A flame-retardant polyethylene cable sheath strength detection device

Abstract

This utility model relates to the field of cable testing technology and discloses a flame-retardant polyethylene cable sheath strength testing device, including a base and an electric guide rail symmetrically mounted on the base, and further including: a mounting seat one fixedly mounted on the base, a mounting plate that is lifted and lowered at the output end of the electric guide rail, and a mounting seat two detachably mounted on the lower part of the mounting plate. Both mounting seats one and two are provided with clamping parts for clamping cables. This utility model improves the adaptability of the device by setting stepped grooves on the clamping plate, with each step equipped with an arc-shaped clamping surface, which can accommodate cable samples of different diameters. Furthermore, the arc-shaped clamping surface on the stepped groove perfectly fits the arc or cylindrical cross-section of the cable sample, increasing the contact area. At the same time, the silicone elastic buffer layer on the arc-shaped clamping surface can buffer the clamping force and prevent local force concentration. The anti-slip texture can effectively prevent the sample from slipping during the stretching process, ensuring the stability of the clamping.

Description

Technical Field

[0001] This utility model relates to the field of cable testing technology, specifically to a device for testing the strength of the outer sheath of flame-retardant polyethylene cables. Background Technology

[0002] Flame-retardant polyethylene cables, with their excellent flame-retardant, insulation, and chemical corrosion resistance, are widely used in construction, rail transportation, energy, and chemical industries. Especially in high-temperature and flammable environments, the outer sheath must not only provide insulation but also possess sufficient mechanical strength to withstand external impacts and tension. If the cable sheath is insufficiently strong, damage and cracking can easily occur during installation, use, and maintenance, leading to exposed internal conductors. This not only reduces the cable's flame-retardant and insulation properties but may also cause short circuits, leakage, or even fires. Therefore, accurate testing of the sheath strength of flame-retardant polyethylene cables is a crucial step in ensuring cable product quality and subsequent safety.

[0003] Currently, the main equipment used for testing the tensile strength of flame-retardant polyethylene cable sheaths is the electronic universal testing machine. This type of equipment typically consists of a frame, fixed clamps, movable clamps, a drive mechanism, a force sensor, and a data display module. During testing, the operator first clamps both ends of the cut cable sheath sample in the fixed clamp and the movable clamp respectively, and fixes the sample by manually adjusting the clamp fastening device. Then, the operating speed of the drive mechanism is set, and after the equipment is started, the drive mechanism drives the movable clamp away from the fixed clamp at a uniform speed, applying axial tension to the sample. The force sensor collects the tensile force data in real time and transmits it to the data display module. When the sample breaks, the equipment automatically records the maximum tensile force value, and the operator then calculates the tensile strength based on the original cross-sectional area of ​​the sample.

[0004] In practical use, certain problems exist. For example, the clamping structure has poor adaptability. Many clamps are planar or V-shaped, while cable sheath samples are mostly arc-shaped or cylindrical. Planar clamps have a small contact area with the sample, and V-shaped clamps easily cause localized stress concentration on the sample, failing to clamp the cable evenly. The sample may slip or shift during the tensile process, significantly affecting the accuracy of the test data. On the other hand, because the cable sheath material is relatively soft and has a certain degree of toughness, the cable is prone to deformation and movement under clamping force, causing a certain deviation between the sample axis and the tensile force direction, which in turn affects the test structure. Therefore, we urgently need a flame-retardant polyethylene cable sheath strength testing device to solve the above problems. Utility Model Content

[0005] This utility model provides a flame-retardant polyethylene cable sheath strength testing device. By setting up two sets of symmetrical clamping plates and stepped grooves, combined with two sets of positioning blocks, it solves the problems mentioned in the background art, such as poor adaptability of clamping structure, localized force concentration, sample slippage and displacement, and deviation of axis and tensile force direction caused by cable deformation and movement.

[0006] This utility model provides the following technical solution: A flame-retardant polyethylene cable sheath strength testing device includes a base and an electric guide rail symmetrically mounted on the base. It also includes: a mounting seat 1 fixedly mounted on the base; a mounting plate that is lifted and lowered at the output end of the electric guide rail; a mounting seat 2 detachably mounted on the lower part of the mounting plate; a clamping part for clamping the cable is provided in both the mounting seat 1 and the mounting seat 2; and a positioning part for positioning the cable is provided on the mounting seat 1 and the mounting seat 2.

