CN114503189A - Actuator unit and musical instrument - Google Patents

Abstract

The actuator unit has: an actuator that vibrates a soundboard of the musical instrument; and a movement allowing unit configured to connect the casing of the musical instrument and the actuator so that the actuator can move within a predetermined range with respect to the casing.

Description

Actuator unit and musical instrument

Technical Field

The present invention relates to an actuator unit and a musical instrument.

The present application claims priority based on japanese patent application No. 2019-190959, filed on 18/10/2019, the disclosure of which is incorporated herein in its entirety.

Background

Conventionally, various musical instruments such as keyboard musical instruments are equipped with actuators for generating sound by vibrating a soundboard (in a predetermined direction) based on an input audio signal.

Patent document 1 discloses a structure in which a sound board and a vibrating body of an actuator are connected by a connecting body. In the structure of patent document 1, a plurality of joint portions for inclining the connecting body with respect to the plate thickness direction of the sound plate and the vibration direction of the vibrating body are provided. By providing the joint portion in the coupling body, the sound board can be appropriately vibrated by the actuator even if the relative position or orientation between the sound board and the actuator changes due to the secular change of the sound board due to the influence of temperature, humidity, or the like.

Patent document 1: japanese patent laid-open publication No. 2015-114457

Disclosure of Invention

However, if the structure (connection structure) for connecting the soundboard and the vibrating body of the actuator includes a joint portion in addition to the connecting body, the connection structure for vibrating together with the vibrating body becomes complicated. Therefore, it becomes difficult to vibrate the sound board at a high frequency, and the play characteristic in a high-pitched range may deteriorate. As a result, there is a problem that the quality of audio playback by the actuator and the soundboard is degraded.

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 that can realize high-quality audio playback by simplifying a connection structure for connecting a soundboard and a vibrating body of an actuator.

One aspect of the present invention is an actuator unit including: an actuator that vibrates a soundboard of the musical instrument; and a movement allowing unit configured to connect a housing of the musical instrument and the actuator so that the actuator can move within a predetermined range with respect to the housing.

Another aspect of the present invention is a musical instrument having the above-described actuator unit.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the embodiments of the present invention, high-quality audio playback can be realized by making the connection structure for connecting the sound board and the vibrating body of the actuator simpler.

Drawings

Fig. 1 is a schematic view of a piano on which an actuator unit according to a first embodiment of the present invention is mounted, as viewed from the lower side.

Fig. 2 is a cross-sectional view showing a state in which the actuator unit according to the first embodiment of the present invention is attached to a piano.

Fig. 3 is a diagram schematically showing the operation of the spherical plain bearing provided in the actuator unit of fig. 2.

Fig. 4 is a cross-sectional view showing a state in which an actuator unit according to a second embodiment of the present invention is attached to a piano.

Fig. 5 is a sectional view showing a state in which an actuator unit according to a third embodiment of the present invention is attached to a piano.

Detailed Description

[ first embodiment ]

Hereinafter, a first embodiment of the present invention will be described with reference to fig. 1 to 3.

Fig. 1 shows a grand piano 100 (hereinafter, also simply referred to as a piano 100), which is one of keyboard musical instruments, as a musical instrument to which the actuator unit 1 according to the first embodiment of the present invention is applied. The Z-axis direction of fig. 1 represents the up-down direction of the piano 100. The piano 100 has a frame 110 and a soundboard 120. As shown in fig. 1, when viewed from the lower side of grand piano 100, a plurality of upright supports 111 and sound boards 120 constituting frame body 110 are visible. As shown in fig. 2, a plurality of straight stays 111 are located below the tone plate 120 (Z-axis negative direction) at intervals from each other.

As shown in fig. 2, the actuator unit 1 according to the present embodiment vibrates the sound board 120 by connecting the housing 110 and the sound board 120 of the piano 100. The actuator unit 1 includes: an actuator 2 for vibrating the tone plate 120; and a movement allowing unit 3 that allows the actuator 2 to move within a predetermined range with respect to the housing 110.

