Uniform EM field in IH non-combustion heating devices

Abstract

The present invention relates to an aerosol generating device for heating an aerosol generating article, the aerosol generating device comprising an induction coil having a plurality of windings and configured to provide an electromagnetic field within a receiving volume configured to receive the aerosol generating article. The induction coil comprises one or more first regions and two or more second regions, the one or more first regions being located between at least two of the two or more second regions in the longitudinal direction of the induction coil, and the diameter of the windings of the coil being such that the diameter of the one or more first regions is greater than the diameter of the two or more second regions. The present invention also relates to an aerosol generating assembly comprising the aerosol generating device and, preferably, a susceptor contained within the aerosol generating article.

Description

Technical Field

[0001] The present invention relates to an aerosol generating device for heating an aerosol generating article, and an assembly comprising a susceptor and an aerosol generating device.

Background Art

[0002] Aerosol generating devices or e-cigarettes are currently the mainstream products that simulate conventional cigarettes. There are many types of aerosol generating devices, one of which has an operating method of heating a tobacco product to generate an aerosol without burning the tobacco. These so-called heat-not-burn (HNB) devices are becoming increasingly popular.

[0003] Heat-not-burn devices generally operate with a tobacco article that is inserted into the device and heated by a heating element included in the heat-not-burn device. Various tobacco articles are commercially available. In recent years, two main forms of heating tobacco have been commonly used, which are resistive heating elements and inductive heating elements.

[0004] Typically, due to the spatial confinement within the aerosol generating device, short coils are typically used for inductive heating assemblies. The assembly consists of a coil (inductor) and a ferromagnetic metal of various shapes, typically stripes (susceptor). The inductor applies an electromagnetic field that induces eddy currents within the susceptor. The eddy currents within the susceptor heat the susceptor. By placing the susceptor in proximity to or even inside the tobacco product, the heat transfers to the tobacco product and heats the tobacco until an aerosol is formed. Existing devices typically have a fixed blade as the susceptor or a non-fixed susceptor incorporated by the tobacco consumable.

[0005] Due to specific limitations, typically only short solenoid coils that form a heterogeneous B-field can be used. Because of the heterogeneity of the B-field, the energy induced in the susceptor is highly dependent on the susceptor's position relative to the coil. Such a heterogeneous B-field can lead to uneven heating of the susceptor, depending on the susceptor's position, as the temperature reached with the constant parameters used in the coil (e.g., PWM duty cycle). Therefore, if the susceptor acting as the heating element does not have the appropriate temperature, the tobacco product may be underheated or overheated. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Therefore, it is desirable to provide an aerosol generating device having an induction heating system that has the above-mentioned advantages but avoids all of the above-mentioned disadvantages by forming a uniform electromagnetic field. [Means for solving the problem]

[0007] One or more of these objectives are achieved by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent claims.

[0008] The present invention provides a device that solves some or all of the above problems.

[0009] In one embodiment, the present invention relates to an aerosol generating device for heating an aerosol generating article, the aerosol generating device comprising an induction coil having a plurality of windings and configured to provide an electromagnetic field within a receiving volume configured to receive the aerosol generating article. The induction coil comprises one or more first regions and two or more second regions, the one or more first regions being located between at least two of the two or more second regions in the longitudinal direction of the induction coil, and the diameter of the windings of the coil being such that the diameter of the one or more first regions is greater than the diameter of the two or more second regions.

[0010] By positioning one or more first regions between two or more second regions, a more uniform electromagnetic field is formed within the coil compared to a coil with a constant diameter. This allows for more uniform heating of the susceptor within the receiving volume, preventing overheating / underheating of tobacco products and improving the effectiveness of the heater assembly. Furthermore, for aerosol-generating articles, the extensive calibration process required to find appropriate heating parameters and precise positions within the receiving volume can be eliminated.

[0011] In a further embodiment, the diameter of the coil windings in one or more first regions has a diameter dispersion of at most 15%, preferably at most 10%, more preferably at most 5%, and most preferably substantially no diameter dispersion, and / or the diameter of the coil windings in two or more second regions has a diameter dispersion of at most 15%, preferably at most 10%, more preferably at most 5%, and most preferably substantially no diameter dispersion.

[0012] By arranging the coils in this way, the susceptor can be heated more uniformly.

[0013] In another embodiment, the diameter of the coil windings in one or more first regions is at least 3%, preferably at least 5%, more preferably at least 7%, and most preferably at least 10%, greater than the diameter of the coil windings in two or more second regions.

[0014] In a further embodiment, in the longitudinal direction of the induction coil, one or more first regions occupy at least 50%, preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, and most preferably at least 90% of the length of the induction coil, and / or preferably, in the longitudinal direction of the induction coil 110, two or more second regions occupy at least 5%, preferably at least 10%, more preferably at least 15%, even more preferably at least 20%, and most preferably at least 30% of the length of the induction coil.

[0015] In yet another embodiment, the two second regions are preferably located at the distal end of the induction coil and at the proximal end of the induction coil.

[0016] The experiment showed that the above dimensions and arrangement of the coils in the first and second regions provided the most uniform electromagnetic field, resulting in the most efficient heating of the susceptor.

[0017] In another embodiment, the induction coil comprises one first region and two second regions.

[0018] In a further embodiment, the induction coil comprises one first region and two second regions, wherein the first side of the first region lies on the first side of one of the two second regions, and the second side of the first region opposite the first side lies on the second first side of the two second regions, and the one first region and the two second regions preferably form a trapezoidal shape.

[0019] In a further embodiment, the induction coil is a single-layer coil.

