Keyboard device for keyboard instrument

Abstract

The present disclosure relates to a keyboard device for a keyboard instrument. A keyboard device for a keyboard instrument capable of obtaining an excellent tactile sensation when key pressing is performed, and also capable of improving responsiveness when a key that has been pressed performs a pivoting return movement to its initial position, and thereby obtaining appropriate string tap repeatability. The keyboard device includes: a keyboard chassis; the keys are arranged on the keyboard chassis; and a hammer pivotally moving below the key in a manner interlocked with the key. The key is configured such that when pressed, it pivotally moves about a virtual pivot located behind a rear end of the key or about a pivot disposed on the rear end of the key and pivotally supported on the keyboard chassis. The key is set such that a moment of inertia of the key is greater than a moment of inertia of the hammer.

Description

Technical Field

[0001] The present invention relates to a keyboard device for a keyboard musical instrument, which is applied to a keyboard musical instrument such as an electronic piano and includes a hammer that pivotally moves in a state interlocked with a depressed key. Background Art

[0002] Conventionally, as a keyboard device of this type, a keyboard device disclosed in, for example, Japanese Laid-Open Patent Publication (Kokai) No. 2023-50758 filed by the present applicant is known. The keyboard device includes a keyboard chassis, keys arranged on the keyboard chassis, and a key support mechanism that engages with the keyboard chassis and supports the keys from below. The key support mechanism includes a first arm and a second arm extending in a front-to-back direction. The first arm and the second arm are pivotally supported on a first pivot and a second pivot of the keyboard chassis, respectively. In addition, the front end portion of the first arm is pivotally and slidably connected to the front portion of the key, while the front end portion of the second arm is pivotally and slidably connected to a predetermined portion of the first arm and its rear end portion is pivotally connected to the rear end portion of the key.

[0003] In the keyboard device constructed as described above, when the front end of the key is pressed down by key pressing, the first arm pivotally moves about the first pivot so that its front end moves downward and the pressure weight provided on its rear end moves upward, and the second arm pivotally moves about the second pivot so that its front end moves upward and its rear end moves downward. In this case, the key pivotally moves about the virtual pivot located behind its rear end so that its front end moves downward.

[0004] Then, when the player's finger is released from the depressed key, the first arm and the second arm cause the key to perform a pivotal return movement to its initial position while pivoting in a direction opposite to the direction of its pivotal movement described above. Specifically, the first arm pushes the front end of the key upward by pivoting, so that the pressure weight on the rear end of the first arm that has moved upward moves downward, and the front end of the first arm moves upward. In addition, the second arm promotes the pivotal movement of the first arm by the downward movement of its front end, and pushes the rear end of the key upward by the upward movement of its rear end. In this case, the key (whose front end pivots upward around the virtual pivot mentioned above) performs a pivotal return movement to its initial position.

[0005] In the above-mentioned keyboard device, by arranging a pressure weight on the first arm, the weight of the first arm is increased, so that during key pressing, a satisfactory response touch is obtained, and during key release, the first arm pivots to thereby push the key upward and cause the key to perform a pivotal return movement to its initial position. In addition, as the pressure weight of the first arm gradually increases, the response to the key pressing increases, thereby making it possible to further improve the touch. However, when the weight of the first arm increases, the moment of inertia of the first arm increases, and the first arm becomes difficult to pivot. As a result, when the pressed key performs a pivotal return movement to its initial position, the responsiveness of the key is reduced, which sometimes makes it impossible to obtain the appropriate string striking repeatability of the key. Therefore, there is room for improvement in the above-mentioned keyboard device. Summary of the invention

[0006] An object of the present invention is to provide a keyboard device for a keyboard musical instrument, which enables an excellent tactile feel to be obtained when key depression is performed, and also enables improved responsiveness when a depressed key performs a pivotal return movement to its initial position, so as to thereby make it possible to obtain appropriate string striking repeatability.

[0007] To achieve the above-mentioned object, the present invention provides a keyboard device for a keyboard musical instrument, comprising: a keyboard chassis; a key, which extends a predetermined length in the front-rear direction and is arranged on the keyboard chassis; and a hammer, which extends in the front-rear direction and is pivotally supported on the keyboard chassis below the key via a hammer supporting shaft, the hammer engaging with the key at a position in front of the hammer supporting shaft so as to pivotally move in a manner interlocked with the pressed key, wherein the key is configured so that when pressed, the key pivotally moves around a virtual pivot located behind the rear end portion of the key or around a pivot provided on the rear end portion of the key and pivotally supported on the keyboard chassis, and wherein the key is set so that the moment of inertia of the key is greater than the moment of inertia of the hammer.

[0008] According to this configuration, a key extending in the front-rear direction by a predetermined length is provided on the keyboard chassis, and a hammer extending in the front-rear direction is pivotally supported on the keyboard chassis below the key via a hammer support shaft. In addition, this hammer engages with the key at a position in front of the hammer support shaft and pivotally moves in a manner interlocked with the pressed key. In addition, the above-mentioned key is configured to pivotally move around a virtual pivot located behind its rear end portion or around a pivot provided on its rear end portion. These keys and hammers are set so that the moment of inertia of the key is greater than the moment of inertia of the hammer.

[0009] As described above, the moment of inertia of the key is set to be greater than the moment of inertia of the hammer, so that the moment of inertia of the key is relatively large. This makes it possible to provide sufficient response to the pressing of the key, so that it is possible to obtain an excellent touch during the key pressing. In addition, the moments of inertia of the key and the hammer are set as described above, so that the moment of inertia of the hammer becomes relatively small. In this case, compared with the case where the moment of inertia of the hammer is large, it is possible to enhance the responsiveness of the key when the pressed key performs a pivot return movement to its initial position, so that it is possible to obtain appropriate string striking repeatability of the key.

