WO2023047696A1 - Linear vibration motor - Google Patents

Abstract

In order to provide a short linear vibration motor at low cost, the present invention provides a linear vibration motor 2 comprising: a casing 10 that is formed by joining a first casing part 12 having at least a top plane part 12A and a second casing part 14 having at least a bottom plane part 14A; a vibrator 50 housed in the casing 10; and two shafts 60 that are arranged, within the casing 10, in approximately parallel with each other along the vibration direction of the vibrator 50 and that support the vibrator 50 in the state where the vibrator 50 can vibrate. The shafts 60 are supported in the state where the shafts 60 are sandwiched from both sides by a first supporting part 20 provided to the first casing part 12 and a second supporting part 30 provided to the second casing part 14. The second supporting part 30 is composed of two second protrusions 32A and 32B or 32C and 32D which are arranged at a predetermined distance along the extending direction of a shaft 60 at a position overlapping the shaft 60 in a plan view. The second protrusions 32A to 32D are formed by bending a metal plate that forms the second casing part 14.

Description

linear vibration motor

The present invention relates to a linear vibration motor that energizes a coil to vibrate a vibrator.

In electronic devices such as portable information terminals, linear vibration motors are sometimes used as vibration generating devices for tactile feedback or for confirming key operations, incoming calls, etc. by vibration. As an example of this linear vibrating motor, there is a linear vibrating motor described in Patent Document 1. FIG. 10A is an exploded perspective view showing Example 1 of the linear vibration motor described in Patent Document 1, and FIG. 10B is an exploded perspective view showing Example 2 of the linear vibration motor described in Patent Document 1. be. In any case, a housing is composed of a bottom wall portion, a peripheral wall portion surrounding the bottom wall portion, and a ceiling wall portion covering the upper side thereof. A mover slidably held by two guide shafts is housed in this housing.

WO2021/06083

Example 1 shown in FIG. 10A has a structure in which both ends of two guide shafts are supported by an intermediate member. With this structure, it is difficult to reduce the height of the housing because it is necessary to accommodate the intermediate member in the housing.
On the other hand, in Example 2 shown in FIG. 10B, there is no intermediate member, and a U-shaped groove is provided in a part of the peripheral wall to support the guide shaft. However, the peripheral wall portion and the bottom wall portion are joined by welding, which requires high manufacturing costs. If the peripheral wall portion and the bottom wall portion were to be made of the same metal plate, the mechanical strength of the peripheral wall portion would be reduced due to the provision of the U-shaped groove, so a thick metal plate would have to be used. This is disadvantageous in reducing the height.

The purpose of this disclosure is to provide a low-cost, low-profile linear vibration motor.

A linear vibration motor according to one aspect of the present disclosure includes:
a housing formed by joining a first housing portion having at least a top surface portion and a second housing portion having at least a bottom surface portion;
a vibrator housed in the housing;
two shafts arranged substantially in parallel along the vibration direction of the vibrator in the housing and supporting the vibrator in a vibrating state;
with
The shaft is supported in a state of being sandwiched from both sides by a first support portion provided in the first housing portion and a second support portion provided in the second housing portion,
The second supporting portion is composed of two second convex portions arranged on each of the shafts at a position overlapping the shaft in a plan view and separated from each other by a predetermined distance along the extension direction of the shaft. ,
The second convex portion is formed by bending a metal plate forming the second housing portion.

According to the present disclosure, a low-cost and low-profile linear vibration motor can be provided.

FIG. 2 is a perspective view of the first housing part that constitutes the housing of the linear vibration motor according to one embodiment of the present invention, viewed from above. It is the perspective view which looked at the 1st housing|casing part shown in FIG. 1A from the lower surface side. FIG. 4 is a perspective view of a second housing part that constitutes the housing of the linear vibration motor according to one embodiment of the present invention, viewed from above. 3 is an exploded perspective view schematically showing that a coil, a magnet and a wiring board are attached to the second casing shown in FIG. 2, and further a vibrator supported by a shaft is attached; FIG. FIG. 4 is a perspective view showing the second housing section after the vibrator is attached from the state shown in FIG. 3 ; FIG. 5 is an enlarged view of the state shown in FIG. 4 in which the first housing is attached on top of the second housing, and is a perspective view showing that the shaft is supported by the first support and the second support; is. FIG. 5 is a cross-sectional side view taken along AA of FIG. 4 and schematically showing a state in which the first casing is also attached; FIG. 7 is a side sectional view schematically showing a section BB of FIG. 6; FIG. 7 is a side sectional view schematically showing a modification of the embodiment shown in FIG. 6; FIG. 9 is a side sectional view schematically showing a modification of the embodiment shown in FIG. 8; 1 is an exploded perspective view showing Example 1 of a linear vibration motor described in Patent Document 1. FIG. 2 is an exploded perspective view showing Example 2 of the linear vibration motor described in Patent Document 1. FIG. FIG. 11 is a side cross-sectional view schematically showing another example of the shaft support structure; 11B is a side sectional view schematically showing a section BB of FIG. 11A. FIG. It is a figure for demonstrating the method of forming a recessed part by bending a metal.

