JP7208743B2 - Keyboard device for electronic keyboard instrument - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyboard device for an electronic keyboard instrument in which a hammer is rotated upward by being pushed up by the rear end of a swingable key extending in the front-rear direction, and more particularly to the structure of the portion of the hammer that contacts the key. .

2. Description of the Related Art Conventionally, a known keyboard device of this type is disclosed in, for example, Patent Document 1 already filed by the applicant of the present invention. This keyboard device includes a pivotable key extending in the front-rear direction, and a hammer vertically rotatable above the rear end of the key. The key is pivotally supported by a balance pin erected near the center in the longitudinal direction of the key. On the other hand, the hammer consists of a synthetic resin hammer body formed in the shape of an arm extending in the front-rear direction, a pair of metal weight plates attached to the front ends of the left and right sides of the hammer body, and screwed into the rear part of the lower surface of the hammer body. It consists of a capstan screw, etc. A circular arc-shaped shaft hole is formed in the rear end of the hammer body, and the shaft hole engages with the hammer support shaft of the hammer support, thereby supporting the hammer so as to be freely rotatable in the vertical direction. . A head having a spherical lower surface is provided at the lower end of the capstan screw screwed into the hammer body. The head of the capstan screw is in contact with the rear end of the upper surface of the key via a cloth made of felt.

In the keyboard device constructed as described above, in the key-released state, the capstan screw is held in a posture in which its axis is inclined with respect to the vertical line. Specifically, the lower the capstan screw is, the more rearward it is located, that is, the lower the capstan screw is. In this case, the front half of the lower surface of the head of the capstan screw contacts the rear end of the upper surface of the key.

When the front end of the key is pushed down from the key release state, the key swings about the balance pin and the rear end of the key rises. Along with this, the hammer is pushed up through the capstan screw and pivoted upward about the hammer support shaft. When the key is pushed all the way down, that is, when the front end of the key is pushed all the way down, the front end of the upper surface of the hammer abuts against the hammer stopper, preventing further rotation.

Japanese Patent Application Laid-Open No. 2013-125236 (Figs. 1 to 4)

As described above, when the hammer rotates upward as the key is depressed, the posture of the capstan screw that contacts the rear end of the upper surface of the key changes. Specifically, the head portion of the capstan screw moves forward relative to the upper end portion of the capstan screw, so that the capstan screw assumes a forward-downward inclined posture. In this case, the rear half of the lower surface of the head of the capstan screw abuts the rear end of the upper surface of the key. In other words, when the hammer rotates upward as the key is depressed, the point of contact between the rear end of the upper surface of the key and the head of the capstan screw, that is, the point of action of the key on the hammer, moves upward and the capstan screw moves upward. It moves from the front half to the rear half of the underside of the head of the stun screw. Accordingly, as the key is depressed, the distance between the hammer support shaft that rotatably supports the hammer and the point of action is gradually shortened. In this case, the load acting on the key from the hammer gradually increases, and especially when the key is pressed slowly and softly during playing, the increased load near the end of the depression makes the key heavy for the player. Sometimes I feel

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and is capable of suppressing an increase in the load acting on the key from the hammer when the key is pressed. To provide a keyboard device for an electronic keyboard instrument, which does not make a player feel that the keys are heavy, and can obtain good playability.

In order to achieve the above object, the invention according to claim 1 provides a key that extends in the front-rear direction and is swingable around a key fulcrum near the center in the length direction, and a key that extends in the front-rear direction and is at the rear end. A hammer that is vertically rotatably supported around a hammer fulcrum provided near the rear end of the key, is placed on the rear end of the upper surface of the key, and rotates in conjunction with the swing of the key. The hammer includes a hammer body that extends in the front-rear direction and is rotatable about the hammer fulcrum at the rear end thereof, and a hammer body that protrudes downward from the rear end of the lower surface of the hammer body to hold the key. a key contact portion that contacts the rear end of the upper surface from above, and the key contact portion has a distance between the contact portion that contacts the upper surface of the key and the hammer fulcrum when the hammer rotates. The key abutting part has a bottom part with a substantially arcuate side surface, and the bottom part constitutes the front half of the bottom part and can abut against the key. and a rear bottom portion which constitutes a rear half portion of the bottom portion and which cannot come into contact with the key .

According to this configuration, the key extending in the front-rear direction is swingable around the key fulcrum near the center in the longitudinal direction, and the hammer extending in the front-rear direction is positioned near the rear end of the key at its rear end. It is supported so as to be vertically rotatable around the provided hammer fulcrum. Further, the hammer has a key abutment portion that protrudes downward from the rear end portion of the lower surface of the hammer body extending in the front-rear direction and contacts the rear end portion of the upper surface of the key from above. The key contact portion is configured such that the distance between the contact portion contacting the top surface of the key and the fulcrum of the hammer is substantially constant when the hammer rotates. As a result, unlike the conventional keyboard device in which the hammer is placed on the rear end of the upper surface of the key through the capstan screw, the load applied from the hammer to the key when the hammer rotates as the key is pressed. increase can be suppressed. As a result, even when the key is pressed slowly and softly during performance, the player does not feel that the key is heavy, and a good playability can be obtained.

