JP2017029889A - Linear vibration motor, and portable electronic apparatus equipped with linear vibration motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate installation work of a plurality of coils, while enabling a decrease in thickness and size, and to improve the vibration resistance or impact resistance of the plurality of coils.SOLUTION: A linear vibration motor is equipped with a movable element 10 equipped with a magnet portion 4 and a weight portion 7; a frame body 2 which stores the movable element 10 so as to reciprocate in one axis direction; coils 3A and 3B which are wound around the magnet portion 4 in a direction intersecting the one axis direction, and applies driving force in the one axis direction on the magnet portion 4; and an elastic member 6 which applies elastic force repelling the driving force on the movable element 10. The plurality of coils 3A and 3B is arranged in the one axis direction, and clearances between the adjacent coils are contacted to be integrated, and then fixed to the frame body 2.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a 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 carriers by vibrations. In wearable electronic devices that are carried by the carriers, , 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.

  As various types of vibration motors have been developed, a linear vibration motor capable of generating a relatively large vibration by linear reciprocating vibration has attracted attention. This linear vibration motor is provided with a linear fixed shaft, and by vibrating the mover along this, stable vibration can be obtained, and the mover can be held by the fixed shaft. Damage resistance during impact can be obtained.

  In the conventional technology of a linear vibration motor having a fixed shaft, a weight and a magnet are provided on the mover side, and a drive force (Lorentz force) is applied to the magnet by energizing a coil provided on the stator side. It has been proposed to form a through hole along the vibration direction and pass a single fixed shaft through the through hole. In particular, in the prior art disclosed in the following Patent Document 1, a plurality of the coils are arranged in the vibration direction so as to be wound around a bobbin so as to ensure a large driving force for vibrating the mover.

JP 2012-16153 A

  With the reduction in size and thickness of portable electronic devices and wearable electronic devices, there is a demand for further reduction in size and thickness of vibration motors installed therein. In particular, in an electronic device having a flat panel display unit such as a smartphone, the space in the device in the thickness direction orthogonal to the display surface is limited. Therefore, the vibration motor provided therein is reduced in size and thickness. There is a high demand.

  Therefore, it is proposed that the bobbin is omitted from the conventional structure shown in Patent Document 1 to reduce the size and thickness. However, when the bobbin is omitted, high precision is required for the work of arranging a plurality of small and thin coils in the vibration direction and fixing them to the housing, or arranging the plurality of coils in an annular shape with respect to the mover. When the relative relationship positions of the plurality of coils are shifted, there is a possibility that desired vibration cannot be obtained.

  This invention makes it an example of a subject to cope with such a problem. That is, it is an object of the present invention to make it possible to make a plurality of coils easy to mount while making it thin and compact.

In order to achieve such an object, a linear vibration motor according to the present invention has the following configuration.
A mover including a magnet part and a weight part, a frame that houses the mover so as to reciprocate along a uniaxial direction, and is wound around the magnet part along a direction intersecting the uniaxial direction. And a coil for applying a driving force along the uniaxial direction to the magnet portion, and an elastic member for applying an elastic force repelling the driving force to the mover, and the coil includes a plurality of coils along the uniaxial direction. A linear vibration motor characterized in that the linear vibration motor is disposed and integrated with another adjacent coil and fixed to the frame.

  Since the present invention is configured as described above, it is possible to achieve an object such as facilitating the mounting operation of a plurality of coils while enabling a reduction in thickness and size.

It is explanatory drawing (decomposed perspective view) which showed the linear vibration motor which concerns on embodiment of this invention. It is explanatory drawing (sectional drawing) which showed the linear vibration motor which concerns on embodiment of this invention. It is explanatory drawing (sectional drawing) which showed a part of coil before melt | fusion. It is explanatory drawing (sectional drawing) which showed a part of coil after melt | fusion. It is explanatory drawing (perspective view) which showed an example of the portable electronic device equipped with the linear vibration motor which concerns on embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings (hereinafter, the same reference numerals in different drawings indicate the same parts, and repeated descriptions in the respective drawings are omitted). 1 to 2 show the overall configuration of a linear vibration motor according to an embodiment of the present invention. The X direction in each figure indicates the vibration direction (uniaxial direction), the Y direction indicates the width direction, and the Z direction indicates the thickness (height) direction.

  The linear vibration motor 1 accommodates a mover 10 having a magnet part 4, a weight part 7, a shaft 8, a connecting member 20 and a connecting piece 29 for connecting them, and a reciprocating movement of the mover 10 along a uniaxial direction. A frame 2 that is wound around the magnet unit 4 along a direction intersecting the uniaxial direction, and a plurality of coils 3A and 3B that apply a driving force to the magnet unit 4 along the uniaxial direction. And an elastic member 6 that imparts an elastic force repelling the force to the mover 10.

