Leather strength detection device

Abstract

The invention relates to the technical field of testing strength characteristics of solid materials through mechanical stress, in particular to a leather strength detection device which comprises a box body and a detection mechanism, the detection mechanism comprises a hydraulic cylinder, the upper end of the hydraulic cylinder is provided with a placing table used for placing a leather sample, a piston and an ejector rod are arranged in the hydraulic cylinder, and one end of the ejector rod is fixedly connected with the piston; the placing table comprises a supporting cylinder coaxially arranged with the hydraulic cylinder, one side of the supporting cylinder is connected with a negative pressure adsorption system, and the negative pressure adsorption system sucks air in the supporting cylinder after the leather sample is placed on the upper side of the supporting cylinder; the pressing cover descends and presses the leather sample after the leather sample is adsorbed on the upper side of the supporting cylinder, so that the edge of the leather sample is clamped and fixed by the supporting cylinder and the pressing cover. The leather sample can be flatly fixed in the detection device, and the accuracy of a detection result is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of testing the strength characteristics of solid materials by using mechanical stress, and in particular to a leather strength detection device. Background Art

[0002] Leather is made of natural protein fibers tightly woven in three-dimensional space. Its surface has a special grain layer with natural grain and luster, and feels comfortable. In order to ensure the quality of leather, each part of the leather needs to be tested before it is put on the market.

[0003] At present, when performing crack detection on leather, a small round leather sample is fixed in a leather crack tester, and then force is applied to the small leather sample until the leather sample breaks, and then the strength of the leather can be obtained by referring to the leather sample rupture time and the corresponding force magnitude. Leather crack testers in the prior art, such as a leather crack tester disclosed in a Chinese utility model patent with authorization announcement number CN204575439U, when fixing the leather sample, the round leather sample is placed in the leather crack tester by hand, and the leather sample is first fixed by hand, and then the leather crack tester is operated to clamp the edge position of the round leather sample. This method of first manually fixing the leather sample and then clamping the leather sample can easily cause the leather sample to be uneven after fixation, thereby affecting the test results. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention proposes a leather strength testing device to solve the technical problem in the prior art that the leather sample is prone to being uneven after being fixed, thus affecting the test structure.

[0005] A leather strength detection device of the present invention adopts the following technical solution: A leather strength testing device comprises a box body and a testing mechanism arranged in the box body, the testing mechanism comprises a hydraulic cylinder whose axis extends in the up-down direction, the upper end of the hydraulic cylinder is provided with a placing table for placing leather samples, the hydraulic cylinder is provided with a piston and a push rod, the push rod is located on the central axis of a supporting tube, one end of the push rod is fixedly connected to the piston, and the other end extends out of the hydraulic cylinder, and is used to break the leather sample on the placing table from bottom to top, the placing table comprises a supporting tube coaxially arranged with the hydraulic cylinder, one side of the supporting tube is connected to a negative pressure adsorption system, the negative pressure adsorption system sucks the air in the supporting tube after the leather sample is placed on the upper side of the supporting tube, so that the leather sample is adsorbed on the upper side of the supporting tube, and the top of the box body is provided with a lifting and lowering downward pressure cover above the placing table, the downward pressure cover descends and presses down the leather sample after the leather sample is adsorbed on the upper side of the supporting tube, so that the edge of the leather sample is clamped and fixed by the supporting tube and the downward pressure cover.

[0006] Furthermore, the support cylinder includes a straight cylinder coaxial with the hydraulic cylinder and a flange located at the upper end of the straight cylinder, and a ring platform coaxial with the flange is provided on the upper end surface of the flange, and the ring platform is used to cooperate with the edge support of the leather sample, and a plurality of center cylinders are coaxially nested in the support cylinder, and the upper end of the center cylinder is flush with the ring platform to support the center of the leather sample, and annular chambers are respectively formed between the support cylinder and the outermost center cylinder and between two adjacent center cylinders, and each annular chamber is respectively connected to the negative pressure adsorption system.

