A special cable insulation shielding volume resistivity detection device and method

Abstract

The present invention discloses a special cable insulation shield volume resistivity detection device and method, which relates to a cable testing technology field, including a shell, the shell is an openable and closable box, two connecting seats are arranged in the shell, a first support and a second support are arranged between the two connecting seats, the first support and the second support are both provided with electric chucks, and a thickness measuring component is also arranged in the second support; two glue spray rods are arranged on one side between the two electric chucks, and a liquid supply box is also arranged in the shell; the present invention has multiple functions such as glue spraying, cutting thickness measurement, and resistance measurement in one device, and can complete multiple test tasks on the same device, simplifying the test process and saving time and cost. At the same time, the structural design of the device is flexible, and can be adjusted and expanded as needed to meet the cable testing needs of different specifications and requirements.

Description

Technical Field

[0001] The invention relates to the technical field of cable testing, in particular to a device and method for detecting the volume resistivity of a special cable insulation shield. Background Art

[0002] Cables are widely used in power systems, communication systems, automotive electrical systems and other fields. The volume resistivity of the insulation shield is one of the important indicators for measuring the quality and performance of cables. The cable insulation shield volume resistivity detection device is mainly used by cable manufacturers, power operating companies, communication operators and other units to carry out cable quality inspection and maintenance. It can also be used in scenarios such as cable installation, maintenance and accident investigation to ensure the safe and reliable operation of the cable. The volume resistivity of the insulation shield of the cable directly affects the insulation and conductivity of the cable, and plays a vital role in the stability and reliability of power transmission and communication transmission.

[0003] The common method for testing the volume resistance of insulation shielding is to cut a certain length of cable and make two circles of conductive electrodes outside the cable insulation layer. The resistance of the cable insulation layer is detected by testing the resistivity between the two conductive electrodes, and the volume resistivity of the insulation shielding is calculated from the thickness, diameter and electrode spacing of the insulation layer. Manual testing requires a lot of manpower and material resources, and the test efficiency is low, which cannot meet the needs of large-scale and rapid cable testing.

[0004] In the prior art, there is a device for detecting the volume resistivity of cable insulation shielding, which automatically applies conductive gel on the surface of the cable to form a conductive electrode by clamping one end of the cable and rotating the cable. However, the clamping device may not be able to effectively fix thinner and softer cables, causing the cable to shake and twist during rotation, affecting the spraying position and uniformity of the conductive gel. In addition, the finished sample needs to be further processed and transferred to an oven for heating before the resistivity test can be performed.

[0005] Therefore, the existing technology has the disadvantages of insufficient clamping and fixing ability, unscientific glue spraying method, high operation technology requirements, lack of automatic adjustment function, etc. in solving the problem of insulation shielding volume resistivity. In order to improve the accuracy and efficiency of cable insulation shielding volume resistivity detection, it is necessary to provide a special cable insulation shielding volume resistivity detection device and method to solve the problems raised in the above background technology. Summary of the invention

[0006] To achieve the above object, the present invention provides the following technical solution: a special cable insulation shield volume resistivity detection device, characterized in that it includes a shell, the shell is an openable and closable box, two connecting seats are arranged in the shell, a first support and a second support are arranged between the two connecting seats, the first support and the second support are both provided with electric chucks, and the second support is also provided with a thickness measuring component;

[0007] Two glue spraying rods are arranged on one side between the two electric chucks, and a liquid supply tank is also arranged in the shell;

[0008] A guide rail is fixed on one side of the liquid supply box, two sliders are slidably provided on the guide rail, two glue spray rods are fixed on the sliders, and the glue spray rods are retractable structures;

[0009] An adjusting screw is rotatably connected to the middle of the guide rail, a lifting sleeve is threadedly connected to the adjusting screw, two connecting rods are symmetrically hinged in the lifting sleeve, and the two connecting rods are respectively hinged to two sliders;

[0010] A conductive wire is fixed above the glue spraying rod.

[0011] Further, as a preference, two sliding rods are connected between the two connecting seats, and the first support and the second support are slidably connected to the sliding rods.