  The mover 10 has a connecting member 20 connected to one end in the uniaxial direction of the magnet portion 4 and a connecting piece 29 connected to the other end. The weight member 7 and the shaft 8 are connected to the connecting member 20 and the connecting piece 29, respectively. The weight portion 7 and the shaft 8 are disposed on one side and the other side along the uniaxial direction with the magnet portion 4 interposed therebetween, and the protruding end side of the shaft 8 protruding from the weight portion 7 is a free end. (See FIG. 1 and FIG. 2).

  The magnet unit 4 includes a plurality of flat rectangular magnet pieces 4A, 4B, and 4C having a polarity along a uniaxial direction (X direction in the drawing) so that the same poles face each other, and the spacer yokes 4D and 4E are interposed therebetween. It is something that is sandwiched and joined. The reinforcing piece portion 22 of the connecting member 20 is fixed to the side portion of the magnet portion 4, and thereby the rigidity of the magnet portion 4 is enhanced.

  The connecting member 20 covers one end of the magnet part 4 and is connected to one shaft 8. The connecting member 20 extends from both ends of the connecting piece 21, and adhesive is applied to both side surfaces of the magnet part 4. It is formed in a U-shape having two reinforcing pieces 22 bonded together. The connecting member 20 is made of, for example, a nonmagnetic metal material having relatively high rigidity such as nonmagnetic stainless steel.

The connecting piece 29 is a flat plate-like member that covers the end of the magnet part 4 opposite to the connecting piece part 21, and the other shaft 8 is inserted and connected along the center axis, and the position away from the center axis To the weight 7. The connecting piece 29 is made of a nonmagnetic metal material having relatively high rigidity, such as nonmagnetic stainless steel.
The end of the connecting piece 29 on the bottom surface side of the frame body 2 protrudes toward the bottom surface side of the frame body 2 from the end surface on the same direction side of the weight portion 7 (see FIG. 2). This protruding portion functions as a contact portion 29C that contacts the slide receiving portion 2R when the mover 10 rotates.

The weight portion 7 is connected to both end portions of the magnet portion 4 in one axial direction (X direction in the drawing) via a connecting piece portion 21 and a connecting piece 29. The weight portion 7 can be made of a metal material having a high specific gravity (for example, tungsten). In the illustrated example, the weight portion 7 has a height in the Z direction larger than the thickness of the magnet portion 4 and is larger than the width of the magnet portion 4. It is formed in a rectangular cross-sectional shape having a large width in the Y direction.
A recess 7C is provided on the shaft protruding direction side of the weight portion 7 so as to be recessed toward the magnet portion 4 along the uniaxial direction, and the shaft 8 is disposed in a space in the recess 7C. The shaft 8 passes through the central portion of the weight portion 7 so as to pass through the bottom surface in the concave portion 7C.
In addition, the concave portion 7 </ b> C includes part or all of the bearing 9, and ensures a relatively large amplitude of the mover 10.

  The frame body 2 only needs to have a frame configuration capable of accommodating each part. In the illustrated example, the frame body 2 includes wall portions 2B, 2C, 2D, and 2E that are erected around the rectangular bottom surface 2A. I have. Moreover, the frame 2 is equipped with the cover plate 2Q which covers the accommodation in the frame 2 as needed. The cover plate 2Q is formed in a rectangular plate shape attached to the upper end surfaces of the wall portions 2B to 2E. The frame 2 can be formed by processing (pressing or the like) a metal plate. In the illustrated example, the frame body 2 has a flat shape in which the dimension in the thickness direction (Z direction in the figure) is smaller and the dimension in the vibration direction (X direction in the figure) is larger than the dimension in the width direction (Y direction in the figure). It has a (flat) substantially rectangular parallelepiped shape (box shape).

  Bearings 9 are fixed on both sides of the bottom surface 2A of the frame 2 in the uniaxial direction so as to slidably support the two shafts 8 respectively. More specifically, on each of one side and the other side in the uniaxial direction, the bottom surface 2A of the frame body 2 is provided with a bearing support portion 2A2 in the form of a vertical plate so as to penetrate the bearing support portion 2A2. A substantially cylindrical bearing 9 is fitted. Each bearing 9 passes through the shaft 8 and slides freely in the axial direction.

