JPH0752339B2 - Keyboard instrument - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to electronic keyboard musical instruments such as electronic organs and electronic pianos, as well as various keyboard musical instruments provided with a rotatable keyboard lid, and particularly to the keyboard lids. Technology related to smooth opening and closing.

[Outline of Invention]

The present invention relates to a keyboard musical instrument having a keyboard lid that opens and closes a keyboard portion by rotating with respect to the musical instrument body, in which the rear end portion of the keyboard lid is biaxially attached to the musical instrument body via levers and shafts at both ends thereof. The keyboard is rotatably supported, and the range of rotation by each axis when the keyboard lid is opened and closed is made different, and elastic members are respectively attached between two members that relatively rotate around each axis, to secure the keyboard lid. Each elastic member elastically deforms in response to the opening / closing operation to generate a return force, and the return force acts to rotate the keyboard lid in the opening direction at the closed position of the keyboard lid and in the closing direction at the open position. However, by setting the return force to be zero at a predetermined position between the closed position and the open position, even a large and heavy keyboard lid can be opened and closed safely and smoothly with a uniform light operating force, and When opening the lid, use the top of the instrument Ri is obtained to be able to be lowered.

[Conventional technology]

An electronic musical instrument having a keyboard such as an electronic organ is generally provided with a keyboard lid that covers and protects the keyboard when not in use.

The keyboard lid is slidable in the front-back direction of the instrument body, and is a slide-type lid body that is housed in the instrument body when the lid is opened, and is rotatably arranged in the up-down direction. There are two types of rotary lids that stand upright on the instrument body when the lid is closed.

However, since the former slide type lid is formed into an armor-like shape by flexibly connecting a large number of lid constituent members in series, the structure is complicated and the number of parts is large, resulting in high manufacturing cost. There's a problem.

On the other hand, the latter rotary lid can be manufactured at a low cost because it may be a single plate-shaped lid, and since it is erected on the instrument body when the lid is opened, a storage space is provided inside the instrument body. It has the advantage that it does not have to be secured.

However, if the depth of the keyboard lid increases and the weight increases, as in the case of an electronic musical instrument with a two-tiered keyboard, not only does it become difficult to open and close, but the keyboard lid also drops suddenly during opening and closing due to the movement of its center of gravity. I could close my hand and put my hand in it.

Therefore, for example, as shown in Japanese Utility Model Publication No. 62-46219, when the keyboard lid is closed, the turning force by its own weight is received and buffered by a braking mechanism using a spring in the latter half of its rotation. There is something.

In addition, when the depth of the keyboard lid is large, the area of the keyboard lid is also large, which gives the player a feeling of pressure when it is erected on the instrument body when the lid is opened.

Therefore, as shown in, for example, Japanese Patent Laid-Open No. 63-11995, a pivot fulcrum of the keyboard lid is provided at a position a certain distance forward and below the lower surface from the rear end of the lid, and the keyboard lid is opened when the lid is opened. The rear end is stored inside the instrument body, and the weight balance before and after the pivotal fulcrum of the keyboard lid allows a relatively light opening and closing operation, and there is no sudden closing and finger pinching. Some of the above are being developed.

[Problems to be Solved by the Invention]

However, in such a conventional keyboard lid opening / closing mechanism,
In each case, the emphasis was mainly on safety when closing the keyboard lid, and little consideration was given to the mitigation of impact when the lid was opened.

As a result, the operating force required during the entire opening / closing operation of the keyboard lid changes considerably, and it may not always be possible to open / close smoothly with good operability.

The present invention has been made in view of such points,
In a keyboard instrument equipped with a pivotable keyboard lid as described above, the operating force required for opening and closing the keyboard lid is made almost uniform throughout the entire opening and closing operations of the keyboard lid, so that the keyboard lid can be opened and closed uniformly with a light operating force. The goal is to be safe and smooth.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a keyboard instrument having a keyboard lid that opens and closes a keyboard portion by rotating with respect to the instrument body, wherein the instrument body has one end at the rear end of the keyboard lid. Of the lever, which is rotatably supported by the shaft of and the other end of which is rotatably supported by the second shaft in a bracket fixed to the instrument body, and the lever and the rear end of the keyboard lid. A first elastic member that is engaged between the second elastic member and a second elastic member that is engaged between the bracket and the lever; and a stopper member that restricts the rotation limit position of the lever in the direction of closing the keyboard lid. To provide.

