CN109040917B

CN109040917B - Exciter and screen sounding device

Info

Publication number: CN109040917B
Application number: CN201810710136.XA
Authority: CN
Inventors: 史德璋; 毛东升; 朱跃光; 刘春发
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2018-07-02
Filing date: 2018-07-02
Publication date: 2021-10-08
Anticipated expiration: 2038-07-02
Also published as: CN109040917A

Abstract

The invention discloses an exciter and a screen sounding device. The exciter includes: the vibration part is suspended in the accommodating cavity through the elastic part and comprises a first permanent magnet which is magnetized in a direction parallel to the vibration direction, and the first permanent magnet forms a middle avoiding space; stator module includes the magnetic core portion and around establishing the coil that surrounds outside the magnetic core portion, and the magnetic core portion is fixed and is held the intracavity, and the magnetic core portion includes the supporting part and sets up the radial bulge in the one end of supporting part, and the other end and the casing of supporting part are connected, and the coil is around establishing outside the supporting part and lie in between casing and the radial bulge, and the coil is located the middle part and dodges in the space and with vibration looks interval.

Description

Exciter and screen sounding device

Technical Field

The invention relates to the technical field of electroacoustic conversion, in particular to an exciter and a screen sounding device.

Background

Electronic terminals with full-screen are more and more popular with people. In order to improve the screen ratio, the front of the electronic terminal needs to be designed without holes, i.e. hole-shaped structures such as a sound outlet of a receiver and a light sensing hole of a camera are eliminated. In some sound generating device designs, a piezoelectric device is placed on a middle frame, and the screen and the front shell of the electronic terminal are driven to vibrate through the vibration of the piezoelectric device, so that sound is radiated.

In other arrangements, the actuators are provided on the screen. The vibration of the exciter drives the screen to vibrate and sound, the exciter can realize the design of no holes on the screen, and meanwhile, the exciter has good hearing experience.

However, the existing exciter has low utilization efficiency of the magnetic field and high power consumption of the product, and simply increasing the magnet or simply increasing the magnet increases the cost of the product material and reduces the competitiveness of the product.

Therefore, a new technical solution is needed to solve the above technical problems.

Disclosure of Invention

It is an object of the present invention to provide a new solution for an actuator.

According to a first aspect of the present invention, an actuator is provided. The exciter includes: the vibration generator comprises a shell, a vibrator assembly and a stator assembly, wherein an accommodating cavity is formed in the shell, the vibrator assembly comprises a vibration part and an elastic part, the vibration part is suspended in the accommodating cavity through the elastic part, the vibration part comprises a first permanent magnet which is magnetized in a direction parallel to the vibration direction, and the first permanent magnet forms a middle avoiding space; the stator assembly comprises a magnetic core part and a coil wound around the periphery of the magnetic core part, the magnetic core part is fixed in the accommodating cavity and comprises a supporting part and a radial protruding part arranged at one end of the supporting part, the other end of the supporting part is connected with the shell, the coil is wound outside the supporting part and positioned between the shell and the radial protruding part, and the coil is positioned in the middle avoiding space and is separated from the vibration part.

Optionally, the housing is made of magnetically permeable material, and the stator assembly is configured to magnetize housing walls corresponding to both ends of the coil.

Optionally, the magnetic conductive core is in a T-shaped structure or a cross-shaped structure.

Optionally, the magnetically permeable core is integrally formed.

Optionally, the magnetic core includes an annular portion and the support portion, the support portion is inserted into a hole of the annular portion, and the annular portion protrudes from the support portion to form the radial protrusion.

Optionally, the supporting portion is a sheet structure, and protrudes outwards from the middle of one side edge of the supporting portion to form an insertion end, and the insertion end is inserted into the hole of the annular portion.

Optionally, the magnetic conduction core includes the I shape structure with the supporting part, the I shape structure includes two sides and is located the connection limit at two side middle parts, an terminal surface of supporting part has the recess, the connection limit card of I shape structure is gone into in the recess, two side bulges in the lateral part of supporting part, in order to form radial bulge.

