Insulation shielding layer resistivity measuring tool
By designing a resistivity measuring fixture for insulation shielding layers suitable for test cables of different outer diameters, the instability and operational complexity of traditional fixtures were solved, achieving stability and accuracy in resistivity measurement.
Patent Information
- Application Number
- CN202422506513.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-17
- Publication Date
- 2025-11-14
- Estimated Expiration
- 2034-10-17
AI Technical Summary
Traditional cable insulation shield resistivity measuring fixtures suffer from problems such as unstable placement, difficulty in fixing, difficulty in controlling the distance between electrodes, cumbersome installation, and incompatibility with test cables of different outer diameters.
An insulating shield resistivity measuring fixture, comprising a base plate, wooden support, electrodes, fixing components, and locking components, is designed to accommodate test cables of different outer diameters. The combination of the wooden support and fixing components ensures stable electrode fixation, and electrodes of specific shapes and materials are used to improve contact stability and measurement accuracy.
It enables stable placement of the tooling, simple operation, and accurate measurement, adapts to test cables of different outer diameters, ensures that the distance between electrodes meets the standard, and improves the stability and accuracy of the measurement.
Smart Images
Figure CN223551799U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a tooling for measuring the resistivity of an insulating shielding layer, belonging to the field of submarine cable technology. Background Technology
[0002] According to JB / T11167.1 and GB / T32346.1 "Cross-linked polyethylene insulated long-length AC submarine cables and accessories - Part 1 Test methods and requirements", the resistivity of the cable insulation shield layer should be measured on separate samples. Samples need to be taken from the insulation core of the untreated cable sample and from the insulation core of the cable sample after aging treatment for material compatibility testing, respectively, to determine the resistivity of the insulation shield layer.
[0003] Traditional resistivity measurement fixtures for cable insulation shielding layers use simple clamps as electrodes (including a pair of current electrodes and a pair of potential electrodes). The electrode positions need to be marked on the insulation shielding layer in advance, and the clamps need to be reinforced before being placed in the test chamber for testing.
[0004] However, the above-mentioned measuring fixture has the following problems during use: it is not stable and is not easy to fix during the test; the distance between the electrodes is difficult to control and it is easy to fail to meet the standard requirements; the installation is cumbersome and requires multiple fixings; for test cables with different outer diameters, it is necessary to replace the clamp electrodes of different specifications. Utility Model Content
[0005] The purpose of this invention is to address the shortcomings of the prior art by providing a fixture for measuring the resistivity of an insulating shielding layer. This fixture is stable, easy to operate, and can be adapted to test cables of different outer diameters.
[0006] The technical solution of this utility model is as follows: an insulating shielding layer resistivity measuring fixture, characterized in that it includes: a base plate for supporting the entire fixture, four sets of wooden supports, two pairs of electrodes (a pair of narrow and long current electrodes and a pair of thin and long potential electrodes), four sets of fixing components, and four sets of locking components.
[0007] The front end of the base plate extends upward with a baffle, which has through holes for corresponding electrodes to pass through. Wooden supports are fixed to the base plate, and the top of each set of wooden supports is arc-shaped to hold the test cable. The top of the wooden supports has a groove. The fixing assembly includes a fixing rod, which is set between the two groove walls of the corresponding wooden support groove. Two pairs of electrodes correspond one-to-one with the four sets of wooden supports, with one pair of potential electrodes in the middle and one pair of current electrodes on both sides. The locking assembly includes a locking seat and a locking bolt. The locking seat is installed on the baffle by bolts. The locking seat has horizontally arranged through holes, and the top of the locking seat has a threaded hole that penetrates the through holes. The through holes of the locking seat correspond one-to-one with the through holes of the baffle.
[0008] In the above scheme, one end of each pair of electrodes is connected to a corresponding fixing rod, and the other end, after forming a clamp around the electrode, passes through the groove of the wooden bracket, the through hole of the baffle, and the through hole of the locking seat in sequence. The locking bolt is then screwed into the threaded hole of the locking seat to lock the electrode. The two middle electrodes are the potential terminals, and the two outer electrodes are the current terminals. According to the test requirements in JB / T11167.1 and GB / T32326.1, the distance between the two electrodes at the potential terminals is 50 mm, and the electrode at the current terminal is at least 25 mm outside the electrode at the voltage terminal.
