WO2021075556A1

WO2021075556A1 - Actuator unit and musical instrument

Info

Publication number: WO2021075556A1
Application number: PCT/JP2020/039129
Authority: WO
Inventors: 石井　潤; 俊允三吉
Original assignee: ヤマハ株式会社
Priority date: 2019-10-18
Filing date: 2020-10-16
Publication date: 2021-04-22
Also published as: JP7276485B2; CN114503189A; JPWO2021075556A1

Abstract

This actuator unit is provided with: an actuator for vibrating a soundboard of a musical instrument; and a movement allowance unit that is configured to connect a housing of the musical instrument with the actuator and that enables movement of the actuator with respect to the housing in a predetermined range.

Description

Actuator unit and musical instrument

The present invention relates to an actuator unit and a musical instrument.
This application claims priority on the basis of Japanese Patent Application No. 2019-190959 filed on October 18, 2019, and incorporates all of its disclosures herein.

Conventionally, various musical instruments such as keyboard instruments are equipped with an actuator that vibrates a soundboard (in a predetermined direction) based on an input audio signal to produce a sound.
Patent Document 1 discloses a configuration in which a soundboard and a vibrating body of an actuator are connected by a connecting body. In the configuration of Patent Document 1, a plurality of joints are provided for inclining the connecting body with respect to the thickness direction of the soundboard and the vibration direction of the vibrating body. By providing joints in the connecting body, even if the relative position and orientation of the soundboard and the actuator change due to aging of the soundboard due to the influence of temperature, humidity, etc., the soundboard can be properly adjusted by the actuator. Can be vibrated to.

Japanese Patent Application Laid-Open No. 2015-114457

However, if the structure (connection structure) that connects the soundboard and the vibrating body of the actuator includes the joint in addition to the connecting body, the connecting structure that vibrates together with the vibrating body becomes complicated. For this reason, it becomes difficult to vibrate the soundboard at a high frequency, and the reproduction characteristics in the high frequency range deteriorate. As a result, there arises a problem that the quality of audio reproduction by the actuator and the soundboard is low.

The present invention has been made in view of the above circumstances. An example of an object of the present invention is to provide an actuator unit and a musical instrument capable of realizing high-quality audio reproduction by simplifying the connection structure for connecting the soundboard and the vibrating body of the actuator.

One aspect of the present invention is configured to connect an actuator that vibrates the soundboard of a musical instrument, a housing of the musical instrument, and the actuator, and the actuator can be moved within a predetermined range with respect to the housing. It is an actuator unit including a movement allowance portion.
Another aspect of the present invention is a musical instrument including the actuator unit described above.

According to the embodiment of the present invention, high quality audio reproduction can be realized by simplifying the connection structure for connecting the soundboard and the vibrating body of the actuator.

It is a schematic diagram which looked at the piano which attached the actuator unit which concerns on 1st Embodiment of this invention from the lower side. It is sectional drawing which shows the state which attached the actuator unit which concerns on 1st Embodiment of this invention to a piano. It is a figure which shows typically the operation of the spherical plain bearing provided in the actuator unit of FIG. It is sectional drawing which shows the state which attached the actuator unit which concerns on 2nd Embodiment of this invention to a piano. It is sectional drawing which shows the state which attached the actuator unit which concerns on 3rd Embodiment of this invention to a piano.

[First Embodiment]
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 3.
FIG. 1 shows a grand piano 100 (hereinafter, also simply referred to as a piano 100), which is a kind of keyboard instrument, as an instrument to which the actuator unit 1 according to the first embodiment of the present invention is applied. The Z-axis direction in FIG. 1 indicates the vertical direction of the piano 100. The piano 100 includes a housing 110 and a soundboard 120. As shown in FIG. 1, when viewed from the lower side of the grand piano 100, a plurality of straight columns 111 and soundboards 120 constituting the housing 110 can be seen. As shown in FIG. 2, the plurality of straight columns 111 are located below the soundboard 120 (in the negative direction of the Z axis) and are spaced apart from each other.

As shown in FIG. 2, the actuator unit 1 according to the present embodiment connects the housing 110 of the piano 100 and the soundboard 120 to vibrate the soundboard 120. The actuator unit 1 includes an actuator 2 for vibrating the soundboard 120 and a movement allowance unit 3 for allowing the actuator 2 to move within a predetermined range with respect to the housing 110.
The actuator 2 includes a main body 11, a vibrating body 12 that vibrates in a predetermined vibration direction (Z-axis direction in FIG. 1) with respect to the main body 11, and a damper portion 13 that connects the vibrating body 12 to the main body 11.