The actuator 2 has: 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 connecting the vibrator 12 to the main body 11.

The main body 11 has a magnetic path forming portion 14 forming a magnetic path. The magnetic path forming portion 14 includes a top plate 15, a yoke portion 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 a plate shape of a circular ring. The yoke 16 includes 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 disc portion 16A and the columnar portion 16B in the direction of the axis a1 (the Z-axis direction in fig. 1). The yoke 16 is arranged such that the circular plate portion 16A opposes the top plate 15 in the axis a1 direction, and the front end portion of the cylindrical portion 16B enters the inside of the top plate 15. The magnet 17 is a permanent magnet formed in an annular shape. The magnet 17 is disposed so as to insert the columnar portion 16B therethrough and to be sandwiched between the top plate 15 and the circular plate 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 periphery of the top plate 15 and the outer periphery of the distal end portion of the columnar portion 16B.

The vibrator 12 includes a cylindrical portion 18 and a cover 19. The cylindrical portion 18 is inserted into a gap between the inner periphery of the top plate 15 and the outer periphery of the cylindrical portion 16B of the yoke portion 16. The lid 19 closes one opening of the cylindrical portion 18.

The cylindrical portion 18 includes a bobbin (not shown) and a voice coil (not shown) wound around the bobbin. The vibrator 12 is located near the first end of the main body 11 where the top plate 15 is located in the direction of the axis a1 of the magnetic circuit forming portion 14.

The damper portion 13 holds the cylindrical portion 18 of the vibrator 12 in a gap between the inner periphery of the top plate 15 and the outer periphery of the cylindrical portion 16B of the yoke portion 16. The damper portion 13 is formed to be elastically deformable. The damper portion 13 holds the cylindrical portion 18 at a predetermined position of the magnetic path forming portion 14 by its elastic force. When the cylindrical portion 18 is displaced from the predetermined position, the damper portion 13 causes the cylindrical portion 18 to move toward the predetermined position by the elastic force of the damper portion 13 itself.

In the actuator 2, a current corresponding to an audio signal flows in the voice coil of the vibration body 12, whereby the vibration body 12 vibrates in the direction of the axis a1 of the main body 11. The audio signal is generated as a drive signal for driving the vibrator 12 based on audio data stored in a storage unit (not shown) in a control device (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 structure of the connecting portion 20 may be arbitrary. The connecting portion 20 of the present embodiment includes a rod portion 21 and a mounting plate portion 22. The rod-like portion 21 extends from the vibration body 12 in the vibration direction (the axis a1 direction) of the vibration body 12. The mounting plate portion 22 is provided at the distal end portion of the rod portion 21 and fixed to the soundboard 120. The base end portion of the rod-shaped portion 21 is fixed to the lid 19 of the vibrator 12.

The movement allowing section 3 is provided to connect the frame body 110 and the actuator 2. The movement allowing section 3 of the present embodiment includes a flat surface sliding bearing 30 and a spherical surface sliding bearing (spherical plain bearing) 40.

The plain sliding bearing 30 includes: first and second flat surface members (a pair of flat surface members) 31 and 32 having flat surfaces 31a and 32 a. The flat surfaces 31a and 32a can move relative to each other while being in surface contact with each other.

The flat sliding bearing 30 includes a movement restricting portion 35 (first movement restricting portion 35) that restricts the range in which the first and second flat members 31, 32 move relative to each other. The specific structure of the first movement restricting portion 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 annularly, and surrounds the second flat surface member 32 which is in surface contact with the flat surface 31a of the first flat surface member 31. This prevents 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 the first flat surface member 31. For example, the second flat surface member 32 may be formed with a peripheral wall portion that surrounds the first flat surface member 31, thereby preventing the first flat surface member 31 from protruding from the edge of the flat surface 32a of the second flat surface member 32.

As described above, by disposing the first and second flat surface members 31 and 32, the actuator 2 can be moved relative to the housing 110 in the directions (X-axis direction and Y-axis direction) along the flat surfaces 31a and 32a of the first and second flat surface members 31 and 32.