[0007] Furthermore, a rolling mechanism is provided on the lower pressure cover, and the rolling mechanism is used to stretch the leather sample in the radial direction of the leather sample to make the surface of the leather sample smooth. The rolling mechanism includes a roller assembly floatingly installed in the lower pressure cover along the up and down directions, and the roller assembly is connected to a driving mechanism. When the lower pressure cover descends, the roller assembly presses down the edge of the leather sample, and the driving mechanism drives the roller assembly to roll to stretch the leather sample in the radial direction of the leather sample.

[0008] Furthermore, a push mechanism is provided in the flange, and the push mechanism includes a wedge plate installed in the flange in a radial direction of the flange, and the end of the wedge plate facing the center of the support tube is a pointed end. When the negative pressure adsorption system adsorbs the leather sample, the wedge plate extends out in the radial direction of the flange and extends into the lower side of the leather sample. The wedge plate and the roller assembly jointly clamp the edge of the leather sample from the upper and lower sides of the leather sample. When the roller assembly rolls, the leather sample is subjected to a radial tensile force.

[0009] Furthermore, the roller assembly and the push mechanism are respectively arranged in multiple groups evenly spaced along the circumference of the support cylinder, and the roller assemblies and the push mechanism are arranged one by one, the roller assembly comprises a bevel gear, an intermediate wheel and a lower pressure wheel arranged side by side, the bevel gear, the intermediate wheel and the lower pressure wheel are rotatably installed in the lower pressure cover from top to bottom in sequence, the axes of the bevel gear, the intermediate wheel and the lower pressure wheel of the same roller assembly are parallel and perpendicular to the radial direction of the support cylinder, the intermediate wheel and the lower pressure wheel are both friction wheels, when the lower pressure cover descends to make the roller assembly press down the edge of the leather sample, the axial ends of the bevel gear are respectively connected with the outer circumferential surface of the intermediate wheel by friction transmission, the outer circumferential surface of the intermediate wheel is connected with the outer circumferential surface of the lower pressure wheel by friction transmission, the driving mechanism drives the bevel gear to rotate, so that the bevel gear drives the lower pressure wheel to rotate through the intermediate wheel.

[0010] Furthermore, return springs are respectively pressed between the bevel gear and the intermediate wheel, between the intermediate wheel and the lower pressure wheel, and between the bevel gear and the lower pressure cover of the same roller assembly. The bevel gear, the intermediate wheel and the lower pressure wheel are respectively movably installed in the lower pressure cover along the up and down directions. The return spring makes the bevel gear, the intermediate wheel and the lower pressure wheel arranged at intervals from each other in the initial state. A pressure ring is provided on the lower side of the roller assembly close to the center of the lower pressure cover on the lower side of the lower pressure cover. The pressure ring is used to press down the edge of the leather sample. In the initial state, the lower side of the lower pressure wheel is lower than the lower end of the pressure ring.

[0011] Furthermore, a transmission gear ring coaxial with the lower pressure cover is rotatably provided inside the lower pressure cover, the outer periphery of the transmission gear ring is provided with helical teeth meshing with the helical gears of each roller assembly for transmission, the inner periphery of the transmission gear ring is provided with internal teeth, the driving mechanism has an output shaft, the output shaft is connected with a transmission gear, and the transmission gear meshes with the internal teeth of the transmission gear ring for transmission.

[0012] Furthermore, a piston hole is opened on the inner wall of the support cylinder, a piston column is movably inserted in the piston hole, the piston column is fixedly connected to the wedge plate, and a tension spring is connected to the end of the piston column away from the center of the support cylinder, and the tension spring drives the wedge plate to retract into the flange along the radial direction of the flange.

[0013] Furthermore, a guide groove extending in the radial direction of the flange is provided on the upper side surface of the flange, and a guide block is provided on the wedge plate. The guide block is located in the guide groove to guide the wedge plate to move in the radial direction of the flange.

