Patent Description:
There is a known non-combustion heating-type smoking device of a type that delivers, to a smoking person, aerosol generated by heating a tobacco rod that contains cut tobacco and an aerosol-source material (glycerin, propylene glycol, and the like) by a heating device, such as an electric heater (refer to, for example, <CIT>).

It has been desired in non-combustion heating-type smoking devices to increase a smoke voluminous feel by increasing the generation amount (delivery amount) of aerosol. To achieve this, it is important to deliver aerosol generated by heating an aerosol-source material to a mouthpiece without a loss.

<CIT> discloses a an aerosol-generating device configured to heat an aerosol-forming substrate using both an internal heater, positioned within the substrate, and an external heater positioned outside the substrate. <CIT> discloses device and method of applying power within the device, so as to repeatedly heat a tobacco product in the same manner, throughout the battery discharge cycle of the device's batteries. <CIT>, which is prior art within the meaning of Art. <NUM>(<NUM>) EPC, discloses a method of controlling power to a heater of an aerosol-generating device to provide consistent feeling of smoking when the device is reused shortly after a previous use.

However, in an existing non-combustion heating-type smoking device, a part whose article temperature is partially low is easily present during heating of a tobacco rod. In some cases, an aerosol-source material that has been once volatilized condenses by being cooled by the part whose article temperature is low. As a result, it may not be possible to deliver a sufficient amount of aerosol to a smoking person, which may decrease smoke voluminous feel. The present invention has been made in condensation of the aforementioned circumstance, and an object of the present invention is to provide a non-combustion heating-type smoking device that is able to suppress aerosol generated by heating from condensing and deliver a sufficient amount of the aerosol to a smoking person.

A non-combustion heating-type smoking device according to the present invention for solving the aforementioned problems includes: a receiving cavity for receiving a tobacco rod containing cut tobacco and an aerosol-source material; an internal heater that is disposed in the receiving cavity to penetrate a tobacco rod inserted into the receiving cavity or to be inserted into a recessed portion formed on an end surface of the tobacco rod, the internal heater being configured to heat the tobacco rod from inside to volatilize the aerosol-source material; and an external heater that is disposed at a side peripheral portion of the receiving cavity and suppresses condensation of aerosol generated during operation of the internal heater by preheating an outer peripheral portion of the tobacco rod during at least a period of preheating the tobacco rod.

A control unit is provided that controls the internal heater and the external heater, and the control unit performs control to cause a temperature of the external heater to be higher than a temperature of the internal heater in a simultaneous heating period in which both the internal heater and the external heater are operated.

At a point of time when an elapsed time since a start of preheating of the tobacco rod by the external heater reaches a predetermined set time or when a temperature of the external heater reaches a predetermined set temperature, the control unit may stop operation of the external heater but continue the operation of the internal heater.

After an operation stop of the external heater, the control unit may increase a temperature of the internal heater compared with that before the operation stop of the external heater.

To start preheating of the tobacco rod, the control unit may cause only the external heater to operate to thereby start the preheating and cause the internal heater to operate by following operation of the external heater.

The receiving cavity may have an insertion port positioned on a leading end side of the side peripheral portion and opening to enable insertion of the tobacco rod, and a cavity bottom portion positioned on a base end side of the side peripheral portion. The side peripheral portion may have a first region including a base end at which the cavity bottom portion is provided and a second region positioned on a side of the insertion port to be adjacent to the first region. The external heater may be not disposed in the first region while being disposed in the second region.

The external heater may be disposed over a whole circumference in a circumferential direction of the side peripheral portion in a partial section or a whole section of the second region.

The internal heater may have n-fold symmetry with respect to a center axis of the receiving cavity, and n may be a whole number more than or equal to <NUM>.

The internal heater may have a columnar shape and may include a conical portion formed on a leading end side thereof.

The internal heater may have a conic solid shape or a frustum shape and may have a shape tapered from a side of the cavity bottom portion toward a side of the insertion port.

The internal heater may have a cone shape or a truncated cone shape.

The side peripheral portion may further have a third region adjacent to the second region and including the insertion port, and the external heater may not be disposed in the third region.

A leading end position of the internal heater may be in correspondence with the second region or the third region in the side peripheral portion.

Note that solutions to problems in the present invention can be employed in combination as far as possible.

According to the present invention, it is possible to provide a non-combustion heating-type smoking device that is able to suppress aerosol generated by heating from condensing and deliver a sufficient amount of the aerosol to a smoking person.

Herein, an embodiment of a non-combustion heating-type smoking device according to the present invention will be described on the basis of the drawings. Note that dimensions, materials, shapes of components, relative arrangements thereof, and the like are described in the present embodiments with no intention to limit the technical scope of the invention thereto only unless specific description is provided in particular.

