Clamping device and method for a leather tensile testing machine used in the production of electrically insulating shoes

Abstract

This invention discloses a clamping device and method for a leather tensile testing machine used in the production of electrically insulating shoes, belonging to the field of electrically insulating shoe production technology. The clamping device for the leather tensile testing machine includes a base plate with two sets of clamping parts slidably disposed on the base plate. Each set of clamping parts includes: a U-shaped plate slidably disposed on the base plate, with a second clamping component disposed within the U-shaped plate; fixed seats symmetrically disposed on both sides of the U-shaped plate, with a sliding block slidably connected to each fixed seat, and a first clamping component disposed between two sliding blocks; and a pulling component. This invention achieves rapid clamping, automatic centering, anti-slip self-locking, and stress dispersion of leather samples through a multi-linkage mechanism of pressing quick clamping, rotating wrapping, wedge-shaped inclined plane self-locking, and arc-shaped clamping plate secondary clamping. This effectively solves the problems of slippage and detachment of traditional clamps, stress concentration at the clamping end, and centering deviation, improving the reliability, data repeatability, and operational efficiency of tensile testing.

Description

Technical Field

[0001] This invention relates to the field of electrical insulating shoe manufacturing technology, and in particular to a clamping device and method for a leather tensile testing machine used in the production of electrical insulating shoes. Background Technology

[0002] The leather industry encompasses core sectors such as leather tanning, shoemaking, leather clothing, leather goods, and fur and its products, as well as supporting industries like leather chemicals, leather hardware, leather machinery, and accessories. It features high upstream and downstream linkages, relies on market demand, boasts evergreen products, and integrates foreign exchange earnings, income generation, and employment. Electrically insulated shoes, as special labor protection equipment, require leather uppers with excellent mechanical properties; therefore, tensile strength, elongation at break, and other indicators must be tested during the production process.

[0003] Existing leather tensile testing machines mostly use flat-plate manual screw clamps or pneumatic flat-jaw pliers for clamping devices. In actual use, these devices have the following problems: First, the surface of leather is smooth and has a certain degree of extensibility. The friction of traditional flat-plate pliers is insufficient, and the specimen is prone to slipping and falling off during the stretching process, resulting in invalid test data. Second, when the rigid clamping surface acts directly on the leather, stress concentration is easily generated at the clamping end, causing the specimen to break near the jaws instead of breaking normally in the gauge section, which seriously affects the accuracy of the test results. Third, clamping and extensometer installation need to be carried out separately, which is cumbersome and makes it difficult to guarantee the positioning accuracy of the extensometer blade. Summary of the Invention

[0004] The purpose of this invention is to solve the problems existing in the prior art, and to propose a clamping device and method for a leather tensile testing machine for the production of electrically insulating shoes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A clamping device for a leather tensile testing machine used in the production of electrically insulating shoes includes a base plate, on which two sets of clamping parts are slidably disposed, each set of clamping parts including:

[0007] A U-shaped plate is slidably mounted on a base plate, and a second clamping assembly is provided inside the U-shaped plate;

[0008] Fixed seats are symmetrically arranged on both sides of the U-shaped plate. Each fixed seat is slidably connected to a sliding block, and a first clamping assembly is arranged between two sliding blocks.

[0009] And the traction assembly, one side of which is slidably set with the U-shaped plate, and the other side is connected to the winch installed on the base plate via a traction rope;

[0010] The first clamping component includes two relatively movable clamping seats. After the two clamping seats clamp the leather, the second clamping component works and drives the first clamping component to move, thereby clamping and positioning the leather clamped by the first clamping component again.

[0011] Preferably, the first clamping assembly further includes a rotating seat rotatably disposed within the sliding block and a first elastic telescopic rod symmetrically arranged on both sides of the end of the rotating seat. The first elastic telescopic rod is fixedly connected to the clamping seat on the same side via a connecting plate.

[0012] Preferably, the rotating seat is slidably provided with a pressing block between the two clamping seats, a first elastic element is provided between the pressing block and the rotating seat, a fixing block is provided on the clamping seat to move against the pressing block, a first extrusion inclined surface is provided on both sides of the end of the pressing block, and a first force-bearing inclined surface is provided on the fixing block to cooperate with the first extrusion inclined surface.

[0013] Preferably, the second clamping assembly includes a bidirectional screw rotatably mounted on a U-shaped plate, sleeves threaded to the upper and lower sides of the bidirectional screw, and an arc-shaped clamping plate fixedly connected to the sleeves via a connecting plate. The arc-shaped clamping plates on the upper and lower sides together form a clamping area for clamping two clamping seats.

[0014] Preferably, the fixed base is provided with a sliding groove for the sliding block to slide, a second elastic element is provided between the sliding groove and the bottom of the sliding block, and the fixed base is provided with a stop block that moves against the sliding block;

[0015] A rack plate is fixed to the outside of the fixed seat, and a movable gear that meshes with the rack plate is provided on the rotating seat.

[0016] Preferably, a lifting rod is slidably disposed on the outer side of the sliding block, a third elastic element is disposed between the lifting rod and the sliding block, and a pressure roller is connected to the lifting rod via a rotating shaft to move against the leather wound around the outer side of the clamping seat.