Optionally, the casing is the cuboid structure, first permanent magnet is bar magnet to be two, two form between the bar magnet the space is dodged at the middle part, two bar magnet's major axis is on a parallel with the long limit of casing, the coil is runway type structure or rectangle structure, the long limit of coil is on a parallel with the long limit of casing.

Optionally, the housing comprises a front shell and a rear cover, the front shell comprises a bottom part and a side wall part arranged around the bottom part, and the rear cover covers one end of the side wall part opposite to the bottom part; any one of the elastic part and the magnetic conduction core part is fixed on the bottom, and the other one is fixed on the rear cover.

Optionally, the elastic portion includes a plurality of elastic pieces, and the plurality of elastic pieces are located on the same side of the vibrating portion parallel to the vibrating direction.

Optionally, the vibrating portion is of a rectangular parallelepiped structure, and the plurality of spring pieces are arranged in parallel along a long side of the vibrating portion in the same mounting direction.

Optionally, the elastic portion includes an elastic sheet, the elastic sheet includes a protruding portion, a first cantilever, a second cantilever, and a first connecting portion connected to the same end of the first cantilever and the second cantilever, one end of the protruding portion is connected to the middle of the first connecting portion, and the protruding portion and the first cantilever are located on the same side of the first connecting portion.

Alternatively, a boss portion protruding inward is formed on the housing, and the first connecting portion and the boss portion are fixed to the boss portion.

According to another aspect of the present invention, there is provided a screen sound emitting apparatus. The device comprises a main body part and a screen body arranged at the open end of the main body part, wherein the exciter provided by the invention is arranged on the screen body.

According to one embodiment of the present disclosure, the exciter has the characteristics of high magnetic field utilization rate and low power consumption.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is an exploded view of an actuator according to one embodiment of the present invention.

Fig. 2 is a cross-sectional view along a long axis of an actuator according to an embodiment of the present invention.

Fig. 3 is an exploded view of a magnetically conductive core according to one embodiment of the invention.

Fig. 4 is a schematic structural diagram of a spring plate according to an embodiment of the invention.

Fig. 5 is an assembly view of a housing and a spring plate according to an embodiment of the invention.

Fig. 6 is a cross-sectional view along a short axis of an actuator according to an embodiment of the present invention.

Fig. 7 is a cross-sectional view along a short axis of another actuator according to an embodiment of the present invention.

Fig. 8 is a cross-sectional view along a short axis of yet another actuator in accordance with an embodiment of the present invention.

Description of reference numerals:

11: a front housing; 12: a spring plate; 13: a first cantilever; 14: a second cantilever; 15: a first connection portion; 16: a projection; 17: an annular magnetic conductive plate; 18: a mass block; 19: a first permanent magnet; 20: an annular portion; 21: a support portion; 22: an insertion end; 23: a coil; 24: FPCB; 26: a boss portion; 30: a rear cover; 31: a second permanent magnet; 32: a bottom; 33: a third permanent magnet; 34: and a fourth permanent magnet.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

According to one embodiment of the present invention, an actuator is provided. The method comprises the following steps: the stator assembly includes a housing, a vibrator assembly, and a stator assembly. The interior of the housing forms a receiving cavity. The vibrator assembly and the stator assembly are disposed within the receiving cavity.

Specifically, the housing has a rectangular parallelepiped structure. The vibrator assembly includes a vibration part and an elastic part. The vibration part is suspended in the accommodating cavity through the elastic part. The vibration part is suspended in the accommodating cavity through the elastic part. The vibrating portion comprises a first permanent magnet 19 magnetized parallel to the direction of vibration. The first permanent magnet 19 forms a central escape space. The middle part avoids the space to avoid the stator assembly. The vibration direction is indicated by the arrow a in fig. 6. The vibrating portion has a set mass to form a vibration sensation. The elastic part is used for providing elastic restoring force. The elastic part is a spring, an elastic sheet 12 or an elastic rubber piece and the like.

