A device and method for detecting filter tip temperature field during cigarette smoking

Abstract

The present invention discloses a device and method for detecting the temperature field of a filter tip during cigarette smoking. The device is composed of a cigarette holder, an airflow sensor, an adjustable speed vacuum pump, a microcontroller, and a host computer, wherein a temperature sensor is arranged inside the cigarette holder. The method is as follows: loading the cigarette into the cigarette holder; starting the host computer and the microcontroller, and then starting the adjustable speed vacuum pump; lighting the cigarette, and starting to collect and display real-time temperature and flow data; issuing instructions through the host computer to control the adjustable speed vacuum pump to simulate standard smoking; the host computer determines the actual suction flow curve and the three-dimensional non-steady-state temperature field of the filter tip through the data uploaded by the microcontroller. The present invention can detect the temperature change of the filter tip in real time under the premise of accurately simulating standard smoking, thereby reflecting the three-dimensional non-steady-state temperature field of the filter tip.

Description

Technical Field

[0001] The present invention relates to the technical field of tobacco temperature measurement, and in particular to a device for detecting the temperature field of a filter tip during cigarette smoking, and also to a detection method for the device for detecting the temperature field of a filter tip during cigarette smoking. Background Art

[0002] The detection of the temperature field of cigarettes is one of the focuses of tobacco science research, because the temperature field of cigarettes is closely related to the density, draw resistance, filter material, etc. of tobacco. Studying the temperature field of cigarettes can provide a scientific basis for the internal structure design of cigarettes and the selection of auxiliary materials.

[0003] In current related experimental research, the detection of cigarette temperature is mainly focused on the burning temperature of cigarettes. There are relatively few measurements of cigarette filter rod temperature. Usually, a quartz capillary and a platinum-rhodium alloy wire are used to detect the cigarette burning temperature or a micro-thermocouple is used to detect the bulk temperature of the cigarette during combustion. For example, patents CN201610094163.X and CN201610094827.2 disclose temperature detection devices that can measure the axial and radial temperature fields of cigarette filter rods, but cannot simultaneously measure the three-dimensional non-steady-state temperature field of the cigarette filter tip. There is no detection method and device specifically for the temperature distribution field of cigarette butts. As for the temperature detection of the cigarette butt part, the clamping and sealing must be considered, so the existing technology cannot be used.

[0004] At the same time, the existing smoking simulation devices are large in size and inconvenient to carry; secondly, they are quite different from the actual smoking state of people, that is, the simulation effect is not ideal. For example, patent CN201710705235.4 discloses a method of using a stepper motor to simulate the standard suction of a smoking machine, but due to the limited suction capacity of the suction device, frequent exhaust is required to ensure repeated suction, and continuous suction cannot be simulated. At the same time, the corresponding suction structure needs to be designed to cooperate with the slide module, which is not conducive to the miniaturization of the device. Summary of the invention

[0005] Based on the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a device for detecting the temperature field of the filter tip during the smoking process of a cigarette, which has a good smoking simulation effect and occupies a small volume.

[0006] Correspondingly, the present invention also provides a method for detecting the temperature field of the filter tip during the smoking process of a cigarette, which can accurately measure the temperature field of the filter tip during the smoking process of a cigarette.

[0007] In order to achieve the above-mentioned purpose, the present invention adopts the following technical measures:

[0008] A device for detecting the temperature field of a filter tip during a cigarette smoking process, comprising: a cigarette holder for clamping and sealing a cigarette filter tip, wherein a temperature measuring probe, a side temperature sensor and an end surface temperature sensor for detecting the temperature of different parts of the cigarette filter tip are arranged inside the cigarette holder; an airflow sensor connected to the cigarette holder for detecting the flow rate of the cigarette filter tip suction, and for simulating a calibration process before suction and determining an actual suction flow rate curve; an adjustable speed vacuum pump connected to the airflow sensor for realizing the suction process of the cigarette filter tip, wherein the suction flow rate is determined by the frequency of an input square wave signal; a microcontroller connected to the temperature sensor, the airflow sensor and the adjustable speed vacuum pump for collecting temperature data and flow rate data, and sending a square wave signal to control the adjustable speed vacuum pump; and a host computer connected to the microcontroller for receiving the temperature data and flow rate data collected by the microcontroller and determining the three-dimensional non-steady-state temperature field of the cigarette filter tip and the actual suction flow rate curve.

