Heating assembly for aerosol generating device

Abstract

A heating assembly for an aerosol generating device comprising a heating chamber (25) having an opening for receiving an aerosol substrate, the heating chamber (25) comprising a first tubular portion (14) made of a ceramic material, at least one second tubular portion (20) made of a metallic material or a heat-resistant plastic, and a heating element (16) configured to heat the first tubular portion (14), the at least one second tubular portion (20) being connected to an end of the first tubular portion (14).

Description

Technical Field

[0001] The present invention relates to a heating assembly for an aerosol generating device and an aerosol generating device comprising such a heating assembly. The present disclosure is particularly applicable to a portable aerosol generating device that can be self - contained and operate at low temperatures.

Background Art

[0002] In order to heat an aerosol substrate, a heating assembly is known that includes a heating chamber for receiving the aerosol substrate and a heating element for heating the heating chamber. The heating chamber is generally wrapped with a metal thin - film heater. However, this heating chamber is not entirely satisfactory.

[0003] Other heating chambers are made of materials that have properties to improve the heating of the aerosol substrate and thus the user experience. For example, heating chambers made of ceramic materials are known.

[0004] However, these heating chambers require a large amount of energy to reach the aerosolization temperature, the heat is evenly dispersed, and it is not possible to target a specific area of the heating chamber.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention aims first to solve at least some of the drawbacks of the prior art. The present invention also aims to provide a heating chamber that causes sufficient heat penetration while concentrating heat on a specific area of the heating assembly.

Means for Solving the Problems

[0006] Accordingly, the present invention relates to a heating assembly for an aerosol generating device, comprising a heating chamber having an opening for receiving an aerosol substrate, wherein the heating chamber comprises a first tubular portion made of a ceramic material, at least one second tubular portion made of a metal material or a heat-resistant plastic, and a heating element configured to heat the first tubular portion. The at least one second tubular portion is connected to the end of the first tubular portion.

[0007] In this invention, heat-resistant plastics, also known as heat-resistant plastics, refer to polymer materials that have relatively high heat resistance, such as those exceeding 100°C or 150°C.

[0008] In the heating assembly according to the present invention, the first tubular portion is connected to a second tubular portion at one of its longitudinal ends, forming a tubular assembly comprising a ceramic portion joined to a metal material portion or a heat-resistant plastic portion.

[0009] In other words, the heating chamber comprises a joint or interface between a first tubular portion made of ceramic and at least one second tubular portion made of a metal material or heat-resistant plastic.

[0010] The connection between a first tubular section made of ceramic material and a second tubular section made of metal or heat-resistant plastic creates a region of changing thermal resistance, leading to the formation of a thermal break. The thermal break reduces or even prevents heat diffusion toward the longitudinal end of the first tubular section.

[0011] When the heating element heats the first tubular portion, the heat diffuses except towards the interface or joint with the second tubular portion. Therefore, the heat is concentrated away from the second tubular portion, and more specifically, on a portion of the first tubular portion that is located away from the joint or interface between the first and second portions. In other words, the joint or interface between the ceramic and metal material or heat-resistant plastic at the longitudinal end of the first tubular portion concentrates heat in a specific area of ​​the first tubular portion.

[0012] Since ceramics are known to have a high thermal mass, ceramic materials require more energy to reach a certain temperature than metal tubular sections. By adding at least one second tubular section of metal or heat-resistant plastic to the longitudinal end of the first tubular section, it is possible to reduce the total thermal mass of the first tubular section and, consequently, reduce the energy consumption required to reach a certain temperature.

[0013] Furthermore, using ceramic material in the heating chamber allows for better heat penetration into the tobacco. This leads to improved sensory performance with a larger volume of vapor and higher nicotine levels, depending on the aerosol substrate.

[0014] The following are some of the particularly simple, convenient, and economical desirable features of the heating assembly according to the present invention.

[0015] The second tubular portion can be made from stainless steel or polyetheretherketone (PEEK). In other words, the metallic material can be stainless steel, while the heat-resistant plastic can be PEEK.

[0016] The metallic material may also be copper or aluminum. The heat-resistant plastic may also be other engineering plastics such as polyetherimide (PEI) or polyphenylene sulfide (PPS). The second tubular portion may abut against the aforementioned end of the first tubular portion.

[0017] The first tubular portion may have a thinned end portion that forms a shoulder, and at least one second tubular portion has an end portion that is in contact with and supports the shoulder.

[0018] At least one second tubular portion may cover the circumferential surface of the first tubular portion located on the end side of the first tubular portion.

