A device for testing the air permeability of nonwoven fabrics

Abstract

This invention relates to the field of air permeability testing devices, and more particularly to an air permeability testing device for nonwoven fabrics. The device includes a base plate, a lower drum suspended and fixed to the base plate, and an upper drum positioned above the lower drum. The openings of the upper and lower drums are arranged opposite each other. A liftable support tray is installed inside the lower drum. A vertical plate is fixed to one side of the base plate, and a U-shaped lifting frame is slidably connected to the vertical plate. A linear module for driving the lifting frame to move up and down is installed on the vertical plate. The upper part of the lifting frame is fixed to the upper drum, and the lower part slides through the side wall of the lower drum and is fixed to the support tray. Through the coordinated operation of a rotating ring, curved guide rail, and linkage mechanism, multiple clamps move radially synchronously, applying a multi-directional uniform tensile force when clamping the fabric. Combined with a tension sensor to monitor the tension in real time, the amount of tension can be precisely adjusted to achieve air permeability testing of the fabric under different degrees of tension.

Description

Technical Field

[0001] This invention relates to the field of air permeability testing devices, and more particularly to an air permeability testing device for nonwoven fabrics. Background Technology

[0002] Nonwoven fabrics, due to their unique porous structure and functionality, are widely used in medical, filtration, and packaging fields. Their air permeability is an important indicator for evaluating material quality, reflecting the fabric's ability to conduct and transmit gas particles. The air permeability of fabrics is often expressed as air permeability rate, which refers to the amount of air passing through a unit area of ​​the fabric per unit time under a certain pressure difference.

[0003] In practical use, nonwoven fabrics are often subjected to varying degrees of tension, which alters the fabric's pore structure and directly affects its air permeability. Therefore, understanding the air permeability of fabrics under different tension conditions helps in evaluating their performance in practical use.

[0004] Currently, most conventional air permeability testing devices use static testing methods, which can only measure the air permeability of fabrics under no external force. They cannot simulate the actual working conditions of fabrics under tension, resulting in discrepancies between test results and actual application performance. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides a nonwoven fabric air permeability testing device.

[0006] The technical solution is as follows: A nonwoven fabric air permeability testing device includes a base plate, a lower drum suspended and fixed to the base plate, and an upper drum positioned above the lower drum. The openings of the upper drum and the lower drum are arranged opposite to each other. A liftable support tray is provided inside the lower drum. A vertical plate is fixed to one side of the base plate. A U-shaped lifting frame is slidably connected to the vertical plate, and a linear module for driving the lifting frame to move up and down is installed on the vertical plate. The upper part of the lifting frame is fixed to the upper drum, and the lower part of the lifting frame slides through the side wall of the lower drum and is fixed to the support tray. The lower part of the lifting frame is connected to the lower drum. The through-hole of the barrel is sealed with a retractable sealing sleeve. An air inlet is opened on the outer wall of the upper barrel, and an air inlet channel communicating with the air inlet is set on the outside of the upper barrel. A fan is installed in the air inlet channel. An exhaust port is opened in the middle of the bottom of the lower barrel, and a gas flow meter is installed in the exhaust port. An installation ring is set on the top of the lower barrel. Multiple fixing plates are arranged circumferentially on the installation ring. All fixing plates can move synchronously along the radial direction of the installation ring. Each fixing plate is connected to a clamp through a linkage mechanism. The linkage mechanism is configured to convert the linear displacement of the fixing plate into the clamping or releasing action of the clamp.

[0007] Preferably, the fixture includes clamp plate one and clamp plate two. Clamp plate two is slidably connected to a fixed plate. A tension sensor is installed inside the fixed plate. The measuring end of the tension sensor is connected to clamp plate two. Clamp plate one is positioned above clamp plate two and is connected to the fixed plate through a linkage mechanism.

