Patent Publication Number: US-11032648-B2

Title: Electroacoustic sound generator

Description:
FIELD OF THE PRESENT DISCLOSURE 
     The present disclosure relates to the field of electro-magnetic transducers, more particularly to an electroacoustic sound generator having an improved front cover. 
     DESCRIPTION OF RELATED ART 
     An electroacoustic sound generator, also named sound generator or speaker, is a very important component equipped in a mobile phone for producing audible sounds. A speaker generally uses a diaphragm to produce vibration and further to generate sounds. In a related sound generator, a frame with an accommodation space is provided to receive a vibration system and to engage with a front cover located above the frame. The vibration system includes a diaphragm. An engaging surface between the front cover and the diaphragm is a planar plane. When the front cover is engaged with the diaphragm by pressing glue disposed therebetween, excessive glue will overflow from the engaging surface, and further adhere some unexpected parts with each other, which badly affect the sound generator and lower the acoustic performance of the sound generator. 
     Therefore, an improved electroacoustic sound generator which cn solve the above-mentioned problems is desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the exemplary embodiment 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 and exploded view of an electroacoustic sound generator in accordance with an exemplary embodiment of the present disclosure. 
         FIG. 2  is an isometric view of the sound generator in  FIG. 1 . 
         FIG. 3  is a cross-sectional view of the sound generator taken along line A-A in  FIG. 1   
         FIG. 4  is an isometric view of a front cover of the sound generator. 
         FIG. 5  is a cross-sectional view of the front cover taken along line B-B in  FIG. 4 . 
         FIG. 6  is an isometric view of a suspension of the sound generator. 
         FIG. 7  is an isometric view of a frame of the sound generator. 
         FIG. 8  is an enlarged view of Part C in  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     The present disclosure will hereinafter be described in detail with reference to an exemplary embodiment. To make the technical problems to be solved, technical solutions and beneficial effects of the present disclosure more apparent, the present disclosure is described in further detail together with the figure and the embodiment. It should be understood the specific embodiment described hereby is only to explain the disclosure, not intended to limit the disclosure. 
     Referring to  FIGS. 1-8 , the present disclosure provides an electroacoustic sound generator (hereinafter “sound generator”) including a frame  1  with an accommodation space, a vibration system  2  received in the accommodation space, a magnetic circuit system  3  received in the accommodation space, a front cover  4  located above the front cover  4 , and a plurality of conductive terminals  5  assembled with the frame  1 . 
     The frame  1  includes an inner side  11  for bounding the accommodation space, an outer side  12  opposite to the inner side and away from a geometric center of the accommodation space, and an upper side  13  for connecting the inner side  11  and the outer side  12 . 
     The vibration system  2  includes a diaphragm  21  and a coil assembly  22  for driving the diaphragm  21  to vibrate for generating sound. The coil assembly  22  is electrically connected to the conductive terminals. 
     The diaphragm  21  includes a suspension  212  and a dome  211  attached to the suspension  212 . The suspension  212  includes a middle portion  2121  connecting to the some  211 , a suspending portion  2122  extending from and surrounding the middle portion  2121 , and positioning portion  2123  extending outwardly from and surrounding the suspending portion  2122 . The positioning portion  2123  is sandwiched between the upper side  13  of the frame  1  and the front cover  4 . 
     The magnetic circuit system  3  includes an upper plate  31 , a magnetic yoke  32 , and a magnet  33  carried by the magnetic yoke  32 . The magnet  33  and the magnetic yoke  32  cooperatively form a magnetic gap for partially receiving the coil assembly  22 . When electrified, the coil assembly  22  interacts with the magnetic field produced in the magnetic gap, and is forced to vibrate due to the Ampere Force. The vibration of the coil assembly  22  drives the diaphragm  21  to vibrate for generating and radiating sound. The upper plate  31  is attached to a top of the magnet  33 , and is made from magnetic conductive materials, for gathering the magnetic flux and improving the magnetic induction performance. 
     The front cover  4  includes a cover body  42  opposite to the middle portion  2121 , and an adhering portion  41  extending from and surrounding the cover body  42 . The front cover  4  further includes a thickened layer  411  extending from the adhering portion  41  along a direction toward the frame  1 . The thickened layer  411  connects to the positioning portion  2123 . The positioning portion  2123  is sandwiched between the upper side  13  of the frame and the adhering portion  41 . In the actual production process, the processing method of the thickened layer  411  includes the steps: stick the thickened layer material to the adhering portion with equal material thickness, and then press or extrude the stacked material to form the thickened layer with the required thickness and edge width through the a die. The thickness of the thickening layer and the width of the edge depend on the requirement of the whole structure design of the sound generator. In fact, it may also be changed during upsetting or extrusion process due to the amount of force applied to the die. 
     As an option, a hardness of the front cover  4  is 150-200 HV. More specifically, the front cover is made of soft stainless steel with hardness 150-200 HV. It will be easier to manufacture the front cover if the material of the front cover has lower hardness. 
     The thickened layer  411  includes a first side  4111  surrounding the adhering portion  41 , and a second side  4112  opposite to the first side  4111  and adjacent to a geometric center of the adhering portion  41 . The first side  4111  is coplanar with the outer side  12  of the frame  1 , and the second side  4112  is coplanar with the inner side  11  of the frame  1 . 
     The thickened layer  411  has a projection on the top side  13  of the frame  1  partially overlapping with a projection of the positioning portion  2123  on the top side  13  of the frame  1 . Preferably, the thickened layer  411  engages with the positioning portion  2123  at stagger positions, by virtue of which, overflowing space for the glue is formed. Thus, the glue for engaging the thickened layer  411  and the positioning portion  2123  is prevented from overflowing out of the thickened layer  411  and the positioning portion  2123 . 
     Alternatively, the positioning portion  2123  further includes a connecting end portion  2123   a  connecting to the suspending portion  2122 , and a free end portion  2123   b  surrounding the connecting end portion  2123   a . The connecting end portion  2123   a  is suspended between the frame  1  and the adhering portion  41 , and the free end portion  2123   b  is sandwiched between the top side  13  of the frame and the thickened layer  411 . 
     The free end portion  2123   b , the top side  13  of the frame  1 , and the thickened layer  411  cooperatively form a semi-sealed first receiving space  811 ; the connecting end portion  2123   a , the second side  4112  of the thickened layer  411 , and the adhering portion  41  cooperatively form a semi-sealed second receiving space  82 . When the thickened layer  411  is adhered with the positioning portion  2123 , excessive glue first flows into the first and second receiving spaces  81 ,  82 , which effectively avoid the overflow, and improves the acoustic performance of the sound generator. 
     The front cover  4  further includes a sound outlet  421  formed in the cover body  42 . For achieving dust-proof performance, the sound generator further includes a metal plate  6  and a permeable isolator  7  corresponding to the sound outlet  421 . The permeable isolator  7  is disposed above the sound outlet  421 , and the metal plate  6  is sandwiched between the permeable isolator  7  and the cover body  42  of the front cover  4 . 
     The adhering portion of the electroacoustic sound generator provided by the present disclosure, for engaging the front cover and the diaphragm, includes the thickened layer for coupling with the diaphragm, which effectively avoid the glue from overflowing. The hardness of the adhering portion is 150˜200 HV, which makes it easier to manufacture the thickened layer. 
     It is to be understood, however, that even though numerous characteristics and advantages of the present exemplary embodiment have been set forth in the foregoing description, together with details of the structures and functions of the embodiment, 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 invention to the full extent indicated by the broad general meaning of the terms where the appended claims are expressed.