WO2022006938A1

WO2022006938A1 - Linear vibration motor

Info

Publication number: WO2022006938A1
Application number: PCT/CN2020/102079
Authority: WO
Inventors: 毛路斌; 李子昂; 崔志勇; 汤赟
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: 2020-07-08
Filing date: 2020-07-15
Publication date: 2022-01-13
Also published as: CN212850206U

Abstract

Disclosed is a linear vibration motor (100), comprising: a housing (1) internally provided with an accommodating space (13); a stator (2) and a vibrator (3), which are accommodated in the accommodating space (13); and an elastic support member (4) for suspending the vibrator (3) in the accommodating space (13). One of the vibrator (3) and the stator (2) comprises a coil assembly (20), and the other comprises a magnetic steel assembly (32) spaced apart from and opposite the coil assembly (20). The magnetic steel assembly (32) comprises magnetic steel arrays (322) located on two sides, relative to a vibration direction of the vibrator (3), of the coil assembly (20); the magnetic steel array (322) comprises inner magnetic steel (3221) directly facing the coil assembly (20), and outer magnetic steel (3222) arranged on two sides of the inner magnetic steel (3221) and arranged side by side with the inner magnetic steel (3221); the magnetizing direction of the inner magnetic steel (3221) is perpendicular to the vibration direction, and an included angle a between the magnetizing direction of the outer magnetic steel (3222) and a winding plane of a coil satisfies the relational expression: 0° < a < 90°; and magnetic lines of force of the outer magnetic steel (3222) which are located on two sides of the same inner magnetic steel (3221) are symmetrically arranged relative to the inner magnetic steel (3221). The linear vibration motor (100) can improve the flatness of a magnetic circuit so as to reduce distortion, and improve the magnetic induction intensity of an energized coil so as to increase the amount of vibration.

Description

A linear vibration motor

technical field

The utility model relates to the technical field of vibration motors, in particular to a linear vibration motor.

Background technique

Linear motor is a transmission device that directly converts electrical energy into linear motion mechanical energy, also known as linear motor, linear motor, push rod motor, etc. A linear motor usually includes a vibrator and a stator. Generally, the reciprocating motion of the vibrator is realized under the action of ampere force, and it does not need to be driven by a transmission mechanism such as gears. Due to the advantages of simple structure, high acceleration, and high precision, linear motors are widely used in different manufacturing and processing technology fields. With the rapid development of technology in various fields, the requirements for motion performance of linear motors in various fields are gradually increasing. .

The magnetic steel of the linear motor in the prior art is usually magnetized parallel to its thickness direction, and the magnetic steel provides a constant magnetic field for the motor through different arrangements. Therefore, the magnetic flux generated by the magnet steel in the existing linear motor is limited in a limited size space, so that the vibration amount of the linear motor is also limited, and the large change of the magnetic field gradient causes the large distortion of the linear motor.

Therefore, it is necessary to provide a linear vibration motor to improve the above problems.

technical problem

The purpose of the utility model is to provide a linear vibration motor which can reduce distortion through oblique magnetization, and increase the magnetic induction intensity of the energized coil to increase the amount of vibration.

technical solutions

The technical solution of the present invention is as follows: a linear vibration motor is provided, which includes a housing with an accommodation space inside, a stator and a vibrator accommodated in the accommodation space, and an elastic support for suspending the vibrator in the accommodation space One of the vibrator and the stator includes a coil assembly, the other of the vibrator and the stator includes a magnetic steel assembly spaced apart from the coil assembly, and the coil assembly includes an iron core and is wound around the coil assembly. The coil on the outer periphery of the iron core, the magnetic steel assembly includes a magnetic steel array located on both sides of the coil assembly relative to the vibration direction of the vibrator; the magnetic steel array includes an inner magnetic steel facing the coil assembly and a set of The outer magnets are arranged on both sides of the inner magnet and side by side with the inner magnet; the magnetization direction of the inner magnet is perpendicular to the vibration direction, and the inner magnet and the adjacent outer magnet The magnetic pole close to the coil assembly is opposite, the angle between the magnetizing direction of the outer magnetic steel and the winding plane of the coil is a, and the angle a satisfies the relationship: 0°<a<90°; The magnetic lines of force of the outer magnets located on both sides of the same inner magnet are symmetrically arranged relative to the inner magnet.

