A device and method for detecting and judging the smoothness of power cable insulation

Abstract

This invention discloses a device and method for detecting and judging the insulation smoothness of power cables. The device includes a base, on which a fixed head, a testing frame, and a movable head are sequentially arranged longitudinally. The fixed head is fixedly connected to the base, while the testing frame and the movable head are slidably connected to the base. A first chuck is fixedly mounted on the fixed head, and a second chuck is fixedly mounted on the movable head. A testing hole is provided at the center of the testing frame, and three displacement sensors are fixedly mounted on the testing frame along the circumference of the testing hole. This invention can complete the determination of the straightness of power cables in one operation, resulting in high efficiency and more accurate measurement results.

Description

Technical Field

[0001] This invention relates to the field of power cable construction equipment technology, and in particular to a device and method for detecting and judging the insulation smoothness of power cables with voltage levels of 10kV and above. Background Technology

[0002] Power cables are the main transmission carriers for urban power supply. During cable operation, the insulation quality of the cable is a crucial factor affecting power supply safety. Before being put into operation, cables are subject to mechanical forces. Some of these forces occur during the cable insulation manufacturing process, causing defects such as dents, bumps, burrs, and protrusions. Others occur during the laying process, causing defects such as bending and deformation of the cable insulation. To reduce the cable insulation failure rate, the cable insulation must be visually inspected and its straightness measured before jointing. Currently, preliminary judgment is usually made using methods such as visual observation and manual measurement. This method is time-consuming, labor-intensive, prone to errors, extremely inconvenient to operate, and the uncertainties in the measurement are difficult to control, affecting the measurement accuracy.

[0003] Because the axis of a power cable is a spatial curve, and only one direction of height difference can be measured at a time, obtaining more accurate straightness requires changing the measurement position and performing multiple measurements. Patent application CN215261538U discloses a straightness measuring device, including a measuring part and multiple positioning parts. The straightness measuring device includes a positioning mechanism, a clamping assembly, a holding assembly, and a straightness measuring element. The positioning mechanism is used to position the workpiece and includes a carrier and a positioning element disposed on the carrier. The positioning element has a positioning groove for initially positioning the positioning part of the workpiece. The clamping assembly is disposed on the carrier and is used to reposition the positioning part of the workpiece along a first direction. The holding assembly is disposed on the carrier and is used to reposition the positioning part of the workpiece along a second direction. The straightness measuring element is disposed on the carrier and is used to detect the straightness of the measuring part of the workpiece. This application achieves rapid positioning of the positioning part of the workpiece through the positioning element, clamping assembly, and holding assembly, and the straightness measuring element measures the straightness of the workpiece. When used for straightness measurement of cylindrical parts, it cannot complete the measurement in one go and requires multiple measurements, resulting in low measurement efficiency. The straightness measuring device disclosed in patent application CN108592767A not only has this technical problem, but also requires manual reading and calculation due to the use of a dial indicator, which is prone to reading errors and mistakes. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a device and method for detecting and judging the insulation smoothness of power cables, so as to solve the problem of time-consuming and labor-intensive measurement of the straightness of power cables and the low measurement efficiency.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A power cable insulation smoothness testing device includes a base. A fixed head, a testing frame, and a movable head are sequentially arranged longitudinally on the base. The fixed head is fixedly connected to the base, while the testing frame and the movable head are slidably connected to the base. A first chuck is fixedly mounted on the fixed head, and a second chuck is fixedly mounted on the movable head. The testing frame has a testing hole at its center. Three displacement sensors are fixedly mounted on the testing frame along the circumference of the testing hole. The probes of the displacement sensors are radially oriented towards the axis of the testing hole. The centers of the first chuck, the second chuck, and the testing hole are located on the same straight line. The movement directions of the testing frame and the movable head are parallel to this straight line. A hole coaxial with the first chuck is formed on the fixed head.

[0007] Furthermore, the base is provided with a track parallel to the axis of the detection hole, and the detection frame and the movable head are slidably connected to the track.

[0008] Furthermore, a lead screw is rotatably connected to one side of the machine base. The lead screw is parallel to the track, and a nut is threaded onto the lead screw. The nut is fixedly connected to the machine base, and a first servo motor for driving the lead screw to rotate is fixedly installed on the machine base.

[0009] Furthermore, the detection frame includes an upper plate and a lower plate that are split vertically. The mating surfaces of the upper and lower plates are located on a plane that passes through the center of the detection hole. The detection hole is divided into two half holes by this plane. One end of the upper plate is hinged to the end of the lower plate, and the lower plate is slidably connected to the machine base. Two displacement sensors are fixedly mounted on the lower plate, and another displacement sensor is fixedly mounted on the upper plate.

