Patent Publication Number: US-2019166914-A1

Title: Electronic cigarette and temperature warning method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation in part of International Patent Application No. PCT/CN2017/093234, filed on Jul. 17, 2017, entitled “electronic cigarette and temperature warning method thereof”, which claims priority to Chinese Patent Application No. 201610571435.0, filed on Jul. 19, 2016; No. 201620763821.5, filed on Jul. 19, 2016; No. 201610571333.9, filed on Jul. 19, 2016. All of the aforementioned patent applications are hereby incorporated by reference in their entireties. 
    
    
     FIELD 
     The present disclosure relates to the technical field of electronic cigarette, in particular to an improved electronic cigarette and a temperature warning method thereof. 
     BACKGROUND 
     A conventional baking type electronic cigarette is provided with an atomizing chamber therein. The atomizing chamber is provided with a heating cup for loading and heating solid smoke substrate such as tobacco shred, tobacco paste or the like. The electronic cigarette is further provided with a cover for opening or closing the atomizing chamber through a buckle structure. However, after long-term use, the buckle structure may be mechanically worn, resulting in the cover cannot be to securely close the atomizing chamber during use. Once the cover is loosened or mis-opened due to the mechanical wear of the buckle structure during use, the high temperature component (eg, the heating cup) in the atomizing chamber is exposed, thereby may cause accidental burns to the user. 
     On the other hand, some of the components of the atomizing chamber (e.g., heating cup) requires cleaning after use. Since the temperature of the atomizing chamber is high during use, after the user stops inhaling, if the user clean the electronic cigarette without knowing whether the temperature of the component to be cleaned falls to the safe temperature or below the safe temperature, it may cause burns. 
     SUMMARY 
     The object of the present disclosure is to provide an electronic cigarette having a safety protection function. 
     An electronic cigarette includes a main housing, an atomizing assembly located in the main housing; and a cover attached to the atomizing assembly, the electronic cigarette further includes an electric locking device located between the main housing and the cover, and a control circuit board, when the atomizing assembly is energized, the control circuit board controls the locking member to lock the cover; when the atomizing assembly is powered off, the control circuit board controls the locking member to unlock the cover. 
     In one embodiment, the main housing is provided with a electric locking device mounting groove, the electric locking device is an electric plug lock, the electric locking device includes a locking body and a locking member disposed at the locking body, the locking tongue can extend out of the lock body and can also be retracted from the outer side of the lock body into the lock body, the lock body is mounted in the electric locking device mounting groove, the cover defines a locking hole for the locking member to be inserted into or withdrawn therefrom to lock or unlock the cover. 
     In one embodiment, the top surface of the main housing is provided with an atomizing component installation groove for mounting the atomizing assembly, the electric locking device mounting groove is located adjacent to the atomizing component installation groove, the atomizing component installation groove includes a first groove and a second groove located above the first groove, two opposite sides of the second groove extends through the corresponding opposite sides of the main housing, an arcuate groove is laterally opened along the main housing on the inner wall of the another opposite sides of the groove top section, the locking hole is defined at bottom surface of the cover, the locking member is inserted into or withdrawn from the locking hole along a vertical direction of the main housing. 
     In one embodiment, the cover includes a cover plate and a projection protruding from the bottom surface of the cover plate, the atomizing assembly includes a heating component, the heating component is located in the first groove of the atomizing component installation groove, the outer circumference of the projection is provided with a latch. 
     In one embodiment, the upper surface of the cover plate is provided with a smoke guiding passage corresponding to the position of the projection, the smoke guiding passage extends through the projection. 
     In one embodiment, the atomizing assembly includes a heating component, a filter screen, and a sealing ring, the filter screen is located in the atomizing component installation groove, a third groove is provided at the junction of the first groove and the second groove, the sealing ring is received in the third groove. 
     In one embodiment, the electric locking device further includes a locking cover, the locking cover is provided with a through hole for the locking member to pass through, the lock cover is located at the opening of the top end of the electric locking device mounting groove. 
     In one embodiment, when the cover is covered on the atomizing assembly, the peripheral side of the cover is at least partially embedded in the main housing, the locking hole is defined on one side surface of the cover, the locking member can be inserted into or withdrawn from the locking hole laterally along the main housing. 
     In one embodiment, the electric locking device is an electromagnetic lock, the electromagnetic lock includes an electromagnet and a magnetic member, the main housing is provided with an electric locking device mounting groove, the cover is provided with a locking hole, the electromagnet is mounted in the electric locking device mounting groove, the magnetic member is located in the locking hole. 
     In one embodiment, the electronic cigarette further includes a battery cover, an inner bracket and a battery, a mounting window is defined at one side of the main housing, one side of the inner mounting bracket away from the mounting window is configured for mounting the control circuit board, the opposite side of the inner mounting bracket is provided with a battery compartment, the battery is received in the battery compartment, the battery cover is releasably covered on the mounting window. 
     The beneficial effects of the device are: 
     The electronic cigarette of the disclosure has an electric locking device. In use, the locking member of the electric locking device protrudes into the corresponding locking hole of the cover or attracts the magnetic member through the electromagnet of the electric locking device, so that the cover cannot be opened and locked. After use, the locking member of the electric locking device is retracted, the magnetic attraction of the electromagnet disappears, and then the cover can be opened, thereby improving the safety of the use of the electronic cigarette. 
     The disclosure further provides an electronic cigarette and a temperature warning method thereof, which can monitor the temperature of the component to be cleaned in the atomizing chamber after the user has finished inhaling, and prevent the user from causing burns when the temperature does not fall to a safe temperature or below. 
     An electronic cigarette includes a main housing, an atomizing assembly located in the main housing, and a cover attached to the atomizing assembly, the electronic cigarette further includes an electric locking device and/or alarm device, a temperature sensor and a control circuit board, the atomizing assembly includes a component need to be cleaned, the temperature sensor is disposed on or adjacent to the component to be cleaned for detecting the temperature of the component to be cleaned and fed back to the control circuit board, the control circuit board is pre-stored with a safe temperature, the control circuit board is also used to determine the relationship between the safe temperature and the temperature of the component to be cleaned, and controlling the action of the electric lock device and/or the alarm device according to the judgment result; 
     when the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board controls the alarm device to issue an alarm and/or the control circuit board controls the electric locking device to lock the cover; 
     when the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board controls the alarm device to release the alarm and/or the control circuit board controls the electric locking device to unlock the cover. 
