Airtightness testing device and testing method for high-precision cassette furnace

Abstract

The application discloses a kind of high-precision gas-tightness testing device and testing method for cartridge stove, and relates to gas appliance detection equipment field.The device includes placing table, sealing cover, lifting drive mechanism, inflation unit, pressure detection unit and flow detection unit;Independent air inlet and air outlet channels are provided in the placing table, the air inlet channel is connected to the inflation unit, and the air outlet channel is connected to the cartridge stove gas tank interface to be tested;The sealing cover is driven by the lifting drive mechanism, and is buckled with the placing table to form a sealed detection cavity, and the cartridge stove to be tested is completely contained therein;The pressure detection unit is provided in the sealing cover, and the flow detection unit is provided at the air outlet end of the air outlet channel.The testing method is based on the device, and the gas-tightness detection is completed by inflation, pressure detection, and double-parameter determination.The application does not need to block the cartridge stove combustion head, is suitable for multiple models of products, uses pressure and flow double-parameter detection, is anti-interference, has high detection accuracy and efficiency, and is suitable for large-scale inspection requirements.

Description

Technical Field

[0001] This invention relates to the technical field of gas appliance performance testing equipment, specifically to a device and supporting testing method for testing the airtightness of cassette stoves. Background Technology

[0002] With the increasing popularity of outdoor camping, outdoor work, portable catering, and temporary home cooking, portable gas stoves have gained widespread application due to their compact size, portability, and flexibility. Portable gas stoves deliver fuel through internal gas pipelines, control valves, and gas cylinder interfaces; their overall sealing performance directly affects safety—gas leaks can easily lead to further gas leakage, abnormal combustion, and other safety issues. Therefore, according to industry standards and production quality control requirements, portable gas stoves must undergo rigorous airtightness testing before leaving the factory.

[0003] At present, the airtightness testing of cassette furnaces is mainly divided into two mainstream methods: internal positive pressure testing and traditional external pressure testing. However, both of them have obvious limitations in actual mass production applications.

[0004] Conventional internal positive pressure testing requires introducing test gas into the cassette burner through the gas canister interface, while simultaneously sealing the burner head outlet completely with a sealing fixture. The sealing performance is then assessed by observing changes in pressure decay within the burner. However, cassette burner heads are often complex, porous, and irregularly shaped structures. Different specifications and models of burner heads vary significantly in size, necessitating the use of various sealing fixtures for production. This not only results in high fixture manufacturing costs and cumbersome replacement processes, but also in time-consuming and labor-intensive manual sealing operations, severely impacting the production line's testing cycle time and efficiency. Furthermore, the porous structure of the burner head makes complete sealing difficult, easily leading to incomplete sealing and false leaks, which in turn cause misinterpretations of test results and reduce testing reliability.

[0005] Meanwhile, conventional single pressure monitoring mode only uses pressure changes as the basis for judgment. However, the normal temperature fluctuations in the production environment will cause slight volume changes in the gas, which can easily mask the pressure changes caused by minor leaks in the cassette furnace. This makes it difficult to effectively identify minor leak defects, and there is a long-term risk of missed detection, which is not conducive to the overall quality control of the product.

[0006] While traditional external pressure testing changes the direction of gas filling, its structural design still relies on the forced sealing of the burner head. If the burner head sealing structure is removed, the furnace inner cavity will be directly connected to the sealed cavity, causing the testing gas to leak out directly. All products will be deemed unqualified, making normal testing impossible. Therefore, this method still depends on sealing fixtures and cannot fundamentally solve the shortcomings of existing testing methods.

[0007] In addition, existing conventional testing equipment also suffers from problems such as fragmented structural layout, reliance on a single pressure parameter for judgment (limited detection dimensions and weak resistance to environmental interference), low overall automation level, and numerous manual operation steps, making it difficult to adapt to the continuous, efficient, and stable batch testing needs of modern production lines. Summary of the Invention

[0008] I. Purpose of the Invention This invention addresses the shortcomings of existing technologies by providing a high-precision airtightness testing device and method for cartridge ovens. It solves the technical problems of existing testing methods, such as reliance on burner head sealing fixtures, poor product compatibility, cumbersome operation, susceptibility to environmental interference from single pressure testing, weak ability to identify minute leaks, and poor testing stability.

