Keyboard device for keyboard musical instrument

Abstract

A keyboard device for a keyboard musical instrument, which is capable of obtaining an excellent touch during key depression and improving the responsiveness of a depressed key when performing a pivotal return movement to its original position, thereby providing appropriate string striking repeatability. The keyboard device includes: a keyboard base; a key, which is arranged on the keyboard base; and a hammer, which is pivotally moved under the key in a state interlocked with the key. When the key is configured to move pivotally around a virtual fulcrum, the key rear portion weight is arranged on the rear end of the key, and when the key is configured to move pivotally around the fulcrum, the key rear portion weight is arranged on the rear end of the key at a position behind the fulcrum. Each key rear portion weight is made of a material having a larger specific gravity than the key.

Description

Technical Field

[0001] The present invention relates to a keyboard device for a keyboard musical instrument, which is suitable for a keyboard musical instrument such as an electronic piano and includes hammers that pivotally move in a state of being interlocked with depressed keys. Background Art

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

[0003] In the keyboard device constructed as described above, when the front end of the key is pressed downward by key pressing, the first arm is pivotally moved around the first pivot axis so that the front end of the first arm moves downward, and the weight provided on the rear end of the first arm moves upward, and the second arm is pivotally moved around the second pivot axis so that the front end of the second arm moves upward, and the rear end of the second arm moves downward. Thus, the key is pivotally moved around the virtual fulcrum located behind the rear end thereof so that the front end of the key moves downward.

[0004] Then, when the player's finger is released from the key that has been pressed downward, the first arm and the second arm cause the key to perform a pivotal return movement to its original position while pivotally moving in a direction opposite to the above-described direction of the pivotal movement of the first arm and the second arm. Specifically, the first arm pushes up the front end of the key by pivotally moving, so that the 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. Furthermore, the second arm promotes the pivotal movement of the first arm by the downward movement of the front end of the second arm, and pushes up the rear end of the key by the upward movement of the rear end of the second arm. Thus, the key (whose front end pivotally moves upward around the virtual fulcrum mentioned above) performs a pivotal return movement to its original position.

[0005] In the keyboard device described above, the weight of the first arm is increased by providing a weight on the first arm, thereby obtaining a satisfactorily responsive tactile feel during key depression, and, during key release, the first arm is pivotally moved to thereby push up the key and cause the key to perform a pivotal return movement to its original position. Furthermore, as the weight of the first arm gradually increases, the response to the key depression increases, thereby further improving the tactile feel. However, when the weight of the first arm increases, thereby causing an increase in the moment of inertia of the first arm, the first arm becomes difficult to be pivotally moved. As a result, when the pressed key performs a pivotal return movement to its original position, the responsiveness of the key is reduced, which sometimes makes it impossible to obtain appropriate string striking repeatability of the key. Therefore, the keyboard device described above has room for improvement. Summary of the invention

[0006] An object of the present invention is to provide a keyboard device for a keyboard musical instrument, which is capable of obtaining an excellent touch when performing key depression, and further capable of achieving improved responsiveness when the depressed key performs a pivotal return movement to its original position, thereby making it possible to obtain appropriate string-strike repeatability.

[0007] In order to achieve the above objectives, the present invention provides a keyboard device for a keyboard musical instrument, comprising: a keyboard base; a key, which extends a predetermined length in the front-rear direction and is arranged on the keyboard base; and a hammer, which extends in the front-rear direction and is pivotally supported on the keyboard base below the key via a hammer supporting shaft, the hammer engaging with the key at a position in front of the hammer supporting shaft for being pivotally moved in a manner interlocked with the pressed key, wherein the key is configured so that when pressed, the key pivotally moves around a virtual fulcrum located behind the rear end of the key or around a fulcrum arranged on the rear end of the key and is pivotally supported on the keyboard base, wherein, in the case where the key is configured to pivotally move around the virtual fulcrum, a key rear portion weight made of a material having a larger specific gravity than the key is arranged on the rear end of the key, and wherein, in the case where the key is configured to pivotally move around the fulcrum, a key rear portion weight made of a material having a larger specific gravity than the key is arranged on the rear end of the key at a position rearward of the fulcrum.

