A cold-end temperature automatic compensation device for thermocouple temperature measurement

Abstract

The present invention relates to an automatic cold-end temperature compensation device for thermocouple temperature measurement, belonging to the technical field of electronic cigarette temperature detection. A thermocouple is mounted at the bottom end of the upper cavity of the electronic cigarette housing. The hot-end lead of the thermocouple is connected to the resistance input of a bimetallic temperature-controlled rheostat via a wire. The cold-end lead of the thermocouple contacts the metal wire within the bimetallic temperature-controlled rheostat via a thermocouple cold-end compensation wire. The resistance input of the bimetallic temperature-controlled rheostat is simultaneously connected to the IN terminal of a controller, and the resistance output of the bimetallic temperature-controlled rheostat is simultaneously connected to the OUT terminal of the controller. The bimetallic temperature-controlled rheostat is mounted at the bottom of the lower cavity of the electronic cigarette housing. The present invention forms the bimetallic wire into a vertical or flat spiral shape. Heat is transferred between the bimetallic wire and the cold end of the thermocouple. The deformation of the bimetallic wire caused by heating drives the rheostat slider to rotate, thereby changing the resistance value of the rheostat and compensating for the effects of the increased cold-end temperature of the thermocouple.

Description

Technical Field

[0001] The invention relates to a cold-end temperature automatic compensation device for thermocouple temperature measurement, belonging to the technical field of electronic cigarette temperature detection. Background Art

[0002] During use, e-cigarettes require rapid heating of the cartridge, maintaining a constant temperature above 350°C to rapidly atomize the liquid. Because the temperature control of the cartridge heater affects the atomization of the e-cigarette cartridge and, in turn, the vaping experience, stable, real-time temperature measurement and control are essential. Due to the small size, light weight, portability, and low power consumption of e-cigarettes, conventional temperature measurement components are no longer suitable for measuring the temperature of the cartridge heater. For example, thermal resistors have slow response times, while thermistors have poor temperature measurement stability. Summary of the Invention

[0003] The present invention proposes an automatic cold-end temperature compensation device for thermocouple temperature measurement, which is used to solve the problem that when electronic cigarettes use thermocouples to measure temperature, the cold-end temperature of the thermocouple is not 0°C and fluctuates, resulting in errors in thermocouple temperature measurement.

[0004] Thermocouple temperature measurement has the characteristics of simple structure, small size, good dynamic performance, high accuracy, wide temperature measurement range, and easy transmission and processing of temperature signals. Therefore, this device electronic cigarette uses thermocouples for temperature measurement.

[0005] This device uses thermocouple temperature measurement. The principle of thermocouple temperature measurement is to form a closed circuit between two dissimilar metal conductors, utilizing the Seebeck effect generated at different temperatures. The greater the temperature difference between the two conductors, the greater the thermoelectric potential generated. Thermoelectric potential is composed of contact potential and thermoelectric potential. Contact potential is the electromotive force generated when two dissimilar conductors come into contact, resulting from the diffusion of electrons from the denser conductor to the less dense conductor, and dynamic equilibrium is achieved. Thermoelectric potential is the electromotive force generated by the temperature difference between the two ends of the same conductor.

[0006] The temperature of the cold end of conductor AB is t, and the temperature of the hot end is t0. A thermoelectric potential E will be generated at both ends of conductor AB. AB (t, t0), the temperature difference potential generated by the same conductor is e A (t, t0), e B (t, t0), the formula is as follows:

[0007]

[0008] Contact potential generated by different conductors: e AB (t), e AB (t0), the formula is as follows:

[0009]

[0010] e is the unit charge, K is the Boltzmann constant, δA and δB are the Thomson coefficients of conductors A and B respectively, N A 、N B —are the electron densities of conductors A and B when the junction temperature is T, and T is the thermodynamic temperature at the contact point of the two conductors.

[0011] The thermoelectric potential of thermocouple temperature measurement is the sum of contact potential and temperature difference potential.

[0012]

[0013] According to the above formula, when the thermocouple metal material is constant, the thermoelectric potential E of the thermocouple AB (t, t0) is the function f of temperature t and t0 AB (T, 0) difference. When the temperature t0 at one end of the conductor is constant, f AB (t 0, 0) is a fixed constant C, E AB (t, t0) = f AB (t,0)-C, when C=0, the thermoelectric potential of the thermocouple is only related to the hot end temperature t.

[0014] To ensure that the thermoelectric potential of a thermocouple is solely dependent on the hot-end temperature, the cold-end temperature of the thermocouple must be 0°C. Changes in the cold-end temperature can lead to temperature measurement errors. In actual e-cigarette temperature measurement, several factors can affect the cold-end temperature: When the e-cigarette is not in use, the cold-end of the thermocouple is affected by the ambient temperature, and its initial temperature is generally consistent with the ambient temperature, not 0°C. When the e-cigarette is turned on, the heating element heats intermittently, and when inhaling, the oral cavity conducts heat to the smoking device intermittently, causing the cold-end temperature to rise and fluctuate. In actual use, when the cold-end temperature deviates from 0°C and fluctuates, the measurement error caused by this change in cold-end temperature must be compensated for. There are several methods for cold-end temperature compensation: 1. Use the compensation wire method to extend the cold-end compensation wire, but the space of the electronic cigarette is small, and the distance between the hot and cold ends of the thermocouple is too small, which cannot achieve the effect of significantly reducing the cold-end temperature; 2. Use the cold-end constant temperature method to place the cold end in an ice point tank or a constant temperature box. Electronic cigarettes are portable and can be used at any time, so this method is not applicable; 3. Use the calculation correction method to add the measured thermoelectric potential value to the potential value corresponding to the cold-end temperature to obtain the actual temperature potential value. When the electronic cigarette starts to be used, due to the unknown ambient temperature and the different puffing frequencies of users, the cold-end temperature rise of the electronic cigarette fluctuates and is unknown, so this method is not applicable. 4. Use the analog compensation method to design an analog circuit to dynamically detect and compensate for the potential difference generated by the cold-end temperature change, so that the thermocouple temperature measuring device can more accurately measure the actual temperature of the heating plate, thereby realizing precise control of the heating temperature of the electronic cigarette.

[0015] The cold end temperature compensation of this device adopts the simulation compensation method, assuming that the actual thermoelectric potential E t It can be equivalent to the power supply E and the power supply internal resistance R', and the thermocouple is equivalent to the resistance R 热 According to Kirchhoff's current law, the current flowing out of the equivalent power source E through the internal resistance R' is I. Assuming that the cold end temperature of the thermocouple AB is t and the hot end temperature is t0, the thermoelectric potential E can be obtained from the thermocouple intermediate temperature law. t =f AB (t0, 0)-f AB (t, 0), the cold end temperature t increases, then f AB (t, 0) increases, the thermoelectric potential E t The current I1 in the circuit is equal to the current I1 flowing through the bimetallic temperature variable resistor R and the current I2 flowing through the thermocouple R. 热 The formula is: I = I1 + I2. When the temperature of the thermocouple's cold junction changes from t to t1, the temperature change is Δt = t1 - t. The resistance of the bimetallic temperature resistor R changes with the temperature change Δt, and this resistance change causes a current change of ΔI1. At this time, the circuit current I = (I2 - ΔI2) + (I1 + ΔI1). When ΔI1 = ΔI2, the circuit current I remains constant, thus achieving the purpose of thermocouple cold junction temperature compensation.

