WO2016167297A1

WO2016167297A1 - Linear vibration motor

Info

Publication number: WO2016167297A1
Application number: PCT/JP2016/061943
Authority: WO
Inventors: 慎小田島; 昇生川; 片田　好紀; 栞石井
Original assignee: 日本電産コパル株式会社
Priority date: 2015-04-17
Filing date: 2016-04-13
Publication date: 2016-10-20
Also published as: CN107534375A; CN107534375B; JP2016208607A

Abstract

The present invention minimizes the generation of a contact sound by minimizing the rotation of a movable element and obtains stable vibration even when the movable element is configured to have a flat shape. A linear vibration motor 1 is provided with: a movable element 10 provided with a magnetic pole 2 and a weight section 3; a frame 4 that supports the movable element 10 so as to be capable of reciprocating vibration; a coil 5 that is fixed with respect to the frame 4 and that applies driving force to the magnetic pole 2; a guide shaft 6 that limits vibration of the movable element 10 to one axial direction; and an elastic member 6 that is provided between the frame 4 and the movable element 10 and that elastically deforms as a result of reciprocating vibration of the movable element 10. The movable element 10 has a flat shape in which the width in a direction intersecting the axial direction of the guide shaft 6 is larger than the thickness in a direction intersecting the axial direction of the guide shaft 6. The elastic member 7 is provided with plate springs 71A, 71B having plate widths that follow the thickness direction of the movable element 10.

Description

Linear vibration motor

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

Vibration motors (or vibration actuators) are widely used as devices that are built in portable electronic devices and transmit signal generation such as incoming calls and alarms to mobile users by vibration. In recent years, vibration motors have attracted attention as devices for realizing haptics (skin sensation feedback) in human interfaces such as touch panels.

As the vibration motor has been developed in various forms, a linear vibration motor that can generate a relatively large vibration by linear reciprocating vibration of the 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

As mobile electronic devices become smaller and thinner, vibration motors equipped with them are required to be further reduced in size and thickness. 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 thinning the linear vibration motor, if the magnet volume is sufficiently secured to obtain a desired driving force and the weight of the weight is sufficiently secured to obtain a desired inertial force, the magnet and the weight are The mover provided is made flat, and the thickness is reduced while ensuring the magnet volume and the gravity of the weight. In this case, if the mover rotates around the linear vibration axis, the flat shaped mover is shaped so that the side part is easy to come into contact with the surrounding frame body by the rotation, so that a contact sound is generated. For example, stable operation cannot be obtained. For this reason, the prior art provides two guide shafts to suppress rotation of the movable element around the vibration axis, and realizes stable linear vibration. However, if two guide shafts are provided, it is necessary to ensure the parallelism of the two guide shafts, and high accuracy is required for assembly, and there is a problem that high productivity is difficult to obtain.

The present invention is an example of a problem to deal with such a problem. In other words, the linear vibration motor can be made thin, and even when the mover is flattened, the rotation of the mover is suppressed, the generation of contact noise is suppressed, and stable vibration is obtained. It is an object of the present invention to ensure high productivity by not using simple parts.

In order to achieve such an object, the linear vibration motor of the present invention has the following configuration.
A mover including a magnetic pole part and a weight part, a frame body that supports the mover in a freely reciprocating manner, a coil that is fixed to the frame body and applies a driving force to the magnetic pole part, and a vibration of the mover A guide shaft that regulates in a single axial direction, and an elastic member that is provided between the frame and the movable element and elastically deforms by reciprocating vibration of the movable element, and the movable element is an axis of the guide shaft. The width in the direction intersecting the direction is a rectangular shape equal to or greater than the thickness in the direction intersecting the axial direction of the guide shaft, and the elastic member is a plate width along the thickness direction of the mover A linear vibration motor comprising: a leaf spring having:

In the linear vibration motor of the present invention having such characteristics, the mover vibrates along the guide shaft, but the rotation of the mover relative to the guide shaft is suppressed by the rigidity of the leaf spring. A leaf | plate spring has the rigidity with respect to the displacement along the thickness direction by having the plate | board width along the thickness direction of a needle | mover.