[0009] II. Technical Solution To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A high-precision gas tightness testing device for a cartridge oven, the key features of which include a placement platform (1), a sealing cover (2), a lifting drive mechanism (3), an air filling unit (4), a pressure detection unit (5), and a flow detection unit (6). The placement platform (1) is used to support the cartridge furnace (7) to be tested. The interior of the placement platform is provided with an independent air inlet channel (101) and an air outlet channel (102). The air inlet end of the air inlet channel (101) is connected to the gas filling unit (4), and the air outlet end of the air inlet channel (101) is opened on the support surface of the placement platform (1) for filling the sealed cavity formed by the sealing cover (2) with test gas. The air inlet end of the air outlet channel (102) is sealed and connected to the gas tank interface (701) of the cartridge furnace (7) to be tested, and the air outlet end of the air outlet channel (102) is connected to the outside atmosphere. The lifting drive mechanism (3) is located above the placement platform. The sealing cover (2) is connected to the execution end of the lifting drive mechanism (3) and can move vertically under the drive of the lifting drive mechanism (3) to engage with the bearing surface of the placement platform (1) to form a sealed detection cavity. The cassette furnace (7) to be tested is completely contained inside the detection cavity. The pressure detection unit (5) is disposed on the sealing cover (2) and is used to detect the gas pressure in the detection chamber in real time; The flow detection unit (6) is located at the outlet end of the gas outlet channel (102) and is used to detect the gas flow rate flowing out of the gas outlet channel (102) in real time.

[0010] Furthermore, the lifting drive mechanism (3) includes at least two columns (301), a top plate (302), and a linear drive member (303); the columns (301) are arranged vertically to guide and constrain the sealing cover (2); the top plate (302) is connected to the top of the columns (301); the linear drive member (303) is vertically fixed to the center of the top plate (302), and the telescopic execution end of the linear drive member (303) is fixedly connected to the top center of the sealing cover (2).

[0011] Furthermore, the linear drive (303) is any one of a cylinder, a hydraulic cylinder, or an electric actuator.

[0012] Furthermore, a recessed platform (103) is formed around the support surface of the placement platform (1). The recessed platform (103) is adapted to the opening size of the sealing cover (2), and an elastic sealing ring (104) is provided on its platform. When the sealing cover (2) is fastened to the placement platform (1), its lower edge presses against the elastic sealing ring (104) to ensure that the detection cavity is in a sealed state.

[0013] Furthermore, the inflation unit (4) includes an air pump (401) and an inflation solenoid valve (402). The air pump (401) has a built-in filter drying component and a precision pressure regulating valve. Its air outlet is connected to the inflation solenoid valve (402) through a pipeline. The air outlet of the inflation solenoid valve (402) is connected to the air inlet of the air inlet channel (101).

[0014] Furthermore, the pressure detection unit (5) is a high-precision differential pressure sensor (501), and the measuring end of the high-precision differential pressure sensor (501) is connected to the detection cavity.

[0015] Furthermore, the flow detection unit (6) is a thermal mass flow meter (601), and the measurement channel of the thermal mass flow meter (601) is connected in series to the outlet end of the outlet channel.

[0016] Furthermore, it also includes a control unit, which is electrically connected to the lifting drive mechanism (3), the inflation unit (4), the pressure detection unit (5), and the flow detection unit (6), respectively. The control unit has a built-in detection control program for automatically executing the entire process of lifting the sealing cover (2), filling the gas, holding the pressure, collecting data, and determining the pass / fail status, and storing the detection data and outputting abnormal alarm signals.