[0008] Preferably, the linkage mechanism includes a rotating rod and a vertical rod. The rotating rod is rotatably connected to the top of the fixed plate. The first clamping plate is slidably connected to the rotating rod, and an elastic element is connected between the first clamping plate and the rotating rod. A liftable vertical rod is slidably connected to the fixed plate. The top of the vertical rod is movably connected to the end of the rotating rod away from the first clamping plate, so that the lifting and lowering of the vertical rod is converted into the clamping or releasing action of the first clamping plate relative to the second clamping plate through the rotating rod. A torsion spring is provided on the rotating shaft of the rotating rod to keep the vertical rod in a downward trend.

[0009] Preferably, the mounting ring includes a fixed ring and a rotating ring. The fixed ring is fixed to the top of the lower bucket, and the rotating ring is rotatably connected to the bottom of the fixed ring, with a gap between the rotating ring and the fixed ring. The fixed ring has multiple straight grooves on its circumferential side corresponding to the positions of the fixed plates, and each fixed plate is slidably connected in the groove. The top of the rotating ring has multiple curved guide rails corresponding to the positions of the straight grooves. The bottom end of the vertical rod extends downward into the curved guide rail. The bottom of the curved guide rail is provided with an inclined surface near the center of the rotating ring to guide the vertical rod to rise. When the rotating ring rotates, the curved guide rail can guide the vertical rod to drive the fixed plate to slide linearly along the groove.

[0010] Preferably, a bevel gear 1 is fixedly connected to the bottom of the rotating ring, a motor 1 is installed at the bottom of the fixed ring, and a bevel gear 2 is fixedly connected to the output shaft of the motor 1, with the bevel gear 2 meshing with the bevel gear 1.

[0011] Preferably, a visible gas generator is installed on the bottom plate, and the outlet of the visible gas generator is connected to the air inlet through an air pipe. The outer walls of both the upper and lower barrels are made of transparent material.

[0012] Preferably, a liftable lifting plate is slidably connected inside the upper bucket, and a linear module two for driving the lifting plate to rise and fall is installed inside the upper bucket. An upper wear rod is rotatably connected to the bottom of the lifting plate. The support tray includes two semi-menisci with a gap between them. A liftable U-shaped connecting frame is set in the gap between the two semi-menisci. A lower wear rod is rotatably connected to the middle of the connecting frame. Soft iron blocks are set at both ends of the connecting frame. Two electromagnets corresponding to the positions of the soft iron blocks are set at the bottom of the lifting plate.

[0013] Preferably, a mounting plate is fixedly connected to the middle of the lower barrel. The axis of the mounting plate and the center line of the gap between the two menisci are in the same vertical plane. The measuring probe of the gas flow meter is located inside the mounting plate. Both sides of the mounting plate have air holes that communicate with the measuring probe of the gas flow meter. The connecting frame is slidably connected to the upper part of the mounting plate. Motor 2 is installed inside the mounting plate. The rotating shaft of the lower wear rod and the output shaft of motor 2 are connected by a spline that can slide axially. Motor 3 is installed on the top of the lifting plate to drive the upper wear rod to rotate.

[0014] Preferably, both the lifting plate and the meniscus are equipped with dust collection hoods. The openings of the dust collection hoods on the lifting plate and the meniscus are opposite to each other, and the dust collection hood on the lifting plate is a retractable structure. The dust collection hoods are all connected to the outside of the C-shaped lifting frame through dust exhaust pipes.

[0015] Preferably, lighting is installed on the inner wall of the C-shaped lifting frame.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. This invention uses a rotating ring, curved guide rail and linkage mechanism to work together to make multiple clamps move radially synchronously. When clamping the fabric, a multi-directional uniform tensile force can be applied. Combined with a tension sensor to monitor the tension in real time, the amount of tension can be precisely adjusted to realize the air permeability test of the fabric under different degrees of tension.

[0018] 2. This invention simulates surface damage to the fabric during actual use by rotating the upper and lower wear rods in both directions relative to the upper and lower surfaces of the fabric. Combined with a dust collection hood to remove dust and debris in a timely manner, it ensures the accuracy of the breathability test after wear.

