JP2000056767A - Rotating body support structure - Google Patents

Abstract

(57) [Problem] To provide a keyboard device for an electronic keyboard musical instrument such as an electronic piano, and to support a hammer on a hammer support portion formed integrally with a resin keyboard chassis without causing lateral movement. SOLUTION: A hammer support portion 23 integrally formed with a keyboard chassis 1 made of resin includes a pair of support plate portions 23a and a shaft portion 23b formed between these support plate portions 23a. On the other hand, on both sides of the hammer body 72 above and below the mounting hole 73 of the hammer 71, elastic pieces 8 are provided.
1, 82 are formed. Then, the elastic pieces 81, 82
Are pressed against the support plate 23a. Thereby, the hammer 71- can be supported without causing sideways movement. Note that the hammer 71 can be supported without rattling in the radial direction of the shaft portion 23b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating body support structure, and more particularly to a structure of a hammer support portion integrally formed on a resin keyboard chassis in a keyboard device of an electronic keyboard instrument such as an electronic piano.

[0002]

2. Description of the Related Art For example, in a keyboard device of an electronic keyboard instrument such as an electronic piano, a keyboard chassis is formed of resin, and a key support portion, a hammer support portion and the like are integrally formed on the keyboard chassis. I have. FIG.
(A) and (B) show a hammer support portion in such a keyboard device. A hammer support 102 is provided on the upper surface of the keyboard chassis 101 made of resin. A pair of support plate portions 103 formed opposite to each other on the upper surface of the keyboard chassis 101;
A shaft portion 104 is formed between the support plate portions 103. A shaft portion forming hole 105 is formed at a predetermined position of the keyboard chassis 101 below the shaft portion 104. On the other hand, the hammer 106 has a hammer body 107 made of resin. At a predetermined position of the hammer body 107, a mounting hole 108 and a tapered guide hole 109 connected to the mounting hole 108 are formed. In this case, the minimum width of the guide hole 109 is slightly smaller than the diameter of the mounting hole 107, and the maximum width is slightly larger than the diameter of the mounting hole 107. Since the mounting hole 107 is relatively fitted to the shaft portion 104 via the guide hole 109, the hammer 106 is swingably (rotatably) supported by the hammer support portion 102.

[0003]

When the keyboard chassis 101 having the hammer support 102 is formed by using an upper die and a lower die, the shaft 1 is disposed between a pair of support plates 103.
Due to the relationship of forming the mold 04, the plane indicated by the dashed line in FIG. However, since the upper and lower dies have draft angles, FIG.
As shown in (B), the opposing surfaces of the two support plate portions 103 become tapered surfaces 103a that are gradually separated upward as they go upward on the shaft portion 104, and are gradually separated as they go downward below the shaft portion 104. Tapered surface 10
3b. As a result, there is a problem in that the hammer 106 is caused to move sideways, and this sideways movement is transmitted to the key, thereby impairing the key touch feeling. Further, as shown by a dashed line in FIG. 7A, the shaft 104 is formed by pressing off the semi-circular portions of the upper die and the lower die.
Burrs are likely to be generated on both left and right sides of the shaft, and it is difficult to form a perfect circular shaft portion 104 due to a displacement between the upper mold and the lower mold. Therefore, the semicircular portion of the lower mold is made slightly smaller than the semicircular portion of the upper mold, and the shaft 104 (FIG. 7A) (for example, like the shaft indicated by reference numeral 23b in FIG. 6). Even if burrs occur on the left side of the hammer 106, the mounting hole 10 of the hammer 106
In addition to preventing burrs from being generated at a portion that is substantially fitted to the portion 8, the portion is formed into a shape close to a perfect circle. However, it is not a perfect circle and the shaft 1
04 is slightly shrunk in the radial direction, so that the hammer 106 rattles in the radial direction of the shaft 104,
As a result, there is a problem that the key touch feeling is hindered. An object of the present invention is to support a rotating body such as a hammer without causing side-to-side movement, and to support the rotating body without shaking in a shaft radial direction.