The main body 11 includes a magnetic path forming portion 14 that forms a magnetic path. The magnetic path forming portion 14 has a top plate 15, a yoke 16, and a magnet 17. The top plate 15 and the yoke 16 are made of a soft magnetic material such as soft iron. The top plate 15 is formed in the shape of an annular plate. The yoke 16 has a disc-shaped disc portion 16A and a cylindrical portion 16B protruding from the center of the disc portion 16A. The yoke 16 has a through hole 16C. The through hole 16C penetrates the disk portion 16A and the cylindrical portion 16B in the A1 direction (Z-axis direction in FIG. 1). The yoke 16 is arranged so that the disk portion 16A faces the top plate 15 in the direction of the axis A1 and the tip portion of the cylindrical portion 16B is inside the top plate 15. The magnet 17 is a permanent magnet formed in an annular shape. The magnet 17 is arranged so that the columnar portion 16B is inserted therein and is sandwiched between the top plate 15 and the disk portion 16A.
By providing the magnetic path forming portion 14 configured as described above, a magnetic field is generated in the gap between the inner circumference of the top plate 15 and the outer circumference of the tip portion of the cylindrical portion 16B.

The vibrating body 12 has a tubular portion 18 and a cap 19. The tubular portion 18 is inserted into the gap between the inner circumference of the top plate 15 and the outer circumference of the cylindrical portion 16B of the yoke 16. The cap 19 closes one opening of the tubular portion 18.
The tubular portion 18 includes a bobbin (not shown) and a voice coil (not shown) wound around the bobbin. The vibrating body 12 is located near the first end portion of the main body 11 where the top plate 15 is located in the direction of the axis A1 of the magnetic path forming portion 14.

The damper portion 13 holds the tubular portion 18 of the vibrating body 12 in the gap between the inner circumference of the top plate 15 and the outer circumference of the cylindrical portion 16B of the yoke 16. The damper portion 13 is formed so as to be elastically deformable. The damper portion 13 holds the tubular portion 18 at a predetermined position of the magnetic path forming portion 14 by its elastic force. Further, when the tubular portion 18 deviates from the above-mentioned predetermined position, the damper portion 13 directs the tubular portion 18 to the above-mentioned predetermined position by the elastic force of the damper portion 13 itself.

In the actuator 2, the vibrating body 12 vibrates in the axis A1 direction of the main body 11 by flowing a current corresponding to the audio signal through the voice coil of the vibrating body 12. The audio signal is generated as a drive signal for driving the vibrating body 12 in the control device (not shown) based on the audio data stored in the storage unit (not shown), for example.

The actuator 2 of the present embodiment has a connecting portion 20 for connecting the vibrating body 12 to the soundboard 120. The specific configuration of the connecting portion 20 may be arbitrary. The connection portion 20 of the present embodiment includes a rod-shaped portion 21 and a mounting plate portion 22. The rod-shaped portion 21 extends from the vibrating body 12 in the vibrating direction (axis A1 direction) of the vibrating body 12. The mounting plate portion 22 is provided at the tip end portion of the rod-shaped portion 21 and is fixed to the soundboard 120. The base end portion of the rod-shaped portion 21 is fixed to the cap 19 of the vibrating body 12.

The movement allowance portion 3 is provided so as to connect the housing 110 and the actuator 2. The movement allowance portion 3 of the present embodiment includes a flat slide bearing 30 and a spherical slide bearing 40.
The flat plain bearing 30 includes first and second flat surface members (a pair of flat surface members) 31 and 32 having

flat surfaces

31a and 32a. The

flat surfaces

31a and 32a can move to each other in a state of surface contact with each other.

The flat plain bearing 30 includes a movement regulating unit 35 (first movement regulating unit 35) that regulates a range in which the first and second flat surface members 31 and 32 move relatively. The specific configuration of the first movement control unit 35 may be arbitrary. The first movement restricting portion 35 of the present embodiment is a peripheral wall portion 31B protruding from the peripheral edge of the flat surface 31a of the first flat surface member 31. The peripheral wall portion 31B is formed in an annular shape and surrounds the second flat surface member 32 that is in surface contact with the flat surface 31a of the first flat surface member 31. As a result, it is possible to prevent the second flat surface member 32 from protruding from the edge of the flat surface 31a of the first flat surface member 31. The peripheral wall portion 31B is not limited to being formed on the first flat surface member 31. For example, a peripheral wall portion is formed on the second flat surface member 32, and the peripheral wall portion surrounds the first flat surface member 31, so that the first flat surface member 31 protrudes from the edge of the flat surface 32a of the second flat surface member 32. You may prevent this.