More preferably, the magnetic steel assembly further includes side magnets located at both ends of the coil assembly along the vibration direction and opposite to and spaced from the coil assembly, and the magnetic poles of the side magnets located on different sides are the same. Extremely relative settings.

More preferably, the inner magnetic steel includes a first inner magnetic steel and a second inner magnetic steel symmetrically arranged relative to the coil assembly, and both the first inner magnetic steel and the second inner magnetic steel are close to the coil assembly. The magnetic poles are set opposite to each other.

More preferably, the outer magnetic steel ladle is located on both sides of the first outer magnetic steel and the second outer magnetic steel on both sides of the second inner magnetic steel, the first outer magnetic steel and the positive The magnetic poles of the pair of the second outer magnets are arranged opposite to each other with the same pole.

More preferably, the side magnets are arranged symmetrically with respect to the coil assembly.

More preferably, the coil assembly further includes pole pieces fixed on both ends of the iron core along the vibration direction, and the coil is located between the two pole pieces.

More preferably, the orthographic projection of the outer magnet on the coil perpendicular to the vibration direction at least partially does not overlap the coil.

More preferably, the coil assembly is the stator, and the coil assembly is fixedly connected to the housing; the vibrator further includes a mass block that supports and fixes the magnetic steel assembly, and one end of the elastic support is connected to the outer casing. The mass block is fixed, and the other end is fixed to the housing. A through hole is formed through the mass block. The magnetic steel assembly is accommodated in the through hole and fixed to the mass block. The coil assembly extends at least partially to The through hole is spaced apart from the magnetic steel assembly.

More preferably, the elastic support member includes an elastic arm and a first connecting arm and a second connecting arm respectively connected with opposite ends of the elastic arm; the mass block includes first side edges and The second side is connected between the first sides, the first side and the second side are connected end to end to form the through hole, the first connecting arm and the second side The sides are fixedly connected, and the second connecting arm is fixedly connected with the housing.

More preferably, the vibrator further includes a magnetic conductive sheet sandwiched between the mass block and the magnetic steel, and a glue-receiving groove is provided on the side of the magnetic conductive sheet connected with the magnetic steel assembly, so The magnetic conductive sheet is glued and fixed with the magnetic steel assembly.

More preferably, a damping member is provided between the elastic arm and the first side edge.

More preferably, the housing includes a bottom plate fixedly connected with the stator and a cover body connected with the bottom plate.

More preferably, the linear vibration motor further includes a limit block fixed on the bottom plate, and the limit block is arranged between the mass block and the cover body along the vibration direction.

beneficial effect

The beneficial effect of the present invention is that: the included angle between the magnetizing direction of the outer magnetic steel of the present invention and the winding plane is a, and the included angle a satisfies the relational formula: 0°<a<90°, that is, the outer The magnetic steel is obliquely magnetized, and the obliquely magnetized outer magnetic steel can improve the flatness of the magnetic flux line coefficient curve BL(x) of the overall magnetic circuit of the magnetic steel assembly, thereby reducing the distortion of the linear vibration motor of the utility model. At the same time, the obliquely magnetized outer magnetic steel can also improve the magnetic induction intensity of the energized coil, thereby increasing the vibration amount of the linear vibration motor.

Description of drawings

FIG. 1 is a schematic three-dimensional structure diagram of a linear vibration motor according to an embodiment of the present invention.

FIG. 2 is an exploded view of the linear vibration motor according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 1 .

FIG. 4 is a structural diagram of a coil assembly and a base plate according to an embodiment of the present invention.

FIG. 5 is an internal structure diagram of a linear vibration motor according to an embodiment of the present invention.