The vibrating portion includes a weight portion and a first permanent magnet 19. The first permanent magnet 19 is disposed on the weight portion, and forms a middle escape space. For example, the counterweight is a mass 18. The mass block 18 is a frame structure. The middle avoidance space is used for avoiding the coil 23. The direction of magnetization of the first permanent magnet 19 is parallel to the direction of vibration. The vibration direction is the direction in which the vibrator assembly vibrates. For example, the first permanent magnet 19 has a rectangular structure or a race track-type annular structure, and a central space is formed in the middle of the first permanent magnet 19.

Alternatively, the first permanent magnet 19 is plural. A plurality of first permanent magnets 19 are provided on the counterweight portion and surround the inside of the frame structure to form a middle escape space. The magnetizing directions of the first permanent magnets 19 are parallel to the vibration direction, and the polarities are the same. For example, the center of the mass 18 forms a through hole. Two first permanent magnets 19 are arranged in the through hole and the two first permanent magnets 19 are spaced from each other to form a central escape space. With the arrangement, the number of the first permanent magnets 19 is small, and the structure is simple.

The first permanent magnet 19 is, for example, a bar magnet. The long axes of the two bar magnets are parallel to the long sides of the housing. The long axis is parallel to the long side of the bar magnet. The minor axis is perpendicular to the major axis and the direction of vibration. The coil 23 has a racetrack or rectangular configuration. The long sides of the coil 23 are parallel to the long sides of the housing. In this example, the long side of the coil 23 corresponds to the bar magnet, which makes the driving force of the vibrator assembly larger.

In other examples, the first permanent magnets 19 are four. Four first permanent magnets 19 are fixed in the through-holes and arranged in a rectangular ring-shaped configuration. The middle part of the rectangular annular structure forms a middle avoiding space. This arrangement results in a higher magnetic field strength.

The stator assembly includes a magnetically permeable core and a coil 23 wound around the outer periphery of the magnetically permeable core. The magnetic core is made of a magnetic material, such as iron, cobalt, nickel, etc. The magnetic core portion can gather the magnetic induction lines, thereby improving the magnetic induction strength of the magnetic field formed by the first permanent magnet 19. The magnetic core is fixed in the accommodating cavity.

The magnetic conductive core portion includes a support portion 21 and a radial protrusion 16 provided at one end of the support portion 21. The other end of the support portion 21 is connected to the inner wall of the housing. The coil 23 is wound around the support 21 and is located between the housing and the radial projection 16. The coil 23 is located in the middle avoiding space and spaced apart from the vibrating portion. For example, axial direction is parallel to the vibration direction, and radial direction is perpendicular to the vibration direction. For example, the radial projection 16 is close to the N pole of the first permanent magnet 19. As shown in fig. 6, the radial projections 16 reduce the distance between the magnetically permeable core and the first permanent magnet 19 so that the magnetic induction lines can be gathered and passed through the coil 23 more efficiently.

Preferably, the magnetic conductive core is in a T-shaped structure or a cross-shaped structure. This structure facilitates winding and fixing of the coil 23.

Further, the magnetic conductive core is integrally formed. For example, the magnetic core is made of mild steel by casting, stamping, etc., which results in high structural strength and good durability of the magnetic core.

As shown in fig. 6, the first permanent magnet 19 is magnetized in a direction parallel to the vibration direction, for example, with an N pole at the upper end and an S pole at the lower end. Thus, the magnetic induction line is emitted from the N pole, and reaches the S pole via the radial protrusion 16, the center portion, and the coil 23. The left and right portions of the coil 23 form magnetic circuits, i.e., a first magnetic circuit, respectively. According to the ampere rule, the directions of the ampere force received by the left and right portions of the coil 23 are the same. Since the radial protrusion 16 is close to the first permanent magnet 19, the magnetic induction lines can be gathered effectively, thereby improving the magnetic field intensity and the magnetic field utilization rate and reducing the power consumption of the exciter.

In addition, the mass of the first permanent magnet 19 does not need to be increased in this way, and the manufacturing cost of the exciter is reduced.

