Cable thermal extension test device

Abstract

The utility model discloses a cable thermal extension test device which comprises a drying oven with an oven door, an observation window is arranged on the oven door or the drying oven, and a rotary sample holder for placing a plurality of samples is arranged in the drying oven. A sample shearing assembly capable of shearing a sample is arranged on one side of the rotary sample holder in the drying oven through a vertical moving assembly, and a control operation box for controlling the working and speed of the vertical moving assembly, the working of the test shearing assembly, the working and rotation angle of the rotary fixing assembly and the temperature in the drying oven is arranged on the drying oven. Due to the fact that the sample is provided with the upper marker line and the lower marker line, when the sample shearing assembly moves downwards under the action of the up-down moving assembly, the elongation can be calculated, meanwhile, the sample load is relieved through the sample shearing assembly, and box opening in the whole process is not needed. Therefore, test errors caused by temperature loss or temperature fluctuation due to box opening can be effectively avoided, and meanwhile the risk that testers are scalded is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of heat elongation test equipment, and particularly relates to a cable heat elongation test device. Background Art

[0002] The cross-linked insulating material or sheath material needs to undergo a heat elongation test to determine its cross-linking degree. The heat elongation test is to measure the elongation rate of the insulating layer or sheath layer of a cross-linked cable under heat and load, as well as the permanent deformation after cooling. The method standard on which the test is based is GB / T 2951.21-2008. After the specimen for the heat elongation test is kept in an oven at a specified temperature for a specified time, the load under the specimen needs to be removed. Usually, it is necessary to manually open the oven door, remove the load manually, and then close the oven door to allow the temperature inside the box to rise again. The temperature inside the oven during the cable heat elongation test is usually 200°C. Therefore, when opening the oven to manually remove the load, it is easy to cause scalding of personnel. At the same time, opening the box door will cause a large amount of heat loss, resulting in a large temperature fluctuation inside the box and affecting the accuracy of the test results. Content of the Utility Model

[0003] The utility model intends to propose a cable heat elongation test device, which can effectively avoid test errors caused by temperature loss or fluctuation after opening the box, and at the same time reduce the risk of scalding of test personnel.

[0004] For this purpose, the technical solution adopted by the utility model is as follows: A cable heat elongation test device includes an oven with a box door, an observation window is provided on the box door or the oven, a rotating specimen rack for placing multiple specimens is arranged inside the oven, a specimen shearing assembly capable of shearing the specimen is arranged on one side of the rotating specimen rack inside the oven through an up-and-down moving assembly, and a control operation box for controlling the operation and speed of the up-and-down moving assembly, the operation of the test shearing assembly, the operation and rotation angle of the rotating fixing assembly, and the temperature inside the oven is equipped on the oven.

[0005] As a preference in the above solution, the rotating specimen rack includes a rotating shaft extending up and down inside the oven, at least one support arm for installing a specimen assembly is arranged in the middle of the rotating shaft, and a dividing plate for driving the rotating shaft to rotate by a fixed angle is arranged after the upper end of the rotating shaft passes through the oven.

[0006] Further preferably, the specimen assembly includes an upper chuck for clamping the upper end of the specimen and a lower chuck for clamping the specimen. The upper chuck is installed on the support arm, and a weight hook for loading weights is arranged on the lower chuck and extends downward.

[0007] Further preferably, a plurality of support arms are circumferentially and uniformly arranged in the middle of the rotating shaft.

[0008] Further preferably, the vertical movement component includes a lead screw shaft extending vertically inside the oven. A moving module is screwed onto the lead screw shaft. The specimen shearing component is arranged on the moving module. The upper end of the lead screw shaft passes through the oven and is provided with a variable frequency speed regulating motor for driving the lead screw shaft to rotate.

[0009] Further preferably, a guide shaft for ensuring the vertical movement of the moving module is arranged vertically inside the oven.

[0010] Further preferably, the test shearing component includes a movable blade and a fixed blade. A shearing blade edge is arranged at one end of the movable blade opposite to the fixed blade. One end of the fixed blade is arranged on the vertical movement component through a fixed rod. The movable blade is arranged in a shape of '7'. The corner of the movable blade is arranged on the fixed blade through a hinge shaft. A limiting shaft is arranged at one end of the movable blade except the shearing blade edge. A limiting groove is arranged on the fixed blade, and the limiting shaft is located in the limiting groove. A return spring for keeping the movable blade and the fixed blade in an open state is arranged on the fixed blade and the movable blade. A driving component for realizing the movement of the limiting shaft in the limiting groove is arranged on the limiting shaft. When the driving component works, it can drive the limiting shaft to move in the limiting groove, so as to realize the rotation of the shearing blade edge of the movable blade towards the fixed blade.

