Adhesive force testing mechanism and testing machine for cable

Abstract

The utility model belongs to the technical field of cable performance testing devices, and provides an adhesive force testing mechanism and a testing machine for a cable, and the testing mechanism comprises a clamping part which is used for clamping a conductor layer after the end part of the cable is exposed; the stretching piece is arranged opposite to the clamping piece, the stretching piece comprises a connecting piece and a sleeve which are detachably connected, and a conductor channel is formed in the bottom of the sleeve; and the rotary guide assembly is arranged in the sleeve and comprises a replaceable rotating piece, and the rotating piece is coaxially assembled with the conductor channel and used for guiding the insulating layer to rotate around the axis of the conductor layer and slide in the axial direction. Compared with the prior art, by designing the specific clamping piece, the stretching piece and the rotary guide assembly, the spiral stripping mode between the insulating layer and the conductor layer is realized, and the mode can more accurately simulate the separation condition under the actual use condition, so that a more real adhesive force test result is provided.

Description

Technical Field

[0001] This utility model belongs to the technical field of cable performance testing devices, specifically relating to an adhesion force testing mechanism and testing machine for cables. Background Technology

[0002] Overhead insulated cables are power cables specifically designed for overhead power transmission and distribution systems. They use cross-linked polyethylene (XLPE), polyvinyl chloride (PVC), and other polymer materials to wrap the conductor, combining the ease of installation of overhead lines with the insulation safety of the cable structure. The adhesion force between the insulation layer and the conductor is an important indicator of the cable's structural reliability, directly affecting its long-term stability under conditions such as mechanical stress and temperature changes. Therefore, adhesion force testing is a key quality control step in the cable manufacturing process.

[0003] The traditional testing method for the adhesion strength of overhead insulated cables is as follows: A 300mm sample of the finished cable is taken, and 50mm of insulation is peeled from each end, leaving a 200mm intact insulation section in the middle. The initial positions are marked at both ends of the insulation layer to observe the slippage. The exposed conductor is fixed in the lower clamp of the tensile testing machine, while the upper clamp holds the outer surface of the insulation layer for 50mm with a soft pad (to avoid damage), ensuring axial force alignment. The tensile speed of the tensile testing machine is set to 100±10mm / min, maintaining a uniform loading speed to avoid impact effects. The equipment is started, the upper clamp is raised, and the tensile-displacement curve is continuously recorded until any of the following occurs: the insulation layer completely separates from the conductor, the slippage displacement is ≥25mm (industry standard), or the tensile force value drops to 50% of the peak value; the test ends then. The maximum tensile force value is used as the standard for adhesion strength, and the interfacial bonding performance of the cable structure is comprehensively evaluated in conjunction with the slippage displacement.

[0004] Traditional testing methods have the following shortcomings: (1) Defects in axial peeling process: Stress concentration is easily generated during the axial vertical peeling process between stranded conductor and insulation layer, which leads to conductor wire breakage or abnormal damage to insulation layer, and the sample preparation qualification rate is less than 60% (industry statistics); (2) Clamping interference effect: The clamping torque of 0.5-1.2 N·m needs to be precisely controlled by the upper clamp (according to IEC60228 standard). In actual operation, due to the narrow tolerance range of clamping pressure (±5%), conductor deformation or insulation layer crushing is easily caused, resulting in an artificial increase in peeling resistance (typical deviation reaches 15%-22%). Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide an adhesion force testing mechanism and testing machine for cables, in light of the current state of the technology.

[0006] The technical solution adopted by this utility model to solve the above-mentioned technical problem is as follows: An adhesion force testing mechanism for cables is proposed, used to test the adhesion force between the conductor layer and the insulation layer of the cable. The testing mechanism includes:

[0007] A clamping element for clamping the exposed conductor layer at the end of the cable;

[0008] A tensioning member is disposed opposite to the clamping member, the tensioning member comprising a detachably connected connector and a sleeve, the bottom of the sleeve being provided with a conductor channel;

[0009] A rotary guide assembly, disposed inside the sleeve, includes a replaceable rotating component coaxially mounted with the conductor channel for guiding the insulating layer to rotate about the conductor layer axis and slide axially.

[0010] The connector and the sleeve are fixed by a mechanical locking structure, and the rotating component generates a torque component around the conductor axis under axial tension, which causes the insulating layer to be spirally peeled off from the conductor layer.

[0011] In the aforementioned adhesion testing mechanism for cables, the mechanical locking structure includes a protruding rod and a connecting groove. The connecting groove has a limiting section perpendicular to the cable axis and an entry section parallel to the cable axis. The entry section is used for the protruding rod to enter the limiting section to restrict the separation of the connector and the sleeve along the cable axis.