[0010] Preferably, when the key is configured to pivotally move around a virtual pivot, a rear portion of the key weight made of a material having a larger specific gravity than the key is set on the rear end portion of the key, and when the key is configured to pivotally move around a pivot, a rear portion of the key weight made of a material having a larger specific gravity than the key is set on the rear end portion of the key at a position rearward of the pivot.

[0011] According to the construction of this preferred embodiment, in each of the cases where the key is configured to pivotally move about a virtual pivot and the key is configured to pivotally move about a pivot, since the key rear portion pressure weight made of a material having a larger specific gravity than the key is provided on the rear end portion of the key, the weight of the key is increased, thereby making it possible to easily make the moment of inertia of the key greater than the moment of inertia of the hammer. In addition, in the case where the key is configured to pivotally move about a pivot, since the key rear portion pressure weight is provided on the rear end portion of the key at a position behind the pivot, the key becomes easy to pivotally move in a direction in which the key rear portion pressure weight on the rear end portion of the key moves downward when the key is released, wherein the key rear portion pressure weight moves upward when the key is pressed. Therefore, the weight of the hammer can be reduced, thereby making it possible to further enhance the responsiveness of the key when the key returns to its initial position or when the key is repeatedly struck.

[0012] Preferably, the hammer supporting shaft is arranged so that it is located forward of the position of the center of gravity of the key.

[0013] According to the configuration of this preferred embodiment, since the hammer supporting shaft is located in front of the center of gravity position of the key, the engagement position between the key and the hammer is away from the virtual pivot or pivot, so that even when the weight of the hammer is reduced, it is possible to easily achieve the pivot return movement of the key to its initial position according to the pivot movement of the hammer when the key is released. Therefore, by reducing the weight of the hammer, it is possible to make the moment of inertia of the hammer relatively small, in other words, it is possible to easily make the moment of inertia of the key larger than the moment of inertia of the hammer. In this case, it is possible to enhance the responsiveness of the key when the key is repeatedly struck.

[0014] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1A and 1B is a perspective view of a portion (one octave area) of a keyboard device of an electronic piano to which the present invention is applied, wherein Figure 1A shows the appearance of a keyboard device, and Figure 1B shows a state in which keys other than white keys and black keys at the left end portion of the keyboard device are omitted;

[0016] Figure 2 yes Figure 1B A perspective view of the keyboard device shown in FIG. 1 in a state in which the white keys and the black keys together with the corresponding key supporting mechanisms therefor are removed from the keyboard chassis;

[0017] Figure 3A is a plan view of a keyboard device in which keys other than white keys and black keys are omitted at the left end portion of the keyboard device, and Figure 3B is along Figure 3A A cross-sectional view taken along line AA;

[0018] Figure 4A and 4B is a perspective view of white keys and key support mechanisms therefor, wherein Figure 4A shows the white keys and key support mechanism in a connected state, and Figure 4B The white keys and key support mechanism are shown in a disassembled state;

[0019] Figure 5A and 5B is a perspective view of a black key and a key supporting mechanism therefor, wherein Figure 5A The black keys and key support mechanism are shown in a connected state, and Figure 5B The black keys and key support mechanism are shown in a disassembled state;

[0020] Fig. 6A and 6B is a view useful for explaining the operation of white keys in a keyboard device, wherein Fig. 6A shows the key release state, and Figure 6B shows the key pressing status;

[0021] Fig. 7A and 7B is a view useful for explaining the operation of the black keys in a keyboard device, wherein Fig. 7A shows the key release state, and Figure 7B shows the key pressing status;

[0022] Figure 8 is a view of an essential part that helps explain the present invention, which is a perspective view showing a state in which a single white key and a key supporting mechanism therefor are provided at a left end portion of a keyboard chassis;

[0023] Fig.9A and 9B is a view of a white key having a key rear portion weight at its rear end, wherein Fig.9A is a perspective view, and Fig. 9B It is a side view;

[0024] Fig. 10A and 10B It shows that from Fig.9A and 9B A view of a partially depressed state of a white key after removing the key, wherein Fig. 10A is a perspective view, and Fig. 10B is a side view;

[0025] Fig.11A and 11B is a schematic view showing keyboard devices, each of which includes keys and hammers pivotally moved about a pivot located at a rear end portion of the key, wherein Fig.11A A conventional keyboard arrangement is shown, and Fig. 11B A keyboard device is shown having a weight disposed behind the pivot of a key; and

[0026] Fig. 12A and 12B is a schematic view showing keyboard devices, each of which includes keys and hammers pivotally moved about a pivot located at a rear end portion of the key, wherein Fig. 12A A conventional keyboard arrangement is shown, and Fig. 12B A keyboard device is shown which has a hammer supporting shaft located forward of a center of gravity position of a key and in which an engagement position between the key and the hammer is set at a position closer to a front end portion of the key. DETAILED DESCRIPTION

[0027] The present invention will now be described in detail with reference to the accompanying drawings in which preferred embodiments thereof are shown. Figure 1A Only one octave range of the keyboard device 1 for the electronic piano to which the present invention is applied is shown. Note that, hereinafter, the basic configuration of the keyboard device 1 and its operation will be described first, and then the essential part of the present invention will be described.

[0028] Figure 1B Shows Figure 1A The state of the keyboard device 1 shown in FIG. 1 , in which the keys 2 other than the white keys 2 a and the black keys 2 b at the left end portion of the keyboard device 1 are omitted. Figure 2 Shows Figure 1B 0 shows the state of the keyboard device 1 shown in , in which the white keys 2 a and the black keys 2 b together with the corresponding key supporting mechanisms 6 therefor are removed from the keyboard chassis 4 .

