Abstract:
An electronic cigarette with a sensor assembly in an isolated and protected location includes a heating member and a cigarette holder having an air suction port opened to the air outside. The sensor assembly includes an inductive chamber. An open end of the inductive chamber is in air communication with the air suction port. The heating member is arranged outside of the inductive chamber. Inhalations on the electronic cigarette cause decrease of air pressure in the inductive chamber, the resulting reduced air pressure being sensed by the sensor assembly, which is located in the inductive chamber.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The subject matter herein generally relates to electronic cigarettes. This application is a continuation application of PCT patent application Serial Number PCT/CN2016/090672, filed on Jul. 20, 2016, which claims priority to CN Patent Application Serial Number 201610405471.X, filed on Jun. 8, 2016, the disclosure of which is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The subject matter herein generally relates to electronic cigarettes. 
       BACKGROUND 
       [0003]    A conventional electronic cigarette automatically controls the opening and closing of the electronic cigarette by detecting the suction action of a user, by a sensor arranged in an airflow passage adjacent to an air inlet. However, as the heating member is also located in the airflow passage, and the sensor is located between the heating member and the air inlet, the suction of the user is hindered by the heating member, and thus a greater suction force is needed to allow the airflow in the airflow passage cause air pressure for the detection by the sensor. On the other hand, since the heating member is in liquid communication with a smoke liquid storage member, the smoke liquid in the smoke liquid storage member may leak into the airflow passage through the heating member, and leaked smoke liquid may block the air inlet. Therefore, the air outside of the electronic cigarette may be blocked from entering into the airflow passage, thus affecting the detection by the sensor. Additionally, the leaked smoke liquid may enter into the sensor, which would cause the sensor to short-circuit. In addition, there may be residual smoke in the airflow passage that can cause the airflow passage to be humid. The sensor over a long period under such environment may affect its service life. 
       SUMMARY 
       [0004]    The present disclosure provides an electronic cigarette having a sensor isolated from a heating member. 
         [0005]    The electronic cigarette includes a heating member, a sensor assembly, and a cigarette holder having an air suction port in air communication with the air outside of the electronic cigarette. The sensor assembly includes an inductive chamber and a sensor arranged in the inductive chamber. The heating member is arranged outside of the inductive chamber. One end of the inductive chamber is an open end while the other end is a sealed end. The open end of the inductive chamber is in air communication with the air suction port. 
         [0006]    The electronic cigarette further includes an airflow passage isolated from the inductive chamber and an air inlet in air communication with the air outside of the electronic cigarette. The airflow passage is in air communication with the air suction port and the air inlet. The heating member is arranged in the airflow passage. 
         [0007]    The sensor assembly further includes a splitter plate and a shutoff piece. The splitter plate is arranged in the cigarette holder. The shutoff piece is located at one end of the cigarette holder opposite to the air suction port, and the shutoff piece is coupled to the splitter plate and an inner wall of one side of the cigarette holder. The inner wall of one side of the cigarette holder, one side of the splitter plate, and the shutoff piece together form the inductive chamber. The inner wall of the other side of the cigarette holder and the other side of the splitter plate together form a connection port. The air suction port is in air communication with the connection port, and one end of the airflow passage opposite to the air inlet is in air communication with the connection port. 
         [0008]    The shutoff piece is a shutoff tube. One end of the shutoff tube is an open end, the other end of the shutoff tube is a sealed end. The shutoff tube is located at one end of the cigarette holder opposite to the air suction port, and the open end of the shutoff tube is coupled between the splitter plate and one side of the inner wall of the cigarette holder. The sealed end of the shutoff tube is the sealed end of the inductive chamber. 
         [0009]    The shutoff piece is a shutoff plate. The shutoff plate is located at one end of the cigarette holder opposite to the air suction port, and the shutoff plate is coupled between the splitter plate and one side of the inner wall of the cigarette holder. The shutoff plate is the sealed end of the inductive chamber. 
         [0010]    At least one of the splitter plate and the shutoff piece are integrally formed with the cigarette holder. 
         [0011]    One end of the splitter plate adjacent to the air suction port extends into the air suction port, and divides the air suction port into a first air suction port and a second air suction port. The first air suction port is isolated from the second air suction port. The first air suction port is in air communication with the connection port, and the second air suction port is in air communication with the inductive chamber. 
         [0012]    The sensor assembly further includes a film arranged in the inductive chamber and located above the sensor. 
