JP2015087708A - Buffer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a buffer to be provided in a keyboard instrument comprising a main body and a keyboard lid attached to the main body in a state that it can oscillate freely, the buffer being easily reduced in size and easily designed.SOLUTION: A buffer 10 comprises; an arm part 12 whose base end part 31 is rotatably supported to a main body of a keyboard instrument and whose tip end part 32 contacts a rear surface of a keyboard lid; a rotary damper 13 for applying a brake force to rotation movement of the arm part 12; and an osmund spring 14 for energizing the arm part 12 in a first rotation direction so that the arm part 12 is pushed to a direction for opening the keyboard lid.

Description

  The present invention relates to a shock absorber.

In general, an acoustic piano such as a grand piano or an upright piano, or a keyboard instrument such as an electronic piano includes a keyboard lid that covers the keyboard. The keyboard lid is swingably attached to the main body of the keyboard instrument, and can be opened and closed between a position covering the keyboard portion and a position exposing the keyboard portion.
Since the weight of the keyboard lid is heavy, conventionally, a shock absorber provided with a rotary damper that applies a braking force to the force with which the keyboard lid is closed by its own weight is employed, as in Patent Documents 1 and 2, for example. This prevents the keyboard lid from closing suddenly due to its own weight. Further, the conventional shock absorber is provided with a coil spring as a biasing member that biases the rotary damper to return to its original position when the keyboard cover is opened.

Japanese Patent No. 3470059 JP 2007-132509 A

However, in the conventional shock absorber described above, the rotational movement in the closing direction of the keyboard lid is braked almost only by the braking force of the rotary damper. In this case, there is a problem that the rotary damper becomes large and it is difficult to reduce the size of the shock absorber.
Here, the urging force of the coil spring can also be used to brake the rotational movement of the keyboard lid in the closing direction. However, in the coil spring, the urging force increases as the amount of displacement increases. Therefore, the urging force of the coil spring cannot brake with a constant force against the rotational movement in the closing direction of the keyboard lid. Therefore, there is a problem that the design of a shock absorber suitable for braking the keyboard lid becomes troublesome.
Further, in order to obtain a coil spring having a large urging force, it is necessary to make the coil spring large by extending the axial length of the coil spring or the like, and there is a problem that the size reduction of the shock absorber is hindered. .

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a shock absorber that can be easily downsized and can be easily designed.

  In order to solve the above-described problems, a shock absorber according to the present invention is a shock absorber provided in a keyboard instrument that includes a main body and a keyboard lid that is swingably attached to the main body. An arm portion that is rotatably supported with respect to the main body, a tip portion of which contacts the back surface of the keyboard lid, a rotary damper that applies a braking force to the rotational movement of the arm portion, and the arm portion that is the keyboard And a spring for urging the arm portion in the first rotation direction so as to push the lid in the opening direction.

In the shock absorber of the present invention, when the keyboard cover is rotated in the closing direction from the opened position, the arm portion and the rotary damper correspond to the closed position of the keyboard cover from the initial position corresponding to the opened position of the keyboard cover. Rotates and displaces to the rotating position. Further, the twist angle (twist amount) of the spring spring is also displaced. Thereby, the braking force of the rotary damper and the urging force of the mainspring spring are applied to the rotational movement of the keyboard lid via the arm portion, and the keyboard lid can be gently closed.
On the other hand, when the keyboard cover is rotationally moved in the opening direction from the closed position to the open position, the arm portion and the rotary damper are returned from the rotational position to the initial position by the biasing force of the spring. Also, the twist angle of the spring spring is restored.

According to the shock absorber of the present invention, since the mainspring is adopted as the biasing member for returning the arm portion and the rotary damper to the initial position, the spring is not required to be formed as large as the conventional coil spring. It is possible to easily obtain power.
Further, since the spring constant of the mainspring can be easily set small, the change in the urging force of the mainspring with respect to the displacement of the torsion angle of the mainspring can be suppressed small. That is, when the keyboard cover is rotationally moved from the opened position to the closed position, it is possible to suppress a change in the urging force of the spring spring applied to the rotational movement of the keyboard cover. Therefore, even if both the braking force of the rotary damper and the urging force of the spring spring are used as a brake in the closing direction of the keyboard cover, it is possible to easily design a shock absorber suitable for braking the keyboard cover.
In addition, the spring spring is smaller than the conventional coil spring with equivalent performance, and the rotary damper can be downsized by using the spring force of the spring as a brake in the direction of closing the keyboard cover. Therefore, it is possible to easily reduce the size of the shock absorber.

