Central rod-shaped heating body and low-temperature smoking set

Abstract

The invention belongs to the technical field of smoking articles, and discloses a central rod-shaped heating element and a low-temperature smoking set, the central rod-shaped heating element comprises an insulating base and a heating element body, the heating element body comprises an inner tube electrode, an outer tube electrode, an inner heating tube, an outer heating tube and an inner and outer tube connecting piece; one end of the inner tube electrode is inserted into a mounting hole in the insulating base in a matching manner, and the other end is connected with the inner heating tube; one end of the outer tube electrode is fixedly connected with the insulating base, and the other end of the outer tube electrode is connected with the outer heating tube; and one end of the outer heating tube far away from the outer tube electrode is provided with an inner-outer tube connecting piece which is fixedly connected with the inner heating tube to form a series access. The two SUS304 pipes with different diameters and different resistance values are connected to form a double-pipe series connection structure with the inverted-U-shaped cross section, the double-pipe series connection structure serves as the heating body, the surface temperature uniformity of the heating body is improved, the surface roughness is low, the manufacturing cost is reduced, assembling is convenient, and application and popularization value is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of smoking articles, and relates to a central rod-shaped heating element and a low-temperature smoking article. Background Art

[0002] The central rod heating method has the advantages of fast heating speed, short waiting time for the first puff, large smoke volume, low energy consumption per cigarette, small appearance and volume of the device, and low surface temperature of the device. However, most of the existing central rod heating elements on the market are 95 porcelain printed and sintered, with complex production processes, low production efficiency, and high costs. The current factory price is about 15 yuan or more, which is close to 2 / 3 of the price of the entire temperature control PCB board. The heating element accounts for too high a proportion of the entire device cost, and the service life of the entire heating device is short, about only about 12-15 months, which is not conducive to the market promotion of heating cigarette devices.

[0003] In addition, the surface roughness of the existing 95 ceramic heating rods on the market is high, which is not conducive to the removal of the cigarette from the heating element after heating. The TCR values ​​of the existing 95 ceramic heating rods on the market after sintering are quite different, and the temperature control is not accurate. In subsequent production, TCR needs to be accurately calibrated at high temperature, and the production and assembly stations are many and the cost is high. Summary of the invention

[0004] The purpose of the present invention is to solve the above shortcomings of the existing 95 porcelain heating rod, and to design and develop a rod-shaped heating body with extremely low cost, low surface roughness and production without high temperature calibration.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A central rod-shaped heating element, comprising an insulating base and a heating element body, wherein the heating element body comprises an inner tube electrode, an outer tube electrode, an inner heating tube, an outer heating tube, and an inner and outer tube connector;

[0007] One end of the inner tube electrode is matched and inserted into the mounting hole on the insulating base, and the other end is connected to the inner heating tube;

[0008] The outer tube electrode is sleeved outside the inner tube electrode, one end of which is fixedly connected to the insulating base, and the other end of which is connected to the outer heating tube;

[0009] An inner-outer tube connector is provided at one end of the outer heating tube away from the outer tube electrode and fixedly connected to the inner heating tube to form a series passage;

[0010] Preferably, the resistance of the inner heating tube is greater than the resistance of the outer heating tube.

[0011] Preferably, the resistance of the inner tube electrode is smaller than the resistance of the inner heating tube, and the resistance of the outer tube electrode is smaller than the resistance of the outer heating tube.

[0012] Preferably, the heating element body is made of SUS304 (stainless steel 304).

[0013] Preferably, the outer diameter of the inner heating tube is 1.3-1.4 mm, preferably 1.3 mm; the outer diameter of the outer heating tube is 2.0-2.1 mm, preferably 2.0 mm; the wall thickness of the inner heating tube and the outer heating tube is 0.03-0.05 mm, preferably 0.05 mm.

[0014] Preferably, the inner and outer tube connector is provided with an inner tube limiting shoulder at one end, an outer tube limiting shoulder in the middle, and the other end is in a cone shape.

[0015] Preferably, the inner tube electrode, the outer tube electrode, the inner heating tube and the outer heating tube are all coaxially arranged.