[0016] To achieve dynamic current compensation by making ΔI1 = ΔI2, the resistance R of the bimetallic temperature-controlled variable resistor needs to change linearly with the temperature change Δt. The ideal material for making the variable resistor is pure metal. To ensure that the parallel resistor material is not only pure metal, but also other resistor materials can be used in the cold-end compensation of thermocouple temperature measurement, the present invention designs a bimetallic temperature-controlled variable resistor. The bimetallic wire is deformed by heating, which drives the bimetallic temperature variable resistor slider to move on the ring resistor of other resistance materials. By changing the resistance length between the two terminals, the variable resistor resistance changes linearly with temperature, and the current change ΔI1 flowing through the bimetallic temperature variable resistor is adjusted to compensate for the current decrease ΔI2 flowing through the thermocouple, so that the total current I in the circuit remains unchanged, and the circuit compensates for the error caused by the increase in the cold-end temperature of the thermocouple.

[0017] To address the issue of errors caused by the thermocouple cold-end temperature not being at 0°C and fluctuating when measuring temperature using thermocouples in electronic cigarettes, the present invention proposes an analog compensation method. A bimetallic temperature-controlled rheostat R is connected in parallel at both ends of the thermocouple. The bimetallic temperature-controlled rheostat conducts the cold-end temperature. The vertical spiral bimetallic wire 77 or the flat spiral bimetallic wire 88 deforms when heated, driving the metal rheostat slider 72 or the variable resistor slider 83 to move, changing the resistance of the bimetallic temperature-controlled rheostat R and, in turn, the current flowing through the rheostat. This compensates for the decrease in current flowing through it caused by the increase in the thermocouple cold-end temperature, achieving the purpose of cold-end temperature compensation. This method enables accurate temperature measurement of the heating element of a smoking device using a thermocouple, enabling real-time control of the device's heating temperature and the atomization of the smoke liquid, ensuring a pleasant puffing experience for the user, improving the quality of the smoking device, and enabling mass production of smoking devices.

[0018] The technical solution adopted by the present invention is: a cold-end temperature automatic compensation device for thermocouple temperature measurement, characterized by: comprising an induction excitation coil 1, a cigarette cartridge heating plate 2, a cigarette cartridge 3, a thermocouple 4, a controller 5, a battery 6, a thermocouple cold-end compensation wire 7, a bimetallic temperature control resistor 8, an electronic cigarette device housing 9, a thermocouple hot-end lead wire 20, and a thermocouple cold-end lead wire 21;

[0019] The induction excitation coil 1 is wound on the upper cavity of the electronic cigarette housing 9, the heating plate 2 is fixed to the outer ring of the cigarette cartridge 3 and heats the cigarette cartridge 3, the thermocouple 4 is installed at the bottom end of the upper cavity of the electronic cigarette housing 9, the thermocouple hot end lead wire 20 of the thermocouple 4 is connected to the resistance input end of the bimetallic temperature control resistor 8 through a wire, and the thermocouple cold end lead wire 21 is in contact with the vertical or flat spiral bimetallic wire in the bimetallic temperature control resistor 8 through the thermocouple cold end compensation wire 7. The resistance input end of the bimetallic temperature control resistor 8 is also connected to the IN end of the controller 5, and the resistance output end of the bimetallic temperature control resistor 8 is also connected to the OUT end of the controller 5. The controller 5 is connected to the battery 6, and the bimetallic temperature control resistor 8 is installed at the bottom of the lower cavity of the electronic cigarette housing 9.

[0020] Specifically, the bimetallic temperature-controlled rheostat 8 includes: a resistance input terminal I 71, a metal resistance slider 72, a slider insulating connecting ring 73, a ring resistor I 74, a central fixed shaft 75, a fixing bolt 76, a vertical spiral bimetallic wire 77, an electronic cigarette thermal sleeve I 78, and a connecting fixture I 79;

[0021] The resistance input terminal I 71 is fixed to the surface of either end of the notch on the annular resistor I 74. The first end of the metal resistor slider 72 can slide on the surface of the annular resistor I 74, and its end is fixedly connected to one end of the slider insulating connecting ring 73. The slider insulating connecting ring 73 is placed on the upper end of the central fixed shaft 75. The other end of the slider insulating connecting ring 73 is fixedly connected to the vertical spiral bimetallic wire 77. The annular resistor I 74 is connected to the electronic cigarette thermal conductive sleeve I 78 through a fixing bolt 76. The lower end of the central fixed shaft 75 passes through the middle of the vertical spiral bimetallic wire 77 and is fixed to the bottom of the electronic cigarette thermal conductive sleeve I 78. The vertical spiral bimetallic wire 77 is arranged on the electronic cigarette thermal conductive sleeve I 78. 8, its end is fixed to the bottom of the electronic cigarette thermal sleeve I 78, the vertical spiral bimetallic wire 77 rotates when heated, driving the slider insulating connecting ring 73 and the metal resistor slider 72 to rotate on the surface of the annular resistor I 74 with the central fixed axis 75 as the rotating axis. The bottom of the electronic cigarette thermal sleeve I 78 is installed with a connecting fixture I 79. The thermocouple cold end compensation wire 7 extends into the interior of the electronic cigarette thermal sleeve I 78 through the connecting fixture I 79 and contacts the vertical spiral bimetallic wire 77. The resistor input terminal I 71 is connected to the thermocouple hot end lead wire 20 and the IN terminal of the controller 5 through wires. The metal resistor slider 72 is connected to the OUT terminal of the controller 5.

[0022] Preferably, the metal resistor slider 72 is made of metal material, and the slider insulating connecting ring 73 is made of non-metal material.

[0023] Specifically, the resistor input terminal I 71 and the head end of the metal resistor slider 72 are both provided with a round hole for connecting a wire.

[0024] Specifically, the vertical spiral bimetallic wire 77 is composed of an active metal layer 51 and a passive metal layer 52 . The active metal layer 51 is located on the outer coil of the vertical spiral bimetallic wire, and the passive metal layer 52 is located on the inner coil of the vertical spiral bimetallic wire.

