Sample clamping auxiliary device for fabric tensile test

Abstract

The invention relates to a sample clamping auxiliary device for a fabric tensile test. The sample clamping auxiliary device comprises a side surface auxiliary unit, a clamping unit and a pre-clamping unit, the side auxiliary unit is used for transferring the pre-clamping unit to a proper height, the clamping unit is used for clamping a sample and ensuring the centering property in the y-axis direction by adopting double screws, and the pre-clamping unit is used for ensuring the centering property of the sample on the x-axis direction. Compared with the prior art, it is guaranteed that the longitudinal symmetry axis of the sample is located on the axis of the tensile instrument force twice in sequence, the transverse side line is parallel to the side line of the clamp, the instability of the experimental result caused by the uncertainty of sample clamping by an operator is reduced, and scientific and reasonable evaluation on the tensile mechanical properties of various types of fabrics is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of textile testing equipment, in particular to a sample clamping auxiliary device for fabric tensile testing. Background Art

[0002] During the fabric tensile test, the sample is cut into a square or rectangle according to the requirements of the test standard, and then the two transverse edges of the sample are placed in the upper and lower clamps respectively. The fabric is a flexible body woven by the cross-weaving of warp and weft. The tensile direction of the sample (i.e. the direction of the central axis of the tensile tester) and the slight deviation between the warp and weft of the sample will cause instability in the tensile test results. At present, the sample is clamped entirely by manual visual inspection. In order to avoid the instability of the experimental results, it should be ensured that the longitudinal symmetry axis of the sample is collinear with the central axis of the tensile tester, and the clamping surfaces of the upper and lower clamps are on the same plane. The fabric is soft and easy to twist and deform. With the help of visual observation by human eyes, the subjective consciousness or visual fatigue of the personnel will lead to low efficiency and accuracy of clamping and positioning. Even if the same person repeats the clamping for many times, there will be a problem of poor consistency.

[0003] Patent CN202222906938.2 discloses a sample clamping auxiliary device for a milling machine. By setting a clamping assembly, the sample clamping auxiliary device allows workers to pick up samples more easily, reduces manual contact with the milling machine, and improves placement accuracy. Patent CN202223514664.9 provides support for the workpiece by setting a base, and clamps the workpiece in a fixed position in combination with the marking scale on the base, thereby avoiding the impact of the welding quality due to the offset of the workpiece position during the welding process. The above patents effectively improve the concentricity of the workpiece with the clamping device in a certain direction, but have great limitations for flexible materials such as fabrics.

[0004] The existing technology cannot simultaneously ensure the centering of the flexible specimen in the x and y directions. Summary of the invention

[0005] The purpose of the present invention is to provide a sample clamping auxiliary device for fabric tensile testing in order to overcome the defects of the above-mentioned prior art, which ensures twice that the longitudinal symmetry axis of the sample is located on the axis of the tensile instrument force, and the transverse edge line is parallel to the clamp edge line, thereby reducing the instability of the experimental results caused by the uncertainty of the operator in clamping the sample, and is conducive to making a scientific and reasonable evaluation of the tensile mechanical properties of various types of fabrics.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The present invention provides a sample clamping auxiliary device for fabric tensile testing, comprising: a side auxiliary unit, a clamping unit, and a pre-clamping unit;

[0008] The side auxiliary unit is used to move the pre-clamping unit to a suitable height. The clamping unit is used to clamp the sample and use a double screw to ensure the y-axis centering. The pre-clamping unit is used to ensure the sample on the x-axis centering.

[0009] Furthermore, the side auxiliary unit I is located on the left side of the stretching instrument, and the side auxiliary unit includes: a column, a cantilever stopper, a cantilever and a horizontal base; the column is arranged on the horizontal base, a first scale is engraved on the column, a T-slot is arranged inside the column, and the cantilever can be moved up and down in the T-slot to a set height and then fixed by the cantilever stopper. The horizontal base is provided with a T-slot and a T-shaped protrusion at the bottom of the column, and is placed on the left side of the stretching instrument along the x-axis direction. The material of the column is the standard aluminum profile CS-10-6060A.