By arranging the first and second flat surface members 31 and 32 as described above, the actuator 2 is aligned with the

flat surfaces

31a and 32a of the first and second flat surface members 31 and 32 with respect to the housing 110. It can be moved in the direction (X-axis direction and Y-axis direction).
The flat surface sliding bearing 30 is preferably arranged so that the first and second flat surface members 31 and 32 are arranged in the vertical direction (Z-axis direction).

The spherical slide bearing 40 includes a first spherical member 41 having a spherical convex surface 41a and a second spherical member 42 having a spherical concave surface 42a. The radius of curvature of the spherical convex surface 41a and the spherical concave surface 42a are the same, so that the spherical convex surface 41a and the spherical concave surface 42a come into surface contact with each other. The spherical convex surface 41a and the spherical concave surface 42a can move to each other in a state of being in surface contact with each other.

The spherical slide bearing 40 includes a movement restricting unit 45 (second movement restricting unit 45) that regulates a range in which the first and second

spherical members

41 and 42 move relatively. The specific configuration of the second movement control unit 45 may be arbitrary. The second movement restricting portion 45 of the present embodiment is a peripheral wall portion 41B protruding from the peripheral edge of the spherical convex surface 41a of the first spherical member 41. The peripheral wall portion 41B is formed in an annular shape and surrounds the second spherical member 42 that is in surface contact with the spherical convex surface 41a of the first spherical member 41. This makes it possible to prevent the second spherical member 42 from protruding from the edge of the spherical convex surface 41a of the first spherical member 41. The peripheral wall portion 41B is not limited to being formed on the first spherical member 41. For example, by forming a peripheral wall portion on the second spherical member 42 and surrounding the first spherical member 41, the first spherical member 41 is prevented from protruding from the edge of the spherical concave surface 42a of the second spherical member 42. You may.

In the present embodiment, the first spherical member 41 is located near the actuator 2, and the second spherical member 42 is located near the housing 110. The first spherical member 41 may be located near the housing 110, and the second spherical member 42 may be located near the actuator 2. By arranging the first and second

spherical members

41 and 42 in this way, the actuator 2 can be rotationally moved with respect to the housing 110 about the center of curvature C1 of the spherical convex surface 41a and the spherical concave surface 42a.
The spherical slide bearing 40 is preferably arranged so that the first and second

spherical members

41 and 42 are arranged in the vertical direction (Z-axis direction). Further, it is more preferable that the second spherical member 42 is arranged on the lower side (Z-axis negative direction side) of the first spherical member 41.

The flat plain bearing 30 and the spherical plain bearing 40 are the arrangement direction (Z-axis direction) of the first and second flat surface members 31 and 32 and the arrangement direction of the first and second spherical members 41 and 42 (Z-axis direction). They are arranged so as to line up in the Z-axis direction). In the present embodiment, one of the first and second flat surface members 31 and 32 and one of the first and second

spherical members

41 and 42 are integrally formed. In the example shown in FIG. 2, the second flat surface member 32 and the second spherical surface member 42 are integrally formed, but may be formed separately, for example.

The first and second flat surface members 31 and 32 constituting the movement allowance portion 3 are preferably made of a material that is slippery to each other (a material having a small coefficient of friction). Similarly, the first and second

spherical members

41 and 42 are preferably made of a material that is slippery to each other (a material having a small coefficient of friction). For example, one of the first and second flat surface members 31 and 32 may be made of polyoxymethylene (POM) and the other may be made of ABS resin (also for the first and second spherical members 41 and 42). Similarly). The first and second flat surface members 31 and 32 may be made of the same material or different materials from each other. However, the materials constituting the first and second flat surface members 31 and 32 are preferably selected so that the friction coefficient of the first and second flat surface members 31 and 32 becomes small. Similarly, the materials constituting the first and second

spherical members

41 and 42 are preferably selected so that the friction coefficient of the first and second

spherical members

41 and 42 is small, and even if they are the same, they are different. You may.

The movement allowance portion 3 is fixed to the main body 11 of the actuator 2. The movement allowance portion 3 of the present embodiment is aligned with respect to the actuator 2 in the axis A1 direction of the actuator 2 (that is, the vibration direction of the vibrating body 12). Specifically, the movement allowable portion 3 is fixed to the second end portion of the main body 11 opposite to the first end portion of the main body 11 where the vibrating body 12 is located in the axial direction A1 direction of the actuator 2. In the present embodiment, the first spherical member 41 constituting the movement allowable portion 3 is fixed to the main body 11 of the actuator 2.
When the movement allowance portion 3 is fixed to the actuator 2, the center of curvature C1 of the spherical convex surface 41a and the spherical concave surface 42a is located on the axis A1 of the actuator 2.