[0011] Further preferably, the driving component includes a traction rope fixed at one end on the limiting shaft. A turning wheel is arranged on the vertical movement component. A cam and a fixed column are arranged outside the oven, and the cam can rotate under the action of a driving motor. The other end of the traction rope first passes through the fixed rod, then bypasses the turning wheel and the cam in sequence and is fixed on the fixed column. When the driving motor works, the rotation of the cam can lift the traction rope, so that the limiting shaft moves towards one end of the fixed rod in the limiting groove, thereby realizing the rotation of the shearing blade edge of the movable blade towards the fixed blade.

[0012] The beneficial effects of the present utility model are as follows: Since there are two upper and lower marking lines with a spacing of 10 mm or 20 mm in the middle of the specimen, when the specimen shearing component moves downward under the action of the vertical movement component, timing starts when the upper mark is encountered and ends when the lower mark is encountered. Then, according to the moving speed, the length of the specimen after elongation can be calculated, that is, the calculation of the elongation rate is realized. At the same time, the load on the specimen can be removed through the specimen shearing component, so that it is not necessary to open the box halfway during the whole process, thereby effectively avoiding the test error caused by the temperature loss due to opening the box, and at the same time reducing the risk of scalding for the test personnel. Description of the Drawings

[0013] Figure 1 is the external schematic diagram of the present utility model.

[0014] Figure 2 is the schematic diagram of the present utility model.

[0015] Figure 3 This is a schematic diagram of the sample shearing assembly in the present utility model.

[0016] Figure 4 This is a schematic diagram of the display interface of the control display panel in the present utility model.

[0017] Reference numerals: oven - 1, box door - 2, observation window - 3, rotating shaft - 4, support arm - 5, sample - 6, upper chuck - 7, lower chuck - 8, weight hook - 9, weight - 10, lead screw shaft - 11, moving module - 12, movable blade - 13, fixed blade - 14, limit groove - 14a, fixed rod - 15, hinge shaft - 16, limit shaft - 17, towing rope - 18, steering wheel - 19, cam - 20, fixed column - 21. Detailed implementation manners

[0018] The following further illustrates the present utility model through embodiments in conjunction with the accompanying drawings:

[0019] As Figures 1-4 shown, a cable thermal elongation test device mainly consists of an oven 1, a rotating sample rack, a sample shearing assembly, an up - and - down moving assembly, and a control operation box. Among them, the oven adopts an electric oven with a box door 2 and an observation window 3 in the prior art. Preferably, the observation window is arranged in the middle of the box door.

[0020] A rotating sample rack for placing multiple samples is arranged in the oven 1. At the same time, a sample shearing assembly capable of cutting the sample is arranged on one side of the rotating sample rack in the oven 1 through the up - and - down moving assembly. The oven is equipped with a control operation box for controlling the operation and speed of the up - and - down moving assembly, the operation of the test shearing assembly, the operation and rotation angle of the rotating fixing assembly, and the temperature in the oven.

[0021] The specific structure of the rotating sample rack includes a rotating shaft 4 extending up and down in the oven 1. At least one support arm 5 for installing the sample assembly is arranged in the middle of the rotating shaft 4. A dividing disc for driving the rotating shaft 4 to rotate by a fixed angle is arranged after the upper end of the rotating shaft 4 passes through the oven 1.

[0022] A plurality of support arms 5 are circumferentially and evenly arranged in the middle of the rotating shaft 4. Preferably, three to six support arms are circumferentially and evenly arranged on the rotating shaft, so that multiple samples can be tested synchronously during each test.

[0023] The specimen assembly includes an upper chuck 7 for clamping the upper end of the specimen 6 and a lower chuck 8 for clamping the specimen. The upper chuck 7 is installed on the support arm 5. At the same time, a weight hook 9 for loading weights 10 is provided on the lower chuck 8 and extends downward, so that weights can be added to the weight hook to apply the load required by the standard to the sample. Among them, the upper chuck and the lower chuck are prior arts. To facilitate the collection of the weights after the load is removed, a weight collection tray is also provided below the specimen holder on the rotating shaft.

[0024] The specific structure of the up-and-down moving assembly includes a lead screw shaft 11 extending up and down in the oven 1. A moving module 12 is screwed onto the lead screw shaft 11, and the specimen shearing assembly is arranged on the moving module 12. The upper end of the lead screw shaft 11 passes through the oven 1 and is provided with a variable-frequency speed-regulating motor for driving the rotation of the lead screw shaft 11. The variable-frequency speed-regulating motor drives the rotation of the lead screw shaft to realize the up-and-down movement of the moving module, so as to realize the up-and-down movement of the specimen shearing assembly. Due to the use of a variable-frequency speed-regulating motor, it can adjust the speeds of the upstroke and downstroke of the specimen shearing assembly as needed. Preferably, when moving downward, the speed of the variable-frequency speed-regulating motor is appropriately reduced so that the moving speed of the specimen shearing assembly is less than 100 mm / min, and when moving upward, the moving speed can be appropriately increased.