In one example, as shown in fig. 3, the magnetically permeable core includes an annular portion 20 and a support portion 21. The support portion 21 is inserted into a hole of the ring portion 20. The annular portion 20 projects from the support portion 21 to form the radial projection 16. The entirety of the annular portion 20 and the support portion 21 constitutes a T-shaped structure or a cross-shaped structure.

In the split type setting mode, the annular part 20 and the supporting part 21 are both simple structural members, so that the magnetic conducting core part is low in processing difficulty, high in production efficiency and high in yield.

Preferably, as shown in fig. 3, the support portion 21 has a sheet-like structure, and protrudes outward from the middle of one side edge of the support portion 21 to form the insertion end 22. The insertion end 22 is inserted into the hole of the ring portion 20. For example, the support portion 21 has a convex structure as a whole. The insertion end 22 of the support portion 21 forms a stepped structure, which can effectively support the ring portion 20.

Furthermore, this structure makes the positioning of the annular portion 20 more precise, and the length of the support portion 21 is fixed, facilitating the winding of the coil 23.

In one example, the magnetically conductive core comprises an i-shaped structure and a support portion 21. The I-shaped structure comprises two side edges and a connecting edge positioned in the middle of the two side edges. One end surface of the support portion 21 has a groove. The support portion 21 has a concave structure when viewed from the side. The connecting edge of the I-shaped structure is clamped in the groove. The two sides project from the sides of the support 21 to form radial projections 16. The i-shaped structure and the support portion 21 form a T-shaped structure or a cross-shaped structure.

Similarly, the i-shaped structure and the supporting portion 21 are both simple structural members, which makes the magnetic core portion low in processing difficulty, high in production efficiency and high in yield. The support portion 21 can effectively support the i-shaped structure.

Furthermore, this configuration also makes the positioning of the annular portion 20 more precise, and the length of the support portion 21 is fixed, facilitating the winding of the coil 23.

In one example, the housing is made of a magnetically permeable material. The stator assembly is configured to magnetize the housing walls corresponding to both ends of the coil 23. For example, the magnetic conductive material may be, but is not limited to, iron, cobalt, nickel, or the like, or an alloy material containing the above elements. The magnetizing direction of the first permanent magnet 19 is parallel to the vibration direction, and then the two poles of the first permanent magnet 19 attract the opposite shell wall of the shell. The attractive force increases as the distance between the pole of the first permanent magnet 19 and the opposite housing wall decreases. The attractive force can increase the driving force of the vibrator assembly, increase the amplitude, and improve the vibration sense of the exciter.

For example, as shown in fig. 1, the housing includes a front case 11 and a rear cover 30. The front case 11 includes a bottom portion 32 and side wall portions provided around the bottom portion 32. The rear cover 30 covers an end of the side wall portion opposite to the bottom portion 32. The rear cover 30 and the side wall portions are fixedly connected by, for example, bonding, snapping, riveting, laser welding, or the like. Either one of the elastic portion and the magnetically permeable core is fixed to the bottom 32, and the other is fixed to the rear cover 30. For example, the fixing is performed by means of adhesion, snap-fitting, caulking, laser welding, or the like. Of course, the housing is not limited to the rectangular parallelepiped structure.

In this way, the stator assembly is integrated with the front case 11 or the rear cover 30, and the vibrator assembly is integrated with the other of the front case 11 and the rear cover 30. At the time of assembly, it is only necessary to mount the rear cover 30 to the side wall portion of the front case 11, and at the same time, the stator assembly is inserted into the middle escape space of the vibrator assembly. This makes assembly of the exciter easy.

For example, as shown in fig. 1-2, the stator assembly is fixed to the back cover 30, and the FPCB24 is provided on the back cover 30. The FPCB24 is connected to the outlet terminal and the inlet terminal of the coil 23. The coil 23 receives an electric signal of an external device through the FPCB 24. The vibrator assembly is fixed to the front case 11.