         [0013]    The airflow passage includes a smoke outlet part arranged along a lengthways axial direction of the electronic cigarette and an air inlet part arranged along a direction radiating out from the center line of the axial direction. The heating member is an open-ended and hollow structure. The heating member is in air communication with the air inlet part and the smoke outlet part. One end of the air inlet part opposite to the smoke outlet part is in air communication with the air inlet. One end of the smoke outlet part opposite to the air inlet part is in air communication with the air suction port. 
         [0014]    The airflow passage includes an air inlet part arranged along the lengthways axial direction of the electronic cigarette and a smoke outlet part arranged along the same axial direction and fitted within the air inlet part. An upper end of the air inlet part is in air communication with the air inlet, and a lower end of the air inlet part is in air communication with the heating member. An upper end of the smoke outlet part is in air communication with the air suction port, and a lower end of the smoke outlet part is distanced from the heating member for the air inlet part in air communication with the smoke outlet part. 
         [0015]    The electronic cigarette further includes a controller and a battery assembly. The heating member and the battery assembly are electrically connected with the controller. The sensor is connected with the controller through signals. 
         [0016]    An electronic cigarette includes a heating member, a sensor, and an airflow passage. The heating member is arranged in the airflow passage. A passage wall of the airflow passage is at least partially made of a flexible material, to form an elastic portion. The sensor is arranged on the elastic portion and located outside of the airflow passage. 
         [0017]    The electronic cigarette further includes a cigarette holder and a housing. One end of the cigarette holder defines an air suction port, the other end of the cigarette holder is coupled to the housing. The heating member, the sensor and the airflow passage are received in the housing. The housing defines an air inlet. The airflow passage is in air communication with the air suction port and the air inlet. 
         [0018]    The airflow passage includes an air inlet part arranged along a radial direction of the electronic cigarette and a smoke outlet part arranged along an axial direction of the electronic cigarette. 
         [0019]    The heating member is an open-ended and hollow structure. The heating member is in air communication with the air inlet part and the smoke outlet part. One end of the air inlet part opposite to the smoke outlet part is in air communication with the air inlet. One end of the smoke outlet part opposite to the air inlet part is in air communication with the air suction port. 
         [0020]    The smoke outlet part is an open-ended and hollow tube. The hollow tube is made of the flexible material. The sensor is arranged outside of a wall of the hollow tube. 
         [0021]    The sensor is a strain gauge type transducer or a capacitive type transducer. 
         [0022]    The electronic cigarette further includes a storage member for storing smoke liquid. The heating member is in liquid communication with the storage member. 
         [0023]    The electronic cigarette further includes a controller and a battery assembly. The heating member, the sensor and the battery assembly are electrically connected with the controller. 
         [0024]    The battery assembly includes a battery module and a charging module. The controller and the charging module are electrically connected with the battery module. 
         [0025]    When the electronic cigarette of the present disclosure is being used, one end of the inductive chamber is an open end and the other end is a sealed end. The open end of the inductive chamber is in air communication with the air suction port. The sensor is arranged in the inductive chamber. The heating member is arranged outside of the inductive chamber, so that the suction action of the user may directly act on the sensor without obstruction by the heating member. On the other hand, the inductive chamber is isolated from the airflow passage, thus the detection of the sensor is not affected by the leaked smoke liquid which blocks the air inlet. Since a humid environment in the inductive chamber is avoided, service life of this device is extended. The likelihood of short-circuited of the sensor caused by the leakage of the smoke liquid is also reduced. 
         [0026]    According to another electronic cigarette of the present disclosure, the sensor is arranged outside of the airflow passage and senses the suction state of the user by sensing the deformation of the elastic portion of the airflow passage. The sensor is not arranged in the airflow passage, which can prevent the sensor from shortening a service life caused by an influence of a humid environment in the airflow passage, and also can prevent a circuit of the sensor from being short-circuited caused by the leakage of the smoke liquid. 
         [0027]    The drawings should be combined with specific embodiments to fully describe the disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    Implementations of the present technology will now be described, by way of example only, with reference to the attached figures. 
           [0029]      FIG. 1  is a cross-sectional view of an electronic cigarette in one mode according to a first embodiment. 
           [0030]      FIG. 2  is a cross-sectional view of the electronic cigarette according to the first embodiment in another mode. 
           [0031]      FIG. 3  is a cross-sectional view of yet another mode of the electronic cigarette according to the first embodiment. 
           [0032]      FIG. 4  is a cross-sectional view of an electronic cigarette according to a second embodiment. 