The planar sliding bearing 30 is preferably arranged such that the first and second planar members 31 and 32 are aligned in the vertical direction (Z-axis direction).

Spherical sliding bearing 40 includes: a first spherical member 41 having a spherical convex surface 41 a; and a second spherical element 42 having a spherical concave surface 42 a. The spherical convex surface 41a and the spherical concave surface 42a have the same radius of curvature, and thus the spherical convex surface 41a and the spherical concave surface 42a are in surface contact with each other. The spherical convex surface 41a and the spherical concave surface 42a are movable with respect to each other in a state of surface contact with each other.

The spherical sliding bearing 40 includes a movement restricting portion 45 (second movement restricting portion 45) that restricts the range in which the first and second spherical members 41, 42 move relative to each other. The specific structure of the second movement restricting portion 45 may be arbitrary. The second movement restricting portion 45 of the present embodiment is a peripheral wall portion 41B that protrudes 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 in surface contact with the spherical convex surface 41a of the first spherical member 41. This prevents the second spherical surface member 42 from protruding from the edge of the spherical convex surface 41a of the first spherical surface member 41. The peripheral wall portion 41B is not limited to the first spherical member 41. For example, the second spherical surface member 42 may be provided with a peripheral wall portion that surrounds the first spherical surface member 41, thereby preventing the first spherical surface member 41 from protruding from the edge of the spherical concave surface 42a of the second spherical surface member 42.

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. As described above, by disposing the first and second spherical members 41 and 42, 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 42 a.

The spherical sliding bearing 40 is preferably arranged such that the first and second spherical members 41 and 42 are aligned in the vertical direction (Z-axis direction). Further, the second spherical member 42 is more preferably disposed below the first spherical member 41 (on the Z-axis negative direction side).

The planar slide bearing 30 and the spherical slide bearing 40 are arranged so as to be aligned in the alignment direction (Z-axis direction) of the first and second planar members 31, 32 and the alignment direction (Z-axis direction) of the first and second spherical members 41, 42. In the present embodiment, one of the first and second flat surface members 31, 32 and one of the first and second spherical surface members 41, 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 allowing section 3 are preferably made of materials (materials having a small friction coefficient) that easily slide against each other. Similarly, the first and second spherical members 41 and 42 are preferably made of a material that slides easily (a material having a small friction coefficient). 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 (the same applies to the first and second spherical members 41 and 42). The first and second flat surface members 31, 32 may be made of the same material as each other or different materials from each other. However, the materials constituting the first and second flat surface members 31, 32 are preferably selected so that the friction coefficients of the first and second flat surface members 31, 32 become smaller. Similarly, the materials constituting the first and second spherical members 41 and 42 are preferably selected so that the friction coefficients of the first and second spherical members 41 and 42 are reduced, and may be the same as or different from each other.

The movement allowing portion 3 is fixed to the main body 11 of the actuator 2. The movement allowing portions 3 of the present embodiment are aligned with respect to the actuator 2 in the direction of the axis a1 of the actuator 2 (i.e., the vibration direction of the vibrator 12). Specifically, the movement allowing portion 3 is fixed to a second end portion of the main body 11 opposite to the first end portion of the main body 11 where the vibrator 12 is located in the direction of the axis a1 of the actuator 2 in the main body 11. In the present embodiment, the first spherical member 41 constituting the movement allowing section 3 is fixed to the main body 11 of the actuator 2.

In a state where the movement allowable 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 frame 110 and the sound board 120 of the piano 100. In the present embodiment, the connecting portion 20 (particularly, the mounting plate portion 22) of the actuator unit 1 is fixed to the sound board 120. The movement allowing unit 3 of the actuator unit 1 is fixed to the housing 110. The movement allowing section 3 may be fixed to a side plate of the housing 110, for example, but in the present embodiment, as shown in fig. 1 and 2, it is fixed to a straight support column 111 of the housing 110.

