CN220441936U - Heating mechanism and aerosol generating device - Google Patents

Abstract

The utility model discloses a heating mechanism and an aerosol generating device, comprising: a porous substrate having air holes disposed thereon that allow air to pass therethrough, the air holes allowing air to flow from a distal end face of the porous substrate to a proximal end face of the porous substrate; a heating tube at least partially embedded inside the porous matrix; the temperature measuring component comprises a metal ring and two thermocouple wires, the hot ends of the two thermocouple wires are connected to the metal ring, the metal ring surrounds the outer side face of the porous matrix, and the metal ring is adjacent to the far end face of the porous matrix.

Description

Heating mechanism and aerosol generating device

Technical Field

The utility model relates to the technical field of aerosol generating devices, in particular to a heating mechanism and an aerosol generating device.

Background

The aerosol-generating device may have an air heater which heats air to form a flow of hot air which, after entering the cigarette, heats the cigarette, thereby causing the cigarette to produce aerosol for inhalation by a user.

The aerosol-generating device typically further comprises a thermocouple for detecting the temperature of the air heater, the thermocouple typically being welded to a heat-generating element in the air heater, and air often flowing through a porous matrix in the air heater, so that the temperature detected by the thermocouple differs significantly from the actual temperature of the air flow and the thermocouple is less sensitive to cold air entering the porous matrix, such that the aerosol-generating device cannot accurately sense whether a pumping event has occurred through a temperature change.

Disclosure of Invention

Therefore, the utility model provides a heating mechanism and an aerosol generating device, so as to solve the technical problems in the background technology.

In order to achieve the above purpose, the present utility model adopts the following technical scheme:

a heating mechanism comprising:

a porous substrate having air holes disposed thereon for allowing air to pass therethrough, the air holes allowing air to flow from a distal end face of the porous substrate to a proximal end face of the porous substrate;

a heating tube at least partially embedded inside the porous substrate; and

the temperature measuring component comprises a metal ring and two thermocouple wires made of different materials, wherein the hot ends of the two thermocouple wires are connected to the metal ring, the metal ring surrounds the outer side surface of the porous matrix, and the metal ring is adjacent to the distal end surface of the porous matrix.

In some embodiments, the porous matrix comprises a thermally conductive material having a thermal conductivity greater than or equal to 100W/m.k.

In some embodiments, the heat pipe comprises a resistive heat generating material.

In some embodiments, two electrodes are disposed on the heat pipe, both of the electrodes extending to a distal end of the heat pipe.

In some embodiments, the heating mechanism further comprises two wires welded to the two electrodes, respectively.

In some embodiments, the proximal end of the heat-generating tube is disposed within and isolated from the proximal end face of the porous matrix.

In some embodiments, the porous matrix is partially a first portion and partially a second portion, and the distal surface of the porous matrix is an end surface of the second portion;

the heating tube is embedded in the first part, and the metal ring surrounds the outer side face of the second part.

In some embodiments, the second portion has a groove thereon, the hot ends of the two thermocouple wires are connected to the inner surface of the metal ring, and the hot ends of the two thermocouple wires are located in the groove.

In some embodiments, at least one of the air holes is in fluid communication with the recess.

In some embodiments, the outer diameter of the metal ring is equal to the outer diameter of the first portion.

In some embodiments, the first portion has a mounting hole in the center thereof and the second portion has an access hole therein through which the heat pipe is configured to be embedded in the mounting hole.

In some embodiments, the metal ring has an extension length in the longitudinal direction of the porous matrix of between 1mm and 2mm.

In some embodiments, the heating mechanism further comprises a heat insulating tube, the porous matrix is held within the heat insulating tube, and a receiving cavity for receiving at least part of a cigarette is formed within the heat insulating tube, the receiving cavity being located downstream of the porous matrix in the direction of airflow within the heat insulating tube.

In some embodiments, the heating mechanism further comprises a ceramic support disposed about the periphery of the porous substrate, and the ceramic support abuts the thermal insulation tube.

The embodiment also provides an aerosol generating device, which comprises the heating mechanism and further comprises a power supply component, wherein the power supply component is used for controlling the heating mechanism to work.