[0016] Preferably, a temperature measuring element is further provided in the inner heating tube, one end of the temperature measuring element is inserted into a positioning hole provided at one end of the inner and outer tube connecting piece, and the other end passes through the inner tube electrode and extends to the outside of the insulating base. In this way, the internal space of the inner tube electrode can be fully utilized to assemble the temperature measuring element and obtain the actual heating temperature of the heating element.

[0017] Preferably, the insulating base is further provided with a pair of electrode wire holes, in which electrode wires are installed, and the pair of electrode wires are respectively connected to the inner tube electrode and the outer tube electrode.

[0018] Preferably, the insulating base is a PCB board.

[0019] A low-temperature smoking device comprises the above-mentioned central rod-shaped heating element.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention utilizes the characteristic of large resistivity of existing SUS304 tubes, connects two SUS304 tubes of different diameters and different resistance values ​​by laser welding to form a double-tube series structure with an inverted U-shaped cross section, and uses it as the main body of the heating element. Since the resistance of the inner heating tube is greater than that of the outer heating tube, the heating temperature of the inner heating tube is higher than that of the outer heating tube, and there is a gap between the inner and outer heating tubes. When the outer heating tube is heated by itself, it will also be subjected to the high temperature conduction of the inner heating tube, making the surface temperature of the outer heating tube more uniform; the wall thickness of the inner and outer tube electrodes is correspondingly smaller than that of the inner and outer heating tubes, so that the heat dissipated by the inner and outer tube electrodes is reduced, and the heat conduction to the smoking device is reduced, so that the heating temperature of the cigarette by the inner and outer heating tubes is increased; thermocouples are provided in the inner heating tube and the inner tube electrode to monitor the heating temperature in real time; the heating element material cost is low, the manufacturing process is simple, and the unit price of the heating element is less than 5 yuan, which is about 30% of the unit price of the existing heating elements on the market. It has its own temperature-sensing thermocouple, and does not require high-temperature calibration of the production line during production. The assembly process is simple, the production cost of the device is low, and the service life is long, which has the value of promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a front cross-sectional view of the central rod-shaped heating element.

[0023] Figure 2 It is a side sectional view of the central rod-shaped heating element.

[0024] Figure 3 Axial view of the central rod-shaped heating element Figure 1 .

[0025] Figure 4 Axial view of the central rod-shaped heating element Figure 2 .

[0026] Figure 5 This is an axial view of the insulating base.

[0027] Figure 6 It is a three-dimensional schematic diagram of the inner and outer pipe connector.

[0028] Figure 7 This is an exploded view of the central rod-shaped heating element.

[0029] Figure 8 Schematic diagram of the assembly process of the central rod-shaped heating element.

[0030] Fig. 9 This is a schematic diagram of a low-temperature smoking device.

[0031] In the figure: 1-inner and outer tube connector, 101-thermocouple positioning hole, 102-outer tube limiting shoulder, 103-inner tube limiting shoulder, 2-outer tube first welding seam, 3-inner tube first welding seam, 4-outer heating tube, 5-inner heating tube, 6-thermocouple, 601-thermocouple ceramic insulation layer, 7-thermocouple wire, 8-thermocouple wire insulation layer, 9-outer tube second welding seam, 10-inner tube second welding seam, 11-outer tube electrode , 12-inner tube electrode, 13-PCB board, 1301-inner tube electrode mounting hole, 1302-positive electrode wire hole, 1303-negative electrode wire hole, 1304-fixing screw hole, 1305-outer tube electrode pad, 1306-inner tube electrode pad, 14-positive electrode wire, 15-negative electrode wire, 16-cigarette, 17-shell, 18-cigarette holder, 19-fixing screw, 20-temperature control board, 21-battery. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", "one end", "the other end" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] Example 1: Figure 1-7 ;

[0035] The present embodiment provides a central rod-shaped heating element, which is one of the preferred embodiments of the present invention, and comprises an insulating base and a heating element body, wherein the heating element body comprises an inner tube electrode 12, an outer tube electrode 11, an inner heating tube 5, an outer heating tube 4, and an inner-outer tube connector 1; one end of the inner tube electrode 12 is matched and inserted into the mounting hole on the insulating base, and the other end is connected to the inner heating tube 5; the outer tube electrode 11 is sleeved outside the inner tube electrode 12, one end is fixedly connected to the insulating base, and the other end is connected to the outer heating tube 4; an inner-outer tube connector 1 is provided at one end of the outer heating tube 4 away from the outer tube electrode 11 and is fixedly connected to the inner heating tube 5 to form a series path; the resistance of the inner heating tube 5 is greater than the resistance of the outer heating tube 4.

