JP3856274B2 - Opening and closing device for keyboard lid in keyboard instrument - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a keyboard lid opening / closing device in a keyboard instrument that can easily open a keyboard lid during a lid opening operation and prevents a sudden drop of the keyboard lid during a lid opening operation.
[0002]
[Prior art]
A keyboard instrument such as a general piano or an electronic piano has an openable / closable keyboard cover that covers the upper part of the keyboard when not playing. This keyboard cover is long and heavy, and the rear end side is pivotally attached to the instrument body side or the back of the keyboard cover via a hinge. Because it needs to be supported and pushed up, a large operating force is required. In addition, when the lid is closed, the center of gravity moves suddenly from the middle of the operation, causing it to fall suddenly, hitting the mouth stick violently and making a loud impact sound, or accidentally placing the finger on the mouth stick and the keyboard lid. It was sometimes caught between
[0003]
Therefore, in order to solve such inconvenience, various opening / closing devices have been provided so as to prevent the keyboard lid from dropping suddenly. For example, JP-A-8-211861 discloses an opening / closing device such as a lid applied to a keyboard lid of an upright piano. As shown in FIG. 8, this switchgear includes a rotary damper 2 and an arm 3, and a support base 4 provided integrally with the rotary damper 2 is attached to a top surface of a beat tree 5 which is a constituent member of the instrument body. The roller 7 provided at the tip of the arm 3 is pressed against the lower surface of the keyboard lid 8 by a leaf spring 9, so that the keyboard is operated by the fluid resistance of the opening / closing device 1 and the leaf spring 9 during the closing operation. The lid 8 is configured to brake. Therefore, it can be slowly rotated and closed gradually. On the other hand, when opening the keyboard cover 8, the leaf spring 9 acts in the opening direction and can be opened with a relatively small force.
[0004]
[Problems to be solved by the invention]
However, since the above-described conventional opening / closing device 1 is installed on the upper surface of the beat tree 5, there is a problem in that it becomes an obstacle during performance and lowers performance. Moreover, the structure installed on the time tree 5 in this way is not smart because the entire apparatus is visually recognized, which is not preferable in terms of piano design.
In addition, since the opening angle of the keyboard lid 8 may vary depending on the type of keyboard instrument, the operating point of the switching device 1 varies depending on the installation position of the switching device 1. For this reason, it is necessary to adjust the distance between the keyboard lid 8 and the roller 7 when fully opened. This distance is an important factor in relation to the operating point of the damper when the lid is closed. Furthermore, when the leaf spring 9 is incorporated in the rotary damper 2, the size of the damper itself is restricted, so the size, shape, spring constant, etc. of the leaf spring 9 are also limited, and the degree of freedom in design is reduced. There was also.
[0005]
The present invention has been made to solve the above-described conventional problems, and the object of the present invention is to increase the design freedom of the spring and reduce the size without impairing the performance and appearance. An object of the present invention is to provide a keyboard lid opening / closing device for a keyboard instrument.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a keyboard lid opening / closing device for a keyboard instrument that brakes the keyboard lid by the viscous resistance of a fluid during a lid closing operation. A rotary shock absorber having a rotation arm having a roller and a spring are incorporated, and the rotation arm protrudes upward from an opening formed on the top surface of the beat tree, and the keyboard lid is attached to the keyboard lid by the spring. The roller is biased in the opening direction to press the roller against the lower surface of the keyboard cover, and one end of the spring is connected to the rotating arm, and the other end is fixed to the storage chamber .
In such a configuration, the portion protruding above the time tree of the rotary shock absorber can be reduced, so that it does not get in the way of performance and does not impair the aesthetics of the design.
The rotary shock absorber has a low fluid viscous resistance during the opening operation. At this time, since the spring acts in the direction of opening the keyboard cover, it can be opened with a smaller operating force than usual. On the other hand, the rotary shock absorber brakes the movement of the keyboard lid because the viscous resistance of the fluid gradually increases during the lid closing operation. At this time, the spring also acts to brake the movement of the keyboard lid. Therefore, the keyboard lid closes slowly without being accelerated by its own weight.
Further, since the spring is not incorporated in the rotary shock absorber, the degree of freedom in design such as spring force is increased, and the rotary shock absorber can be miniaturized.
[0007]
According to a second invention, in the first invention, the spring is constituted by a tension coil spring .