[0019] 3. This invention, through the combination of a transparent barrel and a visible gas generator, allows for direct observation of the gas penetration process through the fabric. The lighting further optimizes the observation environment, ensuring that detection details can still be observed under low light conditions. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0021] Figure 2 This is a three-dimensional structural cross-sectional view of the present invention.

[0022] Figure 3 This is an exploded view of the three-dimensional structure of the present invention.

[0023] Figure 4 This is a three-dimensional structural cross-sectional view of the mounting ring of the present invention.

[0024] Figure 5 This is a schematic diagram of the installation structure of bevel gear one, motor one, and bevel gear two of the present invention.

[0025] Figure 6 This is a three-dimensional structural diagram of the fixture of the present invention.

[0026] Figure 7 This is a schematic diagram of the installation structure of the linkage mechanism of the present invention.

[0027] Figure 8 This is a cross-sectional view of the installation structure of the dust cover of the present invention.

[0028] Figure 9This is a cross-sectional view of the installation structure of the lifting plate of the present invention.

[0029] Figure 10 This is a cross-sectional view of the installation structure of the upper and lower wear rods of the present invention.

[0030] Figure 11 This is an exploded view of the wear rod, connecting frame, and motor II of the present invention.

[0031] Explanation of reference numerals in the attached drawings: 101-Base plate, 102-Upright plate, 2-Upper bucket, 3-Lower bucket, 4-Supporting tray, 401-Half-mensplate, 5-Lifting frame, 6-Linear module one, 7-Sealing sleeve, 8-Air inlet, 9-Fan, 10-Gas flow meter, 11-Mounting ring, 1101-Fixing ring, 1102-Rotating ring, 1103-Slide groove, 1104-Curved guide rail, 1105-Inclined surface, 12-Fixing plate, 13-Clamp, 1301-Clamping plate one, 1302-Clamping plate two, 1303-Tension sensor 1304-Elastic component, 14-Linkage mechanism, 1401-Rotating rod, 1402-Vertical rod, 1403-Torsion spring, 1501-Bevel gear one, 1502-Motor one, 1503-Bevel gear two, 16-Visible gas generator, 17-Lifting plate, 18-Linear module two, 19-Upper wear rod, 20-Connecting frame, 21-Lower wear rod, 22-Soft iron block, 23-Electromagnet, 24-Mounting plate, 25-Motor two, 26-Motor three, 27-Dust hood, 28-Dust exhaust pipe, 29-Lighting lamp. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] An embodiment provides a nonwoven fabric air permeability testing device, such as Figures 1-11As shown, the system includes a base plate 101, a lower bucket 3, and an upper bucket 2. The lower bucket 3 is suspended and fixed to the base plate 101 via supports. The upper bucket 2 is positioned above the lower bucket 3, with the openings of the upper bucket 2 and lower bucket 3 facing each other. A liftable support tray 4 is installed inside the lower bucket 3 to temporarily support the fabric to be tested. A vertical plate 102 is fixed to one side of the base plate 101. A U-shaped lifting frame 5 is slidably connected to the vertical plate 102, and a vertical shaft is installed on the vertical plate 102 to drive the lifting frame 5 to move up and down. Linear module 6, in this embodiment, is a lead screw linear module. The lifting frame 5 is threadedly connected to the lead screw of the linear module 6. The upper part of the lifting frame 5 is fixedly connected to the upper bucket 2, and the lower part of the lifting frame 5 slides through the side wall of the lower bucket 3 and is fixedly connected to the support tray 4. By driving the lifting frame 5 to rise and fall through the linear module 6, the upper bucket 2 and the support tray 4 can be raised and lowered synchronously, thereby forming or releasing the sealed detection chamber. The lower part of the lifting frame 5 is sealed to the penetration part of the lower bucket 3 with a bellows-type telescopic seal. Set 7 ensures that the internal space of the lower bucket 3 and the external space can maintain air pressure isolation during the lifting process of the lifting frame 5, preventing air leakage from affecting the test results. An air inlet is opened on the outer wall of the upper bucket 2, and an air inlet channel 8 connected to the air inlet is provided on the outside of the upper bucket 2. A fan 9 is installed in the air inlet channel 8. An exhaust port is opened in the middle of the bottom of the lower bucket 3, and a gas flow meter 10 is installed in the exhaust port. In this embodiment, the gas flow meter 10 is electrically connected to the external control system. The gas flow meter 10 is used to measure the flow rate of the gas discharged through the exhaust port of the lower bucket 3 and feeds it back to the external control system for analysis and calculation of the air permeability of the fabric, providing data support for material quality assessment. An installation ring 11 is provided on the top of the lower bucket 3. Multiple fixing plates 12 are arranged circumferentially on the installation ring 11. All fixing plates 12 can move synchronously along the radial direction of the installation ring 11. Each fixing plate 12 is connected to a clamp 13 through a linkage mechanism 14. The linkage mechanism 14 is configured to convert the linear displacement of the fixing plate 12 into the clamping or releasing action of the clamp 13.