[0008] According to this configuration, a key extending in the front-rear direction by a predetermined length is provided on the keyboard base, and a hammer extending in the front-rear direction is pivotally supported on the keyboard base via a hammer support shaft below the key. Further, the hammer engages with the key at a position in front of the hammer support shaft, and is pivotally moved in a manner interlocked with the key that has been pressed. In addition, the key described above is configured to pivotally move around a virtual fulcrum located behind its rear end or around a fulcrum provided on the rear end of the key.

[0009] In the case where the key is configured to move pivotally around the virtual fulcrum mentioned above, a weight of the rear portion of the key made of a material having a larger specific gravity than the key is provided on the rear end of the key. As a result, the weight of the key is increased to thereby increase the moment of inertia of the key. This makes it possible to provide a full response to the key pressing, thereby obtaining an excellent touch during the key pressing. Furthermore, an excellent touch can be obtained by increasing the weight of the key, thereby suppressing the increase in the weight of the hammer. As a result, compared to the case where only the weight of the hammer is increased, the responsiveness of the key when the pressed key performs a pivotal return movement to its original position can be improved, thereby obtaining appropriate string striking repeatability of the key.

[0010] On the other hand, in a case where the key is configured to move pivotally around a fulcrum provided on its rear end, a weight of the rear portion of the key made of a material having a greater specific gravity than the key is provided on the rear end of the key at a position rearward of the fulcrum. This increases the weight of the key to thereby increase the moment of inertia of the key. Thus, as in the case where the key moves pivotally around the virtual fulcrum mentioned above, an excellent touch and appropriate string striking repeatability can be obtained during key pressing. In addition, in a case where the key moves pivotally around the fulcrum, the weight of the rear portion of the key is provided behind the fulcrum so that when the key is released, the key becomes easy to move pivotally in the direction in which the key performs a pivotal return movement to its original position. As a result, when the pressed key performs a pivotal return movement to its original position, the responsiveness of the key can be improved, thereby obtaining appropriate string striking repeatability of the key.

[0011] Preferably, a key front portion weight made of a material having a larger specific gravity than the key is provided in the front portion of the key.

[0012] According to the construction of this preferred embodiment, since a weight for the front part of the key is also arranged in the front part of the key in addition to the weight for the rear part of the key described above, the moment of inertia of the key is further increased, thereby further improving the tactile feel during key depression without reducing the repeatability of the key striking.

[0013] The above objects, features and advantages and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1A and Figure 1B is a perspective view of a portion (one octave section) of a keyboard device for an electronic piano to which the present invention is applicable, 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 of the keyboard device are omitted;

[0015] Figure 2is in a state in which the white keys and the black keys are removed from the keyboard base together with the corresponding key supporting mechanisms for the white keys and the black keys Figure 1B A perspective view of the keyboard device shown in ;

[0016] Figure 3A is a plan view of the keyboard device from which keys other than white keys and black keys at the left end of the keyboard device are omitted, and, Figure 3B It is along Figure 3A A cross-sectional view taken along line AA;

[0017] Figure 4A and Figure 4B is a perspective view of white keys and key support mechanisms for the white keys, wherein Figure 4A shows the white keys and key support mechanism in a connected state, and, Figure 4B showing the white keys and key support mechanism in a disassembled state;

[0018] Figure 5A and Figure 5B is a perspective view of a black key and a key supporting mechanism for the black key, wherein Figure 5A The black keys and key support mechanism are shown in a connected state, and Figure 5B showing the black keys and key support mechanism in a disassembled state;

[0019] Fig. 6A and Figure 6B is a view useful in explaining the operation of the white keys in a keyboard device, wherein Fig. 6A shows the key release state, and, Figure 6B Shows the key pressed state;

[0020] Fig. 7A and Figure 7B is a view useful in 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 pressed state;

[0021] Figure 8 is a view useful in explaining the essential part of the present invention, which is a perspective view showing a state in which a single white key and a key supporting mechanism for the white key are provided at the left end of the keyboard base;

[0022] Fig. 9A and Fig. 9B is a view of a white key with a key rear portion weight disposed at the rear end of the white key, wherein Fig. 9A is a perspective view, and Fig. 9B It is a side view;

[0023] Fig. 10A and Fig. 10Bis a diagram showing the weight of the key rear portion from Fig. 9A and Fig. 9B A view of the state where the white key is removed, where Fig. 10A is a perspective view, and Fig. 10B is a side view; and

[0024] Fig.11A and Fig. 11B is a schematic view showing a keyboard device, each of which includes a key pivotally moving about a fulcrum located at a rear end of the key, and a hammer, wherein Fig.11A A conventional keyboard arrangement is shown, and Fig. 11B A keyboard device having a weight disposed behind a fulcrum of a key is shown. DETAILED DESCRIPTION

[0025] The present invention will now be described in detail with reference to the accompanying drawings in which preferred embodiments of the invention are shown. Figure 1A Only one octave section of the keyboard device 1 for the electronic piano to which the present invention is applied is shown. Note that, hereinafter, a description will be given first of the basic configuration of the keyboard device 1 and its operation, and then a description of the essential part of the present invention will be given.

