A fabric air permeability tester

Abstract

The present invention relates to the technical field of fabric performance testing devices, and in particular to a fabric air permeability tester, comprising a frame, a fan, a gas delivery unit, an air cavity, a vent plate, a clamp and a differential pressure gauge, wherein the fan is connected to the air cavity through the gas delivery unit, and the gas delivery unit comprises a delivery pipeline, a solenoid valve and a flow meter, one end of the delivery pipeline is connected to the fan, and the other end is connected to the air cavity, the solenoid valve is arranged on the delivery pipeline, the flow meter is arranged on the delivery pipeline between the solenoid valve and the air cavity, the vent plate is arranged directly above the air cavity, the clamp is arranged directly above the vent plate, the clamp is used to press the fabric sample on the vent plate, and the differential pressure gauge is connected to the air cavity and the inner cavity of the clamp respectively. This solution will not cause pipeline blockage, is more stable for long-term operation, is suitable for constant pressure air volume measurement test, is simpler to operate, has higher test data accuracy, and is more competitive in the market.

Description

Technical Field

[0001] The invention relates to the technical field of fabric performance testing devices, and in particular to a fabric air permeability tester. Background Art

[0002] Fabric is a flat soft piece of material made of small and long pieces that are crossed, entangled or bonded. As the main material of clothing, its various usage indicators are also highly valued by the clothing industry. Breathability, as one of the main parameters of fabric usage indicators, greatly affects the comfort of fabric. Winter clothing needs lower breathability to ensure warmth, while summer clothing needs higher breathability to ensure coolness.

[0003] At present, the air permeability of fabrics is generally tested by air permeability testing devices. The air permeability testing device directly relies on a simple small nozzle to suck air, and obtains the pressure difference between the upper and lower surfaces of the fabric by quantifying the amount of sucked air, and then obtains the air permeability index according to the relevant calculation formula. However, when using the above quantitative pressure measurement air permeability testing device, the nozzle structure is small and very easy to be blocked by dust. The long-term air permeability test has poor stability and the test results are not accurate enough. At the same time, the control of the ventilation volume is relatively difficult and is easily affected by many factors such as the fan, resulting in inaccurate test data and affecting the fabric air permeability analysis results. Summary of the invention

[0004] To this end, a fabric air permeability tester is needed to solve the problems that the existing air permeability test device is prone to nozzle clogging, has poor long-term working stability, and the air volume control accuracy of the quantitative pressure test device is not high, resulting in poor test data accuracy.

[0005] To achieve the above-mentioned purpose, the inventor provides a fabric air permeability tester, which includes a frame, a fan, a gas delivery unit, an air cavity, a breathable orifice plate, a clamp and a differential pressure gauge, wherein the fan is connected to the air cavity through the gas delivery unit, and the gas delivery unit includes a delivery pipeline, a solenoid valve and a flow meter, one end of the delivery pipeline is connected to the fan, and the other end is connected to the air cavity, the solenoid valve is arranged on the delivery pipeline, the flow meter is arranged on the delivery pipeline between the solenoid valve and the air cavity, the air cavity is fixed on the frame, the breathable orifice plate is arranged directly above the air cavity, the clamp is arranged directly above the breathable orifice plate, a gap for placing a fabric sample is provided between the clamp and the breathable orifice plate, the clamp is used to press the fabric sample onto the breathable orifice plate, the differential pressure gauge is connected to the air cavity and the inner cavity of the clamp respectively, and the differential pressure gauge is used to measure the air pressure difference between the upper surface and the lower surface of the fabric sample.

[0006] As a preferred structure of the present invention, the clamp includes an upper pressure head, a pressure cover, a guide shaft, a compression spring, a sample pressing head, a pressure plate and a blocking plate. The upper pressure head and the pressure plate are both hollowly sleeved outside the sample pressing head. The pressure plate is located above the upper pressure head. The guide shaft is evenly arranged around the outside of the sample pressing head. One end of the guide shaft is fixed to the sample pressing head, and the other end is hollowly sleeved in the axial hole of the upper pressure head. The guide shaft can slide along the axial hole. The compression spring is sleeved outside the guide shaft, and the blocking plate is fixed to the upper end of the upper pressure head.