[0029] The keyboard device 1 includes a keyboard chassis 4, a plurality of keys 2 (including white keys 2a and black keys 2b, and arranged side by side in the left-right direction), and for each key, each key support mechanism 6 is pivotally mounted on the keyboard chassis 4 so as to support an associated one of the keys 2 from below, and key switches 3 (each for detecting key pressing information of an associated one of the keys 2).

[0030] The keyboard chassis 4 includes a chassis main body 4a formed as a resin molded product, which is made by, for example, injection molding a predetermined resin material (eg, ABS resin) into a predetermined shape. Figure 3A and 3B As shown in FIG. 1 , the chassis body 4a has a front portion 11, a middle portion 12, and a rear portion 13, each of which is arranged in the left-right direction (along the Figure 3A The front portion 11, the middle portion 12 and the rear portion 13 are integrally formed with each other via a plurality of ribs 14, wherein the plurality of ribs 14 are arranged with spacing therebetween in the left-right direction and each extends in the front-back direction. It should be noted that in the following description, the front portion 11, the middle portion 12 and the rear portion 13 of the chassis body 4a of the keyboard chassis 4 will be referred to as "chassis front portion 11", "chassis middle portion 12" and "chassis rear portion 13", respectively.

[0031] The chassis front part 11 is mainly used to guide the white key 2a during the pressing of the white key 2a, and to limit the upper limit position and the lower limit position of the front end of the white key 2a. On the chassis front part 11, a plurality of white key guides 11a are erected, each of which is inserted into one of each associated one of the white keys 2a from below to prevent the lateral swing of the white key 2a in the state of being arranged side by side in the left-right direction. In addition, the chassis front part 11 has engagement holes 11b and 11b extending vertically through it, which are formed on the left and right sides of each white key guide 11a, respectively. A pair of left and right upper limit position regulating parts 21 and 21 of the white key 2a referred to below engage with the corresponding engagement holes 11b and 11b in the state of being inserted through it. In addition, the chassis front part 11 has its front end, and its front end is formed with a stopper mounting part 11c protruding forward and extending along the entire chassis body 4a in the left-right direction. The key upper limit stopper 16a and the key lower limit stopper 16b for the white key 2a are respectively mounted on the lower surface and the upper surface of the stopper mounting portion 11c so as to extend in the left-right direction. It should be noted that the stopper mounting portion 11d for the black key is provided at a predetermined position of the chassis front portion 11 behind each white key guide 11a, and the stopper mounting portion 11d extends along the entire chassis body 4a in the left-right direction, and the key upper limit stopper 17 for the black key is mounted on the stopper mounting portion 11d so as to extend in the left-right direction.

[0032] The chassis middle portion 12 is mainly used to guide the black key 2b during the depression of the black key 2b, and swingably supports the first arm 31 and the second arm 32 of each of the key support mechanism 6a associated with the white key and the key support mechanism 6b associated with the black key, which are described below. The chassis middle portion 12 has a flat portion 12a in the form of a flat plate extending in the left-right direction, and a plurality of black key guides 12b erected on the flat portion 12a and arranged with appropriate spacing therebetween in the left-right direction. Each black key guide 12b is inserted into an associated one of the black keys 2b from below to prevent the lateral swing of the black key 2b. In addition, the chassis middle portion 12 has its front portion, which is provided with a first arm support portion 18 so as to support the first arm 31 of the key support mechanism 6. The first arm support portion 18 has a plurality of first pivots 18a, each of which is provided between every two adjacent ribs 14 and 14 so that the first pivots 18a extend in the left-right direction. The first arm 31 is swingably supported on the associated first pivot 18a. In addition, the chassis middle portion 12 has a rear portion thereof, and the rear portion thereof is provided with a second arm support portion 19 so as to support the second arm 32 of the key support mechanism 6. The second arm support portion 19 has a plurality of second pivots 19a, each of which is provided between every two adjacent ribs 14 and 14, so that the second pivot 19a extends in the left-right direction. The plurality of second pivots 19a are arranged on the same axis, which extends in the left-right direction at a position behind the first pivot 18a and higher than the first pivot 18a, and the second arm 32 is swingably supported on the associated second pivot 19a. It should be noted that the first arm lower limit stopper 10b extending in the left-right direction along the entire chassis body 4a is provided at a predetermined position of the middle rail 8 referred to below, and the middle rail 8 is provided below the chassis middle portion 12.

[0033] Furthermore, the above-mentioned key switch 3 is provided on the lower portion of the keyboard chassis 4 between the above-mentioned chassis front portion 11 and chassis middle portion 12. The key switch 3 is formed of a laterally elongated printed circuit board 3a extending in the left-right direction and a plurality of switch bodies 3b formed of rubber switches attached to the printed circuit board 3a in a key-by-key manner so as to be depressed by the associated first arm 31 when a key is pressed.

[0034] The chassis rear portion 13 is mainly used to guide the key 2 in the vertical direction through its rear end portion, while preventing the key 2 from swinging sideways, and to limit the upper limit position of the rear end portion of the associated first arm 31. Figure 2 and 3A As shown in FIG. 1 , the chassis rear portion 13 has a plurality of partition walls 13 a formed with a predetermined spacing therebetween in the left-right direction so that every two adjacent keys 2 and 2 are separated from each other. Figure 3BAs shown in the figure, a first arm upper limit stopper 10a extending along the entire chassis body 4a in the left-right direction is provided at a predetermined position on the upper part of the chassis rear portion 13. When the first arm 31 having a function as a hammer so as to increase the touch weight of the key 2 pivotally moves upward and downward, the first arm upper limit stopper 10a and the first arm lower limit stopper 10b provided on the chassis middle portion 12 are used to limit the upper limit position and the lower limit position of the first arm 31, respectively. In addition, a metal cover plate 15 extending along the entire chassis body 4a in the left-right direction and provided to cover the rear end portion of the key 2 is mounted on the upper part of the chassis rear portion 13.

