Breathability testing device for cloth

Abstract

The invention relates to the technical field of detection, in particular to a cloth air permeability testing device which comprises a workbench and a pressing mechanism, and the pressing mechanism comprises a supporting ring, a driving assembly and a pressing assembly. In the process that the two supporting rings get close to each other, the pressing assembly firstly provides a plurality of drawing forces which are evenly distributed in the circumferential direction of the installation cylinder and act in the direction away from the axis of the installation cylinder in the radial direction of the installation cylinder for cloth on the outer side of the cylinder opening of the installation cylinder to conduct primary flattening on wrinkles of the cloth, and then the pressing assembly conducts secondary flattening on the cloth corresponding to the cylinder opening of the installation cylinder. A plurality of stretching forces which are uniformly distributed in the circumferential direction of the mounting cylinder and act in the radial direction of the mounting cylinder towards the direction away from the axis of the mounting cylinder are provided for secondary flattening, so that the cloth is hermetically connected with the cylinder opening of the mounting cylinder, and the cloth is stretched and flattened twice to prevent the cloth from wrinkling or bulging during detection to influence the detection result.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and particularly relates to a device for testing the air permeability of fabrics. Background Art

[0002] The air permeability is a physical index characterizing the air penetration performance in the tested sample, mainly for materials with large air permeability such as porous materials, such as textiles, sponges, leather, etc. For fabric materials, the size of its air permeability is related to factors such as the gaps between warp and weft yarns and fiber gaps in the fabric, warp and weft density, yarn twist, fiber properties, yarn structure, fabric thickness, etc. During the process of detecting the air permeability, in order to obtain the air permeability of a large area of the fabric, the fabric is usually straightened as a whole to facilitate obtaining the air permeability data of the fabric detection area. The commonly used differential pressure method or flow method is used to detect the air permeability of the fabric.

[0003] In the prior art, for example, in a Chinese patent with the publication number CN117191665B and the name of "Device for Detecting the Air Permeability of Curtain Fabrics", the disclosed technical solution records that it includes an installation box, an operating table is provided on the installation box, a fabric air permeability detector is provided on one side of the top of the operating table, a detection cantilever is connected to the inner side of the fabric air permeability detector, an installation opening communicating with the installation box is vertically penetrated through the middle of the top surface of the operating table, a ventilation seat is vertically provided in the installation opening, a movable seat is vertically and movably inserted in the ventilation seat, a sealing groove is horizontally opened around the opening of the top surface of the movable seat, and a rubber gasket is horizontally placed in the sealing groove. During the test, the rubber gasket in the sealing groove is taken out, after the fabric to be detected is horizontally placed on the top of the movable seat, the rubber gasket is placed on the top of the fabric to be detected, and the detection cantilever clamped in the push plate is pushed by controlling the electric push rod to press the fabric on the top of the movable seat, so as to press the fabric at the bottom of the rubber gasket into the sealing groove, thereby playing a role in tightly sealing the periphery of the pressed fabric, and then the air permeability is detected by controlling the blower to blow air. However, after the fabric is pressed into the sealing groove and tightened, due to the wrinkles of the fabric itself, there may be wrinkles in the test area of the fabric, resulting in inaccurate air permeability detection. Summary of the Invention

[0004] The present invention provides a device for testing the air permeability of fabrics to solve the above problems.

[0005] A device for testing the air permeability of fabrics according to the present invention adopts the following technical solution: A device for testing the air permeability of fabrics includes a workbench and a pressing mechanism; an upwardly open detection groove is provided on the workbench; air vent holes are provided on the bottom wall of the detection groove; an installation box is fixed below the workbench; a gas supply mechanism is arranged inside the installation box; the gas supply mechanism is used to provide an air flow with a preset air pressure into the air vent holes; the upper end surface of the workbench is set as a placement surface.