In one example, as shown in fig. 4, the dome 12 for the actuator includes a plurality of cantilever arms and a first connection portion 15. The same ends of the plurality of cantilevers are connected to the first connection portion 15. For example, the first connection portion 15 and the cantilever each have a sheet-like structure. The first connection portion 15 is for connection with an inner wall of the case or the vibration portion, and the other end of the cantilever is connected with the inside of the case or the vibration portion so that the vibration portion is suspended in the accommodation space. For example, the other ends of the plurality of cantilevers are welded to the vibrating portion, respectively.

In this example, the spring plate 12 further includes a first projecting portion 16 projecting from a side portion of the first connecting portion 15 in the thickness direction. The first protrusion 16 increases the area of the first connection portion 15 so that the connection area of the spring plate 12 with the case or with the vibration portion is increased. The first connection portion 15 is welded to the housing or the mass 18 of the vibrating portion, for example, by welding. In this way, the connection of the spring plate 12 to the housing or the vibrating portion is more secure.

Alternatively, the first protrusion 16 and the first connecting portion 15 may be located on the same plane, different planes or at any angle, so long as the connection with the housing or the vibrating portion is facilitated.

Preferably, the plurality of cantilevers are parallel to each other. For example, a plurality of cantilevers extend obliquely upward along the first connection portion 15 or the cantilevers have an arc shape. The parallel arrangement mode each other, the direction of stretching out and drawing back of many cantilevers is the same, and then makes the atress of vibration portion more balanced, can not take place lateral shifting.

For example, the first projecting portion 16 is located between two adjacent cantilevers. This arrangement prevents the first projecting portion 16 from occupying a space other than the area surrounded by the elastic sheet 12 to avoid interference with other components.

For example, the first projecting portion 16 and the plurality of cantilever arms are located on the same side of the first connecting portion 15, or the first projecting portion 16 is located opposite to the plurality of cantilever arms. The arrangement can be made by those skilled in the art according to actual needs as long as the arrangement does not interfere with other components.

In one example, there are two cantilevers. Namely a first cantilever 13 and a second cantilever 14. The first projection 16 is located between the two cantilevers. The two cantilever arms are symmetrically arranged with respect to the first projection 16. The spring plate 12 has a simple structure and is easy to process and manufacture.

In addition, the two cantilever arms which are symmetrically arranged enable the elastic force of the elastic sheet 12 to be more balanced.

In one example, as shown in fig. 4, the elastic piece 12 further includes a second connection portion. The other ends of the plurality of cantilevers are connected with the second connecting portion. The first connection portion 15 and the second connection portion are located at both end portions of the plurality of cantilevers, respectively. For example, the first connecting portion 15 is used to connect with the inner wall of the housing, and the second connecting portion makes the connection between the elastic sheet 12 and the vibrating portion easier, and only one welding is needed. When the second connecting portion is not provided, each cantilever needs to be welded.

Preferably, the elastic piece 12 further includes a second protrusion 16 protruding from a side portion of the second connection portion in the thickness direction. Similarly, the second protruding portion 16 increases the area of the second connecting portion, so that the connection area between the elastic sheet 12 and the housing or between the elastic sheet 12 and the vibrating portion is increased, and the connection strength of the elastic sheet 12 is improved.

Preferably, the first connection portion 15 and the second connection portion are parallel to each other, and the plurality of cantilevers form an obtuse angle or an acute angle with the first connection portion 15. For example, the first connection portion 15 and the second connection portion each have a sheet-like structure and are located on different planes in the vibration direction, so that each cantilever forms a height difference. This effectively increases the spring force of the spring plate 12.

The distance between the first connection portion 15 and the second connection portion can be set by those skilled in the art according to actual needs.

Preferably, the resilient tab 12 is integrally formed. For example, the metal sheet is integrally formed into any one of the elastic sheets 12 by stamping, which facilitates the processing of the elastic sheet 12 and improves the structural strength of the elastic sheet 12.

