Temperature measurement system for aerosol generator, aerosol generator equipped with temperature measurement system, and method for measuring the temperature inside an aerosol generator.

Abstract

A temperature measurement system for an aerosol generating device according to the invention comprises a magnetic field source, a ferromagnetic or ferrimagnetic body, and a force sensor configured to measure an attractive force between the magnetic field source and the ferromagnetic or ferrimagnetic body. The temperature measurement system further comprises a memory in which pre-recorded data is stored associating at least one force value with a value indicative of a temperature of the ferromagnetic or ferrimagnetic body, and a control unit configured to determine temperature information based on the measured force values ​​from the force sensor and the pre-recorded data. A method for measuring a temperature in an aerosol generating device according to the invention comprises the steps of providing a magnetic field source, a ferromagnetic or ferrimagnetic body, and a force sensor, measuring the attractive force between the magnetic field source and the ferromagnetic or ferrimagnetic body with the force sensor, and determining temperature information based on the measured force values ​​obtained from the force sensor and the pre-recorded data associating at least one force value with a value indicative of a temperature of the ferromagnetic or ferrimagnetic body.

Description

Technical Field

[0001] The present invention generally relates to the field of aerosol generating devices. More particularly, the present invention is directed to a temperature measurement system for an aerosol generating device, an aerosol generating device comprising such a temperature measurement system, and a method of measuring the temperature within an aerosol generating device.

Background Art

[0002] In recent years, devices that heat substances rather than burning or combusting them to generate vapors or aerosols intended for inhalation by users have become increasingly popular.

[0003] Such commonly used devices typically use tobacco and / or other suitable substances that are heated rather than burned to produce an inhalable aerosol. The tobacco and / or other suitable substances may also be referred to as aerosol generating substances, and the device may be referred to as an aerosol generating device.

[0004] Typically, the aerosol generating substance is placed within a container, also referred to as a stick or tobacco stick, which can be inserted into and removed from the aerosol generating device by the user. In other words, the stick or tobacco stick is a consumable.

[0005] Generally, the user inserts the consumable into the heating section of the aerosol generating device. The heating section of the aerosol generating device is also known as a heating chamber or oven chamber. When the user inserts the consumable into the heating section, the user can turn on the heating of the aerosol generating device by operating an operation button. Thereafter, the user waits until the heated aerosol generating substance progresses to a state where it generates an aerosol that can be consumed by the user.

[0006] In this regard, the temperature of the aerosol-generating material plays a crucial role in the use of an aerosol generator. On the one hand, it is necessary to reach a minimum temperature of the aerosol-generating material in order to obtain an appropriate amount of aerosol. On the other hand, extremely high temperatures should also be avoided, for example, because the polymer layer in the fluid chamber and nozzle may begin to melt, and the aerosol ejected from the aerosol generator may burn or be too hot for the user to consume. Furthermore, excessively high temperatures can lead to the formation of undesirable or even harmful components in the aerosol. In addition, different types of aerosol-generating materials may require different temperatures for aerosol generation. Finally, users of aerosol generators may have different personal preferences regarding the preferred heating temperature of the aerosol-generating material.

[0007] Considering the above, it is necessary to measure the temperature of the aerosol-generating substance. However, due to the limited available space within the oven chamber, it is inherently difficult to measure the temperature within the consumable itself, or even in direct proximity to it. Furthermore, the accuracy of the temperature probe may be compromised depending on the type of heating employed, for example, when a conductive temperature probe is inserted into an oven chamber heated by induction heating.

[0008] Therefore, conventionally known devices focus on safety measures that are tailored to avoid excessively high temperatures.

[0009] For example, European Patent Application Publication No. 3606363A1 proposes holding and heating an aerosol-forming liquid using an open-porous, inductively heatable ceramic material, in which heating occurs primarily or exclusively as a result of hysteresis loss. The material is preferably ferrimagnetic or ferromagnetic and non-conductive. In this case, the inductive heating property essentially disappears above the Curie temperature. This effect is used to control the maximum heating temperature of the susceptor.

[0010] European Patent Application Publication No. 3788893A1 discloses an aerosol generator comprising a housing and a control unit. The housing comprises a cavity for inserting an aerosol generating article and a magnetic element. If an excessively high temperature is detected, a magnetic element control module controls the magnetic element to generate a magnetic repulsive force on the aerosol generating article, causing the article to displace.