[0034] In this embodiment, the clamp 13 includes a first clamping plate 1301 and a second clamping plate 1302. The second clamping plate 1302 is slidably connected to the fixed plate 12. A tension sensor 1303 is installed inside the fixed plate 12. The measuring end of the tension sensor 1303 is connected to the second clamping plate 1302. The first clamping plate 1301 is positioned above the second clamping plate 1302 and is connected to the fixed plate 12 via a linkage mechanism 14. In this embodiment, the tension sensor 1303 is electrically connected to an external control system. The tension sensor 1303 monitors the tensile tension of the fabric by the clamp 13 in real time and feeds it back to the external control system.

[0035] In this embodiment, the linkage mechanism 14 includes a rotating rod 1401 and a vertical rod 1402. The rotating rod 1401 is rotatably connected to the top of the fixed plate 12. The clamping plate 1301 is slidably connected to the rotating rod 1401, and an elastic element 1304 is connected between the clamping plate 1301 and the rotating rod 1401. The vertical rod 1402, which can be raised and lowered, is slidably connected to the fixed plate 12. The top end of the vertical rod 1402 is movably connected to the end of the rotating rod 1401 away from the clamping plate 1301, so that the raising and lowering of the vertical rod 1402 is converted into the clamping or releasing action of the clamping plate 1301 relative to the clamping plate 1302 through the rotating rod 1401. A torsion spring 1403 is provided on the rotating shaft of the rotating rod 1401 so that the vertical rod 1402 maintains a downward trend, so that the clamp 13 can automatically release the fabric when there is no external force.

[0036] In this embodiment, the mounting ring 11 includes a fixed ring 1101 and a rotating ring 1102. The fixed ring 1101 is fixed to the top of the lower bucket 3, and the rotating ring 1102 is rotatably connected to the bottom of the fixed ring 1101, with a gap between the rotating ring 1102 and the fixed ring 1101. The fixed ring 1101 has a plurality of straight grooves 1103 corresponding to the positions of the fixed plates 12 circumferentially. Each fixed plate 12 is slidably connected in the grooves 1103. The top of the rotating ring 1102 is fixed with a plurality of curved guide rails 1104 corresponding to the positions of the straight grooves 1103. The bottom end of the vertical rod 1402 extends downward into the curved guide rail 1104. The bottom of the curved guide rail is provided with an inclined surface 1105 near the center of the rotating ring 1102 to guide the vertical rod 1402 to rise. When the rotating ring 1102 rotates, the curved guide rail 1104 can guide the vertical rod 1402 to drive the fixed plate 12 to slide linearly along the grooves 1103.

