WO2021237786A1

WO2021237786A1 - Linear vibration electric motor

Info

Publication number: WO2021237786A1
Application number: PCT/CN2020/094694
Authority: WO
Inventors: 崔志勇; 马杰; 王尧
Original assignee: 瑞声声学科技(深圳)有限公司; 瑞声科技(新加坡)有限公司
Priority date: 2020-05-27
Filing date: 2020-06-05
Publication date: 2021-12-02
Also published as: CN212811536U

Abstract

A linear vibration electric motor (100), comprising a housing (1) with an accommodating space (10), a vibration unit (2) arranged in the accommodating space, an elastic member (3), a coil assembly (4), a second iron core (5) and metal sheets (6), wherein the vibration unit comprises a magnetic steel assembly (22); the coil assembly is positioned at one side of the vibration unit in a direction perpendicular to the vibration direction, and comprises a first iron core (41) fixed on the housing and a coil (42) wound around the first iron core, and the first iron core is opposite the magnetic steel assembly; and the metal sheets are stacked on one side of the second iron core close to the magnetic steel assembly, the second iron core and the first iron core are arranged on two opposite sides of the magnetic steel assembly, the metal sheets are positioned in a magnetic field of the magnetic steel assembly, and when the vibration unit vibrates, the metal sheets are used for generating a damping force for hindering the vibration of the vibration unit. The linear vibration electric motor is simple in structure and more reliable.

Description

Linear vibration motor

Technical field

The utility model relates to a vibration motor, in particular to a linear vibration motor used for portable consumer electronic products.

Background technique

With the development of electronic technology, portable consumer electronic products are becoming more and more sought after by people, such as mobile phones, handheld game consoles, navigation devices or handheld multimedia entertainment equipment, etc., generally use vibration motors for system feedback, such as mobile phones. Incoming call reminder, information reminder, navigation reminder, vibration feedback of game console, etc. Such a wide range of applications requires the vibration motor to have high performance, good stability and long service life.

A related-art linear vibration motor includes a housing having a housing space, a vibration unit placed in the housing space, an elastic member that suspends the vibration unit in the housing space, and a housing fixed to the housing. A coil assembly that drives the vibration unit to vibrate; the vibration unit includes a mass with a through hole and a magnetic steel assembly fixed in the through hole; in order to increase the driving force, the coil assembly includes a mass fixed to the shell The first iron core of the body and the coil wound around the first iron core, but the first iron core is magnetized after the coil is energized, which generates an attractive or repulsive force perpendicular to the vibration direction to the magnetic steel assembly, which affects the vibration unit In order to overcome the attractive or repulsive force of the first iron core to the magnetic steel component, in the prior art, dual voice coil components are often arranged symmetrically up and down on both sides of the vibration unit along the direction perpendicular to the vibration, but At the same time, it also brings problems such as complicated circuit connection and large space occupation.

technical problem

On the other hand, the linear vibration motor of the related art realizes the damping of the vibration unit by adding damping materials such as magnetic fluid or damping foam, but the temperature characteristics of the magnetic fluid or damping foam are poor. The damping material is easy to fail and the damping cannot be adjusted, resulting in failure of the linear vibration motor and poor reliability. In the prior art, a linear vibration motor includes both a voice coil assembly that provides driving force for the vibration unit and a self-conducting voice coil assembly that provides damping force for the vibration unit. Similarly, this double The structure of the voice coil assembly makes the circuit connection of the entire linear vibration motor complicated and takes up a large space, which increases the weight and volume of the entire linear vibration motor, so that the linear vibration motor has a very limited space perpendicular to the vibration direction. Conducive to its design.

Therefore, it is necessary to provide a new linear vibration motor to solve the above technical problems.

Technical solutions

The purpose of the utility model is to provide a linear vibration motor with simple structure and good reliability.