The actuator unit 1 is attached to the piano 100 so as to connect the housing 110 of the piano 100 and the soundboard 120. In the present embodiment, the connecting portion 20 (particularly the mounting plate portion 22) of the actuator unit 1 is fixed to the soundboard 120. Further, the movement allowable portion 3 of the actuator unit 1 is fixed to the housing 110. The movement allowance portion 3 may be fixed to the side plate of the housing 110, for example, but in the present embodiment, it is fixed to the straight support 111 of the housing 110 as shown in FIGS. 1 and 2.

Specifically, as shown in FIG. 2, the first flat surface member 31 of the movement allowance portion 3 is fixed to the straight support 111 via the intervening component 5. The intervening component 5 is fixed to the side surface (the surface extending in the Z-axis direction) of the straight support 111. The intervening component 5 has a support plate portion 51 extending from the side surface of the straight column 111 in a direction orthogonal to the side surface of the straight column 111 (negative direction on the X axis). The first flat surface member 31 is fixed on the support plate portion 51 (the surface facing the support plate portion 51 facing the soundboard 120). In this state, the first flat surface member 31, the second flat surface member 32 and the second spherical member 42 integrally formed, and the first spherical member 41 are in this order upward from the support plate portion 51 (in this order). Lined up in the positive direction of the Z axis).

In the piano 100 to which the actuator unit 1 is attached, the vibration of the vibrating body 12 in response to the audio signal is transmitted to the soundboard 120 via the connecting portion 20, so that the soundboard 120 vibrates. The vibration of the soundboard 120 becomes an acoustic sound propagating in the air. This causes the audio to be played.

In the piano 100 to which the actuator unit 1 is attached, the actuator 2 can be moved with respect to the housing 110 by the movement allowance unit 3. Therefore, even if the mounting portion of the soundboard 120 to which the actuator 2 is mounted changes due to the aging of the soundboard 120, the orientation and position of the actuator 2 can be made to follow the change of the soundboard 120.

For example, when the mounting portion of the soundboard 120 is displaced in the direction along the surface of the soundboard 120 (X-axis direction or Y-axis direction), the first and second flat surface members 31 and 32 are the flat surfaces 31a. , 32a moves relatively in the direction (X-axis direction or Y-axis direction). As a result, the position of the actuator 2 can be made to follow the displacement of the soundboard 120. That is, the movement allowance portion 3 has two translational axes (X-axis and Y-axis) of freedom. When the mounting portion of the soundboard 120 is displaced in the thickness direction (Z-axis direction) of the soundboard 120, the vibrating body 12 of the actuator 2 vibrates in the vibrating direction (Z-axis direction) of the vibrating body 12 with respect to the main body 11. ). That is, the actuator unit 1 has a total of three translational degrees of freedom.

Further, for example, as shown in FIG. 3, when the orientation of the mounting portion of the soundboard 120 changes, the first and second

spherical members

41 and 42 are in surface contact with the spherical convex surface 41a and the spherical concave surface 42a. Move relatively. As a result, the orientation of the actuator 2 (particularly the orientation of the axis A1 of the vibrating body 12) can be made to follow the change in the orientation of the soundboard 120. In FIG. 3, the first spherical member 41 rotates with respect to the second spherical member 42 with the Y axis as the axis in response to a change in the orientation of the soundboard 120 with the Y axis as the axis, so that the direction of the actuator 2 is Follows the change in the orientation of the soundboard 120.

Although not shown, in the present embodiment, the first spherical member 41 rotates with respect to the second spherical member 42 with the X axis as the axis in response to a change in the orientation of the soundboard 120 with the X axis as the axis. It is also possible to make the orientation of the actuator 2 follow the change in the orientation of the soundboard 120.
Further, in the present embodiment, the first and second

spherical members

41 and 42 rotate relative to each other with the Z axis as the axis, or the first and second

spherical members

41 and 42 rotate relative to each other in response to a change in the orientation of the soundboard 120 with the Z axis as the axis. By rotating the first and second flat surface members 31 and 32 relative to the Z axis as an axis, the direction of the actuator 2 can be made to follow the change in the direction of the soundboard 120.
From the above, the movement allowance portion 3 of the present embodiment has a degree of freedom of three rotation axes.

