Patent Publication Number: US-11665471-B1

Title: Sounding device

Description:
FIELD OF THE PRESENT DISCLOSURE 
     The present disclosure relates to electroacoustic transducers, in particular to a sounding device. 
     DESCRIPTION OF RELATED ART 
     With the emergence of the mobile Internet Era, smart mobile devices are increasing. Mobile phones are undoubtedly the most common and portable in numerous smart mobile devices. At present, mobile phones have extremely diverse functions, one of which is the high-quality sound function. Therefore, sounding devices are widely used in smart mobile devices. 
     A sounding device in the related art includes a frame, a vibration system and a magnetic circuit system fixed to the frame. The vibration system includes a diaphragm fixed to the frame, and a voice coil fixed to the diaphragm and locating in a magnetic gap of the magnetic circuit system for driving the diaphragm to vibrate and generate sound. The sounding device, however, does not have a rear cavity or has an open rear cavity, which is bad to low-frequency acoustic performances. 
     Thus, it is necessary to provide a novel sounding device to solve the problem. 
     SUMMARY 
     An objective of the present disclosure is to provide a sounding device which has a better low-frequency acoustic performance. 
     In order to achieve the objective mentioned above, the present disclosure discloses a sounding device including a frame, a vibration system, a magnetic circuit system, and an air-permeable mesh. The vibration system includes a diaphragm and a voice coil for driving the diaphragm to vibrate and generate sound. The magnetic circuit system includes a yoke fixed to the frame, a first magnet mounted on the yoke, and a second magnet in a ring shape around and spaced apart from the first magnet for forming a magnetic gap for receiving the voice coil. The air-permeable mesh is in a ring shape and arranged between the second magnet and the frame. One end of the air-permeable mesh is fixed to the second magnet, and another end of the air-permeable mesh is fixed to the frame. A rear cavity is formed jointly by the frame, the yoke, the second magnet and the air-permeable mesh. Compared with the related art, the rear cavity can improve low-frequency acoustic performances of the sounding device. 
     Further, the rear cavity is filled with sound-absorbing powders for forming a virtual acoustic cavity. 
     Further, the frame includes a bottom wall, and a side wall bending and extending from a periphery of the bottom wall for supporting the vibration system. The yoke is fixed to the bottom wall. The one end of the air-permeable mesh is fixed to a side of the second magnet away from the yoke, and the another end of the air-permeable mesh is fixed to the bottom wall. 
     Further, the air-permeable mesh includes a main body part in a ring shape facing the side wall, a first extension part bending and extending from one end of the main body part close to the bottom wall toward the side wall, and a second extension part bending and extending from another end of the main body part away from the bottom wall toward the second magnet. The first extension part is fixed to the bottom wall. The second extension part is fixed to the side of the second magnet away from the yoke. 
     Further, the main body part is spaced apart from the side wall. 
     Further, the first extension part is glued to the bottom wall, and the second extension part is glued to the second magnet. 
     Further, the magnetic circuit system includes a pole plate in a ring shape fixed to the side of the second magnet away from the yoke and spaced apart from the second extension part. 
     Further, the yoke includes a plate body facing and spaced apart from the bottom wall, and a supporting wall bending and extending from the plate body toward the bottom wall. The first magnet is mounted on a side of the plate body away from the bottom wall. The supporting wall is fixed to the bottom wall. 
     Further, the supporting wall extends from a periphery of the plate body along a vibration direction of the vibration system and is spaced apart from the main body part. 
     Further, the supporting wall includes a plurality of sub walls spaced apart from each other. The frame is made of a metal material. The sub walls are fixed to the bottom wall by welding. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawing are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. 
         FIG.  1    is an isometric view of a sounding device in accordance with an exemplary embodiment of the present disclosure. 
         FIG.  2    is a cross-sectional view of the sounding device taken along line A-A in  FIG.  1   . 
         FIG.  3    is an exploded view of the air-permeable mesh and part of the frame of the sounding device in  FIG.  1   . 
         FIG.  4    is an isometric view of an assembly of the magnetic circuit system, the air-permeable mesh and part of the frame of the sounding device in  FIG.  1   . 
         FIG.  5    is an isometric view of the sounding device in  FIG.  1   , removing part of the frame. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The present disclosure will hereinafter be described in detail with reference to the embodiments. To make the technical problems to be solved, and technical solutions and beneficial effects of the present disclosure more apparent, the present disclosure is described in further detail together with the figures and the embodiments. It should be understood the embodiments described hereby are only to explain the disclosure, not intended to limit the disclosure. 
     Referring to  FIGS.  1 - 5   , the present disclosure discloses a sounding device  100  including a frame  1 , a vibration system  2  fixed to the frame  1 , a magnetic circuit system  3  fixed to the frame  1  for driving the vibration system  2  to vibrate and generate sound, and an air-permeable mesh  4  in a ring shape. 
     The magnetic circuit system  3  includes a yoke  31  fixed to the frame  1 , a first magnet  32  mounted on the yoke  31 , and a second magnet  33  in a ring shape around and spaced apart from the first magnet  32  for forming a magnetic gap  30 . 
