JP6871082B2 - Linear vibration motor and electronic equipment - Google Patents

Description

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

Vibration motors (or vibration actuators) are built into portable electronic devices and are widely used as devices that transmit signals such as incoming calls and alarms to the carrier by vibration. Has become an indispensable device. Further, the vibration motor has been attracting attention in recent years as a device that realizes haptics (skin sensory feedback) in a human interface such as a touch panel.

While various forms of such a vibration motor have been developed, a linear vibration motor capable of generating a relatively large vibration by linear reciprocating vibration of a mover has attracted attention. In a linear vibration motor, a weight and a magnet are provided on the mover side, and the Lorentz force acting on the magnet is used as the driving force by energizing the coil provided on the stator side, and the mover is elastically supported along the vibration direction. It reciprocates in the uniaxial direction.
For example, Patent Document 1 describes a vibration actuator in which a mover is fastened to a side wall of a lid via a leaf spring so as to elastically bend a leaf spring with vibration of a mover (weight). Has been done.

Japanese Unexamined Patent Publication No. 2017-18958

By the way, according to the above-mentioned conventional technique, when the linear vibration motor is dropped in the vibration direction of the mover, the drop impact can be absorbed to some extent by the elastic deflection of the leaf spring.
However, when the linear vibration motor is dropped in the direction intersecting the vibration direction of the mover, it is difficult to obtain elastic deflection of the leaf spring, so a load acts locally on the anchoring point of the leaf spring, and the leaf spring There is a risk of causing plastic deformation or damage.

In order to solve such a problem, the present invention has the following configurations.
A mover, a base that vibrates the mover, a coil that vibrates the mover along the base, and a leaf spring that elastically bends along the vibration direction of the mover are provided. The substrate is integrally provided with a support portion that can be elastically deformed in a direction intersecting the vibration direction, and the leaf spring has one end fixed to the mover and the other end fixed to the support portion. A linear vibration motor characterized by being worn.

It is a perspective view which shows an example of the linear vibration motor which concerns on this invention. It is an exploded perspective view which shows the linear vibration motor. It is a bottom view which shows the state which omitted the substrate part, the coil and the like about the linear vibration motor. It is a vertical cross-sectional view of the linear vibration motor, and shows a state in which a mover is in contact with a substrate part. It is a perspective view which shows an example of the electronic device provided with 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 figures indicate parts having the same function, and duplicate description in each figure will be omitted as appropriate.

As shown in FIGS. 1 to 4, the linear vibration motor 1 includes a mover 10, a box-shaped base 20 that oscillates the mover 10, and a coil 30 that vibrates the mover 10 along the base 20. And two leaf springs 40, 40 that elastically bend along the vibration direction of the mover 10.

The mover 10 is formed in a long shape in which the dimension in the intersecting direction with respect to the vibration direction is longer than the dimension in the vibration direction.
The mover 10 includes a pair of long magnets 11 and 11, weights 12 and 12 fixed to both ends of the magnets 11 and 11 in the longitudinal direction, and surfaces of the magnets 11 and 11 on the anti-coil side. It is provided with a yoke 13 fixed in the longitudinal direction, and is supported so as to vibrate in the lateral direction (Y direction in the drawing) via leaf springs 40, 40 on both sides.

Each magnet 11 is formed in a long rectangular parallelepiped shape, and one of the directions orthogonal to the coil 30 plane (Z direction in the drawing) is the N pole and the other is the 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 the yoke 13.

The weights 12 and 12 are 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 lateral direction (Y direction in the drawing), each weight body 12 comes into contact with the cushioning material 14 fixed to the inner surface of the cover portion 22 of the substrate 20 to be described later.
The cushioning material 14 is formed in a block shape from an elastic material such as rubber, receives the mover 10 when vibrated, transmits the impact to the cover portion 22, and prevents the generation of vibration noise by elastically deforming.

The yoke 13 is formed in a long shape covering the anti-coil side surfaces of the pair of magnets 11 and 11, and has projecting piece portions 13a and 13a protruding toward the coil 30 on both end sides in the longitudinal direction thereof. Each projecting piece portion 13a is provided with a convex portion 13a1 for positioning and supporting the leaf spring 40.
The yoke 13 is formed to have a substantially concave cross section, for example, by bending a substantially rectangular plate made of a magnetic metal material.