<FIG> is a schematic view of an internal structure of a non-combustion heating-type smoking device <NUM> according to Embodiment <NUM>. The non-combustion heating-type smoking device <NUM> includes a housing <NUM> that is a housing for housing various types of constituent parts. In the housing <NUM>, a heating device <NUM>, a controller (control unit) <NUM>, a power source <NUM>, and the like are housed.

<FIG> is a schematic view of a configuration of a non-combustion heating-type smoking article <NUM> to be used in the non-combustion heating-type smoking device <NUM>. The non-combustion heating-type smoking article <NUM> includes a tobacco rod <NUM> and a mouthpiece portion <NUM>. Hereinafter, an end of the non-combustion heating-type smoking article <NUM> on the side of the tobacco rod <NUM> is referred to as the leading end, and an end portion thereof on the side of the mouthpiece portion <NUM> is referred to as the base end. The tobacco rod <NUM> is constituted by a filling material <NUM> containing cut tobacco and an aerosol-source material, and wrapping paper <NUM> that wraps the filling material <NUM>. The material of the cut tobacco is not particularly limited and can be a publicly known material, such as laminas and midribs. The filling material <NUM> contains an aerosol-source material that generates aerosol. The type of the aerosol-source material is not particularly limited, and a substance extracted from various natural products can be selected, as appropriate, in accordance with an intended use. As examples of the aerosol-source material, glycerin, propylene glycol, triacetin, <NUM>,<NUM>-butanediol, mixture thereof, and the like can be presented. As examples of the filling material <NUM> containing cut tobacco and an aerosol-source material, there can be presented a restructured tobacco base material that contains homogenized tobacco such as tobacco fine particles, and an additive such as a binding agent, a gelling agent, a crosslinking agent, a flavor, a hydrophilic flavor, a lipophilic flavor, a viscosity modifier, a moisturizing agent, a reinforcing material, and the like. The restructured tobacco base material are, for example, sheet tobacco, cut sheet tobacco, tobacco granules, and the like. The filling material <NUM> may contain a flavor. The type of the flavor is not particularly limited.

The mouthpiece portion <NUM> includes a filter segment or the like in which cellulose acetate molded into, for example, a columnar shape is wrapped by roll-up paper. During smoking, the mouthpiece portion <NUM> filters portion of aerosol generated at the tobacco rod <NUM>. Off course, the mouthpiece portion <NUM> may include segments other than the filter segment. The tobacco rod <NUM> and the mouthpiece portion <NUM> are mutually connected by being integrally rolled up by tip paper <NUM>.

<FIG> is a schematic view of a longitudinal section of a heating device <NUM>. Specifically, a sectional structure of the heating device <NUM> in A-A arrow-view section in <FIG> is illustrated in <FIG>. <FIG> is a perspective view of an overall structure of the heating device <NUM>.

The heating device <NUM> includes a heater housing <NUM> having a bottomed cylindrical shape. The heater housing <NUM> has a bottom portion <NUM> having a disc shape and a cylindrical outer cylinder wall <NUM> extending from the bottom portion <NUM>. An open end of the outer cylinder wall <NUM> in the heater housing <NUM> is open toward the outside of the housing <NUM> through an opening portion provided in the housing <NUM> and forms a receiving cavity <NUM>, which is a columnar cavity portion into which the tobacco rod <NUM> of the non-combustion heating-type smoking article <NUM> is insertable.

Here, on the leading end side of the outer cylinder wall <NUM> of the heater housing <NUM>, a thick portion <NUM> having an inner diameter smaller by one step than the other parts is formed. The leading end of the outer cylinder wall <NUM> mentioned here is an end portion of the outer cylinder wall <NUM> opposite to the base end thereof connected to the bottom portion <NUM>. In addition, a cavity side peripheral wall <NUM> having a cylindrical shape is provided on the inner side of the outer cylinder wall <NUM> of the heater housing <NUM>. The outer diameter of the cavity side peripheral wall <NUM> is equal to the inner diameter of the thick portion <NUM> of the outer cylinder wall <NUM>. As illustrated in <FIG>, an annular hollow air thermal-insulation portion <NUM> is formed between the inner surface of the outer cylinder wall <NUM> of the heater housing <NUM> and an outer peripheral surface 32b of the cavity side peripheral wall <NUM>. At the leading end of the cavity side peripheral wall <NUM>, an insertion port <NUM> opening to enable insertion of the tobacco rod <NUM> is formed. The end portion of the cavity side peripheral wall <NUM> opposite to the leading end side where the insertion port <NUM> is formed is referred to as a base end 32c.

On the side of the bottom portion <NUM> of the heater housing <NUM>, a heat-resistant cup <NUM> having a bottomed cylindrical shape is provided. The heat-resistant cup <NUM> is formed of a heat-resistant material, for example, aluminum or the like and has a cavity bottom portion <NUM> having a disc shape and a cavity side peripheral wall <NUM> extending from the cavity bottom portion <NUM>. The cavity bottom portion <NUM> of the heat-resistant cup <NUM> is disposed in a state of being stacked on the inner side of the bottom portion <NUM> of the heater housing <NUM> and forms the cavity bottom portion of the receiving cavity <NUM>. The cavity side peripheral wall <NUM> and the cavity side peripheral wall <NUM> form a side peripheral portion of the receiving cavity <NUM>.

