Device for testing stress cracking resistance of cable material

Abstract

The utility model relates to a device for testing the stress cracking resistance of a cable material, which comprises a base, at least one sample box used for placing a sample wafer of the cable material to be tested is arranged on the top surface of the base; the plurality of fixing columns are vertically arranged on the base; the stress applying mechanism comprises a top plate and at least one pressing hammer vertically arranged on the bottom surface of the top plate, the top plate is arranged above the base in parallel at intervals, and the bottom end of the pressing hammer can be pressed against the corresponding cable material sample wafer to be tested; the top plate can move up and down relative to the base, and the top plate and the fixing column can be locked and fixed through a locking assembly. The locking and fixing position of the top plate can be determined by at least one balancing weight placed on the stress applying mechanism, and the balancing weight can be removed after the top plate is locked and fixed. According to the utility model, the stress cracking resistance of the cable material can be tested more truly.

Description

Technical Field

[0001] This utility model relates to the field of cable material performance testing, and in particular to a device for testing the stress cracking resistance of cable materials. Background Technology

[0002] The cable industry is a crucial foundational industry, providing the "blood vessels" and "nerves" for almost all sectors, including energy, communications, transportation, and industry. Currently, with society's increasing reliance on electricity and the growing complexity of electricity usage scenarios, cable safety has evolved from the traditional requirement of "ensuring power supply" to a comprehensive requirement of "ensuring the reliability, fire resistance, intelligence, and environmental friendliness of the entire system lifecycle." Cracks in the cable sheath are a direct and serious precursor to cable failure, and their hazards are insidious, gradual, and catastrophic. Cracks are not merely a cosmetic defect; they signify the collapse of the cable protection system, triggering a series of chain reactions that ultimately lead to system failure and even significant safety and economic losses.

[0003] The existing standard GB / T 32129 contains many test methods related to the crack resistance of cables, such as thermal stress (thermal aging, thermal shock test), mechanical stress (bending test, low-temperature impact, low-temperature tensile test, etc.), environmental stress (environmental stress cracking resistance), and comprehensive stress (high and low temperature cycling, etc.). However, cable material cracking can be either thermal or cold. Thermal cracking occurs because the material's strength decreases rapidly after heating, resulting in insufficient strength and cracking. Cold cracking occurs because the material's toughness decreases after cooling, and it cannot offset the internal and external stresses through its own elongation, thus causing cracking. The methods in the existing standard GB / T 32129 only cover thermal cracking, not cold cracking. The factors contributing to cable sheath cracking are complex, including high temperature, low temperature, high and low temperature cycling (sudden cooling and heating), and long-term aging. GB / T 32129 applies internal stress to the material through load-bearing and winding, but after the cable is laid, it is also subjected to external stresses, such as the external stresses applied by the cable rack and internal steel strips, which can also lead to cable cracking. Therefore, most existing methods for testing crack resistance are qualitative. On the one hand, existing methods do not apply external stress to the material for a long period of time, which is inconsistent with the cracking mechanism. On the other hand, they are not suitable for the cable design, laying environment, and application scenarios. Even if the above properties are qualified, there is still a risk of cable cracking. Utility Model Content

[0004] The purpose of this invention is to provide a device for testing the stress crack resistance of cable materials, which can more realistically test and evaluate the stress crack resistance of cable materials.

[0005] The purpose of this utility model is achieved as follows: a test device for stress cracking resistance of cable material includes: a base with at least one sample box on its top surface for placing a sample of cable material to be tested; multiple fixed columns vertically disposed on the base; a stress application mechanism including a top plate and at least one pressure hammer vertically disposed on the bottom surface of the top plate, the top plate being disposed parallel and spaced above the base, and the bottom end of the pressure hammer being able to press against the corresponding sample of cable material to be tested; the top plate being able to move up and down relative to the base and being able to lock and fix the top plate and the fixed columns by a locking assembly; the locking and fixing position of the top plate being able to be determined by at least one counterweight placed on the stress application mechanism, and the counterweight being able to be removed after the top plate is locked and fixed.

[0006] In a preferred embodiment of the present invention, the locking assembly includes a plurality of locking nuts, the top of the fixing column is provided with an external thread, the top plate is provided with a plurality of mounting holes, and the top plate is sleeved on the plurality of fixing columns through the plurality of mounting holes; the locking nuts can be threaded to the top of the fixing column after a counterweight is placed on the stress application mechanism, and abut against the top surface of the top plate.