In the shock absorber, the mainspring may be wound around the rotor portion of the rotary damper.
According to the above configuration, it is possible to further reduce the size of the shock absorber by reducing the number of components of the shock absorber.

Further, the shock absorber may include a gear mechanism that connects the arm portion and the spring spring so that a displacement of a twist angle of the spring spring with respect to a rotation angle of the arm portion is increased.
In the above configuration, the substantial spring constant of the mainspring can be further reduced by increasing the displacement of the twisting angle of the mainspring with respect to the rotation angle of the arm portion by the gear mechanism. Therefore, it is possible to further easily design a shock absorber suitable for braking the keyboard lid.

  According to the present invention, it is possible to easily design a shock absorber suitable for braking the keyboard lid by adopting a spring spring as a means for returning the arm portion and the rotary damper to their original positions. Miniaturization can be achieved.

It is side sectional drawing which shows the principal part of the piano which provided the buffering device which concerns on 1st embodiment of this invention. 1 is a perspective view showing a shock absorber according to a first embodiment of the present invention. FIG. 3 is an exploded perspective view of the shock absorber in FIG. 2. 4 is a cross-sectional view showing the arrangement of a pair of bearing portions, a base end portion of an arm portion, a rotary damper, and a spring spring in the shock absorber shown in FIGS. It is a perspective view which shows the buffering device which concerns on 2nd embodiment of this invention. FIG. 6 is a cross-sectional view showing a mounting state of the spring spring to the base and a mounting state of the rotary damper to the base end portion of the arm portion in the shock absorber of FIG. 5. FIG. 6 is a cross-sectional view showing a gear mechanism in the shock absorber of FIG. 5.

[First embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, a shock absorber 10 according to this embodiment is provided in a piano (keyboard instrument) 1. The piano 1 of this embodiment is an upright piano that is a kind of acoustic piano, and includes a main body 2 and a keyboard lid 3 that is swingably connected to the main body 2.

The main body 2 includes a housing 4 and a keyboard portion 5 provided on the front side of the housing 4. The main body 2 also includes conventional hammers, strings, action mechanisms (all not shown) and the like provided inside the housing 4.
The keyboard lid 3 covers the keyboard part 5, and is between a cover position (closed position) CL that covers the keyboard part 5 and an open position (open position) OP that exposes the keyboard part 5 to the outside. It is attached to the main body 2 so as to be swingable about the rotation axis L1.
The shock absorber 10 is provided between the keyboard lid 3 and the beat tree 6 of the housing 4 covered by the keyboard lid 3 together with the keyboard portion 5, and as shown in FIGS. 2 to 4, the base 11 and the arm portion 12. A rotary damper 13 and a spring 14.

The base 11 is fixed to the beat tree 6 (see FIG. 1), and includes a base plate portion 21 and a pair of bearing portions 22 and 22.
The base plate portion 21 is fixed to the upper surface of the beat tree 6 facing the keyboard lid 3 disposed at the cover position CL by bonding, screwing, or the like (see FIG. 1). The pair of bearing portions 22, 22 support a base end portion 31 of the arm portion 12 to be described later in a freely rotatable manner, and are fixed on the base plate portion 21. In the illustrated example, each bearing portion 22 is fixed to the base plate portion 21 with screws 23, but may be fixed, for example, with an adhesive or the like, or may be formed integrally with the base plate portion 21, for example.

  The arm part 12 is formed in a rod shape. One end portion (base end portion 31) in the longitudinal direction of the arm portion 12 is rotatably supported by a pair of bearing portions 22. The base end portion 31 of the arm portion 12 is formed in a cylindrical shape. The other end portion (tip portion 32) of the arm portion 12 is a portion that comes into contact with the back surface of the keyboard lid 3 (the surface facing the keyboard portion 5 and the time signature 6 in a state of being arranged at the cover position CL). A roller 33 is rotatably provided at the distal end portion 32 of the arm portion 12, and this roller 33 comes into contact with the back surface of the keyboard lid 3.

  The rotary damper 13 includes a case 35 in which oil or the like is enclosed, and a rotor portion 36 that is rotatably attached to the case 35. The case 35 has a cylindrical appearance. The rotor portion 36 protrudes from one end portion of the case 35 in the axial direction. The rotary damper 13 is accommodated in the base end portion 31 of the arm portion 12. In the state where the rotary damper 13 is accommodated in the base end portion 31, the axes of the base end portion 31 and the rotary damper 13 coincide with each other.