[0026] Figure 1B Show Figure 1A 1 is a state of the keyboard device 1 shown in , in which the keys 2 except the white keys 2 a and the black keys 2 b at the left end of the keyboard device 1 are omitted. Figure 2 Show Figure 1B , in which the white keys 2 a and the black keys 2 b are removed from the keyboard base 4 together with the corresponding key support mechanisms 6 for the white keys 2 a and the black keys 2 b.

[0027] The keyboard device 1 is composed of: a keyboard base 4; a plurality of keys 2, which include white keys 2a and black keys 2b and are arranged side by side in the left-right direction; a key supporting mechanism 6, each of which is pivotally mounted on the keyboard base 4 for each key 2 so as to support an associated one of the keys 2 from below; and a key switch 3, each of which is used to detect key pressing information of an associated one of the keys 2.

[0028] The keyboard base 4 includes a base 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 Figure 3B As shown in FIG. 1 , the base body 4a has a front portion 11, a middle portion 12, and a rear portion 13, each of which is integrally formed along the left-right direction (along the Figure 3AThe front portion 11, the middle portion 12, and the rear portion 13 are formed integrally with each other via a plurality of ribs 14, which are provided with certain intervals therebetween in the left-right direction and each extend in the front-rear direction. Note that in the following description, the front portion 11, the middle portion 12, and the rear portion 13 of the base body 4a of the keyboard base 4 will be referred to as "base front portion 11", "base middle portion 12", and "base rear portion 13", respectively.

[0029] The base front portion 11 is mainly used to guide the white key 2a during the depression of the white key 2a and limit the upper limit position and the lower limit position of the front end of the white key 2a. On the base front portion 11, a plurality of white key guides 11a are erected, each of which is inserted into each associated white key 2a in the white key 2a from below, so as to prevent the white key 2a from swinging laterally in a state of being arranged side by side in the left-right direction. Furthermore, the base front portion 11 has an engagement hole 11b and an engagement hole 11b extending vertically through the base front portion 11, and the engagement hole 11b and the engagement hole 11b are respectively formed on the left and right sides of each of the white key guides 11a. The paired left upper limit position regulating portion 21 and the right upper limit position regulating portion 21 mentioned below of the white key 2a are engaged with the corresponding engagement hole 11b and the engagement hole 11b in a state of being inserted through the corresponding engagement hole 11b and the engagement hole 11b. Furthermore, the base front portion 11 has its front end formed with a stopper mounting portion 11c, which protrudes forward and extends in the left-right direction along the entirety of the base body 4a. The key upper limit stopper 16a and the key lower limit stopper 16b for the white key 2a are mounted on the lower surface and the upper surface of the stopper mounting portion 11c, respectively, so that the key upper limit stopper 16a and the key lower limit stopper 16b extend in the left-right direction. Note that the stopper mounting portion 11d for the black key extending in the left-right direction along the entirety of the base body 4a is provided at a predetermined position of the base front portion 11 behind each white key guide 11a, and the key upper limit stopper 17 for the black key is mounted on the stopper mounting portion 11d so that the key upper limit stopper 17 extends in the left-right direction.