[0025] Specifically, the bimetallic temperature-controlled rheostat 8 includes: a fixing nut 80, a resistor output terminal 81, a resistor input terminal II 82, a variable resistor slider 83, a ring resistor II 84, an electronic cigarette thermal sleeve II 85, a central rotating shaft 86, a bearing 87, a planar spiral bimetallic wire 88, and a connecting fixture II 89; the planar spiral bimetallic wire 88 is deformed by heat, driving the variable resistor slider 83 to slide on the surface of the ring resistor II 84, thereby changing the effective resistance between the resistor output terminal 81 and the resistor input terminal II 82, thereby achieving the purpose of changing the resistance value with temperature;

[0026] The resistor output terminal 81 is fixed to the bottom surface of the notch on the annular resistor II 84. The end ring of the resistor output terminal 81 is inserted into the upper end of the central shaft 86. The resistor input terminal II 82 is fixed to the surface of either end of the notch on the annular resistor II 84. The head end of the variable resistor slider 83 can rotate along the surface of the annular resistor II 84, and its end is fixedly connected to the upper end of the central shaft 86. The annular resistor II 84 is fixedly connected to the electronic cigarette thermal sleeve II 85. The lower end of the central shaft 86 is placed in the bearing 87 at the bottom center of the electronic cigarette thermal sleeve II 85. The plane The outermost ring terminal of the spiral bimetallic wire 88 is fixed to the electronic cigarette thermal sleeve 85 through the connecting fixture II 89, the inner ring terminal of the planar spiral bimetallic wire 88 is fixed to the central rotating shaft 86, the bearing 87 is fixed to the bottom center of the electronic cigarette thermal sleeve II 85, the thermocouple cold end compensation wire 7 is in contact with the planar spiral bimetallic wire 88 through the connecting fixture II 89, the resistance input terminal II 82 is connected to the thermocouple hot end lead wire 20 and the IN end of the controller 5 through wires, and the resistance output terminal 81 is connected to the OUT end of the controller 5.

[0027] Preferably, the resistor output terminal 81 is fixed to the bottom surface of the notch on the annular resistor II 84 by a fixing nut 80. The annular resistor II 84 is composed of a constantan wire or a nickel-chromium wire as the resistance material wound on an annular ceramic frame, or the resistance material is "plated" on an annular insulating frame, and the surface of the resistance material is coated with high-temperature resistant enamel paint.

[0028] Specifically, the head ends of the resistance output terminal 81 and the resistance input terminal II 82 are both provided with round holes for connecting wires.

[0029] Specifically, the planar spiral bimetallic wire 88 includes an active metal layer 61 and a passive metal layer 62. The active metal layer 61 is located on the outside of the planar spiral bimetallic wire 88, while the passive metal layer 62 is located on the inside of the planar spiral bimetallic wire 88. The planar spiral bimetallic wire 88 deforms when heated, driving the central shaft 86 to rotate. The central shaft 86 drives the variable resistor slider 83 to slide across the surface of the annular resistor II 84, thereby changing the effective resistance between the resistor output terminal 81 and the resistor input terminal 82, thereby achieving the purpose of temperature-dependent resistance change.

[0030] The beneficial effect of the present invention is: utilizing the characteristic of bimetallic materials that deform with temperature, a bimetallic temperature-controlled rheostat whose resistance value can automatically change with temperature is made. Connecting the bimetallic temperature-controlled rheostat in parallel to both ends of a thermocouple can solve the problem that when electronic cigarettes use thermocouples for temperature measurement, the temperature of the thermocouple cold end is not 0°C and fluctuates due to the intermittent operation of the heating plate and the heat conduction from suction, resulting in inaccurate thermocouple temperature measurement and the inapplicability of conventional cold end temperature compensation methods. Using the analog compensation method to compensate for the cold end temperature of the thermocouple makes the temperature measurement of electronic cigarettes using thermocouples more real-time and accurate. By accurately measuring the temperature of the cartridge heating plate, the heating of the cartridge heating plate is controlled in real time to ensure that the electronic cigarette liquid achieves the best atomization effect, optimize the user's electronic cigarette smoking experience, and achieve electronic cigarette quality control and large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the overall structure of the smoking device with thermocouple temperature measurement;

[0032] Figure 2 Thermocouple structure diagram;

[0033] Figure 3 Measuring the circuit diagram of thermocouple equivalent resistance;

[0034] Figure 4 Cold junction temperature compensation circuit diagram for thermocouple temperature measurement;

[0035] Figure 5 Schematic diagram of vertical spiral bimetallic wire structure;

[0036] Figure 6 Schematic diagram of the planar spiral bimetallic wire structure;

[0037] Figure 7 Vertical spiral bimetallic temperature control resistor structure diagram;

[0038] Figure 8 Structural diagram of a planar spiral bimetallic temperature-controlled resistor.

[0039] The numbers in the figure are: 1 induction excitation coil, 2 cartridge heater, 3 cartridge, 4 thermocouple, 5 controller, 6 battery, 7 thermocouple cold end compensation wire, 8 bimetallic temperature control resistor, 9 electronic cigarette device shell, 20 thermocouple hot end lead wire, 21 thermocouple cold end lead wire. DETAILED DESCRIPTION

[0040] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0041] The present invention uses an analog circuit method to perform cold-end temperature compensation to solve the problem of cold-end temperature fluctuations and non-zero degrees Celsius when measuring temperature with thermocouples used in electronic cigarettes. An analog circuit is designed to compensate for the current changes caused by the increase in the cold-end temperature of the thermocouple. Specifically, a vertical or flat spiral bimetallic temperature-controlled variable resistor R, whose resistance changes with the cold-end temperature, is connected in parallel at both ends of the thermocouple to compensate for the decrease in current caused by the increase in the cold-end temperature of the thermocouple, thereby achieving the purpose of cold-end temperature compensation. The present invention aims to achieve a temperature-dependent resistance change of the variable resistor, utilizing the basic principles of a spiral bimetallic wire and a sliding variable resistor. The spiral bimetallic wire is composed of two metals with different temperature expansion coefficients. The present invention winds the metal wire into a vertical spring shape or a flat fly disc shape. Based on the two different structural designs of the bimetallic wire, there are two options for the structural design of the bimetallic temperature-controlled variable resistor.

[0042] Example 1: Figure 1 、 2 , 3, 4, 5, and 7, a device for automatically compensating the cold end temperature of thermocouple temperature measurement, characterized in that it includes an induction excitation coil 1, a cigarette cartridge heating plate 2, a cigarette cartridge 3, a thermocouple 4, a controller 5, a battery 6, a thermocouple cold end compensation wire 7, a bimetallic temperature control resistor 8, an electronic cigarette device housing 9, a thermocouple hot end lead wire 20, and a thermocouple cold end lead wire 21;

[0043] The induction excitation coil 1 is wound on the upper cavity of the electronic cigarette housing 9, the heating plate 2 is fixed to the outer ring of the cigarette cartridge 3 and heats the cigarette cartridge 3, the thermocouple 4 is installed at the bottom end of the upper cavity of the electronic cigarette housing 9, the thermocouple hot end lead wire 20 of the thermocouple 4 is connected to the resistance input end of the bimetallic temperature control resistor 8 through a wire, and the thermocouple cold end lead wire 21 contacts the metal wire inside the bimetallic temperature control resistor 8 through the thermocouple cold end compensation wire 7. The resistance input end of the bimetallic temperature control resistor 8 is also connected to the IN end of the controller 5, and the resistance output end of the bimetallic temperature control resistor 8 is also connected to the OUT end of the controller 5. The VCC and GND ends of the controller 5 are connected to the battery 6. The bimetallic temperature control resistor 8 is installed at the bottom of the lower cavity of the electronic cigarette housing 9.

[0044] The temperature measurement signal of the thermocouple 4 is temperature compensated by the thermocouple cold end compensation wire 7 and the bimetallic temperature control resistor 8, and then the temperature signal is transmitted to the IN / OUT terminal of the controller 5 through the wire.