When the keyboard lid is opened and closed, the lever is locked to the stopper member in a rotation range from a completely closed position where the keyboard lid is completely closed to a predetermined position on the way to a fully opened position where the keyboard lid is completely opened. The keyboard lid rotates about the first axis with respect to the lever, and the keyboard lid moves the first axis with respect to the lever in the rotation range from the predetermined position to the fully open position. The lever rotates about the center and the lever rotates about the second shaft with respect to the bracket.

Further, the first elastic member is in a standard state in which a restoring force is not generated at a predetermined rotation position in the middle of the rotation range of the keyboard lid and the lever, and the keyboard lid is opened from the predetermined rotation position. It is a member that elastically deforms so as to generate a restoring force in the range in which the keyboard lid is closed, and to generate a restoring force in the direction in which the keyboard lid is opened from the predetermined rotation position in the rotation range in which the keyboard lid is closed.

The second elastic member is in a neutral state in which a restoring force is not generated at a predetermined rotation position in the middle of the rotation range of the lever and the bracket, and is in a rotation range where the keyboard lid is opened from the predetermined rotation position. It is a member that elastically deforms so as to generate a restoring force in the closing direction of the keyboard lid, and to generate a restoring force in the opening direction of the keyboard lid in a rotation range in which the keyboard lid is closed from its predetermined rotation position.

[Action]

The keyboard instrument according to the present invention has the above-mentioned configuration, and when the lid is opened, the keyboard lid is moved to the predetermined position (half-open position) on the way from the fully closed position to the fully opened position with respect to the lever locked at the rotation limit position. Since it rotates about the axis of No. 1, the position of the rotation fulcrum does not change, but if it is further opened from the above predetermined position,
Since the lever is rotated about the second axis with respect to the bracket fixed to the instrument body, the keyboard lid is rotated about two axes, and the first axis is displaced along with the rotation of the lever. Therefore, the latter half of the keyboard lid can be lowered from the top plate of the instrument body.

Further, each elastic member engaged between the members that relatively rotate around the respective axes in response to the opening / closing operation of the keyboard lid is elastically deformed to generate a restoring force, and the restoring force is the same as that of the keyboard lid. It acts to rotate the keyboard lid in the opening direction in the closed position and in the closing direction in the open position, and the restoring force thereof changes in different rotation ranges of the keyboard lid, so that between the closed position and the open position. Since the restoring force becomes zero at a predetermined position of, the synthetic force of the restoring force of each elastic member (also referred to as assisting force in the description of the embodiment) and the turning force due to the weight of the keyboard lid are almost balanced, and the entire stroke is achieved. You can open and close the keyboard lid safely and smoothly with an almost uniform light operating force.

〔Example〕

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 and FIG. 2 are side views showing the inside of an electronic keyboard instrument according to an embodiment of the present invention, omitting parts other than those necessary for explaining the keyboard lid opening / closing mechanism.

2 shows a state in which the keyboard lid starts to open with a solid line, and shows a state in which the keyboard lid is opened slightly larger than the horizontal with a phantom line, and FIG. The states of the two positions are shown by virtual lines.

In the electronic keyboard musical instrument of this embodiment, the keyboard lid 13 is openably and closably supported with respect to the musical instrument body 11, and when not in use, this keyboard lid 13
By closing, the upper and lower two keyboards 12A and 12B
It is designed so that it can be covered and protected.

The illustrated keyboard lid opening / closing mechanism is provided on both sides of the musical instrument body 11.

At the rear end of the keyboard lid 13, a dogleg-shaped arm member 14 is fixedly mounted, and a roller 15 is rotatably attached to it by a shaft 16.

On the other hand, a bracket 17 is fixedly installed in the instrument body 11, and one end of an L-shaped lever 18 which is a link member is fixed to the second shaft 19 thereof.
The lever 19 is rotatably supported by the first shaft 20, and the other end of the lever 19 is rotatably supported by the first shaft 20 in the central portion of the doglegged arm member 14.

Further, a bar receiving portion is provided outside the middle portion (bending portion) of the lever 18.
18a is formed, and a torsion bar 21 as a first elastic member is attached between the bar receiving portion 18a and the rear end of the keyboard lid 13.

Further, a roller guide 22 forming a guide rail surface 22a for guiding the roller 15 is fixedly provided on the shelf plate 11b of the musical instrument body 11.

Reference numeral 11a is a top plate of the musical instrument body 11, 11c is a side plate, 11d is a mouth stick, and 11e is a back plate.

