WO2016084811A1

WO2016084811A1 - Electromagnetic actuator

Info

Publication number: WO2016084811A1
Application number: PCT/JP2015/082955
Authority: WO
Inventors: 笠原　貴; 武彦熊谷; 朋和朝倉
Original assignee: 日本電産コパル株式会社
Priority date: 2014-11-25
Filing date: 2015-11-24
Publication date: 2016-06-02
Also published as: CN206951531U; JP2016097382A

Abstract

Provided is an electromagnetic actuator which uses magnets as a movable element, wherein a variance in adhesive strength is eliminated when the magnets and another metal body are joined via an adhesive, and an electromagnetic actuator which is capable of stable operation is produced at high yield. The present invention includes a movable element 2 provided with magnets 11, 12, 13 and a coil 3 for applying a drive force to the magnets 11, 12, 13. The movable element 2 is provided with a metal body (weight 20) that is joined to the magnets 11, 12, 13 and operates integrally with the magnets 11, 12, 13. The magnets 11, 12, 13 and the metal body (weight 20) are all covered with a plating film, with an organic coating being formed on the plating film, and are joined to one another via an adhesive applied over the organic coating.

Description

Electromagnetic actuator

The present invention relates to an electromagnetically driven actuator having a magnet joined with a metal body.

The electromagnetic drive actuator uses a Lorentz force generated between a magnet and a coil by passing a current through the coil as a driving force, and is known to operate a magnet as a mover by fixing the coil to a frame. . At this time, the magnet, which is a mover, operates integrally with various constituent members, thereby becoming an actuator having various functions.

A vibration motor (or vibration actuator) that can be cited as an example of an electromagnetically driven actuator generates vibrations when an incoming call is received from a communication device or an alarm is issued from various electronic devices, and the operator of the communication device or touches the various electronic devices. The state of signal input by vibration is conveyed to various electronic devices such as portable information terminals including mobile phones. Such a vibration motor includes a mover in which a magnet and a weight vibrate integrally (see Patent Document 1 below).

Further, as another example of the electromagnetic drive actuator, there is a lens drive device that drives the lens frame in the optical axis direction or in a direction intersecting the optical axis to adjust the focus of the lens and shake correction. Such a lens driving device includes a mover in which a magnet and a lens frame operate integrally (see Patent Document 2 below).

JP 2014-176841 A JP 2012-113236 A

Conventionally, in an electromagnetic drive actuator, a component that operates integrally with a magnet is joined integrally with the magnet through an adhesive in consideration of workability during assembly. In this case, if this component is a metal body, the plating treatment is performed on both the metal body and the magnet before joining in consideration of corrosion, so there is a variation in the finish of the plating film formed on the surface. As a result, there is a problem that the adhesive strength easily varies due to the influence.

The present invention is an example of a problem to deal with such a problem. That is, in an electromagnetic drive actuator using a magnet as a mover, when joining a magnet and another metal body via an adhesive, an electromagnetic drive actuator capable of stable operation with no variation in adhesive strength is obtained with a high yield. It is an object of the present invention to be able to produce in

In order to achieve such an object, the present invention has the following configuration.
A mover including a magnet and a coil that applies a driving force to the magnet; the mover includes a metal body that is joined to the magnet and operates integrally with the magnet; and the magnet and the metal body are: An electromagnetically driven actuator characterized in that both are covered with a plating film, an organic film is formed on the plating film, and they are bonded to each other via an adhesive applied on the organic film.

According to the present invention having such a feature, in an electromagnetically driven actuator using a magnet as a mover, when bonding a magnet and another metal body via an adhesive, there is no variation in adhesive strength and stable operation is achieved. Can be produced with a high yield.

FIG. 3 is a perspective view showing the internal structure of a vibration motor that is an example of an electromagnetically driven actuator according to an embodiment of the present invention. FIG. 2 is a plan view showing an internal structure of a vibration motor that is an example of an electromagnetically driven actuator according to an embodiment of the present invention. 1 is an exploded perspective view showing an internal structure of a vibration motor that is an example of an electromagnetically driven actuator according to an embodiment of the present invention. FIG. 3 is an explanatory view showing an electronic device (mobile information terminal) including a vibration motor that is an example of an electromagnetically driven actuator according to an embodiment of the present invention.