[0010] Furthermore, the top surface of the lower plate is provided with a frustum-shaped boss, and the bottom surface of the upper plate is provided with a recess for engaging with the boss.

[0011] Furthermore, a first connecting plate is hinged to one end of the upper plate, and a second connecting plate is hinged to the end of the lower plate corresponding to the first connecting plate. The end of the first connecting plate away from the upper plate is hinged to the end of the second connecting plate away from the lower plate.

[0012] Furthermore, it also includes a controller and an industrial computer connected to the controller. The controller is electrically connected to the first servo motor, and the displacement sensors are all connected to the industrial computer via signal connection.

[0013] Furthermore, both the first and second chucks are three-jaw chucks; the displacement sensor is a self-resetting displacement sensor.

[0014] Furthermore, the detection frame includes a base slidably connected to the machine base and a turntable rotatably connected to the base. The detection hole and displacement sensor are both set on the turntable. A gear ring is fixedly set on the circumference of the turntable, and a gear meshes on the gear ring. A second servo motor that is connected to the gear transmission is fixedly set on the base.

[0015] A method for determining the smoothness of power cable insulation, using a power cable insulation smoothness detection device, includes the following steps:

[0016] Step 1: Pass the power cable through the hole on the fixed head, the first chuck, and the detection hole in sequence. Then, use the first chuck and the second chuck to clamp the section of the power cable to be measured. The probe of the displacement sensor is pressed against the outer circumference of the power cable.

[0017] Step 2: The industrial control computer controls the first servo motor to rotate through the control controller. The rotation of the lead screw drives the detection frame to move along the axial direction of the detection hole. The three displacement sensors transmit the radial displacement of the three probes along the detection hole to the industrial control computer in real time.

[0018] Step 3: The industrial control computer collects real-time displacement data from the three displacement sensors through the acquisition card, obtains the real-time center position coordinates of the power cable, calculates and obtains the distance and deviation direction between the real-time center of the power cable and the axis of the detection hole, and calculates the straightness of the power cable based on the length of the measured section of the power cable.

[0019] The positive effects of this invention are:

[0020] 1. This invention includes a first chuck, a second chuck, and a movable detection frame. The detection frame is equipped with three circumferentially distributed displacement sensors. These three sensors determine the real-time center of the power cable. The industrial control computer collects the real-time center coordinates of the power cable and uses 3D software to generate a spatial curve. The straightness of the power cable can then be obtained using 3D software. Therefore, the straightness of the power cable can be measured in one operation, resulting in high efficiency and more accurate results.

[0021] 2. The testing frame is divided into an upper plate and a lower plate, which are hinged together, making it easier for the power cable 1 to enter the measuring hole on the testing frame and avoiding damage caused by the displacement sensor colliding with the power cable 1.

[0022] 3. The lower plate has a boss and the upper plate has a recess. The boss and the recess work together to accurately position the upper plate and prevent misalignment between the upper and lower plates, making the measurement results more accurate.

[0023] 4. The upper plate and the lower plate are hinged together by the first connecting plate and the second connecting plate. During the process of the upper plate covering the lower plate, the end of the upper plate can move vertically relative to the lower plate 17, so that the boss can enter the corresponding recess more easily and avoid jamming. Attached Figure Description

[0024] Figure 1 This is the front view of Embodiment 1;

[0025] Figure 2 yes Figure 1 A cross-sectional view of the AA section;

[0026] Figure 3 This is a schematic diagram of the testing frame in Example 2;

[0027] Figure 4 This is a schematic diagram of the detection frame when it is closed in Example 3;

[0028] Figure 5 This is a schematic diagram of the detection frame after it has been opened in Example 3;

[0029] Figure 6 yes Figure 4 A magnified view of a section of the central I area;

[0030] Figure 7 This is a structural schematic diagram of Example 4;

[0031] In the picture:

[0032] 1. Power cable; 2. Fixed head; 3. First chuck; 4. Displacement sensor; 5. Detection frame; 6. Probe; 7. Second chuck; 8. Movable head; 9. Track; 10. Lead screw; 11. Cantilever; 12. Nut; 13. Base; 14. Support leg; 15. First servo motor; 16. Upper plate; 17. Lower plate; 18. Recess; 19. Boss; 20. Handle; 21. First connecting plate; 22. Second connecting plate; 23. Detection hole; 24. Gear ring; 25. Second servo motor; 26. Gear; 27. Roller. Detailed Implementation