And, there is a space between the lower edge of the top plate 11a and the upper edge of the back plate 11e.
24 is formed, and inside thereof, there is provided a falling object discharge panel 23 having an inclined surface that descends toward the back surface from a position close to the locus of the rear end of the keyboard lid 13.

Reference numeral 25 is an operation panel for arranging various key switches and the like, and 26 is a music score receiver. Further, a transformer 27, which is a mounting component, is arranged on the rear shelf plate 11b in the musical instrument body 11.

Next, the construction of the keyboard lid 13 and the main part of the opening / closing mechanism of this embodiment will be described in more detail with reference to FIGS.

As shown in FIG. 3, the keyboard lid 13 is composed of a first lid member 131 made of transparent resin, such as acrylic, which constitutes the front half portion, and a second lid member 132, which is made of metal such as aluminum and constitutes the latter half portion.
It consists of

Then, in the joint portion of the second lid member 132 with the first lid member 131, along the longitudinal direction (key arrangement direction), there is a channel-shaped strip holding portion 132a, and two strip-shaped holding portions 132a are provided on both sides thereof. The pressing protrusions 132b, 132c and the L-shaped locking piece 132d for restricting the rear end position of the first lid member 131 are integrally formed.

Into the channel-shaped band plate holding portion 132a, a band-shaped plate 133 in which cylindrical screw receiving members 134 (female threads are cut) are fixed at intervals in the longitudinal direction by caulking or the like is inserted and held. Then, the through hole formed in the vicinity of the rear end of the first lid member 131 is fitted into the screw receiving member 134, and the upper surface thereof is projected 1
The rear end faces of 32b and 132c are brought into contact with the L-shaped locking pieces 132d, respectively.

Then, the entire length of the rear end portion of the first lid member 131 and the L-shaped locking piece 132d is pressed by the L-shaped pressing member 135, and the set screw 1
36 to the screw receiving member 134, and set screw 137 to L
Each of the shape locking pieces 132d is fixed with a screw.

Therefore, the first cover member 131 and the second cover member 132 are firmly connected without any set screw or the like appearing on the upper surface side of the keyboard cover 13.

Further, a resin finger hook member 138 and a cushion material 139 are attached to the front edge portion of the first lid member 131.

A bent portion 132e is provided at a rear end portion of the second lid member 132, an L-shaped locking portion 132f is provided in front of the bent portion 132e, and a contact portion also serving as a reinforcement on both sides thereof.
132g and 132h are formed respectively, and the bent portion 132e
A dogleg-shaped arm member 14 is locked between the locking portion 132f and the locking portion 132f, as shown in FIG.

That is, the claw portion 14c formed on the lower surface near the tip of the one arm portion 14a of the doglegged arm member 14 is hooked on the locking portion 132f and inserted into the screw hole provided in the bent portion 132e. Screw 28
Is screwed into the tap hole of the other arm portion 14b of the dogleg-shaped arm member 14 and tightened, whereby it is pulled and firmly fixed in the direction of arrow B.

A pair of roller support pieces 1 is provided on the lower surface of the arm portion 14b of the doglegged arm member 14.
4d is a fixed shaft that supports roller 15 rotatably on it.
Holds both ends of 16.

The roller 15 rolls and moves on the guide rail surface 22a of the roller guide 22 shown in FIG.

The roller guide 22 is integrally molded of synthetic resin, and actually has a lightening shape as shown in FIGS. 1 and 2 in order to save material and prevent sink marks, but in FIG. It is shown in the figure.

On the other hand, the side plate 11c is provided with the armor metal fitting 29 forming the lower case together with the shelf plate 11b, the mouthpiece 1d, and the back plate 11e of the musical instrument body 1 shown in FIG.
And the upper inclined surface 29a as shown in FIG.
A channel-shaped bracket 17 is fixed to the.

A shaft 19 having a torsion coil spring 30 inserted therein is rotatably supported between both side walls 17a, 17b of the bracket 17, and one end of the shaft 19 (the other end is supported by the shaft 20). (A shaft-supported member is centrally supported on the V-shaped arm member 14) and a spring locking plate 31 having a notch groove 31a is fixed to the other end. The stop plate 31 is fitted and locked in the notch groove 31a, and the other end is fitted and locked in the notch groove 17c formed in one side wall 17a of the bracket 17.

A stopper pin 32, which is a stopper member, is provided on the side wall 17a of the bracket 17 so as to project from the position shown in FIG. 4 when the lever 18 rotates counterclockwise (to close the keyboard lid 13). At the limit position, the stopper recess 18b engages with the stopper pin 32 to prevent its rotation.