[0012] In the aforementioned adhesion testing mechanism for cables, at least two protrusions are evenly distributed around the outer periphery of the sleeve, and the connector is provided with connecting grooves corresponding to the protrusions. One end of the connecting groove penetrates one side wall of the connector and communicates with the outside, thereby forming a notch on the connector for the protrusions to enter the connecting groove.

[0013] In the aforementioned adhesion testing mechanism for cables, the sleeve is provided with an observation window communicating with its interior, for observing the separation state of the insulation layer and the conductor layer.

[0014] In the aforementioned adhesion testing mechanism for cables, the rotary guide assembly further includes a connecting sleeve, which is detachably connected to the sleeve and coaxially arranged with the rotating component to provide support for the rotating component.

[0015] In the aforementioned adhesion testing mechanism for cables, a slot coaxial with the conductor channel is provided inside the sleeve, and the connecting sleeve is installed in the slot.

[0016] In the aforementioned adhesion testing mechanism for cables, the tensile member further includes a clamping rod connected to the end of the connector away from the sleeve.

[0017] In the aforementioned adhesion testing mechanism for cables, the outer peripheral wall of the clamping rod is provided with anti-slip texture.

[0018] In the aforementioned adhesion testing mechanism for cables, the rotating component is a planar bearing.

[0019] This utility model solves the above-mentioned technical problems and also proposes an adhesion force test for cables, including: the above-mentioned adhesion force test mechanism for cables;

[0020] A drive member, connected to the tension member, is used to provide a power source for moving the tension member relative to the clamping member.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) By designing specific clamping parts, stretching parts and rotating guide components, a spiral peeling method between the insulation layer and the conductor layer is realized. This method can more accurately simulate the separation under actual use conditions, thereby providing more realistic adhesion test results.

[0023] (2) The mechanical locking structure design ensures a firm and stable connection between the connector and the sleeve, avoiding unnecessary separation or movement during axial tensile testing, and improving the stability and reliability of the testing process.

[0024] (3) The design of equally spaced protruding rods and corresponding connecting grooves not only simplifies the installation and disassembly process between the sleeve and the connector, but also ensures the tightness and stability of the connection between the two, which helps to improve the consistency and repeatability of the test. Attached Figure Description

[0025] Figure 1 This is a plan view of an adhesion force testing mechanism for cables according to this utility model.

[0026] Figure 2 yes Figure 1 Enlarged view of the cross-section at point A.

[0027] In the diagram, 10 is the cable; 11 is the conductor layer; 12 is the insulation layer; 100 is the clamping component; 200 is the tensioning component; 210 is the connecting component; 211 is the connecting groove; 211a is the limiting section; 211b is the entry section; 220 is the sleeve; 221 is the conductor channel; 222 is the protruding rod; 223 is the observation window; 230 is the clamping rod; 300 is the rotary guide assembly; 310 is the rotating component; and 320 is the connecting sleeve. Detailed Implementation

[0028] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0029] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0030] like Figures 1 to 2 As shown, this utility model discloses an adhesion force testing mechanism for cables, used to test the adhesion force between the conductor layer 11 and the insulation layer 12 of a cable 10. The testing mechanism includes: a clamping member 100, a tensioning member 200, and a rotary guide assembly 300.

[0031] Specifically, the clamping member 100 is used to clamp the conductor layer 11 after it is exposed at the end of the cable 10. The tensioning member 200 is arranged opposite to the clamping member 100 and includes a detachably connected connector 210 and a sleeve 220. The bottom of the sleeve 220 is provided with a conductor channel 221. The rotating guide assembly 300 is disposed inside the sleeve 220 and includes a replaceable rotating member 310. The rotating member 310 is coaxially assembled with the conductor channel 221 and is used to guide the insulation layer 12 to rotate around the axis of the conductor layer 11 and slide axially. The connector 210 and the sleeve 220 are fixed by a mechanical locking structure. The rotating member 310 generates a torque component around the conductor axis under the action of axial tension, so that the insulation layer 12 and the conductor layer 11 are spirally peeled off.

[0032] Before the adhesion test begins, a fixed length of cable 10, approximately 300 mm long, is cut. The insulation layer 12 at one end is cut axially to the surface of the conductor layer 11, with a stripped length of approximately 100 mm. Then, approximately 25 mm of the insulation layer 12 is stripped from the middle of the other end of the cable 10, exposing the conductor layer 11 in that section. This is used to observe the separation between the conductor layer 11 and the insulation layer 12 during the experiment.

[0033] After the cable 10 sample is prepared, the end of the cable 10 with the insulation layer 12 not removed is passed through the conductor channel 221, so that most of the conductor is inside the sleeve 220, and the other end of the cable 10 is exposed outside the sleeve 220. Then, the end of the cable 10 with the insulation layer 12 removed is clamped and fixed by the clamping member 100.