The electromagnetic drive actuator according to the embodiment of the present invention includes a mover including a magnet and a coil for applying a driving force to the magnet. The mover includes a metal body that is joined to the magnet and operates integrally with the magnet. The magnet and the metal body are both covered with a plating film, an organic film is formed on the plating film, and bonded to each other via an adhesive applied on the organic film.

The magnet used as the mover can be a neodymium magnet, an alnico magnet, a ferrite magnet, a samarium cobalt magnet, or the like. There are various metal bodies to be joined to the magnet depending on the application of the electromagnetic drive actuator. The weight of the vibration motor is made of tungsten, iron, an alloy of tungsten and iron, an alloy of tungsten and other metals, or the like. A powder sintered body or the like can be used.

The plating film covering the surface of the magnet and the metal body is electroplating or electroless plating that is coated before joining the two, and can be selected from electro nickel plating, electroless nickel plating, zinc plating, chrome plating, etc. it can. In addition, the present invention is not limited to this, and may be copper plating, tin plating, gold plating, silver plating, palladium plating, cobalt plating, or the like, or may be alloy plating.

As the organic film formed on the plating film, for example, a film obtained by dissolving an organic acid or a mixed acid containing an organic acid in a solvent and the like can be used. It can be selected from acids, amino acids, hydroxy acids and the like. The organic coating is not limited to the above-described example as long as the surface of the plating film can be modified to improve the adhesiveness with the adhesive. As the adhesive applied on the organic film, an epoxy resin adhesive or a silicone resin adhesive can be used. Moreover, not only this but all the adhesives suitable for adhere | attaching metals, such as an acrylic resin adhesive, a urethane resin adhesive, and a phenol resin adhesive, can be used.

According to the electromagnetic drive actuator having such a feature, a metal body that operates integrally with the magnet can be joined to the magnet with a uniform adhesive strength. As a result, an electromagnetically driven actuator capable of stable operation can be manufactured with a high yield.

Hereinafter, a vibration motor which is an example of an electromagnetic drive actuator according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, the vibration motor 1 includes a mover 2, a coil 3, a frame 4, an elastic member 5, and a guide shaft 6, and the mover 2 is uniaxially (X-axis direction shown in the drawing). Vibration is generated by reciprocating linearly along the axis.

The mover 2 includes a magnetic pole portion 10 and a weight 20. In the illustrated example, the weights 20 are provided on both sides of the mover 2 in the uniaxial direction (X-axis direction in the figure), but the present invention is not limited to this and may be provided on only one side. The magnetic pole part 10 includes magnets 11, 12 and 13 and

yokes

14 and 15. Here, the three magnets 11, 12, 13 and the two

yokes

14, 15 are provided. However, the present invention is not limited to this. For example, the magnetic pole portion 10 can be constituted by two magnets and one yoke.

The magnets 11, 12, and 13 have magnetic pole directions along one axial direction (X-axis direction in the drawing). The yoke 14 is sandwiched between the same poles of the pair of magnets 11 and 12, and the yoke 15 is sandwiched between the same poles of the pair of magnets 12 and 13. The magnetic pole portion 10 can reinforce the connection between the magnets 11, 12, 13 and the

yokes

14, 15 by fixing the reinforcing plate 16 to the side surface thereof.

The coil 3 (3A, 3B) is disposed so as to surround the

yokes

14, 15 of the magnetic pole part 10. Here, two

coils

3A and 3B having opposite winding directions are arranged so as to correspond to the two

yokes

14 and 15, but when one yoke is provided, one coil is arranged.