Each projecting piece portion 13a has a fitting piece portion 13a2 bent toward the center in the width direction (Y direction in the drawing) so as to be sandwiched between the pair of magnets 11 and 11 with respect to the magnets 11 and 11. It is glued through an adhesive.

Further, the substrate 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 surface of the anti-coil, and has a long box shape along the coil 30 and the mover 10. It is composed.

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

The cover portion 22 is formed in a rectangular box shape in which the substrate portion 21 side is opened from a metal plate material, and has a rectangular flat plate portion 22a in a plan view facing the substrate portion 21 with a mover 10 and a coil 30 in between. It has four side walls 22b, 22b, 22c, 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 mover 10. The cover portion 22 is fixed by fitting the protruding ends of the side walls 22b, 22b, 22c, 22c to the cover portion 22.

Of the four side walls, the two side walls 22b and 22b facing each other on both sides of the mover 10 in the vibration direction (Y direction in the figure) are spaced apart from each other in the direction orthogonal to the vibration direction (X direction in the figure). It has two notches 22b1,22b1, and a support portion 22d for supporting the leaf spring 40 is provided between these two notches 22b1,22b1.

Each notch portion 22b1 is formed in a slit shape that is continuous from the flat plate portion 22a side to the substrate portion 21 side of the side wall 22b.

The support portion 22d protrudes from the flat plate portion 22a side to the substrate portion 21 side so as to be located between the two notch portions 22b1, and the protruding end portion thereof and the opposing substrate portion 21 surface and terminal plate 21a surface. A gap s is secured between the two.
Therefore, when the linear vibration motor 1 receives a relatively strong impact such as a drop impact, the support portion 22d has the flat plate portion 22a side as a fulcrum and the gap s side X due to the force component in the X direction due to the impact. It is slightly elastically deformed so as to swing in the direction (see FIG. 1).
The elastic deformation of the support portion 22d is smaller than the amount of deflection of the leaf spring 40. That is, the rigidity of the support portion 22d in the crossing direction (X direction in the drawing) is set to be larger than the rigidity in the bending direction (Y direction in the drawing) of the leaf spring 40.

The coil 30 is an air-core coil that does not include a core material, is wound in a long flat shape, and has a substantially constant gap between the surfaces of the pair of magnets 11 and 11 on the anti-yoke 13 side. It is anchored 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 modulus of the leaf spring 40 is supplied to the coil 30 via the terminals T and T. Will be done.

Two leaf springs 40 are arranged point-symmetrically on both sides of the mover 10 in the lateral direction.
Each leaf spring 40 is formed by bending an elastically flexible metal long plate material into a substantially L shape.
More specifically, the leaf spring 40 is substantially orthogonal to the one piece 41 extending diagonally along the end faces of the pair of magnets 11 and 11 in the lateral direction (Y direction in the drawing). It has another piece 42 and the like.

The one piece portion 41 is located between the end surface of the magnet 11 in the lateral direction and the side wall 22b of the cover portion 22, and is formed in the shape of a long plate along the longitudinal direction of the magnet 11.
One end side of the one piece 41 is fastened to one side of the mover 10 in the longitudinal direction (specifically, between the yoke 13 and the weight 12) via the other piece 42.
Further, the other end side of the same piece 41 is obliquely extended to the other side of the mover 10, and is fastened to the support portion 22d.

The one piece portion 41 is formed with a constricted portion 41a that gradually reduces the thickness direction of the mover 10 near the center in the longitudinal direction, and a fastening piece portion 41b is provided near the end portion on the support portion 22d side. Be done.

The constricted portion 41a disperses the stress applied to the connecting portion between the one piece portion 41 and the supporting portion 22d, the bending portion between the one piece portion 41 and the other piece portion 42, etc. due to the vibration of the mover 10.

Further, the fastening piece portion 41b is formed in a flat plate shape substantially parallel to the support portion 22d, and is welded and fixed to the support portion 22d.

Further, the other 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 through-shaped fitting hole 42a is fitted into the convex portion 13a1 on the yoke 13 side. .. This fixing means can be, for example, welding, adhesion, or the like.

A cushioning material 41c made of an elastic material such as rubber is fixed to the back side (anti-support portion 22d side) of the fastening piece portion 41b. The cushioning material 41c prevents a piece 41 of the leaf 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 configuration will be described in detail.
When AC power is supplied to the coil 30, the mover 10 reciprocates in the lateral direction due to the magnetic action between the coil 30 and the pair of magnets 11 and 11, and the leaf springs 40 and 40 on both sides reciprocate with this reciprocating motion. It flexes elastically, and the vibration due to this reciprocating motion is transmitted to the substrate 20 via the support portion 22d and the like.