[0006] There are two pressing mechanisms symmetrically arranged up and down and distributed on both sides of the placement surface; the pressing mechanism includes a support ring, a pressing component, and a driving component; the upper support ring is arranged on the workbench so as to move up and down; the lower support ring and the inner side wall of the detection groove are in sealing sliding up and down, and the detection groove is blocked into a detection cavity; mounting cylinders are coaxially fixed on the end faces of the two support rings close to each other; the mounting cylinders communicate with the detection cavity; the mouths of the mounting cylinders correspond to the areas of the fabric to be detected.

[0007] The pressing component is arranged between the two mounting cylinders; during the process of the two support rings approaching each other, the pressing component first provides a plurality of tensile forces acting in the radial direction away from the axis of the mounting cylinder and evenly distributed in the circumferential direction of the mounting cylinder to the fabric outside the mouth of the mounting cylinder to initially flatten the wrinkles of the fabric, and then, the pressing component provides a plurality of tensile forces acting in the radial direction away from the axis of the mounting cylinder and evenly distributed in the circumferential direction of the mounting cylinder to the fabric corresponding to the mouth of the mounting cylinder for secondary flattening, so that the fabric is hermetically connected to the mouth of the mounting cylinder. After the fabric is stretched and flattened twice, it can prevent the fabric from wrinkling or bulging during detection and affecting the detection result.

[0008] The driving component is used to drive the two support rings to approach each other.

[0009] Further, the pressing component includes an intermediate ring and a flattening plate; The intermediate ring is coaxial with the mounting cylinder and is a conical ring with the large end facing the placement surface; the intermediate ring is an elastic ring; the middle part of the intermediate ring is hinged to the end of the mounting cylinder close to the placement surface through a hinged structure.

[0010] There are a plurality of flattening plates; the plurality of flattening plates are distributed in the circumferential direction of the intermediate ring at the large end of the intermediate ring; the flattening plate is an arc-shaped plate, and the plurality of flattening plates enclose a conical cylinder shape with the large end facing the placement surface; the taper of the flattening plate is smaller than the taper of the intermediate ring; the end of the flattening plate away from the placement surface is fixedly connected to the large end of the intermediate ring.

[0011] Further, a rubber film is pasted between the side wall of the small end of the intermediate ring close to the support ring and the inner side wall of the mounting cylinder; the rubber film is used to seal the gap between the mounting cylinder and the intermediate ring.

[0012] Further, the pressing assembly further includes a support cylinder; the support cylinder is coaxially arranged inside the middle ring; the support cylinder is an elastic conical cylinder with its small end facing the placement surface; the large end of the support cylinder is fixedly connected to the small end of the middle ring; a plurality of avoidance notches are evenly distributed along the circumferential direction of the support cylinder on the cylinder wall at the small end of the support cylinder; the avoidance notches are V-shaped with their large ends facing the placement surface. During the process of the two support rings approaching each other, the upper and lower corresponding spreading plates on the two middle rings sandwich the fabric, and the two support rings continue to approach each other. The spreading plate drives the middle ring to rotate against its own elastic force, so that the small end of the middle ring drives the support cylinder to approach the fabric. In the initial state, the middle ring is a conical ring with its large end facing the placement surface; when the middle ring rotates to the point where the large end and the small end of the middle ring are on the same horizontal plane, the middle ring is at the critical point of flipping into a conical ring with its small end facing the placement surface. During this process, the middle ring first drives the spreading plate to move radially away from the axis of the mounting cylinder along the middle ring, and a relative sliding occurs between the spreading plate and the fabric, so as to initially flatten the fabric through the sliding friction force and pre-flatten the wrinkles of the fabric. Then, the middle ring is driven to continue rotating, and then the small end of the support cylinder is made to abut against the fabric. As the middle ring continues to rotate, the small end of the support cylinder gradually fits on the surface of the fabric.