[0045] Furthermore, the bimetallic temperature-controlled rheostat 8 includes: a resistance input terminal I 71, a metal resistance slider 72, a slider insulating connecting ring 73, a ring resistor I 74, a central fixed shaft 75, a fixing bolt 76, a vertical spiral bimetallic wire 77, an electronic cigarette thermal sleeve I 78, and a connecting fixture I 79;

[0046] The resistance input terminal I 71 is fixed to the surface of either end of the notch on the annular resistor I 74. The first end of the metal resistor slider 72 can slide on the surface of the annular resistor I 74, and its end is fixedly connected to one end of the slider insulating connecting ring 73. The slider insulating connecting ring 73 is placed on the upper end of the central fixed shaft 75. The other end of the slider insulating connecting ring 73 is fixedly connected to the vertical spiral bimetallic wire 77. The annular resistor I 74 is connected to the electronic cigarette thermal conductive sleeve I 78 by a fixing bolt 76. The lower end of the central fixed shaft 75 passes through the middle of the vertical spiral bimetallic wire 77 and is fixed to the bottom of the electronic cigarette thermal conductive sleeve I 78. The vertical spiral bimetallic wire 77 is arranged on the electronic cigarette thermal conductive sleeve I Inside 78, its end is fixed at the bottom of the electronic cigarette thermal sleeve I78. The vertical spiral bimetallic wire 77 rotates to drive the slider insulation connecting ring 73 and the metal resistor slider 72 to rotate on the surface of the annular resistor I74 with the central fixed axis 75 as the rotating axis. The connecting fixture I79 is installed at the bottom of the electronic cigarette thermal sleeve I78. The thermocouple cold end compensation wire 7 extends into the interior of the electronic cigarette thermal sleeve I78 through the connecting fixture I79 and contacts the vertical spiral bimetallic wire 77. The resistance input terminal I71 is connected to the thermocouple hot end lead wire 20 and the IN end of the controller 5 through wires. The metal resistor slider 72 is connected to the OUT end of the controller 5.

[0047] The vertical spiral bimetallic wire 77 rotates, driving the slider insulation connecting ring 73 and the metal resistor slider 72 to rotate on the surface of the ring resistor I 74 around the central fixed axis 75. The thermocouple cold end compensation wire 7 is introduced into the bottom of the electronic cigarette thermal sleeve I 78 through the connector fixture I 79.

[0048] Furthermore, the annular resistor I 74 has a gap for fixing the resistor input terminal 71, so that the annular resistor is not a closed loop. The metal resistor slider 72 is made of metal material, and the slider insulating connecting ring 73 is made of non-metal material.

[0049] Furthermore, the first end of the resistance input terminal 171 and the metal resistance slider 72 are both provided with a round hole for connecting a wire. The resistor section between the resistance input terminal 71 and the metal resistance slider 72 without a gap is the effective resistance of the bimetallic temperature control resistor.

[0050] Specifically, vertical spiral bimetallic wire 77 consists of an active metal layer 51 and a passive metal layer 52. Active metal layer 51 is located on the outer coil of the vertical spiral bimetallic wire, while passive metal layer 52 is located on the inner coil. Heating of vertical spiral bimetallic wire 77 causes deformation, driving metal resistor slider 72 to slide across the surface of ring resistor I 74. This in turn changes the effective resistance between resistor input terminal 71 and metal resistor slider 72, achieving temperature-dependent resistance.

[0051] The operating principle of this embodiment is as follows: the vertical spiral bimetallic wire 77 rotates, driving the insulated slider ring 73 and the metal resistor slider 72 to rotate on the surface of the ring resistor I 74 around the central fixed axis 75. The thermocouple cold-end compensation wire 7 is inserted into the bottom of the electronic cigarette thermal sleeve I 78 via a connector fixture I 79. Heat is transferred between the thermocouple cold-end compensation wire 7 and the bimetallic wire. Due to the different temperature coefficients of the bimetallic components, the bimetallic wire deforms, driving the insulated slider ring 73 and the metal resistor slider 72 to rotate on the surface of the ring resistor I 74 around the central fixed axis 75. This changes the resistance between the resistor input terminal 71 and the metal resistor slider 72, achieving the temperature-dependent resistance of the bimetallic temperature-controlled rheostat. When this vertical spiral bimetallic temperature-controlled rheostat is connected to a circuit, current flows from the resistor input terminal 71 through the ring resistor I 74 and out through the metal resistor slider 72.

[0052] The specific calculation formulas for determining the thermocouple cold end temperature difference ΔT=T1-T0 and the rotation angle θ′ of the metal resistor slider 72 after the vertical spiral bimetallic wire is heated and the metal wire length S are as follows:

[0053] The formula for the curvature K0 of the vertical spiral bimetallic wire is:

[0054]

[0055] a0 and a1 are the thermal expansion coefficients of the active and passive layers of the bimetallic metal;

[0056] m is the thickness of the bimetallic wire;

[0057] ΔT is the temperature difference of the thermocouple cold end;

[0058] The rotation angle θ′ of the vertical spiral bimetallic wire after heating is the product of its curvature K0 and length S. Then the rotation angle θ′ when the temperature of the cold end of the bimetallic wire rises from T0 to T1 can be obtained.

[0059]

[0060] From the above formula, the length of the vertical spiral bimetallic wire can be obtained

[0061] In summary, the formula Substituting the obtained θ′ into the above formula, we can get the length S of the vertical spiral bimetallic wire.

[0062] With the center of the bottom of the bimetallic wire as the origin, a three-dimensional polar coordinate system is established, and the equation group is established as

[0063] x=rcost,y=rsint,

[0064] r is the radius of the bottom surface of the spiral tube;

[0065] t is the polar coordinate angle of the spring-shaped bimetallic wire, t = 2πn;

[0066] n is the number of turns of the bimetallic wire material;

[0067] d is the turn spacing value of the bimetallic wire with equal spacing between turns.

[0068] S is the length of the vertical spiral bimetallic wire, and the formula is as follows:

[0069]

[0070] will be The obtained S is the length of the vertical spiral bimetallic wire. Substituting it into the above formula can determine the functional relationship between the number of turns n of the bimetallic wire and the turn spacing value d of the bimetallic wire.

[0071] Through the above calculation, it can be determined that the temperature difference ΔT at the cold end of the thermocouple is linearly related to the rotation angle θ′ of the bimetallic temperature variable resistor. By changing the resistance value of the bimetallic temperature variable resistor R connected in parallel to the circuit through the reaction of the spiral bimetallic wire to the cold end temperature, the reduced current value is compensated to achieve the effect of automatic compensation of the cold end temperature of the thermocouple and realize the purpose of reducing the temperature measurement error of the thermocouple.

[0072] Example 2: Figure 1 、 2 As shown in , 3, 4, 6, and 8, the difference between this embodiment and embodiment 1 is that the structure of the bimetallic temperature-controlled resistor 8 is different.