As described above, according to the actuator unit 1 of the present embodiment, the movement allowing portion 3 is interposed between the housing 110 and the actuator 2. Therefore, in the actuator unit 1 of the present embodiment, the actuator 2 does not need to be provided with a conventional joint portion in the connection structure for connecting the vibrating body 12 of the actuator 2 and the soundboard 120 including the connection portion 20 and the like. The direction and position of the soundboard 120 can be made to follow the change of the soundboard 120 based on the secular change. As a result, the connection structure that vibrates together with the vibrating body 12 can be made simpler than before. As a result, the reproduction band by the actuator 2 and the soundboard 120 can be expanded to a higher frequency range. Therefore, audio reproduction in a wide frequency band can be performed, and high-quality audio reproduction can be realized.

Further, in the actuator unit 1 of the present embodiment, the actuator 2 can be linearly moved with respect to the housing 110 by the flat plain bearing 30. As a result, even if the mounting portion of the soundboard 120 to which the actuator 2 is mounted is displaced in the direction along the surface of the soundboard 120 (the plane direction of the soundboard 120), the flat slide bearing 30 allows the actuator 2 to be mounted on the soundboard 120. Can be made to follow the displacement in the plane direction of.

Further, in the actuator unit 1 of the present embodiment, the actuator 2 can be rotationally moved with respect to the housing 110 by the spherical slide bearing 40. As a result, even if the orientation of the attachment portion of the soundboard 120 to which the actuator 2 is attached changes, the orientation of the actuator 2 (particularly the orientation of the axis A1 of the vibrating body 12) is set to the orientation of the soundboard 120 by the spherical plain bearing 40. It can be made to follow changes.

Further, in the actuator unit 1 of the present embodiment, one of the first and second flat surface members 31 and 32 and one of the first and second

spherical members

41 and 42 are integrally formed. Therefore, the number of parts constituting the movement allowance unit 3 can be reduced. As a result, the actuator unit 1 including the movement allowance portion 3 can be easily assembled.

Further, in the actuator unit 1 of the present embodiment, the movement allowance portion 3 is aligned with the actuator 2 in the axis A1 direction (vibration direction) of the actuator 2. In this case, when the actuator unit 1 is arranged so that the axis A1 of the actuator 2 (vibration direction of the vibrating body 12) faces in the vertical direction, the first and second flat surface members 31 and 32 that slide with each other are lined up in the vertical direction. .. Similarly, in this state, the first and second

spherical members

41 and 42 that slide on each other are lined up in the vertical direction. Therefore, it is possible to prevent the first and second flat surface members 31 and 32 from moving with each other due to gravity. Similarly, it is possible to prevent the first and second

spherical members

41 and 42 from moving with each other due to gravity. That is, the movement allowance portion 3 is less likely to be affected by gravity. From the above, the actuator unit 1 of the present embodiment is particularly effective in the grand piano 100 in which the thickness direction of the soundboard 120 is substantially vertical.

Further, in the actuator unit 1 of the present embodiment, the center of curvature C1 of the spherical convex surface 41a of the first spherical member 41 and the spherical concave surface 42a of the second spherical member 42 is located on the axis A1 of the actuator 2. Therefore, the first and second

spherical members

41 and 42 can be moved to each other in a state where the spherical convex surface 41a and the spherical concave surface 42a are in surface contact with each other. Therefore, the orientation of the actuator 2 can be reliably made to follow the change in the orientation of the soundboard 120.

In the first embodiment, the two members (for example, the first and second flat surface members 31 and 32) that form the movement allowance portion 3 and can move in surface contact with each other are made of a material whose surfaces are slippery. It may be composed of.

Further, in the first embodiment, for example, a lubricant may be interposed between two members that form the movement allowance portion 3 and can move in a state of being in surface contact with each other. With the presence of lubricant, the two members become more slippery.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. In the description of the second embodiment, the same components of the second embodiment as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 4, the actuator unit 1D of the second embodiment is applied to the same grand piano 100 as that of the first embodiment. The actuator unit 1D of the second embodiment includes the actuator 2D and the movement allowance unit 3D as in the first embodiment.

The actuator 2D includes a main body 11, a vibrating body 12, and a damper portion 13 similar to those in the first embodiment. However, in the second embodiment, the main body 11 is formed with a receiving portion 23D for receiving the supporting portion 60D of the movement permitting portion 3D, which will be described later. The receiving portion 23D is recessed in a concave shape and is located on the axis A1 of the main body 11. The receiving portion 23D may be formed directly on, for example, the magnetic path forming portion 14. In the second embodiment, the receiving portion 23D is formed in the lid portion 24D that closes the through hole 16C of the yoke 16. The lid portion 24D may be provided near the tip end portion of the cylindrical portion 16B as in the example shown in FIG. 4, but may be provided, for example, near the base end portion of the cylindrical portion 16B (near the disk portion 16A). ..