The frame body 4 includes a magnetic pole frame portion 30 that holds the coil 3. The magnetic pole frame part 30 constitutes a magnetic circuit that forms a magnetic flux across the coil 3 together with the magnetic pole part 10 of the mover 2. As a result, a driving force is applied along the uniaxial direction (X-axis direction in the drawing) to the magnetic pole part 10 of the mover 2 by causing a current to flow through the coil 3 fixed to the magnetic pole frame part 30. The frame 4 is provided with an input terminal 18 for inputting a drive signal to the coil 3.

The magnetic pole frame portion 30 includes an upper surface portion 31, a lower surface portion 32, and a side surface portion 33 so as to surround the coil 3. In the illustrated example, the upper surface portion 31 and the lower surface portion 32 have a plane portion along the X axis and the Y axis, and the side surface portion 33 has a plane portion along the X axis and the Z axis.

Further, in the illustrated example, the frame 4 is formed by connecting the upper frame 40 and the lower frame 41 to form a frame that accommodates the mover 2 therein. The upper frame body 40 includes the upper surface portion 31 and the side surface portion 33 described above, and the lower frame body 41 includes the lower surface portion 32 described above, the front wall portion 41A, and the side wall portion 41B.

The guide shaft 6 is a shaft member that guides the vibration of the mover 2 along the uniaxial direction (the X-axis direction in the drawing) within the frame body 4. In the illustrated example, the guide shaft 6 is disposed along the center of gravity axis of the mover 2 such that one end is fixed to the weight 20 and the other end protrudes outside the weight 20. 6A and 6B are attached. The other end side of the guide shaft 6 (6A, 6B) is slidably supported by a bearing 17 provided on the frame body 4. Here, an example of the guide shaft 6 fixed to the weight 20 is shown, but the guide shaft 6 can also be constituted by a single shaft that penetrates the mover 2 along the X-axis direction, for example. In this case, both ends of the guide shaft 6 are fixed to the front wall portion 41 </ b> A of the frame body 4.

The illustrated

guide shafts

6A and 6B are fixed in a recess 20A formed in the weight 20 along the X-axis direction. The recess 20A has a width in the Y-axis direction that allows the bearing 17 to enter, and has a depth in the X-axis direction that allows the amplitude of the mover 2. Further, the weight 20 includes an engagement recess 20B on the opposite side to the recess 20A, and the magnets 11 and 13 of the magnetic pole portion 10 are engaged and fixed to the engagement recess 20B.

The elastic member 5 is disposed in the frame body 4 and applies an elastic force to the mover 2 that repels the driving force applied to the magnetic pole portion 10 by the current flowing through the coil 3. The illustrated elastic member 5 is disposed between one end of the weight 20 in the axial direction (X-axis direction) and the front wall portion 41A of the frame body 4, and is compressed against vibration in the axial direction of the mover 2. It is composed of springs, and four are arranged on both the left and right sides with the

guide shafts

6A and 6B interposed therebetween.

In such a vibration motor 1, the movable element 2 has a thickness (Z in the figure) in which the width (width in the Y axis direction in the figure) orthogonal to the uniaxial direction (X axis direction in the figure) is orthogonal to the uniaxial direction (X axis direction in the figure). It has a flat shape larger than the thickness in the axial direction. That is, each of the magnetic pole part 10 and the weight 20 has a flat shape in which the width in the Y direction in the drawing is larger than the thickness in the Z direction in the drawing. Corresponding to the flat shape of the mover 2, the outer shape of the frame body 4 also has a flat shape in which the width in the Y direction in the drawing is larger than the thickness in the Z direction in the drawing. Thus, by making the mover 2 and the frame 4 flat, it is possible to obtain a thin vibration motor 1 with a reduced thickness in the Z-axis direction.

The surfaces of the magnets 11, 12, 13 and the

yokes

14, 15 are covered with a plating film (for example, nickel plating). Similarly, the surface of the weight 20 is covered with a plating film (for example, nickel plating).

The magnets 11 and 12 and the yoke 14, the magnets 12 and 13 and the yoke 15, the magnet 11 and one weight 20, and the magnet 13 and the other weight 20 are joined via an adhesive, respectively. An organic film is formed on the plating films. For example, the organic coating is formed by coating or dipping a solution obtained by dissolving an organic acid or a mixed acid containing an organic acid in a solvent on the plating films of the magnets 11, 12, 13, the

yokes

14, 15 and the weight 20. Form by wearing.