[0013] The two support rings continue to approach each other. Before the middle ring rotates to the critical point, the spreading plate disengages from the fabric, and the small end of the support cylinder gradually fits on the surface of the fabric and bends into an L-shaped cross-section in the vertical direction. The L-shaped bending deformation of the support cylinder makes the avoidance notches gradually become smaller. At this time, the two support rings continue to approach each other. After the middle ring crosses the critical point, the elastic force of the middle ring is released, so that the middle ring quickly converts to the state of a conical ring with its small end facing the placement surface, making the small end of the middle ring drive the small end of the support cylinder to move radially away from the axis of the mounting cylinder along the middle ring. A relative sliding occurs between the small end of the support cylinder and the fabric, so as to perform secondary flattening on the fabric corresponding to the mouth of the mounting cylinder through the sliding friction force. At the same time, the L-shaped bending deformation of the support cylinder makes the avoidance notches decrease to closure, so that the small ends of the support cylinder enclose into a ring that fits the fabric, and the small ends of the support cylinders of the two pressing assemblies press the fabric, and cooperate with the rubber film to achieve a sealed connection between the fabric and the mouth of the mounting cylinder.

[0014] Further, the end of the spreading plate of the upper pressing assembly close to the placement surface is convex in an arc shape, and the end of the spreading plate of the lower pressing assembly close to the placement surface is concave in an arc shape. When the upper and lower corresponding spreading plates on the two middle rings approach each other and sandwich the fabric, the approaching ends of the upper and lower corresponding spreading plates bite together, increasing the contact area with the fabric and improving the flattening effect.

[0015] Further, the hinge structure includes a hinge ring; the hinge ring is coaxial with the middle ring; the hinge ring is fixed in the middle of the middle ring; the hinge ring is rotationally matched with the end of the mounting cylinder close to the placement surface.

[0016] Further, the driving assembly includes an upper driving structure and a lower driving structure. The upper driving structure is used to drive the upper support ring to move up and down. The lower driving structure is used to drive the lower support ring to move up and down.

[0017] Further, the upper driving structure includes a driving arm. The driving arm is horizontally arranged and is arranged above the workbench and can move up and down. One end of the driving arm is threadedly connected with a vertically arranged lead screw. The lead screw is rotatably installed on the workbench. The lead screw is driven to rotate by a driving motor. The other end of the driving arm is fixed with a driving ring. The driving ring and the support ring are coaxial. A plurality of vertically arranged sliding rods are annularly distributed on the driving ring. The lower ends of the sliding rods are fixedly connected with the upper support ring. Springs are sleeved on the sliding rods. One end of each spring abuts against the driving ring, and the other end abuts against the upper support ring.

[0018] Further, the lower driving structure includes a plurality of electric telescopic rods that are annularly distributed and vertically arranged. The electric telescopic rods are arranged in the detection cavity. The two ends of each electric telescopic rod are respectively set as a fixed end and a telescopic end. The fixed end of the electric telescopic rod is fixedly connected with the lower cavity wall of the detection cavity, and the telescopic end of the electric telescopic rod is fixedly connected with the lower support ring. The electric telescopic rods drive the lower support ring to drive the pressing assembly to move upward through the installation cylinder, and make the end of the spreading plate close to the placement surface and the placement surface be in the same plane.

[0019] Further, a barometric pressure sensor is arranged in the detection groove. A control center is arranged on the workbench.

[0020] The beneficial effects of the present invention are as follows: 1. During the process of the two support rings approaching each other, the pressing assembly first provides a plurality of tensile forces that are evenly distributed along the circumferential direction of the installation cylinder and act in the direction away from the axis of the installation cylinder on the fabric outside the barrel opening of the installation cylinder to initially flatten the wrinkles of the fabric. Then, the pressing assembly provides a plurality of tensile forces that are evenly distributed along the circumferential direction of the installation cylinder and act in the direction away from the axis of the installation cylinder on the fabric corresponding to the barrel opening of the installation cylinder for secondary flattening, so that the fabric is hermetically connected to the barrel opening of the installation cylinder. The fabric undergoes two stretching and flattening processes, preventing the fabric from wrinkling or bulging during detection and affecting the detection results.