[0017] Based on the above-mentioned device, the present invention also provides a method for testing the airtightness of a cassette furnace, characterized by comprising the following steps: S1 Pretreatment: Close all valves of the cartridge furnace (7) to be tested completely, place the cartridge furnace to be tested stably on the support surface of the placement platform (1), and seal the gas outlet channel (102) and the gas tank interface (701) of the cartridge furnace to be tested. S2 sealing cavity formation: The control lifting drive mechanism (3) drives the sealing cover (2) to descend and engage with the bearing platform of the placement table (1) to form a sealed detection cavity, in which the cassette furnace (7) to be tested is completely contained; S3 Inflation and Pressurization: Control the inflation unit (4) to fill the detection chamber with dry detection gas through the air inlet channel (101) until the pressure detection unit (5) detects that the pressure in the detection chamber has reached the set detection pressure, stops inflation and closes the inflation circuit; S4 Pressure Holding Detection: Pressure holding time is set, and pressure data from pressure detection unit (5) and flow data from flow detection unit (6) are collected in real time; S5 Qualification Judgment: If the pressure drop exceeds the set threshold during the pressure holding stage, or the flow detection unit (6) detects a continuous gas flow, the gasket (7) under test is deemed to be unqualified for air tightness; if the pressure drop does not exceed the set threshold and the flow detection unit (6) does not detect a continuous gas flow, the gasket (7) under test is deemed to be qualified for air tightness. S6 Test Finishing: After the pressure holding is completed, the test gas in the test chamber is discharged, the lifting drive mechanism (3) is controlled to drive the sealing cover (2) to move upward and reset, and the test cassette furnace is taken out.

[0018] Furthermore, step S5 also includes the determination of internal and external leakage: if a continuous gas flow is detected during the pressure holding stage, the burner valve of the cassette furnace (7) to be tested is opened for a second test. If the flow rate increases significantly, it is determined that the internal leakage of the cassette furnace valve is unqualified; if the flow rate does not change significantly, it is determined that the external leakage of the cassette furnace pipeline is unqualified.

[0019] III. Beneficial Effects Compared with the prior art, the significant effects of the present invention are as follows: 1. No need to seal the burner head, eliminating tooling dependence and strong adaptability. This invention adopts an external cavity pressurized detection structure, eliminating the need for sealing the burner head of the cassette furnace throughout the entire process. It also eliminates the need for multiple sealing tooling options, is not limited by the shape, structure, or specifications of the burner head, and can be used for universal detection of various types of cassette furnaces. This significantly simplifies the loading and unloading process, shortens the detection time per unit, and effectively improves the detection efficiency of batch production.

[0020] 2. Employing dual-dimensional collaborative detection of pressure and flow rate, it boasts strong anti-interference capabilities and higher detection accuracy. Abandoning the traditional single-pressure judgment mode, it simultaneously collects pressure change data from the sealed cavity and flow rate data from the furnace exhaust end. Through mutual verification of these dual signals, it effectively reduces pressure interference caused by slight temperature fluctuations in the environment, stably captures airflow changes caused by minute leaks, reduces false alarms, lowers the probability of missing minute leaks, and improves overall detection accuracy and stability.

[0021] 3. The cavity sealing structure is reasonable, the sealing effect is stable, and the equipment operation is highly reliable. Through the compression sealing structure of the placement platform and the annular elastic sealing ring, combined with the overall closed design of the cover, the detection cavity is guaranteed to be stable and sealed for a long time, avoiding detection errors caused by leakage of the equipment itself; the overall mechanical structure layout is regular, the lifting operation is stable, and it is suitable for long-term continuous operation of the production line.

[0022] 4. High degree of automation, simple operation, and easy to promote industrialization. The integrated control unit integrates various actuators to automatically complete the entire process of cavity closure, pressure stabilization and inflation, timed pressure maintenance, data acquisition, and result judgment. The operator only needs to place and remove the product, which reduces labor intensity, makes operation simple and convenient, and can be directly adapted to automated production lines, showing good prospects for industrial application.

[0023] 5. Flexible selection of testing media and low operating costs. This solution can use ordinary air as the testing media, without the need for special inert gases, and has no special usage restrictions or safety concerns. The equipment has low maintenance costs, is convenient for daily use, and is suitable for long-term routine quality inspection operations in factories. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a first-view perspective perspective view of the high-precision airtightness testing device for cartridge ovens in this invention. Figure 2 This is a second-view perspective perspective view of the high-precision gas tightness testing device for cartridge ovens in this invention; Figure 3 This is a front view of the high-precision gas tightness testing device for cartridge ovens in this invention; Figure 4 This is a third-view perspective view of the high-precision gas tightness testing device for cartridge ovens in this invention; Figure 5 yes Figure 4 Enlarged view of part A in the middle; The markings in the diagram are as follows: 1-Placement platform, 101-Inlet channel, 102-Outlet channel, 103-Recessed platform, 104-Elastic sealing ring; 2-Sealing cover; 3-Lifting drive mechanism, 301-Column, 302-Top plate, 303-Linear drive component, 304-Buffer and shock absorption component; 4-Inflation unit, 401-Air pump, 402-Inflation solenoid valve; 5-Pressure detection unit, 501-High-precision differential pressure sensor; 6-Flow detection unit, 601-Thermal mass flow meter; 7-Cartridge furnace under test, 701-Gas tank interface. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] The high-precision airtightness testing device and method for cartridge ovens provided in this embodiment are used for comprehensive airtightness testing of cartridge oven products. They do not require sealing of the cartridge oven burner head, can achieve high-precision dual-parameter testing, and are suitable for flexible batch testing needs of multiple product models.