If the linear vibration motor 1 is accidentally dropped and a force in the crossing direction (X direction in the figure) with respect to the vibration direction is applied to the mover 10 and the leaf spring 40, the support portion 22d becomes a notch on both sides. Since the 22b1, 22b1 is slightly elastically deformed in the crossing direction, the drop impact can be absorbed by this elastic deformation.
Further, when the force in the crossing direction due to dropping or the like is relatively large, as shown in FIG. 4, the mover 10 is tilted as shown in FIG. 4 due to the elastic deformation of the support portion 22d in the crossing direction. Then, the end side (specifically, the weight body 12) of the mover 10 in the long direction comes into contact with the flat plate portion 22a of the substrate portion 21 or the cover portion 22, so that the deformation of the leaf spring 40 can be suppressed. it can.
Therefore, it is possible to prevent the leaf spring 40 from being plastically deformed or damaged in the vicinity of the fastening portion with the support portion 22d, and it is possible to improve the impact resistance of the linear vibration motor 1.

Next, an electronic device including the linear vibration motor 1 will be described.
FIG. 5 illustrates a portable information terminal 100 as an electronic device including the linear vibration motor 1 according to the embodiment of the present invention.
The mobile information terminal 100 is configured to vibrate the linear vibration motor 1 in response to a touch operation of the touch operation panel 50 (including the touch display), and its responsiveness is good, and in the unlikely event that it is dropped. However, it has excellent impact resistance.

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

Further, according to the above embodiment, the support portion 22d is provided on the side wall 22b on the lateral end side of the cover portion 22, but as another example, the side wall 22c on the longitudinal end side of the cover portion 22 is provided. It is also possible to provide a projecting piece portion that protrudes inward of the cover portion 22, and to use this projecting piece portion as a supporting portion 22d for supporting the leaf spring 40.
Further, as another example, it is also possible to provide the substrate portion 21 with a projecting piece portion protruding toward the cover portion 22 side, and to use this projecting piece portion as a support portion 22d for supporting the leaf spring 40.

Further, according to the above embodiment, the support portion 22d is elastically deformed along the longitudinal direction of the mover 10 (X direction in the drawing), but as another example, the support portion 22d is formed with the thickness of the mover 10. It is also possible to elastically deform in the direction (Z direction in the drawing) and prevent the leaf spring 40 from being deformed or damaged by this elastic deformation.

Although the embodiments of the present invention have been described in detail above, the specific configuration is not limited to these embodiments, and even if there is a design change or the like within a range that does not deviate from the gist of the present invention. Included in the invention. Further, the above-described embodiments can be combined by diverting the technologies of each other as long as there is no particular contradiction or problem in the purpose and configuration thereof.

1: Linear vibration motor 10: Mover 11: Magnet 12: Weight 13: Yoke 20: Base 21: Board part 22: Cover part Flat plate part: 22a
22b, 22c: Side wall 22d: Support part 30: Coil 40: Leaf spring 41: One piece 42: Other piece 100: Mobile information terminal (electronic device)

Claims (5)

It includes a mover, a base that vibrates the mover, a coil that vibrates the mover along the base, and a leaf spring that elastically bends along the vibration direction of the mover.
The substrate is integrally provided with a support portion that can be elastically deformed in a direction intersecting the vibration direction.
The leaf spring is a linear vibration motor characterized in that one end side is fixed to the mover and the other end side is fixed to the support portion. The substrate has side walls located on both sides of the mover in the vibration direction.
The linear vibration motor according to claim 1, wherein the side wall has two notches spaced apart from each other in the intersecting direction, and a portion between the two notches is used as the support portion. .. The linear vibration motor according to claim 2, wherein the mover is tilted to come into contact with the substrate due to the elastic deformation of the support portion. The mover is formed in an elongated shape in which the dimension in the crossing direction is longer than the dimension in the vibration direction.
The leaf spring has one end side fixed to one side in the longitudinal direction of the mover, and the other end side is obliquely extended to the other side in the longitudinal direction of the mover and fixed to the support portion. The linear vibration motor according to claim 3, wherein the linear vibration motor is provided. An electronic device including the linear vibration motor according to any one of claims 1 to 4.

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