As a result, even when the mover has a square shape, the mover can be prevented from rotating around the guide shaft and coming into contact with the frame or the like, and stable reciprocating vibration without contact sound can be obtained. it can. At this time, since it is not necessary to use two guide shafts, stable vibration can be obtained without using highly accurate parts. In addition, since high-precision assembly is not required, high productivity can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing an overall configuration of a linear vibration motor according to a first embodiment of the present invention (FIG. It is explanatory drawing (plan view of the state except a cover) which shows the internal structure of the linear vibration motor which concerns on 1st Embodiment of this invention. FIG. 6 is an explanatory diagram (a is a plan view and (b) is a cross-sectional view taken along line AA) showing a modification of the first embodiment of the present invention. It is explanatory drawing (plan view of the state which removed the cover body) which shows the internal structure of the modification of 1st Embodiment of this invention. FIG. 6 is an explanatory diagram ((a) is a plan view and (b) is an AA cross-sectional view) illustrating an overall configuration of a linear vibration motor according to a second embodiment of the present invention. It is explanatory drawing (plan view of the state except a cover body) which shows the internal structure of the linear vibration motor which concerns on 2nd Embodiment of this invention. It is explanatory drawing ((a) is a top view, (b) is AA sectional drawing) which shows the whole structure of the linear vibration motor which concerns on 3rd Embodiment of this invention. It is explanatory drawing (plan view of the state except a cover body) which shows the internal structure of the linear vibration motor which concerns on 3rd Embodiment of this invention. FIG. 10 is an explanatory view (a is a plan view and (b) is an AA cross-sectional view) showing a modification of the third embodiment of the present invention. It is explanatory drawing (plan view of the state except a cover body) which shows the modification of 3rd Embodiment of this invention. It is explanatory drawing which showed the portable electronic device (mobile information terminal) equipped with the linear vibration motor which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, the X direction indicates the vibration direction of the mover, the Y direction indicates the width direction of the mover perpendicular to the X direction, and the Z direction indicates the thickness direction of the mover perpendicular to the X direction. Common parts in the drawings are denoted by the same reference numerals, and redundant description is omitted.

1 and 2 show a linear vibration motor 1 according to a first embodiment of the present invention. The linear vibration motor 1 includes a movable element 10 including a magnetic pole part 2 and a weight part 3 as a common part in the following embodiments, a frame body 4 that supports the movable element 10 so as to freely reciprocate, and a frame body 4. Are provided between the frame 4 and the movable element 10. The coil 5 is fixed to the magnetic pole part 2 and applies a driving force to the magnetic pole part 2. The guide shaft 6 restricts the vibration of the movable element 10 in one axis direction. And an elastic member 7 that is elastically deformed by reciprocating vibration.

The mover 10 includes a movable frame 11 that also serves as the weight portion 3, and a pair of magnets 2 A and 2 B are fixed to the movable frame 11. The mover 10 has a rectangular shape whose width in the Y direction in the figure is greater than or equal to the thickness in the Z direction in the figure. Specifically, it has a flat shape in which the width in the Y direction in the figure is larger than the thickness in the Z direction in the figure. The magnetic pole portion 2 includes a pair of magnets 2A, 2B and a back yoke 2S, and the pair of magnets 2A, 2B are magnetized in opposite directions along the Z direction (thickness direction of the mover 10). The rear surface is connected to the rear yoke 2S.

The frame body 4 includes a case frame 40 in which the mover 10 is accommodated and a lid frame 41 that covers the case frame 40. Both ends of one guide shaft 6 are supported in the case frame 40, and the mover 10 has an insertion portion 10 A through which the guide shaft 6 is inserted and a bearing 12. It is slidably supported along.

The coil 5 is fixed to the cover frame 41 of the frame body 4 via a flexible substrate 50 on the surface facing the case frame 40. The coil 5 is wound along a surface defined by the width direction of the mover 10 (Y direction in the drawing) and the axial direction of the guide shaft 6 (X direction in the drawing), and a pair of the cover 5 and the lid frame 41 along the surface. Between the magnets 2A and 2B.

The elastic member 7 disposed between the mover 10 and the frame 4 includes a pair of

coil springs

70A and 70B and a pair of

leaf springs

71A and 71B. The pair of

coil springs

70A and 70B are arranged coaxially with the guide shaft 6, and the pair of

plate springs

71A and 71B have a plate width along the thickness direction (Z direction in the drawing) of the mover 10, and have one end portion. Is attached to the side surface of the frame 4 (case frame 40), and the other end is attached to the side surface of the mover 10 (movable frame 11).

