JP2016131915A - Linear vibration motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably vibrate a flat-shaped movable element, by a structure reducing a number of components and avoiding the complication of assembling.SOLUTION: A linear vibration motor 1 includes: a platy body 2 made from a magnetic body having a planar supporting surface 2A; a movable element 4 which partially contacts with plural portions of the supporting surface 2A directly or through a contact piece 3, and vibrates in uniaxial direction along the supporting surface 2A; an elastic member 7 which elastically repulses to the vibrations of the movable element 4; and a coil 8 which is fixed to the platy body 2, and disposes a winding part 8A intersecting the uniaxial direction between the movable element 4 and the platy body 2. The movable element 4 is equipped with a magnet 9 which forms a magnetic flux passing through the winding part 8A of the coil 8 between the platy body 2 and the movable element 4, and magnetically attracts the movable element 4 to the supporting surface 2A side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a linear vibration motor that linearly reciprocates a mover by signal input.

  Vibration motors (or vibration actuators) generate vibrations by receiving incoming communications equipment or sending alarms from various electronic devices, etc. It is communicated and is equipped in various electronic devices such as portable information terminals including mobile phones.

  As various types of vibration motors have been developed, a linear vibration motor that can generate a relatively large vibration by linear reciprocating vibration of a mover is known. A conventional linear vibration motor is provided with a weight and a magnet on the mover side, and a Lorentz force acting on the magnet by energizing a coil provided on the stator side serves as a driving force, which is elastically supported along the vibration direction. The child is reciprocally vibrated (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 installed therein. In particular, in an electronic device equipped with 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. is there.

  When considering thinning of a linear vibration motor, if a sufficient volume of the magnet is obtained to obtain a desired driving force and a mass of the weight is sufficiently secured to obtain a desired inertial force, the magnet and the weight are It is conceivable to reduce the thickness by making the mover provided flat. In this case, if the mover oscillates (rolls) around the linear vibration axis, the flat mover has a shape in which the side portion along the vibration direction easily comes into contact with the surrounding frame. Therefore, a stable operation cannot be obtained due to the generation of contact sound. For this reason, in the conventional technique, two guide shafts are provided to suppress the swing of the mover around the vibration axis, thereby realizing stable linear vibration.

  However, when two guide shafts are provided, the number of parts is increased, and since the two guide shafts are arranged in parallel, high accuracy is required for mounting, and thus there is a problem that the assembling work becomes complicated.

  This invention makes it an example of a subject to cope with such a problem. In other words, by making the mover flat, it is possible to achieve a thin linear vibration motor, reduce the number of parts, and avoid the complexity of assembly work, and stably vibrate the flat mover. That is the purpose of the invention.

In order to achieve such an object, the present invention has the following configuration.
A plate-like body made of a magnetic material having a planar support surface; a movable element that is in partial contact with a plurality of locations of the support surface directly or via a contact and vibrates in a uniaxial direction along the support surface; An elastic member that elastically repels vibration of the mover, and a coil that is fixed to the plate-like body and that has a winding portion that intersects the uniaxial direction in the gap between the mover and the plate-like body; The mover includes a magnet that forms a magnetic flux that passes through a winding portion of the coil with the plate-like body and magnetically attracts the mover to the support surface side. Linear vibration motor.

  In the present invention having such a feature, the movable element is brought into partial contact with a planar support surface of the plate-like body at a plurality of locations, and the movable element vibrates in a uniaxial direction while being magnetically attracted to the support surface side. To do. For this reason, it is possible to stably vibrate the flat movable element along the planar support surface without using a guide shaft or the like. As a result, the linear vibration motor of the present invention can stably vibrate the flat movable member with a structure that reduces the number of parts and avoids the complexity of assembly.

1 is an exploded perspective view showing an overall configuration of a linear vibration motor according to an embodiment of the present invention. It is explanatory drawing ((a) is a top view, (b) is AA sectional drawing) which showed the whole structure of the linear vibration motor which concerns on embodiment of this invention. It is explanatory drawing (BB sectional drawing in Fig.2 (a)) of the linear vibration motor which concerns on embodiment of this invention. 1 is an external perspective view of a linear vibration motor according to an embodiment of the present invention. It is explanatory drawing which showed the portable electronic device (mobile information terminal) provided 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. In the following drawings, the same reference numerals are given to the common parts shown in the respective drawings, and a duplicate description is omitted. In the figure, the vibration direction (uniaxial direction) is defined as the X-axis direction, and the directions orthogonal thereto are defined as the Y-axis direction (width direction) and the Z-axis direction (height direction).

