Composite sensor for cable insulation defect detection

Abstract

The invention belongs to the technical field of intelligent sensors, and particularly relates to a composite sensor for cable insulation defect detection, which comprises a control machine head, two mounting plates and a left detection box, the control machine head is mounted at the top of the mounting plate on the same side, the left detection box is mounted between the two mounting plates, and a right detection box is mounted between the two mounting plates. A laser detection unit is arranged in the left detection box and is used for detecting the outer diameter of the cable; a right detection box is installed between the two installation plates, and a temperature measurement unit is arranged in the right detection box and used for detecting the temperature of a cable insulation layer. By means of the composite sensor, online detection of multiple defects such as the outer diameter, ovality, bubbles and cracks of the cable can be achieved, detection is comprehensive, temperature difference interference is eliminated, the detection precision is improved, meanwhile, it can be avoided that impurities such as dust affect the detection precision as much as possible, multiple detection structures work cooperatively, and high-quality production of the cable is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of intelligent sensors, and in particular relates to a composite sensor for detecting cable insulation defects. Background Art

[0002] Cables are the core carriers of electricity and communications. Insulation defects can easily cause short circuits, signal attenuation, and even safety accidents. Online testing during production can eliminate unqualified products in real time, prevent hidden dangers from entering the market, and ensure the safety of terminal applications.

[0003] Currently, there are many defects in cables, such as bubbles, cracks, and uneven thickness. A single sensor cannot comprehensively detect insulation defects. To improve such problems, a composite sensor can be used to detect insulation defects in cables. For example, patent announcement number CN107037342A discloses a composite sensor for detecting cable insulation defects. However, when in use, the composite sensor generally only integrates multiple detection probes to independently detect multiple parameters of multiple cables. These probes are independent of each other and cannot fully utilize the collaborative detection advantages of the composite sensor. Summary of the Invention

[0004] The object of the present invention is to provide a composite sensor for detecting cable insulation defects in view of the above problems.

[0005] To achieve the above object, the present invention adopts the following technical solution: a composite sensor for detecting cable insulation defects, comprising a control head and two mounting plates, wherein the control head is mounted on top of the mounting plates on the same side, and further comprising:

[0006] A left detection box is installed between the two mounting plates, wherein a laser detection unit is provided inside the left detection box, and the laser detection unit is used to detect the outer diameter of the cable;

[0007] A right detection box is installed between the two mounting plates, wherein a temperature measuring unit is provided inside the right detection box, and the temperature measuring unit is used to detect the temperature of the cable insulation layer;

[0008] A capacitance detection unit is provided between the left detection box and the right detection box, and the left detection box and the right detection box are connected through the capacitance detection unit, and the capacitance detection unit is used to detect the capacitance value of the cable insulation layer;

[0009] A heating unit is provided on the side wall of the left detection box, and the cable passes through the heating unit and enters the left detection box. The heating unit is used to heat the cable at a constant temperature;

[0010] The heat dissipation unit is installed between the left detection box and the right detection box, and is used to dissipate heat and cool the cable.

[0011] Preferably, the laser detection unit includes two conical mounting sleeves fixedly installed inside the left detection box, and the two conical mounting sleeves are symmetrical to each other, a plurality of laser lamps are installed on the inner side wall of one of the conical mounting sleeves, and a plurality of laser receivers are installed on the inner side wall of the other conical mounting sleeve, and the laser beams emitted by each of the laser lamps are reflected to the laser receiver through the cable, and the laser lamp and the laser receiver are electrically connected to the control head.

[0012] Preferably, the temperature measuring unit includes a mounting ring fixedly installed inside the right detection box, and a plurality of arc-shaped infrared temperature measuring probes are installed on the inner wall of the mounting ring, and each arc-shaped infrared temperature measuring probe is evenly distributed on the inner side of the mounting ring, and each arc-shaped infrared temperature measuring probe is electrically connected to the control head.

[0013] Preferably, the capacitance detection unit includes an insulating mounting tube fixedly installed between the left detection box and the right detection box, two electrode rings are installed inside the insulating mounting tube, and the cable passes through the inner sides of the two electrode rings in turn, and the two electrode rings are electrically connected to the control head.

