Cold shield fastener cold and hot cycle test device and test method

Abstract

The invention discloses a cold screen fastener cold and hot cycle test device and test method, and belongs to the technical field of cold screen fastener anti-loosening test. In the device, a workpiece assembly is arranged in a heat insulation vacuum container and comprises a first workpiece and a second workpiece; the fastener comprises a screw rod, a gasket and a nut and is used for fastening the first workpiece and the second workpiece; the cooling assembly is arranged on the workpiece assembly and used for cooling the workpiece assembly and the fastener; the heating assembly is arranged in the heat insulation vacuum container and used for heating the workpiece assembly and the fastener. The temperature sensor is arranged on the workpiece assembly and used for measuring the temperature. The pressure sensor is arranged between the first workpiece and the second workpiece and used for measuring the clamping force of the fastener. According to the invention, a cold and hot cycle test can be carried out on fasteners of various anti-loosening schemes to evaluate the anti-loosening effect of the fasteners, the anti-loosening effect of the fasteners can be optimized, the structure is simple, the cost is low, and the test operation is convenient.

Description

Technical Field

[0001] The present invention belongs to the technical field of cold shield fastener loosening prevention tests, and particularly relates to a cold shield fastener thermal cycling test device and a test method. Background Art

[0002] In a cold shield structure of a fusion device, it is generally divided into multiple cold shield plates, which are connected by bolts. During the installation, commissioning, operation, and shutdown maintenance processes of the fusion device, the cold shield structure will experience multiple thermal cycling processes from normal temperature (about 300K) to low temperature (about 80K) and then back to normal temperature (about 300K). The cold shield structure needs to maintain structural stability throughout the life cycle of the fusion device. Moreover, a large number of bolts are used in the cold shield structure. After the fusion device is installed, it is impossible to perform secondary pre-tightening inspection on the bolts in most places of the cold shield structure. Therefore, it is required that the bolt-connected structure still maintains the pre-tightening force effect as designed after experiencing multiple thermal cycles. During the research and development process of the cold shield structure, various anti-loosening solutions for bolts need to be tested to evaluate the anti-loosening effect. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. For this reason, an object of the present invention is to provide a cold shield fastener thermal cycling test device and a test method, which can perform thermal cycling tests on fasteners with various anti-loosening solutions to evaluate the anti-loosening effect of the fasteners, can optimize the anti-loosening effect of the fasteners, has a simple structure, low cost, and convenient test operation.

[0004] According to an embodiment of the present invention, the cold shield fastener thermal cycling test device includes: A heat-insulating vacuum container; A workpiece assembly, which is arranged in the heat-insulating vacuum container and includes a first workpiece and a second workpiece; A fastener, which includes a screw rod, a gasket, and a nut. The screw rod is used to pass through the second workpiece, the first workpiece, and the gasket and is threadedly engaged with the nut to fasten the first workpiece and the second workpiece; A cooling assembly, which is arranged on the workpiece assembly and is used to cool the workpiece assembly and the fastener; A heating assembly, which is arranged in the heat-insulating vacuum container and is used to heat the workpiece assembly and the fastener; A temperature sensor, which is arranged on the workpiece assembly and is used to measure the temperature; A pressure sensor, which is arranged between the first workpiece and the second workpiece and is used to measure the clamping force of the fastener.

[0005] The cold screen fastener thermal cycling test device according to the embodiments of the present invention has the following advantages: On the one hand, it can perform thermal cycling tests on the fasteners (bolts) of various anti-loosening schemes that may be applied to the cold screen structure of a fusion device to evaluate the anti-loosening effect of the fasteners, so as to select the fasteners that still have good locking effects under changing ambient temperatures, ensuring the structural stability of the cold screen structure throughout the life cycle of the fusion device; on the other hand, when the fasteners are evaluated to have a poor anti-loosening effect after the thermal cycling test, the nuts, gaskets or screws of different materials or structures can be replaced and the thermal cycling test of the fasteners can be carried out again, so as to select the nuts, gaskets or screws of appropriate materials or structures and optimize the anti-loosening effect of the fasteners. On the further hand, the cold screen fastener thermal cycling test device according to the embodiments of the present invention is not limited to performing thermal cycling tests on the fasteners (bolts) that may be applied to the cold screen structure of a fusion device, but can also perform thermal cycling tests on the anti-loosening fasteners in other application scenarios with temperature changes. In addition, the cold screen fastener thermal cycling test device 1000 according to the embodiments of the present invention has a simple structure, low cost, convenient test operation and reliable test data.