Hereinafter, embodiments and modifications for carrying out the present invention will be described with reference to the drawings. Corresponding members having the same function are denoted by the same reference numerals in each drawing. In the description of the embodiments and modifications that will be described later, descriptions of matters common to those described above will be omitted, and only differences will be described. The vertical direction in the following description and drawings indicates the vertical direction when the linear vibration motor is placed on a substantially horizontal surface.

(Linear vibration motor according to one embodiment)
First, an outline of a linear vibration motor according to one embodiment of the present invention will be described with reference to FIGS. The linear vibration motor 2 includes a housing 10 and a vibrator 50 housed within the housing 10 . The housing 10 is configured by joining a first housing section 12 having a top surface and a second housing section 14 having a bottom surface. The vibrator 50 is supported by two shafts 60 so as to vibrate. The two shafts 60 are respectively supported by a first support portion 20 provided on the first housing portion 12 and a second support portion 30 provided on the second housing portion 14 .

The vibrator 50 includes a weight portion 52 and a first magnet M1, and further includes a second magnet M2 and a third magnet M3 at both ends in the vibrating direction. A coil 70 (see FIG. 3), a magnet holder 40 (M4) having a fourth magnet M4 and a magnet holder 40 (M5) having a fifth magnet M5 are attached to the second housing portion 14 . When power is supplied to the coil 70 via the flexible printed circuit (FPC) 72 arranged on the bottom surface portion 14A of the second housing portion 14, a magnetic field is generated, and a driving force is applied to the first magnet M1 of the vibrator 50 to vibrate. Child 50 vibrates. A second magnet M2 (on the vibrator side) and a fourth magnet M4 (on the housing side), and a third magnet M3 (on the vibrator side) and a fifth magnet M5 (on the housing side), which are arranged to face each other. constitute a magnetic spring. This magnetic spring can strongly transmit the vibration of the vibrator 50 to the main body 10 .

<Case>
Next, the housing according to this embodiment will be described with reference to FIGS. 1A, 1B, and 2. FIG. FIG. 1A is a top perspective view of a first housing part that constitutes a housing of a linear vibration motor according to one embodiment of the present invention. FIG. 1B is a perspective view of the first housing shown in FIG. 1A as viewed from below. FIG. 2 is a perspective view of the second housing part that constitutes the housing of the linear vibration motor according to one embodiment of the present invention, viewed from the upper surface side.

The housing 10 is formed by joining a first housing portion 12 and a second housing portion 14 . The first housing portion 12 is formed by bending one metal plate. The first housing portion 12 includes a top surface portion 12A having a substantially rectangular planar shape and first side wall portions 12B surrounding the top surface portion 12A. The first side wall portion 12B is composed of first short side wall portions 12B1 and 12B2 connected to the top surface portion 12A at its short side S, and first long side wall portions 12B3 and 12B4 connected to the top surface portion 12A at its long side L. It is The top surface portion 12A and the first side wall portion 12B are bent so as to be substantially perpendicular to each other.

The second housing part 14 is also formed by bending one metal plate. The second housing portion 14 is composed of a bottom portion 14A having a substantially rectangular planar shape and a second side wall portion 14B surrounding the bottom portion 14A. The second side wall portion 14B is composed of second short side wall portions 14B1 and 14B2 connected to the bottom surface portion 14A at its short side S, and second long side wall portions 14B3 and 14B4 connected to the bottom surface portion 14A at its long side L. It is The bottom portion 14A and the second side wall portion 14B are bent so as to be substantially perpendicular to each other.

In the present embodiment, the first housing portion 12 and the second housing are arranged such that at least a portion of the first side wall portion 12B of the first housing portion 12 and the second side wall portion 14B of the second housing portion 14 overlap each other. The portion 14 is fitted to form the housing 10 . At this time, the first side wall portion 12B of the first housing portion 12 is fitted so as to surround the second side wall portion 14B of the second housing portion 14 . More specifically, the first short side wall portion 12B1 is arranged to overlap on the outside of the second short side wall portion 14B1, the first long side wall portion 12B3 is arranged to overlap on the outside of the second long side wall portion 14B3, The first short side wall portion 12B2 is arranged to overlap on the outside of the second short side wall portion 14B2, and the first long side wall portion 12B4 is arranged to overlap on the outside of the second long side wall portion 14B4.

