JP2017063583A - Linear vibration motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve workability during assembly of a linear vibration motor compatible of thinning, by eliminating constraints on assembly procedure in a linear vibration motor, and suppressing occurrence of production defect such as coil disconnection.SOLUTION: A linear vibration motor 1 includes a mover 2 having a magnet 2A and a weight 2B, a housing 3 housing the mover 2, a pair of coils 4A, 4B imparting a driving force for vibrating the mover 2 to the magnet 2A, and an elastic member 5 provided in the housing 3 and imparting an elastic force repelling the driving force to the mover 2. The housing 3 includes a pair of support surfaces 3A, 3B in the vibration direction of the mover 2, and the pair of coils 4A, 4B are fixed to the pair of support surfaces 3A, 3B, respectively, with the magnet 2B interposed therebetween.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a linear vibration motor.

  Vibration motors (or vibration actuators) are widely used as devices that are built in portable electronic devices and transmit signal generation such as incoming calls and alarms to vibration 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.

  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 includes a stator having a casing and a coil, and a mover having a magnet and a weight (weight), and a driving force (Lorentz force) applied to the magnet by energizing a driving current to the coil. ) Linearly vibrates the mover (see Patent Document 1 below).

Japanese Patent Laying-Open No. 2015-95943

  The above-described linear vibration motor supports the mover in a single axial direction via a spring in the casing, and a coil fixed in the casing is wound around the vibration axis of the mover. In such a linear vibration motor, the magnet of the mover is disposed inside the coil. Therefore, if the weight of the mover is enlarged to secure a sufficient mass of the weight, the weight and the magnet Before connecting the magnets, it is necessary to dispose the magnet inside the coil, and the assembly procedure is restricted, resulting in a problem that good productivity cannot be obtained. In addition, when the mover is passed through the inside of the coil, there is a problem that the mover and the coil are in contact with each other and a defect such as disconnection of the coil is likely to occur.

  In addition, along with miniaturization and thinning of portable electronic devices, there is a demand for further miniaturization and thinning of linear vibration motors installed therein. In particular, in an electronic device having a flat panel display unit such as a smartphone, the space is limited in the device in the thickness direction intersecting with the display surface, and thus the linear vibration motor deployed there is highly thin. There is a request. When considering the thinning of the linear vibration motor described above, the coil wound around the vibration axis must be flattened, so the work of passing the mover inside the coil without touching the coil is required. Further, it becomes more difficult, and there is a problem that good workability at the time of assembly cannot be obtained.

  An object of the present invention is to solve such a problem. That is, reducing the restrictions on the assembly procedure in the linear vibration motor, suppressing the occurrence of defective production such as coil disconnection, improving the workability at the time of assembly in the linear vibration motor corresponding to the thinning, etc. It is the subject of the present invention.

In order to solve such a problem, a linear vibration motor according to the present invention has the following configuration.
A mover comprising a magnet part and a weight part; a housing for housing the mover; a pair of coils for applying a driving force to vibrate the mover to the magnet part; and the housing, An elastic member that imparts an elastic force repelling a driving force to the mover, the housing includes a pair of support surfaces along a vibration direction of the mover, and the pair of coils includes the magnet unit. A linear vibration motor characterized in that the linear vibration motor is fixed to the pair of support surfaces in between.

1 is an exploded perspective view showing an overall configuration of a linear vibration motor according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing ((a) is an external appearance top view, (b) is AA sectional drawing in (a)) which shows the whole structure of the linear vibration motor which concerns on embodiment of this invention. It is explanatory drawing ((a) is a perspective view of the state which open | released the cover body, (b) is a top view of the state which open | released the cover body) of the linear vibration motor which concerns on other embodiment of this invention. It is explanatory drawing which showed the electronic device (mobile information terminal) equipped with the linear vibration motor which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings (hereinafter, the same reference numerals in different drawings indicate parts having the same functions, and redundant description in each drawing will be omitted). 1 and 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 includes a mover 2 having a magnet portion 2A and a weight portion 2B, a housing 3 that houses the mover 2, and a pair of coils that are respectively fixed to a pair of support surfaces 3A and 3B of the housing 3. 4A, 4B and an elastic member 5 provided in the housing 3 are provided. The pair of coils 4A and 4B applies a driving force to vibrate the mover 2 to the magnet portion 2A by energizing the driving current, and the elastic member 5 applies the driving force generated by energizing the pair of coils 4A and 4B. A repelling elastic force is applied to the mover 2.

