Vacuum test device

Abstract

The utility model belongs to the technical field of aerospace, and discloses a vacuum test device. The vacuum test device comprises a bell jar, a sealing element, a bottom plate, a first flange ring and a fastener, the bell jar comprises a bell jar body and an outer flange, the outer flange is arranged at an opening of the bell jar body in the circumferential direction of the bell jar body, the bell jar body is buckled on the bottom plate, the sealing element is clamped between the bottom plate and the outer flange, and the first flange ring is connected with the fastener. The bell jar body is sleeved with the first flange ring, at least part of the first flange ring abuts against the outer flange, the fastener is arranged on the first flange ring in a penetrating mode and is in threaded connection with the bottom plate, and when the airtight cavity is vacuumized through the through hole, the first flange ring is in threaded connection with the bottom plate, so that the airtight cavity is formed by the bell jar body and the bottom plate in a surrounding mode, and a through hole is formed in the bottom plate and communicated with the airtight cavity. The air leakage rate of the closed cavity is reduced, and the vacuumizing efficiency is improved; moreover, when the airtight cavity is inflated through the through hole after the test is finished, the risk that the bell jar is jacked up due to too high inflation speed is effectively prevented, and the safety of the device is enhanced.

Description

TECHNICAL FIELD

[0001] The utility model relates to aerospace technology field especially relates to vacuum test device. BACKGROUND

[0002] In the field of aerospace, microsatellites and their on-board instruments must be tested in vacuum before launch to detect whether their performance meets the standard.

[0003] At present, the vacuum test of microsatellites and their on-board instruments is usually constructed by vacuum test device to build a vacuum cavity, which includes a bell jar and a bottom plate. The bell jar is buckled on the bottom plate, and the bell jar and the bottom plate form a cavity. The bottom plate is provided with an air extraction hole, through which the gas in the cavity is extracted to make the cavity vacuum. However, in the actual test process, there is a certain roughness and flatness between the bottom of the bell jar and the upper surface of the bottom plate. When the air is extracted, there will be a certain gap between the bottom of the bell jar and the bottom plate, which will affect the efficiency of the vacuum extraction. In addition, when the bell jar is inflated after the test is completed, the fast inflation rate is also easy to cause the bell jar to be lifted up, which is dangerous.

[0004] Therefore, there is an urgent need for a vacuum test device to solve the above problems. UTILITY MODEL CONTENT

[0005] The purpose of the utility model is to provide a vacuum test device, which reduces the air leakage rate of the closed cavity, improves the efficiency of vacuum extraction, and enhances the safety of the device.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] The vacuum test device comprises:

[0008] The bell jar comprises a bell jar main body and an outer flange. The outer flange is arranged at the opening of the bell jar main body along the circumference of the bell jar main body.

[0009] The sealing element is arranged between the outer flange and the bottom plate.

[0010] The bottom plate is provided with a through hole, which is in communication with the closed cavity.

[0011] The first flange ring is sleeved on the bell jar main body, and at least part of the first flange ring is pressed on the outer flange.

[0012] The fastener is threaded through the first flange ring and is screwed with the bottom plate.

[0013] Preferably, the first flange ring comprises a ring body and a pressing part, at least part of the pressing part is pressed against the outer flange, the fastener is threaded through the ring body and is screwed with the bottom plate.

[0014] Preferably, along the radial direction of the bell main body, the pressing part is provided with a first assembly gap with the bell main body, and the ring body is provided with a second assembly gap with the outer flange.

[0015] Preferably, the fastener comprises a fastening screw, a plurality of mounting holes are uniformly arranged along the circumferential direction of the ring body, each fastening screw is threaded through one of the mounting holes and is screwed with the bottom plate, and the screw head of the fastening screw is pressed against the side of the ring body away from the bottom plate.

[0016] Preferably, the bottom plate is provided with an annular groove, and at least part of the sealing element is arranged in the annular groove.

