WO2023074762A1

WO2023074762A1 - Vibration actuator

Info

Publication number: WO2023074762A1
Application number: PCT/JP2022/040012
Authority: WO
Inventors: 雄太種村
Original assignee: フォスター電機株式会社
Priority date: 2021-10-29
Filing date: 2022-10-26
Publication date: 2023-05-04
Also published as: JP2023067105A

Abstract

A vibration actuator 1 includes a movable element 30 that forms a magnetic drive unit together with a coil 24 provided in a cylindrical case 10 and vibrates in the axial direction of the case 10 while being supported by the case 10 via a leaf spring 2. The movable element 30 is configured to include a magnet 34 and a yoke 32. The yoke 32 is provided in the central portion of the movable element 30.

Description

vibration actuator

The present disclosure relates to vibration actuators.

In International Publication WO2020/175610, a yoke and a coil are fixed to the inner periphery of a cylindrical case to form a case-side drive unit (stator), and a mover made up of magnets, pole pieces, and masses is arranged in the case. A vibration actuator is disclosed that is elastically supported on a body. In this vibration actuator, AC power is applied to the coil to generate magnetic repulsion and magnetic attraction with the magnetic circuit of the mover, thereby vibrating the mover.

By the way, in order to increase the thrust of the mover, it is desirable to reduce the gap between the magnet and the yoke.

On the other hand, due to the magnetic force of the magnet, a force acts between the magnet and the yoke in a direction that pulls them together. Therefore, as in International Publication WO2020/175610, when the position of the magnet is displaced with respect to the yoke that constitutes the stator, if the gap between the magnet and the yoke is too small, the magnet will be attracted to the yoke by the magnetic force. There is a possibility that the shaft center of the mover may be displaced due to being pulled.

In consideration of the above facts, an object of the present disclosure is to provide a vibration actuator capable of reducing the gap between the magnet and the yoke by preventing the shift of the axis of the mover.

A vibration actuator according to a first aspect of the present disclosure includes a cylindrical case, a coil provided in the case, elastic members provided at one end and the other end in the axial direction of the case, a magnet, and a yoke. a mover that constitutes a magnetic driving unit together with the coil and vibrates along the axial direction of the case while being supported by the case via the elastic member; The vibration actuator, wherein the yoke is provided at the center of the mover.

In the vibration actuator according to the first aspect, the coil provided in the cylindrical case constitutes the magnetic drive unit, and the movable actuator vibrates along the axial direction of the case while being supported by the case via the elastic member. have a child. The mover includes a magnet and a yoke. The yoke is provided at the center of the mover and vibrates integrally with the magnet. Therefore, the position of the magnet is not displaced with respect to the yoke. As a result, it is possible to prevent the axial center of the mover from shifting due to the magnetic force of the magnet, and to reduce the gap between the magnet and the yoke.

A vibration actuator according to a second aspect of the present disclosure is the mover according to the first aspect, wherein the magnets are arranged at intervals in the vibration direction and arranged on one side of the yoke in the vibration direction. It has a first magnet and a second magnet arranged on the other side of the yoke in the vibration direction.

According to the vibration actuator of the second aspect, the magnets are composed of the first magnet arranged on one side of the yoke in the vibration direction and the second magnet arranged on the other side of the yoke, and are spaced apart in the vibration direction. By arranging a part of the yoke between two magnets that are spaced apart from each other, the magnet is connected through the yoke to the center of the vibration direction of the magnet. As a result, the magnet and the yoke can be easily connected without requiring a complicated structure for passing the yoke through the center of the vibration direction of the magnet.

A vibration actuator according to a third aspect of the present disclosure is the mover configured according to the second aspect, wherein the first magnet and the second magnet are magnetized in the same direction along the vibration direction. there is

In the vibration actuator according to the third aspect, the magnetization directions of the first magnet and the second magnet are the same in the axial direction. A strong magnetic adsorption force acts on the As a result, the magnet and the yoke can be strongly connected using the magnetic attraction force, and the bonding strength between the members can be easily ensured.

A vibration actuator according to a fourth aspect of the present disclosure is the mover according to any one of the first to third aspects, wherein the yoke has a central portion passing through the center of the magnet in the vibration direction. and side portions extending from the outer edge of the central portion to one side and the other side in the vibration direction and covering the outer periphery of the magnet.

In the vibration actuator according to the fourth aspect, the side portions extend on one side and the other side in the vibration direction with respect to the central portion of the yoke passing through the center of the magnet in the vibration direction, and cover the outer periphery of the magnet. As a result, two magnetic gaps can be formed on both sides in the vibration direction across the center of the yoke. Conventional vibration actuators have a structure in which two coils are arranged spaced apart in the direction of vibration and each is arranged in two magnetic gaps in a case. However, since these generally form a magnetic gap by arranging one magnet at the center of the vibration direction, it is difficult to adjust the position of the magnetic gap in consideration of the vibration mass. On the other hand, by adopting a configuration in which two magnetic gaps can be formed on both sides in the vibration direction with the center of the yoke separated, the plate thickness of the center of the yoke can be changed to reduce the vibration mass and the magnetic gap. Adjustment of the position can be easily performed.

A vibration actuator according to a fifth aspect of the present disclosure is the configuration according to any one aspect of the fourth aspect, wherein the mover further includes a pole piece arranged outside in the vibration direction with respect to the magnet. wherein the coil is arranged between the pole piece and the yoke on the outer peripheral side of the magnet, and a first region arranged in a magnetic gap formed between the pole piece and the yoke; , and a second region exposed from the magnetic gap in the direction of vibration.

In the vibration actuator according to the fifth aspect, the pole piece is arranged outside the magnet in the vibration direction, and the coil is arranged in the magnetic gap formed between the pole piece and the yoke. Here, the coil has a first region located within the magnetic gap and a second region exposed from the magnetic gap in the direction of vibration. As a result, in a vibrating state in which the mover moves relative to the coil, it is possible to secure a region for the coil arranged in the magnetic gap, and to stabilize the magnetic flux penetrating the coil. Also, even if the displacement of the mover increases due to an increase in the vibration mass, the same structure can be used.

A vibration actuator according to a sixth aspect of the present disclosure, in the configuration described in the fifth aspect, includes a cylindrical bobbin that is provided in the case and covers an outer circumference of the pole piece, and the coil is configured to cover the bobbin. wrapped around the circumference.