[0036] An outer tube limiting shoulder 102 is provided in the middle of the inner and outer tube connector 1, and an inner tube limiting shoulder 103 is provided at one end. The outer tube limiting shoulder 102 and the inner tube limiting shoulder 103 respectively limit the end of the outer heating tube 4 away from the outer tube electrode 11 and the end of the inner heating tube 5 away from the inner tube electrode 12, and are fixed by laser welding, forming the first outer tube welding seam 2 and the first inner tube welding seam 3 at the connection, and then the outer heating tube 4 and the inner heating tube 5 are coaxially connected together. The first outer tube welding seam 2 makes the inner and outer tube connector 1 and the outer wall of the outer heating tube 4 smoothly transition, and the outer heating tube 4, the inner and outer tube connector 1, and the inner heating tube 5 jointly form a coaxial double-tube series structure with an inverted U-shaped cross section. After the two tubes are connected in series, the total resistance is between 0.50 and 0.65Ω. The other end of the inner and outer tube connector 1 is conical, which is convenient for the cigarette to be inserted into the heating body. In addition, the inner and outer tube connector 1 and the outer heating tube 4 and the inner heating tube 5 can also be connected by interference fit.

[0037] The material of the outer tube electrode 11 is SUS304 (stainless steel 304). Laser welding is performed between the outer tube electrode 11 and the outer heating tube 4 to form the outer tube second welding seam 9 at the connection, so that the outer tube electrode 11 is fixedly connected to the outer heating tube 4 and the outer wall is smoothly transitioned. The wall thickness of the outer tube electrode 11 is greater than the wall thickness of the outer heating tube 4 (to avoid contact between the outer tube electrode 11 and the inner tube electrode 12, it is best to set an electrode insulation layer), and the length is shorter than that of the outer heating tube 4. Therefore, the resistance value is smaller than that of the outer heating tube 4, and the heat generated during operation is smaller. In addition, the thermal conductivity of the SUS304 material is 16W / m•K at room temperature. Compared with steel (thermal conductivity is about 50W / m•K) and aluminum alloy (about 120 200W / m•K), the thermal conductivity of SUS304 is relatively low. Therefore, the heat generated by the external heating tube 4 during operation is relatively small and is transferred to the insulating base and the surface of the smoking device through the external tube electrode 11, thereby improving the user experience and avoiding burns.

[0038] The material of the inner tube electrode 12 is SUS304. Laser welding is performed between the inner tube electrode 12 and the inner heating tube 5. The second inner tube welding seam 10 is formed at the welding position, so that the inner tube electrode 12 is fixedly connected to the inner heating tube 5. The wall thickness of the inner tube electrode 12 is greater than the wall thickness of the inner heating tube 5, and the length is shorter than that of the inner heating tube 5. Therefore, the resistance value is smaller than that of the inner tube 5, and the heat generated during operation is smaller. Therefore, the heat generated by the inner heating tube 5 during operation is conducted to the insulating base and the surface of the smoking device through the inner tube electrode 12, which is relatively small, avoiding scalding the user.

[0039] The material of the heating element body is SUS304, that is, the material of the inner heating tube 5, the outer heating tube 4, and the inner and outer tube connector 1 is also SUS304. The different parts of the heating element body are all made of the same SUS304 material, mainly because the production cost of SUS304 is low, and the surface of the SUS304 tube is relatively smooth and the surface roughness is low, but the wall thickness of each part is different. Since the tube body is in series, the reason for the thickening of the electrode wall is to reduce the resistance of the electrode. The smaller the resistance, the smaller the power and the smaller the heat generated, so that the heat of the heating element is mainly concentrated in the heating element body section, especially the inner and outer heating tube sections.

