Patent Publication Number: US-2023143064-A1

Title: Vibration unit, speaker and manufacturing method of the vibration unit

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority benefit of Chinese invent Application No. 202111304392.7, filed on Nov. 5, 2021, and the entire contents of which are incorporated herein by reference. 
     This application claims priority benefit of Chinese invent Application No. 202210656763.6, filed on Jun. 11, 2022, and the entire contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The invention relates to vibration units, in particular to a vibration unit, a speaker and a manufacturing method of the vibration unit. 
     BACKGROUND 
     Vibration units in the market can be divided into three categories. The first category uses a motor to drive a rotor to rotate; the vibration frequency is directly related to the speed of the motor and the vibration frequency is difficult to control, so that it is difficult to achieve an accurate vibration frequency effect. Moreover, there is mechanical vibration noise, which cannot synchronize with an audio. The second category uses a moving-coil to drive a vibrating plate to achieve a vibration effect, but the low power of vibration cannot meet product requirements and cannot drive the products with a large weight. The third category uses electromagnetic drive to achieve the vibration effect by elastic sheet suppression, but it still cannot reduce the mechanical noise. 
     Therefore, it is necessary to develop a vibration unit which can synchronize with an audio and has low mechanical noise. 
     SUMMARY 
     Aiming at the above problems existing in the prior art, the present invention provides a vibration unit, a speaker and a manufacturing method of a vibration unit thereof. 
     The purpose of the present invention is realized by the following technical scheme: 
     A vibration unit includes a shell with a hollow cavity and a vibration shaft arranged in the hollow cavity, wherein the shell is provided with two elastic support structures located at two ends of the vibration shaft, and at least two permanent magnet rings and at least one magnetic insulator ring are fixed to an outer periphery of the vibration shaft, with each magnetic insulator ring arranged between every two adjacent permanent magnet rings; and the vibration unit further includes coils fixed on an inner wall of the hollow cavity and located on an outer periphery of each of the permanent magnet rings, wherein a change in a current flowing through each of the coils causes magnetic field force at two ends of each of the permanent magnet rings to change, so as to produce vibration of each of the permanent magnet rings in proportion to the change in the current, which in turn drives the vibration shaft to vibrate in proportion. The structure uses two or more permanent magnet rings, so that the vibration effect is improved. 
     Typically, two ends of the vibration shaft extend to outer ends of the hollow cavity and are fixedly connected to the elastic support structures; each of the elastic support structures includes an elastic sheet and a reinforcing sheet; the elastic sheet has one end fixedly connected to the shell and another end fixedly connected to one end of the reinforcing sheet; and another end of the reinforcing sheet is fixedly connected to each of the two ends of the vibration shaft. The structure uses a thin metal sheet as the elastic sheet, which provides an elastic support effect with small resistance and a long service life. 
     Typically, each of the elastic support structures further includes rivets used for fixedly connecting the elastic sheet and the reinforcing sheet, and a noise-reduction spacer through which the rivets pass and arranged between the elastic sheet and the reinforcing sheet. The noise-reduction spacer further reduces the noise caused by vibration of the vibration shaft transmitted to the shell through the elastic sheet. 
     Typically, two ends of the shell are each provided with a clearance recess, which provides a vibration space for one end of the elastic sheet connected to the reinforcing sheet. With the clearance recess arranged inward, the shape of the unit remains as a complete cuboid structure, which is compact overall and aesthetically pleasing and has a high strength. 
     Typically, the reinforcing sheet is at least three times thicker than the elastic sheet; the center of the elastic sheet is provided with an oval hollow to provide a vibration space for the reinforcing sheet, and a width of a middle section of the reinforcing sheet is smaller than widths of two ends of the reinforcing sheet, so as to form a waist-shaped middle section part and provide a larger free vibration space for the vibration shaft. The reinforcing sheet is thick and not easy to deform, and elastic support is completely performed by the elastic sheet, so as to avoid interference between the reinforcing sheet and the elastic sheet in an elastic deformation process. The oval hollow and the waist-shaped middle section part effectively prevent collision between the reinforcing sheet and the elastic sheet during vibration. 
     Typically, the shell is of a cuboid structure; the hollow cavity is provided with an upper opening for the coils to be installed into the hollow cavity; a side edge of the upper opening is provided with a plurality of notches for passage of wires of the coils; an installation side recess for embedded installation of a printed circuit board (PCB) is provided at an outer side of the notches; and an outer side of the PCB is provided with electrical contacts to connect the wires. The upper opening facilitates installation of the coil; and the installation side recess facilitates embedding of the PCB into the cuboid structure, thereby maintaining a cuboid shape and providing an appealing appearance. 
     Typically, a bottom of the clearance recess is provided with an anti-collision spacer corresponding to positions of the rivets; and the vibration shaft is provided with snap rings located at outer ends of the permanent magnet rings. The anti-collision spacer can prevent the rivet and the shell from being damaged in extreme circumstances; and the snap ring is convenient for the installation of the permanent magnet rings. 
     Typically, the vibration shaft is a copper shaft, the quantity of the permanent magnet rings is three, the quantity of the at least one magnetic insulator ring is two, the quantity of the coils is two, and the coils are each located on an outer periphery of one respective magnetic insulator ring; the two coils are connected in series with each other, and ends with the same name are connected together; and the magnetic insulator rings are made of plastics, and adjacent ends of the permanent magnet rings are of the same polarity. The structure is provided with the two coils generating magnetic fields in opposite directions; and the coils are kept at a distance from each other, thereby generating a radial electromagnetic field extending in a direction of a plane (that is, a direction perpendicular to an axial direction of the vibration shaft) at a gap between the coils. Permanent magnet rings with the same polarity are added at two ends of the permanent magnet ring located in a middle position on the vibration shaft, so that the magnetic field extends and is enhanced radially to form a radial ,permanent magnet field; and a direction of the radial electromagnetic field is opposite to a direction of the radial permanent magnetic field. When a varying current passes through the coils, the vibration shaft will be caused to vibrate in proportion. Because radial extension of the magnetic field can increase strength of the magnetic field, the vibration unit can be used for a large current input, thus forming a vibration output with a higher power (that is, high power electric energy is converted into mechanical energy). The vibration shaft is made of copper with a relatively high density, and the copper does not conduct magnetism and will also improve potential energy during vibration and improve the vibration effect. 
     The present invention provides a speaker, which includes an audio bass enhancement aid device, wherein the audio bass enhancement aid device includes the vibration unit described above. The vibration unit with low noise is used to provide better sound quality. 
     A manufacturing method of the vibration unit of the present invention includes the following assembling steps: sleeving at least two permanent magnet rings and at least one magnetic insulator ring alternately onto a vibration shaft with each magnetic insulator ring arranged between every two adjacent permanent magnet rings, and fixing the rings by snap rings to form a vibration shaft assembly; embedding coils into a hollow cavity from an upper opening of a shell to make the coils coaxial with the shell; passing the vibration shaft into the hollow cavity from one end of the shell; and installing one elastic support structure at each of two ends of the shell and the vibration shaft, wherein 
     the above-mentioned steps adopt an automatic assembly mode with an automatic conveying guide rail, with the upper opening of the shell facing up and the steps starting from a feeding position:   a first station is a feeding station, and the shell is placed on a jig seat;   at a second station, the coils are put into the upper opening;   at a third station, the vibration shaft assembly is passed into the hollow cavity of the shell from one side by a pushing mechanism;   at a fourth station, the two elastic support structures are installed to the two ends of the shell and the vibration shaft, respectively; and   a fifth station is a discharge station, at which the assembled product is taken out from the jig seat.   