[0021] 2. There is relative sliding between the spreading plate and the fabric, and between the small end of the support cylinder and the fabric, reducing the wear on the fabric.

[0022] 3. Relative sliding occurs between the small end of the support cylinder and the fabric. While the sliding friction force is used to secondarily flatten the fabric corresponding to the barrel opening of the installation cylinder, the avoidance notch is reduced to close so that the small end of the support cylinder encloses a ring that fits the fabric, improving the sealing performance. Description of the Drawings

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 Structural schematic diagram of an embodiment of an air permeability testing device for a kind of fabric of the present invention; Figure 2 Side view of an embodiment of an air permeability testing device for a kind of fabric of the present invention; Figure 3 For Figure 2 Cross-sectional view at A - A in Figure 4 For Figure 3 Enlarged view at B in Figure 5 For Figure 3 Isometric view of Figure 6 For Figure 5 Enlarged view at C in Figure 7 For Figure 5 State diagram when the avoidance notch in is reduced to be closed so that the small ends of the support cylinders enclose a ring shape that fits the fabric; Figure 8 For Figure 7 Enlarged view at D in Figure 9 Schematic diagram of the intermediate ring, spreading plate, and support cylinder of an embodiment of an air permeability testing device for a kind of fabric of the present invention.

[0025] In the figure: 100, workbench; 110, detection groove; 111, ventilation hole; 112, detection cavity; 200, control center; 300, support ring; 310, installation cylinder; 311, rubber membrane; 400, intermediate ring; 410, hinge ring; 500, spreading plate; 600, support cylinder; 610, avoidance notch; 710, driving arm; 720, driving ring; 730, electric telescopic rod. Detailed implementation manners

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0027] An embodiment of a breathability testing device for a fabric of the present invention is as Figures 1 to 9 shown, and it includes a workbench 100 and a pressing mechanism; a detection groove 110 with an upward opening is provided on the workbench 100; an air vent 111 is provided on the bottom wall of the detection groove 110; an installation box is fixed below the workbench 100; a gas supply mechanism is arranged inside the installation box; the gas supply mechanism is used to supply an air flow with a preset air pressure into the air vent 111; a pressure sensor is arranged in the detection groove 110; a control center 200 is provided on the workbench 100. The gas supply mechanism can be a nozzle. By selecting a suitable orifice plate, the air pressure of the air flow supplied into the air vent 111 is adjusted. The upper end surface of the workbench 100 is set as a placement surface.

[0028] There are two pressing mechanisms symmetrically arranged up and down and distributed on both sides of the placement surface; the pressing mechanism includes a support ring 300, a pressing component, and a driving component; the upper support ring 300 is arranged on the workbench 100 so as to move up and down; the lower support ring 300 and the inner side wall of the detection groove 110 are hermetically slidable up and down and block the detection groove 110 into a detection cavity 112; mounting cylinders 310 are coaxially fixed on the end faces of the two support rings 300 close to each other; the mounting cylinders 310 communicate with the detection cavity 112; the orifice of the mounting cylinder 310 corresponds to the area of the fabric to be detected.

[0029] The pressing component is arranged between the two mounting cylinders 310; during the process of the two support rings 300 approaching each other, the pressing component first provides a plurality of tensile forces that are evenly distributed along the circumferential direction of the mounting cylinder 310 and act in the direction away from the axis of the mounting cylinder 310 on the fabric outside the orifice of the mounting cylinder 310 to initially flatten the wrinkles of the fabric, and then, the pressing component provides a plurality of tensile forces that are evenly distributed along the circumferential direction of the mounting cylinder 310 and act in the direction away from the axis of the mounting cylinder 310 on the fabric corresponding to the orifice of the mounting cylinder 310 for secondary flattening, so that the fabric is hermetically connected to the orifice of the mounting cylinder 310. After the fabric is stretched and flattened twice, it is prevented that the fabric wrinkles or bulges during detection and affects the detection result.