[0009] Preferably, the microcontroller is composed of an STM32F407 chip and a multi-channel temperature acquisition circuit, and has an analog-to-digital conversion function to collect temperature data from the temperature sensor inside the cigarette holder, collecting a set of data every 10 ms, and a set of data can contain 24 temperature data; it has a communication function to obtain flow data from the airflow sensor; and it has the function of generating square waves of different frequencies to control the adjustable speed vacuum pump.

[0010] Furthermore, a hole is punched at the front end of the cigarette holder according to the temperature measuring position, and a temperature measuring probe is inserted into the hole and the front end of the temperature measuring probe is located at the center of the cigarette holder; a sealant is used to seal the gap between the temperature measuring probe and the hole to detect the temperature of the inner center of the front end of the cigarette filter.

[0011] Furthermore, a hole is punched at the lead outlet of the side temperature sensor on the cigarette holder, and the side temperature sensor is evenly attached to the circumferential inner wall of the cigarette holder; the lead of the side temperature sensor is led out from the punched hole, and the gap between the lead of the side temperature sensor and the punched hole is sealed with sealant.

[0012] Furthermore, a hole is punched at the lead outlet of the end face temperature sensor on the cigarette holder, and the end face temperature sensor is fixed in the end face notch of the cigarette holder; the lead of the end face temperature sensor is led out from the punched hole, and the gap between the lead of the end face temperature sensor and the punched hole is sealed with sealant.

[0013] Optionally, the cigarette holder is composed of two upper and lower clamping plates.

[0014] Optionally, the side temperature measuring sensor comprises a plurality of temperature measuring sensors arranged in a straight line at equal intervals. The end surface temperature measuring sensor comprises a plurality of temperature measuring sensors evenly arranged within a cross-sectional circle of the filter tip.

[0015] Furthermore, the response time of the airflow sensor is 10 ms.

[0016] The key points of the above are, first, the use of a cigarette holder with contact temperature sensors arranged on the inner wall and the end surface and a vertical penetration temperature probe. Compared with the existing ordinary cigarette clamping device, it can ensure temperature measurement while clamping and sealing. Compared with general cigarette temperature measurement methods such as thermocouple temperature measurement, it realizes multi-point temperature measurement on the surface and inside, so that the temperature field change is obtained through a large amount of data calculation; second, the adjustable vacuum pump and high-response airflow sensor can make the suction flow closer to the standard flow curve or the actual suction situation.

[0017] The method for detecting the filter tip temperature field during cigarette smoking of the present invention comprises the following steps:

[0018] S1. Selecting cigarette samples that meet the requirements;

[0019] S2, placing the selected cigarette sample in the cigarette holder, the side temperature sensor and the end temperature sensor inside the cigarette holder contact the outer edge and the end surface of the filter respectively, and the temperature probe penetrates the filter;

[0020] S3, start the host computer and microcontroller, and then start the adjustable speed vacuum pump;

[0021] S4, light the cigarette, and the microcontroller collects and uploads the real-time temperature and flow data of the cigarette filter to the host computer;

[0022] S5, sending instructions to the microcontroller through the host computer, so that the microcontroller sends square wave signals of different frequencies to the adjustable speed vacuum pump to simulate standard suction;

[0023] S6. The host computer determines the actual suction flow curve and the three-dimensional non-steady-state temperature field of the cigarette filter through the data uploaded by the microcontroller.