[0007] As a preferred structure of the present invention, the tester also includes a clamping and lifting mechanism, which includes a connecting long plate, a swing arm, a base, a gas spring, an electromagnet and a limit rod. The connecting long plate is arranged on the swing arm, and one end of the connecting long plate is fixed to the clamper. The swing arm is hinged and fixed to the base, and the swing arm can rotate around a hinge point with the base. One end of the gas spring is connected to the frame, and the other end is connected to the swing arm. The limit rod is connected to the electromagnet, and the limit rod is inserted into or moved out of the limit slot on the swing arm under the drive of the electromagnet.

[0008] As a preferred structure of the present invention, the clamp also includes a buckle and a positioning pin, the buckle is arranged at one end of the upper pressure head, the positioning pin is arranged on the side wall of the upper pressure head, a positioning hole is opened on the connecting long plate, the positioning hole is adapted to the positioning pin, and the connecting long plate is connected to the upper pressure head by the buckle.

[0009] As a preferred structure of the present invention, at least two contact holes are formed on the side of the connecting long plate facing the upper pressure head, and a contact rod is provided on the side wall of the upper pressure head, and the contact rod can extend into the contact hole for contact and conduction.

[0010] As a preferred structure of the present invention, the clamp further comprises a rubber gasket, and the rubber gasket is arranged on the lower end surface of the sample pressing head.

[0011] As a preferred structure of the present invention, the clamp further comprises a pipe joint, one end of which is connected to the central inner hole of the sample pressing head, and the other end of which is connected to the differential pressure gauge.

[0012] As a preferred structure of the present invention, the gas delivery units are at least two groups, and the at least two groups of gas delivery units are respectively connected to the ventilator and the air cavity.

[0013] As a preferred structure of the present invention, a rubber pad is further provided between the air cavity and the air permeable plate, and the air cavity, the air holes of the air permeable plate and the central inner hole of the sample pressing head are aligned vertically.

[0014] As a preferred structure of the present invention, an annular receiving groove is further provided at the upper end surface of the air cavity, a support net is provided in the annular receiving groove, and a filter net is further provided inside the air cavity, and the gas in the air cavity enters the conveying pipeline through the filter net.

[0015] Different from the prior art, the above technical solution has the following advantages: the present invention is a fabric air permeability tester, which is configured by placing a fabric sample on a breathable plate, and pressing the fabric sample by a clamp to prevent leakage at the edge, starting the fan, and exhausting the gas. The gas enters the fan through the clamp, the fabric sample, the breathable plate, the air cavity and the gas delivery unit in sequence, and is discharged to the outside of the frame. The gas delivery unit is provided with an electromagnetic valve for controlling the on-off of the delivery channel. The gas drawn in by the fan enters the delivery pipeline from the air cavity, and the gas flow is measured by a flow meter provided on the delivery pipeline. The differential pressure gauge is connected to the air cavity and the inner cavity of the clamp respectively, and the differential pressure gauge is used to measure the air pressure difference between the upper and lower surfaces of the fabric sample. In this solution, by fixing the air pressure difference between the upper and lower surfaces of the fabric sample, when the differential pressure gauge measures that the air pressure difference between the upper and lower surfaces of the fabric sample reaches the specified requirement, the flow value currently measured on the flow meter is the air permeability of the fabric sample. The fabric air permeability tester of the present invention is ventilated through a large pipe, will not be blocked, and is more stable when working for a long time. At the same time, it is suitable for a test method of measuring air volume at a constant air pressure. The test is simpler, the test data is more accurate, and the market competitiveness is stronger. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a cross-sectional structure of a fabric air permeability tester according to a specific implementation method;

[0017] Figure 2 It is a schematic diagram of the oblique structure of a fabric air permeability tester according to a specific implementation method;

[0018] Figure 3 It is a schematic diagram of the cross-sectional structure of a clamp in a fabric air permeability tester described in a specific implementation manner.