In summary, the utility model has the following beneficial effects:

in the heating mechanism and the aerosol generating device provided by the application, the air holes on the porous matrix allow air to flow from the distal end face of the porous matrix to the proximal end face of the porous matrix, namely cold air enters the porous matrix from the distal end face of the porous matrix, so that the temperature change of the distal end face of the porous matrix is most severe when a pumping event occurs. The hot ends of the two thermocouple wires are connected to the metal ring, so that the two thermocouple wires and the metal ring form a thermocouple capable of detecting temperature, the metal ring surrounds the outer side face of the porous base, and the metal ring is arranged adjacent to the far end face of the porous base, so that the thermocouple can accurately detect temperature change caused by cold air entering, and an accurate and reliable basis can be provided for judging whether a suction event occurs or not.

Drawings

Fig. 1 is a schematic view of an aerosol-generating device provided in an embodiment of the present application;

FIG. 2 is a cross-sectional view of a heating mechanism in combination with a cigarette according to one embodiment of the present application;

FIG. 3 is a cross-sectional view of a heating mechanism provided in an embodiment of the present application;

FIG. 4 is a cross-sectional view of a porous substrate in combination with a metal ring provided in an embodiment of the present application;

FIG. 5 is a schematic illustration of a porous substrate bonded to a metal ring according to one embodiment of the present application;

FIG. 6 is a schematic illustration of a porous matrix and ceramic scaffold combination provided in an embodiment of the present application;

in the figure:

1. a cigarette;

2. a heating mechanism; 21. a porous matrix; 211. air holes; 212. a groove; 213. a first portion; 214. a second portion;

22. a heating tube; 23. a wire; 24. a heat insulating pipe; 25. a receiving cavity; 251. a first chamber; 252. a second chamber; 26. a ceramic support; 261. a first bracket; 262. a second bracket; 27. a temperature measuring part; 271. thermocouple wires; 272. a metal ring;

3. and a power supply assembly.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals refer to the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of the present application. The embodiments described below by referring to the drawings are exemplary and intended for the purpose of explaining the present application and are not to be construed as limiting the present application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

Embodiments of the present application are described in detail below with reference to the accompanying drawings.

In the description of the present application, it should be noted that, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be fixedly connected, or indirectly connected through intermediaries, for example, or may be in communication with each other between two elements or in an interaction relationship between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

In the description of the present application, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate an orientation or a positional relationship based on the drawings, which are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or display that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or display.

A heating mechanism and an aerosol-generating device according to embodiments of the present application will be described in detail below with reference to fig. 1 to 6. It is noted that the following examples are merely for explaining the present application and are not to be construed as limiting the present application.

Example 1:

referring mainly to fig. 1, an embodiment of the present application provides an aerosol-generating device comprising a heating mechanism 2, at least part of a cigarette 1 being receivable in the aerosol-generating device, the heating mechanism 2 being adapted to heat air to form a flow of hot air, the flow of hot air flowing into the cigarette 1 and to bake tobacco in the cigarette 1, such that the cigarette 1 produces an aerosol that can be consumed by a user.

Referring mainly to fig. 2 and 3, the heating mechanism 2 includes a porous substrate 21 and a heat generating tube 22.

The heating tube 22 is hollow and tubular, and is at least partially embedded in the porous substrate 21, i.e., the heating tube 22 may be formed in the porous substrate 21 by insert molding, or the heating tube 22 may be coupled to the porous substrate 21 by insertion. The heat generating pipe 22 is used for generating heat and can release the heat.

The heating tube 22 may contain a resistive heating material capable of generating joule heat when energized. Suitable resistive materials include, but are not limited to: semiconductors such as doped ceramics, conductive ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, metal alloys, and composites made of ceramic materials and metal materials. Such composite materials may include doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, constantan (Constantan), nickel-containing alloys, cobalt-containing alloys, chromium-containing alloys, aluminum-containing alloys, titanium-containing alloys, zirconium-containing alloys, hafnium-containing alloys, niobium-containing alloys, molybdenum-containing alloys, tantalum-containing alloys, tungsten-containing alloys, tin-containing alloys, gallium-containing alloys, manganese-containing alloys, and iron-containing alloys, as well as nickel-, iron-, cobalt-based superalloys, stainless steel, iron-aluminum-based alloys, and iron-manganese-aluminum-based alloys. In the composite material, the resistive material may be embedded in, encapsulated or coated by the insulating material, or vice versa, as desired, depending on the kinetics of energy transfer and the desired external physicochemical properties.