[0017] Preferably, the side of the bottom plate away from the bell main body is provided with a connecting pipe and a second flange ring, one end of the connecting pipe is connected with the bottom plate, the connecting pipe is communicated with the through hole, the other end of the connecting pipe is connected with the second flange ring, and the second flange ring can be connected with a vacuum pumping device.

[0018] Preferably, one end of the connecting pipe is welded with the bottom plate, and the other end of the connecting pipe is welded with the second flange ring.

[0019] Or, the bottom plate, the connecting pipe and the second flange ring are integrally formed.

[0020] Preferably, the connecting part between the bell main body and the outer flange is provided with a circular arc transition part.

[0021] Preferably, the through hole is located at the center position of the bell projected on the bottom plate.

[0022] Preferably, the bell is made of transparent material.

[0023] Advantages:

[0024] The utility model provides a vacuum test device, bell main body is buckled on the bottom plate, and the sealing element is clamped between the outer flange and the bottom plate, so that the outer flange of bell is sealed and abuts to the bottom plate, the first flange ring is sleeved on the bell main body, at least part of the first flange ring is pressed against the outer flange, the fastener is passed through the first flange ring and is screwed with the bottom plate, can add downward pressure for bell before pumping, ensure that bell is connected closely with the bottom plate, when pumping the airtight cavity through the through hole, reduce the air leakage rate of airtight cavity, improve the efficiency of pumping, and when filling air in the airtight cavity through the through hole after the test is finished, effectively prevent the risk that bell is lifted up because of too fast filling air, and the safety of the device is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the explosion drawing of the vacuum test device provided by the embodiment of the utility model;

[0026] Figure 2 is the structure schematic view of the vacuum test device provided by the embodiment of the utility model;

[0027] Figure 3 is Figure 2 the section view of A-A of

[0028] Figure 4 is Figure 3 the enlarged view of B of

[0029] Figure 5 is the top view of the vacuum test device provided by the embodiment of the utility model.

[0030] In the drawing:

[0031] 1, bell jar; 11, bell jar main body; 12, outer flange; 13, closed cavity;

[0032] 2, bottom plate; 21, through hole; 22, annular groove;

[0033] 3, first flange ring; 31, ring body part; 32, compression part; 33, mounting hole;

[0034] 4, fastener;

[0035] 51, first assembly gap; 52, second assembly gap;

[0036] 6, sealing element; 7, connecting pipe;

[0037] 8, second flange ring; 81, connecting port. DETAILED DESCRIPTION

[0038] The utility model will be further described in detail below in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the utility model, and not limited to the utility model. In addition, it should be noted that in order to facilitate the description, only the part related to the utility model is shown in the drawing, not all the structures.

[0039] In the description of the utility model, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements or the interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0040] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can include direct contact between the first and second features, or indirect contact between the first and second features through another feature therebetween. Moreover, the first feature "on", "above" and "over" the second feature includes the first feature directly above and obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature "under", "below" and "under" the second feature includes the first feature directly below and obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0041] In the description of the present application, the terms "up", "down", "right", "left", "horizontal", "vertical", "top", "bottom", "front", "back", "position", "orientation" and other orientation or position relationships are based on the orientation or position relationships shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used to distinguish in the description, and have no special meaning.

[0042] The present application provides a kind of vacuum test device, as shown in Figures 1-2 The vacuum test device includes bell jar 1, sealing element 6, bottom plate 2, first flange ring 3 and fastener 4. Bell jar 1 includes bell jar main body 11 and outer flange 12, outer flange 12 is set to the opening of bell jar main body 11 along the circumference of bell jar main body 11. Bell jar main body 11 is buckled on the bottom plate 2, sealing element 6 is clamped between the bottom plate 2 and the outer flange 12, so that the bell jar main body 11 and the bottom plate 2 are surrounded to form a closed cavity 13, and the bottom plate 2 is provided with a through hole 21, which is in communication with the closed cavity 13. The first flange ring 3 is sleeved on the bell jar main body 11, and at least part of the first flange ring 3 is pressed on the outer flange 12. The fastener 4 is threaded through the first flange ring 3 and is screwed with the bottom plate 2. The vacuum test device can apply downward pressure to the bell jar 1 before vacuumizing, and ensure that the bell jar 1 is tightly connected with the bottom plate 2 when the closed cavity 13 is vacuumized through the through hole 21, reduce the air leakage rate of the closed cavity 13, and improve the efficiency of vacuumizing. When the closed cavity 13 is inflated through the through hole 21 after the test is completed, the risk of the bell jar 1 being lifted due to too fast inflation is effectively prevented, and the safety of the device is enhanced.