Further, in this accommodated state, relative rotation between the base end portion 31 of the arm portion 12 and the case 35 is restricted. In the present embodiment, the outer peripheral surface of the case 35 is formed as an uneven surface that undulates in the circumferential direction like a spline shaft, and the inner peripheral surface of the base end portion 31 is formed as an uneven surface corresponding to the outer peripheral surface of the case 35. Thus, relative rotation between the base end portion 31 and the case 35 is restricted. In addition, the above-mentioned relative rotation may be controlled by fixing the case 35 to the base end part 31 of the arm part 12, for example.
On the other hand, the rotor portion 36 is fixed to the bearing portion 22 of the base 11. In the present embodiment, a key 37 is formed at the front end of the rotor portion 36 in the protruding direction, and a key groove 24 into which the key 37 of the rotor portion 36 is inserted is formed in one bearing portion 22A of the base 11. . Thereby, the rotor part 36 is fixed to the base 11 so as not to rotate.

The mainspring 14 urges the arm 12 in the first rotation direction R1 so that the arm 12 pushes in the direction OD that opens the keyboard lid 3 (see FIG. 1). The mainspring 14 is formed by spirally winding an elastic body such as a metal formed in a plate shape and has a cylindrical appearance. One end in the longitudinal direction of the mainspring 14 located on the inner peripheral side is fixed to the rotor portion 36 of the rotary damper 13. That is, the mainspring 14 of the present embodiment is wound around the rotor portion 36. In this state, the axes of the rotary damper 13 and the spring spring 14 coincide with each other.
Further, the mainspring 14 of this embodiment is accommodated in the base end portion 31 of the arm portion 12 together with the rotary damper 13. The other end of the mainspring 14 located on the outer peripheral side is fixed to the base end portion 31 of the arm portion 12.

In the shock absorber 10 according to the present embodiment configured as described above, the axes of the base end portion 31 of the arm portion 12, the rotary damper 13, and the mainspring spring 14 coincide with each other. 1 to 4, the axis lines of the rotary damper 13 and the spring spring 14 are indicated by a symbol L2.
The shock absorber 10 according to the present embodiment is attached to the piano 1 by fixing the base 11 to the upper surface of the beat tree 6 so that the first rotation direction R1 side of the arm portion 12 faces the back surface of the keyboard lid 3.

Next, the operation of the shock absorber 10 of this embodiment will be described.
When the keyboard lid 3 is rotationally moved in the closing direction CD from the open position OP to the cover position CL, the case 35 of the arm portion 12 and the rotary damper 13 is moved to the open position OP of the keyboard lid 3 with respect to the rotor portion 36. From the corresponding initial position IP to the rotation position RP corresponding to the cover position CL of the keyboard lid 3, the rotation and displacement in the second rotation direction R2. At this time, the twist angle (twist amount) of the mainspring 14 is also displaced, and the mainspring 14 biases the arm portion 12 in the first rotation direction R1. Thereby, the braking force of the rotary damper 13 and the biasing force of the mainspring spring 14 are applied to the rotational movement of the keyboard lid 3 via the arm portion 12, and the keyboard lid 3 can be gently closed.
On the other hand, when the keyboard lid 3 is rotationally moved in the opening direction OD from the cover position CL to the open position OP, the case 35 of the arm portion 12 and the rotary damper 13 is moved from the rotational position RP to the initial position by the urging force of the mainspring spring 14. Return to IP. Further, the twist angle of the spring 14 is also restored.

By the way, in the piano 1 of this embodiment, as shown in FIG. 1, the open position OP of the keyboard cover 3 is set to an angle larger than 90 degrees (for example, 130 degrees) with respect to the cover position CL. Further, in a state where the keyboard lid 3 is arranged at the open position OP, the keyboard lid 3 is separated from the arm portion 12 located at the initial position IP.
Then, the keyboard cover 3 rotates in the closing direction CD from the open position OP, and reaches the position (contact position TO) where the keyboard cover 3 can rotate in the closing direction CD by its own weight. It abuts on the arm portion 12 disposed on the IP. The contact position TO of the keyboard lid 3 may be set so that, for example, the opening angle θ of the keyboard lid 3 with respect to the cover position CL is 45 degrees or more and 90 degrees or less.

