Large-section aluminum conductor direct-current resistance measuring clamp, using method and measuring device

Abstract

The invention discloses a large-section aluminum conductor direct-current resistance measuring clamp, a using method and a measuring device, and belongs to the technical field of cable manufacturing, and the large-section aluminum conductor direct-current resistance measuring clamp is characterized by comprising a plurality of sections of rotating arms, a plurality of conductor clamps and a plurality of rotating mechanisms. The adjacent rotating arms are rotationally connected to form a measuring table for supporting a conductor; the conductor clamps are respectively arranged on the top surfaces of the corresponding rotating arms and are used for clamping and fixing conductors; the rotating mechanism is arranged between the adjacent rotating arms and is used for driving the rotating arms to rotate relatively, so that the measuring table is bent, the linear distance between the two ends of the conductor is shortened, and the influence of an overlong copper wire on a measuring result is eliminated.

Description

Technical Field

[0001] This invention relates to a DC resistance measuring fixture for large cross-section aluminum conductors, its usage method, and a measuring device, belonging to the field of cable manufacturing technology. Background Technology

[0002] Currently, portable bridge devices are commonly used for field measurement of the DC resistance of large-section aluminum conductors, based on the direct DC current-voltage drop method. During operation, the aluminum conductor is elevated, and soft copper wire is wound around its surface to form current electrodes (C1, C2) and potential electrodes (P1, P2). Current flows into C1 and out through C2. The potential electrodes collect the voltage signal, and the resistance value is calculated using Ohm's law. This method relies on the soft copper wire connecting the electrodes, and the portability of the equipment meets the needs of field measurement.

[0003] According to the national standard GB / T3048.4 requirements for the length of DC resistance test specimens for large cross-section aluminum conductors, the effective length of the specimen between the potential electrodes should be: 3m when the nominal cross-sectional area of ​​the conductor is 185mm2 or less, and 5m when the nominal cross-sectional area of ​​the conductor is above 185mm2; in case of dispute, 5m when the nominal cross-sectional area of ​​the conductor is 185mm2 or less, and 10m when the nominal cross-sectional area of ​​the conductor is above 185mm2.

[0004] Since the length of large-section aluminum conductor samples is usually several meters, the distance between the electrodes at both ends of the conductor is too large. The length of the soft copper wire used when connecting the bridge increases accordingly. The resistance of the copper wire itself cannot be ignored, which will directly affect the voltage drop, causing the measurement results to deviate from the true value and affecting the measurement accuracy. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing a large-section aluminum conductor DC resistance measuring fixture, its usage method, and a measuring device. By bending the conductor, the straight-line distance between the two ends of the conductor is shortened, i.e., the distance between the electrodes at both ends of the conductor is shortened, thus eliminating the influence of excessively long copper wire on the measurement results.

[0006] The technical solution of the present invention is as follows: The first objective of this invention is to provide a DC resistance measuring fixture for large-section aluminum conductors, comprising: several rotating arms, several conductor clamps, and several rotating mechanisms. Adjacent rotating arms are rotatably connected to form a measuring platform for supporting the conductor; the conductor clamps are respectively mounted on the top surface of the corresponding rotating arms for clamping and fixing the conductor; the rotating mechanisms are disposed between adjacent rotating arms for driving the rotating arms to rotate relative to each other, causing the measuring platform to bend, thereby shortening the straight-line distance between the two ends of the conductor.

[0007] In the above scheme, the two rotating arms can rotate relatively independently. The conductor is clamped by the conductor clamp and the rotating arm is driven to rotate by the rotating mechanism. The flexible measuring table formed by the rotating arm and the rotating mechanism shortens the straight distance between the two ends of the conductor and eliminates the influence of the resistance of the long copper wire itself on the measurement results.

[0008] Preferably, the conductor clamp includes: a clamp base, an adjusting bolt assembly, a first clamping block, and a second clamping block. The top surface of the clamp base has an adjusting cavity with an open top, the adjusting cavity being enclosed by front, rear, left, and right cavity walls; the adjusting bolt assembly is disposed within the adjusting cavity and penetrates the front and rear cavity walls; the first clamping block and the second clamping block are arranged opposite to each other, slidingly engaging with the left and right cavity walls of the adjusting cavity respectively, and are threadedly connected to the adjusting bolt assembly respectively; by rotating the adjusting bolt assembly, the first clamping block and the second clamping block are driven to move linearly along the left and right cavity walls respectively, enabling precise displacement of the clamping blocks and achieving clamping or releasing of the conductor.