In one example, the elastic sheet 12 is plural. The plurality of elastic pieces 12 are disposed on the same side of the vibrating portion in the vibrating direction. For example, the plurality of resilient pieces 12 are located on a side of the vibrating portion away from the FPCB 24. This way, compared to disposing a plurality of the elastic pieces 12 at both sides of the vibration part, can save the installation space, thereby reducing the height of the exciter.

In one example, as shown in fig. 5, the plurality of resilient pieces 12 are juxtaposed in the same mounting orientation. The same mounting orientation means that the angle at which the spring 12 is mounted and the orientation of the set portion are the same. For example, the vibrating portion has a rectangular parallelepiped structure. The height direction of the vibrating portion is parallel to the vibrating direction. The long sides of the vibrating portion are parallel to the long sides of the case. The spring plate 12 includes only the first connecting portion 15 and two cantilever arms. The ends of the two cantilevers opposite the first connection 15 form open ends. When attached, the plurality of spring pieces 12 are arranged in parallel in the longitudinal direction of the vibrating portion. The plurality of first connecting portions 15 are each connected to the housing with the open end facing in the same direction, for example, toward the same short side of the vibrating portion. The arrangement mode enables the working stroke of each elastic sheet 12 to be the same, so that the elastic force of the elastic sheets 12 is the same, and the stress of the vibration part is more balanced.

In one example, the elastic sheet 12 is plural. The plurality of resilient pieces 12 are respectively provided on different sides of the vibrating portion in the vibrating direction. For example, the same number of spring plates 12 are respectively located on the upper and lower sides of the vibrating portion in the vibrating direction, and the positions of the plurality of spring plates 12 located on the upper side correspond one-to-one to the positions of the plurality of spring plates 12 located on the lower side. This makes the forces on both sides of the vibrating portion in the vibrating direction more balanced, and the vibration stability of the exciter is excellent.

In one example, as shown in FIG. 5, an inwardly projecting boss 26 is formed on the housing. The first connecting portion 15 and the first projecting portion 16 are fixed on the boss portion 26. The inward projection is a projection directed toward the receiving chamber. For example, the housing is stamped to form the boss 26. The first connecting portion 15 and the first projecting portion 16 are welded to the boss portion 26. In this way, the space in which the dome 12 vibrates is increased. When the spring plate 12 is compressed, a gap is formed between the cantilever and the part of the housing except the convex part 26, thereby effectively preventing the spring plate 12 from impacting the housing.

The height of the projection 26 can be set by those skilled in the art according to actual needs.

In one example, the vibrator assembly further includes an auxiliary permanent magnet. The auxiliary permanent magnet is disposed outside the first permanent magnet 19 perpendicular to the vibration direction. The auxiliary permanent magnet is configured to enhance the strength of the magnetic field passing through the coil 23.

In one example, as shown in fig. 7, the auxiliary permanent magnet includes a second permanent magnet 31. The magnetizing direction of the second permanent magnet 31 is perpendicular to the vibration direction. The second permanent magnet 31 is configured to form a second magnetic circuit with the housing and the magnetically conductive core to guide the lines of magnetic induction outside the first permanent magnet 19 through the coil 23. The outer side is the side far away from the middle avoiding space. For example, when the first permanent magnet 19 is a ring magnet, the second permanent magnet 31 is also a ring magnet and is sleeved outside the first permanent magnet 19, for example, in a rectangular ring shape or a racetrack ring shape.

For example, when the first permanent magnet 19 is a plurality of bar magnets, the second permanent magnet 31 is also a plurality of bar magnets and is disposed outside the first permanent magnet 19, for example, four bar magnets surround a rectangular ring structure.