[0004]

According to the first aspect of the present invention,
A rotating body supporting structure in which a rotating body is rotatably supported by a rotating body supporting portion integrally formed with a resin chassis, wherein a pair of rotating body supporting portions are formed opposite to the chassis. And a shaft portion formed between these support plate portions. The rotating body has a mounting hole, a guide hole continuous with the mounting hole, and the both ends near the mounting hole. An elastic piece formed on both sides facing the support plate, the fitting hole is relatively fitted to the shaft via the guide hole, and the elastic piece is pressed against the support plate. It was made. According to the first aspect of the present invention, since the elastic piece formed on the rotating body is pressed against the support plate,
Due to the elasticity of the elastic pieces, the swing of the rotating body can be absorbed, and the swing body can be supported without causing the swing. The invention according to claim 2 is a rotating body supporting structure in which a rotating body is rotatably supported by a rotating body supporting section integrally formed with a resin chassis, wherein the rotating body supporting section is provided on the chassis. A pair of support plate portions formed opposite to each other, and a shaft portion formed between these support plate portions, the rotating body, the mounting hole, a guide hole continuous with the mounting hole, An elastic piece formed in the mounting hole, the mounting hole is relatively fitted to the shaft via the guide hole, and the elastic piece is pressed against the shaft. . According to the second aspect of the present invention, since the elastic piece formed on the rotating body is pressed against the shaft, the elasticity of the elastic piece absorbs the rattling of the rotating body in the radial direction. Thus, the rotating body can be supported without rattling in the shaft radial direction. The invention according to claim 3 is a rotating body supporting structure in which a rotating body is rotatably supported by a rotating body supporting portion formed integrally with a resin chassis, wherein the rotating body supporting portion is provided on the chassis. A pair of support plate portions formed opposite to each other, and a shaft portion formed between these support plate portions, the rotating body, the mounting hole, a guide hole continuous with the mounting hole, A first elastic piece formed on both sides facing the support plate portions in the vicinity of the mounting hole, and a second elastic piece formed in the mounting hole; Are relatively fitted through the guide holes, the first elastic pieces are pressed against the support plate, and the second elastic pieces are pressed against the shaft. According to the third aspect of the present invention, since the first elastic piece formed on the rotating body is pressed against the support plate, the first elastic piece is pressed.
The elasticity of the elastic piece can absorb the horizontal displacement of the rotating body, and the second elastic piece formed on the rotating body is pressed against the shaft. The rattling in the radial direction can be absorbed, and therefore, the rotating body can be supported without causing sideways movement and without rattling in the shaft portion radial direction.

[0005]

FIG. 1 is a plan view of a main part of a keyboard device according to an embodiment of the present invention, and FIG.
3 is a plan view of the keyboard chassis, and FIG. 4 is a cross-sectional view taken along line YY of FIG. This keyboard device includes a keyboard chassis 1 made of resin. Next, the keyboard chassis 1 will be described with reference to FIGS.

[0006] The keyboard chassis 1 has a first open front surface.
A channel 2 is provided. That is, the first channel-shaped portion 2 extends from an upper plate portion 2a, a rear plate portion 2b extending substantially downward from a rear end of the upper plate portion 2a, and a predetermined intermediate portion of the rear plate portion 2b. And a lower plate portion 2c. White key guides 3 are formed to extend upward at predetermined plural locations on the upper surface of the front end of the upper plate 2a. Lower plate 2
The rib plate 4 is formed at a plurality of predetermined positions below the rear plate portion 2b and the lower plate portion 2c below c.

[0007] Behind the first channel portion 2, a second channel portion 5 having an open upper surface is provided sharing the rear plate portion 2b of the first channel portion 2. That is, the second channel-shaped portion 5 includes a shared rear plate portion 2b, a lower plate portion 5a extending rearward from a lower end of the rear plate portion 2b,
A first intermediate plate portion 5b extending substantially upward from a rear end of the lower plate portion 5a; a second intermediate plate portion 5c extending rearward from an upper end portion of the first intermediate plate portion 5b; and a second intermediate plate portion The rear plate 5d extends substantially upward from the rear end of the rear plate 5c. Rib plates 6 are formed at a plurality of predetermined positions between the rear plate portion 2b, the lower plate portion 5a, and the first intermediate plate portion 5b so as to extend in the front-rear direction. At predetermined positions of the lower plate portion 5a, two bosses 7 each having an attachment hole to a not-shown bottom plate (instrument main body) are formed for each octave. Lower plate 5a and first
At the intersection with the intermediate plate 5b, the keyboard chassis 1 is
(Asahi Gas Injection) A gas channel 8 is formed when formed by molding (a method of injecting a resin and subsequently injecting a gas followed by molding).