[0034] During testing, the tensioning member 200 drives the rotary guide assembly 300 to move away from the clamping member 100, with the movement path parallel to the axial direction of the cable 10. As the rotating member 310 of the rotary guide assembly 300 presses against the end of the insulation layer 12 and continues to move under the drive of the tensioning member 200, it pushes the insulation layer 12 of the cable 10 to separate from the conductor layer 11. During the separation process, since the conductor layer 11 of the cable 10 is formed by twisting multiple conductors together and has a spiral structure, while the insulation layer 12 is bonded to the conductor layer 11 through a three-layer co-extrusion process, the rotating member 310 rotates along the twisting direction of the conductors while rotating, thereby eliminating the influence of the nested structure between the insulation layer 12 and the conductor layer 11 on the adhesion force when testing the adhesion force between them.

[0035] The aforementioned testing method minimizes stress concentration during the axial vertical peeling process between the stranded conductor and the insulation layer 12, ensuring that the conductor filaments are less likely to break or the insulation layer 12 is less likely to suffer abnormal damage. Furthermore, the length of the insulation layer 12 along the axial direction of the cable 10, i.e., the direction of movement of the rotating member 310, is significantly greater than its radial length. The method of separating the insulation layer 12 from the conductor layer 11 by axially pushing the insulation layer 12 with the rotating member 310, instead of using a clamping mechanism to hold the insulation layer 12 in the prior art, completely avoids clamping interference effects and ensures the accuracy of the experimental data.

[0036] In this solution, by designing specific clamping member 100, stretching member 200 and rotary guide assembly 300, a spiral peeling method between insulating layer 12 and conductor layer 11 is achieved. This method can more accurately simulate the separation under actual use conditions, thereby providing more realistic adhesion test results.

[0037] It is worth noting that the above-mentioned mechanical locking structure includes a protruding rod 222 and a connecting groove 211. The connecting groove 211 has a limiting section 211a perpendicular to the axis of the cable 10 and an entry section 211b parallel to the axis of the cable 10. The entry section 211b is used to allow the protruding rod 222 to enter the limiting section 211a to restrict the separation of the connector 210 and the sleeve 220 along the axis of the cable 10.

[0038] The mechanical locking structure design ensures a firm and stable connection between the connector 210 and the sleeve 220, avoiding unnecessary separation or movement during axial tensile testing, and improving the stability and reliability of the testing process.

[0039] In one embodiment, the protruding rod 222 is fixed to the connector 210 and perpendicular to the axial direction of the sleeve 220. The fixing between the protruding rod 222 and the connector 210 can be achieved by welding, threaded connection, or integral molding. The connecting groove 211 is provided on the sleeve 220, and its entry section 211b penetrates through one side wall of the sleeve 220, forming a notch for the protruding rod 222 to enter.

[0040] In another embodiment, at least two protrusions 222 are evenly distributed on the outer periphery of the sleeve 220, and the connector 210 is provided with connecting grooves 211 corresponding to the protrusions 222 one by one. One end of the connecting groove 211 penetrates one side wall of the connector 210 and communicates with the outside, so as to form a notch on the connector 210 for the protrusions 222 to enter the connecting groove 211.

[0041] The design of equally spaced protruding rods 222 and corresponding connecting grooves 211 not only simplifies the installation and disassembly process between the sleeve 220 and the connector 210, but also ensures the tightness and stability of the connection between the two, which helps to improve the consistency and repeatability of the test.

[0042] Furthermore, the bushing 220 is provided with an observation window 223 that communicates with its interior, for observing the separation state of the insulating layer 12 and the conductor layer 11.

[0043] The observation window 223 on the bushing 220 allows the operator to directly observe the separation state of the insulation layer 12 and the conductor layer 11, which is very helpful for real-time monitoring of the test progress and determining the test endpoint, thus improving test efficiency and accuracy.

[0044] In this solution, the rotary guide assembly 300 also includes a connecting sleeve 320, which is detachably connected to the sleeve 220 and coaxially arranged with the rotating component 310 to provide support for the rotating component 310.

[0045] The introduction of a detachable connecting sleeve 320 provides additional support for the rotating component 310, enhancing its stability and durability, while facilitating maintenance and replacement to meet the testing needs of cables 10 of different specifications.

[0046] The sleeve 220 is provided with a slot coaxial with the conductor channel 221, and the connecting sleeve 320 is installed in the slot.