The heating tube 22 may include a base tube, and the resistive heating material may be disposed on the base tube, for example, the resistive heating material may be prepared as a heating coil, a heating line, a heating film, a heating mesh, or the like, and the resistive heating material may be bonded on the base tube by winding, sintering, embedding, printing, spraying, or the like. It should be noted that, in some embodiments, the heating tube 22 may be made of conductive ceramics.

The heating tube 22 may further include two electrodes electrically connected to opposite ends of the resistive heating material, respectively. Both electrodes may extend to the distal end of the heat pipe 22, thereby facilitating welding of both electrodes to the lead wire 23.

Referring to fig. 1 and 5, the aerosol-generating device further comprises a power supply assembly 3, the power supply assembly 3 comprising a battery cell and a circuit board, the circuit board being electrically connected to the battery cell, the circuit board being configured to control the power supplied from the battery cell to the heating mechanism, so that the power supply assembly 3 is capable of controlling the operation of the heating mechanism 1, and in particular, the power supply assembly 3 is capable of controlling the operation of the heating tube 22 by controlling the power supplied to the heating tube 22. The heating mechanism 2 further comprises two wires 23, one ends of the two wires 23 are respectively welded with the two electrodes, and the other ends of the two wires 23 are respectively connected with the power supply assembly 3, so that the heating tube 22 can take electricity from the power supply assembly 3 through the two wires 23, and further joule heat is generated.

The porous substrate 21 is provided with air holes 211 allowing air to pass therethrough, and the number of the air holes 211 may be one or more. Air can flow from the distal end face of the porous substrate 21 to the proximal end face of the porous substrate 21 through the air holes 211, that is, the air inlet of the air holes 211 is opened on the distal end face of the porous substrate 21, and the air outlet of the air holes 211 is opened on the proximal end face of the porous substrate 21, wherein the distal end face of the porous substrate 21 and the proximal end face of the porous substrate 21 are two oppositely arranged end faces. Also, the proximal face of the porous matrix 21 may be closer to the cigarette 1 received in the aerosol-generating device than the distal face of the porous matrix 21. Accordingly, when the cigarette received in the aerosol-generating device is smoked, i.e. when a smoking event occurs, cold air enters the air holes 211 and the porous matrix 21 from the air inlet of the air holes 211, and the cold air is heated during the flow within the air holes 211, eventually forming a hot air flow which exits the air holes 211 and the porous matrix 21 from the air outlet of the air holes 211.

The porous matrix 21 is not self-heating, and heats up mainly by absorbing heat released from the heat receiving and transmitting pipe 22 and releases at least part of the absorbed heat to heat the air flowing through the air holes 211, so that the air flowing through the air holes 211 forms a hot air flow.

The porous matrix 21 may contain a thermally conductive material, which refers to a material having a thermal conductivity greater than or equal to 100W/m.k, and may be, for example, graphite, graphene, graphite alloy, aluminum, copper, zinc, steel, silver, or the like. Therefore, the porous substrate 21 can rapidly transfer heat under the heat released by the heating tube 22, so that the heat can be uniformly distributed on the porous substrate 21, which is beneficial to reducing the temperature distribution gradient on the porous substrate 21 and uniformly heating the air flowing through the air holes 211.

Referring to fig. 6, the air holes 211 have a plurality of air holes 211, and the plurality of air holes 211 may be arranged in layers around the periphery of the heat generating tube 22, for example, the plurality of air holes 211 may be arranged in a plurality of layers, and each layer may form a concentric circle with the heat generating tube 22. In more detail, the heating tube 22 may be located at the center of the porous substrate 21.

In some embodiments, referring to fig. 2 and 3, the proximal end surface of the porous substrate 21 is disposed facing the bottom of the cigarette 1 received in the aerosol-generating device, and the proximal end surface of the porous substrate 21 is parallel to the bottom of the cigarette 1, in order to prevent the tobacco tar permeated by the cigarette 1 from leaking into the heating tube 22, the proximal end of the heating tube 22 is disposed inside the porous substrate 21 and the proximal end of the heating tube 22 is isolated from the proximal end surface of the porous substrate 21, so that the tobacco tar leaked onto the proximal end surface of the porous substrate 21 cannot contact the heating tube 22, thereby protecting the heating tube 22.