In the vibration actuator according to the sixth aspect, the outer circumference of the pole piece is covered with a cylindrical bobbin provided in the case, and the coil is wound around the outer circumference of the bobbin. That is, the bobbin is arranged between the pole piece that constitutes the mover and the coil that constitutes the stator. This ensures insulation between the pole piece and the bobbin even when a strong external impact is applied to the case.

A vibration actuator according to a seventh aspect of the present disclosure is the configuration according to any one of the first to sixth aspects, wherein the mover is a connection arranged along the axial center of the case. It is supported by the elastic member via a member.

In the vibration actuator according to the seventh aspect, the mover that vibrates in the axial direction of the case is supported by the elastic members provided at one end and the other end in the axial direction of the case via the connecting member. As a result, the mover does not need to have a complicated shape for joining with the elastic member provided on the case side, so that the cost of the parts can be reduced.

A vibration actuator according to an eighth aspect of the present disclosure is the configuration according to the seventh aspect, wherein the case has a cylindrical extension portion arranged with a gap from the inner circumference, The connecting member is arranged inside the extending portion, and the outermost peripheral portion thereof is arranged to face the inner periphery of the extending portion in close proximity.

According to the vibration actuator according to the eighth aspect, the case has the cylindrical extension portion arranged with a gap from the inner circumference, and the connection member is arranged inside the extension portion. be done. Here, since the outermost peripheral portion of the connecting member is arranged to face the extending portion in close proximity, the outermost peripheral portion of the connecting member extends even when a strong external impact is applied to the case. It is possible to suppress the contact of the movable part with the coil by contacting the part.

A vibration actuator according to a ninth aspect of the present disclosure is configured according to the seventh aspect or the eighth aspect, wherein a tip portion of the connection member is inserted through a through hole formed through the elastic member. In addition, it is joined to the elastic member in a crushed and crimped state.

In the vibration actuator according to the ninth aspect, the connecting member is joined to the elastic member by crushing and crimping the distal end portion. Therefore, since additional parts such as screws for joining are not required to join the connection member and the elastic member, the cost of the parts can be reduced.

A vibration actuator according to a tenth aspect of the present disclosure is the configuration according to any one of the first to ninth aspects, wherein in the mover, the magnet and the yoke are bonded via an adhesive. At least one of the bonding surfaces facing each other is formed with a recess recessed in the bonding direction, and the recess extends along the outer periphery of the bonding surface and is configured to be able to accommodate a portion of the adhesive. .

In the vibration actuator according to the tenth aspect, the magnet and the yoke that constitute the mover are joined with an adhesive. At least one of the opposing bonding surfaces of the magnet and the yoke is formed with a concave portion recessed in the bonding direction. The recess extends along the outer periphery of the adhesive surface and is configured to accommodate a portion of the adhesive. As a result, when the magnet and the yoke are adhered, part of the remaining adhesive is pushed out to the outer peripheral side and accommodated in the recess. As a result, it is possible to suppress interference between the adhesive and the coil due to leakage of the surplus adhesive to the outside of the adhesive surface.

A vibration actuator according to an eleventh aspect of the present disclosure includes a cylindrical case, a coil provided in the case, elastic members provided at one end and the other end in the axial direction of the case, a magnet, and a yoke. and a mover that constitutes a magnetic driving unit together with the coil and vibrates along the axial direction of the case while being supported by the case via the elastic member, wherein the magnet vibrates in the vibration direction The yoke has a first magnet and a second magnet spaced apart from each other, and the yoke is partly sandwiched between the first magnet and the second magnet. Bonded in the direction of vibration.

In the vibration actuator according to the eleventh aspect, the coil provided in the cylindrical case constitutes the magnetic drive unit, and the movable actuator vibrates along the axial direction of the case while being supported by the case via the elastic member. have a child. The mover includes a magnet and a yoke, and the magnet has a first magnet and a second magnet spaced apart in the vibration direction. Here, the yoke is joined to the first magnet and the second magnet in the vibration direction so that a part of the yoke is sandwiched between the first magnet and the second magnet. As a result, the yoke constitutes a part of the mover and vibrates integrally with the magnet, so that the position of the magnet does not change with respect to the yoke. As a result, it is possible to prevent the axial center of the mover from shifting due to the magnetic force of the magnet, and to reduce the gap between the magnet and the yoke.

As described above, the vibration actuator according to the present disclosure has the excellent effect of preventing the shift of the axis of the mover and reducing the gap between the magnet and the yoke.

FIG. 2 is a partial cross-sectional perspective view of the vibration actuator according to the present embodiment, a part of which is cut along the axial centerline of the case. It is an exploded perspective view of a mover concerning this embodiment. FIG. 2 is a cross-sectional view of the vibration actuator according to the present embodiment cut along the axial centerline of the case; 4A and 4B are schematic diagrams for explaining the operation of the vibration actuator according to the present embodiment; FIG. 4 is a cross-sectional view corresponding to FIG. 3 showing an example of usage of the vibration actuator according to the present embodiment; FIG. It is a figure which shows the frequency of the vibration actuator which concerns on an Example, and the relationship of a displacement. It is a figure which shows the frequency of the vibration actuator which concerns on an Example, and the relationship of an acceleration. It is a figure which shows the frequency of the vibration actuator which concerns on an Example, and the relationship of excitation force. FIG. 4 is a cross-sectional view corresponding to FIG. 3 showing a first modification of the vibration actuator of the present embodiment; FIG. 4 is a cross-sectional view corresponding to FIG. 3 showing a second modification of the vibration actuator of the present embodiment; FIG. 8 is a cross-sectional view corresponding to FIG. 3 showing a third modification of the vibration actuator of the present embodiment; FIG. 11 is a cross-sectional view corresponding to FIG. 3 showing a fourth modification of the vibration actuator of the present embodiment; FIG. 11 is a cross-sectional view corresponding to FIG. 3 showing a fifth modification of the vibration actuator of the present embodiment; FIG. 11 is a cross-sectional view corresponding to FIG. 3 showing a sixth modification of the vibration actuator of the present embodiment; FIG. 10 is a schematic diagram corresponding to FIG. 4 showing the magnetization direction of a magnet, showing a seventh modification of the vibration actuator of the present embodiment;

A vibration actuator 1 according to the present embodiment will be described below with reference to FIGS. 1 to 5. FIG. 1 to 4 indicate the center line of the vibration actuator 1 in the vibration direction (axial direction).

