Vacuum connecting structure and vacuum cavity assembly
By combining flanges and sealing rings with progressively decreasing hardness, along with a hardened layer and vacuum annealing, the problem of low-hardness vacuum chambers being unable to achieve high vacuum levels is solved, resulting in a higher vacuum sealing connection suitable for aluminum alloy vacuum chamber applications.
Patent Information
- Application Number
- CN202520760051.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2035-04-21
AI Technical Summary
In the existing technology, vacuum chambers with low hardness, such as aluminum alloy chambers, cannot achieve a fully metal-sealed connection with other components, resulting in an ultimate vacuum level that can only reach the order of 10⁻⁶ Pa, which cannot meet the requirements for higher vacuum levels.
The system employs a combination structure consisting of a first metal flange, a second metal flange, and a third metal sealing ring, with the hardness decreasing sequentially. A hardened layer is provided on the sealing end face and the knife edge surface of the first metal flange. The sealing ring is connected by cutting into it through the flange knife edge. The hardness of the sealing ring is reduced by vacuum annealing and silver plating, and the fastening bolts provide compressive force to ensure sealing performance.
It achieves an all-metal sealed connection between a vacuum chamber with low hardness and other components, and can achieve a higher vacuum level than that of O-ring seals, making it suitable for accelerator, satellite component testing and ion thruster experiments and other fields.
Smart Images
Figure CN223825820U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of vacuum sealing connection, and more specifically, to a vacuum connection structure and a vacuum cavity assembly. Background Technology
[0002] Achieving ultra-high vacuum within a vacuum chamber typically requires an all-metal sealing connection structure with extremely low leakage rates. In existing technologies, commonly used metal connectors such as CF (Conflat Flange), also known as knife-edge flanges, are typically used in conjunction with oxygen-free copper or other soft metal sealing rings. The knife edge on the flange cuts into the sealing ring, deforming it to fill minute defects, thus achieving extremely high sealing performance between the metals. However, this connection structure has a prerequisite: the hardness of the flange material must be higher than the hardness of the sealing ring material; otherwise, the flange knife edge will not be able to cut into the sealing ring.
[0003] Commonly used vacuum chamber materials include stainless steel, titanium alloys, and 6061 series aluminum alloys. Stainless steel and titanium alloys have a much higher hardness than oxygen-free copper (80-90 HV) and can be directly machined into CF flanges. 6061 series aluminum alloys have a hardness of approximately 100-150 HV, only slightly higher than oxygen-free copper, making them unsuitable for CF flange manufacturing. However, compared to stainless steel and titanium alloys, aluminum alloy vacuum chambers offer advantages such as lower cost, easier machining, lower magnetic permeability, lower radioactivity, higher thermal conductivity, and lower density, making them more suitable for applications such as accelerator and satellite component testing, and ion thruster experiments.
[0004] In existing technologies, aluminum alloy vacuum chambers typically use O-rings as seals. However, due to the relatively high leakage rate, permeability, and gas release rate of O-rings, the ultimate vacuum level of aluminum alloy vacuum chambers using O-rings can mostly only reach 10. -6 Pa level.
[0005] Therefore, there is an urgent need for a connection structure suitable for vacuum cavities with low hardness, such as a connection structure suitable for aluminum alloy vacuum cavities, so that the vacuum cavity with low hardness can achieve a fully metal-sealed connection with other components, thereby enabling the vacuum cavity with low hardness to achieve a higher degree of vacuum while having the advantages of low cost. Utility Model Content
[0006] The first objective of this invention is to provide a vacuum connection structure to solve the technical problem that existing vacuum connection structures cannot meet the requirements of high vacuum environments due to their low hardness.
[0007] The vacuum connection structure provided by this utility model includes a first metal flange, a second metal flange, and a third metal sealing ring, wherein the hardness of the second metal flange, the first metal flange, and the third metal sealing ring decreases sequentially; the sealing end face of the first metal flange is provided with a first flange knife edge, and the surfaces of the sealing end face of the first metal flange and the first flange knife edge are provided with a hardened layer; the sealing end face of the second metal flange is provided with a second flange knife edge; the first metal flange and the second metal flange are fixedly connected along the axial direction, and the first flange knife edge and the second flange knife edge respectively cut into the third metal sealing ring from both sides.