[0035] like Figure 2 and 3A As shown in the figure, the chassis body 4a of the keyboard chassis 4 constructed as described above is formed with a plurality of first openings 5a opened upward and forward and a plurality of second openings 5b opened upward. The first arms 31 of the key support mechanism 6 are respectively engaged with the associated first pivots 18a from the outside via the above-mentioned first openings 5a. In addition, the second arms 32 are respectively engaged with the associated second pivots 19a from the outside via the above-mentioned second openings 5b.

[0036] Furthermore, in the above-mentioned keyboard chassis 4, a plurality of chassis main bodies 4a are connected to each other in a state of being arranged side by side in the left-right direction, and each chassis main body 4a is screwed to a front rail 7, a middle rail 8, and a rear rail 9 (each of which is made of metal) in a state of being placed thereon, each of the rails 7, 8, and 9 extending in the left-right direction and arranged with a predetermined spacing therebetween in the front-rear direction. The keyboard chassis 4 is fixed to a key bed (not shown) of an electronic piano via the front rail 7 and the rear rail 9.

[0037] Next, the key 2 and the key supporting mechanism 6 will be described. Figure 4A The white keys 2a and the key supporting mechanisms 6a for the white keys 2a are shown in an enlarged scale, and Figure 4B They are shown in exploded state. Figure 4A and 4B As shown in , the white key 2a is formed, for example, by injection molding a predetermined resin material (e.g., AS resin) into a hollow shape, wherein the hollow shape extends a predetermined length in the front-rear direction and is open downward. The white key 2a has a front end portion thereof, and a pair of left and right upper limit position regulating portions 21 and 21 are formed at the front end portion thereof, which protrude downward from the corresponding side walls of the front end portion of the white key 2a, and each has its lower end portion bent forward. As described above, the left and right upper limit position regulating portions 21 and 21 are engaged with the corresponding left and right engaging holes 11b and 11b of the chassis front portion 11 in a state where they are inserted therethrough.

[0038] Furthermore, a key front side connecting portion 22 connected to the first arm 31 of the key supporting mechanism 6a is formed at a predetermined position behind the upper limit position adjusting portion 21 and at the front portion of the white key 2a. The key front side connecting portion 22 includes a connecting recess 22a, which is formed into a U-shape having a groove-like shape in a side view and is open forward. Furthermore, the connecting recess 22a has a padding member 20 attached thereto, which is formed to cover the entire inner peripheral surface of the connecting recess 22a so as to suppress the generation of noise when the connecting shaft 35b of the first arm 31 referred to below slides in the inner peripheral surface of the connecting recess 22a. It should be noted that in the front portion of the white key 2a, between the upper limit position adjusting portion 21 mentioned above and the key front side connecting portion 22, a key pressure weight 30 (see Figure 3B ) in order to add a desired touch weight to the white key 2a during depression of the white key 2a.

[0039] In addition, the white key 2a has a rear portion thereof, which is provided with a key rear side connection portion 23 connected to the second arm 32 of the key support mechanism 6a. The key rear side connection portion 23 has a plate-like connection body portion 23a, which is suspended downward from the lateral center portion of the white key 2a and has a predetermined thickness in the left-right direction, and a pair of left and right engagement protrusions 23b and 23b, wherein the connection body portion 23a is suspended downward from the lateral center portion of the white key 2a and has a predetermined thickness in the left-right direction, and the pair of left and right engagement protrusions 23b and 23b protrude coaxially from the left and right side surfaces of the connection body portion 23a, respectively. In addition, the rear portion of the white key 2a is formed with a tool insertion hole 24 extending vertically through the rear portion, and the tool insertion hole 24 is used to insert a predetermined tool therein from above so as to disconnect the white key 2a from the second arm 32 of the key support mechanism 6a, for example, at the time of maintenance of the keyboard device 1.

[0040] On the other hand, the key supporting mechanism 6a includes a first arm 31 and a second arm 32 which are engaged with each other and are respectively connected to the key front side connecting portions 22 and the key rear side connecting portions 23 of the white keys 2a.

[0041] like Figure 4BAs shown in , the first arm 31 includes an arm body 33 and two weights 34 and 34 attached to the arm body 33. The arm body 33 is formed as a resin molded product, which is made, for example, by injection molding a predetermined resin material (e.g., polyacetal resin) into a predetermined shape. The arm body 33 extends a predetermined length in the front-to-back direction and has a front end portion thereof, and a first arm front side connecting portion 35 connected to the key front side connecting portion 22 of the white key 2a is formed at the front end portion thereof. The first arm front side connecting portion 35 includes a box portion 35a having a box-like shape open upward and forward, and is provided with a connecting shaft 35b so that the connecting shaft 35b extends in the left-to-right direction in a state where the front upper ends of the left side wall and the right side wall of the box portion 35a are connected to each other. The connecting shaft 35b is connected to the connecting recess 22a of the key front side connecting portion 22 of the white key 2a so that the connecting shaft 35b can be pivotally moved and can slide in the front-to-back direction.