According to a third aspect of the present invention, in the second aspect of the present invention, a vibration preventing cover that houses a coil portion of the tension coil spring is provided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
FIG. 1 is an external perspective view showing the main part of an upright piano provided with a keyboard lid opening / closing device according to the present invention when the lid is opened, and FIG. 2 is a cross-sectional view when the keyboard portion incorporating the opening / closing device is closed. 3 is a side view showing a part of the opening / closing device, FIG. 4 is a front view of the rotary shock absorber, FIG. 5 is a cross-sectional view of the shock absorber, and FIG. 6 is an enlarged cross-sectional view taken along line VI-VI in FIG. 7 and 7 are perspective views of the rotary connector.
[0009]
1 and 2, the upright piano 20 includes a pair of left and right parent plates 22 (only one is shown) constituting the instrument body 21 and a pair of left and right arms 23 projecting forward from the respective parent plates 22. (Only one is shown), a shelf 24 laid horizontally between the arms 23, a mouth bar 25 provided at the front end of the shelf 24, an upper front plate 26, a lower front plate, not shown A board, a bottom board, and the like are provided, and 88 keyboards 27 composed of white keys and black keys, a keyboard key 28 and a pair of left and right time signatures 5 are arranged on the shelf plate 24. Further, the shelf plate 24 is supported by a pair of left and right pedestals 29, and an openable / closable keyboard lid 8 that covers the keyboard portion A is provided above.
[0010]
The keyboard lid 8 is composed of a flat lid body 8A having a musical score plate 33 attached to the lower surface side, and a front plate 8B foldably attached to the front end of the lid body 8A by a hinge 32. The rear end of 8A is pivotally attached to the front end of the keyboard lid back 31 by a hinge 30 so as to be rotatable in the vertical direction. The opening / closing angle of the keyboard lid 8 is, for example, about 130 °. When the lower surface of the front plate 8B comes into contact with the upper surface of the mouth bar 25 in the closed state, the keyboard lid 8 is held in a substantially horizontal state as shown in FIG. When the angle is opened, the front end surface of the lid main body 8A comes into contact with and is supported by the rubber button 34 provided on the surface of the upper front plate 26.
[0011]
A keyboard lid opening / closing device 40 according to the present invention is incorporated in the time tree 5 with a part protruding upward. The opening / closing device 40 includes a rotary shock absorber 41 that brakes the keyboard lid 8 to prevent a sudden drop during the closing operation, and a tension coil that biases the keyboard lid 8 in the opening direction via the rotary shock absorber 41. And a spring 42. For this reason, a storage chamber 43 for storing the rotary shock absorber 41 and the tension coil spring 42 is formed inside the time signature 5 and an opening 44 communicating with the storage chamber 43 is formed near the rear end of the upper surface. Has been.
[0012]
3 to 7, the rotary shock absorber 41 uses a fluid viscous resistance, and includes a cylindrical damper case 45 and a mounting portion 46 integrally provided at a lower portion of the damper case 45. The mounting portion 46 is fixed in the storage chamber 43 by a plurality of screws (not shown) so that an upper portion of the damper case 45 and a rotation lever 48 to be described later protrude from the opening 44 above the timepiece 5. Yes. Therefore, it can be said that the lower side of the rotary shock absorber 41 is buried in the time signature 5.
[0013]
The damper case 45 is formed in a cylindrical body whose one end is open, an incompressible damping oil 50 is enclosed therein, and a rotation shaft 51 is rotatably disposed via an O-ring 52. A ring 53 that prevents the rotation shaft 51 from coming off is fitted to the opening end.
[0014]
Further, a stopper 54 is integrally projected on the inner peripheral surface of the damper case 45 toward the center, and the tip end surface is close to the outer peripheral surface of the rotating shaft 51 and preferably faces the passage of the damping oil 50. So as to be relatively slidable so as not to form a contact.
[0015]
The rotating shaft 51 is formed in a cylindrical body having a different diameter with one end closed, so that the closed end side forms a small diameter portion 51A and the open end side forms a large diameter portion 51B, and the end surface of the small diameter portion 51A A columnar projection 56 is integrally projected. The protrusion 56 is provided with its center aligned with the center of the rotation shaft 51 and is rotatably fitted in a bearing hole 57 formed on the inner surface of the damper case 45 on the closed end side. A blade 58 extending in the radial direction is integrally provided on the outer peripheral surface of the small-diameter portion 51 </ b> A of the rotating shaft 51, and a movable valve 60 is provided at the tip of the blade 58. The inside of the damper case 45 is divided into two chambers, that is, the first and second buffer chambers 61A and 61B by the rotating shaft 51, the blade 58, the movable valve 60 and the stopper 54 as shown in FIG. Partitioning.