[0017] Preferably, an anti-slip structure is provided between the two clamping seats, wherein a retaining strip is fixed on the clamping surface of one of the clamping seats, and a retaining groove that mates with the retaining strip is provided on the clamping surface of the other clamping seat.

[0018] Preferably, the smooth section of the bidirectional screw is provided with a drum, a pull rope is wound and connected to the drum, a second elastic telescopic rod is connected to the end of the pull rope away from the drum, a connecting plate is connected to the end of the second elastic telescopic rod away from the drum, and the connecting plate is disposed between the fixing seats on both sides of the U-shaped plate.

[0019] The fixed base is equipped with a limiting frame for restricting the direction of movement of the pull rope.

[0020] Preferably, the traction assembly includes a traction block slidably disposed on the sliding block, a fourth elastic element disposed between the traction block and the fixed seat, a traction plate connected to the traction block via a connecting rod, a force-bearing block slidably disposed in the clamping seat, a positioning clamp fixedly connected to the force-bearing block, and a fifth elastic element disposed between the positioning clamp and the clamping seat. A tension sensor is disposed between the traction block and the sliding block.

[0021] The traction block and the force-bearing block move against each other. The traction block is provided with a second compression slope, and the force-bearing block is provided with a second force-bearing slope that cooperates with the second compression slope.

[0022] This invention also discloses a clamping method for a leather tensile testing machine used in the production of electrically insulating shoes. The clamping method involves using the aforementioned clamping device for the leather tensile testing machine used in the production of electrically insulating shoes, and includes the following steps:

[0023] S1: In the initial state, the two clamping seats of the first clamping assembly are close to each other under the action of the first elastic telescopic rod; the operator presses the pressing block on the rotating seat by hand, and the first pressing slope at the end of the pressing block abuts against the first force-bearing slope of the fixed block on the clamping seat, pushing the two clamping seats to overcome the elastic force of the first elastic telescopic rod and separate from each other.

[0024] Place one end of the leather sample to be tested into the opening between the two clamping seats, release the pressing block, the first elastic element and the first elastic telescopic rod return to their original state, and the two clamping seats automatically close, thus achieving the initial clamping of the leather end.

[0025] S2: Rotate the bidirectional screw. When the bidirectional screw rotates, it drives the drum on its smooth section to rotate synchronously. The drum winds up the pull rope. The pull rope transmits the tension to the connecting plate through the second elastic telescopic rod. The connecting plate drives the sliding blocks on both sides to slide along the slide groove towards the U-shaped plate. When the sliding blocks move, they drive the entire first clamping assembly to move together.

[0026] At the same time, the movable gear on the outside of the rotating seat meshes with the rack plate, causing the rotating seat to rotate during the movement. The rotation of the rotating seat drives the two clamping seats to rotate, so that the clamped leather is automatically wrapped around the outer circumference of the two clamping seats, forming multiple layers of wrapping. During this process, the pressure roller, under the action of the third elastic element, always keeps in contact with the surface of the wrapped leather and continues to press down, ensuring that each layer of leather is tightly attached and eliminating gaps between layers.

[0027] S3: The sliding block continues to move until it contacts the stop on the fixed seat and can no longer move forward. At this time, the two clamping seats are located in the clamping area between the upper and lower arc-shaped clamping plates.

[0028] Continue rotating the bidirectional screw. Since the sliding block can no longer move, the tension of the pull rope causes the second elastic telescopic rod to begin to stretch. At the same time, the two sleeves on the bidirectional screw approach each other axially under the drive of the screw thread, and the two arc-shaped clamps close together to perform secondary clamping and positioning on the two clamping seats that wrap the leather. The secondary clamping will press the leather wrapped around the outer periphery of the clamping seats tightly to form a double lock.

[0029] S4: Repeat steps S1-S3 on the other side of the clamping part on the base plate to complete the clamping of the other end of the leather sample.

[0030] S5: Then start the winches on both sides, apply tension to the traction plate through the traction rope, and the traction plate drives the traction block to slide on the sliding block through the connecting rod. When the traction block moves, the second extrusion inclined surface on it abuts against the second force inclined surface on the force block, converting the horizontal traction force into the normal clamping force in the vertical direction. After the force block is subjected to force, it drives the positioning clamping plate to press against the leather surface clamped between the two clamping seats. As the tensile load increases, the normal clamping force of the wedge surface also increases synchronously, achieving the self-locking effect that the greater the tension, the tighter the clamping.

[0031] S6: The tension sensor installed between the traction block and the sliding block collects load data in real time during the tensioning process and transmits it to the control system to generate a tension-displacement curve.

[0032] Compared with the prior art, the present invention provides a clamping device and method for a leather tensile testing machine for the production of electrically insulating shoes, which has the following beneficial effects:

[0033] 1. This invention employs a triple-locking structure: the initial clamping of the first clamping component, the rotation of the rotating seat causing the leather to wrap around the outer periphery of the clamping seat, and the secondary clamping of the arc-shaped clamping plate. This structure creates a multi-layered frictional entanglement between the leather and the clamping seat. Simultaneously, the pulling component incorporates a wedge-shaped inclined traction block and a force-bearing block. The greater the tension during the stretching process, the greater the normal pressure of the positioning clamping plate on the leather, achieving self-locking anti-slip. This multi-layered anti-slip mechanism effectively solves the problem of leather slipping and falling off due to insufficient friction in traditional flat jaws, ensuring smooth stretching tests and guaranteeing the integrity and validity of the data.

