JP6479557B2 - Linear vibration motor - Google Patents

Description

  The present invention relates to a linear vibration motor that generates reciprocating vibration by an input signal.

  A vibration motor (or vibration actuator) is built in a portable electronic device and widely used as a device for transmitting a signal generation such as an incoming call or an alarm to a portable person by vibration. In addition, a vibration motor has recently been attracting attention as a device for realizing haptics (skin sensation feedback) in a human interface such as a touch panel.

  Among various types of vibration motors being developed, linear vibration motors are known that can generate relatively large vibrations due to linear reciprocating vibration of the mover. In the conventional 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 movable is elastically supported along the vibration direction The element is oscillated back and forth (see Patent Document 1 below).

JP 2011-97747 A

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

  In order to obtain a desired driving force while securing a sufficient magnet volume and achieving a desired inertia force by securing a sufficient weight of a weight to realize a thin linear vibration motor, the magnet and the weight are By making the provided mover flat, it is possible to reduce the thickness while securing the volume of the magnet and the weight of the weight. In this case, if the mover rotates about a linear vibration axis, the flat mover has a shape in which the side portion easily collides with the surrounding frame due to the rotation, so abnormal noise due to the collision is generated. A stable operation can not be obtained as it occurs. For this reason, in the prior art, two guide shafts are provided to suppress the rotation of the mover around the vibration axis to realize stable linear vibration. However, when two guide shafts are provided, it is necessary to ensure the parallelism of the two guide shafts, and high accuracy is required for assembly, so there is a problem that improvement of productivity becomes difficult.

  The present invention takes an example of the problem to address such a problem. That is, the linear vibration motor can be made thinner, and even when the mover is flattened, the mover can be prevented from rotating around the vibration axis and noise can be generated. It is an object of the present invention to obtain stable vibration without using and to obtain high productivity.

In order to achieve such an object, the linear vibration motor according to the present invention has the following configuration.
A mover, a frame supporting the mover in a reciprocating manner, a drive member fixed to the frame and driving the mover, and provided between the frame and the mover. The movable member includes: an elastic member elastically deformed by reciprocating vibration of the mover; and a pressure member applying pressure to the mover in a direction crossing the vibration direction of the mover, the mover including the vibration The width in the direction intersecting the direction is a square or larger than the thickness in the direction intersecting the vibration direction, and the pressure member is disposed between the surface along the width of the mover and the frame Linear vibration motor characterized in that it is a leaf spring .

  The linear vibration motor according to the present invention having such features includes the pressure-applying member that applies pressure to the mover in the direction crossing the vibration direction, so the mover can be made flat to cope with thinning. Also in this case, it is possible to prevent the mover from rotating around the vibration axis and emitting noise. Further, since there is no need to support the mover by two axes, stable vibration can be obtained without using high precision parts, and high productivity can be obtained.

1 is an exploded perspective view of a linear vibration motor according to an embodiment of the present invention. An assembled state diagram of the linear vibration motor according to the embodiment of the present invention ((a) is a plan view, (b) is an AA sectional view in (a)). It is a perspective view which shows an example of a pressurizing member. Explanatory drawing ((a) is a top view, (b) is a front view, (c) is a side view) which shows an example of a pressurizing member. It is an explanatory view showing a portable electronic device (portable information terminal) provided with a linear vibration motor concerning an embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the linear vibration motor 1 according to the embodiment of the present invention includes a mover 2, a frame 3, a drive member 4, an elastic member 5, and a pressure member 6. In the figure, the X direction indicates the vibration direction of the mover 2, the Y direction indicates the width direction intersecting the vibration direction of the mover 2, and the Z direction indicates the thickness direction intersecting the vibration direction of the mover 2.

  The mover 2 includes a magnetic pole member 20 including a magnet and a yoke as necessary, and a weight 21. The mover 2 is supported by the frame 3 so as to oscillate back and forth along the X direction. In the illustrated example, in the illustrated example, a pole member 20 having a rectangular cross-sectional shape extending in the X direction is disposed at the center in the X direction, and weights 21 having a rectangular cross section are connected to both ends in the X direction. .