[0016]
The blade 58 extends over the entire length of the small-diameter portion 51A, and a fluid passage 62 that communicates the first and second buffer chambers 61A and 61B is formed at an appropriate portion of the tip.
[0017]
The movable valve 60 rotates integrally with the blades 58 along the inner peripheral surface of the damper case 45 and has the same length as the blades 58. Further, since the cross-sectional shape in a plane orthogonal to the axis of the rotation shaft 51 is U-shaped, the pair of side wall portions 60A and 60B facing each other across the blade 58, and the side wall portions 60A and 60B The recess 65 is formed by a connecting portion 60C that connects the base and slides along the inner peripheral surface of the damper case 45, and the tip of the blade 58 is engaged with the rotating direction of the rotating shaft 51 with appropriate play. have. In the pair of side wall portions 60A and 60B, fluid passages 63 and 64 having different cross-sectional areas are formed corresponding to the fluid passages 62 of the blades 58, respectively. Specifically, the fluid passage 63 formed in the side wall 60A on the closing direction side when the rotation shaft 51 rotates in the direction in which the keyboard lid 8 is closed (counterclockwise in FIG. 6) has an extremely large cross-sectional area. The fluid passage 64 of the side wall 60B on the opening direction side when the pivot shaft 51 rotates in the direction in which the keyboard lid 8 opens (clockwise in FIG. 6) is set to be sufficiently larger than the fluid passage 63. And has substantially the same cross-sectional area as the fluid passage 62 of the blade 58.
[0018]
If the cross-sectional areas of the fluid passages 63 and 64 of the side wall portions 60A and 60B are made different in this way, the viscous resistance of the damping oil 50, in other words, the rotational resistance can be changed according to the rotational direction of the rotational shaft 51. it can. That is, when the rotation shaft 51 rotates in the closing direction in FIG. 6, the tip of the blade 58 abuts on the inner surface of the side wall 60 </ b> A on the closing direction side and rotates. At this time, the damping oil 50 in the first buffer chamber 61B moves to the second buffer chamber 61B through the fluid passage 63, the fluid passage 62, the gap 58 between the blade 58 and the side wall portion 60B, and the fluid passage 64. The viscous resistance of the damping oil 50 at this time becomes large because the cross-sectional area of the fluid passage 63 is extremely small, and a very large rotational torque is generated. On the other hand, when the rotation shaft 51 rotates in the opening direction, the tip of the blade 58 contacts the inner surface of the side wall 60B on the opening direction side and rotates. At this time, most of the damping oil 50 in the second buffer chamber 61B moves to the first buffer chamber 61A through the gap between the fluid passage 64-fluid passage 62-blade 58 and the side wall portion 60A. Accordingly, the viscous resistance of the damping oil 50 at this time is small, and almost no rotational torque is generated. As a result, the rotary shock absorber 41 does not exhibit a damper function (braking function) when the rotating shaft 51 rotates in the opening direction, and exhibits a damper function only when rotating in the closing direction. The rotational torque can be freely changed depending on the cross-sectional area of the fluid passage 63, and the smaller the smaller the torque, the greater the rotational torque.
[0019]
5 and 7, the rotary connector 68 is fitted in the opening 67 of the rotating shaft 51 so as to be prevented from being pulled out and can be inserted and removed, and is urged in a protruding direction by a compression coil spring 69. . The rotary connector 68 is formed in a rectangular cylindrical body whose one end is open, and the closing side end 68A forms a shaft portion of the rotating arm 48 and protrudes from the opening 67 to the outside. Further, one of the four side surfaces is integrally provided with a drop prevention portion 70 formed of an arcuate convex portion. The opening 67 is not a perfect circle, but is formed in an oval shape that is flat at both ends and into which the rotary shaft 51 can be fitted, so that the rotary shaft 51 and the rotary connector 68 are rotated together. Yes.
[0020]
3 to 5, the rotating arm 48 includes a base portion 48A that is fitted to the damper case 45 from above, an elongated arm portion 48B, and a pair of spring locking portions 48C.
[0021]
The base portion 48A includes a semi-cylindrical plate 72a and a pair of side plates 72b and 72c that are connected to both ends in the axial direction of the semi-cylindrical plate 72a so as to rotate on the outer peripheral surface of the damper case 45. Fits freely. The base portion 48A is covered with a cover 71, and the upper end portion of the base portion 48A protrudes above the time signature 5 from the opening 44 together with the arm portion 48B.