[0007] As a preferred technical solution of this utility model, the clamping part includes inclined sliding grooves symmetrically opened on mounting base one and mounting base two. Each of the mounting base one and mounting base two is provided with clamping plates for clamping cables, and the two sets of clamping plates abut against the inclined sliding grooves to form a sliding area.

[0008] As a preferred technical solution of this utility model, both mounting base one and mounting base two are fixedly mounted with electric push rods for driving clamping plates. The output end of the electric push rod is fixedly connected to a circular disk. The top of both sets of clamping plates is bolted with a fastening plate, and a placement area is formed between the fastening plate and the clamping plate. The circular disk is located in the placement area. When the electric push rod works, the circular disk pushes the two sets of clamping plates to move up and down along the inner wall of the inclined slide groove.

[0009] As a preferred technical solution of this utility model, the opposite sides of the two sets of clamping plates are provided with stepped grooves for adapting cables, and the diameter of each step of the stepped groove decreases from top to bottom.

[0010] As a preferred technical solution of this utility model, the positioning part includes positioning plates symmetrically arranged on mounting base one and mounting base two, wherein one side of the positioning plate is fixedly installed on mounting base one and mounting base two by bolts, and the other side of the positioning plate is slidably connected to mounting base one and mounting base two through a sliding groove.

[0011] As a preferred embodiment of this utility model, the positioning plate is provided with an arc-shaped protrusion for pressing against the cable.

[0012] As a preferred technical solution of this utility model, a lead screw for driving the positioning plate is rotatably connected in the sliding groove. The connection of the positioning plate is threaded onto the lead screw. When the two sets of arc-shaped protrusions contact the cable, a positioning area is formed.

[0013] Compared with the prior art, this utility model provides a flame-retardant polyethylene cable sheath strength testing device, which has the following beneficial effects: 1. In this flame-retardant polyethylene cable sheath strength testing equipment, by setting stepped grooves on the clamping plate, each step is equipped with an arc-shaped clamping surface, which can accommodate cable samples of different diameters, greatly improving the adaptability of the equipment. Furthermore, the arc-shaped clamping surface on the stepped groove perfectly fits the arc or cylindrical cross-section of the cable sample, increasing the contact area. At the same time, the silicone elastic buffer layer on the arc-shaped clamping surface can buffer the clamping force, prevent local force concentration, and the anti-slip texture can effectively prevent the sample from slipping during the stretching process, ensuring the stability of the clamping.

[0014] 2. In this flame-retardant polyethylene cable sheath strength testing equipment, the arc-shaped protrusions can fit tightly against the cable. Combined with the positioning plate driven by the ball screw, the cable sample can be accurately positioned, preventing the cable from deforming and moving under the clamping force. This ensures that the sample axis is consistent with the direction of the tensile force, thus improving the accuracy of the test results.

[0015] The parts of this device not covered herein are the same as or can be implemented using existing technologies. This utility model achieves adaptive clamping and uniform force application for cables of different specifications, effectively preventing sample slippage and displacement. At the same time, it solves the problem that cables are prone to deformation and movement during clamping due to their soft material and high toughness, which causes deviation between the sample axis and the direction of tension. This achieves accurate positioning of the cable during sample preparation, thereby improving the accuracy and reliability of the test data. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, the elements or parts are not necessarily drawn to actual scale.

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the second mounting base of this utility model; Figure 3 This is a schematic diagram of the inclined slide and positioning plate structure of this utility model; Figure 4 This is a schematic diagram of the clamping plate structure of this utility model.

[0018] In the diagram: 1. Base; 2. Electric guide rail; 3. Mounting seat one; 4. Mounting plate; 5. Mounting seat two; 6. Inclined slide groove; 7. Clamping plate; 8. Electric push rod; 9. Circular disc; 10. Fastening plate; 11. Stepped groove; 12. Positioning plate; 13. Arc-shaped protrusion; 14. Lead screw. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Example: Reference Figures 1-4 A flame-retardant polyethylene cable sheath strength testing device includes a base 1 and electric guide rails 2 symmetrically mounted on the base 1.

[0021] Here, the base 1 is integrally cast from high-strength cast iron. Shock-absorbing pads are fixed to the four corners of the bottom with bolts. The shock-absorbing pads are equipped with a double shock-absorbing structure of rubber buffer layer and metal spring. The upper surface of the base 1 is provided with an installation groove that is compatible with the electric guide rail 2. The inner wall of the groove is provided with positioning pin holes for precise positioning and installation of the electric guide rail 2.

