Method and system for screening whether heating tube is good or not

Abstract

The invention discloses a method and system for screening whether heating tubes are good or not, and relates to the technical field of test calibration. The method comprises the steps that the initial resistance value and the initial temperature of a to-be-tested heating group in a heating tube are obtained, the heating tube comprises edge heating sections arranged at the two ends of the heating tube and at least one middle heating section located between the edge heating sections at the two ends, and the to-be-tested heating group comprises a middle heating section and an edge heating section; for each to-be-tested heating group, acquiring a heating resistance value of the to-be-tested heating group after heating and a target temperature corresponding to the heating resistance value; determining a resistance temperature coefficient of the to-be-tested heating group according to the initial resistance value, the initial temperature, the target temperature and the heating resistance value of the to-be-tested heating group; and when the resistance temperature coefficient of each heating group to be detected is within a set threshold range, judging that the heating tube is a good product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of test calibration, and in particular to a method and system for screening whether a heating pipe is a good product. BACKGROUND

[0002] As a key component in a heat-not-burn device, the heating performance and consistency of a heating pipe directly determine the smoking experience and use safety of the heat-not-burn device. Common heating pipes are generally divided into two-segment heating pipes and three-segment heating pipes. In a three-segment heating pipe, the heating segments are generally divided into an upper segment, a middle segment and a lower segment, and are tested and used in a parallel manner. In order to ensure the performance consistency of the heating pipe, the heating pipe is generally subjected to temperature coefficient of resistance (TCR) measurement in the existing process.

[0003] In the measurement of the temperature coefficient of resistance, the existing full inspection equipment can only detect two heating segments. When a three-segment heating pipe is encountered, it needs to be detected twice. This method results in low detection efficiency, which cannot meet the needs of high-speed detection on the production line. Multiple tests are easily affected by environmental changes, introducing errors and reducing the accuracy of the detection results. The detection process is complex, and the design and operation costs of the equipment are high. For a three-segment heating pipe, it cannot reflect the overall working characteristics at one time, and the screening accuracy is insufficient.

[0004] Therefore, the existing technology still has problems such as low efficiency, insufficient accuracy and limited discrimination when facing the detection of a three-segment heating pipe. SUMMARY

[0005] The technical problem solved by the present application is to provide a simple and accurate method and system for judging whether a three-segment heating pipe is a good product.

[0006] According to a first aspect, a method for screening whether a heating pipe is a good product is provided in an embodiment, comprising:

[0007] obtaining an initial resistance value and an initial temperature of a to-be-tested heating group in the heating pipe, wherein the heating pipe comprises edge heating segments arranged at both ends of the heating pipe and at least one middle heating segment between the edge heating segments at both ends, and the to-be-tested heating group comprises a middle heating segment and one edge heating segment;

[0008] For each to-be-tested heating group: obtaining a heated resistance value after heating and a target temperature corresponding to the heated resistance value; determining a temperature coefficient of resistance of the to-be-tested heating group according to the initial resistance value, the initial temperature, the target temperature and the heated resistance value of the to-be-tested heating group;

[0009] When the temperature coefficients of resistance of the to-be-tested heating groups are within a set threshold range, it is determined that the heating pipe is a good product.

[0010] In one embodiment, the heat pipe comprises a first edge heating section and a second edge heating section arranged at two ends of the heat pipe, and a middle heating section between the first edge heating section and the second edge heating section.

[0011] The to-be-tested heating group comprises a first to-be-tested heating group and a second to-be-tested heating group in parallel, the first to-be-tested heating group comprises a first edge heating section and a middle heating section in series, and the second to-be-tested heating group comprises a middle heating section and a second edge heating section in series.

[0012] In one embodiment, the method further comprises:

[0013] obtaining a temperature coefficient of resistance of the first to-be-tested heating group and a temperature coefficient of resistance of the second to-be-tested heating group;

[0014] calculating a difference between the temperature coefficient of resistance of the first to-be-tested heating group and the temperature coefficient of resistance of the second to-be-tested heating group as a temperature coefficient of resistance difference;

[0015] when the temperature coefficient of resistance of the first to-be-tested heating group and the temperature coefficient of resistance of the second to-be-tested heating group are within a set threshold range, and the temperature coefficient of resistance difference is within a set difference range, determining that the heat pipe is a good product.

[0016] In one embodiment, the method further comprises:

[0017] obtaining a pre-measurement resistance value of the first edge heating section, a pre-measurement resistance value of the second edge heating section, and a pre-measurement resistance value of the middle heating section;

[0018] when the pre-measurement resistance value of the first edge heating section, the pre-measurement resistance value of the second edge heating section, and the pre-measurement resistance value of the middle heating section are within a set resistance value range, the temperature coefficient of resistance of the first to-be-tested heating group and the temperature coefficient of resistance of the second to-be-tested heating group are within a set threshold range, and the temperature coefficient of resistance difference is within a set difference range, determining that the heat pipe is a good product.