[0024] The adjustable speed vacuum pump simulates standard suction by first establishing a mapping relationship between the frequency of the input square wave signal and the actual suction flow rate, and then inputting square wave signals of different frequencies into the adjustable speed vacuum pump at certain time intervals according to the mapping relationship and the standard flow curve.

[0025] The present invention can detect the temperature change of the filter tip in real time under the premise of accurately simulating standard smoking, thereby reflecting the three-dimensional non-steady-state temperature field of the filter tip. Compared with the prior art, the device and method for detecting the temperature field of the filter tip during cigarette smoking of the present invention have at least the following beneficial effects:

[0026] 1. Not only can it accurately simulate the standard suction process, but it can also simulate other suction flow curves by modifying the program.

[0027] 2. The acquisition time of a set of synchronous temperature data and flow data can reach a fast response of 10ms.

[0028] 3. It can reflect the three-dimensional non-steady-state temperature field during simulated suction.

[0029] 4. Simple principle and easy integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic structural diagram of a device for detecting the filter temperature field during cigarette smoking in a preferred embodiment of the present invention.

[0031] Figure 2 It is a schematic diagram of the interior of a cigarette holder of the filter tip temperature field detection device during cigarette smoking of the present invention;

[0032] Figure 3 It is a schematic diagram of the side temperature measuring sensor in the device for measuring the temperature field distribution of cigarette butts of the present invention;

[0033] Figure 4 It is a schematic diagram of the end surface temperature measuring sensor in the device for measuring the temperature field distribution of cigarette butts of the present invention.

[0034] Figure 5 It is a simulation curve diagram of the standard suction of the present invention and the theoretical suction of the adjustable vacuum pump.

[0035] Among them: 1-cigarette holder; 2-airflow sensor; 3-adjustable speed vacuum pump; 4-microcontroller; 5-host computer; 1.1-temperature probe; 1.2-side temperature sensor; 1.3-end temperature sensor; 1.4-cigarette holder housing. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] like Figure 1 As shown, the device for detecting the filter temperature field during cigarette smoking provided by an embodiment of the present invention comprises a cigarette holder 1, an airflow sensor 2, an adjustable speed vacuum pump 3, a microcontroller 4, and a host computer 5.

[0039] like Figure 2 As shown, the cigarette holder 1 is divided into an upper clamping piece and a lower clamping piece. When an external force is applied to make the upper and lower clamping pieces fit tightly together, the cigarette filter can be clamped and sealed. The inner wall and the end of the cigarette holder 1 are provided with contact temperature sensors (side temperature sensor 1.2 and end temperature sensor 1.3), and a piercing temperature probe 1.1 is provided to detect the internal temperature of the cigarette filter. The diameter of the temperature probe 1.1 can be less than 2mm, and can be made of a thermal resistor or a thermocouple wire; the side temperature sensor 1.2 is made of 5 thermistors mounted on a printed circuit board at equal intervals within the length of the filter (cigarette butt); the end temperature sensor 1.3 is made of 5 thermistors mounted evenly on a printed circuit board within the cross-section of the cigarette butt, and the unwired part is hollowed out.

[0040] Among them, the steps of fixing the temperature measuring probe 1.1 on the cigarette holder include: punching a hole at the front end of the cigarette holder according to the temperature measuring position; inserting the temperature measuring probe 1.1 into the hole and making the front end of the temperature measuring probe be at the center of the cigarette holder, that is, the center of the cigarette butt after the cigarette is loaded; sealing the gap between the temperature measuring probe and the hole with sealant to detect the temperature of the inner center of the front end of the cigarette filter.

[0041] The steps of fixing the side temperature sensor 1.2 on the cigarette holder include: punching a hole at the lead outlet of the side temperature sensor on the cigarette holder; evenly attaching the side temperature sensor 1.2 to the circumferential inner wall of the cigarette holder; leading the lead of the side temperature sensor out of the punched hole; and sealing the gap between the lead of the side temperature sensor and the punched hole with sealant.