[0030] The base middle portion 12 is mainly used to guide the black key 2b during depression of the black key 2b and swingably supports the first arm 31 and the second arm 32 described below of each of the key support mechanism 6a associated with the white key and the key support mechanism 6b associated with the black key. The base 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 with appropriate intervals provided 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 lateral swinging of the black key 2b. Furthermore, the base middle portion 12 has its front portion provided with a first arm support portion 18 for supporting the first arm 31 of the key support mechanism 6. The first arm support portion 18 has a plurality of first pivot shafts 18a, each of which is provided between the rib 14 and each adjacent two of the ribs 14 so that the first pivot shafts 18a extend in the left-right direction. The first arm 31 is swingably supported on the associated first pivot shaft 18a among the first pivot shafts 18a. In addition, the base middle portion 12 has its rear portion provided with a second arm support portion 19 for supporting the second arm 32 of the key support mechanism 6. The second arm support portion 19 has a plurality of second pivot shafts 19a, each of which is provided between the rib 14 and each adjacent two of the ribs 14, so that the second pivot shaft 19a extends in the left-right direction. The plurality of second pivot shafts 19a are arranged on the same axis extending in the left-right direction at a position higher than the first pivot shaft 18a behind the first pivot shaft 18a, and the second arm 32 is swingably supported on the associated second pivot shaft 19a among the second pivot shafts 19a. Note that the first arm lower limit stopper 10b extending in the left-right direction along the entirety of the base body 4a is provided at a predetermined position of the intermediate stop 8 mentioned below provided below the base middle portion 12.

[0031] Furthermore, the above-mentioned key switch 3 is provided on the lower portion of the keyboard base 4 between the above-described base front portion 11 and the base 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 on a key-by-key basis for being pressed by an associated one of the first arms 31 when a key is pressed.

[0032] The base rear portion 13 is mainly used to guide the key 2 in the vertical direction through the rear end of the key 2, while preventing the key 2 from swinging laterally, and to limit the upper limit position of the rear end of the associated first arm 31 in the first arm 31. Figure 2 and Figure 3A As shown in , the rear portion 13 of the base has a plurality of partition walls 13a formed with predetermined intervals therebetween in the left-right direction so as to separate each adjacent two of the keys 2 from each other. Figure 3B As shown in the figure, the first arm upper limit stopper 10a extending in the left-right direction along the entirety of the base body 4a is provided at a predetermined position of the upper portion of the base rear portion 13. The first arm upper limit stopper 10a and the first arm lower limit stopper 10b provided on the base middle portion 12 are used to limit the upper limit position and the lower limit position of the first arm 31, respectively, when the first arm 31 having a function as a hammer for adding a touch weight to the key 2 is pivotally moved upward and downward. In addition, a metal cover plate 15 extending in the left-right direction along the entirety of the base body 4a and provided to cover the rear end of the key 2 is mounted on the upper portion of the base rear portion 13.

[0033] like Figure 2 and Figure 3A As shown in FIG. 1 , the base body 4a of the keyboard base 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 pivot shafts 18a of the first pivot shafts 18a from the outside via the above-mentioned first openings 5a. Furthermore, the second arms 32 are respectively engaged with the associated second pivot shafts 19a of the second pivot shafts 19a from the outside via the above-mentioned second openings 5b.

[0034] Furthermore, in the keyboard base 4 described above, a plurality of base bodies 4a are connected to each other in a state of being arranged side by side in the left-right direction, and each is screwed to the front rail 7, the middle rail 8, and the rear rail 9 in a state of being placed on the front rail 7, the middle rail 8, and the rear rail 9, each of which is made of metal and extends in the left-right direction and is arranged with a predetermined interval therebetween in the front-back direction. The keyboard base 4 is fixed to a key bed, not shown, of an electronic piano via the front rail 7 and the rear rail 9.

[0035] 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 The white keys 2a and the key support mechanisms 6a for the white keys 2a are shown in a disassembled state. Figure 4A and Figure 4BAs 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 extending a predetermined length in the front-to-rear direction and open downward. The white key 2a has its front end formed with a pair of left upper limit position regulating parts 21 and right upper limit position regulating parts 21, which protrude downward from the corresponding side walls of the front end of the white key 2a and each have its lower end bent forward. As described above, the left upper limit position regulating part 21 and the right upper limit position regulating part 21 are engaged with the corresponding left engagement holes 11b and right engagement holes 11b of the base front part 11 in a state of being inserted through them.

[0036] Furthermore, at a predetermined position of the front portion of the white key 2a, behind the upper limit position adjusting portion 21, a key front side connecting portion 22 connected to the first arm 31 of the key supporting mechanism 6a is formed. The key front side connecting portion 22 includes a connecting recess 22a formed in a U shape having a narrow groove shape in a side view and open to the front. Furthermore, the connecting recess 22a has a buffer component 20 attached to the connecting recess 22a, and the buffer component 20 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 mentioned below of the first arm 31 slides in the inner peripheral surface of the connecting recess 22a. Note 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 weight 30 (see FIG. 2 ) for adding a desired touch weight to the white key 2a during the pressing of the white key 2a is installed. Figure 3B ).