[0019] In other words, at least a portion of the second tubular portion completely surrounds the surface of the first tubular portion.

[0020] The circumferential surface of the first tubular portion covered by the second tubular portion may be the inner surface of the first tubular portion.

[0021] The first tubular portion and at least one second tubular portion may be connected by an interference fit.

[0022] The first tubular portion and at least one second tubular portion can be sealed. "Sealing" means any method by which the first tubular portion is joined liquid-tightly to at least one second tubular portion. Thus, the first tubular portion and the second tubular portion can be sealed by brazing, welding, bonding, screwing, riveting, shrinking, or by applying a sealant such as a high-temperature silicone sealant.

[0023] The first tubular portion may occupy 10% to 90% of the length of the heating chamber. Preferably, the first tubular portion may occupy about 50% of the length of the heating chamber.

[0024] The ceramic material of the first tubular portion may be aluminum nitride (AlN), silicon carbide (SiC), silicon nitride (Si2N4), or beryllium oxide (BeO). In this application, aluminum nitride is preferred.

[0025] The heating element can be formed as a meander pattern on the first tubular portion.

[0026] The first tubular portion comprises one or more flat regions extending in the axial direction of the heating chamber.

[0027] The heating assembly may comprise two second tubular portions. The two second tubular portions may be connected to the first tubular portion at the first end of the first tubular portion and at the second end of the first tubular portion axially opposite the first end, respectively, and the two second tubular portions are arranged at an axial interval in the heating chamber.

[0028] The second tubular portion may be made of stainless steel or PEEK (polyether ether ketone).

[0029] With the two second tubular portions axially positioned at both ends of the first tubular portion, heat is more concentrated in the first tubular portion.

[0030] The second tubular portion may be abutted against the first end and the second end of the first tubular portion.

[0031] The first tubular portion may be located at the center between the first end of the heating chamber and the second end of the heating chamber axially opposite the first end.

[0032] The heating element may extend axially on the first tubular portion between the second tubular portions.

[0033] According to another aspect, the present invention relates to an aerosol generating device comprising a battery and a heating assembly as described above, wherein the heating element is powered by the battery.

[0034] The aerosol generating device presents the same advantages as those described in relation to the heating assembly.

[0035] Other particularities and advantages of the present invention will become apparent from the following description.

[0036] The attached drawings, given by non-limiting examples, are as follows: [Brief explanation of the drawing]

[0037] [Figure 1] The diagram shows an aerosol generating device, which is represented in a generally semi-transparent manner and comprises a battery and a heating assembly according to the present invention. [Figure 2] This is a perspective view of a heating assembly according to a specific embodiment of the present invention. [Figure 3] Figure 2 is a cross-sectional view of the heating assembly passing through axis A. [Modes for carrying out the invention]

[0038] Figure 1 shows an aerosol generating device 1 according to one embodiment. The aerosol generating device 1 is shown assembled in a way that allows the internal components to be seen. The aerosol generating device 1 is a heated, non-combustion device, sometimes referred to as a tobacco vapor device, and comprises a heating assembly 10 and a battery electrically connected to the heating assembly 10.

[0039] The heating assembly 10 is configured to receive an aerosol substrate, such as a rod of aerosol generating material, for example, a cigarette. The heating assembly is also configured to convert electrical energy supplied by the battery 5 into thermal energy. To achieve this objective, the heating assembly 10 is operable to heat the rod of aerosol generating material rather than burn it, thereby generating vapor or aerosol for inhalation by the user. Naturally, those skilled in the art will understand that the aerosol generating device 1 shown in Figure 1 is merely an illustrative aerosol generating device according to the present invention. Other types and configurations of cigarette vapor products, vaporizers, or e-cigarettes may also be used as aerosol generating devices according to the present invention.

[0040] According to one embodiment, the heating assembly 10 is most commonly seen in Figures 2 and 3.

[0041] The heating assembly 10 includes a heating chamber 25, also called a thermally conductive shell, configured to hold an aerosol substrate, also called a consumable. In particular, the heating chamber 25 defines a substantially cylindrical cavity in which a rod of the aerosol substrate can be positioned. The heating chamber 25 is tubular, for example substantially cylindrical, and defines a central passage 13 that opens to a first end 11 of the heating chamber 25 and to a second end 12 of the heating chamber 25, which is axially opposite to the first end 11. In other words, the central passage 13 is accessible through openings from each of the first end 11 and the second end 12.

[0042] Alternatively, the central passage may have only one opening located at either the first or second end of the heating chamber.