The second permanent magnet 31 can shorten the magnetic circuit outside the first permanent magnet 19 and form a second magnetic circuit. For example, the side of the second permanent magnet 31 close to the first permanent magnet 19 is the S pole. The magnetic induction line of the first permanent magnet 19 is emitted from the N pole, then reaches the S pole of the second permanent magnet 31, then starts from the N pole of the second permanent magnet 31, reaches the magnetic conduction core column through the shell, then penetrates out from the side part of the magnetic conduction core column, passes through the coil 23, and then reaches the S pole of the first permanent magnet 19. By providing the second permanent magnet 31, the magnetic field deviating from the middle avoiding space can be guided to the magnetically conductive core column and pass through the coil 23. Thus, the second magnetic circuit can effectively increase the amount of the magnetic induction lines passing through the coil 23, improve the magnetic induction strength at the coil 23, and improve the magnetic field force received by the coil 23. This enables the driving force of the actuator to be effectively increased with higher sensitivity.

Furthermore, the vibration of the exciter will be stronger for the same current, which results in a higher efficiency and lower power consumption of the exciter.

Of course, the directions of the magnetic poles of the first permanent magnet 19 and the second permanent magnet 31 are not limited to the above-described embodiment, and can be set by those skilled in the art according to actual needs.

In one example, as shown in fig. 8, the auxiliary permanent magnet includes a third permanent magnet 33 and a fourth permanent magnet 34. The third permanent magnet 33 and the fourth permanent magnet 34 have main body directions perpendicular to the vibration direction, and are stacked. The main body direction is the extension direction of the main plane. The N pole of the third permanent magnet 33 is close to the N pole of the first permanent magnet 19, and the S pole of the fourth permanent magnet 34 is close to the S pole of the first permanent magnet 19. For example, when the first permanent magnet 19 is a ring magnet, the third permanent magnet 33 and the fourth permanent magnet 34 are also ring magnets, and are fitted around the first permanent magnet 19, for example, in a rectangular ring shape or a racetrack ring shape.

For example, when the first permanent magnet 19 is a plurality of bar magnets, the third permanent magnet 33 and the fourth permanent magnet 34 are also a plurality of bar magnets and are disposed outside the first permanent magnet 19, for example, four bar magnets surround a rectangular ring structure.

The N pole of the third permanent magnet 33 is repelled from the N pole of the first permanent magnet 19. The S pole of the fourth permanent magnet 34 is repelled from the N pole of the first permanent magnet 19. The third permanent magnet 33 and the fourth permanent magnet 34 make the first permanent magnet 19 pass through more magnetic induction lines from the middle avoiding space, that is, the magnetic induction strength of the first magnetic circuit is enhanced, that is, more magnetic induction lines can pass through the coil 23, so that the magnetic induction strength at the coil 23 is increased. In this way, the coil 23 is subjected to a greater magnetic force, resulting in a greater driving force and greater sensitivity of the actuator.

In other examples, the first permanent magnet 19 includes four bar magnets. The four bar magnets form a rectangular ring shape. The auxiliary permanent magnets are located on the first permanent magnet 19, which is longer in length. The auxiliary permanent magnet is, for example, a bar magnet.

Alternatively, the first permanent magnet 19 is a rectangular ring magnet or a racetrack ring magnet. The auxiliary permanent magnets are located on the long sides of the first permanent magnets 19. The auxiliary permanent magnet is, for example, a bar magnet.

In this example, the auxiliary permanent magnet can also increase the driving force of the actuator, and can save raw materials.

In one example, as shown in fig. 1, 2 or 7, the vibrator assembly further comprises an annular magnetically permeable plate 17. An annular magnetic conductive plate 17 is provided on the upper end surface of the first permanent magnet in the vibration direction. The upper end face, that is, the end face of the first permanent magnet 19 opposite to the FPCB 24. The annular magnetic conduction plate 17 is made of magnetic conduction materials. The annular magnetic conduction plate 17 can effectively gather magnetic induction lines, so that the magnetic induction intensity in the middle avoidance space is further improved.

In addition, in this example, the spring plate 12 is welded to the annular magnetic conductive plate 17.

According to another embodiment of the present invention, a screen sound emitting device is provided. The screen sounding device comprises a main body part and a screen body arranged at the open end of the main body part, wherein the exciter provided by the invention is arranged on the screen body.

The screen sounding device has the characteristic of good sounding effect.

Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. An actuator, comprising: the vibration generator comprises a shell, a vibrator assembly and a stator assembly, wherein an accommodating cavity is formed in the shell, the vibrator assembly comprises a vibration part and an elastic part, the vibration part is suspended in the accommodating cavity through the elastic part, the vibration part comprises a first permanent magnet which is magnetized in a direction parallel to the vibration direction, and the first permanent magnet forms a middle avoiding space;

the stator assembly comprises a magnetic core part and a coil wound around the periphery of the magnetic core part, the magnetic core part is fixed in the accommodating cavity, the magnetic core part comprises a supporting part and a radial protruding part arranged at one end of the supporting part, the other end of the supporting part is connected with the shell, the coil is wound outside the supporting part and positioned between the shell and the radial protruding part, and the coil is positioned in the middle avoiding space and is spaced from the vibration part;

The elastic part comprises an elastic sheet, the elastic sheet comprises a protruding part, a first cantilever, a second cantilever and a first connecting part connected to the same end of the first cantilever and the second cantilever, one end of the protruding part is connected with the middle part of the first connecting part, and the protruding part and the first cantilever are positioned on the same side of the first connecting part;

wherein a boss portion protruding inward is formed on the case, the first connection portion and the boss portion being fixed on the boss portion;

wherein the vibrator assembly further includes an auxiliary permanent magnet disposed at an outer side of the first permanent magnet perpendicular to the vibration direction;

the auxiliary permanent magnet includes a second permanent magnet having a magnetizing direction perpendicular to a vibration direction, the second permanent magnet being configured to form a second magnetic circuit together with the case and the magnetically permeable core.

2. An actuator according to claim 1, wherein the housing is made of magnetically permeable material and the stator assembly is configured for magnetizing the housing walls corresponding to the two ends of the coil.

3. The exciter of claim 1, wherein the magnetically conductive core is in a T-shaped configuration or a cross-shaped configuration.

4. An actuator according to claim 3, wherein the magnetically conductive core is integrally formed.

5. The exciter of claim 3, wherein the magnetically conductive core comprises an annular portion and the support portion, the support portion being inserted into a bore of the annular portion, the annular portion projecting from the support portion to form the radial projection.

6. An actuator according to claim 5, wherein the support portion is of a plate-like configuration and projects outwardly from a central portion of one side edge of the support portion to form an insertion end which is inserted into the hole of the ring-shaped portion.

7. The exciter of claim 3, wherein the magnetically conductive core comprises an i-shaped structure and the support portion, the i-shaped structure comprises two side edges and a connecting edge located at the middle of the two side edges, one end surface of the support portion has a groove, the connecting edge of the i-shaped structure is clamped into the groove, and the two side edges protrude from the side portions of the support portion to form the radial protrusion.

8. The exciter according to claim 1, wherein the housing is a rectangular parallelepiped structure, the first permanent magnet is two bar magnets, the middle avoiding space is formed between the two bar magnets, the long axes of the two bar magnets are parallel to the long side of the housing, the coil is in a racetrack structure or a rectangular structure, and the long side of the coil is parallel to the long side of the housing.

9. The exciter of claim 1, wherein the housing comprises a front shell and a rear cover, the front shell comprising a bottom portion and a sidewall portion disposed around the bottom portion, the rear cover covering an end of the sidewall portion opposite the bottom portion; any one of the elastic part and the magnetic conduction core part is fixed on the bottom, and the other one is fixed on the rear cover.

10. The actuator according to claim 1, wherein said elastic portion comprises a plurality of resilient pieces, said plurality of resilient pieces being located on the same side of said vibrating portion parallel to the direction of vibration.

11. An actuator according to claim 10, wherein said vibration portion has a rectangular parallelepiped configuration, and a plurality of said resilient pieces are juxtaposed in the same mounting orientation along a long side of said vibration portion.

12. A screen sound generating device comprising a main body portion and a screen body disposed at an open end of the main body portion, the actuator of any one of claims 1 to 11 being disposed on the screen body.