key is pressed, the key is configured to rotate around a virtual fulcrum located behind the rear end of the key, or around a pivot point located at the rear end of the key and rotatably supported on the keyboard chassis, and the key is configured so that its moment of inertia is greater than the moment of inertia of the hammer.

[0009] According to this configuration, a key extending a predetermined length in the front-rear direction is disposed on the top of the keyboard chassis, while a hammer extending in the front-rear direction is rotatably supported on the keyboard chassis via a hammer spindle below the key. The hammer engages with the key forward of the hammer spindle and rotates in conjunction with the pressed key. The key is configured to rotate around a virtual fulcrum located behind its rear end, or around a rotation fulcrum at the rear end of the key. The key and hammer are configured so that the moment of inertia of the key is greater than the moment of inertia of the hammer.

[0010] As described above, by setting the moment of inertia of the key to be larger than that of the hammer, the moment of inertia of the key becomes relatively large. This makes it possible to provide a sufficient response when the key is pressed, and a good touch feeling can be obtained when the key is pressed. Furthermore, by setting the moments of inertia of the key and the hammer as described above, the moment of inertia of the hammer becomes relatively small. This makes it possible to improve the responsiveness when the pressed key rotates back to its original position compared to when the moment of inertia of the hammer is large, and allows for appropriate repeated keystrokes.

[0011] The invention of claim 2 is characterized in that, in the keyboard device of the keyboard instrument described in claim 1, when the key is configured to rotate around a virtual fulcrum, a key rear weight made of a material having a greater specific gravity than the key is provided at the rear end of the key, and when the key is configured to rotate around a pivot point, a key rear weight made of a material having a greater specific gravity than the key is provided at the rear end of the key, behind the pivot point.

[0012] According to this configuration, whether the key is configured to rotate around a virtual fulcrum or a pivot, the key weight is made of a material with a higher specific gravity than the key and is provided at the rear end of the key, so that the weight of the key becomes heavier and the moment of inertia of the key can be easily made larger than that of the hammer. Also, when the key is configured to rotate around a pivot, the key weight is provided behind the pivot at the rear end of the key, so that the key weight at the rear end, which rises when the key is pressed, tends to rotate in a direction that causes the key weight at the rear end to fall when the key is released. As a result, the weight of the hammer can be reduced, and the responsiveness of the key when returning or repeatedly striking the key can be further improved.

[0013] The invention according to claim 3 is the keyboard device for a keyboard instrument according to claim 1 or 2, characterized in that the hammer spindle is provided so as to be located forward of the center of gravity of the key.

[0014] According to this configuration, the hammer spindle is located forward of the center of gravity of the key, so that the engagement position between the key and the hammer is far from the virtual fulcrum or pivot point, and therefore, even if the weight of the hammer is light, the key can easily return to its original position when the hammer rotates when the key is released. Therefore, by making the weight of the hammer light, the moment of inertia of the hammer can be made relatively small, in other words, the moment of inertia of the key can be easily made larger than that of the hammer. This improves responsiveness when the key is repeatedly struck. [Brief description of the drawings]

[0015] [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] FIG. 1 is a diagram for explaining the main part of the present invention, and is a perspective view showing the state in which a single white key and a key support mechanism are arranged at the left end part of the keyboard chassis. [Figure 9] 1A and 1B are diagrams showing a white key having a key tail weight at the rear end of the key, where (a) is a perspective view and (b) is a side view. [Figure 10] 10A and 10B are diagrams showing the state in which the key tail weight has been removed from the white key shown in FIG. 9, where (a) is a perspective view and (b) is a side view. [Figure 11] FIG. 1 is a schematic diagram showing a keyboard device equipped with a key and a hammer that rotate around a pivot point at the rear end of the key, where (a) shows a conventional keyboard device, and (b) shows a keyboard device in which a weight is provided behind the pivot point of the key. [Figure 12]FIG. 1 is a schematic diagram showing a keyboard device equipped with a key and a hammer that rotate around a pivot point at the rear end of the key, where (a) is a conventional keyboard device, and (b) is a keyboard device in which the hammer pivot is located forward of the center of gravity of the key and the engagement position between the key and the hammer is set toward the front end of the key. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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).

[0043] 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.

[0044] 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).

[0045] 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.

[0046] Next, the main features of the present invention will be described with reference to Figures 8 to 12. The main feature of the present invention is that the moment of inertia of the key is set to be larger than the moment of inertia of the hammer such as the first arm.

[0047] Fig. 8 is a diagram similar to Fig. 1(b) and shows a single key (white key) 51 arranged at the left end of the keyboard chassis 4, and this key 51 is supported from below by the key support mechanism 6 having the first arm 31 and second arm 32 described above. Fig. 9 shows an enlarged view of the key 51 in Fig. 8, with (a) being a perspective view and (b) being a side view. The only difference between the key 51 shown in these figures and the white key 2a described above is that a key tail weight 50 is provided.

