Patent Publication Number: US-2021180696-A1

Title: Sealing plug

Description:
TECHNICAL FIELD 
     The present disclosure relates to a sealing plug, and in particular, to a sealing plug for use in a vehicle. 
     BACKGROUND 
     In vehicles, especially in vehicles using batteries as driving energy sources, there is a need for a sealing plug to separate a space where the batteries are placed from a space inside a vehicle compartment. 
     SUMMARY OF THE DISCLOSURE 
     Exemplary embodiments of the present disclosure can solve at least some technical problems in the prior art. For example, the present disclosure provides a sealing plug for sealing a hole in a panel. The sealing plug comprises a plug body, a support portion arranged around central axis of the plug body, at least two holding arms and a sealing portion. Each of the at least two holding arms extends downward from the bottom of the support portion of the plug body and has a holding portion. The holding portions extend obliquely downward in a direction away from the central axis. The sealing portion is arranged on an outer edge of the support portion of the plug body. The plug body is made of a metal material, and the sealing portion is made of a material with a melting point lower than that of the metal material. 
     In the sealing plug according to the present disclosure, the sealing plug is configured such that when the sealing plug is mounted in the hole in the panel, the holding portions of the at least two holding arms are located below the panel, the support portion and the sealing portion are located above the panel, and the sealing portion comes into contact with the panel such that the hole is sealed by the sealing plug. 
     In the sealing plug according to the present disclosure, the sealing portion is made of a flexible material. 
     In the sealing plug according to the present disclosure, the sealing portion is made of rubber or plastics. 
     In the sealing plug according to the present disclosure, the sealing portion is made of an ethylene-vinyl acetate copolymer. 
     In the sealing plug according to the present disclosure, the at least two holding arms respectively have root portions connected to the support portion, and a distance r from the root portions to the central axis is less than a radius R of the hole of the panel. 
     In the sealing plug according to the present disclosure, the support portion of the plug body comprises a support body portion and the outer edge, and the outer edge is arranged around the support body portion. The outer edge comprises at least two first outer edge portions and at least two second outer edge portions. The at least two first outer edge portions extend obliquely outward and downward from the support body portion. The at least two second outer edge portions are arranged to separate the at least two first outer edge portions and extend in an extending direction of the support body portion, wherein the at least two holding arms are respectively arranged corresponding to the at least two second outer edge portions. 
     In the sealing plug according to the present disclosure, a lowest position of a free end of each of the at least two first outer edge portions is located in the same plane as a lower surface of each of the at least two second outer edge portions. 
     In the sealing plug according to the present disclosure, the plug body further comprises an insertion portion, which extends downward from the support portion, the support portion is arranged around the insertion portion, the at least two holding arms are arranged around the insertion portion, and the insertion portion is configured to be insertable into the hole of the panel. 
     In the sealing plug according to the present disclosure, the plug body is integrally formed from sheet metal. 
     In the sealing plug according to the present disclosure, the at least two holding arms comprise two holding arms, which are symmetrically arranged with respect to the central axis of the plug body. 
     In the sealing plug according to the present disclosure, the at least two holding arms comprise four holding arms, which are uniformly arranged in a circumferential direction of the plug body. 
