WO2019102704A1

WO2019102704A1 - Linear vibration motor and electronic apparatus

Info

Publication number: WO2019102704A1
Application number: PCT/JP2018/034961
Authority: WO
Inventors: 片田　好紀; 大祐福田
Original assignee: 日本電産コパル株式会社
Priority date: 2017-11-22
Filing date: 2018-09-21
Publication date: 2019-05-31
Also published as: JP7079590B2; JP2019093336A

Abstract

The present invention reduces a leakage magnetic flux and suppresses swinging of a movable element in the intersecting direction with respect to a desired vibration direction. The present invention is provided with: a movable element 10 integrally having a weight body 11 and a coil 12; an elastic body 20 that supports the movable element 10 such that the movable element can vibrate; a first magnet 30 that faces the coil 12 on one side in the intersecting direction with respect to the vibrating direction of the movable element 10; a second magnet 40 that faces the coil 12 on the other side in the intersecting direction; and magnetic members 51, 52 that fix the magnets, respectively. The movable element 10 is vibrated due to a magnetic force that is generated when the coil 12 is energized.

Description

Linear vibration motor and electronic equipment

The present invention relates to a linear vibration motor and an electronic device provided with the linear vibration motor.

A vibration motor (or vibration actuator) is incorporated in a portable electronic device, widely used as a device for transmitting a signal such as an incoming call or an alarm to a portable person by vibration, and it is used in wearable electronic devices worn and carried by a portable person. Has become an essential device. The vibration motor is a device that realizes haptics (skin sensory feedback) in a human interface such as a touch panel.

While various forms of such vibration motors have been developed, a linear vibration motor that can generate relatively large vibrations due to linear reciprocating vibration of the mover has attracted attention.
For example, as described in Patent Document 1, a conventional linear vibration motor includes a mover integrally including a weight and two magnets, a leaf spring that vibratably supports the mover, and a mover. The coil has a coil facing the magnet on one side in a direction intersecting with the vibration direction, and the mover is reciprocally vibrated by the Lorentz force when the coil is energized. The two magnets are formed in a flat rectangular parallelepiped shape, and the plane side of one of the magnets is an N pole, whereas the plane side of the other magnet is an S pole.

JP 2017-18958 A

By the way, in the above-mentioned conventional linear vibration motor, the magnetic flux of the magnet integrated with the mover may leak out of the case and adversely affect external devices (for example, a transceiver, a SIM card, etc.). Therefore, it is conceivable to magnetically shield the case by using a magnetic material, but in such a case, the magnet is magnetically attracted to the case, and the mover oscillates in the cross direction with respect to the desired vibration direction, It may cause contact noise or vibration noise.
Further, in the conventional linear vibration motor described above, when the magnet is displaced with respect to the coil due to the movement of the mover accompanying the vibration, the direction of magnetic force lines of the magnet orthogonal to the current direction changes with respect to the current direction of the coil A Lorentz force in the cross direction with respect to the vibration direction is generated, and the Lorentz force may cause the mover to move in the cross direction, which may impair the noise reduction and the durability.

In order to solve such a subject, the present invention comprises the following composition.
A mover integrally including a weight and a coil, an elastic body that vibratably supports the mover, and a first magnet facing the coil on one side in a direction intersecting with the vibration direction of the mover; The second magnet facing the coil on the other side in the same cross direction and a magnetic member for fixing each magnet are provided, and the mover is vibrated by the magnetic force generated when the coil is energized. Linear vibration motor.