  As shown in FIG. 1 (disassembled perspective view), FIG. 2 ((a) is a plan view, (b) is an AA cross-sectional view), and FIG. 3 (BB cross-sectional view in FIG. 2 (a)) A linear vibration motor 1 according to an embodiment of the invention includes a plate-like body 2, a mover 4, an elastic member 7, a coil 8, and a frame body 10.

  In the illustrated example, the plate-like body 2 constitutes an upper cover in the non-magnetic frame 10 having an open top, and is made of a magnetic body having a planar support surface 2A. The mover 4 includes a weight 5, a magnet 9, and a connecting body 6 that connects them. The movable element 4 is in partial contact with a plurality of locations (preferably three locations) of the support surface 2 </ b> A in the plate-like body 2 via the contact 3. ing. In the illustrated example, the plate-like body 2 and the movable element 4 are in partial contact with each other via the contact 3. However, a protrusion protruding in the Z-axis direction from the plate-like body 2 side or the movable element 4 side is shown. It may be provided and both are in direct partial contact.

  The contactor 3 is preferably a rolling element that is in rolling contact with the plate-like body 2 side and the movable element 4 side. As shown in the figure, the rolling element is a sphere that makes point contact with the plate-like body 2 side and the mover 4 side, or a cylindrical body (roller) that makes line contact with the plate-like body 2 side and the mover 4 side. can do.

  The mover 4 vibrates in a uniaxial direction (X-axis direction in the drawing) along the support surface 2 </ b> A while maintaining partial contact with the plate-like body 2. A guide groove 11 for holding the contact 3 is provided on the movable element 4 side, and the guide groove 11 extends along the vibration direction (X-axis direction in the drawing) of the movable element 4. In the illustrated example, the guide groove 11 is provided on the movable element 4 side, and the holding groove 12 for holding the contactor 3 is provided on the plate body 2 side. However, the guide groove 11 is provided on the plate body 2 side. 11 may be provided, the holding groove 12 may be provided on the movable element 4 side, and the guide groove 11 may be provided on both the plate-like body 2 side and the movable element 4 side.

  The coil 8 for driving the mover 4 is fixed to the plate-like body 2, and the winding portion intersects the gap between the mover 4 and the plate-like body 2 in the uniaxial direction (X-axis direction in the drawing). 8A is arranged. In the illustrated example, the coil 8 is wound flat in the gap between the magnet 9 and the plate-like body 2. The winding portion 8A described above defines the direction of the current that generates the Lorentz force for vibrating the mover 4 in the X-axis direction. If such a winding portion 8A is formed, the coil portion 8A The winding method itself is not limited to the example shown in the figure.

  The magnet 9 included in the mover 4 forms a magnetic flux passing through the winding portion 8A of the coil 8 between the magnet 9 and the plate-like body 2 that is a magnetic body (yoke). 2 has a function of being magnetically attracted to the support surface 2A side. In the illustrated example, the magnet 9 includes a pair of magnet pieces 9A and 9B having magnetization directions opposite to each other in a direction intersecting the support surface 2A (Z-axis direction in the figure), and the magnet pieces 9A and 9B. Is disposed opposite to the winding portion 8A of the coil 8 to form a magnetic flux passing through the winding portion 8A in the Z-axis direction. Moreover, the magnetic attractive force of the magnet 9 and the plate-shaped body 2 which is a magnetic body is heightened by using the frame 10 as a non-magnetic body.

  A pair of weights 5 provided in the mover 4 is disposed along a uniaxial direction (X-axis direction in the drawing) with the magnet 9 interposed therebetween. Thereby, a pair of weights 5 and a magnet 9 disposed therebetween are arranged in parallel on the mover 4 along a uniaxial direction (X-axis direction in the drawing). The connection body 6 that integrally connects the weight 5 and the magnet 9 includes a magnet support portion 6A that supports the lower surface side of the magnet 9 (the side opposite to the side facing the plate-like body 2), and the upper surface side (plate) of the weight 5. It is a refracted plate-like member provided with a weight support portion 6B for supporting the side facing the shaped body 2). The magnet 9, the weight 5 and the coupling body 6 are joined together by adhesion or welding. Further, the magnet support 6A is provided with a reinforcement 6A1 that is refracted in the Z-axis direction as necessary.

  A guide groove 11 for holding the contact 3 on the connection body 6 can be provided in the weight support portion 6 </ b> B of the connection body 6. By providing the guide groove 11 in the connecting body 6 in this way, the material of the connecting body 6 can be selected, and the contact resistance with the contact 3 in the guide groove 11 can be reduced.