[0012] Furthermore, preferably, a screw rod is provided between the two sliding rods, the screw rod is rotatably connected to the two connecting seats, the threads of the screw rod are opposite to each other at the front and rear sections separated by the center, and the first support and the second support are respectively threadedly connected to the two sections of the screw rod.

[0013] Further, as a preference, both the first support and the second support are provided with a driving motor, and the driving motor can drive the corresponding electric chuck to rotate.

[0014] Further, as a preference, the liquid supply box is provided with a liquid supply pump capable of supplying liquid to the glue spray rod.

[0015] Further, as a preference, an air outlet slot is fixed below the glue spray rod, the air outlet slot is aligned with the glue spray rod, and one end of the air outlet slot is connected to a hot air blower.

[0016] Further, as a preference, the thickness measuring assembly includes a base, the base is fixed on the second support, a fixing ring concentric with the electric chuck on the second support is fixed on the base, a plurality of conductive knives are distributed circumferentially on the fixing ring, and the conductive knives are slidably connected to the fixing ring.

[0017] Further, as a preference, one end of the conductive knife away from the center of the fixed ring penetrates outside the fixed ring, a rotating ring is rotatably provided outside the fixed ring, a plurality of arc grooves are circumferentially distributed in the rotating ring, and each conductive knife is slidably connected to the arc groove through a sliding pin;

[0018] A telescopic cylinder is hinged between the swivel and the base.

[0019] A method for detecting the volume resistivity of special cable insulation shielding, comprising:

[0020] S1. Installation and adjustment;

[0021] S1-1, passing the cable from the first support through the corresponding electric chuck and into the electric chuck in the second support, clamping the cable by the two electric chucks, and the electric chuck records the diameter D of the clamped cable;

[0022] S1-2, by rotating the screw rod, the first support and the second support can be moved closer or farther away, so that the electric chuck is tightened and straightened;

[0023] S1-3. Adjust the position of the glue spray rod, evenly adjust the distance between the two glue spray rods, record the distance L between the two glue spray rods, and adjust the extension length of the glue spray rod according to the cable diameter so that it is aligned with the cable surface and the conductive wire above the glue spray rod is close to the cable;

[0024] S1-4, adjust the telescopic cylinder in the thickness measuring assembly so that the initial position of the conductive knife is the diameter D of the cable;

[0025] S1-5. Connect the cable to the power supply;

[0026] S2, glue coating and thickness measurement;

[0027] S2-1, start the driving motor to make the two electric chucks rotate synchronously, driving the cable to rotate;

[0028] S2-2, start the liquid supply pump, so that the glue spraying rod starts to spray silver paint on the cable surface to form an electrode;

[0029] S2-3. While the cable is rotating, adjust the telescopic cylinder to drive the conductive knife to retract and start cutting the cable skin. When the conductive knife contacts the cable core, the conductive knife is energized and the cutting depth, i.e. the thickness T of the insulating shielding layer, is recorded.

[0030] S3, resistance measurement;

[0031] S3-1, close the housing, and preheat the temperature inside the housing to and maintain it for minutes by using a hot air blower;

[0032] S3-2, use a measurement circuit with a power of 100mW to measure the resistance between the two conductive wires and record the resistance value R;

[0033] S4, volume resistivity calculation;

[0034] Volume resistivity calculation formula

[0035] Where: ρ is the volume resistivity, and the potential is in ohm-meter;

[0036] R is the resistance between the conductive wires, in ohms;

[0037] D is the outer diameter of the cable, in meters;

[0038] T is the insulation shield thickness in meters;

[0039] L is the distance between potential electrodes, in meters;

[0040] The measured resistance value R, cable outer diameter D, insulation shield thickness T and potential electrode spacing L are substituted into the formula to calculate the volume resistivity ρ.