Further, on the bottom surface 2 </ b> A of the frame body 2, a slide receiving portion 2 </ b> R is provided so as to correspond to the position of the connecting piece 29.
When the mover 10 rotates around the shaft 8, the sliding receiving portion 2 </ b> R receives the contact portion 29 </ b> C of the connecting piece 29 and prevents the weight portion 7 from directly contacting the inner surface of the frame body 2. Since it is difficult to process the surface of the weight part 7 with low friction, if the weight part 7 comes into contact with the inner surface of the frame body 2 and slides, the sliding load increases and the generation of abnormal noise may increase. There is. However, in this embodiment, since the contact portion 29C of the connecting piece 29 that is easy to process is slid on the slide receiving portion 2R, the mover 10 can be vibrated smoothly and gently. In addition, the life of the linear vibration motor 1 can be extended.

A plurality of coils 3 </ b> A and 3 </ b> B are arranged along the uniaxial direction and are fixed to the frame body 2.
Each of the two coils 3 </ b> A and 3 </ b> B is an air-core coil that does not include a core material, and is wound in a rectangular shape that surrounds the cross section of the magnet unit 4.
These two coils 3A and 3B are connected in series with their winding directions reversed so that the magnetic poles when energized are reversed. The two coils 3A and 3B connected in series electrically connect both ends of the wire to the terminals T1 and T2 of the signal input unit 2A1 exposed to the outside from the frame body 2.

The two coils 3 </ b> A and 3 </ b> B are connected and integrated at adjacent ends, and are fixed to the frame 2. Each coil 3A (or 3B) is arranged so as to straddle the adjacent magnet pieces 4A and 4B (or 4B and 4C).
Particularly, in a preferred example of the present embodiment, as shown in FIG. 2, the boundary portion (spacer yoke 4D or 4E) of the adjacent magnet pieces 4A, 4B (or 4B, 4C) is in the non-energized state. It is biased in the direction away from the other coil 3B (or 3A) with respect to the axial center portion P1 (or P2) of one coil 3A (or 3B) straddling the part.
According to this configuration, when the mover 10 moves in one direction along one axial direction by energization of the coils 3A and 3B, the boundary portion side of the adjacent magnet pieces 4A and 4B (or 4B and 4C). This magnetic pole is affected by the magnetic field of the other coil 3 </ b> B (or 3 </ b> A), and it is possible to reduce the action of a force in the opposite direction to the one direction on the mover 10. That is, loss due to magnetic interference in the vicinity of the maximum amplitude position can be reduced, and the mover 10 can be reciprocally oscillated with high efficiency.

  The operation of assembling the mover 10 in the coils 3A and 3B is performed in the state where the connecting piece 29, the weight part 7 and the shaft 8 on one side are removed from the mover 10 so that the magnet part 4 is integrated with the coil 3A. , 3B, and thereafter, the connecting piece 29 is connected to the ends of both reinforcing piece portions 22 of the connecting member 20, the shaft 8 is then connected to the connecting piece 29, and the weight portion 7 is The shaft 8 is annularly mounted and connected to the connecting piece 29.

  The elastic member 6 is disposed non-coaxially with the pair of shafts 8 along the uniaxial direction, and gives the movable element 10 an elastic force repelling a driving force generated by the coil 3 and the magnet unit 4. . In the illustrated example, a coil spring that extends and contracts along the uniaxial direction (X direction) is used as the elastic member 6, and two elastic members 6 on one side are placed between the weight portion 7 and the wall portions 2 </ b> B and 2 </ b> C of the frame 2. Is intervening. In the illustrated example, the elastic member 6 is disposed in parallel with the pair of shafts 8. One end of the elastic member 6 is locked to a support protrusion 2P (see FIG. 1) provided on the walls 2B and 2C of the frame body 2, and the other end of the elastic member 6 is provided at the end of the weight portion 7. It is latched by the support protrusion (not shown).

Next, the manufacturing process of the coils 3A and 3B described above will be described in detail.
As shown in FIG. 3, the wire L constituting the coils 3 </ b> A and 3 </ b> B includes a linear conductor L <b> 1 located at the center, an insulating coating layer L <b> 2 that covers the outer peripheral surface of the linear conductor L <b> 1, and an outer periphery of the insulating coating layer And a hot melt layer L3 covering the surface. In the wire L, the hot-melt layers L3 between the adjacent wire L in a state of being wound in a coil shape are heat-sealed.
The linear conductor L1 is, for example, a copper wire, and the insulating coating layer L2 is, for example, a polyurethane resin. As the linear conductor L1 and the insulating coating layer L2, a known polyurethane copper wire, other enameled wire, or the like can be used.
The heat-melting layer L3 is, for example, a polyamide-based heat-melting resin layer and covers the entire circumference of the insulating coating layer L2.

