JP2019041548A - Linear oscillation motor and electronic equipment - Google Patents

Abstract

To improve attenuation performance of oscillation.SOLUTION: A linear oscillation motor includes an oscillating movable element 10, a leaf spring 40 bending at an oscillation direction side of the movable element 10, a support 22d for supporting the leaf spring 40 at the oscillation direction side, and a coil 30 for oscillating the movable element 10. The movable element 10 has a magnet 11 at an end side in an oscillation direction, and the leaf spring 40 has one end side for connection with the movable element 10, and the other end side for connection with the support 22d. Between the one end side and the other end side, a bending piece 41 bending as the movable element 10 oscillates, approaching the magnet 11 or being separated therefrom is provided, and at least the bending piece 41 is formed of a magnetic material.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a linear vibration motor and an electronic apparatus including the linear vibration motor.

  Vibration motors (or vibration actuators) are widely used as devices that are built into portable electronic devices and transmit signal generation such as incoming calls and alarms to the carriers by vibrations. Has become an indispensable device. In recent years, a vibration motor has attracted attention as a device that realizes haptics (skin sensation feedback) in a human interface such as a touch panel.

Among various types of vibration motors that have been developed, attention has been focused on linear vibration motors that can generate relatively large vibrations by linear reciprocating vibration of the mover. The linear vibration motor has a weight and a magnet on the mover side, and the Lorentz force acting on the magnet becomes a driving force by energizing the coil provided on the stator side, and the mover that is elastically supported along the vibration direction. It reciprocates in one axis direction.
For example, Patent Literature 1 describes a vibration actuator in which a mover is fixed to a side wall of a lid portion via a leaf spring so that the leaf spring is elastically bent with vibration of the mover (weight). Has been.

JP 2017-18958 A

  By the way, according to the above prior art, even if the coil is switched from the energized state to the non-energized state, the mover continues free vibration due to inertia, and therefore it takes some time until the vibration is completely stopped. For this reason, for example, in a situation where the electronic device is repeatedly vibrated and stopped in response to a quick repetition of the touch operation, there is a risk that the responsiveness may be felt.

In order to solve such a problem, the present invention has the following configuration.
A movable element that vibrates, a leaf spring that bends on the vibration direction side of the movable element, a support that supports the leaf spring on the vibration direction side, and a coil that vibrates the movable element, , Having a magnet on the end side in the vibration direction, the leaf spring has one end connected to the mover and the other end connected to the support, and between these one end and the other end, A linear vibration motor characterized by having a bent piece portion that is bent in accordance with the vibration of the mover and moves toward or away from the magnet, and at least the bent piece portion is formed of a magnetic material.

It is a perspective view which shows an example of the linear vibration motor which concerns on this 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 omitted the board | substrate part, the coil, etc. about the linear vibration motor, and has shown the state in which a needle | mover is located in the approximate center of a vibration direction. It is the figure which excluded the board | substrate part, the coil, etc. about the linear vibration motor, and has shown the state in which a needle | mover is biased and located in one of the vibration directions. It is a perspective view which shows an example of the electronic device which comprised the 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 indicate parts having the same function, and repeated description in each drawing will be omitted as appropriate.

  The linear vibration motor 1, as shown in FIGS. 1 to 4, vibrates the movable element 10, the box-shaped base body 20 that supports the movable body 10 so as to vibrate, and the movable body 10 vibrates along the base body 20. A coil 30 and two leaf springs 40 and 40 that are elastically bent in a 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 crossing direction with respect 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 of the vibration direction, weights 12 and 12 fixed to both ends of the magnets 11 and 11 in the crossing direction, and magnets 11 and 11. A yoke 13 fixed to the surface on the side opposite to the coil in the longitudinal direction is provided, and is supported so as to vibrate in the lateral direction (Y direction in the figure) via leaf springs 40 on both sides.

Each magnet 11 is formed in a rectangular parallelepiped shape that is long in the direction intersecting the vibration direction, and one of the directions orthogonal to the surface of the coil 30 (Z direction in the drawing) is an N pole and the other is an 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 the other magnet 11.
The pair of magnets 11 and 11 are integrally fixed by a yoke 13.

The weights 12 and 12 are formed in a substantially rectangular parallelepiped shape using a metal material having a high specific gravity (for example, tungsten).
Each weight 12 abuts against a cushioning material 14 fixed to the inner surface of a cover portion 22 of the base body 20 described later when the mover 10 vibrates in the short direction (Y direction shown in the drawing).
The shock absorbing material 14 is formed in a block shape from an elastic material such as rubber, receives the mover 10 when it vibrates, transmits the impact to the cover part 22, and prevents the generation of vibration sound by elastic deformation.