As illustrated in <FIG> and <FIG>, in the heating device <NUM>, the heat-resistant cup <NUM> and the cavity side peripheral wall <NUM> form the receiving cavity <NUM>, which is a cavity portion for receiving the tobacco rod <NUM>. In addition, as illustrated in <FIG> and <FIG>, the cavity side peripheral wall <NUM> is provided with an annular external heater <NUM> facing the receiving cavity <NUM>. The external heater <NUM> is housed in a recessed portion of the cavity side peripheral wall <NUM> so as to be flush with an inner peripheral surface 32a of the cavity side peripheral wall <NUM>. Here, the sign 35a denotes a heating surface facing the receiving cavity <NUM>. The annular external heater <NUM> is disposed over the whole circumference along the inner peripheral surface 32a of the cavity side peripheral wall <NUM>. In other words, the external heater <NUM> is disposed over the whole circumference of the side peripheral portion in the circumferential direction of the receiving cavity <NUM>. Note that the sign CL1 indicated in <FIG> denotes the center axis of the heater housing <NUM>. The center axis CL <NUM> is, at the same time, the center axis of each of the receiving cavity <NUM> and the cavity side peripheral wall <NUM>.

As illustrated in <FIG> and <FIG>, an internal heater <NUM> is provided in the receiving cavity <NUM>. The internal heater <NUM> has a truncated cone shape and projects vertically from a center portion of the bottom portion <NUM> of the heater housing <NUM> toward the side of the receiving cavity <NUM>. A through hole is formed at a center portion of the cavity bottom portion <NUM> of the heat-resistant cup <NUM>, and the internal heater <NUM> is inserted through the through hole to thereby project from the cavity bottom portion <NUM> toward the side of the receiving cavity <NUM>. The center axis of the internal heater <NUM> is the same as the center axis CL of the heater housing <NUM> (the receiving cavity <NUM>). The sign 36a denotes the base end portion of the internal heater <NUM>, and the sign 36b denotes the leading end portion of the internal heater <NUM>. The internal heater <NUM> extends from the cavity bottom portion <NUM> toward the insertion port <NUM> and is tapered gradually from the base end portion 36a toward the leading end portion 36b. Although the types of the internal heater <NUM> and the external heater <NUM> are not particularly limited, for example, a steel material on which a heat generating wire (for example, nichrome, iron chrome, iron nickel, and the like) is disposed to be laid out, or a ceramic heater, a sheath heater (Sheathed Heater), or the like is usable. Note that the sheath heater is a heater in which a heat wire is covered together with a filler by a metal pipe.

In the present embodiment, the cavity side peripheral wall <NUM> is formed of a known heat insulating and heat resistant material to resist the heat of the external heater <NUM> and suppress the heat of the external heater <NUM> from dispersing. As a material to be used for the cavity side peripheral wall <NUM> having such heat insulation capacity and heat resistance capacity, there can be presented, for example, an alumina silica ceramic material, resins of highly heat-resistant PEEK (polyether ether ketone), PPS (polyphenylene sulfide), PTFE (polytetrafluoroethylene), and the like.

In the present embodiment, the inner peripheral surface 32a of the cavity side peripheral wall <NUM>, an inner peripheral surface 332a of the cavity side peripheral wall <NUM> of the heat-resistant cup <NUM>, and the heating surface 35a of the external heater <NUM> are flush with each other without a step, and thus, the inner diameter of the receiving cavity <NUM> is constant in the direction of the center axis CL <NUM>. In the present embodiment, the inner diameter of the receiving cavity <NUM> may be equal to the outer diameter of the tobacco rod <NUM> or may be slightly larger than the outer diameter of the tobacco rod <NUM>.

Here, the signs R1 to R3 indicated in <FIG> denote a first region to a third region in the cavity side peripheral wall <NUM> (side peripheral portion). The first region R1 in the cavity side peripheral wall <NUM> is a region that includes the base end 32c where the cavity bottom portion <NUM> is provided. The second region R2 in the cavity side peripheral wall <NUM> is a region positioned on the side of the insertion port <NUM> to be adjacent to the first region R1 and is a region in which the external heater <NUM> is disposed in a partial section or the whole section thereof. That is, the second region R2 has a meaning as a region that defines a maximum range in which the external heater <NUM> is formed, and the external heater <NUM> is disposed in the whole region or a partial region of the second region R2. The third region R3 in the cavity side peripheral wall <NUM> is a region that is adjacent to the second region and that includes the insertion port <NUM>. The first region R1 to the third region R3 are regions formed along the center axis CL1 of the receiving cavity <NUM> and are formed in the order of the first region R1, the second region R2, and the third region R3 from the cavity bottom portion <NUM> toward the insertion port <NUM>. The length in the direction of the center axis CL1 of each of the first region R1 to the third region R3 can be changed, as appropriate. As illustrated in <FIG>, the external heater <NUM> is disposed only in the second region R2 in the cavity side peripheral wall <NUM>, and the external heater <NUM> is not disposed in the first region R1 and the third region R3. In the example illustrated in <FIG>, the external heater <NUM> is disposed in the whole section of the second region R2 of the cavity side peripheral wall <NUM>; however, the external heater <NUM> may be provided in only a partial section of the second region R2.