[0037] Furthermore, the white key 2a has its rear portion 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-shaped connection body portion 23a which hangs downward from the transverse 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 right engagement protrusions 23b which coaxially protrude from the left and right sides of the connection body portion 23a, respectively. Further, the rear portion of the white key 2a is formed with a tool insertion hole 24 which extends vertically through the rear portion and is used to insert a predetermined tool into the tool insertion hole 24 from above for disconnecting the white key 2a from the second arm 32 of the key support mechanism 6a, for example, when maintaining the keyboard device 1.

[0038] 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 key 2a.

[0039] like Figure 4BAs shown in FIG. 1 , the first arm 31 is composed of an arm main body 33 and two weights 34 and the weights 34 attached to the arm main body 33. The arm main 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 main body 33 extends a predetermined length in the front-to-back direction, 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 its front end. The first arm front-side connecting portion 35 includes: a box portion 35a having a box shape that is open upward and forward; and a connecting shaft 35b, which is arranged so that it extends in the left-to-right direction in a state where the front upper ends of the left and right side walls 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.

[0040] 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 that is open downward in a side view, and is pivotally engaged with the first pivot shaft 18a of the keyboard base 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 for connection 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, wherein respective opposite ends of the connection shaft 37a protrude outward from the left and right sides of the arm main body 33. The opposite ends of the connection shaft 37a are engaged with the connection recess 45b and the connection recess 45b of the second arm front side connection portion 45 mentioned below of the second arm 32.

[0041] The two weights 34 formed as elongated and narrow plates and the weights 34 are mounted on the weight mounting portion 38 in a state of sandwiching the weight mounting portion 38, which is the rear portion of the arm body 33. Note that each 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 stamping a metal plate into a predetermined shape.

[0042] The second arm 32 is formed as a resin molded product having a predetermined shape by injection molding of the same resin material as that 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. Further, the second arm 32 has a bearing portion 41 having a C-shape opened forward in a side view near its longitudinal center. The bearing portion 41 is pivotally engaged with an associated one of the second pivot shafts 19a of the keyboard base 4.

[0043] Furthermore, the second arm 32 has its rear portion 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 forked shape, and has two left connecting arm portions 43 and right connecting arm portions 43 extending in parallel with each other by a predetermined length along the longitudinal direction of the second arm 32. Each connecting arm portion 43 has its rear end 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 the connecting arm portion 43 sandwich the connecting body portion 23a of the key rear side connecting portion 23 of the white key 2a between their rear ends from the left and right, 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.

[0044] Furthermore, the second arm 32 has its front portion 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. The connection portions 45a and 45a are each formed with a connection recess 45b having a U-shape having a slit-like shape in a side view and 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 respective opposite ends of the connection shaft 37a of the first arm 31 via the connection recesses 45b and 45b thereof.

[0045] Figure 5A The black key 2b and the key supporting mechanism 6b for the black key 2b are shown in an enlarged scale, and Figure 5B The black key 2b and the key support mechanism 6b are shown in a disassembled state. The black key 2b is formed, for example, by injection molding a resin material that is the same as the resin material of the white key 2a into a hollow shape that extends in the front-to-back direction by a predetermined length that is shorter than the predetermined length of the white key 2a and is open downward. The black key 2b has its front lower end provided with a key front side connecting portion 26 that is formed substantially the same as the key front side connecting portion 22 of the white key 2a. The key front side connecting portion 26 has a connecting recess 26a that is formed in a U shape that has a narrow groove shape in a side view and is open forward. Furthermore, the key front side connecting portion 26 has an extension portion 26b on the lower front end 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 regulating portion of the black key 2b. Note that in the following description, members of the black keys 2b and key supporting mechanisms 6b having the same configurations as those of the white keys 2a and key supporting mechanisms 6a described above are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0046] The key supporting mechanism 6b supporting the black key 2b is constructed substantially the same as the key supporting mechanism 6a associated with the white key described above. Specifically, the arm body 33 of the first arm 31 of the key supporting mechanism 6b and the second arm 32 thereof are constructed completely the same in shape and size as the arm body 33 and the second arm 32 of the key supporting mechanism 6a associated with the white key. Note that although Figure 5A and Figure 5B , the two left weights 34 and right weights 34 of the key supporting mechanism 6b for the black key 2b are illustrated exactly the same as the weights 34 and weights 34 of the key supporting mechanism 6a for the white key 2a, but the shapes and lengths of the weights 34 and weights 34 of the key supporting mechanism 6a and the key supporting mechanism 6b are changed as deemed appropriate depending on the touch weight required for the key 2, etc.