Referring to fig. 4 and 5, the heating mechanism 1 may further include a temperature measuring part 27, and the temperature measuring part 27 is connected to the porous substrate 21, so that the temperature measuring part 27 can detect the temperature of the porous substrate 21. Since the air flowing through the air holes 211 is warmed up mainly by absorbing heat released from the porous substrate 21 and the heat generating pipe 22 is warmed up and heated up under the control of the power supply module 3, the temperature of the porous substrate 21 is closer to the temperature of the air flowing through the air holes 211 than the temperature of the heat generating pipe 22. It will be appreciated that the temperature measuring member 27 may also be connected to the power supply assembly 3 to transmit at least one electrical parameter or data to the power supply assembly 3 caused by the temperature of the porous matrix 21.

Specifically, the temperature measuring part 27 may include two thermocouple wires 271 and a metal ring 272, the two thermocouple wires 271 are made of different materials, the metal ring 272 may be made of a heat conductive material such as copper or a copper alloy, and the metal ring 272 surrounds the outer side of the porous substrate 21 such that the metal ring 272 has substantially the same temperature as the outer side of the porous substrate 21. The hot ends of the two thermocouple wires 271 may be welded together to the metal ring 272 after being connected to each other, or the hot ends of the two thermocouple wires 271 may both be welded to the metal ring 272 and the two thermocouple wires 271 are electrically connected through the metal ring 272. The two thermocouple wires 271 and the metal ring 272 constitute a thermocouple for detecting the temperature of the porous substrate 21, and the thermocouple is connected to the outer side surface of the porous substrate 21, so that the temperature of the outer side surface of the porous substrate 21 can be detected. The cold ends of the two thermocouple wires 271 are used for connection with the circuit board of the power supply unit 3.

Since the cool air can pass through the porous substrate 21 through the air holes 211 and exchange heat with the porous substrate 21 during the passing through the porous substrate 21, a temperature change of the porous substrate 21 is caused when a large amount of cool air flows into the air holes 211, so that it is possible to determine whether a pumping event occurs by checking the temperature change of the porous substrate 21. The heating tube 22 is heated and warmed up under control of the power supply assembly 3, so that the temperature change of the heating tube 22 is not significant relative to the temperature change of the porous substrate 21 upon occurrence of a pumping event. The detection of the temperature change of the porous substrate 21 by the temperature measuring part 27 is more accurate and reliable than the detection of the temperature change of the heating tube 22 to judge the pumping event. When the temperature measuring member 27 is connected to the outer side surface of the porous base 21 and the heating tube 22 is located at the center of the porous base 21, the temperature change is more remarkable and severe than that of the outer side surface of the porous base 21 when a pumping event occurs, so that the sensitivity and accuracy of the pumping event judgment can be further improved and the missing judgment and the erroneous judgment can be reduced by connecting the temperature measuring member 27 to the outer side surface of the porous base 21.

More specifically, referring to fig. 4, the porous substrate 21 may be partially formed into the first portion 213 and partially formed into the second portion 214, and the first portion 213 and the second portion 214 may be integrally formed, or the first portion 213 and the second portion 214 may be separately formed and then assembled or connected to form a part of the porous substrate 21. The distal end face of the porous matrix 21 is the end face of the second portion 214, whereby the air holes 211 penetrate the first portion 213 and the second portion 214, and the second portion 214 is located upstream of the first portion 213 along the flow direction of the air flow in the porous matrix 21. Wherein the heat pipe 22 is embedded in the first portion 213, e.g., the heat pipe 22 is embedded in the center of the first portion 213; the metal ring 272 surrounds the outer side of the second portion 214, i.e., the metal ring 272 is located upstream of the heating tube 22; and a space is provided between the metal ring 272 and the heat generating tube 22 in the radial direction of the porous base 21. Therefore, when cool air is introduced or when there is a pumping event, the temperature measuring part 27 can greatly improve the detection precision and accuracy of the pumping event by detecting the temperature change of the surface of the second part 214, compared to the first part 213 and other parts of the porous substrate 21, in which the temperature change of the second part 214 is most remarkable and intense. Wherein, referring to fig. 4, the center of the first portion 213 may be provided with a mounting hole, which may be a blind hole closed at a proximal end, and the second portion 214 may be provided with an inlet hole communicating with the mounting hole, and the heating tube 22 may be configured to pass through the inlet hole and be embedded in the mounting hole.