  The connecting body 6 is a magnetic body, and the magnet 9 and the plate-like body 2 constitute a magnetic circuit. At this time, since the weight support portion 6B in which the guide groove 11 for holding the contact 3 is formed is in a state of being close to the plate-like body 2 via the contact 3, the weight support portion 6B and the plate-like body 2 Thus, the movable element 4 can be magnetically attracted to the plate-like body 2 side while the contactor 3 is securely held between the guide groove 11 and the holding groove 12.

  The elastic member 7 is a spring (for example, a coil spring) that elastically repels vibrations along the uniaxial direction of the mover 4, and is supported in the frame body 10. One end side of the elastic member 7 is supported by the end face of the weight 5, and the other end side of the elastic member 7 is supported by a support portion 10 </ b> A provided on the frame body 10.

  Such a linear vibration motor 1 is driven by a Lorentz force acting on the magnet 9 by energizing the coil 8, and linearly reciprocates along one axial direction (X-axis direction in the drawing). At this time, the flat movable element 4 is in a state of being in partial contact with the planar support surface 2A of the plate-like body 2 at a plurality of locations (preferably three locations) by magnetic attraction between the plate-like body 2 and the magnet 9. While maintaining, it vibrates along the support surface 2A. Thereby, it is possible to suppress the flat movable element 4 from swinging around the vibration axis, and it is possible to obtain stable linear vibration.

  Moreover, the linear vibration motor 1 forms the plane of the support surface 2A in the plate-like body 2 with high accuracy, so that an assembling operation with high accuracy is not required during assembly. Further, since the guide shaft can be omitted, the number of parts can be reduced. As a result, workability during assembly can be improved.

  FIG. 4 shows the assembled linear vibration motor 1. The linear vibration motor 1 has a housing structure in which the plate-like body 2 serves as an upper cover that covers one surface side of the movable element 4 and the other surface side is covered with the frame body 10. In the plate-like body 2, a signal input terminal portion 2 </ b> B to which the terminal of the coil 8 is connected is formed so as to protrude to the side portion.

  FIG. 5 shows a portable information terminal 100 as an example of a portable electronic device equipped with the linear vibration motor 1 according to the embodiment of the present invention. The portable information terminal 100 provided with the linear vibration motor 1 that can obtain stable vibration and can be thinned and compact in the width direction is unlikely to generate abnormal noise at the start and end of an incoming call or alarm function in a communication function. It can be transmitted to the user with stable vibration. 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 motor 1 has a compact shape in which each part is housed in a rectangular parallelepiped housing having a reduced thickness, the linear vibration motor 1 can be efficiently installed in the thinned portable information terminal 100.

  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.

1: Linear vibration motor,
2: plate-like body, 2A: support surface, 2B: signal input terminal,
3: contact (rolling element), 4: mover, 5: weight,
6: Connection body, 6A: Magnet support part, 6A1: Reinforcement part,
6B: Weight support part,
7: elastic member, 8: coil, 8A: winding part,
9: Magnet, 9A, 9B: Magnet piece,
10: frame, 10A: support part, 11: guide groove, 12: holding groove,
100: Portable information terminal (mobile electronic device)

Claims (7)

A plate-like body made of a magnetic body having a planar support surface;
A mover that makes partial contact with a plurality of locations on the support surface directly or via a contact, and vibrates in a uniaxial direction along the support surface;
An elastic member elastically repelling vibration of the mover;
A coil that is fixed to the plate-like body and arranges a winding portion that intersects the uniaxial direction in a gap between the mover and the plate-like body;
The movable element includes a magnet that forms a magnetic flux that passes through a winding portion of the coil between the movable member and the magnet so that the movable element is magnetically attracted to the support surface side. motor.   The linear vibration motor according to claim 1, wherein the contact is a rolling element and makes point or line contact with the plate-like body side and the movable element side. The magnet includes a pair of magnet pieces having magnetization directions opposite to each other in a direction intersecting the support surface,
The linear vibration motor according to claim 1, wherein the coil is wound in a flat shape with a gap between the magnet and the plate-like body. The mover includes a pair of weights arranged along the one-axis direction with the magnet interposed therebetween, and a connecting body that integrally connects the magnet and the weight,
The linear vibration motor according to claim 1, wherein the coupling body is made of a magnetic body.   The linear vibration motor according to claim 4, wherein the contact is held on the coupling body.   The plate-like body covers one surface side of the mover, the other surface side of the mover is covered with a non-magnetic frame body, and the elastic member is supported in the frame body. The linear vibration motor according to any one of claims 1 to 5.   A portable electronic device provided with the linear vibration motor described in any one of Claims 1-6.

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