It is an exploded perspective view showing an example of a linear vibration motor concerning the present invention. It is the longitudinal cross-sectional view which cut | disconnected the linear vibration motor in the center part of the transversal direction. It is the longitudinal cross-sectional view which cut | disconnected the linear vibration motor in the center part of the longitudinal direction. It is a top view which shows the state which removed the cover member and the magnetic member about the linear vibration motor. It is a perspective view which shows the state which removed the cover member and the magnetic member about the linear vibration motor. It is a schematic diagram which shows the effect | action of the linear vibration motor, (a) shows an initial state, (b) shows the state which the needle | mover (coil) moved. It is a perspective view which shows an example of an electronic device. About the other example of the linear vibration motor which concerns on this invention, it is a schematic diagram which shows an effect | action, (a) shows an initial state, (b) shows the state which the needle | mover (coil) moved. It is a perspective view which shows the state which removed the cover member and the magnetic member about the other example of the linear vibration motor which concerns on this invention. It is a perspective view which shows the state which removed the cover member and the magnetic member about the other example of the linear vibration motor which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals in different drawings denote portions having the same functions, and redundant description in each drawing will be appropriately omitted.

As shown in FIGS. 1 to 6, the linear vibration motor 1 includes a mover 10 integrally including a weight 11 and a coil 12, an elastic body 20 that vibratably supports the mover 10, and a mover 10. A first magnet 30 facing the end face of the coil 12 on one side orthogonal to the vibration direction (the X direction according to the illustrated example) and a coil 12 end face on the other side of the orthogonal direction And

magnetic members

51 and 52 which fix the first and

second magnets

30 and 40 from both sides in the orthogonal direction, and flexible to supply power to the coil 12 Power supply wiring 60 and a cover member 70 covering these members, and when the coil 12 is energized, the mover 10 is reciprocated linearly in one axial direction due to the magnetic force generated.

The mover 10 is formed by integrally fixing the coil 12 to the weight 11.

The weight 11 is made of a metal material (for example, tungsten) having a high specific gravity, and according to the illustrated example, is formed in a frame shape elongated in the vibration direction. And the hollow part 11a which opened one side and the other side of the thickness direction orthogonal to a vibration direction is provided in the planar view center side of this weight 11. As shown in FIG. Moreover, the coil fixing | fixed part 11b is formed in the side wall of the both sides which comprise the weight 11. As shown in FIG.

In the hollow portion 11a, the first magnet 30 is inserted into the opening on one side and the second magnet 40 is inserted into the opening on the other side, and weights around the first magnet 30 and the second magnet 40 A space for vibrating the body 11 is secured (see FIGS. 2 to 4).
The first magnet 30 and the second magnet 40 are inserted into the hollow portion 11a in a non-contact state with play in the vibration direction.

Two coil fixing portions 11 b are provided so as to be respectively positioned on one side wall and the other side wall of the weight 11. Each coil fixing portion 11 b is a concave portion formed in the side wall of the weight 11, and the side end of the coil 12 is mounted.

The coil 12 is a flat air core coil in which one half side 12a and the other half side 12b sandwiching the air core are disposed on both sides in the vibration direction, and the central axis thereof is in the thickness direction of the weight 11 It fixes and fixes to the approximate center of the vibration direction and thickness direction of the weight 11 so as to substantially match.
More specifically, the coil 12 is provided in the form of a bridge across the hollow portion 11a, and one end side and the other end side thereof are respectively fitted to the coil fixing portions 11b of the weight 11 and fixed by adhesion.

Two elastic bodies 20 are provided point-symmetrically in a plan view on one end side and the other end side of the movable element 10 in the vibration direction.
Each elastic body 20 is a plate spring in which an elastically bendable plate is formed in a predetermined bending shape, and according to an example shown in FIG. 4, fixed to the outer surface of the weight 11 near the end in the vibration direction Connecting pieces that connect the one end sides of the

fastening pieces

21 and 22, and the fastening pieces 22 fastened to the inner surface of the side wall 72 (or 73) of the cover member 70; And is formed in a U-shape in plan view along the end side of the weight 11 in the vibration direction.
The elastic body 20 elastically bends and deforms a bent portion between the fastening piece 21 and the connecting piece 23 and a bending portion between the connecting piece 23 and the fastening piece 22.