[0008] Furthermore, the third metal sealing ring is a vacuum-annealed sealing ring that has undergone vacuum annealing treatment.
[0009] Furthermore, a fourth metal layer is plated on both sides of the third metal sealing ring, and the hardness of the fourth metal layer is lower than that of the third metal sealing ring.
[0010] Furthermore, the fourth metal layer has a higher ductility than the third metal sealing ring.
[0011] Furthermore, the first metal flange is an aluminum alloy knife-edge flange, the second metal flange is a stainless steel knife-edge flange or a titanium alloy knife-edge flange, the third metal sealing ring is an oxygen-free copper sealing ring, and the fourth metal layer is a silver layer.
[0012] Furthermore, the first metal flange has a plurality of first through holes along its axial direction, and the plurality of first through holes are circumferentially distributed on the outside of the first flange knife edge; the second metal flange has a plurality of second through holes along its axial direction, and the plurality of second through holes are circumferentially distributed on the outside of the second flange knife edge, and are respectively corresponding to the plurality of first through holes; the vacuum connection structure also includes a plurality of fastening bolts and a plurality of fastening nuts, the fastening bolts passing through the corresponding first through holes and second through holes, and cooperating with the fastening nuts to provide the first metal flange and the second metal flange with a compressive force to compress the third metal sealing ring.
[0013] Furthermore, a plurality of first through holes are evenly distributed along the circumference of the first metal flange, and a plurality of second through holes are evenly distributed along the circumference of the second metal flange.
[0014] Furthermore, the first flange blade is coaxially arranged with the first metal flange, the second flange blade is coaxially arranged with the second metal flange, and the second flange blade is arranged opposite to the first flange blade.
[0015] Furthermore, the first metal flange includes a body and a connecting pipe integrally connected to the body, the connecting pipe being used to connect to an opening of a vacuum chamber.
[0016] The vacuum connection structure provided by this utility model can produce the following beneficial effects:
[0017] The vacuum connection structure provided by this utility model has a hardened layer on the sealing end face and the knife edge surface of the first metal flange, which increases the hardness of the sealing end face and the knife edge surface of the first metal flange. The knife edge of the first flange can cut into one side of the third metal sealing ring, so that the first metal flange and the second metal flange can cut into the third metal sealing ring from both sides respectively. This causes both sides of the third metal sealing ring to deform to fill the gap between it and the corresponding metal flange and the defects of the three, ultimately achieving a full metal sealing connection between the first metal flange with lower hardness and the second metal flange with higher hardness, meeting the usage requirements in high vacuum environments.
[0018] This vacuum connection structure is particularly suitable for connecting vacuum chambers with low hardness made of a first metal to other components. For example, a first metal flange can be integrally set at the outlet of the first metal vacuum chamber. Since this vacuum connection structure can achieve an all-metal sealed connection, the vacuum chamber can achieve a higher level of vacuum than when using an O-ring.
[0019] The second objective of this invention is to provide a vacuum chamber assembly to solve the technical problem that the existing vacuum connection structure cannot meet the requirements of high vacuum environments due to its low hardness.
[0020] The vacuum chamber assembly provided by this utility model includes a vacuum chamber and the aforementioned vacuum connection structure. The vacuum chamber and the first metal flange of the vacuum connection structure are made of the same material, and the connecting pipe of the first metal flange is integrally formed with or welded to the vacuum chamber.
[0021] The vacuum chamber assembly provided by this utility model uses a first metal with low hardness, which has the inherent advantages of the first metal. Furthermore, due to the use of the above-mentioned vacuum connection structure, it can achieve a fully metal-sealed connection with other components, achieving a higher degree of vacuum than when using O-rings. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0023] Figure 1 This is a schematic diagram of the structure of the first metal flange in the vacuum connection structure provided in this embodiment of the utility model;
[0024] Figure 2 An exploded view of the vacuum connection structure provided in this embodiment of the utility model;
[0025] Figure 3 This is a schematic diagram of the vacuum connection structure provided in an embodiment of the present utility model;
[0026] