Vacuum high-low temperature mechanical loading test system

Abstract

The invention discloses a vacuum high-low temperature mechanical loading test system which comprises a vacuum system, a low-temperature cold head, a heater, a heat conducting cable, a test cabin, a supporting frame, a positioning assembly, a force generator, a mechanical loading system, a temperature measuring element and a temperature measuring and controlling computer. The test cabin is mounted and fixed through the support frame; the low-temperature cold head is arranged on one side of the vacuum system and is connected with the test cabin; the mechanical loading system is mounted on the other side of the vacuum system and is supported by a positioning assembly; the force generator is mounted on the mechanical loading system; the heat-conducting cable is connected with the test cabin and the low-temperature cold head; heaters are arranged at the front end of the low-temperature cold head and the surface of the test cabin; the temperature measuring element is arranged on the tested product and beside the heater loop; and the temperature measurement and control computer is respectively connected with the heater and the temperature measurement element. According to the scheme, the problems that in the prior art, cooling efficiency and uniformity cannot be achieved at the same time, mechanical equipment is poor in precision and universality under vacuum high and low temperature, and the reliability of a cross-pressure measurement structure is poor are solved.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft and aircraft environmental simulation technology, and particularly relates to a vacuum high and low temperature mechanical loading test system. Background Technology

[0002] With the increasing number of deep space exploration missions, higher requirements are being placed on product performance and environmental testing, such as harsher operating temperatures and performance evaluation under the combined effects of multiple factors. To fully and realistically examine product performance, a vacuum-thermal-mechanical joint testing system is needed to simulate real on-orbit operating conditions.

[0003] Currently, cryogenic methods in a vacuum environment include liquid nitrogen heat sink radiation cooling, gas helium heat sink radiation cooling, and cryogenic cold head contact cooling. Liquid nitrogen heat sink radiation cooling cannot meet the product's -220℃ temperature limit, gas helium heat sink radiation cooling has strict requirements for heat leakage and low product cooling efficiency, while cryogenic cold head contact cooling has advantages such as fast cooling rate and low temperature limit. However, for thin-walled structures of spacecraft components, this method often cannot meet the product's temperature uniformity requirements, which brings risks to the experiment.

[0004] Existing environmental tests are mostly single-item mechanical tests, with thermal tests completed by vacuum and thermal coupling. A small number of mechanical tests are completed at high and low temperatures under normal pressure. For combined vacuum-thermal-mechanical tests, there are often few mechanical testing equipment that can work stably and accurately measure mechanical parameters in vacuum and high and low temperature environments. This results in high requirements for test equipment, high costs, and poor versatility. Meanwhile, mechanical equipment that works at normal pressure and room temperature faces problems of dynamic sealing and force transmission efficiency loss in pressure differential environments, as well as the reliability of measurement results in high-temperature environments under pressure. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a vacuum high and low temperature mechanical loading test system, which aims to solve the problems of the prior art, such as the inability to achieve both cooling efficiency and uniformity, poor accuracy and versatility of mechanical equipment under vacuum high and low temperatures, and reliability of cross-pressure measurement structures.

[0006] To address the aforementioned technical problems, this invention discloses a vacuum high and low temperature mechanical loading test system, comprising: a vacuum system, a cryogenic cold head, heaters, heat-conducting cables, a test chamber, a support frame, a positioning assembly, a force generator, a mechanical loading system, temperature measuring elements, and a temperature control computer; wherein, the test chamber is installed within the vacuum cavity of the vacuum system via the support frame; sealed flange interfaces A and B are respectively provided on the two side walls of the vacuum system; the cryogenic cold head is installed at flange interface A and connected to the test chamber; the mechanical loading system is installed at flange interface B and supported and positioned by the positioning assembly; the force generator is installed on the mechanical loading system; one end of the heat-conducting cable is connected to the test chamber, and the other end is connected to the cryogenic cold head; several heaters are evenly arranged at the front end of the cryogenic cold head and on the surface of the test chamber; several temperature measuring elements are arranged on the test product and beside each heater circuit according to the test requirements; the temperature control computer is connected to each heater and each temperature measuring element.

[0007] In the aforementioned vacuum high and low temperature mechanical loading test system, the mechanical loading system includes: a flange, a bellows, a force transmission rod, a heat insulation head, adjusting screws, a fixed plate, a fixed pulley, and a counterweight. The flange and fixed plate are connected by several adjusting screws. The force transmission rod passes through the center interface of the flange, with one part located inside the vacuum chamber of the vacuum system and the other part located outside the vacuum system. The fixed pulley is installed on the outside of the fixed plate, and the counterweight is connected to the atmospheric side of the force transmission rod through the fixed pulley and its lead wire. The heat insulation head is installed on the side of the force transmission rod that extends into the vacuum system. The bellows is fitted onto the force transmission rod; one end of the bellows is sealed to the atmospheric side of the force transmission rod, and the other end is sealed to the flange interface. A force generator is vertically installed inside the fixed plate.

[0008] In the aforementioned vacuum high and low temperature mechanical loading test system, the adjusting screw is used to adjust the distance between the fixed plate and the atmospheric side of the force transmission rod.

[0009] In the aforementioned vacuum high and low temperature mechanical loading test system, the positioning component is located inside the vacuum chamber of the vacuum system, below the force transmission rod, to support the force transmission rod and ensure that the force generator, force transmission rod, bellows, fixed pulley, lead wire, and loading point of the test product are aligned in a straight line.

[0010] In the aforementioned vacuum high and low temperature mechanical loading test system, the contact part between the positioning component and the force transmission rod is made of a heat-insulating, low-friction coefficient material to reduce force loss during the displacement process.

[0011] In the above-mentioned vacuum high and low temperature mechanical loading test system, S2 < S1 < S3; where S1 represents the displacement of the force transmission rod that can be pushed by the force generator, S2 represents the distance between the heat insulation head and the test product, and S3 represents the ultimate elastic compression length of the bellows.

[0012] In the aforementioned vacuum high and low temperature mechanical loading test system, the support frame is used to provide thermal insulation support for the test chamber, ensuring that the test chamber and the low temperature cold head mounting surface are at the same height.

[0013] In the aforementioned vacuum high and low temperature mechanical loading test system, a temperature control computer is used to record the temperature data collected by the temperature measuring element; and based on the temperature data, it controls the power of the heater to ensure the cooling efficiency and uniformity of the test product through multiple heat transfer paths of radiation and conduction.

[0014] In the aforementioned vacuum high and low temperature mechanical loading test system, the inner surface of the test chamber is coated with a high emissivity coating, and the outer surface is covered with multiple layers of heat insulation components.

[0015] In the aforementioned vacuum high and low temperature mechanical loading test system, the vacuum system is used to provide a vacuum level better than 10. -4 A vacuum environment of Pa.

[0016] The present invention has the following advantages:

[0017] This invention discloses a vacuum high and low temperature mechanical loading test system. The test product is thermally connected to a low-temperature cold head via a six-sided test chamber, allowing the test product to obtain cooling through radiation and conduction, ensuring temperature uniformity while maintaining efficient cooling for thin-walled test products. Through the cooperation of bellows, fixed pulleys, and counterweights, a cross-pressure differential seal is achieved. The appropriate selection of counterweights ensures that the mechanical loading process is within the ideal displacement range of the bellows. Mechanical testing equipment that would normally require a vacuum high and low temperature environment can now be used at room temperature and pressure, resolving sensor accuracy drift under vacuum high and low temperature conditions. Furthermore, only the canister flange needs to be replaced to adapt to different vacuum systems and mechanical testing equipment. Additionally, the pre-calibration correction process under the same operating temperature reduces system deviations and improves test reliability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a vacuum high and low temperature mechanical loading test system according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of a mechanical loading system according to an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0021] Reference Figure 1In this embodiment, the vacuum high and low temperature mechanical loading test system includes: a vacuum system 1, a cryogenic cold head 2, a heater 3, a heat-conducting cable 4, a test chamber 5, a support frame 6, a positioning component 7, a force generator 8, a mechanical loading system 9, temperature measuring elements 11, and a temperature control computer 12. The test chamber 5 is installed inside the vacuum chamber of the vacuum system 1 via the support frame 6. Sealed flange interfaces A and B are respectively provided on the side walls of the vacuum system 1. The cryogenic cold head 2 is installed at flange interface A and connected to the test chamber 5. The mechanical loading system 9 is installed at flange interface B and supported and positioned by the positioning component 7. The force generator 8 is installed on the mechanical loading system 9. One end of the heat-conducting cable 4 is connected to the test chamber 5, and the other end is connected to the cryogenic cold head 2. Several heaters 3 are evenly arranged at the front end of the cryogenic cold head 2 and on the surface of the test chamber 5. Several temperature measuring elements 11 are arranged on the test product 10 and beside the circuits of each heater 3 according to the test requirements. The temperature control computer 12 is connected to each heater 3 and each temperature measuring element 11.

[0022] Preferably, vacuum system 1 is used to provide a vacuum level better than 10. -4 A vacuum environment of Pa.