Specifically, as shown in fig. 2, the first flat surface member 31 of the movement allowing section 3 is fixed to the straight support column 111 via the intermediary member 5. The intermediary member 5 is fixed to a side surface (a surface extending in the Z-axis direction) of the straight support 111. The intermediary member 5 has a support plate portion 51 extending from the side surface of the straight strut 111 in the direction (X-axis negative direction) orthogonal to the side surface of the straight strut 111. The first flat surface member 31 is fixed to the supporting plate portion 51 (the surface opposite to the supporting plate portion 51 facing the sound board 120). In this state, the first flat surface member 31, the integrally formed second flat surface member 32 and second spherical surface member 42, and the first spherical surface member 41 are arranged in this order in the upward direction (Z-axis positive direction) from the support plate portion 51.

In the piano 100 with the actuator unit 1 mounted thereon, vibrations of the vibrating body 12 corresponding to an audio signal are transmitted to the sound board 120 via the connecting portion 20, whereby the sound board 120 vibrates. The vibration of the sound board 120 becomes a sound propagated in the air. Thereby playing the audio.

In the piano 100 to which the actuator unit 1 is attached, the actuator 2 is movable relative to the housing 110 by the movement allowing section 3. Therefore, even if the attachment position of the sound board 120 to which the actuator 2 is attached changes with the change of the sound board 120 over time, the orientation and position of the actuator 2 can be made to follow the change of the sound board 120.

For example, in the case where the mount portion of the tone plate 120 is displaced in the direction along the surface of the tone plate 120 (X-axis direction, Y-axis direction), the first and second flat surface members 31, 32 are relatively moved in the direction along their flat surfaces 31a, 32a (X-axis direction, Y-axis direction). This allows the position of the actuator 2 to follow the displacement of the sound board 120. That is, the movement allowing unit 3 has the degree of freedom of translation 2 axis (X axis and Y axis). When the mounting portion of the sound board 120 is displaced in the board thickness direction (Z-axis direction) of the sound board 120, the vibrating body 12 of the actuator 2 is displaced in the vibration direction (Z-axis direction) of the vibrating body 12 with respect to the main body 11. That is, the actuator unit 1 has a degree of freedom of translation 3 axes in total.

For example, as shown in fig. 3, when the orientation of the attachment portion of the soundboard 120 is changed, the first and second spherical members 41 and 42 move relative 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. This allows the orientation of the actuator 2 (particularly, the orientation of the axis a1 of the vibrating body 12) to follow the change in the orientation of the sound board 120. In fig. 3, the first spherical member 41 rotates about the Y axis with respect to the second spherical member 42 in accordance with a change in the orientation of the soundboard 120 about the Y axis, whereby the orientation of the actuator 2 follows the change in the orientation of the soundboard 120.

Although not shown, in the present embodiment, the first spherical member 41 is rotated about the X axis with respect to the second spherical member 42 in accordance with a change in the orientation of the soundboard 120 about the X axis, and thereby the orientation of the actuator 2 can also be made to follow the change in the orientation of the soundboard 120.

In the present embodiment, in accordance with a change in the orientation of the soundboard 120 about the Z axis, the first and second spherical members 41 and 42 are relatively rotated about the Z axis, or the first and second flat surface members 31 and 32 are relatively rotated about the Z axis, whereby the orientation of the actuator 2 can be made to follow the change in the orientation of the soundboard 120.

As described above, the movement allowing unit 3 of the present embodiment has the degree of freedom of rotation 3 axes.

As described above, according to the actuator unit 1 of the present embodiment, the movement allowing portion 3 is sandwiched between the housing 110 and the actuator 2. Therefore, in the actuator unit 1 of the present embodiment, even if a joint portion as in the conventional art is not provided in a connection structure that connects the vibrating body 12 of the actuator 2 and the sound board 120 including the connection portion 20 and the like, the orientation and position of the actuator 2 can be made to follow the change of the sound board 120 due to the secular change. This makes the connection structure that vibrates together with the vibrator 12 simpler than in the related art. As a result, the playback frequency band obtained by the actuator 2 and the soundboard 120 can be expanded to a higher pitch range. Therefore, audio playback over a wide band is possible, and high-quality audio playback is possible.