The movement allowance portion 3D is arranged in the axis A1 direction of the actuator 2D with respect to the actuator 2D as in the first embodiment. Further, the movement allowable portion 3D is arranged near the second end portion of the main body 11 in the axis A1 direction as in the first embodiment, but is not fixed to the actuator 2D.

The movement allowance 3D includes a flat plain bearing 30D similar to that of the first embodiment. The flat plain bearing 30D illustrated in FIG. 4 is configured by stacking three

flat surface members

31D, 32D, 33D, but is configured by stacking two

flat surface members

31D, 32D as in the first embodiment. May be.

The movement allowable portion 3D of the second embodiment further includes a support portion 60D protruding from the flat slide bearing 30D. The support portion 60D projects toward the main body 11 of the actuator 2D and supports the actuator 2D so as to be swingable. The specific configuration of the support portion 60D may be arbitrary.
The support portion 60D of the second embodiment includes a base portion 61D, a rod-shaped portion 62D, and a spherical portion 63D. The base portion 61D is fixed to one of the three

flat surface members

31D, 32D, and 33D, the flat surface member 33D. The rod-shaped portion 62D extends vertically upward (Z-axis positive direction) from the base portion 61D. The spherical portion 63D is provided at the tip of the rod-shaped portion 62D. The spherical portion 63D is housed in the receiving portion 23D of the main body 11. As a result, the actuator 2D can swing with the spherical portion 63D (receiving portion 23D) as a fulcrum. The fulcrum (receiving portion 23D) of the actuator 2D is preferably located above the center of gravity of the actuator 2D (particularly the main body 11) in the vertical direction, for example.

In the piano 100 to which the actuator unit 1D of the second embodiment is attached, the actuator 2D can be moved with respect to the housing 110 by the movement allowance portion 3D as in the first embodiment. Therefore, even if the mounting portion of the soundboard 120 to which the actuator 2D is mounted changes due to the aging of the soundboard 120, the orientation and position of the actuator 2D can be made to follow the change of the soundboard 120.

For example, when the mounting portion of the soundboard 120 is displaced in the direction along the surface of the soundboard 120 (X-axis direction or Y-axis direction), the flat slide bearing 30D housings the actuator 2D as in the first embodiment. It is displaced with respect to the body 110 in the direction along the surface of the soundboard 120. Further, when the mounting portion of the soundboard 120 is displaced in the thickness direction (Z-axis direction) of the soundboard 120, the vibrating body 12 of the actuator 2D is in the vibrating direction (Z-axis direction) of the vibrating body 12 with respect to the main body 11. ). That is, the actuator unit 1D of the second embodiment has three translational degrees of freedom as in the first embodiment.

On the other hand, when the orientation of the mounting portion of the soundboard 120 changes, the actuator 2D swings with respect to the housing 110 by the support portion 60D, so that the orientation of the actuator 2D (particularly the orientation of the vibrating body 12 in the vibration direction). ) Can be made to follow the change in the orientation of the soundboard 120. Specifically, the actuator 2D swings with the X-axis as the axis in response to the change in the orientation of the soundboard 120 with the X-axis as the axis, so that the direction of the actuator 2D follows the change in the orientation of the soundboard 120. To do. Similarly, the actuator 2D swings with the Y axis as the axis in response to the change in the orientation of the soundboard 120 with the Y axis as the axis, so that the direction of the actuator 2D follows the change in the orientation of the soundboard 120. Further, in response to a change in the orientation of the soundboard 120 with the Z axis as the axis, the plurality of

flat surface members

31D, 32D, 33D rotate relative to the Z axis as the axis, so that the orientation of the actuator 2D resonates. It follows the change in the orientation of the plate 120.
From the above, the movement allowance unit 3D of the second embodiment has three degrees of freedom of rotation as in the first embodiment.

According to the actuator unit 1D of the second embodiment, the same effect as that of the first embodiment is obtained.
Further, in the actuator unit 1D of the second embodiment, the actuator 2D can be rotationally moved with respect to the housing 110 by the support portion 60D. As a result, even if the orientation of the attachment portion of the soundboard 120 to which the actuator 2D is attached changes, the orientation of the actuator 2D (particularly the orientation of the vibrating body 12 in the vibration direction) is changed by the support portion 60D. Can be made to follow.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. In the description of the third embodiment, the same components of the third embodiment as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 5, the actuator unit 1E of the third embodiment is an upright piano 100E (hereinafter, also simply referred to as a piano 100E) in which the thickness direction of the soundboard 120E is substantially horizontal (X-axis direction in FIG. 5). .) Applies to. The actuator unit 1E of the third embodiment includes an actuator 2 and a movement allowance unit 3 similar to those of the first embodiment.