[0014] Furthermore, a pneumatic telescopic cylinder is connected to the upper side of the lower pressure cover, an L-shaped support arm is fixed to the top of the box body, the lower end of the pneumatic telescopic cylinder is fixedly connected to the upper side of the lower pressure cover, and the upper end of the pneumatic telescopic cylinder is fixedly connected to the support arm.

[0015] The beneficial effect of the present invention is that a leather strength detection device of the present invention, by setting up a negative pressure adsorption system, when in use, first uses the negative pressure adsorption system to adsorb and fix the leather sample placed on the support tube, and then uses the downward pressure cover above to press down the edge of the leather sample, without the need for manual fixation of the leather sample. Under the adsorption action of the negative pressure adsorption system, the entire leather sample is subjected to a uniform adsorption force, which makes it easier to make the leather sample in a flat state.

[0016] Furthermore, the present invention is provided with a flat push mechanism and a roller assembly, and after the negative pressure adsorption system adsorbs the leather sample, the edge of the leather sample is stretched and unfolded. When the lower pressure cover descends, the roller assembly is pressed on the upper side of the leather sample, and the wedge plate and the roller assembly clamp the edge of the leather sample from the upper and lower sides of the leather sample, and then the roller assembly is rolled, so that the leather sample is subjected to a radially outward stretching force, so that the edge of the leather sample is stretched in all directions, ensuring that the leather sample is in a flat state. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work. Those skilled in the art should understand that these drawings are not necessarily drawn to scale.

[0018] Figure 1 It is a three-dimensional schematic diagram of an embodiment of a leather strength detection device of the present invention; Figure 2 It is a three-dimensional schematic diagram of a detection mechanism in one embodiment of a leather strength detection device of the present invention; Figure 3 It is a cross-sectional schematic diagram of a detection mechanism in one embodiment of a leather strength detection device of the present invention; Figure 4 for Figure 3 A magnified view of the part A in the middle; Figure 5 for Figure 3 A magnified view of the part B in the middle; Figure 6 Another cross-sectional schematic diagram of a detection mechanism in one embodiment of a leather strength detection device of the present invention; Figure 7 for Figure 6 Enlarged view of part C in the middle.

[0019] In the figure: 100, box body; 200, support arm; 300, detection mechanism; 310, hydraulic cylinder; 311, hydraulic oil port; 312, hydraulic chamber; 313, piston; 314, push rod; 315, radial connecting hole; 316, center tube; 317, piston hole; 318, guide groove; 320, annular connecting cover; 321, connecting pipe; 330, lower pressure cover; 331, mounting groove; 332, pressure ring; 333, lower pressure wheel; 334, intermediate wheel; 335, bevel gear; 336, transmission gear ring; 340, pneumatic telescopic cylinder; 350, driving mechanism; 351, transmission gear; 360, leather sample; 370, piston column; 371, tension spring; 380, push mechanism; 381, guide block; 382, ​​wedge plate. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] An embodiment of a leather strength detection device of the present invention is as follows Figures 1 to 7 As shown, the leather strength detection device includes a box 100 and a detection mechanism 300 disposed in the box 100, the box 100 is provided with a display screen and a control button, the structure of the box 100 and the control button are both prior art and will not be described in detail here. In the present invention, the detection mechanism 300 includes a hydraulic cylinder 310 whose axis extends in the up-down direction, the hydraulic cylinder 310 has a hydraulic chamber 312, a piston 313 and a push rod 314 are disposed in the hydraulic cylinder 310, the push rod 314 is located on the central axis of the support cylinder, one end of the push rod 314 is fixedly connected to the piston 313, and the other end extends out of the hydraulic cylinder 310, the lower end of the hydraulic cylinder 310 is provided with a hydraulic oil port 311, the hydraulic oil port 311 is connected to the hydraulic system disposed in the box 100, and the piston 313 drives the push rod 314 to move up and down by controlling the inflow and outflow of the hydraulic oil.