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 slide bearing 30. Thus, even if displacement in a direction along the surface of the sound board 120 (the surface direction of the sound board 120) occurs at the mounting location of the sound board 120 to which the actuator 2 is mounted, the actuator 2 can follow the displacement in the surface direction of the sound board 120 by the planar sliding bearing 30.

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 plain bearing 40. Accordingly, even if the orientation of the 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) can be changed to follow the orientation of the soundboard 120 by the spherical sliding bearing 40.

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 surface members 41 and 42 are integrally formed. Therefore, the number of components constituting the movement allowing section 3 can be reduced. Thereby, the actuator unit 1 including the movement allowing portion 3 can be easily assembled.

In the actuator unit 1 of the present embodiment, the movement allowing portions 3 are aligned with respect to the actuator 2 in the direction of the axis a1 (vibration direction) of the actuator 2. In this case, in a state where the actuator unit 1 is disposed such that the axis a1 of the actuator 2 (the vibration direction of the vibrator 12) is oriented in the vertical direction, the first and second flat surface members 31 and 32 that slide against each other are aligned in the vertical direction. Similarly, in this state, the first and second spherical members 41 and 42 sliding on each other are aligned in the vertical direction. Therefore, the first and second flat surface members 31 and 32 can be prevented from moving relative to each other due to gravity. Similarly, the first and second spherical members 41 and 42 can be prevented from moving relative to each other due to gravity. That is, the movement allowable portion 3 is not easily affected by gravity. As described above, the actuator unit 1 of the present embodiment is particularly effective in the grand piano 100 in which the thickness direction of the sound board 120 is oriented substantially in the vertical direction.

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 relative to each other in a state where the spherical convex surface 41a and the spherical concave surface 42a are reliably brought into surface contact with each other. Therefore, the direction of the actuator 2 can be reliably made to follow the change in the direction of the sound board 120.

In the first embodiment, the two members (for example, the first and second flat surface members 31 and 32) which constitute the movement allowing section 3 and are movable in a state of surface contact with each other may be made of a material which is easily slidable only on the surfaces thereof.

In the first embodiment, for example, a lubricant may be interposed between two members that constitute the movement allowing section 3 and are movable in a state of surface contact with each other. With the lubricant sandwiched, the two components become more easily slidable.

[ second embodiment ]

Next, a second embodiment of the present invention will be described with reference to fig. 4. In the description of the second embodiment, the same components of the second embodiment as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

As shown in fig. 4, the actuator unit 1D of the second embodiment is applied to the grand piano 100 identical to that of the first embodiment. The actuator unit 1D of the second embodiment includes an actuator 2D and a movement allowing portion 3D, as in the first embodiment.

The actuator 2D includes the same body 11, vibrator 12, and damper portion 13 as in the first embodiment. However, in the second embodiment, the main body 11 is formed with a receiving portion 23D for receiving a support portion 60D of a movement allowing portion 3D described later. The bearing portion 23D is recessed in a concave shape, and is located on the axis a1 of the main body 11. The carrier portion 23D may be formed directly on the magnetic path forming portion 14, for example. In the second embodiment, the receiving portion 23D is formed in the lid portion 24D that closes the through hole 16C of the yoke portion 16. The lid portion 24D may be provided near the distal end portion of the columnar portion 16B as in the example shown in fig. 4, or may be provided near the base end portion of the columnar portion 16B (near the circular plate portion 16A), for example.

The movement allowable portion 3D is aligned with respect to the actuator 2D in the direction of the axis a1 of the actuator 2D, as in the first embodiment. The movement allowing portion 3D is disposed near the second end of the body 11 in the direction of the axis a1, but is not fixed to the actuator 2D, as in the first embodiment.

The movement allowable portion 3D has the same planar slide bearing 30D as the first embodiment. The flat sliding bearing 30D illustrated in fig. 4 is configured by overlapping three flat surface members 31D, 32D, and 33D, and may be configured by overlapping two flat surface members 31D and 32D as in the first embodiment.