[0034] 2. This invention uses a rotating seat to automatically wrap the leather around the outer circumference of two clamping seats, so that the tensile force is evenly distributed to the entire clamping area through multi-layer frictional winding. This avoids stress concentration caused by rigid clamping at the corners of traditional clamps. At the same time, the pressure roller continuously compresses the wrapped leather under the action of the third elastic element, eliminating gaps between layers and making the force more uniform. This ensures that the sample breaks normally in the gauge section rather than at the clamping end, improving the accuracy of testing indicators such as tensile strength and elongation at break, and avoiding invalid testing and repetitive work caused by clamping.

[0035] 3. In this invention, the two fixed seats are rigidly connected by a connecting plate, and the winding drum is driven by a bidirectional screw to wind the rope. This causes the sliding blocks on both sides to slide synchronously and equidistantly along the slide groove, forcing the first clamping assembly and the leather it clamps to move symmetrically to the center position along the stretching axis. At the same time, the movable gear on the rotating seat meshes with the fixed rack plate to ensure that the rotation center of the two clamping seats is consistent and the winding direction is synchronized. The automatic centering structure eliminates the skewness caused by manual placement of the sample and the bending stress introduced therefrom, ensuring that the force axis of the sample is strictly coincident with the stretching direction, and improving the repeatability and reliability of data such as elongation.

[0036] 4. This invention, through a single rotation of the bidirectional screw, sequentially drives the drum to wind up the rope, causing the sliding block to move horizontally; the gear and rack mesh to rotate the rotating seat, causing the leather to wrap around; the pressure roller to compact the wrapped layer; and the arc-shaped clamping plate to close and clamp and position the wrapped leather. This achieves the sequential linkage of four actions—translation, rotation, compaction, and locking—during the clamping process. The operator only needs to press the pressing block to place the leather and rotate the bidirectional screw to complete the entire clamping process of a set of clamping parts in two steps, which greatly shortens the clamping time and reduces the difficulty of operation. It is suitable for the rapid testing needs of large batches of leather samples on the production line of electrical insulation shoes. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0038] Figure 2 for Figure 1 Enlarged structural diagram of section A in the middle;

[0039] Figure 3 This is a schematic diagram of the structure of the two clamping parts of the present invention;

[0040] Figure 4 for Figure 3 Enlarged structural diagram of section B in the middle;

[0041] Figure 5 This is a schematic diagram of the structure of the second clamping component of the present invention when it is not in operation;

[0042] Figure 6 This is a schematic diagram of the second clamping component of the present invention during operation;

[0043] Figure 7 This is a cross-sectional structural diagram of the clamping base of the present invention;

[0044] Figure 8 for Figure 7 Enlarged structural diagram of section C;

[0045] Figure 9 This is a schematic diagram of the external structure of the rotating seat of the present invention;

[0046] Figure 10 This is a schematic diagram of the structure when the pressing block and the fixing block of the present invention are in contact;

[0047] Figure 11 This is a schematic diagram of the external structure of the bidirectional screw of the present invention.

[0048] In the diagram: 1. Base plate; 2. U-shaped plate; 3. Fixed seat; 301. Stop block; 4. Sliding block; 5. Clamping seat; 501. Locking strip; 502. Locking groove; 503. Fixed block; 6. Rotating seat; 601. First elastic telescopic rod; 7. Pressing block; 701. First elastic element; 8. Bidirectional screw; 801. Sleeve; 802. Arc-shaped clamping plate; 9. Slide groove; 901. Second elastic element; 10. Rack plate; 1001. Movable gear; 11. Lifting rod; 111. Third elastic element; 112. Pressure roller; 12. Drum; 121. Pull rope; 122. Second elastic telescopic rod; 123. Connecting plate; 13. Limiting frame; 14. Traction block; 141. Fourth elastic element; 142. Traction plate; 15. Force-bearing block; 151. Positioning clamping plate; 152. Fifth elastic element. Detailed Implementation

[0049] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0050] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0051] like Figures 1 to 5 As shown, this embodiment proposes a clamping device for a leather tensile testing machine used in the production of electrically insulating shoes, including a base plate 1. Two sets of clamping parts are slidably disposed on the base plate 1, and each set of clamping parts includes:

[0052] U-shaped plate 2 is slidably mounted on base plate 1, and a second clamping assembly is provided inside U-shaped plate 2;

[0053] Fixed bases 3 are symmetrically arranged on both sides of the U-shaped plate 2. Each fixed base 3 is slidably connected with a sliding block 4, and a first clamping component is arranged between two sliding blocks 4.