[0011] An alternative method is explored in Korean Patent Publication No. 102231229B1. This document suggests placing a diamagnetic or paramagnetic material between the heating element and the temperature measuring instrument, thereby minimizing the maximum measurement error caused by eddy currents generated by the electromagnetic waves of the coil. In other words, the temperature of the heating element is measured indirectly in this document.

[0012] The specification of Chinese Patent Application Publication No. 110236230A relates to a temperature control device for e-cigarettes comprising a thermocouple, an electromotive force sampling circuit, and a control module. The high-temperature end of the temperature difference thermocouple is connected to the atomizer of the e-cigarette, and the electromotive force sampling circuit is connected to the low-temperature end. The control module is connected to the electromotive force sampling circuit and a temperature sensor. The control module acquires the electromotive force according to the temperature information at the low-temperature end of the thermocouple and a pre-set temperature-electromotive force comparison table. The atomizer temperature is controlled by acquiring the temperature at the high-temperature end in real time with the help of the temperature-electromotive force comparison table. [Overview of the project] [Means for solving the problem]

[0013] The present invention is intended to address one or more of the above technical problems. One or more of these problems can be improved by the subject matter of the independent claims. Further preferred embodiments are defined in the dependent claims.

[0014] In particular, taking into consideration the problems discussed above, the inventors have devised a temperature measurement system for an aerosol generator comprising a magnetic field source, a ferromagnetic material, and a force sensor configured to measure the attractive force between the magnetic field source and the ferromagnetic material. The temperature measurement system further comprises a memory that stores pre-recorded data relating at least one force value to a value indicating the temperature of the ferromagnetic material, and a control unit configured to determine temperature information based on the force value measured from the force sensor and the pre-recorded data.

[0015] In particular, the inventors have surprisingly discovered that the interrelationship between the temperature and magnetic susceptibility of a given ferromagnetic material can be used for temperature measurement. Specifically, the present invention specifies a system comprising a magnetic field source and a ferromagnetic material. The ferromagnetic material is magnetized by the magnetic field generated from the magnetic field source, resulting in an attractive force between the magnetic field source and the ferromagnetic material. A force sensor is configured to measure the attractive force between the magnetic field source and the ferromagnetic material. As described above, the magnetic susceptibility, and thus the attractive force between the magnetic field source and the ferromagnetic material, depends on the temperature of the ferromagnetic material (see Figure 3). In the present invention, this causal relationship is utilized by pre-recording and storing reference data in memory, and then determining temperature information by evaluating the force value measured from the force sensor against the pre-recorded reference data.

[0016] In other words, the physical principle of this wireless thermometer is based on the fact that the attractive force between a ferromagnetic material and a magnetic field source is a function of ferromagnetic susceptibility, which is a function of temperature (see Figure 3). By calibrating the force / temperature reading of the transfer function, it is possible to determine the temperature of the ferromagnetic material that will function as a temperature sensor without wiring to electronic equipment, and thus wirelessly. Thanks to this wireless characteristic, the ferromagnetic material can be placed in locations where wiring is impossible or difficult, such as inside consumables or oven chambers.

[0017] Instead of ferromagnetic materials, ferrimagnetic materials can also be used. It should be noted that all features and preferred embodiments presented in relation to one embodiment using ferromagnetic materials can also be implemented using ferrimagnetic materials.

[0018] The quantitative relationship between attractive force and temperature can preferably be established by performing corresponding calibrations. Alternatively, the quantitative correlation between attractive force and temperature can be estimated based on specific materials (type of magnetic field source and ferromagnetic material, distance between them, Curie constant, etc.) and equations such as Curie's law and the Curie-Weiss law. The correlation data between attractive force and temperature can then be pre-recorded in the memory of the temperature measurement system. During use of the aerosol generator, the control unit can then retrieve the force value measured from the force sensor and compare the value with the pre-recorded data. Based on this comparison, the control unit determines the temperature information for the ferromagnetic material.

[0019] According to one embodiment of the present invention, the pre-recorded correlation data may include only one threshold for the attractive force and one correlation value indicating the temperature of the ferromagnetic material. In the above embodiment having a single pre-recorded threshold for the attractive force, the control unit can compare the measured force value with the threshold. If the measured force value is lower than the threshold, the control unit determines that the target temperature (which may be the minimum temperature, optimal temperature, or maximum temperature) has not yet been reached. If the measured force value is greater than or equal to the threshold, the control unit determines that the target temperature has been achieved or exceeded. In this embodiment, the temperature information determined by the control unit is a binary parameter, and the possible parameter values ​​are "target temperature achieved or exceeded" and "target temperature not achieved".