     The manufacturing method adopts an automatic conveying guide rail, which can enable quick assembly and enhance production capacity. 
     Generally speaking, compared with the prior art, the present invention has the following beneficial effects. The present invention uses two or more permanent magnet rings, so that the vibration effect is improved. Further, a thin metal sheet is used as the elastic sheet, which provides an elastic support effect with small resistance and a long service life. The noise-reduction spacer further reduces the noise caused by vibration of the vibration shaft transmitted to the shell through the elastic sheet. With the clearance recess arranged inward, the shape of the unit remains as a complete cuboid structure, which is compact overall and aesthetically pleasing and has a high strength. The reinforcing sheet is thick and not easy to deform, and elastic support is completely performed by the elastic sheet, so as to avoid interference between the reinforcing sheet and the elastic sheet in an elastic deformation process. The oval hollow and the waist-shaped middle section part effectively prevent collision between the reinforcing sheet and the elastic sheet during vibration. The upper opening facilitates installation of the coil; and the installation side recess facilitates embedding of the PCB into the cuboid structure, thereby maintaining a cuboid .shape, providing an appealing appearance, and also facilitating automatic assembly. The assembly method of the vibration unit of the present invention is suitable for adopting automatic equipment to realize automatic assembly. The vibration unit of the present invention can be widely used in small Bluetooth speakers, electric sports gamepads, electric sports headphones, massage devices, electric toys and other products. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a sectional view of a specific embodiment of a vibration unit of the present invention; 
         FIG.  2    is an exploded perspective view of the embodiment of  FIG.  1   ; 
         FIG.  3    is a perspective view of a vibration shaft portion of the embodiment of  FIG.  1   ; 
         FIG.  4    is an exploded view of  FIG.  3   ; 
         FIG.  5    is a perspective view of a shell of the embodiment of  FIG.  1   ; 
         FIG.  6    is an exploded view of  FIG.  5   ; 
         FIG.  7    is a perspective view of an elastic support structure of the embodiment of  FIG.   1   ; and 
         FIG.  8    is an exploded view of  FIG.  7   . 
     
