Keyboard device for keyboard instrument

Abstract

A keyboard device for a keyboard instrument includes: a swingable key; an action unit that performs a predetermined operation in conjunction with the pressing of the key; and a hammer placed on the action unit via the hammer protruding portion and rotated upward via the action unit according to the depression of the key. The hammer includes a hammer body made of synthetic resin, and the hammer protruding portion includes: a protruding portion body protruding downward and integrally formed with the hammer body; and a roller bushing attached to the hammer body in a state of covering the protruding portion body.

Description

Technical Field

[0001] The present invention relates to a keyboard device for a keyboard musical instrument, and more particularly to a keyboard device for a keyboard musical instrument including: an action unit that operates in conjunction with key depression; and hammers that are placed on the action unit and driven upward via the action unit in accordance with the key depression. Background Art

[0002] Generally, a grand piano, which is an acoustic piano, is equipped with an action that operates in response to key depression and causes hammers to rotate upward to strike the strings. For example, JP 2003-167572A, filed by the present applicant, discloses an example of such an action. The action is provided for each key and includes: a wippen rotatably supported and placed on the rear portion of the key; a repetition rod and a jack rotatably attached to the wippen; a repetition rod spring that biases the repetition rod and jack in a predetermined direction; a repetition rod screw and an adjustment button that adjust the rotation of the repetition rod and jack, respectively; and the like.

[0003] The hammer includes a hammer shank extending in the front-rear direction, and has a shank roller attached to a proximal end portion side, a hammer head attached to a distal end portion thereof, etc. The hammer is rotatably supported at the proximal end portion of the hammer shank.

[0004] In the above-described action, the repetition rod is provided with a jack guide hole that penetrates the repetition rod in the vertical direction, and the hammer is placed near the jack guide hole via the shank roller. Furthermore, the jack is formed into an L-shaped side surface shape, and the distal end portion of the hammer-pushing portion extending in the vertical direction is inserted from below into the jack guide hole of the repetition rod, is movably engaged in the front-rear direction, and faces the shank roller.

[0005] In a grand piano with hammers and an action constructed as described above, when a key is depressed, the upwardly pushed linkage at the rear portion of the key rotates upward, and accordingly, the vibrator rod and the jack also move upward. First, while the shank roller slides, the vibrator rod pushes the hammer upward via the shank roller, causing the hammer to rotate upward. The shank roller is then locked against the shank rod screw, causing the jack to push the hammer upward via the shank roller. Then, when the hammer rotates to just before striking the upwardly tensioned string, the jack is released (disengaged) from the shank roller by engaging the adjustment button. This disengagement of the jack releases the hammer from the action and key, allowing it to strike the string while freely rotating. Note that when the jack is disengaged, the change in the touch weight (static load) of the key (specifically, the click sensation caused by the sharp increase in touch weight and the subsequent sharp decrease) allows the player to experience a so-called release sensation in the tactile sensation when playing the piano.

[0006] Thereafter, when the key is released and returns to approximately 1 / 3 of the keyboard depth, the repetition lever begins to operate and rotates in a predetermined direction by the spring force of the repetition lever spring, causing the shank roller to be pushed upward while sliding. As a result, the jack rotates in a predetermined direction by the spring force of the repetition lever spring and returns to its original position, allowing the next string strike to be performed even if the key has not fully returned to its position in the key-released state.

[0007] On the other hand, in electronic pianos, a keyboard device such as that disclosed in JP 2010-262129A, which has already been filed by the present applicant, is known as a keyboard device that rotates hammers when a key is depressed and provides a release feeling similar to that of a grand piano. A keyboard device for an electronic piano includes: a key extending in the front-to-back direction and swingable about a balance pin provided near the center in the longitudinal direction; an action chassis provided on the rear side of the key; hammers rotatably supported by the action chassis and placed on the rear end portion of the key; a release member attached to the action chassis and providing a release feeling to the key via the hammers when the key is depressed; and the like.

[0008] In this electronic piano, when a key is depressed, the rear end of the key rises, pushing the hammer upward and causing it to rotate upward. During the hammer's rotation, the hammer's engagement portion temporarily engages with a release member. In this state, the hammer engages with the release member, compressing it. Due to its reaction force, a repulsive force from the release member acts on the hammer, causing the touch weight of the key to increase dramatically due to the rotational resistance generated at that time. When the hammer rotates further to release its engagement with the release member, the rotational resistance disappears, causing the touch weight of the key to decrease dramatically. Due to the rapid increase and decrease in the touch weight of the key described above, a release feel similar to that of a grand piano is imparted to the tactile feel of the key.

[0009] Citation List

[0010] Patent Literature

[0011] Patent Document 1: JP 2003-167572 A

[0012] Patent Document 2: JP 2010-262129 A Summary of the Invention

[0013] However, in a grand piano, the number of parts constituting the action and hammers is large, and a part that rotates (hereinafter referred to as a "rotating part") and a part that supports the rotating part (hereinafter referred to as a "supporting part") are connected via pins. Specifically, in the supporting part, a portion supporting the rotating part is formed in a forked shape, and in a state in which the supporting part is set inside the portion, the rotating part is rotatably connected to the supporting part by inserting a pin into a connecting hole of the two parts. As described above, in a grand piano, there are many parts of the action and hammers, and furthermore, the assembly work thereof is complicated at the time of manufacturing, which requires time and effort. In addition, in the hammers driven by the action, the attachment position of the hammer shank roller and its form (for example, hardness, surface friction and shape) may vary. Therefore, in order to properly operate the hammers, it is necessary to adjust the rotation range of each part of the action and hammers, and the adjustment work is complicated.