The movement allowing portion 3D of the second embodiment further has a support portion 60D protruding from the planar slide bearing 30D. The support portion 60D protrudes toward the main body 11 of the actuator 2D to support the actuator 2D swingably. The specific structure of the support portion 60D may be arbitrary.

The support portion 60D of the second embodiment includes a base portion 61D, a rod portion 62D, and a spherical portion 63D. The base portion 61D is fixed to one flat surface member 33D of the three flat surface members 31D, 32D, 33D. The rod-like portion 62D extends from the base portion 61D in the vertical direction upper side (Z-axis positive direction). The spherical portion 63D is provided at the tip of the rod-shaped portion 62D. The spherical portion 63D is accommodated in the bearing portion 23D of the main body 11. Thereby, the actuator 2D can swing with the spherical portion 63D (bearing portion 23D) as a fulcrum. The fulcrum (bearing portion 23D) of the actuator 2D is preferably located, for example, vertically above the center of gravity of the actuator 2D (particularly, the main body 11).

In the piano 100 on which the actuator unit 1D of the second embodiment is mounted, the actuator 2D is movable relative to the frame body 110 by the movement allowing section 3D, as in the first embodiment. Therefore, even if the attachment position of the tone plate 120 to which the actuator 2D is attached changes with the time-dependent change of the tone plate 120, the orientation and position of the actuator 2D can be made to follow the change of the tone plate 120.

For example, when the mount portion of the sound board 120 is displaced in the direction along the surface of the sound board 120 (X-axis direction, Y-axis direction), the actuator 2D is displaced in the direction along the surface of the sound board 120 with respect to the housing 110 by the flat slide bearing 30D, as in the first embodiment. When the mounting portion of the sound board 120 is displaced in the board thickness direction (Z-axis direction) of the sound board 120, the vibrating body 12 of the actuator 2D is displaced 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 the degree of freedom of translation 3 axes, as in the first embodiment.

On the other hand, when the orientation of the attachment portion of the sound board 120 is changed, the orientation of the actuator 2D (particularly, the orientation of the vibration direction of the vibrating body 12) can be changed to follow the orientation of the sound board 120 by the actuator 2D swinging with respect to the housing 110 via the support portion 60D. Specifically, the actuator 2D swings about the X axis as an axis in accordance with a change in the orientation of the sound board 120 about the X axis, whereby the orientation of the actuator 2D follows the change in the orientation of the sound board 120. Similarly, the actuator 2D swings with the Y-axis as the axis in accordance with the change in the orientation of the tone plate 120 with the Y-axis as the axis, whereby the orientation of the actuator 2D follows the change in the orientation of the tone plate 120. Further, in accordance with a change in the orientation of the sound board 120 about the Z axis, the plurality of flat surface members 31D, 32D, and 33D are relatively rotated about the Z axis, and the orientation of the actuator 2D follows the change in the orientation of the sound board 120.

As described above, the movement allowable portion 3D of the second embodiment has a degree of freedom of 3-axis rotation, as in the first embodiment.

According to the actuator unit 1D of the second embodiment, the same effects as those of the first embodiment are achieved.

In the actuator unit 1D according to the second embodiment, the actuator 2D can be rotationally moved with respect to the housing 110 by the support portion 60D. Thus, even if the orientation of the attachment site of the sound board 120 to which the actuator 2D is attached changes, the orientation of the actuator 2D (particularly, the orientation of the vibration direction of the vibrating body 12) can be changed to follow the orientation of the sound board 120 by the support portion 60D.

[ third embodiment ]

Next, a third embodiment of the present invention will be described with reference to fig. 5. In the description of the third embodiment, the same components of the third embodiment as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

As shown in fig. 5, the actuator unit 1E of the third embodiment is applied to an upright piano 100E (hereinafter, also simply referred to as piano 100E) in which the plate thickness direction of a sound board 120E is oriented substantially in the horizontal direction (X-axis direction in fig. 5). The actuator unit 1E of the third embodiment includes the same actuator 2 and movement allowing unit 3 as those of the first embodiment.