The torsion coil spring 30 is the second elastic member, and the lever 18
Becomes a neutral state (assist force is zero) when it is rotated halfway, and further turning to the left causes it to be wound up to generate a right-turning direction (a restoring force (assisting force) in the direction of opening the keyboard lid 13), and the lever 18 When it is turned right from the intermediate position, it is rewound to generate a return force (auxiliary force) in the left turn direction.

Therefore, when the lever 18 at the time of opening the lid shown in FIG. 4 is turned to the right, the maximum restoring force in the counterclockwise direction is generated, which pushes the keyboard lid 13 up against its own weight. Since it acts as the torque of, the operating force (main force) by the performer's hand from the outside required for starting the closing can be reduced.

On the other hand, the torsion bar 21 which is the first elastic member is
As shown in the figure, it is composed of an intermediate portion 21b and both end portions 21c which are formed in a crank shape in a symmetrical manner centering on the central convex portion 21a,
Protrusions 21d for preventing slipping off are pressed on both ends 21c.

Then, the four positions of the intermediate portion 21b shown by the broken line in FIG. 5 are attached to the bent portion 132e of the second lid member 132 of the keyboard lid 13 by the attachment fittings 33 as shown in FIG. Convex part 21a
Is abutted on the inner surface of the second lid member 132, and both end portions 21c are fitted and locked to the bar receiving portions 18a of the levers 18 on the left and right sides, respectively, and are prevented from coming off by the protrusions 21d on both sides thereof.

The torsion angle α shown in FIG. 5 of the torsion bar 21 is 28 degrees in the standard state, but since the opening / closing operation of the keyboard lid 13 changes the angle formed by the lever 18 and the second lid member 132. , About 80 degrees in the closed state and about 48 degrees in the opened state, and the restoring torque changes the rotational torque applied between the keyboard lid 13 and the lever 18.

FIG. 6 is a perspective view of the musical instrument main body 11 with a part of the musical instrument main body 11 cut away with the keyboard lid 13 closed, as seen from an obliquely upper side. The relationship between the face plate 11e, the keyboard lid 13 and the falling object discharge panel 23 is clearly shown.

An arrow-shaped cushioning member 34 formed of soft resin is fitted to the front edge of the top plate 11a.

Next, the operation of this embodiment will be described.

At the time of opening the lid, the keyboard lid 13 is completely closed, and the finger hook member 138 at the front end thereof is put on the finger and lifted up to the second position.
The position P1 shown in the figure is set, and further the position P2 in the figure and the positions P3 and P4 in FIG.

In the meantime, the roller 15 is fixed to the guide rail surface 22 of the roller guide 22.
Always transfer to a and move. The guide rail surface 22a can be designed quite freely, but in this embodiment, it has two curved surfaces, large and small.

Then, between the positions P1 and P2 shown in FIG. 2, the roller 15 is in rolling contact with the small curved surface above the guide rail surface 22a,
During this time, the lever 18 engages with the stopper pin 32 and is locked at the upper limit position and does not rotate, and only the dog-legged arm member 14 is held.
At the same time, it turns right about the shaft 20 in FIG.

Therefore, the outer surface of the second lid member 132 of the keyboard lid 13 is
The top plate 11a is rotated at a position extremely close to the cushioning member 34 at the front end.

Further, at the position P1 at the beginning of opening, the torsion bar 21 attached between the bar receiving portion 18 of the lever 18 and the keyboard lid 13 shown by the solid line makes an angle of about 100 degrees, so that the twist angle is It is about 80 degrees, and the keyboard lid 13 is given a relatively large rotational torque in the opening direction by the restoring force of the torsion bar 21 with respect to the rotational torque in the closing direction due to its own weight. Therefore, the keyboard lid 13 can be lifted relatively lightly.

After that, as the keyboard lid 13 opens, the doglegged arm member 14
2 rotates rightward with respect to the lever 18 in FIG. 2, the torsion angle of the torsion bar 21 becomes smaller, but the torque in the left-handed direction due to the weight of the keyboard lid 13 also becomes smaller, so that the balance is maintained.

Furthermore, at the position P3 in FIG.
When it reaches the protrusion of a and then moves to the downward large curved surface, the lever 18 pivots right about the shaft 19 in the figure, and the second lid member 132 of the keyboard lid 13 of the musical score receiver 26 moves. It begins to be housed in the musical instrument body 11 through a gap between the rear end and the cushioning member 34 at the front end of the top plate 11a.

