CN209807156U - Initiative oil feed formula electron atomizing cigarette bullet based on miniature liquid pump - Google Patents

Abstract

The utility model belongs to the technical field of the electron cigarette technique and specifically relates to an initiative fuel feeding formula electronic atomization cigarette bullet based on miniature liquid pump, including sealed complex shell and base, shell integrated into one piece has suction nozzle and trachea, be equipped with a mount pad in the shell, the sealed smoke cavity that forms in mount pad upper end shaping sleeve pipe top, the mount pad lower extreme forms the atomizer chamber with the base cooperation, miniature liquid pump is installed to one side of mount pad, the ceramic heat-generating body is installed to the bottom of mount pad, miniature liquid pump and tobacco tar chamber intercommunication, trachea and atomizer chamber intercommunication, tobacco tar in the tobacco tar chamber is through the heating surface of miniature liquid pump pressure transport to ceramic heat-generating body, tobacco tar sees through the atomizing of ceramic heat-generating body and gets into the atomizer chamber, in the suction process, form the negative pressure in the atomizer chamber, the air gets into the atomizer chamber under the negative pressure effect, send into along the trachea with the aerosol that the tobacco tar atomizing produced, the utility model discloses can solve the fuel feeding that the uncontrollable fog fuel feeding The problems of frying oil and oil leakage caused by dry burning and excessive oil supply of the chemical equipment.

Description

Initiative oil feed formula electron atomizing cigarette bullet based on miniature liquid pump

Technical Field

The utility model relates to an electron cigarette technical field, concrete field is an initiative oil feed formula electron atomizing cigarette bullet based on miniature liquid pump.

Background

The existing oil supply mode of the electronic cigarette cartridge can be mainly divided into a negative pressure mode and a contact mode, wherein the negative pressure type oil supply is passive oil guide, the atomizer works to generate steam, the steam is pumped out to form negative pressure in the atomizing chamber, and oil guide is started, and the oil supply mode easily causes that the atomizer cannot supply oil to form dry burning; the contact type oil supply is carried out no matter whether the atomizer works or not, the oil supply is carried out, the oil supply mode easily causes excessive oil supply, the phenomenon of oil frying occurs when the atomizer generates heat and is heated, if the atomizer is poor in sealing, the phenomenon of oil leakage occurs in the suction process, and the taste is influenced.

The cigarette atomizer with the T-shaped air passage and the electronic cigarette provided with the same described in CN108283331A are characterized in that the T-shaped air passage is designed at the tail of the main air passage of the traditional electronic cigarette product, the T-shaped top end is used for realizing shunting, the top end of the T-shaped air passage blocks condensed oil drops flying in the smoking process, and the oil drops are prevented from entering the mouth, so that the mode is tried to structurally avoid poor taste caused by oil leakage. But the problem of oil leakage commonly existing in the current market electronic cigarette is not fundamentally solved; the heating wire of "electronic atomization cigarette bullet" described in CN108272141A is wound on the oil guide body to form a heating body, and the tobacco tar in the tobacco tar cavity permeates into the heating area through the oil guide body to realize tobacco tar atomization, which is a relatively typical passive oil guide way in the commercially available electronic cigarette products. The phenomenon that oil supply is not in time easily occurs, so that the core is burnt, scorched flavor is generated in the pumping process, and the taste is influenced; the cigarette atomizer and the electronic cigarette provided with the same described in CN108272139A reduce the oil guiding rate by coating the oil guiding cotton outside the ceramic heater to prevent the oil supply from being excessive due to the direct contact between the smoke chamber and the ceramic atomizer, which also belongs to a passive oil guiding mode.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an initiative fuel feeding formula electronic atomization cigarette bullet based on miniature liquid pump to solve the problem of the oil burst and the oil leak that the atomizer dry combustion method that the fuel feeding that present cigarette bullet product fuel feeding volume is not controllable to appear and the fuel feeding leads to excessively leads to too little or untimely.