[0020] In yet another embodiment, the induction coil is a multilayer coil.

[0021] In another embodiment, the induction coil is formed by a single wire.

[0022] In yet another aspect, the wire forming the induction coil has a diameter variation of at most 15%, preferably at most 10%, more preferably at most 5%, and most preferably substantially no diameter variation, in at least 70%, preferably at least 80%, more preferably at least 90%, and most preferably at least 95% of the wire length in one or more first regions and / or two or more second regions.

[0023] In another aspect, the aerosol-forming material is uniformly distributed within the aerosol-generating article.

[0024] By providing the aerosol-generating material (such as tobacco material) in a homogeneous manner, the aerosol-generating article can be consumed in an even manner. As a result, all parts of the aerosol-generating article are consumed similarly, reducing waste of the material.

[0025] In another aspect, the induction coil further comprises one or more third regions, and the diameter of the coil winding in the third region is smaller than the diameter of the winding in the first region and larger than the diameter of the winding in the second region, and the one or more third regions are arranged between the one or more first regions and the two or more second regions.

[0026] In a further aspect, the diameter of the winding in the third region preferably increases from the portion closest to the second region, which preferably contacts the second region, to the portion closest to the first region, which preferably contacts the first region. Preferably, the diameter of the winding in the third region increases linearly from the portion closest to the second region to the portion closest to the first region.

[0027] In another aspect, in the longitudinal direction of the induction coil, the one or more third regions occupy at least 2%, preferably at least 5%, more preferably at least 10%, even more preferably at least 20%, and most preferably at least 30% of the length of the induction coil.

[0028] In a further aspect, the first outer surface of the coil in the first region is parallel to the second outer surface of the coil in the second region, and the third outer surface of the coil in the third region is arranged at an angle of 10° to 80° with respect to the first outer surface and the second outer surface.

[0029] By including the third region having the above characteristics, the electromagnetic field can be provided in an even more uniform manner. Thereby, the heating efficiency is further improved.

[0030] In a further aspect, the aerosol generating device further comprises a coil holder around which the coil is wound, and the coil holder has recesses, each recess receiving one turn of the induction coil.

[0031] Having such a holder for receiving the coil improves the durability and elasticity of the induction coil assembly against damage.

[0032] In another aspect, the coil holder has a substantially solenoid shape with an inner surface and an outer surface arranged in the longitudinal direction of the coil holder, the outer surface being configured to receive the induction coil, and the inner surface delimiting the receiving volume.

[0033] The coil holder thus formed provides optimal protection for the coil and operability for heating the tobacco product within the receiving volume.

[0034] In a further aspect, the coil holder comprises a high-temperature polymer and the coil holder is preferably manufactured using an additive manufacturing process or an injection molding process.

[0035] Providing the coil holder in this way enables the coil for receiving the coil to be manufactured at a low cost. Furthermore, the coil holder can be easily adapted to various shapes of the coil and vice versa.

[0036] In another embodiment, the receiving volume is designed to fully receive the cigarette portion of the aerosol-generating article and, advantageously, has a longitudinal offset due to interest having one of the ends of the induction coil.

[0037] As described above, the amount of tobacco product within the receiving volume can be maximized. Furthermore, by positioning the tobacco portion longitudinally offset from one of the ends of the induction coil, the tobacco portion is placed in the region with the most uniform electromagnetic field, thereby resulting in more consistent heating of the tobacco. Thus, non-uniform electromagnetic fields at the ends of the coil can be avoided.

[0038] In further embodiments, the induction coil comprises at least 5 turns, preferably at least 7 turns, more preferably at least 10 turns, even more preferably at least 12 turns, most preferably at least 16 turns, and / or at most 50 turns, preferably at most 30 turns, more preferably at most 25 turns, even more preferably at most 20 turns, most preferably at most 16 turns.

[0039] Another aspect of the present invention preferably relates to an aerosol generating assembly comprising a susceptor contained in an aerosol generating article and an aerosol generating device as defined above.

[0040] In another embodiment, the longitudinal length of the susceptor is shorter than the longitudinal length of the induction coil.

[0041] As described above, the precise position of the susceptor within the receiving volume is not so critical due to the homogeneous electromagnetic field provided by the aerosol generating device defined above, thus facilitating the positioning of the susceptor within the receiving volume of the coil. Herein, preferred embodiments will be described as examples only, with reference to the attached drawings. [Brief explanation of the drawing]

[0042] [Figure 1a] This is a schematic diagram of an induction coil. [Figure 1b] These are schematic side views of the outer surfaces of the coil in the first, second, and third regions in an exemplary embodiment. [Figure 2] This is a schematic diagram of an aerosol-generating article in an exemplary embodiment. [Figure 3a] This shows the magnetic flux density within the receiving volume of a conventional induction coil. [Figure 3b] This shows the magnetic flux density within the receiving volume of the induction coil according to the present invention. [Figure 4] This shows a comparison of the B-field distribution obtained by the induction coil according to the present invention and the induction coil of the prior art. [Figure 5a] This is a side view of an induction coil positioned on a coil holder in an exemplary embodiment. [Figure 5b] This is a cross-sectional view of an induction coil positioned on a coil holder in an exemplary embodiment. [Figure 5c] This is a cross-sectional view of an induction coil and a coil holder in an exemplary embodiment. [Figure 6] This is a schematic diagram of an aerosol generation assembly according to an exemplary embodiment. [Modes for carrying out the invention]

[0043] Preferred embodiments of the present invention will be described below with reference to the drawings.