[0043] As shown in Figure 3As shown, the first flange ring 3 comprises a ring body part 31 and a pressing part 32, the pressing part 32 extends to the inner side of the ring body part 31 along the radial direction of the ring body part 31, when the ring body part 31 is sleeved on the bell jar 1, at least part of the pressing part 32 presses against the outer flange 12, the fastener 4 is threaded through the ring body part 31 and is screwed with the bottom plate 2, on the one hand, by tightening the fastener 4, the pressing part 32 presses the outer flange 12, and the lower surface of the outer flange 12 is sealed and abuts against the bottom plate 2, which ensures the integrity and stability of the entire device structure, on the other hand, it reduces the small gap between the outer flange 12 and the bottom plate 2, and the fastener 4 plays a role in auxiliary sealing, further improving the sealing performance of the vacuum test device.

[0044] In some embodiments, a flat washer is arranged between the fastener 4 and the ring body part 31, which increases the force bearing area between the fastener 4 and the ring body part 31, the force on the ring body part 31 is more uniform, and the risk of damage to the ring body part 31 is reduced. In other embodiments, a spring washer is arranged between the fastener 4 and the ring body part 31, which can prevent the fastener 4 from loosening, ensure the stability of the connection between the fastener 4 and the bottom plate 2, and improve the reliability of the vacuum test device.

[0045] As shown in the drawings, Figures 1-4 As shown, along the radial direction of the bell jar body 11, the pressing part 32 and the bell jar body 11 are provided with a first assembly gap 51, and the ring body part 31 and the outer flange are provided with a second assembly gap 52, on the one hand, the existence of the first assembly gap 51 and the second assembly gap 52 provides a fault tolerance space for the first flange ring 3 to be sleeved on the bell jar body 11, which avoids scratching or damaging the outer surface of the bell jar body 11 during assembly, and the operator can easily align and adjust the pressing part 32 and the outer flange 12, which reduces the assembly difficulty and improves the assembly efficiency, on the other hand, when the vacuum test is carried out in the sealed cavity 13, temperature changes may occur, the first assembly gap 51 and the second assembly gap 52 can provide enough space for thermal expansion and contraction, prolong the service life of the equipment and reduce the maintenance cost.

[0046] In this embodiment, the outer flange 12 is a ring-shaped outer flange, which contacts the bottom plate 2 more regularly and continuously during assembly, can make the assembly force evenly distributed, reduce the risk of local stress concentration, and ensure the stability and reliability of the assembly. In addition, the processing of the ring-shaped outer flange is relatively simple, which can reduce the process complexity and cost during manufacturing, improve the production efficiency, and is conducive to large-scale production and application.

[0047] In some embodiments, the outer flange 12 is a petal-shaped outer flange, which comprises a ring-shaped body and a plurality of protrusions arranged circumferentially along the ring-shaped body, the plurality of protrusions can be used as obvious alignment references, which can help the operator to find the position more intuitively and quickly, facilitate the alignment and adjustment of the outer flange 12 and the pressing part 32, further reduce the assembly difficulty, and improve the assembly efficiency.