In order to achieve the above object, the utility model provides a following technical scheme: the utility model provides an initiative fuel feeding formula electron atomizing cigarette bullet based on miniature liquid pump, is including sealed complex shell and base, shell integrated into one piece suction nozzle and trachea, be equipped with a mount pad in the shell, the sealed smoke chamber that forms in mount pad upper end shaping sleeve pipe top, the mount pad lower extreme forms the atomizer chamber with the base cooperation, miniature liquid pump is installed to one side of mount pad, ceramic heat-generating body is installed to the bottom of mount pad, miniature liquid pump and smoke chamber intercommunication, trachea and atomizer chamber intercommunication, the tobacco tar of smoke intracavity are carried to the heating surface of ceramic heat-generating body through miniature liquid pump pressure, and the tobacco tar sees through ceramic heat-generating body atomizing and gets into the atomizer chamber, and the suction in-process forms the negative pressure in the atomizer chamber, and the air gets into the atomizer chamber under the negative pressure effect, send the aerosol that the tobacco tar atomizing produced into along the trachea into the mouth.

Preferably, the side of mount pad is equipped with miniature liquid pump installation face, the bottom of mount pad is equipped with ceramic heat-generating body holding tank, be equipped with inlet port, oil outlet and locating flange on the miniature liquid pump installation face, miniature liquid pump corresponds locating flange sets up the locating hole and the adaptation block in miniature liquid pump installation face, the influent stream mouth of miniature liquid pump with the inlet port switches on, the effluent stream mouth of miniature liquid pump with the oil outlet switches on, the oil guide hole has been seted up on the ceramic heat-generating body holding tank, inlet port and tobacco tar chamber intercommunication, oil outlet and oil guide hole intercommunication.

Preferably, concentric annular grooves are formed in the outer edges of the oil inlet hole and the oil outlet hole respectively, and sealing rings are arranged in the grooves.

Preferably, the electrodes at two ends of the micro-liquid pump are respectively led to the outer surface of a "C" type insulating outer covering plate through elastic conductors, 2 "L" type metal conductive foils are embedded in the outer surface of the "C" type insulating outer covering plate and are respectively contacted with the elastic conductors, and the "C" type insulating outer covering plate is clamped and mounted on the upper limiting surface and the lower limiting surface of the micro-liquid pump mounting surface of the mounting base.

Preferably, the heating surface of the ceramic heating body is used for silk-screen printing of the heating wire and the electrode, an oil guide groove is formed in the back surface of the heating surface, the groove depth is 0.1-0.2 mm, the projection of the groove surface of the oil guide groove on the heating surface covers the silk-screen printing area of the heating wire, the ceramic heating body is embedded into the heat insulation sealing sleeve, only the heating surface and the groove surface of the oil guide groove are exposed, and are matched and clamped with the ceramic heating body accommodating groove on the mounting seat, and the heating surface faces the atomizing chamber.

Preferably, the end face of the base is provided with 4 electrode column holes, the electrode column holes are respectively and hermetically provided with electrode columns, 2I-shaped electrode columns are respectively contacted with screen printing electrodes at two ends of the ceramic heating body, and the other 2 II-shaped electrode columns are respectively contacted with 2L-shaped metal conductive foils led out from electrodes at two ends of the miniature liquid pump.

Preferably, the end face of the base is provided with an air inlet hole at the central position of the heating surface facing the ceramic heating element.

Preferably, the top of the forming sleeve at the upper end of the mounting seat is compressed and sealed through the adaptation of the silica gel plug, a step hole is formed in the center of the silica gel plug, a liquid-proof and breathable film is applied to the step surface of the step hole, and the top of the silica gel plug is pressed onto the top wall of the shell.

Compared with the prior art, the beneficial effects of the utility model are that: the oil supply is carried out under the pressure of the micro liquid pump, the tobacco tar can be more stably, more quickly and more timely conveyed to the heating surface of the heating element, and meanwhile, the oil supply amount of the micro liquid pump is adjustable, so that the oil supply method belongs to an active oil supply mode, the dynamic balance of the tobacco tar supply consumption is realized by matching with the oil consumption of the ceramic heating element and simultaneously introducing a feedback mechanism, the tobacco tar is fully atomized, and the phenomena of dry burning and oil frying of the ceramic heating element caused by insufficient or insufficient oil supply or excessive oil supply are fundamentally avoided; simultaneously structural arranging the flue outside the oil smoke pocket, realizing the oil smoke separation, further prevent to smoke in-process oil smoke by the suction nozzle to promote experience.