[0041] Further, as a preference, step S2-3 also includes step S2-3-1, specifically:

[0042] Among the multiple conductive knives of the thickness measuring assembly, the cutting depth of each conductive knife when it contacts the cable core is recorded as t1, t2, t3...t n , the thickness of the insulation shielding layer:

[0043]

[0044] Where: t is the cutting depth of a single conductive knife, in meters;

[0045] n is the number of conductive blades;

[0046] The average thickness of the insulating shield is thereby determined.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] By tightening and straightening the cable, it can be ensured that the cable maintains a stable rotation state during the test, avoiding uneven rotation caused by the cable itself being loose or deformed, and ensuring that the spraying position of the glue spray rod on the cable surface is uniform, thereby improving the accuracy and reliability of the test results.

[0049] The application of the automatic components such as the driving motor and the liquid supply pump in the present invention realizes the automatic control and operation of the electric chuck, the glue spraying rod and other components, improves the convenience and efficiency of the operation, and ensures the accuracy and consistency of the test results.

[0050] The present invention integrates multiple functions such as glue spraying, cutting thickness measurement, and resistance measurement, and can complete multiple test tasks on the same device, simplifying the test process and saving time and cost; at the same time, the structural design of the device is flexible and can be adjusted and expanded as needed to meet the cable testing needs of different specifications and requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a structural schematic diagram of a special cable insulation shield volume resistivity detection device;

[0052] Figure 2 It is a schematic diagram of the structure of the first support and the second support in the present invention;

[0053] Figure 3 It is a structural schematic diagram of the guide rail in the present invention;

[0054] Figure 4 It is a structural schematic diagram of the thickness measuring component in the present invention;

[0055] Figure 5 It is a structural schematic diagram of the glue spraying rod in the present invention;

[0056] In the figure: 1. outer shell; 2. connecting seat; 21. sliding rod; 22. screw rod; 3. first support; 4. second support; 5. electric chuck; 51. driving motor; 6. thickness measuring assembly; 61. base; 62. fixing ring; 63. conductive knife; 64. swivel; 65. arc groove; 66. telescopic cylinder; 7. glue spray rod; 71. liquid supply pump; 72. conductive wire; 8. liquid supply box; 9. guide rail; 10. slider; 11. adjusting screw; 12. lifting sleeve; 13. connecting rod; 14. air outlet slot; 15. hot air blower. DETAILED DESCRIPTION

[0057] See also Figure 1-Figure 5 In an embodiment of the present invention, a special cable insulation shield volume resistivity detection device includes a shell 1, the shell 1 is an openable and closable box, two connecting seats 2 are arranged in the shell 1, a first support 3 and a second support 4 are arranged between the two connecting seats 2, the first support 3 and the second support 4 are both provided with an electric chuck 5, and the second support 4 is also provided with a thickness measuring component 6;

[0058] Two glue spraying rods 7 are provided on one side between the two electric chucks 5, and a liquid supply tank 8 is also provided in the housing 1. The cable to be tested passes through the corresponding electric chuck 5 from the first support 3 and penetrates into the electric chuck 5 in the second support 4. The cable is clamped by the two electric chucks 5, and the glue spraying rod 7 can spray silver paint in the cable, thereby testing the conductivity between the silver paints.

[0059] See also Figure 2In this embodiment, two sliding rods 21 are connected between the two connecting seats 2, and the first support 3 and the second support 4 are slidably connected to the sliding rods 21.

[0060] In this embodiment, a screw rod 22 is provided between the two slide rods 21, and the screw rod 22 is rotatably connected to the two connecting seats 2. The screw rod 22 has two opposite threads at the front and rear sections separated by the center, and the first support 3 and the second support 4 are respectively threadedly connected to the two sections of the screw rod 22. One end of the screw rod 22 passes through one of the connecting seats 2 and is connected to a crank. By rotating the screw rod 22, the first support 3 and the second support 4 can be moved closer or farther away. When the cable is clamped by the two electric chucks 5, the cable can be tightened and straightened by moving the first support 3 and the second support 4 away from each other, ensuring that the glue spray rod 7 is sprayed accurately on the cable surface.

[0061] In this embodiment, a driving motor 51 is provided in each of the first support 3 and the second support 4, and the driving motor 51 can drive the corresponding electric chuck 5 to rotate. When the two electric chucks 5 rotate in the same direction of the cable, the glue spray rod 7 can spray the outer surface of the cable in an annular direction, and since the two ends of the cable rotate synchronously, the cable can be ensured to rotate evenly.