Coil 3A, 3B advances simultaneously the winding process which winds the wire L in a coil shape, and the melt | fusion process which heats the wire L and fuse | melts the hot-melt layer L3 between the adjacent wire L Thus, it is configured in an integral coil shape.
More specifically, as shown in FIGS. 3 and 4, the wire L is simultaneously wound around the outer peripheral surface of the temporary core material C having a rectangular cross section, and at the same time with hot air at a temperature of 140 to 170 ° C. Heated. For this reason, the hot melt layer L3 is melted, and the adjacent wire rods L are thermally fused. The wire L is wound around the outer periphery of the temporary core material C in a plurality of layers (three layers according to the illustrated example) so as to constitute each coil 3A (or 3B).
After one coil 3A is completed by the winding step and the fusing step, the winding step and the fusing step are performed by winding the wire L in the reverse direction, and the other coil 3B is formed. Then, after all the winding and fusing operations of the two coils 3A and 3B are completed, the temporary core material C is removed from the coils 3A and 3B.
Therefore, the coil 3A and the coil 3B are wound in opposite directions, the adjacent ends are heat-sealed, and the adjacent wires L are also heat-sealed to form an integral cylindrical shape.

According to the linear vibration motor 1 having the above-described configuration, the coils 3A and 3B arranged in a single axial direction are integrated into an air core having a rectangular cross section, so that each part including the coils 3A and 3B is thinned. In addition, it is possible to reduce the size, and in addition, it is easy to wrap the plurality of coils 3A and 3B around the magnet portion 4 or to fix the coils 3A to the frame 2.
In addition, since the plurality of coils 3A and 3B are integrated by thermal fusion, compared to the case where a plurality of independent coils are used, the bonding strength between the coils and between the coil and the frame 2 is excellent, and consequently Vibration resistance and impact resistance can be improved.

According to the linear vibration motor 1 configured as described above, when not driven (non-energized state), the mover 10 is stationary at the vibration center position where the elastic force of the elastic member 6 is balanced.
When a vibration generating current having a resonance frequency determined by the mass of the mover 10 and the elastic coefficient of the elastic member 6 is input to the coil 3 via the signal input portion 2A1 of the frame 2, the magnet portion 4 is uniaxially (not shown) A driving force (Lorentz force) in the X direction acts, and the movable element 10 reciprocates stably along a uniaxial direction by the driving force and the elastic repulsive force of the elastic member 6.

Next, the portable electronic device 100 which is an example of the electronic device equipped with the linear vibration motor 1 according to the embodiment of the present invention will be described (see FIG. 4).
The portable electronic device 100 includes a linear vibration motor 1 mounted in a thin flat box-shaped housing to constitute a portable information terminal (for example, a smartphone or a tablet personal computer).
According to this configuration, a stable vibration can be obtained by the linear vibration motor 1 and the thickness can be reduced and the width can be reduced, and an abnormal sound is generated at the start and end of an incoming call or alarm function in a communication function. Difficult and stable vibration can be transmitted to the user with good responsiveness. Moreover, the portable electronic device 100 pursuing high portability or design can be obtained by making the linear vibration motor 1 thin and compact. Furthermore, since the linear vibration motor 1 has a compact shape in which each part is housed in a rectangular parallelepiped frame 2 with a reduced thickness, the linear vibration motor 1 can be efficiently installed inside the thinned portable electronic device 100. . Moreover, since the linear vibration motor 1 has high impact resistance strength and high durability, it is possible to obtain a portable electronic device 100 that has a long life and is unlikely to fail.

  In addition, according to the said embodiment, although the shaft 8 was provided in the needle | mover 10, as another example, the shaft 8 is fixed to the frame 2 side, and the magnet part 4 is along this fixed shaft 8. Further, it is possible to adopt a mode in which the weight portion 7 and the like are vibrated.

  Moreover, according to the said embodiment, although several coil 3A, 3B from which the winding direction differs was connected in series, as an example, the aspect which connected several coil 3A, 3B of the same winding direction, or several coil It is also possible to adopt a mode in which 3A and 3B are connected in parallel. In these other examples, the magnetic pole position of the magnet unit 4 is changed so that the mover 10 reciprocates.

  Moreover, according to the said embodiment, the winding process which winds the wire L in a coil shape, and the melt | fusion process which heats the wire L and fuse | melts the hot melt layers L3 between the adjacent wire L are carried out. Although the wire L is heat-sealed at the same time, as another example, the winding step and the fusion step are alternately repeated, or the fusion by heating after the winding step is completed. It is also possible to heat-bond between the wire rods L by performing a bonding process.