[0040] The insulating base adopts a PCB board 13. The material of the PCB board 13 is FR4, which is one of the most commonly used PCB materials at present. It is made of glass fiber reinforced epoxy resin-based material, has good insulation, heat resistance and mechanical properties, and has low thermal conductivity. The PCB board 13 is provided with an inner tube electrode mounting hole 1301 that runs through from top to bottom. The length of the inner tube electrode 12 is longer than that of the outer tube electrode 11, and one end of the inner tube electrode 12 is matched and plugged into the inner tube electrode mounting hole 1301; the upper surface of the PCB board 13 is provided with an outer tube electrode pad 1305, and the lower surface is provided with an inner tube electrode pad 1306. One end of the outer tube electrode 11 is welded and fixed to the PCB board 13 at the outer tube electrode pad 1305 by soldering, and one end of the inner tube electrode 12 is welded and fixed to the PCB board 13 at the inner tube electrode pad 1306 by soldering.

[0041] The PCB board 13 is provided with a positive wire hole 1302 and a negative wire hole 1303 which are respectively connected to the positive wire 14 and the negative wire 15 by soldering. One end of the positive wire 14 and the negative wire 15 are connected to the inner tube electrode 12 and the outer tube electrode 11 respectively, and the other end is connected to the power supply in the smoking device; the PCB board 13 is provided with a fixing screw hole 1304 to facilitate fixing the entire heating element inside the smoking device.

[0042] In addition, a temperature measuring element is provided in the heating element body, and the temperature measuring element adopts a thermocouple. A thermocouple positioning hole 101 is provided in the center of one end of the inner and outer tube connecting piece 1, and one end of the thermocouple 6 is assembled in the thermocouple positioning hole 101 and bonded and fixed in the thermocouple positioning hole 101. The thermocouple wire 7 passes through the inner heating tube 5, and a thermocouple wire insulation layer 8 is passed through the thermocouple wire 7 to play an insulating role. The thermocouple 6 located in the inner heating tube 5 is coated with a ceramic insulation layer 601 to play an insulating role.

[0043] The working principle of this embodiment is:

[0044] The resistivity of SUS304 is 7.15x106Ω·m. It can be used as a heating wire in the industrial field. SUS304 can maintain a certain stability at high temperatures. When working as a heating wire to generate heat, even if the temperature rises, it can still maintain its own structural stability and will not be quickly damaged or seriously degraded in performance, thereby ensuring the continuity of its heating function. In addition, it has good corrosion resistance. In different use environments (such as a heating environment that may be exposed to water vapor, etc.), SUS304 is not easily corroded, thereby extending the service life of the heating wire and reducing the performance degradation and failure risks caused by corrosion. The SUS304 tube is used as the external heating tube 4, and its outer wall surface roughness is low, which is conducive to the cigarette being pulled out from the heating element after heating is completed;

[0045] The thin-walled small diameter SUS304 tubes available on the market have a large resistivity and can be used as heating tubes, but the length of the tobacco part of the cigarette is certain (the length of the tobacco is generally 10~11mm), so the length of the heating tube must also be within this length range. Although the thin-walled small diameter SUS304 tube has a large resistivity, the resistance value of the SUS304 tube with a length of 10~11mm, an outer diameter of ¢2mm, and a wall thickness of 0.05mm is only 0.26Ω. Under the voltage of 3.7V, the current will reach about 14A. The current is too large, and the battery and other components cannot withstand such a large current value. At present, the resistance value of the general heating wire is 0.5~0.8Ω, and the power is about 20W. In order to achieve a resistance value of 0.5~0.8Ω for the SUS304 tube at a length of 10~11mm, another SUS304 small tube with an outer diameter of ф1.3mm, a length of 10~11mm, a wall thickness of 0.05mm, and a resistance of 0.39Ω is axially sleeved together with the first SUS304 tube. The upper ends of the two tubes are limited by a SUS304 machined part (i.e., the inner and outer tube connector 1) and the two tubes are connected together by laser welding to form a double-tube series structure with an inverted U-shaped cross section. After the series connection, the total resistance of the two tubes is 0.65Ω, reaching the required resistance range;