[0073] The bimetallic temperature-controlled rheostat 8 of this embodiment includes: a fixing nut 80, a resistance output terminal 81, a resistance input terminal II 82, a variable resistor slider 83, a ring resistor II 84, an electronic cigarette thermal sleeve II 85, a central rotating shaft 86, a bearing 87, a flat spiral bimetallic wire 88, and a connecting fixture II 89;

[0074] The resistor output terminal 81 is fixed to the bottom surface of the notch on the annular resistor II 84 through a fixing nut 80. The end ring of the resistor output terminal 81 is inserted into the upper end of the central rotating shaft 86. The central rotating shaft 86 can rotate within the end ring of the resistor output terminal 81. The resistor input terminal II 82 is fixed to the surface of either end of the notch on the annular resistor II 84. The head end of the variable resistor slider 83 rotates along the surface of the annular resistor II 84, and its end is fixedly connected to the upper end of the central rotating shaft 86. The annular resistor II 84 is fixedly connected to the electronic cigarette thermal sleeve II 85, and the lower end of the central rotating shaft 86 is placed on the electronic cigarette thermal sleeve II. Inside bearing 87 at the center of the bottom of 85, the outermost terminals of planar spiral bimetallic wire 88 are fixed to the electronic cigarette thermal sleeve 85 via connector and fixture II 89. The inner terminals of planar spiral bimetallic wire 88 are fixed to central rotating shaft 86. Bearing 87 is fixed to the center of the bottom of electronic cigarette thermal sleeve II 85. The thermocouple cold-end compensation wire 7 contacts planar spiral bimetallic wire 88 via connector and fixture II 89. Resistor input terminal II 82 is connected to the thermocouple hot-end lead wire 20 and the IN terminal of controller 5 via wires, and resistor output terminal 81 is connected to the OUT terminal of controller 5. Planar spiral bimetallic wire 88 deforms when heated, driving central rotating shaft 86 to rotate within the ring at the end of resistor output terminal 81 and within bearing 87. Central rotating shaft 86 drives variable resistor slider 83 to rotate along the surface of ring-shaped resistor II 84.

[0075] Furthermore, the resistor output terminal 81 is fixed to the bottom surface of the notch on the annular resistor II 84 by a fixing nut 80. The annular resistor II 84 is composed of a constantan wire or a nickel-chromium wire as the resistance material wound on an annular ceramic frame, or the resistance material is "plated" on an annular insulating frame. The surface of the resistance material is coated with a high-temperature resistant enamel paint and bonded to the ceramic chassis.

[0076] Furthermore, the head ends of the resistance output terminal 81 and the resistance input terminal II 82 are both provided with round holes for connecting wires.

[0077] Furthermore, the planar spiral bimetallic wire 88 includes an active metal layer 61 and a passive metal layer 62. The active metal layer 61 is located on the outside of the planar spiral bimetallic wire 88, while the passive metal layer 62 is located on the inside of the planar spiral bimetallic wire 88. The planar spiral bimetallic wire 88 deforms when heated, driving the central shaft 86 to rotate. The central shaft 86 drives the variable resistor slider 83 to slide across the surface of the annular resistor II 84, thereby changing the effective resistance between the resistor output terminal 81 and the resistor input terminal 82, thereby achieving the purpose of temperature-dependent resistance change.

[0078] The operating principle of this embodiment is as follows: A bimetallic wire is wound into a flat spiral coil shape. The central end of the flat spiral bimetallic wire 88 is fixedly connected to the central shaft 86, and the outermost terminal is fixed to the outside of the connector fixture II 89. The thermocouple cold-end compensation wire 7 is introduced into the interior of the thermal sleeve 85 through the connector fixture II 89, where it conducts heat to the bimetallic wire. This deforms the bimetallic wire, which in turn rotates the central shaft 86. The central shaft 86 drives the variable resistor slider 83 to slide across the surface of the ring resistor II 84, changing the length of the resistor between the resistor output terminal 81 and the resistor input terminal II 82, thereby changing the resistance of the resistor, thereby achieving the purpose of changing the resistance value with the cold-end temperature. When this flat spiral bimetallic temperature-controlled resistor is connected to a circuit, current flows from the resistor input terminal II 82 through the variable resistor slider 83 and out through the resistor output terminal 81. The effective resistance of the flat spiral bimetallic temperature-controlled resistor is the resistance of the uncut section between the resistor input terminal II 82 and the variable resistor slider 83.

[0079] The rotation angle of the flat spiral bimetallic wire 88 after heating The length of the planar spiral bimetallic wire 88 can be obtained

[0080] K1 is the specific bending of the bimetallic wire;

[0081] ΔT=T1-T0 is the temperature difference of the thermocouple cold end;

[0082] m is the thickness of the bimetallic wire;

[0083] When the electronic cigarette is heated stably, the cold end temperature changes from T0 to T1, and the hot end temperature is T2. From the following step (4), it can be obtained that the angle that the plane spiral bimetallic wire 88 needs to drive the variable resistor slider 83 to rotate is

[0084]

[0085] Substitute the obtained angle of rotation of the slider into The length S of the planar spiral bimetallic wire 88 can be obtained, and the relationship between the number of turns n and the turn spacing D of the bimetallic wire can be determined by substituting the length S into the following formula.

[0086] The calculation formula for the length S of the planar spiral bimetallic wire 88 is:

[0087]

[0088] r1 is the innermost circle radius;

[0089] D is the turn spacing value of equal turn spacing;

[0090] m is its thickness;

[0091] n is the number of turns;

[0092] According to the above formula, the temperature difference ΔT at the cold end of the thermocouple and the rotation angle of the bimetallic temperature resistor are

[0093] θ′ is in a linear relationship, and the size of θ′ can be determined by ΔT. The length S of the bimetallic wire is obtained from θ′, and the relationship between the number of turns n and the turn spacing D is determined by the length S to design the bimetallic temperature-controlled resistor.

[0094] The theoretical principles of Example 1 and Example 2 are described in detail below.

[0095] After the vertical spiral bimetallic temperature-controlled resistor introduces the thermocouple cold-end compensation wire 7 into the electronic cigarette thermal sleeve Ⅰ78 through the connecting fixture Ⅰ79, it conducts heat with the vertical spiral bimetallic wire 77. The vertical spiral bimetallic wire 77 is deformed by heat, thereby driving the metal variable resistor slider 72 to rotate on the surface of the annular resistor Ⅰ74, changing the resistance length of the unnotched section between the resistance input terminal 71 and the metal variable resistor slider 72, thereby changing the resistance value of the vertical spiral bimetallic temperature-controlled resistor.

[0096] After the planar spiral bimetallic temperature-controlled rheostat introduces the thermocouple cold-end compensation wire 7 into the electronic cigarette thermal sleeve II 85 through the connecting fixture II 89, it conducts heat with the planar spiral bimetallic wire 88. The planar spiral bimetallic wire 88 is deformed by heat, driving the central rotating shaft 86 to rotate. The central rotating shaft 86 drives the variable resistor slider 83 to rotate on the surface of the annular resistor II 84, changing the resistance length of the unnotched section between the resistance input terminal II 82 and the resistance output terminal 81, thereby changing the resistance value of the planar spiral bimetallic temperature-controlled rheostat.