     The sealing plug according to the present disclosure can seal a hole in a panel, and the hole can be substantially sealed by the plug body even when the ambient temperature is relatively high. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the present disclosure may be better understood by reading the following detailed description with reference to the accompanying drawings. The same reference numerals represent the same components throughout the accompanying drawings, in which: 
         FIG. 1A  is a perspective view of an embodiment of a sealing plug according to the present disclosure viewed from top to bottom; 
         FIG. 1B  is a perspective view of the sealing plug shown in  FIG. 1A  viewed from bottom to top; 
         FIG. 1C  is an exploded view of the sealing plug shown in  FIG. 1A ; 
         FIG. 2A  is a perspective view of a plug body of the sealing plug shown in  FIG. 1C  viewed from top to bottom; 
         FIG. 2B  is a perspective view of the plug body of the sealing plug shown in  FIG. 1C  viewed from bottom to top; 
         FIG. 3A  is a front view of the sealing plug shown in  FIG. 1A ; 
         FIG. 3B  is a side view of the sealing plug shown in  FIG. 1A ; 
         FIG. 3C  is a cross-sectional view of the sealing plug shown in  FIG. 3A  taken along a line  3 C- 3 C in  FIG. 3A ; 
         FIG. 3D  is a cross-sectional view of the sealing plug shown in  FIG. 3B  taken along a line  3 D- 3 D in  FIG. 3B ; 
         FIG. 4A  is an assembly view sealing plug, wherein the sealing plug is mounted in a panel; 
         FIG. 4B  is a exploded view of the sealing plug and the panel shown in  FIG. 4A ; 
         FIG. 5A  shows a cross-sectional view of the sealing plug when being placed above the panel taken along a line  5 A- 5 A in  FIG. 4B ; 
         FIG. 5B  shows a cross-sectional view of the sealing plug of  FIG. 5A  having a first holding arm and a second holding arm of the sealing plug coming into contact with a wall of a hole of the panel but not being deformed; 
         FIG. 5C  shows a cross-sectional view of the the sealing plug of  FIG. 5A , the first holding arm and the second holding arm of the sealing plug coming into contact with the wall of the hole of the panel and being deformed; 
         FIG. 5D  shows a cross-sectional view of the sealing plug of  FIG. 5A , wherein the sealing plug is mounted on the panel and held in place; 
         FIG. 6  is a cross-sectional view of another embodiment of a sealing plug according to the present disclosure; and 
         FIG. 7  is a perspective view of yet another embodiment of a sealing plug according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Various specific embodiments of the present disclosure are described below with reference to the accompanying drawings which constitute part of this description. It should be understood that although the terms, such as “upper”, “lower”, “top”, “side” and “bottom”, indicating orientations are used in the present disclosure to describe various exemplary structural parts and elements in the present disclosure, these terms are merely used herein for ease of illustration, and are determined based on the exemplary orientations as shown in the accompanying drawings. Since the embodiments disclosed in the present disclosure can be arranged in different directions, these terms indicating directions are only illustrative and should not be considered as limitations. In the following accompanying drawings, the same reference numerals are used for the same components, and similar reference numerals are used for similar components. 
       FIG. 1A  is a perspective view of an embodiment of a sealing plug according to the present disclosure viewed from top to bottom;  FIG. 1B  is a perspective view of the sealing plug  100  shown in  FIG. 1A  viewed from bottom to top; and  FIG. 1C  is an exploded view of the sealing plug  100  shown in  FIG. 1A , these figures show the specific structure of the sealing plug  100 . As shown in  FIGS. 1A-1C , the sealing plug  100  comprises a plug body  102 , a first holding arm  106 , a second holding arm  107 , and a sealing portion  104 . The first holding arm  106  and the second holding arm  107  extend downward from the bottom of a support portion  218  (as shown in  FIGS. 2A and 2B ) of the plug body  102 . The sealing portion  104  is annular and is disposed on an outer edge  222  of the support portion  218  of the plug body  102  (see  FIGS. 2A and 2B ). Specifically, the sealing portion  104  surrounds and wraps around the outer edge  222  of the support portion  218  of the plug body  102 . 
       FIG. 2A  is a perspective view of the plug body  102  of the sealing plug  100  shown in  FIG. 1A  viewed from top to bottom; and  FIG. 2B  is a perspective view of the plug body  102  shown in  FIG. 1A  viewed from bottom to top, these figures show the specific structure of the plug body  102 . As shown in  FIGS. 2A and 2B , the plug body  102  is substantially in the shape of a bowl with a central axis X. The plug body  102  comprises the support portion  218  and an insertion portion  250  extending downward from the support portion  218 . The support portion  218  is arranged around the insertion portion  250 , the insertion portion  250  is generally in the shape of a cylinder with a closed bottom and an open top, and the support portion  218  and the insertion portion  250  form the bowl-shaped plug body  102  together. Specifically, the insertion portion  250  comprises a bottom plate  212 , an inclined portion  214 , and a side wall  216  which are sequentially arranged from top to bottom. The bottom plate  212  is substantially circular. The inclined portion  214  is arranged around a lateral edge of the bottom plate  212  and extends upward and outward by a certain distance. The side wall  216  is arranged around an upper edge of the inclined portion  214  and extends upward by a certain distance. 