[0043] During use, the user can insert the aerosol substrate through the opening of the heating chamber 25 so that the aerosol substrate is positioned within the heating chamber 25 and in contact with the inner surface of the heating chamber 25. The length of the heating chamber 25 may be configured so that a portion of the aerosol substrate protrudes from the heating chamber 25 through the opening, i.e., outside the heating assembly 10, and can be received in the user's mouth.

[0044] According to a particular embodiment of the present invention, the heating chamber 25 includes a first tubular portion 14 and two second tubular portions 20 connected to the first tubular portion 14.

[0045] Alternatively, the heating chamber 25 may include a first tubular portion and a single second tubular portion connected to one end of the first tubular portion.

[0046] The first tubular portion 14 here has a circular cross-section and has a first end and a second end on the axial opposite side of the first end. In other words, the first tubular portion 14 is tubular, for example, substantially cylindrical.

[0047] Alternatively, the first tubular portion may be substantially cylindrical but comprises one or more flat regions extending in the axial direction of the heating chamber.

[0048] The first tubular portion 14 is made of a ceramic material, more specifically, aluminum nitride (abbreviated as AlN) in the illustrated example.

[0049] Due to the structure of the first tubular portion made of ceramic material, the first tubular portion 14 has a high thermal mass, which leads to good thermal penetration into the aerosol substrate, especially when the aerosol substrate contains tobacco. This makes it possible to improve sensory performance with a larger volume of vapor and a higher nicotine level when the aerosol substrate contains tobacco.

[0050] The first tubular portion 14 is provided with thinned end portions 15 at its first and second ends. The thinned end portions 15 have a thickness smaller than the thickness of the remaining portion of the first tubular portion 14. In particular, the inner diameter of the first tubular portion 14 in the thinned end portions 15 is larger than the inner diameter of the remaining portion of the first tubular portion 14. In other words, the first tubular portion 14 is provided with counterbore holes at its first and second ends.

[0051] Alternatively, the inner diameter of the first tubular portion may be constant along its entire length, while the outer diameter of the thinned end portion may be smaller than the outer diameter of the rest of the first tubular portion.

[0052] A shoulder portion 19 is formed by a change in diameter at the thinned end portion 15 of the first tubular portion 14. In the illustrated example, the shoulder portion 19 is formed on the inner surface 18 of the first tubular portion 14.

[0053] Alternatively, the shoulder portion may be formed on the outer surface of the first tubular portion.

[0054] The thinned end portions 15 extend to a length of 15% to 25% of the length of the first tubular portion 14. In particular, each thinned portion 15 has a length equal to 0.25 mm to 2 mm, preferably 0.75 mm to 1.5 mm, and more preferably 1 mm, in the longitudinal direction of the first tubular portion 14.

[0055] The thinned end portion 15 has a thickness of 0.10 mm to 0.5 mm. The first tubular portion 14 has a thickness of 0.15 mm to 0.75 mm in the remaining part of its length, i.e., excluding the thinned end portion.

[0056] The heating assembly 10 includes a heating element 16 configured to function as a Joule heater when an electric current is supplied to it. In other words, the heating element 16 is configured to release heat in response to the flow of electric current. This physical phenomenon is sometimes called Joule heating, resistance heating, or ohmic heating. During use, power may be supplied to the heating element 16, for example from a battery 5, so that the temperature of the heating element 16 rises and thermal energy is transferred throughout the heating chamber 25, more specifically to the first tubular portion 14. The aerosol substrate received in the heating assembly 1 is conductively heated by the heating chamber 25 to generate an aerosol for the user to inhale.

[0057] The heating element 16 is located here on the outer surface 17 of the first tubular portion 14. Alternatively, the heating element may be incorporated into the first tubular portion, i.e., located between the inner and outer surfaces of the first tubular portion. According to another alternative, the heating element may be located at a distance from the first tubular portion, i.e., without direct contact, and may transfer heat, for example, by convection.

[0058] The heating element 16 is formed here as a meander or meandering pattern coating on the outer surface 17 of the first tubular portion 14. For example, the heating element 16 may be shaped by etching, masking, or laser cutting to form the illustrated pattern. Naturally, those skilled in the art will understand that the specific pattern formed by the heating element 16 may vary depending on the functional requirements of the heating assembly 1. The pattern forms an electrical path so that the current supplied from the battery 5 to the heating element 16 during use travels along the electrical path and generates thermal energy. The heating element 16 can be made from any material that functions as a Joule heater when supplied with current, such as tungsten. Other materials having a coefficient of thermal expansion that substantially matches that of ceramic materials may also be considered.