Further, according to the above configuration, in the key contact portion having the bottom portion whose side surface is formed in a substantially arcuate shape, the front bottom portion, which is the front half portion of the bottom portion, is configured to be able to contact the key. The rear bottom portion, which is the rear half portion of the key, is configured so as not to come into contact with the key. As a result, when the hammer rotates upward as the key is depressed, only the front bottom portion of the front half of the key contact portion of the hammer contacts the rear end of the upper surface of the key, thereby preventing the head of the capstan screw from moving upward. Unlike the conventional keyboard device in which the rear half of the key is in contact with the rear end of the upper surface of the key, it is relatively easy to shorten the distance between the abutting portion where the key abutting portion is in contact with the upper surface of the key and the fulcrum of the hammer. can be suppressed, and thereby the above-described actions and effects can be easily realized.

According to a second aspect of the invention, in the keyboard device for an electronic keyboard instrument according to the first aspect, the key is provided on the rear end of the upper surface of the key immediately in front of the key abutting portion, and is positioned on the lower surface of the hammer when the key is released. A hammer cushion with a predetermined portion abutting from above is further provided, and the front bottom portion is arcuate with a predetermined radius of curvature in order to maintain the hammer in substantially the same posture when the key is released before and after the hammer cushion is deformed over time. characterized by being formed in

According to this configuration, a hammer cushion is provided on the rear end portion of the upper surface of the key immediately in front of the key contact portion, and in the key released state, a predetermined portion of the lower surface of the hammer contacts from above. As a result, when the depressed key is released, the hammer returns to its original position by coming into contact with the hammer cushion, thereby suppressing the impact and momentum when the hammer returns to its original position. .

Further, when the electronic keyboard instrument is used for a long period of time, the hammer cushion is repeatedly pressed from above by the hammer, so that the hammer cushion is gradually crushed and deformed over time. In this case, when the front bottom portion of the key contact portion is formed in an arc shape having a relatively small radius of curvature, the posture of the hammer in the key released state is different from the proper posture of the hammer cushion before deformation over time. As a result, the timing and volume of musical tones generated by the electronic keyboard instrument may deviate from proper ones. Therefore, the front bottom portion of the key contact portion is formed in an arc shape having a relatively large predetermined radius of curvature so that the hammer remains substantially in the same posture in the key released state before and after the hammer cushion is deformed over time. As a result, even if the hammer cushion deforms over time, it is possible to maintain the hammer in a proper posture for a long period of time in the key-released state, thereby preventing the above problems from occurring.

The invention according to claim 3 is the keyboard device for an electronic keyboard instrument according to claim 1 or 2 , wherein the key contact part is formed integrally with the hammer body and has a convex shape projecting downward. It is characterized by comprising a convex portion, a convex portion cover having a front bottom portion and a rear bottom portion and detachably attached to the contact convex portion.

According to this configuration, by attaching the projection cover having the front bottom portion and the rear bottom portion to the contact projection integrally formed with the hammer body, the key contact portion having the front bottom portion and the rear bottom portion can be compared. can be configured easily. In addition, since the projection cover can be attached to and detached from the contact projection of the hammer body, when the design of the front bottom and rear bottom is changed, only the projection cover can be changed without changing the entire hammer. can be easily dealt with.

1A and 1B show a part of a keyboard device of an electronic piano to which a keyboard device according to an embodiment of the present invention is applied, wherein (a) is a perspective view and (b) is a side view; FIG. 10 is a perspective view showing a part of the front rail on which the front pin is erected and the front of the reed, in which (a) shows a state in which the front of the reed is attached to the front rail, and (b) shows a state in which the front rail is omitted. FIG. 2 is a perspective view showing two pre-reed molded products that are connected to each other, where (a) is a state in which both pre-reed molded products before and after connection are viewed obliquely from above, and (b) is both reeds before and after connection. The state when the pre-molded product is viewed obliquely from below is shown. FIG. 2 is a plan view showing two pre-reed molded products to be connected to each other, (a) showing a state where both pre-reed formed products are connected, and (b) showing a state before both pre-reed formed products are connected. (a) is a perspective view showing a white key and a black key, and (b) is an enlarged perspective view of rear end portions of both keys, showing a hammer contact height regulating portion and a hammer cushion of each key. is decomposed and shown. 1 is a perspective view showing a hammer support, (a) showing the entire hammer support for one octave, (b) showing a partially cutaway state, and showing an enlarged cross section of the hammer fulcrum shaft. . It is a figure which shows a hammer support, (a) is a top view, (b) is a front view. FIG. 3 is a perspective view showing a hammer; FIG. 4 is a diagram for explaining a hammer and a projection cover attached to its contact projection, (a) is a side view of the hammer, and (b) is a view of the hammer centered on the contact projection and the projection cover. It is sectional drawing which cut|disconnected one part lengthwise, (c) is a perspective view which shows a convex part cover. FIG. 4 is an enlarged view of the rear portion of the hammer for explaining the contact position of the hammer with respect to the key; 10(a) and 10(b) correspond to FIGS. 10(a) and 10(b), respectively, and are enlarged views showing the rear part of the hammer of the comparative example. FIG. 10 is a diagram showing an example of changes in load according to key strokes from the start of key depression to the end of key release, for an example and a comparative example; FIG. 10 is a diagram showing an example of transition of keystrokes when a key is fully depressed and returned to the original position by releasing the key, in the example and the comparative example;