[0010] Furthermore, the cantilever limiting block includes: a T-bolt, a first nut and a triangular block.

[0011] Furthermore, the cantilever includes: a T-shaped protrusion, a block, and a cantilever body. The T-shaped protrusion is used for guiding movement on the z-axis. The block is connected to the cantilever body. The block is used to enhance the bending resistance of the cantilever body. A second scale is provided on the upper surface of the cantilever body. The cantilever body is used to carry the slider and ensure the movement accuracy of the slider on the y-axis. A U-shaped notch runs through the center of the cantilever. The width of the U-shaped notch is 50mm, which can leave enough space for the fabric to drape from top to bottom. The small T-shaped slot inside the cantilever is used for the slider limit block to move on the y-axis.

[0012] Furthermore, the clamping unit includes: a left connecting piece, a left clamp, a guide rod, a right clamp, a right connecting piece, an external spline handle, a U-shaped block, and a double screw. The left connecting piece and the right connecting piece are symmetrically distributed, and the left connecting piece and the right connecting piece have only a degree of freedom of movement on the y-axis. The left clamp and the right clamp are made of steel, and the double screw is made of steel. An inner spline hole is provided on the inner cylindrical surface on the right side of the double screw, and the depth of the inner spline hole is 50mm. The inner spline hole cooperates with the outer spline handle, and the double screw can be rotated by turning the outer spline handle; the left connecting piece and the right connecting piece are made of lightweight aluminum alloy, and a first through hole is provided on the right connecting piece to ensure that the outer spline handle can pass through; the U-shaped block is provided with a smooth square through hole, and the square through hole and the square cylinder on the left connecting piece are fitted together. The first blind hole and the second blind hole provided on both sides of the left connecting piece play the role of fixing the double screw and the guide rod; the double screw and the guide rod are parallel, and the double screw is provided in the holes on the outside of the left connecting piece and the right connecting piece. The double screw passes through the first through hole of the right connecting piece and cooperates with the outer spline handle.

[0013] Furthermore, when the present invention is in the initial position, the distance from the bottom surface of the guide rod and the double screw to the bottom of the first blind hole and the second blind hole is 10 mm. When the left clamp and the right clamp move, the distance is continuously reduced until the left clamp and the right clamp clamp the fabric; the x-direction width of the left clamp and the right clamp is 100 mm. By comparing the coplanarity of the two side surfaces of the cantilever with the left clamp and the right clamp, the centering of the auxiliary device in the x-axis direction is determined, and the fabric is then placed with the left clamp and the right clamp as the reference. This is the first time that the centering of the fabric in the x-axis direction is guaranteed.

[0014] Furthermore, the twin screw is provided with a left thread and a right thread, the left thread is left-handed, the right thread is right-handed, and the middle section is no longer threaded to save processing costs. In order to meet the high-precision requirements and the multiple relationship of the size, the thread parameters of the left thread and the right thread are the same. Specifically: the pitch P is 2mm, the number of spiral turns N is 10, the total length L of the thread section is greater than the single-side stroke, which is 20mm; the thread profile angle α is 60°, and the thread diameter d2 is 15mm;

[0015] By formula

[0016] Thread lead angle is 2.43°, satisfying The thread has good self-locking property.

[0017] Twin screw wear resistance p and strength σ ca The calculation is as follows:

[0018]

[0019] In the formula, F is the axial force acting on the twin screw; h is the working height of the left and right threads, h = 1mm; H is the thickness of the left clamp 2.2 and the right clamp 2.4, H = 16.5mm; d1 is the minor diameter of the left thread 2.8.1 and the right thread 2.8.2, d1 = 14mm; T is the torque on the twin screw 2.8, T = Fd3, d3 is the maximum length of the wrench, d3 = 100mm, assuming that the maximum axial force F that can be applied by a hand is 300N, then the torque T = 30N·m. Substituting into formulas (1) and (2), we get: p = 0.8Mpa < [p] = 7.5Mpa, σ ca =97Mpa<0.3σ s =118Mpa, the design size and material selection meet the requirements of safe use.