[0014] Preferably, the heating unit includes a thermal insulation feed pipe fixedly mounted on the side wall of the left detection box, and the thermal insulation feed pipe is connected to the interior of the left detection box. An annular electric heater electrically connected to the control head is installed inside the thermal insulation feed pipe, and the cable passes through the interior of the annular electric heater and enters the interior of the left detection box.

[0015] Preferably, the heat dissipation unit includes a hollow cylinder body fixedly installed between the left detection box and the right detection box, a piston block is slidingly arranged inside the hollow cylinder body, and a non-magnetic spring is arranged between the side wall of the piston block and the hollow cylinder body, a permanent magnet block is installed on the side wall of the hollow cylinder body away from the non-magnetic spring, an electromagnetic block corresponding to the position of the permanent magnet block is installed inside the hollow cylinder body, an air intake pipe is fixedly connected to the side wall of the hollow cylinder body, and an air intake one-way valve is installed inside the air intake pipe, the air intake pipe is connected to the insulating mounting pipe, and an air intake hole is opened at the position of the pipe wall of the insulating mounting pipe away from the side of the air intake pipe, an air outlet pipe is fixedly connected to the end of the hollow cylinder body away from the electromagnetic block, and an air outlet one-way valve is installed inside the air outlet pipe, the air outlet pipe is installed with a cleaning mechanism, and the electromagnetic block is electrically connected to the control head.

[0016] Preferably, the cleaning mechanism includes a hollow ring fixedly mounted on the end of the thermal insulation feed pipe, the inner ring wall of the hollow ring is conical, and a plurality of air injection holes are provided on the inner wall of the hollow ring, and the hollow ring is connected to the air outlet pipe.

[0017] Preferably, a discharge pipe is connected to the side wall of the right detection box, and multiple support rings are installed inside the thermal insulation feed pipe, insulating mounting tube and discharge pipe, and a ceramic ring is installed on the inner wall of each support ring, and the cable slides through the inside of each ceramic ring.

[0018] Compared with existing technologies, the advantages of a composite sensor for cable insulation defect detection are:

[0019] 1. Through the cooperation of the control head, mounting plate, left detection box, laser detection unit, right detection box and capacitance detection unit, the outer diameter and ovality of the cable can be detected online by laser to avoid the outer diameter deviation of the cable insulation layer affecting the safety of the cable. The capacitance detection unit can measure the capacitance value of the cable insulation layer, thereby performing online detection of the looseness, bubbles and thickness defects of the cable insulation layer. Through composite detection, the comprehensiveness of cable insulation defect detection is increased.

[0020] 2. The heating unit can be used to heat the cable at a constant temperature before testing to avoid changes in the thickness and cracks of the cable insulation layer caused by temperature differences, thereby improving the accuracy of laser and capacitance detection. The heating unit is combined with the heat dissipation unit and temperature measurement unit to further perform online detection of defects such as damage and bubbles in the cable insulation layer based on the temperature heat dissipation differences of the cable insulation layer, thereby further improving the comprehensiveness and accuracy of cable insulation defect detection.

[0021] 3. Through the cleaning mechanism, the airflow generated by the heat dissipation unit can be used to blow away dust and other impurities that may be attached to the cable surface before testing the cable, thereby preventing these impurities from affecting the accuracy of subsequent testing. The various testing structures work together to effectively improve the accuracy of the test results, which is conducive to high-quality cable production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural schematic diagram of a composite sensor for cable insulation defect detection provided by the present invention;

[0023] Figure 2 This is a schematic diagram of the internal structure of a left detection box and a right detection box of a composite sensor for cable insulation defect detection provided by the present invention;

[0024] Figure 3 This is a side structural schematic diagram of a temperature measuring unit of a composite sensor for detecting cable insulation defects provided by the present invention;

[0025] Figure 4 The present invention provides a composite sensor for detecting cable insulation defects. Figure 2 A magnified view of the structure of part A;

[0026] Figure 5 This is a structural schematic diagram of a heating unit of a composite sensor for detecting cable insulation defects provided by the present invention;

[0027] Figure 6 The present invention provides a schematic structural diagram of a heat dissipation unit of a composite sensor for detecting cable insulation defects.