[0008] Behind the second channel-shaped portion 5, there is provided a third channel-shaped portion 11 having an open lower surface, sharing the rear plate portion 5d of the second channel-shaped portion 5. That is, the third channel-like portion 11 is shared with the shared rear plate portion 5d,
An upper plate 11a extending rearward from the upper end of the rear plate 5d.
And a rear plate 11b extending substantially downward from the rear end of the upper plate 11a. Black key guides 12 are formed to extend upward at predetermined plural locations on the upper surface of the front end of the upper plate 11a. Black key stopper piece insertion holes 13 are formed in the rear plate 5d and the upper plate 11a on both left and right sides of the black key guide 12. Note that no rib plate is formed in the third channel-shaped portion 11. This allows the upper plate portion 11a to be elastically deformable, and changes the height position to some extent between the keyboard chassis 1 on the front side of the upper plate portion 11a and the keyboard chassis 1 on the rear side of the upper plate portion 11a. This is to easily cope with the need to perform this.

Behind the third channel-shaped portion 11, a third
A fourth channel-shaped portion 14 having an open upper surface is provided sharing the rear plate portion 11b of the channel-shaped portion 11.
That is, the fourth channel portion 14 is shared with the rear plate portion 1.
1b, a lower plate 14a extending obliquely rearward and upward from the lower end of the rear plate 11b, a first rear plate 14b extending substantially upward from the rear end of the lower plate 14a, and the first rear plate. Second rear plate portion 14c extending substantially downward from the lower end of portion 14b
It consists of The rear plate portion 11b, the lower plate portion 14a and the first
Rib plates 15 extend in the front-rear direction at a plurality of predetermined positions between the rear plate 14b and the rear plate 14b. At a plurality of predetermined locations on the lower plate portion 14a, key insertion detecting switch insertion holes 16 are formed. Circuit board supporting projections 17 are formed at a plurality of predetermined locations on the upper front surface of the second rear plate portion 14c.

[0010] Behind the fourth channel portion 14, the fourth
First and second rear plate portions 14b, 14 of the channel portion 14
5th channel-shaped part 2 which opened the lower surface, sharing c
1 is provided. That is, the fifth channel-shaped portion 2
1 is a shared first and second rear plate portion 14b, 14c, and an upper plate portion 21a extending rearward from the upper end of the first rear plate portion 14b.
A first rear plate 21b extending obliquely downward and rearward from the rear end of the upper plate 21a; and a second rear plate 21c extending substantially downward from the lower end of the first rear plate 21b. I have. First and second rear plate portions 14b, 14c and upper plate portion 21a
A plurality of rib plates 22 extend in the front-rear direction at a plurality of predetermined positions between the first and second rear plate portions 21b and 21c. Hammer support portions 23 are provided at a plurality of predetermined locations on the upper surface of the upper plate portion 21a. The hammer support 23 is
As will be described in detail later, a pair of support plate portions 23a formed opposite to each other on the upper surface of the upper plate portion 21a,
and a shaft 23b formed between them. Shaft 2
A shaft portion forming hole 24 is formed at a predetermined position of the upper plate portion 15a below 3b.

A plate-like portion 25 is provided behind the fifth channel-like portion 21. That is, the plate-like portion 25 is
An inclined plate portion 25a extending obliquely rearward and upward from the upper end of the second rear plate portion 21c of the channel-shaped portion 21;
An upper plate portion 25b extending rearward from a rear end portion of the upper plate portion 5a, a projecting portion 25c formed on a lower surface of a front end portion of the upper plate portion 25b,
A rib portion 25 extending substantially upward from the rear end of the upper plate portion 25b
d and a rib 25e described later. At two or more predetermined positions of the inclined plate portion 25a, there are two holes 2 for inserting a hammer.
6 are formed. A gas channel 27 is formed in the projection 25c. Key support portions 28 are provided at a plurality of predetermined locations on the upper surface of the upper plate portion 25b. Key support 2
Reference numeral 8 denotes a pair of elastically deformable support plate portions 28a formed on the upper surface of the upper plate portion 25b so as to face each other, and shafts formed at predetermined positions on the opposing surfaces of the support plate portions 28a. And a portion 28b. A shaft portion forming hole 29 is formed at a predetermined position of the upper plate portion 25b below the shaft portion 28b. On the upper surface of the upper plate portion 25b on the front side of the key support portion 28, a coil spring mounting protrusion 30 is formed. On the upper surface of the upper plate portion 25b on the rear side of the key support portion 28, a rib portion 25e is formed extending to the rib portion 25d. As a result, the rib 25
A substantially T-shaped rib portion composed of e and a rib portion 25d in the vicinity thereof is formed.