At this time, the restoring force of the torsion coil spring 30 shown in FIG. 4 acts in the direction of pulling in the keyboard lid 13, so that the keyboard bar 13 is smoothly accommodated in combination with the action of the torsion bar 21.

Then, in the state of position P4 in FIG. 1, the torsion bar 21 returns to the standard state in which the twist angle is 28 degrees and no restoring force (assisting force) is generated, and the familiar coil spring 30 in FIG. 4 also returns the restoring force (assisting force). However, the retraction force does not act on the keyboard lid 13, but the keyboard lid 13 rotates clockwise due to the turning force of its own weight and descends.

As a result, the torsion angle of the torsion bar 21 increases again, the restoring force acts in the direction of closing the keyboard lid 13 to generate a braking force, and the torsion coil spring 30 is also rewound.
The return force creates a braking force that gradually increases in the direction of closing the keyboard lid 13 against the clockwise rotation of the lever 18, so that the keyboard lid 13
Does not drop suddenly, and the roller 15 smoothly descends while rollingly contacting the guide rail surface 22a, and finally reaches the open position P5 shown by the solid line in FIG.

Meanwhile, the guide rail surface 22a regulates the movement trajectory of the keyboard lid 13 so that the outer surface of the second lid member 132 of the keyboard lid 13 always moves close to the buffer member 34.

Therefore, the gap between the buffer member 34 and the keyboard lid 13 can be made extremely small.

Even so, there is a risk that a score, a piece of paper, a clip, or the like may get inside the instrument body 11 from a slight gap between them.
Even if such a situation occurs, it slides down on the fallen object discharge panel 23 as shown by the arrow in FIGS. 1 and 6, and from the gap 24 between the top plate 11a and the back plate 11e. It is discharged to the outside.

Therefore, it is not necessary to provide a large dust cover or rotate the top plate 11a each time to open the upper part of the musical instrument body 11 to take out a fallen object.

Further, since the rotation trajectory of the rear end portion of the keyboard lid 13 in the instrument body 11 can be regulated by the roller guide 22, the space required for the rotation can be made smaller than before, and the transformer 27 or the like can be mounted. It is easy to secure the installation space for parts.

In addition, in FIGS. 1 and 2, the transformer 27 is a roller.
Seems to protrude into the movement path of 15, but the keyboard lid 13
Since the opening and closing mechanisms other than the above are provided only on both sides of the musical instrument body 11, they do not interfere unless they protrude into the movement path of the rear end of the keyboard lid 13.

When the keyboard lid 13 is closed, the tip of the keyboard lid 13 at the lid opening position P5 in FIG. 1 is grasped, and the keyboard lid 13 is pulled upward while being lifted upward. From positions P4 to P3 in FIG. 1, and from position P2 in FIG.
It should be rotated through P1.

In this embodiment, according to the opening / closing operation of the keyboard lid 13, the keyboard lid 13 is moved toward the open position at the closed position and toward the closed position at the open position.
As an elastic member that generates a return force that makes the force zero at a predetermined position between the closed position and the open position, an elastic body having two different elastic moduli, that is, the torsion bar 21 And a torsion coil spring 30 are installed, and the keyboard lid 13
Since I tried to balance the turning power by the self-weight of
The operating force required for opening and closing can be made almost uniform at any of the open position, the closed position, and the intermediate position.

In addition, at least the keyboard lid 13 is provided by the torsion bar 21.
A strong restoring force in the open position direction can be applied in the vicinity of the closed position, and it is also easy to apply a uniform assisting force on both sides by one torsion bar, which simplifies the configuration.

The twist angles of the torsion bar 21 when the lid is closed, when the lid is opened, and at predetermined positions between them are α1, α2, α.
If it is set to 3, in the above-described embodiment, the following relationship is set, but α1 = 80 °, α2 = 48 °, α3 = 28 ° Not limited to this, the condition of α1>α2> α3 is satisfied. If it satisfies, it can be set arbitrarily.

Further, in this embodiment, the torsion coil spring is used as a supplemental member for cushioning action when the lid is opened by the torsion bar, but the torsion coil spring may be used as a supplemental member for cushioning action when the lid is closed by the torsion bar.

Further, the torsion coil spring may be used as a supplementary member for the cushioning action of the torsion bar both when the lid is opened and when the lid is closed, or the torsion coil spring may be the main elastic member and the torsion bar may be the auxiliary elastic member, or either one of them. Only one elastic member may be used, or another elastic member may be used.