[0019] In one embodiment, after heating the first to-be-tested heating group at a set power for a first set time length, a heating resistance value after heating of the first to-be-tested heating group and a target temperature corresponding to the heating resistance value of the first to-be-tested heating group are obtained; after heating the second to-be-tested heating group at the set power for a second set time length, a heating resistance value after heating of the second to-be-tested heating group and a target temperature corresponding to the heating resistance value of the second to-be-tested heating group are obtained.

[0020] In one embodiment, before obtaining the heating resistance value after heating of the second to-be-tested heating group and the target temperature corresponding to the heating resistance value of the second to-be-tested heating group, the heat pipe is cooled for a third set time length.

[0021] According to a second aspect, a system for screening a heating pipe is provided in an embodiment, and has the following characteristics.

[0022] A selection driving module is connected to the heating pipe, the heating pipe includes edge heating sections arranged at both ends of the heating pipe and at least one middle heating section between the edge heating sections at both ends, and the selection driving module turns on the edge heating sections and the middle heating section according to the heating sections in a to-be-tested heating group, wherein the to-be-tested heating group includes a middle heating section and an edge heating section.

[0023] A collection module is configured to acquire an initial resistance value and an initial temperature of the to-be-tested heating group in the heating pipe, and acquire a heating resistance value of the to-be-tested heating group after heating and a target temperature corresponding to the heating resistance value.

[0024] A control module is configured to determine a resistance temperature coefficient of the to-be-tested heating group according to the initial resistance value, the initial temperature, the target temperature and the heating resistance value of the to-be-tested heating group, and determine that the heating pipe is a good product when the resistance temperature coefficients of the to-be-tested heating groups are within a set threshold range.

[0025] In an embodiment, the heating pipe includes a first edge heating section and a second edge heating section arranged at both ends of the heating pipe, and a middle heating section between the first edge heating section and the second edge heating section.

[0026] The to-be-tested heating group includes a first to-be-tested heating group and a second to-be-tested heating group in parallel, the first to-be-tested heating group includes the first edge heating section and the middle heating section in series, and the second to-be-tested heating group includes the middle heating section and the second edge heating section in series.

[0027] In an embodiment, the selection driving module includes a first switch unit, a second switch unit, a third switch unit and a fourth switch unit, the first switch unit is connected to a first end of the first edge heating section, the second switch unit is connected to a second end of the first edge heating section and a first end of the middle heating section, the third switch unit is connected to a second end of the middle heating section and a first end of the second edge heating section, and the fourth switch unit is connected to a second end of the second edge heating section.

[0028] When the initial resistance value of the first to-be-tested heating group and the heating resistance value of the first to-be-tested heating group are acquired, the first switch unit and the third switch unit are turned on.

[0029] When the initial resistance value of the second to-be-tested heating group and the heating resistance value of the second to-be-tested heating group are acquired, the second switch unit and the fourth switch unit are turned on.

[0030] According to a third aspect, a computer readable storage medium is provided in an embodiment, on which a computer program is stored, which computer program is executable by a processor to implement the method described in any of the above embodiments.

[0031] According to the method and system for screening whether the heating pipe is a good product, in the method, the initial resistance value and the initial temperature of the heating group to be tested in the heating pipe are obtained, wherein the heating group to be tested includes an intermediate heating section and an edge heating section. The heating resistance value and the corresponding target temperature of each heating group to be tested after heating are obtained. The resistance temperature coefficient of each heating group to be tested is calculated according to the initial resistance value, the initial temperature, the heating resistance value and the target temperature of each heating group to be tested. If the resistance temperature coefficients of the heating groups to be tested are all within the set threshold range, the heating pipe is a good product. The application can evaluate the conduction and heating characteristics of the intermediate heating section under different thermal coupling conditions by testing the combination of the intermediate heating section and the edge heating section respectively, avoiding the problem of insufficient information when testing a certain heating section alone, thereby improving the comprehensiveness of detection. Since the intermediate heating section is introduced during testing, the performance difference of this section in different combinations can be amplified. In this way, not only can the abnormality of the edge heating section be identified, but also the problem of whether the intermediate heating section has concentrated or uneven heating can be more sensitively reflected, improving the ability to distinguish between good and bad products. Through the heating group to be tested, the evaluation of local heating performance and overall uniformity can be completed at the same time in one heating process, and compared with independent testing of each section, the detection efficiency is higher, which can reduce the time required for calibration and screening. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 Structure diagram of a system for screening whether a heating pipe is a good product in an embodiment Figure One ;

[0033] Figure 2 Structure diagram of a heating pipe in an embodiment

[0034] Figure 3 Structure diagram of a system for screening whether a heating pipe is a good product in an embodiment Figure Two ;

[0035] Figure 4 Circuit diagram of a selection driving module in an embodiment

[0036] Figure 5 Method flow of a method for screening whether a heating pipe is a good product in an embodiment Figure One ;

[0037] Figure 6 Method flow of a method for screening whether a heating pipe is a good product in an embodiment Figure Two ;

[0038] Figure 7 Method flow of the method for screening whether the heating tube is a good product in an embodiment Figure Three . DETAILED DESCRIPTION

[0039] The application will be described in further detail below with specific reference to the drawings. Like elements in different embodiments are denoted by like reference numerals. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the application. However, it will be apparent to one skilled in the art that some features, which are not necessarily the most important to an adequate design, can be omitted or substituted for the sake of clarity or understanding. In some instances, detailed descriptions of structures and / or methods can be omitted or simplified for the sake of clarity.