[0006] In some embodiments, the heat-insulating vacuum container includes a vacuum container and a heat-insulating layer coated on the outer surface of the vacuum container.

[0007] In some embodiments, the first workpiece is a gantry, the first workpiece is directly supported inside the heat-insulating vacuum container, a positioning concave hole for fitting and placing the second workpiece is provided on one side surface of the first workpiece, and a first screw hole is provided at the bottom of the positioning concave hole; the second workpiece is a pressing block, and the second workpiece is provided with a second screw hole; when the second workpiece is placed in the positioning concave hole, the second screw hole is coaxial with the first screw hole.

[0008] In some embodiments, the second workpiece includes a column section and a stop portion connected to an axial end of the column section, the outer diameter dimension of the column section is adapted to the inner diameter dimension of the positioning concave hole, the outer diameter dimension of the stop portion is larger than the inner diameter dimension of the positioning concave hole, and the second screw hole axially penetrates through the column section and the stop portion; when the column section is fitted and placed in the positioning concave hole, there is a gap between the end surface of the column section and the bottom surface of the positioning concave hole, the stop portion is located outside the positioning concave hole and is opposite to one side surface of the first workpiece, and the pressure sensor is arranged between the stop portion and one side surface of the first workpiece.

[0009] In some embodiments, there are multiple pressure sensors, and the multiple pressure sensors are arranged at intervals along the circumferential direction of the column section between the stop portion and one side surface of the first workpiece.

[0010] In some embodiments, the cooling assembly includes a cooling pipeline, which is arranged on the surface of the first workpiece and around the first screw hole, and the cooling pipeline cools the workpiece assembly and the fastener by introducing a cooling medium.

[0011] In some embodiments, the cooling medium is liquid nitrogen, cryogenic helium or liquid helium.

[0012] In some embodiments, the temperature sensors are distributed on the first workpiece and / or the second workpiece.

[0013] In some embodiments, the heating assembly includes heating resistance wires.

[0014] According to the test method of the cold shield fastener thermal cycling test device of the embodiment of the present invention, the following steps are included: S1: Use the fastener to lock the first workpiece and the second workpiece so that the clamping force of the fastener reaches the design torque; wherein, the pressure sensor is arranged between the first workpiece and the second workpiece, and the temperature sensor is arranged on the first workpiece and / or the second workpiece and close to the fastener, and the clamping force and temperature changes are monitored in real time through the pressure sensor and the temperature sensor; S2: Seal the heat-insulating vacuum container, use the heating assembly to dehumidify the heat-insulating vacuum container, and use a vacuum pumping device to evacuate the heat-insulating vacuum container; S3: Use the cooling assembly to cool down to the lower limit temperature, and after the lower limit temperature remains stable for a first preset time period, stop the cooling of the cooling assembly; S4: Use the heating assembly to heat the internal space environment of the heat-insulating vacuum container to the upper limit temperature, and after the upper limit temperature remains stable for a second preset time period, stop the heating of the heating assembly; S5: Repeat steps S3 and S4. After reaching the required number of thermal cycling tests or when the clamping force is lower than the required range, output the curve graphs of the temperature measured by the temperature sensor and the clamping force measured by the pressure sensor over time during the whole process.

[0015] Since the test method of the cold shield fastener thermal cycling test device of the embodiment of the present invention uses the cold shield fastener thermal cycling test device of the above-mentioned embodiment of the present invention, therefore, the test method of the cold shield fastener thermal cycling test device of the embodiment of the present invention has basically the same technical effects as the cold shield fastener thermal cycling test device of the above-mentioned embodiment of the present invention, and will not be elaborated here.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 is a schematic structural diagram of a cold screen fastener thermal cycling test device according to an embodiment of the present invention; Figure 2 is an enlarged schematic diagram of a partial structure of a cold screen fastener thermal cycling test device according to an embodiment of the present invention; Figure 3 is a temperature and clamping force curve diagram output by a test method of a cold screen fastener thermal cycling test device according to an embodiment of the present invention.