[0037] In this embodiment, a bevel gear 1501 is fixedly connected to the bottom of the rotating ring 1102, and a motor 1502 is installed at the bottom of the fixed ring 1101. A bevel gear 1503 is fixedly connected to the output shaft of the motor 1502. The bevel gear 1503 meshes with the bevel gear 1501. When the motor 1502 starts, the rotating ring 1102 can be driven to rotate through the meshing action of the bevel gear 1503 and the bevel gear 1501. Then, the vertical rod 1402 is guided to rise and fall through the curved guide rail 1104, so as to realize the synchronous clamping or releasing action of the clamp 13. This design can ensure that multiple clamps 13 apply multi-directional uniform tensile force when clamping the fabric, thereby improving the accuracy of detection.

[0038] In this embodiment, a visible gas generator 16 is provided on the base plate 101. The outlet of the visible gas generator 16 is connected to the air inlet 8 through an air pipe. When visual detection is required, the visible gas generator 16 can produce visible gas and deliver it into the air inlet 8. The outer walls of the upper barrel 2 and the lower barrel 3 are made of transparent material to allow for a direct view of the air permeability of the fabric inside the sealed detection chamber.

[0039] In this embodiment, a liftable lifting plate 17 is slidably connected inside the upper drum 2. A linear module 2 18 for driving the lifting plate 17 to rise and fall is installed inside the upper drum 2. In this embodiment, the linear module 2 18 is a lead screw linear module. The lifting plate 17 is threadedly connected to the lead screw of the linear module 1 6. An upper abrasion rod 19 is rotatably connected to the bottom of the lifting plate 17 for abrading the upper surface of the fabric. The support tray 4 includes two menisci 401 with a gap between them. A liftable U-shaped connecting frame 20 is provided in the gap between the two menisci 401. A rotatable U-shaped connecting frame 20 is rotatably connected to the middle of the connecting frame 20. The lower abrasion rod 21 is used to abrade the lower surface of the fabric. Soft iron blocks 22 are provided at both ends of the connecting frame 20. Two electromagnets 23 corresponding to the positions of the soft iron blocks 22 are provided at the bottom of the lifting plate 17. When the lifting plate 17 descends to the point where the upper abrasion rod 19 contacts the upper surface of the fabric, the distance between the electromagnets 23 and the soft iron blocks 22 reaches its minimum value. At this time, the electromagnets 23 are energized, and the electromagnets 23 can attract the soft iron blocks 22 to drive the connecting frame 20 to rise, so that the lower abrasion rod 21 contacts the lower surface of the fabric. After the power is turned off, the connecting frame 20 descends and resets under its own gravity.

[0040] In this embodiment, a mounting plate 24 is fixedly connected to the center of the lower tank 3. The axis of the mounting plate 24 and the center line of the gap between the two menisci 401 are in the same vertical plane. The measuring probe of the gas flow meter 10 is located inside the mounting plate 24. Both sides of the mounting plate 24 have air holes communicating with the measuring probe of the gas flow meter 10. The connecting bracket 20 is slidably connected to the upper part of the mounting plate 24. The top of the mounting plate 24 is made of magnetic material. A second motor 25 is installed inside the mounting plate 24. The rotating shaft of the lower wear rod 21 and the output shaft of the second motor 25 are connected by a spline that can slide axially. Specifically, the outer circumferential surface of the output shaft of the second motor 25 is provided with an axially extending... The inner wall of the shaft of the lower wear rod 21 is provided with spline teeth that cooperate with the spline groove. This spline connection structure allows the shaft of the lower wear rod 21 to slide along the axial direction of the output shaft of the second motor 25. At the same time, when the output shaft of the second motor 25 rotates, the torque is transmitted to the shaft of the lower wear rod 21 through the meshing of the spline groove and the spline teeth, thereby driving the shaft of the lower wear rod 21 to rotate synchronously. The top of the lifting plate 17 is equipped with a third motor 26 for driving the upper wear rod 19 to rotate. In this embodiment, when the second motor 25 and the third motor 26 are working, the output shafts of the two rotate in opposite directions.