[0054] And the traction assembly, one side of which is slidably set with the U-shaped plate 2, and the other side is connected to the winch installed on the base plate 1 via a traction rope;

[0055] The first clamping component includes two relatively movable clamping seats 5. After the two clamping seats 5 clamp the leather, the second clamping component works and drives the first clamping component to move, thereby clamping and positioning the leather clamped by the first clamping component for a second time.

[0056] Specifically, one end of the leather sample to be tested is placed between two clamping seats 5, and the two clamping seats 5 are driven to move relative to each other, clamping the end of the leather from both sides to complete the initial clamping; the second clamping component is activated, and the second clamping component works and drives the first clamping component to move as a whole towards the U-shaped plate 2. The first clamping component carries the clamped leather to the clamping area of ​​the second clamping component. The second clamping component performs secondary clamping and positioning on the leather clamped by the first clamping component to enhance the clamping firmness. Then, the clamping part on the other side of the base plate 1 clamps the other end of the leather to complete the clamping of the other end of the leather sample. Finally, the winch on base plate 1 is activated. The winch applies tension to the traction assembly via a traction rope, which then transfers the tension to the clamped leather sample for tensile testing. The double-clamping structure subjectes the leather to two independent clamping actions within the clamping area, significantly increasing the contact area and friction between the leather and the clamping components. This effectively prevents the leather from slipping and falling off during the stretching process, ensuring the integrity and validity of the test data. Furthermore, the sequential clamping of the leather by the first and second clamping components distributes the clamping force across two different clamping positions, avoiding concentrated stress at a single clamping point. After the initial clamping, the leather is repositioned through a second clamping, resulting in more uniform stress distribution in the clamping area. This reduces the risk of sample breakage at the clamping end due to stress concentration at the corners of traditional clamps, promoting normal breakage within the gauge length and improving test accuracy.

[0057] like Figure 7 , Figure 9 and Figure 10 As shown, in a preferred embodiment, based on the above method, the first clamping assembly further includes a rotating seat 6 rotatably disposed in the sliding block 4 and a first elastic telescopic rod 601 symmetrically arranged on both sides of the end of the rotating seat 6. The first elastic telescopic rod 601 is fixedly connected to the clamping seat 5 on the same side through a connecting plate.

[0058] Furthermore, a pressing block 7 is slidably disposed between the two clamping seats 5 on the rotating seat 6, and a first elastic element 701 is disposed between the pressing block 7 and the rotating seat 6. A fixing block 503 is disposed on the clamping seat 5 to move against the pressing block 7. A first extrusion slope is provided on both sides of the end of the pressing block 7, and a first force-bearing slope is provided on the fixing block 503 to cooperate with the first extrusion slope.

[0059] Specifically, the operator presses the pressing block 7 with their finger, causing it to slide against the elastic force of the first elastic element 701 on the outside of the rotating seat 6. The first pressing inclined surface at the end of the pressing block 7 contacts and slides against the first force-bearing inclined surface on the fixed block 503, generating a thrust perpendicular to the inclined surface direction. This pushes the two fixed blocks 503 to separate to both sides. The fixed blocks 503 drive the clamping seats 5 to move outward against the elastic force of the first elastic telescopic rod 601, and the two clamping seats 5 open, forming an opening for the leather to be inserted. One end of the leather sample to be tested is placed into the opening between the two clamping seats 5, and the leather position is adjusted. Position it at the center of the clamping area; after releasing the pressing block 7, the first elastic element 701 releases its elastic force, pushing the pressing block 7 back to its initial position. At the same time, the first elastic telescopic rod 601 retracts and resets, and the two clamping seats 5 clamp the leather end from both sides, completing the initial clamping. The clamping force is determined by the elasticity of the elastic telescopic rod, which has flexible buffering characteristics. Compared with the rigid clamping structure, the elastic clamping avoids the risk of pressure marks or breakage to the leather caused by instantaneous strong clamping. It is especially suitable for thinner or softer leather materials commonly used in the production of electrical insulating shoes, ensuring that the sample remains in good condition before testing.

[0060] like Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 11 As shown, in a preferred embodiment, based on the above method, the second clamping assembly further includes a bidirectional screw 8 rotatably mounted on the U-shaped plate 2, a sleeve 801 threadedly connected to the upper and lower sides of the bidirectional screw 8, and an arc-shaped clamping plate 802 fixedly connected to the sleeve 801 via a connecting plate. The arc-shaped clamping plates 802 on the upper and lower sides together form a clamping area for clamping the two clamping seats 5.

[0061] Furthermore, the fixed base 3 is provided with a groove 9 for sliding the sliding block 4, and a second elastic element 901 is provided between the groove 9 and the bottom of the sliding block 4. The fixed base 3 is provided with a stop block 301 that moves against the sliding block 4.

[0062] A rack plate 10 is fixedly provided on the outer side of the fixed base 3, and a movable gear 1001 that meshes with the rack plate 10 is provided on the rotating base 6;

[0063] Furthermore, the smooth section of the bidirectional screw 8 is provided with a drum 12, and a pull rope 121 is wound and connected on the drum 12. The end of the pull rope 121 away from the drum 12 is connected to a second elastic telescopic rod 122, and the end of the second elastic telescopic rod 122 away from the drum 12 is connected to a connecting plate 123. The connecting plate 123 is located between the fixing seats 3 on both sides of the U-shaped plate 2.