[0022] Furthermore, the electric guide rail 2 is symmetrically installed in the mounting groove of the base 1. It adopts a ball screw drive and is equipped with a servo motor and a high-precision position sensor. The servo motor is electrically connected to the PLC control system, which can realize precise control of speed and direction. The position sensor can provide real-time feedback on the position information of the mounting plate 4 and transmit the data to the PLC control system to form a closed-loop control. The surface of the guide rail body of the electric guide rail 2 is coated with a wear-resistant coating, and a grease storage cavity is provided between the slider and the guide rail.

[0023] In this embodiment, a ball screw drive combined with a servo motor ensures high precision and stability in the lifting motion of the mounting plate 4, meeting the detection requirements for different stretching speeds and strokes. The closed-loop control system can correct the positional deviation of the mounting plate 4 in real time, ensuring the accuracy of the stretching process. The wear-resistant coating and grease reservoir reduce wear between the guide rail and the slider, extending the service life of the electric guide rail 2. It also includes a mounting base 3 fixedly installed on the base 1, a mounting plate 4 with lifting and lowering settings at the output end of the electric guide rail 2, and a mounting base 5 detachably installed on the lower part of the mounting plate 4.

[0024] Here, mounting base 1 3 is fixedly mounted on the center position of the upper surface of the base 1 by bolts, and mounting base 2 5 is fixedly mounted on the center position of the lower part of the mounting plate 4 by bolts. The structure of mounting base 2 5 is symmetrically arranged with mounting base 1 3. The symmetrical structure design ensures the coaxiality of the upper and lower clamping parts and the positioning parts, avoids uneven force on the cable sample due to structural asymmetry, and accurately calculates the tensile amount of the cable sample. Both mounting base 1 3 and mounting base 2 5 have cavities for placing the clamping plate 7.

[0025] In this embodiment, the mounting plate 4 is fixedly installed on the slider output end of the electric guide rail 2. In other embodiments, the edge of the mounting plate 4 is provided with scale lines with an accuracy of 0.1mm. The mounting plate 4 is provided with reinforcing ribs in a cross-shaped distribution.

[0026] Both mounting base 3 and mounting base 5 are equipped with clamping parts for holding cables. The clamping parts include inclined slide grooves 6 symmetrically opened on mounting base 3 and mounting base 5. Both mounting base 3 and mounting base 2 are equipped with clamping plates 7 for holding cables, and the two sets of clamping plates 7 abut against the inclined slide grooves 6 to form a sliding area. Both mounting base 3 and mounting base 2 are fixedly equipped with electric push rods 8 for driving the clamping plates 7. The output end of the electric push rod 8 is fixedly connected to a circular disk 9. The top of both sets of clamping plates 7 are bolted with fastening plates 10, and a placement area is formed between the fastening plates 10 and the clamping plates 7. The circular disk 9 is located in the placement area. When the electric push rod 8 is working, the circular disk 9 pushes the two sets of clamping plates 7 to move up and down along the inner wall of the inclined slide groove 6.

[0027] Here, inclined slides 6 are symmetrically opened on the inner walls of the cavities of mounting base 1 3 and mounting base 2 5, and their inclination angle is preferably 45 degrees. The inner wall of the inclined slides 6 is provided with a wear-resistant ceramic coating, and buffer blocks are provided at both ends of the inclined slides 6. The clamping plate 7 is adapted to the inner wall of the inclined slides 6.

[0028] Furthermore, the 45° tilt angle enables the clamping plate 7 to generate a horizontal clamping force during the lifting process, and the magnitude of the clamping force can be precisely controlled by the stroke of the electric push rod 8. The wear-resistant ceramic coating reduces the wear between the clamping plate 7 and the tilting slide 6, improving the service life of the equipment. The buffer block can prevent the clamping plate 7 from being damaged by impact when it moves to the limit position. The clamping plate 7 can slide stably in the tilting slide 6, avoiding jamming or displacement.

[0029] Here, two sets of clamping plates 7 abut against the inclined slide 6 to form a sliding area. Each side of the clamping plate 7 is provided with a stepped groove 11. The diameter of each step of the stepped groove 11 decreases from top to bottom. The inner wall of each step is provided with an arc-shaped clamping surface. The curvature of the arc-shaped clamping surface is adapted to the outer diameter of common cables. An elastic buffer layer is pasted on the arc-shaped clamping surface. The elastic buffer layer is made of silicone and has anti-slip texture on the surface. The top of the clamping plate 7 is provided with bolt holes for connecting the fastening plate 10.

