Aerosol generating device including a heating plate including a ceramic portion and a metal portion and related control method - Patents.com

Abstract

The present invention relates to an aerosol generating device configured to operate with a flat shaped tobacco article (12) and comprising a flat shaped heating chamber (50), the heating chamber (50) configured to receive the flat shaped tobacco article (12) and comprising a heating plate (70) at least partially forming the walls (54A, 54B) of the heating chamber (50), the heating plate (70) comprising a ceramic portion (72) and a metal portion (74) different from and engaged with the ceramic portion (72), both portions (72, 74) being arranged to heat the flat shaped tobacco article (12).

Description

[Technical field]

[0001] The present invention relates to an aerosol generating device that includes a heating plate that includes a ceramic portion and a metallic portion.

[0002] In particular, the aerosol generating device according to the invention is configured to operate with tobacco articles, e.g. flat shaped tobacco articles comprising a solid substrate capable of forming an aerosol when heated. Thus, such types of aerosol generating devices, also known as non-combustion heating devices, are adapted to heat, by conduction, convection and / or radiation, rather than burning, a substrate, to generate an aerosol for inhalation.

[0003] The present invention also relates to a method of controlling an aerosol generating device. [Background technology]

[0004] The popularity and use of risk reduction or risk modification devices (also known as vaporizers) has grown rapidly in recent years as an aid to support habitual smokers who wish to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos and roll-up cigarettes. A variety of devices and systems are available that heat or warm a vaporizable substance, as opposed to lighting the tobacco of a traditional tobacco product.

[0005] Commonly available risk reduction or risk modification devices are heated substrate aerosol generating devices or heated non-combustion devices. This type of device typically generates an aerosol or vapor by heating an aerosol substrate, which typically includes moist tobacco or other suitable vaporizable material, to a temperature typically in the range of 150°C to 350°C. By heating the aerosol substrate but not burning or igniting it, an aerosol is released that includes components that are desired by the user but are not the toxic and carcinogenic by-products of combustion and ignition. Furthermore, because the aerosol generated by heating tobacco or other vaporizable material typically does not include the burnt or bitter taste that results from combustion and ignition, which can be unpleasant to the user, the substrate therefore does not require the sugar and other additives that are typically added to such materials to make the smoke and / or vapor more palatable to the user.

[0006] Tobacco articles that can be used with such types of aerosol generating devices can take a variety of forms, some of which can be elongated sticks or any other suitable shape, such as a flat shape, however, the design of a tobacco article is often a trade-off between its aesthetic value and heating efficiency.

[0007] Some of the known aerosol generating devices that operate in conjunction with tobacco articles include heaters that consume a lot of energy to bring the heater to a predetermined temperature, and therefore the tobacco article, to a target temperature.

[0008] For example, WO 2019 / 128551 describes an aerosol generating device that includes a heating zone including at least one electromagnetic induction heating device or at least one resistive heating device and a heating chamber configured to receive a sheet of tobacco. Summary of the Invention [Problem to be solved by the invention]

[0009] One object of the present invention is to provide an aerosol generating device that requires less energy to heat a tobacco article to a target temperature. [Means for solving the problem]

[0010] To this end, the present invention provides an aerosol generating device adapted to operate with a flat shaped tobacco article and including a flat shaped heating chamber, comprising: the heating chamber is configured to receive a flat shaped tobacco article and includes a heating plate at least partially forming a wall of the heating chamber; The heating plate relates to an aerosol generating device that includes a ceramic portion and a metal portion distinct from and engaged with the ceramic portion, both portions being positioned to heat a flat shaped tobacco article.

[0011] These features make it possible to provide an aerosol generating device that heats the tobacco article in an optimal manner and at the same time requires less energy to heat the tobacco article to a target temperature. In particular, the metal part allows the tobacco article to be heated quickly with little energy, allowing the user to puff the cigarette quickly. Furthermore, the metal part is advantageously configured to heat the ceramic part by thermal conduction. The high thermal mass of the ceramic part allows uniform heating of the surface of the tobacco article. Furthermore, the ceramic part has a high thermal penetration into the tobacco article and can generate more vapor compared to a heater comprising only a metal part. Thus, the user experience during use of the aerosol generating device may be improved. A heating plate comprising a metal part and a ceramic part allows reducing the energy required to heat the heating plate to a given temperature and obtaining a uniform heating of the heating plate during a puff session compared to the energy used to heat a heating plate comprising only a ceramic part to said temperature. The combination of the metal part and the ceramic part therefore allows optimizing the heating of a flat-shaped tobacco article.