       
    
    
       [0033]    Referring to  FIGS. 1-4, 100 and 200  represent an electronic cigarette in a first embodiment and in a second embodiment respectively. As between the two embodiments,  10  and  10   a  represent a cigarette holder,  11  and  11   a  represent an air suction port,  12  represents a connection port,  111  represents a first air suction port,  112  represents a second air suction port,  20  and  20   a  represent a heating member, and  30  and  30   a  represent a controller.  40  represents a sensor assembly,  41  represents an inductive chamber,  411  represents a first open end,  412  represents a first sealed end,  42  and  42   a  represent a sensor,  43  represents a splitter plate,  44  represents a shutoff piece,  441  represents a second open end,  442  represents a second sealed end,  443  represents an inner chamber,  45  represents a film,  50  and  50   a  represent a battery assembly,  51  and  51   a  represent a battery module,  52  and  52   a  represent a charging module, and  60  and  60   a  represent an airflow passage.  61  and  61   a  represent an air inlet part,  62  and  62   a  represent a smoke outlet part,  70  and  70   a  represent a storage member,  71  and  71   a  represent a liquid inlet hole,  80  and  80   a  represent a housing, and  81  and  81   a  represent an air inlet. 
       DETAILED DESCRIPTION 
       [0034]    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 may 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. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features. The description is not to be considered as limiting the scope of the embodiments described herein. 
         [0035]    Several definitions that apply throughout this disclosure will now be presented. 
         [0036]    The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection may be such that the objects are permanently connected or releasably connected. The term “outside” refers to a region that is beyond the outermost confines of a physical object. The term “substantially” is defined to be essentially conforming to the particular dimension, shape, or other feature that the term modifies, such that the component need have that exact feature. 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. 
         [0037]    The terms “first”, “second” and other terms in the present disclosure are only used as textual symbols as the circumstances may require, but such a practice of ordination is not limited to using only these terms. It should be further noted that these terms can be used interchangeably. 
         [0038]    Referring to  FIG. 1 , in a first embodiment, an electronic cigarette  100  includes a cigarette holder  10 , a heating member  20 , a controller  30 , a sensor assembly  40 , and a battery assembly  50 . The cigarette holder  10  has an air suction port  11  in air communication with the air outside of the electronic cigarette  100 . The sensor assembly  40  includes an inductive chamber  41  and a sensor  42  arranged in the inductive chamber  41 . The heating member  20  and the battery assembly  50  are electrically connected with the controller  30 , and the sensor  42  is connected with the controller  30  through signals. The heating member  20  is arranged outside of the inductive chamber  41 . The inductive chamber  41  has two ends, one end of the inductive chamber  41  is a first open end  411 , and the other end of the inductive chamber  41  is a first sealed end  412 . The first open end  411  of the inductive chamber  41  is in air communication with the air suction port  11 . 
         [0039]    When a user inhales through the air suction port  11 , at least part of air within the inductive chamber  41  is sucked out. Air pressure in the inductive chamber  41  decreases, thus the sensor  42  may detect the change of the pressure, generate a trigger signal, and send the trigger signal to the controller  30 . The controller  30  receives the trigger signal, and controls the battery assembly  50  to supply electrical power to the heating member  20 . 
         [0040]    When the user stops inhaling through the air suction port  11 , the inductive chamber  41  is in air communication with the air outside of the electronic cigarette  100  by the air suction port  11 , to restore the air pressure in the inductive chamber  41 . Thus, the sensor  42  may sense the restored air pressure, and generate a shutdown signal and transmit the shutdown signal to the controller  30 . The controller  30  receives the shutdown signal, and controls the battery assembly  50  to stop supplying electrical power to the heating member  20 . 
         [0041]    The sensor assembly  40  includes a splitter plate  43  and a shutoff piece  44 . The splitter plate  43  is arranged in the cigarette holder  10 . The shutoff piece  44  is located at one end of the cigarette holder  10  opposite to the air suction port  11 , and the shutoff piece  44  is coupled to the splitter plate  43  and an inner wall of one side of the cigarette holder  10 . Thus, the inner wall of one side of the cigarette holder  10 , one side of the splitter plate  43 , and the shutoff piece  44  together form the inductive chamber  41 . An inner wall of the other side of the cigarette holder  10  and the other side of the splitter plate  43  together form a connection port  12 . The connection port  12  is in air communication with the air suction port  11 . 