    
    
     
       
         
           
               
               
               
               
             
               
                 List of reference numerals 
               
             
            
               
                 
                   10 
                 
                 Shell 
                 
                   100 
                 
                 Hollow cavity 
               
               
                 
                   101 
                 
                 Clearance recess 
                 
                   102 
                 
                 Upper opening 
               
               
                 
                   103 
                 
                 Notch 
                 
                   104 
                 
                 Installation side recess 
               
               
                 
                   109 
                 
                 Anti-collision spacer 
                 
                   19 
                 
                 Self-tapping screw 
               
               
                 
                   20 
                 
                 Vibration shaft 
                 
                   21 
                 
                 Permanent magnet ring 
               
               
                 
                   22 
                 
                 Magnetic insulator ring 
                 
                   28 
                 
                 Snap ring 
               
               
                 
                   29 
                 
                 Machine screw 
                 
                   30 
                 
                 Elastic support structure 
               
               
                 
                   31 
                 
                 Elastic sheet 
                 
                   311 
                 
                 Oval hollow 
               
               
                 
                   32 
                 
                 Reinforcing sheet 
                 
                   321 
                 
                 Waist-shaped middle section part 
               
               
                 
                   33 
                 
                 Rivet 
                 
                   34 
                 
                 Noise-reduction spacer 
               
               
                 
                   40 
                 
                 Coil 
                 
                   50 
                 
                 PCB 
               
               
                 
                   51 
                 
                 Electrical contact 
                 
                   99 
                 
                 Surface sticker 
               
            
           
         
       
