A muffler air tightness testing device

Abstract

The present invention relates to the field of muffler detection technology, and specifically to a muffler air tightness detection device. The present invention includes: a test bench, a detection chamber installed on the top of the test bench, a gas supply module for supplying detection gas, a loading and unloading module for sending the muffler to be tested into the detection chamber or taking out the muffler that has been tested from the detection chamber before testing, and a detection module for performing air tightness detection on the muffler; the loading and unloading module includes: a slide rail fixedly installed on the top of the test bench, a supporting basket slidably installed on the slide rail, a sub-magnetic component evenly spaced and installed on the slide rail, a mother magnetic component fixedly installed on the supporting basket and matched with the sub-magnetic component, and a correction component for correcting the posture of the muffler; the loading and unloading module of the present invention can respectively correct the circumferential position and axial position of the muffler while loading.

Description

Technical Field

[0001] The invention relates to the technical field of muffler detection, and in particular to a muffler air tightness detection device. Background Art

[0002] Fan duct silencer is mainly used to reduce and control the noise generated by various fans, such as blowers, Roots blowers, air compressors, axial flow exhaust fans, centrifugal fans, etc. when entering and exiting the air duct. The fan duct silencer usually has a special structural design inside, such as a large-hole pressure-reducing injection silencer structure; high-pressure steam is processed in the silencer through flow control, multiple expansion and pressure reduction, etc., which converts part of the internal energy of the airflow into sound energy, greatly weakening the noise power; good air tightness can ensure the stability of the pressure inside the silencer, so that the silencer structure can function normally, thereby achieving the expected silencer effect.

[0003] An internal combustion engine muffler air tightness detection device with application number CN202121321091.0 comprises a base, a bracket arranged on the upper side of the base, a detection platform arranged on the top of the bracket, and a carrier arranged on the side of the detection platform, a positioning assembly is arranged on the top of the detection platform, and a storage assembly is arranged on one side surface of the carrier; the storage assembly comprises a carrier box, the carrier box is arranged on one side surface of the carrier, a reel is rotatably arranged in the middle of the carrier box, a water outlet pipe is wound on the outer surface of the reel, one end of the water outlet pipe passes through the first opening, the other end of the water outlet pipe is connected to a water hose, one end of the water hose passes through the second opening, the first opening is arranged on one side of the lower surface of the carrier box, the second opening is arranged on one side of the upper surface of the carrier box, and the reel is respectively sleeved with a first torsion spring and a second torsion spring. The above patent application can automatically reel the water outlet pipe, which is convenient for the storage and placement of the water outlet pipe, and can also quickly position and clamp the internal combustion engine muffler, which is convenient for its disassembly and assembly, and improves the detection efficiency.

[0004] However, the fixing effect of the pipe silencer in this patent is poor, and the posture of the silencer cannot be corrected while loading.

[0005] Therefore, it is necessary to provide a new technical solution to overcome the above-mentioned defects. Summary of the invention

[0006] The purpose of the present invention is to provide a muffler air tightness detection device which can effectively solve the above technical problems.

[0007] In order to achieve the purpose of the present invention, the following technical scheme is adopted:

[0008] A silencer air tightness testing device, comprising: a test bench, a testing chamber installed on the top of the test bench, a gas supply module for supplying testing gas, a loading and unloading module for sending a muffler to be tested into the testing chamber before testing or taking out a muffler that has been tested from the testing chamber, and a testing module for performing air tightness testing on the muffler;

[0009] The loading and unloading module includes: a slide rail fixedly mounted on the top of the test bench, a carrying basket slidably mounted on the slide rail, sub-magnetic components evenly spaced and mounted on the slide rail, a mother magnetic component fixedly mounted on the carrying basket and matched with the sub-magnetic components, and a correction component for correcting the posture of the muffler;

[0010] The correction assembly includes: a circumferential correction piece for correcting the circumferential posture of the muffler, and an axial correction piece for correcting the axial position of the muffler;

[0011] The bottom of the circumferential correcting member is magnetically connected to the female magnetic member;

[0012] During loading, the female magnetic attraction part is energized to drive the carrying basket to slide into the detection cavity, and the circumferential posture and axial posture of the muffler are respectively corrected during sliding.