[0022]
Bearing holes 73 and 74 are formed in the pair of side plates 72b and 72c, respectively. The bearing hole 73 of one side plate 72b is a round hole, and is rotatably fitted to a shaft portion 75 formed of a cylindrical convex portion protruding from the closed end face of the damper case 45. The bearing hole 74 of the other side plate 72c is a square hole, and the closed end 68A of the rotary connector 68 is fitted. Therefore, the rotation arm 48 is rotatable with respect to the damper case 45, but is configured to rotate integrally with the rotary connector 68 and the rotation shaft 51. The rotation angle θ (FIG. 3) of the rotation arm 48 is approximately 110 ° in the present embodiment, but this angle θ can be freely set by the rotation angle of the rotation shaft 51. Further, the rotation angle α from the vertical state to the rear side is about 0 to 20 °. Note that the rotary connector 68 is prevented from coming out of the bearing hole 74 by having the distal end surface of the slip-off preventing portion 70 pressed against the inner surface of the side plate 72c by the compression coil spring 69.
[0023]
The arm portion 48B is integrally projected at the center of the surface of the semi-cylindrical plate 72a, and a rotatable roller 76 is mounted in a recess 77 provided on the rear surface side of the tip portion.
[0024]
The pair of spring locking portions 48C are integrally projected on the inner surface side of the semi-cylindrical plate 72a in the direction opposite to the arm portion 48B, thereby extending below the base portion 48A and at the tip. One end side locking portion 42a of the tension coil spring 42 is locked.
[0025]
The tension coil spring 42 is disposed substantially horizontally in the storage portion 43 of the beat tree 5 so as to be positioned in front of the rotary shock absorber 41, and the other end side locking portion 42b has a beat tree as shown in FIG. The coil portion 42c is housed in a vibration preventing cover 80 formed of synthetic resin or the like. The tension coil spring 42 presses the roller 76 against the lower surface of the keyboard lid 8 by imparting a clockwise turning behavior to the turning arm 48 in the closed state shown in FIG.
[0026]
Next, the operation of the above opening / closing device 40 will be described.
The keyboard lid 8 has an opening / closing angle of approximately 130 °, and is held in a substantially horizontal state in contact with the mouth bar 26 when the lid is closed. The rotary shock absorber 41 is held in the state shown in FIG. 2 when the lid is closed. In this state, the arm portion 48B of the rotating arm 48 is held substantially horizontally, and the spring locking portion 48C is positioned behind the damper case 45. Therefore, the tension coil spring 42 is set and held in an extended state, applies a clockwise rotational force to the rotating arm 48, and presses the roller 76 against the lower surface of the keyboard lid 8. The tension coil spring 42 is shortened to almost return to its natural length when the pivot arm 48 is pivoted to a substantially vertical state, and the spring force is almost extinguished.
[0027]
When the keyboard cover 8 is gradually opened by hand from this state, the rotating arm 48 is rotated in the opening direction in FIGS. 2 and 6 by the spring force of the tension coil spring 42 and acts to push up the keyboard cover 8. To do. At this time, the rotary shock absorber 41 hardly functions because the viscous resistance of the damping oil 50 is small. Therefore, it can be opened with an operating force that is smaller by the spring force of the tension coil spring 42 than when the keyboard cover of a conventional piano without a shock absorber is opened, and the upper front plate as shown by the two-dot chain line in FIG. It can lean against the front of 26. This spring force is maximum at the initial stage when the lid is opened, and gradually decreases as the lid is opened, and becomes almost zero when the keyboard lid 8 is opened to a substantially vertical state. This is to prevent the keyboard cover 8 from rotating by the movement of the center of gravity and not being accelerated by the spring force of the tension coil spring 42 when the keyboard cover 8 is tilted backward after passing the vertical state.
[0028]
In a state where the keyboard cover 8 is fully opened, the keyboard cover 8 is inclined backward at an angle of approximately 30 ° with respect to the vertical plane, and the rotating arm is inclined backward by an angle α (α≈0 to 20 °). ing. In this state, the roller 76 is preferably separated from the keyboard lid 8. This is to prevent the rotary shock absorber 41 from braking the keyboard lid 8 in the initial stage of the lid closing operation. Further, since the tension coil spring 42 hardly acts until the keyboard cover 8 becomes substantially vertical, the keyboard cover 8 is rotated until the keyboard cover 8 becomes substantially vertical with substantially the same operating force as when the conventional keyboard cover is closed. Can be made.