  In such a linear vibration motor 1, the casing 3 includes a pair of support surfaces 3A and 3B along the vibration direction of the mover 2, and the pair of coils 4A and 4B sandwich the magnet portion 2A. Since it is fixed to the pair of support surfaces 3A and 3B, the work of passing the magnet portion 2A of the mover 2 through the coil becomes unnecessary. Thereby, the restrictions of the assembly procedure in the linear vibration motor 1 can be reduced. Moreover, since the needle | mover 2 can be easily arrange | positioned in the housing | casing 3 without touching the coils 4A and 4B, generation | occurrence | production of production defects, such as a coil disconnection, can be suppressed. Further, in the linear vibration motor corresponding to the thinning, it is not necessary to perform the operation of passing the mover through the flat coil, so that the workability at the time of assembly can be improved.

  Details will be described below with reference to the illustrated example, but the embodiment of the present invention is not particularly limited thereto.

  The magnet part 2A of the mover 2 includes three magnet pieces 11, 12, 13 and two spacers 14, 15 arranged between them. The illustrated magnet pieces 11, 12, 13 are magnetized along the illustrated X direction (vibration direction of the mover 2), and the magnetic poles of the magnet pieces 11, 12 close to each other and the magnet pieces 12, 13 are close to each other. The magnetization direction is set so that the magnetic poles to be made have the same polarity. The spacer 14 disposed between the magnet pieces 11 and 12 and the spacer 15 disposed between the magnet pieces 12 and 13 may be a magnetic body (yoke) or a non-magnetic body. In the case where a holding member for holding the magnet pieces 11, 12, 13 at a predetermined interval is separately provided, the spacers 14, 15 can be omitted to make the interval a gap.

  The pair of coils 4A and 4B for applying a driving force to the magnet portion 2A are wound along the X direction (vibration direction of the mover 2) and the Y direction (width direction of the mover 2) shown in the drawing, respectively. . The pair of coils 4A and 4B are energized with a drive current so that the current directions of both are opposite to each other, and the Y-direction winding portions of the coils 4A and 4B are disposed on the portions where the spacers 14 and 15 are disposed. Thus, it is being fixed to a pair of support surfaces 3A and 3B in the housing | casing 3, respectively.

  The weight 2B of the mover 2 has weights 20 disposed on both sides in the vibration direction (X direction in the drawing) of the mover 2, and the weight 20 and the magnet 2B are connected via a connecting member 21. ing. The weight body 20 can be made of a metal material having a high specific gravity (for example, tungsten). In the illustrated example, the weight body 20 has a height in the Z direction larger than the thickness of the magnet portion 2B and is larger than the width of the magnet portion 2B. It has a rectangular cross-sectional shape having a width in the Y direction.

  Between the pair of connecting members 21, reinforcing members 22 are disposed on both sides of the magnet portion 2B. Both ends of the reinforcing member 22 are connected to the connecting member 21 so that the magnet portion 2A including the plurality of magnet pieces 11, 12, 13 and the plurality of spacers 14 and 15 and the weight portion 2B including the plurality of weight bodies 20 are integrated. The rigidity of the mover 2 is enhanced by reinforcement.

  The movable element 2 has a thickness that intersects the vibration direction (X direction) and the width direction (Y direction) with respect to the dimension in the width direction (Y direction) that intersects the linear vibration direction (X direction). It has a thin shape with a small dimension in the vertical direction (Z direction in the figure). On the other hand, the contents (inside the housing 3) are accommodated by reducing the thickness of the pair of coils 4A and 4B wound in the illustrated X direction and the illustrated Y direction in the illustrated Z direction. The mover 2 and the coils 4A and 4B) can be thinned.