Drawings

Fig. 1 is a schematic structural view of the present invention;

FIG. 2 is a sectional view of the structure of the present invention;

fig. 3 is a schematic structural view of the mounting base of the present invention;

fig. 4 is a schematic structural view of another view angle of the mounting base of the present invention;

FIG. 5 is a schematic structural view of the base of the present invention;

FIG. 6 is a schematic structural view of the silicone rubber plug of the present invention;

FIG. 7 is a schematic view of a micro liquid pump according to the present invention;

FIG. 8 is a schematic view of the micro-fluid pump according to another aspect of the present invention;

FIG. 9 is a schematic structural view of a ceramic heater according to the present invention;

FIG. 10 is a schematic structural view of another perspective of the ceramic heater of the present invention;

FIG. 11 is a drawing showing a suction state of the micro-fluid pump according to the present invention;

fig. 12 is a drainage state diagram of the micro liquid pump according to the present invention.

In the figure: 10. the micro-fluid-heating device comprises a shell, 101, a suction nozzle, 102, an air pipe, 103, a limiting boss, 20, a base, 201, an electrode column hole, 202, an air inlet hole, 30, a mounting seat, 301, a micro-fluid pump mounting surface, 302, an oil inlet hole, 303, an oil outlet hole, 304, an annular groove, 305, a smoke guide hole, 306, a positioning flange, 307, a sleeve, 308, an oil guide hole, 309, a ceramic heating element accommodating groove, 40, a micro-fluid pump, 401, a fluid inlet, 402, a fluid outlet, 403, a C-shaped insulating outer covering plate, 404, an elastic conductor, 405, L-shaped metal conductive foil, 406, a vibrator, 407, a pump cavity, 50, a ceramic heating element, 501, a heating surface, 502, an oil guide groove, 503, a heat insulation sealing sleeve, 504 heating wires, 60, a silica gel plug, 601, a stepped hole, 602, a liquid-proof breathable film, 70, a smoke cavity, 80, a flue, 90, an atomization chamber, 110, 120 and an electrode column, 130. type II electrode column.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1-10, the present invention provides a technical solution: an active oil supply type electronic atomized smoke cartridge based on a micro liquid pump comprises a shell 10 and a base 20, wherein the base 20 is provided with a groove, a sealing ring is arranged in the groove, the shell 10 is clamped with the base 20 and is sealed through the sealing ring, a suction nozzle 101 and an air pipe 102 are integrally formed on the shell 10, the suction nozzle 101 and the air pipe 102 are integrally communicated to form a flue 80, a mounting seat 30 is arranged in the shell 10, the top of a forming sleeve 307 at the upper end of the mounting seat 30 is sealed to form a smoke chamber 70, the lower end of the mounting seat 30 is matched with the base 20 to form an atomizing chamber 90, a micro liquid pump 40 is arranged on one side of the mounting seat 30, a ceramic heating body 50 is arranged at the bottom of the mounting seat 30, the micro liquid pump 40 is communicated with the smoke chamber 70, the lower end of the air pipe 102 is hermetically connected with a smoke guide hole 305 on the mounting seat 30 so as to be communicated with the, the tobacco tar penetrates through the ceramic heating body 50 to be atomized and enters the atomizing chamber 90, negative pressure is formed in the atomizing chamber 90 in the suction process, air enters the atomizing chamber 90 under the action of the negative pressure, aerosol generated by tobacco tar atomization is sent into an opening along the air pipe 102, in the application, the oil supply is controlled by the miniature liquid pump 40, oil is directly sent to the heating surface 501 of the ceramic heating body 50 under the pressure action of the pump, the miniature liquid pump 40 has good one-way stopping performance, whether the miniature liquid pump 40 needs certain pressure or an outlet valve can be opened, in addition, the compact ceramic heating body 50 is adopted in the application, on one hand, the oil has good structural strength, the property change cannot be generated, on the other hand, the one-way stopping effect can be realized, when the pressure action of the miniature liquid pump 40 is not available, the oil cannot penetrate through the compact ceramic heating body 50, and the problems that the dry combustion and the oil supply of an atomizer caused by the fact that oil supply is not timely or too little oil supply Excess oil results in problems of frying oil and leaking oil.