[0048] As shown in Figure 1 and Figure 5 , the fastener 4 includes fastening screws, a plurality of mounting holes 33 are uniformly arranged along the circumference of the ring body part 31, each fastening screw is screwed with one mounting hole 33 and the bottom plate 2, and the nail cap of the fastening screw is pressed on the side of the ring body part 31 away from the bottom plate 2. On the one hand, the pre-tightening force between the first flange ring 3 and the bottom plate 2 can be accurately adjusted by the tightening degree of the fastening screw, and the pre-tightening force is adjusted by tightening or loosening the fastening screw, and then the pressing effect of the pressing part 32 on the turned-up edge 12 is adjusted, so as to ensure that the turned-up edge 12 is sealed and abuts against the bottom plate 2, improve the safety of the vacuum test in the sealed cavity 13, on the other hand, the uniformly distributed mounting holes 33 and fastening screws help to realize accurate positioning and installation during assembly, in addition, the fastening screws are convenient to install and disassemble, which reduces the difficulty of maintenance and repair of the vacuum test device and improves the reliability of the vacuum test device.

[0049] As shown in Figures 1-4 , the bottom plate 2 is provided with an annular groove 22, and at least part of the sealing element 6 is arranged in the annular groove 22, and the turned-up edge 12 presses the sealing element 6. When the pressing part 32 is pressed on the turned-up edge 12, the fastener 4 on the ring body part 31 is tightened, the sealing element 6 deforms to fill the annular groove 22, ensuring that the sealed cavity 13 is isolated from the outside world to maintain a sealed environment, and at the same time, during assembly, the annular groove 22 provides a clear installation position for the sealing element 6, so that the operator can quickly put the sealing element 6 into the annular groove 22, reducing the air leakage problem caused by improper installation position of the sealing element 6, and improving the assembly efficiency of the vacuum test device.

[0050] Optionally, the material of the sealing element 6 can be rubber, silicone or the like, which can be selected according to the specific vacuum test conditions, which is not limited here.

[0051] As shown in Figures 2-3As shown, the side of the bottom plate 2 away from the bell main body 11 is provided with a connecting pipe 7 and a second flange ring 8. One end of the connecting pipe 7 is connected with the bottom plate 2, and the connecting pipe 7 communicates with the through hole 21. The other end of the connecting pipe 7 is connected with the second flange ring 8, and the second flange ring 8 communicates with the connecting port 81 of the second flange ring 8. The second flange ring 8 can be connected with a vacuum air extraction device. On the one hand, the second flange ring 8 provides the connecting port 81 for connecting different types and specifications of vacuum air extraction devices, and the operator can flexibly select and replace the vacuum air extraction device according to actual needs, thereby enhancing the versatility and compatibility of the vacuum test device. On the other hand, the connecting pipe 7 communicates the through hole 21 of the bottom plate 2 with the connecting port 81 of the second flange ring 8 to form a vacuum air extraction channel, thereby ensuring the unobstructed airflow transmission between the vacuum air extraction device and the sealed cavity 13, minimizing the pressure loss and airflow resistance during the air extraction process, enabling the sealed cavity 13 to quickly reach the required vacuum degree, meeting the needs of vacuum testing, and improving the convenience and stability of the operation of the vacuum test device.

[0052] In some embodiments, one end of the connecting pipe 7 is welded to the bottom plate 2, and the other end of the connecting pipe 7 is welded to the second flange ring 8. The welded components can maintain the connection performance unchanged for a long time. During the use of the vacuum test device, the connection performance will not degrade due to environmental factors or repeated disassembly and assembly of the vacuum air extraction device by the second flange ring 8, thereby improving the service life of the vacuum test device. In addition, the bottom plate 2, the connecting pipe 7, and the second flange ring 8 can be separately processed and assembled and welded according to actual needs, thereby improving the flexibility of selecting each component.

[0053] In some embodiments, the bottom plate 2, the connecting pipe 7, and the second flange ring 8 are integrally formed. On the one hand, the integrally formed design enables the bottom plate 2, the connecting pipe 7, and the second flange ring 8 to form a continuous and seamless whole structure, and there is no weak connection position, thereby avoiding the erosion and damage of external media to the connection position and improving the reliability of the vacuum test device. On the other hand, compared with the separate manufacturing of each component and then connecting them, the integrally formed design simplifies the production and processing steps, reduces the manufacturing errors and quality control difficulties caused by the connection process, and improves the reliability of the vacuum test device.