[0012] The ceramic part may be made of a single element. In a variant, the ceramic part may be made of at least two elements.

[0013] The metal part may be made of a single element. In a variant, the metal part may be made of at least two elements. The metal part may form a resistive element designed to be powered by a power source. The supply of power may be controlled by a control unit of the aerosol generating device. The metal part may be connected to an electric wire supplying the power, for example by welding to the metal part of the electric wire. According to another embodiment, a polyimide film heater is placed adjacent to, in particular in contact with, the metal part in order to heat the metal part by thermal conduction. According to another embodiment of the invention, the heating chamber comprises a magnetic element capable of causing heating of the metal part by magnetic induction.

[0014] According to some embodiments, the ceramic portion extends around the metal portion.

[0015] This feature improves thermal conduction from the metal portion to the ceramic portion. The metal portion and the ceramic portion extending around the metal portion may be in contact. Thus, having the ceramic portion extending around the metal portion allows for an increased contact area between the ceramic portion and the metal portion, which may result in improved thermal conduction from the metal portion to the ceramic portion.

[0016] According to some embodiments, the ceramic portion defines a recess that receives the metal portion.

[0017] This feature allows the heating plate to be easily manufactured, since the provision of the recesses can be done by known tools and known manufacturing methods. Furthermore, this feature makes it possible to obtain a compact heating plate adapted for its integration in an aerosol generating device. The recesses can correspond to blind holes.

[0018] According to some embodiments, the ceramic portion and the metal portion engaged with the ceramic portion form a planar surface designed to contact or face a flat shaped tobacco article.

[0019] According to this feature, the heating plate has a surface designed to contact or face a flat shaped tobacco article, the shape of which is complementary to the flat shape of the flat shaped tobacco article. The part of the plane formed by the ceramic part may be continuous. In a variant, the part of the plane made by the ceramic part has zones separated from one another. The part of the plane formed by the metal part may be continuous. In a variant, the part of the plane formed by the metal part has zones separated from one another. As an alternative, the surfaces formed by the ceramic part and the metal part have a shape other than flat, for example a rounded shape.

[0020] According to some embodiments, the metal portions form at least 50%, preferably at least 60%, advantageously at least 70% of the total area of ​​the plane.

[0021] This feature allows efficient and rapid heating of the flat-shaped tobacco article by the metal part. Moreover, this feature allows optimal heating of the ceramic part by the metal part. Moreover, this feature allows the part of the plane formed by the ceramic part to be located adjacent to or in front of the end of the tobacco part of the tobacco article, so that efficient heating of said tobacco part is achieved. This results in better extraction of tobacco from the tobacco part of the flat-shaped tobacco article.

[0022] According to some embodiments, the recess forms a shape complementary to the contour of the metal portion so as to fit closely with the metal portion.

[0023] This feature results in a compact heating plate, which can therefore be easily integrated into an aerosol generating device.

[0024] According to some embodiments, the recess preferably forms a substantially parallelepiped shape with rounded corners.

[0025] This feature makes the heater plate easy to manufacture since the parallelepiped shape can be provided using well known tooling and manufacturing methods.

[0026] According to some embodiments, the heating plate is designed to extend substantially along the entire area of ​​the tobacco portion contained in the flat shaped tobacco article.

[0027] This feature allows the entire area of ​​the tobacco portion to be heated. According to some embodiments, the heating plate is designed to protrude from the end of the tobacco portion defined along the device axis. This ensures proper heating of the end of the tobacco portion defined by the device axis and thus better extraction of tobacco from the tobacco portion of the flat shaped tobacco article.

[0028] According to some embodiments, both the ceramic portion and the metal portion are designed to contact or face the tobacco portion of a flat shaped tobacco article.

[0029] For example, the ceramic portion directly contacts or faces the end of the tobacco portion such that the end of the tobacco portion is heated during every puff session. By "directly", it is understood that there are no intermediate elements extending between the ceramic plate and the end of the tobacco portion.

[0030] According to some embodiments, the ceramic portion is configured to be heated by thermal conduction through the metallic portion.

[0031] This feature makes it possible to achieve optimal heating of the heating plate during an inhalation session whilst requiring less energy to heat the metal and therefore the ceramic parts.

[0032] According to some embodiments, the heating chamber includes two heating plates forming at least partially opposing walls of the heating chamber.

[0033] This feature provides uniform heating.