The hot ends of the two thermocouple wires 271 may be closer to the distal end of the metal ring 272 than to the proximal end of the metal ring 272 to further improve the sensitivity and accuracy of detecting aspiration events.

The circuit board in the power supply module 3 may count the number of suction ports based on the suction event and control the heat generation temperature of the heat generation pipe 22 based on the number of suction ports. Alternatively, the circuit board in the power supply assembly 3 may control other operations of the aerosol-generating device based on the puff event, such as controlling a respiratory light on the aerosol-generating device to flash or a motor to vibrate, etc.

The metal rings 272 may have an extension length in the longitudinal direction of the porous substrate 21 of between 1mm and 2mm. The second portion 214 may have an extension in the longitudinal direction of the porous substrate 21 of between 1mm and 2mm. The extension length of the metal ring 272 in the longitudinal direction of the porous base 21 may be equal to the extension length of the second portion 214 in the longitudinal direction of the porous base 21.

Referring to fig. 2 and 3, the heating mechanism 2 further includes a heat insulating pipe 24.

The thermal barrier 24 may be made of a thermally insulating material, meaning that the thermal conductivity of the material is less than 100W/m.k, preferably less than 40W/m.k or less than 10W/m.k at 23 ℃ and 50% relative humidity. For example, the insulating material may be made of at least one of PAEK-like material, PI material, or PBI material, wherein the PAEK-like material includes PEEK, PEKK, PEKEKK or PEK material. Alternatively, as shown in FIG. 3, the thermal insulation tube 24 is a vacuum tube with a vacuum interlayer.

Referring to fig. 2 and 3, the porous substrate 21 is held in the heat insulating tube 24, and the heat insulating tube 24 helps to reduce heat loss on the porous substrate 21, and helps to improve the heating efficiency of the porous substrate 21 to air and reduce energy consumption. The interior of the insulating tube 24 may also be formed with a receiving chamber 25 for receiving at least part of the cigarette 1, the receiving chamber 25 being located downstream of the porous matrix 21 in the direction of the airflow within the insulating tube 24.

Referring to fig. 3 and 6, the heating mechanism 1 further includes a ceramic support 26, the ceramic support 26 is disposed on the periphery of the porous substrate 21, and the ceramic support 26 abuts against the heat insulation tube 24. The ceramic scaffold 26 may further insulate the porous matrix 21 on the one hand and may help to retain the porous matrix 21 in the insulating tube 24 on the other hand.

The ceramic support 26 may include a first support 261 having a substantially semicircular shape and a second support 262 having a substantially semicircular shape, the porous substrate 21 being surrounded by the first support 261 and the second support 262, and the first support 261 and the second support 262 may be mirror images of each other. By dividing the ceramic support 26 into the first support 261 and the second support 262, the difficulty in assembling the porous base 21 into the ceramic support 26 is reduced, and it can be ensured that the porous base 21 is not worn out when the porous base 21 is assembled into the ceramic support 26.

In embodiments where the insulating tube 24 is a vacuum tube, the insulating tube 24 may be made of metal, such as stainless steel, which has a relatively high hardness, the inner and outer side walls of the vacuum tube may be relatively small in thickness, thereby helping to reduce the overall thickness of the vacuum tube and to miniaturize the heating mechanism 2. However, the metal has a higher thermal conductivity and the gas flow temperature near the proximal face of the porous matrix 21 is highest, so that the wall of the insulating tube 24 near the proximal face of the porous matrix 21 has a higher temperature.

In order to prevent the bottom of the cigarette 1 from being burnt by high temperature or burning at high temperature, the receiving chamber 25 of the heat insulating tube 24 may have a first chamber 251 and a second chamber 252 which are communicated with each other, the second chamber 252 being located between the first chamber 251 and the porous substrate 21, the second chamber 252 having an inner diameter larger than that of the first chamber 251, the bottom of the cigarette 1 being accommodated in the second chamber 252 such that the bottom of the cigarette 1 is spaced from the wall of the heat insulating tube 24 defining the second chamber 252.