The yoke 13 is formed in a long shape covering the side opposite to the coil of the pair of magnets 11 and 11 and has projecting pieces 13a and 13a projecting toward the coil 30 at both ends in the longitudinal direction. Each protrusion 13a is provided with a convex portion 13a1 for positioning and supporting the leaf spring 40.
For example, the yoke 13 is formed in a substantially concave cross section by bending a substantially rectangular plate made of a magnetic metal material.
Each protruding piece 13a has a fitting piece 13a2 bent toward the center in the width direction (Y direction in the figure), and the fitting piece 13a2 is sandwiched between the pair of magnets 11 and 11. The magnets 11 and 11 are bonded via an adhesive.

  The base body 20 includes a substrate portion 21 that supports and fixes the coil 30, and a cover portion 22 that covers the periphery of the mover 10 and the side opposite to the coil, and has a long box shape along the coil 30 and the mover 10. Composed.

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

  The cover portion 22 is formed in a rectangular box shape having an opening on the substrate portion 21 side from a metal plate material, and has a rectangular plate-like flat portion 22a facing the substrate portion 21 with the mover 10 and the coil 30 interposed therebetween. The flat plate portion 22a has four side walls 22b, 22b, 22c, and 22c that protrude from the four sides of the flat plate portion 22a toward the substrate portion 21 and surround the four sides of the movable element 10. The cover portion 22 is fixed by fitting the protruding ends of the side walls 22b, 22b, 22c, and 22c to the substrate portion 21.

  Of the four side walls, the two side walls 22b and 22b facing each other in the vibration direction (Y direction shown in the figure) of the mover 10 are spaced apart in the direction orthogonal to the vibration direction (X direction shown in the figure). The two cutout portions 22b1 and 22b1 are provided as a support portion 22d for supporting the leaf spring 40 between the two cutout portions 22b1 and 22b1.

The support portion 22d protrudes from the flat plate portion 22a side to the substrate portion 21 side so as to be positioned between the two slit-shaped cutout portions 22b1, and the protruding end portion, the opposing substrate portion 21 surface, and the terminal plate A gap s1 is secured between 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 uses the force component in the X direction due to the impact as a fulcrum to support the gap s1 side as X. It is elastically deformed slightly as it is swung in the direction.
The elastic deformation of the support portion 22d is smaller than the bending amount of the leaf spring 40. That is, the rigidity of the support portion 22d in the intersecting direction (X direction in the drawing) is set to be larger than the rigidity of the leaf spring 40 in the bending direction (Y direction in the drawing).

The coil 30 is an air-core coil that does not include a core material, is wound in a long and flat shape, and has a substantially constant gap with respect to the surface on the side opposite to the yoke 13 of the pair of magnets 11, 11. It is fixed to the part 21.
For example, a drive 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 leaf spring 40 is supplied to the coil 30 via terminals T and T. Is done.

Two leaf springs 40 are arranged point-symmetrically so as to be located in spaces 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 portion 22d, and is bent between the one end and the other end with the vibration of the mover 10 to the magnet 11. It has a bent piece 41 that approaches and leaves, and this bent piece 41 is a magnetic material that can be attracted by the magnet 11.

  More specifically, the plate spring 40 is formed by bending a long plate made of a magnetic metal that can be bent elastically into a substantially L shape, and the short direction of the pair of magnets 11 and 11 (Y in the drawing). Direction), a bending piece 41 extending obliquely along the end surface, a fixing piece 42 fixed to the movable element 10 on one end side of the bending piece 41, and the other bending piece 41. And a fastening piece portion 43 secured to the support portion 22d on the end side.

The bending piece 41 is formed in an inclined piece shape that gradually separates from the magnet 11 from one end side toward the other end side. The bent piece portion 41 is positioned so as to be magnetically attracted by the magnet 11 when approaching the magnet 11.
Near the center of the bending piece 41 in the longitudinal direction, a constricted portion 41a for gradually reducing the dimension in the thickness direction of the mover 10 is provided. The constricted portion 41a disperses the stress applied to the bent portions and the connecting portions on both ends, but can be omitted.
Moreover, according to the example of illustration, only the bending piece part 41 is provided in the space where this bending piece part 41 bends and deforms. In other words, there is no member other than the bending piece 41 in the entire length range in the X direction of the bending piece 41 between the magnet 11 and the side wall 22b of the cover portion 22. Therefore, the bending piece part 41 can be bent and deformed without interfering with other members. In addition, as an example other than the illustrated example, it is possible to adopt a mode in which a member other than the bending piece portion 41 (for example, a cushioning material or other members) is provided in the space.