A plurality of rib plates 31 are formed at a plurality of predetermined positions between the second rear plate portion 21c, the inclined plate portion 25a, and the upper plate portion 25b so as to extend in the front-rear direction. Predetermined two rib plates 31
A plate portion 32 is provided on the rear surface of the lower end portion of the second rear plate portion 21c between the two.
Are formed two for each octave.
Is formed with a boss 33 having a mounting hole for a bottom plate (instrument main body). A lower portion of the rear end of each rib plate 31 is formed with a sixth channel-shaped portion 34 whose lower surface is open. Notches 35 for arranging the upper limit stopper member for the hammer are formed in all the rib plates 31 on the front side of the sixth channel portion 34. At predetermined positions on the rear surface of the sixth channel portion 34, two bosses 36 each having an attachment hole to a bottom plate (instrument main body) are formed for each octave. The bosses for attaching the keyboard chassis 1 to the bottom plate (instrument body) may be only the front and rear bosses 7 and 36, and the intermediate boss 33 may be omitted.

Next, a description will be given with reference to FIG. Greases 41 and 42 are applied to the key guides 3 and 12, respectively. A not-shown white key light emitting diode (light emitting element) is provided at a predetermined position on the upper surface of the upper plate portion 2a of the first channel-shaped portion 2.
Is attached. A band-shaped upper limit stopper member 44 for white key made of felt or the like is attached to the lower surface of the upper plate portion 2a of the first channel-shaped portion 2. A band-shaped white key lower limit stopper member 45 made of felt or the like is attached to the upper surface of the lower plate portion 2c of the first channel-shaped portion 2.

The second intermediate plate 5c of the second channel 5
A belt-like lower limit stopper member 46 for black key made of felt or the like is attached to the upper surface of the lower plate. A band-shaped black key upper limit stopper member 47 made of felt or the like is attached to the lower surface of the upper plate portion 11a of the third channel-shaped portion 11.
A circuit board 48 provided with a black key light emitting diode (not shown) is attached to a predetermined position on the upper surface of the upper plate portion 11a of the third channel-shaped portion 11.

On the lower surface of the lower plate portion 14a of the fourth channel portion 14, there is provided a circuit board 52 provided with a keying detection switch 51 formed of a push button type self-returning rubber switch on the upper surface. The circuit board 52 has its rear end supported by the circuit board supporting projections 17, and a plurality of predetermined portions thereof are attached to the lower plate portion 14 a by screws 53. The keying detection switch 51 protrudes above the lower plate portion 14a through the keying detection switch insertion fool hole 16. Here, the angle of inclination of the lower plate portion 14a will be described. An extension of the lower plate portion 14a substantially passes through the shaft portion 28b of the key support portion 28. When the lower surface of the switch pressing portion 65 of the white key 61 described later is not a predetermined inclined surface but a substantially horizontal surface, the lower plate portion 14a may be substantially horizontal.

A belt-like lower limit stopper member 54 for hammer made of felt or the like is attached to the lower surface of the rear end of the upper plate portion 25b of the plate portion 25. Sixth channel portion 34
The rear upper surface of the hard film 55 is attached to the lower surface of the hard film 55. A band-shaped hammer upper limit stopper member 56 made of felt or the like is attached to the front upper surface of the hard film 55 in the cutout portion 35.

On the upper side of the keyboard chassis 1, a plurality of resin keys (see FIG. 1, white key 61 and black key 62, but mainly the white key 61 will be described) are arranged in parallel. The white key 61 has a substantially L-shaped stopper piece 64 formed below a front end portion of a key body 63 having a substantially inverted U-shaped cross section, and a switch pressing portion 65 having a predetermined shape is formed below a central portion of the key body 63.
Are formed, a coil spring mounting protrusion 66 is formed on the lower rear side of the key body 63, and mounting holes 67 are formed on both sides of the rear end of the key body 63. Then, the rear end of the key body 63 is press-fitted between a pair of elastically deformable support plates 28a of the key support 28 (see FIG. 1), and the respective mounting holes 67 are relatively fitted to the shaft 28b. As a result, the white key 61 is swingably disposed above the keyboard chassis 1. A coil spring 68 is mounted between the two coil spring mounting protrusions 30 and 66. The substantially L-shaped stopper piece 69 of the black key 62
Is vertically movably inserted into the black key stopper piece insertion hole 13 (see FIG. 3).