In order to achieve the above-mentioned objective, the present invention provides a linear vibration motor, which includes a housing with a housing space, a vibration unit placed in the housing space, and elasticity for suspending the vibration unit in the housing space. And a coil assembly that is fixed to the housing and drives the vibration unit to vibrate, the vibration unit includes a magnetic steel assembly housed in the accommodating space; the coil assembly is located along the vibration unit perpendicular to the vibration On one side of the direction, the coil assembly includes a first iron core fixed to the housing and a coil wound around the first iron core, and the first iron core is opposite to the magnetic steel assembly; The linear vibration motor also includes a second iron core fixed to the housing and a metal sheet stacked on a side of the second iron core close to the magnetic steel component. The second iron core is connected to the first iron core. The core is arranged on opposite sides of the magnetic steel assembly; the metal sheet is located in the magnetic field of the magnetic steel assembly, and when the vibration unit vibrates, the metal sheet generates a damping force that hinders the vibration of the vibration unit.

Preferably, the metal sheet is a copper sheet.

Preferably, the magnetizing direction of the magnetic steel component is perpendicular to the vibration direction.

Preferably, the vibration unit further includes a mass with a through hole, and the magnetic steel component is fixed in the through hole.

Preferably, the magnetic steel component includes a first magnetic steel, a second magnetic steel, and a third magnetic steel that are spaced apart from each other and arranged in sequence along the vibration direction. The polarities are opposite, the first magnetic steel and the third magnetic steel have the same polarity; the coil assembly is set as two spaced apart from each other along the vibration direction, and neither of the coil assemblies is connected to The first magnet or the second magnet or the third magnet is arranged directly opposite to each other.

Preferably, the mass includes a first groove and a second groove formed along opposite sides perpendicular to the vibration direction in the direction of the magnetic steel component, and the through hole is formed by the first groove. The metal sheet is at least partially received in the first recess, and the coil component is at least partially received in the second recess.

Preferably, the linear vibration motor further includes a bracket located in the first groove and covering the through hole, and the magnetic steel component is fixedly connected to the bracket.

Preferably, the coil assembly further includes a magnetic conductive sheet disposed on a side of the first iron core away from the magnetic steel assembly, and the first iron core is fixed to the housing through the magnetic conductive sheet.

Preferably, the elastic pieces are arranged as two respectively located at opposite ends of the vibration unit along the vibration direction, and the two elastic pieces are arranged symmetrically; each of the elastic pieces includes an elastic arm, The opposite ends of the elastic arm are respectively a first connecting arm and a second connecting arm that are bent and extended in the same direction; the elastic arm and the mass are spaced apart, and the first connecting arm is fixedly connected to the mass The second connecting arm is fixedly connected to the housing.

Preferably, the linear vibration motor further includes at least two first reinforcing blocks and two second reinforcing blocks, each of the first reinforcing blocks is located on a side of each of the first connecting arms away from the mass block So that the first connecting arm is fixed to the mass; each second reinforcing block is located on the side of each second connecting arm away from the housing so that the second connecting arm is fixed to The housing.

Beneficial effect

Compared with the related art, in the linear vibration motor of the present invention, the coil assembly is located on one side of the vibration unit perpendicular to the vibration direction. At this time, the circuit design provided to the coil is simpler, and at the same time The volume of the entire linear vibration motor is saved, the space utilization rate is better, the mass of the entire linear vibration motor is reduced, and the structure is simple. The second iron core is located on the side of the metal sheet away from the magnetic steel assembly, the metal sheet generates a damping force that hinders the vibration of the vibration unit, and the second iron core guides the magnetic field lines of the magnetic steel assembly to pass through the metal sheet , So that the eddy current damping force generated by the metal sheet due to the cutting of the magnetic lines of force is improved, and the reliability is better; at the same time, the second iron core and the first iron core are arranged on opposite sides of the vibration unit, that is, this The structure enables the second iron core to form an attractive force on the magnetic steel assembly perpendicular to the vibration direction, which overcomes the attractive force of the first iron core on the magnetic steel assembly. The force is relatively balanced or small, and the force applied along the direction perpendicular to the vibration direction can be ignored, so that the vibration effect of the linear vibration motor is better.