[0044] The aerosol generating device 100 for heating the aerosol generating article 200 will be described in more detail below. The aerosol generating device 100 includes an induction coil 110 having a plurality of windings 120, forming a receiving volume 130 for receiving the aerosol generating article 200. The aerosol generating device 100 is configured to provide an electromagnetic field within the receiving volume 130 formed by the plurality of windings 120. The induction coil 110 of the aerosol generating device 100 includes one or more first regions 111 and two or more second regions 112. The one or more first regions 111 are arranged in the longitudinal direction of the induction coil 110 between at least two of the two or more second regions 112. The diameter of the windings 120 of the coil 110 is such that the diameter in one or more first regions 111 is greater than the diameter in two or more second regions 112. Preferably, one or more first regions 111 and two or more second regions 112 are arranged such that the outer surface of the induction coil 110 has a trapezoidal shape (or referred to as a "plateau shape").

[0045] Figure 2 shows an aerosol-generating article according to an exemplary embodiment. The aerosol-generating article 200 may comprise an aerosol-generating material 230 configured to generate an aerosol when heated. The aerosol-generating material 230 may comprise a tobacco material. Furthermore, or alternatively, the aerosol-generating material 230 may comprise a non-tobacco aerosol-generating substance and / or a flavoring agent. In some examples, the aerosol-generating material 230 may comprise a material susceptible to electromagnetic fields. The electromagnetic field-sensitive material may function as a susceptor 140 for the induction coil 110 of the aerosol-generating device 110. For example, when a changing power is applied to the induction coil 110, the induction coil 110 provides a changing magnetic field to the receiving volume 130. When the aerosol-generating article 200 is inserted into the receiving volume 130, eddy currents are generated in the susceptor 140 by the electromagnetic field. Due to the electrical resistance of the susceptor, the eddy currents heat the susceptor by Joule heating. Eddy currents / Joule heating may be generated in such a way that the susceptor 140 heats the aerosol generating material 230 until an aerosol is generated by the aerosol generating material 230. The aerosol generating article 200 / aerosol generating material 230 may be heated in a desired / constant manner by controlling the power supplied to the aerosol generating device 100, and thus the electromagnetic field induced in the receiving volume 130. In order to control the power supply to the aerosol generating device 100, and thus control the electromagnetic field in the receiving volume 130, the aerosol generating device 100 may be provided with, or connected to, control means for controlling the heating of the aerosol generating device 100.

[0046] Preferably, tobacco materials, non-tobacco aerosol-generating substances, flavorings, and / or materials / susceptors susceptible to electromagnetic fields are uniformly distributed within the aerosol-generating article 200. This means that individual materials of the aerosol-generating material 230 do not accumulate in individual areas of the aerosol-generating article 200, but are mixed together during the manufacture of the aerosol-generating material 230. By providing the materials to be uniformly mixed, the heat distribution within the aerosol-generating article 200 is constant / evenly distributed when the article 200 is heated. This avoids large heat accumulation in some areas of the aerosol-generating article 200, and temperatures that are too low for aerosol generation from the aerosol-generating material in some other areas.

[0047] The aerosol generating article 200 may comprise multiple parts having different properties. For example, the aerosol generating article 200 may comprise a tobacco part 210 comprising tobacco material (or other aerosol generating material), and / or a filter part 220 comprising a filter for filtering harmful substances from the aerosol, and / or an additional susceptor part comprising an additional susceptor 140 (and / or additional material susceptible to electromagnetic fields), and / or an offset part configured to set the position of the tobacco material within the receiving volume 130 of the induction coil 110.

[0048] Figure 1a shows an exemplary induction coil 110 for generating an electromagnetic field to heat an aerosol-generating article 200. The windings 120 of the induction coil 110 form a receiving volume 130 for receiving the aerosol-generating article 200, and the induction coil 110 is configured to induce an electromagnetic field within the receiving volume 130 when power is applied to the coil 110. The induction coil 110 shown in Figure 1a comprises a first region 111 and two second regions 112, the first region 111 being located between the two second regions 112 in the longitudinal direction of the induction coil 110. The exemplary induction coil 110 in Figure 1a may comprise any number of first regions 111 and second regions 112, but the exemplary induction coil 110 shown in Figure 1a comprises only one first region 111 and two second regions 112, wherein the first side of the first region (the left side of the first region 111 in Figure 1a) may be located on the first side of one of the two second regions (the right side of the second region 111 to the left of the two second regions 112 in Figure 1a), and the second side of the first region opposite the first side (the right side of the first region 111 in Figure 1a) may be located on the second first side of the two second regions (the left side of the second region 111 to the right of the two second regions 112 in Figure 1a). In the longitudinal direction of the coil, two second regions 112 are allocated to the two ends (proximal and distal) of the induction coil 110, and the first region 111 is allocated to the center of the induction coil 110. However, in other examples, the induction coil 110 may also comprise two or more first regions 111 and / or three or more second regions 112. The diameter of the coil windings 120 in one or more first regions 111 is greater than the diameter of the coil windings 120 in two or more second regions 112. This means that the coil extends further in the transverse / short direction in the first region 111 than in the two or more second regions 112. Preferably, the diameter of the coil windings 120 is substantially constant within each region. That is, preferably, the diameter of the windings 120 of the induction coil 110 in one or more first regions 111 is substantially constant, and / or the diameter of the windings 120 of the induction coil 110 in two or more second regions 112 is substantially constant.Preferably, the difference in diameter of the coil windings 120 in one or more first regions 111 is at least 3% larger, more preferably at least 5% larger, even more preferably at least 7% larger, even more preferably at least 10% larger, more preferably at least 12% larger, and most preferably at least 15% larger than the difference in diameter of the coil windings 120 in two or more second regions 112. In one particular example, the diameter of the winding 120 in the first region 111 is 4.00 mm to 4.20 mm, and the diameter of the winding 120 in two or more second regions 112 is 3.6 mm to 3.8 mm, preferably the diameter of the winding 120 in the first region 111 is 4.05 mm to 4.15 mm, and the diameter of the winding 120 in two or more second regions 112 is 3.65 mm to 3.75 mm, more preferably the diameter of the winding 120 in the first region 111 is 4.1 mm to 4.13 mm, and the diameter of the winding 120 in two or more second regions 112 is 3.68 mm to 3.72 mm, most preferably the diameter of the brewing vat in the first region 111 is 4.12 mm, and the diameter of the winding 120 in two or more second regions 112 is 3.7 mm. Preferably, the diameter of the coil windings in each region, for example, one or more first regions 111 and / or two or more second regions 112, has a diameter dispersion of at most 15%, more preferably at most 10%, even more preferably at most 5%, and most preferably substantially no diameter dispersion.