[0029]
When the keyboard cover 8 rotates forward and contacts the roller 76, the rotation arm 48 rotates in the closing direction due to the weight of the keyboard cover 8. Further, as the pivot arm 48 pivots, the pivot shaft 51 also pivots in the closing direction, so that the rotary shock absorber 41 acts as a large rotational resistance against the keyboard cover 8, in other words, the damper function works and the keyboard. The movement of the lid 8 is braked. When the pivot arm 48 pivots in the closing direction, the tension coil spring 42 is gradually extended to increase the spring force, and cooperates with the shock absorber 41 to brake the keyboard lid 8. Therefore, the keyboard cover 8 is not accelerated by its own weight, but closes slowly and contacts the mouth stick 25.
[0030]
Here, in the present invention, the opening / closing device 40 is embedded in the time signature tree 5 in a state where a part of the opening / closing device 40 is protruded, so that the performance of the opening / closing device is improved as compared with the opening / closing device disclosed in Japanese Patent Laid-Open No. 8-211181. The performance of the piano can be improved without disturbing the time. In addition, since the portion protruding above the time tree 5 is only the upper end portion of the base portion 48A and the arm portion 48B covered by the cover 71 of the rotating arm 48, the appearance of the piano is hardly impaired.
[0031]
Further, since the tension coil spring 42 that imparts the rotational behavior in the opening direction to the rotation arm 48 is not incorporated in the rotary shock absorber 41, there are few restrictions on the tension coil spring 42, and the spring force, size, and length are reduced. Etc. can be freely changed. In particular, it is easy to adjust the distance between the keyboard lid 8 and the roller 76 when fully opened. Further, the rotary shock absorber 41 can be reduced in size because the tension coil spring 42 is not incorporated.
[0032]
In addition, if the thing which adjusted the position of the roller 76 with the model of a keyboard musical instrument is prepared, it can be integrated also in the existing model only by exchanging the time signature 5.
[0033]
【The invention's effect】
As described above, according to the keyboard lid opening / closing device of the keyboard instrument according to the present invention, since a part of the timepiece tree is embedded, there are few portions protruding above the timepiece tree, and performance is not disturbed during performance. Can be improved. In addition, it looks neat and does not impair the design of the keyboard instrument.
[0034]
In addition, the present invention uses a tension coil spring as a spring and is covered with an anti-vibration cover, so that it does not vibrate during performance and does not generate annoying noise. Furthermore, since the tension coil spring is externally attached to the rotary shock absorber, the shock absorber can be reduced in size and the design freedom of the spring can be increased.
[Brief description of the drawings]
FIG. 1 is an external perspective view showing an essential part of an upright piano provided with a keyboard lid opening / closing device according to the present invention when the lid is opened.
FIG. 2 is a cross-sectional view of the keyboard portion incorporating the same opening / closing device when the lid is closed.
FIG. 3 is a side view showing a part of the opening / closing device in a cutaway manner.
FIG. 4 is a front view of the rotary shock absorber.
FIG. 5 is a sectional view of the shock absorber.
6 is an enlarged sectional view taken along line VI-VI in FIG.
FIG. 7 is a perspective view of a rotary connector.
FIG. 8 is a perspective view of a conventional opening / closing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 5 ... Beat tree, 8 ... Keyboard cover, 40 ... Opening and closing device, 41 ... Rotary shock absorber, 42 ... Tension coil spring, 43 ... Storage chamber, 44 ... Opening, 45 ... Damper case, 48 ... Turning arm, 50 ... Damping Oil, 51 ... rotating shaft, 76 ... roller.

Claims (3)

In a keyboard lid opening / closing device in a keyboard instrument that brakes the keyboard lid by the viscous resistance of the fluid during the closing operation,
A storage chamber is formed inside the time signature tree, a rotary shock absorber provided with a rotation arm having a roller at the upper end and a spring are incorporated in the storage chamber, and the rotation arm is located upward from an opening formed on the upper surface of the time signature tree. The spring is urged by the spring in the direction in which the keyboard lid opens, the roller is pressed against the lower surface of the keyboard lid , one end of the spring is connected to the rotary arm, and the other end is An opening / closing device for a keyboard lid in a keyboard instrument characterized by being fixed in a storage room . In the keyboard lid opening and closing device in the keyboard musical instrument according to claim 1,
A keyboard lid opening and closing device for a keyboard instrument, wherein the spring is constituted by a tension coil spring . In the keyboard lid opening and closing device in the keyboard instrument according to claim 2,
  An opening / closing device for a keyboard lid in a keyboard instrument, comprising a vibration prevention cover for accommodating a coil portion of the tension coil spring.

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