[0041] In this embodiment, both the lifting plate 17 and the meniscus 401 are equipped with dust collection hoods 27. The dust collection hoods 27 on the lifting plate 17 are telescopic structures to adapt to the height changes when the lifting plate 17 is raised or lowered. The openings of the dust collection hoods 27 on the lifting plate 17 and the meniscus 401 are arranged opposite to each other. The dust collection hoods 27 are connected to the outside of the U-shaped lifting frame 5 through the dust exhaust pipe 28. During the fabric wear detection process, the dust collection hoods 27 can promptly suck up the generated dust and prevent the dust and debris from affecting the air permeability test results.

[0042] In this embodiment, a lighting lamp 29 is installed on the side of the C-shaped lifting frame 5 away from the upright plate 102 to enhance the brightness of the detection environment.

[0043] The working process of this invention is as follows: When it is necessary to test the air permeability of fabric after stretching, the fabric to be tested is cut into a circle and placed on the support tray 4 and the clamping plates 1302 of each clamp 13. The motor 1502 drives the bevel gear 1503 to rotate. Under the meshing transmission of the bevel gear 1503 and the bevel gear 1501, the rotating ring 1102 rotates relative to the fixed ring 1101, so that the curved guide rail on the rotating ring 1102 moves relative to the vertical rod 1402. Then, the vertical rod 1402 is pushed upward by the inclined surface 1105 of the curved guide rail, forcing the rotating rod 1402 to rise. 1. Overcoming the elastic force of the torsion spring 1403, the clamping plate 1301 rotates, causing it to clamp the fabric towards the clamping plate 1302. Simultaneously, the curved guide rail guides the vertical rod 1402, causing the fixing plate 12 to move linearly away from the center of the fixing ring 1101 along the slide groove 1103. This allows the fixing plate 12 to stretch the fabric while clamping it, along with the clamping plates 1301 and 1302. Under the synchronous stretching of multiple clamps 13, multi-directional uniform stretching can be applied to the fabric, facilitating the testing of the fabric's breathability after stretching. The tensile tension of the fabric is monitored in real time by a tension sensor 1303, and the feedback is sent to the external control system to adjust the operating status of motor 1502 to achieve the preset tension, facilitating the detection of the fabric's air permeability under different tension levels. Next, the linear module 6 drives the lifting frame 5 to descend vertically along the upright plate 102. The lifting frame 5 lowers the upper drum 2 and the support tray 4 together, causing the open ends of the upper drum 2 and the lower drum 3 to press against each other, forming a sealed detection chamber. Simultaneously, the support tray 4 descends to the lower part of the lower drum 3, keeping the fabric independent between the openings of the upper drum 2 and the lower drum 3. During the process, the retractable sealing sleeve 7 can ensure the relative movement between the lower part of the lifting frame 5 and the side wall of the lower drum 3, while ensuring the air pressure isolation between the internal space and the external space of the lower drum 3. Subsequently, the fan 9 works to inject external gas into the upper drum 2 through the air inlet 8. As the air pressure in the upper drum 2 increases, some gas can pass through the pores of the fabric and enter the lower drum 3 through the pressure difference. Finally, it is discharged through the measuring probe of the gas flow meter 10 and the exhaust port. The gas flow meter 10 can measure the motion properties of the discharged gas for subsequent calculation and analysis of the fabric's air permeability.

[0044] When it is necessary to visualize the air permeability testing process, the connection between the external gas and the air inlet 8 is disconnected, and visible gas is produced by the visible gas generator 16. The visible gas is then used as a gas source and delivered to the air inlet 8. The air permeability testing process described above is then repeated. The difference in this testing process is that the outer walls of the upper barrel 2 and the lower barrel 3 are made of transparent material, allowing clear observation of the process of visible gas passing through the fabric, thus making the entire testing process visible. In addition, when there is insufficient light, the ambient brightness can be enhanced by the lighting lamp 29 to improve the observation effect.