[0054] In some embodiments, the bell main body 11 and the outer flange 12 are connected by a circular arc transition part (not shown in the figure). The circular arc transition part can effectively uniformly disperse stress. When the bell main body 11 receives internal pressure, external pressure, or vibration load, the circular arc transition part can avoid stress accumulation at the connection point, thereby reducing the risk of material fatigue and crack initiation caused by long-term stress concentration, prolonging the service life of the bell 1, and improving the structural reliability of the bell 1.

[0055] As shown in FIG. 1, the bell 1 comprises a bell main body 11, an outer flange 12, a bottom plate 2, a sealing ring 3, a sealing ring 4, a sealing ring 5, a sealing ring 6, a connecting pipe 7, a second flange ring 8, a first flange ring 9, a first flange ring 10, and a sealing cavity 13. Figure 1 and Figure 5As shown, the through hole 21 is located at the center of the projection of the bell jar 1 on the bottom plate 2, ensuring the uniformity and stability of the pressure field in the sealed cavity 13, providing a more reliable environment for vacuum testing, and avoiding the situation that the through hole 21 is located at the eccentric position of the projection of the bell jar 1 on the bottom plate 2, and the pressure inside the sealed cavity 13 is uneven. If the through hole 21 is not located at the center of the projection of the bell jar 1 on the bottom plate 2, an unbalanced pressure will occur at the initial stage of pumping, the internal and external pressure difference near the through hole 21 is large, while the internal and external pressure difference far from the through hole 21 is small. The outer surface of the bell jar 1 will be extruded by the unbalanced external pressure. If there is a small gap between the outer flange 12 of the bell jar 1 and the sealing element 6 at this time, external air will easily flow into the bell jar 1 from the place with large pressure difference, causing the bell jar 1 to be lifted open, thereby posing a serious threat to the safety of the equipment operation and the surrounding environment, and causing a safety accident.

[0056] In some embodiments, a plurality of through holes 21 are provided on the bottom plate 2, which optimizes the efficiency of vacuum pumping, enables the sealed cavity 13 to quickly reach the required vacuum degree for vacuum testing in a shorter time, significantly shortens the experimental period, improves the overall work efficiency, reduces the external interference factors that may be introduced due to the long vacuum pumping process, and further improves the accuracy and reliability of the experimental results.

[0057] In this embodiment, the bell jar 1 is made of transparent material, so that the operator can clearly observe the phenomena and process of the vacuum test in the sealed cavity 13, facilitating the operator to timely master the test dynamics, make accurate judgments and adjustments, and helping in-depth research and analysis of the test. Alternatively, the bell jar 1 can be a transparent glass bell jar, a transparent acrylic bell jar, etc., which is not specifically limited here.

[0058] In summary, the actual operation process of the vacuum test device is as follows:

[0059] (1) Check whether the bell jar 1, the bottom plate 2, the first flange ring 3, the fastener 4 and other components are intact, ensure that the surface of each component is clean and free of impurities, place the sealing element 6 in the annular groove 22 of the bottom plate 2 to ensure the subsequent sealing effect;

[0060] (2) The outer flange 12 of the bell jar body 11 abuts against the bottom plate 2, the first flange ring 3 is sleeved on the bell jar body 11, the position of the first flange ring 3 is adjusted to keep the first assembly gap 51 between the pressing part 32 and the bell jar body 11, and the second assembly gap 52 between the ring body 31 and the outer flange 12, the fastening screw is passed through the mounting hole 33 of the ring body 31 and is screwed with the bottom plate 2, the outer flange 12 is pressed by the pressing part 32 by tightening the fastening screw, the lower surface of the outer flange 12 is sealed and abuts against the bottom plate 2, and the bell jar 1 and the bottom plate 2 form a sealed cavity 13;

[0061] (3) The vacuum air extraction device is connected with the second flange ring 8, and the vacuum air extraction device is started, and along with the air extraction, the gas in the closed cavity 13 is gradually extracted, and the pressure is gradually reduced, and in the air extraction process, the vacuum degree change in the closed cavity 13 can be monitored by observing the pressure display instrument or other related monitoring equipment on the vacuum air extraction device;

[0062] (4) When the closed cavity 13 reaches the required vacuum degree, corresponding vacuum tests can be carried out in the cavity, and in the test process, the transparent bell jar 1 can be used to observe and record the experimental conditions in the closed cavity 13, so as to analyze the experimental process and results;

[0063] (5) After the test is completed, the vacuum air extraction device slowly fills the closed cavity 13 with air, and after the pressure in the closed cavity 13 is balanced, the fastening screw is loosened, the bell jar 1 is taken off from the bottom plate 2, and each part is cleaned and properly stored for next use.