  In the mover 2, the shapes of both the magnetic pole member 20 and the weight 21 are such that the width in the direction (Y direction in the drawing) intersecting in the X direction in the drawing is greater than the thickness in the direction (Z direction in the drawing) A square shape, specifically, a flat shape in which the width in the Y direction is larger than the thickness in the Z direction, and having such a shape realizes thinning of the linear vibration motor 1.

  The magnetic pole member 20 can be configured, for example, by arranging a plurality of magnets magnetized in the X direction so that the same magnetic poles face each other, and arranging a yoke between the arranged magnets.

  The frame 3 may be any one as long as it supports the mover 2 so as to oscillate back and forth, but in the illustrated example, the width direction (Y direction) is configured in a rectangular shape of thickness direction (Z direction) or more A case frame 30 provided with 30A, a pair of side walls 30B and a pair of front walls 30C, and a cover frame 31 covering the case frame 30 are provided. The lid frame 31 is provided with an input terminal portion 31A for energizing the drive member 4 (coil 40) described later.

  An elastic member 5 is provided between the mover 2 and the frame 3 along the X direction. The elastic member 5 is elastically deformed by reciprocating vibration of the mover 2 in the X direction, and in the illustrated example, a total of four compression coil springs 50 each having an axis along the X direction are disposed at two sides on each side. ing. One end of the compression coil spring 50 is held by a spring holding portion 33 provided inside the front wall 30C of the frame 3, and the other end is held by the end of the weight 21 of the mover 2.

  Although various configurations can be implemented as the configuration for supporting the mover 2 in a freely reciprocating manner, in the illustrated example, a pair of guide shafts 7 extending along the X direction is attached to the mover 2, A bearing 32 slidably supporting the guide shaft 7 is attached to the bottom surface 30A of the frame 3 (case frame 30). Not limited to this, both ends of the guide shaft are supported by the front wall 30C of the frame 3 and a structure for sliding the mover 2 along the guide shaft and a guide shaft are not provided. The movable element may be slid along the moving surface.

  The driving member 4 is a member that generates a driving force that causes the movable element 2 to oscillate in a reciprocating manner along the X direction in cooperation with the driven member (magnetic pole member 20) included in the movable element 2. In the illustrated example, A coil 40 is wound around the magnetic pole member 20 of the mover 2 and fixed to the frame 3. In the illustrated example, a coil 40 fixed to the frame 3 is disposed around the yoke of the magnetic pole member 20. By energizing the coil 40 with an alternating current drive signal having a resonance frequency determined by the weight of the weight 21 and the elastic coefficient of the elastic member 5, the mover 2 can be oscillated back and forth. The drive member 4 fixed to the frame 3 and the driven member mounted on the mover 2 should be appropriately selected so that the mover 2 oscillates in the X direction by using a coil and a magnet. Can.

  The pressurizing member 6 is a member that applies a pressurizing force to the mover 2 supported in a reciprocating manner in the frame 3 in a direction intersecting the vibration direction. The pressure member 6 can be constituted by a plate spring 60 disposed between the surface along the width of the mover 2 and the frame 3. The pressure member 6 is not limited to this, and may be configured by a torsion coil spring or the like.

  As shown in FIGS. 2 and 3, a plate spring 60 which is an embodiment of the pressure applying member 6 is a plate-like member disposed along the bottom surface 30A of the frame 3 and is installed with a flat installation portion 61 The pressure portion 62 is bent from the portion 61 and is inclined and rises in a cantilever shape. In the illustrated example, a pair of pressurizing portions 62 is provided along the vibration direction (X direction) of the mover 2, and the installation portion 61 is provided in a portion excluding the pressurizing portions 62.

  The pressurizing portion 62 is a portion which is partially cut out and refracted from a highly elastic plate member forming a leaf spring, and includes an arm portion 62A extending in a direction intersecting the X direction and a pair of arm portions 62A. The arm portion 62A is refracted so as to be inclined at a predetermined angle with respect to the installation portion 61 installed along the bottom surface 30A of the frame 3.