[0062] See also Figure 3 In this embodiment, a guide rail 9 is fixed on one side of the liquid supply box 8, and two sliders 10 are slidably provided on the guide rail 9. The two glue spray rods 7 are fixed on the sliders 10, and the glue spray rods 7 are a retractable structure.

[0063] In this embodiment, the middle of the guide rail 9 is rotatably connected with an adjusting screw 11, a lifting sleeve 12 is threadedly connected to the adjusting screw 11, two connecting rods 13 are symmetrically hinged to the lifting sleeve 12, and the two connecting rods 13 are respectively hinged to the two sliders 10. That is, by rotating the adjusting screw 11, the lifting sleeve 12 can be raised and lowered, and the two sliders 10 can be pushed to slide synchronously in the direction of approaching or moving away, so that the distance between the two glue spraying rods 7 can be evenly adjusted to evenly spray silver paint on the cable.

[0064] In this embodiment, the liquid supply box 8 is provided with a liquid supply pump 71 capable of supplying liquid to the glue spray rod 7 .

[0065] In this embodiment, an air outlet slot 14 is fixed below the glue spray rod 7 , the air outlet slot 14 is aligned with the glue spray rod 7 , and one end of the air outlet slot 14 is connected to a hot air blower 15 .

[0066] See also Figure 4In this embodiment, the thickness measuring component 6 includes a base 61, and the base 61 is fixed on the second support 4. A fixing ring 62 which is concentric with the electric chuck 5 on the second support 4 is fixed on the base 61. A plurality of conductive knives 63 are distributed circumferentially on the fixing ring 62, and the conductive knives 63 are slidably connected to the fixing ring 62.

[0067] In this embodiment, one end of the conductive knife 63 away from the center of the fixed ring 62 penetrates outside the fixed ring 62, and a rotating ring 64 is rotatably provided outside the fixed ring 62. A plurality of arc grooves 65 are circumferentially distributed in the rotating ring 64, and each conductive knife 63 is slidably connected to the arc groove 65 through a sliding pin.

[0068] A telescopic cylinder 66 is hinged between the rotating ring 64 and the base 61. That is, the rotating ring 64 can be driven to rotate by the telescopic cylinder 66 to change the position of the sliding pin in the arc groove 65, so that each conductive knife 63 is synchronously close to or away from the center of the fixed ring 62; when the cable rotates, the conductive knife 63 slides in the direction close to the center of the fixed ring 62, and can cut the cable skin; and by supplying electricity to the cable, the conductive knife 63 can conduct electricity when it contacts the cable core, so as to record the cutting depth of the conductive knife 63.

[0069] See also Figure 5 In this embodiment, a conductive wire 72 is fixed above the glue spray rod 7. The conductive wire 72 is made of elastic material. When the cable is fixed between the two electric chucks 5, the conductive wire 72 fits on the cable and can energize the electrode formed by the silver paint on the cable.

[0070] A method for detecting volume resistivity of special cable insulation shielding

[0071] S1. Installation and adjustment;

[0072] S1-1, passing the cable from the first support 3 through the corresponding electric chuck 5 and into the electric chuck 5 in the second support 4, clamping the cable by the two electric chucks 5, and the electric chuck 5 records the diameter D of the clamped cable;

[0073] S1-2, by rotating the screw rod 22, the first support 3 and the second support 4 can be moved closer or farther away, so that the electric chuck 5 is tightened and straightened;

[0074] S1-3, adjust the position of the glue spray rod 7, evenly adjust the distance between the two glue spray rods 7, record the distance L between the two glue spray rods 7, and adjust the extension length of the glue spray rod 7 according to the cable diameter so that it is aligned with the cable surface, and the conductive wire 72 above the glue spray rod 7 is close to the cable;

[0075] S1-4, adjusting the telescopic cylinder 66 in the thickness measuring assembly 6 so that the initial position of the conductive knife 63 is the diameter D of the cable;

[0076] S1-5. Connect the cable to the power supply.