[0007] In a preferred embodiment of the present invention, the hammer includes a connecting column and a hammer head connected vertically. The width of the hammer head is greater than the diameter of the connecting column. The top of the connecting column is connected to the top plate, and the bottom of the hammer head is used to press against the corresponding sample of cable material to be tested.

[0008] In a preferred embodiment of this utility model, the hammer head is a triangular prism structure, and the top and bottom surfaces of the prism are both right triangles. The side surface of the triangular prism structure corresponding to one of the right-angled sides of the right triangle is arranged horizontally downward and can press against the sample of the cable material to be tested.

[0009] In a preferred embodiment of this utility model, the bottom end of the hammer head is an arc-shaped head.

[0010] In a preferred embodiment of the present invention, the counterweight has a notch, and the counterweight can be inserted into the corresponding fixed post through the notch and abut against the hammer head.

[0011] In a preferred embodiment of this utility model, there are multiple sample boxes and multiple pressure hammers.

[0012] In a preferred embodiment of this utility model, a connecting crossbar is connected between at least some of two adjacent fixed columns.

[0013] In a preferred embodiment of this utility model, both the base and the top plate are rectangular plates, the number of fixing columns is four and they are distributed at the four top corners of the base, and the number of connecting crossbars is two and they are located at both ends of the length direction of the base.

[0014] In a preferred embodiment of the present invention, the cable material stress cracking resistance testing device further includes a test chamber, which is equipped with a heating device and / or a cooling device, and a base, a fixing column and a stress application mechanism are placed inside the test chamber.

[0015] As described above, the cable material stress cracking resistance testing device of this utility model, by adding a pre-set weight counterweight to the stress application mechanism, can apply a pre-set external stress to the cable material sample to be tested. The top plate and the fixing column are locked and fixed by the locking assembly. Even after the counterweight is removed, the pressure hammer can still apply the pre-set external stress to the cable material sample to be tested. This can better simulate the situation where the actual cable will be subjected to external stress after laying and cracks will occur after a long period of external stress. It is more conducive to the realistic testing of the stress cracking resistance of cable materials, and helps to more objectively evaluate the crack resistance of cable materials. This can guide cable manufacturers to control the quality of materials and prevent cable sheath cracking accidents. Attached Figure Description

[0016] The following figures are intended only to illustrate and explain the present invention and do not limit the scope of the present invention. Wherein:

[0017] Figure 1 A schematic diagram of the structure of the cable material stress cracking resistance testing device provided by this utility model.

[0018] Figure 2 A schematic diagram of the structure of the hammer provided by this utility model when it adopts a triangular prism structure.

[0019] Figure 3 A longitudinal cross-sectional view of the hammer head provided by this utility model when the bottom end adopts an arc head.

[0020] Figure 4 A schematic diagram of the counterweight provided by this utility model.

[0021] Explanation of icon numbers:

[0022] 1. Base; 11. Sample box;

[0023] 2. Fixed post; 21. External thread; 22. Connecting crossbar;

[0024] 3. Top slab;

[0025] 4. Pressure hammer; 41. Connecting column; 42. Hammer head;

[0026] 5. Tighten the nut;

[0027] 6. Counterweight; 61. Notch. Detailed Implementation

[0028] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described with reference to the accompanying drawings.

[0029] like Figures 1 to 4 As shown, this application provides a device for testing the stress cracking resistance of cable materials, comprising:

[0030] The base 1 has at least one sample box 11 on its top surface for placing a sample of the cable material to be tested;

[0031] Multiple fixed columns 2 are vertically mounted on the base 1;

[0032] The stress application mechanism includes a top plate 3 and at least one pressure hammer 4 vertically disposed on the bottom surface of the top plate 3. The top plate 3 is disposed parallel to and spaced above the base 1. The bottom end of the pressure hammer 4 can press against the corresponding cable material sample to be tested. The top plate 3 can move up and down relative to the base 1 and can be locked and fixed by a locking assembly. The locking and fixing position of the top plate 3 can be determined by at least one counterweight 6 placed on the stress application mechanism, and the counterweight 6 can be removed after the top plate 3 is locked and fixed.