[0034] The present invention also relates to a method of controlling an aerosol generating device as described above, comprising the step of heating a metal part, the heated metal part heating the ceramic part by thermal conduction.

[0035] The invention and its advantages will be better understood from reading the following description, given by way of non-limiting example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0036] [Figure 1] FIG. 1 is a perspective view of an aerosol generation assembly according to the present invention, the aerosol generation assembly including an aerosol generation device according to the present invention and a tobacco article that can be used with the aerosol generation device. [Diagram 2] FIG. 2 is a perspective view of the tobacco article of FIG. 1. [Diagram 3] 2 is a partial cross-sectional view of the aerosol generation assembly of FIG. 1 according to plane III, the aerosol generation device including a heating plate according to the present invention. [Figure 4] FIG. 2 is a partial cross-sectional view of the aerosol generation assembly of FIG. 1 taken along plane IV. [Diagram 5] FIG. 4 is a detailed view of the heating plate of FIG. 3. [Figure 6] FIG. 6 is a front view of the heating plate of FIG. 5 along arrow VI. [Figure 7] FIG. 6 is a front view of the ceramic portion of the heating plate of FIG. 5. [Figure 8] FIG. 8 is a cross-sectional view of the ceramic part of FIG. 7 according to plane VIII. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Before the present invention is described, it is to be understood that the invention is not limited to the details of construction set forth in the following description. It will be apparent to one skilled in the art having the benefit of this disclosure that the invention is capable of other embodiments and of being practiced or carried out in various ways.

[0038] In the following, the expression "substantially equal" is understood as being equal to plus or minus 10%, preferably plus or minus 5%.

[0039] As used herein, the term "aerosol generating device" or "device" may include an inhalation device for delivering an aerosol to a user, including an aerosol for inhalation, using a heater element, which will be described in further detail below. The device may be portable. "Portable" may refer to a device for use when held by a user. The device may be adapted to generate a variable amount of aerosol, for example by activating the heater element for various amounts of time (as opposed to a fixed amount of aerosol), which may be controlled by a trigger. The trigger may be one that is activated by the user, such as an inhale button and / or a draw sensor. The draw sensor may be sensitive to the duration of the draw as well as the intensity of the draw (to mimic the smoking effect of a conventional combustion-based smoking article, such as a cigarette, cigar, or pipe, etc.), to allow for the provision of a variable amount of vapor. The device may include a temperature regulation control device for driving the temperature of the heater and / or heated aerosol-generating material (aerosol precursor) to a specific target temperature and then maintaining the temperature at a target temperature that can efficiently generate aerosol.

[0040] As used herein, the term "aerosol" may include a suspension of vaporizable material as one or more of solid particles, liquid droplets, and gas. The suspension may be in a gaseous state, including air. Aerosol herein may generally refer to / include a vapor. Aerosol may include one or more components of vaporizable material.

[0041] As used herein, the term "vaporizable material" or "precursor" may refer to a smokable material that may include, for example, nicotine or tobacco and an aerosol-forming agent. Tobacco may take the form of various materials, such as cut tobacco, granulated tobacco, tobacco leaf, and / or reconstituted tobacco. Suitable aerosol-forming agents include polyols (e.g., glycols such as sorbitol, glycerol, and propylene glycol or triethylene glycol), non-polyols (e.g., monohydric alcohols, acids such as lactic acid, glycerol derivatives, esters such as triacetin, triethylene glycol diacetate, triethyl citrate, glycerin, or vegetable glycerin). In some embodiments, the aerosol-generating agent may be glycerol, propylene glycol, or a mixture of glycerol and propylene glycol. The substrate may also include at least one of a gelling agent, a binder, a stabilizer, and a humectant.

[0042] Figure 1 shows an aerosol generating assembly 10 including an aerosol generating device 11 and a tobacco article 12. The aerosol generating device 11 is intended to operate with a tobacco article 12, which is shown in more detail in Figure 2.

[0043] In this example of Fig. 2, the tobacco article 12 is a flat-shaped tobacco article, for example, a flat-shaped rectangular parallelepiped extending along the article axis X and having external dimensions L12 x W12 x D12. In a typical example, the length L12 of the article 12 along the article axis X is substantially equal to 33 millimeters (mm), while its width W12 and depth D12 are substantially equal to 12 mm and 1.2 mm, respectively. According to another example, the values ​​L12, W12 and D12 can be selected, for example, within a range of + / - 40%. The depth D12 of the tobacco article 12 is formed by a pair of parallel walls 13A, 13B, hereinafter referred to as narrow walls 13A, 13B, and the width W12 of the tobacco article 12 is formed by a pair of parallel walls 14A, 14B, hereinafter referred to as wide walls 14A, 14B. In some embodiments, the edges between the wide and narrow walls 13A, 13B, 14A, 14B may be rounded. According to other embodiments of the present invention, the tobacco article 12 may have any other suitable shape and / or external dimensions. According to still other embodiments, the tobacco article 12 may exhibit any other suitable shape, such as a stick shape.