Preferred embodiments of the present invention will now be described in detail with reference to the drawings. 1(a) and 1(b) show a part of the keyboard device of an electronic piano to which the keyboard device according to one embodiment of the present invention is applied in the key-released state. As shown in both figures, this keyboard device 1 includes a large number of keys 2 (two white keys 2a and one black key 2b are shown in FIG. 1(a)) arranged in the horizontal direction of an electronic piano. A keyboard chassis 3 supporting a key 2, a hammer support 4 connected to the rear end of the keyboard chassis 3, and a large number of hammers provided for each key 2 and rotating in conjunction with the depressed key 2. 5 (in FIG. 1A, one hammer 5a for the white key and one hammer 5b for the black key are shown), and a large number of hammers 5 are provided for each hammer 5 to give a let-off feeling when the key 2 is depressed. It consists of a let-off part 6 (only one is shown in FIG. 1(b)), a key switch 7 for detecting key depression information of the key 2, and the like.

The keyboard chassis 3 includes three support rails 9 each extending in the left-right direction and including a front rail 9a, a middle rail 9b, and a rear rail 9c arranged at a predetermined distance in the front-rear direction, and a plurality of support rails 9 extending in the front-rear direction. and the reinforcing ribs 10 are assembled in a parallel cross shape, and fixed on a shelf plate (not shown). Each of these support rails 9 and ribs 10 is composed of a metal plate formed into a predetermined shape by punching and bending by a press.

A front reed 11 and a middle reed 12 are fixed to the lower surface of the front rail 9a and the upper surface of the middle rail 9b, respectively. The front reed 11 and the middle reed 12 are made of synthetic resin and have a thick plate-like shape, and extend in the left-right direction over the entire front rail 9a and middle rail 9b. In the reed middle 12, a number of balance pins 13 (key fulcrums) are provided at front and back positions corresponding to the white keys 2a and the black keys 2b. (the balance pin 13b is shown in the figure) are erected in a state of being aligned in the left-right direction. In addition, a large number of front pins 14 are erected on the reed front 11 in a state of being aligned in the left-right direction.

FIG. 2 shows the front rail 9a on which the front pin 14 is erected and part of the reed front 11. (a) shows the state where the reed front 11 is attached to the front rail 9a, and (b) shows the front rail. 9a is omitted. As shown in FIG. 4A, the top plate 15 of the front rail 9a has a plurality of pin openings 15a having a diameter larger than the outer diameter of the front pins 14 at positions corresponding to the plurality of front pins 14 respectively. are formed, and the front pins 14 protrude upward through these pin openings 15a. The two screws 16, 16 shown in FIG. 2 are for fixing the front portion of the rib 10 (see FIG. 1(b)) of the keyboard chassis 3 to the lower surface of the top plate 15 of the front rail 9a. .

The reed front 11 is configured by connecting a plurality of reed front moldings 21 extending in the left-right direction to each other in the left-right direction. 3 and 4 show two pre-reed moldings 21, 21 forming part of the pre-reed 11. FIG. Each pre-reed molded product 21 is made of a predetermined synthetic resin (for example, ABS resin or polystyrene), and includes a main body portion 22 having a plurality of pin holes 22a and 22b for fixing the front pins 14, and a right end of the main body portion 22. A right connecting portion 23 and a left connecting portion 24 are provided so as to protrude from the front portion and the left end portion, respectively, and connect the adjacent reed front molded products 21, 21 to each other.

At the front end of the main body 22, seven pin holes 22a are formed in the left-right direction for erecting the front pins 14a (see FIGS. 1 and 2) for the white keys 2a with their lower ends being press-fitted. They are formed at predetermined intervals. On the other hand, at the rear end of the main body 22, there are five pin holes 22b for erecting front pins 14b (see FIGS. 1 and 2) for the black keys 2b in the same manner as for the white keys 2b. They are formed at predetermined intervals in the direction. Each pre-reed molded product 21 shown in FIGS. 3 and 4 is configured to correspond to one octave.

On the other hand, the right connecting portion 23 and the left connecting portion 24 are formed such that the lower half and the upper half thereof are substantially notched, respectively. In addition, the right connecting portion 23 of one pre-reed molded product 21 and the left connecting portion 24 of the other pre-reed molded product 21 are not movable relative to each other in the front-rear direction and the left-right direction while being vertically fitted to each other. is configured to engage a

Specifically, the right connecting portion 23 includes a base portion 25 that is continuous with the right end portion of the main body portion 22 and has a width in the front-rear direction approximately equal to that of the base portion 25, and projects rightward from the base portion 25 and has a horizontal T-shape in plan view. It has a connecting engagement protrusion 26 formed in a shape. That is, the connecting engagement convex portion 26 includes a narrow width portion 26a having a width smaller than the width of the base portion 25 in the front-rear direction and projecting rightward from the base portion 25 by a predetermined length. A widened portion 26b protrudes rightward by a predetermined length and has a width in the front-rear direction that is larger than that of the narrow portion 26a and smaller than that of the base portion 25. As shown in FIG.

Further, the base portion 25 of the right connecting portion 23 is formed with long holes 25a and 25b that penetrate vertically and slightly extend laterally at the front and rear ends, respectively. Further, as shown in FIG. 3(b), a cylindrical screw projection 26c protrudes downward for a predetermined length at a predetermined position on the lower surface of the connecting engagement projection 26 and has a female thread formed on the inner peripheral surface. is projected.