[0046] Although the power of the inner heating tube 5 is greater than that of the outer heating tube 4 during heating, and the temperature is higher, the diameter of the outer tube electrode 11 is 2.0-2.1mmmm, the wall thickness is 0.15-0.2mm, the diameter of the inner tube electrode 12 is 1.3-1.4mm, the wall thickness is 0.15-0.2mm (the outer wall of the inner tube electrode 12 is smoothly connected to the inner heating tube 5), and the gap between the inner and outer heating tubes is about 0.3mm. Surrounded by tobacco, the temperature difference between the inner and outer heating tubes is not large and is relatively uniform. The reason is that the temperature of the inner heating tube 5 is higher than that of the outer heating tube 4, and the surface of the outer heating tube 4 is heated as a whole. In the case of a gap between the inner and outer heating tubes, the heat emitted to the outside by the inner heating tube 5 through the air in the gap is more uniform. When the outer heating tube 4 is heated by itself, it will be subjected to the high temperature conduction of the inner heating tube, which improves the uniformity of the surface temperature of the outer heating tube 4. Compared with the heating of the existing 95 porcelain heating element printed heating wire, it will not form a small point of high temperature in the area, so the degree of adhesion between the tobacco and the heating element due to sintering can be reduced. The material of the inner and outer tube electrodes at the other end of the inner and outer heating tubes is also SUS304, with thicker wall thickness and smaller resistance than the heating tubes. After being connected in series with the inner and outer heating tubes, no more heat will be generated during operation.

[0047] After the inner and outer tube electrodes are connected to the inner and outer heating tubes, they are fixed on the PCB board 13 by soldering, and then fixed in the smoking device through the fixing screw holes on the PCB board 13. The material of the PCB is FR4, which is made of glass fiber reinforced epoxy resin-based material and has good insulation, heat resistance and mechanical properties. The thermal conductivity of the non-conductive board of FR4 is 0.2 W / m / K. Fixing the heating element with the PCB board 13 can effectively prevent the heat of the heating element from being transferred to the surface of the main body of the smoking device, thereby reducing the surface temperature of the smoking device. Although the inner tube electrode 12 and the outer tube electrode 11 are also made of SUS304 material, as electrodes, they do not need to be too long. The smaller their length is compared with the inner heating tube 5 and the outer heating tube 4, the greater the uniform temperature length of the heating rod inserted into the cigarette.

[0048] The assembly process of the central rod-shaped heating element in this embodiment is as follows: first, the inner heating tube 5 and the inner tube electrode 12 are welded, and then one end of the thermocouple 6 is inserted into the thermocouple positioning hole 101 at one end of the inner and outer tube connector 1 and fixed by bonding, and then the inner heating tube 5 and the inner tube electrode 12 are sleeved on the thermocouple 6, and the end of the inner heating tube 5 is positioned with the inner tube limiting shoulder 103 on the inner and outer tube connector 1, and fixed by welding at the connection; then, the outer heating tube 4 and the outer tube electrode 11 are welded, and then the two are sleeved on the inner tube electrode 12, and the end of the outer heating tube 4 is positioned with the outer tube limiting shoulder 102 on the inner and outer tube connector 1, and fixed by welding at the connection. After that, one end of the inner tube electrode 12 is inserted into the inner tube electrode mounting hole 1301 of the PCB board 13, and the inner tube electrode 12 is welded and fixed to the inner tube electrode pad 1306 on the lower surface of the PCB board 13, and the outer tube electrode 11 is welded and fixed to the outer tube electrode pad 1305 on the upper surface of the PCB board 13; the positive wire 14 and the negative wire 15 are respectively inserted into the positive wire hole 1302 and the negative wire hole 1303 on the PCB board 13 and fixed, and then the positive wire 14 and the negative wire 15 are connected to the inner tube electrode 12 and the outer tube electrode 11, and the central rod-shaped heating element described in this embodiment can be obtained.

