WO2019044127A1

WO2019044127A1 - Linear vibration motor and electronic apparatus

Info

Publication number: WO2019044127A1
Application number: PCT/JP2018/023427
Authority: WO
Inventors: 栞久信田
Original assignee: 日本電産コパル株式会社
Priority date: 2017-08-29
Filing date: 2018-06-20
Publication date: 2019-03-07
Also published as: JP2019041548A; JP6971714B2; CN211830531U

Abstract

The present invention improves vibration damping performance. The present invention is provided with: a movable element 10 that vibrates; a plate spring 40 that warps on the vibration direction side of the movable element 10; a supporting section 22d that supports the plate spring 40 on the vibration direction side; and a coil 30 that vibrates the movable element 10. The movable element 10 has a magnet 11 on the end section side in a vibration direction, the plate spring 40 has one end side that is connected to the movable element 10, and the other end side that is connected to the supporting section 22d, and has, between the one end side and the other end side, a warping piece 41 which comes close to and separates from the magnet 11 by warping with the vibration of the movable element 10. At least the warping piece 41 is formed of a magnetic material.

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. In addition, a vibration motor has recently attracted attention as a device for realizing 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. In a linear vibration motor, a weight and a magnet are provided on the mover side, and Lorentz force acting on the magnet becomes a driving force by energizing the coil provided on the stator side, and the mover elastically supported along the vibration direction It is made to reciprocate in a uniaxial direction.
For example, Patent Document 1 describes a vibration actuator in which a mover is fixed to a side wall of a lid via a plate spring so as to elastically bend the plate spring with the vibration of the mover (weight). It is done.

JP 2017-18958 A

By the way, according to the above-mentioned prior art, even when the coil is energized or de-energized, the mover continues free vibration due to inertia, so it takes some time for the vibration to stop completely. For this reason, for example, in a situation where vibration and stop of the electronic device are repeated in response to repeated quick touch operation, there is a possibility that the responsiveness may be felt as slow.

In order to solve such a subject, the present invention comprises the following composition.
The movable element includes: a movable element that vibrates; a plate spring that bends in the vibration direction of the movable element; a support that supports the flat spring on the vibration direction side; and a coil that vibrates the movable element A magnet is provided at an end side in the vibration direction, and the plate spring connects one end side to the movable element and connects the other end side to the support portion, and between the one end side and the other end side, A linear vibration motor comprising: a bending piece which bends with vibration of the mover to move closer to or away from the magnet, and at least the bending piece is formed of a magnetic material.

It is a perspective view showing an example of a linear vibration motor concerning the present invention. It is a disassembled perspective view which shows the linear vibration motor. It is a longitudinal cross-sectional view of the linear vibration motor. It is the figure which abbreviate | omitted the board | substrate part, the coil, etc. about the same linear vibration motor, and has shown the state to which the mover is located in the approximate center of the vibration direction. It is the figure which abbreviate | omitted the board | substrate part, the coil, etc. about the same linear vibration motor, and has shown the state which the mover has deviated to one side of a vibration direction. It is a perspective view which shows an example of the electronic device which equipped the same linear vibration motor.

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 4, the linear vibration motor 1 vibrates the mover 10 that vibrates, a box-like base 20 that supports the mover 10 in a vibratable manner, and the mover 10 along the base 20. The coil 30 and the two

leaf springs

40 and 40 elastically bent in the space on the vibration direction side of the mover 10 are provided.

The mover 10 is formed in a long shape in which the dimension in the cross direction to the vibration direction is longer than the dimension in the vibration direction.
The mover 10 includes a pair of

magnets

11 and 11 positioned at both ends in the vibration direction,

weights

12 and 12 fixed to both ends in the cross direction of the

magnets

11 and 11, and

magnets

11 and 11. A yoke 13 fixed in the longitudinal direction is provided on the surface on the opposite side of the coil, and is supported so as to vibrate in the short direction (Y direction in the figure) via the plate springs 40 on both sides.

Each magnet 11 is formed in the shape of a rectangular solid elongated in the cross direction with respect to the vibration direction, and one of the directions (Z direction in the drawing) orthogonal to the surface of the coil 30 is N pole and the other is S pole.
The pair of

magnets

11 and 11 are provided substantially in parallel with a predetermined gap. One magnet 11 has a magnetic pole opposite to that of the other magnet 11.
The pair of

magnets

11 and 11 are integrally fixed by a yoke 13.

The

weight

12, 12 is formed in a substantially rectangular parallelepiped shape by a metal material having a high specific gravity (for example, tungsten) or the like.
When the mover 10 vibrates in the short direction (Y direction in the drawing), each weight 12 abuts on a shock absorbing material 14 fixed to the inner surface of a cover 22 of a base 20 described later.
The buffer material 14 is formed in a block shape from an elastic material such as rubber, receives the mover 10 when it is vibrated, transmits its impact to the cover portion 22, and elastically deforms to prevent generation of vibration noise.