The first magnet 30 has a magnet piece 31 in which one magnetic pole (for example, the N pole) is opposed to one half side 12a of the coil 12 (the left half side according to FIG. 2) The magnetic pole (for example, S pole) is comprised from the magnet piece 32 which made the other half part side 12b (according to FIG. 2 right half part side) of the coil 12 be opposite.
The two

magnet pieces

31 and 32 are permanent magnets of the same shape and of the same material, and are disposed at intervals in the vibration direction so that the magnetic poles are reverse as described above. The

magnet pieces

31 and 32 are adhered and fixed to the coil side surface of the magnetic member 51 with a predetermined clearance between the

magnet pieces

31 and 32 and the end surface of the coil 12.

Further, the second magnet 40 is disposed point-wise so that the direction of the magnetic pole is reversed with respect to the first magnet 30 in the cross direction to the vibration direction (the thickness direction of the weight 11 according to the illustrated example). It consists of the two magnet pieces 41 and 42 (refer FIG. 2).
The

magnet pieces

41 and 42 are the same members as the

magnet pieces

31 and 32, and a predetermined clearance is secured between the

magnet pieces

31 and 32, and the

magnet pieces

41 and 42 are adhered and fixed to the coil side surface of the magnetic member 52.

The

magnetic members

51 and 52 are flat plate-like magnetic materials (iron, magnetic stainless steel, etc.) covering the surfaces of the first magnet 30 and the second magnet 40 on the opposite coil side (in other words, the opposite side to the coil side) While increasing the magnetic force of each of the

magnets

30 and 40 and preventing the magnetic flux from leaking to the side opposite to the coil.
The surface of the one magnetic member 51 on the side opposite to the coil is adhered and fixed to the inner surface of the cover member 70.
The other magnetic member 52 is fixed to cover the opening of the cover member 70 and also functions as a case member.

Further, the feed wiring 60 is a flexible electric wiring material for supplying power to the coil 12, and according to a preferred example of the present embodiment, a tape-like flexible wiring substrate (TAB (Tape Automated Bonding) and (It may be called).
The feed wiring 60 is provided along one elastic body 20 (a plate spring) so as to be bent along with the vibration of the mover 10. According to an example shown in FIG. 4 and FIG. 5, the feed wire 60 is superimposed in a substantially L shape on the outer surfaces of the fastening piece 21 and the connecting piece 23 of the elastic body 20. The other end side terminal is exposed to the outside from between the cover portion 51 and the base portion 52.

The cover member 70 is formed in a box shape with a lower opening, and has a rectangular top wall 71,

side walls

72 and 73 projecting downward from both ends of the top wall 71, and front and rear of the top wall 71. It has a front wall 74 and a rear wall 75 protruding downward from the end.
The cover member 70 is connected to the peripheral end of the magnetic member 52 so as to cover the above-described members.

Next, the characteristic operation and effect of the linear vibration motor 1 having the above-described configuration will be described in detail.
First, in an initial state in which the coil 12 is not energized, the mover 10 is biased approximately equally by the elastic members 20 on both sides, and is positioned approximately at the center of the cover member 70. Therefore, as shown in FIG. 6A, the half side 12a of the coil 12 is positioned between the magnet piece 31 of the first magnet 30 and the magnet piece 42 of the second magnet 40, and The other half 12 b of the coil 12 is positioned between the magnet piece 32 of the first magnet 30 and the magnet piece 41 of the second magnet 40.

In the initial state, when AC power is supplied to the coil 12, the mover 10 reciprocates in the X direction and the anti-X direction by the magnetic action between the coil 12 and the first magnet 30 and the second magnet 40. Vibrate.
The magnetic flux generated during the reciprocation is magnetically shielded by the

magnetic members

51 and 52 and hardly leaks to the outside.

More specifically, as shown in FIG. 6A, when a current in one direction flows through the coil 12, the direction (anti-Y direction) of the current on the half side 12a of the coil 12 and the magnet piece 31 And the direction of the line of magnetic force M1 between the magnet pieces 42 and the direction (Y direction) of the current on the other half 12b of the coil 12 and the direction of the line of magnetic force M2 between the

magnet pieces

32 and 41 According to the relationship, Lorentz force in the X direction is generated in the coil 12, and the mover 10 moves in the X direction. When a current in the reverse direction flows through the coil 12, the moving direction of the mover 10 is reversed.