Further, the first housing portion 12 and the second housing portion 14 are formed with a first support portion 20 and a second support portion 30, respectively, which support two shafts 60 that hold the vibrator 50 so as to vibrate. It is

Each of the four corners of the top surface portion 12A of the first housing portion 12 has four first protrusions 22A to 22D that are formed by being cut and bent. A first convex portion 22A is formed in a corner region CA between the first short side wall portion 12B1 and the first long side wall portion 12B3, and a corner region CB between the first long side wall portion 12B3 and the first short side wall portion 12B2. , a first convex portion 22B is formed, a first convex portion 22D is formed in a corner region CD between the first short side wall portion 12B2 and the first long side wall portion 12B4, and the first long side wall portion 12B4 and the first short side wall portion 12B4 are formed in the corner region CD. A first convex portion 22C is formed in the corner region CC between the side wall portions 12B1. In this embodiment, the first supporting portion 20 is configured by the four first protrusions 22A to 22D.

On the other hand, at each of the four corners of the bottom surface portion 14A of the second housing portion 14, there are four second convex portions 32A to 32D formed by partially notching and partially bending, and formed by notching and bending. It has four openings 36A-36D. A corner region CA between the second short side wall portion 14B1 and the second long side wall portion 14B3 is formed with a second convex portion 32A and an opening portion 36A. A second convex portion 32B and an opening 36B are formed in the corner region CB of the second convex portion 32B and an opening portion 36B, and a second convex portion 32D and an opening portion 36D are formed in the corner region CD between the second short side wall portion 14B2 and the second long side wall portion 14B4. are formed, and a second convex portion 32C and an opening 36C are formed in a corner region CC between the second long side wall portion 14B4 and the second short side wall portion 14B1. In this embodiment, the second support portion 30 is configured by the four second convex portions 32A to 32D.

A central region of the second long side wall portion 14B4 is cut away, and a substrate support portion 14C is formed in the region with the bottom surface portion 14A extending outward. The substrate support portion 14C extends to the outside of the second long side wall portion 14B4. A concave portion 14C1 is formed in an inner region of the substrate supporting portion 14C excluding the outer edge portion. As will be described later, a flexible printed circuit board (FPC) 72 is placed in the concave portion 14C1 of the printed circuit board support portion 14C. A part of the long side L and the short side S, which are the boundaries between the bottom surface portion 14A and the second side wall portion 14B, are notched to form a support portion 14D in which the metal plate is not bent. The tip of the support portion 14D extends slightly outside the second side wall portion 14B.

In the present embodiment, the housing 10 is formed by joining the first housing portion 12 and the second housing portion 14 together by welding or the like. At this time, a plurality of support portions 14D protruding slightly outward from the second side wall portion 14B of the second housing portion 14 can support the lower portion of the fitted first housing portion 12 . Further, when joining the first housing portion 12 and the second housing portion 14 by welding, the support portion 14D can be used as a base for fillet welding. With such a fitting structure, the housing 10 having an internal space separated from the outside can be obtained. However, there may be a case where the support portion 14D is not provided.

Thus, the first housing portion 12 and the second housing portion 14 have high rigidity due to the first side wall portion 12B and the second side wall portion 14B formed by bending, and are firmly joined by the fitting structure. be done. Thereby, the housing 10 having high strength is obtained.

When the first casing portion 12 and the second casing portion 14 are fitted and joined in this way, in a plan view, the first projections 22A to 22D and the second projections 32A to 32D formed at the four corners 32D are arranged at overlapping positions. As a result, the shaft 60 supporting the vibrator 50 can be sandwiched and supported from both upper and lower sides by the first protrusions 22A to 22D and the second protrusions 32A to 32D. Details will be described later.

In this embodiment, the first housing part 12 and the second housing part 14 are formed from non-magnetic metal plates such as stainless steel plates. In particular, for the second housing portion 14, which is often bent, it is preferable to use, for example, SUS316 (JIS/AISI316) in order to ensure that the non-magnetic properties are maintained even after processing. However, depending on the amount of processing, SUS304 (JIS/AISI304), which is a general stainless steel, can also be used. SUS304 (JIS/AISI304) can be used for the first housing part 12 because it requires less bending than the second housing part 14 . In this embodiment, the drive magnet is provided on the vibrator side. , the magnetic force of the drive magnet can also be increased.

In the present embodiment, the thickness of the metal plates that constitute the first casing portion 12 and the second casing portion 14 can be exemplified to be approximately 0.1 to 0.5 mm. The vertical (short side), horizontal (long side), and height dimensions of the housing 10 according to the present embodiment are approximately 12 mm, approximately 19 mm, and approximately 1.6 mm, respectively. can be adopted. In any case, a low profile (low height) housing 10 is preferred.