[0030] The pressing assembly includes an intermediate ring 400, a flattening plate 500, and a support cylinder 600; the intermediate ring 400 is coaxial with the mounting cylinder 310 and is a conical ring with its large end facing the placement surface; the intermediate ring 400 is an elastic ring; the middle part of the intermediate ring 400 is hinged to one end of the mounting cylinder 310 close to the placement surface through a hinge structure. A rubber film 311 is pasted between the side wall of the small end of the intermediate ring 400 close to the support ring 300 and the inner side wall of the mounting cylinder 310; the rubber film 311 is used to seal the gap between the mounting cylinder 310 and the intermediate ring 400. The hinge structure includes a hinge ring 410; the hinge ring 410 is coaxial with the intermediate ring 400; the hinge ring 410 is fixed to the middle part of the intermediate ring 400; the hinge ring 410 is rotatably matched with one end of the mounting cylinder 310 close to the placement surface.

[0031] There are multiple flattening plates 500; the multiple flattening plates 500 are circumferentially distributed at the large end of the intermediate ring 400; the flattening plate 500 is an arc-shaped plate, and the multiple flattening plates 500 enclose a conical cylinder shape with its large end facing the placement surface; the taper of the flattening plate 500 is smaller than that of the intermediate ring 400; the end of the flattening plate 500 away from the placement surface is fixedly connected to the large end of the intermediate ring 400. The end of the flattening plate 500 of the upper pressing assembly close to the placement surface is convex in an arc shape, and the end of the flattening plate 500 of the lower pressing assembly close to the placement surface is concave in an arc shape. When the upper and lower corresponding flattening plates 500 on the two intermediate rings 400 approach each other and clamp the fabric, the approaching ends of the upper and lower corresponding flattening plates 500 bite together, increasing the contact area with the fabric and improving the flattening effect.

[0032] The support cylinder 600 is coaxially arranged inside the middle ring 400; the support cylinder 600 is an elastic conical cylinder with its small end facing the placement surface; the large end of the support cylinder 600 is fixedly connected to the small end of the middle ring 400; a plurality of avoidance notches 610 are evenly distributed along the circumferential direction of the support cylinder 600 on the cylinder wall at the small end of the support cylinder 600; the avoidance notches 610 are V-shaped with their large ends facing the placement surface. During the process of the two support rings 300 approaching each other, the spreading plates 500 corresponding up and down on the two middle rings 400 clamp the fabric, and the two support rings 300 continue to approach each other. The spreading plates 500 drive the middle ring 400 to rotate against its own elastic force, so that the small end of the middle ring 400 drives the support cylinder 600 to approach the fabric. In the initial state, the middle ring 400 is a conical ring with its large end facing the placement surface; when the middle ring 400 rotates to the point where the large end and the small end of the middle ring 400 are on the same horizontal plane, the middle ring 400 is at the critical point of flipping into a conical ring with its small end facing the placement surface. During this process, the middle ring 400 first drives the spreading plate 500 to move radially away from the axis of the mounting cylinder 310 along the middle ring 400, and a relative sliding occurs between the spreading plate 500 and the fabric, so as to initially flatten the fabric through the sliding friction force and pre-flatten the wrinkles of the fabric. Then, the middle ring 400 is driven to continue rotating, and then the small end of the support cylinder 600 is driven to abut against the fabric. As the middle ring 400 continues to rotate, the small end of the support cylinder 600 gradually adheres to the surface of the fabric.