     The support portion  218  comprises a support body portion  260  and an outer edge  222  arranged around the support body portion  260 . The outer edge  222  of the support portion  218  is the outer edge  222  of the plug body  102 . The support body portion  260  is arranged around the top of the side wall  216  and extends outward by a certain distance in a direction generally perpendicular to the central axis X of the plug body  102 . The outer edge  222  is arranged around the support body portion  260 . 
     The outer edge  222  of the plug body  102  comprises two first outer edge portions  204 ,  205  and two second outer edge portions  208 ,  209 . The first outer edge portion  204  and the first outer edge portion  205  are respectively disposed between the second outer edge portion  208  and the second outer edge portion  209 . In other words, the two first outer edge portions  204 ,  205  and the two second outer edge portions  208 ,  209  are arranged separately with respect to each other. The specific structures of the two first outer edge portions  204 ,  205  and the two second outer edge portions  208 ,  209  will be described below with reference to  FIGS. 3A-3D . 
       FIG. 3A  is a front view of the sealing plug  100  shown in  FIG. 1 , and  FIG. 3B  is a side view of the sealing plug  100  shown in  FIG. 1 , these figures show the relative positional relationship between the sealing portion  104 , the insertion portion  250  of the plug body  102  and the two holding arms  106 ,  107 .  FIG. 3C  is a cross-sectional view of the sealing plug shown in  FIG. 3A  along a line A-A in  FIG. 3A , and  FIG. 3D  is a cross-sectional view of the sealing plug shown in  FIG. 3B  along a line B-B in  FIG. 3B , these figures show details of the sealing plug  100 . In the orientation shown in  FIGS. 3A-3D , the central axis X of the plug body  102  extends generally in a vertical direction, and the support body portion  260  extends generally in a horizontal direction. The following description of the structure of the sealing plug  100  takes the above orientation as a reference direction, so as to make the description clearer. 
     As shown in  FIGS. 3A-3D , the two first outer edge portions  204 ,  205  of the plug body  102  respectively extend obliquely outward and downward from the support body portion  260  by a certain distance. Free ends  332 ,  333  of the two first outer edge portions  204 ,  205  are lowest ends of the two first outer edge portions  204 ,  205 , and the free ends  332 ,  333  are located in the same horizontal plane. 
     As shown in  FIGS. 3A-3D , the first holding arm  106  and the second holding arm  107  respectively extend downward from the bottom of the support portion  218  of the plug body  102 , and are symmetrically arranged with respect to the central axis X of the plug body. Specifically, the first holding arm  106  comprises a root portion  310 , a vertical portion  312 , a holding portion  314 , and a retract portion  316 . The root portion  310 , the vertical portion  312 , the holding portion  314 , and the retract portion  316  are sequentially connected to one another. The root portion  310  is connected to the bottom of the support portion  218 , and the vertical portion  312  extends vertically downward from the root portion  310  by a certain distance. The holding portion  314  extends downward and outward by a certain distance from the bottom of the vertical portion  312 , such that the holding portion  314  is bent outward relative to the vertical portion  312  in a direction away from the central axis X. The retract portion  316  extends downward and inward from the bottom of the holding portion  314  by a certain distance, such that the retract portion  316  is bent inward relative to the holding portion  314  in a direction toward the central axis X. The second holding arm  107  has the same structure as the first holding arm  106 . Specifically, the second holding arm  107  comprises a root portion  311 , a vertical portion  313 , a holding portion  315 , and a retract portion  317 . The root portion  311 , the vertical portion  313 , the holding portion  315 , and the retract portion  317  are sequentially connected to one another. The root portion  311  is connected to the bottom of the support portion  218 , and the vertical portion  313  extends vertically downward from the bottom of the plug body  102  by a certain distance. The holding portion  315  extends downward and outward by a certain distance from the bottom of the vertical portion  313 , such that the holding portion  315  is bent outward relative to the vertical portion  313  in a direction away from the central axis X. The retract portion  317  extends downward and inward from the bottom of the holding portion  315  by a certain distance, such that the retract portion  317  is bent inward relative to the holding portion  315  in a direction toward the central axis X. A distance from the root portions  310 ,  311  of the first holding arm  106  and the second holding arm  107  to the central axis X is r. A distance from lowest ends of the retract portion  316  and the retract portion  317  to the central axis X is r 1 . A distance from bottoms of the holding portion  314  and the holding portion  315  (i.e., parts of the holding portions  314 ,  315  that are connected to the retract portions  316 ,  317 ) to the central axis X is r 2 , wherein, r is less than r 2 , and r 1  is less than r 2 . 