As described above, since the first housing portion 12 is formed by bending one metal plate, a housing having sufficient strength can be obtained at low cost. Similarly, since the second housing portion 14 is also formed by bending one metal plate, a housing having sufficient strength can be obtained at low cost. In particular, a thin metal plate can be used as the material of the housing 10 because metal has sufficient strength even if it is thin. As a result, the low first side wall portion 12B and the low second side wall portion 14B can be reliably formed by bending, so that the low-profile housing 10 can be realized at low cost.

(Members housed in the housing)
Next, each member accommodated in the housing 10 will be described with reference to FIGS. 3, 4 and 5. FIG. FIG. 3 is an exploded perspective view schematically showing that a coil, a magnet, and a wiring board are attached to the second housing portion shown in FIG. 2, and further a vibrator supported by a shaft is attached. FIG. 4 is a perspective view showing the second housing section after the vibrator is mounted in the state shown in FIG. 3. FIG. FIG. 5 is an enlarged view of a state in which the first housing is attached on the second housing from the state shown in FIG. It is a perspective view showing a place to do.

<Coil>
The coil 70 arranged on the bottom surface portion 14A of the second housing portion 14 is formed by winding a conductor wire around an imaginary winding axis. The coil 70 is fixed to the housing 10 so that its winding axis is substantially perpendicular to the upper surface of the bottom surface portion 14A and faces the first magnet M1 of the vibrator 50 . The shape of the coil 70 when viewed from the winding axis direction is a rectangular shape with rounded corners. By forming the coil 70 by winding a flat wire in a single layer, the lamination factor of the conductor wire of the coil 70 is improved and the height dimension in the axial direction of the coil 70 is reduced (thickness of the coil is reduced). be able to.

When a current flows through the coil 70, a Lorentz force is applied to the coil 70 by the magnetic field of the first magnet M1 in a direction orthogonal to the direction of the magnetic field and the direction of current flow. On the other hand, since the coil 70 is fixed to the housing 10, the reaction force of the Lorentz force is applied to the first magnet M1. Therefore, the coil 70 can apply a driving force along the vibration direction (long side direction) to the first magnet M1 and, by extension, to the vibrator 50 by energization. That is, the first magnet M1 functions as a driving magnet in the linear vibration motor 2. As shown in FIG.

As described above, when the coil 70 has a rectangular shape when viewed from the axial direction, the direction of the Lorentz force described above is more likely to align with the vibration direction than when the coil 70 is annular. Therefore, the driving force along the vibration direction applied to the vibrator 50 is increased, which is preferable.

In this embodiment, a conductor wire in which a core wire having a thickness of 0.02 to 0.05 mm and a width of 0.14 to 0.15 mm is coated with a polyamideimide insulating film having a thickness of 4 μm is wound in a single layer with 36 to 60 turns. A coil 70 is formed by winding. By using an insulating film containing polyamide-imide, it is possible to obtain sufficient insulating performance with a small thickness compared to the case of using an insulating film containing polyurethane or the like. Therefore, it is possible to contribute to miniaturization of the coil 70 and thus miniaturization of the linear vibration motor 2 .

<Flexible substrate>
A flexible printed circuit (FPC) 72 is arranged in the concave portion 14C1 of the substrate supporting portion 14C of the second housing portion 14. As shown in FIG. A flexible printed circuit board (FPC) 72 extends from the inner peripheral side of the coil 70 to the outside of the second long side wall portion 14B4. Two electrodes 72A and 72B are provided in a region outside the second long side wall portion 14B4 of the flexible printed circuit board (FPC) 72 . Conductor wires drawn from the inner and outer peripheries of the coil 70 are electrically connected to electrodes 72A and 72B by wiring printed on a flexible printed circuit board (FPC) 72, respectively.

Thereby, the coil 70 can be connected to an electronic circuit of an electronic device such as a portable information terminal, which will be described later, via the electrodes 72A and 72B. The coil 70 can be energized by power supply from the electronic device side. Since the flexible printed circuit (FPC) 72 is arranged in the recess 14C1, it is possible to reliably supply power to the coil 70 while suppressing the dimension in the height direction. This can contribute to thinning (reducing the height) of the linear vibration motor 2 .

<Magnet holder>
The fourth magnet M4 and the fifth magnet M5, which constitute the magnetic spring, are attached with metal parts 42 made of soft iron for enhancing the magnetic force, and magnet holders 40 (M4) and 40 (M5) are formed. The metal portions 42 of the magnet holders 40 (M4) and 40 (M5) have a central region 44 in contact with the magnets M4 and M5, respectively, and two extended regions 46 extending from the central region 44 along the short side S to both sides. have. Accordingly, it can be said that the magnet holders 40 (M4) and 40 (M5) are arranged along the two short sides S of the bottom surface portion 14A in plan view. Here, "along the short side S" means that the magnet holders 40 (M4) and 40 (M5) are arranged near the short side S or in contact with the short side S, and the magnet holders 40 (M4) and 40 ( M5) extends substantially parallel to the short side S.