[0064] The fixed base 3 is provided with a limiting bracket 13 for restricting the movement direction of the pull rope 121;

[0065] Specifically, the operator clamps one end of the leather between the two clamping seats 5 by pressing the block 7, completing the initial clamping. At this time, the sliding block 4 is located at the initial end of the groove 9, the second elastic element 901 is in a naturally extended state, and the sliding block 4 has not yet contacted the stop block 301. The double-acting screw 8 is rotated, which drives the drum 12 to rotate synchronously. The drum 12 winds up the pull rope 121, and the pull rope 121 transmits the tension to the connecting plate 123 through the second elastic telescopic rod 122. After the connecting plate 123 is subjected to force, it drives the fixed seats 3 on both sides to move towards the U-shaped plate 2. The sliding block 4 drives the entire first clamping assembly to move towards the U-shaped plate 2. At the same time, the second elastic element 901 is compressed and stores energy. During the movement of the sliding block 4, the movable gear 1001 on the rotating seat 6 meshes with the rack plate 10, causing the rotating seat 6 to rotate around its own axis while moving. The rotation of the rotating seat 6 drives the two clamping seats 5 to rotate, so that the clamped leather is wrapped around the outer circumference of the two clamping seats 5. The wrapping and covering allows the tensile force to be evenly distributed to the entire clamping area through multi-layer frictional contact, avoiding the stress concentration caused by rigid clamping at the corners of traditional clamps. This ensures the sample breaks normally at the gauge length rather than at the clamping end, improving test accuracy. The sliding block 4 continues to move until it contacts the stop block 301 and can no longer advance. At this point, the two clamping seats 5 are located within the clamping area between the upper and lower arc-shaped clamping plates 802. Continuing to rotate the bidirectional screw 8, since the sliding block 4 can no longer move, the tension of the pull rope 121 causes the second elastic telescopic rod 122 to begin stretching. Simultaneously, the two sleeves 801 on the bidirectional screw 8 continue to approach each other axially under the drive of the screw thread, causing the upper and lower arc-shaped clamping plates 802 to close towards each other until they are fully closed. The two clamping seats 5 of the leather are used for secondary clamping and positioning. Then, the above steps are repeated on the other side of the clamping part on the base plate 1 to complete the clamping of the other end of the leather sample. By rotating the bidirectional screw 8, the drum 12 can be driven to wind up the rope 121 to make the sliding block 4 move, the movable gear 1001 can be engaged with the rack plate 10 to make the rotating seat 6 rotate and drive the leather to wind, and the sleeve 801 can drive the arc-shaped clamping plate 802 to close for secondary clamping. The three actions are driven by the same power source, the timing is coordinated, no additional operation is required, the clamping process is simplified, and the work efficiency is improved.

[0066] like Figure 5 , Figure 6 and Figure 7 As shown, in a preferred embodiment, based on the above method, a lifting rod 11 is further slidably arranged on the outside of the sliding block 4, a third elastic element 111 is arranged between the lifting rod 11 and the sliding block 4, and a pressure roller 112 that moves against the leather wound on the outside of the clamping seat 5 is connected to the lifting rod 11 through a rotating shaft.

[0067] Specifically, before the leather is wrapped, the pressure roller 112 moves against the outer peripheral surface of the clamping seat 5 under the elastic force of the third elastic element 111, and is in the lowest position. When the rotating seat 6 rotates and drives the clamping seat 5 to rotate, the leather begins to wrap around the outer peripheral surface of the clamping seat 5. As the clamping seat 5 rotates, the leather layer gradually covers the outer peripheral surface of the clamping seat 5. Under the elastic force of the third elastic element 111, the pressure roller 112 always keeps in contact with the surface of the leather wrapped on the outside of the clamping seat 5, pressing the leather layer being wrapped, eliminating the gaps between the layers, and making each layer of leather fit tightly together. As the number of leather wrapping layers increases, the overall outer diameter of the leather on the outside of the clamping seat 5 gradually increases. The pressure roller 112 drives the lifting rod 11 to slide upward against the elastic force of the third elastic element 111 through the rotating shaft, always maintaining stable contact with the leather surface and continuous downward pressure. The dense wrapping structure makes each layer of leather form a whole, avoiding relative sliding between layers, and enhancing the stability of the wrapping and the clamping effect.

[0068] like Figure 7 and Figure 8 As shown, in a preferred embodiment, based on the above method, a non-slip structure is further provided between the two clamping seats 5, wherein a clip 501 is fixedly provided on the clamping surface of one clamping seat 5, and a slot 502 that cooperates with the clip 501 is provided on the clamping surface of the other clamping seat 5.