[0009] Preferably, the adjusting bolt assembly includes: an adjusting screw and an adjusting sleeve. The adjusting screw consists of a stepped shaft structure formed by connecting a large-diameter section and a small-diameter section; the large-diameter section is provided with external threads, and the small-diameter section is a smooth rod; the first clamping block is threadedly connected to the large-diameter section of the adjusting screw; the adjusting sleeve is sleeved outside the small-diameter section of the adjusting screw, and its tail end is limited by the stepped surface of the adjusting screw; the adjusting sleeve is provided with external threads and is threadedly connected to the second clamping block.

[0010] During conductor clamping adjustment: rotating the adjusting sleeve drives the second clamping block, which is threaded to it, to move linearly along the left and right cavity walls; rotating the adjusting screw drives the first clamping block, which is threaded to it, to move linearly along the left and right cavity walls. Since the adjusting sleeve is fitted onto the small-diameter section of the adjusting screw, both can rotate independently without interference. The positions of the two clamping blocks can be adjusted independently, ensuring that the conductor axis coincides with the rotation center of the corresponding rotating arm. This results in more even force distribution on the conductor during bending, preventing conductor breakage and fracture due to excessive tension on one side, thus ensuring sample integrity.

[0011] Preferably, the head of the adjusting screw sleeve is provided with a large disc for easy manual operation, and the end of the small-diameter section of the adjusting screw is provided with a hexagonal head for easy application of force by tools.

[0012] Preferably, the conductor clamp further includes a strain gauge force sensor, which is disposed on the clamping surface of the first clamping block or the second clamping block for real-time detection of clamping force.

[0013] Preferably, the clamping surfaces of the first clamping block and the second clamping block are respectively provided with detachable pads, which can be matched with conductors of different specifications, and strain gauge force sensors are set on the pads.

[0014] When the rotating arm bends, the sensors inside the pad continuously and accurately monitor the clamping pressure applied to the conductor and transmit this data in real time as an electrical signal to the controller (or computer). Operators can then adjust the output force of the rotating arm (controlling the rotation angle) based on this real-time data, thereby achieving intelligent control of the conductor bending force. This not only ensures the consistency and high quality of the rotating arm's bending arc, preventing conductor surface damage or internal structural deformation due to pressure overload, but also greatly improves the safety of the testing process and the reliability of the measurement results.

[0015] Preferably, the strain gauge force sensor is communicatively connected to a display so as to view the bending stress of the conductor at the corresponding position.

[0016] Preferably, two adjacent rotating arms are connected by overlapping the upper and lower step surfaces and achieve relative rotation through a rotating mechanism.

[0017] Preferably, the rotating mechanism includes a stepper motor and an intermediate shaft. The intermediate shaft is fixedly connected to the upper step surface and rotatably connected to the corresponding lower step surface via bearings; the stepper motor is driven by a pair of meshing gears to drive the rotating arm belonging to the upper step surface to rotate, thereby realizing the bending deformation of the measuring platform.

[0018] The stepper motor drives the rotating arm through a gear pair and can precisely control the rotation direction and angle. Furthermore, the stepper motor provides a mechanical self-locking function, allowing the rotating arm to maintain the set rotation angle, exhibiting extremely high stability and safety. It will not move due to external loads, keeping the test bench in the set bending posture.

[0019] Preferably, it also includes a controller, which is communicatively connected to the strain gauge force sensor and each rotating mechanism, for collecting clamping force data and controlling the rotation angle of the rotating arm.

[0020] The second objective of this invention is to provide a method for using a DC resistance measuring fixture for large cross-section aluminum conductors, comprising the following steps: Insert the conductor into the conductor clamp and fix it in place. Adjust the position of the conductor by adjusting the bolt assembly so that the conductor axis coincides with the rotation center of the corresponding rotating arm. Start the rotation mechanism to drive the measuring stage to retract symmetrically inward; Based on the clamping force data fed back by the strain gauge force sensor, the conductor is bent to the minimum allowable diameter; According to national standards, appropriate points are selected at both ends of the conductor, and soft copper wire is used as electrodes to complete the resistance measurement.

[0021] The third objective of this invention is to provide a DC resistance measuring device for large cross-section aluminum conductors, including the aforementioned measuring fixture.