Of the openings 36A to 36D provided at the four corners, the openings 36A and 36C arranged along the short side S are closed by the magnet holder 40 (M4), and the openings arranged along the short side S are closed. The parts 36B and 36D are closed by the magnet holder 40 (M5). By extending the metal parts 42 for strengthening the magnetic force of the magnets M4 and M5 to both sides of the short sides S of the magnets M4 and M5, the openings 36A to 36D generated by notching and bending can be reliably closed. . As a result, it is possible to provide a highly reliable linear vibration motor that includes the housing 10 that is highly sealed. Furthermore, as will be described later with reference to FIGS. 5 and 6, the magnet holders 40 (M4) and 40 (M5) can have a function of restraining movement of the shaft 60 in the vibrating direction.

Rare earth magnets such as neodymium-iron-boron or samarium-cobalt are used as materials for the fourth magnet M4 and the fifth magnet M5. However, like the second magnet M2 and the third magnet M3, which will be described later, it is preferable to use a samarium-cobalt-based rare earth magnet that has a small temperature change rate of magnetic force and can stably exert the magnetic spring effect described later. For fixing the fourth magnet M4 and the fifth magnet to the metal portion 42, for example, an epoxy-based adhesive can be used.

<Vibrator>
The vibrator 50 includes a weight portion 52, a first magnet M1, a second magnet M2 and a third magnet M3. Sleeves 54 for engaging the vibrator 50 with the shaft 60 are attached to both sides of the weight portion 52 . nothing. The weight portion 52 is formed of a laminated body, but instead of the laminated body, an integrally molded sintered body or molded body can be adopted.

Each thin plate constituting the laminate includes a metal thin plate, a metal composite thin plate that is a composite material of metal powder and a resin material, a ceramic composite thin plate that is a composite material of ceramic powder and a resin material, metal powder and ceramic Included are resin-containing sheets, such as powder-free resin sheets. Materials for the thin metal plate and metal powder include tungsten and alloys containing it, stainless steel such as SUS304 (JIS/AISI304), aluminum and alloys containing it, and the like. As the material of the resin material, for example, an olefinic thermoplastic elastomer or the like can be used. As a material of the ceramic powder, for example, tungsten carbide can be used.

In order to increase the mass of the vibrator 50 and transmit a large vibration to the housing 10 via the magnetic spring mechanism, the material of the thin plate should be a material with a large specific gravity such as tungsten or an alloy containing it. preferable. The plurality of thin plates are maintained in a laminated state by adhesion using, for example, an epoxy adhesive. However, the maintenance of the laminated state is not limited to the above. For example, methods such as spot welding may be used.

The first magnet M1, which serves as the driving magnet, is arranged so that five magnets form a Halbach array along the vibration direction. The number of magnets forming the Halbach array of the first magnets M1 is not limited to five, and may include an odd number of three or more magnets arrayed along the vibration direction. In this disclosure, a Halbach array is broadly referred to as an array of drive magnets that allows the magnetic field of the drive magnets to be concentrated between the drive magnets and the coil that drives the oscillator. Therefore, the number of magnets forming the Halbach array should be an odd number of 3 or more.

As the material of the first magnet M1, for example, a rare earth magnet such as a neodymium-iron-boron system or a samarium-cobalt system can be used. However, for the first magnet M1, it is preferable to use a neodymium-iron-boron-based rare earth magnet that has a strong magnetic force and can increase the driving force of the vibrator 50. FIG. An epoxy-based adhesive, for example, can be used to fix the first magnet M1 to the weight portion 52 .

A second magnet M2 and a third magnet M3 are attached to both ends of the vibrator 50 in the vibration direction. The second magnet M2 and the fourth magnet M4 attached to the housing 10, and the third magnet M3 and the fifth magnet M5 attached to the housing 10 are arranged to face each other so as to magnetically repel each other. ing. Each constitutes a magnetic spring mechanism for vibration of the vibrator 50 . The vibration of the vibrator 50 is transmitted to the housing 10 by this magnetic spring mechanism.

Rare earth magnets such as neodymium-iron-boron or samarium-cobalt are used as materials for the second magnet M2 and the third magnet M3. However, it is preferable to use a samarium-cobalt rare earth magnet that has a small rate of change in magnetic force with temperature and that can stably exhibit a magnetic spring effect to be described later. An epoxy-based adhesive, for example, can be used to fix the second magnet M2 and the third magnet M3 to the weight portion 52 .