     The arrangement of the holding portions  314 ,  315  enables the sealing plug  100  to be held in a hole  406  of a panel  402  by means of the holding portions  314 ,  315  (as shown in  FIG. 5D ). The arrangement of the retract portions  316 ,  317  enables the two holding arms  106 ,  107  to deform toward the central axis X without the need for manual compressing, so that the holding portions  314 ,  315  can pass through the hole  406 . The retract portions and the holding portions together form a bent shape, which can help to enhance a holding force of the holding portions  314 ,  315  when the sealing plug  100  is mounted in place. 
     As shown in  FIG. 3D , the holding portions  314 ,  315  and the retract portions  316 ,  317  of the two holding arms  106 ,  107  directly face the inclined portion  214  of the insertion portion  250  of the plug body  102 . Due to the arrangement of the inclined portion  214 , the two holding arms  106 ,  107  have a larger deformation space, which makes it easier to insert the sealing plug  100 . 
     The two second outer edge portions  208 ,  209  respectively extend outward by a certain distance in the extending direction of the support body portion  260  of the support portion  218 , namely, the horizontal direction shown in the figures. The two first outer edge portions  204 ,  205  and the two second outer edge portions  208 ,  209  are arranged such that a lowest position of the free end  332  (i.e., the distal end) of the first outer edge portion  204 , a lowest position of the free end  333  (i.e., the distal end) of the first outer edge portion  205 , a lower surface  334  of the second outer edge portion  208  and a lower surface  335  of the second outer edge portion  209  are located in the same horizontal plane. 
     The sealing portion  104  is annular-shaped and wraps around the outer edge  222  of the plug body  102 . In an embodiment of the present disclosure, the sealing portion  104  fully wraps around the two first outer edge portions  204 ,  205  and the two second outer edge portions  208 ,  209 . The sealing portion  104  may be made of a flexible material with a melting point lower than that of a metal. For example, the sealing portion  104  may be made of rubber or plastics. More specifically, the sealing portion  104  may be made of an ethylene-vinyl acetate copolymer. As an example, the sealing portion  104  may be connected to the outer edge  222  of the plug body  102  by means of injection molding. 
     In an embodiment of the present disclosure, the plug body  102 , the first holding arm  106  and the second holding arm  107  may be formed from a metal plate by means of sheet metal stamping, cutting, bending and other processes. The specific formation process is as follows, for example: first, an insertion portion  250  of a plug body  102  is formed by stamping a notch on a metal plate by using a stamping process. Subsequently, a metal plate zone around the top of the insertion portion  250  is selected as a support body portion  260  of a support portion  218 , then the metal plate around an outer periphery of the support body portion  260  is cut into four portions, wherein two opposite portions are used to form first outer edge portions  204 ,  205 , and the other two opposite portions are used to form second outer edge portions  208 ,  209 , a first holding arm  106  and a second holding arm  107 . The two metal plate portions, which form the second outer edge portions  208 ,  209 , the first holding arm  106  and the second holding arm  107 , are firstly trimmed to have appropriate lengths, and then form the first holding arm  106 , the second holding arm  107  and the second outer edge portions  208 ,  209  shown in figures by using a bending process. The two metal plate portions, which form the first outer edge portions  204 ,  205 , are firstly trimmed to have an appropriate length, and are then bent downward to form the inclined first outer edge portions  204 ,  205 . Since the second outer edge portions  208 ,  209  are as thick as two layers of metal plates while the first outer edge portions  204 ,  205  are only as thick as one layer of metal plate, with the inclination of the first outer edge portions  204 ,  205 , a lowest position of the free end  332  (i.e., the distal end) of the first outer edge portion  204 , a lowest position of the free end  333  (i.e., the distal end) of the first outer edge portion  205 , a lower surface  334  of the second outer edge portion  208  and a lower surface  335  of the second outer edge portion  209  can be located in the same horizontal plane. 