     In one embodiment, the heating component is a heating cup, the temperature sensor is mounted on the bottom surface of the heating cup. 
     In one embodiment, the electric locking device is an electric plug lock, the electric locking device includes a locking body and a locking member disposed at the locking body, the locking tongue can extend out of the lock body and can also be retracted from the outer side of the lock body into the lock body, the cover defines a locking hole for the locking member to be inserted into or withdrawn therefrom to lock or unlock the cover. 
     In one embodiment, the top surface of the main housing is provided with an atomizing component installation groove for mounting the atomizing assembly, the atomizing component installation groove includes a first groove and a second groove located above the first groove two opposite sides of the second groove extends through the corresponding opposite sides of the main housing, an arcuate groove is laterally opened along the main housing on the inner wall of the another opposite sides of the groove top section, the locking hole is defined at bottom surface of the cover, the locking member is inserted into or withdrawn from the locking hole along a vertical direction of the main housing. 
     In one embodiment, the cover includes a cover plate and a projection protruding from the bottom surface of the cover plate, the outer circumference of the projection is provided with a latch, the upper surface of the cover plate is provided with a smoke guiding passage corresponding to the position of the projection, the smoke guiding passage extends through the projection, the atomizing assembly includes a filter screen, the filter screen is located in the atomizing component installation groove. 
     In one embodiment, when the cover is covered on the atomizing assembly, the peripheral side of the cover is at least partially embedded in the main housing, the locking hole is defined on one side surface of the cover, the locking member can be inserted into or withdrawn from the locking hole laterally along the main housing. 
     In one embodiment, the electric locking device is an electromagnetic lock, the electromagnetic lock includes an electromagnet and a magnetic member, the main housing is provided with an electric locking device mounting groove, the cover is provided with a locking hole, the electromagnet is mounted in the electric locking device mounting groove, the magnetic member is located in the locking hole. 
     In one embodiment, the alarm device is selected from at least one of a warning light, a voice device, a buzzer device, and a display device. 
     The present disclosure also provides another electronic cigarette. 
     An electronic cigarette includes a main housing, an atomizing assembly located in the main housing and a cover attached to the atomizing assembly, the electronic cigarette further includes an electric locking device and/or alarm device, a temperature sensor, and a control circuit board, the atomizing assembly includes a heating component, the heating portion of the heating component is made of a material having a temperature coefficient of resistance characteristic, the control circuit board pre-stores the safe temperature, a correspondence table between the resistance of the heating portion and the temperature of the heating component, the control circuit board is configured for detecting the resistance of the heating portion, and calculating the temperature of the heating component according to the correspondence relationship between the resistance of the heating portion and the temperature of the heating component, the control circuit board is also configured to determine the relationship between the temperature of the heating component and the safe temperature, and controlling the action of the electric lock device and/or the alarm device according to the judgment result; 
     when the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board controls the alarm device to issue an alarm and/or the control circuit board controls the electric locking device to lock the cover; 
     When the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board controls the alarm device to release the alarm and/or the control circuit board controls the electric locking device to unlock the cover. 
     In one embodiment, the electric locking device is an electric plug lock, the electric locking device includes a locking body and a locking member disposed at the locking body, the locking tongue can extend out of the lock body and can also be retracted from the outer side of the lock body into the lock body, the cover defines a locking hole for the locking member to be inserted into or withdrawn therefrom to lock or unlock the cover. 
     In one embodiment, the electric locking device is an electromagnetic lock, the electromagnetic lock includes an electromagnet and a magnetic member, the main housing is provided with an electric locking device mounting groove, the cover is provided with a locking hole, the electromagnet is mounted in the electric locking device mounting groove, the magnetic member is located in the locking hole. 
     In one embodiment, the alarm device is selected from at least one of a warning light, a voice device, a buzzer device, and a display device. 
     The present disclosure also provides a temperature warning method for an electronic cigarette. 
     A temperature warning method of an electronic cigarette, the electronic cigarette includes a main housing, an atomizing assembly located in the main housing, a cover attached to the atomizing assembly, an electric locking device and/or alarm device, a temperature sensor and a control circuit board pre-stored with a safe temperature, the atomizing assembly includes a component need to be cleaned, the temperature warning method includes: 
     the temperature sensor detects the temperature of the component to be cleaned, and feeds back the temperature of the component to be cleaned to the control circuit board; 
     the control circuit board determines the relationship between the temperature of the component to be cleaned and the safe temperature; 
     when the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board controls the alarm device to issue an alarm and/or the control circuit board controls the electric locking device to lock the cover; 
     when the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board controls the alarm device to release the alarm and/or the control circuit board controls the electric locking device to unlock the cover. 
     In one embodiment, the electric locking device is an electric plug lock, the electric locking device is located in the main housing, the electric locking device includes a locking body and a locking member, the cover defines a locking hole, 
     When the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board controls the locking member to extend out and be inserted into the locking hole, and then the cover is locked. When the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board controls the locking member to exit the locking hole, and then the cover is unlocked. 
     In one embodiment, the electric locking device is an electromagnetic lock, the electromagnetic lock includes an electromagnet and a magnetic member, the electromagnet and the magnetic member are respectively mounted on the main housing and the cover, the electronic cigarette further includes a battery, the electromagnet is electrically connected to the battery; 
     when the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board controls the circuit between the electromagnet and the battery to be turned on, the electromagnet generates magnetic attraction to attract the magnetic member, and then the cover is locked; 
     when the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board controls the circuit between the electromagnet and the battery to be disconnected, the magnetic attraction of the electromagnet disappears, and then the cover is unlocked. 
     The present disclosure also provides another temperature warning method for an electronic cigarette. 
     A temperature warning method of an electronic cigarette, the electronic cigarette includes a main housing, an atomizing assembly located in the main housing, a cover attached to the atomizing assembly, an electric locking device and/or alarm device, a temperature sensor and a control circuit board pre-stored with a safe temperature, the temperature warning method includes: 
     the control circuit board detects the resistance of the heating portion of the heating component; 
     the control circuit board calculates the temperature of the heating component based on the correspondence relationship between the resistance of the heating portion and the temperature of the heating component; 