As shown in FIGS. 1 to 3, the vibration actuator 1 of the present embodiment has a plane of symmetry S (see FIG. 3) perpendicular to the center line O at a half of the vibration direction (the center of the vibration direction). A member having the same shape is provided as a boundary. Accordingly, with respect to the configuration of each member, only one symmetrical configuration will be described, and the description of the other members will be omitted by denoting the same reference numerals unless there is a particular need. The term "center of the mover" refers to the center side of the mover in the vibration direction, and the inside and outside directions with the center line O as the axis are expressed as the inner circumference or the outer circumference with the center line O as the reference. do.

The vibration actuator 1 mainly includes a cylindrical case 10 forming an outer shell, a stator 20 provided inside the case 10, a mover 30 capable of vibrating by the stator 20, and a vibration axis of the mover 30. A plate spring 2 is provided to elastically support both ends in the direction with respect to the case 10 .

The case 10 includes a cylindrical case body 12 whose axial direction is the vibration direction of the vibration actuator 1, a cover case (not shown) that closes openings at both ends of the case body 12, and an inner peripheral portion near the opening of the case body 12. A coil frame 14 is provided. In this embodiment, the case main body 12, the cover case, and the coil frame 14 are each made of a resin material such as ABS, but the material is not limited to the resin material. A terminal (not shown) to which a lead wire is connected is formed on the outer surface of the case body 12 .

The coil frame 14 has an annular frame portion 14A provided along the opening of the case body 12. The frame portion 14A has a plurality of boss portions 16 protruding from the inner peripheral portion. In this embodiment, three boss portions 16 are provided at regular intervals along the circumferential direction of the frame portion 14A. The outer peripheral portion of the leaf spring 2 is arranged on the upper side of the frame portion 14A, and the leaf spring 2 is fixed to the coil frame 14 using a pin 18 crimped to the boss portion 16 . The case main body 12 and the frame portion 14A of the coil frame 14 may be joined by screws, adhesion, or welding.

Further, the coil frame 14 has an extension portion 14C formed through the stepped portion 14B inside the frame portion 14A. The extending portion 14C has a substantially cylindrical shape extending from the inner edge of the stepped portion 14B toward the center in the vibration direction, and has an outer diameter smaller than that of the frame portion 14A. The extending portion 14</b>C is arranged radially inward from the inner peripheral surface of the case body 12 with a gap therebetween, and supports the stator 20 on the outer peripheral side facing the inner periphery of the case body 12 .

The vibration actuator 1 includes a stator 20 provided inside the case 10 and a mover 30 that can be vibrated by the stator 20 to form an electromagnetic drive section.

The stator 20 has a bobbin 22 made of paper and a coil 24 fixed to the bobbin 22 . The bobbin 22 is fixed to the outer periphery of the extending portion 14C of the coil frame 14 using an adhesive, and has a substantially cylindrical shape extending from the extending portion 14C toward the center in the vibration direction. The coil 24 is wound along the outer periphery of the bobbin 22 and fixed to the bobbin 22 using an adhesive.

The coil 24 is arranged within the case 10 with a gap provided between it and the inner circumference of the case body 12 . Also, the coil 24 is arranged in a magnetic gap G between a yoke 32 and a pole piece 36, which will be described later. In order to prevent the pole piece 36 from coming into contact with the coil 24 during vibration, the bobbin 22 is supported by the coil frame 14 so as to cover the surface (outer circumference) of the pole piece 36 so that the inner circumference of the bobbin 22 and the pole piece are separated. A gap is provided between the outer circumference of 36 . A lead wire of the coil 24 is connected to a terminal (not shown) on the outer surface side of the case body 12 so that a magnetic field can be generated by energization from the terminal.

The mover 30 is arranged in the case body 12 so as to vibrate along the center line O direction, which is the axial direction of the cylindrical case 10 . The mover 30 includes a yoke 32 , a magnet 34 , a pole piece 36 and a connection member 40 . The magnet 34 , the pole piece 36 and the connection member 40 are arranged in this order inside the case body 12 from the center in the vibration direction toward the outside. Further, in this embodiment, the yoke 32 and the pole piece 36 are made of a metallic soft magnetic material, and the connection member 40 is made of a resin material such as ABS.

The yoke 32 is formed in a bottomed cylindrical shape that opens outward in the vibration direction, and includes a central portion 321 and side portions 322 . The central portion 321 has a disc shape and is arranged at the center of the case body 12 in the vibration direction. The side portion 322 has a cylindrical shape extending outward in the vibration direction from the outer edge of the central portion 321 . This yoke 32 and the yoke 32 on the other side arranged symmetrically with respect to the plane of symmetry S perpendicular to the direction of the center line O (vibration direction) are integrated by bonding their respective center portions 321 together. there is That is, by integrating the two yokes 32 arranged on one side and the other side with respect to the center of the vibration direction of the case body 12, the inside of the case body 12 has a substantially cross section along the vibration direction. An H-shaped yoke 32 is arranged.

The magnet 34 has a substantially disk shape and is arranged outside the central portion 321 of the yoke 32 in the vibration direction. Further, a disk-shaped pole piece 36 is arranged outside the magnet 34 in the vibration direction. The side portion 322 of the yoke 32 described above covers the outer periphery of the magnet 34 and the pole piece 36 and is arranged with a gap between the outer periphery of the magnet 34 and pole piece 36 and the inner periphery of the side portion 322 . A coil 24 of the stator 20 is arranged in a magnetic gap G formed between the pole piece 36 and the yoke 32 .

Here, the coil 24 has a region (first region) arranged in the magnetic gap G and a region (second region) exposed from the magnetic gap G in the vibration direction. Therefore, in a vibrating state in which the mover 30 is relatively displaced with respect to the coil 24, it is possible to secure the area of the coil arranged in the magnetic gap G and stabilize the magnetic flux penetrating the coil 24. can.

The magnetic gap G referred to here is a region where the outer circumference of the pole piece 36 and the inner circumference of the side portion 322 of the yoke 32 face each other.