[0009] Furthermore, the current electrode is made of thin copper sheet with a narrow and long structure; the potential electrode is made of silver-plated copper wire with a slender structure.
[0010] In the above scheme, the current electrode requires a large cross-sectional area with the test cable, using thin copper sheet material. A larger contact area provides more stable potential measurement, reduces contact resistance, and ensures the stability and accuracy of the potential. The potential electrode uses thin, long, silver-plated copper wire, which allows for better contact with the test cable, reducing the contact area between the two, resulting in more accurate measurement results and reducing current density concentration. By limiting the contact area at the current end, the current can be distributed more evenly in the working area of the electrode, improving the electrode's stability and lifespan.
[0011] Furthermore, the other ends of the two pairs of electrodes are bent into arc shapes to facilitate pulling the electrodes and to better form a clamp so as to make full contact with the test cable.
[0012] Furthermore, each set of fixing components is equipped with two parallel fixing rods arranged at a certain distance. One fixing rod is used to connect the electrode end, and the other fixing rod is used to press down the electrode, which can facilitate the electrode to be wrapped around to form a clamp.
[0013] Furthermore, each set of fixing components is also equipped with two fixing plates, which are respectively fixed to the two outer sides of the corresponding wooden bracket; the two fixing rods in the same set pass through the groove wall and fixing plate of the corresponding wooden bracket at both ends, and are respectively fixed to the corresponding fixing plate.
[0014] Furthermore, the base plate is a metal base plate, which can improve the stability of the entire tooling; an insulating plate is provided between the wooden support and the metal base plate, and the electrodes are placed on the insulating plate to form an isolation from the metal base plate, ensuring the accuracy of the test.
[0015] In use, this invention involves removing all outer coverings from the insulated wire core to prepare an insulated shielded test cable. The test cable is then passed through a clamp formed by four electrodes and placed on the arc-shaped surface at the top of a wooden support. The electrodes are then pulled to ensure each electrode is firmly against the insulated shielding layer of the test cable, and the locking bolts are tightened. Next, current and potential measuring devices are connected to the electrodes using suitable clamps. The fixture is placed in an oven preheated to a specified temperature, and the resistance between the electrodes is measured after at least 30 minutes of constant temperature.
[0016] This invention uses a metal base plate, which makes it more stable when placed; during the process of pressing the sample, the four electrode positions are pressed together by pulling the electrodes, and the distance between the electrodes is fixed, simplifying the installation steps; it can measure the outer diameter of the test cable in various ranges, with a wide measurement range. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of this utility model;
[0018] Figure 2 This is a cross-sectional view of the present invention at the current electrode.
[0019] Figure 3 for Figure 2 Enlarged view of section A in the middle;
[0020] Figure 4 This is a schematic diagram of the wooden support frame in this utility model;
[0021] Figure 5 This is a schematic diagram of the locking seat in this utility model;
[0022] In the diagram: 1. Metal base plate, 1-1. Baffle, 2. Wooden support, 2-1. Groove, 3. Current electrode, 4. Potential electrode, 5-1. Fixing rod, 5-2. Fixing plate, 6-1. Locking seat, 6-1-1. Through hole, 6-1-2. Threaded hole, 6-1-2. Locking bolt, 6-2. Insulating plate. Detailed Implementation
[0023] An insulating shielding layer resistivity measuring fixture, such as Figure 1 As shown, it includes: a metal base plate 1, four sets of wooden supports 2, a pair of current electrodes 3 made of thin copper sheet (with a large contact area with the test cable), a pair of potential electrodes 4 made of silver-plated copper wire (with a small contact area with the test cable), four sets of fixing components, and four sets of locking components.
[0024] like Figure 1 , 2 As shown, a baffle 1-1 extends upward from the front end of the base plate, and the baffle is provided with through holes for the corresponding electrodes to pass through.
[0025] Four sets of wooden supports are fixed to the base plate. The two middle wooden supports are 50mm apart, serving as supports for the potential electrodes. The two outer wooden supports are at least 25mm away from the middle wooden supports, serving as supports for the current electrodes. Figure 4 As shown, the top of the wooden support is an arc surface, and the top of the wooden support has a groove 2-1.