The present invention can be applied not only to the keyboard lid opening / closing mechanism shown in the above-mentioned embodiment but also to the case of using other pivotable keyboard lid opening / closing mechanisms, and the object is not limited to the electronic keyboard musical instrument, but an organ or upright piano. It is also applicable to general keyboard musical instruments such as.

〔The invention's effect〕

As described above, according to the present invention, when the keyboard lid is opened / closed, the keyboard lid is pivoted about two shafts linked by levers, and is attached between the members which are relatively pivoted around the respective shafts. In addition, the restoring force of the first and second elastic members and the turning force by the weight of the keyboard lid are balanced, and the keyboard lid can be opened and closed safely and smoothly with a substantially uniform light operating force in the entire process.

Therefore, it is possible to pinch your fingers between the front edge of the keyboard lid and the mouth stick of the instrument body when closing the lid, or to pinch your fingers between the outer surface of the keyboard lid and the front edge of the top plate when opening the lid. Disappear.

Further, when the keyboard lid is opened, the latter half of the keyboard lid can be lowered from the top plate of the instrument main body, so that even a keyboard instrument having a large keyboard lid will not give a feeling of pressure to the player during the performance.

[Brief description of drawings]

1 and 2 are side views showing the inside of an electronic keyboard instrument according to an embodiment of the present invention, except for the parts necessary for explaining the keyboard lid opening / closing mechanism, and FIG. 3 is a side view of the keyboard lid. FIG. 4 is a cross-sectional view showing the structure, FIG. 4 is a perspective view showing the main part of the keyboard lid opening / closing mechanism, FIG. 5 is a perspective view of the torsion bar 21 in FIG. 4, and FIG. 6 is a state in which the keyboard lid 13 is closed. FIG. 3 is a perspective view of a musical instrument body 11 partially cut away and viewed obliquely from above. 11 …… instrument body, 11a …… top plate, 11b …… shelf plate 11c …… side plate, 11d …… mouth stick, 11e …… rear plate 13 …… keyboard cover, 14 …… dog-shaped arm member 15 …… Roller, 18 …… Lever, 19 …… Shaft 21 …… Torsion bar (first elastic member) 22 …… Roller guide, 22a …… Guide rail surface 23 …… Falled material discharge panel, 24 …… Gap 27 …… Transformer (Mounted parts), 29 …… Arm brackets 30 …… Torsion coil spring (second elastic member)

Claims (1)

[Claims] 1. A keyboard musical instrument comprising a keyboard lid (13) that opens and closes a keyboard portion by rotating with respect to the musical instrument body (11), wherein the musical instrument body (11) has one end with the keyboard lid (13). ) Is rotatably supported by a first shaft (20) at the rear end of the musical instrument body (1).
A lever (18) pivotally supported by a second shaft (19) on a bracket (17) fixed to 1), and the lever (18) and the rear end of the keyboard lid (13) A first elastic member (21) engaged between the lever (18) and a second elastic member (30) engaged between the bracket (17) and the lever (18). A stopper member (32) for restricting the limit position of rotation of the keyboard lid (13) in the closing direction is provided, and when the keyboard lid (13) is opened and closed, the keyboard lid (13) is completely closed. In the rotation range from the position to the predetermined position on the way to the fully open position, the lever (18)
Is locked to the stopper member (32), and the keyboard lid (13) rotates about the first shaft (20) with respect to the lever, and rotates from the predetermined position to the fully open position. In the range, the keyboard lid (13) rotates with respect to the lever (18) about the first shaft (20) and the lever (18).
Is rotated about the second shaft (19) with respect to the bracket (17), and the first elastic member (21) includes the keyboard lid (13) and the lever (18). At a predetermined rotation position in the middle of the rotation range, a standard state where no return force is generated is generated, and in a rotation range where the keyboard cover (13) opens from the predetermined rotation position, a return force in a direction to close the keyboard cover (13). And the keyboard lid (13) from the predetermined rotation position.
Is a member that elastically deforms so as to generate a restoring force in the direction in which the keyboard lid (13) is opened in the closing rotation range. The second elastic member (30) includes the lever (18) and the bracket (17). At a predetermined rotation position in the middle of the rotation range between and, it is in a neutral state in which no restoring force is generated, and in the rotation range where the keyboard lid (13) opens from the predetermined rotation position, the keyboard lid (13) is closed in the direction of closing. A keyboard that is elastically deformed so as to generate a restoring force and generate a restoring force in a direction in which the keyboard lid (13) is opened in a rotation range in which the keyboard lid (13) is closed from the predetermined rotation position. Musical instrument.