The movement allowance portion 3 is fixed to the main body 11 of the actuator 2 as in the first embodiment. However, the movement allowable portions 3 of the third embodiment are arranged in the radial direction of the actuator 2 (the direction orthogonal to the vibration direction of the vibrating body 12) with respect to the actuator 2. Specifically, the first spherical member 41 of the movement allowance portion 3, the second spherical member 42 and the second flat surface member 32 integrally formed, and the first flat surface member 31 have the diameters of the actuators 2 in this order. They are arranged in a direction away from the actuator 2 (Z-axis negative direction in FIG. 5).

The movement allowance portion 3 may be fixed directly to the main body 11, for example, or may be fixed to the main body 11 via the intervening component 7E as illustrated in FIG. The specific configuration of the intervening component 7E may be arbitrary.
The intervening component 7E illustrated in FIG. 5 has first and

second plate portions

71E and 72E which are formed by bending a plate-shaped member or the like and extend in directions orthogonal to each other. The first plate portion 71E is overlapped and fixed on the top plate 15 in the axial direction A1 direction of the main body 11. On the other hand, the second plate portion 72E is overlapped and fixed on the first spherical member 41 facing the main body 11 in the radial direction of the main body 11.

The actuator unit 1E is attached to the piano 100E so as to connect the housing 110E of the piano 100E and the soundboard 120E, as in the first embodiment. That is, the connecting portion 20 of the actuator unit 1E is fixed to the soundboard 120E, and the movement allowable portion 3 of the actuator unit 1E is fixed to the housing 110E.
However, in the piano 100E of the third embodiment, the axis A1 (vibration direction of the vibrating body 12) of the actuator 2 is substantially horizontal (the X-axis direction in FIG. 5) with the actuator unit 1E attached to the soundboard 120E. Turn to. On the other hand, the movement allowance unit 3 is located on the lower side in the vertical direction (negative direction on the Z axis) with respect to the actuator 2 as in the first embodiment. The movement allowance portion 3 may be directly fixed to the housing 110E as illustrated in FIG. 5, or is fixed to the housing 110E via, for example, an intervening component 5 (see FIG. 2) similar to that of the first embodiment. May be done.

In the piano 100E to which the actuator unit 1E of the third embodiment is attached, the actuator 2 can be moved with respect to the housing 110E by the movement allowance unit 3 as in the first embodiment. Therefore, even if the mounting portion of the soundboard 120E to which the actuator 2 is mounted changes due to the aging of the soundboard 120E, the orientation and position of the actuator 2 can be made to follow the change of the soundboard 120E.

For example, when the mounting portion of the soundboard 120E is displaced in the horizontal direction (Y-axis direction) along the surface of the soundboard 120E, the actuator 2 is placed on the surface of the soundboard 120E with respect to the housing 110E by the flat slide bearing 30. Displace horizontally along. When the mounting portion of the soundboard 120E is displaced in the thickness direction (X-axis direction) of the soundboard 120E, the flat slide bearing 30 causes the actuator 2 to move in the thickness direction of the soundboard 120E with respect to the housing 110E. Displace. That is, the actuator unit 1E of the third embodiment has two translational degrees of freedom.

On the other hand, when the orientation of the mounting portion of the soundboard 120E is changed, the first and second

spherical members

41 and 42 are in surface contact with the spherical convex surface 41a and the spherical concave surface 42a, as in the first embodiment. Move relatively. As a result, the first spherical member 41 rotates with respect to the second spherical member 42 with the X axis as the axis in response to the change in the orientation of the soundboard 120E with the X axis as the axis, so that the direction of the actuator 2 resonates. It follows the change in the orientation of the plate 120E. Further, the first spherical member 41 rotates with respect to the second spherical member 42 with the Y axis as the axis in response to the change in the orientation of the soundboard 120E with the Y axis as the axis, so that the direction of the actuator 2 is the soundboard. Follows the change in orientation of 120E. Further, the first and second

spherical members

41 and 42 rotate relative to the Z axis in response to a change in the orientation of the soundboard 120E with the Z axis as the axis, or the first and second

spherical members

41 and 42 rotate relative to the Z axis. The flat surface members 31 and 32 rotate relative to each other with the Z axis as the axis, so that the orientation of the actuator 2 follows the change in the orientation of the soundboard 120E.
From the above, the movement allowance unit 3 of the third embodiment has three degrees of freedom of rotation as in the first embodiment.