[0022] The upper end of the hydraulic cylinder 310 is provided with a placing table for placing the leather sample 360, and the placing table includes a supporting cylinder coaxially arranged with the hydraulic cylinder 310. When in use, the circular leather sample 360 ​​is placed on the upper side of the supporting cylinder, and one side of the supporting cylinder is connected to a negative pressure adsorption system (not shown in the figure). After the leather sample 360 ​​is placed on the upper side of the supporting cylinder, the negative pressure adsorption system sucks the air in the supporting cylinder so that the leather sample 360 ​​is adsorbed on the upper side of the supporting cylinder. The top of the box 100 is provided with a lifting and lowering downward pressure cover 330 above the supporting cylinder. After the leather sample 360 ​​is adsorbed on the upper side of the supporting cylinder, the downward pressure cover 330 descends and presses down the leather sample 360, so that the edge of the leather sample 360 ​​is clamped and fixed by the supporting cylinder and the downward pressure cover 330. After the leather sample 360 ​​is clamped and fixed, the piston 313 in the hydraulic cylinder 310 is controlled to drive the push rod 314 to move upward, and the upper end of the push rod 314 pushes the leather sample 360 ​​upward to achieve a cracking test on the leather sample 360.

[0023] In this embodiment, the support cylinder includes a straight cylinder coaxial with the hydraulic cylinder 310 and a flange located at the upper end of the straight cylinder. A ring platform coaxial with the flange is provided on the upper end surface of the flange. The outer diameter of the ring platform is adapted to the diameter of the circular leather sample 360. In this way, when the leather sample 360 ​​is placed on the upper side of the support cylinder, the leather sample 360 ​​is just located on the ring platform. The ring platform is used to cooperate with the edge support of the leather sample 360. In order to prevent the middle of the leather sample 360 ​​from collapsing downward, a plurality of center cylinders 316 are coaxially nested in the support cylinder. The upper end of the center cylinder 316 is flush with the ring platform to support the middle of the leather sample 360. In this embodiment, an annular chamber is formed between the support cylinder and the outermost center cylinder 316 and between two adjacent center cylinders 316, and each annular chamber is connected to the negative pressure adsorption system. Specifically, a plurality of radial communication holes 315 are provided on the straight side wall of the support tube, one end of each radial communication hole 315 is connected to each annular chamber, an annular communication cover 320 is provided on the periphery of the support tube, the other end of each radial communication hole 315 is connected to the inside of the annular communication cover 320, and the annular communication cover 320 is connected to the negative pressure adsorption system through a communication pipe 321. When the present invention is used, the negative pressure adsorption system is first used to adsorb and fix the leather sample 360 ​​placed on the support tube, and then the upper downward pressure cover 330 is used to press down the edge of the leather sample 360, without manual work to fix the leather sample 360, under the adsorption action of the negative pressure adsorption system, the entire leather sample 360 ​​is subjected to uniform adsorption force, which makes it easier to keep the leather sample 360 ​​in a flat state.