[0040] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. Meanwhile, the steps or actions in the method description can also be sequentially adjusted or changed in a manner that is apparent to those skilled in the art. Therefore, the order in the specification and the drawings is only for the purpose of clearly describing a certain embodiment, and does not mean that the order is necessary, unless otherwise stated that a certain order must be followed.

[0041] The serial numbers of components in this paper, such as "first", "second", etc., are only used to distinguish the described objects, and do not have any order or technical meaning. The "connection" and "coupling" in this application include direct and indirect connection (coupling) unless otherwise specified.

[0042] Please refer to Figure 1 In an embodiment, the application provides a system 100 for screening whether the heating tube is a good product, which comprises a selection driving module 110, a collection module 120 and a control module 130.

[0043] In an embodiment, the selection driving module 110 is connected to the heating tube, and is used for circuit selection and on-off control of different heating sections in the heating group to be tested in the heating tube. The heating tube comprises edge heating sections arranged at both ends of the heating tube, and at least one intermediate heating section between the edge heating sections at both ends. In the detection process, the heating group to be tested is not tested independently for each heating section, but a heating group to be tested composed of an intermediate heating section and any one edge heating section is constructed, thereby forming different test combinations.

[0044] It should be noted that the edge heating sections are mainly distributed at both ends of the heating element and are usually susceptible to heat dissipation and boundary effects during operation. The middle heating section is located in the middle of the heating element, in the core thermal coupling region, and its performance has a significant impact on heating consistency.

[0045] In one embodiment, the acquisition module 120 is used to acquire the electrical and thermal parameters of the heating element under test in real time, mainly including: before heating, acquiring the resistance value of the heating element under test as the initial resistance value; using a temperature sensor or the correspondence between resistance and temperature to obtain the initial temperature of the heating element under test; after applying a certain power or current to heat the heating element under test, acquiring the change in its resistance value, and the final resistance value is the heating resistance value; similarly, using a temperature sensor or the correspondence between resistance and temperature, obtaining the target temperature corresponding to the heating resistance value.

[0046] In one embodiment, the control module 130 determines the resistance temperature coefficient of each heating element under test based on its initial resistance, initial temperature, target temperature, and heating resistance.

[0047] The temperature coefficient of resistance can be calculated using the following formula:

[0048]

[0049] Where TCR represents the temperature coefficient of resistance; R t R represents the heating resistance of the heating element under test; R0 represents the initial resistance of the heating element under test; T t T0 represents the target temperature of the heating group to be tested; T0 represents the initial temperature of the heating group to be tested.

[0050] It should be noted that since the intermediate heating section participates in the testing of the heating elements under test, the control module 130 can use the two sets of data for cross-validation and error compensation, thereby improving the accuracy and stability of the resistance temperature coefficient measurement. Furthermore, by utilizing the overlapping effect of the intermediate heating section in the testing of each heating element under test, errors caused by heat dissipation interference and environmental fluctuations can be reduced. The resistance temperature coefficient of each heating element under test is compared with a set threshold range. When the resistance temperature coefficient of each heating element under test is within the set threshold range, the heating element is determined to be a good product; if any exceeds the threshold, it is determined to be a defective product.

[0051] Please refer to Figure 2 In one embodiment, the heating element of this application is more specifically aimed at a three-segment heating element. Specifically, the heating element includes a first edge heating segment disposed at one end of the heating element (i.e., Figure 2 The upper section of the heating element is located at the upper edge of the heating element, which is the second edge heating section at the other end of the heating element. Figure 2the middle section in the middle section of the three-section heating tube), and the middle heating section (i.e. Figure 2

[0052] In an embodiment, the first heating group to be tested is composed of the first edge heating section and the middle heating section in series, for reflecting the overall heating and conduction characteristics of the first edge heating section and the middle heating section in the working state. The second heating group to be tested is composed of the middle heating section and the second edge heating section in series, for reflecting the overall heating and conduction characteristics of the second edge heating section and the middle heating section in the working state. The first heating group to be tested and the second heating group to be tested are connected in parallel to each other, forming a detection network. In the detection process, the first heating group to be tested or the second heating group to be tested can be independently turned on by selecting the driving module 110, so as to realize the measurement of the heating characteristics of different combinations.

[0053] It should be noted that, since the middle heating section participates in the detection of the first heating group to be tested and the second heating group to be tested at the same time, it is equivalent to a common detection section. In this way, cross verification of the middle heating section can be realized, the accuracy and robustness of the measurement are improved, and the interference of the middle heating section to the adjacent heating sections when dissipating heat is weakened, so that the real performance of the edge heating section is more easily detected. By decomposing the three-section heating tube into two series combinations, the number of tests required for measuring the three sections individually can be reduced. Only two detections are needed to indirectly obtain the performance judgment of the three heating sections, thereby greatly improving the detection efficiency.