The yoke 13 is formed in a long shape so as to cover the side opposite to the coil of the pair of

magnets

11 and 11 and has projecting

pieces

13a and 13a protruding toward the coil 30 at both ends in the longitudinal direction. Each protrusion 13 a is provided with a protrusion 13 a 1 for positioning and supporting the plate spring 40.
The yoke 13 is formed, for example, in a substantially concave shape in cross section by bending a substantially rectangular plate made of a magnetic metal material.
Each projecting piece 13a has a fitting piece 13a2 bent toward the center in the width direction (Y direction in the drawing), and the fitting piece 13a2 is sandwiched between a pair of

magnets

11 and 11 And the

magnets

11 and 11 are bonded via an adhesive.

In addition, the base 20 includes a base portion 21 for supporting and fixing the coil 30, and a cover portion 22 covering the periphery of the mover 10 and the side opposite to the coil, and in a long box shape along the coil 30 and the mover 10. Configured

The substrate portion 21 is formed in a substantially rectangular shape, and the terminal board 21a is made to project from the long side portion. Two terminals T, T are provided on the surface of the terminal plate 21a, and the terminals T, T are electrically connected to both ends of the wire forming the coil 30, respectively.

The cover portion 22 is formed of a metal plate material in a rectangular box shape with the substrate portion 21 opened, and the flat plate portion 22a having a rectangular shape in plan view facing the substrate portion 21 with the mover 10 and the coil 30 interposed therebetween. The four

side walls

22b, 22b, 22c, and 22c that project from the four sides of the flat plate portion 22a toward the substrate portion 21 and surround the four sides of the mover 10 are provided. The cover portion 22 is fixed by fitting the projecting ends of the

side walls

22b, 22b, 22c, and 22c to the substrate portion 21.

Of the four side walls, two

side walls

22b and 22b opposed on both sides in the vibration direction (Y direction in the drawing) of the mover 10 are respectively spaced in a direction perpendicular to the vibration direction (X direction in the drawing). The two notches 22b1 and 22b1 are provided, and a space between these two notches 22b1 and 22b1 is used as a support 22d for supporting the plate spring 40.

The supporting portion 22 d is projected between the flat plate portion 22 a side to the substrate portion 21 side so as to be located between the two slit-like notched portions 22 b 1, and the projecting end portion, the opposing substrate portion 21 surface and the terminal plate A gap s1 is secured between the surface 21a and the surface 21a.
For this reason, when the linear vibration motor 1 receives a relatively strong impact such as a drop impact, for example, the support portion 22d has the flat portion 22a as a fulcrum with the gap s1 side as the fulcrum by the force component in the X direction by the impact. It is slightly elastically deformed as it is rocked in the direction.
The elastic deformation of the support portion 22 d is smaller than the amount of deflection of the plate spring 40. That is, the rigidity in the cross direction (X direction in the drawing) of the support portion 22 d is set larger than the rigidity in the bending direction (Y direction in the drawing) of the plate spring 40.

The coil 30 is an air core coil which does not have a core material, is wound in a long flat shape, and places a substantially constant gap with respect to the surface on the side opposite to the yoke 13 of the pair of

magnets

11 and 11. It is fastened to the part 21.
A driving signal composed of an alternating current or a pulse current having a resonance frequency (natural frequency) determined by the mass of the mover 10 and the elastic coefficient of the plate spring 40 is supplied to the coil 30 through the terminals T and T, for example. Be done.

Two plate springs 40 are point-symmetrically arranged so as to be respectively located in the space on both sides in the vibration direction of the mover 10 (see FIG. 4).
Each leaf spring 40 has one end connected to the mover 10 and the other end connected to the support 22d, and is bent between the one end and the other end along with the vibration of the mover 10 to the magnet 11 It has a bending piece portion 41 which approaches and separates, and this bending piece portion 41 is made of a magnetic material which can be attracted by the magnet 11.

More specifically, the leaf spring 40 is formed by bending an elastic flexible long metal plate made of magnetic metal into a substantially L shape, and the short direction of the pair of magnets 11 and 11 (Y in the figure And the other attachment piece 42 fixed to the mover 10 at one end of the deflection piece 41, and the other deflection piece 41. And a fastening piece 43 fastened to the support 22d at the end.

The bending piece portion 41 is adjacent to the magnet 11 in the vibration direction, and is formed in an inclined piece shape that gradually separates from the magnet 11 from one end side to the other end side. The bending piece portion 41 is positioned so as to be magnetically attracted by the magnet 11 when approaching the magnet 11.
A narrowed portion 41 a is provided near the center in the longitudinal direction of the bending piece portion 41 so as to gradually reduce the dimension in the thickness direction of the mover 10. The constricted portion 41a is intended to disperse the stress applied to the bent portion, the connection portion and the like on both end sides, but can be omitted.
Further, according to the illustrated example, only the bending piece portion 41 is provided in the space where the bending piece portion 41 is bent and deformed. In other words, there is no member other than the bending piece portion 41 between the magnet 11 and the side wall 22 b of the cover portion 22 and in the entire length range of the bending piece portion 41 in the X direction. Therefore, the bending piece portion 41 can be bent and deformed without interfering with other members. In addition, it is also possible to set it as the aspect by which members (for example, shock absorbing material, other members etc.) other than the bending piece part 41 were provided in the said space as another example except the example of illustration.