[0049] In the longitudinal direction of the induction coil 110, one or more first regions 111 occupy at least 50%, preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, and most preferably at least 90% of the length of the induction coil 110. Furthermore, two or more second regions 112 preferably occupy at least 5%, preferably at least 10%, more preferably at least 15%, even more preferably at least 20%, and most preferably at least 30% of the length of the induction coil 110 in the longitudinal direction. In one particular example, in the longitudinal direction, the first regions 111 occupy 45% to 95% of the length of the induction coil 110, preferably 47% to 93%, and more preferably 50% to 90%. Additionally or alternatively, each of two or more second regions 112 occupies 3% to 35% of the length of the induction coil 110, preferably 4% to 32%, and most preferably 5% to 30% of the length of the induction coil 110.

[0050] In one embodiment, the induction coil 110 is a single-layer coil. This means that the individual winding regions 120 of the induction coil 110 are allocated adjacent to each other, but do not overlap on top of each other. Alternatively, the induction coil 110 may be a multi-layer coil, in which the individual windings 120 of the induction coil 110 are stacked on top of each other. In the embodiment shown in the figure, a single-layer coil is used.

[0051] The diameter / or cross-section of the wire used in the induction coil 110, i.e., the diameter / cross-section of each individual winding 120, is preferably substantially constant, and preferably Litz wire is used for the induction coil 110. Preferably, the wire forming the induction coil has a cross-sectional area with substantially no diameter variation, having a maximum diameter variation of 15%, preferably a maximum diameter variation of 10%, more preferably a maximum diameter variation of 5%, in at least 70%, preferably at least 80%, more preferably at least 90%, and most preferably at least 95% of the length of the wire in one or more first regions and / or two or more second regions.

[0052] Preferably, the induction coil comprises at least 5 turns 120, preferably at least 7 turns 120, more preferably at least 10 turns 120, even more preferably at least 12 turns 120, most preferably at least 16 turns 120, and / or a maximum of 50 turns 120, preferably a maximum of 30 turns 120, more preferably a maximum of 25 turns 120, even more preferably a maximum of 20 turns 120, most preferably a maximum of 16 turns 120.

[0053] Figure 1b shows a schematic diagram of another exemplary induction coil 110, showing the diameter of the windings 120 at each longitudinal position of the induction coil 110. In addition to the characteristics described with respect to Figure 1, the induction coil 110 may further comprise one or more third regions 113 between two or more second regions 112 and one or more first regions 111. The outer surface of one or more third regions 113 forms an angle with the outer surface of an adjacent first region 111 and / or adjacent second region 112. In the particular example of Figure 1b, the induction coil 110 comprises two third regions 113. The diameter of the windings 120 in one or more third regions 113 is smaller than the diameter of the windings 120 in the first region 111 and larger than the diameter of the windings 120 in the second region. Preferably, as shown in Figure 1b, the diameter of the winding 120 in a third region adjacent to (or near) one of two or more second regions 112 is smaller than the diameter of the winding 120 in a third region adjacent to (or near) one or more first positions. Preferably, the diameter of the winding 120 of the induction coil 110 in the third region increases from a diameter approximately the same as the diameter of the winding 120 of the induction coil 110 in two or more second regions 112 to a diameter approximately the same as the diameter of the winding 120 of the induction coil 110 in one or more first regions 111. Furthermore, in the longitudinal direction of the induction coil 110, one or more third regions 113 may occupy at least 2%, preferably at least 5%, more preferably at least 10%, even more preferably at least 20%, and most preferably at least 30% of the length of the induction coil 110. Preferably, the wires forming the induction coils have a cross-sectional area with a maximum diameter dispersion of 15%, preferably a maximum diameter dispersion of 10%, more preferably a maximum diameter dispersion of 5%, and most preferably substantially no diameter dispersion, in at least 70%, preferably at least 80%, more preferably at least 90%, and most preferably at least 95% of the length of the wire in one or more third regions 113.

[0054] Figures 3a and 3b show magnetic flux density simulations of a conventional induction coil 110a (known in the art), i.e., an induction coil 110 with a constant coil diameter (Figure 3a), and an induction coil 110 as described above (Figure 3b). Both coils used for the simulation have a length of approximately 25 mm in the longitudinal direction. In both simulations, a similar constant power was applied to the induction coil 110. The resulting magnetic flux density norms are plotted against the corresponding spatial positions (coordinates in 2D space), and the magnetic flux density values ​​are normalized to a maximum value of 10. Normalizing the magnetic flux density values ​​makes it easier to compare the simulation results shown in Figure 3a with those shown in Figure 3b. Thus, the magnetic flux density value of 5 in Figure 3a is the same as the magnetic flux value of 5 in Figure 3b, and the magnetic flux value of 7 in Figure 3a corresponds to the magnetic flux value of 7 in Figure 3b.