[0013] Furthermore, the circumferential correcting member is arc-shaped and is slidably mounted on the supporting basket.

[0014] Furthermore, the circumferential correcting member is composed of an outer shell slidably connected to the supporting basket, an inner shell slidably mounted on the outer shell, balls rollingly mounted on the inner shell, and a buffer member connecting the inner shell and the outer shell.

[0015] Furthermore, there are a plurality of inner shells, which are connected to the outer shell at even intervals along the circumferential direction.

[0016] Furthermore, the axial correction member includes: a vertical plate, a mounting seat slidably mounted on the vertical plate, a first motor mounted on the mounting seat, a connecting member connected to the output end of the first motor, and a lifting member at the bottom of the mounting seat for driving the mounting seat to rise and fall; a capsule is detachably mounted on the end of the connecting member.

[0017] Furthermore, the sac is in a semi-filled state; and a telescopic rod is detachably connected to the surface of the sac.

[0018] Furthermore, the mother magnetic attraction component is an electromagnetic coil; and the child magnetic attraction component is a permanent magnet.

[0019] Furthermore, the detection module includes: a pressure sensor for collecting real-time pressure in the detection cavity, a controller electrically connected to the pressure sensor, and a display electrically connected to the controller.

[0020] Furthermore, the steps of the detection module detecting the air tightness of the muffler are as follows:

[0021] S1, the controller controls to open the detection chamber; the silencer to be detected is placed on the carrying basket; the controller controls the loading and unloading module to transport the silencer into the detection chamber, and after completion, the detection chamber is closed;

[0022] S2, the controller starts the gas source to fill the detection chamber with gas until the gas pressure in the detection chamber reaches a preset value;

[0023] S3, closing the gas source and maintaining the gas source for a preset time; the pressure sensor monitors the gas pressure change in the detection chamber in real time and records the pressure data in real time;

[0024] S4, the controller generates a pressure-time curve in response to the pressure data measured by the pressure sensor, analyzes the pressure change trend, and determines the air tightness of the muffler;

[0025] S5, the display shows the test results and stores the test data;

[0026] S6. After completing the air tightness test, open the pressure relief valve. When the gas pressure in the test chamber drops to a preset value, open the test chamber, control the loading and unloading modules to slide outward, and take out the muffler.

[0027] Further, step S4 includes the following steps:

[0028] S4.1. Preset a standard fluctuation curve and preset a fluctuation threshold of the pressure-time curve;

[0029] S4.2. Check the fluctuation of the pressure-time curve;

[0030] S4.2.1. If the fluctuation is within the fluctuation threshold range, it shall be ignored;

[0031] S4.2.2, if the fluctuation is outside the fluctuation threshold range, analyzing whether the fluctuation is irregular fluctuation;

[0032] S4.2.2.1. When the fluctuation is irregular, perform subsequent fluctuation comparison. If the fluctuation continues to be irregular, check whether the detection chamber and the detection module have faults.

[0033] If the irregular fluctuation does not continue, step S2 is executed;

[0034] S4.2.2.2, when it is a regular fluctuation, execute step S4.3;

[0035] S4.3, comparing the real-time generated pressure-time curve with the standard fluctuation curve;

[0036] S4.3.1. Divide the test time into several segments, analyze each segment curve separately, and determine the fluctuation time;

[0037] S4.3.2. Based on the analysis results of each segment, comprehensively evaluate the pressure changes during the entire test cycle;

[0038] S4.3.3. If the pressure fluctuation in any period of time exceeds the preset threshold, the silencer is judged to have an airtightness problem and a detailed test report is generated; if the pressure fluctuation in all time periods is within the preset threshold, the silencer is judged to have good airtightness and a normal test report is generated.