[0047] Next, a description will be given of the operations of the keys 2 and the key supporting mechanism 6 of the keyboard device 1 constructed as described above. Fig. 6A and Figure 6B It is a view useful in explaining the operation of the white keys 2a and the key support mechanisms 6a associated with the white keys 2a. Fig. 7A and Figure 7B It is a view useful in explaining the operation of the black key 2b and the key supporting mechanism 6b associated with the black key 2b.

[0048] When from Fig. 6A When the player presses the front end of the white key 2a with his / her finger from the key release state shown in FIG. 1 , the key front side connection portion 22 of the white key 2a moves downward, whereby the first arm 31 pivotally moves in the counterclockwise direction around the first pivot axis 18a. Further, in accordance with the pivotal movement of the first arm 31, the second arm front side connection portion 45 engaged with the connection axis 37a of the first arm 31 via the connection recess 45b and the connection recess 45b moves upward. Thereby, the second arm 32 pivotally moves in the clockwise direction around the second pivot axis 19a. Then, in accordance with this pivotal movement of the second arm 32, the key rear side connection portion 23 connected to the second arm 32 via the second arm rear side connection portion 42 formed at the rear end of the second arm 32 is pulled downward, whereby the rear end of the white key 2a moves downward.

[0049] Note 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 from above by the bottom wall of the box portion 35a. As a result, in the electronic piano, key depression information of the depressed key 2 is detected, and based on the detected key depression information, a sound is produced from a speaker not shown.

[0050] As described above, in the case where the white key 2a is depressed, according to the counterclockwise pivotal movement of the first arm 31, as shown in FIG. Figure 6B , the weight 34 of the first arm 31 is tilted so that the weight 34 becomes higher as it extends rearward, whereby the rear end of the weight 34 contacts the first arm upper limit stopper 10a from below. This prevents further pivotal movement of the first arm 31. When the front end of the white key 2a is pressed to its lowest position, the front end of the white key 2a contacts the key lower limit stopper 16b, which prevents further pressing of the white key 2a.

[0051] The white key 2a pressed as above is operated so that the white key 2a is pivotally moved about the virtual fulcrum P located behind its rear end. For example, the position of the virtual fulcrum P is set so that the distance from the front end of the white key 2a is approximately as long as twice the length of the white key 2a itself. Thus, when the front end of the white key 2a is pressed to the lowest position, the white key 2a is in the same position as the white key 2a. Fig. 6A Compared with the case in the key release state shown in , the front end of the white key 2a is positioned at a lower predetermined key stroke (e.g., 10 mm), and the rear end of the white key 2a is positioned at approximately half the distance of the lower predetermined key stroke (e.g., 5 mm).

[0052] On the other hand, when the finger is released from the depressed 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 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 fulcrum P. Then, a predetermined portion of the first arm 31 at the rear of the first pivot axis 18a moves to contact the first arm lower limit stopper 10b from above, and both the upper limit position regulating portion 21 of the white key 2a and the upper limit position regulating portion 21 move to contact the key upper limit stopper 16a from below, thereby preventing further pivotal movement of the white key 2a, and the white key 2a returns to its original key release state.

[0053] Furthermore, when the black key 2b is depressed, the same operation as the above-described operation of the white key 2a and the key support mechanism 6a is performed. More specifically, when the black key 2b is depressed, the white key 2a and the key support mechanism 6a are operated. Fig. 7AWhen the front end of the black key 2b is pressed down from the key release state shown in the figure, the first arm 31 pivotally moves in the counterclockwise direction around the first pivot axis 18a, and the second arm 32 pivotally moves in the clockwise direction around the second pivot axis 19a. Thus, the black key 2b is operated so that the black key 2b pivotally moves around the virtual fulcrum Q located behind its rear end. Note that, similar to the above-mentioned virtual fulcrum P of the white key 2a, the position of the virtual fulcrum 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 2b itself, for example. Therefore, when the front end of the black key 2b is pressed down to its lowest position, the position of the black key 2b is approximately twice the length of the black key 2b itself. Fig. 7A Compared to the case in the key-release state shown in , the front end of the black key 2b is positioned at a lower predetermined keystroke, and the rear end of the black key 2b is positioned nearly half the distance of the lower predetermined keystroke.