[0055] The induction coil 110 used for the magnetic flux density simulation in Figure 3a has a constant diameter of approximately 5 mm. As can be seen from Figure 3a, a region 320 with a high magnetic flux density of value 7 (slightly greater than 7) is formed in the center of the volume of the induction coil 110. From the highest magnetic flux in the center of the internal volume of the induction coil 110, the magnetic flux density decreases to a value of approximately 4 to 5 at the ends of the induction coil 110. That is, the highest magnetic flux density of 7 is achieved in the region of -9 mm to +9 mm on the y-axis of the plot in Figure 3a, and the magnetic flux density is greater near the wires of the winding 120 of the induction coil 110, decreasing towards the center of the receiving volume within the induction coil 110. Thus, the region 310 with a low magnetic flux density extends from 7 to 12.5 (-7 to -12.5, respectively) in the center of the receiving volume.

[0056] For comparison, the induction coil 110 used for the magnetic flux density simulation in Figure 3b corresponds to the induction coil 110 in the example above. In this particular example, the induction coil 110 comprises two second regions 112 having a diameter of approximately 5 mm (similar to the diameter of the induction coil 110 in Figure 3b) and a first section having a diameter of approximately 7 mm. The two second regions 112 of the induction coil 110 are located at the two ends of the coil. Each of the two second regions 112 extends approximately 3.3 mm in the longitudinal direction, and the first region 111 extends approximately 16 mm. The induction coil 110 used for this simulation also comprises two third regions 113 connecting the first region 111 to the two second regions 112, with each of the two third regions 113 extending approximately 1.2 mm in the longitudinal direction. As can be seen from Figure 3b, the induction coil according to the present invention also forms a large region 320 with a high magnetic flux density within the receiving volume of the induction coil 110. In the region with high magnetic flux density, the magnetic flux density reaches a maximum value of approximately 7 (slightly less than 7). In this example, the region with high magnetic flux density extends in the region from -12 mm to +12 mm on the y axis of the plot shown in Figure 3b. Contrary to the conventional induction coil 110a, in the receiving volume 130 of the induction coil 110 according to the present invention, the magnetic flux density decreases toward the center of the receiving volume of the induction coil 110, as in the example above. Only at the edges of the induction coil 110 does the magnetic flux density decrease to a value of approximately 4 to 5. Therefore, the region with low magnetic flux density 310 is relatively small and extends from 9.5 to 12.5 (-9.5 to -12.5, respectively) in the center of the receiving volume.

[0057] With the coil in the example above,

number

[0058] By comparing the results obtained from the simulations in Figures 3a and 3b, it can be seen that the spatial magnetic flux density distribution, i.e., the magnetic field, is more homogeneous within the receiving volume of the induction coil 110 shown in Figure 3b compared to the induction coil 110 with a constant diameter shown in Figure 3a. That is, although the absolute values ​​of the magnetic flux density in the region 320 with high magnetic flux density and the region 310 with low magnetic flux density are similar, the sizes of the region 320 with high magnetic flux density and the region 310 with low magnetic flux density are very different. In particular, compared to the induction coil 110 according to the present invention, the region 310 with low magnetic flux density is substantially larger near the center of each induction coil 110 in the induction coil 110 with a constant diameter.

[0059] To further highlight the difference in magnetic flux density distribution between the induction coil 110 according to the present invention and the conventional induction coil 110a, their respective normalized magnetic fields were plotted against their longitudinal positions, as shown in Figure 4. For ease of comparison, the exemplary coil arrangement features in Figures 1a and 1b are provided at the corresponding positions in the plots.

[0060] As can be seen from the plot in Figure 4, the magnetic flux distribution 420 of a conventional induction coil 110a, i.e., the magnetic field strength, has a roughly semi-elliptical shape. That is, the magnetic flux density is highest at the very center of the induction coil 110, gradually decreases from the center of the coil, and the amount of decrease in magnetic flux density increases with distance to the center of the coil (in the longitudinal direction). Conversely, the magnetic flux distribution 410 of the magnetic field generated within the receiving volume of the induction coil 110 according to the present invention remains constant throughout. In particular, the decrease in magnetic flux density in the two second regions 112 is similar to the decrease in magnetic flux density at similar locations in a conventional induction coil 110a, but the magnetic flux density is roughly constant in the first region. Therefore, the magnetic flux density distribution of the induction coil 110 according to the present invention is roughly trapezoidal.

[0061] When an aerosol-generating article 200 having a susceptor 140 is inserted into the receiving volume of each induction coil 110, the aerosol-generating article 200 inserted into conventional induction coil 110a will naturally be heated more in the region 320 with high magnetic flux density (i.e., the center of the receiving volume) and less in the region of the receiving volume that is spaced further away from the center. Therefore, the aerosol-generating article 200 is not heated uniformly. This can lead to overheating of the material in the center (giving the user a burning sensation) and underheating of the material further away from the center (and furthermore, inability to generate aerosols). Consequently, the smoking experience may be unsatisfactory for the user, and / or the smoking material is wasted. Furthermore, controlling the temperature supplied to the aerosol-generating material within the aerosol-generating article 200 can be difficult because changing the power supplied to the induction coil 110 does not similarly result in a similar change across all regions of the aerosol-generating article 200.