[0045] When it is necessary to test the breathability of the fabric after wear, the lifting plate 17 is lowered by the linear module 2 18 until the upper wear rod 19 contacts the upper surface of the fabric. Then, the electromagnet 23 is energized, causing it to attract the soft iron block 22 of the connecting frame 20 below. This causes the connecting frame 20 to move the lower wear rod 21 upward to contact the lower surface of the fabric. Subsequently, the lower wear rod 21 and the upper wear rod 19 are driven to rotate in opposite directions by the motors 25 and 26 respectively. Thus, the upper wear rod 19 wears the upper surface of the fabric, while the lower wear rod 21 wears the lower surface of the fabric, simulating the actual wear conditions of the fabric. After the wear is completed, When the electromagnet 23 is de-energized, the connecting frame 20 is driven by its own gravity to lower and reset the lower wear rod 21. The linear module 2 18 drives the lifting plate 17 to move the upper wear rod 19 in the opposite direction and reset it. The above air permeability test process is repeated. The difference in this test process is that both the upper and lower surfaces of the fabric have been worn. The air permeability test obtained is the air permeability after wear. This result can be compared with the air permeability of the fabric before wear. In addition, by connecting the external negative pressure device to the dust exhaust pipe 28 of the dust hood 27, the dust generated during the wear process of the fabric can be sucked up to avoid the dust affecting the air permeability test results of the fabric.

[0046] The above description is merely an embodiment of the present invention and is not intended to limit the present invention. All equivalent substitutions made within the principles of the present invention should be included within the scope of protection of the present invention. Contents not described in detail in this invention are existing technologies known to those skilled in the art.