[0054] On the other hand, when the finger is released from the black key 2b that has been depressed, 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 fulcrum Q. Then, the extending portion 26b of the key front side connecting portion 26 of the black key 2b is moved to come into contact with the key upper limit stopper 17 from below, whereby further pivotal movement of the black key 2b is stopped, and the black key 2b returns to its original key-released state.

[0055] Next, refer to Figures 8 to 11A and Fig. 11B The essential part of the present invention is described. The essential part of the present invention is that the key has its rear end provided with a key rear part weight made of a material having a greater specific gravity than the key.

[0056] Figure 8 As mentioned above Figure 1B Approximately the same, and a state in which a single key (white key) 51 is provided at the left end of the keyboard base 4 is shown. This key 51 is supported from below by the key support mechanism 6 including the first arm 31 and the second arm 32 described above. Furthermore, Fig. 9A and Fig. 9B Shown at 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 Fig. 9B The key 51 shown in FIG. 1 is different from the white key 2 a described above only in that the key 51 is provided with a key rear portion weight 50 .

[0057] Specifically, the key 51 includes a weight receiving portion 52 extending backward and obliquely upward at its rear end. The weight receiving portion 52 has a box shape opened upward and is formed integrally with the key 51.

[0058] Fig. 10A and Fig. 10B 1 shows a state in which 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 Fig. 10B As shown in the figure, the key rear part weight 50 is formed into a block shape having a predetermined thickness in the left-right direction and approximately a parallelogram in a side view. The key rear part weight 50 is made of a material (e.g., metal, such as iron) having a greater specific gravity than the key 51. Note that, like the key 2 described above, the key 51 has a key weight 30 (key front part weight) mounted on the front part, and the key weight 30 is made of the same material as the key rear part weight 50 described above.

[0059] In the keyboard device including the key 51 configured as described above, similarly to the keyboard device 1 described above, when the key 51 is pressed, the key 51 pivotally moves about the virtual fulcrum located behind the rear end thereof.

[0060] The key rear portion weight 50 described above is provided on the rear end of the key 51, whereby the weight of the key 51 is increased to thereby increase the moment of inertia of the key 51. This makes it possible to provide a sufficient response to the depression of the key 51, whereby an excellent touch can be obtained during the key depression. Furthermore, an excellent touch can be obtained by the increase in the weight of the key 51, whereby an increase in the weight of the first arm 31 as a hammer can be suppressed. Thus, compared with a case in which only the weight of the first arm 31 is increased, the responsiveness of the key 51 when the depressed key 51 performs a pivot return movement to its original position can be improved, whereby appropriate string striking repeatability of the key 51 can be obtained.

[0061] Furthermore, since not only the key weight 30 but also the key rear portion weight 50 is installed on the key 51, the moment of inertia of the key 51 is further increased, thereby further improving the tactile feel during the pressing of the key 51 without reducing the repeatability of the string striking of the key 51.

[0062] Fig.11A and Fig. 11B is a schematic view showing keyboard devices, each of which includes a key pivotally moving about a fulcrum located at a rear end of the key, and a hammer. Fig.11A A conventional keyboard arrangement is shown, and Fig. 11B A keyboard device having a weight disposed behind a fulcrum of a key is shown.

[0063] Fig.11AThe conventional keyboard device shown in FIG. 1 and indicated by reference numeral 60 is composed of the following: keys indicated by reference numeral 61, which are arranged in a front-to-back direction (such as in FIG. Fig.11A The key 61 is provided with an actuator portion 61b protruding downward at its front portion. The actuator portion 61b is engaged with the front end of the hammer 62 in a state of contacting the front end of the hammer 62 from above. Furthermore, a hammer weight 62b having a predetermined weight is formed at the rear end of the hammer 62.