  In the housing 3, a guide shaft 6 is provided between the pair of coils 4A and 4B to support the mover 2 so as to vibrate along a uniaxial direction. In the illustrated example, the guide shaft 6 is divided and arranged along one axial direction (X direction in the drawing), one end side thereof is fixed to the weight body 20, and the other end side protrudes in the opposite direction to form a free end. ing. The guide shaft 6 is arranged coaxially with the center of gravity axis of the mover 2 and guides the vibration of the mover 2 along a uniaxial direction. Here, the guide shaft 6 is divided and arranged. However, the guide shaft 6 may be fixed through the magnet portion 2B or slidably supported through the magnet portion 2B.

  In the illustrated example, the weight body 20 includes a guide shaft support portion 20 </ b> A for supporting the guide shaft 6. The guide shaft support portion 20A is a portion that is recessed along the uniaxial direction from the end portion 20B of the weight body 20, and the guide shaft 6 supported at one end side by the guide shaft support portion 20A is the support surface 3A of the housing 3. Is slidably supported along a uniaxial direction (the X direction in the drawing) on the bearing 7 attached via the bearing support portion 7A. At this time, the guide shaft support portion 20A of the weight body 20 has a width enough to accommodate the bearing 7, and the bearing 7 enters the guide shaft support portion 20A, thereby ensuring a large amplitude of the movable element 2. doing.

  In the illustrated example, one end side of the guide shaft 6 is fixed to the mover 2 side (weight body 20), and the other end side of the guide shaft 6 is slidable by a bearing 7 provided in the housing 3. Although the example which supports is shown, it replaces with this and the one end side of the guide shaft 6 is fixed to the housing | casing 3 side, and the other end side of the guide shaft 6 is attached to the bearing provided in the needle | mover 2 (weight body 20). And may be slidably supported.

  The elastic member 5 is disposed between the mover 2 and the housing 3. In the illustrated example, the elastic member 5 is arranged non-coaxially with the pair of guide shafts 6 along the uniaxial direction, and an elastic force repelling a driving force generated by the coils 4A and 4B and the magnet portion 2B is applied to the mover. 2 is given. In the illustrated example, a coil spring that extends and contracts along the uniaxial direction (X direction) is used as the elastic member 5, and two elastic members 5 on one side are disposed between the end 20 </ b> B of the weight body 20 and the housing 3. Is intervening. Here, the elastic member 5 is disposed in parallel with the pair of guide shafts 6. One end of the elastic member 5 is supported by a support protrusion 16 provided on the housing 3, and the other end of the elastic member 5 is supported by a support protrusion 17 provided on an end 20 </ b> B of the weight body 20.

  The casing 3 only needs to have a case-like configuration capable of accommodating each part, but in the illustrated example, the casing 3 is constituted by a frame body 30 and a lid body 31 each having an accommodation part. The frame 30 has a rectangular bottom surface 30A, has side walls 30B, 30C, 30D, and 30E erected on the periphery thereof, and has a box shape in which the bottom surface 30A is open. The lid 31 is a plate-like member that covers the opened bottom surface 30A.

  The frame 30 can be formed by processing (pressing or the like) a metal plate. In the example shown in the figure, the frame 30 has a thin 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 substantially rectangular parallelepiped shape (box shape). On the other hand, the lid body 31 is formed in a rectangular plate shape that is attached to the upper end surfaces of the side walls 30 </ b> B to 30 </ b> E of the frame body 30.

  The support surface 3A of the housing 3 is provided on the bottom surface 30A of the frame 30, the support surface 3B of the housing 3 is provided on the inner surface 31A of the lid 31, and the pair of coils 4A and 4B. One coil 4A is fixed to the frame body 30 side, and the other coil 4B is fixed to the lid body 31 side. According to this, it is possible to arrange the pair of coils 4 </ b> A and 4 </ b> B simply by attaching the lid 31 to the frame 30.