[0062] In contrast, when the aerosol generating article 200 according to the present invention is inserted into the receiving volume of the induction coil 110, the magnetic field density is substantially constant throughout the aerosol generating article 200. Therefore, by changing the power supplied to the induction coil 110, the same change in the magnetic field is similarly applied to all areas of the aerosol generating article 200. This makes it easy to control the temperature of the aerosol generating material so that all of the aerosol generating material within the aerosol generating article 200 is heated evenly. For example, the temperature control means of the aerosol generating device 100 can set the power supplied to the heating element comprising the induction coil 110 according to the present invention, thereby bringing the temperature within the aerosol generating device 100 to a point where the aerosol generating material, such as tobacco material, generates an aerosol that can be inhaled by the user. In some embodiments, constant heating of the aerosol article does not require further sensors or control means to provide a good user experience along with optimized material consumption.

[0063] Furthermore, as can be seen from Figure 4, the magnetic flux density (i.e., magnetic field strength) generated by the induction coil 110 according to the present invention is homogeneous, particularly in the receiving volume of the induction coil 110 corresponding to the first region. At the edges of the induction coil 110, the magnetic flux density decreases, similar to that of a conventional induction coil 110a. Therefore, preferably, the aerosol generating article 200 is inserted into the receiving volume in such a manner that materials susceptible to electromagnetic fields and / or aerosol generating materials are allocated only within the receiving volume corresponding to the first region. For example, the aerosol generating article 200 may be inserted into the receiving volume 130 offset in the longitudinal direction, thereby preventing the aerosol generating article 200 from entering the receiving volume 130 corresponding to one of the two or more second regions 112. Alternatively, the aerosol generating article 200 may be configured such that the aera of the aerosol generating article 200 corresponding to two or more second regions 112 does not contain materials susceptible to electromagnetic fields and / or aerosol generating materials such as cigarettes. Additionally or alternatively, the aerosol generating device 100 may be configured such that the aerosol generating article 200 cannot be inserted into one of the two or more second regions 112. For example, the receiving volume 130 for receiving the aerosol generating article 200 may be shaped to extend only to regions corresponding to one of the two or more second regions 112 and one first region 111.

[0064] To facilitate the provision of the induction coil 110 in the above example, the aerosol generating device 100 may include a coil holder 500 around which the coil winding 120 is wound. One exemplary coil holder 500 is shown in Figures 5a, 5b, and 5c. Figure 5a shows the coil holder 500 with the induction coil 110 wound around it. Figure 5b shows the coil holder 500 with the induction coil 110 wound around it, and the outer surface of the coil holder 500 that receives the induction coil 110 is shown. Figure 5c shows a cross-sectional view of the coil holder 500 and the induction coil 110, and shows the internal receiving volume of the coil holder 500 / induction coil 110. The coil holder 500 may be fixed to the device body or to an internal chassis extending through the device body.

[0065] The coil holder 500 may have recesses 510, preferably each recess 510 is configured to receive one turn of the induction coil 110. The coil holder 500 preferably has a substantially solenoid shape with an inner surface 511 and an outer surface 512 arranged in the longitudinal direction of the coil holder 500, the outer surface 512 being configured to receive the induction coil 110 and the inner surface 511 dividing the receiving volume. The inner surface of the coil holder 500 preferably forms a tubular shape that divides the receiving volume for receiving the aerosol generating article 200. Preferably, the coil holder 500 forms the receiving volume so as to completely fill the cavity when a tubular aerosol generating article 200, such as an aerosol generating article 200 having the shape of a cigarette, is inserted. Preferably, the receiving volume 130 formed by the inner surface 511 of the coil holder 500 is configured to completely receive the cigarette portion of the aerosol generating article 200.

[0066] The recess 510 may also be a single recess 510 that is spirally wound around the outer surface 512 of the coil holder 500, such that the coil holder 500 appears to have more than one recess. Thus, below, the multiple recesses 510 also include configurations of a single recess 510 that appear to have multiple recesses 510 because they are spirally configured.

[0067] The coil holder 500 comprises one or more first regions 521 and two or more second regions 522, wherein the one or more first regions 521 are arranged between at least two of the two or more second regions 522 in the longitudinal direction of the coil holder 500. The diameter of the coil holder 500 is such that the diameter of the one or more first regions 521 is greater than the diameter of the two or more second regions 522.

[0068] This means that in the first region 521, the coil holder 500 extends further in the lateral / short direction than in two or more second regions 522. Preferably, the diameter of the coil holder 500 is substantially constant within each region. Preferably, the diameter of the coil holder 500 in each region has a diameter variance of at most 15%, more preferably at most 10%, even more preferably at most 5%, and most preferably substantially no diameter variance. Thus, preferably, the diameter of the coil holder 500 in one or more first regions 521 is substantially constant, and / or the diameter of the coil holder 500 in two or more second regions 522 is substantially constant. Therefore, the diameter of the coil holder 500 preferably has a diameter dispersion of at most 15%, more preferably at most 10%, even more preferably at most 5%, in one or more first regions 521 and / or two or more second regions 522, and most preferably substantially no diameter dispersion. In other words, the coil holder 500 defines a complementary shape to the shape of the coil. Preferably, the difference in diameter of the coil holder 500 in one or more first regions 521 is at least 3%, more preferably at least 5%, even more preferably at least 7%, even more preferably at least 10%, even more preferably at least 12%, and most preferably at least 15%, than the difference in diameter of the coil holder 500 in two or more second regions 522.In one particular example, the diameter of the first region 521 of the coil holder 500 is 4.00 mm to 4.20 mm, and the diameter of the coil holder 500 in two or more second regions 522 is 3.6 mm to 3.8 mm, preferably the diameter of the coil holder 500 in the first region 521 is 4.05 mm to 4.15 mm, and the diameter of the coil holder 500 in two or more second regions 522 is 3.65 mm to 3.75 mm, more preferably the diameter of the coil holder 500 in the first region 521 is 4.1 mm to 4.13 mm, and the diameter of the coil holder 500 in two or more second regions 522 is 3.68 mm to 3.72 mm, most preferably the diameter of the coil holder 500 in the first region 521 is 4.12 mm, and the diameter of the coil holder 500 in two or more second regions 522 is 3.7 mm.