According to the actuator unit 1E of the third embodiment, the same effect as that of the first embodiment is obtained.
Further, in the actuator unit 1E of the third embodiment, the movement allowable portions 3 are arranged in the radial direction of the actuator 2 with respect to the actuator 2. In this case, when the actuator unit 1E is arranged so that the axis A1 of the actuator 2 (vibration direction of the vibrating body 12) faces the horizontal direction, the first and second flat surface members 31 and 32 that slide with each other are lined up in the vertical direction. .. Similarly, in this state, the first and second

spherical members

41 and 42 from moving with each other due to gravity. That is, the movement allowance portion 3 is less likely to be affected by gravity. From the above, the actuator unit 1E of the third embodiment is particularly effective in the upright piano 100E in which the thickness direction of the soundboard 120E is substantially horizontal.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the order of superimposing the flat surface member and the spherical member may be reversed, and the superimposition of the spherical member may be provided under the superposition of the flat surface member. In that case, the curvature of the spherical member may be appropriately adjusted according to the displacement amount of the actuator.

In one embodiment of the present invention, for example, the actuator unit may not be provided with a connecting portion, and the vibrating body may be directly fixed to the soundboard.

The musical instrument provided with the actuator unit according to any embodiment of the present invention is not limited to a piano, and may be a stringed musical instrument having a soundboard such as a guitar.

The present invention may be applied to an actuator unit.

1,1D, 1E ...

Actuator unit

2,2D ...

Actuator

3,3D ... Movement allowable part 11 ... Main body 12 ... Vibrating body 13 ... Damper part 20 ... Connection part 23D ... Receiving

part

30, 30D ... Flat plain bearing 31 ... First Flat surface member 31a ...

Flat surface

31D, 32D, 33D ... Flat surface member 32 ... Second flat surface member 32a ... Flat surface 40 ... Spherical plain bearing 41 ... First spherical member 41a ... Spherical convex surface 42 ... Second spherical surface member 42a ... Spherical concave surface 60D ... Support 100 ... Grand piano (instrument)
100E ... Upright piano (musical instrument)
110, 110E ...

Housing

120, 120E ... Soundboard C1 ... Center of curvature

Claims

An actuator that vibrates the soundboard of an instrument and
A movement allowance unit configured to connect the housing of the musical instrument and the actuator and allowing the actuator to move within a predetermined range with respect to the housing.
Actuator unit with.
The movement allowance portion includes a flat surface sliding bearing including a first flat surface member having a first flat surface and a second flat surface member having a second flat surface in surface contact with the first flat surface.
The first flat surface member and the second flat surface member are configured to be relatively movable in a state where the first flat surface and the second flat surface are in surface contact with each other. Actuator unit.
The movement permitting portion includes a spherical slide bearing including a first spherical member having a spherical convex surface and a second spherical member having a spherical concave surface in surface contact with the spherical convex surface.
The actuator according to claim 1 or 2, wherein the first spherical member and the second spherical member are configured to be relatively movable in a state where the spherical convex surface and the spherical concave surface are in surface contact with each other. unit.
The movement allowance portion is
A spherical slide bearing including a first spherical member having a spherical convex surface and a second spherical member having a spherical concave surface in surface contact with the spherical convex surface.
A flat plain bearing including a first flat surface member having a first flat surface and a second flat surface member having a second flat surface in surface contact with the first flat surface.
With
The first spherical member and the second spherical member are configured to be relatively movable in a state where the spherical convex surface and the spherical concave surface are in surface contact with each other.
The first flat surface member and the second flat surface member are configured to be relatively movable in a state where the first flat surface and the second flat surface are in surface contact with each other.
The actuator unit according to claim 1, wherein one of the first spherical member and the second spherical member and one of the first flat surface member and the second flat surface member are integrally formed.
The actuator unit according to any one of claims 1 to 4, wherein the movement allowance portion and the actuator are aligned in the vibration direction of the actuator.
The movement allowance portion and the actuator are aligned in the vibration direction of the actuator.
The actuator unit according to claim 3 or 4, wherein the center of curvature of the spherical convex surface and the spherical concave surface is located on the axis of the actuator extending in the vibration direction.
The actuator unit according to any one of claims 1 to 4, wherein the movement permitting portion and the actuator are arranged in a direction orthogonal to the vibration direction of the actuator.
The actuator unit according to claim 2, wherein the movement allowable portion includes a support portion that projects from the flat slide bearing and supports the actuator so as to be swingable.
A musical instrument including the actuator unit according to any one of claims 1 to 8.