Claims

1. A device for testing the air permeability of nonwoven fabrics, characterized in that: The device includes a base plate (101), a lower bucket (3) suspended and fixed to the base plate (101), and an upper bucket (2) positioned above the lower bucket (3). The openings of the upper bucket (2) and the lower bucket (3) are arranged opposite to each other. A liftable support tray (4) is provided inside the lower bucket (3). A vertical plate (102) is fixed to one side of the base plate (101). A U-shaped lifting frame (5) is slidably connected to the vertical plate (102). A linear module (6) for driving the lifting frame (5) to lift is installed on the vertical plate (102). The upper part of the lifting frame (5) is fixed to the upper bucket (2), and the lower part of the lifting frame (5) slides through the side wall of the lower bucket (3) and is fixed to the support tray (4). The lower part of the lifting frame (5) passes through the lower bucket (3). The sealing connection is provided with a retractable sealing sleeve (7). An air inlet is opened on the outer wall of the upper barrel (2). An air inlet channel (8) connected to the air inlet is provided on the outside of the upper barrel (2). A fan (9) is installed in the air inlet channel (8). An exhaust port is opened in the middle of the bottom of the lower barrel (3). A gas flow meter (10) is installed in the exhaust port. An installation ring (11) is provided on the top of the lower barrel (3). Multiple fixing plates (12) are arranged circumferentially on the installation ring (11). All fixing plates (12) can move synchronously along the radial direction of the installation ring (11). A clamp (13) is connected to each fixing plate (12) through a linkage mechanism (14). The linkage mechanism (14) is configured to convert the linear displacement of the fixing plate (12) into the clamping or releasing action of the clamp (13). The clamp (13) includes clamp plate one (1301) and clamp plate two (1302). Clamp plate two (1302) is slidably connected to the fixed plate (12). A tension sensor (1303) is installed in the fixed plate (12). The measuring end of the tension sensor (1303) is connected to clamp plate two (1302). Clamp plate one (1301) is located above clamp plate two (1302), and clamp plate one (1301) is connected to the fixed plate (12) through a linkage mechanism (14). The linkage mechanism (14) includes a rotating rod (1401) and a vertical rod (1402). The rotating rod (1401) is rotatably connected to the top of the fixed plate (12). The clamping plate (1301) is slidably connected to the rotating rod (1401), and an elastic element (1304) is connected between the clamping plate (1301) and the rotating rod (1401). The vertical rod (1402) is slidably connected to the fixed plate (12). The top end of the vertical rod (1402) is movably connected to the end of the rotating rod (1401) away from the clamping plate (1301) so that the lifting and lowering of the vertical rod (1402) is converted into the clamping or releasing action of the clamping plate (1301) relative to the clamping plate (1302) through the rotating rod (1401). A torsion spring (1403) is provided on the rotating shaft of the rotating rod (1401) so that the vertical rod (1402) maintains a downward trend. The mounting ring (11) includes a fixed ring (1101) and a rotating ring (1102). The fixed ring (1101) is fixed to the top of the lower bucket (3), and the rotating ring (1102) is rotatably connected to the bottom of the fixed ring (1101), with a gap between the rotating ring (1102) and the fixed ring (1101). The fixed ring (1101) has multiple straight grooves (1103) on its circumferential side corresponding to the positions of the fixed plates (12). Each fixed plate (12) is slidably connected in the groove (1103), and the rotating ring (1102) is rotatably connected to the bottom of the fixed ring (1101). 02) Multiple curved guide rails (1104) corresponding to the positions of the straight groove (1103) are fixed at the top. The bottom end of the vertical rod (1402) extends downward into the curved guide rail (1104). The bottom of the curved guide rail is provided with an inclined surface (1105) for guiding the vertical rod (1402) to rise near the center of the rotating ring (1102). When the rotating ring (1102) rotates, the curved guide rail (1104) can guide the vertical rod (1402) to drive the fixed plate (12) to slide linearly along the groove (1103). A bevel gear 1 (1501) is fixedly connected to the bottom of the rotating ring (1102), a motor 1 (1502) is installed at the bottom of the fixed ring (1101), and a bevel gear 2 (1503) is fixedly connected to the output shaft of the motor 1 (1502). The bevel gear 2 (1503) meshes with the bevel gear 1 (1501). The upper bucket (2) is slidably connected to a lifting plate (17). The upper bucket (2) is equipped with a linear module two (18) for driving the lifting plate (17) to rise and fall. The bottom of the lifting plate (17) is rotatably connected to an upper wear rod (19). The support tray (4) includes two half-menisses (401) with a gap between them. A lifting U-shaped connecting frame (20) is provided in the gap between the two half-menisses (401). A lower wear rod (21) is rotatably connected in the middle of the connecting frame (20). Soft iron blocks (22) are provided at both ends of the connecting frame (20). Two electromagnets (23) corresponding to the positions of the soft iron blocks (22) are provided at the bottom of the lifting plate (17). A mounting plate (24) is fixedly connected to the middle of the lower bucket (3). The axis of the mounting plate (24) and the center line of the gap between the two half-menisses (401) are in the same vertical plane. The measuring probe of the gas flow meter (10) is located inside the mounting plate (24). Both sides of the mounting plate (24) have air holes that communicate with the measuring probe of the gas flow meter (10). The connecting frame (20) is slidably connected to the upper part of the mounting plate (24). The second motor (25) is installed inside the mounting plate (24). The rotating shaft of the lower wear rod (21) and the output shaft of the second motor (25) are connected by a spline that can slide axially. The top of the lifting plate (17) is equipped with a third motor (26) for driving the upper wear rod (19) to rotate.

2. The nonwoven fabric air permeability testing device according to claim 1, characterized in that: A visible gas generator (16) is installed on the base plate (101). The outlet of the visible gas generator (16) is connected to the air inlet (8) through the air pipe. The outer walls of the upper barrel (2) and the lower barrel (3) are made of transparent material.

3. The nonwoven fabric air permeability testing device according to claim 2, characterized in that: Dust hoods (27) are provided on both the lifting plate (17) and the meniscus (401). The openings of the dust hoods (27) on the lifting plate (17) and the meniscus (401) are opposite to each other. The dust hoods (27) on the lifting plate (17) are telescopic structures. The dust hoods (27) are all connected to the outside of the C-shaped lifting frame (5) through the dust exhaust pipe (28).

4. The nonwoven fabric air permeability testing device according to claim 3, characterized in that: A lighting lamp (29) is installed on the inner wall of the C-shaped lifting frame (5).

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