[0029] like Figures 1 to 5 As shown, the high-precision gas tightness testing device for cartridge ovens includes a placement platform 1, a sealing cover 2, a lifting drive mechanism 3, an air filling unit 4, a pressure detection unit 5, a flow detection unit 6, and a control unit.

[0030] The placement platform 1 is a horizontally positioned rigid platform, serving as the supporting foundation for the entire device. The top surface of the placement platform 1 is a flat support surface for stably placing the cartridge furnace 7 to be tested. The placement platform 1 has two independent and non-communicating flow channels inside: an inlet channel 101 and an outlet channel 102. The inlet end of the inlet channel 101 is located on the side wall of the placement platform 1, connecting to the pipeline of the gas filling unit 4. The outlet end of the inlet channel 101 is located on the support surface of the placement platform 1, with its opening situated within the locking range of the sealing cover 2, allowing for the uniform filling of the sealed cavity formed by the sealing cover 2 with the test gas. The inlet end of the outlet channel 102 is located on the support surface of the placement platform 1, sealingly connecting to the gas canister interface 701 of the cartridge furnace 7 to be tested. The outlet end of the outlet channel 102 is located on the other side wall of the placement platform 1, directly connecting to the outside atmosphere.

[0031] The lifting drive mechanism 3 is fixedly installed above the placement platform 1 and is used to drive the sealing cover 2 to achieve vertical lifting and opening / closing. The lifting drive mechanism 3 includes four columns 301, a top plate 302, and a linear drive component 303. The four columns 301 are vertically fixed at the four corners of the support surface of the placement platform 1, forming a stable support frame; the top plate 302 is horizontally fixed at the top of the four columns 301, forming an installation reference; the linear drive component 303 is vertically fixed at the center of the top plate 302, with the telescopic actuator end of the linear drive component 303 facing downwards, and the bottom end of the telescopic actuator end is fixedly connected to the top center of the sealing cover 2. In this embodiment, the linear drive component 303 is a double-acting cylinder, which can achieve stable telescopic drive through a pneumatic circuit. In other optional embodiments, the linear drive component 303 can also be a hydraulic cylinder or an electric push rod, which can be flexibly selected according to the power configuration of the production site. To ensure the smoothness of the lifting and lowering process of the sealing cover 2, the four corners of the sealing cover 2 are slidably engaged with the four columns 301 to form a guiding constraint, preventing the sealing cover 2 from shifting during the lifting and lowering process and ensuring the sealing accuracy when fastened. In this embodiment, a buffer and shock absorption component 304 is also provided in the lower section of the columns to provide buffering when the sealing cover 2 descends to its position, preventing hard impacts from causing damage to components or misalignment of the seals, and further improving the long-term stability of the equipment.

[0032] The sealing cover 2 is a rigid cover with an opening at the bottom, made of transparent acrylic material, which facilitates observation of the status of the cartridge furnace 7 under test inside. The opening size of the sealing cover 2 is adapted to the size of the recess 103 on the support surface of the placement platform 1. The sealing cover 2 can move downward under the drive of the linear drive 303, and its lower edge is embedded in the recess 103, which is fastened with the placement platform 1 to form a sealed detection cavity. The cartridge furnace 7 under test is completely contained inside the detection cavity, with no part exposed. To ensure the sealing performance of the detection cavity, an annular groove is opened on the surface of the recess 103, and an elastic sealing ring 104 is embedded in the groove. The elastic sealing ring 104 is made of fluororubber, which is wear-resistant and has excellent sealing performance. When the sealing cover 2 moves downward to fasten, its lower edge completely presses against the elastic sealing ring 104, realizing complete sealing and isolation between the sealing cover 2 and the placement platform 1, and avoiding cavity leakage during the detection process.