As shown in FIG. 3, pole piece 36 is connected to the center of leaf spring 2 via connecting member 40 . The connection member 40 has a cylindrical shape whose axial direction is the vibration direction, and is arranged along the axial center of the case body 12 . The connecting member 40 is arranged coaxially with through

holes

361 and 21 formed through the pole piece 36 and the leaf spring 2 at the openings at both ends thereof. The pole piece 36 and the connection member 40 are fixed by inserting the first fixing pin 42 into the through hole 361 of the pole piece 36 and the opening of the connection member 40 from the center side in the vibration direction. The connection member 40 and the leaf spring 2 are fixed by inserting a second fixing pin 44 through the through hole 21 of the leaf spring 2 and the opening of the connection member 40 from the outside in the vibration direction. As a result, the mover 30 composed of the yoke 32 , the magnet 34 and the pole piece 36 is elastically supported by the case 10 via the plate spring 2 .

The symmetrical configuration inside the vibration actuator 1 will be described below. In the following description, the mover 30 arranged on one side with respect to the center of the vibration direction of the case 10 is referred to as a first mover 30A, and the yoke 32 constituting the first mover 30A is referred to as a first mover 30A. , the magnet 34 and the pole piece 36 will be referred to as a yoke 32A, a first magnet 34A and a first pole piece 36A, respectively. Further, the mover 30 arranged on the other side with respect to the center of the vibration direction of the case 10 is referred to as a second mover 30B. These will be referred to as two yokes 32B, second magnets 34B, and second pole pieces 36B. Also, the coil 24 arranged in the magnetic gap G of the first armature 30A will be referred to as the first coil 24A, and the coil 24 arranged in the magnetic gap G of the second armature 30B will be referred to as the second coil 24B. .

The vibration actuator 1 of this embodiment has a first mover 30A arranged on one side of the case 10 in the vibration direction and a second mover 30B arranged on the other side. The first movable element 30A and the second movable element 30B are arranged so as to form a symmetrical structure with respect to a plane of symmetry S perpendicular to the vibration direction, thereby forming a first magnet 34A of the first movable element 30A and a second movable element 30A. The second magnet 34B of the child 30B is arranged with an interval in the vibration direction. The center portions 321 of the yoke 32A and the second yoke 32B are joined to the first magnet 34A and the second magnet 34B in the vibrating direction so as to be sandwiched between the first magnet 34A and the second magnet 34B. That is, the yokes (yoke 32A, second yoke 32B) of the present embodiment are partially arranged so as to pass through the center of the magnet 34 (first magnet 34A, second magnet 34B) in the vibration direction. As a result, the first magnet 34A and the second magnet 34B, which constitute the magnetic drive section, are configured to vibrate in a state in which the relative positional relationship with the yoke 32A and the second yoke 32B is not displaced.

Here, the magnetization directions of the first magnet 34A and the second magnet 34B are the same along the vibration direction. Therefore, as indicated by arrows in FIG. 4, in the first mover 30A and the second mover 30B of the present embodiment, the magnetic lines of force of the second magnet 34B pass through the central portions 321 of the

yokes

32A and 32B. A magnetic circuit is formed that reaches the first magnet 34A, passes through the magnetic gap G, the side portion 322 of the yoke 32A, the side portion 322 of the second yoke 32B, and passes through the magnetic gap G. Therefore, each member arranged along the vibration direction is strongly connected by the magnetic adsorption force.

In this embodiment, since no repelling magnetic field is generated between the first mover 30A and the second mover 30B, magnetization can be performed after the first mover 30A and the second mover 30B are assembled.

As shown in FIG. 3, the vibration actuator 1 has a first leaf spring 2A attached to one axial end of the case 10 and a second leaf spring 2B attached to the other axial end. The first armature 30A and the second armature 30B are respectively supported by the first leaf spring 2A and the second leaf spring 2B via a connection member 40 arranged along the axial center (center line O) of the case 10. ing.

The connection member 40 may be made of a lightweight resin material such as ABS. Alternatively, a mass formed of a relatively heavy non-magnetic material such as metal or resin for adjusting the load mass between the first and

second movers

30A and 30B and the first and second plate springs 2A and 2B. may be configured as

The first leaf spring 2A and the second leaf spring 2B are composed of one or more metal leaf springs. For example, in this embodiment, a thin stainless steel plate is used. The material of the first leaf spring 2A and the second leaf spring 2B is not limited to metal, and may be a composite material containing resin or fiber. Moreover, the material of the first leaf spring 2A and the second leaf spring 2B may be any material that is excellent in durability and flexibility, and may be, for example, a coil spring. The first leaf spring 2A and the second leaf spring 2B correspond to the "elastic member" in the present disclosure.

Each of the first leaf spring 2</b>A and the second leaf spring 2</b>B has three arms 23 spirally extending from the central portion in the outer peripheral direction. The portion 14A and the boss portion 16 of the case body 12 are connected and supported.

In this embodiment, the first leaf spring 2A and the second leaf spring 2B are provided symmetrically with the plane of symmetry S as a boundary. The spiral directions of the arms 23 of these two leaf springs are opposite to each other. As a result, when the vibration actuator 1 vibrates, the first mover 30A and the second mover 30B receive torques in opposite directions from the first leaf spring 2A and the second leaf spring 2B, respectively, so that they vibrate in the vibration direction. does not rotate around the axis along the center line O.

The first leaf spring 2A and the second leaf spring 2B configured in this manner are elastically deformable within a predetermined range in the direction of vibration (the direction of the center line O) and in the plane direction of the plane of symmetry S orthogonal to the direction of vibration. This predetermined range corresponds to the amplitude range of the first mover 30A and the second mover 30B when the vibration actuator 1 is normally used. Therefore, the predetermined range is a range in which at least the first leaf spring 2A and the second leaf spring 2B do not contact the case 10, and a range in which the elastic deformation of the first leaf spring 2A and the second leaf spring 2B does not exceed the limit. .

(action and effect)

In the vibration actuator 1 configured as described above, the first and

second movers

30A and 30B, as shown in FIG. and the center of the

second coils

24A and 24B.

When vibrating the first and

second movers

30A and 30B, magnetic fields of opposite polarities are alternately applied to the first and

second coils

24A and 24B via terminals (not shown) provided on the outer surface of the case 10. AC power is applied in the direction of generation. That is, the same polarity is generated in the adjacent portions of the first and second coils 24B.