     the control circuit board determines the relationship between the temperature of the heating component and the safe temperature; 
     when the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board controls the alarm device to issue an alarm and/or the control circuit board controls the electric locking device to lock the cover; 
     when the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board controls the alarm device to clear the alarm and/or the control circuit board controls the electric locking device to unlock the cover. 
     In one embodiment, the electric locking device is an electric plug lock, the electric locking device is located in the main housing, the electric locking device includes a locking body and a locking member, the cover defines a locking hole, 
     when the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board controls the locking member to extend out and be inserted into the locking hole, and then the cover is locked. When the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board controls the locking member to exit the locking hole, and then the cover is unlocked. 
     In one embodiment, the electric locking device is an electromagnetic lock, the electromagnetic lock includes an electromagnet and a magnetic member, the electromagnet and the magnetic member are respectively mounted on the main housing and the cover, the electronic cigarette further includes a battery, the electromagnet is electrically connected to the battery; 
     when the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board controls the circuit between the electromagnet and the battery to be turned on, the electromagnet generates magnetic attraction to attract the magnetic member, and then the cover is locked; 
     when the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board controls the circuit between the electromagnet and the battery to be disconnected, the magnetic attraction of the electromagnet disappears, and then the cover is unlocked. 
     The beneficial effects of the device are: 
     After the user inhales, the temperature information is transmitted to the control circuit board through the temperature sensor, or the control circuit board calculates the heating component through the resistance of the heating portion of the heating component. Thus, the temperature of the component to be cleaned in the atomizing chamber can be monitored in real time, preventing the user from scalding when the temperature above the safe temperature. 
     The invention also provides an electronic cigarette which cannot be opened when the temperature in the atomization chamber is greater than the safe temperature, thereby improving the safety of use. 
     An electronic cigarette includes a main housing, an atomizing assembly located in the main housing and a cover attached to the atomizing assembly, the electronic cigarette further includes a memory switch disposed between the main housing and the cover, the action of the memory switch is according to the temperature conducted by the atomizing assembly to lock the cover on the main housing or release the cover from the main housing. 
     In one embodiment, the top surface of the main housing is provided with a mounting groove, The mounting groove has a stepped groove structure including a first groove and a second groove, the heating component is located in the first groove, an assembly gap formed between the upper end of the heating component and the inner side wall of the second groove, and a stepped surface formed between the second groove and the first groove is configured for mounting the memory switch. 
     In one embodiment, the top outer peripheral side of the second groove extends upwardly to form a covered edge, the cover includes a cover plate and a projection protruding from the bottom surface of the cover plate, the projection is inserted in the covered edge. 
     In one embodiment, the memory switch ‘includes a body and a locking member disposed on the body, the body is located on the stepped surface between the second groove and the first groove, the locking member protrudes from the assembly gap between the upper end of the heating component and the inner side wall of the second groove. 
     In one embodiment, the memory switches&#39; includes two locking members, The outer peripheral surface of the projection adjacent to the lower surface of the projection defines a receiving groove along the lateral direction of the cover, the bottom surface of the receiving groove is provided with a locking hole extending through the lower surface of the projection, for the locking member to extend through, according to the conducted temperature of the heating component, the locking members are flared outwardly to a maximum distance between the two locking members that is greater than the aperture of the locking hole to lock the cover, or the locking members are contracted inwardly to a maximum distance between the two locking members that is less than or equal to the aperture of the locking hole to unlock the cover. 
     In one embodiment, the heating component is a heating cup, the inner cavity of the heating cup forms an atomizing chamber, the main housing is provided with an air intake hole not shown, an air inlet in communication with the air intake hole is defined in the bottom surface of the bottom portion, the bottom surface of the heating cup is provided with at least one ventilation hole, the ventilation hole is in communication with the air inlet. 
     In one embodiment, the bottom surface of the heating cup further extends toward the bottom surface of the first groove with a support frame, the heating cup is supported by the support frame on the bottom surface of the first groove, an air gap is formed between the bottom surface of the heating cup and the bottom surface of the first groove. 
     In one embodiment, the upper surface of the cover plate is provided with a smoke guiding passage corresponding to the position of the projection, the bottom end of the smoke guiding passage passes through the projection and is in communication with the heating component. 
     In one embodiment, the atomizing assembly includes a filter screen, the filter screen is located in the smoke guiding passage. 
     In one embodiment, the electronic cigarette further includes a battery cover, an inner bracket and a battery, a mounting window is defined at one side of the main housing, one side of the inner mounting bracket away from the mounting window is configured for mounting the control circuit board, the opposite side of the inner mounting bracket is provided with a battery compartment, the battery is received in the battery compartment, the battery cover is releasably covered on the mounting window. 
     The beneficial effects of the device are: 
     A memory switch is disposed between the cover of the electronic cigarette and the main housing. When the temperature of the memory switch rises to a transition temperature (room temperature&lt;transition temperature≤safe temperature) or above the transition temperature, the locking member of the memory switch is locked with the locking hole corresponding to the cover, and then the cover cannot be opened. After use, the temperature of the memory switch drops below the transition temperature, the locking member is restored to the original shape and can be released from the locking hole, and then the cover can be opened, thus improving the safety of the use of electronic cigarettes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of an electronic cigarette of the first embodiment. 
         FIG. 2  is an exploded view of the electronic cigarette shown in  FIG. 1 . 
         FIG. 3  is a cross-sectional view of the open state of the electronic cigarette shown in  FIG. 1 . 
         FIG. 4  is a cross-sectional view showing the locked state of the electronic cigarette shown in  FIG. 1 . 
         FIG. 5  is a cross-sectional view of the second embodiment of the electronic cigarette. 
         FIG. 6  is a flow chart of a temperature warning method for the electronic cigarette of the third embodiment. 
         FIG. 7  is a flow chart of another temperature warning method for the electronic cigarette of the third embodiment. 
         FIG. 8  is a schematic structural view of an electronic cigarette of the fourth embodiment. 
         FIG. 9  is an exploded view of the electronic cigarette shown in  FIG. 8 . 
         FIG. 10  is a cross-sectional view showing the open state of the electronic cigarette shown in  FIG. 8 ; 
         FIG. 11  is a cross-sectional view showing the locked state of the electronic cigarette shown in  FIG. 8 . 
     