[0028] In the figure: 1 control head, 2 mounting plate, 3 left detection box, 4 laser detection unit, 41 conical mounting sleeve, 42 laser light, 43 laser receiver, 5 right detection box, 6 temperature measuring unit, 61 mounting ring, 62 arc infrared temperature measuring probe, 7 capacitance detection unit, 71 insulating mounting tube, 72 electrode ring, 8 heating unit, 81 thermal insulation feed pipe, 82 annular electric heater, 9 heat dissipation unit, 91 hollow cylinder, 92 piston block, 93 non-magnetic spring, 94 permanent magnet block, 95 electromagnetic block, 96 suction pipe, 97 suction check valve, 98 suction hole, 99 exhaust pipe, 910 exhaust check valve, 10 cleaning mechanism, 101 hollow ring, 102 air jet hole, 11 discharge pipe, 12 support ring, 13 ceramic ring. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] like Figures 1-6 As shown, a composite sensor for detecting cable insulation defects includes a control head 1 and two mounting plates 2. The control head 1 is installed on the top of the mounting plate 2 on the same side. It also includes: a left detection box 3, which is installed between the two mounting plates 2. A laser detection unit 4 is provided inside the left detection box 3. The laser detection unit 4 is used to detect the outer diameter of the cable. The laser detection unit 4 includes two conical mounting sleeves 41 fixedly installed inside the left detection box 3, and the two conical mounting sleeves 41 are symmetrical to each other. A plurality of laser lamps 42 are installed on the inner side wall of one of the conical mounting sleeves 41, and a plurality of laser receivers 43 are installed on the inner side wall of the other conical mounting sleeve 41. The laser beam emitted by each laser lamp 42 is reflected to the laser receiver 43 through the cable. The laser lamp 42 and the laser receiver 43 are both electrically connected to the control head 1.

[0031] The right detection box 5 is installed between the two mounting plates 2. A temperature measuring unit 6 is provided inside the right detection box 5. The temperature measuring unit 6 is used to detect the temperature of the cable insulation layer. The temperature measuring unit 6 includes a mounting ring 61 fixedly installed inside the right detection box 5. A plurality of arc-shaped infrared temperature measuring probes 62 are installed on the inner wall of the mounting ring 61, and each arc-shaped infrared temperature measuring probe 62 is evenly distributed on the inner side of the mounting ring 61. Each arc-shaped infrared temperature measuring probe 62 is electrically connected to the control head 1.

[0032] The capacitance detection unit 7 is arranged between the left detection box 3 and the right detection box 5, and the left detection box 3 and the right detection box 5 are connected through the capacitance detection unit 7. The capacitance detection unit 7 is used to detect the capacitance value of the cable insulation layer. The capacitance detection unit 7 includes an insulating mounting tube 71 fixedly installed between the left detection box 3 and the right detection box 5. Two electrode rings 72 are installed inside the insulating mounting tube 71, and the cable passes through the inner side of the two electrode rings 72 in turn. The two electrode rings 72 are electrically connected to the control head 1.

[0033] The heating unit 8 is arranged on the side wall of the left detection box 3, and the cable passes through the heating unit 8 and enters the left detection box 3. The heating unit 8 is used to heat the cable at a constant temperature. The heating unit 8 includes a thermal insulation feed pipe 81 fixedly installed on the side wall of the left detection box 3, and the thermal insulation feed pipe 81 is connected to the interior of the left detection box 3. The interior of the thermal insulation feed pipe 81 is equipped with an annular electric heater 82 electrically connected to the control head 1, and the cable passes through the interior of the annular electric heater 82 and enters the interior of the left detection box 3. The annular electric heater 82 can heat the entering cable, and the heating temperature can be set by the control head 1.