[0042] Furthermore, the arm main body 33 has a bearing portion 36 formed at a predetermined position immediately behind the first arm front side connection portion 35. The bearing portion 36 has an inverted U shape opened downward in a side view, and is pivotally engaged with the first pivot shaft 18a of the keyboard chassis 4. Furthermore, the arm main body 33 has a first arm rear side connection portion 37 formed at a predetermined position behind the bearing portion 36 so as to be connected to the second arm 32. Specifically, the first arm rear side connection portion 37 has a connection shaft 37a extending in the left-right direction, and respective opposite ends of the connection shaft 37a protrude outward from the left and right side surfaces of the arm main body 33. The opposite ends of the connection shaft 37a are engaged with connection recesses 45b and 45b of a second arm front side connection portion 45 referred to below of the second arm 32.

[0043] Two ballast weights 34 and 34 formed as elongated and narrow flat plates are mounted on a ballast weight mounting portion 38 in a state of sandwiching the ballast weight mounting portion 38, which is a rear portion of the arm body 33. It should be noted that each ballast weight 34 is made of a material (metal, such as iron) having a larger specific gravity than the arm body 33, and is formed, for example, by pressing a metal plate into a predetermined shape.

[0044] The second arm 32 is formed into a resin molded article having a predetermined shape by injection molding of the same resin material as the resin material of 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. In addition, the second arm 32 has a bearing portion 41 having a C-shape opened forward in a side view at about the longitudinal center of the second arm 32. The bearing portion 41 is pivotally engaged with an associated one of the second pivot shafts 19a of the keyboard chassis 4.

[0045] Furthermore, the second arm 32 has a rear portion thereof provided with a second arm rear side connecting portion 42 connected to the key rear side connecting portion 23 of the white key 2a. The second arm rear side connecting portion 42 is formed in a bifurcated shape and has two left and right connecting arm portions 43 and 43 extending in parallel with each other by a predetermined length in the longitudinal direction of the second arm 32. Each connecting arm portion 43 has a rear end portion thereof formed with a connecting hole 43a extending through the connecting arm portion 43 in the left-right direction. The two connecting arm portions 43 and 43 sandwich the connecting body portion 23a of the key rear side connecting portion 23 of the white key 2a between their rear end portions from the left and right sides, and each connecting hole 43a has an associated one of the engaging protrusions 23b of the key rear side connecting portion 23 pivotally fitted therein.

[0046] Furthermore, the second arm 32 has a front portion thereof provided with a second arm front side connection portion 45 connected to the first arm rear side connection portion 37 of the first arm 31. The second arm front side connection portion 45 has a pair of left and right connection portions 45a and 45a arranged with a predetermined interval in the left-right direction. Each of the connection portions 45a and 45a is formed with a connection recess 45b having a U-shape having a groove-like shape in a side view and is open forward. The left and right connection portions 45a and 45a of the second arm front side connection portion 45 are pivotally and slidably engaged with the corresponding opposite ends of the connection shaft 37a of the first arm 31 via the connection recesses 45b and 45b thereof.

[0047] Figure 5A The black key 2b and the key supporting mechanism 6b therefor are shown in an enlarged scale, and Figure 5B The black key 2b and the key support mechanism 6b in the disassembled state are shown. The black key 2b is formed into a hollow shape by injection molding of the same resin material as the resin material of the white key 2a, for example, and its predetermined length extending in the front-to-back direction is shorter than the predetermined length extending in the front-to-back direction of the white key 2a, and is open downward. The black key 2b has a front lower end portion thereof, and a key front side connecting portion 26 formed substantially similarly to the key front side connecting portion 22 of the white key 2a is provided at the front lower end portion thereof. The key front side connecting portion 26 has a connecting recess 26a, which is formed into a U-shape having a groove-like shape in a side view, and is open forward. In addition, the key front side connecting portion 26 has an extension portion 26b on the lower front end portion of the connecting recess 26a. The extension portion 26b extends a predetermined length in front of the front surface of the main body of the black key 2b. The extension portion 26b functions as an upper limit position adjusting portion of the black key 2b. Note that, in the following description, components of the black keys 2b and key supporting mechanisms 6b having the same configurations as those of the above-described white keys 2a and key supporting mechanisms 6a are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0048] The key support mechanism 6b supporting the black key 2b is constructed substantially similarly to the key support mechanism 6a associated with the above-mentioned white key. Specifically, the arm body 33 of the first arm 31 and the second arm 32 of the key support mechanism 6b are constructed completely similarly in shape and size to the arm body 33 and the second arm 32 of the key support mechanism 6a associated with the white key. It should be noted that although Figure 5A and 5B , the left and right pressure weights 34 and 34 of the key supporting mechanism 6b of the black key 2b are illustrated exactly the same as the pressure weights 34 and 34 of the key supporting mechanism 6a of the white key 2a, but the shapes and lengths of the pressure weights 34 and 34 of the key supporting mechanisms 6a and 6b can be changed when necessary according to the touch weight required for the key 2, etc.

[0049] Next, the operations of the keys 2 and the key supporting mechanism 6 of the keyboard device 1 constructed as described above will be described. Fig. 6A and 6B 1 and 2 are views useful for explaining the operation of the white keys 2a and the key support mechanisms 6a associated therewith. Fig. 7A and 7B 1 and 2 are views useful for explaining the operation of the black keys 2b and the key supporting mechanisms 6b associated therewith.

[0050] When the tip end of the white key 2a is moved by the player with his / her fingers from Fig. 6A When the key release state shown in is pressed, the key front side connection part 22 of the white key 2a moves downward, whereby the first arm 31 pivotally moves in the counterclockwise direction around the first pivot 18a. In addition, according to the pivotal movement of the first arm 31, the second arm front side connection part 45 engaged with the connection shaft 37a of the first arm 31 via the connection recesses 45b and 45b moves upward. In this case, the second arm 32 pivotally moves in the clockwise direction around the second pivot 19a. Thereafter, according to such pivotal movement of the second arm 32, the key rear side connection part 23 connected to the second arm 32 via the second arm rear side connection part 42 formed on the rear end part of the second arm 32 is pulled down, whereby the rear end part of the white key 2a moves downward.

[0051] It is to be noted that, during the above-mentioned pivotal movement of the first arm 31, the box portion 35a of the first arm front side connecting portion 35 moves downward, and therefore, the switch body 3b of one of the key switches 3 associated with the depressed key 2 is pressed down from above by the bottom wall of the box portion 35a. Therefore, in the electronic piano, key depression information of the depressed key 2 is detected, and sound is generated from a speaker (not shown) based on the detected key depression information.

[0052] As described above, when the white key 2a is pressed, according to the counterclockwise pivotal movement of the first arm 31, the weight 34 of the first arm 31 is tilted so that the weight 34 becomes higher when extending backward, whereby the rear end of the weight 34 comes into contact with the first arm upper limit stopper 10a from below, as shown in FIG. Figure 6B This prevents further pivotal movement of the first arm 31. When the front end portion of the white key 2a is depressed to its lowest position, the front end portion of the white key 2a comes into contact with the key lower limit stopper 16b, which prevents the white key 2a from being further depressed.

[0053] The white key 2a pressed as above is operated so that it pivotally moves about the virtual pivot P located behind its rear end portion. The position of the virtual pivot P is set so that, for example, the distance from the front end portion of the white key 2a is about twice as long as the length of the white key 2a itself. In this case, when the front end portion of the white key 2a is pressed to the lowest position, the virtual pivot P is located at a position about 1 / 2 of the distance from the white key 2a. Fig. 6A Compared with the key release state shown in , the front end portion of the white key 2a is positioned lower than a predetermined key stroke (e.g., 10 mm), and the rear end portion of the white key 2a is positioned lower than a distance (e.g., 5 mm) which is approximately half of the predetermined key stroke.

[0054] On the other hand, when the finger is released from the pressed white key 2a, the first arm 31 of the key support mechanism 6a is pivotally moved in the direction opposite to the above-mentioned direction by the own weight of the pressing weight 34, and accordingly, the second arm 32 is also pivotally moved in the direction opposite to the above-mentioned direction. According to this pivotal movement of the second arm 32, the white key 2a is pivotally moved upward around the virtual pivot axis P. Thereafter, a predetermined portion of the first arm 31, behind the first pivot axis 18a, moves from above to contact with the first arm lower limit stopper 10b, and both the upper limit position regulating portions 21 and 21 of the white key 2a move from below to contact with the key upper limit stopper 16a, whereby further pivotal movement of the white key 2a is blocked, and the white key 2a returns to its initial key release state.

[0055] Furthermore, when the black key 2b is depressed, an operation similar to the above-described operation of the white key 2a and the key support mechanism 6a is performed. More specifically, when the front end portion of the black key 2b is depressed from Fig. 7AWhen the key release state shown in is pressed, the first arm 31 pivots and moves in the counterclockwise direction around the first pivot 18a, and the second arm 32 pivots and moves in the clockwise direction around the second pivot 19a. In this case, the black key 2b is operated so that it pivots and moves around the virtual pivot Q located behind its rear end portion. It should be noted that, similar to the virtual pivot P of the white key 2a mentioned above, the position of the virtual pivot Q is set so that, for example, the distance from the front end portion of the black key 2b is approximately twice the length of the black key 2b itself. Thus, when the front end portion of the black key 2b is pressed to its lowest position, it is at a distance from the black key 2b. Fig. 7A Compared with the case of the key release state shown in , the front end portion of the black key 2b is positioned lower than the predetermined key stroke, and the rear end portion is positioned lower than the predetermined key stroke by a distance that is approximately half of the predetermined key stroke.

[0056] On the other hand, when the finger is released from the depressed black key 2b, the first arm 31 and the second arm 32 of the key supporting mechanism 6b are pivotally moved in respective directions opposite to the above-mentioned directions, and accordingly, the black key 2b is pivotally moved upward about the virtual pivot axis Q. Thereafter, the extending portion 26b of the key front side connecting portion 26 of the black key 2b moves from below to come into contact with the key upper limit stopper 17, whereby further pivotal movement of the black key 2b is prevented, and the black key 2b returns to its initial key-released state.

[0057] Next, we will refer to Figures 8 to 12A The essential part of the present invention is mainly that the inertia moment of the key is set larger than the inertia moment of the hammer (such as the first arm).

[0058] Figure 8 Approximately similar to the above Figure 1B , and shows a state where a single key (white key) 51 is provided at the left end portion of the keyboard chassis 4. The key 51 is supported from below by a key support mechanism 6 including the first arm 31 and the second arm 32 described above. In addition, Fig.9A and 9B Shown on an enlarged scale Figure 8 The key 51 appears in Fig.9A is a perspective view, and Fig. 9B It is a side view. Fig.9A and 9B The key 51 shown in FIG. 1 is different from the above-mentioned white key 2 a only in that the key 51 is provided with a key rear portion depression weight 50 .

[0059] Specifically, the key 51 includes a weight receiving portion 52 extending rearward and tilted upward at a rear end thereof. The weight receiving portion 52 has a box shape opened upward and is formed integrally with the key 51.

[0060] Fig. 10Aand 10B 4 shows a state where the key rear portion weight 50 is removed from the weight receiving portion 52 of the key 51, wherein Fig. 10A is a perspective view, and Fig. 10B is a side view. Fig. 10A and 10B As shown in the figure, the key rear part pressure weight 50 is formed into a block shape that is approximately parallelogram in side view and has a predetermined thickness in the left-right direction. The key rear part pressure weight 50 is made of a material (e.g., metal, such as iron) having a larger specific gravity than the key 51. It should be noted that, similar to the above-mentioned key 2, the key 51 has a key pressure weight 30 (key front part pressure weight) installed on the front part, and the key pressure weight 30 is made of the same material as the material of the above-mentioned key rear part pressure weight 50.

[0061] In the keyboard device including the key 51 configured as described above, similarly to the above-described keyboard device 1, when the key 51 is pressed, the key 51 pivotally moves about the virtual pivot located behind the rear end portion thereof.

[0062] The above-mentioned key rear portion pressing weight 50 is provided on the rear end portion of the key 51, thereby increasing the weight of the key 51, thereby increasing the moment of inertia of the key 51. This makes it possible to provide a sufficient response to the depression of the key 51, thereby making it possible to obtain an excellent touch during the key depression. In addition, it is possible to obtain an excellent touch by increasing the weight of the key 51, thereby making it possible to suppress the increase in the weight of the first arm 31 as a hammer. In this case, compared with the case where only the weight of the first arm 31 is increased, it is possible to enhance the responsiveness of the key 51 when the depressed key 51 performs a pivot return movement to its initial position, thereby making it possible to obtain appropriate string striking repeatability of the key 51.

[0063] In addition, since not only the key rear portion pressure weight 50 but also the key pressure weight 30 are installed on the key 51, the moment of inertia of the key 51 is further increased, thereby making it possible to further improve the tactile feel during depression of the key 51 without reducing the repeatability of the string striking of the key 51.

[0064] Fig.11A and 11B is a schematic diagram showing keyboard devices each of which includes keys and hammers pivotally moved about pivots located at rear end portions of the keys. Fig.11A A conventional keyboard arrangement is shown, and Fig. 11B A keyboard arrangement is shown with weights provided behind the pivots of the keys.

[0065] Fig.11A The conventional keyboard device (indicated by reference numeral 60) shown in FIG. 1 includes: a key (indicated by reference numeral 61) which is arranged in a front-to-back direction (eg Fig.11A61) and is pivotally movable about a pivot (indicated by reference numeral 61a) located at the rear end of the key; and a hammer (indicated by reference numeral 62) extending in the front-rear direction and pivotally supported on the keyboard chassis below the key 61 via a hammer support shaft 62a. The key 61 has a front portion thereof, and an actuator portion 61b protruding downward is provided at the front portion thereof. The actuator portion 61b is engaged with the front end portion of the hammer 62 in a state of contacting therewith from above. In addition, a hammer pressure weight 62b having a predetermined weight is formed at the rear end portion of the hammer 62.

[0066] In the keyboard device 60 constructed as described above, when the key 61 is pressed, the key 61 moves along the pivot 61a as shown in FIG. Fig.11A The hammer 62 is pivotally moved in the counterclockwise direction as viewed in FIG. 1 , and therefore, the hammer 62 is moved about the hammer support shaft 62a along the direction as viewed in FIG. Fig.11A Then, when the key 61 is released, the hammer 62 moves along the hammer support shaft 62a as shown in FIG. Fig.11A The key 61 is pivotally moved in the clockwise direction as viewed in FIG. 1 , so that the key 61 is pushed upward by the actuator portion 61 b ​​and moves about the pivot 61 a along the direction as shown in FIG. Fig.11A , and pivotally moves in the clockwise direction as observed in , to return to its initial position. It should be noted that the above-mentioned keyboard device 60 is disclosed in, for example, Japanese Laid-Open Patent Publication (Kokai) No. 2015-87591 filed by the present applicant.

[0067] Different from this, Fig. 11B As shown in , a keyboard device 70 to which the present invention is applied includes: a key 71 extending in the front-to-back direction by a predetermined length and being pivotally movable about a pivot 71a located at a rear end portion thereof; and a hammer 72 extending in the front-to-back direction and being pivotally supported on a keyboard chassis below the key 71 via a hammer support shaft 72a. Similar to the key 61 of the above-mentioned keyboard device 60, the key 71 has an actuator portion 71b protruding downward at a predetermined position at its front portion. The actuator portion 71b is engaged with the front end portion of the hammer 72 and is in a state of contacting it from above. In addition, the key 71 has an actuator portion 71b at the rear of the pivot 71a (as shown in FIG. 1 ). Fig. 11B The key rear portion pressure weight 71c is provided on the rear end portion thereof at a position (right side as viewed in FIG. 1 ). The key rear portion pressure weight 71c is made of a material (e.g., metal, such as iron) having a larger specific gravity than the key 71. On the other hand, the hammer 72 has a hammer pressure weight 72b with a predetermined weight at the rear end portion thereof. Since the rotational force caused by the gravity of the key rear portion pressure weight 71c acts on the key 71 in a direction in which the key 71 performs pivotal return movement to its initial position, the hammer pressure weight 72b can be set so that it has a smaller weight than the hammer pressure weight 62b of the above-mentioned keyboard device 60.

[0068] As described above, in the keyboard device 70, the above-mentioned key rear part pressure weight 71c is arranged on the rear end of the key 71 at the rear position of the pivot 71a, and therefore by increasing the weight of the key 71, the inertia moment of the key 71 increases. Similar to the case where the above-mentioned key 51 pivots around the virtual pivot, during the pressing of the key 71, it is possible to obtain excellent touch and appropriate string striking repeatability. In addition, when the key 71 pivots around the pivot 71a, since the key rear part pressure weight 71c is arranged behind the pivot 71a, the key 71 is easy to pivot along the direction of the pivot return movement to its initial position according to the release of the key 71. Therefore, when the pressed key 71 performs a pivot return movement to its initial position, it is possible to improve the responsiveness of the key 71, thereby it is possible to obtain the appropriate string striking repeatability of the key 71.