[0069] In the longitudinal direction of the coil holder 500, one or more first regions 521 occupy at least 50%, preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, and most preferably at least 90% of the area for receiving the wires of the induction coil 110. Furthermore, two or more second regions 522 preferably occupy at least 5%, preferably at least 10%, more preferably at least 15%, even more preferably at least 20%, and most preferably at least 30% of the length of the area for receiving the wires of the induction coil 110 in the longitudinal direction. In one particular example, in the longitudinal direction, the first region 521 occupies 45% to 95% of the length of the area for receiving the wires of the induction coil 110, preferably 47% to 93%, and more preferably 50% to 90%. Additionally or alternatively, each of the two or more second regions 522 occupies 3% to 35% of the length of the region receiving the wires of the induction coil 110, preferably 4% to 32%, and most preferably 5% to 30% of the length of the region receiving the wires of the induction coil 110.

[0070] Preferably, the coil holder 500 further comprises one or more third regions 523, the diameter of the coil holder 500 in the third region 523 being smaller than the diameter of the coil holder 500 in the first region 521 and larger than the winding diameter in the second region 522, and the one or more third regions 523 being located between one or more first regions 521 and two or more second regions 522.

[0071] Preferably, each of the recesses 510 configured to receive the wires of the induction coil 110 has a cross-sectional area similar to the cross-sectional area of ​​the wire used for the induction coil 110, i.e., each of the individual windings 120 of the induction coil 110. Preferably, the cross-sectional area of ​​the recesses 510 configured to receive the wires is substantially constant, and preferably, Litz wire is used for the induction coil 110. Preferably, the cross-sectional area of ​​the recesses 510 configured to receive the wires has a diameter dispersion of at most 15%, preferably at most 10%, more preferably at most 5%, and most preferably substantially no diameter dispersion in at least 70%, preferably at least 80%, more preferably at least 90%, and most preferably at least 95% of the length of the recess 510 in one or more first regions 521 and / or two or more second regions 522.

[0072] Preferably, the recess 510 of the coil holder 500 is configured to create an induction coil 110 having at least 5 turns 120, preferably at least 7 turns 120, more preferably at least 10 turns 120, even more preferably at least 12 turns 120, most preferably at least 16 turns 120, and / or at most 50 turns 120, preferably at most 30 turns 120, more preferably at most 25 turns 120, even more preferably at most 20 turns 120, most preferably at most 16 turns 120, when the wire of the induction coil 110 is inserted into the recess.

[0073] The use of the coil holder 500 facilitates the manufacture of the induction coil 110 according to the present invention. For example, the induction coil may be manufactured by winding the induction coil wire around the coil holder 500, thereby placing the wire in the recess 510 during the manufacturing process. This improves the stability of the induction coil 110 during the manufacturing process and ensures that the individual windings 120 of the induction coil 110 have the desired position / diameter. Furthermore, the durability / stability of the induction coil 110 according to the present invention is improved when positioned in the coil holder 500. Moreover, the coil holder 500 allows the induction coil 110 to be constructed from various wires, as even flexible wires are held in place. For example, if it is preferable to use a litz wire that may be flexible for the induction coil 110, the coil holder 500 is configured to a) move the litz wire to the desired position and b) hold the litz wire in the desired position even when an external force is applied to the aerosol generating device 100. This improves the durability of the induction coil 110 and the heating device.

[0074] To avoid damage to the coil holder 500 and to ensure that the wires of the induction coil 110 are guided to the correct position even at high temperatures, the coil holder 500 is preferably equipped with high temperature capabilities. Preferably, the coil holder 500 is manufactured using an additive manufacturing process such as material extrusion, binder injection, directed energy deposition, material jetting, powder bed melting, sheet lamination, or vat polymerization, or an injection molding process.

[0075] Therefore, the coil holder 500 described above is configured to guide the wire to a position that provides a uniform electromagnetic field by the susceptor within the receiving volume of the induction coil 110 / coil holder 500, thereby uniformly heating the aerosol generating article 200 inserted into the receiving volume.

[0076] The present invention also relates to an aerosol generating assembly 600 comprising the aerosol generating device 100 described above and, preferably, a susceptor 140 included in the aerosol generating article 200. Figure 6 shows an aerosol generating assembly 600 according to an exemplary embodiment. The aerosol generating assembly 600 may further comprise a battery 620 for providing power to the components of the aerosol generating assembly 600. Additionally or alternatively, the aerosol generating assembly 600 may comprise a control means 610. The control means 610 is configured to control the power supplied to the aerosol generating device 110, thereby controlling heating and the supply of aerosol to the user. [Explanation of Symbols]

[0077] 100 Aerosol Generating Devices 110 Induction Coil 110a Conventional induction coil 111 First Domain 112 Second Domain 113 The Third Domain 120 rolls 130 Receiving volume 140 Susceptors 200 Aerosol-generating items 210 Tobacco portion 220 !!! section 230 Aerosol generating materials 310 Regions with low magnetic flux density 320 Regions with high magnetic flux density 410 Normalized magnetic field distribution of induction coil 420 Normalized magnetic field distribution of a conventional induction coil 500 Coil Holder 510 recess 511 Inner surface of coil holder 512 Outer surface of coil holder 521 First area of ​​the coil holder 522 Second area of ​​the coil holder 523 Third area of ​​the coil holder 600 Aerosol Generating Assembly 610 Control means 620 Battery