[0059] The second tubular portion 20 here has a circular cross-section, and each has a first end and a second end opposite the first end in the axial direction. In other words, the second tubular portion 20 is tubular, for example, substantially cylindrical.

[0060] Alternatively, the second tubular portion may be substantially cylindrical but may comprise one or more flat regions extending in the axial direction of the heating chamber.

[0061] Each second tubular portion 20 has a constant cross-section; that is, the outer diameter and inner diameter of the second tubular portion are constant along the length of the second tubular portion.

[0062] Alternatively, the second tubular portion has a thinned end portion located at one end of the second tubular portion, similar to the thinned end portion described for the first tubular portion. If the second tubular portion has a thinned portion, the first tubular portion does not need to have a thinned end portion.

[0063] The second tubular portion 20 has a thickness of 0.05 mm to 0.15 mm.

[0064] The second tubular portion 20 is made from a metal material or a heat-resistant plastic. For example, the metal material may be stainless steel, copper, aluminum, or other suitable material. The heat-resistant plastic may be an engineering plastic such as polyetherimide (PEI), polyphenylene sulfide (PPS), or polyetheretherketone (PEEK).

[0065] In some cases, PEEK may be preferred over stainless steel because it has more similar thermal expansion properties to the ceramic material of the first tubular portion 14.

[0066] As shown in Figures 2 and 3, each second tubular portion 20 is connected to one end of the first tubular portion 14.

[0067] In the illustrated embodiment, each second tubular portion 20 is at least partially inserted into the first tubular portion 14 at the location of the thinned portion 15. The second tubular portion 14 is inserted by translational movement along the longitudinal direction of the first tubular portion 14 until the second tubular portion 20 contacts the shoulder portion 19. The second tubular portions 20 are therefore positioned axially apart from each other by the first tubular portion 14. Thus, the second tubular portions 20 abut against the first and second ends of the first tubular portion 14.

[0068] The thinned end portion 15 of the first tubular portion 14 surrounds at least a portion of the second tubular portion 20 in the circumferential direction. In other words, the thinned end portion 15 overlaps at least partially with a portion of the second tubular portion 20. Accordingly, at least a portion of the second tubular portion 20 overlaps with the inner surface 18 of the first tubular portion 14 at the position of the thinned end portion 15.

[0069] Alternatively, at least a portion of the second part covers the outer surface of the first tubular portion at the location of the thinned portion, or at the end of the first tubular portion if the first tubular portion does not have a thinned portion.

[0070] Each second tubular portion 20 is inserted into the first tubular portion 14 by an interference fit. The interference fit reduces vapor leakage, thus helping to deliver a larger volume of aerosol to the user. The interference fit also improves contact and heat exchange between the first tubular portion 14 and the second tubular portion 20. Therefore, there is at least one contact area between the first tubular portion 14 and the second tubular portion 20. In particular, the first contact area is located between the shoulders 19 and the surfaces of each second tubular portion 20 that are in contact with and support these shoulders 19. The second contact area is formed between the inner surface 18 of the first tubular portion 14 and a portion of the outer surface 22 of the second tubular portion 20 at the location of the tapered portion 15. The second contact area is preferably circumferential.

[0071] To achieve an interference fit, the outer diameter of the second tubular portion 20 is slightly smaller than or equal to the inner diameter of the first tubular portion 14 in the tapered portion 15.

[0072] Alternatively, the outer diameter of the first tubular portion is smaller than the inner diameter of the second tubular portion at the thinned end portion. This is applicable when the second tubular portion has a thinned end portion, or when the first tubular portion has a thinned end portion and the shoulder portion is located on the outer surface.

[0073] Alternatively, the first tubular portion and the second tubular portion may be joined by threading, provided that the inner or outer surface at the location of the thinned end portion is threaded. If the first tubular portion has a tapered end portion, the inner or outer surface of the second tubular portion is threaded in cooperation with the threads on the circumferential surface of the thinned end portion. If each of the second tubular portions has a thinned end portion, the inner or outer surface of the first tubular portion is threaded in cooperation with the threads on the circumferential surface of the thinned end portion.

[0074] Alternatively, neither the first nor the second tubular portion has thinned end portions. In this case, these portions are fixed together at their ends, i.e., by their end faces, without overlapping with the circumferential surface of the first tubular portion. These portions can be held together, for example, by adhesive, welding, or positioning pins. Naturally, those skilled in the art will understand that the specific means for assembling the first tubular portion 14 and the second tubular portion 20 may vary depending on the functional requirements of the heating chamber 25.