Each of <FIG> and <FIG> is a view of a state in which the tobacco rod <NUM> of the non-combustion heating-type smoking article <NUM> is inserted into the receiving cavity <NUM> through the insertion port <NUM> in the heating device <NUM>. The internal heater <NUM> of the heating device <NUM> in the present embodiment has a truncated cone shape and is tapered toward the leading end portion 36b, which enables the internal heater <NUM> to penetrate with respect to the tobacco rod <NUM> (the filling material <NUM>) when the tobacco rod <NUM> (the filling material <NUM>) is inserted into the receiving cavity <NUM>. In the present embodiment, insertion of the tobacco rod <NUM> into the receiving cavity <NUM> is completed at a point of time when a leading end surface 11a (refer to <FIG>) of the tobacco rod <NUM> comes into contact with the bottom portion of the receiving cavity <NUM>, that is, the cavity bottom portion <NUM> of the heat-resistant cup <NUM>. As illustrated in <FIG>, in the state in which insertion of the tobacco rod <NUM> with respect to the receiving cavity <NUM> has been completed, a rear end portion <NUM>1b of the tobacco rod <NUM> is positioned in correspondence with the third region R3 of the above-described cavity side peripheral wall <NUM>. The sign P1 indicated in <FIG> denotes a position (hereinafter referred to as "received-rod rear end position") corresponding to the rear end portion <NUM>1b of the tobacco rod <NUM> in the state in which insertion of the tobacco rod <NUM> with respect to the receiving cavity <NUM> has been completed. In the present embodiment, a clearance between the received-rod rear end position P1 and the external heater <NUM> is set to about <NUM>, which is a comparatively small clearance.

The heating device <NUM> having the aforementioned structure includes the external heater <NUM> disposed at a side peripheral portion of the receiving cavity <NUM>, and the internal heater <NUM> disposed near the center of a cross section of the receiving cavity <NUM> along the center axis CL1. The external heater <NUM> and the internal heater <NUM> of the heating device <NUM> generate heat by being supplied with electric power from the power source <NUM>. The power source <NUM> may be, for example, a rechargeable lithium ion battery but is not particularly limited. Although connection between the power source <NUM> and each of the external heater <NUM> and the internal heater <NUM> in the heating device <NUM> is not illustrated in <FIG>, the external heater <NUM> and the internal heater <NUM> are each connected to the power source. A controller <NUM> is electrically connected to the power source <NUM>, and the controller <NUM> controls power supply from the power source <NUM> with respect to the external heater <NUM> and the internal heater <NUM>. The non-combustion heating-type smoking device <NUM> is provided with a user interface (for example, an operation button and the like), not illustrated, operable by a user (smoking person), and the controller <NUM> is electrically connected to the user interface. The controller <NUM> performs control relating to the operation of the heating device <NUM> (the external heater <NUM> and the internal heater <NUM>) by detecting the operation with respect to the user interface by a user Hereinafter, control of the external heater <NUM> and the internal heater <NUM> by the controller <NUM> in the non-combustion heating-type smoking device <NUM> will be described.

For example, in a state in which the power of the non-combustion heating-type smoking device <NUM> is turned off, when a predetermined turn-on operation is performed on an operation button of the non-combustion heating-type smoking device <NUM> by a user, the controller <NUM> starts power supply from the power source <NUM> to the heating device <NUM> and performs heating control that heats the tobacco rod <NUM> in a state of being received, as illustrated in <FIG>, in the receiving cavity <NUM> of the heating device <NUM>. <FIG> is a time chart indicating operation states of the external heater <NUM> and the internal heater <NUM> during the heating control of the heating device <NUM> executed by the controller <NUM>. <FIG> is a graph for describing transition of surface temperatures of the external heater <NUM> and the internal heater <NUM> during the heating control.

In <FIG>, the time T0 represents a time (hereinafter referred to as "heating start time") at which a turn-on operation with respect to the operation button of the non-combustion heating-type smoking device <NUM> is detected by the controller <NUM>. As illustrated in <FIG>, the controller <NUM> starts power supply from the power source <NUM> with respect to only the external heater <NUM> at the heating start time.