    
    
     The following table list various components and reference numerals thereof. 
     
       
         
           
               
               
             
               
                   
               
             
            
               
                 Locking hole 412 
                 Filter 22 
               
               
                 Main housing 10 
                 Sealing ring 23 
               
               
                 Atomizing component installation 
                 Electric locking device 30 
               
               
                 groove 11 
               
               
                 Electric locking device mounting 
                 Locking body 31 
               
               
                 groove 12 
               
               
                 Mounting window 13 
                 Locking member 32 
               
               
                 Atomizing assembly 20 
                 Locking cover 33 
               
               
                 Heating component 21 
                 Electromagnet 34 
               
               
                 Mounting groove 17 
                 Button hole 18 
               
               
                 Blocking member 37 
                 Main body 36 
               
               
                 Magnetic member 35 
                 Battery compartment 71 
               
               
                 cover 40 
                 Battery 80 
               
               
                 Cover plate 41 
                 Battery cover 90 
               
               
                 Projection 42 
                 First groove 111 
               
               
                 Temperature sensor 50 
                 Second groove 112 
               
               
                 Control board 60 
                 Sealing groove 113 
               
               
                 Inner mounting bracket 70 
                 Smoke guiding passage 411 
               
               
                 Memory switch 30′ 
               
               
                   
               
            
           
         
       
     