On the other hand, the left connecting portion 24 is connected to the left end portion of the main body portion 22, and has substantially the same planar shape as the above-described base portion 25 and the connecting engagement convex portion 26 of the right connecting portion 23, and is one step lower by the thickness thereof. It has a connecting engagement recess 27 formed in the . More specifically, the connecting engagement concave portion 27 corresponds to the narrow width portion 26a and the widened portion 26b of the connecting engagement convex portion 26, respectively, and has the narrow width portion 27a and widened width portion 27a having substantially the same inner dimensions as the outer dimensions thereof. A portion 27b is provided. In addition, an insertion hole 27c is formed in the center of the connection engagement recess 27 so as to penetrate vertically and into which the screw projection 26c is inserted when the reed front molded products 21, 21 are connected to each other. Further, elongated holes 28a and 28b are formed in the left front end and rear end of the connecting engagement recess 27, respectively, so as to penetrate in the vertical direction and extend slightly in the horizontal direction.

In addition, the left connecting portion 24 is provided with a plurality of (four in this embodiment) adhesive injection holes 29 for injecting adhesive from the lower surface side to the upper surface side. Specifically, an adhesive injection hole 29 penetrating vertically is formed around the insertion hole 27c of the connecting engagement recess 27. As shown in FIG. A plurality of (eight in this embodiment) grooves 29a are formed on the upper surface of the connecting engagement recess 27 so as to extend radially in the radial direction while continuing from each adhesive injection hole 29. As shown in FIG.

The reed front molded product 21 configured as described above constitutes the reed front 11 extending in the left-right direction by being connected as follows. First, in the two pre-reed molded products 21, 21 to be connected, the connecting engagement convex portion 26 and the screw convex portion 26c of one of the pre-reed molded products 21 are connected to the connecting engagement concave portions 27 of the other pre-reed molded product 21. and the insertion hole 27c from above. Next, the crimping screw 31 is screwed into the screw protrusion 26c inserted into the insertion hole 27c (see FIG. 3(b)). A predetermined adhesive is injected into each of the four adhesive injection holes 29 . As a result, the adhesive injected into each adhesive injection hole 29 flows into each radial groove 29a connected to the adhesive injection hole 29, and the connecting engagement projection 26 of one pre-reed molded product 21 and the other The connecting engagement concave portion 27 of the pre-reed molded product 21 is adhered.

As described above, the reed front 11 configured by connecting the plurality of pre-reed molded products 21 is the front side of the left and right connecting portions 23 and 24 of the two reed front molded products 21 and 21 that are connected to each other. Mounting screws 32a and 32b are inserted from below into the long holes 25a and 28a and the rear long holes 25b and 28b, respectively, and are fixed to the front rail 9a by screwing them into the screw holes of the top plate 15 of the front rail 9a. .

FIG. 5(a) shows white keys 2a and black keys 2b. As shown in the figure, the key 2 includes a wooden key body 41 extending in the front-rear direction and having a rectangular cross-section, and a synthetic resin key cover 42 adhered to the upper surface and front surface of the front half of the key body. have. A balance pin hole 43 is formed near the center in the length direction of the key body 41 , and the key 2 swings through the balance pin hole 43 on the balance pin 13 erected in the reed center 12 . freely supported.

Each balance pin hole 43 of the key 2 is formed in the vicinity of the lower surface of the key body 41 in a substantially circular shape, and the entire upper part connected to the hole is formed in the shape of an elongated hole extending in the longitudinal direction of the key body 41 . ing. Further, felt 43a is provided on the left and right inner surfaces of the balance pin hole 43 so that the key 2 slides smoothly on the balance pin 13 when the key 2 swings.

A cushion 44 is adhered to the upper surface of the key body 41 behind the balance pin hole 43 . This cushion 44 is for preventing the front end of the hammer 5 from hitting the key 2 directly during performance or maintenance.

A downwardly opening front pin hole 45 (see FIG. 1(b)) is formed at a predetermined position in the front portion of the key body 41, and the front pin hole 45 is erected on the front of the reed 11. By engaging with the front pin 14, it is possible to prevent the key 2 from wobbling in the left-right direction when it swings.

Further, as shown in FIGS. 5(a) and 5(b), at the rear end portions of the key bodies 41 of the white key 2a and the black key 2b, there is provided a contact height of the hammer 5 in the key released state. A hammer contact height regulating portion 46 and a hammer cushion 47 are attached to which the hammer 5 contacts when the key is released, and which contacts when the hammer 5 returns to its original position after being rotated in response to key depression.

The hammer contact height regulating portion 46 is formed of a molded article having a predetermined shape and made of hard synthetic resin (for example, ABS resin). Specifically, an upper piece 51 extending a predetermined length in the front-rear direction, a rear piece 52 continuing to the rear of the upper piece 51 and extending downward, and a lower piece continuing to the lower end of the rear piece 52 and extending forward for a predetermined length. 53, the side surface is formed in a U-shape. A side wall 54 that continues to the upper piece 51 and the rear piece 52 is provided on the left side surface of the hammer contact height regulating portion 46 .