[0044] The tobacco article 12 includes a tobacco portion 15 and a mouthpiece portion 16 disposed along the article axis X. For example, the tobacco portion 15 may be slightly longer than the mouthpiece portion 16. The tobacco portion 15 is formed by parallel walls 15A, 15B that are part of the broad walls 14A, 14B of the tobacco article 12. For example, a length L15 of the tobacco portion 15 along the article axis X may be substantially equal to 18 mm. A width W15 of the tobacco portion 15 is equal to a width W12 of the tobacco article 12. A length L16 of the mouthpiece portion 16 along the article axis X may be substantially equal to 15 mm. The tobacco portion 15 defines an abutment end 18 of the article 12, and the mouthpiece portion 16 defines a mouth end 20 of the article 12. The tobacco portion 15 and the mouthpiece portion 16 may be secured to one another by a wrapper 21 that extends around the substrate axis X. The wrapper 21 forms the narrow and broad walls 13A, 13B, 14A, 14B of the tobacco article 12. In some embodiments, the wrapper 21 is formed from the same wrapping sheet. In some other embodiments, the wrapper 21 is formed by separate wrapping sheets that wrap the portions 15, 16 separately and are secured together by any other suitable means. The wrapper 21 may comprise, for example, paper, and / or nonwoven fabric, and / or aluminum foil. The wrapper 21 may be porous or air impermeable and forms a plurality of air flow passages extending inside the article 12 between the abutment end 18 and the mouth end 20.

[0045] The mouthpiece portion 16 includes a core 27 intended to act, for example, as a cooler to slightly cool the vapour before it is inhaled by the user. The core 27 may for example comprise corrugated paper for this purpose. The core 27 may be formed into a stable shape via an extrusion and / or rolling process. Advantageously, the core 27 is arranged inside the mouthpiece portion 16 so as to be in full contact with the inner surface of the wrapper 21 and to define the boundary of this mouthpiece portion 16.

[0046] As will be explained in more detail below, tobacco portion 15 includes a vaporizable material and is intended to be heated by a heating chamber.

[0047] 1, the aerosol generating device 11 comprises a device body 40 and a mouthpiece 42 extending along a device axis Y. According to the example described below, the mouthpiece 42 and the device body 40 form two different parts. In particular, according to this example, the mouthpiece 42 is designed to be fixed to a fixed end of the device body 40.

[0048] As shown in FIG. 3, the mouthpiece 42 includes a central portion 43 and a peripheral portion 44 extending around the central portion 43. The peripheral portion 44 defines, for example, a collar that partially covers the outer surface of the device body 40 when the mouthpiece 42 is fixed to the fixed end of the device body 40. For example, the peripheral portion 44 can be designed to work with a gasket 45 disposed at the fixed end of the device body 40 to seal a space formed between the peripheral portion 44 and the outer surface of the device body 40. The peripheral portion 44 also defines an intermediate portion, for example, extending transversely to the device axis Y and forming a transition between the central portion 43 of the mouthpiece 42 and the collar defined by the peripheral portion 44. The central portion 43 of the mouthpiece 42 defines a through hole 46 adapted to at least partially receive the tobacco article 12. Specifically, as shown in FIG. 3, the through hole 46 can be adapted to receive at least a portion of the mouthpiece portion 16 of the tobacco article 12. Advantageously, the through hole 46 may be adapted to closely fit the mouthpiece portion 16 of the tobacco article 12 to avoid or minimize flow leakage between the walls bounding the through hole 46 and the outer surface of the tobacco article 12. In some embodiments, the tobacco article 12 may be held by, for example, friction in the through hole 46. In this case, for example, it is possible to first insert the mouthpiece portion 16 of the tobacco article 12 inside the through hole 46 while both elements are secured to the fixed end of the device body 40.

[0049] 3, an interior volume 47 is formed between an inner surface 48 of the mouthpiece 42 and the fixed end of the device body 40. This interior volume 47 is intersected by the tobacco article 12 when inserted inside the device body 40. For example, the tobacco article 12 may divide the interior volume 47 into two symmetrical portions.