     
     DETAILED DESCRIPTION 
     In order to fully understand the technical content of the present invention, the technical scheme of the present invention is further introduced and explained in connection with specific embodiments, but is not limited thereto. 
     According to the embodiment shown in  FIGS.  1 - 8   , a vibration unit includes a shell  10  with a hollow cavity  100  and a vibration shaft  20  arranged in the hollow cavity  100 . The shell  10  is provided with two elastic support structures  30  located at two ends of the vibration shaft  20 . Three permanent magnet rings  21  and two magnetic insulator rings  22  each arranged between two adjacent permanent magnet rings  21  are fixed to an outer periphery of the vibration shaft  20 . The vibration unit further includes coils  40  fixed on an inner wall of the hollow cavity  100  and located on an outer periphery of each of the permanent magnet rings  21 , wherein a change in a current flowing through each of the coils  40  causes magnetic field force at two ends of each of the permanent magnet rings  21  to change, so as to produce vibration of each of the permanent magnet rings  21  in proportion to the change in the current, which in turn drives the vibration shaft  20  to vibrate in proportion. The structure uses two or more permanent magnet rings  21 , so that the vibration effect is improved. 
     More specifically, two ends of the vibration shaft  20  extend to outer ends of the hollow cavity and are fixedly connected to the elastic support structures  30 ; each of the elastic support structures  30  includes an elastic sheet  31  and a reinforcing sheet  32 ; the elastic sheet  31  has one end fixedly connected to the shell  10  (by self-tapping screws  19  in this embodiment) and another end fixedly connected to one end of the reinforcing sheet  32 ; and another end of the reinforcing piece  32  is fixedly connected to each of the two ends of the vibration shaft  20  (by a machine screw  29  in this embodiment). The structure uses a thin metal sheet as the elastic sheet, which provides an elastic support effect with small resistance and a long service life. 
     More specifically, each of the elastic support structures  30  further includes rivets  33  used for fixedly connecting the elastic sheet  31  and the reinforcing sheet  32 , and a noise-reduction spacer  34  through which the rivets  33  pass and arranged between the elastic sheet  31  and the reinforcing sheet  32 . The noise-reduction spacer  34  further reduces the noise caused by vibration of the vibration shaft  20  transmitted to the shell  10  through the elastic sheet  31 . 
     More specifically, two ends of the shell  10  are each provided with a clearance recess  101 , which provides a vibration space for one end of the elastic sheet  31  connected to the reinforcing sheet  32 . With the clearance recess  101  arranged inward, the shape of the unit remains as a complete cuboid structure, which is compact overall and aesthetically pleasing and has a high strength. In this embodiment, the clearance recess  101  is of a sloped structure, that is, an inner side where the rivet  33  is located is the deepest, and the position where one end of the elastic sheet  31  is fixedly connected to the shell  10  is the shallowest. 
     More specifically, the reinforcing sheet  32  is at least three times thicker than the elastic sheet  31 ; the center of the elastic sheet  31  is provided with an oval hollow  311  to provide a vibration space for the reinforcing sheet  32 ; and a width of a middle section of the reinforcing sheet  32  is smaller than widths of two ends of the reinforcing sheet, so as to form a waist-shaped middle section part  321  and provide a larger free vibration space for the vibration shaft  20 . The reinforcing sheet  32  is thick and not easy to deform, and elastic support is completely performed by the elastic sheet  31 , so as to avoid interference between the reinforcing sheet and the elastic sheet in an elastic deformation process. The oval hollow  311  and the waist-shaped middle section part  321  effectively prevent collision between the reinforcing sheet and the elastic sheet during vibration. 
     More specifically, the shell  10  is of a cuboid structure; the hollow cavity  100  is provided with an upper opening  102  for the coils  40  to be installed into the hollow cavity; a side edge of the upper opening  102  is provided with a plurality of notches  103  for passage of wires of the coils  40 ; an installation side recess  104  for embedded installation of a PCB  50  is provided at an outer side of the notches  103 ; and an outer side of the PCB  50  is provided with electrical contacts  51  to connect the wires. The upper opening  102  facilitates installation of the coils  40 ; and the installation side recess  104  facilitates embedding of the PCB  50  into the cuboid structure, thereby maintaining a cuboid shape and providing an appealing appearance. After assembly is completed, a surface sticker  99  is installed on the upper opening  102  to cover the upper opening  102 . The bottom of the shell  10  is further provided with a bottom sticker  98 . 
     More specifically, a bottom of the clearance recess  101  is provided with an anti-collision spacer  109  corresponding to positions of the rivets; and the vibration shaft  20  is provided with snap rings  28  located at outer ends of the permanent magnet rings  21 . The anti-collision spacer  109  can prevent the rivet  33  and the shell  10  from being damaged in extreme circumstances; and the snap ring  28  is convenient for the installation of the permanent magnet rings  21 . 
     More specifically, the vibration shaft  20  is a copper shaft, the quantity of the permanent magnet rings  21  is three, the quantity of the at least one magnetic insulator ring  22  is two, the quantity of the coils  40  is two, and the coils are each located on an outer periphery of one respective magnetic insulator ring  22 ; the two coils  40  are connected in series with each other, and ends with the same name are connected together; and the magnetic insulator rings  22  are made of plastics, and adjacent ends of the permanent magnet rings  21  are of the same polarity. The structure is provided with the two coils generating magnetic fields in opposite directions; and the coils are kept at a distance from each other, thereby generating a radial electromagnetic field extending in a direction of a plane (that is, a direction perpendicular to an axial direction of the vibration shaft) at a gap between the coils. Permanent magnet rings with the same polarity are added at two ends of the permanent magnet ring located in a middle position on the vibration shaft, so that the magnetic field extends and is enhanced radially to form a radial permanent magnet field; and a direction of the radial electromagnetic field is opposite to a direction of the radial permanent magnetic field. When a varying current passes through the coils, the vibration shaft will be caused to vibrate in proportion. Because radial extension of the magnetic field can increase strength of the magnetic field, the vibration unit can be used for a large current input, thus forming a vibration output with a higher power (that is, high power electric energy is converted into mechanical energy). The vibration shaft is made of copper with a relatively high density, and the copper does not conduct magnetism and will also improve potential energy during vibration and improve the vibration effect. 
     The present invention further discloses a speaker, which includes an audio bass enhancement aid device, wherein the audio bass enhancement aid device includes the vibration unit described above. The vibration unit with low noise is used to provide better sound quality. 
     The present invention further discloses a manufacturing method of the vibration unit, which includes the following assembling steps: sleeving at least two permanent magnet rings and at least one magnetic insulator ring alternately onto a vibration shaft with each magnetic insulator ring arranged between every two adjacent permanent magnet rings, and fixing the rings by snap rings to form a vibration shaft assembly; embedding coils into a hollow cavity from an upper opening of a shell to make the coils coaxial with the shell; passing the vibration shaft into the hollow cavity from one end of the shell; and installing one elastic support structure at each of two ends of the shell and the vibration shaft, wherein 
     the above-mentioned steps adopt an automatic assembly mode with an automatic conveying guide rail, with the upper opening of the shell facing up and the steps starting from a feeding position:   a first station is a feeding station, and the shell is placed on a jig seat;   at a second station, the coils are put into the upper opening;   at a third station, the vibration shaft assembly is passed into the hollow cavity of the shell from one side by a pushing mechanism;   at a fourth station, the two elastic support structures are installed to the two ends of the shell and the vibration shaft, respectively; and   a fifth station is a discharge station, at which the assembled product is taken out from the jig seat.   