During movement of the coil 12 in one direction as described above, as shown in FIG. 6B, the half-portion side 12a of the coil 12 includes one

magnet piece

31 or 42 and the

other magnet piece

32 or 41 in the vibration direction. And the direction of the magnetic lines of force M3 between the

magnet pieces

31 and 32 on both sides of the first magnet 30 is the X direction with respect to the direction (anti-Y direction) of the current flowing through the half side 12a. Therefore, a Lorentz force in the Z direction is generated on the half side 12a, but the direction of the magnetic line of force M4 between the

magnet pieces

41 and 42 on both sides of the second magnet 40 is the anti-X direction. An anti-Z direction Lorentz force is also generated on the side 12a, and these two opposite Lorentz forces are offset. Therefore, the mover 10 can be prevented from swinging in the Z direction or the anti-Z direction while moving in the one direction.

Therefore, according to the linear vibration motor 1 configured as described above, it is possible to reduce the leakage magnetic flux, and in addition, it is possible to suppress the swing of the mover 10 in the direction crossing the desired vibration direction. Can be smoothly reciprocated in a straight line, and the movement of the mover 10 can be stabilized and the noise can be reduced.

Next, an electronic device provided with the linear vibration motor 1 will be described.
FIG. 7 exemplifies a portable information terminal 100 as an electronic device provided with the linear vibration motor 1 according to the embodiment of the present invention.
The portable information terminal 100 is configured to vibrate the linear vibration motor 1 according to the reception of an external signal, the touch operation of a touch operation panel (including a touch display), etc., and the leakage of magnetic flux from the linear vibration motor 1 In addition to reducing adverse effects on the handset and SIM card, it is possible to reduce noise and noise when the linear vibration motor 1 vibrates.

In addition, as another example of the electronic device on which the linear vibration motor 1 is mounted, a wearable computer, a tablet personal computer, a game machine, or the like may be used other than the illustrated example.

Moreover, in the linear vibration motor 1 of the said structure, although each of the 1st magnet 30 and the 2nd magnet 40 was comprised by two magnet pieces, as another example, it is like the linear vibration motor 2 shown in FIG. It is also possible to replace the first magnet 30 and the second magnet 40 with a first magnet 30 'and a second magnet 40' consisting of a single piece of magnet, respectively.

The first magnet 30 ′ is an integral permanent magnet having an N pole on one end side in the vibration direction and an S pole on the other end side, and ensures a predetermined clearance with the end face of the coil 12. And adhesively fixed to the magnetic member 51.
The second magnet 40 'is a permanent magnet having the same shape and the same material as the first magnet 30', and is disposed point-symmetrically to reverse the direction of the magnetic pole with respect to the first magnet 30 '. The magnetic member 52 is adhesively fixed to the magnetic member 52 while maintaining a predetermined clearance with the coil 12.

Therefore, according to the linear vibration motor 2, similarly to the linear vibration motor 1, magnetic flux leakage can be reduced by the

magnetic members

51 and 52, and as shown in FIGS. 8 (a) and 8 (b) The Lorentz force can be offset to move the mover 10 back and forth smoothly and linearly.

Moreover, in the linear vibration motor 1 of the said structure, although the electric power feeding wiring 60 was overlap | superposed on the elastic body 20, as another example, like the linear vibration motor 3 shown in FIG. 9, and the linear vibration motor 4 shown in FIG. It is possible to configure the feed wiring.

The linear vibration motor 3 shown in FIG. 9 is obtained by replacing the power supply wiring 60 in the linear vibration motor 1 with a power supply wiring 60 ′.
The feed wiring 60 'is an L-shaped flexible wiring substrate (TAB) similar to the feed wiring 60, and the thickness direction of the weight 11 (in the reverse Z direction according to FIG. 9) with respect to one elastic body 20. ) Is provided so as to be bent and deformed at the shifted position.
Therefore, according to the linear vibration motor 3, interference of the power supply wiring 60 'with the elastic body 20 can be reduced, and noise reduction and durability can be improved.