[0020] Preferably, the control unit is also configured to control heating based on the acquired temperature information.

[0021] According to a preferred embodiment of the present invention, the control unit of the temperature measurement system is configured to determine whether the ferromagnetic material has a temperature below and / or above its Curie temperature. At the Curie temperature (or above), the magnetic susceptibility of the ferromagnetic material is very small (see Figure 3). Therefore, it is possible to determine with relatively high reliability whether the temperature of the ferromagnetic material is below or above the Curie temperature based on the attractive force between the magnetic field source and the ferromagnetic material. In a particularly preferred embodiment, the ferromagnetic material exhibits a Curie temperature of particular interest in relation to the aerosol generator, for example, between 150°C and 350°C, more preferably between 200°C and 300°C, and even more preferably between 230°C and 270°C. This makes it possible to reliably determine temperatures that are particularly relevant in the use of the aerosol generator, such as the minimum, optimal, or maximum temperature required to generate a sufficient amount of aerosol. Preferably, the ferromagnetic material exhibits a Curie temperature corresponding to the maximum temperature, i.e., the highest recommended temperature for the aerosol generating material, ±20°C, preferably ±10°C. This is because the temperature dependence of magnetic susceptibility becomes more pronounced below the Curie temperature, making it easier to reliably determine temperatures within this temperature range of interest, i.e., below the maximum temperature of the aerosol-generating material.

[0022] According to a preferred embodiment, pre-recorded data associates multiple force values ​​with corresponding temperatures of a ferromagnetic material, and the control unit is configured to determine the temperature of the ferromagnetic material. In this preferred embodiment, a specific relationship between attractive force and temperature can be established by performing calibration that associates all discrete temperature values ​​within a given temperature range with corresponding force values ​​or force ranges. For example, the resulting pre-recorded data can associate all temperatures between 0°C and 400°C with corresponding force ranges in 0.1°C or 1°C steps. To avoid ambiguity, each force value can be associated with only one temperature value.

[0023] According to a preferred embodiment of the present invention, the force sensor includes a strain gauge, a load cell, or a system configured to convert force into displacement and measure the displacement. Because these types of force sensors are typically relatively small, they can be easily implemented in the limited space adjacent to the oven chamber. Furthermore, because these sensors can be acquired with high sensitivity, reliable results can be ensured even with relatively small suction forces.

[0024] A preferred embodiment of the present invention relates to an aerosol generator comprising the temperature measurement system described above and an oven chamber having oven walls.

[0025] In a preferred embodiment of the aerosol generator, the ferromagnetic material is provided on the inner surface of the oven wall, and the force sensor and magnetic field source are provided on the outer surface of the oven wall, facing the ferromagnetic material. This setup ensures highly reliable temperature measurement by reducing the distance between the ferromagnetic material and the consumables inserted into the oven chamber. In other words, the temperature of the ferromagnetic material is very similar to the temperature of the aerosol-generating material in the consumables.

[0026] According to another preferred embodiment of the present invention, the aerosol generator comprises a consumable, preferably a tobacco stick, at least partially inserted into an oven chamber. Furthermore, a ferromagnetic material is provided inside the consumable within the oven chamber, and a force sensor and a magnetic field source are provided on the outer surface of the oven wall, facing the ferromagnetic material. In this arrangement, the ferromagnetic material is in direct contact with the aerosol-generating material in the consumable. Therefore, the temperature of the ferromagnetic material is essentially the same as the temperature of the aerosol-generating material in the consumable. Preferably, the oven chamber and the consumable have a concentric cylindrical shape, and the ferromagnetic material is placed on the cylindrical axis (of the consumable) within the consumable. This ensures a continuous distance between the ferromagnetic material and the magnetic field source, and thus reliable measurement.

[0027] According to a preferred embodiment of the present invention, the oven chamber of the aerosol generator is made entirely of a non-magnetic material or includes a non-magnetic window between the ferromagnetic material and the force sensor and the magnetic field source. This feature significantly improves the sensitivity of the attractive force measurement. In the context of the present invention, the term non-magnetic material refers to a paramagnetic material and / or a diamagnetic material.