As shown in FIG. 5(b), the upper piece 51 constitutes a front half portion thereof, and has an upper piece fixing portion 51a for fixing the upper piece 51 itself to the rear end portion of the upper surface of the key body 41, and an upper piece fixing portion 51a. It has a hammer receiving portion 51b which constitutes the rear half of 51 and has a flat upper surface for receiving a key contact portion 76 of the hammer 5 while supporting it from below. The upper piece fixing portion 51a is formed to be thinner than the hammer receiving portion 51b, and the upper piece 51 is attached to the rear end portion of the upper surface of the key body 41 by driving a U-shaped fixing metal fitting (not shown) from above. is fixed to

The block-shaped hammer cushion 47 is fixed on the upper piece fixing portion 51a of the upper piece 51 by adhesion. The hammer cushion 47 is made of soft urethane foam having low impact resilience. This flexible urethane foam has low impact resilience, is lightweight, and has excellent shock absorption and cushioning properties. When the hammer 5 returns to its original position before the key is depressed with the release of the key after the key is depressed, the hammer cushion 47 is in contact with the cushion abutting portion 84 of the hammer 5, which will be described later. It is intended to suppress the momentum of

The hammer contact height regulating portion 46 has three surfaces, namely, the lower surface of the upper piece 51, the front surface of the rear piece 52, and the side wall 54, which correspond to the upper surface, the rear end surface, and the left side surface of the rear end portion of the key body 41, respectively. , and the lower piece 53 is attached to the rear end portion of the key body 41 in a state of contact with the rear end portion of the lower surface of the key body 41 .

As shown in FIG. 1(b), the key 2 to which the hammer contact height regulating portion 46 is attached is such that the rear piece 52 of the hammer contact height regulating portion 46 rests on the rear rail 9c when the key is released. It rests on a fixed cushion 55 . As a result, the height of the hammer receiving portion 51b of the hammer contact height regulating portion 46 is the same for all the keys 2 in the key-released state.

6 and 7 show the hammer support 4. FIG. As shown in both figures, the hammer support 4 is made of synthetic resin, for example, is formed by connecting a plurality of moldings corresponding to one octave in the horizontal direction. , are screwed to the rear rail 9c of the keyboard chassis 3. As shown in FIG. The hammer support 4 is composed of a hammer support portion 61 erected near the rear rail 9c, a switch mounting portion 62 extending obliquely upward from the upper end portion of the hammer support portion 61, and the like. A hammer fulcrum shaft 63 (hammer fulcrum) for rotatably supporting each hammer 5 is provided at the upper end portion of the hammer support portion 61 .

Further, the hammer support 4 has a plurality of partition walls 64 partitioning the adjacent hammers 5 with a predetermined interval in the left-right direction. A shaft 63 extends in the left-right direction. As shown in FIG. 6(b), the hammer fulcrum shaft 63 has a so-called elliptical cross-sectional shape obtained by notching two front and rear portions of a circle centered on the axis of the hammer fulcrum shaft 63. As shown in FIG.

Specifically, the outer peripheral surface of the hammer fulcrum shaft 63 is composed of a pair of upper and lower curved surface portions 63a, 63a and a pair of front and rear flat portions 63b, 63b extending between the curved surface portions 63a, 63a. . In the hammer fulcrum shaft 63 configured in this manner, the upper and lower curved surface portions 63a, 63a are set to arcs having a diameter of length L1, while the distance between the front and rear flat portions 63b, 63b is the length L1. is set to a length L2 that is shorter than

8 and 9(a) show the hammer 5. FIG. As shown in both figures, the hammer 5 has an arm-shaped hammer body 71 extending in the front-rear direction, and two weight plates 72, 72 attached via rivets 70 to the front ends of the left and right sides thereof. are doing. The hammer body 71 is made of hard synthetic resin, and the weight plate 72 is made of a metal material having a relatively large specific gravity, such as iron.

An engaging portion 73 that engages with the hammer fulcrum shaft 63 of the hammer support 4 is provided at the rear end portion of the hammer body 71 . The engaging portion 73 is formed with an arc-shaped shaft hole 74 having a C-shaped side surface. , 75 are provided. The shaft hole 74 has a diameter slightly larger than the diameter (length L1) of the upper and lower curved surface portions 63a, 63a of the hammer fulcrum shaft 63. , 63b and is slightly longer than the length L1. The hammer 5 can be attached to and detached from the hammer fulcrum shaft 63 of the hammer support 4 through the opening of the shaft hole 74. When the shaft hole 74 engages with the hammer fulcrum shaft 63, the hammer It is rotatably supported by the support 4 .

As shown in FIG. 9(a), a key contact portion 76 protrudes downward at a predetermined position on the rear bottom surface of the hammer 5 and contacts the hammer contact height regulating portion 46 of the key 2 from above. is provided. The key contact portion 76 includes a contact protrusion 77 integrally formed with the hammer body 71 of the hammer 5 and a protrusion cover 78 attached to the hammer body 71 so as to cover the contact protrusion 77 . It consists of

As shown in FIG. 9B, the contact projection 77 of the key contact portion 76 protrudes downward and has an arcuate lower surface. Further, the hammer body 71 is formed with a hook receiving portion 79 that engages with a hook 82 of the projection cover 78 , which will be described later, on the upper front side of the contact projection 77 . The hook receiving portion 79 is formed in a concave shape that opens downward, and has an engaging concave portion 79a at its upper end.