[0019] Description of reference numerals:

[0020] 1. Frame;

[0021] 2. Fan;

[0022] 3. Gas delivery unit;

[0023] 31. Delivery pipeline; 32. Solenoid valve; 33. Flow meter;

[0024] 4. Air cavity;

[0025] 5. Ventilation plate;

[0026] 6. Clamp;

[0027] 61, upper pressure head; 610, positioning pin; 620, touch rod;

[0028] 62. Gland;

[0029] 63. Guide shaft;

[0030] 64. Compression spring;

[0031] 65, sample pressing head; 650, blocking plate;

[0032] 66. Press plate;

[0033] 67. Buckle

[0034] 68. Rubber gasket;

[0035] 69. Pipe joint;

[0036] 7. Differential pressure gauge;

[0037] 8. Fabric samples;

[0038] 9. Clamping and lifting mechanism;

[0039] 91. Connect the longboard;

[0040] 92. Arm swing;

[0041] 93. Base;

[0042] 94. Gas spring;

[0043] 95. Electromagnet;

[0044] 96. Limit rod;

[0045] 97. Pin;

[0046] 98. Buckle;

[0047] 10. Rubber pad;

[0048] 11. Support net;

[0049] 12. Filter. DETAILED DESCRIPTION

[0050] In order to explain the technical content, structural features, achieved objectives and effects of the technical solution in detail, the following is a detailed description in conjunction with specific embodiments and accompanying drawings.

[0051] See also Figures 1 to 3The present invention provides a fabric air permeability tester, the tester includes a frame 1, a fan 2, a gas delivery unit 3, an air cavity 4, a breathable plate 5, a clamp 6 and a differential pressure gauge 7, the fan 2 is connected to the air cavity 4 through the gas delivery unit 3, the gas delivery unit 3 includes a delivery pipeline 31, a solenoid valve 32 and a flow meter 33, one end of the delivery pipeline 31 is connected to the fan 2, and the other end is connected to the air cavity 4, the solenoid valve 32 is arranged on the delivery pipeline 31, and the flow meter 33 is arranged On the delivery pipeline 31 between the solenoid valve 32 and the air cavity 4, the air cavity 4 is fixed on the frame 1, the air vent plate 5 is arranged directly above the air cavity 4, the clamp 6 is arranged directly above the air vent plate 5, there is a gap between the clamp 6 and the air vent plate 5 for placing the fabric sample 8, the clamp 6 is used to press the fabric sample 8 on the air vent plate 5, the differential pressure gauge 7 is connected to the air cavity 4 and the inner cavity of the clamp 6 respectively, and the differential pressure gauge 7 is used to measure the air pressure difference between the upper surface and the lower surface of the fabric sample 8. The frame 1 is used as the main structure of the tester of the present invention, and is used to install and carry components such as the fan 2, the gas delivery unit 3, the air cavity 4, the air vent plate 5, the clamp 6 and the differential pressure gauge 7. Preferably, the frame 1 is made of stainless steel, and the frame 1 is not easy to rust and affect the normal use of the device.