[0020] Furthermore, the pre-clamping unit includes: a slider, a clamping spring, a nut, a clamping head, a clamping handle, a slider limit block, and a positioning sheet;

[0021] To ensure synchronous operation of upper and lower clamping, the slider has a mirroring characteristic. The eight contact surfaces of the slider in the z direction are all in contact with the cantilever, limiting its height position. On the y-axis, the movement of the slider is not restricted. A clamp column is installed on the top surface of the slider. In the x-axis direction, the axis of the clamp column is aligned with the clamping surface of the fabric. A pointer is provided on the slider, and the position marked on the second scale is compared according to the axis of the tensile gauge force. This is the first time to ensure the clamping centering of the fabric in the y-axis direction. Turn the external spline handle to rotate the double screw, driving the left clamp and the right clamp to move towards each other. When the clamps on both sides move 10 mm along the y-axis, the serrated meshing surfaces overlap, the fabric is clamped, and the second centering operation in the y-axis direction is completed.

[0022] Furthermore, the top surface of the slider is also provided with a through U-shaped groove to ensure that the fabric can be suspended vertically to the bottom surface of the slider; the clamp handle and the chuck are connected by a second through hole, and the two can be disassembled for use; the upper and lower handle bodies of the clamp handle are supported by clamp springs, and when subjected to a pinching force, the part close to the chuck moves in the opposite direction, and the jaws open; the surface of the clamp handle close to the chuck is perforated and widened, and can contact the notch surface of the slider, limit the rotation of the handle body around the z-axis, and ensure that the clamping surface is parallel to the notch, and a second through hole is provided in the center of the handle body, which fits with the clamp column on the top and bottom surfaces of the slider, and is tightened with a nut to prevent loosening; to avoid damaging the sample surface, the inner surface of the chuck needs to be smooth enough. To ensure that the upper and lower sides of the sample are parallel, the length of the two chucks just covers the distance of the entire notch. There is a ruler in millimeters engraved from the beginning of the clamp. Mark the midpoint of the specimen's latitudinal width. Use the zero scale line on the surface of the chuck to compare the midpoint mark of the specimen and adjust the clamping position of the specimen to ensure that the upper and lower sides of the specimen are parallel. This operation is the second time to meet the clamping centering of the specimen in the x-axis direction.

[0023] Furthermore, the slider limit block includes: a second nut, a bolt and a T-shaped block. To prevent the slider from sliding on the cantilever plane during the subsequent clamping operation, two slider limit blocks are placed on each side, a total of four slider limit blocks, to limit the movement of the slider in the y-axis direction.

[0024] The principle of the present invention is as follows:

[0025] The cantilever, clamp, slider, reverse twin screw and other parts cooperate with each other to ensure the centration of the fabric clamping twice on the x and y axes, so that the fabric can be clamped on the axis of the tensile testing machine as accurately as possible, reducing the influence of the operator's operation and the error of the clamping device itself on the test results of the tensile properties of the fabric, which is conducive to making a scientific and reasonable evaluation of the tensile mechanical properties of the fabric.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] The present invention ensures twice that the longitudinal symmetry axis of the sample is located on the axis of the tensile tester force, and the transverse edge line is parallel to the clamp edge line, thereby reducing the instability of the experimental results caused by the uncertainty of the operator clamping the sample, and is conducive to making a scientific and reasonable evaluation of the tensile mechanical properties of various types of fabrics. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the sample clamping auxiliary device for fabric tensile testing of the present invention;

[0029] Figure 2 is a schematic diagram of the structure of the side auxiliary unit;

[0030] Figure 2-a It is a structural schematic diagram of the cantilever limit block;

[0031] Figure 2-b It is a schematic diagram of the structure of the cantilever;

[0032] Figure 3 is a schematic diagram of the structure of the clamping unit;

[0033] Figure 3-a It is a schematic diagram of the structure of a twin screw;

[0034] Figure 4 is a structural schematic diagram of a pre-clamping unit;

[0035] Figure 4-a It is a structural schematic diagram of the slider limit block.