[0069] Specifically, after releasing the pressing block 7, the two clamping seats 5 approach and close to each other under the elastic force of the first elastic telescopic rod 601. During the closing process, the locking strip 501 first contacts the leather surface and partially presses the leather into the locking groove 502. When the two clamping seats 5 are completely closed, the locking strip 501 presses the leather into the locking groove 502, so that the leather forms a concave-convex deformation in the clamping area corresponding to the shape of the locking strip 501 and the locking groove 502. The part of the leather embedded in the locking groove 502 is squeezed by the locking strip 501 and restricted by the side wall of the locking groove 502, forming a mechanical interlocking structure, which effectively prevents the leather from sliding along the clamping surface. Compared with the planar clamping that relies solely on friction, the anti-slip effect is significantly improved, and it can effectively prevent the leather from slipping and falling off even under a large tensile load.

[0070] like Figure 1 , Figure 2 , Figure 3 , Figure 5 and Figure 6As shown, in a preferred embodiment, based on the above method, the traction assembly further includes a traction block 14 slidably disposed on the sliding block 4, a fourth elastic element 141 disposed between the traction block 14 and the fixed seat 3, a traction plate 142 connected to the traction block 14 via a connecting rod, a force-bearing block 15 slidably disposed in the clamping seat 5, a positioning clamping plate 151 fixedly connected to the force-bearing block 15, and a fifth elastic element 152 disposed between the positioning clamping plate 151 and the clamping seat 5. A tension sensor is provided between the traction block 14 and the sliding block 4.

[0071] The traction block 14 and the force-bearing block 15 move against each other. The traction block 14 is provided with a second extrusion slope, and the force-bearing block 15 is provided with a second force-bearing slope that cooperates with the second extrusion slope.

[0072] Specifically, the winch on the base plate 1 is started. The winch applies a pulling force to the traction plate 142 through the traction rope. The traction plate 142 drives the traction block 14 to overcome the elastic force of the fourth elastic element 141 and slide along the sliding block 4 towards the winch on the same side. During the sliding process, the second pressing inclined surface on the traction block 14 gradually contacts and abuts against the second force-receiving inclined surface on the force-receiving block 15. As the traction block 14 continues to slide, the second pressing inclined surface slides along the second force-receiving inclined surface, decomposing the horizontal traction force of the traction block 14 into a vertical component through the inclined surface. This pushes the force-receiving block 15 to overcome the elastic force of the fifth elastic element 152 and move into the clamping seat 5. The movement of the force-receiving block 15 drives the positioning clamp 151, which is fixedly connected to it, to move towards the leather surface clamped between the two clamping seats 5. After the positioning clamp 151 contacts the leather surface, it continues to apply pressure, further pressing the leather between the clamping seats 5. As the tensile load increases, the tension on the traction block 14 increases, and the normal pressure between the second extrusion slope and the second force-bearing slope increases accordingly, achieving the effect of greater tension and tighter compression, ensuring that the leather will not slip under high load. Throughout the stretching process, the tension sensor collects the tension data between the traction block 14 and the sliding block 4 in real time, and transmits it to the control system to generate a tension-displacement curve for analyzing the mechanical properties of the leather. It should be noted that the leather clamping area is located between the two force-bearing blocks 15 of the same clamping seat 5. When the clamping seat 5 rotates and wraps the leather, the force-bearing block 15 protruding from the clamping seat 5 will not affect the wrapping of the leather.

[0073] This invention also discloses a clamping method for a leather tensile testing machine used in the production of electrically insulating shoes. The clamping method involves using the aforementioned clamping device for the leather tensile testing machine used in the production of electrically insulating shoes, and includes the following steps:

[0074] S1: In the initial state, the two clamping seats 5 of the first clamping assembly are close to each other under the action of the first elastic telescopic rod 601; the operator presses the pressing block 7 on the rotating seat 6 by hand, and the first pressing slope at the end of the pressing block 7 abuts against the first force-bearing slope of the fixing block 503 on the clamping seat 5, pushing the two clamping seats 5 to overcome the elastic force of the first elastic telescopic rod 601 and separate from each other.

[0075] Place one end of the leather sample to be tested into the opening between the two clamping seats 5, release the pressing block 7, the first elastic element 701 and the first elastic telescopic rod 601 return to their original state, and the two clamping seats 5 automatically close, thus achieving the initial clamping of the leather end.

[0076] S2: Rotate the bidirectional screw 8. When the bidirectional screw 8 rotates, it drives the drum 12 on its smooth section to rotate synchronously. The drum 12 winds up the pull rope 121. The pull rope 121 transmits the tension to the connecting plate 123 through the second elastic telescopic rod 122. The connecting plate 123 drives the sliding blocks 4 on both sides to slide along the slide groove 9 towards the U-shaped plate 2. When the sliding blocks 4 move, they drive the entire first clamping assembly to move together.

[0077] At the same time, the movable gear 1001 on the outside of the rotating seat 6 meshes with the rack plate 10, causing the rotating seat 6 to rotate during the movement. The rotation of the rotating seat 6 drives the two clamping seats 5 to rotate, so that the clamped leather is automatically wrapped around the outer circumference of the two clamping seats 5 to form multiple layers of wrapping. During this process, the pressure roller 112, under the action of the third elastic element 111, always maintains contact with the surface of the wrapped leather and continues to press down to ensure that each layer of leather is tightly attached and eliminates gaps between layers.

[0078] S3: The sliding block 4 continues to move until it contacts the stop block 301 on the fixed seat 3 and can no longer move forward. At this time, the two clamping seats 5 are located in the clamping range between the upper and lower arc-shaped clamping plates 802.