[0033] The two support rings 300 continue to approach each other. Before the middle ring 400 rotates to the critical point, the spreading plate 500 disengages from the fabric, and the small end of the support cylinder 600 gradually adheres to the surface of the fabric and bends into an L-shaped cross-section in the vertical direction. The L-shaped bending deformation of the support cylinder 600 causes the avoidance notches 610 to gradually become smaller. At this time, the two support rings 300 continue to approach each other. After the middle ring 400 passes the critical point, the elastic force of the middle ring 400 is released, so that the middle ring 400 quickly switches to the state of a conical ring with its small end facing the placement surface, so that the small end of the middle ring 400 drives the small end of the support cylinder 600 to move radially away from the axis of the mounting cylinder 310 along the middle ring 400, and a relative sliding occurs between the small end of the support cylinder 600 and the fabric, so as to secondarily flatten the fabric corresponding to the mouth of the mounting cylinder 310 through the sliding friction force. At the same time, the L-shaped bending deformation of the support cylinder 600 causes the avoidance notches 610 to decrease to closure, so that the small ends of the support cylinder 600 of the two pressing assemblies enclose a ring that fits the fabric, and the small ends of the support cylinder 600 of the two pressing assemblies press the fabric, and cooperate with the rubber film 311 to realize a sealed connection between the fabric and the mouth of the mounting cylinder 310.

[0034] The driving assembly is used to drive the two support rings 300 to approach each other. The driving assembly includes an upper driving structure and a lower driving structure; the upper driving structure is used to drive the upper support ring 300 to move up and down; the lower driving structure is used to drive the lower support ring 300 to move up and down.

[0035] The upper driving structure includes a driving arm 710; the driving arm 710 is horizontally arranged and is arranged above the workbench 100 in a vertically movable manner; one end of the driving arm 710 is threadedly connected with a vertically arranged lead screw; the lead screw is rotatably installed on the workbench 100; the lead screw is driven to rotate by a driving motor; the other end of the driving arm 710 is fixed with a driving ring 720; the driving ring 720 and the supporting ring 300 are coaxial; a plurality of vertically arranged sliding rods are annularly distributed on the driving ring 720; the lower ends of the sliding rods are fixedly connected with the upper supporting ring 300; a spring is sleeved on the sliding rods; one end of the spring abuts against the driving ring 720, and the other end abuts against the upper supporting ring 300. The lower driving structure includes a plurality of electric telescopic rods 730 which are annularly distributed and vertically arranged; the electric telescopic rods 730 are arranged in the detection cavity 112; both ends of the electric telescopic rods 730 are respectively set as a fixed end and a telescopic end; the fixed end of the electric telescopic rod 730 is fixedly connected with the lower cavity wall of the detection cavity 112, and the telescopic end of the electric telescopic rod 730 is fixedly connected with the lower supporting ring 300. The electric telescopic rod 730 drives the lower supporting ring 300 to drive the pressing assembly to move upward through the mounting cylinder 310, and makes the end of the flattening plate 500 close to the placement surface and the placement surface be in the same plane.

[0036] Combined with the above embodiments, the working principle and process of the present invention are as follows: When in use, in the first step, parameters are set on the operation screen of the control center 200 first. First, the differential pressure method is selected, and the air permeability unit mm / s is selected, and then the differential pressure is set. Usually, the set differential pressure value for clothing fabrics is 100 Pa, and the set differential pressure value for industrial fabrics is 200 Pa; finally, the tare is clicked.

[0037] In the second step, the fabric is flattened and placed on the placement surface of the workbench 100. Then, the driving motor is started to drive the lead screw to drive the driving arm 710 to move downward. The driving arm 710 drives the driving ring 720 to move downward. The driving ring 720 drives the corresponding intermediate ring 400 to move downward through the upper supporting ring 300. The electric telescopic rod 730 drives the lower supporting ring 300 to drive the corresponding intermediate ring 400 to move upward through the mounting cylinder 310, and makes the end of the flattening plate 500 close to the placement surface and the placement surface be in the same plane.