[0036] Figure markings: Ⅰ-side auxiliary unit, Ⅱ-clamping unit, Ⅲ-pre-clamping unit, 1.1-column, 1.2-cantilever limit block, 1.3-cantilever, 1.4-horizontal base, 1.1.1-first scale, 1.1.2-T-slot, 1.2.1-T-bolt, 1.2.2-first nut, 1.2.3-triangle block, 1.3.1-T-shaped protrusion, 1.3.2-square block, 1.3.3-cantilever body, 1.3.4-second scale, 1.3.5-small T-slot, 2.1-left connecting piece, 2.1.1-square column, 2.1.2-first blind hole, 2.1.3-second blind hole, 2.2-left clamp , 2.3-guide rod, 2.4-right clamp, 2.5-right connecting piece, 2.5.1-first through hole, 2.6-external spline handle, 2.7-U-shaped block, 2.7.1-square through hole, 2.8-double screw, 2.8.1-left-hand thread, 2.8.2-right-hand thread, 2.8.3-inner spline hole, 3.1-slider, 3.1.1-clip column, 3.2-clip spring, 3.3-nut, 3.4-chuck, 3.4.1-ruler, 3.5-clamp handle, 3.5.1-second through hole, 3.6-slider limit block, 3.7-pointer, 3.6.1-second nut, 3.6.2-bolt, 3.6.3-T-shaped block. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms and other features not clearly described in this technical solution are all considered to be common technical features disclosed in the prior art.

[0038] In the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer", "front", "back" and the like indicate directions or positional relationships based on the attached Figure 1 The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0039] Example 1

[0040] This embodiment provides a sample clamping auxiliary device for fabric tensile testing, such as Figure 1 As shown, it includes: side auxiliary unit I, clamping unit II, and pre-clamping unit III;

[0041] The side auxiliary unit I is used to move the pre-clamping unit III to a suitable height, the clamping unit II is used to clamp the sample and use a double screw to ensure the y-axis centering, and the pre-clamping unit III is used to ensure the sample on the x-axis centering.

[0042] In a specific embodiment, the side auxiliary unit I is located on the left side of the stretching instrument; Figure 2 As shown, the side auxiliary unit I includes: two columns 1.1, four cantilever limit blocks 1.2, cantilever 1.3 and horizontal base 1.4; the column 1.1 is arranged on the horizontal base 1.4, the column 1.1 is engraved with a first scale 1.1.1, the column 1.1 is provided with a T-slot 1.1.2 inside, and the cantilever 1.3 can be moved up and down in the T-slot 1.1.2 to a set height and then fixed by the cantilever limit block 1.2. The horizontal base is provided with a T-slot and a T-shaped protrusion at the bottom of the column, and is placed on the left side of the tensile tester along the x-axis direction. The material of the column 1.1 is the standard aluminum profile CS-10-6060A.

[0043] In a specific embodiment, Figure 2-a As shown, the cantilever limit block 1.2 comprises: a T-bolt 1.2.1, a first nut 1.2.2 and a triangular block 1.2.3.

[0044] In a specific embodiment, Figure 2-b As shown, the cantilever 1.3 has a width of 100 mm, and includes: a T-shaped protrusion 1.3.1, a block 1.3.2, and a cantilever body 1.3.3. The T-shaped protrusion 1.3.1 is used for guiding movement on the z-axis, the block 1.3.2 is connected to the cantilever body 1.3.3, the block 1.3.2 is used to enhance the bending resistance of the cantilever body 1.3.3, and a second scale 1.3.4 is provided on the upper surface of the cantilever body 1.3.3. The cantilever body 1.3.3 is used to carry the slider 3.1 and ensure the movement accuracy of the slider 3.1 on the y-axis; a U-shaped notch runs through the center of the cantilever 1.3, and the width of the U-shaped notch is 50 mm, which can leave enough space for the fabric to drape from top to bottom. The small T-shaped slot 1.3.5 inside the cantilever 1.3 is used for the slider limit block 3.6 to move on the y-axis.