<Shaft>
The two shafts 60 are slidably inserted into sleeves 54 fixed to both sides of the weight portion 52 . Here, "fit together by insertion" means inserting and fitting the shaft 60 into each sleeve 54 so that the play is suppressed with the accuracy defined by the dimensional tolerance. The shaft 60 can be made of stainless steel such as SUS304 (JIS/AISI304).

(Shaft support structure)
Next, a support structure for two shafts 60 that support the vibrator 50 in a vibrating state will be described with reference to FIGS. 5 to 7. FIG. FIG. 5 is an enlarged view of a state in which the first housing is attached on top of the second housing from the state shown in FIG. Fig. 30 is a perspective view showing the support of the shaft at 30; FIG. 6 is a side cross-sectional view schematically showing a state in which the first housing section is also attached, taken along a cross section AA in FIG. 7 is a side sectional view schematically showing section BB of FIG. 6. FIG.

In the present embodiment, the first projections 22A and 22B that constitute the first support portion 20 overlap one shaft 60 in a plan view and are separated from each other by a predetermined distance along the extending direction of one shaft 60. are placed. Similarly, the second protrusions 32A and 32B that constitute the second support portion 30 are also positioned to overlap one shaft 60 in plan view, and extend a predetermined distance along the extending direction of the one shaft 60. placed apart. Therefore, the first protrusions 22A and 22B are arranged at positions overlapping the second protrusions 32A and 32B in plan view. As a result, one shaft 60 is sandwiched and supported from both upper and lower sides by the first protrusion 22A and the second protrusion 32A near one end, and is supported near the other end by the first protrusion 22B and the second protrusion 32A. It is sandwiched and supported from both upper and lower sides by the second protrusions 32B.

The same is true for the other shaft 60, and the first projections 22C and 22D forming the first support portion 20 overlap the other shaft 60 in a plan view, and along the extension direction of the other shaft 60 are placed at a predetermined distance apart. Similarly, the second protrusions 32C and 32D that constitute the second support portion 30 are arranged at positions overlapping the other shaft 60 in a plan view and spaced apart from each other by a predetermined distance along the extending direction of the other shaft 60. It is Therefore, the first protrusions 22C and 22D are arranged at positions overlapping the second protrusions 32C and 32D in plan view. As a result, the other shaft 60 is sandwiched and supported from both upper and lower sides by the first protrusion 22C and the second protrusion 32C near one end, and is supported near the other end by the first protrusion 22D and the second protrusion 32C. It is sandwiched and supported from both upper and lower sides by the second protrusions 32D. In other words, it can be said that the shaft 60 is fixed so as to be bridged by the first support portion 20 and the second support portion 30 with a predetermined distance therebetween.

By arranging the first support portion 20 and the second support portion 30 in this way, the two shafts 60 can be arranged along the two long sides L of the bottom portion 14A of the second housing portion 14. Here, “along the long side L” means that the shaft 60 is arranged in the vicinity of the long side L, and the extending direction of the shaft 60 is substantially parallel to the long side L.

As described above, since the shaft 60 is sandwiched and supported from both sides by the first support portion 20 and the second support portion 30, the shaft 60 can be reliably fixed. Since the first housing portion 12 and the second housing portion are made of thin metal plates, the shaft 60 is strongly sandwiched and held between the first support portion 20 and the second support portion 30 by the elastic force of this metal. can be done.

Further, the first support portion 20 is configured by first projections 22A to 22D arranged at positions overlapping the second projections 32A to 32D in plan view on each shaft 60. As shown in FIG. Then, as described above, the first convex portions 22A to 22D are formed by bending the metal plate forming the first housing portion 12. As shown in FIG.

In this way, since the first convex portions 22A to 22D are also formed by bending a metal plate, the first support portion 20 having sufficient strength can be formed at low cost while saving space. This makes it possible to provide a low-cost, low-profile linear vibration motor 2 .

Furthermore, in this embodiment, as shown in FIG. 7, a concave portion 34 is provided at the tip of the second convex portion 32C, and the shaft 60 is inserted into this concave portion 34. As shown in FIG. The same applies to the other second protrusions 32A, B, and D. With such a structure, it is possible to restrain the movement of the shaft 60 in the direction intersecting with the vibration direction. As described above, since the shaft 60 is sandwiched and supported by the first support portion 20 and the second support portion 30 from both upper and lower sides, the horizontal movement of the shaft 60 can be restrained by the frictional force. However, considering the case where the linear vibration motor 2 is subjected to a strong impact, it is more preferable to support the shaft 60 on the inner surface of the recess 34 . In addition, in order to easily insert the shaft 60 into the recess 34 , it is preferable to have a slight gap between the outer surface of the shaft 60 and the inner surface of the recess 34 .