On the other hand, the projection cover 78 is made of a predetermined elastic material (e.g., elastomer) and is a molded product having a predetermined shape. Specifically, as shown in FIGS. 9(b) and 9(c), the projection cover 78 includes a cover body 81 that is opened upward and accommodates the contact projection 77 in a covered state, and the cover. A hook 82 extends upward from the front end of the body 81 and engages the hook receiving portion 79 of the hammer body 71 .

As shown in FIGS. 9B and 9C, the front half of the bottom surface of the cover body 81 (the left half of FIG. 9B) has an arcuate front bottom portion having a relatively large radius of curvature. 81a is provided, while the rear half portion is provided with an arcuate rear bottom portion 81b having a smaller radius of curvature than the front bottom portion 81a. The rear bottom portion 81b is formed as if the rear half portion of the bottom portion of the cover main body 81 is notched, and is located inside (upper side) the imaginary line when the arc-shaped outline of the front bottom portion 81a is extended rearward. ), it is formed to have a step.

Further, a claw portion 82a is provided at the upper end portion of the hook 82 of the convex portion cover 78, and the claw portion 82a is engaged with the locking concave portion 79a of the hook receiving portion 79, whereby the convex portion cover 78 is closed. is firmly attached to the hammer body 71 while being attached to the contact projection 77 .

As shown in FIGS. 8 and 9A, the bottom surface of the hammer body 71 is provided with a cushion contact portion 84 (predetermined portion) that contacts the hammer cushion 47 fixed to the rear end portion of the upper surface of the key 2. ing. The cushion contact portion 84 is provided at a predetermined position in front of the key contact portion 76 and has a flat lower surface.

Further, the hammer main body 71 is provided with an actuator portion 86 for actuating the key switch 7 by pressing it when the key is pressed, above the front side of the engaging portion 73 at the rear end portion. Further, the hammer main body 71 has a plate-shaped engaging projection 87 protruding near the center in the front-rear direction of the upper surface thereof, which engages with the let-off component 6 when the key is depressed.

As shown in FIG. 1, the key switch 7 is composed of a switch board 7a made of a printed circuit board and a switch body 7b made of a rubber switch provided for each key 2 on the lower surface of the switch board 7a. The rear end of the switch board 7 a is inserted into the switch mounting portion 62 of the hammer support 4 and screwed to the switch mounting portion 62 . Further, the switch body 7b faces the actuator portion 86 of the hammer 5 with a gap therebetween in the key-released state.

The let-off part 6 is made of an elastic material and has a predetermined shape, and is attached to the switch attachment portion 62 of the hammer support 4 as shown in FIG. The let-off component 6 extends obliquely downward from the switch mounting portion 62, and a head portion 6a is formed at the distal end thereof via a constricted portion. The head 6a faces the engagement projection 87 of the hammer 5 in the key-released state.

Further, as shown in FIG. 1, the switch mounting portion 62 of the hammer support 4 is provided with a hammer stopper 88 on the bottom surface of the front end portion thereof for restricting the upward rotation of the hammer 5 . The hammer stopper 88 is attached to the switch attachment portion 62 so as to extend in the left-right direction.

Next, the operation of the keyboard device 1 configured as described above will be described. When the key 2 is pressed from the key-released state shown in FIG. 1, the key 2 rotates about the balance pin 13 in the counterclockwise direction in FIG. It is pushed up via the contact portion 76 and rotates upward (clockwise in FIG. 1B) about the hammer fulcrum shaft 63 .

During rotation of the hammer 5, the engaging projection 87 engages with the head 6a of the let-off part 6 and presses the let-off part 6 through the head 6a while compressing the let-off part 6. , the reaction force acting on the hammer 5 increases. As the rotation of the hammer 5 progresses, the engaging projection 87 is disengaged from the head 6a, and the reaction force from the let-off component 6 disappears rapidly. Such an increase and disappearance of the reaction force of the let-off part 6 provides a let-off feeling similar to that of an acoustic piano.

After that, the front portion of the hammer 5 comes into contact with the upper hammer stopper 88, thereby completing the upward rotation of the hammer 5. As shown in FIG. During the upward rotation of the hammer 5, the actuator portion 86 presses the switch body 7b of the key switch 7 to turn on the key switch 7, thereby pressing the key 2 according to the amount of rotation of the hammer 5. Key information is detected and output to a sound generation control device (not shown). Then, the sound generation control device controls the sound generation of the electronic piano based on the detected key depression information.

Here, with reference to FIGS. 10 to 12, the contact state between the key 2 and the hammer 5 and the weight of the touch when the key is pressed will be described. 10(a) and 10(b) respectively show the contact position of the hammer 5 against the key 2 in the key-released state and the key-pressed state, that is, the hammer contact height regulating portion 46 at the rear end of the key 2. It shows the contact position of the key contact portion 76 of the hammer 5 with respect to the receiving portion 51b (only the position of the upper surface is shown in FIGS. 10 and 11). As shown in FIG. 10(a), in the key-released state, the key abutment portion 76 of the hammer 5 is positioned such that the predetermined position P1 of the front bottom portion 81a of the bottom surface of the convex cover 78 of the hammer 5 touches the hammer receiving portion 51b of the key 2. abutting. In this case, there is a distance R1 between the center of the hammer fulcrum shaft 63 of the hammer support 4 and the predetermined position P1. Also, in this case, the cushion contact portion 84 of the hammer 5 is placed on the hammer cushion 47 of the key 2 .