[0030] Furthermore, the electric actuator 8 is fixedly mounted at the top center of mounting base 3 and mounting base 5 via a flange. It employs a multi-stage telescopic structure and is equipped with a pressure sensor and limit switches. The pressure sensor can detect the output pressure of the electric actuator 8 in real time and transmit the data to the PLC control system. The limit switches are set at the maximum and minimum travel positions of the electric actuator 8, providing overload protection. The electric actuator 8 is electrically connected to the PLC control system, enabling precise adjustment of the thrust and telescopic speed.

[0031] Furthermore, the circular disc 9 is fixedly connected to the output end of the electric push rod 8 via a coupling. Its outer circumference is provided with a smooth chrome-plated layer. The diameter of the circular disc 9 is smaller than the placement area formed between the fastening plate 10 and the clamping plate 7. The smooth chrome-plated layer reduces the frictional resistance between the circular disc 9 and the fastening plate 10, making the transmission smoother. The smaller diameter ensures that the circular disc 9 can stably push the fastening plate 10 to drive the clamping plate 7 to move, ensuring that the two sets of clamping plates 7 move synchronously.

[0032] In this embodiment, when the two sets of clamping plates 7 abut against the inner wall of the inclined slide 6, the fastening plate 10 is installed on the corresponding clamping plate 7. At this time, after the circular disk 9 is placed in the placement area, when the electric push rod 8 drives the circular disk 9 to move downward, the two sets of clamping plates 7 approach each other and compress the placement area, but the circular disk 9 will not affect the movement of the clamping plates 7.

[0033] Both sets of clamping plates 7 have stepped grooves 11 on their opposite sides for accommodating cables, and the diameter of each step of the stepped groove 11 decreases from top to bottom.

[0034] Here, the stepped groove 11 can accommodate cable samples of different diameters, improving the adaptability of the equipment; the arc-shaped clamping surface perfectly fits the arc or cylindrical cross-section of the cable sample, greatly increasing the contact area and avoiding localized force concentration; the silicone elastic buffer layer can buffer the clamping force and prevent the cable sheath from deforming due to excessive clamping force, while the anti-slip texture can effectively prevent the sample from slipping during the stretching process; the top bolt hole achieves a firm connection with the fastening plate 10, ensuring the stability of the transmission.

[0035] A positioning part for positioning the cable is provided on mounting base 3 and mounting base 5. The positioning part includes positioning plates 12 symmetrically arranged on mounting base 3 and mounting base 5. One side of the positioning plate 12 is fixedly installed on mounting base 3 and mounting base 5 by bolts, and the other side of the positioning plate 12 is slidably connected to mounting base 3 and mounting base 5 through a sliding groove. A screw 14 for driving the positioning plate 12 is rotatably connected in the sliding groove. The connection of the positioning plate 12 is threaded to the screw 14. When the two sets of arc-shaped protrusions 13 come into contact with the cable, a positioning area is formed.

[0036] Here, one set of positioning plates 12 is fixedly installed by bolts, while the other set of positioning plates is slidably connected by a lead screw 14. The lead screw 14 is rotatably connected in the sliding groove via a bearing. One end of the lead screw 14 extends to the outside of the sliding groove and is fixedly connected to a handwheel with graduation markings. The lead screw 14 adopts a ball screw structure, and its surface is coated with wear-resistant grease. The lead screw 14 is threadedly connected to the slider of the positioning plate 12. When the lead screw 14 is rotated, it drives the movable end positioning plate 12 to move along the sliding groove. When the lead screw 14 rotates forward, the two sets of positioning plates 12 move closer to each other; when the lead screw 14 rotates in reverse, the two sets of positioning plates 12 move further apart.

[0037] The positioning plate 12 has an arc-shaped protrusion 13 for pressing against the cable. Here, the arc-shaped protrusion 13 is integrally formed on the opposite side of the positioning plate 12. The curvature of the arc-shaped protrusion 13 is adapted to the outer diameter of common cables, and a rubber anti-slip layer is pasted on the surface of the arc-shaped protrusion 13. The arc-shaped protrusion 13 with the adapted curvature can fit tightly with the cable sample to achieve accurate positioning. The rubber anti-slip layer can increase the friction between the cable and the sample, preventing the cable from moving during the testing process.