[0049] In addition, in other embodiments of the present invention, the inner tube electrode 12 and the outer tube electrode 11 made of SUS304 tube in Embodiment 1 can also be made of other low-cost materials with a resistance value lower than SUS304, which can also achieve the effect of reducing the heat transfer from the heating body to the surface of the smoking device. The inner heating tube 5 and the outer heating tube 4 can also be made of customized tubes with similar properties to SUS304.

[0050] Example 2: Fig. 9 ;

[0051] This embodiment provides a low-temperature smoking device, which includes the central rod-shaped heating element, the outer shell 17, the cigarette holder 18, the temperature control board 20 and the battery 21 as described in Example 1. The central rod-shaped heating element is installed in the outer shell 17 by fixing screws 19, and the cigarette 16 is inserted into the heating cavity in the cigarette holder 18 and then installed on the central rod-shaped heating element. When the smoking device is working, the temperature of the heating element is obtained through the thermocouple 6 and the heating temperature is controlled by the temperature control board 20. The other structures except the central rod-shaped heating element are all existing technologies and will not be repeated here.

[0052] The above description is only used to illustrate the technical solution of the present invention and is not intended to limit it. Any modification or replacement of the technical solution made by other technicians in the field should be included in the scope of the claims of the present invention as long as it does not deviate from the connotation of the technical solution of the present invention.

Claims

1. A central rod-shaped heating element, comprising an insulating base and a heating element body, characterized in that: The heating body comprises an inner tube electrode (12), an outer tube electrode (11), an inner heating tube (5), an outer heating tube (4), and an inner and outer tube connector (1); One end of the inner tube electrode (12) is matched and inserted into the mounting hole on the insulating base, and the other end is connected to the inner heating tube (5); The outer tube electrode (11) is sleeved outside the inner tube electrode (12), one end of which is fixedly connected to the insulating base, and the other end of which is connected to the outer heating tube (4); An inner and outer tube connector (1) is provided at one end of the outer heating tube (4) away from the outer tube electrode (11), and the inner heating tube (5) is fixedly connected to form a series passage.

2. The central rod-shaped heating element according to claim 1, characterized in that: The resistance of the inner heating tube (5) is greater than the resistance of the outer heating tube (4).

3. The central rod-shaped heating element according to claim 2, characterized in that: The resistance of the inner tube electrode (12) is smaller than the resistance of the inner heating tube (5), and the resistance of the outer tube electrode (11) is smaller than the resistance of the outer heating tube (4).

4. The central rod-shaped heating element according to claim 2 or 3, characterized in that: The heating element body is made of 304 stainless steel.

5. The central rod-shaped heating element according to claim 4, characterized in that: The outer diameter of the inner heating tube (5) is 1.3-1.4 mm; the outer diameter of the outer heating tube (4) is 2-2.1 mm; and the wall thickness of the inner heating tube (5) and the outer heating tube (4) is 0.03-0.05 mm.

6. The central rod-shaped heating element according to claim 1, characterized in that: The inner and outer tube connecting piece (1) is provided with an inner tube limiting shaft shoulder (103) at one end, an outer tube limiting shaft shoulder (102) at the middle, and the other end is in a cone shape.

7. The central rod-shaped heating element according to any one of claims 1 to 6, characterized in that: A temperature measuring element is also provided in the inner heating tube (5), one end of the temperature measuring element is inserted into a positioning hole provided at one end of the inner and outer tube connector (1), and the other end passes through the inner tube electrode (12) and extends to the outside of the insulating base.

8. The central rod-shaped heating element according to any one of claims 1 to 6, characterized in that: The insulating base is also provided with a pair of electrode wire holes, in which electrode wires are installed, and the pair of electrode wires are respectively connected to the inner tube electrode (12) and the outer tube electrode (11).

9. The central rod-shaped heating element according to any one of claims 1 to 6, characterized in that: The insulating base adopts a PCB board (13).

10. A low-temperature smoking device, comprising the central rod-shaped heating element as claimed in any one of claims 1 to 9.

Images