[0033] Example 1

[0034] like Figure 1As shown, a power cable insulation smoothness testing device includes a cast base 13 with a flat top. A fixed head 2, a testing frame 5, and a movable head 8 are arranged longitudinally from left to right on the base 13. Support legs 14 are welded to the four corners of the base 13. The fixed head 2 is fixedly connected to the left end of the base 13. The testing frame 5 and the movable head 8 are slidably connected to the base 13. A first chuck 3 is fixedly mounted on the right side of the fixed head 2, and a second chuck 7 is fixedly mounted on the left side of the movable head 8. Both the first chuck 3 and the second chuck 7 are three-jaw chucks. The upper part of the testing frame 5 is plate-shaped, and the testing frame 5 is vertically arranged. A testing hole 23 is provided in the center of the testing frame 5.

[0035] Combination Figure 2 As shown, three displacement sensors 4 are evenly distributed along the circumference of the detection hole 23 on the side of the detection frame 5 near the first chuck 3. All three displacement sensors 4 are self-resetting type and are fixedly connected to the detection frame 5. The probes 6 of each displacement sensor 4 are radially oriented towards the axis of the detection hole 23 and are perpendicular to the axis of the detection hole 23. The centers of the first chuck 3, the second chuck 7, and the detection hole 23 are located on the same straight line. The movement directions of the detection frame 5 and the movable head 8 are parallel to this straight line. The fixed head 2 has a hole coaxial with the first chuck 3.

[0036] The base 13 is fixed with a track 9 parallel to the axis of the detection hole 23 by screws. The upper cross section of the track 9 is triangular. There are two tracks 9, which are symmetrically arranged about the central axis of the base 13. The bottom of the detection frame 5 and the bottom of the movable head 8 are provided with sliding grooves for sliding cooperation with the track 9.

[0037] A lead screw 10 is provided on the front side of the base 13. The lead screw 10 is parallel to the track 9. Lugs are welded to the front side of the base 13 at positions corresponding to both ends of the lead screw 10. The two ends of the lead screw 10 are respectively rotatably connected to the corresponding lugs. A nut 12 is threaded onto the lead screw 10. A 7-shaped cantilever 11 is welded to the front side of the detection frame 5. The bottom end of the cantilever 11 is welded to the nut 12. A first servo motor 15 is fixedly mounted on the lug at the left end of the lead screw 10. The output shaft of the first servo motor 15 is connected to the lead screw 10 via a coupling.

[0038] The present invention also includes a controller and an industrial control computer electrically connected to the controller. The controller is electrically connected to the first servo motor 15, and the displacement sensors 4 are all connected to the industrial control computer via signals.

[0039] The steps for measuring the straightness of power cables according to this invention are as follows:

[0040] Step 1: Pass the power cable 1 through the hole on the fixed head 2, the first chuck 3 and the detection hole 23 from left to right. Push the movable head 8 longitudinally. Then, the first chuck 3 and the second chuck 7 will clamp the section of the power cable 1 to be measured. The probe 6 of the displacement sensor 4 will be pressed against the outer circle of the power cable 1.

[0041] Step 2: The industrial control computer controls the first servo motor 15 to rotate through the control controller, and the lead screw 10 rotates to drive the detection frame 5 to move along the axial direction of the detection hole 23. The three displacement sensors 4 transmit the radial displacement of the three probes 6 along the detection hole 23 to the industrial control computer in real time.

[0042] Step 3: The industrial control computer collects real-time displacement data from the three displacement sensors 4 and the longitudinal displacement of the detection frame 5 through the acquisition card. Based on the principle that three points can determine a circle, the real-time center position coordinates of the power cable 1 can be obtained. The distance and deviation direction between the real-time center of the power cable 1 and the axis of the detection hole 23 are calculated and obtained. The straightness of the power cable 1 is calculated in combination with the length of the measured section of the power cable 1.

[0043] Therefore, the straightness measurement can be completed by moving the test frame 5 along the power cable 1 once, which saves time and effort, has high measurement efficiency, and the measurement results are more accurate.

[0044] In practical applications, by measuring the real-time center coordinates of power cable 1, the actual centerline of the measured section of power cable 1 can be obtained using 3D software on an industrial control computer. This centerline is a spatial curve, and after processing with the 3D software, the straightness of the power cable can be directly determined. Currently, several 3D scanning software programs can be used to measure geometric tolerances, such as Geomagic Control X.