  One fastening piece 42 extends in a plate shape in a direction orthogonal to the vibration direction of the mover 10. The fastening piece portion 42 is sandwiched and fixed between the outer surface of the protruding piece portion 13a and the weight body 12 so that the penetrating fitting hole 42a is fitted to the convex portion 13a1 on the yoke 13 side. . This fixing means can be, for example, welding or adhesion.

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 buffer material 44 made of an elastic material such as rubber is fixed to the back side of the fastening piece portion 43 (on the side opposite to the support portion 22d). The buffer material 44 prevents the leaf spring 40 from coming into contact with the side surface of the magnet 11 and generating noise when the mover 10 vibrates.

Next, the characteristic 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 leaf springs 40, 40 on both sides accompany this reciprocation. It is elastically bent, and vibration due to this reciprocating motion is transmitted to the base 20 through the support portion 22d and the like.

During the reciprocation, as shown in FIG. 5, when the gap s <b> 2 between the side surface of one magnet 11 and the bending piece portion 41 is narrowed, the magnet 11 and the bending piece portion 41 are attracted by magnetic force.
For this reason, when the power supply to the coil 30 is cut off and the mover 10 is stopped from the vibration state, the vibration of the mover 10 is caused by the magnetic attractive force between the magnet 11 and the bending piece 41 described above. Can be attenuated rapidly. That is, the damping performance when the mover 10 is stationary is good.

Next, an electronic device including the linear vibration motor 1 will be described.
FIG. 6 illustrates a portable information terminal 100 as an electronic apparatus 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 accordance with a touch operation on the touch operation panel 50 (including a touch display), and has a good vibration attenuation performance. Therefore, for example, even when the mobile information terminal 100 is repeatedly vibrated and stopped in response to a quick touch operation, good responsiveness can be obtained.

  As another example, the linear vibration motor 1 can be mounted on an electronic device that does not include 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, as another example, the aspect which provided the leaf | plate spring 40 and the support part 22d only in the one side of the vibration direction. It is also possible. In this case, the other side with respect to the one side may be configured such that the movable element 10 is supported by a structure other than the illustrated structure, or the movable element 10 is not supported.

  Moreover, in the said embodiment, although the leaf | plate spring 40 formed the whole including the bending piece part 41 from a magnetic metal material, as another example of the leaf | plate spring 40, only the bending piece part 41 is formed from a magnetic metal material, and others. It is also possible to form the portion (fastening piece portions 42, 43, etc.) from a material other than the magnetic metal material.

  Moreover, according to the said embodiment, although the needle | mover 10 was made to vibrate in a transversal direction, it is also possible to set it as the aspect which vibrates a needle | mover in a longitudinal direction as another example.

  As described above, the embodiments of the present invention have been described in detail. However, the specific configuration is not limited to these embodiments, and even if there is a design change or the like without departing from the gist of the present invention, Included in the invention. In addition, the above-described embodiments can be combined by utilizing each other's technology as long as there is no particular contradiction or problem in the purpose and configuration.

DESCRIPTION OF SYMBOLS 1: Linear vibration motor 10: Movable element 11: Magnet 20: Base body 21: Substrate part 22: Cover part 22d: Support part 30: Coil 40: Bending leaf spring 41: Bending piece part 42, 43: Fastening piece part 100 : Personal digital assistant (electronic equipment)

Claims (5)

A movable element that vibrates, a leaf spring that bends on 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 leaf spring has one end connected to the mover and the other end connected to the support, and is bent between the one end and the other end due to the vibration of the mover. A linear vibration motor characterized by having a bent piece portion that approaches or separates, and at least the bent piece portion is formed of a magnetic material.   2. The linear vibration motor according to claim 1, wherein the bending piece is formed in an inclined piece shape that gradually moves away from the magnet from the one end side toward the other end side.   The linear vibration motor according to claim 1, wherein the magnet, the leaf 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 in which the bending piece portion is bent and deformed. The electronic device provided with the linear vibration motor of any one of Claims 1-4.

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