For example, in the case of the polarities shown in FIG. 4, the first and

second movers

30A and 30B generate a thrust toward the other vibration direction side (downward in FIG. 4) indicated by a solid arrow A, If the currents flowing through the

coils

24A and 24B are reversed, the first and

second movers

30A and 30B generate a thrust toward one vibration direction (upward in FIG. 4) indicated by the dotted arrow B.

Thus, when AC power is applied to the first and

second coils

24A and 24B, the first and

second movers

30A and 30B are biased by the first and second plate springs 2A and 2B from both sides. It vibrates along the direction of the center line O while receiving it.

By the way, the thrust generated in the first and second

movable elements

30A and 30B basically conforms to the thrust given based on Fleming's left-hand rule. In the present embodiment, since the first and

second coils

24A and 24B are fixed to the case 10, the first and

second movers

30A and 30B to which the first and

second magnets

34A and 34B are attached are connected to the first and

second movers

30A and 30B. Thrust is generated as a reaction force of the forces generated in the first and

second coils

24A and 24B. Therefore, the horizontal component of the magnetic flux of the first and

second magnets

34A and 34B (the component in the plane direction of the plane of symmetry S) contributes to the thrust. Since the first and

second yokes

32A, 32B increase the horizontal component of the magnetic flux of the first and

second magnets

34A, 34B, the first and

second magnets

34A, 34B and the first and

second yokes

34A, 34B Magnetic forces that attract each other act between the

yokes

32A and 32B.

Therefore, if the first and

second yokes

32A, 32B constitute a stator fixed to the case 10 side, the first and

second magnets

34A, 34B and the first and

second yokes

32A, 32B If the gap between them becomes too small, there is a possibility that the axial center of the mover 30 will shift due to the action of magnetic forces that attract each other. Therefore, in order to increase the thrust of the first and

second movers

30A, 30B, it is possible to reduce the gap between the first and

second magnets

34A, 34B and the first and

second yokes

32A, 32B. become difficult.

On the other hand, according to the present embodiment, the yoke 32 composed of the first and

second yokes

32A and 32B is partially aligned with the center of the vibration direction of the magnet 34 composed of the first and

second magnets

34A and 34B. As shown, it is joined to the magnet 34 in the vibration direction. Therefore, since the yoke 32 constitutes a part of the mover 30 and vibrates together with the magnet 34 , the position of the magnet 34 is not displaced with respect to the yoke 32 . As a result, the magnetic force of the magnet 34 prevents the axial center of the mover 30 from deviating, and the gap between the magnet 34 and the yoke 32 can be reduced.

Further, according to the present embodiment, the magnet 34 is composed of the first magnet 34A arranged on one side in the vibration direction with respect to the central portion 321 of the yoke 32 and the second magnet 34B arranged on the other side, By disposing a part of the yoke between two magnets spaced apart in the vibration direction, the magnet 34 is connected through the yoke 32 to the center of the vibration direction. As a result, the magnet 34 and the yoke 32 can be easily connected without requiring a complicated structure for passing the yoke through the center of the vibration direction of the magnet 34 .

Further, according to the present embodiment, since the magnetization directions of the first magnet 34A and the second magnet 34B are the same in the axial direction, the first magnet 34A is positioned across the center portion 321 of the yoke 32 passing through the center. and the second magnet 34B. As a result, the magnet 34 and the yoke 32 can be firmly connected using the magnetic attraction force, and the bonding strength between the members can be easily ensured.

Further, according to this embodiment, the yoke 32A and the second yoke 32B are connected and integrated to form one yoke 32 having an H-shaped cross section along the vibration direction. Therefore, the side portions 322 extend on one side and the other side in the vibration direction with respect to the central portion 321 of the yoke 32 passing through the center of the magnet 34 in the vibration direction, and cover the outer periphery of the magnet 34 . As a result, two magnetic gaps G can be formed on both sides in the vibrating direction across the central portion 321 of the yoke 32 . Conventional vibration actuators have a structure in which two coils are arranged spaced apart in the direction of vibration and each is arranged in two magnetic gaps in a case. However, since these generally form a magnetic gap by arranging one magnet at the center of the vibration direction, it is difficult to adjust the position of the magnetic gap in consideration of the vibration mass. On the other hand, by adopting a configuration in which two magnetic gaps G can be formed on both sides in the vibration direction across the central portion 321 of the yoke 32, the plate thickness of the central portion 321 of the yoke 32 can be changed to vibrate. The mass and the position of the magnetic gap G can be easily adjusted.

In this embodiment, the pole piece 36 is arranged outside the magnet 34 in the vibration direction, and the coil 24 is arranged in the magnetic gap G formed between the pole piece 36 and the yoke 32. . Here, the coil 24 has a first region located within the magnetic gap G and a second region exposed from the magnetic gap G in the vibration direction. As a result, in a vibrating state in which the mover 30 moves relative to the coil 24, the area of the coil 24 arranged in the magnetic gap G can be secured, and the magnetic flux passing through the coil 24 can be stabilized. can be done. Further, even if the displacement of the mover 30 increases due to an increase in the vibration mass, the same structure can be used.

Further, according to this embodiment, the outer circumference of the pole piece 36 is covered with the cylindrical bobbin 22 provided on the case 10 , and the coil 24 is wound around the outer circumference of the bobbin 22 . That is, the bobbin 22 is arranged between the pole piece 36 forming the mover 30 and the coil 24 forming the stator 20 . Thereby, even when a strong external impact is applied to the case 10, insulation between the pole piece 36 and the bobbin 22 can be ensured.

Further, in this embodiment, the mover 30 vibrating in the axial direction of the case 10 is the first plate provided at one end and the other end of the case 10 in the axial direction via the connection member 40 without interposing a mass. It is elastically supported by the spring 2A and the second leaf spring 2B. As a result, the vibration actuator 1 does not require a mass having a complicated shape in consideration of weight and balance characteristics, so that the cost of parts can be reduced.

Further, in this embodiment, a first mover 30A having a yoke 32A, a first magnet 34A and a first pole piece 36A, and a second mover having a second yoke 32B, a second magnet 34B and a second pole piece 36B The mover 30 is configured by 30B. Here, the first movable element 30A and the second movable element 30B are arranged so that the yoke 32A and the second yoke 32B are opposed to each other on the center side of the vibration direction of the case 10 and joined to form a symmetrical structure in the vibration direction. ing. As a result, common functional parts can be shared between the first mover 30A and the second mover 30B, and the cost of parts can be reduced. Also, assembly can be facilitated.