[0018] Reference numerals: Cold screen fastener thermal cycling test device 1000; heat-insulating vacuum container 1; vacuum container 101; heat-insulating layer 102; workpiece assembly 2; first workpiece 201; positioning concave hole 2011; first screw hole 2012; platen 2013; second workpiece 202; second screw hole 2021; column section 2022; stop portion 2023; fastener 3; screw 301; gasket 302; nut 303; cooling assembly 4; cooling pipeline 401; heating assembly 5; heating resistance wire 501; temperature sensor 6; pressure sensor 7. Detailed Description of the Embodiments

[0019] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0020] Next, in conjunction with Figures 1 to 3 a cold screen fastener thermal cycling test device 1000 and a test method according to an embodiment of the present invention will be described.

[0021] As Figures 1 to 3 shown, a cold screen fastener thermal cycling test device 1000 according to an embodiment of the present invention includes a heat-insulating vacuum container 1, a workpiece assembly 2, a fastener 3, a cooling assembly 4, a heating assembly 5, a temperature sensor 6, and a pressure sensor 7.

[0022] Specifically, the heat-insulating vacuum container 1 mainly provides an environmental space for the thermal cycling test of the fastener 3. The heat-insulating vacuum container 1 can make the internal test environment temperature of itself not affected by the external environment temperature, which is beneficial to the smooth progress of the test.

[0023] The workpiece assembly 2 is arranged in the heat-insulating vacuum container 1 and includes a first workpiece 201 and a second workpiece 202. The first workpiece 201 and the second workpiece 202 are two workpieces that need to be locked and connected together by a fastener 3.

[0024] The fastener 3 includes a screw 301, a gasket 302 and a nut 303. The screw 301 is used to pass through the second workpiece 202, the first workpiece 201 and the gasket 302 and is threadedly engaged with the nut 303 to fasten the first workpiece 201 and the second workpiece 202. The fastener 3 is the object of the anti-loosening test of the cold shield fastener thermal cycling test device 1000 of the embodiment of the present invention. It should be noted that the arrangement direction of the fastener 3 can be selected according to the arrangement direction of the fastener 3 in the actual use scenario, so that the force condition of the fastener 3 is more in line with the force condition of the fastener 3 in the actual use scenario; for example, if the arrangement direction of the fastener 3 in the actual use scenario is vertically arranged and the nut 303 of the fastener 3 is located on the upper side of the workpiece to be fastened, then the arrangement direction of the fastener 3 in the embodiment of the present invention can be selected as Figure 1 and Figure 2 the vertical arrangement shown. If the arrangement direction of the fastener 3 in the actual use scenario is horizontally arranged, then the arrangement direction of the fastener 3 in the embodiment of the present invention can be selected as the horizontal arrangement (not shown in the figure).

[0025] The cooling component 4 is arranged on the workpiece component 2 and is used for cooling the workpiece component 2 and the fastener 3. The heating component 5 is arranged in the heat-insulating vacuum container 1 and is used for heating the workpiece component 2 and the fastener 3. By means of the cooling component 4 and the heating component 5, the ambient temperature in the heat-insulating vacuum container 1 can be controlled and changed, enabling the workpiece component 2 and the fastener 3 to experience a cold and hot cycle process; for example, when conducting a cold and hot cycle test on the fastener 3 of various solutions that may be applied to the cold screen structure of a fusion device, the workpiece component 2 and the fastener 3 can be cooled from room temperature to low temperature and stably maintained at low temperature for a period of time through the cooling component 4, and the workpiece component 2 and the fastener 3 can be heated from low temperature to room temperature and stably maintained at room temperature for a period of time through the heating component 5. Then, the workpiece component 2 and the fastener 3 can be cooled from room temperature to low temperature and stably maintained at low temperature for a period of time through the cooling component 4 again, and the workpiece component 2 and the fastener 3 can be heated from low temperature to room temperature and stably maintained at high temperature for a period of time through the heating component 5 again. By repeating this cycle, the workpiece component 2 and the fastener 3 can experience a cold and hot cycle process. Another example is that when conducting a cold and hot cycle test on the anti-loosening fastener 3 in other application scenarios with temperature changes, according to the temperature environment requirements of the test, the workpiece component 2 and the fastener 3 are heated from room temperature to high temperature and stably maintained at high temperature for a period of time through the heating component 5, and the workpiece component 2 and the fastener 3 are cooled from high temperature to room temperature and stably maintained at room temperature for a period of time through the cooling component 4. Then, the workpiece component 2 and the fastener 3 are heated from room temperature to high temperature and stably maintained at high temperature for a period of time through the heating component 5 again, and the workpiece component 2 and the fastener 3 are cooled from high temperature to room temperature and stably maintained at room temperature for a period of time through the cooling component 4 again. By repeating this cycle, the workpiece component 2 and the fastener 3 can experience a cold and hot cycle process. Thus, the temperature change of the actual application site of the fastener 3 can be simulated through the cooling component 4, the heating component 5, and the heat-insulating vacuum container 1.