[0064] Obviously, the above embodiments of the utility model are only examples for clearly illustrating the utility model, and are not the limitation of the embodiments of the utility model. For ordinary skilled in the art, various obvious changes, re-adjustment and replacement can be carried out without departing from the protection scope of the utility model. Here, all the embodiments need not and cannot be exhausted. Any modification, equivalent replacement and improvement made in the spirit and principle of the utility model should be included in the protection scope of the utility model claim.

Claims

1. Vacuum test device, characterized in that The utility model relates to a bell jar (1) comprising a bell jar body (11) and an outer flange (12) arranged at an opening of the bell jar body (11) along a circumference of the bell jar body (11); a sealing member (6); a bottom plate (2) on which the bell jar body (11) is buckled, and the sealing member (6) is clamped between the bottom plate (2) and the outer flange (12) to form a closed cavity (13) with the bell jar body (11) and the bottom plate (2); the bottom plate (2) is provided with a through hole (21) in communication with the closed cavity (13); a first flange ring (3) is sleeved on the bell jar body (11), and at least part of the first flange ring (3) is pressed against the outer flange (12); a fastener (4) is threaded through the first flange ring (3) and is screwed with the bottom plate (2). The first flange ring (3) comprises a ring body portion (31) and a pressing portion (32), at least part of the pressing portion (32) is pressed against the outer flange (12), and the fastener (4) is threaded through the ring body portion (31) and is screwed with the bottom plate (2). Along the radial direction of the bell jar body (11), the pressing portion (32) is provided with a first assembly gap (51) with the bell jar body (11), and the ring body portion (31) is provided with a second assembly gap (52) with the outer flange (12). The fastener (4) comprises a fastening screw, a plurality of mounting holes (33) are uniformly arranged along the circumference of the ring body portion (31), each fastening screw is threaded through one of the mounting holes (33) and is screwed with the bottom plate (2), and the head of the fastening screw is pressed against one side of the ring body portion (31) away from the bottom plate (2). The bottom plate (2) is provided with an annular groove (22), and at least part of the sealing member (6) is arranged in the annular groove (22). The bottom plate (2) is provided with a connecting pipe (7) and a second flange ring (8) on the side away from the bell jar body (11), one end of the connecting pipe (7) is connected with the bottom plate (2), the connecting pipe (7) is in communication with the through hole (21), the other end of the connecting pipe (7) is connected with the second flange ring (8), and the second flange ring (8) can be connected with a vacuum pumping device.

2. The vacuum test device of claim 1, wherein, One end of the connecting pipe (7) is welded with the bottom plate (2), and the other end of the connecting pipe (7) is welded with the second flange ring (8).

3. The vacuum test device of claim 2, wherein, Alternatively, the bottom plate (2), the connecting pipe (7) and the second flange ring (8) are integrally formed.

4. The vacuum test device of claim 2, wherein, The bell jar body (11) is provided with a circular arc transition portion at the connection with the outer flange (12).

5. The vacuum test device of claim 1, wherein, The through hole (21) is located at the center position of the projection of the bell jar (1) on the bottom plate (2).

6. The vacuum test device of claim 1, wherein, The bell jar (1) is made of transparent material.

7. The vacuum test device of claim 6, wherein, ​ ​ 8. Vacuum test device according to any of claims 1-7, characterized in that ​ 9. Vacuum test device according to any of claims 1-7, characterized in that ​ 10. Vacuum test device according to any of claims 1-7, characterized in that ​

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