[0014] On the other hand, since the electronic piano has a relatively simple structure (in which the hammer is directly pushed upward and rotated by the rear end portion of the depressed key), the load change relative to the depression amount of the front end portion of the key when the key is depressed and the tactile feeling when the key is depressed (such as the stopping feeling) are slightly different from those of the grand piano. Further, in the electronic piano described above, a release member is used to obtain the release feeling due to the disengagement of the top rod in the action of the grand piano, but the hammer is not driven by a mechanism such as the action of the grand piano. Therefore, the electronic piano is different from the keyboard of the grand piano in the change of the response feeling from soft strikes to hard strikes and the controllability (such as continuous strikes, staccato and trills). Therefore, in the electronic piano described above, it is difficult to say that the controllability when performing high-pitched playing within the extreme playing range of the grand piano can be fully reproduced, and there is room for improvement.

[0015] The present invention has been made to solve the problems described above, and an object of the present invention is to provide a keyboard device for a keyboard musical instrument, which can improve productivity and maintainability by reducing the number of components and reducing the number of adjustment parts compared to a grand piano, and can obtain the touch and playing properties equivalent to those of a grand piano when playing by obtaining hammers with high dimensional accuracy.

[0016] To achieve the above object, the present invention according to claim 1 includes: a key extending a predetermined length in the front-rear direction and being swingable at a fulcrum near the center in the length direction; an action unit provided in a rear portion of the key and configured to perform a predetermined operation in conjunction with depression of the key; a hammer support provided on the rear side of the key; and a hammer extending a predetermined length in the front-rear direction, rotatably supported at the rear end portion by a hammer support shaft extending in the left-right direction of the hammer support, placed on the action unit via a hammer protrusion provided so as to protrude downwardly immediately on the front side of the hammer support shaft, and driven upward via the action unit in accordance with depression of the key, wherein the hammer includes a hammer body extending a predetermined length in the front-rear direction and made of synthetic resin, and the hammer protrusion includes: a protrusion body protruding downwardly and formed integrally with the hammer body; and a protrusion cover formed of a molded product made of a predetermined material and attached to the hammer body in a state covering the protrusion body.

[0017] According to this configuration, the action unit is arranged at the rear portion of the key, and the hammer (the rear end portion of which is rotatably supported by the hammer support shaft of the hammer support member) is placed on the action unit via the hammer protrusion immediately in front of the hammer support shaft. When the front end portion of the key is pushed downward when the key is pressed, the rear end portion of the key moves upward, and accordingly, the action unit performs a predetermined operation so that the hammer is driven upward. The hammer has a hammer body made of synthetic resin. In addition, the hammer protrusion placed on the action unit includes: a protrusion body, which is formed integrally with the hammer body; and a protrusion cover, which is attached to the hammer body in a state of covering the protrusion body.

[0018] In a keyboard device, by locating the action unit at the rear end of the key and reducing the number of components and adjustment points compared to a grand piano action, productivity and maintainability can be improved. The hammer protrusion corresponds to the shank roller in a grand piano hammer, and the protrusion body of the hammer protrusion is integrally formed with the hammer body. A molded protrusion cover is attached while covering the protrusion body, resulting in hammers with high dimensional accuracy. Furthermore, the action unit performs predetermined operations, such as those performed by a grand piano action in conjunction with key depression, making it possible to achieve a touch and playing quality equivalent to that of a grand piano during performance.

[0019] In addition, since the projection cover made of a molded product is attached to the hammer body in a state of covering the projection body, the form (for example, hardness, surface friction, shape, etc.) of the portion placed on the action unit in each hammer can be made uniform. As a result, it is possible to stably obtain a release feeling when each key is depressed.

[0020] The present invention according to claim 2 is characterized in that, in the keyboard device for a keyboard musical instrument according to claim 1, the protrusion cover includes: a cover body which is open upward and is attached to the protrusion body in a state in which the protrusion body is assembled; and two left and right hooks which protrude upward from the cover body and are arranged at predetermined intervals in the left and right directions, and the hammer body includes two left and right hook receivers which are arranged on the left and right sides to be immediately above the protrusion body and engage the two hooks in a disconnection prevention state when the cover body is attached to the protrusion body.

[0021] According to this configuration, the projection cover has a cover body and two left and right hooks, and when the cover body is attached to the projection body, the two hooks engage with the two left and right hook receivers of the hammer body in the disconnection prevention state. This ensures that the projection cover is firmly and stably attached to the hammer body and prevents the projection cover from being separated from the projection body during operation of the hammer.

[0022] The invention according to claim 3 is characterized in that, in the keyboard device for a keyboard musical instrument according to claim 2 , the cover body has a side surface shape that is convexly curved downward and is formed in an arc shape having a predetermined curvature.