Such a linear vibration motor 1 supplies the coil 5 with a drive current having a resonance frequency determined by the weight of the mover 10 and the spring constant of the elastic member 7, so that the mover 10 is uniaxially along the guide shaft 6. Vibrates back and forth. At this time, the

leaf springs

71A and 71B are elastically deformed with respect to the vibration along the X direction of the movable element 10, but are rigid with respect to the movement of the movable element 10 in the Z direction. Even if the child 10 tries to rotate around the guide shaft 6, the rotation is restrained by the rigidity of the

leaf springs

71A and 71B. Accordingly, it is possible to avoid a problem that the movable element 10 contacts the frame body 4 or the coil 5 and generates a contact sound during the reciprocating vibration of the movable element 10.

The linear vibration motor 1 is arranged at a position where the guide shaft 6 is shifted from the center of gravity of the mover 10 to one side, and the

leaf springs

71A, 71B are arranged at a position shifted from the center of gravity to the other side. As a result, rotation around the center of gravity of the mover 10 is suppressed by both the guide shaft 6 and the

leaf springs

71A and 71B, and a stable planar reciprocating vibration can be realized.

A linear vibration motor 1A shown in FIGS. 3 and 4 is a modification of the linear vibration motor 1 shown in FIGS. In this example, the pair of magnets 2A and 2B in which the magnetic pole portion 2 is magnetized in the opposite directions along the thickness direction (Z direction in the figure) of the mover 10 and the pair of magnets 2A and 2B are the mover. The counter yoke 2 R is arranged with an interval in the thickness direction (Z direction in the figure). Then, the coil 5 is wound along a surface defined in the width direction of the mover 10 (Y direction in the drawing) and the axial direction of the guide shaft 6 (X direction in the drawing), and the opposing yoke 2R and the pair of magnets 2A, It is arrange | positioned in the space | interval with 2B. The coil 5 here is held by a coil holding body 51 and fixed to the frame body 4.

Similar to the linear vibration motor 1, such a linear vibration motor 1A is also in contact with the frame 4 and the coil 5 during the reciprocal vibration of the mover 10 due to the rigidity of the

leaf springs

71A and 71B. Problems that generate sound can be avoided.

In the linear vibration motor 1B shown in FIGS. 5 and 6, the frame 4 is elongated in the X direction (vibration direction), and the mover 10 has a larger width in the Y direction than the thickness in the Z direction. It has a flat shape.

Further, in the linear vibration motor 1B, the guide shaft 6 has one end fixed to the end of the mover 10 and is disposed so as to protrude in opposite directions from both ends of the mover 10. The frame 4 is provided with a bearing 12 that slidably supports the guide shaft 6, and coil springs 70 A and 70 B arranged coaxially with the guide shaft 6 are arranged between the movable frame 11 and the frame 4. Has been. According to such a linear vibration motor 1B, since the guide shaft 6 does not have to penetrate the mover 10, the magnets 2A and 2B can be arranged in the entire width direction (Y direction) of the mover 10, and the narrow width Even when the movable element 10 is used, a sufficient driving force can be obtained.

The linear vibration motor 1C shown in FIGS. 7 and 8 includes a pair of magnets 2C and 2D in which the magnetic pole portion 2 is magnetized in opposite directions along the guide shaft 6, and a spacer yoke 2P disposed therebetween. It has. The coil 5 is wound around the spacer yoke 2P and is fixed to the frame 4 around it.

This linear vibration motor 1C also has a single guide shaft 6 but the rigidity of the

leaf springs

71A and 71B prevents the mover 10 from rotating around the guide shift 6 so that the mover 10 can be used as the frame 4 or the coil 5. It is possible to avoid a problem that a contact sound is generated by touching the contact.

A linear vibration motor 1D shown in FIGS. 9 and 10 is a modification of the linear vibration motor 1C, and the movable element 10 and the frame body 4 are elongated along the vibration direction (X direction in the drawing). According to this, even when the width (Y direction) of the linear vibration motor 1D is reduced to improve the installation space efficiency in the width direction, effective reciprocating vibration can be obtained.

Since the mover 10 of the linear vibration motors 1 to 1D described above is slidably supported along the uniaxial guide shaft 6, it rotates around the guide shaft 6 without the

leaf springs

71A and 71B. However, the rotation is restrained by the rigidity of the

leaf springs

71A and 71B.