[0033] The inflation unit 4 is used to fill the detection chamber with clean, pressure-stable detection gas. The inflation unit 4 includes an air pump 401 and an inflation solenoid valve 402. The air pump 401 is an oil-free, silent air pump. Internally, the air pump 401 integrates a filter and drying component and a precision pressure regulating valve. The filter and drying component removes moisture, dust, and oil from the compressed air, preventing impurities from entering the detection chamber or the cartridge furnace. The precision pressure regulating valve accurately adjusts the output gas pressure to ensure stable inflation pressure. The outlet of the air pump 401 is connected to the inlet of the inflation solenoid valve 402 via a high-pressure hose. The outlet of the inflation solenoid valve 402 is sealed to the inlet of the air inlet channel 101 of the placement platform 1 via a pipeline. The inflation solenoid valve 402 controls the on / off state of the inflation circuit, working in conjunction with the control unit to achieve automatic inflation and pressure maintenance. To enhance the safety performance of the device, as a preferred embodiment, a safety valve can also be installed in the inflation circuit. The air inlet of the safety valve is connected to the air inlet channel 101, and the opening pressure of the safety valve is matched with the detection set pressure. When the pressure in the detection chamber exceeds the set threshold, the safety valve automatically opens to release pressure, preventing overpressure damage to the device or the product under test.

[0034] The pressure detection unit 5 is used to detect the gas pressure in the detection chamber in real time. The pressure detection unit 5 adopts a high-precision differential pressure sensor 501, which is embedded and fixed on the side wall of the sealing cover 2. Its measuring end penetrates the wall of the sealing cover 2 and is directly connected to the internal space of the detection chamber. It can collect the pressure data in the detection chamber in real time and transmit the data to the control unit.

[0035] The flow detection unit 6 is used to detect the gas flow rate from the gas outlet channel 102 in real time. The flow detection unit 6 adopts a thermal mass flow meter 601. The measurement channel of the thermal mass flow meter 601 is installed in series at the gas outlet end of the gas outlet channel 102. It can accurately capture small gas flow signals, is not affected by gas temperature and pressure, has high detection accuracy and fast response speed, and can transmit flow data to the control unit in real time.

[0036] The control unit employs a PLC programmable controller. It is electrically connected to the solenoid valve of the lifting drive mechanism 3, the air pump 401 and air filling solenoid valve 402 of the air filling unit 4, the high-precision differential pressure sensor 501 of the pressure detection unit 5, and the thermal mass flow meter 601 of the flow detection unit 6. The control unit has a built-in standardized detection and control program that can automatically execute the entire process of lifting the sealing cover 2, filling with detection gas, pressure holding detection, data acquisition, and qualification determination. It can also store the detection data of all products for easy quality traceability. When a product is found to be unqualified or an abnormality occurs in the device, it can output an audible and visual alarm signal.

[0037] This embodiment also provides a method for testing the airtightness of a cassette gasket. This method is based on the aforementioned high-precision airtightness testing device for cassette gaskets, and the specific steps are as follows: S1 Pretreatment: Turn the main valve and all burner valves of the cassette furnace 7 to be tested to the closed position to ensure that the valves are completely closed; place the cassette furnace 7 to be tested stably on the preset position of the support platform of the placement table 1, and seal the air inlet end of the air outlet channel 102 to the gas tank interface 701 of the cassette furnace 7 through the special quick connector to ensure that there is no leakage at the connection point.

[0038] S2 Sealed cavity formation: The lifting drive mechanism 3 is activated by the control unit. The telescopic execution end of the linear drive 303 moves downward, driving the sealing cover 2 to move smoothly down along the column 301 until the lower edge of the sealing cover 2 completely presses against the elastic sealing ring 104 in the recess 103, forming a sealed detection cavity. At this time, the cassette furnace 7 to be tested is completely contained inside the detection cavity, with no part exposed.

[0039] S3 Inflation and Pressurization: The control unit controls the inflation solenoid valve 402 to open and simultaneously starts the air pump 401, which fills the detection chamber with dried and filtered detection gas through the air inlet channel 101. The high-precision differential pressure sensor 501 collects the pressure data in the detection chamber in real time and transmits it to the control unit. When the pressure in the detection chamber reaches the preset detection pressure, the control unit controls the inflation solenoid valve 402 to close and simultaneously stops the air pump 401, thus completing the inflation and pressurization.