[0050] The device body 40 defines an interior space of the device 11 that accommodates various elements designed to perform different functions of the device 11. This interior space may accommodate, for example, a battery to power the device 11, a control module to control the operation of the device 11, a flat-shaped heating chamber 50 (hereinafter "heating chamber 50") for heating the tobacco portion 15 of the tobacco article 12, etc. Of these elements, only the flat-shaped heating chamber 50 will be described in further detail with reference to FIG.

[0051] In particular, as shown in this Fig. 3, the heating chamber 50 is configured to receive the tobacco article 12. The heating chamber 50 has a flat shape adapted to receive at least the tobacco portion 15 and in some cases at least a portion of the mouthpiece portion 16 of the tobacco article 12. As the tobacco article 12, the heating chamber 50 may also form a rectangular parallelepiped shape extending along the device axis Y and including a pair of parallel narrow walls 53A, 53B (shown in Fig. 4) extending along the device axis Y, a pair of parallel wide walls 54A, 54B also extending along the device axis Y, and a bottom wall 58 adjacent each of said walls and extending perpendicular to the device axis Y. The bottom wall 58 thus forms a closed end of the chamber 50. The heating chamber 50 defines an opening 60 opposite the bottom wall 58 that is configured to receive the tobacco article 12 such that the corresponding broad walls 14A, 14B of the tobacco article 12 face the corresponding broad walls 54A, 54B of the heating chamber 50, the corresponding narrow walls 13A, 13B of the tobacco article 12 face the corresponding narrow walls 53A, 53B of the heating chamber 50, and the abutting end 18 of the tobacco article 12 abuts the bottom wall 58 or at least a rib extending from the bottom wall 58. Alternatively, the abutting end 18 faces the bottom wall 58 without contacting it. The flat shaped heating chamber 50 is therefore configured to receive the tobacco article 12 such that the narrow wall 13A (or 13B) of the tobacco article 12 faces the narrow wall 53B (or 53A) of the heating chamber 50 and the wide wall 14A (or 14B) of the tobacco article 12 faces the wide wall 54B (or 54A) of the heating chamber 50. The opposing wide walls 14A, 14B, 54A, 54B and the opposing narrow walls 13A, 13B, 53A, 53B may be in contact with each other or may be spaced apart from each other.

[0052] The heating chamber 50 includes a heating plate that at least partially forms a wall of the heating chamber 50. Such a wall is, for example, one of the broad walls 54A, 54B of the heating chamber 50. The heating plate is designed to contact or face the tobacco portion 15 of the tobacco article 12. In particular, the heating plate is designed to contact or face one of the broad walls 15A, 15B of the tobacco portion 15. According to a particular example, the heating plate is designed to extend along the entire area of ​​the tobacco portion 15 contained in the tobacco article 12. That is, the heating plate extends at least along the entire length L15 of the tobacco portion 15 and at least along the entire width W15 of the tobacco portion 15. According to a particular example, the length of the heating plate along the device axis Y is greater than the length of the tobacco portion 15. Thus, each heating plate 70 protrudes from both ends of the tobacco portion 15 defined along the device axis Y.

[0053] In the particular example shown in Fig. 3, the heating chamber 50 includes two heating plates 70 forming at least partially opposing walls of the heating chamber 50. The opposing walls are, for example, the broad walls 54A, 54B of the heating chamber 50. Each heating plate 70 is designed to contact or face the tobacco portion 15 of the tobacco article 12. In particular, each heating plate 70 is designed to contact or face the respective broad wall 15A, 15B of the tobacco article 15. In the example shown in Fig. 3, each heating plate 70 faces the respective broad wall 15A, 15B of the tobacco article 15, and a gap is defined between the heating plate 70 and said respective broad wall 15A, 15B of the tobacco article 15. The gap is 0.1 mm or less. Each heating plate 70 has a length W70 defined along the device axis Y, a width W70 (see FIG. 6 showing the dimensions L70 and W70 for one of the two heating plates 70) and a depth D70 (see FIG. 5 showing D70). Each heating plate 70 is designed to extend along the entire area of ​​the tobacco portion 15. In other words, the length L70 of the heating plate 70 is at least equal to the length L15 of the tobacco portion 15, and the width W70 of the heating plate 70 is at least equal to the width W15 of the tobacco portion 15. According to the particular example shown in FIG. 3, the length L70 of each heating plate 70 is greater than the length L15 of the tobacco portion 15. Thus, each heating plate 70 protrudes from both ends of the tobacco portion 15 defined along the device axis Y. This ensures proper heating of the ends of the tobacco portion 15 defined along the device axis Y. The depth D70 of the heating plate 70 depends on the dimensions of the tobacco article 15. For example, the depth D70 of the heating plates 70 is greater than or equal to 0.25 mm and less than or equal to 0.75 mm. As also shown in FIG.