[0045] Example 2

[0046] like Figure 3 As shown, the difference between this embodiment and Embodiment 1 is that:

[0047] The detection frame 5 includes an upper plate 16 and a lower plate 17 that are split vertically. The mating surfaces of the upper plate 16 and the lower plate 17 are located on a plane that passes through the center of a detection hole 23. The detection hole 23 is divided into two half-holes by this plane. The right end of the upper plate 16 is hinged to the right end of the lower plate 17. The lower plate 17 is slidably connected to a track 9. Two displacement sensors 4 are fixedly mounted on the lower plate 17, and another displacement sensor 4 is fixedly mounted on the upper plate 16. A handle 20 is welded to the left end of the upper plate 16.

[0048] Because the power cable 1 is very rigid, directly threading it into the detection hole 23 will obstruct the probe 6 of the displacement sensor 4, potentially damaging it. By using the handle 20 to lift the upper plate 16, the upper displacement sensors 4 are moved away from the power cable 1. After placing the power cable 1 between the two lower displacement sensors 4, the first chuck 3 and the second chuck 7 are tightened, and the upper plate 16 is closed. This clamps the power cable 1 between the probes 6 of the three displacement sensors 4, preventing damage to the probes 6 and making it easier for the cable 1 to enter the detection hole 23.

[0049] Example 3

[0050] like Figure 4 As shown, the difference between this embodiment and Embodiment 2 is that:

[0051] The lower plate 17 has two frustum-shaped protrusions 19 symmetrically arranged on its top surface, and the upper plate 16 has a corresponding recess 18 on its bottom surface for engaging with the protrusions 19.

[0052] The upper plate 16 can be precisely positioned by the cooperation of the frustum-shaped boss 19 and the recess 18, preventing misalignment between the upper plate 16 and the lower plate 17, thus making the measurement results more accurate.

[0053] like Figure 5 and Figure 6 As shown, the upper plate 16 is hinged to the right end of a first connecting plate 21, and the lower plate 17 is hinged to the right end of a second connecting plate 22. The end of the first connecting plate 21 away from the upper plate 16 is hinged to the end of the second connecting plate 22 away from the lower plate 17.

[0054] After the first connecting plate 21 and the second connecting plate 22 are set, the right end of the upper plate 16 can move vertically relative to the right end of the lower plate 17 during the process of the upper plate 16 covering the lower plate 17, so that the boss 19 can enter the corresponding recess 18 more easily and avoid jamming.

[0055] Example 4

[0056] like Figure 7 As shown, the difference between this embodiment and Embodiment 1 is that:

[0057] The detection frame 5 includes a base 29 slidably connected to the track 9 and a turntable 28 rotatably connected to the base 29. The detection hole 23 and the displacement sensor 4 are both disposed on the turntable 28. A gear ring 24 is fixedly disposed at the middle position on the circumference of the turntable 28, and a gear 26 meshes on the gear ring 24. A second servo motor 25 is fixedly disposed on the base 29. The output shaft of the second servo motor 25 is fixedly connected to the gear 26, and the second servo motor 25 is electrically connected to the controller.

[0058] A pair of rollers 27 are symmetrically arranged on the base 29 with the turntable 28 as the center. Each roller 27 has an annular groove at the middle of its outer circle for the gear ring 24 to pass through. The turntable 28 is supported on the two rollers 27. The gear ring 24 is located in the groove, thereby axially limiting the gear ring 24 and preventing the turntable 28 from moving axially during rotation.

[0059] The controller controls the second servo motor 25 to drive the turntable 28 to rotate, which in turn causes the three displacement sensors 4 to rotate around the circumference of the power cable 1. Combined with the linear movement of the three displacement sensors 4 along the track driven by the turntable 28, the smoothness of the outer surface of the power cable 1 can be measured, thereby detecting defects such as bumps, dents, burrs, and protrusions on the surface of the power cable 1.

[0060] The above-described embodiments are detailed and specific, illustrating preferred embodiments of the present invention. They are only used to illustrate the technical ideas and features of the present invention, aiming to enable those skilled in the art to understand and implement the invention. However, they are not limited to the present invention, and the patent scope of the present invention should not be limited to these embodiments. Any equivalent changes or modifications made to the spirit disclosed in the present invention, without departing from the structure of the present invention, such as local improvements within the system and alterations or transformations between subsystems, are still within the patent scope of the present invention. Currently, the technical solution of this application has undergone pilot testing, i.e., small-scale experiments before large-scale mass production. After the pilot testing, user surveys were conducted on a small scale, and the survey results showed high user satisfaction. Preparations are now underway for the formal production and industrialization of the product, including intellectual property risk warning surveys.