Since the assembly of such linear vibration motors 1 to 1D does not require the parallelism of the two axes to be adjusted with high accuracy as in the prior art, it can be assembled relatively easily. Therefore, a high-efficiency flat linear vibration motor with less mechanical noise can be realized without using high-precision parts.

FIG. 11 shows a portable information terminal 100 as an example of an electronic device equipped with the linear vibration motor 1 (1A to 1D) according to the embodiment of the present invention. The portable information terminal 100 having the linear vibration motor 1 (1A to 1D) that can obtain a stable vibration and can be thinned and made compact in the width direction is different at the start and end of operations such as an incoming call and an alarm function in a communication function. It can be transmitted to the user with stable vibration that is less likely to generate sound. In addition, the portable information terminal 100 pursuing high portability or design can be obtained by making the linear vibration motor 1 (1A to 1D) thin and compact in the width direction. Furthermore, since the linear vibration motor 1 (1A to 1D) has a compact shape in which each part is housed in a rectangular parallelepiped frame 4 with a reduced thickness, the space-efficient mobile information terminal 100 has a space efficient. Can be equipped.

As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. In particular, the number and arrangement of the coils and magnets described above are not limited to the examples described above, and any appropriate form can be selected as long as linear reciprocal vibration can be obtained. In addition, the above-described embodiments can be combined by utilizing each other's technology as long as there is no particular contradiction or problem in the purpose and configuration.

1, 1A, 1B, 1C, 1D: linear vibration motor,
2: Magnetic pole part, 2A, 2B, 2C, 2D: Magnet,
2S: Back yoke, 2P: Spacer yoke, 2R: Opposing yoke,
3: weight part, 4: frame, 40: case frame, 41: lid frame,
5: Coil, 50: Flexible substrate, 51: Coil holder
6: Guide shaft,
7: elastic member, 70A, 70B: coil spring, 71A, 71B: leaf spring,
10: mover, 10A: insertion part,
11: movable frame, 12: bearing, 100: portable electronic device (portable information terminal)

Claims

A mover including a magnetic pole part and a weight part;
A frame that supports the mover in a freely reciprocating manner;
A coil that is fixed to the frame and applies a driving force to the magnetic pole part;
A guide shaft that regulates vibration of the mover in a uniaxial direction;
An elastic member provided between the frame and the mover and elastically deformed by reciprocating vibration of the mover;
The movable element has a rectangular shape whose width in the direction intersecting the axial direction of the guide shaft is equal to or greater than the thickness in the direction intersecting the axial direction of the guide shaft,
The linear vibration motor, wherein the elastic member includes a leaf spring having a leaf width along the thickness direction of the mover.
2. The linear device according to claim 1, wherein the guide shaft is disposed at a position shifted to one side from the center of gravity of the mover, and the leaf spring is disposed at a position shifted from the center of gravity to the other side. Vibration motor.
The magnetic pole portion includes a pair of magnet portions that are held in opposite directions along the thickness direction of the mover,
The linear vibration motor according to claim 1, wherein the coil is wound along a surface defined by a width direction of the mover and an axial direction of the guide shaft.
The magnetic pole portions are arranged in a pair of magnet portions magnetized in opposite directions along the thickness direction of the mover, and the pair of magnet portions are spaced apart from each other in the thickness direction of the mover. With a yoke,
3. The coil according to claim 1, wherein the coil is wound along a plane defined by a width direction of the mover and an axial direction of the guide shaft, and is disposed within the interval. Linear vibration motor.
The magnetic pole part includes a magnet magnetized along the guide shaft,
The linear vibration motor according to claim 1, wherein the coil is wound around the magnetic pole portion.
Both ends of the guide shaft are supported by the frame body,
6. The linear vibration motor according to claim 1, wherein the movable element is slidably supported along the guide shaft.
The guide shaft has one end fixed to the end of the mover, and is arranged to protrude in opposite directions from both ends of the mover.
6. The linear vibration motor according to claim 1, wherein the frame body is provided with a bearing that slidably supports the guide shaft.
The linear vibration motor according to any one of claims 1 to 7, wherein the elastic member includes a compression coil spring disposed coaxially with the guide shaft.
A portable electronic device comprising the linear vibration motor according to any one of claims 1 to 8.