[0052] The fan 2 is an exhaust fan and a negative pressure fan, which is used to draw gas from the outside of the body into the holder 6 through the gas delivery unit 3 and the air cavity 4, so as to perform the air permeability test of the fabric sample 8. The gas delivery unit 3 is used to deliver gas between the fan 2 and the air cavity 4. Specifically, the gas delivery unit 3 includes a delivery pipeline 31, a solenoid valve 32 and a flow meter 33. The delivery pipeline 31 is used for gas delivery, the solenoid valve 32 is used to control the on and off of the delivery channel, and the flow meter 33 is used to measure the air volume passing through the delivery pipeline 31 in real time, that is, the gas flow through the fabric sample 8. The air cavity 4 is used as a gas accommodating space. The gas passes through the central through hole of the holder 6, passes through the fabric sample 8, the air permeable plate 5 in turn, enters the air cavity 4, and then is transported through the gas delivery unit 3. By transporting gas through the above large pipeline flow path, there will be no nozzle clogging as in the traditional test device, and it is more stable for long-term operation. The air permeable plate 5 is used to carry the flat fabric sample 8 and limit the test area of ​​the fabric sample 8, which is more convenient for air permeability testing. The clamp 6 is used to firmly fix the fabric sample 8 on the air perforated plate 5, on the one hand to prevent the fabric sample 8 from being blown away and displaced, and on the other hand to seal the outer edge of the fabric sample 8 to prevent inaccurate test results due to gas leakage. The differential pressure gauge 7 is connected to the air cavity 4 and the inner cavity of the clamp 6 respectively, and the differential pressure gauge 7 is used to measure the air pressure difference between the upper surface and the lower surface of the fabric sample 8.

[0053] In this embodiment, the experimenter first places a permeable plate 5 that meets the requirements on the upper opening of the air cavity 4, and lays the fabric sample 8 on the permeable plate 5, then clamps the fabric sample 8 through the clamp 6, and then starts the fan 2 to start the air permeability test. The airflow passes through the fabric sample 8, the permeable plate 5, the air cavity 4, the gas delivery unit 3 and the fan 2 in sequence from the clamp 6. When the fan 2 is running, after the gas passes through the fabric sample 8, a certain pressure difference is generated between the upper and lower surfaces of the fabric sample 8, and the pressure difference between the upper and lower surfaces of the fabric sample 8 is measured by the differential pressure gauge 7 set in the tester. When the pressure difference detected by the differential pressure gauge 7 meets the system requirements, the flow value measured by the flow meter 33 set on the delivery pipeline 31 is the air permeability of the fabric sample 8 under the current test area. The experimenter can then obtain the air permeability index according to the relevant calculation formula.

[0054] The present embodiment is a fabric air permeability tester, which is configured by placing a fabric sample 8 on a breathable plate 5, and pressing the fabric sample 8 by a clamp 6 to prevent air leakage at the edge, starting the fan 2, and exhausting the air. The gas enters the fan 2 through the clamp 6, the fabric sample 8, the breathable plate 5, the air cavity 4 and the gas delivery unit 3 in sequence, and is discharged to the outside of the frame 1. The gas delivery unit 3 is provided with a solenoid valve 32 for controlling the on-off of the delivery channel. The gas drawn in by the fan 2 enters the delivery pipeline 31 from the air cavity 4, and the gas flow is measured by a flow meter 33 provided on the delivery pipeline 31. The differential pressure gauge 7 is connected to the air cavity 4 and the inner cavity of the clamp 6 respectively, and the differential pressure gauge 7 is used to measure the air pressure difference between the upper surface and the lower surface of the fabric sample 8. In this scheme, by fixing the air pressure difference between the upper and lower surfaces of the fabric sample 8, when the differential pressure gauge 7 measures that the air pressure difference between the upper and lower surfaces of the fabric sample 8 reaches the specified requirement, the flow value currently measured on the flow meter 33 is the air permeability of the fabric sample 8. The fabric air permeability tester of the present invention is ventilated through a large pipe, will not be blocked, and is more stable when working for a long time. At the same time, it is suitable for a test method of measuring air volume at a constant air pressure. The test is simpler, the test data is more accurate, and the market competitiveness is stronger.