[0042] The steps of fixing the end face temperature sensor 1.3 on the cigarette holder include: punching a hole at the end face temperature sensor lead outlet on the cigarette holder; fixing the end face temperature sensor 1.3 in the end face notch of the cigarette holder; leading the lead of the end face temperature sensor out of the punched hole; and sealing the gap between the lead of the end face temperature sensor and the punched hole with sealant.

[0043] The clamping and sealing of the cigarette, the insertion of the temperature measuring probe and the contact between the side temperature measuring sensor and the outer edge of the cigarette butt are all achieved in the process of clamping the two clamping pieces up and down.

[0044] When the cigarette is completely loaded into the cigarette holder, the temperature measuring probe can penetrate into the center of the cigarette, the side temperature measuring sensor contacts the outer edge of the cigarette butt, and the end temperature measuring sensor contacts the end of the cigarette butt.

[0045] The airflow sensor 2 of the present invention adopts the Sixiang FS4003 series gas mass flow sensor, which is connected to the cigarette holder 1 through a quick-insert air pipe joint and an air pipe, and is used to detect the flow rate of the cigarette filter suction, and is used to simulate the calibration process before suction and the determination of the actual suction flow curve. The fastest response time of the airflow sensor 2 is 10ms. The adjustable speed vacuum pump 3 is a three-chamber vacuum diaphragm pump, which is connected to the airflow sensor 2 through a quick-insert air pipe joint and an air pipe, and is used to realize the suction process of the cigarette filter. The suction flow rate is determined by the frequency of the input square wave signal. When the frequency of the input square wave signal changes, the suction flow rate of the adjustable speed vacuum pump 3 can also change rapidly.

[0046] The microcontroller 4 of the present invention is connected to the temperature sensor, the airflow sensor 2 and the adjustable speed vacuum pump 3, and is used to collect temperature data and flow data of the cigarette filter, and send out a square wave signal to control the adjustable speed vacuum pump 3. The microcontroller 4 is composed of an STM32F407 chip and a multi-channel temperature acquisition circuit, and has an analog-to-digital conversion function to collect temperature data of the temperature sensor inside the cigarette holder, and collects a group of data every 10ms, and a group of data can contain 24 temperature data; it has a communication function with the airflow sensor 2 to obtain flow data; it has a function of generating square waves of different frequencies to control the adjustable speed vacuum pump 3.

[0047] The host computer 5 of the present invention (the host computer is an executable program / software on the PC side, which is connected to the microcontroller by a data line and receives data, calculates the three-dimensional non-steady-state temperature field through the 24 temperature data received at different times and the layout positions of each temperature sensor inside the clamp, and draws the suction flow curve through the instantaneous flow data received at different times) is connected to the microcontroller 4, and is used to receive the temperature data and flow data collected by the microcontroller 4 and determine the three-dimensional non-steady-state temperature field of the cigarette filter and the actual suction flow curve.

[0048] Accordingly, the detection method of the detection device of the filter tip temperature field during the smoking process of the cigarette in this embodiment includes the following steps:

[0049] Step 1, calibrate the device, that is, use the microcontroller 4 to input different frequency square waves with a certain amplitude and the same duty cycle to the adjustable speed vacuum pump 3, use the airflow sensor 2 to measure the suction flow of the adjustable speed vacuum pump 3 at different input square wave frequencies, and establish the functional relationship ν=f(Q) between the frequency ν of the input square wave and the suction flow Q.

[0050] Step 2, such as Figure 5 As shown, the bell-shaped flow diagram of standard suction is approximated as a function Q=g(t) with respect to time t, and Q=g(t) is processed and converted into a step-shaped flow simulation curve, which is recorded as Q′=h(t);

[0051] Preferably, when Q=g(t) is converted into Q′=h(t), the time of each segment is 10 ms.

[0052] Step 3, using the flow simulation curve Q′=h(t) and the calibration result ν=f(Q), the function of the square wave frequency ν and time t ν=f(Q′)=f(h(t))=q(t) is obtained.