Next, at the time T1, the controller <NUM> starts power supply from the power source <NUM> with respect to the internal heater <NUM> while continuing power supply from the power source <NUM> to the external heater <NUM>. Hereinafter, the time T1 is referred to as "internal heating start time". Next, at the time T2, the controller <NUM> stops power supply from the power source <NUM> with respect to the external heater <NUM> while continuing power supply from the power source <NUM> to the internal heater <NUM>. Hereinafter, the time T2 is referred to as "external heating stop time". Next, at the time T3 after a lapse of a predetermined smoking period since the time T0 (heating start time), power supply from the power source <NUM> with respect to the internal heater <NUM> is stopped. Hereinafter, the time T3 is referred to as "heating stop time".

As described above, the non-combustion heating-type smoking device <NUM> in the present embodiment causes only the external heater <NUM> to operate at the heating start time at which heating with respect to the tobacco rod <NUM> is started and performs preheating (initial heating) of the tobacco rod <NUM>. Here, the external heater <NUM> is disposed along the cavity side peripheral wall <NUM> positioned at the outer peripheral portion (side surface) of the receiving cavity <NUM> and thus can efficiently heat the outer peripheral portion of the tobacco rod <NUM> received in the receiving cavity <NUM>. That is, it is possible to efficiently preheat, in particular, the outer peripheral portion of the tobacco rod <NUM> before heating of the tobacco rod <NUM> by the internal heater <NUM> is started at the time T1 (internal heating start time). Here, a period from the time T0 (heating start time) to the time T1 (internal heating start time) is referred to as "preheating period". The preheating period can be set as a period from the heating start time (that is, start of preheating) to a point of time when an elapsed time since the heating start time reaches a predetermined set time or when the temperature of the external heater <NUM> reaches a predetermined set temperature. For example, during the preheating period, the controller <NUM> may set the set temperature to control the external heater <NUM> at <NUM>.

The tobacco rod <NUM> is heated by both the external heater <NUM> and the internal heater <NUM> during a period (hereinafter referred to as "simultaneous heating period") from the heating start time to a point of time when an elapsed time since the heating start time reaches a predetermined set time or when the temperature of the external heater <NUM> reaches a predetermined set temperature, that is, from the time T1 (internal heating start time) to the time T2 (external heating stop time). As described above, the internal heater <NUM> is disposed to have the same axis as the center axis CL1 of the receiving cavity <NUM>. Therefore, the heat of the internal heater <NUM> penetrating the tobacco rod <NUM> (the filling material <NUM>) is transmitted radially from the center side toward the outer peripheral side of the tobacco rod <NUM>. As a result, it is possible to efficiently heat the tobacco rod <NUM> and possible to volatilize an aerosol-source material (for example, glycerin and the like) contained in the filling material <NUM> of the tobacco rod <NUM> and a flavor component contained in cut tobacco in a short period and generate aerosol containing a flavor component.

In the filling material <NUM> of the tobacco rod <NUM> containing an aerosol-source material (for example, glycerin and the like), water (moisture) in the filling material <NUM> first evaporates with an increase in the article temperature. The evaporation occurs at around the boiling point (<NUM>) of water. It is considered that, when the article temperature of the filling material <NUM> in the tobacco rod <NUM> is further increased, nicotine whose atmospheric boiling point is about <NUM> next starts to be volatilized, and, when the article temperature is further increased, glycerin whose atmospheric boiling point is <NUM> evaporates and sucked as aerosol. As is obvious for a person skilled in the art, various types of components in various forms are contained in a tobacco raw material, and these components are present as chemical compounds. It is thus considered that, scientifically, principle components evaporate (are volatilized) in the order of the boiling points thereof although simple evaporation events do not occur only in the vicinity of the boiling point of a pure substance, such as water, nicotine, and glycerin described above.

As illustrated in <FIG>, the controller <NUM> controls the temperature of the external heater <NUM> to be higher than the temperature of the internal heater <NUM> during the simultaneous heating period (times T1 to T2). For example, during the simultaneous heating period, the controller <NUM> sets the set temperature of the external heater <NUM> to <NUM> and the set temperature of the internal heater <NUM> to <NUM> and control the external heater <NUM> and the internal heater <NUM>. In the present embodiment, the temperature of the outer peripheral portion of the tobacco rod <NUM> is increased rapidly and efficiently by the external heater <NUM> in contact with or close to the outer peripheral portion during the preheating period of the tobacco rod <NUM>, and the temperature of the external heater <NUM> is controlled to be higher than the temperature of the internal heater <NUM> also during the subsequent simultaneous heating period. Consequently, it is possible to actively increase the temperature of the outer peripheral portion of the tobacco rod <NUM> having difficulty in receiving heat from the internal heater <NUM> due to a distance from the internal heater <NUM> and having a likelihood of easily receiving an influence (heat radiation loss) of outdoor air. That is, it is possible to efficiently heat the center side in the cross section of the tobacco rod <NUM> by the internal heater <NUM> and to efficiently heat, by the external heater <NUM>, the outer peripheral portion of the tobacco rod <NUM> having difficulty in receiving heat of the internal heater <NUM> and having a likelihood of easily receiving an influence (heat radiation loss) of outdoor air. Consequently, it is possible to uniformly heat the entirety of the tobacco rod <NUM> to a temperature at which an aerosol-source material is sufficiently volatilized.