[0045] In a specific embodiment, Figure 3As shown, the clamping unit II includes: a left connecting piece 2.1, a left clamp 2.2, a guide rod 2.3, a right clamp 2.4, a right connecting piece 2.5, an external spline handle 2.6, a U-shaped block 2.7, and a double screw 2.8. The left connecting piece 2.1 and the right connecting piece 2.5 are symmetrically distributed, and the left connecting piece 2.1 and the right connecting piece 2.5 have only the degree of freedom of movement on the y-axis. The left clamp 2.2 and the right clamp 2.4 are made of 45 steel, and the double screw 2.8 is made of 45 steel. An inner spline hole 2.8.3 is provided on the inner cylindrical surface on the right side of the twin screw 2.8. The inner spline hole 2.8.3 has a depth of 50 mm. The inner spline hole 2.8.3 cooperates with the outer spline handle 2.6. The twin screw 2.8 can be rotated by turning the outer spline handle 2.6. The left connecting piece 2.1 and the right connecting piece 2.5 are made of light aluminum alloy. A first through hole 2.5.1 is provided on the right connecting piece 2.5 to ensure that the outer spline handle 2.6 can pass through. The U-shaped block 2.7 is provided with a smooth square through hole 2.7. 1, the square through hole 2.7.1 and the square column 2.1.1 on the left connecting piece 2.1 are fitted together, and the first blind hole 2.1.2 and the second blind hole 2.1.3 provided on both sides of the left connecting piece 2.1 play the role of fixing the double screw 2.8 and the guide rod 2.3; the double screw 2.8 and the guide rod 2.3 are parallel, and the double screw 2.8 is arranged in the holes outside the left connecting piece 2.1 and the right connecting piece 2.5, and the double screw 2.8 passes through the first through hole 2.5.1 of the right connecting piece 2.5 and cooperates with the external spline handle 2.6.

[0046] In a specific embodiment, when the present invention is in the initial position, the distance from the bottom surface of the guide rod 2.3 and the double screw 2.8 to the bottom of the first blind hole 2.1.2 and the second blind hole 2.1.3 is 10mm. When the left clamp 2.2 and the right clamp 2.4 move, the distance is continuously reduced until the left clamp 2.2 and the right clamp 2.4 clamp the fabric; the x-direction width of the left clamp 2.2 and the right clamp 2.4 is 100mm. By comparing the coplanarity of the two side surfaces of the cantilever 1.3 with the left clamp 2.2 and the right clamp 2.4, the centering of the auxiliary device in the x-axis direction is determined, and the fabric is then placed with the left clamp 2.2 and the right clamp 2.4 as the reference. This is the first time to ensure the centering of the fabric in the x-axis direction.

[0047] In a specific embodiment, Figure 3-a As shown, the twin screw 2.8 is provided with a left thread 2.8.1 and a right thread 2.8.2. The left thread 2.8.1 is left-handed, and the right thread 2.8.2 is right-handed. The middle section is no longer threaded to save processing costs. In order to meet the high-precision requirements and the multiple relationship of the size, the thread parameters of the left thread 2.8.1 and the right thread 2.8.2 are the same. Specifically: the pitch P is 2mm, the number of spiral turns N is 10, the total length L of the thread section is greater than the single-side stroke, which is 20mm; the thread profile angle α is 60°, and the thread middle diameter d2 is 15mm;

[0048] By formula

[0049] Thread lead angle is 2.43°, satisfying The thread has good self-locking property.