Specifically, as shown in fig. 3 and 4, a micro liquid pump mounting surface 301 is disposed on a side surface of the mounting base 30, a ceramic heat generating body accommodating groove 309 is disposed at the bottom of the mounting base 30, an oil inlet hole 302, an oil outlet hole 303 and a positioning flange 306 are disposed on the micro liquid pump mounting surface 301, a positioning hole is formed in the positioning flange 306 corresponding to the micro liquid pump 40 and is adapted to be clamped on the micro liquid pump mounting surface 301, a fluid inlet 401 of the micro liquid pump 40 is communicated with the oil inlet hole 302, a fluid outlet 402 of the micro liquid pump 40 is communicated with the oil outlet hole 303, an oil guide hole 308 is formed in the ceramic heat generating body accommodating groove 309, the oil inlet hole 302 is communicated with the smoke cavity 70, the oil outlet hole 303.

Preferably, the outer edges of the oil inlet hole 302 and the oil outlet hole 303 are respectively provided with a concentric annular groove 304, a sealing ring is arranged in the groove, and the oil inlet hole 302 and the oil outlet hole 303 can be isolated by the sealing ring to prevent oil leakage.

Specifically, as shown in fig. 7 and 8, the electrodes at the two ends of the micro-fluid pump 40 are respectively led to the outer surface of a "C" shaped insulating outer cover plate 403 through elastic conductors 404, 2 "L" shaped metal conductive foil pieces 405 are embedded in the outer surface of the "C" shaped insulating outer cover plate 403 and are respectively contacted with the elastic conductors 404, and the "C" shaped insulating outer cover plate 403 is clamped and mounted on the upper and lower limiting surfaces of the micro-fluid pump mounting surface 301 of the mounting base 30.

Further, as shown in fig. 9 and 10, the heating surface 501 of the ceramic heating element 50 is silk-screened with the heating wire 504 and the electrodes, the back surface of the heating surface 501 is provided with an oil guiding groove 502 with a depth of 0.1mm to 0.2mm, the projection of the groove surface of the oil guiding groove 502 on the heating surface 501 covers the silk-screened area of the heating wire 504, the ceramic heating element 50 is embedded into the heat insulation sealing sleeve 503, only the groove surfaces of the heating surface 501 and the oil guiding groove 502 are exposed, and are matched and clamped with the ceramic heating element accommodating groove 309 on the mounting base 30, and the heating surface 501 faces the atomizing chamber 90.

Further, as shown in fig. 5, 4 electrode post holes 201 are provided on the end surface of the base 20, and electrode posts are hermetically installed in the electrode post holes 201, wherein 2 i-type electrode posts 120 are respectively in contact with screen printing electrodes at two ends of the ceramic heating body, and the other 2 ii-type electrode posts 130 are respectively in contact with 2 "L" -type metal conductive foils 405 led out from electrodes at two ends of the micro-liquid pump 40.

Preferably, the air inlet hole 202 is opened at the center of the heating surface 501 of the end surface of the base 20 facing the ceramic heating element 50, when the atomizing chamber 90 forms negative pressure, air enters the atomizing chamber 90 through the air inlet hole, so that the suction resistance can be reduced, and meanwhile, aerosol generated by tobacco tar atomization is sent into the inlet along the flue 80 to complete suction.

Preferably, the top of the molding sleeve 307 at the upper end of the mounting seat 30 is adapted to be compressed and sealed by the silicone plug 60, as shown in fig. 6, the center of the silicone plug 60 is provided with a step hole 601, a liquid-proof and breathable film 602 is applied to the step surface of the step hole 601, and the top of the silicone plug 60 is pressed against the top wall of the housing 10.

The working principle of the micropump 40 is as follows: as shown in fig. 11 and 12, the operation process of the micro-fluid pump 40 can be divided into two processes of suction and discharge, when the vibrator 406 bends upwards, the volume of the sealed pump cavity 407 increases, the pressure in the cavity decreases, the valve plate opens the inlet valve and closes the outlet valve under the action of the pressure difference between the two sides, and the smoke oil flows into the pump cavity 407 through the inlet valve to complete the suction of the smoke oil; when the vibrator 406 bends downward, the volume of the sealed pump cavity 407 decreases, the pressure in the cavity increases, the outlet valve opens, the inlet valve closes, and the smoke oil discharging process is completed. When continuous alternating signals are applied to the electrodes at the two ends of the micro liquid pump 40, the micro liquid pump 40 completes the continuous oil suction and oil discharge process, and the purpose of pressure oil supply is achieved.