       FIG. 4A  is an assembly view of the sealing plug  100 , wherein the sealing plug  100  is mounted in the panel  402 ; and  FIG. 4B  is an exploded view corresponding to the assembly view shown in  FIG. 4A . As shown in  FIGS. 4A and 4B , the panel  402  has a circular hole  406 . The hole  406  has a wall  410 . The sealing plug  100  is positioned above the panel  402  and moved downward, then inserted into the hole  406 , and held in place. The process of mounting the sealing plug  100  to the panel  402  will be described in detail with reference to  FIGS. 5A-5D . 
       FIGS. 5A-5D  are cross-sectional views of the sealing plug  100  at different relative positions in the process of being mounted on the panel  402 .  FIG. 5A  shows a cross-sectional view of the sealing plug  100  when being placed above the panel  402 , to show the relative size relationship between the sealing plug  100  and the hole  406  in the panel  402 . Specifically, the radius of the hole  406  is R. The radius R of the hole  406  is greater than the distance r 1  from the lowest end of the retract portion  317  to the central axis X, and the radius R of the hole  406  is less than the distance r 2  from the bottom of the holding portion  315  (i.e. the part of the holding portion  315  that is connected to the retract portion  317 ) to the central axis X. That is to say, in the embodiments shown in  FIGS. 5A-5D , the distance  2   r   1  between lowest ends of the retract portions  316 ,  317  of the two holding arms is less than the diameter  2 R of the hole  406 , so that the lowest ends of the retract portions  316 ,  317  can be inserted into the hole  406  even in a free state without force application. On the other hand, the distance  2   r   2  between the lowest ends of the holding portions  314 ,  315  of the two holding arms is greater than the diameter  2 R of the hole  406 . Therefore, the holding portions  314 ,  315  of the two holding arms need to be deformed by force before being inserted into the hole  406 . 
       FIG. 5B  shows a cross-sectional view of the retract portion  316  of the first holding arm  106  and the retract portion  317  of the second holding arm  107  of the sealing plug  100  when coming into contact with the wall  410  of the hole  406  of the panel  402  but not being subjected to an external force. As shown in  FIG. 5B , the sealing plug  100  continues to move downward, the lowest ends of the retract portions  316 ,  317  of the two holding arms  106 ,  107  are inserted into the hole  406 , and the retract portions  316 ,  317  then come into contact with the wall  410  of the hole  406 . 
       FIG. 5C  shows a cross-sectional view of the retract portion  316  of the first holding arm  106  and the retract portion  317  of the second holding arm  107  of the sealing plug  100  when coming into contact with the wall  410  of the hole  406  of the panel  402  and being subjected to an external force. As shown in  FIG. 5C , as the sealing plug  100  continues to move downward, the retract portions  316 ,  317  are subjected to the inward external force exerted by the panel  402 . This external force causes the retract portions  316 ,  317  of the two holding arms to deform together with the holding portions  314 ,  315 , and this deformation causes the two holding arms to move toward the central axis X as a whole. When the first holding arm  106  and the second holding arm  107  are deformed such that the distance  2   r   2  between the lowest ends of the deformed holding portions  314  and  315  is generally equal to the radius R of the hole  406 , the bent shape formed by the holding portions and the retract portions of the first holding arm  106  and the second holding arm  107  can pass through the hole  406 , such that the lowest ends of the holding portion  314  and the holding portion  315  reach below the hole  406 . 