[0026] The temperature sensor 6 is arranged on the workpiece component 2 and is used for measuring temperature. Since the fastener 3 is in contact connection with the first workpiece 201 and the second workpiece 202, when the cooling component 4 cools or the heating component 5 heats, heat conduction can occur between the fastener 3, the first workpiece 201, and the second workpiece 202, and the temperature measured by the temperature sensor 6 can basically represent the temperature of the workpiece component 2 and the fastener 3. In addition, the temperature sensor 6 is arranged on the workpiece component 2, and the arrangement is relatively convenient.

[0027] The pressure sensor 7 is arranged between the first workpiece 201 and the second workpiece 202 and is used for measuring the clamping force of the fastener 3. Whether the fastener 3 is loose can be known through the clamping force measured by the pressure sensor 7.

[0028] The cold screen fastener thermal cycling test device 1000 according to the embodiment of the present invention can perform thermal cycling tests on fasteners 3, i.e., bolts, of various solutions that may be applied to the cold screen structure of a fusion device, so as to evaluate the loosening prevention effects of the fasteners 3 of various solutions, and ensure that the fasteners 3 applied to the cold screen structure of the fusion device maintain the pre-tightening force effect as designed during the entire life cycle of the fusion device, and ensure the stability of the cold screen structure.

[0029] The method for the cold screen fastener thermal cycling test device 1000 according to the embodiment of the present invention to perform thermal cycling tests on fasteners 3 of various loosening prevention solutions that may be applied to the cold screen structure of a fusion device is specifically as follows: First, use the fastener 3 to lock the first workpiece 201 and the second workpiece 202, so that the clamping force of the fastener 3 reaches the designed torque; wherein, the pressure sensor 7 is arranged between the first workpiece 201 and the second workpiece 202, and the temperature sensor 6 is arranged on the first workpiece 201 or the second workpiece 202 and close to the fastener 3, and the clamping force and temperature changes are monitored in real time through the pressure sensor 7 and the temperature sensor 6; then, seal the heat-insulating vacuum container 1, use the heating component 5 to dehumidify the heat-insulating vacuum container 1 and use the vacuum pumping device to pump the heat-insulating vacuum container 1; then, use the cooling component 4 to cool, so that the temperature drops from normal temperature (about 300K) to low temperature (about 80K), and after the low temperature (about 80K) is stable for the first preset time period, stop the cooling of the cooling component 4; then, use the heating component 5 to heat the workpiece assembly 2 and the fastener 3 to normal temperature (about 300K), and after the normal temperature is stable for the second preset time period, stop the heating of the heating component 5; then, repeat step S3 and step S4. After reaching the required number of thermal cycling test times or when the clamping force is lower than the required range, output the curve graph of the temperature measured by the temperature sensor 6 and the clamping force measured by the pressure sensor 7 changing with time during the whole process (reference Figure 3 ), through which the loosening prevention effect of the fastener 3 can be conveniently evaluated.