[0064] In the keyboard device 60 constructed as described above, when the key 61 is pressed, the key 61 moves along the Fig.11A The hammer 62 is pivotally moved in the counterclockwise direction as viewed in FIG. Fig.11A Then, when the key 61 is released, the hammer 62 moves along the counterclockwise direction as viewed in FIG. Fig.11A The key 61 is pivotally moved about the hammer support shaft 62a in the clockwise direction as viewed in FIG. 1 , whereby the key 61 is pushed up by the actuator portion 61b and moves along the Fig.11A The keyboard device 60 is pivotally moved about the fulcrum 61a in the clockwise direction as viewed in the figure to return to its original position. Note that the keyboard device 60 described above is disclosed in, for example, Japanese Laid-Open Patent Publication (Kokai) No. 2015-87591 which has been filed by the present applicant.

[0065] In contrast, Fig. 11B As shown in , the keyboard device 70 to which the present invention is applicable includes: a key designated by reference numeral 71, which extends in the front-to-back direction by a predetermined length and is pivotally movable around a fulcrum designated by reference numeral 71a located at its rear end; and a hammer designated by reference numeral 72, which extends in the front-to-back direction and is pivotally supported on the keyboard base below the key 71 via a hammer support shaft 72a. Like the key 61 of the keyboard device 60 described above, the key 71 has an actuator portion 71b protruding downward from a predetermined position of its front portion. The actuator portion 71b engages with the front end of the hammer 72 in a state of contacting the front end of the hammer 72 from above. Furthermore, the key 71 has a fulcrum 71a at the rear (as in Fig. 11BA key rear portion weight 71c is provided on the rear end of the key 71 at a position (on the right side as viewed in the figure). The key rear portion weight 71c is made of a material (e.g., metal, such as iron) having a greater specific gravity than the key 71. On the other hand, the hammer 72 has a hammer weight 72b on its rear end, and the hammer weight 72b has a predetermined weight. Since the rotational force caused by the gravity of the key rear portion weight 71c acts on the key 71 in the direction in which the key 71 performs a pivotal return movement to its original position, the hammer weight 72b can be set so that it has a smaller weight than the hammer weight 62b of the keyboard device 60 described above.

[0066] As described above, in the keyboard device 70, the key rear portion weight 71c described above is provided on the rear end of the key 71 at a position behind the fulcrum 71a, and, therefore, by increasing the weight of the key 71, the inertia moment of the key 71 increases. As in the case described above in which the key 51 is pivotally moved around the virtual fulcrum, an excellent touch and appropriate string-strike repeatability of the key 71 can be obtained during the pressing of the key 71. In addition, when the key 71 is pivotally moved around the fulcrum 71a, since the key rear portion weight 71c is provided behind the fulcrum 71a, the key 71 is easily pivotally moved in the direction of the pivotal return movement to the original position of the key 71 according to the release of the key 71. As a result, when the key 71 that has been pressed performs the pivotal return movement to its original position, the responsiveness of the key 71 can be improved, thereby obtaining appropriate string-strike repeatability of the key 71.

[0067] Note that the present invention is not limited to the embodiments described above, but the present invention can be practiced in various forms. Furthermore, the details of the configurations of the keyboard devices 1 and 70, keyboard base 4, keys 2, 51 and 71, first arm 31, hammer 72, and key rear portion weights 50 and 71c shown in the embodiments are given only by way of example, and, where appropriate, they can be modified within the scope of the subject matter of the present invention.

[0068] It will be further appreciated by those skilled in the art that the foregoing are preferred embodiments of the present invention and that various changes and modifications may be made without departing from the spirit and scope of the present invention.

Claims

1. A keyboard device for a keyboard musical instrument, comprising: Keyboard dock; A key extending a predetermined length in the front-rear direction and disposed on the keyboard base; as well as a hammer extending in the front-rear direction and being pivotally supported on the keyboard base below the key via a hammer support shaft, the hammer engaging with the key at a position forward of the hammer support shaft for being pivotally moved in a manner interlocked with the key that has been depressed, wherein the key is configured so that when pressed, the key pivotally moves about a virtual fulcrum located behind a rear end of the key or about a fulcrum provided on the rear end of the key and is pivotally supported on the keyboard base, wherein, in a case where the key is configured to move pivotally about the virtual fulcrum, a key rear portion weight made of a material having a greater specific gravity than the key is provided on the rear end of the key, and, Wherein, in a case where the key is configured to move pivotally about the fulcrum, a key rear portion weight made of a material having a greater specific gravity than the key is provided on the rear end of the key at a position rearward of the fulcrum.

2. The keyboard device according to claim 1, wherein: A key front portion weight made of a material having a larger specific gravity than the key is provided in the front portion of the key.

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