     Optionally, The vibration system  2  includes a diaphragm  21  fixed to the frame  1 , a voice coil  22  locating in the magnetic gap  30  for driving the diaphragm  21  to vibrate and generate sound, and a skeleton  23  for connecting the diaphragm  21  and the voice coil  22 . 
     The air-permeable mesh  4  is arranged between the second magnet  33  and the frame  1 . One end of the air-permeable mesh  4  is fixed to the second magnet  33 , and another end of the air-permeable mesh  4  is fixed to the frame  1 . A rear cavity  40  is formed jointly by the frame  1 , the yoke  31 , the second magnet  33  and the air-permeable mesh  4  for improving low-frequency acoustic performances of the sounding device  100 . Compared with the related art, the rear cavity  40  can improve low-frequency acoustic performances of the sounding device  100 . 
     The air-permeable mesh  4  may choose a cloth mesh or a metal mesh. The rear cavity  40  is filled with sound-absorbing powders for forming a virtual acoustic cavity. The sound-absorbing powders may choose zeolite materials. Because the second magnet  33  is in a ring shape, an inner cavity enclosed by the magnetic circuit system  3  and the vibration system  2  does not communicate with the rear cavity  40 , the sound-absorbing powders filled in the rear cavity  40  will not enter the inner cavity and affect the voice coil  22 , thereby improving reliabilities of the sounding device  100 . 
     The frame  1  includes a bottom wall  11 , and a side wall  12  bending and extending from a periphery of the bottom wall  11  for supporting the vibration system  2 . In order to facilitate the assembly of the vibration system  2  and the magnetic circuit system  3 , the side wall  12  includes a first side wall  121 , and a second side wall  122  assembled on the first side wall  121  and integrally formed with the bottom wall  11 . The first side wall  121  and the second side wall  122  are two independent parts. The vibration system  2  is fixed to an inner surface of the first side wall  121 . The bottom wall  11  and the second side wall  122  together form an accommodating room for receiving the magnetic circuit system  3 . When assembling the sounding device  100 , the vibration system  2  and the magnetic circuit system  3  can be assembled separately. Firstly, assembling the vibration system  2  to the first side wall  121 , meanwhile, assembling the magnetic circuit system  3  to the accommodating room, and then aligning and assembling the first side wall  121  and the second side wall  122 . Thus, the assembly of the vibration system  2  and the magnetic circuit system  3  is finished. 
     The yoke  31  is fixed to the bottom wall  11 . The one end of the air-permeable mesh  4  is fixed to a side of the second magnet  33  away from the yoke  31 , and the another end of the air-permeable mesh  4  is fixed to the bottom wall  11 . 
     Optionally, the air-permeable mesh  4  includes a main body part  41  in a ring shape facing the second side wall  122 , a first extension part  42  bending and extending from one end of the main body part  41  close to the bottom wall  11  toward the second side wall  122 , and a second extension part  43  bending and extending from another end of the main body part  41  away from the bottom wall  11  toward the second magnet  33 . The first extension part  42  is fixed to the bottom wall  11 . The second extension part  43  is fixed to the side of the second magnet  33  away from the yoke  31 . Optionally, the first extension part  42  is glued to the bottom wall  11 , and the second extension part  43  is glued to the second magnet  33 . The main body part  41  is spaced apart from the second side wall  122 . 
     Optionally, the magnetic circuit system  3  further includes a pole plate  34  in a ring shape fixed to the side of the second magnet  33  away from the yoke  31  and spaced apart from the second extension part  43 . 
     Optionally, the yoke  31  includes a plate body  311  facing and spaced apart from the bottom wall  11 , and a supporting wall  312  bending and extending from the plate body  311  toward the bottom wall  11 . The first magnet  32  is mounted on a side of the plate body  311  away from the bottom wall  11 . The supporting wall  312  is fixed to the bottom wall  11 . Because the supporting wall  312  is formed by bending the yoke  31  toward the bottom wall  11  and is fixed to the bottom wall  11 , a connection area of a periphery of the yoke  31  and the bottom wall  11  can be enlarged, the fastness of connection between the yoke  31  and the bottom wall  11  is increased, and the overall structural strength is improved, thereby reducing the risk of separation between the yoke  31  and the bottom wall  11  during dropping, and improving dropping reliabilities of the sounding device  100 . Optionally, the supporting wall  312  extends from a periphery of the plate body  311  along a vibration direction of the vibration system  2  and is spaced apart from the main body part  41 , thereby providing support for the yoke  31  in the vibration direction and further reducing the risk of separation between the yoke  31  and the bottom wall  11  during dropping. 
     Optionally, the supporting wall  312  includes a plurality of sub walls  3120  spaced apart from each other. The frame  1  is made of a metal material, so that the sub walls  3120  can be fixed to the bottom wall  11  by welding. In this way, it can effectively save space. The amount of the sub walls  3120  can be four. The plate body  311  is in a rectangular shape. The four sub walls  3120  bend and extend from four sides of the plate body  311  respectively. In other embodiments, the supporting wall  312  may be an integral ring structure bending and extending from the plate body  311 . 
     It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms where the appended claims are expressed.