The working principle of the application is as follows: during suction, the micro liquid pump 40 and the ceramic heating element 50 start to work, smoke oil in the smoke oil chamber 70 enters a pump chamber through a fluid inlet 401 of the micro liquid pump 40 communicated with an oil inlet 302 on the mounting seat 30, the smoke oil is boosted under the action of the micro liquid pump 40, pumped out through a fluid outlet 402 of the micro liquid pump 40, enters the oil duct 110, enters the oil guide groove 502 through the oil guide hole 308, the smoke oil rapidly penetrates through the ceramic heating element 50 under the action of pressure to reach a heating surface 501 of the ceramic heating element 50, a silk-screen heating wire 504 on the heating surface 501 is electrified to rapidly reach the atomizing temperature, the smoke oil penetrating through the ceramic heating element 50 is atomized, negative pressure is formed in the atomizing chamber 90 during suction, air enters the atomizing chamber 90 through the air inlet 202 under the action of the negative pressure, aerosol generated by smoke oil atomization is sent into the inlet along the flue 80, and suction is completed.

In the process of one-time pumping, the control circuit is divided into two branches to simultaneously supply power to the micro liquid pump 40 and the ceramic heating element 50, firstly a positive-negative-positive type reference square wave alternating voltage signal is provided for the micro liquid pump 40, so that the micro liquid pump 40 generates a reference pump oil quantity, a positive-zero-positive type reference square wave alternating voltage signal is provided for the heating wire 504 of the ceramic heating element 50, so that the heating wire 504 of the ceramic heating element 50 generates a reference atomization quantity, when the voltage at two ends of the ceramic heating element 50 is positive, the ceramic heating element 50 generates heat to atomize smoke oil, when the voltage at two ends of the ceramic heating element 50 is zero, the control circuit monitors the resistance value of the heating wire 504 of the ceramic heating element 50 at the current state, and then the atomization temperature of the heating wire 504 of the ceramic heating element 50 at the current state is calculated according to the variation, when the atomization temperature is higher than the optimal atomization temperature set by the control chip, the control circuit can reduce the voltage values at two ends of the heating wire 504 of the ceramic heating body 50, so that the atomization power is reduced, meanwhile, the voltage values at two ends of the micro liquid pump 40 are improved, the oil pumping quantity is increased, the constant atomization temperature is realized through the autonomous learning and correction of the chip, and the dry burning caused by insufficient oil supply is prevented; when the atomizing temperature is lower than the optimal atomizing temperature set by the control chip, the control circuit can improve the voltage values at two ends of the heating wire 504 of the ceramic heating body 50, so that the atomizing power is improved, meanwhile, the voltage values at two ends of the micro liquid pump 40 are reduced, the oil pumping amount is reduced, the constancy of the atomizing temperature is realized through the autonomous learning and correction of the chip, and the oil is prevented from being excessively supplied to form oil frying and oil leakage.

By matching the oil supply amount of the micro-liquid pump 40 and the porosity and oil consumption of the ceramic heating element 50, the balance of oil supply and consumption can be realized, and the phenomena of dry burning, oil frying and oil leakage caused by uncontrollable oil supply of the commercially available electronic cigarette can be avoided.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (8)

1. The utility model provides an initiative fuel feeding formula electron atomizing cigarette bullet based on miniature liquid pump, includes sealed complex shell (10) and base (20), shell (10) integrated into one piece suction nozzle (101) and trachea (102), its characterized in that: a mounting seat (30) is arranged in the shell (10), the top of a forming sleeve (307) at the upper end of the mounting seat (30) is sealed to form a smoke chamber (70), the lower end of the mounting seat (30) is matched with the base (20) to form an atomizing chamber (90), a micro liquid pump (40) is arranged on one side of the mounting seat (30), a ceramic heating body (50) is arranged at the bottom of the mounting seat (30), the miniature liquid pump (40) is communicated with the tobacco tar cavity (70), the air pipe (102) is communicated with the atomizing chamber (90), the tobacco tar in the tobacco tar cavity (70) is conveyed to the heating surface (501) of the ceramic heating element (50) through the miniature liquid pump (40) under pressure, the tobacco tar is atomized to enter the atomizing chamber (90) through the ceramic heating element (50) in the process of pumping, negative pressure is formed in the atomizing chamber (90), air enters the atomizing chamber (90) under the action of the negative pressure, and aerosol generated by tobacco tar atomization is sent into an inlet along the air pipe (102).