[0079] Continue rotating the bidirectional screw 8. Since the sliding block 4 can no longer move, the tension of the pull rope 121 causes the second elastic telescopic rod 122 to begin to stretch. At the same time, the two sleeves 801 on the bidirectional screw 8 approach each other axially under the thread drive, and the two arc-shaped clamps 802 close together to perform secondary clamping and positioning on the two clamping seats 5 wrapped with leather. The secondary clamping will press the leather wrapped around the outer periphery of the clamping seats 5 tightly to form a double lock.

[0080] S4: Repeat steps S1-S3 on the other side of the clamping part on the base plate 1 to complete the clamping of the other end of the leather sample.

[0081] S5: Then start the winches on both sides and apply tension to the traction plate 142 through the traction rope. The traction plate 142 drives the traction block 14 to slide on the sliding block 4 through the connecting rod. When the traction block 14 moves, the second pressing slope on it abuts against the second force-bearing slope on the force-bearing block 15, converting the horizontal traction force into the normal pressing force in the vertical direction. After the force-bearing block 15 is subjected to force, it drives the positioning clamping plate 151 to press against the leather surface clamped between the two clamping seats 5. As the tensile load increases, the normal pressing force of the wedge surface also increases synchronously, realizing the self-locking effect that the greater the tension, the tighter the clamping.

[0082] S6: The tension sensor installed between the traction block 14 and the sliding block 4 collects load data in real time during the tensioning process and transmits it to the control system to generate a tension-displacement curve.

[0083] The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.

[0084] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A clamping device for a leather tensile testing machine used in the production of electrically insulating shoes, comprising a base plate (1), wherein two sets of clamping parts are slidably disposed on the base plate (1), characterized in that, Each set of clamping parts includes: The U-shaped plate (2) is slidably disposed on the base plate (1), and a second clamping assembly is provided inside the U-shaped plate (2); Fixed seats (3) are symmetrically arranged on both sides of the U-shaped plate (2). Each fixed seat (3) is slidably connected with a sliding block (4), and a first clamping assembly is provided between two sliding blocks (4). And the traction assembly, one side of which is slidably set with the U-shaped plate (2), and the other side is connected to the winch installed on the base plate (1) by the traction rope; The first clamping component includes two relatively movable clamping seats (5). After the two clamping seats (5) clamp the leather, the second clamping component works and drives the first clamping component to move, thereby clamping and positioning the leather clamped by the first clamping component for a second time.

2. The clamping device for a leather tensile testing machine for producing electrically insulating shoes according to claim 1, characterized in that, The first clamping assembly also includes a rotating seat (6) rotatably disposed in the sliding block (4) and a first elastic telescopic rod (601) symmetrically arranged on both sides of the end of the rotating seat (6). The first elastic telescopic rod (601) is fixedly connected to the clamping seat (5) on the same side through a connecting plate.

3. The clamping device for a leather tensile testing machine for producing electrically insulating shoes according to claim 2, characterized in that, The rotating seat (6) is slidably provided with a pressing block (7) between the two clamping seats (5). A first elastic element (701) is provided between the pressing block (7) and the rotating seat (6). A fixing block (503) is provided on the clamping seat (5) to move against the pressing block (7). A first extrusion slope is provided on both sides of the end of the pressing block (7). A first force-bearing slope is provided on the fixing block (503) to cooperate with the first extrusion slope.

4. The clamping device for a leather tensile testing machine for producing electrically insulating shoes according to claim 3, characterized in that, The second clamping assembly includes a bidirectional screw (8) rotatably mounted on a U-shaped plate (2), a sleeve (801) threadedly connected to the upper and lower sides of the bidirectional screw (8), and an arc-shaped clamping plate (802) fixedly connected to the sleeve (801) via a connecting plate. The arc-shaped clamping plates (802) on the upper and lower sides together form a clamping area for clamping two clamping seats (5).

5. The clamping device for a leather tensile testing machine for producing electrically insulating shoes according to claim 4, characterized in that, The fixed base (3) is provided with a sliding groove (9) for sliding block (4), and a second elastic element (901) is provided between the sliding groove (9) and the bottom of the sliding block (4). The fixed base (3) is provided with a stop block (301) that moves against the sliding block (4). A rack plate (10) is fixedly provided on the outside of the fixed seat (3), and a movable gear (1001) that meshes with the rack plate (10) is provided on the rotating seat (6).

6. The clamping device for a leather tensile testing machine for producing electrically insulating shoes according to claim 5, characterized in that, A lifting rod (11) is slidably arranged on the outside of the sliding block (4). A third elastic element (111) is arranged between the lifting rod (11) and the sliding block (4). A pressure roller (112) is connected to the lifting rod (11) via a rotating shaft to move against the leather wound on the outside of the clamping seat (5).

7. The clamping device for a leather tensile testing machine for producing electrically insulating shoes according to claim 6, characterized in that, An anti-slip structure is provided between the two clamping seats (5). One of the clamping seats (5) has a clamping strip (501) fixed on its clamping surface, and the other clamping seat (5) has a clamping groove (502) that cooperates with the clamping strip (501) on its clamping surface.