[0023] Preferably, the inner surface of the test chamber 5 is coated with a high emissivity coating, and the outer surface is covered with a multi-layer heat insulation component.

[0024] Preferably, the support frame 6 is used to provide thermal insulation support for the test chamber 5, ensuring that the test chamber 5 and the mounting surface of the cryogenic cold head 2 are at the same height. The support frame 6 and the mounting location of the test chamber 5 are equipped with thermal insulation material.

[0025] Preferably, the temperature measurement and control computer 12 is used to record the temperature data collected by the temperature measuring element 11; and according to the temperature data, to control the power of the heater 3, and to ensure the cooling efficiency and uniformity of the test product 10 through multiple heat transfer paths of radiation and conduction.

[0026] In this embodiment, as Figure 2 As shown, the mechanical loading system 9 mainly includes: a flange 91, a bellows 92, a force transmission rod 93, a heat insulation head 94, an adjusting screw 95, a fixed plate 96, a fixed pulley 97, and a counterweight 98. The flange 91 and the fixed plate 96 are connected by several adjusting screws 95; the force transmission rod 93 passes through the center interface of the flange 91, with one part located inside the vacuum chamber of the vacuum system 1 and the other part located outside the vacuum system 1; the fixed pulley 97 is installed on the outside of the fixed plate 96, and the counterweight 98 is connected to the atmospheric side of the force transmission rod 93 through the fixed pulley 97 and a lead wire; the heat insulation head 94 is installed on the side of the force transmission rod 93 that extends into the vacuum system 1; the bellows 92 is fitted onto the force transmission rod 93; one end of the bellows 92 is sealed to the atmospheric side of the force transmission rod 93, and the other end is sealed to the interface of the flange 91; a force generator 8 is vertically installed inside the fixed plate 96.

[0027] Preferably, the adjusting screw 95 is used to adjust the distance between the fixed plate 96 and the force transmission rod 93 on the atmospheric side.

[0028] Preferably, the positioning component 7 is disposed within the vacuum chamber of the vacuum system 1, below the force transmission rod 93, to support the force transmission rod 93, ensuring that the force generator 8, the force transmission rod 93, the bellows 92, the fixed pulley 97, the lead wire, and the loading point of the test product 10 are aligned in a straight line. The contact portion between the positioning component 7 and the force transmission rod 93 is made of a heat-insulating, low-friction coefficient material to reduce force loss during displacement.

[0029] Preferably, the bellows 92 has a welded finned configuration, providing a large elastic compression range. The force transmission rod 93 on the atmospheric side and the outer side of the bellows 92 form a single unit. The limit distance that the force transmission rod 93 can penetrate into the vacuum system 1 is determined by the extension and retraction length of the bellows 92, while the actual penetration distance is determined by the pushing distance of the generator 8. Wherein, S2 < S1 < S3, S1 represents the displacement of the force transmission rod 93 that can be pushed by the force generator 8, S2 represents the distance between the heat insulation head 94 and the test product 10, and S3 represents the limit elastic compression length of the bellows 92.

[0030] In this embodiment, the vacuum high and low temperature mechanical loading test method based on the above-mentioned vacuum high and low temperature mechanical loading test system is as follows:

[0031] The test product is fixedly installed inside the test chamber; the test chamber is fixed on the support frame, and the installation positions of the test chamber and the support frame are equipped with heat insulation material; a low-temperature cold head is connected to one side of the test chamber, and temperature measuring elements and heaters are installed on the test product and the test chamber. The temperature control computer adjusts the output power of the heater based on the data of the temperature measuring elements, obtains a vacuum background based on the vacuum system, and forms a vacuum and high-temperature and low-temperature environment under the linkage of the low-temperature cold head and the heater.

[0032] The mechanical loading system and positioning components are arranged on the other side of the test chamber; the positioning components can be adjusted in height to keep the force transmission rod horizontal. The force transmission rod is connected to the counterweight by a lead wire through a fixed pulley. The counterweight provides preload to counteract the large displacement changes of the bellows caused by the internal and external pressure difference.

[0033] When the test product reaches the test temperature and vacuum conditions, the force generator drives the force transmission rod and bellows to transmit force and displacement to the test product, and the performance and reliability of the test product in the real on-orbit state are evaluated.

[0034] The actual performance data under on-orbit conditions is the data from the force sensor and displacement sensor equipped with the calibrated force generator. The calibration and correction process is as follows: A fixed boundary is placed at the limit displacement position of the test product, and a temperature sensing element is applied to this fixed boundary. The rest remains the same as in the formal test. Mechanical data measured from the start to the arrival at the fixed boundary is collected as the no-load mechanical data at that operating temperature, forming a displacement-force curve and entering it into the force generator. The calibrated and corrected data is the mechanical data collected in the formal test minus the no-load mechanical data at that operating temperature.