By fitting the shaft 60 into the concave portion 34 formed at the tip of the second convex portion 32C in this way, it is possible to suppress the displacement of the shaft 60 in the direction intersecting the vibration direction with a simple structure.

In the shaft support structure shown in FIGS. 5 to 7, recesses 34 are formed by notching the tips of the second protrusions 32A to 32D. However, the concave portion 34 is not limited to being formed by a notch. For example, as shown in FIGS. 11A to 11C, recesses 34 can be formed by bending a metal plate. FIG. 11A is a side cross-sectional view schematically showing another example of the shaft support structure. FIG. 11B is a side sectional view schematically showing section BB of FIG. 11A. FIG. 11C is a diagram for explaining a method of forming recesses by bending metal. In FIG. 11C, the part showing the lower second housing part 14 is simplified and shown as a rectangle, and the parts corresponding to α1 to α4 are placed in four places corresponding to the second convex parts 32A to 32D. It is formed. By performing mountain folds and valley folds along the dotted lines shown in FIG. 11C, recesses 34 as shown in FIGS. 11A and 11B can be formed.

In the present embodiment, as shown in FIG. 6, the extension region 46 of the metal portion 42 of the magnet holder 40 has a hook shape composed of a rear portion 46A, a bottom portion 46B and a front portion 46C, which are formed by bending a metal plate. there is The rear portion 46A is connected to the central region 44 of the metal portion 42 and is in contact with the second short side wall portion 14B1 (14B2).
In this embodiment, the shaft 60 passes over the front portion 46C, and the end surface of the shaft 60 is arranged to closely face the rear portion 46A supported by the second short side wall portions 14B1 (14B2). ing. Thereby, the movement of the shaft 60 in the vibrating direction can be restrained by the rear portion 46A. Instead of forming the front portion 46C with a lower height, it is also possible to provide a recess through which the shaft 60 passes through the front portion 46C.

In addition, the bottom surface portion 46B of the metal portion 42 of the magnet holder 40 can cover the openings 36C (36A, B, D) that are formed in the bottom surface portion 14A by notching or bending. Furthermore, the front surface portion 46C of the metal portion 42 of the magnet holder 40 is in contact with the second protrusions 32C (32A, 32B, 32D). Therefore, the hook shape of the extension region 46 can effectively support the second protrusions 32C (32A, 32B, 32D).

<Modified Example of Shaft Movement Suppression Structure>
Next, a modification of the structure for suppressing movement of the shaft 60 will be described with reference to FIG. 8 is a side sectional view schematically showing a modification of the embodiment shown in FIG. 6. FIG. In this modification, regarding the hook shape provided in the extension region 46' of the metal portion 42 of the magnet holder 40, the heights of the rear surface portion 46A' and the front surface portion 46C' are formed low. As a result, the shaft 60 passes over the rear surface portion 46A' and the front surface portion 46C', and the end surface of the shaft 60 faces the second short wall portion 14B1 (B2) of the second housing portion 14 in close proximity. are arranged as

Thus, the movement of the shaft 60 in the vibrating direction is restrained by the second short side wall portions 14B1 and 14B2 facing both end faces of the shaft 60. As shown in FIG. As a result, displacement of the shaft 60 in the vibrating direction can be suppressed without adding another restraining member. Here, in order to easily accommodate the shaft 60 in the second housing portion 14, it is preferable to have a slight gap between both end surfaces of the shaft 60 and the second short side wall portions 14B1 and 14B2. It should be noted that instead of forming the rear portion 46A' and the front portion 46C' to be low, recesses for allowing the shaft 60 to pass through may be provided in the rear portion 46A' and the front portion 46C'.

<Modification of shaft support structure>
Next, a modified example of the support structure for the shaft 60 will be described with reference to FIG. 9 is a side sectional view schematically showing a modification of the embodiment shown in FIG. 7. FIG. In this modified example, the first projections 22A to 22D are not formed on the first housing portion 12, and instead, a sheet-like elastic member 24 is arranged as the first support portion 20. FIG. In this modified example, the elastic member 24 and the second protrusions 32C (32A, 32B, 32D) formed on the second housing portion 14 sandwich and support the shaft 60 from both upper and lower sides. At this time, the elastic member is compressed to some extent, and the shaft 60 can be reliably held by the elastic force of the elastic member.