One fixing piece portion 42 is extended in a plate shape in a direction perpendicular to the vibration direction of the mover 10. The fastening piece portion 42 is fixed by being sandwiched between the outer surface of the projecting portion 13a and the weight 12 by fitting the through-shaped fitting hole 42a to the convex portion 13a1 on the yoke 13 side. . This fixing means can be, for example, welding, adhesion or the like.

The other fastening piece portion 43 is formed in a plate shape substantially parallel to the side wall 22b of the cover portion 22, and is welded to the support portion 22d of the side wall 22b.
A shock absorbing material 44 made of an elastic material such as rubber is fixed on the back side (the opposite side of the support 22 d) of the fastening piece 43. The cushioning material 44 prevents the plate spring 40 from coming into contact with the side surface of the magnet 11 to generate noise when the mover 10 vibrates.

Next, the characteristic operation and effect of the linear vibration motor 1 having the above-described configuration will be described in detail.
When AC power is supplied to the coil 30, the mover 10 reciprocates in the short direction due to the magnetic action between the coil 30 and the pair of

magnets

11, 11, and the plate springs 40, 40 on both sides are moved along with this reciprocation. The elastic deformation causes vibration due to the reciprocation to be transmitted to the base 20 through the support 22 d and the like.

During the reciprocation, as shown in FIG. 5, when the gap s2 between the side surface of one of the magnets 11 and the bending piece portion 41 is narrowed, the magnet 11 and the bending piece portion 41 are attracted by the magnetic force.
For this reason, when stopping the power supply to the coil 30 and stopping the mover 10 from the vibration state, the vibration of the mover 10 is caused by the magnetic attraction force between the magnet 11 and the bending piece portion 41 described above. It can be attenuated rapidly. That is, the damping performance at the time of stopping the mover 10 is good.

Next, an electronic device provided with the linear vibration motor 1 will be described.
FIG. 6 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 in response to a touch operation on the touch operation panel 50 (including a touch display), and the vibration damping performance is excellent. Therefore, for example, even in the case where the vibration and the stop of the portable information terminal 100 are repeated in response to the repetition of the quick touch operation, it is possible to obtain good responsiveness.

As another example, it is also possible to equip the linear vibration motor 1 in an electronic device that does not have the touch operation panel 50.

Moreover, according to the said embodiment, although the leaf | plate spring 40 and the support part 22d were each provided in the both sides of the vibration direction, the aspect which provided the leaf spring 40 and the support part 22d only in one side of the vibration direction as another example. It is also possible. In this case, the other side with respect to the one side may have a configuration in which the mover 10 is supported by a structure other than illustrated, a configuration in which the mover 10 is not supported, or the like.

In the above embodiment, the entire plate spring 40 including the bending piece 41 is formed of a magnetic metal material, but as another example of the plate spring 40, only the bending piece 41 is formed of a magnetic metal material It is also possible to form the part (the

fastening pieces

42, 43, etc.) of the above from a material other than the magnetic metal material.

Further, according to the above embodiment, although the movable element 10 is vibrated in the lateral direction, as another example, the movable element may be vibrated in the longitudinal direction.

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: Linear vibration motor 10: Mover 11: Magnet 20: Base 21: Substrate 22: Cover 22d: Support 30: Coil 40: Flexible plate spring 41: Flexible piece 42, 43: Fastening piece 100 : Mobile information terminal (electronic equipment)

Claims

A movable element that vibrates, a leaf spring that bends in the vibration direction side of the movable element, a support portion that supports the leaf spring on the vibration direction side, and a coil that vibrates the movable element.
The mover has a magnet on the end side in the vibration direction,
The plate spring has one end connected to the mover and the other end connected to the support, and is bent with the vibration of the mover between the one end and the other end against the magnet What is claimed is: 1. A linear vibration motor comprising: a bending piece portion that approaches and separates, wherein at least the bending piece portion is formed of a magnetic material.
The linear vibration motor according to claim 1, wherein the bending piece portion is formed in an inclined piece shape that gradually separates from the magnet from the one end side toward the other end side.
3. The linear vibration motor according to claim 1, wherein the magnet, the plate spring, and the support portion are provided on both sides in the vibration direction.
The linear vibration motor according to any one of claims 1 to 3, wherein only the bending piece portion is provided in a space where the bending piece portion is bent and deformed.
An electronic apparatus comprising the linear vibration motor according to any one of claims 1 to 4.