[0033] In use, the prepared cable material sample to be tested is placed in the sample box 11, and the pressure hammer 4 is pressed against the sample. Then, according to the test conditions, a counterweight 6 is added to the stress application mechanism to apply stress. Under the weight of the counterweight 6, the pressure hammer 4 can apply a preset stress to the cable material to be tested. The current position of the top plate 3 is locked and fixed using the locking assembly. After locking the top plate 3 and the fixing column 2, the counterweight 6 is removed. Finally, the main body of the test device, consisting of the base 1, the fixing column 2, and the stress application device, is placed in the required test environment, and the test can begin.

[0034] Therefore, the cable material stress cracking resistance testing device of this application, by adding a pre-set weighted counterweight 6 to the stress application mechanism, can apply a pre-set external stress to the cable material sample to be tested. The top plate 3 and the fixing column 2 are locked and fixed by the locking assembly. Even after the counterweight 6 is removed, the pressure hammer 4 can still apply the pre-set external stress to the cable material sample to be tested. This can better simulate the situation where the actual cable will be subjected to external stress after laying and cracks will occur after a long period of external stress. It is more conducive to the realistic testing of the stress cracking resistance of cable materials, and helps to more objectively evaluate the crack resistance of cable materials. This can guide cable manufacturers to control the quality of materials and prevent cable sheath cracking accidents.

[0035] Alternatively, to facilitate locking and securing the top plate 3 after adjusting its position, refer to... Figure 1The locking assembly includes multiple locking nuts 5, the top of the fixing column 2 is provided with external thread 21, the top plate 3 is provided with multiple mounting holes, and the top plate 3 is sleeved on the multiple fixing columns 2 through the multiple mounting holes; the locking nuts 5 can be threaded to the top of the fixing column 2 after the counterweight 6 is placed on the stress application mechanism, and abut against the top surface of the top plate 3.

[0036] The locking nut 5 is located above the top plate 3 and is used to fix the top plate 3. The locking nut 5 can be, for example, an anti-loosening nut, and the top plate 3 can be, for example, a stainless steel plate. The mounting holes are round holes, and the number of mounting holes is the same as the number of fixing posts 2. The specific number depends on the needs. For example, when both the top plate 3 and the base 1 are rectangular plates, four mounting holes are opened at the four corners of the top plate 3. The top plate 3 is fitted onto the four fixing posts 2 through these four mounting holes. In use, after placing the sample of the cable material to be tested, the pressure hammer 4 presses against the sample of the cable material to be tested. After adding the counterweight 6 to apply stress, it is fixed by the locking nut 5. First, tighten it, and then use a torque wrench to fix the locking nut 5. This will lock and fix the current position of the top plate 3. After fixing the locking nut 5, the counterweight 6 can be removed.

[0037] Since the stress can be fixed between the cable material sample and the pressure hammer 4 after tightening the locking nut 5, the counterweight 6 can be removed directly during testing. It should be noted that after adding the counterweight 6, the position of the top plate 3 after tightening the locking nut 5 may be slightly lower than before tightening. However, since this test is for crack resistance rather than thermal deformation, this change in the position of the top plate 3 has negligible impact on the test results. Furthermore, using a torque wrench to tighten the locking nut 5 ensures uniform and consistent force distribution.

[0038] Of course, the locking component can also be used in other ways as needed; this embodiment is only for illustrative purposes.

[0039] Further optional, see Figure 1 The pressure hammer 4 includes a connecting column 41 and a hammer head 42 connected vertically. The width of the hammer head 42 is greater than the diameter of the connecting column 41. The top of the connecting column 41 is connected to the top plate 3. The bottom of the hammer head 42 is used to press against the corresponding cable material sample to be tested.

[0040] Among them, the connecting column 41 is mainly used to connect the top plate 3 and the hammer head 42. The connecting column 41 is vertically arranged in the axis. The connecting column 41 and the hammer head 42 can be welded and fixed together. The connecting column 41 can also be welded and fixed to the bottom surface of the top plate 3. The top plate 3, the connecting column 41 and the hammer head 42 form a whole, that is, a stress application mechanism.