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure. 
     Several definitions that apply throughout this disclosure will now be presented. 
     The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like. 
     When a feature or element is herein referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. 
     Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “/”. 
     The First Embodiment 
     Referring to  FIG. 1  and  FIG. 2 , the present disclosure provides an electronic cigarette, the electronic cigarette includes a main housing  10 , an atomizing assembly  20  located in the main housing  10 , a cover  40  attached to the atomizing assembly  20 , and a locking device located between the main housing  10  and the cover  40 . The cover  40  is releasably covered on the atomizing assembly  20  through the locking device. In the embodiment, the locking device is an electric locking device  30 . In the embodiment, the cover  40  is a top cover, it can be appreciated that, in other embodiments, the cover  40  can be a side cover or a bottom cover. 
     The top surface of the main housing  10  is provided with an atomizing component installation groove  11  and a electric locking device mounting groove  12 . The atomizing component installation groove  11  is configured for mounting the atomizing assembly  20  and engages with the cover  40 . In the embodiment, the atomizing component installation groove  11  includes a first groove  111  and a second groove  112  located above the first groove  111 . The first groove  111  has a cylindrical shape for mounting a heating component  21  of the atomizing assembly  20 . The second groove  112  is an opening with a rectangular shape, two opposite sides of the opening extend through the corresponding opposite sides of the main housing  10 , the cover  40  is at least partially received in the second groove  112 . Further, a sealing groove  113  is provided at the junction of the first groove  111  and the second groove  112 . That is, the sealing groove  113  communicates between the first groove  111  and the second groove  112 . The electric locking device mounting groove  12  is located adjacent to the atomizing component installation groove  11  and is isolated from the atomizing component installation groove  11  for mounting the electric locking device  30 . In the embodiment, the electric locking device mounting groove  12  is a rectangular groove. 
     The atomizing assembly  20  includes a heating component  21 , a filter  22 , and a sealing ring  23 . The heating component  21  is located in the first groove  111  of the atomizing component installation groove  11 , the inner cavity of the heating component  21  forms an atomizing chamber. In one embodiment, the heating component  21  is a heating cup. The filter  22  is located at the top end of the atomizing component installation groove  11 . The filter  22  can allow smoke to pass there through, and also can prevent the tobacco contained in the heating component  21  from falling. In the embodiment, the filter  22  is located in the smoke guiding passage  411  of the cover  40  corresponding to the package portion of the atomizing component installation groove  11 . The sealing ring  23  is received in the sealing groove  113  to enhance the airtightness of the smoke guiding passage  411  through which the smoke flows from the atomizing chamber to the cover  40 . 
     The electric locking device  30  is received in the electric locking device mounting groove  12  for locking the cover  40 . The electric locking device  30  is an electric plug lock and includes a locking body  31  and a locking member  32  disposed at the top end of the locking body  31 . The locking tongue  32  can extend out of the locking body  31  and can also be retracted from the outer side of the locking body  31  into the locking body  31 . Further, the electric locking device  30  further includes a locking cover  33 . The locking cover  33  is provided with a through hole for the locking member  32  to pass through. The locking cover  33  is located at the opening of the top end of the electric locking device mounting groove  12 , the locking body  31  is held in the electric locking device mounting groove  12 . 
     The cover  40  includes a cover plate  41  and a projection  42  protruding from the bottom surface of the cover plate  41 . The upper surface of the cover plate  41  is provided with a smoke guiding passage  411  corresponding to the projection  42 , the bottom of the smoke guiding passage  411  passes through the projection  42  and is in communication with the heating component  21 . A locking hole  412  is defined in the lower surface of the cover plate  41 . The locking hole  412  cooperates with the locking member  32  for the locking member  32  to be inserted into or withdrawn therefrom, so that the cover  40  is locked or unlocked. The projection  42  is located in the second groove  112  of the atomizing component installation groove  11 , such that the smoke in the atomizing chamber can flow into the smoke guiding passage  411  of the cover  40 . 
     Referring to  FIG. 3  and  FIG. 4 , in the embodiment, an arcuate groove laterally along the main housing  10  is defined on the inner wall of the second groove  112  of the atomizing component installation groove  11 . The outer circumference of the projection  42  is provided with a latch (having elasticity) corresponding to the s to arcuate groove. The locking member  32  can be vertically inserted into or withdrawn from the locking hole  412 . When the locking member  32  is inserted into the locking hole  412 , the cover  40  cannot move laterally along the main housing  10 , the latch engages with the arcuate groove to prevent the cover  40  from moving vertically along the main housing  10 , whereby the cover  40  is locked. When the locking member  32  is withdrawn from the locking hole  412 , the cover  40  can be laterally moved along the main housing  10 , and further, the latch can be disengaged from the arcuate groove, whereby the cover  40  can be opened. 
     It can be understood that, in other embodiments, the electric locking device  30  can also make the cover  40  releasably covered on the atomizing assembly  20  by other means. For example, when the cover  40  is covered on the atomizing assembly  20 , the peripheral side of the cover  40  is at least partially embedded in the main housing  10 , the locking hole  412  is defined on one side surface of the cover plate  41 , the locking member  32  can be inserted into or withdrawn from the locking hole  412  laterally along the main housing  10 . When the locking member  32  is inserted into the locking hole  412 , the cover  40  is prevented from being vertically movable along the main housing  10  by the locking member  32 , and since the peripheral side of the cover  40  is at least partially embedded in the main housing  10 , the cover  40  is also unable to move laterally along the main housing  10 , whereby the cover  40  is locked. When the locking member  32  is withdrawn from the locking hole  412 , the cover  40  can be vertically movable along the main housing  10 , whereby the cover  40  can be opened. 
     The electronic cigarette further includes a control circuit board  60 , an inner bracket  70 , a battery  80 , and a battery cover  90 . A mounting window  13  is defined at one side of the main housing  10  for mounting the control circuit board  60 , the inner mounting bracket  70 , and the battery  80  into the inner cavity of the main housing  10 . One side of the inner mounting bracket  70  away from the mounting window  13  is configured for mounting the control circuit board  60 , the opposite side is provided with a battery compartment  71  for receiving the battery  80 . The battery cover  90  is releasably covered on the mounting window  13  of the main housing  10 , correspondingly covers the battery compartment  71 , and fixing the battery  80 . In addition, two or more button holes or panel holes are formed at the side of the main housing  10  opposite to the mounting window  13  for mounting a button or a display panel. A button such as a cigarette light button or a power adjustment button can be mounted in the button hole. In one embodiment, the cigarette light button directly controls the cigarette light circuit of the control circuit board  60  to be turned on/off, so that the circuit between the heating component  21  and the battery  80  is turned on/off. 
     To lock or unlock the electric locking device  30  is depended on whether the atomizing assembly  20  is in an operational state or not. Specifically, when the atomizing assembly  20  is energized, that is, when the circuit between the heating component  21  and the battery  80  is turned on, the control circuit board  60  controls the locking member  32  to extend through and is inserted into the locking hole  412 , whereby the cover  40  is locked. When the atomizing assembly  20  is powered off, that is, when the circuit between the heating component  21  and the battery  80  is disconnected, the control circuit board  60  controls the locking member  32  to exit the locking hole  412 , whereby the cover  40  is unlocked. In this way, the cover  40  can be effectively prevented from being loosened or erroneously opened when the atomizing assembly  20  is in use, thereby preventing the high temperature component (e.g., the heating component  21 ) from being exposed and scalding the user. 