8. The clamping device for a leather tensile testing machine for producing electrically insulating shoes according to claim 7, characterized in that, The smooth section of the bidirectional screw (8) is provided with a drum (12), and a pull rope (121) is wound and connected on the drum (12). The end of the pull rope (121) away from the drum (12) is connected to a second elastic telescopic rod (122), and the end of the second elastic telescopic rod (122) away from the drum (12) is connected to a connecting plate (123). The connecting plate (123) is arranged between the fixing seats (3) on both sides of the U-shaped plate (2). The fixed base (3) is provided with a limiting frame (13) for limiting the movement direction of the pull rope (121).

9. The clamping device for a leather tensile testing machine for producing electrically insulating shoes according to claim 8, characterized in that, The traction assembly includes a traction block (14) slidably disposed on the sliding block (4), a fourth elastic element (141) disposed between the traction block (14) and the fixed seat (3), a traction plate (142) connected to the traction block (14) via a connecting rod, a force-bearing block (15) slidably disposed in the clamping seat (5), a positioning clamp (151) fixedly connected to the force-bearing block (15), and a fifth elastic element (152) disposed between the positioning clamp (151) and the clamping seat (5). A tension sensor is provided between the traction block (14) and the sliding block (4). The traction block (14) and the force-bearing block (15) move against each other. The traction block (14) is provided with a second extrusion slope, and the force-bearing block (15) is provided with a second force-bearing slope that cooperates with the second extrusion slope.

10. A clamping method for a leather tensile testing machine for producing electrically insulating shoes, wherein clamping is performed using the clamping device for the leather tensile testing machine for producing electrically insulating shoes as described in claim 9, characterized in that... Includes the following steps: S1: In the initial state, the two clamping seats (5) of the first clamping assembly are close to each other under the action of the first elastic telescopic rod (601); the operator presses the pressing block (7) on the rotating seat (6) by hand, and the first pressing slope at the end of the pressing block (7) abuts against the first force-bearing slope of the fixing block (503) on the clamping seat (5), pushing the two clamping seats (5) to overcome the elastic force of the first elastic telescopic rod (601) and separate and open from each other; Place one end of the leather sample to be tested into the opening between the two clamping seats (5), release the pressing block (7), the first elastic element (701) and the first elastic telescopic rod (601) recover, and the two clamping seats (5) automatically close, realizing the initial clamping of the leather end; S2: Rotate the bidirectional screw (8). When the bidirectional screw (8) rotates, it drives the drum (12) on its smooth section to rotate synchronously. The drum (12) winds up the pull rope (121). The pull rope (121) transmits the tension to the connecting plate (123) through the second elastic telescopic rod (122). The connecting plate (123) drives the sliding blocks (4) on both sides to slide along the slide groove (9) towards the U-shaped plate (2). When the sliding blocks (4) move, they drive the entire first clamping assembly to move together. At the same time, the movable gear (1001) on the outside of the rotating seat (6) meshes with the rack plate (10) to drive the rotating seat (6) to rotate during the movement. The rotation of the rotating seat (6) drives the two clamping seats (5) to rotate, so that the clamped leather is automatically wrapped around the outer circumference of the two clamping seats (5) to form a multi-layer covering. During this process, the pressure roller (112) always keeps in contact with the surface of the wrapped leather and continues to press down under the action of the third elastic element (111) to ensure that each layer of leather is tightly attached and eliminates the gaps between layers. S3: The sliding block (4) continues to move until it contacts the stop (301) on the fixed seat (3) and can no longer move forward. At this time, the two clamping seats (5) are located in the clamping range between the upper and lower arc-shaped clamping plates (802); Continue rotating the bidirectional screw (8). Since the sliding block (4) can no longer move, the tension of the pull rope (121) causes the second elastic telescopic rod (122) to begin to stretch. At the same time, the two sleeves (801) on the bidirectional screw (8) approach each other axially under the thread drive, and the two arc-shaped clamps (802) close together to each other, performing secondary clamping and positioning on the two clamping seats (5) wrapped with leather. The secondary clamping will press the leather wrapped around the outer periphery of the clamping seats (5) to form a double lock. S4: Repeat steps S1-S3 on the other side of the clamping part on the base plate (1) to complete the clamping of the other end of the leather sample. S5: Then start the winches on both sides and apply tension to the traction plate (142) through the traction rope. The traction plate (142) drives the traction block (14) to slide on the sliding block (4) through the connecting rod. When the traction block (14) moves, the second extrusion slope on it abuts against the second force-bearing slope on the force-bearing block (15), converting the horizontal traction force into the normal pressing force in the vertical direction. After the force-bearing block (15) is subjected to force, it drives the positioning clamp (151) to press against the leather surface clamped between the two clamping seats (5). As the tensile load increases, the normal pressing force of the wedge surface also increases synchronously, realizing the self-locking effect of the greater the tension, the tighter the clamping. S6: The tension sensor installed between the traction block (14) and the sliding block (4) collects load data in real time during the tensioning process and transmits it to the control system to generate a tension-displacement curve.

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