It is also possible to reduce total power consumption, compared with when both the external heater <NUM> and the internal heater <NUM> are operated during the preheating period, by heating the tobacco rod <NUM> with only the external heater <NUM> during the preheating period and causing the internal heater <NUM> to operate after a lapse of the preheating period by following the operation of the external heater <NUM>.

In addition, it is possible to suppress condensation (dew condensation/liquefaction) of an aerosol-source material that has been once volatilized from occurring at the outer peripheral portion of the tobacco rod <NUM> by, as described above, actively heating the outer peripheral portion of the tobacco rod <NUM> during the preheating period and the simultaneous heating period by the external heater <NUM>. Therefore, it is possible to sufficiently ensure the delivery amount of aerosol during, in particular, initial smoking and possible to improve the smoke voluminous feel.

In particular, according to the non-combustion heating-type smoking device <NUM> in the present embodiment, as illustrated in <FIG>, the external heater <NUM> is positioned at the base end side (the side of the mouthpiece portion <NUM>) of the tobacco rod <NUM> received in the receiving cavity <NUM>. It is thus possible to intensively heat, in particular, the region on the base end side of the outer peripheral portion in the tobacco rod <NUM> by the external heater <NUM>. This provides an advantage that it is possible to effectively suppress condensation of aerosol generated on the leading end side (upstream side) of the tobacco rod <NUM> from occurring on the base end side (downstream side) of the tobacco rod <NUM>.

Here, the external-heater width dimension, which is the length of the external heater <NUM> extending in the direction of the center axis CL1 of the receiving cavity <NUM>, is preferably at least a dimension more than or equal to one-third the tobacco rod <NUM>. Consequently, it is possible to sufficiently preheat the outer peripheral portion of the tobacco rod <NUM> during the preheating period of the tobacco rod <NUM> before the start of heating by the internal heater <NUM>.

After the temperature of the entirety of the tobacco rod <NUM> is sufficiently increased, as described above, during the simultaneous heating period, the temperature of the tobacco rod <NUM> can be maintained at a temperature at which condensation of aerosol does not occur by only heating with the internal heater <NUM>. The controller <NUM> thus stops the operation of the external heater <NUM> at a point of time when the external heating stop time (time T2) is reached. At this time, the controller <NUM> stops the operation of the external heater <NUM> before the temperature of the internal heater <NUM> exceeds the temperature of the external heater <NUM>. The external heating stop time (time T2) at which the operation of the external heater <NUM> is stopped can be set as a point of time when an elapsed time since the heating start time (that is, start of preheating) reaches a predetermined set time or when the temperature of the external heater <NUM> reaches a predetermined set temperature. Alternatively, various forms can be employed, and the operation of the external heater <NUM> may be stopped at a point of time when a certain period has elapsed since the temperature of the external heater <NUM> has reached a predetermined set temperature.

After the external heating stop time (time T2) has passed, the tobacco rod <NUM> is heated by only the internal heater <NUM>, and the temperature of the external heater <NUM> decreases naturally. Therefore, as illustrated in <FIG>, the temperature of the internal heater <NUM> exceeds the temperature of the external heater <NUM> at an intermediate point in a period (hereinafter referred to as "internal heating period") from the external heating stop time (time T2) to the heating stop time (time T3).

Heating efficiency in heating the tobacco rod <NUM> is excellent in the internal heater <NUM> disposed at a center portion, compared with the external heater <NUM> disposed on the outer peripheral side of the receiving cavity <NUM>. It is thus possible to generate aerosol stably and continuously by heating the tobacco rod <NUM> with only the internal heater <NUM>, in which heating efficiency is excellent, during a remaining smoking period in which conditions for suppressing easy condensation of aerosol are met due to the temperature of the entirety of the tobacco rod <NUM> being increased sufficiently during the simultaneous heating period.

After stopping the operation of the external heater <NUM>, the controller <NUM> may control power supply from the power source <NUM> to the internal heater <NUM> so as to increase the temperature of the internal heater <NUM> compared with the temperature before stopping of the operation of the external heater <NUM>. For example, the controller <NUM> may change the set temperature of the internal heater <NUM> from <NUM> to <NUM>. The set temperature of the internal heater <NUM> in the internal heating period is preferably set to an appropriate temperature that enables stable and continuous volatilization of an aerosol-source material contained in the tobacco rod <NUM> through heating with only the internal heater <NUM>. When, as described above, the set temperature of the internal heater <NUM> is increased after stopping of the operation of the external heater <NUM>, the power consumption of the internal heater <NUM> increases. It is however possible to reduce the power consumption as a total because the operation of the external heater <NUM> is stopped.

At the time T3 (heating stop time) after a lapse of a predetermined smoking period since the heating start time (time TO), the controller <NUM> stops power supply from the power source <NUM> to the internal heater <NUM>.