[0039] Compared with the prior art, the present invention has the following beneficial effects: the loading and unloading modules of the present invention can respectively correct the circumferential position and the axial position of the muffler while loading the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0041] Figure 1 is an axonometric view of the present invention;

[0042] Figure 2 It is a schematic diagram of the axial side of the present invention;

[0043] Figure 3 It is a structural schematic diagram of the present invention;

[0044] Figure 4 for Figure 2 A partial enlarged view of part A;

[0045] Figure 5 It is a structural schematic diagram of the carrying basket of the present invention;

[0046] Figure 6 for Figure 5 A partial enlarged view of part B;

[0047] Figure 7 is a cross-sectional view of the present invention;

[0048] Figure 8 It is a schematic structural diagram of the axial correction member of the present invention;

[0049] Fig. 9 A side view of the axial correction member of the present invention;

[0050] Fig.10 It is an exploded schematic diagram of the circumferential correction piece of the present invention;

[0051] Fig.11 is a structural schematic diagram of the slide rail;

[0052] Fig.12 It is the principle diagram of the present invention;

[0053] Fig.13 It is a schematic diagram of the process of the present invention.

[0054] In the figure: 1. test bench; 2. detection chamber; 3. air supply module; 5. loading and unloading module; 21. sealing door; 22. power assembly; 51. slide rail; 52. carrying basket; 53. sub-magnetic part; 54. main magnetic part; 551. circumferential correction part; 552. axial correction part; 5511. outer shell; 5512. inner shell; 5513. ball bearing; 5514. buffer part; 5515. reset part; 5521. vertical plate; 5522. mounting seat; 5523. first motor; 5524. connecting part; 5525. lifting part; 5526. capsule; 5527. telescopic rod; 5528. sensing device; 41. pressure sensor; 42. controller; 43. display. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are partial embodiments of the present invention, rather than all embodiments.

[0056] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present invention. When a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a centered component. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centered component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a centered component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0057] like Figures 1 to 13As shown, a silencer air tightness testing device of the present invention comprises: a test bench 1, a testing chamber 2 installed on the top of the test bench 1, a gas supply module 3 for supplying testing gas, a loading and unloading module 5 for sending the silencer to be tested into the testing chamber 2 or taking the tested silencer out of the testing chamber 2 before testing, and a testing module for performing air tightness testing on the silencer.

[0058] A sealing door 21 is installed at the feeding end of the detection chamber 2, and a power component 22 for driving the sealing door 21 to open or close is installed on the top of the detection chamber 2; a sealing structure is provided on the sealing door 21 to seal the chamber body to prevent air leakage in the chamber body; the power component 22 is a ball screw mechanism, or it can be an electric push rod mechanism.

[0059] The gas supply module 3 includes: a gas source for conveying detection gas into the detection chamber 2, a gas flow controller 42 connected to the gas outlet end of the gas source, and the gas outlet end of the gas flow controller 42 is connected to the detection chamber 2; in this embodiment, air can be directly used as the detection gas to reduce the waste gas recovery cost and reduce pollution.

[0060] The loading and unloading module 5 includes: a slide rail 51 fixedly installed on the top of the test bench 1, a supporting basket 52 slidably installed on the slide rail 51, a sub-magnetic component 53 evenly spacedly installed inside the slide rail 51, and a mother magnetic component 54 evenly spacedly fixedly installed in the middle of the bottom of the supporting basket 52. The mother magnetic component 54 cooperates with the sub-magnetic component 53 to enable the supporting basket 52 to slide along the slide rail 51, and a correction component for correcting the posture of the muffler is provided on the supporting basket 52; the sub-magnetic component 53 is preferably a permanent magnet; the mother magnetic component 54 is preferably a three-phase winding or an electromagnetic coil; when the mother magnetic component 54 is passed with three-phase alternating current, a traveling wave magnetic field will be generated, and the traveling wave magnetic field will interact with the magnetic field generated by the permanent magnet of the sub-magnetic component 53 to generate thrust, driving the supporting basket 52 to slide in or out of the detection chamber 2; the slide rail 51 has an opening at the position corresponding to the sealing door 21 to avoid interference with the sealing door 21 or affecting the sealing effect, resulting in air leakage in the detection chamber 2.