[0041] Regarding the shape of the hammer head 42, its bottom end can be arc-shaped, with the arc surface contacting the cable material sample to be tested, such as... Figure 3 As shown; or the hammerhead 42 can also adopt a triangular prism structure, and the top and bottom surfaces of the prism can be acute triangles or right triangles.

[0042] As a preferred option, refer to Figure 2 The hammer 42 is a triangular prism structure, and the top and bottom surfaces of the prism are both right triangles. The side surface of the prism structure corresponding to one of the right-angled sides of the right triangle is arranged horizontally downward and can press against the cable material sample to be tested.

[0043] Since angle iron is used as a support frame during actual cable laying, the weight of the cable material acts directly on the angle iron. The hammer head 42 adopts a triangular prism structure, and the two prism sides corresponding to the two right-angled sides of the right triangle are arranged horizontally and vertically respectively. The horizontally arranged prism sides can press against the cable material sample to be tested, which can more closely resemble the actual laying environment.

[0044] Furthermore, when adding a counterweight 6 to the stress application mechanism, it can be placed directly on the top plate 3 or on the pressure hammer 4. Generally, it is preferred to place the counterweight 6 on the pressure hammer 4, as this is easier to operate.

[0045] Further optional, to facilitate placing the counterweight 6 on the hammer 4, refer to Figure 4 The counterweight 6 has a notch 61, through which it can be inserted into the corresponding fixing post 2 and abut against the hammer head 42. In use, only a certain number of counterweights 6 need to be installed on the connecting post 41 through their notches 61, which is simple and convenient. The notch 61 can be, for example, an arc-shaped notch. The specific number of counterweights 6 and the weight of a single counterweight 6 depend on actual needs; for example, a single counterweight 6 can weigh 1 kg.

[0046] Alternatively, the number of sample boxes 11 and pressure hammers 4 can be multiple.

[0047] The number of sample boxes 11 is the same as the number of pressure hammers 4, and the specific number is determined according to the test requirements. For example, it can be calculated as follows: Figure 1 The sample box 11 and the pressure hammer 4 shown are each provided in threes, and their positions are directly opposite each other.

[0048] The aforementioned base 1 can be a plate structure, serving as the bottom support for the main body of the testing device, ensuring the stability of the entire testing device, and used to fix the sample box 11. The sample box 11 is a box structure with an open top, which can be welded to the base 1 as a whole. The size of the cable material sample to be tested matches the size of the sample box 11, depending on the specific requirements.

[0049] Alternatively, a connecting crossbar 22 may be provided between at least some of the two adjacent fixed columns 2 to ensure structural stability.

[0050] For example, refer to Figure 1 When both the base 1 and the top plate 3 are rectangular plates, there are four fixed columns 2 distributed at the four corners of the base 1, and two connecting crossbars 22 located at both ends of the length of the base 1.

[0051] Furthermore, the cable material stress cracking resistance testing device also includes a test chamber, which is equipped with a heating device and / or a cooling device. The base 1, the fixing column 2 and the stress application mechanism are placed inside the test chamber.

[0052] In use, after placing the cable material sample to be tested and applying a preset external stress, the main body of the testing device, consisting of base 1, fixing column 2, and stress application device, can be placed directly in the outdoor natural environment or inside the aforementioned test chamber. A heating or cooling device can be used to heat or cool the test chamber to a preset temperature, thereby simulating performance testing in an environment closely resembling real-world scenarios. For example, the following four test conditions can be used:

[0053] The first test condition: outdoor natural environment, unobstructed, 3-6 months; that is, after applying external stress, the main body of the test device is placed directly in the outdoor natural environment without any box or cover, without any obstruction, and placed for 3-6 months before observing the sample.

[0054] The second test condition is: 130℃ or 150℃, 1h, 1~7kg load; that is, when adding counterweight 6, add a counterweight 6 with a load of 1~7kg to each hammer 4. After applying external stress, place the main body of the test device in the test box, use the heating device to heat the test box to 130℃ or 150℃, place it for 1h, and then observe the sample.

[0055] The third test condition: -40℃, 4h, 1~7kg load; that is, when adding counterweight 6, add a counterweight 6 with a load of 1~7kg to each pressure hammer 4, apply external stress, place the main body of the test device in the test chamber, use the refrigeration device to cool the test chamber to 1-40℃, place for 4h, and then observe the sample.