Further, as shown in FIG. 10(b), in the key depression state, the key contact portion 76 of the hammer 5 is positioned on the bottom surface of the convex cover 78 at a predetermined position of the front bottom portion 81a, more specifically, at the predetermined position. A predetermined position P2 of the rear end portion of the front bottom portion 81a abuts on the hammer receiving portion 51b of the key 2 slightly behind the position P1. In this case, the distance R2 between the center of the hammer fulcrum shaft 63 of the hammer support 4 and the predetermined position P2 is substantially the same as the distance R1 in the key released state (R2≈R1). In other words, from the start to the end of key depression of the key 2 (the state in which the key 2 is fully depressed), the point of contact between the hammer receiving portion 51b of the key 2 and the key contact portion 76 of the hammer 5, that is, the key to the hammer 5 2 and the center of the hammer fulcrum shaft 63 are substantially constant.

On the other hand, FIGS. 11(a) and 11(b) correspond to FIGS. 10(a) and 10(b), respectively. 4 shows a comparative example in which a projection cover 90 having an arc-shaped bottom portion 90a with a smooth bottom surface is used and the hammer cushion 47 is omitted from the rear end portion of the upper surface of the key 2. FIG. In the key-released state shown in FIG. 11A, the key contact portion 76 of the hammer 5 contacts the hammer receiving portion 51b of the key 2 at a predetermined front position Q1 on the bottom portion 90a of the projection cover 90. . In this case, the distance S1 between the center of the hammer fulcrum shaft 63 of the hammer support 4 and the predetermined position Q1 is substantially the same as the distance R1 shown in FIG. 10(a) (S1≈R1).

11B, the key contact portion 76 of the hammer 5 contacts the hammer receiving portion 51b of the key 2 at a predetermined position Q2 on the rear side of the bottom portion 90a of the projection cover 90. in contact with In this case, the distance S2 between the center of the hammer fulcrum shaft 63 of the hammer support 4 and the predetermined position Q2 is shorter than the distance S1 (S2<S1). That is, in the comparative example in which the convex cover 90 is applied to the key contact portion 76 of the hammer 5, the point of action of the key 2 on the hammer 5 and the hammer fulcrum shaft 63 The distance from the center of the gradually decreases.

FIG. 12 shows an example of the key stroke, which is the downward displacement of the front end of the key 2 when the key is pressed, and the transition of the load as the touch weight corresponding to the key stroke. A solid line) and a comparative example (dashed line) are shown from the start of key depression to the end of key release. As shown in the figure, there is not much difference between the example and the comparative example in the keystroke range of 0 mm to about 6 mm. In addition, when the key stroke is in the range of about 6 mm to about 8 mm, the let-off feeling is caused by the increase and disappearance of the reaction force of the let-off part 6, and the same let-off feeling is obtained in both the example and the comparative example. there is

Furthermore, in the key stroke range of about 8 mm to about 9 mm, the increase in load in the comparative example is greater than that in the example. Therefore, in the comparative example, the depression of the key 2 feels heavy immediately after the let-off feeling is given. On the other hand, in the example, immediately after the let-off feeling is imparted, the load rises more gently than in the comparative example, and the depression of the key 2 does not feel heavy, and a touch feeling similar to that of an acoustic piano is obtained. be able to. The reason why the load suddenly increases when the key stroke is in the range of about 9 mm to about 10 mm is that the hammer 5, which has been rotated upward, abuts against the hammer stopper 88, preventing further rotation. It is due to

When the key 2 is released after the key 2 has been depressed, the hammer 5, which had been rotating upward, rotates downward due to its own weight. downwards. As a result, the key 2 rotates in the direction opposite to that when the key is depressed, and returns to the key-released state shown in FIG. In this case, the cushion contact portion 84 of the hammer 5 abuts against the hammer cushion 47 of the key 2 from above, thereby suppressing the bounce.

FIG. 13 shows an example of the transition of the key stroke when the key 2 is fully depressed and then returns to the original position when the key is released. 47 is shown for a comparative example (broken line) in which 47 is omitted. The 0 mm position of the key stroke shown in the figure is the position of the key 2 in the key released state (hereinafter referred to as "reference position").

When the key 2 starts to be released from the fully depressed state, as shown in FIG. 13, in both the embodiment and the comparative example, after the front end of the key 2 rises, the key 2 vibrates vertically around the reference position. to stop. The vibration of the key 2 is caused by the upward and downward momentum caused by the momentum when the hammer 5, which has been rotating upward, rotates downward and returns to its original position.

As described above, in the comparative example, since there is no hammer cushion 47 on the rear end of the upper surface of the key 2, when the hammer 5 that has been rotated upward returns to its original position, the vertical momentum is not suppressed. . For this reason, as indicated by the dashed line in FIG. 13, the key 2 of the comparative example vibrates relatively large up and down around the reference position, and it takes a long time to stop.

In contrast, in the embodiment, when the hammer 5 that has been rotated upward returns to its original position, the impact of the hammer 5 is suppressed by coming into contact with the hammer cushion 47 from above. As a result, as shown by the solid line in FIG. 13, the key 2 of the embodiment suppresses the vibration of the key 2 centering on the reference position and shortens the time until the key 2 stops compared to the comparative example.