[0061] The correction assembly includes: a circumferential correction piece 551 slidably mounted on the bottom of the supporting basket 52, and an axial correction piece 552 fixedly mounted in the detection cavity 2; the circumferential correction piece 551 is arc-shaped and is symmetrically mounted on both sides of the bottom of the supporting basket 52, and when the mother magnetic suction piece 54 is energized, the bottom of the circumferential correction piece 551 is magnetically connected to the mother magnetic suction piece 54, so that the two relative circumferential correction pieces 551 approach each other to form a clamping posture, clamping the silencer from the side of the silencer so that the axial direction of the silencer is parallel to the movement direction of the supporting basket 52.

[0062] The circumferential correcting member 551 is composed of an outer shell 5511 slidably mounted on the carrying basket 52, an inner shell 5512 slidably mounted on the inner arc side of the outer shell 5511, a ball 5513 rollingly mounted on the inner shell 5512, a buffer member 5514 connecting the inner shell 5512 and the outer shell 5511, and a reset member 5515 connecting the outer shell 5511 and the carrying basket 52; the inner shell 5512 is connected to the outer shell 5511 at even intervals along the circumferential direction, so as to facilitate the adaptation of silencers with different radians or different tube sizes; the ball 5513 is used to enable the silencer to move freely along the axial direction after the circumferential correcting member 551 corrects the posture of the silencer;

[0063] When the muffler does not protrude from the supporting basket 52, the supporting basket 52 moves to the end of the stroke, and the supporting basket 52 hits the axial correcting piece 552. At this time, the muffler slides toward the axial correcting piece 552 due to inertia; when the muffler protrudes from the supporting basket 52, the muffler first contacts the axial correcting piece 552 and is pushed into the supporting basket 52; whether the muffler protrudes from the supporting basket 52 or not, the axial position of the muffler can be effectively corrected.

[0064] Correcting the axial and circumferential positions of the muffler separately helps maintain the consistency of the testing environment; the position and posture of the muffler are almost the same during each test, which can reduce errors caused by inconsistent testing conditions.

[0065] From the above description, it can be seen that the present application can not only drive the loading basket to slide, thereby driving the silencer to slide into or out of the detection chamber 2, but also correct the circumferential posture of the silencer during the sliding process; and further correct the axial posture of the silencer when sliding to the end point.

[0066] The axial correction member 552 includes: a vertical plate 5521 arranged in the vertical direction, a mounting seat 5522 slidably mounted on the vertical plate 5521, a first motor 5523 mounted on the mounting seat 5522, a connecting member 5524 connected to the output end of the first motor 5523, and a lifting member 5525 for driving the mounting seat 5522 to rise and fall is provided at the bottom of the mounting seat 5522; a capsule 5526 is detachably mounted on the end of the connecting member 5524, and the capsule 5526 is filled with a buffer liquid or gas so that the capsule 5526 is in a semi-filled state; when the capsule 5526 contacts the muffler, a certain fit and friction force will be generated, and a plurality of telescopic rods 5527 can be evenly mounted on the surface of the capsule 5526. When the muffler contacts the telescopic rod 5527, the telescopic rod 5527 is inserted into the inside and outside of the muffler to further fix the muffler; the capsule 5526 is made of rubber or silicone material; the lifting member 5525 is a telescopic cylinder.

[0067] The screw is driven to rotate by the second motor, which in turn drives the slider to slide, which in turn drives the mounting seat 5522 to rise and fall, thereby driving the connecting member 5524 to rise and fall to adjust the height of the capsule 5526; the capsule 5526 is driven to rotate by the first motor 5523, which in turn drives the muffler to rotate.

[0068] From the above description, it can be seen that the capsule 5526 in the present application can not only prevent the muffler from being worn due to collision; it can also play a buffering role to prevent the muffler from axial displacement after colliding with the capsule 5526; it can also play a limiting role on the muffler, thereby driving the muffler to rotate.

[0069] The capsule 5526 is installed with a sensing device 5528. When the sensing device 5528 is triggered, the supporting basket 52 immediately stops sliding and closes the sealing door 21. The sensing device 5528 can be a pressure sensor 41, a sensing switch, etc.