[0023] According to this configuration, since the side surface shape of the cover body is convexly curved downward and is an arc shape with a predetermined curvature, the curvature of the side surface shape is appropriately set, so that appropriate and stable operation of the hammer can be ensured through the predetermined operation of the hammer action unit as the key is depressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1A and Figure 1B FIG. 1 illustrates a portion of a keyboard device of an electronic piano to which a keyboard device according to an embodiment of the present invention is applied, wherein Figure 1A is a perspective view, and Figure 1B It is a right side view;

[0025] Figure 2A is a perspective view illustrating an action unit assembled to a key and hammers placed on the action unit, and Figure 2B is an exploded perspective view illustrating the keys, action unit, and hammers;

[0026] Figure 3Aand Figure 3B is a perspective view illustrating a hammer support, wherein Figure 3A is an external view of the hammer support shown in FIG, and Figure 3B is a view showing a hammer support in a partially cutaway state;

[0027] Figure 4A and Figure 4B is a view illustrating a hammer support, wherein Figure 4A is the front view, and Figure 4B is a cross-sectional view taken along line AA;

[0028] Figure 5A and Figure 5B is an enlarged perspective view illustrating the hammer and action unit, wherein Figure 5A The diagram shows a state in which the parts of the action unit are assembled, and Figure 5B The diagram shows the action unit with its components disassembled;

[0029] FIG6 is a right side view illustrating the hammer, and FIG Figure 6B is an enlarged perspective view illustrating a state before the roller bushing is attached to the hammer body;

[0030] Figure 7 is a right side view of the illustrated cage;

[0031] Figure 8 is a right side view of the illustrated tremolo rod;

[0032] Figure 9 is a right side view of the illustrated ejector pin;

[0033] Figure 10A and Figure 10B are explanatory diagrams for sequentially describing the operations of the action unit and hammers when a key is depressed, wherein Figure 10A The diagram shows the key release state, and Figure 10B The diagram shows the state in which the tremolo rod abuts against the tremolo rod stopper when the key is depressed;

[0034] Figure 11A and Figure 11B is Figure 10A and Figure 10B The following explanatory diagram, Figure 11A The diagram shows a state in which the ejector pin abuts against the ejector pin stopper, and Figure 11B The figure shows a state in which the jack is removed from the hammer protrusion;

[0035] Figure 12A and Figure 12B is Figure 11A and Figure 11B The following explanatory diagram, Figure 12AThe diagram shows a state in which the hammer abuts against the hammer stopper, and Figure 12B The diagram illustrates a state in which the hammer rebounds from the hammer stopper and abuts against a backcheck; and

[0036] Figure 13A and Figure 13B is Figure 12A and Figure 12B The following explanatory diagram, Figure 13A The diagram shows a state in which the key pushed downward is slightly returned and the jack is wrapped around the lower side of the hammer protrusion, and Figure 13B A state in which the key returns to the original key-release state is illustrated. DETAILED DESCRIPTION

[0037] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1A and Figure 1B FIG. 1 illustrates a portion of a keyboard device of an electronic piano (to which a keyboard device according to an embodiment of the present invention is applied) in a key-released state, wherein Figure 1A is a perspective view, and Figure 1B It is the right side view.

[0038] like Figure 1A and Figure 1B As shown in FIG, the keyboard device 1 includes a large number of keys 2 ( Figure 1A and Figure 1B only one white key is shown in the figure), which are arranged in the left-right direction of the electronic piano; a keyboard chassis 3, which supports these keys 2; a hammer support 4, which is connected to the rear end portion of the keyboard chassis 3; a hammer 5, which is provided for each key 2 and is rotatably supported by the hammer support 4; an action unit 6, which is provided at the rear end portion of the key 2 and drives the hammer 5 upward along with the depression of the key; a key switch 7, which is used to detect key depression information of the key 2; and the like.

[0039] like Figure 1A and Figure 1B As shown in FIG, the keyboard chassis 3 is formed by connecting three support rails 10 and a plurality of (eg, five) reinforcing ribs 14 ( Figure 1A and Figure 1B Only one is shown in the figure) are assembled in a parallel cross form, and the three support rails extend in the left and right directions and include a front and rear direction ( Figure 1B The front rail 11, the middle rail 12, and the rear rail 13 are arranged at predetermined intervals (in the left-right direction), and the plurality of reinforcing ribs extend in the front-to-back direction and are arranged at predetermined intervals in the left-to-right direction. The support rail 10 and the ribs 14 are formed of an iron plate formed into a predetermined shape by, for example, stamping and bending with a press, and are connected to each other by screws.

[0040] The front rail 11 includes a horizontal top plate portion 11a, a front plate portion 11b bent downward at a right angle from the front end portion of the top plate portion 11a, and a bottom plate portion 11c bent backward at a right angle from the lower end portion of the front plate portion 11b. A reed front portion 15 is fixed to the bottom surface of the top plate portion 11a by screw connection or the like. The reed front portion 15 is formed in the shape of a thick plate made of synthetic resin and extends over the entire front rail 11 in the left-right direction. On the reed front portion 15, a large number of front pins 16 are erected at the front and rear positions corresponding to the white keys 2 and the black keys (not shown), and these front pins are in a state of penetrating the top plate portion 11a of the front rail 11 and arranged in the left-right direction.