[0034] The heat dissipation unit 9 is installed between the left detection box 3 and the right detection box 5. The heat dissipation unit 9 is used to dissipate heat and cool the cable. The heat dissipation unit 9 includes a hollow cylinder 91 fixedly installed between the left detection box 3 and the right detection box 5. A piston block 92 is slidingly provided inside the hollow cylinder 91, and a non-magnetic spring 93 is provided between the side wall of the piston block 92 and the hollow cylinder 91. A permanent magnet block 94 is installed on the side wall of the hollow cylinder 91 away from the non-magnetic spring 93. An electromagnetic block 95 corresponding to the position of the permanent magnet block 94 is installed inside the hollow cylinder 91. The side wall of the hollow cylinder 91 is fixedly plugged with The air intake pipe 96 is provided with an air intake one-way valve 97 installed inside the air intake pipe 96. The air intake pipe 96 is connected to the insulating mounting pipe 71. An air intake hole 98 is provided on the wall of the insulating mounting pipe 71 away from the side of the air intake pipe 96. An air outlet pipe 99 is fixedly connected to the end of the hollow cylinder body 91 away from the electromagnetic block 95, and an air outlet one-way valve 910 is installed inside the air outlet pipe 99. A cleaning mechanism 10 is installed on the air outlet pipe 99. The electromagnetic block 95 is electrically connected to the control head 1. When the electromagnetic block 95 is energized, it will generate magnetic repulsion on the permanent magnet block 94. A shielding electromagnetic structure is provided on the side wall of the hollow cylinder body 91.

[0035] The cleaning mechanism 10 includes a hollow ring 101 fixedly installed on the end of the thermal insulation feed pipe 81. The inner ring wall of the hollow ring 101 is conical, and the inner wall of the hollow ring 101 is provided with multiple air injection holes 102. The hollow ring 101 is connected to the air outlet pipe 99, which can easily blow away dust and other impurities on the surface of the cable.

[0036] A discharge pipe 11 is inserted into the side wall of the right detection box 5, and multiple support rings 12 are installed inside the thermal insulation feed pipe 81, the insulating mounting tube 71 and the discharge pipe 11, and a ceramic ring 13 is installed on the inner wall of each support ring 12, and the cable slides through the inside of each ceramic ring 13. Through the action of the support ring 12 and the ceramic ring 13, it can be ensured that the cable passes coaxially through the thermal insulation feed pipe 81, the insulating mounting tube 71 and the discharge pipe 11, thereby avoiding cable deviation affecting the accuracy of detection.

[0037] The operating principle of the present invention is described as follows: On the cable production line, the finished cable passes through the insulation feed pipe 81, the left detection box 3, the insulation installation pipe 71, the right detection box 5 and the discharge pipe 11 in sequence, and then is reeled by the reeling device. During the reeling process, the online detection of the cable is started by the control head 1;

[0038] After the control head 1 is started, the annular electric heater 82 will be immediately controlled to work. The annular electric heater 82 will heat the cable at a temperature of 60°C ± 1°C. Therefore, the cable will be heated to 60°C before passing through the insulation feed pipe 81 and entering the left detection box 3. Since the insulation layer of the cable is affected by different temperatures, it will experience different "thermal expansion and contraction" phenomena. Therefore, before testing, the cable is heated at a constant temperature to avoid the different "thermal expansion and contraction" phenomena affecting the accuracy of the cable insulation layer testing.

[0039] The laser lamps 42 inside the left detection box 3 will emit a laser beam (the incident angle between the laser beam and the cable insulation layer is 45°). After being reflected by the side wall of the cable, the laser beam will be reflected to the laser receiver 43. When the diameter of the outer wall of the cable is too large, too small or the ovality exceeds the standard, the diameter position of the outer wall of the cable changes, resulting in a change in the reflection position of the laser beam by the cable insulation layer, which causes the laser intensity received by the laser receiver 43 to change. At this time, the electrical signal strength fed back by the laser receiver 43 to the control head 1 exceeds the threshold (the threshold is set based on the cable diameter and ovality tolerance requirements. For example, if the diameter exceeds the tolerance by 0.2 mm, the electrical signal strength is less than 5 mA). The control head 1 will immediately issue an alarm and record the tolerance data.

[0040] The cable passing through the left detection box 3 will enter the insulating installation tube 71 and pass through the two electrode rings 72. After the control head 1 is started, the control head 1 will apply an alternating electric field to the two electrode rings 72 to form a capacitor. When there are defects such as bubbles, moisture, uneven thickness, and looseness in the insulation layer, the capacitance value detected by the control head 1 will change (the dielectric constant of air is low, resulting in a decrease in capacitance, the dielectric constant of water is high, and the capacitance value increases. Changes in the thickness of the cable insulation layer cause capacitance value fluctuations). When the capacitance value change exceeds a threshold value (the threshold value is set based on the requirements for cable insulation defects), the control head 1 will immediately issue an alarm and record the out-of-tolerance data.