[0055] like Figure 1 and Figure 3As shown, in a specific embodiment, the clamp 6 includes an upper pressure head 61, a pressure cover 62, a guide shaft 63, a compression spring 64, a sample pressing head 65, a pressure plate 66 and a plugging plate 650. The upper pressure head 61 and the pressure plate 66 are both hollowly sleeved outside the sample pressing head 65. The pressure plate 66 is located above the upper pressure head 61. The guide shaft 63 is evenly arranged around the outside of the sample pressing head 65. One end of the guide shaft 63 is fixed to the sample pressing head 65, and the other end is hollowly sleeved in the axial hole of the upper pressure head 61 and a pressure cover 62 is provided at the end. The guide shaft 63 can slide along the axial hole. The compression spring 64 is sleeved outside the guide shaft 63, and the plugging plate 650 is fixed to the upper end of the upper pressure head 61. In this embodiment, the experimenter presses the clamp 6 downward through the pressing plate 66, driving the upper pressing head 61 to move downward, so that the guide shaft 63 can move along the shaft hole of the upper pressing head 61, until the compression spring 64 sleeved outside the guide shaft 63 abuts against the upper pressing head 61, and the compression spring 64 contracts, and the spring generated by it pushes the sample pressing head 65 downward, so that the sample pressing head 65 moves downward, so that the sample pressing head 65 presses the fabric sample 8 against the vent plate 5. The setting function of the compression spring 64 is to adapt to fabric samples 8 of different thicknesses, so that the tester of the present invention has a wider range of applications and stronger market competitiveness.

[0056] See also Figure 1As a preferred embodiment of the present invention, the tester further comprises a clamping and lifting mechanism 9, which comprises a connecting long plate 91, a swing arm 92, a base 93, a gas spring 94, an electromagnet 95 and a limit rod 96. The connecting long plate 91 is arranged on the swing arm 92, one end of the connecting long plate 91 is fixed to the clamp 6, the swing arm 92 is hinged and fixed to the base 93, and the swing arm 92 can rotate around the hinge point between it and the base 93. One end of the gas spring 94 is connected to the frame 1, and the other end is connected to the swing arm 92. The limit rod 96 is connected to the electromagnet 95, and the limit rod 96 is inserted into or removed from the limit groove on the swing arm 92 under the drive of the electromagnet 95. Preferably, the swing arm 92 and the base 93 are hinged and fixed by a pin 97. In this embodiment, when the clamp 6 is used to press down and clamp the fabric sample 8, the upper pressure head 61 can drive the connecting long plate 91 to move downward during the pressing process, so that the swing arm 92 hinged to the base 93 moves downward. When the vertical rod section of the swing arm 92 moves downward to a specified position, the electromagnet 95 is energized to control the limit rod 96 to be inserted into the limit groove of the base 93, so as to limit the swing arm 92, and then fix the position of the clamp 6, so that the clamp 6 can press the fabric sample 8 against the air vent plate 5. At this time, one end of the swing arm 92 rotates downward, and the other end must move upward, so that the gas spring 94 extends. At this time, the gas spring 94 has a downward elastic restoring force. When it is necessary to lift the clamp 6, the electromagnet 95 only needs to control the limit rod 96 to move out of the limit groove of the swing arm 92. Under the action of the restoring force of the gas spring 94, the swing arm 92 moves up and down, so that the connecting long plate 91 and the clamp 6 are lifted upward, which makes it more convenient to install and replace the fabric sample 8. Preferably, the spring is a traction gas spring 94. The traction gas spring 94 (tension gas spring 94) is a special gas spring 94. Other gas springs 94 are in the longest position when in a free state, that is, they move from the longest position to the shortest position after being subjected to external force, while the traction gas spring 94 is in the shortest position in the free state, and moves from the shortest position to the longest position when being pulled. The traction gas spring 94 is smaller in size and more convenient to install.

[0057] See also Figures 1 to 3As a preferred embodiment of the present invention, the clamp 6 also includes a buckle 67 and a positioning pin 610, the buckle 67 is arranged at one end of the upper pressure head 61, the positioning pin 610 is arranged on the side wall of the upper pressure head 61, and a positioning hole is opened on the connecting long plate 91, the positioning hole is adapted to the positioning pin 610, and the connecting long plate 91 is connected to the upper pressure head 61 through the buckle 67. The buckle 67, as the name implies, is an object overlapped between two objects for fastening. In this scheme, a positioning pin 610 is arranged on the side wall of the upper pressure head 61, and a positioning hole is arranged at a corresponding position on the connecting long plate 91. Through the cooperation of the positioning pin 610 and the positioning hole, the connecting long plate 91 can be quickly connected to the upper pressure head 61 of the clamp 6, and the docking accuracy is high. Then, the connecting long plate 91 and the upper pressure head 61 are further fixed by the buckle 67, and the fixing is firm and convenient for disassembly and assembly.

[0058] In some specific embodiments, at least two contact holes are formed on the side of the connecting long plate 91 facing the upper pressure head 61, and a touch rod 620 is provided on the side wall of the upper pressure head 61, and the touch rod 620 can be inserted into the contact hole for contact conduction. In this embodiment, the touch control and the touch rod 620 form a trigger structure, and the specification of the current clamp 6 is judged by the number of contact points, and then the specification of the fabric sample 8 currently undergoing the air permeability test is judged, so as to select a suitable air pressure difference and a gas delivery unit 3 for testing. In a specific embodiment, three contact holes are arranged side by side on the side wall of the connecting long plate 91, and a contact point is arranged inside each contact hole. The clamps 6 used have different specifications, and the number or position of the contact rods 620 on the side wall of the upper pressure head 61 of the clamps 6 of different specifications are different. When the contact rods 620 extend into the contact holes and conduct with the contacts, the conduction signal is transmitted to the control system, and the control system can judge the specifications of the clamps 6 currently used through different trigger signals, and can obtain the specifications of the current fabric sample 8 according to the corresponding relationship, so as to facilitate the permeability test. In some preferred embodiments, the gas delivery units 3 are at least two groups, and at least two groups of gas delivery units 3 are connected to the ventilator 2 and the air cavity 4 respectively. In actual work, the gas delivery units 3 are arranged side by side, and the opening or closing of the solenoid valves 32 in the gas delivery units 3 can be controlled by the control system, so that different delivery pipes 31 can be selected for connection according to needs to realize multiple test experiments with different flow rates, and the fabric permeability tester of the present invention has stronger applicability.

[0059] See also Figure 3As a preferred embodiment of the present invention, the clamp 6 further includes a rubber gasket 68, which is disposed on the lower end surface of the sample pressing head 65. The provision of the rubber gasket 68 can further ensure the sealing between the sample pressing head 65 and the outer edge of the fabric sample 8, preventing gas leakage from affecting the accuracy of the test data. In a preferred embodiment, in order to ensure good sealing, a rubber gasket 10 is further provided between the air cavity 4 and the air permeable plate 5, and the air holes of the air cavity 4, the air permeable plate 5 and the central inner hole of the sample pressing head 65 are aligned up and down.

[0060] See also Figure 1 and Figure 3 As a preferred embodiment of the present invention, the holder 6 further comprises a pipe joint 69, one end of which is connected to the central inner hole of the sample pressing head 65, and the other end of which is connected to the differential pressure gauge 7. The arrangement of the pipe joint 69 facilitates the connection between the differential pressure gauge 7 and the central inner hole of the sample pressing head 65, with high connection efficiency and good butt sealing.

[0061] like Figure 3 In the preferred embodiment shown, an annular receiving groove is further provided at the upper end surface of the air cavity 4, a support net 11 is provided in the annular receiving groove, and a filter net 12 is further provided inside the air cavity 4, and the gas in the air cavity 4 enters the delivery pipe 31 through the filter net 12. The support net 11 can be used to support the fabric sample 8 from below when the air holes of the air perforated plate 5 are large, so as to prevent the fabric sample 8 from being greatly deformed due to the negative pressure of the fan 2 when the air is sucked during the test, thereby affecting the accuracy of the test results.

[0062] It should be noted that, although the above embodiments have been described in this article, the scope of patent protection of the present invention is not limited thereby. Therefore, based on the innovative concept of the present invention, changes and modifications made to the embodiments described herein, or equivalent structures or equivalent process changes made using the contents of the present specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields are all included in the scope of protection of the patent of the present invention.