[0024] In this embodiment, a rolling mechanism is provided on the pressing cover 330, and the rolling mechanism is used to stretch the leather sample 360 ​​in the radial direction of the leather sample 360 ​​so as to make the surface of the leather sample 360 ​​flat. Specifically, the rolling mechanism includes a roller assembly floatingly installed in the pressing cover 330 in the up and down directions, and the roller assembly is connected to a driving mechanism 350, and the driving mechanism 350 is a driving motor. When the pressing cover 330 descends, the roller assembly presses down the edge of the leather sample 360, and the driving mechanism 350 drives the roller assembly to roll to stretch the leather sample 360 ​​in the radial direction of the leather sample 360. A horizontal push mechanism 380 is provided in the flange, and the horizontal push mechanism 380 is arranged corresponding to the rolling mechanism up and down, and the horizontal push mechanism 380 and the roller assembly are used to clamp the edge of the leather sample 360 ​​from the upper and lower sides of the leather sample 360. The horizontal push mechanism 380 includes a wedge plate 382 that is installed in the flange in a floating manner along the radial direction of the flange. The end of the wedge plate 382 that faces the center of the support tube is a pointed end. When the negative pressure adsorption system adsorbs the leather sample 360, the wedge plate 382 extends along the radial direction of the flange and extends into the lower side of the leather sample 360. When the lower pressure cover 330 descends, the roller assembly presses on the upper side of the leather sample 360. The wedge plate 382 and the roller assembly clamp the edge of the leather sample 360 ​​from both the upper and lower sides of the leather sample 360, and then the roller assembly rolls, so that the leather sample 360 ​​is subjected to a radially outward tensile force, so that the edge of the leather sample 360 ​​is stretched to all sides, ensuring that the leather sample 360 ​​is in a flat state.

[0025] In this embodiment, the roller assemblies and the parallel pushing mechanisms 380 are arranged in multiple groups at even intervals along the circumference of the support tube, and the roller assemblies and the parallel pushing mechanisms 380 are arranged one by one in the up and down directions. The roller assembly includes a bevel gear 335, an intermediate wheel 334 and a lower pressing wheel 333 arranged side by side, and an installation cavity 331 is opened in the lower pressing cover 330. The bevel gear 335, the intermediate wheel 334 and the lower pressing wheel 333 are rotatably installed in the installation cavity 331 of the lower pressing cover 330 from top to bottom in sequence, and the axes of the bevel gear 335, the intermediate wheel 334 and the lower pressing wheel 333 of the same roller assembly are parallel and perpendicular to the radial direction of the support cylinder, and the intermediate wheel 334 and the lower pressing wheel 333 are both friction wheels. When the lower pressing cover 330 descends to press the edge of the leather sample 360, the axial ends of the bevel gear 335 are respectively connected with the outer peripheral surface of the intermediate wheel 334 by friction transmission, and the outer peripheral surface of the intermediate wheel 334 is connected with the outer peripheral surface of the lower pressing wheel 333 by friction transmission, and the driving mechanism 350 drives the bevel gear 335 to rotate, so that the bevel gear 335 drives the lower pressing wheel 333 to rotate through the intermediate wheel 334. A return spring is respectively pressed between the bevel gear 335 and the intermediate wheel 334, between the intermediate wheel 334 and the lower pressing wheel 333, and between the bevel gear 335 and the lower pressing cover 330 of the same roller assembly. The bevel gear 335, the intermediate wheel 334, and the lower pressing wheel 333 are respectively movably installed in the lower pressing cover 330 in the up-down direction. The return spring makes the bevel gear 335, the intermediate wheel 334, and the lower pressing wheel 333 arranged at intervals from each other in the initial state. A pressing ring 332 is provided on the lower side of the lower pressing cover 330 at one side of the roller assembly close to the center of the lower pressing cover 330. The pressing ring 332 is used to press down the edge of the leather sample 360. In the initial state, the lower side of the lower pressing wheel 333 is lower than the lower end of the pressing ring 332. When the lower pressure cover 330 descends, the lower pressure wheel 333 contacts the leather sample 360 ​​before the pressure ring 332, and under the action of the return spring, the lower pressure wheel 333 and the leather sample 360 ​​are elastically squeezed, and as the lower pressure cover 330 descends, the lower pressure wheel 333, the intermediate wheel 334 and the bevel gear 335 realize two-by-two transmission connection.

[0026] In this embodiment, a transmission gear ring 336 coaxial with the lower pressure cover 330 is rotatably provided inside the lower pressure cover 330, and the outer periphery of the transmission gear ring 336 is provided with helical teeth meshing with the helical gears 335 of each roller assembly for transmission, and the inner periphery of the transmission gear ring 336 is provided with internal teeth, and the driving mechanism 350 has an output shaft, and the output shaft is connected to a transmission gear 351, and the transmission gear 351 meshes with the internal teeth of the transmission gear ring 336 for transmission.