         [0042]    In one mode, the shutoff piece  44  is a shutoff tube. The shutoff tube has two ends. On end of the shutoff tube is a second open end  441 , the other end of the shutoff tube is a sealed end  442 . The second open end  441  of the shutoff tube is coupled to the splitter plate  43  and one side of the inner wall of the cigarette holder  10 , respectively, and the second open end  441  of the shutoff tube is located at one end of the cigarette holder  10  opposite to the air suction port  11 . The second sealed end  442  of the shutoff tube is the first sealed end  412  of the inductive chamber  41 . The shutoff tube has an inner chamber  443 . The inner chamber  443  of the shutoff tube is also a part of the inductive chamber  41 . The sensor  42  may be arranged in the inner chamber  443  of the shutoff tube, so a location of the sensor  42  may be changed according to a suitable size and/or shape of the shutoff tube. In the embodiment, the second sealed end  442  of the shutoff tube is arranged adjacent to the controller  30 . The sensor  42  is arranged in the inner chamber  443  of the shutoff tube, and located at the second sealed end  442  of the shutoff tube, thus facilitating the electrical connection of the sensor  42  with the controller  30 . 
         [0043]    Referring to  FIG. 2 , in another mode, the shutoff piece  44  is a shutoff plate. The shutoff plate is coupled to the splitter plate  43  and one side of the inner wall of the cigarette holder  10 , respectively. The shutoff plate is located at one end of the cigarette holder  10  opposite to the air suction port  11 . The shutoff plate is the first sealed end  412  of the inductive chamber  41 . By using the shutoff plate, a size of the inductive chamber  41  can be reduced, thus space within the electronic cigarette  100  can be saved. The saved space can be used to store the smoke liquid. The sensor  42  is adjacent to the air suction port  11  by using the shutoff plate, thus facilitating the accuracy of the sensor  42  when detecting inhalations of the user. 
         [0044]    In other embodiments, at least one of the splitter plate  43  and the shutoff piece  44  may be integrally formed with the cigarette holder  10 . 
         [0045]    Referring again to  FIG. 1 , one end of the splitter plate  43  adjacent to the air suction port  11  extends into the air suction port  11 , to divide the air suction port  11  into a first air suction port  111  and a second air suction port  112 . The first air suction port  111  and the second air suction port  112  are isolated from each other. The first air suction port  111  is in air communication with the connection port  12 , and the second air suction port  112  is in air communication with the inductive chamber  41 . The smoke created in the electronic cigarette  100  flows from the connection port  12  to the first air suction port  111 , and the air in the inductive chamber  41  is sucked out by the second air suction port  112 , which may prevent the smoke entering into the inductive chamber  41  through a connection (not shown) among the connection port  12 , the inductive chamber  41 , and the air suction port  11 , render the air pressure in the inductive chamber  41  more reliable and prevent detection interference to the sensor  42 . 
         [0046]    Furthermore, the sensor assembly  40  further includes a film  45  arranged in the inductive chamber  41  and located above the sensor  41 . The film  45  may be impermeable and deformable. The arrangement of the film  45  can prevent contamination from the air suction port  11  or the second air suction port  112  from entering into the inductive chamber  41  and polluting the sensor  42 , thereby affecting the sensitivity of the sensor  42 . When the user inhales through the air suction port  11  or the second air suction port  112 , the air within in the inductive chamber  41  and located above the film  45  is at least partially sucked out from the air suction port  11  or the second air suction port  112 . Thus, the film  45  is raised upward toward the air suction port  11  or the second air suction port  112 , and a space formed between the film  45  and one end of the shutoff piece  44  adjacent to the sensor  42  in the inductive chamber  41  increases, thus reducing air pressure in the space below the film  45  within the inductive chamber  41 . The sensor  42  may sense the pressure change, generate the trigger signal, and send the trigger signal to the controller  30 . The controller  30  receives the trigger signal, and controls the battery assembly  50  to supply an electrical power to the heating member  20 . When the user stops inhaling from the air suction port  11  or the second air suction port  112 , the space above the film  45  within the inductive chamber  41  is in air communication with the air outside through the air suction port  11  or the second air suction port  112 , and allows the air pressure to be restored. Thus, a deformation of the film  45  is restored, and the pressure in the space below the film  45  within the inductive chamber  41  is restored. The sensor  42  may sense the restored air pressure, and generate the shutdown signal to the controller  30 . The controller  30  receives the shutdown signal, and controls the battery assembly  50  to stop supplying the electrical power to the heating member  20 . 