As described in detail above, according to the present embodiment, the hammer 5, which is rotated upward when the key 2 is pressed, rotates downward when the key is released, and returns to the original position before the key is pressed. Then, it abuts on the hammer cushion 47 at the rear end of the upper surface of the key 2 via the cushion abutting portion 84 . As a result, it is possible to suppress the momentum when the hammer 5 returns to its original position after the key is pressed, and as a result, the key 2 quickly returns to its original position before the key is pressed, enabling quick performance and good performance. You can get sex.

Further, the hammer cushion 47 is provided at the rear end portion of the upper surface of the key 2 (the upper fixing portion 51a of the hammer contact height regulating portion 46). A portion 84 is provided immediately in front of the key contact portion 76 as a point of action when the key 2 rotates the hammer 5 . As a result, for example, when the hammer 5 returns to its original position before the key is depressed, the hammer 5 can be moved relatively quickly compared to the case where the front end of the lower surface of the hammer 5 contacts the hammer cushion. The cushion 47 can be brought into contact with the hammer cushion 47, and the impact applied to the hammer cushion 47 can be reduced. As a result, when the hammer 5 returns to its original position before the key is pressed, the effect of suppressing the bounce of the hammer 5 can be obtained in a relatively wide rotation range, and the hammer cushion 47 can be used for a long period of time. can.

Further, in the key contact portion 76 of the hammer 5, when the hammer 5 rotates, only the front bottom portion 81a contacts the rear end portion of the upper surface of the key 2 (the hammer receiving portion 51b of the hammer contact height regulating portion 46). Due to the contact, the distance between the contact portion and the center of the hammer fulcrum shaft 63 of the hammer support 4 is substantially constant. As a result, an increase in the load acting on the key 2 from the hammer 5 can be suppressed when the hammer 5 rotates as the key is depressed. As a result, even when the key 2 is pressed down slowly and lightly pressed during performance, the key 2 does not feel heavy to the player, and good playability can be obtained.

Further, when the electronic piano is used for a long period of time, the hammer cushions 47 may be gradually crushed by repeated pressing of the hammers 5, and the top surface height of the hammer cushions 47 may be lowered. However, since the front bottom portion 81a of the key contact portion 76 of the hammer 5 is formed in an arcuate shape having a relatively large radius of curvature, even if the top surface height is lowered, the contact between the hammer 5 and the key 2 will be minimized. The contact height hardly changes, so that the hammer 5 can be maintained in a proper posture for a long period of time in the key released state.

It should be noted that the present invention is not limited to the above described embodiments and can be implemented in various ways. For example, in the embodiment, in the key contact portion 76 of the hammer 5, the front bottom portion 81a that can contact the key 2 and the rear bottom portion 81b that cannot contact the key 2 are formed on the bottom portion of the convex cover 78. The present invention is not limited to this, and can be molded integrally with the hammer body 71 .

Further, the detailed configurations of the keyboard device 1, the keys 2, the hammers 5, and the key abutting portions 76 shown in the embodiment are only examples, and can be appropriately changed within the scope of the present invention.

1 keyboard device 2 key 4 hammer support 5 hammer 13 balance pin (key fulcrum)
47 Hammer cushion 51 Upper piece 51b Hammer receiving portion 63 Hammer fulcrum shaft of hammer support (hammer fulcrum)
71 hammer body 76 key contact portion 77 contact convex portion 78 convex portion cover 81 cover main body 81a front bottom portion 81b of cover main body rear bottom portion 84 cushion contact portion (predetermined portion)
P1 Contact portion P2 Contact portion

Claims (3)

a key extending in the front-rear direction and freely swinging about a key fulcrum near the center in the length direction;
It extends in the front-rear direction and is supported at its rear end so as to be rotatable in the vertical direction about a hammer fulcrum provided near the rear end of the key. a hammer that rotates in conjunction with the swing of the
with
The hammer
a hammer body extending in the front-rear direction and rotatable about the hammer fulcrum at its rear end;
a key abutting portion that protrudes downward from the rear end of the lower surface of the hammer body and contacts the rear end of the upper surface of the key from above;
has
The key contact portion is configured such that the distance between the contact portion contacting the upper surface of the key and the hammer fulcrum is substantially constant when the hammer rotates ,
The key contact portion has a bottom portion with a substantially arcuate side surface,
The bottom portion is composed of a front bottom portion that constitutes a front half portion of the bottom portion and can come into contact with the key, and a rear bottom portion that constitutes a rear half portion of the bottom portion and cannot come into contact with the key. A keyboard device for an electronic keyboard instrument characterized by: a hammer cushion provided immediately in front of the key abutting portion at the rear end portion of the upper surface of the key and abutting against a predetermined portion of the lower surface of the hammer from above when the key is released;
The front bottom portion is formed in an arc shape having a predetermined radius of curvature in order to maintain the hammer in a key-released state in substantially the same posture before and after the hammer cushion is deformed over time. A keyboard device for an electronic keyboard instrument according to Item 1 . The key contact portion is
an abutting convex portion formed integrally with the hammer body and protruding downward;
a convex portion cover having the front bottom portion and the rear bottom portion and detachably attached to the contact convex portion;
3. The keyboard device for an electronic keyboard instrument according to claim 1 , comprising:

Images