Furthermore, the vibration actuator 1 of this embodiment can be implemented in various applications. For example, it can be used for vibration of terminals such as portable terminals such as mobile phones and smart phones, controllers for game machines, facial beauty devices, massage devices and the like, and terminals such as diaphragm pumps. The amplitude (displacement amount) of the first and

second leaf springs

2A and 2B according to the present embodiment can be increased by changing the hardness of these leaf springs to make them more elastically deformable. Therefore, as in the example shown in FIG. 5, by fixing the tip of the connection member 50 that connects the first armature 30A and the first plate spring 2A to the diaphragm 70 made of an elastic material, the reciprocating motion of the diaphragm 70 is suppressed. can be used as an actuator for

In the example shown in FIG. 5, the tip of the connection member 50 is connected to the center of the diaphragm 70 fixed to the housing 60. A suction opening 62 is formed in the upper surface of the housing 60 facing the diaphragm 70. When the vibration actuator 1 is operated, the diaphragm 70 is displaced to the other side of the vibration direction (downward in FIG. 5). , external air is sucked from the opening 62 of the housing 60 . Thus, the vibration actuator 1 of this embodiment can also be used for gas suction. In addition, in FIG. 5, some reference numerals are omitted in order to make the drawing easier to understand.

In addition, to supplement the connection member 50 , the connection member 50 is configured by a first connection member 52 and a second connection member 54 arranged along the axial center of the case 10 . The first connection member 52 has a columnar shape whose axial direction is the vibration direction, and is arranged between the first mover 30A and the first leaf spring 2A. The first connecting member 52 is mechanically joined to the first pole piece 36A using the first fixing pin 42 in the same manner as the connecting member 40 of the above-described embodiment, at the end on the center side in the vibration direction. A projecting portion 521 that is inserted into the through hole 21 of the first plate spring 2A and protrudes outward in the vibration direction is formed at the end portion of the first connection member 52 on the outside in the vibration direction. The second connecting member 54 has a columnar shape with an axial direction in the vibration direction, and a concave portion 541 provided corresponding to the protrusion 521 of the first connecting member 52 is formed at the end on the center side in the vibration direction. there is The first connection member 52 and the second connection member 54 are fixed with the protrusion 521 inserted into the recess 541 so as to sandwich the first plate spring 2A.

[Example]
In order to confirm the effect of the present invention for each actuator application, the inventors conducted a conventional vibration actuator ( For example, the vibration actuator described in International Publication WO 2020/175610), the vibration actuator 1 corresponding to FIGS. 1 to 3 designed for vibration applications, and the drawings designed for suction applications. 5, frequency (Frequency [Hz]) - displacement (Displacement [mm]), frequency (Frequency [Hz]) - acceleration (Acceleration [m / ss]) and frequency (Frequency [Hz ])-exciting force (Forces [N]) relationship was investigated. The results are shown in FIGS. 6 to 8. FIG.

6 to 8, the conventional vibration actuator is indicated by solid lines, the vibration actuator 1 designed for vibration applications is indicated by dashed lines, and the vibration actuator designed for suction applications is indicated by broken lines. 1 is indicated by a dashed line.

In each example, the input power was set to 1 [W], and the two coils that make up the stator had the same performance. Further, the connection member 40 of the above-described embodiment, which is made of a resin material, is changed to be made of a metal soft magnetic material, and the connection member 40 is configured as a mass having a load mass of 100 [g]. Furthermore, in the vibration actuator 1 for vibration and the vibration actuator 1 for attraction, the vibration mass (yoke, magnet, pole piece, and mass sum) is set larger than in the conventional example, and the magnetic Gap G is set small.

The only structural difference between the vibration actuator 1 for vibration and the vibration actuator 1 for suction is the mechanical compliance value (indicated by the reciprocal of the spring constant) of the first and

second leaf springs

2A and 2B. The mechanical compliance value is set to 0.50 [mm/N] for the vibration actuator 1 for vibration, and is set to 1.25 [mm/N] for suction.

As shown in FIG. 6, in the suction vibration actuator 1 indicated by the dashed line, the mechanical compliance values of the first and

second leaf springs

2A and 2B are set larger than those for vibration, and soft springs are used. Therefore, it can be seen that the displacement amount exceeds the conventional example and the vibration actuator in the low frequency band of 40 [Hz] or less.

As shown in FIG. 7, in the vibration actuator 1 for vibration indicated by the dashed line, the vibration mass exceeds that of the conventional example, and the peak value of acceleration exceeds that of the other examples.

As shown in FIG. 8, in the vibrating vibration actuator 1 indicated by the dashed line and the conventional example indicated by the solid line, even though the mass load is common, the vibrating mass including the mass of the yoke, magnet, and pole piece: Since the vibration actuator 1 for vibration exceeds that of the conventional example, it can be seen that the magnitude of the excitation force exceeds that of the conventional example.

[supplementary explanation]
Although the vibration actuator 1 of the present embodiment has been described above, the configuration of each part can be changed or combined without changing the gist thereof. Further, the present disclosure is not limited to the above embodiment, and configurations according to modifications shown in FIGS. 9 to 11 may be applied. 9 to 11 basically follow the configuration of the vibration actuator 1 according to the above-described embodiment, except for some deformed members. Therefore, in order to make the drawings easier to understand, some reference numerals are omitted in each drawing.

(First modification)
In the above-described embodiment, the central portions 321 of the first and

second yokes

32A and 32B are directly sandwiched between the first magnet 34A and the second magnet 34B, but the present disclosure is not limited to this. Like the mover 80 (80A, 80B) according to the first modification shown in FIG. 9, the central portions 321 of the first and

second yokes

32A, 32B are connected to the first magnet 34A and the second magnet via members. It may be configured to be sandwiched between 34B. In this first modification, a disk-shaped intermediate pole made of a metallic soft magnetic material is placed between the center portions 321 of the first and

second yokes

32A and 32B and the first and

second magnets

34A and 34B. A piece 82 is placed. In the above configuration, the position of the mover 80 along the vibration direction can be adjusted using a soft magnetic material with a simple shape, such as the intermediate pole piece 82. Therefore, the height of the magnetic gap with respect to the coil 24 can be adjusted. Easy. In addition, by providing the intermediate pole piece 82, it is possible to ensure the distance between the tip of the stator 20 and the central portions 321 of the first and

second yokes

32A and 32B. The mover 80 can be vibrated at a position where it does not interfere with 32A and 32B.