6 is a schematic diagram of the magnetic circuit principle of the linear vibration motor of the present invention.

FIG. 7 is a schematic diagram of electromagnetic induction when the linear vibration motor of the present invention passes forward current.

FIG. 8 is a schematic diagram of electromagnetic induction when the linear vibration motor of the present invention passes a negative current.

Embodiments of the present invention

The present utility model will be further described below with reference to the accompanying drawings and embodiments.

The utility model provides a linear vibration motor. As shown in FIGS. 1-5 , the linear vibration motor 100 includes a housing 1 , a stator 2 , a vibrator 3 , an elastic support 4 , a soldering piece 5 , a limit block 6 , a damping member 7 and a flexible circuit board 8 .

As shown in FIGS. 1-3 , the stator 2 , the vibrator 3 , the elastic support member 4 , the welding piece 5 , the limiting block 6 and the damping member 7 are all installed in the receiving space 13 of the housing 1 . The stator 2 is fixed on the casing 1 , and the vibrator 3 is fixed on the casing 1 through two elastic support members 4 and then suspended in the accommodating space 13 of the casing 1 . The elastic support 4 is welded with the casing 1 and with the vibrator 3 through the welding piece 5, and the vibrator 3 can reciprocate relative to the stator 2 along the vibration direction of the vibrator.

Specifically, as shown in FIGS. 1-3 , the housing 1 includes a bottom plate 11 , a cover body 12 and a receiving space 13 . As shown in Fig. 2-3, the bottom plate 11 includes a fixing plate 111 and a lower cover plate 112. The fixing plate 111 is fixed on the side of the lower cover plate 112 close to the cover body 12 and is connected with the cover body 12. The fixing plate 111 is fixed with a pole shoe 23 and circuit board 8.

Further, as shown in FIGS. 1-3 , the cover body 12 includes a top cover 121 , a first side plate 122 , a second side plate 123 and two opposite third side plates 124 , and the top cover 121 is opposite to the bottom plate 11 . The first side plate 122 is opposite to the second side plate 123 . The first side plate 122 , the second side plate 123 and the two third side plates 124 are connected to the top cover 121 and the bottom plate 11 to form the receiving space 13 of the housing 1 . As shown in FIG. 1-2 , a first groove 1221 is defined on the side of the first side plate 122 close to the bottom plate 11 . In this embodiment, as shown in FIGS. 1-3 , a first groove 1221 is also defined on the side of the second side plate 123 close to the bottom plate 11 , and the second side plate 123 is symmetric with respect to the stator 2 and the first side plate 122 . In this embodiment, the first side plate 122 , the second side plate 123 and the two third side plates 124 are integrally formed with the top cover 121 to form the cover body 12 .

Specifically, as shown in FIGS. 2-4 , in this embodiment, the stator 2 is the coil assembly 20 and is fixedly connected to the housing 1 . The coil assembly at least partially extends into the through hole 311 and is spaced from the magnetic steel assembly 32 . The coil assembly 20 includes an iron core 21 , a coil 22 and a pole piece 23 . The coil 22 is wound around the outer circumference of the iron core 21 to form a winding plane P, as shown in FIG. 6 , in this embodiment, the vibration direction of the vibrator is the X direction as shown in FIG. 6 .

Further, the pole piece 23 includes a first pole piece 231 and a second pole piece 232, the first pole piece 231 and the second pole piece 232 are respectively welded and fixed to both ends of the iron core 21 along the vibrator vibration direction, and the coil 22 is located in the first pole piece 231 and the second pole piece 232 respectively. Between the first pole piece 231 and the second pole piece 232 , the bottom of the pole piece 23 is welded to the fixing plate 111 of the bottom plate 11 , so that the entire coil assembly 20 is fixed on the bottom plate 11 . By arranging pole pieces 23 on both ends of the iron core 21, when the coil 22 is energized, the pole pieces 23 induce the N pole and the S pole, as shown in Figures 7-8. According to the repulsion of the same sex and the attraction of the opposite, an electromagnetic force is generated between the coil assembly 20 and the first side magnet 3211 and the second side magnet 3212 .