<FIG> show results of a temperature measurement test in which transition of the surface temperature of the external heater <NUM>, the surface temperature of the internal heater <NUM>, and the article temperature of the tobacco rod <NUM> when heating control of the heating device <NUM> was performed by the controller <NUM> was measured. <FIG> is a diagram indicating an article-temperature measurement position of the tobacco rod <NUM>.

In the temperature measurement test, as the article temperature of the tobacco rod <NUM>, temperatures at a first measurement position MP1 to a third measurement position MP3, illustrated in <FIG>, were measured. The clearance between each of the measurement positions MP1 to MP3 and the side peripheral surface (the inner peripheral surface 32a of the cavity side peripheral wall <NUM>) of the receiving cavity <NUM> in the radial direction of the receiving cavity <NUM> is <NUM>. The clearance between each of the measurement positions MP1 to MP3 and the base end portion 36a of the internal heater <NUM> in the radial direction of the receiving cavity <NUM> is <NUM>.

As illustrated in <FIG>, the first measurement position MP1 to the third measurement position MP3 are arranged in the order of the first measurement position MP <NUM>, the second measurement position MP2, and the third measurement position MP3 from the side of the cavity bottom portion <NUM>. In the direction of the center axis CL1 of the receiving cavity <NUM>, the clearance between the cavity bottom portion <NUM> and the first measurement position MP1 is <NUM>. The clearance between the first measurement position MP1 and the second measurement position MP2 is <NUM>. The clearance between the second measurement position MP2 and the third measurement position MP3 is <NUM>. The clearance between the third measurement position MP3 and the received-rod rear end position P1 is <NUM>. In the heating control, the elapsed time since the heating start time to the internal heating start time is set to <NUM> seconds, the elapsed time since the heating start time to the external heating stop time is set to <NUM> seconds, and the elapsed time since the heating start time to the heating stop time is set to <NUM> seconds.

In each of <FIG>, the temperature transition indicated by a solid line indicates temperature transition (hereinafter referred to as "example") at each of the measurement positions MP1 to MP3 when the heating control according to the present embodiment described with <FIG> and <FIG> is performed. The temperature transition indicated by a dashed line indicates temperature transition (hereinafter referred to as "comparative example") at each of the measurement positions MP1 to MP <NUM> when the heating control is performed by using only the internal heater <NUM>, without the use of the external heater. The two-dot chain line indicated in each of <FIG> indicates the target article temperature in heating of the tobacco rod <NUM>. The target article temperature is, for example, <NUM>. As illustrated in <FIG>, at the first measurement position MP1 and the second measurement position MP2, which are present at positions corresponding to the first region R1 in the cavity side peripheral wall <NUM>, there is no remarkable difference in the heating control between the example and the comparative example. It is considered that an influence of the external heater <NUM> is small since the first measurement position MP1 and the second measurement position MP2 are both distanced from the external heater <NUM> and comparatively close to the internal heater <NUM>. Meanwhile, as illustrated in <FIG>, there is a remarkable difference at the third measurement position MP3 between the example and the comparative example. The target article temperature can be easily reached in a shorter time in the example than in the comparative example, and an advantage of the example with respect to the comparative example is confirmed.

As described above, the non-combustion heating-type smoking device <NUM> in the present embodiment includes the internal heater <NUM> that is disposed in the receiving cavity <NUM> and that heats the tobacco rod <NUM> from inside to thereby volatilize the aerosol-source material, and the external heater <NUM> that is disposed at the side peripheral portion of the receiving cavity <NUM> and that preheats the outer peripheral portion of the tobacco rod <NUM> at least during the preheating period of the tobacco rod <NUM> to thereby suppress condensation of aerosol generated during the operation of the internal heater <NUM>. Consequently, the temperature of the outer peripheral portion of the tobacco rod <NUM>, which has difficulty in receiving heat from the internal heater and has a likelihood of easily receiving an influence (heat radiation loss) of outdoor air, can be previously increased sufficiently during the preheating period by the external heater. It is thus possible to suppress occurrence of condensation of aerosol generated during the operation of the internal heater <NUM>. Therefore, it is possible to sufficiently ensure the delivery amount of aerosol during smoking and possible to improve the smoke voluminous feel.

In the aforementioned embodiment, the external heater <NUM> is not disposed in the first region R1 including the base end 32c at which the cavity bottom portion <NUM> of the cavity side peripheral wall <NUM> (side peripheral portion) is provided and the third region R3 including the insertion port <NUM>, and the external heater <NUM> is disposed in the second region R2 positioned closer than the first region R1 to the insertion port <NUM>. It is thus possible to intensively heat, of the outer peripheral portion in the tobacco rod <NUM>, in particular, the region on the base end side by the external heater <NUM>. Consequently, the aerosol generated on the leading end side (upstream side) of the tobacco rod <NUM> can be effectively suppressed from condensing on the base end side (downstream side) of the tobacco rod <NUM>.