The movement allowing portion 3 is fixed to the main body 11 of the actuator 2 as in the first embodiment. However, the movement allowing portions 3 according to the third embodiment are arranged in the radial direction of the actuator 2 (the direction orthogonal to the vibration direction of the vibrator 12) with respect to the actuator 2. Specifically, the first spherical member 41, the second spherical member 42 and the second flat surface member 32, which are integrally formed, and the first flat surface member 31 of the movement allowing section 3 are arranged in this order in the radial direction of the actuator 2 in a direction away from the actuator 2 (the negative direction of the Z axis in fig. 5).

The movement allowing section 3 may be fixed directly to the main body 11, for example, or may be fixed to the main body 11 via an intermediary member 7E as illustrated in fig. 5. The specific structure of the intermediate member 7E may be arbitrary.

The intermediary member 7E illustrated in fig. 5 is formed by bending a plate-like member, and includes first and second plate portions 71E and 72E extending in directions orthogonal to each other. The first plate portion 71E is fixed to the top plate 15 so as to overlap in the direction of the axis a1 of the main body 11. On the other hand, the second plate portion 72E is overlapped and fixed to the first spherical member 41 facing the body 11 in the radial direction of the body 11.

The actuator unit 1E is attached to the piano 100E so as to connect the frame 110E and the tone plate 120E of the piano 100E, as in the first embodiment. That is, the connecting portion 20 of the actuator unit 1E is fixed to the sound board 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 of the actuator 2 (the direction of vibration of the vibrating body 12) is oriented substantially in the horizontal direction (the X-axis direction in fig. 5) in a state where the actuator unit 1E is attached to the soundboard 120E. On the other hand, the movement allowable portion 3 is located on the lower side in the vertical direction (the Z-axis negative direction) with respect to the actuator 2, as in the first embodiment. The movement allowing unit 3 may be directly fixed to the housing 110E as illustrated in fig. 5, or may be fixed to the housing 110E via an intermediary member 5 (see fig. 2) or the like similar to that of the first embodiment.

In the piano 100E on which the actuator unit 1E of the third embodiment is mounted, the actuator 2 is movable relative to the frame body 110E by the movement allowing part 3, as in the first embodiment. Therefore, even if the attachment position of the tone plate 120E to which the actuator 2 is attached changes with the time-dependent change of the tone plate 120E, the orientation and position of the actuator 2 can be made to follow the change of the tone plate 120E.

For example, when the mount portion of sound board 120E is displaced in the horizontal direction (Y-axis direction) along the surface of sound board 120E, actuator 2 is displaced in the horizontal direction along the surface of sound board 120E with respect to casing 110E by flat sliding bearing 30. When the mounting portion of sound board 120E is displaced in the plate thickness direction (X-axis direction) of sound board 120E, actuator 2 is displaced in the plate thickness direction of sound board 120E relative to housing 110E by flat sliding bearing 30. That is, the actuator unit 1E of the third embodiment has a degree of freedom of translation by 2 axes.

On the other hand, when the orientation of the attachment portion of the tone plate 120E is changed, the first and second spherical members 41 and 42 are relatively moved in a state where the spherical convex surface 41a and the spherical concave surface 42a are in surface contact, as in the first embodiment. Accordingly, the first spherical member 41 rotates with respect to the second spherical member 42 about the X-axis as an axis in accordance with a change in the orientation of the tone plate 120E about the X-axis, whereby the orientation of the actuator 2 follows the change in the orientation of the tone plate 120E. Further, in accordance with a change in the orientation of the soundboard 120E with the Y axis as the axis, the first spherical member 41 rotates with respect to the second spherical member 42 with the Y axis as the axis, whereby the orientation of the actuator 2 follows the change in the orientation of the soundboard 120E. Then, in accordance with a change in the orientation of the soundboard 120E about the Z axis, the first and second spherical members 41 and 42 rotate relative to each other about the Z axis, or the first and second flat surface members 31 and 32 rotate relative to each other about the Z axis, whereby the orientation of the actuator 2 follows the change in the orientation of the soundboard 120E.