[0054] Please refer to Figure 3 In an embodiment, when measuring the three-section heating tube, the selection driving module 110 includes a first switching unit 111, a second switching unit 112, a third switching unit 113, and a fourth switching unit 114. The first switching unit 111 is connected to the first end of the first edge heating section, the second switching unit 112 is connected to the second end of the first edge heating section and the first end of the middle heating section, the third switching unit 113 is connected to the second end of the middle heating section and the first end of the second edge heating section, and the fourth switching unit 114 is connected to the second end of the second edge heating section.

[0055] Please refer to Figure 4 In an embodiment, the first switching unit 111 includes a switch tube Q2, the second switching unit 112 includes a switch tube Q4, the third switching unit 113 includes a switch tube Q6, and the fourth switching unit 114 includes a switch tube Q8. The source of the switch tube Q2 is connected to the working power supply (i.e. Figure 4 the B+ in the working power supply), the gate of the switch tube Q2 obtains a PWM1 signal, and the drain of the switch tube Q2 is connected to the first end of the first edge heating section (i.e.​Figure 4 A point in FIG. 1C). The source of the switch tube Q4 is connected to the reference ground, the gate of the switch tube Q4 obtains the PWM2 signal, and the drain of the switch tube Q4 is connected to the second end of the first edge heating section and the first end of the middle heating section (i.e. B point in FIG. 1C). Figure 4 A point in FIG. 1C). The source of the switch tube Q4 is connected to the reference ground, the gate of the switch tube Q4 obtains the PWM2 signal, and the drain of the switch tube Q4 is connected to the second end of the first edge heating section and the first end of the middle heating section (i.e. B point in FIG. 1C). Figure 4 C point in FIG. 1C). The source of the switch tube Q8 is connected to the working power supply (i.e. B+ in FIG. 1C), the gate of the switch tube Q8 obtains the PWM1 signal, and the drain of the switch tube Q8 is connected to the second end of the second edge heating section (i.e. D point in FIG. 1C). Figure 4 C point in FIG. 1C). The source of the switch tube Q8 is connected to the working power supply (i.e. B+ in FIG. 1C), the gate of the switch tube Q8 obtains the PWM1 signal, and the drain of the switch tube Q8 is connected to the second end of the second edge heating section (i.e. D point in FIG. 1C). Figure 4 C point in FIG. 1C). The source of the switch tube Q8 is connected to the working power supply (i.e. B+ in FIG. 1C), the gate of the switch tube Q8 obtains the PWM1 signal, and the drain of the switch tube Q8 is connected to the second end of the second edge heating section (i.e. D point in FIG. 1C).

[0056] In an embodiment, the selection driving module 110 further comprises a first driving unit 115 and a second driving unit 116. The input of the first driving unit 115 obtains the CHK1 signal, and the output of the first driving unit 115 is connected to the drain of the switch tube Q2 through the resistor R16. The input of the second driving unit 116 obtains the CHK2 signal, and the output of the second driving unit 116 is connected to the drain of the switch tube Q8 through the resistor R25. The control module 130 controls the PWM1, PWM2, PWM3, PWM4, CHK1 and CHK2 to select to turn on a certain heating section. That is, when the initial resistance value of the first to-be-tested heating group and the heating resistance value of the first to-be-tested heating group are obtained, the first switch unit 111 and the third switch unit 113 are turned on; when the heating resistance value of the second to-be-tested heating group is obtained, the second switch unit 112 and the fourth switch unit 114 are turned on.

[0057] It should be noted that the switch tube Q2 and the switch tube Q8 are P-channel MOSFETs, and the switch tube Q4 and the switch tube Q6 are N-channel MOSFETs.

[0058] Since the P-channel MOSFET is a high-side switch, when the switch tube Q2 and the switch tube Q8 are turned on, the gate voltage needs to be lower than the source voltage. However, since the levels of the PWM1 and PWM4 signals are only 3.3V or 5V, the gate cannot be directly pulled to a lower potential than the working power supply. Therefore, an additional driving circuit is needed. Therefore, the drains of the switch tube Q2 and the switch tube Q8 are additionally connected to the driving circuit to respectively obtain the detection signals (i.e. CHK1 and CHK4 in FIG. 1C) to drive the switch tube Q2 and the switch tube Q8 according to the detection signals. Figure 3

[0059] ​Since the N-channel MOSFET is a low-side switch, when the switch tube Q4 and the switch tube Q6 are turned on, the gate voltage needs to be greater than the source voltage. The levels of the PWM2 and PWM3 signals connected to the switch tube Q4 and the switch tube Q6 can satisfy the condition that the gate voltage is greater than the source voltage. Therefore, the switch tube Q4 and the switch tube Q6 as N-channel MOSFETs can be directly controlled by PWM, without the need for an additional driving circuit.