[0038] In this invention, during use, firstly, according to the diameter specifications of the cable sample, a suitable stepped groove 11 on the clamping plate 7 is selected. Then, both ends of the cable sample are placed between the clamping parts of mounting base one 3 and mounting base two 5, respectively. The handwheel on the screw 14 is rotated to drive the movable end positioning plate 12 to move, so that the arc-shaped protrusions 13 on both sides of the positioning plate 12 are tightly fitted with the cable sample, thereby achieving the positioning of the cable sample and ensuring that the sample axis is consistent with the direction of the tensile force. Next, the electric push rod 8 is activated, which pushes the circular disk 9 down. The circular disk 9 drives the two sets of clamping plates 7 to slide down along the inclined slide groove 6 through the fastening plate 10. Due to the inclination... The inclined angle of the slide 6 causes the clamping plate 7 to move towards the center as it slides down, clamping the cable sample through the arc-shaped clamping surface of the stepped groove 11. The pressure sensor detects the clamping force in real time, and the electric push rod 8 stops working when the set value is reached. Finally, the electric guide rail 2 is started by the PLC control system, and the servo motor drives the ball screw to rotate, which drives the mounting plate 4 and mounting base 5 to rise, performing tensile testing on the cable sample. The position sensor and distance sensor provide real-time feedback on the position and tensile amount of the mounting plate 4. The operator can observe the condition of the cable sheath through the observation window, and the test data is transmitted to the control system in real time for recording and analysis.

[0039] Components not described in detail in this article are existing technologies.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A flame-retardant polyethylene cable sheath strength testing device, comprising a base (1) and electric guide rails (2) symmetrically mounted on the base (1), characterized in that, Also includes: Mounting seat 1 (3) is fixedly installed on base (1), and mounting plate (4) is lifted and installed at the output end of electric guide rail (2). Mounting seat 2 (5) is detachably installed on the lower part of mounting plate (4). Both mounting seat 1 (3) and mounting seat 2 (5) are provided with clamping parts for clamping cables. Positioning parts for positioning cables are installed on mounting base one (3) and mounting base two (5).

2. The flame-retardant polyethylene cable sheath strength testing device according to claim 1, characterized in that, The clamping part includes inclined slide grooves (6) symmetrically opened on mounting base one (3) and mounting base two (5). The mounting base one (3) and mounting base two (5) are each provided with clamping plates (7) for clamping cables, and the two sets of clamping plates (7) abut against the inclined slide grooves (6) to form a sliding area.

3. The flame-retardant polyethylene cable sheath strength testing equipment according to claim 2, characterized in that, Both mounting base one (3) and mounting base two (5) are fixedly mounted with electric push rods (8) for driving clamping plates (7). The output end of the electric push rod (8) is fixedly connected to a circular disk (9). The top of both sets of clamping plates (7) is bolted with a fastening plate (10), and a placement area is formed between the fastening plate (10) and the clamping plate (7). The circular disk (9) is located in the placement area. When the electric push rod (8) works, the circular disk (9) pushes the two sets of clamping plates (7) to move up and down along the inner wall of the inclined slide (6).

4. The flame-retardant polyethylene cable sheath strength testing equipment according to claim 3, characterized in that, Both sets of clamping plates (7) have stepped grooves (11) on their opposite sides for adapting cables, and the diameter of each step of the stepped groove (11) decreases from top to bottom.

5. The flame-retardant polyethylene cable sheath strength testing device according to claim 1, characterized in that, The positioning part includes positioning plates (12) symmetrically arranged on mounting base one (3) and mounting base two (5). One side of the positioning plate (12) is fixedly installed on mounting base one (3) and mounting base two (5) by bolts, and the other side of the positioning plate (12) is slidably connected to mounting base one (3) and mounting base two (5) through a sliding groove.

6. The flame-retardant polyethylene cable sheath strength testing device according to claim 5, characterized in that, The positioning plate (12) has an arc-shaped protrusion (13) for pressing against the cable.

7. The flame-retardant polyethylene cable sheath strength testing device according to claim 5, characterized in that, A lead screw (14) for driving the positioning plate (12) is rotatably connected in the sliding groove. The connection of the positioning plate (12) is threaded onto the lead screw (14). When the two sets of arc-shaped protrusions (13) come into contact with the cable, a positioning area is formed.

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