[0054] According to an example, the two heating plates 70 are structurally identical. In the following, only one heating plate 70 is described with reference to Figs. 3 to 8. The other heating plate 70 is structurally identical to the described heating plate 70 and therefore will not be described in detail. According to another example, the two heating plates 70 are different. In this case, the heating plate 70 not described below may correspond to any conventional heating plate made, for example, of metal or ceramic.

[0055] The heating plate 70 comprises a ceramic portion 72 and a metal portion 74 different from and engaged with the ceramic portion 72, both portions 72, 74 being arranged to heat the tobacco article 12. Both the ceramic portion and the metal portion 72, 74 of the heating plate 70 are designed to contact or face the tobacco portion 15 of the tobacco article 12, in particular to contact or face one of the broad faces 15A, 15B of the tobacco article 12. The ceramic portion 72 and the metal portion 74 of the heating plate 70 are engaged to form a plane surface 76 designed to contact or face the tobacco article 12 shown in Figures 3, 5 and 6. As an alternative, the surface formed by the ceramic portion 72 and the metal portion 74 has a shape different from a flat shape, for example a rounded shape.

[0056] In the illustrated example, the plane 76 is designed to contact or face at least the tobacco portion 15 contained in the tobacco article 12. More specifically, the plane 76 is designed to contact or face one of the broad sides 15A, 15B of the tobacco article 12. In the example shown in Fig. 3, the plane 76 faces one of the broad sides 15A, 15B of the tobacco article 12, and said gap extends between the plane 76 and said broad sides 15A, 15B of the tobacco article 12. The length of the plane 76 is equal to the length L70 of the heating plate 70, and the depth of the plane 76 is equal to the width W70 of the heating plate 70.

[0057] The plane 76 is formed by a ceramic plane portion 72S bounded by the ceramic portion 72 and a metal plane portion 74S bounded by the metal portion 74. The ceramic plane portion 72S and the metal plane portion 74S are substantially coplanar. By "substantially coplanar", it is understood that the difference in height between the ceramic plane portion 72S and the metal plane portion 74S along a direction perpendicular to these portions 72S, 74S is, for example, 0.2 mm or less.

[0058] The ceramic planar portion 72S is configured to contact or face a portion of the tobacco portion 15. Advantageously, as shown in Figure 3, the ceramic planar portion 72S is configured to directly contact or face an end of the tobacco portion 15 defined along the device axis Y. By "directly" it is understood that there is no intermediate element extending between the ceramic planar portion 72S and the end of the tobacco portion 15. According to an example, the ceramic planar portion 72S protrudes from both ends of the tobacco portion 15 defined along the device axis Y.

[0059] As shown in FIG. 6, the ceramic flat portion 72S surrounds the entire edge of the metal flat portion 74S. In other words, in each plane perpendicular to the plane 76, the ceramic flat portion 72S extends on both sides of the metal flat portion 74S. The ceramic flat portion 72S is, for example, continuous. In each plane perpendicular to the plane 76 that intersects both the metal portion 74 and the ceramic portion 72 and extends along the device axis Y, the length of the ceramic flat portion 72S is equal to the difference in length between the length of the plane 76 and the length of the metal flat portion 74S. In each plane perpendicular to the plane 76 that intersects both the metal portion 74 and the ceramic portion 72 and extends along the device axis Y, the depth of the ceramic flat portion 72S is equal to the difference in length between the depth of the plane 76 and the depth of the metal flat portion 74S. In a variant, the ceramic flat portion 72S has zones separated from each other.

[0060] The metal plane portion 74S is configured to contact or face the central portion of the tobacco portion 15. The metal plane portion 74S forms a substantially central zone of the plane 76. Moreover, in each plane perpendicular to the plane 76 intersecting both the metal portion 74 and the ceramic portion 72, the metal plane portion 74S is disposed between two pairs of the ceramic plane portions 74S. The metal plane portion 74S of the plane 76 is, for example, continuous. In this case, the length of the metal plane portion 74S is equal to the length of the metal portion 74, which will be described in detail below. Moreover, the depth of the metal plane portion 74S is equal to the depth of the metal portion 74. In a variant, the metal plane portion 74S has zones separated from each other.