[0030] Therefore, the cold screen fastener thermal cycling test device 1000 according to the embodiments of the present invention has the following advantages: on the one hand, it can perform thermal cycling tests on the fasteners 3 (bolts) of various anti-loosening schemes that may be applied to the cold screen structure of the fusion device to evaluate the anti-loosening effect of the fasteners 3, so as to select fasteners 3 that still have good locking effects under changing ambient temperatures, ensuring the structural stability of the cold screen structure throughout the life cycle of the fusion device; on the other hand, when the fasteners 3 are evaluated to have poor anti-loosening effects after thermal cycling tests, the nuts 303, washers 302 or screw rods 301 of different materials or structures can be replaced and the thermal cycling tests of the fasteners 3 can be carried out again, so as to select nuts 303, washers 302 or screw rods 301 of appropriate materials or structures and optimize the anti-loosening effect of the fasteners 3. On the other hand, the cold screen fastener thermal cycling test device 1000 according to the embodiments of the present invention is not limited to performing thermal cycling tests on the fasteners 3 (bolts) that may be applied to the cold screen structure of the fusion device, but can also perform thermal cycling tests on anti-loosening fasteners 3 in other application scenarios with temperature changes. In addition, the cold screen fastener thermal cycling test device 1000 according to the embodiments of the present invention has a simple structure, low cost, convenient test operation and reliable test data.

[0031] In some embodiments, the heat-insulating vacuum container 1 includes a vacuum container 101 and a heat-insulating layer 102 coated on the outer surface of the vacuum container 101. The vacuum container 101 needs to meet certain structural strength and can be made of stainless steel. The heat-insulating layer 102 is coated on the outer surface of the vacuum container 101, which can effectively isolate the ambient temperature inside the vacuum container 101 from being affected by the external ambient temperature. It should be noted that for convenient test operation, the heat-insulating vacuum container 1 is an openable and sealable heat-insulating vacuum container 1.

[0032] In some embodiments, the first workpiece 201 is a mounting table, the first workpiece 201 is directly supported inside the heat-insulating vacuum container 1, a positioning concave hole 2011 for fitting and placing the second workpiece 202 is provided on one side surface of the first workpiece 201, and a first screw hole 2012 is provided at the bottom of the positioning concave hole 2011; the second workpiece 202 is a pressing block, and the second workpiece 202 is provided with a second screw hole 2021; when the second workpiece 202 is placed in the positioning concave hole 2011, the second screw hole 2021 is coaxial with the first screw hole 2012.

[0033] By providing the positioning concave hole 2011 on one side surface of the first workpiece 201, when the second workpiece 202 is assembled with the first workpiece 201, the second screw hole 2021 can be coaxially aligned with the first screw hole 2012, which is convenient for the screw rod 301 to pass through the second screw hole 2021, the first screw hole 2012 and the washer 302 and be threadedly engaged with the nut 303 to fasten the second workpiece 202 and the first workpiece 201, improving the assembly convenience and fastening efficiency.

[0034] In some embodiments, the second workpiece 202 includes a column section 2022 and a stop portion 2023 connected to an axial end of the column section 2022. The outer diameter dimension of the column section 2022 is adapted to the inner diameter dimension of the positioning concave hole 2011, the outer diameter dimension of the stop portion 2023 is larger than the inner diameter dimension of the positioning concave hole 2011, and the second screw hole 2021 axially penetrates through the column section 2022 and the stop portion 2023; when the column section 2022 is suitably placed in the positioning concave hole 2011, there is a gap between the end face of the column section 2022 and the bottom surface of the positioning concave hole 2011, the stop portion 2023 is located outside the positioning concave hole 2011 and is opposite to one side surface of the first workpiece 201, and the pressure sensor 7 is arranged between the stop portion 2023 and one side surface of the first workpiece 201.

[0035] By providing the column section 2022 and the stop portion 2023 on the second workpiece 202, it is convenient to assemble the second workpiece 202 to the first workpiece 201 or remove the second workpiece 202 from the first workpiece 201 by operating the stop portion 2023. In particular, the pressure sensor 7 can be very conveniently arranged between the stop portion 2023 and one side surface of the first workpiece 201.