Thus, after forming an organic film on the plating films of the magnets 11, 12, 13, the

yokes

14, 15, and the weights 20, these are bonded via an adhesive so that the surface of the plating film is formed. It can be uniformly modified, and bonding with little variation in adhesive strength can be performed. Thus, the vibration motor 1 that can obtain stable vibration of the mover 2 can be obtained.

FIG. 4 shows a portable information terminal 100 as an example of an electronic apparatus provided with the vibration motor 1 according to the embodiment of the present invention. The portable information terminal 100 including the vibration motor 1 that can obtain a stable vibration and can be thinned and compact in the width direction is less likely to generate abnormal noise at the start and end of an incoming call or alarm function in a communication function. The vibration can be transmitted to the user. Further, the portable information terminal 100 pursuing high portability or design can be obtained by making the vibration motor 1 thin and compact in the width direction. Furthermore, since the vibration motor 1 has a compact shape in which each part is housed in a rectangular parallelepiped frame 4 with a reduced thickness, the vibration motor 1 can be efficiently installed inside the thinned portable information terminal 100.

In the above-described embodiment, the magnetic pole portion 10 includes the magnets 11, 12, and 13 magnetized in the uniaxial direction (the X-axis direction in the drawing), and the coil 3 is disposed so as to surround the magnetic pole portion 10. The magnetic pole portion may be disposed so as to surround the coil, and the magnetic pole portion has a magnet magnetized in a direction orthogonal to the uniaxial direction (for example, the Z-axis direction in the drawing), and the coil You may arrange | position so that a part may be opposed.

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: vibration motor, 2: mover, 3 (3A, 3B): coil, 4: frame,
5: Elastic member, 6 (6A, 6B): Guide shaft,
10: magnetic pole part,
11, 12, 13: Magnet,
14, 15: York,
16: reinforcing plate, 17: bearing, 18: input terminal,
20: Weight, 20A: recess, 20B: engagement recess,
30: magnetic pole frame part, 31: upper surface part, 32: lower surface part, 33: side part,
40: upper frame, 41: lower frame, 41A: front wall, 41B: side wall 100: portable information terminal

Claims

A mover including a magnet and a coil for applying a driving force to the magnet;
The mover includes a metal body that is joined to the magnet and operates integrally with the magnet.
The magnet and the metal body are both covered with a plating film, an organic film is formed on the plating film, and the magnet and the metal body are bonded to each other via an adhesive applied on the organic film. Electromagnetic drive actuator.
2. The electromagnetically driven actuator according to claim 1, wherein the plating film is selected from electric nickel plating, electroless nickel plating, zinc plating, and chromium plating.
3. The electromagnetically driven actuator according to claim 1, wherein the organic film is a film deposited by dissolving an organic acid or a mixed acid containing an organic acid in a solvent.
The electromagnetic drive actuator according to claim 3, wherein the organic acid is selected from fatty acids, sugar acids, amino acids, and hydroxy acids.
The electromagnetically driven actuator according to any one of claims 1 to 4, wherein the adhesive is an epoxy resin adhesive or a silicone resin adhesive.
6. The electromagnetically driven actuator according to claim 1, wherein the metal body is a weight, and the mover is a vibrator that vibrates.
A magnetic part having a magnet and a mover having a weight;
A coil that encloses the magnetic pole portion and applies a driving force along a uniaxial direction to the mover;
A frame for holding the coil;
An elastic member that is arranged in the frame and imparts an elastic force repelling the driving force to the mover;
A guide shaft that guides the vibration of the mover along the uniaxial direction in the frame body,
The magnet and the weight are both covered with a plating film, an organic film is formed on the plating film, and the magnet and the weight are bonded to each other via an adhesive applied on the organic film. Drive actuator.
A portable information terminal comprising the electromagnetically driven actuator according to any one of claims 1 to 7 as a vibration motor.