[0060] In addition, the sampling resistor R14 is connected between the source and the gate of the switch tube Q2, the sampling resistor R20 is connected between the source and the gate of the switch tube Q4, the sampling resistor R24 is connected between the source and the gate of the switch tube Q6, and the sampling resistor R30 is connected between the source and the gate of the switch tube Q8. Each sampling resistor is 5.1Ω. When current flows through, the voltage can be detected by the analog-to-digital converter, so as to calculate the heating resistance value.

[0061] That is, the collection of the heating resistance value can be detected by the analog-to-digital converter. The basic working principle is that the to-be-measured heating group and the reference resistor with a known resistance value form a voltage dividing circuit, the voltage dividing point voltage is input to the analog-to-digital converter, and the analog-to-digital converter converts the voltage value into a digital quantity for collection. The heating resistance value R of the to-be-measured heating group is calculated by the following formula t .

[0062]

[0063] wherein ADC represents the sampling value of the analog-to-digital converter, and the value range is 0-4095. Since the full-scale range of the 12-bit analog-to-digital converter is 2 12 =4096; R 参 represents the reference resistance, that is, the sampling resistance; and R t represents the heating resistance value of the to-be-measured heating group.

[0064] From the formula, it can be concluded that

[0065]

[0066] That is, when the analog-to-digital converter samples a certain voltage value, the corresponding heating resistance value can be converted by the formula.

[0067] In one embodiment, in the three-section heating tube, when the resistance temperature coefficient of the to-be-measured heating group is determined according to the initial resistance value, the initial temperature, the target temperature and the heating resistance value of the to-be-measured heating group, in the starting stage of the test, the driving module 110 is selected to turn on the first to-be-measured heating group (A point and C point in the Figure 4 second to-be-measured heating group (B point and D point in the Figure 4 ), the initial resistance value of the to-be-measured heating group is read by the collection module 120, and the initial temperature at that time is recorded.

[0068] It should be noted that in order to ensure that the initial resistance value is stable and measurable, the first and second to-be-tested heating sections are heated at a voltage of 8.4V for 1 second. Under the action of short-time low power, the resistance change is not significant, but it is sufficient to eliminate part of the contact resistance and transient error, so as to obtain a more accurate initial resistance value.

[0069] In an embodiment, the control module 130 drives the first to-be-tested heating group to heat at a set power (for example, 40W, and when 40W cannot be actually reached, the maximum power corresponding to a full duty cycle is used) for a first set time length (for example, 1 second). After the heating ends, the acquisition module 120 acquires the heating resistance value of the first to-be-tested heating group, and synchronously measures or converts to obtain the target temperature thereof. According to the formula, the control module 130 can calculate the resistance temperature coefficient of the first to-be-tested heating group.

[0070] In an embodiment, in order to avoid the residual heat of the last heating from affecting the next test result, after the test of the first to-be-tested heating group is completed, the cooling device (for example, a fan) is used to dissipate heat from the heating pipe, so that the temperature of the heating pipe returns to a level close to the initial level within a third set time length (for example, 40 seconds). After the cooling ends, the test of the second to-be-tested heating group is performed. The control module 130 drives the second to-be-tested heating group to heat at the same set power for a second set time length (for example, 1 second), and after the heating ends, the heating resistance value and the corresponding target temperature of the second to-be-tested heating group are acquired. Similarly, according to the formula, the resistance temperature coefficient of the second to-be-tested heating group is calculated.

[0071] In an embodiment, when the heating pipe is tested, the present application not only calculates the resistance temperature coefficient of a single to-be-tested heating group, but also further introduces a difference judgment mechanism and a single-section resistance value detection mechanism to realize more accurate good product screening.

[0072] In an embodiment, the control module 130 respectively acquires the resistance temperature coefficient of the first to-be-tested heating group and the resistance temperature coefficient of the second to-be-tested heating group, and calculates the difference between the two, so as to obtain the resistance temperature coefficient difference. When the resistance temperature coefficient of the first to-be-tested heating group and the resistance temperature coefficient of the second to-be-tested heating group are both within a set threshold range, and the resistance temperature coefficient difference is also within a set difference range, it indicates that the thermal-electric performance consistency of the two to-be-tested heating groups is good.

[0073] In one embodiment, in addition to detecting the combined to-be-tested heating group, the pre-measurement resistance of the first edge heating section, the pre-measurement resistance of the second edge heating section, and the pre-measurement resistance of the middle heating section are further obtained. The pre-measurement resistances of the first edge heating section, the second edge heating section, and the middle heating section are compared with the set resistance range. If all of them are within the range, it indicates that the basic conductive characteristics of each heating section in the unheated state meet the requirements. Only when the above conditions are met at the same time, the heating tube is determined to be a good product. If any condition is not met, it is determined to be a defective product.