[0027] In this embodiment, the wedge plate 382 of the horizontal push mechanism 380 is floatingly arranged in the flange. Specifically, a piston hole 317 is opened on the inner wall of the support cylinder, and a piston column 370 is movably inserted in the piston hole 317. The piston column 370 is fixedly connected to the wedge plate 382. The end of the piston column 370 away from the center of the support cylinder is connected to a tension spring 371, and the tension spring 371 drives the wedge plate 382 to retract into the flange along the radial direction of the flange. When the negative pressure adsorption system adsorbs the leather sample 360, under the action of negative pressure, the piston column 370 moves toward the center of the support cylinder due to the negative pressure, thereby driving the wedge plate 382 to extend along the radial direction of the flange and extend into the lower side of the leather sample 360.

[0028] In this embodiment, a guide groove 318 extending radially along the flange is provided on the upper side surface of the flange, and a guide block 381 is provided on the wedge plate 382. The guide block 381 is located in the guide groove 318 to guide the wedge plate 382 to move radially along the flange. In this embodiment, the guide block 381 is a strip block extending radially along the flange, one end of the guide block 381 is fixedly connected to the wedge plate 382, ​​and the other end is cantilevered and used to cooperate with the edge stop of the leather sample 360. When the wedge plate 382 moves toward the center of the support tube together with the guide block 381, when the cantilevered end of the guide block 381 contacts the edge of the leather sample 360, it is blocked by the leather sample 360 ​​and the guide block 381 stops moving toward the center of the support tube. In this way, when the leather sample 360 ​​is in a wrinkled state, the edge of the leather sample 360 ​​will partially shrink toward the center of the support tube, and the wedge plates 382 at different positions move different distances toward the center of the support tube, so that the clamping force between the roller assembly and the wedge plates 382 at different positions is different.

[0029] In this embodiment, the upper side of the lower pressure hood 330 is connected to a pneumatic telescopic cylinder 340, and an L-shaped support arm 200 is fixed to the top of the box body 100. The lower end of the pneumatic telescopic cylinder 340 is fixedly connected to the upper side of the lower pressure hood 330, and the upper end of the pneumatic telescopic cylinder 340 is fixedly connected to the support arm 200. When in use, the lower pressure hood 330 is lifted or lowered by controlling the extension and retraction of the pneumatic telescopic cylinder 340.