[0036] Further, the first workpiece 201 has a platen 2013, and the positioning concave hole 2011 is opened on the lower surface of the platen 2013. In this way, the second workpiece 202 is placed in the positioning concave hole 2011 from below the platen 2013. After the screw 301 of the fastener 3 sequentially passes through the second screw hole 2021, the first screw hole 2012, and the gasket 302 located on the upper surface of the platen 2013 from below, it is pressed against the upper surface of the gasket 302 by the nut 303 and is threadedly engaged with the nut 303 to lock the second workpiece 202 to the first workpiece 201. Since the nut 303 can be screwed and operated above the platen 2013, it is very convenient to tighten and loosen the nut 303.

[0037] In some embodiments, there are multiple pressure sensors 7, and the multiple pressure sensors 7 are arranged at intervals along the circumferential direction of the column section 2022 between the stop portion 2023 and one side surface of the first workpiece 201. By arranging multiple pressure sensors 7, the accuracy and reliability of the evaluation of the loosening prevention effect of the fastener 3 are further improved.

[0038] In some embodiments, the cooling assembly 4 includes a cooling pipeline 401. The cooling pipeline 401 is arranged on the surface of the first workpiece 201 and around the first screw hole 2012, and the cooling pipeline 401 cools the workpiece assembly 2 and the fastener 3 by introducing a cooling medium. In this way, the workpiece assembly 2 and the fastener 3 can be effectively cooled, and the cooling control is convenient. Moreover, the cooling pipeline 401, the first workpiece 201, and the second workpiece 202 can approximately simulate the fastener 3 and the cold shield plate on the cold shield plate of the fusion device.

[0039] Preferably, the cooling pipeline 401 is arranged on the upper and lower surfaces of the platen 2013 of the first workpiece 201, which is beneficial to improving the cooling efficiency.

[0040] In some embodiments, the cooling medium is liquid nitrogen, cryogenic helium or liquid helium, or other cooling media. It should be noted that liquid nitrogen, cryogenic helium or liquid helium is introduced into the cooling pipeline 401 here, which can simulate the liquid nitrogen, cryogenic helium or liquid helium introduced into the cooling pipeline 401 arranged on the cold shield plate of the fusion device. In this way, it is beneficial for the cold shield fastener thermal cycling test device 1000 of the embodiment of the present invention to perform thermal cycling tests on the fasteners 3 of various anti-loosening schemes that may be applied to the cold shield structure of the fusion device. Among them, when the cooling medium is liquid helium, a lower lower limit temperature can be achieved. For example, the lower limit temperature is 4.2K, which can make the application temperature range of the experiment wider and the lower limit temperature lower (4.2K). In fact, the upper limit temperature can also be a little higher, such as up to 500K.

[0041] In some embodiments, the temperature sensors 6 are distributed on the first workpiece 201 or / and the second workpiece 202 to respectively detect the temperatures of the first workpiece 201 / or and the second workpiece 202. As Figure 1 shown, the temperature sensor 6 is arranged on the second workpiece 202. Specifically, the first workpiece 201 has a platen 2013. The cooling pipeline 401 is arranged on the surface of the first workpiece 201 and around the first screw hole 2012. The positioning concave hole 2011 is opened at the lower surface of the platen 2013. After the screw 301 of the fastener 3 sequentially passes through the second screw hole 2021, the first screw hole 2012 and the gasket 302 located on the upper surface of the platen 2013 from below, it is threadedly engaged with the screw 301 by pressing on the upper surface of the gasket 302 through the nut 303 to lock the second workpiece 202 on the first workpiece 201. The pressure sensor 7 is arranged between the stop portion 2023 and the lower surface of the platen 2013, and the temperature sensor 6 is arranged on the lower surface of the stop portion 2023. Since during the cooling process of the cooling pipeline 401, the cooling process is successively the platen 2013, the gasket 302, the nut 303, the screw 301, and finally the second workpiece 202, therefore, by arranging the temperature sensor 6 on the second workpiece 202, the measured temperature data is reliable and the temperature sensor 6 is convenient to arrange.

[0042] In some embodiments, the number of the temperature sensors 6 can be multiple, and the multiple temperature sensors 6 are distributed on the first workpiece 201 or / and the second workpiece 202. By arranging multiple temperature sensors 6, the accuracy and reliability of the evaluation of the anti-loosening effect of the fastener 3 are further improved.