In particular, the internal heater <NUM> in the present embodiment has a tapered shape whose diameter decreases from the base end portion 36a toward the leading end portion 36b, and therefore, the amount of heat radiation with respect to the tobacco rod <NUM> tends to be smaller at the leading end portion 36b of the internal heater <NUM> than that on the base end side. However, it is possible to suitably compensate for a lacking amount of heat radiation at the leading end portion 36b of the internal heater <NUM> by disposing the external heater <NUM> around (a position corresponding to the leading end portion 36b of the internal heater <NUM>) the leading end portion 36b of the internal heater <NUM>. By not disposing the external heater <NUM> in the first region R1 where the amount of heat radiation from the internal heater <NUM> can be sufficiently ensured, it is also possible to efficiently heat the base end region in the outer peripheral portion of the tobacco rod <NUM> by the external heater <NUM> while suppressing power consumption of the power source <NUM>.

Further, in the present embodiment, the external heater <NUM> is not disposed in the third region R3 in the cavity side peripheral wall <NUM> (side peripheral portion). It is thus possible to suppress, for example, the filter segment positioned at the front end portion of the mouthpiece portion <NUM> from burning or melting due to the heat of the external heater <NUM> when the external heater <NUM> is operated.

In the present embodiment, an example in which the shape of the internal heater <NUM> is a truncated cone shape has been described. By employing the internal heater <NUM> having a shape thus tapered from the side of the cavity bottom portion <NUM> toward the side of the insertion port <NUM>, the internal heater <NUM> is enabled to easily penetrate the filling material <NUM> of the tobacco rod <NUM> inserted into the receiving cavity <NUM>. In addition, it is possible to favorably maintain the contact state between the internal heater <NUM> and the filling material <NUM> in the state in which the internal heater <NUM> penetrate the filling material <NUM>. As a result, generated heat of the internal heater <NUM> is easily transmitted to the filling material <NUM>, which can improve efficiency in heating of the filling material <NUM>. Note that, although the internal heater <NUM> is caused to penetrate the filling material <NUM> of the tobacco rod <NUM> inserted into the receiving cavity <NUM> in the present embodiment, the internal heater <NUM> may be inserted into a recessed portion formed on an end surface of the filling material <NUM> on the leading end side (upstream side) in the tobacco rod <NUM>.

Various shapes can be employed for the internal heater <NUM>. For example, the internal heater <NUM> may have a conic solid shape (cone or pyramid shape) or a frustum shape (truncated cone or pyramid shape) and have a shape tapered from the side of the cavity bottom portion <NUM> toward the side of the insertion port <NUM>. For example, instead of the truncated cone shape, a cone shape may be employed. The internal heater <NUM> may have a columnar shape. In this case, a conical portion may be formed at the columnar part of the internal heater <NUM> on the leading end side thereof. The internal heater <NUM> may have n-fold symmetry with respect to the center axis CL1 of the receiving cavity <NUM>, and n may be a whole number more than or equal to <NUM>.

In the example illustrated in <FIG>, the leading end portion 36b of the internal heater <NUM> in the heating device <NUM> is disposed at a position corresponding to the leading end (an end portion on the side of the insertion port <NUM>) of the second region R2 in the cavity side peripheral wall <NUM> (side peripheral portion). The position of the leading end portion 36b is, however, not limited thereto. For example, as in the modification illustrated in <FIG>, the leading end portion 36b of the internal heater <NUM> may be disposed at a position corresponding to an intermediate portion of the second region R2. As in the modification illustrated in <FIG>, the leading end portion 36b of the internal heater <NUM> may be disposed at a position corresponding to the third region R3. As in the modification illustrated in <FIG>, the leading end portion 36b of the internal heater <NUM> may be disposed at a position corresponding to the first region R1.

Claim 1:
A non-combustion heating-type smoking device (<NUM>) comprising:
a receiving cavity (<NUM>) for receiving a tobacco rod (<NUM>) containing cut tobacco and an aerosol-source material;
an internal heater (<NUM>) that is disposed in the receiving cavity to penetrate a tobacco rod (<NUM>) inserted into the receiving cavity or to be inserted into a recessed portion formed on an end surface of the tobacco rod (<NUM>), the internal heater being configured to heat the tobacco rod (<NUM>) from inside to volatilize the aerosol-source material; and
an external heater (<NUM>) that is disposed at a side peripheral portion of the receiving cavity and suppresses condensation of aerosol generated during operation of the internal heater (<NUM>) by preheating an outer peripheral portion of the tobacco rod (<NUM>) during at least a period of preheating the tobacco rod (<NUM>); and
a control unit (<NUM>) that controls the internal heater and the external heater,
wherein the control unit performs control to cause a temperature of the external heater (<NUM>) to be higher than a temperature of the internal heater (<NUM>) in a simultaneous heating period in which both the internal heater and the external heater are operated.