(Second modification)
In the above embodiment, the yoke 32A and the second yoke 32B, each of which is formed in a cylindrical shape with a bottom, are used to integrate the central portions 321 of the

yokes

32A and 32B, thereby forming a yoke having an H-shaped cross section. The present disclosure is not limited to this. The yoke 32A and the second yoke 32B may be integrally formed to form one component. That is, like the mover 90 according to the second modification shown in FIG. A yoke 92 having an H-shaped cross section in the vibrating direction may be formed by integrally forming a side portion 96 extending vertically.

Further, in the above embodiment, the first and

second pole pieces

36A, 36B and the connection member 40 are configured as separate members. A configuration in which the piece and the connection member are integrally formed may be used. In the pole piece 100 according to the second modification, a columnar connecting portion 104 erected along the axial center of the case 10 is integrally formed with a disk-shaped body portion 102 . The connecting portion 104 is connected to the first and

second leaf springs

2A and 2B by inserting the second fixing pin 44 into a concave portion 104 formed at the tip thereof.

(Third modification)
Further, in the above-described embodiment, the connection member 40 that connects the mover 30 and the plate spring 2 is formed in an elongated cylindrical shape, but the present disclosure is not limited to this. In this third modification, the connecting member 110 includes a cylindrical connecting portion 112, a bottom portion 114 that extends radially from the end of the connecting portion 112 on the center side in the vibration direction, and a bottom portion 114 extending outward in the vibration direction from the outer edge of the bottom portion 114. and a cylindrical outer peripheral wall portion 116 erected on the wall. An outer peripheral wall portion 116 forming the outermost peripheral portion of the connection member 110 is arranged to face the extending portion 14C of the coil frame 14 in close proximity. Therefore, even when an external impact or the like is applied to the vibration actuator 1, the outer peripheral wall portion 116 of the connecting member 110 contacts the extending portion 14C of the coil frame 14, thereby suppressing the contact between the mover 30 and the coil 24. can do. At this time, the size of the gap between the outer peripheral wall portion 116 of the connecting member 110 and the extension portion 14C is set to the size of the gap between the side portion 322 of the yoke 32 constituting the mover 30 and the coil 24. By setting it to be smaller than the height, contact between the mover 30 and the coil 24 can be reliably prevented.

(Fourth modification)
5, the configuration of the suction vibration actuator 1 fixed to the diaphragm 70 using the connection member 50 has been described. Actuators can be configured. A diaphragm 70 is fixed to the bottom surface of the housing 122 of the diaphragm pump 120 , and the volume of the internal chamber C can be changed by deformation (vibration) of the diaphragm 70 . A first channel 124 and a second channel 126 communicating with the chamber C are formed in the housing 122, and a suction valve 130 is attached to the first channel 124, as shown in FIG. , when the diaphragm 70 is displaced in the direction of increasing the volume of the chamber C, the suction valve 130 opens to enter the intake cycle. A discharge valve 140 is attached to the second flow path 126, and as shown in FIG. It opens and becomes a cycle of ejection.

(Fifth Modification)
Further, in the above embodiment, the mover 30 (30A, 30B) and the connection member 40, and the connection member 40 and the plate spring 2 (2A, 2B) are joined via the first and second fixing pins 42, 44, respectively. However, the present disclosure is not limited to this. As shown in FIG. 13, the connection may be made without using fixing pins or screws.

That is, in the vibration actuator 200 shown in FIG. 13, the connection member 250 and the pole piece 240 of the mover 210 (210A, 210B) are fixed using the adhesive 260. Further, the connection member 250 and the leaf spring 2 are inserted through the through hole 21 formed through the tip portion 250A of the connection member 250 at the axial center of the leaf spring 2, and are crushed and crimped to form the leaf spring. 2 is joined. As a result, additional parts such as screws for joining are not required to join the connection member 250, the leaf spring 2, and the mover 210, so that the cost of the parts can be reduced.

Furthermore, in the vibration actuator 200, the case body 302, the coil frame 304, the coil frame 304, and the cover case 306, which constitute the case 300, are joined together using an adhesive (not shown). Since the yoke 220, the magnet 230, and the pole piece 240 that constitute the mover 210 are bonded together using the adhesive 260, the vibration actuator 200 can be assembled without using screws or pins for bonding.

Here, the yoke 220 of the mover 210 has a substantially E-shaped cross section along the vibration direction of the mover (center line O direction). The yoke 220 has a disk-shaped center portion 221 forming a bottom portion, a cylindrical side portion 222 erected from the outer edge of the center portion 221 , and a cylindrical side portion 222 erected from the center portion 221 inside the side portion 222 . and a cylindrical middle column portion 223 formed integrally therewith. That is, the yoke 220 according to the fifth modification corresponds to a structure in which the yoke 32 (32A, 32B) and the intermediate pole piece 82 of the first modification shown in FIG. 9 are integrally formed. Therefore, basically, since the configuration of the mover 80 (80A, 80B) according to the first modified example is followed, the same effects can be obtained. Also, by integrally forming a member corresponding to the intermediate pole piece 82 with the yoke 220, the number of parts can be reduced.

Also, in the yoke 220 and the pole piece 240 of Modification 5, a concave portion 270 recessed in the bonding direction is formed on the bonding surface facing the magnet 230 . The recessed portion 270 extends along the outer periphery of the bonding surface, and is formed in a ring shape in this embodiment. When the magnet 230 and the yoke 220 and the magnet 230 and the pole piece 240 are respectively adhered, part of the surplus adhesive 260 is pushed out to the outer peripheral side of the adhesion surface and accommodated in the concave portion 270 . In this way, it is possible to prevent the surplus adhesive from leaking out of the bonding surface, so that there is no fear of interference between the surplus adhesive and the coil. Thereby, the magnetic gap G of the mover 210 can be set small.

It should be noted that in Modification 5, the recess 270 is formed in the bonding surface of the yoke 220 and the pole piece 240, but the present invention is not limited to this. The concave portion 270 may be provided on at least one of the adhesive surfaces facing each other in the yoke 220 , the magnet 230 , and the pole piece 240 , or the concave portion 270 may be provided on the adhesive surface of the magnet 230 .