[0043] In some embodiments, the heating assembly 5 includes a heating resistance wire 501. By heating the spatial environment inside the heat-insulating vacuum container 1, the working assembly 2 and the fastener 3 can be heated, which is convenient for heating.

[0044] Furthermore, there are multiple heating resistance wires 501. The multiple heating resistance wires 501 are spaced apart and distributed above and below the platen 2013 of the first workpiece 201, which can better heat the working assembly 2 and the fastener 3.

[0045] The present invention also proposes a test method for the cold shield fastener thermal cycling test device 1000 of the above embodiments of the present invention. This method can perform thermal cycling tests on the fasteners 3 of various anti-loosening schemes that may be applied to the cold shield structure of a fusion device.

[0046] The test method for the cold shield fastener thermal cycling test device 1000 of the embodiments of the present invention includes the following steps: S1: Use the fastener 3 to lock the first workpiece 201 and the second workpiece 202, so that the clamping force of the fastener 3 reaches the design torque; wherein, the pressure sensor 7 is arranged between the first workpiece 201 and the second workpiece 202, and the temperature sensor 6 is arranged on the first workpiece 201 or / and the second workpiece 202 and close to the fastener 3. The clamping force and temperature changes are monitored in real time through the pressure sensor 7 and the temperature sensor 6.

[0047] S2: Seal the heat-insulating vacuum container 1, use the heating assembly 5 to dehumidify the heat-insulating vacuum container 1, and use the vacuum pumping device to evacuate the heat-insulating vacuum container 1.

[0048] S3: Use the cooling assembly 4 to cool down to the lower limit temperature. After the lower limit temperature remains stable for the first preset time period, stop the cooling of the cooling assembly 4. For example, by introducing liquid nitrogen or low-temperature helium gas into the cooling pipeline 401 of the cooling assembly 4, the temperature measured by the temperature sensor is reduced from room temperature (about 300K) to the lower limit temperature (about 80K), and the lower limit temperature (about 80K) is maintained within the first preset time period. In this step, the speed of the cooling temperature change can be adjusted, for example, by adjusting the temperature and flow rate of the cooling medium, so as to use more severe working conditions or temperature change working conditions that are more in line with actual applications.

[0049] S4: Use the heating component 5 to heat up the space environment inside the heat-insulating vacuum container 1 to the upper limit temperature (about 300K). After keeping the upper limit temperature stable for the second preset time period, stop heating the heating component 5. Specifically, use the heating resistance wire 501 of the heating component 5 to heat up the space environment inside the heat-insulating vacuum container 1, so that the temperature measured by the temperature sensor 6 rises from 80K to the upper limit temperature (about 300K). In this step, the rate of change of heating up can be adjusted, for example, by adjusting the power of the heating resistance wire 501), so as to use more stringent working conditions or temperature change working conditions that are more in line with actual applications.

[0050] S5: Repeat step S3 and step S4. After reaching the required number of cold and hot cycle tests or when the clamping force is lower than the required range, output the curve graph of the temperature measured by the temperature sensor 6 and the clamping force measured by the pressure sensor 7 changing with time during the whole process). Figure 3 It is a curve graph of temperature change and clamping force output by this experimental method. Through the curve graph, the loosening prevention effect of the fastener 3 can be conveniently evaluated.

[0051] Since the test method of the cold screen fastener cold and hot cycle test device 1000 in the embodiment of the present invention adopts the above-mentioned cold screen fastener cold and hot cycle test device 1000 in the embodiment of the present invention, therefore, the test method of the cold screen fastener cold and hot cycle test device 1000 in the embodiment of the present invention has basically the same technical effects as the above-mentioned cold screen fastener cold and hot cycle test device 1000 in the embodiment of the present invention, and will not be elaborated here.