  Moreover, according to the said embodiment, although several coil 3A, 3B was integrated by heat sealing | fusion, as another example, the aspect which adhere | attached and integrated several coil 3A, 3B with the adhesive agent, or several It is also possible to adopt an embodiment in which the coils 3A and 3B are integrated by fitting connection.

  Moreover, in the said embodiment, although the coil spring was used as the elastic member 6, as another example of the elastic member 6, the aspect using a leaf | plate spring, the aspect using elastic bodies, such as rubber | gum, a coil spring, a leaf | plate spring, It is also possible to adopt an aspect in which the elastic bodies are appropriately combined.

  Moreover, in the said embodiment, as a particularly preferable aspect, the shaft 8 was connected to the both ends of the magnet part 4, and these two shafts 8 were each slidably supported by the bearing 9, but as another example, a magnet It is also possible to adopt a mode in which the shaft 8 is connected to only one end side of the portion 4 and the single shaft 8 is supported by the bearing 9.

  Moreover, in the said embodiment, although the needle | mover 10 was comprised so that it might have integrally the shaft 8 dividedly arrange | positioned at the both ends of the magnet part 4, this invention is not limited to the aspect of the shaft 8. FIG. As another embodiment according to the present invention, an embodiment (not shown) in which the divided shaft 8 is replaced with an integral shaft that passes through the magnet portion 4 and is continuous, or from the movable element 10 described above. A mode (not shown) in which the mover from which the shaft 8 is omitted is engaged with the shaft fixed to the frame 2 and guided in a uniaxial direction, the mover from which the shaft 8 is omitted from the mover 10 It is also possible to adopt a mode in which the elastic member 6 is reciprocally supported by the elastic member 6 without using a shaft.

  Moreover, in the said embodiment, as a preferable aspect which is easy to accommodate especially in the portable electronic device 100, the cross section orthogonal to a uniaxial direction is rectangular (square shape) about the magnet part 4, coil 3A, 3B, the frame 2, etc. The cross section of the entire linear vibration motor 1 has a rectangular shape (square shape). However, as another example, the cross-sectional shape of each part or the entire linear vibration motor 1 may be circular or It is also possible to use shapes other than the illustrated examples, such as squares, polygons.

  Moreover, although the portable electronic device 100 of FIG. 5 has shown the smart phone or tablet personal computer which contained the linear vibration motor 1 as a preferable example, as another example of this portable electronic device 100, the linear vibration motor 1 is contained. Thus, a wearable electronic device including a mobile phone, a portable game machine, a portable communication watch, a wearable communication terminal, and other portable electronic devices can be configured.

1: Linear vibration motor, 2: Frame body, 3A, 3B: Coil 4: Magnet part, 6: Elastic member, 7: Weight part 8: Shaft, 9: Bearing, 10: Movable element 20: Connection member, 21: Connection One part, 22: Reinforcement piece part, 29: Connection piece L: Wire rod, L1: Linear conductor, L2: Insulation coating layer, L3: Thermal melt layer

Claims (7)

A mover including a magnet part and a weight part, a frame that houses the mover so as to reciprocate along a uniaxial direction, and is wound around the magnet part along a direction intersecting the uniaxial direction. A coil for applying a driving force along the uniaxial direction to the magnet portion, and an elastic member for applying an elastic force repelling the driving force to the mover,
A plurality of the coils are arranged along the uniaxial direction, are integrated with each other adjacent to each other, and are fixed to the frame.   The linear vibration motor according to claim 1, wherein the coil is an air-core coil not including a core material.   The magnet part is formed in a shape in which a rectangular cross section is continuous in the uniaxial direction, and the coil is wound in a rectangular shape surrounding the cross section of the magnet part. Or the linear vibration motor of 2.   The wire constituting the coil has a linear conductor located at the center, an insulating coating layer covering the outer peripheral surface of the linear conductor, and a heat melting layer covering the outer peripheral surface of the insulating coating layer, The linear vibration motor according to any one of claims 1 to 3, wherein the heat-melt layers between adjacent wires are fused in a state of being wound in a shape.   The plurality of coils are formed by a manufacturing process including a winding process of winding the wire in a coil shape and a fusion process of heating the wire to fuse the hot melt layers between adjacent wires. The method of manufacturing a linear vibration motor according to claim 4, wherein:   6. The linear vibration motor according to claim 5, wherein after one of the adjacent coils is formed by the manufacturing process, the other coil is reversely wound and formed by the manufacturing process. Method. A portable information terminal comprising the linear vibration motor according to claim 1.

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