  The side walls 30B and 30D of the frame 30 are provided with the above-described support protrusions 16 that support one end side of the elastic member 5, and guide walls are provided on the inner surfaces of the side walls 30B and 30D as necessary. A buffer member (rubber material or the like) 34 is attached as a buffer when the end of 6 collides.

  A suction plate (magnetic plate) 32 and a sliding plate 33 are disposed in the housing 3 as necessary. The attraction plate 32 is a magnetic plate, and is a member that attracts a part of the magnet portion 2 </ b> A in order to pre-rotate the mover 2 in one direction around the guide shaft 6. The sliding plate 33 is a member that is disposed in a portion where the movable element 2 that is urged to rotate in one direction in advance is allowed to come into contact with the movable element 2 so that the movable element 2 can smoothly slide. In the illustrated example, the suction plate 32 is attached to the inner surface 31 </ b> A of the lid body 31, and the sliding plate 33 is attached to the bottom surface 30 </ b> A of the frame body 30.

  Thus, an example of the assembly method of the linear vibration motor 1 is demonstrated. First, the coil 4 </ b> A is fixed to the bottom surface 30 </ b> A of the frame body 30 of the housing 3. When the above-described sliding plate 33 is provided, the sliding plate 33 is attached to the bottom surface 30A. On the other hand, in the mover 2, the magnet portion 2A and the weight portion 2B are integrated in advance, and when the guide shaft 6 is provided, the guide shaft 6 is also fixed to the mover 2 in advance. Then, the guide shaft 6 is pivotally supported by the bearing 7, and the bearing support portion 7 </ b> A is attached to the bottom surface 30 </ b> A of the frame body 30, thereby assembling the mover 2 in the frame body 30. Thereafter, the elastic member 5 is mounted between the end 20B of the weight 20 and the side walls 30B and 30D of the frame 30 in the movable element 2. In this state, the assembling of the contents in the frame 30 is completed.

  On the other hand, the coil 4B is fixed to the inner side 31A of the lid 31 in advance, and the suction plate 32 is attached to the inner side 31A as necessary. As described above, after the assembly of the contents in the frame body 30 is completed, the lid body 31 to which the coil 4B is fixed is attached to the frame body 30 with the inner side surface 31A facing the bottom surface 30A. In this state, the assembly of the contents in the housing 3 is completed. After that, the assembly process of the linear vibration motor 1 is completed by connecting the lead wires of the coils 4A and 4B to the input terminal portion 30F of the frame 30.

  The operation of such a linear vibration motor 1 will be described. In the linear vibration motor 1, a drive unit is configured by the coils 4 </ b> A and 4 </ b> B fixed to the support surfaces 3 </ b> A and 3 </ b> B of the housing 3 and the magnet unit 2 </ b> A of the mover 2. When not driven, the mover 2 is stationary at the vibration center position where the elastic force of the elastic member 5 is balanced. And if the coil 4A, 4B is supplied with a driving current whose current directions are opposite and synchronized, a driving force (Lorentz force) in the X direction is applied to the magnet portion 2A, and this driving force and the elastic repulsive force of the elastic member 5 are applied. As a result, the mover 2 reciprocates along a uniaxial direction (X direction in the drawing). At this time, the drive current supplied to the coils 4A and 4B is preferably an alternating current having a resonance frequency determined by the mass of the mover 2 and the elastic coefficient of the elastic member 5.

  FIG. 3 shows a linear vibration motor according to another embodiment of the present invention. In this linear vibration motor 1A, the movable element 2 includes a side weight body 23 as a weight portion 2B. The side weights 23 are provided on both sides in the Y direction (width direction) of the magnet portion 2A. The side weights 23 are joined to or integrally formed with the weights 20 provided on both sides in the X direction (vibration direction) in the figure. The side weight body 23 is for increasing the mass of the mover 2 and is formed of a material having a high specific gravity such as tungsten, like the weight body 20. In the illustrated example, the movable element 2 has the same width in the Y direction (width direction) in the portion where the side weight body 23 is provided and the portion where the weight body 20 is provided.