       FIG. 5D  shows a cross-sectional view of the sealing plug  100 , wherein the sealing plug  100  is mounted on the panel  402  and held in place. As shown in  FIG. 5D , after the holding portion  314  and the holding portion  315  of the first holding arm  106  and the second holding arm  107  reach below the hole  406 , the distance  2   r  between the root portions  310 ,  311  of the first holding arm  106  and second holding arm  107  is less than the diameter  2 R of the hole  406 , so the sealing plug  100  can continue to move downward, and since the wall  410  of the hole  406  no longer exerts an external force to the first holding arm  106  and the second holding arm  107 , the first holding arm  106  and the second holding arm  107  return to their initial states (i.e., not being deformed). The sealing plug  100  continues to move downward until the bottom of the sealing portion  104  comes into contact with the panel  402 . In this case, the lowest ends of the holding portions  314 ,  315  and the retract portions  316 ,  317  of the first holding arm  106  and the second holding arm  107  are located below the panel  402 , and the sealing portion  104  is located above the panel  402 . 
     Subsequently, an operator may heat the sealing portion  104  using a heating component (not shown), such that the sealing portion  104  is melted and adhered to an upper surface of the panel  402 . This enables the sealing plug  100  and the panel  402  to be connected to each other, and the hole  406  is sealed by the plug body  102  of the sealing plug  100 . 
     The plug body  102 , the first holding arm  106  and the second holding arm  107  of the sealing plug  100  of the present disclosure are formed by means of sheet metal stamping and bending, which can simplify the machining process and reduce manufacturing costs. In addition, metal can provide high heat resistance, so that it is ensured that when the sealing plug  100  experiences a relatively high temperature, even if the sealing portion  104  in the sealing plug  100  is vaporized due to the high temperature, the support portion  218  of the plug body  102  can still cover the hole  406  of the panel  402 , and high sealing performance can also be ensured. Specifically, when the environment where the sealing plug  100  is located is at a relatively high temperature, the sealing portion  104  may be melted and vaporized, and the sealing portion  104  disappears. Since the shortest distance r 3  from the outer edge  222  of the plug body  102  to the central axis X is greater than the radius R of the hole  406 , the first outer edge portions  204 ,  205  and the two second outer edge portions  208 ,  209  of the plug body  102  can be overlapped on the upper surface of the panel  402 , to prevent the sealing plug  100  from escaping from the hole  406 . Since the lowest position of the free end  332  (i.e., the distal end) of the first outer edge portion  204 , the lowest position of the free end  333  (i.e., the distal end) of the first outer edge portion  205 , the lower surface  334  of the second outer edge portion  208  and the lower surface  335  of the second outer edge portion  209  are located in the same horizontal plane (see  FIGS. 3A-3C ), the first outer edge portions  204 ,  205  and the second outer edge portions  208 ,  209  can both come into contact with the upper surface of the panel  402 , and all the portions of the outer edge  222  of the plug body  102  can come into contact with the upper surface of the panel  402 , so that a sealing ring can also be formed by the outer edge  222  of the plug body  102 , thus the plug body  102  can seal the hole  406 . Therefore, the sealing plug  100  of the present disclosure can well adapt to a high-temperature working environment, and can implement the function of sealing the hole  406  of the panel even if the ambient temperature becomes high. 
     It needs to be noted that since, in the embodiment of the present disclosure, the plug body  102 , the first holding arm  106  and the second holding arm  107  are formed from a metal plate by means of sheet metal stamping, cutting, bending and other processes, the second outer edge portions  208 ,  209  are as thick as two layers of metal plates and the first outer edge portions  204 ,  205  are only as thick as one layer of metal plate. Therefore, the first outer edge portions  204 ,  205  are obliquely arranged such that the lowest position of the free end  332  (i.e., the distal end) of the first outer edge portion  204 , the lowest position of the free end  333  (i.e., the distal end) of the first outer edge portion  205 , the lower surface  334  of the second outer edge portion  208  and the lower surface  335  of the second outer edge portion  209  are located in the same horizontal plane. Those skilled in the art can understand that in other embodiments, the sealing plug in the embodiment of the present disclosure may not be formed by means of sheet metal stamping, cutting, bending and other processes, so that the first outer edge portions  204 ,  205  and the second outer edge portions  208 ,  209  in the sealing plug may form a continuous outer edge, may be configured to have the same thickness, and may be planar or be obliquely arranged such that the lowest positions of the lower surfaces of the outer edges (i.e., the first outer edge portions  204 ,  205  and the second outer edge portions  208 ,  209 ) of the support portion  218  are located in the same plane. Therefore, when the sealing portion  104  disappears, the lower surface of the outer edge  222  can abut against the panel  402 , so as to seal the hole  406  of the panel  402  by means of the outer edge  222  of the support portion  218 . 