Furthermore, in this embodiment, the iron core 21 and the pole piece 23 are made of SPCD material of Japanese Industrial Standard.

Specifically, as shown in FIG. 2 , the vibrator 3 includes a mass block 31 , a magnetic steel assembly 32 and four magnetic conductive sheets 33 .

Further, as shown in FIG. 2 , the mass block 31 is used to support and fix the magnetic steel assembly 32 , and the mass block 31 includes a through hole 311 , a pair of first side edges 312 , a pair of second side edges 313 and a second recess. The groove 314, in this embodiment, the through hole 311 is formed through the central area of the mass block. The two first side edges 312 are relatively spaced apart, the two second side edges 313 are respectively connected between the two first side edges, and the first side edges 312 and the second side edges 313 are connected end to end to form the through hole 311, the second groove 314 is arranged on the first side 312, including two oppositely arranged along the vibration direction of the vibrator, as shown in Fig. 2-3. In this embodiment, the through hole 311 is rectangular, a pair of first side edges 312 are close to and spaced from the elastic arm 41 , and a pair of second side edges 313 are connected to the ends of the pair of first side edges 312 . The end of the first connecting arm 42 is fixedly connected to the second side edge 313 of the mass block 31 , and the end of the second connecting arm 43 is fixedly connected to the housing 1 .

Furthermore, as shown in FIGS. 1-3 in conjunction with FIG. 5 , the mass 31 is suspended in the casing 1 around the stator 2 . The mass block 31 and the first connecting arm 42 of the elastic support 4 are welded together by the first welding piece 51 , and the second connecting arm 43 of the elastic support 4 is welded on the third side plate 124 through the second welding The mass 31 is suspended in the housing 1 . Further, as shown in FIGS. 2-3 , the two second side edges 313 are symmetrical with respect to the center of the coil assembly 20 , and both the second side edges 313 and the first connecting arm 42 of the elastic support 4 are fixed by the first solder tabs 51 . In connection, the second groove 314 is opened on the side of the first side 312 close to the elastic arm 41 for filling a part of the damping member 7 . In this embodiment, the damping member 7 is specifically foam.

Specifically, as shown in FIGS. 2-3 in conjunction with FIG. 5 , the magnetic steel assembly 32 is accommodated in the through hole 311 and fixed to the mass block 31 . The magnetic steel assembly 32 is accommodated in the passage 311 , and includes eight magnetic steels spaced apart from the coil assembly 20 . The magnetic steel assembly 32 includes a side magnetic steel 321 and a magnetic steel array 322 .

Specifically, the side magnets 321 are located at both ends of the coil assembly 20 along the vibration direction of the vibrator, and are opposite to and spaced from the coil assembly 20 . The side magnets 321 include a first side magnet 3211 and a second side magnet 3211 . Steel 3212. The first side magnets 3211 and the second side magnets 3212 are respectively disposed on both sides of the winding plane P of the coil assembly 20 and are disposed opposite to the pole pieces 23 at both ends of the coil assembly along the vibration direction. Wherein, the first side magnet 3211 and the second side magnet 3212 are disposed opposite to one side of the same magnetic pole. The first side magnet 3211 and the second side magnet 3212 are symmetrically disposed relative to the coil assembly 20, and are magnetized along the vibration direction and in opposite directions.