[0041] The middle range 12 has a horizontal middle reed placement portion 12a, with the front and rear ends of this portion bent upward at right angles. The middle reed portion 17 is secured to the middle reed placement portion 12a by screws or the like, while the middle reed portion is placed. The middle reed portion 17 is formed into a thick plate made of synthetic resin and extends left and right across the entire middle range 12. Within the middle reed portion 17, a large number of balancing pins 18 are arranged left and right at the front and rear positions corresponding to the white keys 2 and the black keys.

[0042] The rear rail 13 has an upwardly open accommodating recess 13a that engages with the lower portion of the hammer support 4 when accommodated; a cushion placement portion 13b that bends at a right angle from the upper end of the front plate portion of the accommodating recess 13a and extends horizontally forward. When the accommodating recess 13a is in place, it is attached to a cushion 19 extending in the left-right direction; and a connecting portion 13c that extends horizontally forward from the front end of the cushion placement portion 13b. Multiple attachment holes are formed in the front plate portion of the accommodating recess 13a, penetrating the accommodating recess 13a in the front-to-back direction. The lower end portion of the hammer support 4 is screwed to the rear rail 13 through these attachment holes. The accommodating recess 13a and connecting portion 13c are screwed to the rear end portion of each rib 14.

[0043] Figure 2A The action unit 6 assembled to the key 2 and the hammer 5 placed on the action unit 6 are shown, and Figure 2B The keys 2, the action units 6, and the hammers 5 are shown in an exploded manner. Figure 2AAs shown in FIG. 1 , the key 2 includes a wooden key body 21 extending a predetermined length in the front-to-rear direction and having a rectangular cross-section, and a synthetic resin key cover 22 bonded to the top and front surfaces of the front half of the key body 21. A balancing pin hole 23 penetrating the key body 21 in the up-down direction is formed near the center in the longitudinal direction of the key body 21, and the key 2 is swingably supported by a balancing pin 18 erected on the reed middle portion 17 through the balancing pin hole 23.

[0044] The balance pin hole 23 is provided with a substantially circular hole near the bottom surface of the key body 21, and the entire upper portion connected to the hole is formed into an elongated shape extending in the longitudinal direction of the key body 21. In addition, felt 23a is provided on the left and right inner surfaces of the balance pin hole 23 so as to smoothly slide relative to the balance pin 18 when the key 2 swings. The cushioning pad 20 is attached to the top surface of the key body 21 on the rear side of the balance pin hole 23, and the cushioning pad 20 prevents the front end portion of the hammer 5 from directly hitting the key 2 during maintenance, etc.

[0045] In addition, the front pin hole 24 (see Figure 1B ) is formed at a predetermined position of the front portion of the key body 21, and the front pin hole 24 engages with the front pin 16 erected on the front portion 15 of the reed, thereby preventing the key 2 from rocking in the left-right direction during the swing of the key 2.

[0046] Figures 3A to 4B The hammer support 4 is shown. Figures 3A to 4B As shown in FIG, the hammer support member 4 is formed of a molded product made of synthetic resin, for example, and is screwed to the rear rail 13 of the keyboard chassis 3 in a state in which a plurality of molded products corresponding to one octave are connected to each other in the left-right direction. The hammer support member 4 includes: a hammer support portion 31 that stands upright from the vicinity of the rear rail 13; a switch attachment portion 32 that extends obliquely forward and upward from the upper end portion of the hammer support portion; and the like. A hammer support shaft 33 for rotatably supporting each hammer 5 is provided at the upper end portion of the hammer support portion 31.

[0047] The hammer support 4 has a plurality of partition walls 34 that partition adjacent hammers 5 at predetermined intervals in the left-right direction, and the hammer support shaft 33 extends between adjacent partition walls 34 and 34 in the left-right direction. Figure 4B As illustrated in an enlarged manner in FIG, the hammer supporting shaft 33 has a so-called elliptical cross-sectional shape in which two portions, a front portion and a rear portion of a circle centered on the axial center of the hammer supporting shaft 33 , are cut away.

[0048] Specifically, the outer peripheral surface of the hammer supporting shaft 33 includes a pair of upper and lower curved surface portions 33a, 33a, and a pair of front and rear flat surface portions 33b extending between the curved surface portions 33a and 33a. In the hammer supporting shaft 33 constructed as described above, the upper and lower curved surface portions 33a are set to an arc shape having a diameter of length L1, and the distance between the front and rear flat surface portions 33b is set to a length L2 shorter than the length L1.

[0049] like Figure 1A and Figure 1B , the key switch 7 is attached to the switch attachment portion 32 of the hammer support 4. The key switch 7 includes a switch substrate 7a formed of a printed circuit board and a switch body 7b formed of a rubber switch attached to the hammer 5 side of the switch substrate 7a for each key 2.

[0050] like Figures 3A to 4B As shown in FIG, on the rear surface side of the hammer support 4, a repetition rod stopper 35 is provided obliquely below and behind the hammer support shaft 33. A repetition rod 52 (described later) of the action unit 6 abuts against the hammer support 4 when a key is depressed, and the repetition rod stopper 35 locks the repetition rod 52. Furthermore, on the rear surface side of the hammer support 4, a jack stopper 36 is provided below the repetition rod stopper 35. A jack 53 (described later) of the action unit 6 abuts against the hammer support 4 when a key is depressed. The jack stopper 36 locks the jack 53. A cushion pad 37 extending in the left-right direction is attached to the bottom surface of the jack stopper 36.