As described above, the linear vibration motor 2 according to the present embodiment, including modifications,
A housing 10 formed by joining a first housing portion 12 having at least a top surface portion 12A and a second housing portion 14 having at least a bottom surface portion 14A, a vibrator 50 housed in the housing 10, and two shafts 60 arranged substantially parallel along the vibration direction of the vibrator 50 in the housing 10 and supporting the vibrator 50 in a vibrating state. The shafts 60 are provided in the first housing. A first support portion 20 provided in the portion 12 and a second support portion 30 provided in the second housing portion 14 are supported in a sandwiched state from both sides, and the second support portions 30 are supported by the respective shafts. In 60, two second protrusions 32A and 32B or 32C and 32D are arranged at a position overlapping the shaft 60 in plan view and separated by a predetermined distance along the extension direction of the shaft. The portions 32A to 32D are formed by bending a metal plate forming the second housing portion 14. As shown in FIG.

Since the shaft 60 is sandwiched and supported from both sides by the first support portion 20 and the second support portion 30, the shaft 60 can be securely fixed, and the second protrusions 32A to 32D are formed by bending a metal plate. Therefore, it is possible to form the second support portion 30 which is space-saving and has sufficient strength at low cost. This makes it possible to provide a low-cost, low-profile linear vibration motor 2 .

(Electronic device with linear vibration motor)
In an electronic device including the linear vibrating motor 2 according to the above-described embodiment and a device housing that accommodates the linear vibrating motor 2, the thinning of the linear vibrating motor 2 allows the device housing to be thinned.
This makes it possible to reduce the thickness of the electronic device, and moreover, many electronic components can be mounted inside the thin device housing, so that the layout of the battery, which is becoming higher in capacity, is not hindered.

The description of the above embodiment is illustrative in all respects and is not restrictive. Modifications and modifications are possible for those skilled in the art. The scope of the invention is indicated by the claims rather than the above-described embodiments. Further, the scope of the present invention includes modifications from the embodiments within the scope of claims and equivalents.

2 Linear vibration motor 10 Housing 12 First housing portion 12A Top surface portion 12B First side wall portions 12B1, 12B2 First short side wall portions 12B3, 12B4 First long side wall portion 14 Second housing portion 14A Bottom portion 14B Second side wall Portions 14B1, 14B2 Second short side wall portions 14B3, 14B4 Second long side wall portion 14C Substrate support portion 14C1 Recess 14D Support portion 20 First support portions 22A to 22D First projection 24 Elastic member 30 Second support portions 32A to 32D 2 convex portions 34 recessed portions 36A to 36D openings 40, 40 (M4), 40 (M5) magnet holder 42 metal portion 44 central regions 46, 46' extension regions 46A, 46A' rear portions 46B, 46B' bottom portions 46C, 46C ' Front part 50 Vibrator 52 Weight part 54 Sleeve 60 Shaft 70 Coil 72 Flexible printed circuit board (FPC)
72A Electrode M1 Second magnet M2 Second magnet M3 Third magnet M4 Fourth magnet M5 Fifth magnet L Long side S Short side CA, CB, CC, CD Corner area

Claims (7)

1. a housing formed by joining a first housing portion having at least a top surface portion and a second housing portion having at least a bottom surface portion;
   a vibrator housed in the housing;
   two shafts arranged substantially in parallel along the vibration direction of the vibrator in the housing and supporting the vibrator in a vibrating state;
   with
   The shaft is supported in a state of being sandwiched from both sides by a first support portion provided in the first housing portion and a second support portion provided in the second housing portion,
   The second supporting portion is composed of two second convex portions arranged on each of the shafts at a position overlapping the shaft in a plan view and separated from each other by a predetermined distance along the extension direction of the shaft. ,
   A linear vibration motor, wherein the second protrusion is formed by bending a metal plate forming the second housing.
2. wherein the first support portion is composed of a first projection arranged at a position overlapping with the second projection in plan view on each of the shafts,
   2. The linear vibration motor according to claim 1, wherein the first projection is formed by bending a metal plate forming the first casing.
3. A concave portion is provided at the tip of the second convex portion,
   3. The linear vibrating motor according to claim 1, wherein said shaft is inserted into said recess, and movement of said shaft in a direction intersecting said vibrating direction is restrained.
4. The first housing portion and the second housing portion each include a side wall portion, and in a state in which at least a portion of the side wall portion of the first housing portion and the side wall portion of the second housing portion overlap, The linear vibration motor according to any one of claims 1 to 3, wherein the first housing part and the second housing part are joined together to form the housing.
5. The linear vibration motor according to claim 4, characterized in that the side wall portions facing both end surfaces of the shaft restrain movement of the shaft in the vibration direction.
6. The linear vibration motor according to any one of claims 1 to 5, characterized in that the first housing part is formed by bending one metal plate.
7. The linear vibration motor according to any one of claims 1 to 6, characterized in that the second housing part is formed by bending one metal plate.

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