[0077] S2, glue coating and measurement;

[0078] S2-1, start the driving motor 51 to make the two electric chucks 5 rotate synchronously, driving the cable to rotate;

[0079] S2-2, start the liquid supply pump 71, so that the glue spraying rod 7 starts to spray silver paint on the cable surface to form an electrode;

[0080] S2-3, while the cable is rotating, adjust the telescopic cylinder 66 to drive the conductive knife 63 to retract and start cutting the cable skin. When the conductive knife 63 contacts the cable core, the conductive knife 63 is energized and the cutting depth, i.e., the thickness T of the insulating shielding layer, is recorded;

[0081] S3, resistance measurement;

[0082] S3-1, close the housing 1, and use the hot air blower 15 to preheat the temperature inside the housing 1 to and maintain it for 30 minutes.

[0083] S3-2, using a measuring circuit with a power of 100 mW to measure the resistance between the two conductive wires 72, and recording the resistance value R;

[0084] S4, volume resistivity calculation;

[0085] Volume resistivity calculation formula ,

[0086] Where: ρ is the volume resistivity, and the potential is in ohm-meter;

[0087] R is the resistance between the conductive wires, in ohms;

[0088] D is the outer diameter of the cable, in meters;

[0089] T is the insulation shield thickness in meters;

[0090] L is the distance between potential electrodes, in meters;

[0091] The measured resistance value R, cable outer diameter D, insulation shield thickness T and potential electrode spacing L are substituted into the formula to calculate the volume resistivity ρ.

[0092] Wherein, step S2-3 also includes step S2-3-1, which is specifically:

[0093] Among the multiple conductive blades 63 of the thickness measuring assembly 6, the cutting depth of each conductive blade 63 when it contacts the cable core is recorded as t1, t2, t3, ..., t n , the thickness of the insulation shielding layer:

[0094]

[0095] Where: t is the cutting depth of a single conductive knife, in meters;

[0096] n is the number of conductive blades;

[0097] This reduces the error in detecting the thickness of the insulation shielding layer when the cable cross section is uneven (non-circular).

[0098] What has been described above is only a preferred method of using the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A special cable insulation shield volume resistivity detection device, characterized in that: The invention comprises a shell (1), wherein the shell (1) is an openable and closable box, wherein two connecting seats (2) are arranged inside the shell (1), a first support seat (3) and a second support seat (4) are arranged between the two connecting seats (2), an electric chuck (5) is arranged in each of the first support seat (3) and the second support seat (4), and a thickness measuring component (6) is also arranged on the second support seat (4); Two glue spraying rods (7) are provided on one side between the two electric chucks (5), and a liquid supply tank (8) is also provided in the housing (1); A guide rail (9) is fixed on one side of the liquid supply box (8), two sliders (10) are slidably provided on the guide rail (9), and the two glue spray rods (7) are fixed on the sliders (10), and the glue spray rods (7) are retractable structures; An adjusting screw (11) is rotatably connected to the middle of the guide rail (9), a lifting sleeve (12) is threadedly connected to the adjusting screw (11), two connecting rods (13) are symmetrically hinged in the lifting sleeve (12), and the two connecting rods (13) are respectively hinged to the two sliders (10); A conductive wire (72) is fixed above the glue spraying rod (7); The thickness measuring assembly (6) comprises a base (61), the base (61) being fixed on the second support (4), a fixing ring (62) being fixed on the base (61) and being concentric with the electric chuck (5) on the second support (4), a plurality of conductive knives (63) being distributed around the circumference of the fixing ring (62), and the conductive knives (63) being slidably connected to the fixing ring (62); One end of the conductive knife (63) away from the center of the fixed ring (62) penetrates outside the fixed ring (62); a rotating ring (64) is rotatably provided outside the fixed ring (62); a plurality of arc-shaped grooves (65) are circumferentially distributed in the rotating ring (64); each conductive knife (63) is slidably connected to the arc-shaped groove (65) via a sliding pin; A telescopic cylinder (66) is hingedly connected between the rotating ring (64) and the base (61).

2. A special cable insulation shield volume resistivity detection device according to claim 1, characterized in that: Two sliding rods (21) are connected between the two connecting seats (2), and the first support seat (3) and the second support seat (4) are slidably connected to the sliding rods (21).