Specifically, the magnetic steel arrays 322 are located on both sides of the coil assembly 20 relative to the vibration direction of the vibrator and are symmetrically arranged relative to the coil assembly 20 . The magnetic steel array 322 includes an inner magnetic steel 3221 facing the coil assembly 20 and outer magnetic steels 3222 disposed on both sides of the inner magnetic steel 3221 and arranged side by side with the inner magnetic steel 3221 . The projection of the outer magnetic steel 3222 on the coil 22 along the vibration direction perpendicular to the vibrator does not overlap at least partially with the coil. The inner magnet 3221 includes a first inner magnet 32211 and a second inner magnet 32212. The first inner magnet 32211 and the second inner magnet 32212 are symmetrically arranged relative to the coil assembly 20. The first inner magnet 32211 and Both of the second inner magnets 32212 are disposed close to the magnetic poles of the coil assembly 20 and opposite to each other. The magnetization direction of the first inner magnet 32211 and the second inner magnet 32212 is perpendicular to the vibration direction of the vibrator, and the magnetization directions of the two are opposite. The first inner magnet 32211 and the second inner magnet 32212 are close to the magnetic poles of the coil assembly 20 and have the same polarity, and the inner magnet 3221 and its adjacent outer magnet 3222 have opposite magnetic poles close to the coil assembly 20 . In this embodiment, the magnetic pole on the side of the inner magnet 3221 close to the coil assembly 20 is S pole, and the magnetic pole on the side of the outer magnet 3222 close to the coil assembly 20 is N pole, as shown in FIG. 6 .

As shown in FIG. 2 in conjunction with FIG. 5 , the outer magnets 3222 include two first outer magnets 32221 and two second outer magnets 32222 , and the two first outer magnets 32221 are located on both sides of the first inner magnet 32211 and Arranged side by side with the first inner magnet 32211 along the vibration direction of the vibrator, two second outer magnets 32222 are located on both sides of the second inner magnet 32212 and arranged side by side with the second inner magnet 32212 along the vibration direction of the vibrator, the first The outer magnetic steel 32221 and the opposite second outer magnetic steel 32222 are disposed opposite to the same pole side of the magnetic pole. Among them, the angle between the magnetization direction of the outer magnet 3222 and the winding plane is a, and the angle a satisfies the relation: 0°<a<90°. The two first outer magnets 32221 are arranged side by side with the first inner magnet 32211 along the vibration direction of the vibrator and are arranged symmetrically with respect to the first inner magnet 32211, and the two second outer magnets 32222 are aligned with the second inner magnet along the vibration direction of the vibrator. The steels 32212 are arranged side by side and are symmetrical with respect to the second inner magnet 32212 , that is, the magnetic lines of force of the two outer magnets 3222 located on both sides of the same inner magnet 3221 are arranged symmetrically with respect to the inner magnet 3221 . In this embodiment, the magnetic steel assembly 32 provides a magnetic field, and a new type of oblique magnetization is provided in combination with the oblique magnetization (the magnetization direction is neither parallel nor perpendicular to the vibration direction) for the magnetic steel at a specific position. The linear vibration motor of the magnetic circuit. Compared with the existing motor structure, the linear vibration motor provided by the utility model can improve the magnetic flux coefficient curve BL(x) of the overall magnetic circuit of the magnetic steel assembly. The flatness is improved, thereby reducing the distortion of the linear vibration motor of the present utility model. At the same time, the obliquely magnetized outer magnetic steel can also improve the magnetic induction intensity of the energized coil, thereby increasing the vibration amount of the linear vibration motor.

As shown in FIG. 2-3 in conjunction with FIG. 5 , the magnetic conductive sheet 33 is sandwiched between the mass block 31 and the magnetic steel assembly 32 , and the four magnetic conductive sheets 33 are respectively welded to the inner wall 3111 of the rectangular through hole 311 of the mass block 31 . , the side of the magnetic conductive sheet 33 away from the mass block 31 is glued and fixed with the magnetic steel assembly 32 . The first magnetic conductive sheet 331 is opposite to the side magnetic steel 321, the second magnetic conductive sheet 332 is opposite to the magnetic steel array 322, and the four magnetic conductive sheets 33 form a rectangular frame. SPCD material, can play the role of magnetic shielding and magnetic concentration.

Further, as shown in FIG. 2 , glue-receiving grooves 333 are provided on the side of the four magnetic conductive sheets 33 connected with the magnetic steel assembly 32 , and the magnetic conductive sheets 33 and the magnetic steel assembly 32 are glued and fixed. The opening of the glue holding groove 333 can increase the reliability of the glue between the magnetic steel assembly 32 and the magnetic conductive sheet 33, and prevent the risk of glue overflowing.