[0047] The connection between the connecting sleeve 320 and the slot can be fixed by snap-fit ​​or by threaded connection. The slot design allows the connecting sleeve 320 to be accurately positioned inside the sleeve 220 and coaxially set with the conductor channel 221, ensuring the working accuracy of the rotating part 310 and improving the reliability and consistency of the test data.

[0048] Furthermore, the tension member 200 also includes a clamping rod 230, which is connected to the end of the connector 210 away from the sleeve 220.

[0049] The clamping rod 230 is used to connect the tension member 200 to an external power mechanism (such as a tensioning machine). The tensioning machine fixes and drives the clamping rod 230, causing the tension member 200 to move closer to or further away from the clamping member 100, thereby achieving the adhesion force test of the cable 10. The addition of the clamping rod 230 provides a direct object of action for the driving member, making the process of applying tension simpler and more efficient. It also helps to maintain the straightness of the tension direction and reduce errors caused by skewness.

[0050] Preferably, the outer peripheral wall of the clamping rod 230 is provided with anti-slip texture. The anti-slip texture increases the coefficient of friction of the outer peripheral wall of the clamping rod 230, effectively preventing slippage during the application of tensile force, and ensuring the effectiveness of tensile force transmission and the accuracy of test results.

[0051] Preferably, the rotating component 310 is a planar bearing. Using a planar bearing as the rotating component 310 reduces the frictional resistance during rotation, allowing the insulating layer 12 to rotate and slide more smoothly along the axis of the conductor layer 11, reducing energy loss during testing, and improving testing efficiency and the accuracy of results.

[0052] Furthermore, this planar thrust bearing is a PTFE-coated planar bearing, which, compared to ordinary smooth metal bearings, requires no lubrication and has a 30% lower coefficient of friction, making the test data more accurate.

[0053] This solution also proposes a testing machine for the adhesion force of cables, including:

[0054] The above-mentioned adhesion force testing mechanism for cables includes a drive member connected to the tension member 200 for driving the tension member 200 to move relative to the clamping member 100.

[0055] It should be noted that in this invention, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0056] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0057] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. An adhesion testing mechanism for cables, used to test the adhesion force between the conductor layer and the insulation layer of the cable, characterized in that, The testing facility includes: A clamping element for clamping the exposed conductor layer at the end of the cable; A tensioning member is disposed opposite to the clamping member, the tensioning member comprising a detachably connected connector and a sleeve, the bottom of the sleeve being provided with a conductor channel; A rotary guide assembly, disposed inside the sleeve, includes a replaceable rotating component coaxially mounted with the conductor channel for guiding the insulating layer to rotate about the conductor layer axis and slide axially. The connector and the sleeve are fixed by a mechanical locking structure, and the rotating component generates a torque component around the conductor axis under axial tension, which causes the insulating layer to be spirally peeled off from the conductor layer.

2. The adhesion force testing mechanism for cables as described in claim 1, characterized in that, The mechanical locking structure includes a protruding rod and a connecting groove. The connecting groove has a limiting section perpendicular to the cable axis and an entry section parallel to the cable axis. The entry section is used for the protruding rod to enter the limiting section to restrict the separation of the connector and the sleeve along the cable axis.

3. The adhesion force testing mechanism for cables as described in claim 2, characterized in that, At least two protrusions are evenly spaced on the outer periphery of the sleeve. The connector is provided with a connecting groove corresponding to each protrusion. One end of the connecting groove penetrates one side wall of the connector and communicates with the outside, so as to form a notch on the connector for the protrusion to enter the connecting groove.

4. The adhesion force testing mechanism for cables as described in claim 1, characterized in that, The sleeve is provided with an observation window that communicates with its interior, for observing the separation state of the insulating layer and the conductor layer.

5. The adhesion force testing mechanism for cables as described in claim 1, characterized in that, The rotary guide assembly further includes a connecting sleeve, which is detachably connected to the sleeve and coaxially arranged with the rotating component to provide support for the rotating component.

6. The adhesion force testing mechanism for cables as described in claim 5, characterized in that, The sleeve is provided with a slot coaxial with the conductor channel, and the connecting sleeve is installed in the slot.

7. The adhesion force testing mechanism for cables as described in claim 1, characterized in that, The tensioning member further includes a clamping rod connected to the end of the connector away from the sleeve.

8. The adhesion force testing mechanism for cables as described in claim 7, characterized in that, The outer peripheral wall of the clamping rod is provided with anti-slip texture.

9. The adhesion force testing mechanism for cables as described in claim 1, characterized in that, The rotating component is a plane bearing.

10. A testing machine for the adhesion force of cables, characterized in that, include: An adhesion testing mechanism for cables as described in any one of claims 1 to 9; A driving member, which is connected to the stretching member, is used to drive the stretching member to move relative to the clamping member.

Images