[0048] Specifically, the key 51 has a weight receiving portion 52 extending obliquely upward and rearward at its rear end. The weight receiving portion 52 is formed in a box shape that opens upward, and is molded integrally with the key 51.

[0049] 10 shows the state in which the key rear weight 50 has been removed from the weight receiving section 52 of the key 51, with (a) being a perspective view and (b) being a side view. As shown in both figures, the key rear weight 50 has a side shape that is approximately a parallelogram and is formed in the shape of a block having a certain thickness in the left-right direction. This key rear weight 50 is made of a material with a higher specific gravity than the key 51, for example, a metal such as iron. Note that, like the key 2 described above, the key 51 has a key weight 30 (key front weight) attached to its front, and this key weight 30 is made of the same material as the key rear weight 50.

[0050] In a keyboard device equipped with the key 51 configured as above, similarly to the keyboard device 1 described above, when a key is pressed, the key 51 rotates about an imaginary fulcrum located behind its rear end.

[0051] By providing the key rear weight 50 at the rear end of the key 51 as described above, the weight of the key 51 is increased, and the moment of inertia of the key 51 is increased. This allows a sufficient response when the 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 key 51, an increase in the weight of the first arm 31 acting as a hammer can be suppressed. This improves the responsiveness when the pressed key 51 rotates back to its original position, and allows appropriate repeated keystrokes to be obtained, compared to when only the weight of the first arm 31 is increased.

[0052] Furthermore, by attaching the keyboard weight 30 to the key 51 in addition to the key rear weight 50, the moment of inertia of the key 51 is further increased, thereby further improving the touch feeling when pressing the key without reducing the ability to strike repeatedly.

[0053] FIG. 11 shows a schematic diagram of a keyboard device equipped with a key and a hammer that rotates around a pivot point at the rear end of the key, where (a) shows a conventional keyboard device, and (b) shows a keyboard device in which a weight is provided behind the pivot point of the key.

[0054] A conventional keyboard device 60 shown in Fig. 11(a) includes a key 61 that extends a predetermined length in the front-rear direction (left-right direction in Fig. 11) and is rotatable around a pivot point 61a at its rear end, and a hammer 62 that extends in the front-rear direction and is rotatably supported on a keyboard chassis via a hammer pivot 62a below the key 61. An actuator section 61b that protrudes downward is provided at the front of the key 61, and this actuator section 61b engages with the front end of the hammer 62 in abutting contact from above. A hammer weight 62b having a predetermined weight is provided at the rear end of the hammer 62.

[0055] In the keyboard device 60 configured as above, when a key is pressed, the key 61 rotates counterclockwise in FIG. 11 around the pivot 61a, and the hammer 62 rotates counterclockwise in FIG. 11 around the hammer shaft 62a. When the key is released, the hammer 62 rotates clockwise in FIG. 11 around the hammer shaft 62a, which pushes the key 61 up via the actuator 61b, and the key 61 rotates clockwise in FIG. 11 around the pivot 61a and returns to its original position. The above keyboard device 60 is disclosed, for example, in JP 2015-87591 A, which has already been filed by the present applicant.

[0056] In contrast, as shown in Fig. 11(b), a keyboard device 70 to which the present invention is applied includes a key 71 that extends a predetermined length in the front-rear direction and is rotatable around a pivot 71a at the rear end, and a hammer 72 that extends in the front-rear direction and is rotatably supported on the keyboard chassis via a hammer pivot 72a below the key 71. The key 71, like the key 61 of the keyboard device 60, has an actuator part 71b that protrudes downward at a predetermined position on the front part, and this actuator part 71b engages with the front end of the hammer 72 in a state of abutting from above. In addition, the key 71 is provided with a key rear weight 71c made of a material (e.g., a metal such as iron) having a larger specific gravity than the key 71 at the rear side of the pivot 71a (right side of Fig. 11(b)). Meanwhile, the hammer 72 has a hammer weight 72b with a predetermined weight at its rear end. Since a rotational force due to the weight of the key 71 acts in the direction of returning rotation due to the key rear weight 71c, the hammer weight 72b can be set to be lighter in weight than the hammer weight 62b of the keyboard device 60 described above.

[0057] As described above, in the keyboard device 70, the key back weight 71c is provided behind the pivot fulcrum 71a at the rear end of the key 71, so that the weight of the key 71 is increased, and the moment of inertia of the key 71 is increased. As a result, a good touch and appropriate repeated keystrokes can be obtained when the key is pressed, as in the case where the key 51 rotates around the virtual pivot point described above. In addition, when the key 71 rotates around the pivot point 71a, the key 71 is more likely to rotate in the direction of return rotation when the key is released, because the key back weight 71c is provided behind the pivot point 71a. As a result, the responsiveness of the pressed key when it rotates back to its original position can be improved, and appropriate repeated keystrokes can be obtained.