As described above, according to the shock absorber 10 of the present embodiment, when the keyboard lid 3 is closed, the braking force of the rotary damper 13 and the urging force of the mainspring spring 14 are applied to the keyboard lid 3. Can be prevented from closing suddenly.
In addition, according to the shock absorber 10 of the present embodiment, the mainspring spring 14 is employed as a biasing member that returns the arm portion 12 and the rotary damper 13 to the initial position IP, so that it is formed to be large like a conventional coil spring. Even without this, it is possible to easily obtain a large biasing force.

  Furthermore, since the spring constant of the mainspring 14 can be easily set small, the change in the biasing force of the mainspring 14 with respect to the displacement of the torsional angle of the mainspring 14 can be suppressed small. That is, when the keyboard cover 3 is rotationally moved from the open position OP to the cover position CL, it is possible to suppress a change in the urging force of the mainspring 14 applied to the rotational movement of the keyboard cover 3. Therefore, even if both the braking force of the rotary damper 13 and the urging force of the mainspring spring 14 are used as a brake in the closing direction CD of the keyboard lid 3, it is easy to design the shock absorber 10 suitable for braking the keyboard lid 3. It can be carried out.

Further, the mainspring 14 is smaller than the conventional coil spring having the same performance, and the rotary damper 13 is used by utilizing the urging force of the mainspring 14 as a brake in the closing direction CD of the keyboard cover 3. Therefore, the shock absorber 10 can be easily downsized.
In particular, in the present embodiment, since the mainspring 14 is wound around the rotor portion 36 of the rotary damper 13, the number of components of the shock absorber 10 can be reduced and the shock absorber 10 can be further reduced in size.

  In the shock absorber 10 of the first embodiment, the arm portion 12 abuts on the keyboard lid 3 at a position on the way from the open position OP to the cover position CL. You may contact | abut to the lid | cover 3. FIG.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
In this embodiment, compared with the shock absorber 10 of the first embodiment, only a part of the structure is different, and other configurations are the same as those of the first embodiment. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIGS. 5 to 7, the shock absorber 100 of this embodiment includes a base 111, an arm portion 12, a rotary damper 13, and a spring spring 14, as with the shock absorber 10 of the first embodiment.
However, in the shock absorber 100 of the present embodiment, the arm portion 12 and the rotary damper 13 are arranged on the same axis (first axis L3), and the mainspring 14 is on a second axis L4 that is separate from the first axis L3. It is arranged. These two axes L3 and L4 are parallel to each other. In addition, the shock absorber 100 of the present embodiment includes a gear mechanism 115 that couples the arm portion 12 and the spring spring 14 so that the displacement of the twisting angle of the spring spring 14 with respect to the rotation angle of the arm portion 12 becomes large. Hereinafter, the shock absorber 100 of the present embodiment will be described in detail.

As in the first embodiment, the base 111 is fixed to the time tree 6 (see FIG. 1) of the piano 1, and the base end portion 31 of the arm portion 12 and a connecting member 116 to be described later can be freely rotated. A pair of bearings 122 and 122 to support is provided. The base end portion 31 of the arm portion 12 is supported by a pair of bearing portions 122, 122 so as to be rotatable about the first axis L3.
Similar to the first embodiment, the rotary damper 13 is accommodated in the base end portion 31 of the arm portion 12 formed in a cylindrical shape. The case 35 of the rotary damper 13 is fixed to the base end portion 31 of the arm portion 12, and the rotor portion 36 is fixed to one bearing portion 122 </ b> A of the base 111.

  The mainspring spring 14 of this embodiment is wound around a rod-like connecting member 116 that is rotatably supported around a second axis L4 by a pair of bearing portions 122,122. One end in the longitudinal direction of the spring 14 located on the inner peripheral side is fixed to the connecting member 116. Further, the other end of the mainspring 14 located on the outer peripheral side is fixed to the base 111. The mainspring 14 is arranged adjacent to the case 35 of the rotary damper 13 in a direction perpendicular to the two axes L3 and L4.

The gear mechanism 115 includes a first gear 141 formed integrally with the base end portion 31 of the arm portion 12, and a second gear 142 that is fixed to the connecting member 116 and meshes with the first gear 141.
The first gear 141 is integrally formed on the outer peripheral portion of the base end portion 31 at a position shifted in the first axis L3 direction with respect to the case 35 of the rotary damper 13. The second gear 142 is fixed to the connecting member 116 at a position shifted in the second axis L4 direction with respect to the mainspring 14. The diameter of the second gear 142 is set smaller than that of the first gear 141.
The shock absorber 100 of the present embodiment configured as described above is attached to the piano 1 in the same manner as the shock absorber 10 of the first embodiment.