     The manufacturing method adopts an automatic conveying guide rail, which can enable quick assembly and enhance production capacity. 
     To sum up, the present invention uses two or more permanent magnet rings, so that the vibration effect is improved. Further, a thin metal sheet is used as the elastic sheet, which provides an elastic support effect with small resistance and a long service life. The noise-reduction spacer further reduces the noise caused by vibration of the vibration shaft transmitted to the shell through the elastic sheet. With the clearance recess arranged inward, the shape of the unit remains as a complete cuboid structure, which is compact overall and aesthetically pleasing and has a high strength. The reinforcing sheet is thick and not easy to deform, and elastic support is completely performed by the elastic sheet, so as to avoid interference between the reinforcing sheet and the elastic sheet in an elastic deformation process. The oval hollow and the waist-shaped middle section part effectively prevent collision between the reinforcing sheet and the elastic sheet during vibration. The upper opening facilitates installation of the coil; and the installation side recess facilitates embedding of the PCB into the cuboid structure, thereby maintaining a cuboid shape, providing an appealing appearance, and also facilitating automatic assembly The assembly method of the vibration unit of the present invention is suitable for adopting automatic equipment to realize automatic assembly. The vibration unit of the present invention can be widely used in small Bluetooth speakers, electric sports gamepads, electric sports headphones, massage devices, electric toys and other products. 
     The above embodiments are used merely to further explain the technical content of the present invention, so that readers can understand the present invention more easily, and it is not intended that the embodiments of the present invention are limited thereto, and any technical extension or re-creation according to the present invention is protected by the present invention. The scope of protection of the present invention is subject to the appended claims.