Description of the drawings

In order to explain the technical solutions in the embodiments of the present utility model more clearly, the following will briefly introduce the drawings needed in the description of the embodiments. Obviously, the drawings in the following description are only some implementations of the present utility model. For example, for those of ordinary skill in the art, without creative work, other drawings can be obtained based on these drawings, among which:

Figure 1 is a schematic diagram of the three-dimensional structure of the linear vibration motor of the utility model;

Figure 2 is an exploded schematic diagram of the linear vibration motor of the utility model;

Fig. 3 is a cross-sectional view along A-A of Fig. 1.

Embodiments of the present invention

The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, not all of them. Examples. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the scope of protection of the present utility model.

Please refer to FIGS. 1-3 at the same time. The present invention provides a linear vibration motor 100, which includes a housing 1 with a housing space 10, a vibration unit placed in the housing space 10, and the vibration unit 2 The elastic member 3 suspended in the receiving space 10, the coil assembly 4 fixed to the housing 1 and driving the vibration unit 2 to vibrate, the second iron core 5, the metal sheet 6, the bracket 7 and the first reinforcement Block 8 and second reinforcement block 9.

The housing 1 includes an upper housing 11 and a lower housing 12 covering the upper housing 11. The upper housing 11 and the lower housing 12 jointly enclose a receiving space 10.

The vibration unit 2 includes a mass 21 with a through hole 210 and a magnetic steel assembly 22 housed in the receiving space 10. Specifically, the magnetic steel component 22 is fixed in the through hole 210 and the magnetizing direction is perpendicular to the vibration direction.

The mass 21 includes a first groove 211 and a second groove 212 recessed in the direction of the magnetic steel assembly 22 along opposite sides perpendicular to the vibration direction. The through hole 210 is formed by the first groove. The groove 211 penetrates to the second groove 212 to be formed.

The magnetic steel assembly 22 includes a first magnetic steel 221, a second magnetic steel 222, and a third magnetic steel 223 which are spaced apart from each other and arranged in sequence along the vibration direction.

The coil assembly 4 is located on one side of the vibration unit 2 perpendicular to the vibration direction. At this time, the circuit design provided to the coil assembly 4 is simpler, and at the same time, the volume and space of the entire linear vibration motor 100 are saved. The utilization rate is better, and the mass of the entire linear vibration motor 100 is reduced. Specifically, the coil assembly 4 is at least partially housed in the second groove 212 to further reduce the occupied space of the linear vibration motor along the direction perpendicular to the vibration direction.

Specifically, the coil assembly 4 is provided in two and arranged at intervals along the vibration direction. Each coil assembly 4 includes a first iron core 41 fixed to the housing 1, a coil 42 wound around the first iron core, and a first iron core 41 far away from the magnetic steel assembly 22. The magnetic conductive sheet 43 on the side, the first iron core 41 is fixed to the lower housing 12 through the magnetic conductive sheet 43.

After the coil 42 is energized, an ampere force in the vibration direction is formed in the magnetic field generated by the magnetic steel assembly 22 to drive the vibration unit 2 to vibrate and produce a vibration effect; at the same time, the coil 42 after energization makes the first iron core 41 magnetize, so that all The first iron core 41 and the adjacent magnetic steel component 22 have the same or opposite polarity, forming an electromagnetic force that attracts or repels each other.

In this embodiment, the polarities of the first magnet 221 and the second magnet 222 are opposite, and the polarities of the first magnet 221 and the third magnet 223 are the same. None of the coil assemblies 4 is arranged directly opposite to the first magnet 221, the second magnet 222, or the third magnet 223; that is, one of the coil assemblies 4 faces the magnet The orthographic projection of the steel component 22 falls into the first magnetic steel 221 and the second magnetic steel 222 at the same time, and the orthographic projection of the other coil component 4 to the magnetic steel component 22 falls into the second magnetic steel component 22 at the same time. Steel 222 and the third magnetic steel 223.