[0050] Twin screw wear resistance p and strength σ ca The calculation is as follows:

[0051]

[0052] In the formula, F is the axial force acting on the twin screw 2.8; h is the working height of the left thread 2.8.1 and the right thread 2.8.2, h = 1mm; H is the thickness of the left clamp 2.2 and the right clamp 2.4, H = 16.5mm; d1 is the minor diameter of the left thread 2.8.1 and the right thread 2.8.2, d1 = 14mm; T is the torque on the twin screw 2.8, T = Fd3, d3 is the maximum length of the wrench, d3 = 100mm, assuming that the maximum axial force F that can be applied by a human hand is 300N, the torque generated is T = 30N·m. Substituting into formulas (1) and (2), we get: p = 0.8Mpa < [p] = 7.5Mpa, σ ca =97Mpa<0.3σ s =118Mpa, the design size and material selection meet the requirements of safe use.

[0053] In a specific embodiment, Figure 4 As shown, the pre-clamping unit III includes: a slider 3.1, a clamping spring 3.2, a nut 3.3, a clamp head 3.4, a clamping handle 3.5, a slider limit block 3.6, and a positioning piece 3.7;

[0054] To ensure synchronous operation of upper and lower clamping, the slider 3.1 has a mirroring characteristic. The eight contact surfaces of the slider 3.1 in the z direction are all in contact with the cantilever 1.3, limiting its height position. On the y-axis, the movement of the slider 3.1 is not restricted; a clamp column 3.1.1 is installed on the top surface of the slider 3.1. In the x-axis direction, the axis of the clamp column 3.1.1 is aligned with the clamping surface of the fabric. A pointer 3.7 is provided on the slider 3.1, and a comparison is made with the position marked on the second scale 1.3.4 according to the axis of the tensile gauge force. This is the first time to ensure the clamping centering of the fabric in the y-axis direction; the external spline handle 2.6 is turned to rotate the double screw 2.8, driving the left clamp 2.2 and the right clamp 2.4 to move towards each other. When the clamps on both sides move 10 mm along the y-axis, the serrated meshing surfaces overlap, the fabric is clamped, and the second centering operation in the y-axis direction is completed.

[0055] In a specific embodiment, the top surface of the slider 3.1 is also provided with a through U-shaped groove to ensure that the fabric can be suspended vertically to the bottom surface of the slider 3.1; the clamp handle 3.5 and the chuck 3.4 are connected through a second through hole 3.5.1, and the two can be disassembled for use; the upper and lower handle bodies of the clamp handle 3.5 are supported by a clamp spring 3.2, and when subjected to a pinching force, the part close to the chuck 3.4 moves in the opposite direction, and the clamping mouth opens; the surface of the clamp handle 3.5 close to the chuck 3.4 is perforated and widened, and can contact the notch surface of the slider, limit the rotation of the handle body around the z-axis, and ensure that the clamping surface is parallel to the notch, and the center of the handle body is provided with a second through hole 3.5.1, which fits with the clamp column 3.1.1 on the top and bottom surfaces of the slider 3.1, and is tightened with a nut 3.3 to prevent loosening; to avoid damaging the sample surface, the inner surface of the chuck 3.4 needs to be smooth enough. To ensure that the upper and lower sides of the sample are parallel, the length of the two chucks 3.4 just covers the distance of the entire notch. A scale 3.4.1 in millimeters is engraved from the beginning of the clamp mouth. Mark the midpoint of the latitudinal width of the specimen. Use the zero scale line on the surface of the clamp 3.4 to compare the midpoint mark of the specimen and adjust the clamping position of the specimen to ensure that the upper and lower sides of the specimen are parallel. This operation is the second time to meet the clamping centering of the specimen in the x-axis direction.

[0056] In a specific embodiment, Figure 4-a As shown, the slider limit block 3.6 includes: a second nut 3.6.1, a bolt 3.6.2 and a T-shaped block 3.6.3. In order to prevent the slider 3.1 from sliding on the cantilever 1.3 plane during the subsequent clamping operation, two slider limit blocks 3.6 are placed on each side, a total of four slider limit blocks 3.6, to limit the movement of the slider 3.1 in the y-axis direction.