     In addition, in order to facilitate the stable installation of the filter  22  in the smoke guiding passage  411 , one end of the smoke guiding passage  411  adjacent to the projection  42  defines a stepped groove for mounting the filter  22 . 
     The embodiment further provides a control method of the electronic cigarette: 
     the control circuit board  60  determines whether the atomizing assembly  20  is energized, 
     when the atomizing assembly  20  is energized, the control circuit board  60  controls the locking member  32  to extend and be inserted into the locking hole  412 , and then the cover  40  is locked; 
     when the atomizing assembly  20  is powered off and stops working, the control circuit board  60  controls the locking member  32  to exit the locking hole  412 , and then the cover  40  is unlocked. 
     The Second Embodiment 
     Referring to  FIG. 5 , the second embodiment provides an electronic cigarette, which is different from the first embodiment in that the electric locking device  30  is an electromagnetic lock, and the electromagnetic lock includes an electromagnet  34  and a magnetic member  35 . The electromagnet  34  mounted in the electric locking device mounting groove  12 , the magnetic member  35  is mounted in the locking hole  412  of the cover  40 . 
     When the atomizing assembly  20  is energized, that is, when the circuit between the heating component  21  and the battery  80  is turned on, the control circuit board  60  controls the electromagnet  34  to be energized to generate a strong magnetic attraction to attract the magnetic member  35 , thereby, the cover  40  is stably mounted on the main housing  10 . When the atomizing assembly  20  is powered off and stops working, that is, when the circuit between the heating component  21  and the battery  80  is disconnected, the control circuit board  60  controls the electromagnet to be power off, the magnetic attraction of the electromagnet  34  disappears and the cover  40  can be opened. Thereby, it can effectively prevent the cover  40  from being loosened or erroneously opened when the atomizing assembly  20  is in use; further, the user is prevented from being burnt due to exposure of a high temperature component such as the heating component  21 . 
     The embodiment further provides a control method of the electronic cigarette: 
     the control circuit board  60  determines whether the atomizing assembly  20  is energized, 
     when the atomizing assembly  20  is energized, the control circuit board  60  controls the circuit between the electromagnet  34  and the battery  80  to be turned on, the electromagnet  34  generates magnetic attraction to attract the magnetic member  35 , and the cover  40  is locked; 
     when the atomizing assembly  20  is powered off and stops working, the control circuit board  60  controls the circuit between the electromagnet  34  and the battery  80  to be disconnected, the magnetic attraction of the electromagnet  34  disappears, and the cover  40  is unlocked. 
     In the first embodiment and the second embodiment, the user can directly inhale smoke through the smoke guiding passage  411  on the cover  40  or a cigarette holder suction inserted into the smoke guiding passage  411 . In order to prevent the inlet smoke temperature from being too high, a smoke pipe may be disposed between the heating component  21  and the inlet of the smoke guiding passage  411 . 
     The Third Embodiment 
     Some of the components of the atomizing assembly  20  of the electronic cigarette described in first embodiment (e.g., the heating component  21 ) need to be cleaned after use. Since the temperature of the atomizing assembly  20  is high during use, after the user stops inhaling, if the user clean the electronic cigarette without knowing whether the temperature of the component to be cleaned falls to the safe temperature or below the safe temperature, it may cause burns. 
     Please refer to  FIG. 2  and  FIG. 3  again, the third embodiment provides another electronic cigarette, which is different from the first embodiment in that the electronic cigarette further includes a temperature sensor  50  for detecting the component to be cleaned in the electronic cigarette. The temperature is fed back to the control circuit board  60 , which controls the locking or unlocking of the electric locking device  30  based on the relationship between the temperature of the component to be cleaned and the safe temperature. The safe temperature refers to the temperature at which the user suddenly touches the component need to be cleaned in the electronic cigarette without being burnt. In the embodiment, the safe temperature is 40° C. 
     Specifically, the temperature sensor  50  is disposed on or adjacent to the component to be cleaned for detecting the temperature of the component to be cleaned and fed back to the control circuit board  60 . The control circuit board  60  is pre-stored with the safe temperature. The control circuit board  60  is also used to determine the relationship between the safe temperature and the temperature of the component to be cleaned. When the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board  60  controls the locking member  32  to extend out and be inserted into the locking hole  412 , and then the cover  40  is locked. When the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board  60  controls the locking member  32  to exit the locking hole  412 , and then the cover  40  is unlocked. Thereby, it can effectively prevent the user from opening the cover  40  without knowing whether the temperature of the component to be cleaned falls to the safe temperature or below the safe temperature, to prevent users from scalding. 
     It can be understood that, the components to be cleaned having the highest temperature is the heating component  21 . Therefore, if the temperature of the heating component  21  has fallen to the safe temperature or below the safe temperature, the temperature of other components to be cleaned (e.g., the filter  22 ) has also fallen to the safe temperature or below the safe temperature. In this embodiment, the heating component  21  is a heating cup, the temperature sensor  50  is mounted on the bottom surface of the heating cup. 
     It is to be understood that, in other embodiments, the heating portion of the heating component  21  is made of a material having a temperature coefficient of resistance characteristic, the heating portion may function as a temperature sensing portion. In addition to storing the safe temperature, the control circuit board  60  also stores a correspondence table between the resistance of the heating portion and the temperature of the heating component  21 . The control circuit board  60  is configured for detecting the resistance of the heating portion, and calculating the temperature of the heating component  21  according to the correspondence relationship between the resistance of the heating portion and the temperature of the heating component  21 . The control circuit board  60  is also used to determine the relationship between the safe temperature and the temperature of the heating component  21 . When the temperature of the heating component  21  is higher than the safe temperature, the control circuit board  60  controls the locking member  32  to extend out and is inserted into the locking hole  412 , and the topp00 cover  40  is locked. When the temperature of the heating component  21  is less than or equal to the safe temperature, the control circuit board  60  controls the locking member  32  to exit the locking hole  412 , and then the cover  40  is unlocked. 
     It will be appreciated that, in other embodiments, an alarm device may be employed in place of the electric locking device  30 . When the temperature of the component to be cleaned is higher than the safe temperature, the control circuit board  60  controls the alarm device to issue an alarm; when the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board  60  controls the alarm device to release alarm. Therefore, it can effectively remind the user whether the temperature of the component to be cleaned is below the safe temperature or the safe temperature. The alarm device may be selected from at least one of a warning light, a voice device, a buzzer device, and a display device. When the alarm device is a warning light, the following alarm mode may be adopted: when the temperature of the component to be cleaned is greater than the safe temperature, the warning light is red; when the temperature of the component to be cleaned is less than or equal to the safe temperature, the warning light is green. 