         [0047]    The battery assembly  50  includes a battery module  51  and a charging module  52 . The controller  30  and the charging module  52  are electrically connected with the battery module  51 . The battery module  51  is configured to supply the electric power to the heating member  20  under the control of the controller  30 . The charging module  52  is configured to couple to an external power source, to allow the external power source to charge the battery module  51 . 
         [0048]    The electronic cigarette  100  further includes an airflow passage  60 , a storage member  70 , and a housing  80 . The airflow passage  60  is isolated from the inductive chamber  41 . The storage member  70  is configured to store the smoke liquid. One end of the cigarette holder  10  opposite to the air suction port  11  is coupled to the housing  80 . The heating member  20 , the controller  30 , the battery assembly  50 , the airflow passage  60 , and the storage member  70  are received in the housing  80 . In one embodiment, the sensor assembly  40  is received in the cigarette holder  10 . In another embodiment, one part of the sensor assembly  40  is received in the cigarette holder  10 , the other part of the sensor assembly  40  is received in the housing  80 . The housing  80  defines an air inlet  81 . The airflow passage  60  is in air communication with the connection port  12  and the air inlet  81 . The heating member  20  is arranged in the airflow passage  60  and is in liquid communication with the storage member  70 . A wall of the storage member  70  defines a liquid inlet hole  71  aligned with the heating member  20 . The smoke liquid stored in the storage member  70  flows to the heating member  20  through the liquid inlet hole  71 . When the battery module  51  supplies the electric power to the heating member  20 , the heating member  20  heats the smoke liquid to form smoke. Air flows into the airflow passage  60  through the air inlet  81 , flows through the heating member  20  and mixes with the smoke, then flows to the connection port  12 , and finally flows out from the air suction port  11  or the first air suction port  111  when inhaled. 
         [0049]    In the present embodiment, the airflow passage  60  is substantially L-shaped. The airflow passage  60  includes an air inlet part  61  and a smoke outlet part  62 . The smoke outlet part  62  is arranged along an axial and lengthways direction of the electronic cigarette  100  and the air inlet part  61  is arranged along a direction extending radially from the center line of the axial direction of the electronic cigarette  100 . The heating member  20  is a hollow and open-ended structure. The hollow structure allows communication between the air inlet part  61  and the smoke outlet part  62 . One end of the air inlet part  61  opposite to the smoke outlet part  62  is in air communication with the air inlet  81 . One end of the smoke outlet part  62  opposite to the air inlet part  61  is in air communication with the connection port  12 . 
         [0050]    Referring to  FIG. 3 , in another mode, the airflow passage  60  includes an air inlet part  61  and a smoke outlet part  62 . The air inlet part  61  is arranged along the axial direction of the electronic cigarette  100 . The smoke outlet part  62  is arranged along the axial direction of the electronic cigarette  100  and fitted within the air inlet part  61 . An upper end of the air inlet part  61  is in air communication with the air inlet  81 , and a lower end of the air inlet part  61  is connected to the heating member  20 . An upper end of the smoke outlet part  62  is in air communication with the connection port  12 , and a lower end of the smoke outlet part  62  is distanced from the heating member  20  for the air inlet part  61  in air communication with the smoke outlet part  62 . 
         [0051]    In the present mode, the inductive chamber  41  has two ends. One end of the inductive chamber  41  is a first open end  411 , the other end of the inductive chamber  41  is a first sealed end  412 . The open end of the inductive chamber  41  is in air communication with the air suction port  11 . The sensor  42  is arranged in the inductive chamber  41 , and the heating member  20  is arranged outside of the inductive chamber  41 , to allow the suction action of the user directly act on the sensor  42  without obstruction by the heating member  20 . On the other hand, the inductive chamber  41  is isolated from the airflow passage  60 , thus the detection of the sensor  42  is not affected by the leaked smoke liquid which blocks the air inlet  81 . Since a humid environment in the inductive chamber  41  is avoided, service life of this device is extended. The likelihood of short-circuited of the sensor  42  caused by the leakage of the smoke liquid is also reduced. 