  This linear vibration motor 1A has a structure in which the magnet portion 2A of the mover 2 is disposed between the pair of coils 4A and 4B, as in the above-described embodiment, so that both sides of the magnet portion 2A in the width direction are provided. A space for arranging the side weight bodies 23 can be secured. Such a linear vibration motor 1 </ b> A can generate an effective vibration in which the mass of the mover 2 is increased with the same driving force as that of the above-described embodiment.

  The linear vibration motors 1 and 1A described above can be reduced in thickness by reducing the dimension in the thickness direction (Z direction in the figure) relative to the dimension in the width direction (Y direction in the figure) of the mover 2 and the housing 3. Is possible. At this time, since the magnet portion 2A of the mover 2 is disposed between the pair of coils 4A and 4B disposed in the housing 3, even if the structure is thinned, the magnet 4A contacts the coils 4A and 4B. The movable element 2 can be easily arranged in the housing 3 without doing so. As a result, the linear vibration motors 1 and 1A have good workability at the time of assembly, and production with a high yield is possible by suppressing the occurrence of defects such as coil disconnection.

  FIG. 4 shows a portable information terminal 100 as an example of an electronic apparatus equipped with the linear vibration motors 1 and 1A according to the embodiment of the present invention. The portable information terminal 100 including the linear vibration motors 1 and 1A that can obtain a stable vibration and can be thinned and compact in the width direction generates an abnormal sound at the start and end of an operation such as an incoming call or an alarm function in a communication function. It can be transmitted to the user with stable vibration that is difficult to perform. Further, the portable information terminal 100 pursuing high portability or design can be obtained by making the linear vibration motor 1 thin and compact in the width direction. Furthermore, since the linear vibration motors 1 and 1A have a compact shape in which each part is housed in a rectangular parallelepiped housing 3 with a reduced thickness, the linear vibration motors 1 and 1A should be efficiently installed in the thinned portable information terminal 100. Can do.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present 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.

1, 1A: linear vibration motor,
2: mover, 2A: magnet part, 2B: weight part,
3: Housing, 3A, 3B: Support surface,
4A, 4B: a pair of coils,
5: elastic member, 6: guide shaft, 7: bearing, 7A: bearing support,
11, 12, 13: Magnet piece, 14, 15: Spacer,
16, 17: support protrusion,
20: weight, 20A: guide shaft support, 20B: end,
21: connecting member, 22: reinforcing member, 23: lateral weight body,
30: Frame body, 30A: Bottom surface, 30B-30E: Side wall, 30F: Input terminal part,
31: lid, 31A: inner surface, 32: suction plate (magnetic plate), 33: sliding plate,
34: cushioning member,

Claims (5)

A mover including a magnet part and a weight part;
A housing for accommodating the mover;
A pair of coils for applying a driving force to vibrate the mover to the magnet unit;
An elastic member provided in the housing and imparting an elastic force repelling the driving force to the mover;
The housing includes a pair of support surfaces along the vibration direction of the mover,
The linear vibration motor, wherein the pair of coils are respectively fixed to the pair of support surfaces with the magnet portion therebetween. The housing includes a frame body whose bottom surface is open and a lid body that covers the bottom surface,
The linear vibration motor according to claim 1, wherein one of the pair of support surfaces is provided on the bottom surface, and the other of the pair of support surfaces is provided on an inner surface of the lid. The mover has a thin shape in which the dimension in the thickness direction intersecting the vibration direction and the width direction is smaller than the dimension in the width direction intersecting the linear vibration direction,
The linear vibration motor according to claim 2, wherein the coil is wound along the width direction and the vibration direction.   4. The guide shaft according to claim 1, wherein a guide shaft is provided between the pair of coils so as to vibrate the mover along a uniaxial direction. 5. Linear vibration motor.   A portable information terminal comprising the linear vibration motor according to claim 1.

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