Claims

1. A device for detecting the smoothness of power cable insulation, characterized in that, The system includes a base (13), on which a fixed head (2), a testing frame (5), and a movable head (8) are arranged longitudinally. The fixed head (2) is fixedly connected to the base (13), and the testing frame (5) and the movable head (8) are slidably connected to the base (13). A first chuck (3) is fixedly mounted on the fixed head (2), and a second chuck (7) is fixedly mounted on the movable head (8). A testing hole (23) is provided in the center of the testing frame (5). Three displacement sensors (4) are fixedly installed on the detection frame (5) along the circumferential direction of the detection hole (23). The probes (6) of the displacement sensors (4) are all radially oriented toward the axis of the detection hole (23). The center of the first chuck (3), the center of the second chuck (7), and the center of the detection hole (23) are located on the same straight line. The moving directions of the detection frame (5) and the movable head (8) are parallel to this straight line. The fixed head (2) has a hole coaxial with the first chuck (3). The testing frame (5) includes an upper plate (16) and a lower plate (17) that are split open. The mating surfaces of the upper plate (16) and the lower plate (17) are located on a plane that passes through the center of the testing hole (23). The testing hole (23) is divided into two half holes by this plane. One end of the upper plate (16) is hinged to the end of the lower plate (17) that corresponds to it. The lower plate (17) is slidably connected to the base (13). Two displacement sensors (4) are fixedly mounted on the lower plate (17), and another displacement sensor (4) is fixedly mounted on the upper plate (16).

2. The power cable insulation smoothness testing device according to claim 1, characterized in that, The base (13) is provided with a track (9) parallel to the axis of the detection hole (23), and the detection frame (5) and the movable head (8) are slidably connected to the track (9).

3. The power cable insulation smoothness testing device according to claim 2, characterized in that, A lead screw (10) is rotatably connected to one side of the base (13). The lead screw (10) is parallel to the track (9). A nut (12) is threaded onto the lead screw (10). The nut (12) is fixedly connected to the base (13). A first servo motor (15) for driving the lead screw (10) to rotate is fixedly installed on the base (13).

4. The power cable insulation smoothness testing device according to claim 1, characterized in that, The top surface of the lower plate (17) is provided with a frustum-shaped boss (19), and the bottom surface of the upper plate (16) is provided with a recess (18) for cooperating with the boss (19).

5. The power cable insulation smoothness testing device according to claim 1, characterized in that, The upper plate (16) is hinged to one end with a first connecting plate (21), and the lower plate (17) is hinged to the end corresponding to the first connecting plate (21) with a second connecting plate (22). The end of the first connecting plate (21) away from the upper plate (16) is hinged to the end of the second connecting plate (22) away from the lower plate (17).

6. The power cable insulation smoothness testing device according to claim 3, characterized in that, It also includes a controller and an industrial computer connected to the controller. The controller is electrically connected to the first servo motor (15), and the displacement sensors (4) are all connected to the industrial computer via signals.

7. The power cable insulation smoothness testing device according to claim 1, characterized in that, The first chuck (3) and the second chuck (7) are both three-jaw chucks; the displacement sensor (4) is a self-resetting displacement sensor.

8. A method for determining the smoothness of power cable insulation, characterized in that, The power cable insulation smoothness testing device according to claim 6 includes the following steps: Step 1: Pass the power cable (1) through the hole on the fixed head (2), the first chuck (3) and the detection hole (23) in sequence. Then, use the first chuck (3) and the second chuck (7) to clamp the section of the power cable (1) to be measured. The probe (6) of the displacement sensor (4) is pressed against the outer circle of the power cable (1). Step 2: The industrial control computer controls the first servo motor (15) to rotate through the control controller. The screw (10) rotates and drives the detection frame (5) to move along the axial direction of the detection hole (23). The three displacement sensors (4) transmit the radial displacement of the three probes (6) along the detection hole (23) to the industrial control computer in real time. Step 3: The industrial control computer collects the real-time displacement data transmitted by the three displacement sensors (4) through the acquisition card, obtains the real-time center position coordinates of the power cable (1), calculates and obtains the distance and deviation direction between the real-time center of the power cable (1) and the axis of the detection hole (23), and calculates the straightness of the power cable (1) based on the length of the measured section of the power cable (1).

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