[0051] like Figure 1A and Figure 1B As illustrated in FIG, a hammer stopper 38 is provided at an upper portion of the front end of the hammer support 4 , and when the hammer 5 rotates upward, the hammer 5 abuts against the hammer support 4 from below, and the hammer stopper 38 prevents further rotation.

[0052] Figure 5A and Figure 5B The hammer 5 and the action unit 6 are shown in the figure. Figure 5A The diagram illustrates a state in which each component of the action unit is assembled, and Figure 5B The diagram shows a state in which each component of the action unit is disassembled. Figure 6A1 is a right side view of the hammer 5. As shown in these figures, the hammer 5 includes an arm-shaped hammer body 41 extending a predetermined length in the front-to-back direction, and two weight plates 42 and 42 attached to the front end portions of the left and right side surfaces of the hammer body. The hammer body 41 is made of synthetic resin, and the weight plate 42 is made of a metal material with a relatively large specific gravity (such as steel).

[0053] At the rear end of the hammer body 41, an engaging portion 43 is provided for engaging with the hammer support shaft 33 of the hammer support member 4. An arcuate axial hole 44 is formed in the engaging portion 43. The arcuate axial hole 44 penetrates the engaging portion 43 in the left-right direction and has a side surface formed in a C-shape, with the opening of the arcuate axial hole formed to expand outward. The axial hole 44 has a diameter slightly larger than the diameter (length L1) of the upper curved surface portion 33a and the lower curved surface portion 33a of the hammer support shaft 33, and the width L3 of the opening is slightly larger than the length L2 between the front flat surface portion 33b and the rear flat surface portion 33b of the hammer support shaft 33 and smaller than the length L1. The hammer 5 is attached to or detached from the hammer support shaft 33 of the hammer support member 4 through the opening of the axial hole 44 and is rotatably supported by the hammer support member 4 by fitting the axial hole 44 to the hammer support shaft 33.

[0054] In the rear portion of the hammer 5, a switch pressing portion 45 and a hammer protruding portion 46 are respectively provided above and below the right front side of the shaft hole 44. The switch pressing portion 45 has a flat top surface and presses the switch body 7b of the key switch 7 when the hammer 5 rotates upward, thereby detecting key depression information of the key 2 corresponding to the hammer 5.

[0055] On the other hand, the hammer protrusion 46 corresponds to the shank roller of the hammer of the grand piano. Figure 6B 4 is an enlarged view of a state before the roller bushing 49 (projection cover) is attached to the hammer body 41. Figure 6B As illustrated in FIG, the hammer protrusion 46 is formed integrally with the hammer body 41 and has a protrusion body 48 protruding downward, and a roller bushing 49 attached to the hammer body 41 in a state of covering the protrusion body 48 .

[0056] The protruding portion body 48 protrudes downward, and the side surface shape of the distal end portion is formed into an arc shape. The protruding portion body 48 is formed symmetrically, and each side surface ( Figure 6B The right side surface is shown in the figure) is provided with a groove portion 48a extending in the up-down direction and opening outward, and a locking recess portion 48b (hook receiver) provided at an upper end portion of the groove portion 48a.

[0057] On the other hand, the roller bushing 49 is made of a predetermined elastic material (for example, thermoplastic elastomer) and is formed of a molded product having a predetermined shape. Specifically, as Figure 6B As shown in the figure, the roller bushing 49 has: a bushing body 49a (cover body) that is open upward and formed so that the protruding portion body 48 of the hammer body 41 can be mounted thereon, and is attached thereto; and two left and right hooks 49b and 49b that protrude upward from the bushing body 49a and are arranged at predetermined intervals in the left-right direction. The bushing body 49a is formed so that the side surface shape is convexly curved downward and has a predetermined curvature, for example, substantially the same as the curvature of the stem roller of a grand piano. Each hook 49b is formed into a claw shape, with the upper end portion of the hook protruding inward.

[0058] In the hammer protruding portion 46 constructed as described above, the protruding portion body 48 of the hammer body 41 is fitted into the bushing body 49a of the roller bushing 49, and the roller bushing 49 is attached to the hammer body 41 in a state in which the hooks 49b and 49b of the roller bushing 49 are fitted into the corresponding left and right groove portions 48a and locking recess portions 48b of the protruding portion body 48. In this case, the upper end portion of each hook 49b of the roller bushing 49 is locked in the locking recess portion 48b of the protruding portion body 48 in the disconnection prevention state.

[0059] In the key-released state, the hammer protruding portion 46 is placed on a hammer placing portion 74 of a repetition rod 52 (described later) of the action unit 6 .

[0060] like Figure 5A and Figure 5B as well as Figure 6A As shown in FIG, at a predetermined position on the front portion of the hammer 5, a back rail engaging portion 47 is provided which is formed integrally with the hammer body 41, protrudes downward, and can be engaged with a back rail 62 (described later) of the action unit 6. Figure 6A As illustrated in FIG, the backstop engaging portion 47 has vertically long side surfaces, a flat front surface, and a gently curved rear surface.