Furthermore, in this embodiment, the position of the angle a between the magnetization direction of the outer magnetic steel 3222 and the winding plane P is shown in FIG. 6 .

Specifically, as shown in FIGS. 1-2 in combination with FIG. 5 , in this embodiment, there are two elastic support members 4 . The elastic support 4 includes an elastic arm 41 , a first connecting arm 42 and a second connecting arm 43 . The first connecting arm 42 and the second connecting arm 43 are respectively connected with opposite ends of the elastic arm, and are formed by bending and extending both ends of the elastic arm 41 along the vibration direction of the vibrator 3 . The two elastic supports 4 are symmetrically arranged relative to the center of the coil assembly 20 , one end is fixed to the mass block 31 , and the other end is fixed to the casing 1 . The elastic arm 41 is suspended above the limit block 6 , the first connecting arm 42 and the second connecting arm 43 are bent and extended in the same direction, and the first connecting arm 42 and the mass block 31 are welded together by the first welding piece 51 . The two connecting arms 43 weld the elastic support 4 to the third side plate 124 through the second welding piece 52 , thereby suspending the mass 31 in the casing 1 , that is, the elastic support 4 connects the vibrator 3 and the casing through the welding piece 5 1 and provide supporting force and restoring force to the vibrator 3.

Specifically, as shown in FIGS. 1-2 , the linear vibration motor 100 further includes a soldering piece 5 , two first soldering pieces 51 and two second soldering pieces 52 , and the first soldering pieces 51 are used for connecting the elastic support on the same side The first connecting arm 42 of 4 is welded and fixed to the second side edge 313 of the mass block 31 , and the second welding piece 52 is used to weld and fix the second connecting arm 43 of the elastic support member 4 on the same side to the housing 1 .

Specifically, as shown in FIGS. 2-4 , the linear vibration motor 100 further includes two limit blocks 6 , and the two limit blocks 6 are respectively located between the mass block 31 and the first side plate 122 and the mass block 31 along the vibration direction. and the second side plate 123 and fixed on the fixing plate 111 of the bottom plate 11 by welding. In this embodiment, the two limiting blocks 6 are located below the elastic arm 41 of the elastic support member 4 and are respectively close to the first side plate 122 and the second side plate 123 and away from the mass block 31 . The limit block 6 can prevent the vibrator 3 from hitting the housing 1 .

Specifically, as shown in FIGS. 2-3 and 5 , the linear vibration motor 100 further includes a damping member 7 . In this embodiment, the damping member 7 is specifically foam, and the foam is fixed on the elastic arms 41 and 41 of the elastic support member 4 . between the first side edges 312 of the mass block 31 . In this embodiment, two second grooves 314 symmetrical to the coil assembly 20 are further defined on the side of the first side 312 of the mass block 31 close to the elastic arm 41 , and a part of the damping member 7 is filled into the second grooves 314 , and the other is A part is filled between the elastic arm 41 and the first side edge 312 of the mass block 31 to protect and increase the mechanical damping during the vibration of the vibrator 3 .

Specifically, the circuit board 8 is attached to the fixing plate 111 , one end is electrically connected to the coil 22 , and the other end extends out of the casing 1 through the first groove 1221 , as shown in FIGS. 1-3 .

Working principle: As shown in Figure 6, the vibration direction of the vibrator 3 is along the X direction, and the X direction includes the X positive direction pointed by the arrow and the X negative direction opposite to the X positive direction. The magnetization directions of the magnetic steel components 32 are shown by arrows in FIG. 6 , and the included angles a (0°<a<90°) between the magnetization directions of the four outer magnetic steels and the winding plane P are shown in FIG. 8 .