In this embodiment, FIG. 3 is taken as an example for further description. Of course, the magnetic properties of the magnetic steel assembly 22 and the coil assembly 4 are not limited to this. The magnetizing directions of the first magnet 221, the second magnet 222, and the third magnet 223 are shown in FIG. 3. The upper ends of the first magnet 221 and the third magnet 223 are both S poles, and the lower ends are N poles. The upper end of the second magnet is the N pole, and the lower end is the S pole; the coil assembly 4 on the left is energized to make the first iron core 41 magnetize, at this time the upper end of the first iron core 41 is the S pole, and the lower end is N Therefore, the first iron core 41 on the left and the first magnet 221 form an attractive electromagnetic force. After the coil assembly 4 on the right is energized, the first iron core 41 is magnetized. At this time, the upper end of the first iron core 41 is the N pole and the lower end is the S pole, so the first iron core 41 on the right and the third magnet 223 are formed Repulsive electromagnetic force. When the energization directions of the coil assemblies 4 on the left and right sides are changed, the electromagnetic forces on the left and right sides of the coil assembly 4 alternately attract and repel each other.

The second iron core 5 shown is fixed to the housing 1, and the second iron core 5 and the first iron core 41 are arranged on opposite sides of the magnetic steel assembly 22. This structure enables the second iron core 5 to form an attractive force on the magnetic steel assembly 22 along the direction perpendicular to the vibration direction, which overcomes the attractive force of the first iron core 41 on the magnetic steel assembly 22, so that the entire linear vibration motor 100 moves along the vertical direction. The force in the vibration direction is relatively balanced or small, and the force in the direction perpendicular to the vibration direction can be ignored, so that the vibration effect of the linear vibration motor 100 is better.

In this embodiment, the metal sheet 6 is a copper sheet and is at least partially received in the first groove 211. In the magnetic field of the magnetic steel assembly 22, when the vibration unit 2 vibrates, a damping force that hinders the vibration of the vibration unit 2 is generated. Specifically, because the second iron core 5 is located on the side of the metal sheet 6 away from the magnetic steel assembly 22, the second iron core 5 guides the magnetic field lines of the magnetic steel assembly 22 to pass through the metal sheet 6, so that the metal The eddy current damping force of the sheet 6 due to the cutting of the magnetic lines of force is improved, and the vibration performance of the linear vibration motor 100 is better. That is, the metal sheet 6 generates a damping force that hinders the movement of the vibration unit 2 in the entire magnetic field, and the second iron core 5 is located in the magnetic field of the magnetic steel assembly 22 to enhance the damping force of the metal sheet 6 so that The vibration performance of the linear vibration motor 100 is better.

The linear vibration motor 100 further includes a bracket 7 located in the first groove 211 and covering the through hole 210, and the magnetic steel component 22 is fixedly connected to the bracket 7 for better reliability.

In this embodiment, it can be seen from FIG. 3 that the mass 21 includes a first groove 211 and a second groove that are recessed in the direction of the magnetic steel component 22 along opposite sides perpendicular to the vibration direction. A groove 212, and the through hole 210 is formed from the first groove 211 to the second groove 212. The magnetic steel component 22 is located in the through hole 210, the bracket 7 is located in the first groove 211 and covers the through hole 210, the metal sheet 6 is at least partially received in the first groove 211, and the coil component 4 is at least Partly received in the second groove 212. That is, a first groove 211 is provided on the mass block 21 to accommodate the bracket 7 and an escape space for the metal sheet 6 is formed, and a second groove 212 is opened on the mass block 21 to form an escape space for the coil assembly 4 to ensure the quality 21. Under the premise that the weight and the volume of the entire linear vibration motor 100 remain unchanged, the bracket 7, the coil assembly 4 and the metal sheet 6 can be reasonably housed in the linear vibration motor, and the space utilization rate is high. At the same time, each component is located inside the linear vibration motor 100 In different spaces, if one of the components falls during transportation, other components will not be affected, and the reliability is higher.

The elastic member 3 is provided in two. Two elastic members 3 are respectively arranged at opposite ends of the vibration unit 2 along the vibration direction, and the two elastic members 3 are arranged symmetrically. That is to say, the double elastic member structure makes the vibration effect of the linear vibration motor 100 more balanced, and the vibration effect is better; each elastic member 3 includes an elastic arm 31, and the opposite ends of the elastic arm 31 are respectively bent in the same direction The first connecting arm 32 and the second connecting arm 33 extend; the elastic arm 31 is spaced apart from the mass block 21, the first connecting arm 32 is fixedly connected to the mass block 21, and the second connecting arm 33 and the housing 1 are fixedly connected. That is, the elastic member 3 suspends the vibration unit 2 in the containing space 10 to provide vibration conditions for the vibration unit 2. Each of the first reinforcement block 8 and the second reinforcement block 9 includes at least two, and each of the first reinforcement blocks 8 is located on the side of each of the first connecting arms 32 away from the mass block 21 so that the first A connecting arm 32 is fixed to the mass block 21; each of the second reinforcing blocks 9 is located on the side of each of the second connecting arms 33 away from the housing 1 to fix the second connecting arms 33 In the case 1, the reliability is better.