[0035] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0036] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A vacuum high and low temperature mechanical loading test system, characterized in that, include: The system comprises a vacuum system (1), a cryogenic cold head (2), a heater (3), a heat-conducting cable (4), a test chamber (5), a support frame (6), a positioning assembly (7), a force generator (8), a mechanical loading system (9), a temperature measuring element (11), and a temperature control computer (12); wherein, the test chamber (5) is installed in the vacuum chamber of the vacuum system (1) through the support frame (6); sealed flange interfaces A and B are respectively provided on the two side walls of the vacuum system (1); the cryogenic cold head (2) is installed on flange interface A and connected to the test chamber (5); the mechanical loading system... The system (9) is installed on the flange interface B and supported and positioned by the positioning component (7); the force generator (8) is installed on the mechanical loading system (9); one end of the heat conduction cable (4) is connected to the test chamber (5) and the other end is connected to the low temperature cold head (2); several heaters (3) are evenly arranged on the front end of the low temperature cold head (2) and the surface of the test chamber (5); several temperature measuring elements (11) are arranged on the test product (10) and next to the circuit of each heater (3) according to the test requirements; the temperature control computer (12) is connected to each heater (3) and each temperature measuring element (11) respectively.

2. The vacuum high and low temperature mechanical loading test system according to claim 1, characterized in that, The mechanical loading system (9) includes: a flange (91), a bellows (92), a force transmission rod (93), a heat insulation head (94), an adjusting screw (95), a fixed plate (96), a fixed pulley (97), and a counterweight (98); wherein, the flange (91) and the fixed plate (96) are connected by several adjusting screws (95); the force transmission rod (93) is set through the center interface of the flange (91), with one part located inside the vacuum chamber of the vacuum system (1) and the other part located outside the vacuum system (1); A fixed pulley (97) is installed on the outside of the fixed plate (96), and a counterweight (98) is connected to the atmospheric side of the force transmission rod (93) through the fixed pulley (97) and the lead wire; a heat insulation head (94) is installed on the side of the force transmission rod (93) that is inserted into the vacuum system (1); a bellows (92) is fitted on the force transmission rod (93); one end of the bellows (92) is sealed to the atmospheric side of the force transmission rod (93), and the other end is sealed to the flange (91) interface; a force generator (8) is vertically installed on the inside of the fixed plate (96).

3. The vacuum high and low temperature mechanical loading test system according to claim 2, characterized in that, Adjusting screw (95) is used to adjust the distance between the fixed plate (96) and the force transmission rod (93) on the atmospheric side.

4. The vacuum high and low temperature mechanical loading test system according to claim 2, characterized in that, The positioning component (7) is located in the vacuum chamber of the vacuum system (1), below the force transmission rod (93), and is used to support the force transmission rod (93) so that the loading points of the force generator (8), the force transmission rod (93), the bellows (92), the fixed pulley (97), the lead wire, and the test product (10) are on the same straight line.

5. The vacuum high and low temperature mechanical loading test system according to claim 4, characterized in that, The contact part between the positioning component (7) and the force transmission rod (93) is made of heat-insulating low friction coefficient material to reduce force loss during displacement.

6. The vacuum high and low temperature mechanical loading test system according to claim 4, characterized in that, S2 < S1 < S3; Wherein, S1 represents the displacement of the force transmission rod (93) that can be pushed by the force generator (8), S2 represents the distance between the heat insulation head (94) and the test product (10), and S3 represents the ultimate elastic compression length of the bellows (92).

7. The vacuum high and low temperature mechanical loading test system according to claim 1, characterized in that, The support frame (6) is used to heat-insulate and support the test chamber (5), so that the test chamber (5) and the mounting surface of the low-temperature cold head (2) are at the same height.

8. The vacuum high and low temperature mechanical loading test system according to claim 1, characterized in that, Temperature control computer (12) is used to record temperature data collected by temperature measuring element (11); and according to the temperature data, control the power of heater (3) to ensure the cooling efficiency and uniformity of the test product (10) through multiple heat transfer paths of radiation and conduction.

9. The vacuum high and low temperature mechanical loading test system according to claim 1, characterized in that, The inner surface of the test chamber (5) is coated with a high emissivity coating, and the outer surface is covered with multiple layers of heat insulation components.

10. The vacuum high and low temperature mechanical loading test system according to claim 1, characterized in that, Vacuum system (1), used to provide a vacuum level better than 10 -4 A vacuum environment of Pa.

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