[0075] After assembly, the first tubular portion 14 and the second tubular portion 20 are sealed together. In the illustrated example, the first tubular portion 14 is sealed to the second tubular portion 20 by brazing.

[0076] The sealing further reduces the risk of aerosol leakage between the first tubular portion 14 and the second tubular portion 20.

[0077] Since the first tubular portion 14 and the second tubular portion 20 have substantially equal inner diameters except for the thinned portion, the passage 13 of the heating assembly 10 has a substantially constant cross-section when assembled. In particular, this allows for improved aerosol flow within the heating assembly 10.

[0078] The second tubular portion 20 has a length along the longitudinal axis A of the heating chamber 25 that is shorter than the length of the first tubular portion 14. In particular, the cumulative length of the second tubular portion 20 is 10% to 90%, preferably about 50%, of the total length of the heating assembly 10.

[0079] In the illustrated example, the second tubular portion 20 is identical and therefore has the same length. Thus, the first tubular portion 14 is located in the center of the heating assembly 10. In other words, the first tubular portion 14 is located in the center of the heating assembly 10 relative to the first end 11 and the second end 12.

[0080] When the heating element 16 is powered by the current supplied by the battery 5 of the aerosol generating device 1, the heating element 16 converts electrical energy into heat, and this heat is transferred to the first tubular portion 14 by conduction. Due to the assembly of the first tubular portion 14 and the second tubular portion 20 described above, the heat is concentrated in the center of the first tubular portion 14, that is, between its ends.

[0081] According to the present invention, the heating assembly 10, more specifically the first tubular portion 14 made of ceramic material, requires less electrical energy to reach a given temperature compared to a heating assembly formed, for example, by a single ceramic tube. In addition, the present invention provides a heating assembly with a ceramic material portion, which thus improves thermal penetration and concentrates heat transfer compared to a thin metal film.

Claims

1. A heating assembly for an aerosol generating device, comprising a heating chamber (25) having an opening for receiving an aerosol substrate, wherein the heating chamber (25) A first tubular portion (14) made from ceramic material, Two second tubular portions (20) made of metal material or heat-resistant plastic, A heating element (16) configured to heat the first tubular portion (14) and Equipped with, The two second tubular portions (20) are connected to the first tubular portion (14) at a first end of the first tubular portion (14) and at a second end of the first tubular portion (14) on the axial side opposite to the first end, and the two second tubular portions (20) are spaced apart in the axial direction of the heating chamber (25). Heating assembly.

2. The heating assembly according to claim 1, wherein the two second tubular portions (20) are made of stainless steel or PEEK (polyetheretherketone).

3. The heating assembly according to claim 1, wherein the two second tubular portions (20) are in contact with the first end and the second end of the first tubular portion (14), respectively.

4. The heating assembly according to claim 1, wherein both ends (15) of the first tubular portion (14) are thinned to form shoulder portions (19), and each of the two second tubular portions (20) has an end that is in contact with and supports the shoulder portion (19).

5. The heating assembly according to claim 1, wherein the two second tubular portions (20) cover the circumferential surface of the first tubular portion (14) located at the first end side and the second end side of the first tubular portion (14).

6. The heating assembly according to claim 5, wherein the circumferential surface of the first tubular portion (14) covered by the two second tubular portions (20) is the inner surface (18) of the first tubular portion (14).

7. The heating assembly according to claim 1, wherein the first tubular portion (14) and the two second tubular portions (20) are connected by an interlocking fit.

8. The heating assembly according to claim 1, wherein the first tubular portion (14) and the two second tubular portions (20) are sealed by brazing.

9. The heating assembly according to claim 1, wherein the first tubular portion (14) occupies 10% to 90% of the length of the heating chamber (25).

10. The heating assembly according to claim 1, wherein the ceramic material of the first tubular portion (14) is aluminum nitride.

11. The heating assembly according to claim 1, wherein the heating element (16) is formed as a meander pattern on the first tubular portion (14).

12. The heating assembly according to claim 1, wherein the first tubular portion (14) comprises one or more flat regions extending in the axial direction of the heating chamber (25).

13. The heating assembly according to claim 1, wherein the first tubular portion (14) is located midway between a first end of the heating chamber (25) and a second end of the heating chamber (25) that is axially opposite to the first end.

14. The heating assembly according to claim 1, wherein the heating element (16) extends axially on the first tubular portion (14) between the two second tubular portions (20).

15. An aerosol generating device comprising a battery (5) and a heating assembly (10) according to any one of claims 1 to 14, wherein the heating element (16) is powered by the battery (5).

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