Claims

1. A fabric air permeability tester, characterized in that: The tester includes a frame, a fan, a gas delivery unit, an air cavity, a vent plate, a clamp, a differential pressure gauge and a clamping and lifting pressure mechanism. The fan is connected to the air cavity through the gas delivery unit. The gas delivery unit includes a delivery pipeline, a solenoid valve and a flow meter. One end of the delivery pipeline is connected to the fan, and the other end is connected to the air cavity. The solenoid valve is arranged on the delivery pipeline. The flow meter is arranged on the delivery pipeline between the solenoid valve and the air cavity. The air cavity is fixed on the frame, and the vent plate is arranged directly above the air cavity. The clamp is arranged just above the air perforated plate, and the clamp comprises an upper pressure head, a pressure cover, a guide shaft, a compression spring, a sample pressing head, a pressure plate and a blocking plate. The upper pressure head and the pressure plate are both hollowly sleeved outside the sample pressing head, and the pressure plate is located above the upper pressure head. The guide shaft is uniformly arranged around the outside of the sample pressing head, one end of the guide shaft is fixed to the sample pressing head, and the other end is hollowly sleeved in the shaft hole of the upper pressure head, and the guide shaft can slide along the shaft hole, the compression spring is sleeved outside the guide shaft, and the blocking plate is fixed to the upper end of the upper pressure head, and there is a sealing member between the clamp and the air perforated plate. The gap is used to place the fabric sample, and the clamp is used to press the fabric sample on the air vent plate. The clamp also includes a pipe joint, one end of which is connected to the central inner hole of the sample pressing head, and the other end of the pipe joint is connected to a differential pressure gauge, which is connected to the air cavity and the inner cavity of the clamp respectively. The differential pressure gauge is used to measure the air pressure difference between the upper surface and the lower surface of the fabric sample. The clamping and lifting mechanism includes a connecting long plate, a swing arm, a base, a gas spring, an electromagnet and a limit rod. The connecting long plate is arranged on the swing arm, and one end of the connecting long plate is connected to the swing arm. The upper pressure head is fixed with the clamp, and at least two contact holes are formed on the side of the connecting long plate facing the upper pressure head. A contact rod is provided on the side wall of the upper pressure head, and the contact rod can be extended into the contact hole for contact and conduction. The swing arm is hinged and fixed to the base, and the swing arm can rotate around the hinge point with the base. One end of the gas spring is connected to the frame, and the other end is connected to the swing arm. The limit rod is connected to the electromagnet. The limit rod is inserted into or moved out of the limit groove on the swing arm under the drive of the electromagnet to limit the swing arm, thereby fixing the position of the clamp.

2. The fabric air permeability tester according to claim 1, characterized in that: The clamp also includes a buckle and a positioning pin, the buckle is arranged at one end of the upper pressure head, the positioning pin is arranged on the side wall of the upper pressure head, a positioning hole is opened on the connecting long plate, the positioning hole is adapted to the positioning pin, and the connecting long plate is connected to the upper pressure head through the buckle.

3. The fabric air permeability tester according to claim 1, characterized in that: The clamp also includes a rubber gasket, which is arranged on the lower end surface of the sample pressing head.

4. The fabric air permeability tester according to claim 1, characterized in that: The gas delivery units are at least two groups, and the at least two groups of gas delivery units are respectively connected to the ventilator and the air cavity.

5. The fabric air permeability tester according to claim 1, characterized in that: A rubber pad is also arranged between the air cavity and the air permeable plate, and the air cavity, the air holes of the air permeable plate and the central inner hole of the sample pressing head are aligned up and down.

6. The fabric air permeability tester according to claim 1, characterized in that: An annular receiving groove is also provided at the upper end surface of the air cavity, a supporting net is provided in the annular receiving groove, and a filter net is also provided inside the air cavity, and the gas in the air cavity enters the conveying pipeline through the filter net.

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