A hammer 71 is arranged below the white key 61 from the center to the rear. The hammer 71
A mounting hole 73 and a tapered guide hole 74 connected to the mounting hole 73 are formed at predetermined positions of a resin hammer main body 72 (the mounting hole 73 will be described later in detail), and the hammer will be described. A weight 75 made of lead or the like is provided at another predetermined position of the main body 72, and a soft contact portion 76 made of urethane resin or the like is provided at the front end of the hammer main body 72. In this case, the minimum width of the guide hole 74 is slightly smaller than the diameter of the mounting hole 73, and the maximum width is the mounting hole 7.
3 is slightly larger than the diameter. When the hammer main body 72 is inserted into the hammer insertion hole 26 of the plate-like portion 25, the mounting hole 73 is relatively fitted to the shaft portion 23b of the hammer support portion 23 via the guide hole 74. As a result, the hammer 71 is swingably disposed below the white key 61. The soft contact portion 76 made of urethane resin or the like is for preventing generation of noise at the time of keying. The contact portion 76 is a key body 6 of the white key 61.
3 and is rotatably fitted between a predetermined portion 65a of the switch pressing portion 65 and the upper plate portion.

Next, an example of the hammer support portion 23 will be described with reference to FIGS. 5 (A) and 5 (B). When the keyboard chassis 1 having the hammer support 23 is formed using the upper die and the lower die, draft angles are formed in the upper die and the lower die as in the conventional case. As shown, the opposing surfaces of the two support plate portions 23a are the shaft portions 23b.
The tapered surface 23c gradually separates upward as it goes upward, and the taper surface 23db gradually separates downward as it goes below the shaft portion 23b.

On the other hand, on both sides of the hammer body 72 above and below the mounting hole 73 of the hammer 71, elastic pieces 8 are provided.
1, 82 are cantilevered. That is, the upper elastic piece 81 is attached to the hammer main body 72 from above the mounting hole 73.
A substantially hemispherical projection 81a is formed on the outer surface of the upper end portion. The lower elastic piece 82 extends downward from the lower side of the mounting hole 73 along the side surface of the hammer body 72, and a substantially hemispherical projection 82a is formed on the outer surface of the lower end.

Since the mounting hole 73 is relatively fitted to the shaft 23b through the guide hole 74, the hammer 71 is swingably (rotatably) supported by the hammer support 23. . In this state, the protrusion 81a of each upper elastic piece 81 is connected to the upper tapered surface 23c of each support plate portion 23a.
And the projection 82a of each lower elastic piece 82 is pressed against the lower tapered surface 23d of each support plate 23a. As described above, since the elastic pieces 81 and 82 formed on the hammer 71 are pressed against the support plate 23a, the elasticity of the elastic pieces 81 and 82 can absorb the horizontal displacement of the hammer 71, and thus the hammer 71. Can be supported without causing sideways movement.

Next, another example of the hammer support portion 23 will be described with reference to FIG. Elastic pieces 83 and 84 are formed in the upper and lower portions of the mounting hole 73 of the hammer 71. That is, the upper elastic piece 83 is formed of a thin arc-shaped portion below an arc-shaped through hole 85 formed along the attachment hole 73 in the hammer main body 72 above the attachment hole 73, and has a central lower surface. Has a protruding portion 8 having a substantially semicircular cross section.
3a are formed. The lower elastic piece 84 is attached to the mounting hole 7.
3 comprises a thin arcuate portion on the upper side of an arcuate through hole 86 formed along the mounting hole 73 in the hammer main body 72 on the lower side of the hammer main body 72. 84a are formed.

Since the mounting hole 73 is relatively fitted to the shaft portion 23b via the guide hole 74, the hammer 71 is swingably (rotatably) supported by the hammer support portion 23. . In this state, the protruding portion 83a of the upper elastic piece 83 is pressed against the upper surface of the shaft portion 23b, and the protruding portion 84a of the lower elastic piece 84 is pressed against the lower surface of the shaft portion 23b. Since the elastic pieces 84, 84 formed on the hammer 71 are pressed against the shaft 23b, the elastic pieces 83, 84 can be formed even if the shaft 23b is not a perfect circle.
Of the hammer 71 in the radial direction can be absorbed by the elasticity of the hammer 71.
Can be supported without rattling in the radial direction of the shaft portion 23b.