[0061] Next, the action unit 6 will be described. Figure 5A and Figure 5B As illustrated in FIG, the action unit 6 includes: a holder 51, which is fixed to the rear end portion of the key 2; a repetition rod 52 and a top rod 53, which are rotatably attached to the holder; and a repetition rod spring 54 and a top rod spring 55, which bias the repetition rod and the top rod to rotate in a predetermined direction, both of which are coil springs.

[0062] Figure 7 The figure shows a right side view of the retainer 51. Figure 5A and Figure 5B as well as Figure 7 As shown in FIG. , the holder 51 is made of synthetic resin and is formed of a molded product having a predetermined shape and extending in the front-to-back direction. The holder 51 includes: a key attachment portion 61 provided at the front portion and fixed to the rear end portion of the key 2; a back rail 62 provided above the key attachment portion; a repetition rod support shaft 63 provided at the upper end portion near the center in the front-to-back direction and rotatably supporting the repetition rod 52; and a jack support shaft 64 provided at the rear end portion and rotatably supporting the jack 53.

[0063] The key attachment portion 61 has a side surface formed into a U shape by an upper wall 61a, a rear wall 61b, and a lower wall 61c, and the left end portions of these walls are connected by a left side wall 61d. Therefore, when the holder 51 is attached to the rear end portion of the key 2, the upper wall 61a, the rear wall 61b, the lower wall 61c, and the left side wall 61d are firmly fixed by adhesion in a state of contact with the top surface, the rear surface, the bottom surface, and the left side surface at the rear end portion of the key 2.

[0064] The back rail 62 has a predetermined length in the vertical direction and is formed in a gentle arc shape when the back rail engaging portion 47 is tilted forward and upward. When the back rail engaging portion 47 is engaged, the back rail 62 is configured to lock the back rail engaging portion 47 while slidingly contacting the back rail engaging portion 47 of the hammer 5. A friction member (such as synthetic leather) may be attached to at least one of the surfaces of the back rail 62 and the back rail engaging portion 47 that are in sliding contact with each other to increase friction.

[0065] The repetition rod support shaft 63 and the jack support shaft 64 are both formed in a cylindrical shape protruding rightward by a predetermined length and having a predetermined diameter. The repetition rod support shaft 63 is formed at a predetermined position higher than the jack support shaft 64.

[0066] The holder 51 is provided with a repetition rod spring locking portion 65 that locks the upper end portion of the repetition rod spring 54 at a predetermined position located between the back rail 62 and the repetition rod support shaft 63, and in front of the repetition rod support shaft 63. Furthermore, the holder 51 is provided with a jack spring locking portion 66 that locks the upper end portion of the jack spring 55 at a predetermined position located between the repetition rod support shaft 63 and the jack support shaft 64, and in front of the jack support shaft 64. In addition, a slightly downwardly protruding convex portion 67 is provided in the rear portion of the bottom surface of the holder 51, and in the key-released state, the holder 51 is placed on the cushion pad 19 on the back rail 13 via the convex portion 67.

[0067] Figure 8 The figure shows a right side view of the repetition rod 52. Figure 5A and Figure 5Bas well as Figure 8 As shown in FIG, the repetition rod 52 is made of synthetic resin and is formed of a molded product having a predetermined shape and formed to extend in the front-to-back direction. The repetition rod 52 includes: a fitting hole 71 that penetrates the repetition rod 52 in the left-to-right direction and is rotatably fitted to the repetition rod support shaft 63 of the holder 51; a front arm 72 that extends forward from the vicinity of the fitting hole 71; and a hammer placement arm 73 that is formed to extend rearward from the vicinity of the fitting hole 71, on which the hammer 5 is placed and with which the jack 53 is engaged.

[0068] The hammer placement arm 73 of the repetition lever 52 includes: a hammer placement portion 74 having a side surface shape extending rearward and upward at a predetermined length from the fitting hole 71; and an extension portion 75 extending rearward and downward at an angle from the rear end portion of the hammer placement portion 74 and further extending rearward. Furthermore, a jack guide hole 73 a is formed in the hammer placement arm 73, penetrating the hammer placement arm 73 in the vertical direction and extending in the front-rear direction across the hammer placement portion 74 and the extension portion 75. The rear end portion of the extension portion 75 is formed so as to slightly protrude upward, and a cushioning pad 76 is attached to its top surface.

[0069] Figure 9 The figure shows a right side view of the ejector pin 53. Figure 5A and Figure 5B as well as Figure 9 As shown in FIG, the jack 53 is made of synthetic resin and is formed as a molded product having a predetermined shape. The jack 53ba includes: a fitting hole 81 that penetrates the jack 53 in the left-right direction and is rotatably mounted to the jack support shaft 64 of the holder 51; a front arm 82 that extends forward from the vicinity of the fitting hole 81; a hammer-pushing portion 83 that extends upward from the vicinity of the fitting hole 81 by a predetermined length; and a rear arm 84 that extends rearward from the vicinity of the fitting hole 81.