Referring to fig. 4 and 5, the distal end of the porous substrate 21 has a groove 212, a metal ring 272 is disposed at the periphery of the groove 212, and the hot ends of two thermocouple wires 271 are welded with the metal ring 272 in the groove 212. So that the hot end of the wire 271 does not interfere with the assembly of the porous matrix 21 with the ceramic support 26.

Referring to fig. 4 and 5, the outer diameter of the metal ring 272 is equal to the outer diameter of the first portion 213 of the porous substrate 21, so that the metal ring 272 does not affect the assembly of the porous substrate 21 with the ceramic support 26, and helps to ensure that the ceramic support 26 is better able to retain the porous substrate 21.

In the heating mechanism and the aerosol-generating device described above, the air holes in the porous substrate allow air to flow from the distal surface of the porous substrate to the proximal surface of the porous substrate, i.e. cool air enters the porous substrate from the distal surface of the porous substrate, so that the temperature change at the distal surface of the porous substrate is most severe when a pumping event occurs. The hot ends of the two thermocouple wires are connected to the metal ring, so that the two thermocouple wires and the metal ring form a thermocouple capable of detecting temperature, the metal ring surrounds the outer side face of the porous base, and the metal ring is arranged adjacent to the far end face of the porous base, so that the thermocouple can accurately detect temperature change caused by cold air entering, and an accurate and reliable basis can be provided for judging whether a suction event occurs or not.

The foregoing is illustrative of the present utility model and is not to be construed as limiting the scope of the utility model, but rather as enabling modifications, variations in the structure, shape and principles of the utility model, which are obvious to those skilled in the art, are intended to be included within the scope of the utility model.

Claims (10)

1. A heating mechanism, comprising:

a porous substrate having air holes disposed thereon that allow air to pass therethrough, the air holes allowing air to flow from a distal end face of the porous substrate to a proximal end face of the porous substrate;

a heating tube at least partially embedded inside the porous matrix;

the temperature measuring component comprises a metal ring and two thermocouple wires, the hot ends of the two thermocouple wires are connected to the metal ring, the metal ring surrounds the outer side face of the porous matrix, and the metal ring is adjacent to the far end face of the porous matrix.

2. The heating mechanism of claim 1, wherein the heat generating tube comprises a resistive heat generating material; two electrodes are arranged on the heating tube, and the two electrodes extend to the far end of the heating tube; the heating mechanism further comprises two wires, and the two wires are welded with the two electrodes respectively.

3. The heating mechanism of claim 1, wherein a proximal end of the heat generating tube is disposed within and isolated from a proximal face of the porous matrix; the part of the porous matrix is a first part, the part of the porous matrix is a second part, and the far-end surface of the porous matrix is the end surface of the second part; the heating tube is embedded in the first part, and the metal ring surrounds the outer side surface of the second part; the second part is provided with a groove, the hot ends of the two thermocouple wires are connected to the inner surface of the metal ring, and the hot ends of the two thermocouple wires are positioned in the groove; at least one of the air holes is in fluid communication with the recess.

4. A heating mechanism according to claim 3, wherein the outer diameter of the metal ring is equal to the outer diameter of the first portion.

5. The heating mechanism of claim 4, wherein the first portion has a mounting hole in a center thereof and the second portion has an access hole therein, the heat generating tube being configured to be embedded in the mounting hole therethrough.

6. The heating mechanism of claim 1, wherein the metal ring has an extension length in the longitudinal direction of the porous substrate of between 1mm and 2mm.

7. The heating mechanism of claim 1, further comprising a heat insulating tube, wherein the porous matrix is retained within the heat insulating tube, and wherein the interior of the heat insulating tube is further formed with a receiving chamber for receiving at least a portion of a cigarette, the receiving chamber being downstream of the porous matrix in the direction of airflow within the heat insulating tube.

8. The heating mechanism of claim 7, further comprising a ceramic support disposed about the periphery of the porous substrate, the ceramic support abutting the heat pipe.

9. The heating mechanism of claim 1, wherein the porous matrix comprises a thermally conductive material having a thermal conductivity greater than or equal to 100W/m.k.

10. An aerosol-generating device comprising a heating mechanism according to any of claims 1 to 9, and further comprising a power supply assembly for controlling the operation of the heating mechanism.