[0026] like Figure 2 , 3 As shown, the fixing assembly includes two spaced fixing rods 5-1. The two fixing rods are set between the two groove walls of the corresponding wooden bracket groove. One rod is used to connect the electrode end, and the other rod is used to press down the electrode so that the electrode wraps around the wooden bracket groove to form a clamp.
[0027] like Figure 5 As shown, the locking assembly includes a locking seat 6-1 and a locking bolt 6-2. The locking seat is installed on the baffle by bolts. The locking seat has a horizontally arranged through hole 6-1-1. The top of the locking seat has a threaded hole 6-1-2 that passes through the through hole. The through holes of the locking seat correspond one-to-one with the through holes of the baffle.
[0028] In one embodiment of this utility model, the other ends of the two pairs of electrodes are bent into arc shapes to facilitate pulling the electrodes and pressing the sample tightly.
[0029] In one embodiment of this utility model, each set of fixing components is further provided with two fixing plates 5-2. The two fixing plates are respectively fixed to the two outer sides of the corresponding wooden bracket. The two fixing rods in the same set pass through the groove wall of the corresponding wooden bracket and the fixing plate at both ends, and are respectively fixed to the corresponding fixing plates.
[0030] In one embodiment of this utility model, an insulating plate 7 is provided between the wooden support and the metal base plate.
[0031] One end of each of the four electrodes is connected to a fixed rod on a corresponding wooden support, and the other end is pressed down by another fixed rod, forming a clamp around the groove of the wooden support. The electrodes then pass through the groove of the wooden support, the through hole of the baffle, and the through hole of the locking seat, and the locking bolt is screwed into the threaded hole of the locking seat to lock the electrodes. In use, the test cable is passed through the clamp formed by the four electrodes and placed on the arc surface at the top of the wooden support. The electrodes are then pulled to ensure each electrode is in close contact with the insulation shielding layer of the test cable. The locking bolts are then tightened, and the resistance between the electrodes is measured.
Claims
1. A fixture for measuring the resistivity of an insulating shielding layer, characterized in that, include: The base plate is used to support the entire tooling, and a baffle extends upward from the front end of the base plate; Four sets of wooden supports, all fixed to the base plate; The top of each set of wooden supports is rounded to hold the test cable, and the top of the wooden supports is provided with a groove. The fixing components consist of four sets, including fixing rods, which are set between the two groove walls of the wooden bracket groove; The electrodes include a pair of narrow, elongated current electrodes and a pair of thin, elongated potential electrodes; Two pairs of electrodes correspond one-to-one with four sets of wooden supports, with one pair of potential electrodes in the middle and one pair of current electrodes on both sides. The locking assembly consists of four sets, including locking seats and locking bolts. The locking seats are installed on the baffle and have through holes and threaded holes. One end of each pair of electrodes is connected to the corresponding fixing rod, and the other end, after forming a clamp around the perimeter, passes through the groove of the wooden bracket, the through hole of the baffle, and the through hole of the locking seat in sequence. The locking bolts are then screwed into the threaded holes of the locking seats to lock the electrodes.
2. The insulating shielding layer resistivity measuring fixture according to claim 1, characterized in that, The current electrode is made of thin copper sheet with a narrow and long structure; the potential electrode is made of silver-plated copper wire with a slender structure.
3. The insulating shielding layer resistivity measuring fixture according to claim 1 or 2, characterized in that, The other ends of the two pairs of electrodes are bent into arc shapes.
4. The insulating shielding layer resistivity measuring fixture according to claim 1, characterized in that, Each set of fixing components has two parallel fixing rods. One fixing rod is used to connect to the electrode end, and the other fixing rod is used to press down the electrode.
5. The insulating shielding layer resistivity measuring fixture according to claim 4, characterized in that, Each set of fixing components also includes two fixing plates, which are respectively fixed to the two outer sides of the corresponding wooden bracket; The two fixed rods in the same group pass through the groove wall and fixed plate of the corresponding wooden bracket at both ends, and are fixed to the corresponding fixed plate.
6. The insulating shielding layer resistivity measuring fixture according to claim 1, characterized in that, The base plate is a metal base plate, and an insulating plate is provided between the wooden support and the metal base plate.