[0061] More specifically, as shown in Figures 3, 5 and 6, the ceramic portion 72 extends around the metal portion 74. The ceramic portion 72 extends around the entire outer surface of the metal portion 74 except for the metal plane portion 74S. The length L72 of the ceramic portion 72 is equal to the length L70 of the heating plate 70. The length L72 of the ceramic portion 72 is strictly greater than the length L74 of the metal portion 74. According to an example, the width W72 of the ceramic portion 72 is equal to the width W70 of the heating plate 70. The width W72 of the ceramic portion 72 is strictly greater than the width W74 of the metal portion 74. The ceramic portion 72 is in contact with the metal portion 74. The ceramic portion 72 preferably has a substantially parallelepiped shape with rounded corners.

[0062] As shown in Figures 7 and 8, the ceramic portion 72 defines a recess 78 for receiving the metal portion 74. The recess 78 is a concave area in the ceramic portion 72. The recess 78 forms a shape complementary to the outer shape of the metal portion 74 so as to fit closely therewith. The recess 78 preferably forms a substantially parallelepiped shape with rounded corners. The depth of the recess may, for example, be substantially equal to 50% of the depth D70 of the heating plate 70. The depth D721 of the ceramic portion 72 before the recess 78 is thus substantially equal to 50% of the depth D70 of the metal plate 70. The depth D722 of the ceramic portion 72 arranged on the periphery of the recess 78 is equal to the depth D70 of the metal plate 70. A portion of the surface of the ceramic portion 72 arranged to surround the recess 78 defines a ceramic flat portion 72S. The ceramic portion 72 is made in a single piece. In a variant, the ceramic portion 72 is made in at least two pieces.

[0063] Advantageously, the ceramic portion 72 is configured to be heated by thermal conduction through the metal portion 74. According to other embodiments, the heating chamber 50 may further include a heating element configured to heat the ceramic portion 72. The heating element may be a resistive heating element arranged adjacent to the ceramic portion 72. Advantageously, the resistive heating element is arranged adjacent to the ceramic portion 72, for example on an outer surface of the ceramic portion 72, for example as a heating track or a polyimide film heater. According to yet other embodiments, the heating element may include a magnetic element and a plurality of susceptors included in the ceramic portion 72, the magnetic element being capable of causing heating of the plurality of susceptors by magnetic induction.

[0064] By way of example, the metal part 74 is engaged by clipping inside the recess 78. The metal part 74 is held, for example, by force in the recess 78. The recess 78 corresponds to a blind hole. The metal part 74 forms at least 50%, preferably at least 60%, advantageously at least 70% of the total area of ​​the plane surface 76. The metal part 74 has, for example, a parallelepiped shape. The free surface of the metal part 74 engaged inside the recess 78 forms a metal plane part 74S. The depth D74 of the metal part 74 is substantially equal to 50% of the depth of the heating plate 70. The metal of the metal part 74 is, for example, stainless steel or tungsten. The metal part 74 is made in a single piece. In a variant, the metal part 74 is made in at least two pieces.

[0065] According to an embodiment, the metal part 74 forms a resistive element designed to be powered by a power source (not shown). The power supply can be controlled by a control unit (not shown) of the aerosol generating device 11. According to some examples, the metal part 74 is connected to an electric wire supplying the power, for example by welding the electric wire to the metal part 74. According to another embodiment, a polyimide film heater is placed adjacent to, and in particular in contact with, the metal part 74 in order to heat the metal part 74 by thermal conduction. According to another embodiment of the invention, the heating chamber 50 includes a magnetic element capable of causing heating of the metal part 74 by magnetic induction.

[0066] To ensure that the user can puff, an airflow channel is formed inside the aerosol generating device 11, extending from an airflow inlet 65 (shown in FIG. 4) to the closed end of the heating chamber 50. Thus, air can enter the heating chamber 50 through the airflow channel and be delivered to the user first through the tobacco portion 15 and then through the mouthpiece portion 16 of the tobacco article 12. According to the present invention, the airflow inlet 65 is located in the mouthpiece 42, advantageously in the middle portion of the periphery 44 of the mouthpiece 42. The airflow inlet 65 is formed by a through hole.

[0067] A control method for controlling the aerosol generating device 11 of the aerosol generating assembly 10 is described below.

[0068] The control method includes the step of heating the metal portion 74 .

[0069] Heating of the metal part 74 is performed by supplying power to the metal part 74 via an electric wire. More specifically, the supply of power is controlled by a control unit of the aerosol generating device 11. The control unit may control the supply of power by a control law. The control law comprises supplying a predetermined current to the metal part 74 for a predetermined period of time.

[0070] The heated metal portion 74 heats the ceramic portion 72 by thermal conduction.

[0071] The predetermined current supply to metallic portion 74 and the predetermined time period may be selected based on a predetermined heating temperature of ceramic portion 72 .

[0072] According to other embodiments, the control law may include supplying a predetermined current to metal portion 74 for a predetermined period of time such that metal portion 74 is heated, stopping supplying the predetermined current to metal portion 74, and then activating the heating element to heat ceramic portion 72.

[0073] According to another embodiment, the control law includes simultaneously supplying a predetermined current to the metallic portion 74 such that the metallic portion 74 is heated and activating a heating element to heat the ceramic portion 72 .

[0074] According to yet another embodiment, the control law may include first activating a heating element that heats the ceramic portion 72 for a predetermined period of time, and at the end of the predetermined period of time, providing a predetermined current to the metallic portion 74. The control law may include activating the heating element that heats the ceramic portion 72 after the predetermined period of time.

Claims

1. An aerosol generating device (11) is configured to operate with a flat tobacco article (12) and includes a flat heating chamber (50), The heating chamber (50) is configured to receive the flat tobacco article (12) and includes a heating plate (70) that at least partially forms the walls (54A, 54B) of the heating chamber (50). The heating plate (70) includes a ceramic portion (72) and a metal portion (74) which is different from the ceramic portion (72) and engaged with the ceramic portion (72), the metal portion (74) forming a metal flat portion (74S), and both portions (72, 74) are arranged to heat the flat tobacco article (12), in an aerosol generating device (11).

2. The aerosol generating device according to claim 1, wherein the ceramic portion (72) extends around the metal portion (74).

3. The aerosol generating device according to claim 1 or 2, wherein the ceramic portion (72) defines a recess (78) for receiving the metal portion (74), and the recess (78) is preferably a blind hole and has a depth substantially equal to 50% of the depth (D70) of the heating plate (70).

4. The aerosol generating device according to claim 1 or 2, wherein the ceramic portion (72) and the metal portion (74) engaged with the ceramic portion (72) form a plane (76) designed to contact or face the flat tobacco article (12), and the plane (76) includes the metal plane portion (74S).

5. The aerosol generating device according to claim 4, wherein the metal portion (74) forms at least 50%, preferably at least 60%, and advantageously at least 70% of the total area of ​​the plane (76).

6. The aerosol generating device according to claim 3, wherein the recess (78) is formed in a shape complementary to the outer shape of the metal portion (74) so ​​as to fit tightly into the metal portion (74).

7. The aerosol generating device according to claim 3, wherein the recess (78) forms a substantially parallelepiped shape having rounded corners.

8. The aerosol generating device according to claim 1 or 2, wherein the heating plate (70) is designed to extend substantially along the entire surface area of ​​the tobacco portion (15) contained in the flat tobacco article (12).

9. The aerosol generating device according to claim 8, wherein both the ceramic portion and the metal portion (72, 74) are designed to contact or face the tobacco portion (15) of the flat tobacco article (12).

10. The aerosol generating device according to claim 1 or 2, wherein the ceramic portion (72) is configured to be heated by heat conduction from the metal portion (74).

11. The aerosol generating device according to claim 1 or 2, wherein the heating chamber (50) includes two heating plates (70) that form at least partially opposing walls of the heating chamber.

12. The aerosol generating device according to claim 1 or 2, wherein the heating chamber (50) further includes a heating element configured to heat the ceramic portion (72).

13. The aerosol generating device according to claim 12, wherein the heating element is a resistance heating element disposed adjacent to the ceramic portion (72), and preferably a heating track or polyimide film heater disposed adjacent to the ceramic portion (72), for example, on the outer surface of the ceramic portion (72).

14. The aerosol generating device according to claim 13, wherein the heating element comprises a magnetic element and a plurality of susceptors included in the ceramic portion (72), and the magnetic element is capable of causing heating of the plurality of susceptors by magnetic induction.

15. A method for controlling an aerosol generating device (11) according to claim 1 or 2, comprising the step of heating the metal portion (74), wherein the heated metal portion (74) heats the ceramic portion (72) by thermal conduction.

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