       FIG. 6  is a cross-sectional view of another embodiment of a sealing plug  600  according to the present disclosure. The structure of the sealing plug  600  shown in  FIG. 6  is substantially the same as that of the sealing plug  100  shown in  FIG. 5D , and the similarities will not be repeated. This sealing plug differs from the sealing plug  100  shown in  FIG. 5D  in that a first holding arm  106  and a second holding arm  107  of the sealing plug  600  are configured such that when the sealing plug  600  is mounted to the panel  402  and held in place (i.e., a sealing portion  104  of the sealing plug  600  comes into contact with the panel  402 ), the first holding arm  106  and the second holding arm  107  are still in a deformed state. In this case, the wall  410  of the hole  406  still exerts an inward external force on the first holding arm  106  and the second holding arm  107 , such that the panel  402  is clamped by the first holding arm  106  and the sealing portion  104 , and by the second holding arm  107  and the sealing portion  104 . With this clamping configuration, the sealing plug  600  can be fixed in the hole  406  more securely because metal can provide stronger rigidity and deformability. Therefore, compared with the sealing plug  100  shown in  FIG. 5D , the first holding arm  106  and the second holding arm  107  of the sealing plug  600  shown in  FIG. 6  have different dimensions. For example, compared with  FIG. 5D , vertical portions  312 ,  313  of the two holding arms  106 ,  107  of the sealing plug  600  shown in  FIG. 6  are set to be shorter. As another example, compared with  FIG. 5D , inclination angles of the holding portions  314 ,  315  of the two holding arms  106 ,  107  of the sealing plug  600  relative to the vertical portions  312 ,  313  shown in  FIG. 6  are set to be larger. 
       FIG. 7  is a cross-sectional view of yet another embodiment of a sealing plug  700  according to the present disclosure. The structure of the sealing plug  700  shown in  FIG. 7  is substantially the same as that of the sealing plug  100  shown in  FIG. 1 , and the similarities will not be repeated. The sealing plug shown in  FIG. 7  differs from the sealing plug  100  shown in  FIG. 1  in that the sealing plug  700  comprises four holding arms  701 ,  702 ,  703 ,  704 , four first outer edge portions (not shown), and four second outer edge portions (not shown). The four holding arms  701 ,  702 ,  703 ,  704  are uniformly arranged in a circumferential direction of the plug body  102 . Each of the four first outer edge portions is disposed above a corresponding one of the four holding arms  701 ,  702 ,  703 ,  704 . The four second outer edge portions are arranged between the four first outer edge portions. In other words, the four second outer edge portions and the four first outer edge portions are arranged separately with respect to each other. When an operator presses the sealing plug  700  into the hole  406 , the four holding arms  701 ,  702 ,  703 ,  704  can better disperse the external force exerted by the wall  410  of the hole  406  on the holding arms, so that the sealing plug  700  has better stability. 
     Although a sealing plug with two holding arms or four holding arms is shown in the present disclosure, it can be understood by those skilled in the art that sealing plugs with at least two holding arms fall within the scope of protection of the present disclosure. In addition, the number of the first outer edge portions and the number of the second outer edge portions are the same as the number of the holding arms, and the first outer edge portions and the second outer edge portions are arranged separately with respect to each other. For example, it is also possible to provide three holding arms, which are uniformly arranged in a circumferential direction of the plug body, and to provide three first outer edge portions arranged corresponding to the three holding arms on a one-to-one basis, and second outer edge portions arranged between every two adjacent first outer edge portions. 
     Although only some features of the present disclosure are illustrated and described herein, those skilled in the art may make various improvements and changes. Therefore, it should be understood that the appended claims intend to cover all the foregoing improvements and changes that fall within the substantial spirit and scope of the present disclosure.