Claims

1. An aerosol generating device (100) for heating an aerosol generating article (200), The induction coil (110) is configured to provide an electromagnetic field within a receiving volume (130) which is configured to receive an aerosol generating article (200) and has multiple windings (120), and the induction coil (110) The induction coil (110) comprises one or more first regions (111) and two or more second regions (112), wherein the one or more first regions (111) are arranged between at least two of the two or more second regions (112) in the longitudinal direction of the induction coil (110). With respect to the diameter of the winding (120) of the coil (110), the diameter in one or more first regions (111) is greater than the diameter in two or more second regions (112). Aerosol generating device (100).

2. The diameter of the windings (120) of the coil in one or more of the first regions (111) is substantially constant, and / or The diameter of the winding (120) of the coil in the two or more second regions (112) is substantially constant. The aerosol generating device (100) according to claim 1.

3. The diameter of the winding (120) of the coil in one or more first regions (111) is at least 3% larger, preferably at least 5% larger, more preferably at least 7% larger, and most preferably at least 10% larger than the diameter of the winding of the coil in two or more second regions (112). The aerosol generating device (100) according to claim 1 or 2.

4. In the longitudinal direction of the induction coil (110), one or more first regions (111) occupy at least 50%, preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, most preferably at least 90%, and / or, In the longitudinal direction of the induction coil (110), the two or more second regions (112) occupy at least 5%, preferably at least 10%, more preferably at least 15%, even more preferably at least 20%, and most preferably at least 30% of the length of the induction coil. An aerosol generating device (100) according to any one of claims 1 to 3.

5. The aerosol generating device (100) according to any one of claims 1 to 4, wherein the two second regions (112) are located at the distal end of the induction coil (110) and at the proximal end of the induction coil (110).

6. The aerosol generating device (100) according to any one of claims 1 to 5, wherein the induction coil (110) comprises one first region (111) and two second regions (112).

7. The induction coil (110) is a single-layer coil, and / or The induction coil (110) is formed by a single wire, and / or The diameter of the wire of the induction coil (110) has a maximum diameter dispersion of 15%, preferably a maximum diameter dispersion of 10%, more preferably a maximum diameter dispersion of 5%, and most preferably substantially no dispersion, in at least 70%, preferably at least 80%, more preferably at least 90%, and most preferably at least 95% of the length of the wire in the one or more first regions and / or the two or more second regions. An aerosol generating device according to any one of claims 1 to 6.

8. The aerosol generating device (100) according to any one of claims 1 to 7, wherein the induction coil (110) further comprises one or more third regions (113), the diameter of the winding of the coil in the third region (113) is smaller than the diameter of the winding in the first region (111), and larger than the diameter of the winding in the second region (112), and the one or more third regions (113) are arranged between the one or more first regions (111) and the two or more second regions (112).

9. The aerosol generating device (100) according to any one of claims 1 to 8, wherein in the longitudinal direction of the induction coil (110), one or more third regions (113) occupy at least 2%, preferably at least 5%, more preferably at least 10%, even more preferably at least 20%, and most preferably at least 30% of the length of the induction coil (110).

10. The aerosol generating device (100) according to any one of claims 1 to 9, further comprising a coil holder (500) on which the windings of the coil are wound, wherein the coil holder (500) is provided with recesses (510) each recess (510) that receive one winding (120) of the induction coil.

11. The coil holder (500) has a substantially solenoid shape, comprising an inner surface (511) and an outer surface (512) arranged in the longitudinal direction of the coil holder (500). The outer surface (512) is configured to receive the induction coil (110), The inner surface (511) divides the receiving volume (130). An aerosol generating device (100) according to any one of claims 1 to 10.

12. The coil holder (500) comprises a high-temperature polymer, The coil holder (500) is preferably manufactured using an additive manufacturing process or an injection molding process. The aerosol generating device (100) according to claim 10 or 11.

13. The aerosol generating device (100) according to any one of claims 1 to 12, wherein the receiving volume (130) is configured to receive the tobacco portion (210) of the aerosol generating article (200).

14. The aerosol generating device (100) according to claim 13, wherein the receiving volume (130) is configured to receive the tobacco portion (210) of the aerosol generating article (200), and has a longitudinal offset (520) with respect to one end of the induction coil (110).

15. The aerosol generating device (100) according to any one of claims 1 to 14, wherein the receiving volume (130) is configured to completely receive the tobacco portion (210) of the aerosol generating article (200).

16. The aerosol generating device (100) according to claim 15, wherein the receiving volume (130) is configured to fully receive the tobacco portion (210) of the aerosol generating article (200), and has a longitudinal offset (520) with respect to one end of the induction coil (110).

17. The aerosol generating device (100) according to any one of claims 1 to 16, wherein the induction coil (110) comprises at least 5 turns (120), preferably at least 7 turns (120), more preferably at least 10 turns (120), at least 12 turns (120), most preferably at least 16 turns (120), and / or at most 50 turns (120), preferably at most 30 turns (120), more preferably at most 25 turns (120), even more preferably at most 20 turns (120), and most preferably at most 16 turns (120).

18. Preferably, the aerosol generating article (200) contains a susceptor (140), an aerosol generating device (100) according to any one of claims 1 to 17 and Equipped with, Aerosol generating assembly (600).

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