[0040] S4 Pressure Holding Detection: Entering the pressure holding stage, the pressure holding time is preset. During the pressure holding process, the control unit collects the pressure data of the high-precision differential pressure sensor 501 and the flow data of the thermal mass flow meter 601 in real time, and monitors the pressure changes and gas leakage of the detection chamber throughout the process.

[0041] S5 Pass / Fail Judgment: After the pressure holding period ends, the control unit completes the pass / fail judgment based on the collected data: If the pressure drop value of the detection chamber exceeds the preset threshold during the pressure holding stage, or the thermal mass flow meter 601 detects a continuous gas flow, the air tightness of the cassette furnace 7 under test is determined to be unqualified; if the pressure drop value does not exceed the preset threshold and the thermal mass flow meter 601 does not detect a continuous gas flow, the air tightness of the cassette furnace 7 under test is determined to be qualified.

[0042] For products deemed unqualified, internal and external leakage can be distinguished: keep the pressure in the test chamber stable, open the burner valve of the cassette stove 7 to be tested for a second test. If the flow rate detected by the thermal mass flow meter 601 increases significantly, it indicates that the valve of the cassette stove is not closed tightly, and it is judged as unqualified due to internal leakage of the valve; if the flow rate does not change significantly, it indicates that there is damage to the gas pipeline of the cassette stove, and it is judged as unqualified due to external leakage of the pipeline.

[0043] S6 Inspection Completion: After the inspection is completed, the control unit controls the exhaust valve to open and discharge the inspection gas in the inspection chamber. After the pressure in the inspection chamber returns to atmospheric pressure, the control unit controls the lifting drive mechanism 3 to drive the sealing cover 2 to move upward and reset, disconnecting the quick connector from the gas tank interface 701, and taking out the cassette furnace 7 to be tested, thus completing a single inspection process.

[0044] The technical solution provided in this embodiment completely solves the core pain points of existing gas-tightness testing solutions for cassette furnaces, such as difficulty in sealing the burner head, poor versatility, low testing accuracy, and high false judgment rate. It eliminates the need for any sealing of the burner head, enabling fully automated and high-precision gas-tightness testing, and is suitable for the full inspection requirements of large-scale production lines.

[0045] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A high-precision airtightness testing device for cartridge ovens, characterized in that, It includes a placement platform (1), a sealing cover (2), a lifting drive mechanism (3), an inflation unit (4), a pressure detection unit (5), and a flow detection unit (6). The placement platform (1) is used to support the cartridge furnace (7) to be tested. The interior of the placement platform is provided with an independent air inlet channel (101) and an air outlet channel (102). The air inlet end of the air inlet channel (101) is connected to the gas filling unit (4), and the air outlet end of the air inlet channel (101) is opened on the support surface of the placement platform (1) for filling the sealed cavity formed by the sealing cover (2) with test gas. The air inlet end of the air outlet channel (102) is sealed and connected to the gas tank interface (701) of the cartridge furnace (7) to be tested, and the air outlet end of the air outlet channel (102) is connected to the outside atmosphere. The lifting drive mechanism (3) is located above the placement platform. The sealing cover (2) is connected to the execution end of the lifting drive mechanism (3) and can move vertically under the drive of the lifting drive mechanism (3) to engage with the bearing surface of the placement platform (1) to form a sealed detection cavity. The cassette furnace (7) to be tested is completely contained inside the detection cavity. The pressure detection unit (5) is disposed on the sealing cover (2) and is used to detect the gas pressure in the detection chamber in real time; The flow detection unit (6) is located at the outlet end of the gas outlet channel (102) and is used to detect the gas flow rate flowing out of the gas outlet channel (102) in real time.

2. The high-precision airtightness testing device for cartridge ovens according to claim 1, characterized in that, The lifting drive mechanism (3) includes at least two columns (301), a top plate (302), and a linear drive component (303); the columns (301) are arranged vertically to guide and constrain the sealing cover (2); the top plate (302) is connected to the top of the columns (301); the linear drive component (303) is vertically fixed to the center of the top plate (302), and the telescopic execution end of the linear drive component (303) is fixedly connected to the top center of the sealing cover (2).