[0097] The present invention compensates for the cold-end temperature of a thermocouple. First, a bimetallic wire is selected to determine the thermal expansion coefficients a0 and a1 of its active and passive metal layers, the bimetallic element thickness m, the bottom radius r of the vertical spiral bimetallic coil, and the inner radius r1 of the flat spiral bimetallic wire. When an electronic cigarette heats up, the cold-end temperature rises. To design the bimetallic temperature-controlled rheostat, the temperature difference ΔT generated by the cold-end rise must vary linearly with the rotation angle θ′ of the bimetallic temperature-controlled rheostat metal slider 72 or the variable resistor slider 83. The specific steps for calculating the relationship between the two are as follows:

[0098] (1) Calculate the equivalent resistance R of the thermocouple by the shunt method 热 ;

[0099] (2) By the equivalent resistance R 热 Calculate the change in current ΔI2 flowing through the thermocouple based on the potential difference caused by the change in temperature of the cold end.

[0100] (3) Calculate the resistance change ΔR of the bimetallic temperature-controlled resistor from ΔI2;

[0101] (4) Determine the rotation angle θ′ of the bimetallic temperature-controlled rheostat slider from ΔR;

[0102] (5) Solve the length S of the vertical and planar spiral bimetallic wires from θ′.

[0103] Step (1) Calculate the equivalent resistance R of the thermocouple by the shunt method 热 The specific method is:

[0104] The equivalent loop resistance at the thermocouple and in the temperature field can be measured using the equivalent method and the shunt method. During the measurement process, the thermocouple measuring end should be kept at a constant temperature, and the thermocouple lead should maintain the same terminal temperature. Connect the thermocouple in series with the switch K' and the variable resistor r0, and then connect a high-impedance voltmeter v that can measure microvolt voltage in parallel with the two leads of the thermocouple. First, turn on the switch K' and the thermocouple is in an open-loop state. Use the high-impedance voltmeter v to measure the thermoelectric potential E of the thermocouple between the two leads of the thermocouple. t0 Then close the switch K' and adjust the resistance r0 of the variable resistor until the measured voltage becomes the open-loop thermoelectric potential E t0 1 / 2, at this time the resistance of the variable resistor r0 is the same as the resistance of the thermocouple loop. Then remove the variable resistor r0 from the circuit and directly measure its resistance r0 with an ohmmeter. This value is the equivalent resistance R of the thermocouple. 热 .

[0105] The specific method for step (2) to obtain the change ΔI2 of the current flowing through the thermocouple due to the change in the cold end temperature is:

[0106] Two situations are analyzed to determine whether there is a change in the cold end temperature when thermocouple temperature measurement is used:

[0107] Assuming that there is no temperature change at the cold end, when two different metal conductors (A and B) are connected to form a closed loop, according to the Seebeck effect of the thermocouple, the initial cold end temperature is T0. When the electronic cigarette is heated stably, the cold end temperature remains unchanged, the hot end temperature is T2, and the thermocouple thermoelectric potential is E t =f AB (0, T0)+f AB (T0, T2). AB (0, T0) can be obtained by looking up the thermoelectric potential table at time T0, f AB (T0, T2) is the voltage measured across the thermocouple.

[0108] When the cold end temperature changes, the initial cold end temperature of the electronic cigarette is T0. When the electronic cigarette is heated stably, the cold end temperature changes to T1 and the hot end temperature is T2. The thermoelectric potential E of the thermocouple t =f AB (0, T0)+f AB (T0, T1)+fAB (T1, T2), f AB (T1, T2) is the actual voltage across the thermocouple, f AB (T0, T1) is the potential difference caused by the increase in cold end temperature.

[0109] According to the above two equations about thermocouple thermoelectric potential, when the electronic cigarette is heated, the cold end temperature rises from T0 to T1, f AB (T0, T1) becomes larger, the actual voltage f across the thermocouple AB (T1, T2) decreases, and the thermoelectric potential f generated by the cold end temperature change AB (T0, T1) affects the temperature measurement of the thermocouple, so it is necessary to adjust the f caused by the increase in the cold end temperature. AB (T0, T1) is compensated. AB (T0, T1) increases, causing the current I2 flowing through the thermocouple to decrease, and the change is ΔI2, f AB (T0, T1) = ΔI2R 热 , the temperature rise of the cold end of the thermocouple causes the current flowing through the thermocouple to change

[0110] The specific method for obtaining the resistance change ΔR of the bimetallic temperature-controlled resistor in step (3) is:

[0111] If the initial resistance of the bimetallic temperature-controlled resistor is R0, ΔR is the resistance change of the bimetallic temperature-controlled resistor as the cold-end temperature changes. When the electronic cigarette is heated stably, the cold-end temperature changes from T0 to T1, and the hot-end temperature is T2. The bimetallic temperature-controlled resistor is connected in parallel with the thermocouple. The voltage across the bimetallic temperature-controlled resistor is equal to the actual voltage f of the thermocouple. AB (T1, T2) are the same, the change in current flowing through the sliding rheostat R is ΔI1. The equation is: AB (T1, T2) = ΔI1(R0 + ΔR). When the electronic cigarette starts to heat up, the cold end temperature change must be compensated so that the current change flowing through the thermocouple ΔI2 = ΔI1. The resistance change of the bimetallic temperature control resistor is From step (2), we can get Substituting into the above formula, we get

[0112] The specific method for obtaining the slider rotation angle θ′ of the bimetallic temperature-controlled resistor in step (4) is as follows:

[0113] Known R t The maximum resistance of the annular resistor is θ, the maximum angle that the metal resistor slider 72 can rotate on the surface of the annular resistor I 74 (the variable resistor slider 83 on the surface of the annular resistor II 84) is θ, and the initial resistance of the bimetallic temperature control resistor is R0， The change in resistance of the bimetallic temperature-controlled rheostat with temperature is ΔR, and the angle that the bimetallic wire needs to drive the slider to rotate can be calculated as

[0114]

[0115] The specific method for obtaining the length S of the spiral bimetallic wire in step (5) is as follows:

[0116] The present invention aims to achieve a linear change in resistance with temperature in a bimetallic temperature-controlled rheostat. This approach utilizes the material properties of bimetallic materials. Bimetallic materials are composed of multiple metals with different thermal expansion coefficients. When the temperature changes, the metal layers expand or contract by varying amounts, causing the bimetallic spiral to contract or expand. One end of the bimetallic is connected to the cold end of a thermocouple for heat conduction, while the other end drives the slider of the bimetallic temperature-controlled rheostat to rotate, changing the length of the resistor connected to the circuit, thereby adjusting the resistance of the rheostat.

[0117] like Figure 2 The figure shows the structure of the thermocouple temperature measuring element in the present invention. The two different metals on the left and right are connected in series and lead out their hot end lead 20 and cold end lead 21. According to the Seebeck effect, when the temperatures at the two ends of the thermocouple are different, a thermoelectric potential is generated at the two ends of the thermocouple. The temperature of the object being measured can be obtained by using this thermoelectric potential. The thermoelectric potential E between the cold end temperature T1 and the hot end temperature T2 of the thermocouple made of two different metal materials is t The expression is E t =f AB (T1, T2). The cold junction temperature (T1) must be maintained at 0°C or 20°C. When a thermocouple is measuring temperature, the cold junction temperature rises, causing the measured thermoelectric potential to decrease. Therefore, cold junction temperature compensation is required.