[0053] Step 4, use the microcontroller 4 to send a square wave signal to the adjustable speed vacuum pump 3 according to ν=q(t), use the airflow sensor 2 and the microcontroller 4 to collect and upload the flow data, and the host computer 5 determines the actual suction flow curve and compares it with Q=g(t).

[0054] Preferably, if the actual suction flow rate curve differs too much from Q=g(t), Q′=h(t) is corrected and step 4 is repeated until the requirement is met.

[0055] Step 5, placing the above-mentioned device for detecting the filter temperature field during cigarette smoking in a specified test atmosphere, placing the cigarette samples to be tested in the test atmosphere for 48 hours to balance, and selecting them according to the specified selection conditions.

[0056] Step 6, the selected cigarette sample is placed in the cigarette holder 1, the side temperature sensor and the end temperature sensor inside the cigarette holder 1 are in contact with the outer edge and the end surface of the cigarette butt respectively, and the temperature probe penetrates the filter.

[0057] Step 7, light the cigarette, and the microcontroller 4 continuously collects and uploads real-time temperature and flow data to the host computer 5.

[0058] Among them, a set of temperature data and flow data of multiple temperature sensors inside the cigarette holder 1 are collected synchronously, and the collection and upload cycle is once every 10ms.

[0059] Step 8, the host computer 5 sends a command to the microcontroller 4, so that the microcontroller 4 sends a square wave signal to the adjustable speed vacuum pump 3 according to ν=q(t) to simulate standard suction.

[0060] Step 9: The host computer 5 determines the actual suction flow curve and the three-dimensional non-steady-state temperature field of the filter tip through the data uploaded by the microcontroller 4.

[0061] The above description is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be understood by anyone familiar with the technology within the technical scope disclosed by the present invention should be included in the scope of the present invention.

Claims

1. A detection method of a detection device for a filter tip temperature field during cigarette smoking, characterized in that: The detection device comprises: A cigarette holder is used to hold and seal the cigarette filter, and the cigarette holder is provided with a temperature measuring probe, a side temperature sensor and an end surface temperature sensor for detecting the temperature of different parts of the cigarette filter; An airflow sensor connected to the cigarette holder is used to detect the flow rate of the cigarette filter tip and to simulate the calibration process before smoking and the determination of the actual smoking flow rate curve; An adjustable speed vacuum pump is connected to the airflow sensor and is used to realize the suction process of the cigarette filter, and the suction flow rate is determined by the frequency of the input square wave signal; A microcontroller is connected to the temperature sensor, the airflow sensor and the adjustable speed vacuum pump, and is used to collect temperature data and flow data, and send a square wave signal to control the adjustable speed vacuum pump; The host computer is connected to the microcontroller and is used to receive the temperature data and flow data collected by the microcontroller and determine the three-dimensional non-steady-state temperature field of the cigarette filter and the actual suction flow curve. The detection method comprises the following steps: Step 1, calibrating the device, using a microcontroller (4) to input square waves of different frequencies with a certain amplitude and the same duty cycle to the adjustable speed vacuum pump (3), using an airflow sensor (2) to measure the suction flow of the adjustable speed vacuum pump (3) at different input square wave frequencies, and establishing a functional relationship between the frequency ν of the input square wave and the suction flow Q ν = f(Q); Step 2, approximate the bell-shaped flow diagram of standard suction to a function Q=g(t) with respect to time t, and process Q=g(t) to transform it into a step-shaped flow simulation curve, recorded as Q′=h(t); When Q = g(t) is converted to Q′ = h(t), the time of each segment is 10ms; Step 3, using the flow simulation curve Q′=h(t) and the calibration result ν=f(Q), the function of the square wave frequency ν and time t ν=f(Q′)=f(h(t))=q(t); Step 4, using the microcontroller (4) to send a square wave signal to the adjustable speed vacuum pump (3) according to ν=q(t), using the airflow sensor (2) and the microcontroller (4) to collect and upload flow data, and the host computer (5) determines the actual suction flow curve and compares it with Q=g(t); When the actual suction flow curve differs too much from Q = g(t), Q′ = h(t) is corrected and step 4 is repeated until the requirements are met; Step 5, placing the above-mentioned device for detecting the filter temperature field during cigarette smoking in a specified test atmosphere, placing the cigarette samples to be tested in the test atmosphere for 48 hours to balance, and selecting them according to the specified selection conditions; Step 6, placing the selected cigarette sample in the cigarette holder (1), the side temperature sensor and the end temperature sensor inside the cigarette holder (1) contact the outer edge and the end surface of the cigarette butt respectively, and the temperature probe penetrates the filter tip; Step 7, the cigarette is lit, and the microcontroller (4) continuously collects and uploads real-time temperature and flow data to the host computer (5); A set of temperature data and flow data from multiple temperature sensors inside the cigarette holder (1) are collected synchronously, with the collection and upload cycle being once every 10 ms; Step 8, sending a command to the microcontroller (4) through the host computer (5), so that the microcontroller (4) sends a square wave signal to the adjustable speed vacuum pump (3) according to ν=q(t) to simulate standard suction; Step 9, the host computer (5) determines the actual suction flow curve and the three-dimensional non-steady-state temperature field of the filter tip through the data uploaded by the microcontroller (4).