Specifically, as shown in FIG. 2 in conjunction with FIG. 6 , the magnetic steel components 32 are arranged according to the arrangement as shown in FIG. 6 , which can generate a constant magnetic field. The magnetic field lines point from the N pole to the S pole, and the direction of the magnetic field lines is shown in FIGS. 7-8 . . As shown in Fig. 2-4 combined with Fig. 6 , under the action of a constant magnetic field, the energized coil 22 generates an ampere force along the vibration direction according to the left-hand rule. According to the direction of the incoming current, the N pole and the S pole are respectively induced, and when the current direction is changed, the polarity induced by the pole shoe 23 changes accordingly. The first side magnet 3211 and the second side magnet 3212 also generate electromagnetic force on the stator. The resultant force of the electromagnetic force and the ampere force superimposed on the stator 2 is F1. According to the action force and reaction force, the vibrator 3 is subjected to the reaction force F2 of F1, and the forces F2 and F1 required for the movement of the vibrator 3 are the action force and the reaction force. , then F1 and F2 are equal in size and opposite in direction, that is, F1+F2=0.

(1) The direction of the magnetic field lines of the constant magnetic field is shown in Fig. 7. In combination with Fig. 6, when the coil 22 of the stator 2 is supplied with a forward current, according to the right-hand rule, the first pole piece 231 induces the N pole, and the second pole piece 231 induces the N pole, and the second pole piece 232 induces the S pole. According to the magnetization direction of the first side magnet 3211 and the second side magnet 3212, the magnetization direction is shown in Figure 6. Electromagnetic force in the positive direction of X. Meanwhile, according to the left-hand rule, the energized coil 22 generates an ampere force in the positive X direction under the action of a constant magnetic field. The superposition of the electromagnetic force and the ampere force together produces a thrust F1 along the positive X direction. According to the acting force and the reaction force, the vibrator 3 generates a thrust F2 along the negative direction of X, so that the vibrator 3 vibrates in the negative direction of X.

(2) As shown in FIG. 8 , combined with FIG. 6 , when the coil 22 of the stator 2 is supplied with a negative current, it is judged according to the right-hand rule that the first pole piece 231 induces the S pole, and the second pole piece 232 induces the N pole. According to the magnetization direction of the 3211 and 32 magnetic steel assemblies 3212 as shown in Figure 6 and the principle of attraction and repulsion of the same nature, the electromagnetic force along the negative X direction is generated under the action of the external constant magnetic field. Meanwhile, according to the left-hand rule, the energized coil 22 generates an ampere force along the negative X direction under the action of a constant magnetic field. The electromagnetic force and the ampere force superimpose together to generate a thrust F1 along the negative direction of X. According to the action force and reaction force, the vibrator 3 generates a thrust F2 along the positive direction of X, thereby vibrating in the positive direction of X.

To sum up, when an alternating current of a certain frequency is supplied to the coil 22, the vibrator 3 will alternately generate thrusts in the positive and negative directions of X, so that the vibrator 3 vibrates back and forth in the X direction. The magnetic steel assembly adopts a specific arrangement to provide a magnetic field, and a linear vibration motor with a new magnetic circuit of oblique magnetization is provided in combination with the oblique magnetization method for the magnetic steel at a specific position. The utility model provides Compared with the existing motor structure, the linear vibration motor received is the resultant force generated by the electromagnetic force and the ampere force in the same direction as the electromagnetic force, and the oblique magnetization of the outer magnetic steel at a specific position can improve the magnetic force. The flatness of the magnetic induction coefficient curve BL(x) of the overall magnetic circuit of the steel assembly can reduce the distortion of the linear vibration motor of the present utility model. Thus, the vibration amount of the linear vibration motor is increased.

The above are only the embodiments of the present utility model. It should be pointed out 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 belong to The scope of protection of the utility model.