[0118] like Figure 3 The figure shows the thermocouple equivalent resistance R in the present invention. 热 The circuit diagram is shown in Figure 1. The shunt method is used to perform equivalent measurement on the thermocouple circuit under the temperature field. During the measurement process, the thermocouple measuring end should be kept at a constant temperature, and the thermocouple lead pins should maintain the same terminal temperature. 热 Connect the switch K' and the sliding rheostat in series, and then connect the high impedance voltmeter v that can measure microvolt voltage in parallel with the hot and cold end leads 20 and 21 of the thermocouple. The specific measurement method is: first open the switch K', and the thermocouple R 热 For open loop, use voltmeter v to measure the thermoelectric potential E between the two leads of the open loop thermocouple in the temperature field. t0 Then close switch K' and adjust the resistance of the rheostat until the measured voltage becomes 1 / 2 of the open-loop thermoelectric potential. At this time, the resistance of the rheostat is the same as the resistance of the thermocouple loop. Then remove the rheostat from the circuit and directly measure its resistance r0 with an ohmmeter. This value is the equivalent resistance R of the thermocouple.热 .

[0119] like Figure 4 The figure shows the principle diagram of the automatic cold-end temperature compensation circuit of the thermocouple temperature measurement in the present invention. The cold-end temperature compensation of the thermocouple temperature measurement in the present invention adopts the analog compensation method. When the cold-end temperature of the thermocouple increases, the current flowing through the thermocouple decreases. The circuit is designed to compensate for the reduced current value of the thermocouple branch. Assuming that the actual thermoelectric potential E of the thermocouple is t It can be equivalent to the power supply E and the power supply internal resistance R`, and the measured thermocouple is equivalent to the resistance R 热 According to Kirchhoff's current law, the current flowing from the equivalent power source E through the internal resistance R' is I. Assuming that the temperature of the cold end of the thermocouple is T1 and the temperature of the hot end is T2, the thermoelectric potential E can be obtained from the thermocouple intermediate temperature law: t =f AB (T2, 0)-f AB (T1, 0), the cold end temperature T1 increases, then f AB (T1, 0) increases, the thermoelectric potential E t If the current I2 flowing through the thermocouple decreases, the change value is ΔI2. In order to compensate for the change value ΔI2 of the current flowing through the thermocouple, the present invention adopts an analog compensation method. The specific method is to connect a bimetallic temperature control resistor R in parallel at both ends of the thermocouple, and the current flowing through it is I1. The current I in the circuit is equal to the current I1 flowing through the resistor R and the current flowing through the thermocouple R. 热 The sum of the currents I2, that is, I = I1 + I2. When the thermocouple cold junction temperature T1 changes, the resistance of the bimetallic temperature-controlled resistor R changes linearly with the temperature, and the current change caused by this resistance is ΔI1. That is, the circuit current I = (I2 - ΔI2) + (I1 + ΔI1). When ΔI1 = ΔI2, the circuit current I remains constant, thus achieving the purpose of thermocouple cold junction temperature compensation.

[0120] like Figure 5 The figure shows a schematic diagram of the structure of a vertical spiral bimetallic wire 77 in a vertical spiral bimetallic temperature-controlled rheostat according to the present invention. Specifically, the bimetallic strip is formed into a helical spring shape, with r being the base radius of the vertical spiral bimetallic wire, the number of turns of the bimetallic wire being n, the turn spacing being equal, the turn spacing being d, and the wire thickness being m. The bimetallic wire is composed of an active metal layer 51 and a passive metal layer 52. The active metal layer 51 is located on the outside of the vertical spiral bimetallic wire, while the passive metal layer 52 is located on the inside. When heated, the bimetallic wire expands or contracts unequally due to the different thermal expansion coefficients of the bimetallic metals, causing the metal layers to expand or contract unequally, causing the spiral wire to contract or relax. The heated bimetallic wire drives the rheostat slider to move, changing the resistance length between the metal input terminal 71 and the metal resistor slider 72, thereby changing the resistance value of the vertical spiral bimetallic temperature-controlled rheostat.

[0121] like Figure 6 The figure shows a schematic diagram of a planar spiral bimetallic wire structure for cold-junction temperature compensation, which is a schematic diagram of the planar spiral bimetallic wire 88 in a planar spiral bimetallic temperature-controlled rheostat. The bimetallic wire is formed into a planar spiral shape and wound with n turns. The initial radius of the innermost turn is r1, the wire turn spacing is D, and the bimetallic wire thickness is m. The outer turn of the planar spiral bimetallic wire 88 is the active metal layer 61, and the inner turn of the planar spiral bimetallic wire 88 is the passive metal layer 62. Utilizing the material properties of the bimetallic material, the bimetallic wire rotates and contracts or expands when the temperature changes. The outermost turn of the planar spiral bimetallic wire is fixed at one end, and the other end is fixed to the central shaft 86, driving its rotation. The central shaft 86 drives the variable resistor slider 83, which changes the resistance between the resistor input terminal II 82 and the resistor output terminal 81, thereby changing the resistance value of the planar spiral bimetallic temperature-controlled rheostat.

[0122] like Figure 7 Figure 1 shows the first bimetallic temperature-controlled varistor structure design of the present invention: a vertical spiral bimetallic temperature-controlled varistor. Ring resistor I 74 utilizes constantan or nickel-chromium wire as the resistance material, wound around a circular ceramic frame, or the resistance material is plated onto a ring-shaped insulating frame. The surface of the resistance material is coated with a high-temperature resistant enamel and bonded to a ceramic base. The resistance input terminal 71 is fixed to the surface of either end of the notch on both sides of the annular resistor I 74. The head end of the metal resistor slider 72 can slide on the surface of the annular resistor I 74, and its end is fixedly connected to one end of the slider insulating connecting ring 73. The slider insulating connecting ring 73 is placed on the upper end of the central fixed shaft 75. The other end of the slider insulating connecting ring 73 is fixedly connected to the vertical spiral bimetallic wire 77. The annular resistor I 74 is connected to the electronic cigarette thermal conductive sleeve I 78 by a fixing bolt 76. The lower end of the central fixed shaft 75 passes through the middle of the vertical spiral bimetallic wire 77 and is fixed to the bottom of the electronic cigarette thermal conductive sleeve I 78. The vertical spiral bimetallic wire 77 is arranged inside the electronic cigarette thermal conductive sleeve I 78, and its end is fixed to the bottom of the electronic cigarette thermal conductive sleeve I 78. The vertical spiral bimetallic wire 77 rotates, driving the slider insulating connecting ring 73 and the metal resistor slider 72 to rotate on the surface of the annular resistor I 74 with the central fixed shaft 75 as the rotating axis. Thermocouple cold-end compensation wire 7 is introduced through connector fixture I 79 into the bottom of the electronic cigarette thermal sleeve I 78, where it contacts the vertical spiral bimetallic wire 77 inside the sleeve I 78, transferring heat. When heated, the bimetallic wire deforms and rotates, driving the metal resistor slider 72 to rotate, changing the resistance between resistor input terminal I 71 and the metal resistor slider 72. This allows the bimetallic temperature-controlled rheostat to change its resistance with temperature.