Further, in the linear vibration motor 4 shown in FIG. 10, the power supply wiring 60 in the linear vibration motor 1 is replaced with a power supply wiring 60 ′ ′.
The feed wiring 60 ′ ′ is formed of a flexible wiring substrate (TAB), a connection piece 61 ′ ′ along the side surface of the weight 11 and having one end electrically connected to the coil 12, and the connection piece 61 ′ ′. The first extending piece portion 62 ′ ′ bent in a substantially L shape and extended to the other end side, and the first extending piece portion 62 ′ ′ further bent in a substantially V shape and extended And a second extension piece 63 ′ ′.
The feed wiring 60 ′ ′ is provided so as to be bent and deformed at a position shifted to the thickness direction of the weight 11 (anti-Z direction according to FIG. 10) with respect to one elastic body 20. The terminal on the end side of the mounting piece 63 ′ ′ is exposed to the outside.
Therefore, according to the linear vibration motor 3, the interference of the feed wire 60 ′ ′ with the elastic body 20 can be reduced, and the feed wire 60 ′ ′ is the first extended piece portion 62 ′ ′ and the second extended piece portion 63. And so on, which can further improve quietness, durability, and the like.

In the above embodiment, the elastic body 20 is a plate spring as a particularly preferable aspect. However, as another example of the elastic body 20, rubber, a coil spring, or the like can be used.

In the above embodiment, the magnetic member 51 on the first magnet 30 side is formed in a flat plate shape, but as another example, the magnetic member 51 is omitted, and the cover member 70 is formed of a magnetic material. The first magnet 30 may be bonded and fixed to the inner surface of the top wall 71 of the cover member 70.

As mentioned above, although the embodiment of the present invention has been described in detail, the specific configuration is not limited to these embodiments, and even if there is a design change or the like within the scope of the present invention. Included in the invention. In addition, the respective embodiments described above can be combined with each other by utilizing the techniques of each other unless there is a contradiction or a problem in particular in the purpose, the configuration, and the like.

1, 2, 3, 4: linear vibration motor 10: mover 11: weight 11a: hollow 12: coil 12a: one half side 12b: other half side 20: elastic body 30, 30 ': first Magnet 40, 40 ': Second magnet 51, 52:

Magnetic member

60, 60', 60 ": Feeding wire 70: Cover member

Claims

A mover integrally including a weight and a coil, an elastic body that vibratably supports the mover, and a first magnet facing the coil on one side in a direction intersecting with the vibration direction of the mover; The second magnet facing the coil on the other side in the same cross direction and a magnetic member for fixing each magnet are provided, and the mover is vibrated by the magnetic force generated when the coil is energized. Linear vibration motor.
The linear vibration motor according to claim 1, wherein the magnetic members are provided on both sides of the first magnet and the second magnet in the cross direction.
The coil is an air core coil in which one half side and the other half side sandwiching the air core are disposed on both sides in the vibration direction,
Each of the first magnet and the second magnet is characterized in that one magnetic pole is made to face the one half side, and the oppositely facing magnetic pole is made to face the other half side. The linear vibration motor according to Item 1 or 2.
The weight is provided with a hollow portion opened on one side and the other side in the cross direction,
In the hollow portion, the first magnet is inserted into the opening on one side and the second magnet is inserted into the opening on the other side, and the weight body is surrounded around the first magnet and the second magnet The linear vibration motor according to any one of claims 1 to 3, wherein a space for vibrating the motor is secured.
A flexible feed line for supplying power to the coil;
5. The power supply wiring according to claim 1, wherein the one end side terminal is electrically connected to the coil and the other end side terminal is exposed to the outside so that the power supply wiring bends with the vibration of the mover. The linear vibration motor according to any one of the above.
The linear vibration motor according to claim 5, wherein the elastic body is a plate spring, and the feeding wire is provided along the plate spring.
An electronic apparatus comprising the linear vibration motor according to any one of claims 1 to 6.