Claims

A linear vibration motor, comprising a housing with an accommodation space inside, a stator and a vibrator accommodated in the accommodation space, and an elastic support for suspending the vibrator in the accommodation space, the vibrator and the stator are One of them includes a coil assembly, the other of the vibrator and the stator includes a magnetic steel assembly spaced apart from the coil assembly, and the coil assembly includes an iron core and a coil wound around the outer circumference of the iron core. In that, the magnetic steel assembly includes a magnetic steel array located on both sides of the coil assembly relative to the vibration direction of the vibrator; the magnetic steel array includes an inner magnetic steel facing the coil assembly and an inner magnetic steel disposed on the inner magnetic steel. The outer magnets are arranged on both sides of the steel and are arranged side by side with the inner magnets; the magnetization direction of the inner magnets is perpendicular to the vibration direction, and both the inner magnets and the adjacent outer magnets are close to the coil The magnetic poles of the components are opposite, the angle between the magnetization direction of the outer magnet and the winding plane of the coil is a, and the angle a satisfies the relationship: 0°<a<90°; The magnetic lines of force of the outer magnetic steel on both sides of the magnetic steel are symmetrically arranged relative to the inner magnetic steel.
The linear vibration motor according to claim 1, wherein the magnetic steel assembly further comprises side magnets located at both ends of the coil assembly along the vibration direction and opposite to and spaced from the coil assembly, located at both ends of the coil assembly along the vibration direction. The magnetic poles of the side magnets on different sides are arranged opposite to each other with the same pole.
The linear vibration motor according to claim 1, wherein the inner magnetic steel comprises a first inner magnetic steel and a second inner magnetic steel symmetrically arranged relative to the coil assembly, and the first inner magnetic steel and the second inner magnetic steel are symmetrically arranged relative to the coil assembly. The two inner magnets are arranged opposite to each other near the magnetic poles of the coil assembly.
The linear vibration motor of claim 3, wherein the outer magnet ladle is a first outer magnet located on both sides of the first inner magnet and a second outer magnet located on both sides of the second inner magnet The outer magnet steel, the first outer magnet steel and the opposite second outer magnet steel have the same pole opposite to each other.
The linear vibration motor according to claim 2, wherein the side magnets are arranged symmetrically with respect to the coil assembly.
The linear vibration motor according to claim 1, wherein the coil assembly further comprises pole pieces fixed on both ends of the iron core along the vibration direction, and the coil is located between the two pole pieces.
The linear vibration motor according to claim 1, wherein the orthographic projection of the outer magnetic steel on the coil perpendicular to the vibration direction at least partially does not overlap with the coil.
The linear vibration motor according to claim 1, wherein the coil assembly is the stator, and the coil assembly is fixedly connected to the housing; the vibrator further comprises a mass for supporting and fixing the magnetic steel assembly One end of the elastic support member is fixed with the mass block, and the other end is fixed with the shell, the mass block is provided with a through hole, and the magnetic steel assembly is accommodated in the through hole and is connected with the mass The block is fixed, and the coil assembly at least partially extends into the through hole and is spaced apart from the magnetic steel assembly.
The linear vibration motor according to claim 8, wherein the elastic support member comprises an elastic arm and a first connecting arm and a second connecting arm respectively connected with opposite ends of the elastic arm; the mass block It includes a first side edge arranged opposite and spaced apart and a second side edge connected between the first side edges, the first side edge and the second side edge are connected end to end to enclose the through hole, so The first connecting arm is fixedly connected with the second side edge, and the second connecting arm is fixedly connected with the housing.
The linear vibration motor according to claim 8, wherein the vibrator further comprises a magnetic conductive sheet sandwiched between the mass block and the magnetic steel, the magnetic conductive sheet and the magnetic steel assembly The connected side is provided with a glue-receiving groove, and the magnetic-conducting sheet is glued and fixed with the magnetic steel assembly.

11. The linear vibration motor according to claim 9, wherein a damping member is provided between the elastic arm and the first side edge.

12. The linear vibration motor according to claim 8, wherein the housing comprises a bottom plate fixedly connected with the stator and a cover body connected with the bottom plate.

13. The linear vibration motor according to claim 12, characterized in that, the linear vibration motor further comprises a limit block fixed on the bottom plate, and the limit block is arranged on the edge of the mass block and the cover body. between the vibration directions.