[0028] Furthermore, the inventors have devised a method for measuring the temperature inside an aerosol generator, which includes steps of providing a magnetic field source, a ferromagnetic material, and a force sensor, measuring the attractive force between the magnetic field source and the ferromagnetic material using the force sensor, and determining temperature information based on the measured force value obtained from the force sensor and pre-recorded data associating at least one force value with a value indicating the temperature of the ferromagnetic material. For the reasons presented above, this measurement method is suitable for reliably measuring the temperature inside the aerosol generator.

[0029] Hereinafter, the present invention will be described with reference to exemplary embodiments of the present invention.

Brief Description of the Drawings

[0030] [Figure 1] A schematic cross-sectional view of an aerosol generator equipped with a temperature measurement system according to an embodiment of the present invention is shown. [Figure 2] A schematic cross-sectional view of an aerosol generator including another embodiment of the present invention is shown. [Figure 3] It plots the qualitative relationship between the magnetic susceptibility and temperature of a ferromagnetic material (or ferrimagnetic material). [Figure 4] A detailed view of the magnetic field source, the non-magnetic window of the oven wall, the force sensor, and the magnetic field source of the temperature measurement system depicted in FIG. 1.

Modes for Carrying Out the Invention

[0031] The accompanying drawings are included to provide a further understanding of the present invention and are incorporated herein and constitute part of this specification. The drawings illustrate specific embodiments of the present invention and, together with this description, serve to illustrate the principles of the present invention. Many other embodiments of the present invention and the advantages associated with the present invention will become readily apparent upon further detailed description below.

[0032] To facilitate a more abstract view of the embodiments, it will be noted that general and / or well-understood elements that may be useful or necessary in commercially viable embodiments are not necessarily depicted. Elements in the drawings are not necessarily illustrated to scale relative to one another. Certain operations and / or steps in embodiments of the method may be described or illustrated in a particular order, but it will be further noted that those skilled in the art will come to understand that specificity regarding such order is not actually required. It will also be understood that terms and expressions used herein have their ordinary meanings as they do in their respective areas of investigation and study, unless a particular meaning is otherwise defined herein.

[0033] Figure 1 shows a schematic cross-sectional view of an aerosol generator 1 according to one embodiment of the present invention, along the longitudinal direction of the aerosol generator 1.

[0034] The aerosol generator 1 houses an oven chamber equipped with oven walls 5. The oven chamber is configured so that a user can place consumables 6 inside it. Preferably, the oven chamber and consumables have an elongated cylindrical shape. However, the shape of the consumables 6 and the oven chamber should not be considered limiting to the concept of the present invention. The oven chamber comprises one or more oven walls 5. For example, when the shape of the oven chamber is cylindrical as described above, the oven chamber may have cylindrical side walls, or when the shape of the oven chamber is not cylindrical, it may have multiple side walls.

[0035] Although not shown in Figure 1, the aerosol generator 1 may be equipped with a heater for supplying heat to the oven chamber, thereby heating the aerosol-generating material in the consumable 6 when inserted into the heating compartment. The heater is also located in the housing portion of the aerosol generator 1. The heater is preferably a heater that supplies heat to the oven chamber based on resistance heating. However, the type of heating should not be considered limiting to the concept of the present invention.

[0036] The aerosol generator 1 shown in Figure 1 is equipped with a temperature measurement system according to one embodiment of the present invention. This temperature measurement system includes a ferromagnetic material 4 provided on the inner surface of the oven wall 5 defining the oven chamber, specifically on the inner surface of the lower base of the cylindrical oven chamber. The ferromagnetic material 4 is preferably disc-shaped.

[0037] An NdFeB grade N35 magnet is used as magnetic field source 2. The magnet is also a disc shape with a diameter of 10 mm and a thickness of 2 mm. The maximum tensile force generated between a single magnet and a polished thick flat steel plate is approximately 36 N. Alternatively, a grade N52 magnet can be used. At a distance of 0.5 cm, this magnet still generates a tensile force of approximately 0.5 N.

[0038] In this embodiment, the force sensor 3 is a so-called force-sensing resistor (FSR). These sensors are robust polymer thick film (PTF) devices that exhibit a decrease in resistance as the force applied to the sensor surface increases. FSR devices are generally available, with a force sensing range typically selected between approximately 0.2N and 20N. In this embodiment, an Interlink Electronics FSR 402 Short sensor is used. The force sensor comprises, from top to bottom, an adhesive 3a, an upper substrate 3b, a spacer adhesive 3c, and a lower substrate 3d (see Figure 4).