[0030] When a leather strength testing device of the present invention is in use, a leather sample 360 ​​is placed in the ring platform at the upper end of the support tube, and multiple center tubes 316 support the leather sample 360 ​​from the middle of the leather sample 360, and then the negative pressure adsorption system is started to form a negative pressure inside each annular chamber, so that the lower side of the leather sample 360 ​​is tightly fitted with the ring platform and the upper end of the center tube 316, that is, the leather sample 360 ​​completely blocks the upper end of the support tube, so that a negative pressure closed chamber is formed inside the support tube, and under the action of the negative pressure, the piston column 370 drives the wedge plate 382 to move toward the inside of the support tube, and under the action of the tip of the wedge plate 382, ​​the wedge plate 382 enters the lower side of the leather sample 360 ​​and supports the edge of the leather sample 360. Then, the pneumatic telescopic cylinder 340 is driven to extend, so that the lower pressure cover 330 is lowered, and the driving mechanism 350 is started at the same time. When the lower pressure wheel 333 of the roller assembly contacts the upper side of the leather sample 360, the lower pressure wheel 333 begins to overcome the force of the return spring and moves upward relative to the lower pressure cover 330, until the lower pressure wheel 333, the intermediate wheel 334 and the bevel gear 335 are mutually driven, so that the transmission gear ring 336 rotates to drive the lower pressure wheels 333 of all roller assemblies to rotate, and the direction of rotation of the lower pressure wheel 333 can make the edge of the leather sample 360 ​​stretch radially outward, so that the leather sample 360 ​​remains in a stretched state. Then, as the lower pressure cover 330 continues to descend, the pressure ring 332 begins to squeeze and cooperate with the edge of the leather sample 360, so that the leather sample 360 ​​is clamped between the support cylinder and the lower pressure cover 330. Then, the hydraulic oil in the hydraulic cylinder 310 is controlled so that the piston 313 drives the push rod 314 to move upward and break the leather sample 360, thereby completing the cracking test of the leather sample 360. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A leather strength detection device, comprising a box (100) and a detection mechanism (300) arranged in the box (100), characterized in that: The detection mechanism (300) comprises a hydraulic cylinder (310) whose axis extends in the up-down direction; a placement table for placing a leather sample (360) is provided at the upper end of the hydraulic cylinder (310); a piston (313) and a push rod (314) are provided in the hydraulic cylinder (310); the push rod (314) is located on the central axis of the support cylinder; one end of the push rod (314) is fixedly connected to the piston (313); the other end extends out of the hydraulic cylinder (310) and is used to push the leather sample (360) on the placement table from bottom to top; the placement table comprises a piston (313) and a push rod (314) arranged at the same time as the hydraulic cylinder (310); A support cylinder is arranged on the axis, and one side of the support cylinder is connected to a negative pressure adsorption system. After the leather sample (360) is placed on the upper side of the support cylinder, the negative pressure adsorption system sucks the air in the support cylinder so that the leather sample (360) is adsorbed on the upper side of the support cylinder. The top of the box (100) is provided with a downward pressure cover (330) that can be raised and lowered above the placement table. After the leather sample (360) is adsorbed on the upper side of the support cylinder, the downward pressure cover (330) descends and presses down the leather sample (360) so that the edge of the leather sample (360) is clamped and fixed by the support cylinder and the downward pressure cover (330).

2. The leather strength detection device according to claim 1, characterized in that: The support tube comprises a straight tube coaxial with the hydraulic cylinder (310) and a flange located at the upper end of the straight tube, a ring platform coaxial with the flange is provided on the upper end surface of the flange, the ring platform is used to cooperate with the edge support of the leather sample (360), a plurality of center tubes (316) are coaxially nested in the support tube, the upper end of the center tube (316) is flush with the ring platform to support the center of the leather sample (360), and an annular chamber is formed between the support tube and the outermost center tube (316) and between two adjacent center tubes (316), and each annular chamber is connected to a negative pressure adsorption system.

3. The leather strength detection device according to claim 2, characterized in that: The pressing cover (330) is provided with a rolling mechanism, and the rolling mechanism is used to stretch the leather sample (360) in the radial direction of the leather sample (360) so as to make the surface of the leather sample (360) flat. The rolling mechanism comprises a roller assembly floatingly mounted in the pressing cover (330) in the up-down direction, and the roller assembly is connected to a driving mechanism (350). When the pressing cover (330) descends, the roller assembly presses down the edge of the leather sample (360), and the driving mechanism (350) drives the roller assembly to roll so as to stretch the leather sample (360) in the radial direction of the leather sample (360).

4. The leather strength testing device according to claim 3, characterized in that: A horizontal push mechanism (380) is provided in the flange, and the horizontal push mechanism (380) comprises a wedge plate (382) which is installed in the flange in a floating manner along the radial direction of the flange, and the end of the wedge plate (382) facing the center of the support tube is a pointed end. When the negative pressure adsorption system adsorbs the leather sample (360), the wedge plate (382) extends in the radial direction of the flange and extends into the lower side of the leather sample (360). The wedge plate (382) and the roller assembly jointly clamp the edge of the leather sample (360) from the upper and lower sides of the leather sample (360). When the roller assembly rolls, the leather sample (360) is subjected to a tensile force in the radial direction.