     It can be understood that, in other embodiments, the electronic cigarette can include both the electric locking device  30  and the alarm device. Specifically, when the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board  60  controls the locking member  32  to extend out and be inserted into the locking hole  412 , and then the cover  40  is locked, and the control circuit board  60  controls the alarm device to issue an alarm. When the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board  60  controls the locking member  32  to exit the locking hole  412 , and then the cover  40  is unlocked, and the control circuit board  60  controls the alarm device to clear the alarm. 
     It can be understood that, in other embodiments, the electric locking device  30  can employ the electromagnetic lock in the second embodiment in addition to the electric plug lock in the first embodiment. 
     In the cleaning operation, the electric locking device  30  has a safety protection function for the cover  40 , the cover  40  can be opened when the temperature of the component to be cleaned is below the safe temperature or equal to the safe temperature. Otherwise, the cover  40  will be locked by the electric locking device  30  and cannot be opened. Alternatively, the safety of opening the cover  40  is reminded by an alarm device, such as by a warning light, a voice device, a buzzer device or a display device. The alarm will be released when the temperature of the component to be cleaned is below the safe temperature or equal to the safe temperature. Alternatively, the safety of opening the cover  40  is simultaneously protected by the electric locking device  30  and the alarm device, when the temperature of the component to be cleaned is above the safe temperature, the alarm device will issue an alarm and the electric locking device  30  locks the cover  40 . The temperature of the component to be cleaned is below the safe temperature or equal to the safe temperature, the alarm device clears the alarm and the electric locking device  30  unlocks. In this way, safety during cleaning is greatly improved. 
     Referring to  FIG. 6 , when the temperature of the component to be cleaned is detected by the temperature sensor  50 , the temperature warning method of the electronic cigarette is as follows: 
     The temperature sensor  50  detects the temperature of the component to be cleaned, and feeds back the temperature of the component to be cleaned to the control circuit board  60 ; 
     The control circuit board  60  determines the relationship between the temperature of the component to be cleaned and the safe temperature; 
     When the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board  60  controls the alarm device to issue an alarm and/or the control circuit board  60  controls the electric locking device  30  to lock the cover  40 ; 
     When the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board  60  controls the alarm device to release the alarm and/or the control circuit board  60  controls the electric locking device  30  to unlock the cover  40 . 
     Further, when the electric locking device  30  is an electric plug lock, 
     When the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board  60  controls the locking member  32  to extend out and is inserted into the locking hole  412 , and then the cover  40  is locked; 
     When the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board  60  controls the locking member  32  to exit the locking hole  412 , and then the cover  40  is unlocked. 
     Further, when the electric locking device  30  is an electromagnetic lock, 
     When the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board  60  controls the circuit between the electromagnet  34  and the battery  80  to be turned on, the electromagnet  34  generates magnetic attraction to attract the magnetic member  35 , and then the cover  40  is locked; 
     When the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board  60  controls the circuit between the electromagnet  34  and the battery  80  to be disconnected, the magnetic attraction of the electromagnet  34  disappears, and then the cover  40  is unlocked. 
     Referring to  FIG. 7 , when the detected component to be cleaned is the heating component  21  and the heating portion of the heating component  21  is made of a material having a temperature coefficient of resistance characteristic, the temperature warning method of the electronic cigarette is as follows: 
     The control circuit board  60  detects the resistance of the heating portion of the heating component  21 ; 
     The control circuit board  60  calculates the temperature of the heating component  21  based on the correspondence relationship between the resistance of the heating portion and the temperature of the heating component  21 ; 
     The control circuit board  60  determines the relationship between the temperature of the heating component  21  and the safe temperature; 
     When the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board  60  controls the alarm device to issue an alarm and/or the control circuit board  60  controls the electric locking device  30  to lock the cover  40 ; 
     When the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board  60  controls the alarm device to clear the alarm and/or the control circuit board  60  controls the electric locking device  30  to unlock the cover  40 . 
     Further, when the electric locking device  30  is an electric plug lock, 
     When the temperature of the component to be cleaned is greater than the safe temperature, the control circuit board  60  controls the locking member  32  to extend and is inserted into the locking hole  412 , and the cover  40  is locked; 
     When the temperature of the component to be cleaned is less than or equal to the safe temperature, the control circuit board  60  controls the locking member  32  to exit the locking hole  412 , and then the cover  40  is unlocked. 
     Further, when the electric locking device  30  is an electromagnetic lock, 
     When the temperature of the heating component  21  is greater than the safe temperature, the control circuit board  60  controls the circuit between the electromagnet  34  and the battery  80  to be turned on, the electromagnet  34  generates magnetic attraction to attract the magnetic member  35 , and the cover  40  is locked; 
     When the temperature of the heating component  21  is less than or equal to the safe temperature, the control circuit board  60  controls the circuit between the electromagnet  34  and the battery  80  to be disconnected, the magnetic attraction of the electromagnet  34  disappears, and then the cover  40  is unlocked. 
     The Fourth Embodiment 
     Referring to  FIG. 8  and  FIG. 9 , the present disclosure further provides an electronic cigarette comprising a main housing  10 , an atomizing assembly  20  located in the main housing  10 , a cover  40  covering the atomizing assembly  20 , and a locking device disposed between the main housing  10  and the cover  40 . The cover  40  is releasably locked and covered on the atomizing assembly  20  through the locking device. In this embodiment, the locking device is a memory switch  30 ′. 
     The top surface of the main housing  10  is provided with a mounting groove  17  for mounting the atomizing assembly  20  and the memory switch  30 ′, and the mounting groove  17  engages with the cover  40 . The mounting groove  17  has a stepped groove structure including a first groove  111  and a second groove  112  (refer to  FIG. 3  in combination). The first groove  111  engages with the lower end of the heating component  21  of the atomizing assembly  20  for the lower end of the heating component  21  to be inserted. A stepped surface formed between the second groove  112  and the first groove  111  is configured for mounting the memory switch  30 ′, such that the memory switch  30 ′ can be clamped between the inner side surface of the second groove  112  and the outer side of the upper end of the heating component  21 , and the direct contact of the memory switch  30 ′ with the heating component  21  is achieved. In order to accurately and stably mount the cover  40 , the top outer peripheral side of the second groove  112  extends upwardly to form a covered edge  1121  for receiving the cover  40 . 