3. A special cable insulation shield volume resistivity detection device according to claim 2, characterized in that: A screw rod (22) is provided between the two sliding rods (21), and the screw rod (22) is rotatably connected to the two connecting seats (2). The screw rod (22) has two opposite threads at the front and rear ends separated by the center, and the first support seat (3) and the second support seat (4) are respectively threadedly connected to the two ends of the screw rod (22).

4. A special cable insulation shielding volume resistivity detection device according to claim 3, characterized in that: A driving motor (51) is provided in each of the first support (3) and the second support (4), and the driving motor (51) is capable of driving the corresponding electric chuck (5) to rotate.

5. A special cable insulation shielding volume resistivity detection device according to claim 4, characterized in that: The liquid supply box (8) is provided with a liquid supply pump (71) capable of supplying liquid to the glue spraying rod (7).

6. A special cable insulation shield volume resistivity detection device according to claim 5, characterized in that: An air outlet slot (14) is fixed below the glue spray rod (7), the air outlet slot (14) is aligned with the glue spray rod (7), and one end of the air outlet slot (14) is connected to a hot air blower (15).

7. A method for detecting the volume resistivity of special cable insulation shielding, which uses a device for detecting the volume resistivity of special cable insulation shielding as claimed in claim 6, characterized in that: include: S1. Installation and adjustment; S1-1, passing the cable from the first support (3) through the corresponding electric chuck (5) and into the electric chuck (5) in the second support (4), clamping the cable by the two electric chucks (5), and the electric chuck (5) records the diameter D of the clamped cable; S1-2, by rotating the screw rod (22), the first support (3) and the second support (4) can be moved closer or farther away, so that the electric chuck (5) is tightened and straightened; S1-3, adjusting the position of the glue spray rod (7), evenly adjusting the distance between the two glue spray rods (7), recording the distance L between the two glue spray rods (7), and adjusting the extension length of the glue spray rod (7) according to the cable diameter so that the glue spray rod (7) is aligned with the cable surface and the conductive wire (72) above the glue spray rod (7) is close to the cable; S1-4, adjusting the telescopic cylinder (66) in the thickness measuring assembly (6) so that the initial position of the conductive knife (63) is the diameter D of the cable; S1-5. Connect the cable to the power supply; S2, glue coating and thickness measurement; S2-1, starting the driving motor (51) to make the two electric chucks (5) rotate synchronously, thereby driving the cable to rotate; S2-2, starting the liquid supply pump (71) so that the glue spraying rod (7) starts to spray silver paint on the surface of the cable to form an electrode; S2-3, while the cable is rotating, the telescopic cylinder (66) is adjusted to drive the conductive knife (63) to retract and start cutting the cable skin. When the conductive knife (63) contacts the cable core, the conductive knife (63) is energized and the cutting depth, i.e., the thickness T of the insulating shielding layer, is recorded; S3, resistance measurement; S3-1, closing the housing (1), and preheating the temperature inside the housing (1) to a certain temperature using a hot air blower (15) and maintaining the temperature for 30 minutes; S3-2, using a measuring circuit with a power of 100 mW to measure the resistance between the two conductive threads (72), and recording the resistance value R; S4, volume resistivity calculation; Volume resistivity calculation formula , Where: ρ is the volume resistivity, and the potential is in ohm-meter; R is the resistance between the conductive wires, in ohms; D is the outer diameter of the cable, in meters; T is the insulation shield thickness in meters; L is the distance between potential electrodes, in meters; The measured resistance value R, cable outer diameter D, insulation shield thickness T and potential electrode spacing L are substituted into the formula to calculate the volume resistivity ρ.

8. A method for detecting volume resistivity of special cable insulation shielding according to claim 7, characterized in that: Step S2-3 also includes step S2-3-1, which is specifically: Among the multiple conductive knives (63) of the thickness measuring assembly (6), the cutting depth of each conductive knife (63) when it contacts the cable core is recorded as t1, t2, t3, ..., t n , the thickness of the insulation shielding layer: The average thickness of the insulating shield is thereby determined.

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