[0039] In this embodiment, the magnetic field source 2 is attached only to the lower substrate 3b of the force sensor 3. In other words, the magnet can move freely relative to the lower substrate 3b of the force sensor 3. Since the magnet makes the small movements necessary to deform the lower substrate into the gap of the spacer adhesive, the rest of the structure does not need to move. This deformation will change the resistance of the resistor printed on the lower substrate.

[0040] Figure 2 shows a schematic cross-sectional view of an aerosol generator 1 according to another embodiment of the present invention. One main difference from the embodiment in Figure 1 is the position of the ferromagnetic material 4. In this embodiment, the ferromagnetic material is provided within the consumable 6. This configuration brings the ferromagnetic material 4 into contact with the aerosol generating material, thereby (theoretically) increasing the accuracy of temperature measurement. However, as the distance between the ferromagnetic material 4 and the magnetic field source 2 increases, the resulting attractive force is also significantly limited, making it more difficult to accurately determine the temperature based on the measured force value. In addition, the embodiment in Figure 2 differs from the embodiment in Figure 1 in that the magnetic field source 2 and the force sensor 3 are provided on the oven wall on the side of the oven chamber. [Explanation of symbols]

[0041] 1. Aerosol generator 2. Magnetic field source 3 Force Sensors 3a Adhesive 3b Upper circuit board 3c Spacer Adhesive 3d bottom board 4. Ferromagnetic or ferrimagnetic materials 5 Oven wall 6 Consumables 7 Non-magnetic window 8 memory 9 Control Unit

Claims

1. A temperature measurement system for an aerosol generator (1), Magnetic field source (2), A ferromagnetic material or ferrimagnetic material (4) A force sensor (3) configured to measure the attractive force between the magnetic field source (2) and the ferromagnetic or ferrimagnetic material (4), A memory (8) that stores pre-recorded data relating at least one force value to a value indicating the temperature of the ferromagnetic or ferrimagnetic material (4), A control unit (9) configured to determine temperature information based on the force value measured from the force sensor (3) and the pre-recorded data, A temperature measurement system equipped with the following features.

2. The control unit (9) is configured to determine whether the ferromagnetic material or ferrimagnetic material (4) has a temperature below and / or above its Curie temperature. The temperature measurement system according to claim 1.

3. The aforementioned pre-recorded data associates multiple force values ​​with the corresponding temperatures of the ferromagnetic or ferrimagnetic material (4). The control unit (9) is configured to determine the temperature of the ferromagnetic or ferrimagnetic material (4). The temperature measurement system according to claim 1.

4. The temperature measurement system according to claim 1, wherein the force sensor (3) includes a strain gauge, a load cell, or a system configured to convert the force into displacement and measure the displacement.

5. Aerosol generator (1), A temperature measuring system according to any one of claims 1 to 4, and an oven chamber having an oven wall (5), an aerosol generator (1) equipped with the following:

6. The ferromagnetic or ferrimagnetic material (4) is provided on the inner surface of the oven wall (5). The force sensor (3) and the magnetic field source (2) are provided on the outer surface of the oven wall (5), facing the ferromagnetic or ferrimagnetic material (4). The aerosol generating apparatus (1) according to claim 5.

7. The oven chamber is equipped with a consumable (6) which is at least partially inserted into the oven chamber, The ferromagnetic or ferrimagnetic material (4) is provided inside the consumable (6) in the oven chamber. The force sensor (3) and the magnetic field source (2) are provided on the outer surface of the oven wall (5), facing the ferromagnetic or ferrimagnetic material (4). The aerosol generating apparatus (1) according to claim 5.

8. The aerosol generator (1) according to claim 5, wherein the oven chamber is made entirely of a non-magnetic material, or a non-magnetic window (7) is provided between the ferromagnetic or ferrimagnetic material (4) and the force sensor (3) and the magnetic field source (2).

9. A method for measuring the temperature inside an aerosol generator (1), The steps include providing a magnetic field source (2), a ferromagnetic material or ferrimagnetic material (4), and a force sensor (3), The steps include measuring the attractive force between the magnetic field source (2) and the ferromagnetic material or ferrimagnetic material (4) using the force sensor (3), A step of determining temperature information based on the measured force value obtained from the force sensor (3) and pre-recorded data that associates at least one force value with a value indicating the temperature of the ferromagnetic or ferrimagnetic material (4), Methods that include...

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