     The atomizing assembly  20  includes a heating component  21  and a filter  22 . The heating component  21  is received in the mounting groove  17 , the lower end of the heating component  21  is inserted into the first groove  111  of the mounting groove  17 . An assembly gap is formed between the upper end of the heating component  21  and the inner side wall of the second groove  112  for mounting the memory switch  30 ′. The filter  22  is located above the heating component  21  to allow the smoke to pass therethrough while preventing the tobacco contained in the heating component  21  from falling out. In this embodiment, the filter  22  is located in the smoke guiding passage  411 , which is corresponding to the packaging end of the mounting groove  17 . In the embodiment, the heating component  21  is a heating cup, the inner cavity of the heating cup forms an atomizing chamber, the main housing  10  is provided with an air intake hole (not shown). An air inlet  1111  in communication with the air intake hole is defined in the bottom surface of the first groove  111 . The bottom surface of the heating cup is provided with at least one ventilation hole  211 . The ventilation hole  211  is in communication with the air inlet  1111 . The outside air flows into the inner cavity of the heating cup through the intake hole, the air inlet  1111 , and the ventilation hole  211 , and carries the smoke out through the opening of the heating cup. The opening is defined in the upper end of the heating cup. Further, the bottom surface of the heating cup further extends toward the bottom surface of the first groove  111  with a support frame  212 . The heating cup is supported by the support frame  212  on the bottom surface of the first groove  111 , such that an air gap  213  is formed between the bottom surface of the heated cup and the bottom surface of the first groove  111 . The air gap  213  is in communication with the air inlet  1111  and the ventilation hole  211  respectively, can effectively prevent the ventilation hole  211  from being shielded by the bottom surface of the first groove  111 . 
     The memory switch  30 ′ is configured to releasably lock the cover  40 . The memory switch  30 ′ is made of memory alloy material having good thermal conductivity. It is understood that, the component with the highest temperature in the electronic cigarette is the heating component  21 , so that the memory switch  30 ′ is placed close to the heating component  21 . As the temperature of the heating component  21  rises, the temperature of the memory switch  30 ′ also rises. When the temperature of the memory switch  30 ′ is greater than or equal to the transition temperature, the memory switch  30 ′ is deformed, and then the cover  40  is locked. When the temperature of the memory switch  30 ′ is less than the transition temperature, the memory switch  30 ′ is restored to its original state, and then the cover  40  is unlocked. It can be understood that, the room temperature&lt;the transition temperature of the memory switch  30 ′≤the safe temperature, the safe temperature refers to a temperature at which the user suddenly contacts an element at a high temperature in the electronic cigarette without being burnt. In the embedment, the safe temperature is 40° C. Thus, when the components in the electronic cigarette are at a high temperature, the cover  40  cannot be opened, the user can be prevented from being burnt. In the embodiment, the memory switch  30 ′ includes a body  36  and a blocking member  37  disposed on the body  36 . The body  36  is located on the stepped surface between the second groove  112  and the first groove  111 , the blocking member  37  protrudes from the assembly gap between the upper end of the heating component  21  and the inner side wall of the second groove  112 . The number of the memory switches  30 ′ is two, the two memory switches  30 ′ are symmetrically arranged along the central axis of the electronic cigarette, each of the memory switches  30 ′ includes two blocking members  37 , which are axially symmetric along the central axis of the body  36 . When the temperature of the memory switch  30 ′ is greater than or equal to the transition temperature, the blocking member  37  is deformed and the cover  40  is locked; when the temperature of the memory switch  30 ′ is less than the transition temperature, the blocking member  37  is restored and the cover  40  is unlocked. 
     The cover  40  includes a cover plate  41  and a projection  42  protruding from the bottom surface of the cover plate  41 . The upper surface of the cover plate  41  is provided with a smoke guiding passage  411  corresponding to the position of the projection  42 , the bottom end of the smoke guiding passage  411  passes through the projection  42  and is in communication with the heating component  21 . The projection  42  is embedded in the covered edge  1121 , so that the smoke in the atomization chamber flows into the smoke guiding passage  411  of the cover  40 . The outer peripheral surface of the projection  42  adjacent to the lower surface of the projection  42  defines a receiving groove  413  along the lateral direction of the cover  40 . The bottom surface of the receiving groove  413  is provided with a locking hole  412  extending through the lower surface of the projection  42 , for the blocking member  37  to extend through. When the cover  40  is disposed on the atomizing assembly  20 , the projection  42  is embedded in the covered edge  1121 , so that the movement of the cover  40  in the lateral direction of the electronic cigarette is restricted. When the temperature of the memory switch  30 ′ is greater than or equal to the transition temperature, two blocking members  37  of the same body  36  are flared outwardly to a maximum distance between the two blocking members  37  that is greater than the aperture of the locking hole  412 . When the cover  40  moves vertically upward along the electronic cigarette, the locking hole  412  is resisted by the blocking member  37 , whereby the cover  40  is locked. When the temperature of the memory switch  30 ′ is less than the transition temperature, two blocking members  37  on the same body  36  are contracted inwardly to a maximum distance between the two blocking members  37  that is less than or equal to the aperture of the locking hole  412 , and the cover  40  is unlocked. When the smoke moves vertically upward, the locking hole  412  can smoothly pass through the blocking member  37 , whereby the cover  40  is unlocked. 
     The electronic cigarette further includes a control circuit board  60 , an inner mounting bracket  70 , a battery  80  and a battery cover  90 . A mounting window  13  is defined at one side of the main housing  10  for mounting the control circuit board  60 , the inner mounting bracket  70 , and the battery  80  into the inner cavity of the main housing  10 . One side of the inner mounting bracket  70  away from the mounting window  13  is for fixing the control circuit board  60 . The opposite side of the inner mounting bracket  70  is provided with a battery compartment  71  for accommodating the battery  80 . The battery cover  90  is detachably covered on the mounting window  13  of the main housing  10 , the battery compartment  71  is correspondingly covered to secure the battery  80 . In addition, a plurality of button holes  18  or panel holes  14  is defined in one side of the main housing  10  opposite to the mounting window  13  for mounting a button or a display panel. The button hole  18  can be assembled with a button therein, such as a cigarette light key  15 , a power adjustment key  16 , etc., wherein the cigarette light key  15  directly controls the cigarette light circuit of the control circuit board  60  to be turned on/off, so that the circuit between the heating component  21  and the battery  80  is turned On/off. 
     The locking or unlocking of the memory switch  30 ′ is determined by the temperature of the memory switch  30 ′. Specifically, when the atomizing assembly  20  is energized, that is, when the circuit between the heating component  21  and the battery  80  is turned on, the heating component  21  starts to slowly heat up. As the temperature of the heating component  21  rises, when the temperature of the memory switch  30 ′ abutting the heating component  21  rises to the transition temperature, the blocking member  37  at the top of the memory switch  30 ′ is opened. After use, as the temperature of the memory switch  30 ′ drops below the transition temperature, the blocking member  37  of the memory switch  30 ′ returns to the normal temperature state, at which time the cover  40  can be opened. Thereby, it can effectively prevent the cover  40  from being loosened or erroneously opened, to prevent the user from being burnt by the exposed high temperature component (for example, the heating component  21 ). 
     The above-mentioned embodiments merely represent several implementations of the present application, and the descriptions thereof are more specific and detailed, but they shall not be understood as a limitation on the scope of the present application. It should be noted that, for those of ordinary skill in the art, variations and improvements may still be made without departing from the concept of the present application, and all of which shall fall into the protection scope of the present application. Therefore, the scope of protection of the present application shall be subject to the appended claims.