[0074] In summary, in the working process of the heating tube, if there is a defect of local heating concentration, in the initial heating stage, the area will heat up faster than the normal area. Because the temperature is approximately proportional to the resistance, this uneven heating will be directly reflected in the resistance change, so that the heating concentration area shows a higher resistance value under the same test conditions, thereby causing the resistance temperature coefficient to be significantly larger. In order to amplify the difference between the heating concentration area and the normal area, a reference resistance temperature coefficient is obtained for each heating section through statistical analysis, and a fluctuation range (generally ±200) is set, which determines the set threshold range. When the resistance temperature coefficient of a to-be-tested heating group exceeds the set threshold range, it is determined that the heating tube is a defective product, indicating that there is a problem of uneven heating or heating concentration. Secondly, by calculating the difference between the first to-be-tested heating group and the second to-be-tested heating group, if the resistance temperature coefficient difference exceeds the set difference range (generally 150, which is determined based on a large amount of experimental data collection and analysis), it is also determined to be a defective product. This double determination mechanism not only considers the absolute deviation of the single resistance temperature coefficient, but also takes into account the relative difference between the upper and lower sections, so as to effectively identify the uneven heating phenomenon and improve the accuracy and reliability of the heating body screening. Moreover, the single resistance value is also considered, by detecting the initial resistance of the single heating section, the heating section with open circuit, short circuit or local damage can be found in advance, to avoid subsequent misjudgment.

[0075] Please refer to Figure 5 In one embodiment, the application further provides a method for screening whether a heating tube is a good product, comprising the following steps.

[0076] Step S10: obtaining the initial resistance and initial temperature of the to-be-tested heating group in the heating tube.

[0077] In one embodiment, the resistance value of the to-be-tested heating group before heating is collected as an initial resistance value. The initial temperature of the to-be-tested heating group is obtained by using a temperature sensor or a corresponding relationship between resistance and temperature. The heating tube includes edge heating sections arranged at both ends of the heating tube and at least one intermediate heating section between the edge heating sections. In the detection process, the to-be-tested heating group is not tested independently for each heating section, but a to-be-tested heating group composed of the intermediate heating section and any one of the edge heating sections is constructed, thereby forming different test combinations.

[0078] Step S20: obtaining a heating resistance value of the to-be-tested heating group after heating and a target temperature corresponding to the heating resistance value.

[0079] In one embodiment, after the to-be-tested heating group is heated by applying a certain power or current, the change of the resistance value is collected, and the final resistance value is the heating resistance value. The target temperature corresponding to the heating resistance value is obtained by using a temperature sensor or a corresponding relationship between resistance and temperature.

[0080] In one embodiment, for each to-be-tested heating group, the resistance temperature coefficient of the to-be-tested heating group is determined according to the initial resistance value, the initial temperature, the target temperature and the heating resistance value of each to-be-tested heating group.

[0081] The resistance temperature coefficient can be calculated by using the following formula:

[0082]

[0083] Wherein, TCR represents the resistance temperature coefficient; R t represents the heating resistance value of the to-be-tested heating group; R0 represents the initial resistance value of the to-be-tested heating group; T t represents the target temperature of the to-be-tested heating group; T0 represents the initial temperature of the to-be-tested heating group.

[0084] Step S30: when the resistance temperature coefficients of the to-be-tested heating groups are within a set threshold range, the heating tube is determined to be a good product.

[0085] In one embodiment, since the intermediate heating section participates in the test of the to-be-tested heating group, cross-validation and error compensation can be performed by using two groups of data, thereby improving the accuracy and stability of the resistance temperature coefficient measurement. Moreover, by using the overlapping effect of the intermediate heating section in the test of each to-be-tested heating group, the error caused by heat dissipation interference and environmental fluctuations can be reduced. The resistance temperature coefficients of the to-be-tested heating groups are compared with the set threshold range, and when the resistance temperature coefficients of the to-be-tested heating groups are all within the set threshold range, the heating tube is determined to be a good product; if there is a case of exceeding the threshold, it is determined to be a bad product.

[0086] In one embodiment, the heating element of this application focuses more on a three-segment heating element. Specifically, the heating element includes a first edge heating segment disposed at one end of the heating element, a second edge heating segment disposed at the other end of the heating element, and an intermediate heating segment located between the first edge heating segment and the second edge heating segment. The three heating segments are arranged sequentially to form an overall heating path. In order to achieve efficient detection of the heating element, this embodiment combines the three heating segments to form two heating groups to be tested.

[0087] In one embodiment, the first heating element to be tested consists of a first edge heating segment and a middle heating segment connected in series, used to reflect the overall heating and conductivity characteristics of the first edge heating segment and the middle heating segment in the working state. The second heating element to be tested consists of a middle heating segment and a second edge heating segment connected in series, used to reflect the overall heating and conductivity characteristics of the second edge heating segment and the middle heating segment in the working state. The first and second heating elements to be tested are connected in parallel to form a detection network. During the detection process, the first or second heating element to be tested can be independently turned on by selecting the drive module 110, thereby realizing the measurement of the heating characteristics of different combinations.