[0070] The hammer push-up portion 83 extends upward and forward in a state of being tilted forward at a predetermined angle relative to the front arm 82 and the rear arm 84, which extend substantially horizontally in the front-rear direction. In addition, the upper end portion of the hammer push-up portion 83 is formed to have a smaller width in the front-rear direction than the lower portion of the hammer push-up portion. In addition, the rear arm 84 is formed so that the rear end portion protrudes slightly upward.

[0071] In the jack 53, plate-like reinforcing ribs 85a, 85b, and 85c are respectively provided between the front arm 82 and the hammer push-up portion 83, between the hammer push-up portion 83 and the rear arm 84, and between the rear arm 84 and the front arm 82. The strength of the jack 53 is increased by the reinforcing ribs 85a to 85c and the like.

[0072] In the action unit 6 formed as described above, Figure 5A As shown in FIG, the hammer push-up portion 83 of the jack 53 is engaged in a state of being inserted into the jack guide hole 73a of the repetition rod 52 from below. Figure 5A As shown in FIG, the front arm 72 of the repetition rod 52 is biased downward by the repetition rod spring 54, and the front arm 82 of the jack 53 is biased downward by the jack spring 55. As a result, the repetition rod 52 and the jack 53 are respectively rotated about the repetition rod support shaft 63 and the jack support shaft 64. Figure 5A In the holder 51 of the action unit 6 , thin plate-like cushions 91 and 92 are attached to the underside of the front arm 72 of the repetition rod 52 and the underside of the front arm 82 of the jack 53 .

[0073] Next, we will refer to 10A to 13B The operations of the action unit 6 and the hammer 5 when the key 2 is depressed will be described.

[0074] Figure 10A The keyboard device 1 is shown in the key-released state. In the key-released state, the hammers 5 are placed on the hammer placement portions 74 of the repetition lever 52 via the hammer protrusions 46, and the upper end portions of the hammer-pushing portions 83 of the jack 53 face the hammer protrusions 46 with a certain gap. In the key-released state, a gap is provided between the back rail engaging portions 47 of the hammers 5 and the back rail 62 of the holder 51.

[0075] When the front end portion of the key 2 is pushed downward from the key release state, the key 2 swings forward and downward about the balance pin 18, and the rear end portion of the key 2 moves upward. Therefore, the action unit 6 also moves upward integrally with the rear end portion of the key 2, and the hammer 5 is pushed upward by the repetition rod 52 via the hammer protrusion 46. As a result, the hammer 5 rotates upward about the hammer support shaft 33 (at Figure 10A and Figure 10B (clockwise in the middle).

[0076] Next, when the key depression progresses and the action unit 6 moves upward, the rear end portion of the repetition rod 52 abuts against the repetition rod stopper 35 of the hammer support 4 from below via the cushion 76, as shown in FIG. Figure 10B As a result, when the rear end portion of the repetition rod 52 is locked, the upper end portion of the hammer pushing-up portion 83 of the jack 53 abuts against the hammer protruding portion 46 from below. As a result, the hammer 5 is pushed upward by the hammer pushing-up portion 83 of the jack 53 and further rotated upward.

[0077] Next, when the key depression further proceeds and the action unit 6 moves further upward, the rear end portion of the rear arm 84 of the jack 53 abuts against the jack stopper 36 (cushion 37) from below, as shown in FIG. Figure 11AAs a result, the push rod support shaft 64 moves upward in a state where the rear end portion of the rear arm 84 is locked, so that the push rod 53 moves along the push rod support shaft 64 around the push rod support shaft 64. Figure 11A The result is that the Figure 11B , the upper end portion of the hammer pushing-up portion 83 of the jack 53 moves rearward and comes out of the hammer protruding portion 46 of the hammer 5. By this disengagement of the jack 53, the hammer 5 is separated from the action unit 6 and the key 2, and further rotates upward in a free rotation state.

[0078] Note that when the jack 53 is disengaged, a click feeling is generated due to a sharp increase and decrease in the touch weight of the key 2, whereby a sense of release is obtained in the touch of the player who depresses the key.

[0079] Figure 12A The diagram shows a state in which the hammer 5, which has been rotated upward, abuts against the hammer stopper 38 located at the upper portion of the front end of the hammer support 4. In this state, the front portion of the hammer body 41 of the hammer 5 abuts against the hammer stopper 38 from below, preventing further rotation of the hammer 5. In this state, the switch pressing portion 45 of the hammer 5 presses the switch body 7b of the key switch 7 from below to turn on the key switch 7, thereby detecting key depression information of the key 2 corresponding to the rotation speed of the hammer 5, etc., and outputting it to the sound generation control device (not shown). In addition, the tone generation control device outputs piano sounds from the speaker (not shown) of the electronic piano based on the key depression information.

[0080] Figure 12B The diagram shows a state immediately after the hammer 5 abuts against the hammer stopper 38, specifically, a state in which the hammer 5 rebounds from the hammer stopper 38 and rotates downward (counterclockwise) toward the original position before the key is depressed, and the back stop engaging portion 47 of the hammer 5 is locked to the back stop 62 of the holder 51. In this case, when the back stop engaging portion 47 is locked while being in sliding contact with the back stop 62, the hammer 5 is stopped by being prevented from rotating further downward, and the occurrence of rebound or vibration of the hammer 5 is prevented. In this case, the load due to the rebound of the hammer 5 is transmitted to the key 2. As a result, the player can clearly feel the stopping feeling of the key 2 when the key 2 is depressed.