In FIG. 6, for example, an elastic piece 81 as shown in FIG. 5 is formed above the upper through hole 85, and an elastic piece 82 as shown in FIG. May be formed. In this case, the hammer 7
1 can be supported without causing lateral displacement and without rattling in the radial direction of the shaft portion 23b.

[0025]

As described above, according to the first aspect of the present invention, since the elastic piece formed on the rotating body is pressed against the supporting plate, the rotating body is caused to sway by the elasticity of the elastic piece. Can be absorbed, and thus the rotating body can be supported without causing lateral movement. According to the second aspect of the present invention, since the elastic piece formed on the rotating body is pressed against the shaft, it is possible to absorb the play of the rotating body in the radial direction of the shaft by the elasticity of the elastic piece. Accordingly, the rotating body can be supported without rattling in the shaft radial direction. According to the third aspect of the present invention, since the first elastic piece formed on the rotating body is pressed against the support plate portion, the elasticity of the first elastic piece can absorb the horizontal displacement of the rotating body,
In addition, since the second elastic piece formed on the rotating body is pressed against the shaft, the backlash of the rotating body in the radial direction of the rotating body can be absorbed by the elasticity of the second elastic piece. Can be supported without causing lateral displacement and without rattling in the shaft portion radial direction.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a keyboard device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG. 1;

FIG. 3 is a plan view of the keyboard chassis shown in FIG. 1;

FIG. 4 is a sectional view taken along the line YY of FIG. 3;

FIG. 5A is a vertical side view of an example of a hammer support portion, and FIG. 5B is a cross-sectional view taken along the line BB.

FIG. 6 is a longitudinal sectional side view of another example of the hammer support portion.

FIG. 7A is a longitudinal side view of a conventional hammer support portion, and FIG. 7B is a cross-sectional view taken along the line BB.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Keyboard chassis 23 Hammer support part 23a Support plate part 23b Shaft part 71 Hammer 72 Hammer main body 73 Mounting hole 74 Guide hole 81-84 Elastic piece

Claims (4)

[Claims] 1. A rotating body supporting structure in which a rotating body is rotatably supported by a rotating body supporting portion formed integrally with a resin chassis, wherein the rotating body supporting portion faces the chassis. A pair of support plate portions formed in the above manner, and a shaft portion formed between these support plate portions, wherein the rotating body has a mounting hole, a guide hole continuous with the mounting hole, Elastic pieces formed on both sides facing the both support plate parts in the vicinity, wherein the mounting hole is relatively fitted to the shaft part via the guide hole, and the elastic piece is provided on the support plate. A rotating body support structure being pressed against a part. 2. A rotating body supporting structure in which a rotating body is rotatably supported by a rotating body supporting portion formed integrally with a resin chassis, wherein the rotating body supporting portion is opposed to the chassis. A pair of support plate portions formed in the above-mentioned manner, and a shaft portion formed between these support plate portions, wherein the rotating body includes a mounting hole, a guide hole continuous with the mounting hole, A rotating body, wherein the mounting hole is relatively fitted to the shaft portion via the guide hole, and the elastic piece is pressed against the shaft portion. Support structure. 3. A rotating body supporting structure in which a rotating body is rotatably supported by a rotating body supporting section integrally formed with a resin chassis, wherein the rotating body supporting section is opposed to the chassis. A pair of support plate portions formed in the above manner, and a shaft portion formed between these support plate portions, wherein the rotating body has a mounting hole, a guide hole continuous with the mounting hole, A first portion formed on both side surfaces facing the both support plate portions in the vicinity.
An elastic piece and a second elastic piece formed in the mounting hole, wherein the mounting hole is relatively fitted to the shaft portion via the guide hole, and the first elastic piece is provided on the support plate. A rotating member supporting structure, wherein the rotating member is pressed against the shaft portion and the second elastic piece is pressed against the shaft portion. 4. The invention according to claim 1, wherein the chassis is a keyboard chassis, the rotating body supporting portion is a hammer supporting portion, and the rotating body is a hammer. Rotating body support structure.