[0041] Among them, after the control head 1 is started, the electromagnetic block 95 will be controlled to work at a frequency of power on for 2 seconds and power off for 3 seconds. When the electromagnetic block 95 is working, the electromagnetic block 95 generates a magnetic repulsive force on the permanent magnet block 94, thereby pushing the piston block 92 to move toward the air outlet pipe 99. At this time, the air inside the hollow cylinder body 91 is compressed and discharged through the air outlet pipe 99. When the electromagnetic block 95 is powered off, under the action of the non-magnetic spring 93, the piston block 92 begins to move back and reset. At this time, under the action of the pressure difference between the inside and outside of the hollow cylinder body 91, the air inside the external insulating mounting tube 71 is sucked into the hollow cylinder body 91. At the same time, the external cold air enters the insulating mounting tube 71 through the air intake hole 98, that is, intermittent air will be generated inside the insulating mounting tube 71. The air flows through the cable surface and the heat is quickly taken away by the air flow. When the cable enters the right detection box 5 after heat dissipation, each arc-shaped infrared temperature measuring probe 62 will detect the temperature of the cable. When there are defects such as micropores, bubbles, cracks, etc. inside the cable, the thermal resistance of the defective area increases due to air filling or structural damage, and the heat conduction efficiency is lower than that of the normal position. After the heat is dissipated, the internal defects of the cable insulation layer will cause local temperature hysteresis or abnormal accumulation. The control head 1 compares the temperature difference detected by each arc-shaped infrared temperature measuring probe 62. When the difference exceeds the threshold, the temperature generally exceeds 2°C, which indicates that there is a defect inside the cable insulation layer. The cable detected by the right detection box 5 is finally removed through the discharge pipe 11.

[0042] The air discharged through the air outlet pipe 99 will enter the hollow ring 101 and be ejected through each air jet hole 102. The ejected air flow will be blown to the surface of the cable, thereby removing dust and other impurities attached to the surface of the cable insulation layer as much as possible in advance to prevent them from affecting the accuracy of subsequent laser and other inspections.

[0043] The cable is heated at a constant temperature by the heating unit 8, so that the cable maintains a stable temperature when passing through the laser and capacitor detection, which can ensure the accuracy of the laser and capacitor detection. After the capacitor detection is completed, timely heat dissipation and the difference in heat dissipation capacity at the cable defect position can be used to facilitate the temperature measurement unit 6 to detect insulation defects. At the same time, the airflow generated during heat dissipation can remove dust and other impurities that affect the accuracy of laser detection, so that laser, capacitor and temperature detection complement each other. The composite detection method of laser, capacitor and temperature can greatly improve the comprehensiveness and accuracy of cable insulation defect detection.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A composite sensor for detecting cable insulation defects, comprising a control head (1) and two mounting plates (2), wherein the control head (1) is mounted on top of the mounting plates (2) on the same side, and characterized in that: Also includes: A left detection box (3) is installed between the two mounting plates (2), wherein a laser detection unit (4) is provided inside the left detection box (3), and the laser detection unit (4) is used to detect the outer diameter of the cable; A right detection box (5) is installed between the two mounting plates (2), and a temperature measuring unit (6) is provided inside the right detection box (5). The temperature measuring unit (6) is used to detect the temperature of the cable insulation layer; A capacitance detection unit (7) is provided between the left detection box (3) and the right detection box (5), and the left detection box (3) and the right detection box (5) are connected via the capacitance detection unit (7), and the capacitance detection unit (7) is used to detect the capacitance value of the cable insulation layer; A heating unit (8) is arranged on the side wall of the left detection box (3), and the cable passes through the heating unit (8) and enters the left detection box (3). The heating unit (8) is used to heat the cable at a constant temperature; A heat dissipation unit (9) is installed between the left detection box (3) and the right detection box (5), and the heat dissipation unit (9) is used to dissipate heat and cool the cable.