[0069] As mentioned above Fig.11A and 11B similar, Fig. 12A and 12B is a schematic diagram showing keyboard devices each of which includes keys and hammers pivotally moved about pivots located at rear end portions of the keys. Fig. 12A A conventional keyboard arrangement is shown, and Fig. 12B A keyboard device having a hammer supporting shaft located forward of a center of gravity position of a key and in which an engagement position between a key and a hammer is set at a position closer to a front end portion of the key is shown.

[0070] Fig. 12A The conventional keyboard device 60 shown in FIG. Fig.11A In this conventional keyboard device 60, the hammer supporting shaft 62a is located behind the center of gravity position G of the key 61, and the engagement position between the actuator portion 61b of the key 61 and the front end portion of the hammer 62 is set near the middle position between the front end portion of the key 61 and the center of gravity position G.

[0071] On the other hand, Fig. 12BAs shown in FIG. 1 , a keyboard device (indicated by reference numeral 80) to which the present invention is applied includes: a key (indicated by reference numeral 81) extending in the front-rear direction by a predetermined length and pivotally movable about a pivot shaft (indicated by reference numeral 81a) located at a rear end thereof; and a hammer (indicated by reference numeral 82) extending in the front-rear direction and pivotally supported on a keyboard chassis below the key 81 via a hammer support shaft (indicated by reference numeral 82a). In this keyboard device 80, the hammer support shaft 82a is disposed so that it is located in front of the center of gravity position G of the key 81, and the engagement position between the actuator portion 81b of the key 81 and the front end of the hammer 82 is set at a position closer to the front end of the key 81. In addition, since the engagement position between the key 81 and the hammer 82 is located near the front end of the key 81, the hammer pressing weight 82b of the keyboard device 80 is set so that it has a smaller weight than the hammer pressing weight 62b of the keyboard device 60.

[0072] As described above, the engagement position between the actuator portion 81b of the key 81 and the front end portion of the hammer 82 is set to be located at a position closer to the front end portion of the key 81, so that the distance D2 between the engagement position between the key 81 and the hammer 82 and the pivot 81a is greater than the distance D1 between the engagement position between the key 61 and the hammer 62 of the keyboard device 60 and the pivot 61a (D2>D1). In this case, even when the weight of the hammer 82 is reduced by reducing the weight of the hammer pressure weight 82b of the hammer 82, when the key 81 is released, it is possible to easily achieve the pivotal return movement of the key 81 to its initial position according to the pivotal movement of the hammer 82. Therefore, by reducing the weight of the hammer 82, it is possible to make the inertia moment of the hammer 82 relatively small, in other words, it is possible to easily make the inertia moment of the key 81 larger than the inertia moment of the hammer 82. In this case, it is possible to enhance the responsiveness of the key 81 when the key 81 is repeatedly struck.

[0073] It should be noted that the present invention is not limited to the above-described embodiment, but can be implemented in various forms. For example, although in the above-described embodiment, the inertia moments of the keys 51, 71, and 81 are made larger than the corresponding inertia moments of the first arm 31 and the hammers 72 and 82 by providing the key rear portion pressure weights 50 and 71c at the respective rear end portions of the keys 51 and 71, or by setting the engagement position between the key 81 and the hammer 82 near the front end portion of the key 81, the above-described relationship between the inertia moments of the keys 51, 71, and 81 and the corresponding inertia moments of the first arm 31 and the hammers 72 and 82 may be achieved by another appropriate method.

[0074] Furthermore, although detailed data items are omitted, preferably, the moments of inertia of the keys 51 , 71 and 81 are set so that they become predetermined multiples (for example, two to twenty times) of the respective moments of inertia of the first arm 31 and the hammers 72 and 82 .

[0075] In addition, the details of the construction of the keyboard devices 1, 70 and 80, keyboard chassis 4, keys 2, 51, 71 and 81, first arm 31, hammers 72 and 82, and key rear portion weights 50, 71c shown in the embodiments are given only by way of example, and can be modified as needed within the scope of the subject matter of the present invention.

[0076] It will also be appreciated by those skilled in the art that the foregoing is a preferred embodiment of the present invention and that various changes and modifications may be made without departing from the spirit and scope thereof.

Claims

1. A keyboard device for a keyboard musical instrument, comprising: Keyboard chassis; A key, which extends a predetermined length in the front-rear direction and is arranged on the keyboard chassis; as well as a hammer extending in the front-rear direction and pivotally supported on the keyboard chassis below the key via a hammer support shaft, the hammer engaging the key at a position forward of the hammer support shaft so as to pivotally move in a manner interlocked with the key that has been pressed, wherein the key is configured so that when pressed, the key pivotally moves about a virtual pivot located behind a rear end portion of the key or about a pivot provided on a rear end portion of the key and pivotally supported on the keyboard chassis, and The key is set so that the moment of inertia of the key is greater than the moment of inertia of the hammer.

2. The keyboard device according to claim 1, wherein: In the case where the key is configured to pivotally move about the virtual pivot, a key rear portion pressure weight made of a material having a larger specific gravity than the key is provided on a rear end portion of the key, and Wherein, when the key is configured to pivotally move about the pivot, a key rear portion weight made of a material having a larger specific gravity than the key is provided on a rear end portion of the key at a position rearward of the pivot.

3. The keyboard device according to claim 1 or 2, wherein: The hammer supporting shaft is disposed so as to be located forward of the position of the center of gravity of the key.

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