5. The leather strength detection device according to claim 4, characterized in that: The roller assembly and the horizontal push mechanism (380) are respectively arranged in multiple groups at even intervals along the circumference of the support cylinder, and the roller assembly and the horizontal push mechanism (380) are arranged one by one. The roller assembly includes a helical gear (335), an intermediate wheel (334) and a lower pressure wheel (333) arranged side by side. The helical gear (335), the intermediate wheel (334) and the lower pressure wheel (333) are rotatably installed in the lower pressure cover (330) from top to bottom in sequence. The axes of the helical gear (335), the intermediate wheel (334) and the lower pressure wheel (333) of the same roller assembly are parallel and perpendicular to In the radial direction of the support cylinder, the intermediate wheel (334) and the lower pressing wheel (333) are both friction wheels. When the lower pressing cover (330) descends to cause the roller assembly to press down the edge of the leather sample (360), the axial ends of the bevel gear (335) are respectively connected to the outer peripheral surface of the intermediate wheel (334) by friction transmission. The outer peripheral surface of the intermediate wheel (334) and the outer peripheral surface of the lower pressing wheel (333) are connected by friction transmission. The driving mechanism (350) drives the bevel gear (335) to rotate, so that the bevel gear (335) drives the lower pressing wheel (333) to rotate through the intermediate wheel (334).

6. The leather strength testing device according to claim 5, characterized in that: Return springs are respectively pressed between the bevel gear (335) and the intermediate wheel (334), between the intermediate wheel (334) and the lower pressing wheel (333), and between the bevel gear (335) and the lower pressing cover (330) of the same roller assembly. The bevel gear (335), the intermediate wheel (334), and the lower pressing wheel (333) are movably installed in the lower pressing cover (330) in the upper and lower directions. The return springs enable the bevel gear (335), the intermediate wheel (334), and the lower pressing wheel (333) to be arranged spaced apart from each other in an initial state. A pressing ring (332) is provided on the lower side of the roller assembly at a side close to the center of the lower pressing cover (330). The pressing ring (332) is used to press down the edge of the leather sample (360). In the initial state, the lower side of the lower pressing wheel (333) is lower than the lower end of the pressing ring (332).

7. The leather strength testing device according to claim 6, characterized in that: A transmission gear ring (336) coaxial with the lower pressure cover (330) is rotatably arranged inside the lower pressure cover (330), the outer periphery of the transmission gear ring (336) is provided with helical teeth meshing with the helical gears (335) of each roller assembly, the inner periphery of the transmission gear ring (336) is provided with internal teeth, and the driving mechanism (350) has an output shaft, the output shaft is connected to a transmission gear (351), and the transmission gear (351) meshes with the internal teeth of the transmission gear ring (336) for transmission.

8. The leather strength testing device according to claim 7, characterized in that: A piston hole (317) is provided on the inner wall of the support cylinder. A piston column (370) is movably inserted into the piston hole (317). The piston column (370) is fixedly connected to the wedge plate (382). A tension spring (371) is connected to the end of the piston column (370) that is away from the center of the support cylinder. The tension spring (371) drives the wedge plate (382) to retract into the flange along the radial direction of the flange.

9. The leather strength testing device according to claim 8, characterized in that: A guide groove (318) extending in the radial direction of the flange is provided on the upper side surface of the flange, and a guide block (381) is provided on the wedge plate (382). The guide block (381) is located in the guide groove (318) to guide the wedge plate (382) to move in the radial direction of the flange.

10. The leather strength testing device according to claim 9, characterized in that: The upper side of the downward pressure cover (330) is connected to a pneumatic telescopic cylinder (340); an L-shaped support arm (200) is fixed to the top of the box body (100); the lower end of the pneumatic telescopic cylinder (340) is fixedly connected to the upper side of the downward pressure cover (330); and the upper end of the pneumatic telescopic cylinder (340) is fixedly connected to the support arm (200).

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