[0088] It should be noted that, in order to ensure that the initial resistance is stable and measurable, the first and second heating segments under test are heated with a voltage of 8.4V for 1 second. Under the action of short-term low power, the resistance change is not significant, but it is enough to eliminate some contact resistance and transient error, thereby obtaining a more accurate initial resistance value.

[0089] In one embodiment, the first heating element under test is driven to heat at a set power (e.g., 40W; if 40W cannot be achieved in practice, the maximum power corresponding to the full duty cycle is used) for a first set duration (e.g., 1 second). After heating is completed, the heating resistance value of the first heating element under test is obtained, and its target temperature is simultaneously measured or calculated. The temperature coefficient of resistance of the first heating element under test can be calculated according to the formula for calculating the temperature coefficient of resistance.

[0090] In one embodiment, to avoid residual heat from the previous heating affecting the next test result, after completing the test of the first heating element, a cooling device (e.g., a fan) is used to dissipate heat from the heating element, allowing its temperature to recover to near its initial level within a third set time period (e.g., 40 seconds). After cooling, the second heating element is then tested. The second heating element is driven to heat for a second set time period (e.g., 1 second) with the same set power. After heating, the heating resistance value and corresponding target temperature of the second heating element are obtained, and the temperature coefficient of resistance of the second heating element is calculated according to the formula for calculating the temperature coefficient of resistance.

[0091] Please refer to Figure 6In one embodiment, the method for screening whether the heat-generating tube is a good product further comprises step S40: when the resistance temperature coefficient of the first heat-generating group to be tested and the resistance temperature coefficient of the second heat-generating group to be tested are within the set threshold range, and the difference between the resistance temperature coefficients is within the set difference range, it is determined that the heat-generating tube is a good product (since step S40 adds a judgment condition to step S30, when step S40 is used to determine whether it is a good product, step S30 does not need to be executed again).

[0092] In one embodiment, the resistance temperature coefficient of the first heat-generating group to be tested and the resistance temperature coefficient of the second heat-generating group to be tested are obtained respectively, and the difference between the two is calculated to obtain the difference between the resistance temperature coefficients. When the resistance temperature coefficient of the first heat-generating group to be tested and the resistance temperature coefficient of the second heat-generating group to be tested are both within the set threshold range, and the difference between the resistance temperature coefficients is also within the set difference range, it indicates that the thermoelectric properties of the two heat-generating groups to be tested are good.

[0093] Please refer to Figure 7 In one embodiment, the method for screening whether the heat-generating tube is a good product further comprises step S50: when the pre-measurement resistance of the first edge heat-generating section, the pre-measurement resistance of the second edge heat-generating section, and the pre-measurement resistance of the middle heat-generating section are within the set resistance range, and the resistance temperature coefficient of the first heat-generating group to be tested and the resistance temperature coefficient of the second heat-generating group to be tested are within the set threshold range, and the difference between the resistance temperature coefficients is within the set difference range, it is determined that the heat-generating tube is a good product (since step S50 adds a judgment condition to step S40, when step S50 is used to determine whether it is a good product, step S40 does not need to be executed again).

[0094] In one embodiment, in addition to detecting the combined heat-generating group to be tested, the pre-measurement resistance of the first edge heat-generating section, the pre-measurement resistance of the second edge heat-generating section, and the pre-measurement resistance of the middle heat-generating section are further obtained. The pre-measurement resistance of the first edge heat-generating section, the pre-measurement resistance of the second edge heat-generating section, and the pre-measurement resistance of the middle heat-generating section are compared with the set resistance range, and if all three are within the range, it indicates that the basic conductive characteristics of each heat-generating section under the unheated state meet the requirements. Only when all the above conditions are met, it is determined that the heat-generating tube is a good product, and if any condition is not met, it is determined to be a bad product.

[0095] Those skilled in the art can understand that all or part of the functions of various methods in the above embodiments can be realized by hardware or by a computer program. When all or part of the functions in the above embodiments are realized by a computer program, the program can be stored in a computer readable storage medium, which can include a read-only memory, a random access memory, a magnetic disk, an optical disk, a hard disk, and the like. The above functions are realized by executing the program by a computer. For example, the program is stored in a memory of a device, and the above functions are realized by executing the program in the memory by a processor. In addition, when all or part of the functions in the above embodiments are realized by a computer program, the program can also be stored in a storage medium such as a server, another computer, a disk, an optical disk, a flash disk, or a mobile hard disk, and is saved in a memory of a local device by downloading or copying, or the system of the local device is updated, and the above functions are realized by executing the program in the memory by a processor.

[0096] The above application of specific examples to the present application is described, which is only used to help understand the present application and does not limit the present application. According to the idea of the present application, those skilled in the art can make several simple deductions, deformations, or substitutions.