[0038] During the process of the two support rings 300 approaching each other, the flattening plates 500 corresponding up and down on the two intermediate rings 400 clamp the fabric. As the two support rings 300 continue to approach each other, the flattening plates 500 drive the intermediate rings 400 to rotate against their own elastic force, so that the small ends of the intermediate rings 400 drive the support cylinders 600 to approach the fabric. In the initial state, the intermediate rings 400 are conical rings with their large ends facing the placement surface; when the intermediate rings 400 rotate to the point where the large ends and small ends of the intermediate rings 400 are on the same horizontal plane, the intermediate rings 400 are at the critical point of flipping into conical rings with their small ends facing the placement surface. During this process, the intermediate rings 400 first drive the flattening plates 500 to move radially away from the axis of the mounting cylinder 310 along the intermediate rings 400, and relative sliding occurs between the flattening plates 500 and the fabric, so as to initially flatten the fabric through sliding friction and pre-flatten the wrinkles of the fabric. Then, the intermediate rings 400 are driven to continue rotating, and then the small ends of the support cylinders 600 are driven to abut against the fabric. As the intermediate rings 400 continue to rotate, the small ends of the support cylinders 600 gradually fit on the surface of the fabric.

[0039] The two support rings 300 continue to approach each other. And before the intermediate rings 400 rotate to the critical point, the flattening plates 500 disengage from the fabric, and the small ends of the support cylinders 600 gradually fit on the surface of the fabric and bend into an L-shaped cross-section in the vertical direction. The L-shaped bending deformation of the support cylinders 600 causes the avoidance notches 610 to gradually become smaller. At this time, as the two support rings 300 continue to approach each other, after the intermediate rings 400 cross the critical point, the elastic force of the intermediate rings 400 is released, causing the intermediate rings 400 to quickly switch to the state of conical rings with their small ends facing the placement surface, so that the small ends of the intermediate rings 400 drive the small ends of the support cylinders 600 to move radially away from the axis of the mounting cylinder 310 along the intermediate rings 400, and relative sliding occurs between the small ends of the support cylinders 600 and the fabric, so as to secondarily flatten the fabric corresponding to the mouth of the mounting cylinder 310 through sliding friction. At the same time, the L-shaped bending deformation of the support cylinders 600 causes the avoidance notches 610 to decrease to closure, so that the small ends of the support cylinders 600 of the two pressing assemblies enclose a ring that fits the fabric, and the small ends of the support cylinders 600 of the two pressing assemblies press the fabric, cooperating with the rubber film 311 to achieve a sealed connection between the fabric and the mouth of the mounting cylinder 310.

[0040] Step 3: Conduct the air permeability test by the differential pressure method.

[0041] Step 4: After completion, move the fabric, replace the area to be tested, and repeat the above process.

[0042] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An air permeability testing device for a fabric, characterized in that: It includes a workbench and a pressing mechanism; There is a detection groove with an upward opening on the workbench; there are ventilation holes on the bottom wall of the detection groove; an installation box is fixed below the workbench; a gas supply mechanism is arranged inside the installation box; the gas supply mechanism is used to supply an air flow with a preset air pressure into the ventilation holes; the upper end surface of the workbench is set as a placement surface; There are two pressing mechanisms symmetrically arranged up and down and distributed on both sides of the placement surface; the pressing mechanism includes a support ring, a pressing component, and a driving component; the upper support ring is arranged on the workbench so as to move up and down; the lower support ring and the inner side wall of the detection groove are hermetically slid up and down and block the detection groove into a detection cavity; on the end faces of the two support rings close to each other, mounting cylinders are coaxially fixed; the mounting cylinders communicate with the detection cavity; the openings of the mounting cylinders correspond to the areas of the fabric to be detected; The pressing component is arranged between the two mounting cylinders; during the process of the two support rings approaching each other, the pressing component first provides a plurality of tensile forces that are evenly distributed along the circumferential direction of the mounting cylinder and act in the direction away from the axis of the mounting cylinder on the fabric outside the opening of the mounting cylinder to initially flatten the wrinkles of the fabric, and then, the pressing component provides a plurality of tensile forces that are evenly distributed along the circumferential direction of the mounting cylinder and act in the direction away from the axis of the mounting cylinder on the fabric corresponding to the opening of the mounting cylinder for secondary flattening, so that the fabric is hermetically connected to the opening of the mounting cylinder; The driving component is used to drive the two support rings to approach each other.