         [0052]    Referring to  FIG. 4 , in a second embodiment, an electronic cigarette  200  includes a cigarette holder  10   a , a heating member  20   a , a controller  30   a , a sensor  42   a , a battery assembly  50   a , an airflow passage  60   a , a storage member  70   a  storing a smoke liquid, and a housing  80   a . The cigarette holder  10   a  has two ends. One end of the cigarette holder  10   a  defines an air suction port  11   a , the other end of the cigarette holder  10   a  is coupled to the housing  80   a . The heating member  20   a , the controller  30   a , the sensor  42   a , the battery assembly  50   a , the airflow passage  60   a , and the storage member  70   a  are received in the housing  80   a . The heating member  20   a , the sensor  42   a , and the battery assembly  50   a  are electrically connected with the controller  30   a . The housing  80   a  defines an air inlet  81   a . The airflow passage  60   a  is in air communication with the air suction port  11   a  and the air inlet  81   a . The heating member  20   a  is arranged in the airflow passage  60   a , and is in liquid communication with the storage member  70   a . The airflow passage  60   a  has a passage wall. The passage wall of the airflow passage  60   a  is at least partially made of a flexible material, to form an elastic portion. The sensor  42   a  is arranged on the elastic portion and located outside of the airflow passage  60   a.    
         [0053]    When the user inhales through the air suction port  11   a , an air pressure within the airflow passage  60   a  decreases, and the elastic portion deforms. Thus, the sensor  42   a  may sense the deformation, and generate a trigger signal and send the trigger signal to the controller  30   a . The controller  30   a  receives the trigger signal, and controls the battery assembly  50   a  to supply an electrical power to the heating member  20   a . A wall of the storage member  70   a  defines a liquid inlet hole  71   a  aligned with the heating member  20   a . The smoke liquid stored in the storage member  70   a  flows to the heating member  20   a  through the liquid inlet hole  71   a . The heating member  20   a  heats the smoke liquid to create smoke. Air from outside flows into the airflow passage  60   a  through the air inlet  81   a , then mixes with the smoke, and finally flows out from the air suction port  11   a.    
         [0054]    When the user stops inhaling through the air suction port  11   a , the airflow passage  60   a  is in air communication with the air outside of the electronic cigarette  200  through the air suction port  11   a . The air pressure in the airflow passage  60   a  is restored and the deformation of the elastic portion is discontinued. Thus, the sensor  42   a  can sense the restoration of the elastic portion, and generates a shutdown signal to the controller  30   a . The controller  30   a  receives the shutdown signal, and controls the battery assembly  50   a  to stop supplying the electrical power to the heating member  20   a.    
         [0055]    The sensor  42   a  may be a strain gauge type transducer or a capacitive type transducer. 
         [0056]    In one embodiment, the airflow passage  60   a  is substantially L-shaped. The airflow passage  60   a  includes an air inlet part  61   a  and a smoke outlet part  62   a . The air inlet part  61   a  is arranged radially from the lengthways axis of the electronic cigarette  200 , and the smoke outlet part  62   a  is arranged along the lengthways axis. The heating member  20   a  is a hollow and open-ended structure. The hollow structure communicates between the air inlet part  61   a  and the smoke outlet part  62   a . One end of the air inlet part  61   a  opposite to the smoke outlet part  62   a  is in air communication with the air inlet  81   a . One end of the smoke outlet part  62   a  opposite to the air inlet part  61   a  is in air communication with the air suction port  11   a . The smoke outlet part  62   a  is a hollow and open-ended tube. The smoke outlet part  62   a  is made of a flexible material. The sensor  42   a  is arranged outside of the wall of the hollow tube. 
         [0057]    The battery assembly  50   a  includes a battery module  51   a  and a charging module  52   a . The controller  30   a  and the charging module  52   a  are electrically connected the battery module  51   a . The battery module  51   a  is configured to supply the electric power to the heating member  20   a  under the control of the controller  30   a . The charging module  52   a  is configured to couple to an external power source, to allow the external power source to charge the battery module  51   a.    
         [0058]    In this embodiment, the sensor  42   a  of the electronic cigarette  200  is arranged outside of the airflow passage  60   a , to sense inhalations of the user by sensing the deformation of the elastic portion of the airflow passage  60   a . By not arranging the sensor  42   a  in the airflow passage  60   a , the service life of the sensor  42   a  is prolonged due to a less humid environment, and also the likelihood of the sensor  42   a  being short-circuited caused by the leakage of the smoke liquid is reduced. 
         [0059]    The embodiments shown and described above are only examples. Many details are often found in the art such as the other features of an electronic cigarette. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structure and function of the embodiments, the present disclosure is illustrative only, and changes may be made in details, including in the matters of shape, size, and arrangement of parts within the principles of the embodiments to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.