  As shown in FIG. 2B, the plate spring 60 serving as the pressure applying member 6 is disposed between the bottom surface 30A of the frame 3 (case frame 30) and the mover 2, and the pressure applying portion 62 is the mover The two weights 21 are elastically held. As a result, the connecting portion (tip portion) 62B of the pressure-applying portion 62 comes into contact with the end in the width direction of the weight 21 of the mover 2, and the mover 2 is guided by the guide shaft 7 It is elastically held in a state of being rotated by a predetermined angle around it, and a pressure is applied in a direction crossing the vibration direction.

  The mover 2 is provided with projections at both ends in the width direction of the weight 21 to be the sliding portions 21A. The sliding portion 21A is in contact with the sliding portion 60A on the pressure member 6 with a small contact area so as to reduce the contact resistance. The slid portion 60A is a flat portion formed along the X direction in the figure, and by sliding on the slid portion 60A, the mover 2 can vibrate with a small contact resistance. In the illustrated example, the sliding portions 21A are provided at both end portions in the width direction of the weight 21. However, the sliding portions 21A may be provided at both end portions in the thickness direction of the weight 21. In that case, it is good to provide a sliding part corresponding to it.

  The movable element 2 of such a linear vibration motor 1 is a guide in a state in which a pressure is applied in the direction intersecting the vibration direction of the movable element 2 (in the example shown, around one axis along the guide shaft 7) It oscillates back and forth along the shaft 7. As a result, the mover 2 can be vibrated in a state in which the rotation around the guide shaft 7 is suppressed by the applied pressure, and even if a force that causes the mover 2 to rotate during the vibration operation is applied. The mover 2 can maintain a stable vibration state by the pressure applied by the pressure member 6, and the mover 2 rotates to generate abnormal noise or the mover 2 becomes unstable due to instability. Vibration can be suppressed.

  FIG. 5 shows a portable information terminal 100 as an example of an electronic device equipped with the linear vibration motor 1 according to the embodiment of the present invention. The portable information terminal 100 including the linear vibration motor 1 capable of obtaining stable vibration and thinning and downsizing in the width direction is unlikely to generate abnormal noise at the start and end of operations such as an incoming call and an alarm function in the communication function. A stable vibration can be transmitted to the user. In addition, it is possible to obtain the portable information terminal 100 in which high portability or design is pursued by thinning the linear vibration motor 1 and downsizing in the width direction. Furthermore, since the linear vibration motor 1 has a compact shape in which each part is accommodated in the rectangular parallelepiped frame 3 with a reduced thickness, space can be efficiently installed inside the thinned portable information terminal 100. .

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and changes in design etc. within the scope of the present invention are not limited. Are included in the present 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,
2: mover, 20: magnetic pole member (magnet and yoke),
21: Weight, 21A: Sliding part,
3: Frame, 30: Case frame, 30A: Bottom, 30B: Side wall, 30C: Front wall,
31: lid frame, 31A: input terminal portion, 32: bearing, 33: spring holding portion,
4: Drive member, 40: Coil,
5: elastic member, 50: compression coil spring,
6: pressure member, 60: leaf spring, 60A: sliding portion,
61: installation part, 62: pressurization part, 62A: arm part, 62B: connection part,
7: Guide shaft

Claims (4)

With the mover,
A frame for supporting the mover reciprocally and vibratably;
A driving member fixed to the frame and driving the mover;
An elastic member provided between the frame and the mover and elastically deformed by reciprocating vibration of the mover;
And a pressure member for applying pressure to the mover in a direction intersecting the vibration direction of the mover .
The movable element has a rectangular shape whose width in the direction intersecting the vibration direction is greater than or equal to the thickness in the direction intersecting the vibration direction,
The linear vibration motor according to claim 1, wherein the pressure applying member is a plate spring disposed between a surface along a width of the mover and the frame . The movable element is provided with a sliding portion sliding on the plate spring at both end portions in the width direction, and a flat slidable portion on which the sliding portion slides on the plate spring The linear vibration motor according to claim 1, wherein: The flat spring according to claim 1, wherein the flat spring comprises: a flat plate-like installation portion installed on a bottom surface of the frame; and a pressure portion which is bent from the installation portion and elastically holds the mover. The linear vibration motor according to 1 or 2 . The portable electronic device provided with the linear vibration motor of any one of Claims 1-3 .

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