[0123] like Figure 8The figure shows the second bimetallic temperature-controlled variable resistor structure design scheme of the present invention - a planar spiral bimetallic temperature-controlled variable resistor. A fixing nut 80 secures the resistor output terminal 81 to the bottom surface of the notch of the annular resistor II 84. The end ring of the resistor output terminal 81 is inserted into the upper end of the central rotating shaft 86. The central rotating shaft 86 can rotate within the end ring of the resistor output terminal 81. The resistor input terminal 82 is fixed to the surface of either end of the notch of the annular resistor II 84. The head end of the variable resistor slider 83 can rotate along the surface of the annular resistor II 84, and its end is fixedly connected to the upper end of the central rotating shaft 86. The annular resistor II 84 is fixedly connected to the electronic cigarette thermal sleeve II 85. The upper end of the central rotating shaft 86 is placed in the end ring of the resistor output terminal 81, and the lower end is placed in the center of the electronic cigarette thermal sleeve II 85 through a bearing 87. The outermost ring of the planar spiral bimetallic coil 88 The terminal is fixed to the electronic cigarette thermal sleeve 85 through the connecting fixture II 89, the inner ring terminal of the planar spiral bimetallic coil 88 is fixed on the central rotating shaft 86, and the bearing 87 is fixed at the bottom center of the electronic cigarette thermal sleeve II 85. The thermocouple cold end compensation wire 7 contacts the planar spiral bimetallic coil 88 through the connecting fixture II 89. The planar spiral bimetallic coil 88 deforms after being heated, driving the central rotating shaft 86 to rotate in the circular ring at the end of the resistor output end 81 and in the bearing 87. The central rotating shaft 86 drives the variable resistor slider 83 to rotate along the surface of the annular resistor II 84, changing the resistance between the resistor input end 82 and the resistor output end 81, thereby achieving the purpose of changing the resistance of the bimetallic temperature-controlled resistor with temperature.

[0124] This design uses a thermocouple cold-junction temperature simulation compensation method. It utilizes a bimetallic temperature-controlled rheostat to sense the cold-junction temperature and adjust its resistance linearly with temperature. This rheostat is connected in parallel with the thermocouple to achieve automatic compensation for the thermocouple cold-junction temperature. This eliminates the error caused by the thermocouple's cold-junction temperature not being at 0°C and fluctuating, thereby improving the accuracy of thermocouple temperature measurement. This allows for accurate real-time measurement of the heating element temperature of the smoking device, allowing for precise control of the heating temperature, ensuring a pleasant puff experience for the user, improving the quality of the smoking device, and enabling mass production of smoking devices.

[0125] The specific embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in this field without departing from the scope of the present invention.

Claims

1. A cold-end temperature automatic compensation device for thermocouple temperature measurement, characterized by: The electronic cigarette device comprises an induction excitation coil (1), a cigarette cartridge heating plate (2), a cigarette cartridge (3), a thermocouple (4), a controller (5), a battery (6), a thermocouple cold end compensation wire (7), a bimetallic temperature control resistor (8), an electronic cigarette device housing (9), a thermocouple hot end lead wire (20), and a thermocouple cold end lead wire (21); The induction excitation coil (1) is wound on the upper cavity of the electronic cigarette shell (9), the heating plate (2) is fixed on the outer ring of the cigarette cartridge (3) and heats the cigarette cartridge (3), the thermocouple (4) is installed at the bottom end of the upper cavity of the electronic cigarette shell (9), the thermocouple hot end lead wire (20) of the thermocouple (4) is connected to the resistance input end of the bimetallic temperature control resistor (8) through a wire, the thermocouple cold end lead wire (21) contacts the metal wire in the bimetallic temperature control resistor (8) through the thermocouple cold end compensation wire (7), the resistance input end of the bimetallic temperature control resistor (8) is simultaneously connected to the IN end of the controller (5), the resistance output end of the bimetallic temperature control resistor (8) is simultaneously connected to the OUT end of the controller (5), the controller (5) is connected to the battery (6), and the bimetallic temperature control resistor (8) is installed at the bottom of the lower cavity of the electronic cigarette shell (9); The bimetallic temperature-controlled rheostat (8) comprises: a resistance input terminal I (71), a metal resistance slider (72), a slider insulating connecting ring (73), a ring-shaped resistor I (74), a central fixed shaft (75), a fixing bolt (76), a vertical spiral bimetallic wire (77), an electronic cigarette thermal conductive sleeve I (78), and a connecting fixture I (79); The resistance input terminal Ⅰ (71) is fixed on the surface of either end of the notch on both sides of the annular resistor Ⅰ (74), the first end of the metal resistor slider (72) can slide on the surface of the annular resistor Ⅰ (74), and the end thereof is fixedly connected to one end of the slider insulating connecting ring (73), the slider insulating connecting ring (73) is placed on the upper end of the central fixed shaft (75), and the other end of the slider insulating connecting ring (73) is fixedly connected to the vertical spiral bimetallic wire (77), the annular resistor Ⅰ (74) is connected to the electronic cigarette thermal conductive sleeve Ⅰ (78) through a fixing bolt (76), the lower end of the central fixed shaft (75) passes through the middle of the vertical spiral bimetallic wire (77) and is fixed to the bottom of the electronic cigarette thermal conductive sleeve Ⅰ (78), and the vertical spiral bimetallic wire (77) is arranged on the electronic cigarette thermal conductive sleeve Ⅰ (78) ) inside, and its end is fixed at the bottom of the electronic cigarette thermal sleeve I (78). When the vertical spiral bimetallic wire (77) rotates, it drives the slider insulation connecting ring (73) and the metal resistor slider (72) to rotate on the surface of the annular resistor I (74) with the central fixed axis (75) as the rotating axis. The bottom of the electronic cigarette thermal sleeve I (78) is installed with a connecting fixture I (79). The thermocouple cold end compensation wire (7) extends into the electronic cigarette thermal sleeve I (78) through the connecting fixture I (79) and contacts the vertical spiral bimetallic wire (77). The resistance input terminal I (71) is connected to the thermocouple hot end lead wire (20) and the IN end of the controller (5) through the wire. The metal resistor slider (72) is connected to the OUT end of the controller (5).

2. The cold-end temperature automatic compensation device for thermocouple temperature measurement according to claim 1, characterized in that: The metal resistor slider (72) is made of metal material, and the slider insulating connecting ring (73) is made of insulating non-metallic material.

3. The cold-end temperature automatic compensation device for thermocouple temperature measurement according to claim 1, characterized in that: The resistance input terminal I (71) and the head end of the metal resistance slider (72) are both provided with a circular hole for connecting a wire.

4. The cold-end temperature automatic compensation device for thermocouple temperature measurement according to claim 1, characterized in that: The vertical spiral bimetallic wire (77) is composed of an active metal layer (51) and a passive metal layer (52), wherein the active metal layer (51) is located in the outer ring of the vertical spiral bimetallic wire, and the passive metal layer (52) is located in the inner ring of the vertical spiral bimetallic wire.

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