The above are only the embodiments of the present utility model. It should be pointed out here that for those of ordinary skill in the art, improvements can be made without departing from the inventive concept of the present utility model, but these all belong to The scope of protection of the utility model.

Claims

A linear vibration motor includes a housing with a housing space, a vibration unit placed in the housing space, an elastic member that suspends the vibration unit in the housing space, and is fixed to the housing and driven The coil assembly vibrated by the vibrating unit is characterized in that the vibrating unit includes a magnetic steel assembly housed in the accommodating space; the coil assembly is located on one side of the vibrating unit perpendicular to the vibration direction, so The coil assembly includes a first iron core fixed to the housing and a coil wound around the first iron core, and the first iron core is opposite to the magnetic steel assembly; the linear vibration motor also includes a fixed The second iron core of the housing and the metal sheet stacked on the side of the second iron core close to the magnetic steel assembly, the second iron core and the first iron core are arranged on the magnetic On opposite sides of the steel component; the metal sheet is located in the magnetic field of the magnetic steel component, and when the vibration unit vibrates, the metal sheet generates a damping force that hinders the vibration of the vibration unit.
The linear vibration motor of claim 1, wherein the metal sheet is a copper sheet.
The linear vibration motor of claim 1, wherein the magnetizing direction of the magnetic steel component is perpendicular to the vibration direction.
The linear vibration motor according to claim 1, wherein the vibration unit further comprises a mass with a through hole, and the magnetic steel component is fixed in the through hole.
The linear vibration motor according to claim 1, wherein the magnet assembly comprises a first magnet, a second magnet, and a third magnet that are spaced apart from each other and arranged in sequence along the vibration direction, and The polarities of the first magnet and the second magnet are opposite, and the polarities of the first magnet and the third magnet are the same; the coil assembly is arranged as two mutually spaced apart along the vibration direction One, none of the coil components is arranged directly opposite to the first magnet or the second magnet or the third magnet.
The linear vibration motor according to claim 4, wherein the mass includes a first groove and a second groove that are recessed in the direction of the magnetic steel assembly along opposite sides perpendicular to the vibration direction The through hole is formed by penetrating the first groove to the second groove; the metal sheet is at least partially received in the first groove, and the coil assembly is at least partially received in the second groove.内内。 In the groove.
The linear vibration motor of claim 6, wherein the linear vibration motor further comprises a bracket located in the first groove and covering the through hole, the magnetic steel assembly and the bracket Fixed connection.
The linear vibration motor of claim 1, wherein the coil assembly further comprises a magnetic conductive sheet disposed on a side of the first iron core away from the magnetic steel assembly, and the first iron core passes through the magnetic steel assembly. The magnetic conductive sheet is fixed to the casing.
The linear vibration motor according to claim 1, wherein the elastic members are arranged as two respectively located at opposite ends of the vibration unit along the vibration direction, and the two elastic members are arranged symmetrically in the center; Each of the elastic members includes an elastic arm, a first connecting arm and a second connecting arm respectively bent and extended in the same direction from opposite ends of the elastic arm; the elastic arm and the mass are spaced apart, the The first connecting arm is fixedly connected with the mass block, and the second connecting arm is fixedly connected with the housing.
The linear vibration motor according to claim 9, wherein the linear vibration motor further comprises at least two first reinforcement blocks and two second reinforcement blocks, and each of the first reinforcement blocks is located in each of the One side of the first connecting arm away from the mass block so that the first connecting arm is fixed to the mass block; each of the second reinforcing blocks is located on the side of each second connecting arm away from the housing One side is such that the second connecting arm is fixed to the housing.