[0052] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0053] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A cold screen fastener thermal cycling test device, characterized in that Comprising: A heat-insulating vacuum container; A workpiece assembly disposed in the heat-insulating vacuum container, including a first workpiece and a second workpiece; A fastener, the fastener including a screw rod, a gasket and a nut, the screw rod being used to pass through the second workpiece, the first workpiece and the gasket and threadedly cooperate with the nut to fasten the first workpiece and the second workpiece; A cooling assembly disposed on the workpiece assembly for cooling the workpiece assembly and the fastener; A heating assembly disposed in the heat-insulating vacuum container for heating the workpiece assembly and the fastener; A temperature sensor disposed on the workpiece assembly for measuring temperature; A pressure sensor disposed between the first workpiece and the second workpiece for measuring the clamping force of the fastener.

2. The cold and hot cycle test device for cold screen fasteners according to claim 1, characterized in that, The heat-insulating vacuum container includes a vacuum container and a heat-insulating layer coated on the outer surface of the vacuum container.

3. The cold screen fastener thermal cycling test device according to claim 1, characterized in that, The first workpiece is a mounting table, the first workpiece is directly supported inside the heat-insulating vacuum container, a positioning concave hole for fitting and placing the second workpiece is provided on one side surface of the first workpiece, and a first screw hole is provided at the bottom of the positioning concave hole; the second workpiece is a pressing block, and the second workpiece is provided with a second screw hole; when the second workpiece is placed in the positioning concave hole, the second screw hole is coaxial with the first screw hole.

4. The cold screen fastener thermal cycling test device according to claim 3, wherein, The second workpiece includes a column section and a stop portion connected to an axial end of the column section, the outer diameter dimension of the column section is adapted to the inner diameter dimension of the positioning concave hole, the outer diameter dimension of the stop portion is larger than the inner diameter dimension of the positioning concave hole, and the second screw hole axially penetrates through the column section and the stop portion; when the column section is adapted to be placed in the positioning concave hole, there is a gap between the end surface of the column section and the bottom surface of the positioning concave hole, the stop portion is located outside the positioning concave hole and is opposite to one side surface of the first workpiece, and the pressure sensor is arranged between the stop portion and one side surface of the first workpiece.

5. The cold screen fastener thermal cycling test device according to claim 4, wherein The number of the pressure sensors is multiple, and the multiple pressure sensors are arranged at intervals along the circumferential direction of the column section between the stop portion and one side surface of the first workpiece.

6. The cold screen fastener thermal cycle test device according to claim 4, characterized in that The cooling assembly includes a cooling pipeline, the cooling pipeline is arranged on the surface of the first workpiece and around the first screw hole, and the cooling pipeline cools the workpiece assembly and the fastener by introducing a cooling medium.

7. The cold shield fastener thermal cycling test device according to claim 6, characterized in that, The cooling medium is liquid nitrogen, cryogenic helium or liquid helium.

8. The cold screen fastener thermal cycling test device according to claim 6, characterized in that, The temperature sensors are distributed on the first workpiece or / and the second workpiece.

9. The cold screen fastener thermal cycling test device according to claim 6, characterized in that, The heating assembly includes heating resistance wires.

10. A test method for a cold screen fastener thermal cycling test device according to any one of claims 1-9, characterized in that, Including the following steps: S1: Lock the first workpiece and the second workpiece with the fastener so that the clamping force of the fastener reaches the design torque; wherein, the pressure sensor is arranged between the first workpiece and the second workpiece, the temperature sensor is arranged on the first workpiece or / and the second workpiece and close to the fastener, and the clamping force and the temperature change are monitored in real time through the pressure sensor and the temperature sensor; S2: Seal the heat-insulating vacuum container, dehumidify the heat-insulating vacuum container using the heating component, and evacuate the heat-insulating vacuum container using the vacuum pumping device; S3: Use the cooling component to cool down to the lower limit temperature, and after keeping the lower limit temperature stable for the first preset time period, stop the cooling of the cooling component; S4: Use the heating component to heat the space environment inside the heat-insulating vacuum container to the upper limit temperature, and after keeping the upper limit temperature stable for the second preset time period, stop the heating of the heating component; S5: Repeat step S3 and step S4. After reaching the required number of hot and cold cycle tests or when the clamping force is lower than the required range, output the curve graph of the temperature measured by the temperature sensor and the clamping force measured by the pressure sensor over time during the whole process.

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