2. The air permeability testing device for a fabric according to claim 1, characterized in that: The pressing component includes an intermediate ring and a spreading plate; The intermediate ring is coaxial with the mounting cylinder and is a conical ring with the large end facing the placement surface; the intermediate ring is an elastic ring; the middle part of the intermediate ring is hinged to one end of the mounting cylinder close to the placement surface through a hinge structure; There are multiple spreading plates; the multiple spreading plates are distributed along the circumferential direction of the intermediate ring at the large end of the intermediate ring; the spreading plates are arc-shaped plates, and the multiple spreading plates enclose a conical cylinder shape with the large end facing the placement surface; the taper of the spreading plate is smaller than that of the intermediate ring; the end of the spreading plate far from the placement surface is fixedly connected to the large end of the intermediate ring.

3. The air permeability testing device for a fabric according to claim 2, characterized in that: A rubber film is pasted between the side wall of the small end of the intermediate ring close to the support ring and the inner side wall of the mounting cylinder.

4. The air permeability testing device for a fabric according to claim 3, characterized in that: The pressing component further includes a support cylinder; the support cylinder is coaxially arranged inside the intermediate ring; the support cylinder is an elastic conical cylinder with the small end facing the placement surface; the large end of the support cylinder is fixedly connected to the small end of the intermediate ring; a plurality of avoidance notches are evenly distributed along the circumferential direction of the support cylinder on the cylinder wall at the small end of the support cylinder; the avoidance notches are V-shaped with the large end facing the placement surface.

5. The air permeability testing device for a fabric according to claim 4, characterized in that: The end of the spreading plate of the upper pressing component close to the placement surface is convex in an arc shape, and the end of the spreading plate of the lower pressing component close to the placement surface is concave in an arc shape.

6. The air permeability testing device for a fabric according to claim 2, characterized in that: The hinge structure includes a hinge ring; the hinge ring is coaxial with the intermediate ring; the hinge ring is fixed in the middle of the intermediate ring; the hinge ring is rotationally matched with one end of the mounting cylinder close to the placement surface.

7. The air permeability testing device for a fabric according to claim 1, characterized in that: The driving component includes an upper driving structure and a lower driving structure; the upper driving structure is used to drive the upper support ring to move up and down; the lower driving structure is used to drive the lower support ring to move up and down.

8. The air permeability testing device for a fabric according to claim 7, characterized in that: The upper driving structure includes a driving arm; the driving arm is horizontally arranged and is arranged above the workbench and can move up and down; one end of the driving arm is threadedly connected with a vertically arranged lead screw; the lead screw is rotatably installed on the workbench; the lead screw is driven to rotate by a driving motor; the other end of the driving arm is fixed with a driving ring; the driving ring and the supporting ring are coaxial; a plurality of vertically arranged sliding rods are annularly distributed on the driving ring; the lower ends of the sliding rods are fixedly connected with the upper supporting ring; springs are sleeved on the sliding rods; one end of each spring abuts against the driving ring, and the other end abuts against the upper supporting ring.

9. The air permeability testing device for a fabric according to claim 2, characterized in that: The lower driving structure includes a plurality of electric telescopic rods that are annularly distributed and vertically arranged; the electric telescopic rods are arranged in the detection cavity; the two ends of each electric telescopic rod are respectively set as a fixed end and a telescopic end; the fixed end of the electric telescopic rod is fixedly connected with the lower cavity wall of the detection cavity, and the telescopic end of the electric telescopic rod is fixedly connected with the lower supporting ring.

10. The air permeability testing device for a fabric according to claim 1, characterized in that: A barometric pressure sensor is arranged in the detection groove; a control center is arranged on the workbench.

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