As described above, the movement allowable portion 3 of the third embodiment has the degree of freedom of 3-axis rotation, as in the first embodiment.

According to the actuator unit 1E of the third embodiment, the same effects as those of the first embodiment are achieved.

In the actuator unit 1E of the third embodiment, the movement allowing portions 3 are arranged in the radial direction of the actuator 2 with respect to the actuator 2. In this case, in a state where the actuator unit 1E is disposed such that the axis a1 of the actuator 2 (the vibration direction of the vibrator 12) is oriented in the horizontal direction, the first and second flat surface members 31 and 32 that slide against each other are arranged in the vertical direction. Similarly, in this state, the first and second spherical members 41 and 42 sliding on each other are aligned in the vertical direction. Therefore, the first and second flat members 31 and 32 can be prevented from moving relative to each other due to gravity. Similarly, the first and second spherical members 41 and 42 can be prevented from moving relative to each other due to gravity. That is, the movement allowable portion 3 is not easily 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 plate thickness direction of the soundboard 120E is oriented substantially in the horizontal direction.

While the embodiments of the present invention have been described in detail, the present invention is not limited to the embodiments, and various modifications can be made without departing from the scope of the present invention. For example, the order of overlapping the flat surface members and the spherical surface members may be reversed, and the overlapping of the spherical surface members may be provided below the overlapping of the flat surface members. In this 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 have a connecting portion, and the vibrating body may be directly fixed to the sound board.

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

Industrial applicability

The invention can also be applied to an actuator unit.

Description of the reference numerals

1. 1D, 1E … actuator unit

2. 2D … actuator

3. 3D … movement allowance part

11 … Main body

12 … vibration body

13 … damper section

20 … connecting part

23D … bearing part

30. 30D … plane sliding bearing

31 … first plane member

31a … flat surface

31D, 32D, 33D … Flat face component

32 … second planar member

32a … flat side

40 … spherical surface sliding bearing

41 … first spherical part

41a … spherical convex surface

42 … second spherical element

42a … spherical concave surface

60D … support portion

100 … grand piano (musical instrument)

100E … vertical piano (musical instrument)

110. 110E … frame body

120. 120E … soundboard

Center of curvature of C1 …

Claims (9)

1. An actuator unit having:

an actuator that vibrates a soundboard of the musical instrument; and

and a movement allowing unit configured to connect a housing of the musical instrument and the actuator so that the actuator can move within a predetermined range with respect to the housing.

2. The actuator unit of claim 1,

the movement allowing portion has a flat sliding bearing including: a first planar member having a first planar face; and a second flat surface member having a second flat surface that makes 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.

3. The actuator unit according to claim 1 or 2, wherein,

the movement-allowable portion has a spherical sliding 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 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.

4. The actuator unit of claim 1,

the movement allowing part has a spherical sliding bearing and a planar sliding bearing,

the spherical sliding bearing includes: 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 plain sliding bearing includes: a first planar member having a first planar face; and a second flat surface member having a second flat surface that makes surface contact with the first flat surface,

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,

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,

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.

5. The actuator unit according to any one of claims 1 to 4, wherein,

the movement allowing section and the actuator are arranged in a vibration direction of the actuator.

6. The actuator unit according to claim 3 or 4, wherein,

the movement allowing portion and the actuator are arranged in a vibration direction of the actuator,

the centers of curvature of the spherical convex surface and the spherical concave surface are located on an axis of the actuator extending in the vibration direction.

7. The actuator unit according to any one of claims 1 to 4, wherein,

the movement allowing portion and the actuator are arranged in a direction orthogonal to a vibration direction of the actuator.

8. The actuator unit of claim 2,

the movement allowing portion has a support portion that protrudes from the planar sliding bearing to support the actuator swingably.

9. A musical instrument having the actuator unit of any one of claims 1 to 8.

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