3. The high-precision airtightness testing device for cartridge ovens according to claim 2, characterized in that, The linear drive (303) is any one of a cylinder, a hydraulic cylinder, or an electric push rod.

4. The high-precision airtightness testing device for cartridge ovens according to claim 1, characterized in that, A recessed platform (103) is formed around the support surface of the placement platform (1). The recessed platform (103) is adapted to the opening size of the sealing cover (2), and an elastic sealing ring (104) is provided on its platform. When the sealing cover (2) is fastened to the placement platform (1), its lower edge presses against the elastic sealing ring (104) to ensure that the detection cavity is in a sealed state.

5. The high-precision airtightness testing device for cartridge ovens according to claim 1, characterized in that, The inflation unit (4) includes an air pump (401) and an inflation solenoid valve (402). The air pump (401) has a built-in filter drying component and a precision pressure regulating valve. Its outlet end is connected to the inflation solenoid valve (402) through a pipeline. The outlet end of the inflation solenoid valve (402) is connected to the inlet end of the air inlet channel (101).

6. The high-precision airtightness testing device for cartridge ovens according to claim 1, characterized in that, The pressure detection unit (5) is a high-precision differential pressure sensor (501), and the measuring end of the high-precision differential pressure sensor (501) is connected to the detection cavity.

7. The high-precision airtightness testing device for cartridge ovens according to claim 6, characterized in that, The flow detection unit (6) is a thermal mass flow meter (601), and the measurement channel of the thermal mass flow meter (601) is connected in series to the outlet end of the outlet channel.

8. The high-precision airtightness testing device for cartridge ovens according to any one of claims 1-7, characterized in that, It also includes a control unit, which is electrically connected to the lifting drive mechanism (3), the inflation unit (4), the pressure detection unit (5), and the flow detection unit (6), respectively. The control unit has a built-in detection control program for automatically executing the entire process of lifting the sealing cover (2), filling the gas, holding the pressure, collecting data, and determining the pass / fail status, and storing the detection data and outputting abnormal alarm signals.

9. A method for testing the airtightness of a portable gasket, characterized in that, The high-precision gas tightness testing device for cartridge ovens as described in any one of claims 1-8 is implemented by including the following steps: S1 Pretreatment: Close all valves of the cartridge furnace (7) to be tested completely, place the cartridge furnace to be tested stably on the support surface of the placement platform (1), and seal the gas outlet channel (102) and the gas tank interface (701) of the cartridge furnace to be tested. S2 sealing cavity formation: The control lifting drive mechanism (3) drives the sealing cover (2) to descend and engage with the bearing platform of the placement table (1) to form a sealed detection cavity, in which the cassette furnace (7) to be tested is completely contained; S3 Inflation and Pressurization: Control the inflation unit (4) to fill the detection chamber with dry detection gas through the air inlet channel (101) until the pressure detection unit (5) detects that the pressure in the detection chamber has reached the set detection pressure, stops inflation and closes the inflation circuit; S4 Pressure Holding Detection: Pressure holding time is set, and pressure data from pressure detection unit (5) and flow data from flow detection unit (6) are collected in real time; S5 Qualification Judgment: If the pressure drop exceeds the set threshold during the pressure holding stage, or the flow detection unit (6) detects a continuous gas flow, the gasket (7) under test is deemed to be unqualified for air tightness; if the pressure drop does not exceed the set threshold and the flow detection unit (6) does not detect a continuous gas flow, the gasket (7) under test is deemed to be qualified for air tightness. S6 Test Finishing: After the pressure holding is completed, the test gas in the test chamber is discharged, the lifting drive mechanism (3) is controlled to drive the sealing cover (2) to move upward and reset, and the test cassette furnace is taken out.

10. The method for testing the airtightness of a cassette furnace according to claim 9, characterized in that, In step S5, the internal and external leakage distinction judgment is also included: if a continuous gas flow is detected during the pressure holding stage, the burner valve of the cassette furnace (7) to be tested is opened for secondary detection. If the flow rate increases significantly, it is determined that the internal leakage of the cassette furnace valve is unqualified; if the flow rate does not change significantly, it is determined that the external leakage of the cassette furnace pipeline is unqualified.

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