[0056] The fourth test condition: -40℃ to +40℃ or (70℃, 90℃, 130℃) high and low temperature cycling for 5 days; that is, after applying external stress, the main body of the test device is placed in the test chamber, and the high and low temperature cycle is applied to the test chamber using heating and cooling devices, and the sample is observed after 5 days.

[0057] Of course, the specific test conditions depend on the actual test requirements; the four test conditions mentioned above are only illustrative examples. After placing the sample under the set test conditions for a preset time, remove the sample for observation and check whether it breaks or shows stress whitening, thereby evaluating its stress cracking resistance.

[0058] In summary, the testing device of this application has the following advantages:

[0059] (1) It can be used to test the stress cracking resistance of cable materials, evaluate the stress cracking resistance of cable materials, and improve the quality control capabilities of cable materials manufacturers.

[0060] (2) The device applies external stress through counterweight 6 on the one hand, and places the device with fixed stress and the cable material sample to be tested in different environments on the other hand, so as to comprehensively evaluate the crack resistance of the material.

[0061] (3) This device combines the cable laying environment and application scenario to test the stress resistance of cable materials. Using this device to test the stress cracking resistance is closer to actual application.

[0062] (4) The testing method of this device is more suitable for the application scenarios of cable materials and can be applied to different testing conditions, especially different stress and temperature conditions. The device is easy to operate, has little human interference, and the test results are consistent.

[0063] The above are merely illustrative embodiments of this utility model and are not intended to limit the scope of this utility model. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of this utility model should fall within the protection scope of this utility model.

Claims

1. A device for testing the stress cracking resistance of cable materials, characterized in that, include: The base has at least one sample box on its top surface for placing a sample of the cable material to be tested; Multiple fixed columns are vertically mounted on the base; A stress application mechanism includes a top plate and at least one pressure hammer vertically disposed on the bottom surface of the top plate. The top plate is disposed parallel to and spaced above the base. The bottom end of the pressure hammer can press against the corresponding sample of the cable material to be tested. The top plate can move up and down relative to the base and can be locked and fixed by a locking assembly. The locking and fixed position of the top plate can be determined by at least one counterweight placed on the stress application mechanism, and the counterweight can be removed after the top plate is locked and fixed.

2. The cable material stress cracking resistance testing device as described in claim 1, characterized in that, The locking assembly includes multiple locking nuts, the top of the fixing column is provided with external threads, the top plate is provided with multiple mounting holes, and the top plate is sleeved on the multiple fixing columns through the multiple mounting holes; the locking nut can be threaded to the top of the fixing column after the counterweight is placed on the stress application mechanism, and abuts against the top surface of the top plate.

3. The cable material stress cracking resistance testing device as described in claim 1, characterized in that, The pressure hammer includes a connecting column and a hammer head connected vertically. The width of the hammer head is greater than the diameter of the connecting column. The top of the connecting column is connected to the top plate, and the bottom of the hammer head is used to press against the corresponding sample of the cable material to be tested.

4. The cable material stress cracking resistance testing device as described in claim 3, characterized in that, The hammer head is a triangular prism structure, and the top and bottom faces of the prism are both right triangles. The side face of the prism corresponding to one of the right-angled sides of the right triangle is arranged horizontally downward and can press against the cable material sample to be tested.

5. The cable material stress cracking resistance testing device as described in claim 3, characterized in that, The bottom of the hammer head is arc-shaped.

6. The cable material stress cracking resistance testing device as described in claim 3, characterized in that, The counterweight has a notch, through which it can be inserted into the corresponding fixed post and abut against the hammer head.

7. The cable material stress cracking resistance testing device as described in claim 1, characterized in that, There are multiple sample boxes and multiple pressure hammers.

8. The cable material stress cracking resistance testing device as described in claim 1, characterized in that, A connecting crossbar is connected between at least two adjacent fixed posts.

9. The cable material stress cracking resistance testing device as described in claim 8, characterized in that, Both the base and the top plate are rectangular plates. There are four fixing columns distributed at the four corners of the base, and two connecting crossbars located at both ends of the base along its length.

10. The cable material stress cracking resistance testing device as described in claim 1, characterized in that, The cable material stress cracking resistance testing device also includes a test chamber, which is equipped with a heating device and / or a cooling device. The base, the fixing column and the stress application mechanism are placed inside the test chamber.

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