Claims

1. A method for screening whether heating elements are of good quality, characterized in that, include: The initial resistance and initial temperature of the heating element to be tested in the heating tube are obtained, wherein the heating tube includes edge heating segments disposed at both ends of the heating tube and at least one intermediate heating segment located between the edge heating segments at both ends, and the heating element to be tested includes an intermediate heating segment and an edge heating segment; For each heating element to be tested: obtain the heating resistance value of the heating element after heating and the target temperature corresponding to the heating resistance value; determine the temperature coefficient of resistance of the heating element to be tested based on the initial resistance value, initial temperature, target temperature and heating resistance value; When the temperature coefficient of resistance of each heating element under test is within the set threshold range, the heating element is determined to be of good quality.

2. The method for screening whether a heating element is of good quality as described in claim 1, characterized in that, The heating element includes a first edge heating segment and a second edge heating segment disposed at both ends of the heating element, and an intermediate heating segment located between the first edge heating segment and the second edge heating segment; The heat-generating group to be tested includes a first heat-generating group to be tested and a second heat-generating group to be tested connected in parallel. The first heat-generating group to be tested includes a first edge heat-generating segment and a middle heat-generating segment connected in series. The second heat-generating group to be tested includes a middle heat-generating segment and a second edge heat-generating segment connected in series.

3. The method for screening whether a heating element is of good quality as described in claim 2, characterized in that, The method further includes: Obtain the temperature coefficient of resistance of the first heating element under test and the temperature coefficient of resistance of the second heating element under test; The difference between the temperature coefficient of resistance of the first heating group under test and the temperature coefficient of resistance of the second heating group under test is calculated as the temperature coefficient difference. If the temperature coefficient of resistance of the first heating element under test and the temperature coefficient of resistance of the second heating element under test are within a set threshold range, and the difference between the temperature coefficients of resistance is within a set difference range, the heating element is determined to be a good product.

4. The method for screening whether a heating element is of good quality as described in claim 3, characterized in that, The method further includes: Obtain the pre-measurement resistance values ​​of the first edge heating segment, the second edge heating segment, and the middle heating segment; If the resistance values ​​of the first edge heating segment, the second edge heating segment, and the middle heating segment before measurement are within a set resistance range, and the resistance temperature coefficients of the first and second heating groups under test are within a set threshold range, and the difference between the resistance temperature coefficients is within a set difference range, then the heating tube is determined to be a good product.

5. The method for screening whether a heating element is of good quality as described in any one of claims 2-4, characterized in that, After heating the first heating group under test with a set power for a first set time, the heating resistance value of the first heating group under test and the target temperature corresponding to the heating resistance value of the first heating group under test are obtained; after heating the second heating group under test with the set power for a second set time, the heating resistance value of the second heating group under test and the target temperature corresponding to the heating resistance value of the second heating group under test are obtained.

6. The method for screening whether a heating element is of good quality as described in claim 5, characterized in that, Before obtaining the heating resistance value of the second heating element after heating and the target temperature corresponding to the heating resistance value of the second heating element, the heating tube is cooled for a third set time.

7. A system for screening whether heating elements are of good quality, characterized in that, include: The selection drive module is connected to the heating tube. The heating tube includes edge heating segments disposed at both ends of the heating tube and at least one intermediate heating segment located between the edge heating segments at both ends. The selection drive module connects the edge heating segment and the intermediate heating segment according to the heating segment in the heating group to be tested. The heating group to be tested includes an intermediate heating segment and an edge heating segment. The acquisition module is used to acquire the initial resistance and initial temperature of the heating element under test in the heating tube; and to acquire the heating resistance and target temperature of the heating element under test after heating. The control module determines the resistance temperature coefficient of each heating element under test based on its initial resistance, initial temperature, target temperature, and heating resistance. When the resistance temperature coefficient of each heating element under test falls within a set threshold range, the heating element is deemed to be of good quality.

8. The system for screening whether heating elements are of good quality as described in claim 7, characterized in that, The heating element includes a first edge heating segment and a second edge heating segment disposed at both ends of the heating element, and an intermediate heating segment located between the first edge heating segment and the second edge heating segment; The heat-generating group to be tested includes a first heat-generating group to be tested and a second heat-generating group to be tested connected in parallel. The first heat-generating group to be tested includes a first edge heat-generating segment and a middle heat-generating segment connected in series. The second heat-generating group to be tested includes a middle heat-generating segment and a second edge heat-generating segment connected in series.

9. The system for screening whether heating elements are of good quality as described in claim 8, characterized in that, The selection drive module includes a first switch unit, a second switch unit, a third switch unit, and a fourth switch unit. The first switch unit is connected to a first end of the first edge heating segment, the second switch unit is connected to a second end of the first edge heating segment and a first end of the middle heating segment, the third switch unit is connected to a second end of the middle heating segment and a first end of the second edge heating segment, and the fourth switch unit is connected to a second end of the second edge heating segment. When obtaining the heating resistance value of the first heating group to be tested, the first switching unit and the third switching unit are turned on; When obtaining the heating resistance value of the second heating element to be tested, the second switching unit and the fourth switching unit are turned on.

10. A computer-readable storage medium, characterized in that, The medium stores a computer program that can be executed by a processor to implement the method as described in any one of claims 1-6.

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