[0025] To ensure the stability of the up-and-down movement of the moving module, guide shafts for ensuring the up-and-down movement of the moving module 12 are arranged up and down in the oven 1. Preferably, at least two or four guide shafts are provided, and the guide shafts and the moving module are in sliding fit.

[0026] To facilitate the operation of the specimen shearing assembly outside the oven to remove the load on the specimen, the specific structure of the test shearing assembly includes a movable blade 13 and a fixed blade 14. A shearing edge is provided at one end of the movable blade 13 opposite to the fixed blade 14, and one end of the fixed blade 14 is arranged on the up-and-down moving assembly through a fixing rod 15. To realize the movable fixation of the movable blade, the movable blade 13 is set in a 7-shaped form. At the same time, the corner of the movable blade 13 is arranged on the fixed blade 14 through a hinge shaft 16. A limit shaft 17 is arranged at one end of the movable blade 13 except for the shearing edge, a limit groove 14a is arranged on the fixed blade 14, and the limit shaft 17 is located in the limit groove 14a. At the same time, a return spring for keeping the movable blade 13 and the fixed blade 14 in an open state is arranged on the fixed blade 14 and the movable blade 13.

[0027] To realize the opening and closing of the movable blade, a driving assembly for realizing the movement of the limit shaft 17 in the limit groove 14a is arranged on the limit shaft 17. When the driving assembly works, it can drive the limit shaft 17 to move in the limit groove 14a, so as to realize the rotation of the shearing edge of the movable blade 13 towards the fixed blade 14.

[0028] The driving assembly includes a towing rope 18 with one end fixed to the limit shaft 17. A steering wheel 19 is provided on the up-and-down moving assembly. A cam 20 and a fixed column 21 are provided outside the oven 1, and the cam 20 can rotate under the action of a driving motor. The other end of the towing rope 18 first passes through the fixed rod 15, then successively bypasses the steering wheel 19 and the cam 20 and is fixed to the fixed column 21. When the driving motor works, the rotation of the cam can lift the towing rope 18, so that the end of the towing rope between the steering wheel and the cam moves upward after being stressed, and the towing rope between the limit shaft and the steering wheel moves towards the lead screw shaft, thereby driving the limit shaft 17 in the sample shearing assembly to move towards one end of the fixed rod 15 in the limit groove 14a, realizing the rotation of the shearing edge of the movable blade 13 towards the fixed blade 14.

[0029] Preferably, a temperature sensor for detecting the temperature inside the oven is further equipped in the oven. The control operation box is electrically connected to the indexing plate, the variable frequency speed regulating motor, the driving motor, the control display panel, the temperature sensor and the heating assembly inside the oven. The control operation box adopts the prior art including a control display panel with an interaction function and a control system for realizing information reception, transmission and processing. The display interface of the control display panel can be as Figure 4 shown.

[0030] In this embodiment, the length of the sample after elongation can be calculated by the time and speed of the downward movement of the sample shearing assembly. The specific operation is as follows: Since there are two upper and lower marking lines marked on the sample, when the sample shearing assembly moves downward under the action of the up-and-down moving assembly, timing starts when the upper marking line is encountered and ends when the lower marking line is encountered. Then, the length of the sample after elongation can be calculated according to the moving speed.

[0031] Since there are multiple support arms, to facilitate the measurement of the samples installed on the other support arms, after the previous sample is unloaded, the sample shearing assembly continues to move downward until it stops below the sample. Then the indexing plate works, and through the rotation of the rotating shaft, the next fixed support moves to the position corresponding to the sample shearing assembly. Then the sample shearing assembly quickly moves upward under the action of the up-and-down moving assembly. When it exceeds the upper marking line, it stops moving, and then repeats the above process of sample measurement and load unloading.

[0032] Therefore, when using this embodiment for testing, it includes the following steps:

[0033] 1. Installation of the sample. First, fix the lower chuck at the lower end of the sample, and at the same time load the load weight meeting the standard requirements on the weight hook. Then open the box door, fix the sample with the load on the upper chuck. After the fixing is completed, close the box door.

[0034] 2. Calculation of elongation rate. After the temperature in the oven reaches the standard temperature within the specified time and remains at this temperature for a certain period, when the specimen shearing assembly moves downward under the action of the up-and-down moving assembly and starts timing when it encounters the upper marking line of the specimen, and ends timing when it encounters the lower marking line. Then, based on the moving speed, the length of the specimen after elongation can be calculated, and through the fixed length between the upper and lower marking lines before elongation, the elongation rate can be calculated.