2. The active oil supply type electronic atomization cartridge based on the micro liquid pump as claimed in claim 1, wherein: the side of mount pad (30) is equipped with miniature liquid pump installation face (301), the bottom of mount pad (30) is equipped with ceramic heat-generating body holding tank (309), be equipped with inlet port (302), oil outlet (303) and positioning flange (306) on miniature liquid pump installation face (301), miniature liquid pump (40) correspond positioning flange (306) are seted up the locating hole and the adaptation block in miniature liquid pump installation face (301), the influent stream matter mouth (401) of miniature liquid pump (40) with inlet port (302) switch on, the effluent matter mouth (402) of miniature liquid pump (40) with oil outlet (303) switch on, lead oilhole (308) have been seted up on ceramic heat-generating body holding tank (309), inlet port (302) and oil smoke chamber (70) intercommunication, oil outlet (303) and lead oilhole (308) intercommunication.

3. The active oil supply type electronic atomization cartridge based on the micro liquid pump as claimed in claim 2, wherein: the outer edges of the oil inlet hole (302) and the oil outlet hole (303) are respectively provided with a concentric annular groove (304), and a sealing ring is arranged in each groove.

4. The active oil supply type electronic atomization cartridge based on the micro liquid pump as claimed in claim 1, wherein: electrodes at two ends of the micro-liquid pump (40) are respectively led to the outer surface of a C-shaped insulating outer covering plate (403) through elastic conductors (404), 2L-shaped metal conductive foils (405) are embedded into the outer surface of the C-shaped insulating outer covering plate (403) and are respectively contacted with the elastic conductors (404), and the C-shaped insulating outer covering plate (403) is clamped and installed on the upper limiting surface and the lower limiting surface of a micro-liquid pump installation surface (301) of the installation seat (30).

5. The active oil supply type electronic atomization cartridge based on the micro liquid pump as claimed in claim 4, wherein: heating surface (501) silk screen printing heater (504) and the electrode of ceramic heat-generating body (50), open at the back of heating surface (501) and led oil groove (502), the groove depth is 0.1mm ~ 0.2mm, the groove face of leading oil groove (502) is in projection on heating surface (501) covers the silk screen printing region of heater (504), in ceramic heat-generating body (50) embedding heat-insulating seal cover (503), only expose the groove face of heating surface (501) and leading oil groove (502), and with ceramic heat-generating body holding tank (309) adaptation block on mount pad (30), heating surface (501) orientation fog chamber (90).

6. The active oil supply type electronic atomization cartridge based on the micro liquid pump as claimed in claim 5, wherein: the end face of the base (20) is provided with 4 electrode column holes (201), electrode columns are respectively installed in the electrode column holes (201) in a sealing mode, 2I-shaped electrode columns (120) are respectively contacted with screen printing electrodes at two ends of the ceramic heating body, and the other 2 II-shaped electrode columns (130) are respectively contacted with 2L-shaped metal conductive foils (405) led out from electrodes at two ends of the miniature liquid pump (40).

7. The active oil supply type electronic atomization cartridge based on the micro liquid pump as claimed in claim 1, wherein: an air inlet hole (202) is formed in the central position of the end face of the base (20), which is opposite to the heating surface (501) of the ceramic heating body (50).

8. The active oil supply type electronic atomization cartridge based on the micro liquid pump as claimed in claim 1, wherein: the top of the forming sleeve (307) at the upper end of the mounting seat (30) is pressed and sealed through the adaptation of the silica gel plug (60), a step hole (601) is formed in the center of the silica gel plug (60), a liquid-proof and breathable film (602) is applied to the step surface of the step hole (601), and the top of the silica gel plug (60) is pressed onto the top wall of the shell (10).