2. The detection method of the device for detecting the filter tip temperature field during cigarette smoking according to claim 1, characterized in that: The microcontroller is composed of an STM32F407 chip and a multi-channel temperature acquisition circuit, and has an analog-to-digital conversion function to collect temperature data from a temperature sensor inside the cigarette holder, collecting a set of data every 10 ms, and a set of data can contain 24 temperature data; Having a communication function to obtain flow data of the air flow sensor; It has the function of generating square waves of different frequencies to control the adjustable speed vacuum pump.

3. The detection method of the device for detecting the filter tip temperature field during cigarette smoking according to claim 1, characterized in that: A hole is punched at the front end of the cigarette holder according to the temperature measurement position, and the temperature measurement probe is inserted into the hole so that the front end of the temperature measurement probe is located at the center of the cigarette holder; The gap between the temperature measuring probe and the punched hole is sealed with sealant to detect the temperature of the inner center of the front end of the cigarette filter.

4. The detection method of the device for detecting the filter tip temperature field during cigarette smoking according to claim 1, characterized in that: A hole is punched at the lead outlet of the side temperature sensor on the cigarette holder, and the side temperature sensor is evenly attached to the circumferential inner wall of the cigarette holder; the lead of the side temperature sensor is led out from the punched hole, and the gap between the lead of the side temperature sensor and the punched hole is sealed with sealant.

5. The detection method of the device for detecting the filter tip temperature field during cigarette smoking according to claim 1, characterized in that: A hole is punched at the lead outlet of the end face temperature sensor on the cigarette holder, and the end face temperature sensor is fixed in the end face notch of the cigarette holder; the lead of the end face temperature sensor is led out from the punched hole, and the gap between the lead of the end face temperature sensor and the punched hole is sealed with sealant.

6. The detection method of the device for detecting the filter tip temperature field during cigarette smoking according to claim 1, characterized in that: The cigarette holder is composed of two upper and lower holding pieces.

7. The detection method of the device for detecting the filter tip temperature field during cigarette smoking according to claim 1, characterized in that: The side temperature measuring sensor includes a plurality of temperature measuring sensors which are arranged in a straight line at equal intervals.

8. The detection method of the device for detecting the filter tip temperature field during cigarette smoking according to claim 1, characterized in that: The end surface temperature measuring sensor includes a plurality of temperature measuring sensors evenly arranged within the filter tip cross-section circle.

9. The detection method of the device for detecting the filter tip temperature field during cigarette smoking according to claim 1, characterized in that: The response time of the air flow sensor is 10 ms.

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