[0057] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0058] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A sample clamping auxiliary device for fabric tensile testing, characterized in that: include: Side auxiliary unit (Ⅰ), clamping unit (Ⅱ), pre-clamping unit (Ⅲ); The side auxiliary unit (I) is used to move the pre-clamping unit (III) to a suitable height. The clamping unit II is used to clamp the sample and use a double screw to ensure the y-axis centering. The pre-clamping unit III is used to ensure the sample is centered on the x-axis.

2. A sample clamping auxiliary device for fabric tensile testing according to claim 1, characterized in that: The side auxiliary unit (I) comprises: a column (1.1), a cantilever stop block (1.2), a cantilever (1.3) and a horizontal base (1.4); the column (1.1) is arranged on the horizontal base (1.4); a first scale (1.1.1) is engraved on the column (1.1); a T-shaped slot (1.1.2) is arranged inside the column (1.1); the cantilever (1.3) can be moved up and down in the T-shaped slot (1.1.2) to a set height and then fixed by the cantilever stop block (1.2).

3. A sample clamping auxiliary device for fabric tensile testing according to claim 2, characterized in that: The cantilever limit block (1.2) comprises: a T-shaped bolt (1.2.1), a first nut (1.2.2) and a triangular block (1.2.3).

4. A sample clamping auxiliary device for fabric tensile testing according to claim 2, characterized in that: The cantilever (1.3) comprises: a T-shaped protrusion (1.3.1), a block (1.3.2), and a cantilever body (1.3.3); the T-shaped protrusion (1.3.1) is used for guiding movement on the z-axis; the block (1.3.2) is connected to the cantilever body (1.3.3); the block (1.3.2) is used to enhance the bending resistance of the cantilever body (1.3.3); a second scale (1.3.4) is provided on the upper surface of the cantilever body (1.3.3); the cantilever body (1.3.3) is used to carry the slider (3.1) and ensure the movement accuracy of the slider (3.1) on the y-axis; a U-shaped notch runs through the center of the cantilever (1.3); and a small T-shaped slot (1.3.5) inside the cantilever (1.3) is used for the slider limit block (3.6) to move on the y-axis.

5. The sample clamping auxiliary device for fabric tensile testing according to claim 1, characterized in that: The clamping unit (II) comprises: a left connecting piece (2.1), a left clamp (2.2), a guide rod (2.3), a right clamp (2.4), a right connecting piece (2.5), an external spline handle (2.6), a U-shaped block (2.7), and a double screw (2.8). The left connecting piece (2.1) and the right connecting piece (2.5) are symmetrically distributed. An internal spline hole (2.8.3) is provided on the right inner cylindrical surface of the double screw (2.8). The internal spline hole (2.8.3) cooperates with the external spline handle (2.6). The double screw (2.8) can be rotated by rotating the external spline handle (2.6). A first through hole (2.5.1) is provided on the right connecting piece (2.5) to ensure that the external spline handle (2.6) The U-shaped block (2.7) is provided with a smooth square through hole (2.7.1), the square through hole (2.7.1) and the square column (2.1.1) on the left connecting piece (2.1) are fitted together, and the first blind hole (2.1.2) and the second blind hole (2.1.3) provided on both sides of the left connecting piece (2.1) play the role of fixing the double screw rod (2.8) and the guide rod (2.3); the double screw rod (2.8) and the guide rod (2.3) are parallel, and the double screw rod (2.8) is arranged in the holes on the outside of the left connecting piece (2.1) and the right connecting piece (2.5), and the double screw rod (2.8) passes through the first through hole (2.5.1) of the right connecting piece (2.5) and cooperates with the external spline handle (2.6).