[0022] This invention uses mechanical transmission to bend the conductor, replacing long-distance soft copper wire connections and reducing contact resistance; it also uses a sensor to provide real-time feedback of the clamping force, ensuring stable measurement during DC resistance measurement and improving mechanical stability. Attached Figure Description

[0023] Figure 1 This is a side view of the measuring fixture of the present invention; Figure 2 This is a top view of the measuring fixture of the present invention; Figure 3 This is a diagram showing the usage state of the measuring fixture of the present invention; Figure 4 This is a schematic diagram of the conductor clamp of the present invention; Figure 5 for Figure 4 Top view; Figure 6 This is a schematic diagram of the adjusting bolt assembly in the conductor clamp of the present invention; Figure 7 for Figure 6 Exploded view; In the figure: 1. Rotating arm; 2. Conductor clamp; 3. Rotating mechanism; 4. Clamp base; 5. Adjusting bolt assembly; 6. First clamping block; 7. Second clamping block; 8. Adjusting cavity; 9. Adjusting screw; 10. Large diameter section; 11. Small diameter section; 12. Large disc; 13. Hexagonal head; 14. Pad; 15. Conductor; 16. Detailed Implementation

[0024] Example 1 A large-section aluminum conductor DC resistance measuring fixture, such as Figure 1-3 As shown, it includes: several rotating arms 1 (the middle rotating arm serves as the central base), several conductor clamps 2, and several rotating mechanisms 3. Adjacent rotating arms are rotatably connected to form a measuring platform for supporting the conductor; the conductor clamps are respectively installed on the top surface of the corresponding rotating arms for clamping and fixing the conductor; the rotating mechanisms are arranged between adjacent rotating arms for driving the rotating arms to rotate relative to each other, causing the measuring platform to bend, thereby shortening the straight-line distance between the two ends of the conductor.

[0025] Conductor clamp 2, such as Figure 4-5 As shown, it includes: a clamp base 4, an adjusting bolt assembly 5, a first clamping block 6, and a second clamping block 7. The top surface of the clamp base is provided with an adjusting cavity 8 with an open top, which is surrounded by front, rear, left, and right cavity walls; the adjusting bolt assembly is set in the adjusting cavity and passes through the front and rear cavity walls; the first clamping block and the second clamping block are arranged opposite to each other and slide in cooperation with the left and right cavity walls of the adjusting cavity, respectively.

[0026] Adjusting bolt assembly 5, such as Figure 6-7As shown, it includes: an adjusting screw 9 and an adjusting sleeve 10. The adjusting screw consists of a stepped shaft structure formed by connecting a large-diameter section 11 and a small-diameter section 12; the large-diameter section has external threads, and the small-diameter section is a smooth rod. The first clamping block is threadedly connected to the large-diameter section of the adjusting screw; the adjusting sleeve is fitted outside the small-diameter section of the adjusting screw, and its tail end is limited by the stepped surface of the adjusting screw; the adjusting sleeve has external threads and is threadedly connected to the second clamping block. By rotating the adjusting sleeve, the second clamping block threaded to it is driven to move linearly along the left and right cavity walls; by rotating the adjusting screw, the first clamping block threaded to it is driven to move linearly along the left and right cavity walls. The positions of the two clamping blocks can be adjusted independently to ensure that the conductor axis coincides with the rotation center of the corresponding rotating arm.

[0027] The head of the adjusting screw sleeve is provided with a large disc 13 for easy manual operation, and the end of the small diameter section of the adjusting screw is provided with a hexagonal head 14 for easy application of force by tools.

[0028] The clamping surfaces of the first and second clamping blocks are each equipped with detachable pads 15, which can be matched with conductors of different specifications. Each pad is equipped with a strain gauge force sensor, which communicates with a display for real-time detection of the clamping force.

[0029] Two adjacent rotating arms are connected by overlapping upper and lower step surfaces and achieve relative rotation through a rotating mechanism. The rotating mechanism includes a stepper motor and an intermediate shaft. The intermediate shaft is fixedly connected to the upper step surface and rotatably connected to the corresponding lower step surface through bearings; the stepper motor is driven by a pair of meshing gears to drive the rotating arm belonging to the upper step surface to rotate, thereby achieving the bending deformation of the measuring platform.

[0030] The controller can be a PLC controller, which communicates with strain gauge force sensors to collect clamping force data, and communicates with stepper motors to control the rotation angle of the rotating arm.