Next, the operation of the shock absorber 100 of this embodiment will be described.
When the keyboard lid 3 is rotationally moved in the closing direction CD from the open position OP to the cover position CL (see FIG. 1), the arm portion 12 and the case 35 of the rotary damper 13 are moved as in the first embodiment. The rotor unit 36 rotates and displaces in the second rotational direction R2 from the initial position IP to the rotational position RP. Further, since the rotational movement of the arm portion 12 is transmitted to the mainspring 14 via the gear mechanism 115, the torsion angle of the mainspring spring 14 is also displaced, and the mainspring 14 biases the arm portion 12 in the first rotation direction R1. Thereby, the braking force of the rotary damper 13 and the biasing force of the mainspring spring 14 are applied to the rotational movement of the keyboard lid 3 via the arm portion 12, and the keyboard lid 3 can be gently closed.
On the other hand, when the keyboard lid 3 is rotationally moved in the opening direction OD from the cover position CL to the open position OP (see FIG. 1), the urging force of the mainspring spring 14 is transmitted to the arm portion 12 via the gear mechanism 115. Therefore, the case 35 of the arm portion 12 and the rotary damper 13 is returned from the rotational position RP to the initial position IP by the biasing force of the mainspring spring 14. Further, the twist angle of the spring 14 is also restored.

According to the shock absorber 100 of the present embodiment, the same effects as those of the first embodiment can be obtained.
Further, according to the shock absorber 100 of the present embodiment, the arm portion 12 and the spring 12 are connected by the gear mechanism 115 including the first gear 141 having a large diameter and the second gear 142 having a small diameter. The displacement of the twisting angle of the mainspring spring 14 with respect to the rotation angle of the arm portion 12 and the rotary damper 13 becomes large. Thereby, the substantial spring constant of the mainspring 14 can be further reduced as compared with the case of the first embodiment. Therefore, it is possible to more easily design a shock absorber suitable for braking the keyboard lid 3.
Further, according to the shock absorber 100 of the present embodiment, the mainspring 14 has a very large displacement of the torsional angle (for example, 360) as compared with the configuration of Patent Document 1 in which the “torsion coil spring” is used as the biasing member. The degree of freedom in designing the shock absorber 100 can be improved.

Although the present invention has been described in detail with two embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, the shock absorbers 10 and 100 include the bases 11 and 111. However, for example, they may not be included. In this case, the proximal end portion 31 and the connecting member 116 of the arm portion 12 may be attached to the arm of the housing 4 so as to be rotatable, for example.

  Further, the shock absorbers 10 and 100 of the present invention are not limited to being provided in the upright piano as in the above embodiment, and may be provided in a grand piano, for example. The present invention is not limited to being applied to an acoustic piano that strikes a string with a hammer such as an upright piano or a grand piano. For example, various keyboards such as an electronic piano having a keyboard lid similar to an acoustic piano. It can also be applied to musical instruments.

DESCRIPTION OF SYMBOLS 1 ... Piano (keyboard instrument), 2 ... Main body, 3 ... Keyboard cover, 10,100 ... Shock absorber, 11, 111 ... Base, 12 ... Arm part, 13 ... Rotary damper, 14 ... Spring spring, 35 ... Case, 36 ... rotor part, 115 ... gear mechanism, 141 ... first gear, 142 ... second gear, CL ... cover position (closed position), OP ... open position (open position), OD ... opening direction, IP ... initial position , RP ... rotational position, R1 ... first rotational direction, R2 ... second rotational direction

Claims (3)

A shock absorber provided in a keyboard instrument comprising a main body and a keyboard lid that is swingably attached to the main body,
A base end portion that is rotatably supported with respect to the main body, and a distal end portion that abuts against the back surface of the keyboard lid; and
A rotary damper that applies a braking force to the rotational movement of the arm part;
A shock absorber comprising: a spring for urging the arm portion in a first rotation direction so that the arm portion pushes the keyboard lid in a direction to open the keyboard lid.   The shock absorber according to claim 1, wherein the mainspring is wound around a rotor portion of the rotary damper. The shock absorber according to claim 1, further comprising a gear mechanism that connects the arm portion and the mainspring spring so that a displacement of a twist angle of the mainspring spring with respect to a rotation angle of the arm portion is increased.

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