[0058] FIG. 12, like FIG. 11 described above, shows a schematic diagram of a keyboard device equipped with a key and a hammer that rotate around a pivot point at the rear end of the key, where (a) shows a conventional keyboard device, and (b) shows a keyboard device in which the hammer pivot is located forward of the center of gravity of the key and the engagement position between the key and the hammer is set toward the front end of the key.

[0059] The conventional keyboard device 60 shown in Fig. 12(a) is the same as the keyboard device 60 shown in Fig. 11(a) described above. In this conventional keyboard device 60, the hammer spindle 62a is located behind the center of gravity G of the key 61, and the engagement position between the actuator part 61b of the key 61 and the front end of the hammer 62 is set to be approximately halfway between the front end of the key 61 and the center of gravity G.

[0060] 12(b), a keyboard device 80 to which the present invention is applied includes a key 81 that extends a predetermined length in the front-rear direction and is rotatable around a pivot point 81a at the rear end, and a hammer 82 that extends in the front-rear direction and is rotatably supported on the keyboard chassis via a hammer pivot 82a below the key 81. In this keyboard device 80, the hammer pivot 82a is located forward of the center of gravity G of the key 81, and the engagement position between the actuator part 81b of the key 81 and the front end of the hammer 82 is set closer to the front end of the key 81. In addition, since the engagement position between the key 81 and the hammer 82 is near the front end of the key 81, the hammer weight 82b of the keyboard device 80 is set to be lighter in weight than the hammer weight 62b of the keyboard device 60.

[0061] As described above, by setting the engagement position between the actuator part 81b of the key 81 and the front end of the hammer 82 to be located closer to the front end of the key 81, the distance D2 between the engagement position of the key 81 and the hammer 82 and the pivot fulcrum 81a becomes longer than the distance D1 between the engagement position of the key 61 and the hammer 62 of the keyboard device 60 and the pivot fulcrum 61a (D2>D1). As a result, even if the weight of the hammer 82 is reduced by reducing the weight of the hammer 82 by reducing the weight of the hammer 82, the key 81 can easily rotate back to its original position in response to the rotation of the hammer 82 when the key is released. Therefore, by reducing the weight of the hammer 82, the moment of inertia of the hammer 82 can be made relatively small, in other words, the moment of inertia of the key 81 can be easily made larger than that of the hammer 82. As a result, the responsiveness of the key 81 when it is repeatedly struck can be improved.

[0062] The present invention is not limited to the above-described embodiment, and can be embodied in various forms. For example, in the embodiment, the key rear weight 50, 71c is provided at the rear end of the key 51, 71, and the engagement position between the key 81 and the hammer 82 is set near the front end of the key 81, so that the moment of inertia of the key 51, 71, 81 is made larger than the moment of inertia of the first arm 31 and the hammer 72, 82, but the above-described relationship in the moment of inertia between the key 51, 71, 81 and the first arm 31 or the hammer 72, 82 may be realized by other methods.

[0063] Although detailed data is omitted, it is preferable to set the moment of inertia of the key 51, 71, 81 to be a predetermined number of times (for example, 2 to 20 times) larger than the moment of inertia of the first arm 31 or the hammer 72, .

[0064] Furthermore, the detailed configurations of the keyboard device 1, 70, 80, keyboard chassis 4, keys 2, 51, 71, 81, first arm 31, hammers 72, 82, and key rear weights 50, 71c shown in the embodiments are merely examples and can be modified as appropriate within the spirit and scope of the present invention. [Explanation of symbols]

[0065] 1 Keyboard device 2 keys 4 Key Chassis 6 Key support mechanism 18 First arm support part 18a First spindle (hammer spindle) 19 Second arm support part 19a 2nd support shaft 30 Keyboard weights 31 First Arm (Hammer) 32 Second Arm 50 Key rear weight 51 keys 60 Conventional keyboard device 70 Keyboard device 71 key 71a Pivot point 71b Actuator section 71c Weight for the rear of the key 72 Hammer 72a Hammer spindle 72b Hammer weight 80 Keyboard device 81 keys 81a Pivot point 81b Actuator section 82 Hammer 82a Hammer spindle 82b Hammer 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 hammer extending in a front-rear direction, rotatably supported on the keyboard chassis via a hammer spindle below the key, engaging with the key forward of the hammer spindle and rotating in conjunction with the pressed key; Equipped with The key is configured to rotate, when pressed, around a virtual fulcrum located behind a rear end of the key, or around a pivot point that is provided at the rear end of the key and rotatably supported by the keyboard chassis; 1. A keyboard device for a keyboard instrument, wherein the key has a moment of inertia greater than a moment of inertia of the hammer.

2. When the key is configured to rotate around the virtual fulcrum, a key tail weight made of a material having a greater specific gravity than the key is provided at the rear end of the key; 2. The keyboard device of claim 1, wherein when the key is configured to rotate around the pivot point, a key rear weight made of a material having a greater specific gravity than the key is provided behind the pivot point at the rear end of the key.

3. 3. The keyboard device for a keyboard instrument according to claim 1, wherein the hammer spindle is disposed forward of the center of gravity of the key.

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