6. A sample clamping auxiliary device for fabric tensile testing according to claim 5, characterized in that: When the present invention is in the initial position, the distance from the bottom surface of the guide rod (2.3) and the double screw (2.8) to the bottom of the first blind hole (2.1.2) and the second blind hole (2.1.3) is 10 mm. When the left clamp (2.2) and the right clamp (2.4) move, the distance is continuously reduced until the left clamp (2.2) and the right clamp (2.4) clamp the fabric. By comparing the coplanarity of the two side surfaces of the cantilever (1.3) and the left clamp (2.2) and the right clamp (2.4), the centering of the auxiliary device in the x-axis direction is determined, and the fabric is then placed in the center with the left clamp (2.2) and the right clamp (2.4) as the reference. This is the first time that the centering of the fabric in the x-axis direction is ensured.

7. The sample clamping auxiliary device for fabric tensile testing according to claim 5, characterized in that: The twin screw (2.8) is provided with a left thread (2.8.1) and a right thread (2.8.2), wherein the left thread (2.8.1) is left-handed and the right thread (2.8.2) is right-handed, and the thread parameters of the left thread (2.8.1) and the right thread (2.8.2) are the same.

8. The sample clamping auxiliary device for fabric tensile testing according to claim 5, characterized in that: The pre-clamping unit (III) comprises: a slider (3.1), a clamping spring (3.2), a nut (3.3), a clamping head (3.4), a clamping handle (3.5), a slider limit block (3.6), and a positioning piece (3.7); In order to ensure the synchronous operation of the upper and lower clamping, the slider (3.1) has a mirroring characteristic. The eight contact surfaces of the slider (3.1) in the z direction are all in contact with the cantilever (1.3) to limit its height position. On the y axis, the movement of the slider (3.1) is not restricted. A clamp column (3.1.1) is installed on the top surface of the slider (3.1). In the x axis direction, the axis of the clamp column (3.1.1) is aligned with the clamping surface of the fabric. A pointer (3.1) is provided on the slider (3.1). .7), compare the position marked on the second scale (1.3.4) according to the axis of the tensile tester force, this is the first time to ensure the clamping centering of the fabric in the y-axis direction; turn the external spline handle (2.6) to rotate the double screw (2.8), driving the left clamp (2.2) and the right clamp (2.4) to move towards each other, when the clamps on both sides move 10mm along the y-axis, the serrated meshing surfaces overlap, the fabric is clamped, and the second centering operation in the y-axis direction is completed.

9. A sample clamping auxiliary device for fabric tensile testing according to claim 8, characterized in that: The top surface of the slider (3.1) is also provided with a through U-shaped groove to ensure that the fabric can be suspended vertically to the bottom surface of the slider (3.1); the clamping handle (3.5) and the clamping head (3.4) are connected through a second through hole (3.5.1), and the two can be disassembled for use; the upper and lower handle bodies of the clamping handle (3.5) are supported by clamping springs (3.2), and when subjected to a pinching force, the part close to the clamping head (3.4) moves in the opposite direction, and the clamping mouth opens; the surface of the clamping handle (3.5) close to the clamping head (3.4) is perforated and widened, so that it can contact the notch surface of the slider, thereby limiting the rotation of the handle body around the z-axis , and ensure that the clamping surface is parallel to the notch. A second through hole (3.5.1) is provided in the center of the handle body, which fits with the clamp column (3.1.1) on the top and bottom surfaces of the slider (3.1) and is tightened with a nut (3.3) to prevent loosening; a scale (3.4.1) in millimeters is engraved from the beginning of the clamp mouth, and a mark is made at the midpoint of the latitudinal width of the sample. The zero scale line on the surface of the chuck (3.4) is used to compare the midpoint mark of the sample and adjust the clamping position of the sample to ensure that the upper and lower sides of the sample are parallel. This operation is the second time to meet the clamping centering of the sample in the x-axis direction.

10. The sample clamping auxiliary device for fabric tensile testing according to claim 8, characterized in that: The slider limit block (3.6) comprises: a second nut (3.6.1), a bolt (3.6.2) and a T-shaped block (3.6.3).

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