[0070] The detection module includes: a pressure sensor 41 for collecting real-time pressure in the detection chamber 2, a controller 42 electrically connected to the pressure sensor 41, and a display 43 for displaying the detection results; the controller 42 is electrically connected to the mother magnetic suction part 54 respectively; the pressure sensor 41 adopts a pressure sensor 41 with an accuracy of 0.01MPa; the processor is preferably a PLC controller 42; the display 43 is preferably a liquid crystal display.

[0071] In this application, the steps for the detection module to detect the air tightness of the muffler are as follows:

[0072] S1, the controller 42 controls the sealing door 21 to be opened; the muffler to be tested is placed on the carrying basket 52; the controller 42 controls the loading and unloading module 5 to transport the muffler into the testing chamber 2, and after completion, the sealing door 21 is closed;

[0073] S2, the controller 42 starts the gas source to fill the detection chamber 2 with gas until the gas pressure in the detection chamber 2 reaches a preset value;

[0074] S3, close the gas source and maintain it for a preset time; the pressure sensor 41 monitors the gas pressure change in the detection chamber 2 in real time and records the pressure data in real time;

[0075] S4, the controller 42 generates a pressure-time curve in response to the pressure data measured by the pressure sensor 41, analyzes the pressure change trend, and determines the air tightness of the muffler;

[0076] S5, the display 43 displays the test results, which is convenient for the operator to view in real time; and stores the test data, which is convenient for subsequent tracing of the test results;

[0077] S6. After completing the air tightness test, open the pressure relief valve. When the gas pressure in the test chamber 2 drops to a preset value, open the sealing door 21, control the loading and unloading module 5 to slide outward, and take out the muffler.

[0078] Preferably, step S4 comprises the following steps:

[0079] S4.1. Preset a standard fluctuation curve and preset a fluctuation threshold of the pressure-time curve;

[0080] S4.2. Check the fluctuation of the pressure-time curve;

[0081] S4.2.1. If the fluctuation is within the fluctuation threshold range, it shall be ignored;

[0082] S4.2.2, if the fluctuation is outside the fluctuation threshold range, analyzing whether the fluctuation is irregular fluctuation;

[0083] S4.2.2.1. When irregular fluctuations occur, subsequent fluctuation comparisons are performed. If irregular fluctuations continue, check whether the detection chamber 2 and the detection module are faulty. Continuous monitoring of irregular fluctuations can avoid erroneous detection results caused by problems with the detection equipment itself and improve the reliability of detection.

[0084] If the irregular fluctuation does not continue, step S2 is executed; retest to avoid inaccurate test results of the muffler due to a failure of the test equipment;

[0085] S4.2.2.2, when it is a regular fluctuation, execute step S4.3;

[0086] S4.3, comparing the real-time generated pressure-time curve with the standard fluctuation curve; this can provide a more intuitive and quantitative comparison, not only to determine whether the fluctuation is regular, but also to compare with the standard in terms of overall shape and trend;

[0087] S4.3.1. Divide the test time into several segments, analyze each curve separately, and determine the fluctuation time; this can more carefully evaluate the pressure changes in different time periods during the entire test cycle;

[0088] S4.3.2. Based on the analysis results of each segment, comprehensively evaluate the pressure changes during the entire test cycle;

[0089] S4.3.3. If the pressure fluctuation within any period of time exceeds the preset threshold, the silencer is judged to have an airtightness problem, and a detailed test report is generated, recording the time period and fluctuation amplitude of the abnormal fluctuation; if the pressure fluctuation within all time periods is within the preset threshold, the silencer is judged to have good airtightness, and a normal test report is generated.

[0090] The standard parts used in the present invention can all be purchased from the market, and special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the prior art. Machinery, parts and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here. The content not described in detail in this specification belongs to the prior art known to professional and technical personnel in this field.