[0035] 3. Removal of the load. After the measurement of the elongation length is completed, the specimen shearing assembly continues to move downward. When it moves to a suitable shearing position below the lower marking line, the drive motor operates, causing the movable blade to move towards the fixed blade, thereby cutting the specimen, and the load is removed.

[0036] 4. Calculation of elongation rate and removal of load for all specimens. When the specimen shearing assembly stops moving after moving below the next specimen, then the indexing plate operates. Through the rotation of the rotating shaft, the next support arm moves to the position corresponding to the specimen shearing assembly. Then the specimen shearing assembly quickly moves upward under the action of the up-and-down moving assembly. When it exceeds the upper marking line, it stops moving. Then repeat steps 2 and 3 until the calculation of elongation rate and removal of load for all specimens are completed.

[0037] 5. Completion of the test. Leave the specimen after load removal in the oven for a period of time, then take out the specimen and slowly cool it to room temperature, and measure the length between the upper and lower marking lines again after cooling.

Claims

1. A cable thermal elongation test device, comprising an oven (1) with a door (2), and an observation window (3) is provided on the door (2) or the oven (1), characterized in that: A rotary sample rack for placing a plurality of samples is provided inside the oven (1). A sample shearing assembly capable of shearing the samples is provided on one side of the rotary sample rack inside the oven (1) through an up-and-down moving assembly. The oven is equipped with a control operation box for controlling the operation and speed of the up-and-down moving assembly, the operation of the test shearing assembly, the operation and rotation angle of the rotary fixing assembly, and the temperature inside the oven.

2. The cable thermal elongation test device according to claim 1, characterized in that: The rotary sample rack includes a rotary shaft (4) extending vertically inside the oven (1). At least one support arm (5) for installing a sample assembly is provided in the middle of the rotary shaft (4). A dividing plate for driving the rotary shaft (4) to rotate by a fixed angle is provided after the upper end of the rotary shaft (4) passes through the oven (1).

3. The cable thermal elongation test device according to claim 2, characterized in that: The sample assembly includes an upper chuck (7) for clamping the upper end of the sample (6) and a lower chuck (8) for clamping the sample. The upper chuck (7) is installed on the support arm (5). A weight hook (9) for loading weights (10) is provided on the lower chuck (8) and extends downward.

4. The cable thermal elongation test device according to claim 2, characterized in that: A plurality of support arms (5) are evenly arranged circumferentially in the middle of the rotary shaft (4).

5. The cable thermal elongation test device according to claim 1, characterized in that: The up-and-down moving assembly includes a lead screw shaft (11) extending vertically inside the oven (1). A moving module (12) is screwed on the lead screw shaft (11). The sample shearing assembly is arranged on the moving module (12). A variable frequency speed regulating motor for driving the lead screw shaft (11) to rotate is provided after the upper end of the lead screw shaft (11) passes through the oven (1).

6. The cable thermal elongation test device according to claim 5, wherein: A guide shaft for ensuring the up-and-down movement of the moving module (12) is vertically arranged inside the oven (1).

7. The cable thermal elongation test device according to claim 1, characterized in that: The test shearing assembly includes a movable blade (13) and a fixed blade (14). A shearing blade edge is provided at one end of the movable blade (13) opposite to the fixed blade (14). One end of the fixed blade (14) is arranged on the up-and-down moving assembly through a fixed rod (15). The movable blade (13) is arranged in a shape of '7'. The corner of the movable blade (13) is arranged on the fixed blade (14) through a hinge shaft (16). A limiting shaft (17) is provided at one end of the movable blade (13) except the shearing blade edge. A limiting groove (14a) is provided on the fixed blade (14), and the limiting shaft (17) is located in the limiting groove (14a). A return spring for keeping the movable blade (13) and the fixed blade (14) in an open state is provided on the fixed blade (14) and the movable blade (13). A driving assembly for realizing the movement of the limiting shaft (17) in the limiting groove (14a) is provided on the limiting shaft (17). When the driving assembly works, it can drive the limiting shaft (17) to move in the limiting groove (14a), so as to realize the rotation of the shearing blade edge of the movable blade (13) towards the fixed blade (14).

8. The cable thermal elongation test device according to claim 7, characterized in that: The driving component includes a traction rope (18) with one end fixed to the limit shaft (17). A steering wheel (19) is arranged on the vertical movement component. A cam (20) and a fixed column (21) are arranged outside the oven (1), and the cam (20) can rotate under the action of a driving motor. The other end of the traction rope (18) first passes through the fixed rod (15), then bypasses the steering wheel (19) and the cam (20) in sequence, and is fixed to the fixed column (21). When the driving motor works, the rotation of the cam can lift the traction rope (18), so that the limit shaft (17) moves towards the end of the fixed rod (15) in the limit groove (14a), thereby realizing the rotation of the cutting edge of the movable blade (13) towards the fixed blade (14).

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