[0031] Example 2 A method for using a DC resistance measuring fixture for large cross-section aluminum conductors: Insert the conductor into the conductor fixture and fix it. Adjust the conductor position using the adjusting bolt assembly so that the conductor axis coincides with the rotation center of the corresponding rotating arm. Activate the rotating mechanism to drive the measuring stage to symmetrically retract inwards. Based on the clamping force data fed back by the strain gauge force sensor, bend the conductor to the minimum allowable diameter. According to national standards, select suitable points at both ends of the conductor and connect them using soft copper wire as electrodes to complete the resistance measurement.

[0032] Example 3 A DC resistance measuring device for large cross-section aluminum conductors includes the measuring fixture described in Example 1.

Claims

1. A DC resistance measuring fixture for a large cross-section aluminum conductor, characterized in that it comprises: Several rotating arms are rotatably connected to each other to form a measuring stage for supporting the conductor; Several conductor clamps are respectively installed on the top surface of the corresponding rotating arm for clamping and fixing conductors; Several rotating mechanisms are arranged between adjacent rotating arms to drive the rotating arms to rotate relative to each other, causing the measuring stage to bend, thereby shortening the straight-line distance between the two ends of the conductor.

2. The DC resistance measuring fixture for a large cross-section aluminum conductor according to claim 1, characterized in that, The conductor clamp includes: The fixture base has an adjustment cavity with an open top on its top surface, and the adjustment cavity is formed by front, rear, left and right cavity walls; An adjusting bolt assembly is disposed within the adjusting cavity and penetrates the front and rear cavity walls; The first clamping block and the second clamping block are arranged opposite to each other, and slide in contact with the left and right walls of the adjusting cavity, respectively, and are threadedly connected to the adjusting bolt assembly. By rotating the adjusting bolt assembly, the first clamping block and the second clamping block are driven to move linearly along the left and right cavity walls respectively, thereby clamping or releasing the conductor.

3. A DC resistance measuring fixture for a large cross-section aluminum conductor according to claim 2, characterized in that, The adjusting bolt assembly includes: The adjusting screw is a stepped shaft structure formed by connecting a large-diameter section and a small-diameter section; the large-diameter section is provided with external threads, the small-diameter section is a smooth rod, and the first clamping block is threadedly connected to the large-diameter section of the adjusting screw. An adjusting screw sleeve is fitted outside the small-diameter section of the adjusting screw, and its tail end is limited by the stepped surface of the adjusting screw; the adjusting screw sleeve is provided with external threads and is threadedly connected to the second clamping block.

4. A DC resistance measuring fixture for a large cross-section aluminum conductor according to claim 3, characterized in that, The conductor clamp also includes a strain gauge force sensor, which is disposed on the clamping surface of the first clamping block or the second clamping block and is used to detect the clamping force in real time.

5. A DC resistance measuring fixture for a large cross-section aluminum conductor according to claim 3, characterized in that, The head of the adjusting screw sleeve is provided with a large disc for easy manual operation, and the end of the small diameter section of the adjusting screw is provided with a hexagonal head for easy application of force by tools.

6. A DC resistance measuring fixture for a large cross-section aluminum conductor according to claim 1, characterized in that, Two adjacent rotating arms are connected by overlapping the upper and lower step surfaces and achieve relative rotation through a rotating mechanism.

7. A DC resistance measuring fixture for a large cross-section aluminum conductor according to claim 6, characterized in that, The rotating mechanism includes: Stepper motor; The intermediate shaft is fixedly connected to the upper step surface and rotatably connected to the corresponding lower step surface via a bearing. The stepper motor is connected to the intermediate shaft via a pair of meshing gears, driving the rotating arm of the upper step surface to rotate, thereby achieving the bending deformation of the measuring platform.

8. A DC resistance measuring fixture for a large cross-section aluminum conductor according to claim 4, characterized in that, It also includes a controller, which is communicatively connected to the strain gauge force sensor and each rotating mechanism, and is used to collect clamping force data and control the rotation angle of the rotating arm.

9. The method of using the measuring fixture as described in any one of claims 1-8, characterized in that, Includes the following steps: Insert the conductor into the conductor clamp and fix it in place. Adjust the position of the conductor by adjusting the bolt assembly so that the conductor axis coincides with the rotation center of the corresponding rotating arm. Start the rotation mechanism to drive the measuring stage to retract symmetrically inward; Based on the clamping force data fed back by the strain gauge force sensor, the conductor is bent to the minimum allowable diameter; According to national standards, appropriate points are selected at both ends of the conductor, and soft copper wire is used as electrodes to complete the resistance measurement.

10. A DC resistance measuring device for a large cross-section aluminum conductor, characterized in that, Including the measuring fixture as described in any one of claims 1-8.

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