[0091] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A muffler air tightness detection device, characterized in that: include: A test bench, a detection chamber installed on the top of the test bench, a gas supply module for supplying detection gas, a loading and unloading module for sending the muffler to be tested into the detection chamber before detection or taking the muffler that has been tested out of the detection chamber, and a detection module for performing air tightness detection on the muffler; The loading and unloading module includes: a slide rail fixedly mounted on the top of the test bench, a carrying basket slidably mounted on the slide rail, sub-magnetic components evenly spaced and mounted on the slide rail, a mother magnetic component fixedly mounted on the carrying basket and matched with the sub-magnetic components, and a correction component for correcting the posture of the muffler; The correction assembly includes: a circumferential correction piece for correcting the circumferential posture of the muffler, and an axial correction piece for correcting the axial position of the muffler; The bottom of the circumferential correcting member is magnetically connected to the female magnetic member; During loading, the female magnetic attraction part is energized to drive the carrying basket to slide into the detection cavity, and the circumferential posture and axial posture of the muffler are respectively corrected during sliding; The circumferential correcting member is arc-shaped and is slidably mounted on the carrying basket; The circumferential correction member is composed of an outer shell slidably connected to the carrying basket, an inner shell slidably mounted on the outer shell, a ball rollingly mounted on the inner shell, and a buffer member connecting the inner shell and the outer shell; There are a plurality of inner shells, which are connected to the outer shell at even intervals along the circumferential direction; The axial correction member is fixedly installed in the detection cavity, and comprises: a vertical plate, a mounting seat slidably installed on the vertical plate, a first motor installed on the mounting seat, a connecting member connected to the output end of the first motor, and a lifting member for driving the mounting seat to rise and fall is also provided at the bottom of the mounting seat; a capsule is detachably installed at the end of the connecting member; The sac is in a semi-filled state; and a telescopic rod is detachably connected to the surface of the sac; The mother magnetic attraction component is an electromagnetic coil; the child magnetic attraction component is a permanent magnet.

2. A muffler air tightness detection device as claimed in claim 1, characterized in that: The detection module includes: a pressure sensor for collecting real-time pressure in the detection cavity, a controller electrically connected to the pressure sensor, and a display electrically connected to the controller.

3. A muffler air tightness detection device as claimed in claim 2, characterized in that: The steps of the detection module to detect the air tightness of the muffler are as follows: S1, the controller controls to open the detection chamber; the silencer to be detected is placed on the carrying basket; the controller controls the loading and unloading module to transport the silencer into the detection chamber, and after completion, the detection chamber is closed; S2, the controller starts the gas source to fill the detection chamber with gas until the gas pressure in the detection chamber reaches a preset value; S3, closing the gas source and maintaining the gas source for a preset time; the pressure sensor monitors the gas pressure change in the detection chamber in real time and records the pressure data in real time; S4, the controller generates a pressure-time curve in response to the pressure data measured by the pressure sensor, analyzes the pressure change trend, and determines the air tightness of the muffler; S5, the display shows the test results and stores the test data; S6. After completing the air tightness test, open the pressure relief valve. When the gas pressure in the test chamber drops to a preset value, open the test chamber, control the loading and unloading modules to slide outward, and take out the muffler.

4. A muffler air tightness detection device as claimed in claim 3, characterized in that: Step S4 includes the following steps: S4.

1. Preset a standard fluctuation curve and preset a fluctuation threshold of the pressure-time curve; S4.

2. Check the fluctuation of the pressure-time curve; S4.2.

1. If the fluctuation is within the fluctuation threshold range, it shall be ignored; S4.2.2, if the fluctuation is outside the fluctuation threshold range, analyzing whether the fluctuation is irregular fluctuation; S4.2.2.

1. When the fluctuation is irregular, perform subsequent fluctuation comparison. If the fluctuation continues to be irregular, check whether the detection chamber and the detection module have faults. If the irregular fluctuation does not continue, step S2 is executed; S4.2.2.2, when it is a regular fluctuation, execute step S4.3; S4.3, comparing the real-time generated pressure-time curve with the standard fluctuation curve; S4.3.

1. Divide the test time into several segments, analyze each segment curve separately, and determine the fluctuation time; S4.3.

2. Based on the analysis results of each segment, comprehensively evaluate the pressure changes during the entire test cycle; S4.3.

3. If the pressure fluctuation in any period of time exceeds the preset threshold, the silencer is judged to have an airtightness problem and a detailed test report is generated; if the pressure fluctuation in all time periods is within the preset threshold, the silencer is judged to have good airtightness and a normal test report is generated.

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