(Sixth modification)
Further, in the fifth modified example, the yoke 220 is provided with the central column portion 223 to adjust the position of the mover 80 along the vibration direction, but the present invention is not limited to this. As in the sixth modification shown in FIG. 14, the position of the mover 80 is adjusted by placing a plate-like spacer 280 between two yokes 220 spaced apart along the vibration direction. may The spacer 280 may be made of a nonmagnetic material that does not constitute the magnetic circuit, or may be made of a soft magnetic material and constitutes a part of the magnetic circuit together with the yoke 220 . Note that the sixth modification has the same configuration as the fifth modification except that a plate-shaped spacer 280 is arranged between the two yokes 220, so detailed description will be omitted. In addition, in FIG. 14, some reference numerals are omitted for easier understanding of the drawing.

(Seventh Modification)
In the above embodiment, the magnetization directions of the first magnet 34A and the second magnet 34B are set in the same direction along the vibration direction, but the present disclosure is not limited to this. As in the seventh modification shown in FIG. 15, the magnetization directions of the first magnet 34A and the second magnet 34B can be magnetized in opposite directions along the vibration direction. In this case, as indicated by the arrow in FIG. 15, the first magnet 34A forms a magnetic circuit passing through the first pole piece 36A, the magnetic gap G, and the yoke 32A. Further, a magnetic circuit is formed through the second pole piece 36B, the magnetic gap G, and the second yoke 32B by the second magnet 34B.

In the magnetic circuit described above, the second magnet 34B acts as a repulsive magnet for the first magnet 34A, and magnetic leakage can be suppressed. Although a repelling magnetic field is generated between the first yoke 32A and the second yoke 32B, the thickness of the central portion 321 is ensured, thereby increasing the mechanical strength when the first yoke 32A and the second yoke 32B are joined. can be ensured. Also, the first mover 30A and the second mover 30B can be assembled by magnetizing the first magnet 34A and the second magnet 34B in advance and then joining them with an adhesive or the like.

In addition, in each of the above-described embodiments and modified examples, the dimensions and shapes of the yokes, magnets, and pole pieces are configured to be the same for the first mover 30A and the second mover 30B, but this is not essential. In other words, it is not essential to arrange the mover 30 of the magnetic drive unit in a symmetrical structure with respect to the center of the vibration direction. For example, the sizes of the first magnet 34A and the second magnet 34B are different. may be configured.

Also, in the present embodiment, the first yoke 32A and the second yoke 32B are arranged inside the case 10, but the present disclosure is not limited to this. That is, since at least one yoke is provided at the center of the mover and is joined to the magnet in the vibration direction, the second yoke 32B, the second pole piece 36B, and the second coil are installed from the inside of the case 10. 24B may be omitted.

In the above embodiment and each modified example, the coil 24 has a region (first region) arranged in the magnetic gap G and a region (second region) exposed from the magnetic gap G in the vibration direction. However, the present disclosure is not limited to this. A configuration in which the coil length in the axial direction of the wound coil is set short and the entire coil is arranged in the magnetic gap G may be employed. Even in this configuration, by setting the coil length short, the entire coil can be placed in the magnetic gap G even during vibration of the mover. can be reduced.

The disclosure of Japanese Patent Application No. 2021-178095 filed on October 29, 2021 is incorporated herein by reference in its entirety.
All publications, patent applications and technical standards mentioned herein are to the same extent as if each individual publication, patent application and technical standard were specifically and individually noted to be incorporated by reference. incorporated herein by reference.

Claims

a tubular case,
a coil provided in the case;
elastic members respectively provided at one end and the other end in the axial direction of the case;
a mover that includes a magnet and a yoke, constitutes a magnetic driving unit together with the coil, and vibrates along the axial direction of the case while being supported by the case via the elastic member;
In the mover, the yoke is provided at the center of the mover,
vibration actuator.
In the mover, the magnets are arranged at intervals in the vibration direction, and consist of a first magnet arranged on one side of the yoke in the vibration direction and a second magnet arranged on the other side of the yoke in the vibration direction. 2. The vibration actuator of claim 1, comprising:
3. The vibration actuator according to claim 2, wherein the first magnet and the second magnet are magnetized in the same direction along the vibration direction in the mover.
In the mover, the yoke has a side portion extending to one side and the other side of the center portion of the mover and covering an outer circumference of the magnet. A vibration actuator according to any one of the preceding paragraphs.
The mover further comprises a pole piece arranged outside in the vibration direction with respect to the magnet,
the coil is arranged between the pole piece and the yoke on the outer peripheral side of the magnet, a first region arranged in a magnetic gap formed between the pole piece and the yoke; 5. The vibration actuator of claim 4, comprising a second region exposed from the magnetic gap in a direction.
A cylindrical bobbin provided in the case and covering the outer periphery of the pole piece,
6. The vibration actuator according to claim 5, wherein the coil is wound around the bobbin.
The vibration actuator according to any one of claims 1 to 6, wherein the mover is supported by the elastic member via a connection member arranged along the axial center of the case.
The case has a cylindrical extension that is arranged with a gap from the inner circumference,
8. The vibration actuator according to claim 7, wherein said connecting member is arranged inside said extending portion, and the outermost peripheral portion of said connecting member is arranged so as to closely face the inner periphery of said extending portion.
9. The connecting member according to claim 7 or 8, wherein the tip portion of the connecting member is inserted through a through-hole formed through the elastic member and joined to the elastic member in a crushed and crimped state. A vibration actuator as described.
In the mover, the magnet and the yoke are joined with an adhesive, and at least one of the mutually facing adhering surfaces is formed with a recess recessed in the adhering direction,
10. The vibration actuator according to any one of claims 1 to 9, wherein the recess extends along the outer periphery of the adhesive surface and is configured to accommodate a portion of the adhesive.
a tubular case,
a coil provided in the case;
elastic members respectively provided at one end and the other end in the axial direction of the case;
a mover including a magnet and a yoke, forming a magnetic driving unit together with the coil, and vibrating along the axial direction of the case while being supported by the case via the elastic member;
The magnet has a first magnet and a second magnet spaced apart in the vibration direction,
The yoke is joined to the first magnet and the second magnet in the vibration direction such that a part of the yoke is sandwiched between the first magnet and the second magnet.
vibration actuator.