2. A composite sensor for detecting cable insulation defects according to claim 1, characterized in that: The laser detection unit (4) comprises two conical mounting sleeves (41) fixedly mounted inside the left detection box (3), and the two conical mounting sleeves (41) are symmetrical to each other, a plurality of laser lamps (42) are mounted on the inner side wall of one of the conical mounting sleeves (41), and a plurality of laser receivers (43) are mounted on the inner side wall of the other conical mounting sleeve (41), and the laser beams emitted by each of the laser lamps (42) are reflected to the laser receiver (43) through a cable, and the laser lamps (42) and the laser receiver (43) are both electrically connected to the control head (1).

3. The composite sensor for detecting cable insulation defects according to claim 1, characterized in that: The temperature measuring unit (6) includes a mounting ring (61) fixedly mounted inside the right detection box (5), a plurality of arc-shaped infrared temperature measuring probes (62) are mounted on the inner wall of the mounting ring (61), and each arc-shaped infrared temperature measuring probe (62) is evenly distributed on the inner side of the mounting ring (61), and each arc-shaped infrared temperature measuring probe (62) is electrically connected to the control head (1).

4. The composite sensor for detecting cable insulation defects according to claim 1, characterized in that: The capacitance detection unit (7) comprises an insulating mounting tube (71) fixedly mounted between the left detection box (3) and the right detection box (5), two electrode rings (72) being mounted inside the insulating mounting tube (71), and cables passing through the inner sides of the two electrode rings (72) in sequence, and the two electrode rings (72) being electrically connected to the control head (1).

5. The composite sensor for detecting cable insulation defects according to claim 4, characterized in that: The heating unit (8) includes a heat-insulating feed pipe (81) fixedly mounted on the side wall of the left detection box (3), and the heat-insulating feed pipe (81) is connected to the interior of the left detection box (3). An annular electric heater (82) electrically connected to the control head (1) is installed inside the heat-insulating feed pipe (81), and an electric cable passes through the interior of the annular electric heater (82) and enters the interior of the left detection box (3).

6. The composite sensor for detecting cable insulation defects according to claim 4, characterized in that: The heat dissipation unit (9) comprises a hollow cylinder (91) fixedly mounted between the left detection box (3) and the right detection box (5); a piston block (92) is slidably mounted inside the hollow cylinder (91); a non-magnetic spring (93) is mounted between the side wall of the piston block (92) and the hollow cylinder (91); a permanent magnet block (94) is mounted on the side wall of the hollow cylinder (91) away from the non-magnetic spring (93); an electromagnetic block (95) corresponding to the position of the permanent magnet block (94) is mounted inside the hollow cylinder (91); and an absorbent element is fixedly plugged into the side wall of the hollow cylinder (91). The air pipe (96) is provided with an air intake check valve (97) installed inside the air intake pipe (96). The air intake pipe (96) is connected to the insulating mounting pipe (71). An air intake hole (98) is provided on the wall of the insulating mounting pipe (71) away from the side of the air intake pipe (96). An air outlet pipe (99) is fixedly connected to the end of the hollow cylinder (91) away from the electromagnetic block (95), and an air outlet check valve (910) is installed inside the air outlet pipe (99). A cleaning mechanism (10) is installed on the air outlet pipe (99). The electromagnetic block (95) is electrically connected to the control head (1).

7. A composite sensor for detecting cable insulation defects according to claim 6, characterized in that: The cleaning mechanism (10) comprises a hollow ring (101) fixedly mounted on the end of the heat-insulating feed pipe (81), the inner ring wall of the hollow ring (101) being conical, and a plurality of air injection holes (102) being provided on the inner wall of the hollow ring (101), and the hollow ring (101) being connected to the air outlet pipe (99).

8. The composite sensor for detecting cable insulation defects according to claim 5, characterized in that: A discharge pipe (11) is inserted into the side wall of the right detection box (5), and a plurality of support rings (12) are installed inside the thermal insulation feed pipe (81), the insulating installation pipe (71) and the discharge pipe (11), and a ceramic ring (13) is installed on the inner wall of each support ring (12), and the cable slides through the interior of each ceramic ring (13).

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