[0081] Figure 13A The diagram shows a state in which the depressed key 2 is slightly returned (for example, 1 / 3 of the keyboard depth) due to the release of the key. Figure 12B When you release key 2 in the state shown in Figure 13AAs shown in FIG, the front end portion of the key 2 moves upward, while the rear end portion thereof moves downward, and accordingly, the action unit 6 moves downward integrally with the rear end portion of the key 2. In this case, the back stop 62 moves obliquely backward and downward, so that the hammer 5 is released from the engagement achieved by the back stop 62 and released from the stopped state. In addition, the front arm 72 of the repetition lever 52 is pushed downward by the biasing force of the repetition lever spring 54, so that the repetition lever rotates counterclockwise ( Figure 13A Similarly, the front arm 82 of the ejector 53 is pushed downward by the biasing force of the ejector spring 55, causing the ejector to rotate counterclockwise around the ejector support shaft 64 ( Figure 13A As a result, Figure 13A As shown in the figure, the upper end portion of the hammer push-up portion 83 of the top rod 53 is wrapped around the lower side of the hammer protrusion 46 of the hammer 5, and as a result, the hammer 5 can be driven by the string action unit 6 even if the key 2 does not completely return to the position in the key release state.

[0082] When key 2 is fully released, as Figure 13B As illustrated in FIG, the keys 2, hammers 5, and the repetition rods 52 and jacks 53 of the action unit 6 return to their original positions in the key-release state.

[0083] As described above in detail, according to the present embodiment, the keyboard device 1 including the keys 2, action unit 6, and hammers 5 described above can achieve operations similar to those of a grand piano, making it possible to obtain a touch and playing quality equivalent to that of a grand piano when playing. In addition, in the action unit 6 of the keyboard device 1, since the number of components can be reduced and the number of adjustment parts can be reduced compared to the action of a grand piano, the productivity and maintainability of the keyboard device 1 can be improved.

[0084] Furthermore, in the keyboard device 1, the hammer protrusions 46 of the hammers 5 correspond to the shank rollers in the hammers of a grand piano, the protrusion bodies 48 of the hammer protrusions 46 are formed integrally with the hammer bodies 41, and the roller bushings 49 made of molded products are attached in a state covering the protrusion bodies 48, making it possible to obtain hammers 5 with high dimensional accuracy. Furthermore, since the action units 6 perform operations similar to those performed by the action of a grand piano in conjunction with key depression, it is possible to obtain a touch and playing quality equivalent to those of a grand piano when playing.

[0085] Furthermore, since the roller bushing 49 made of a molded product is attached to the hammer body 41 in a state of covering the protruding portion body 48, the form (for example, hardness, surface friction, shape, etc.) of the portion placed on the action unit 6 can be made uniform in each hammer 5 of the keyboard device 1. As a result, it is possible to stably obtain a release feeling when each key 2 is depressed.

[0086] Note that the present invention is not limited to the embodiment described above, but can be implemented in various modes. For example, in this embodiment, the case where the present invention is applied to a keyboard device of an electronic piano has been described, but the present invention is not limited thereto, and the present invention can also be applied to a keyboard device in which, instead of the key switches 7, strings similar to those of a grand piano are stretched over the hammers 5 and the strings are struck by the hammers 5.

[0087] The detailed configurations of the keyboard device 1 , keys 2 , hammers 5 , and action units 6 described in the embodiments are merely examples and may be appropriately changed within the scope of the gist of the present invention.

Claims

1. A keyboard device for a keyboard musical instrument, the keyboard device comprising: a piano key extending in the front-rear direction by a predetermined length and capable of swinging with a vicinity of the center in the length direction as a fulcrum; an action unit provided in a rear portion of the key and configured to perform a predetermined operation in conjunction with depression of the key; a hammer support provided on the rear side of the key; as well as a hammer extending a predetermined length in the front-rear direction, rotatably supported at a rear end portion by a hammer support shaft extending in the left-right direction of the hammer support, placed on the action unit via a hammer protruding portion provided so as to protrude downward immediately on the front side of the hammer support shaft, and driven upward via the action unit in accordance with depression of the key, wherein The hammer includes a hammer body extending a predetermined length in the front-rear direction and made of synthetic resin, and The hammer protrusion comprises: a protrusion body that protrudes downward and is formed integrally with the hammer body, and A projection cover is formed of a molded product made of a predetermined material and is attached to the hammer body in a state of covering the projection body.

2. The keyboard device for a keyboard musical instrument according to claim 1, wherein The projection cover comprises: a cover body which opens upward and is attached to the protruding portion body in a state in which the protruding portion body is assembled, and two left and right hooks protruding upward from the cover body and arranged at predetermined intervals along the left-right direction, and The hammer body includes two left and right hook receivers that are provided on left and right sides immediately above the projection body and engage two hooks in a disconnection prevention state when the cover body is attached to the projection body.

3. The keyboard device for a keyboard musical instrument according to claim 2, wherein The cover body has a side surface shape that is convexly curved downward and is formed in an arc shape having a predetermined curvature.

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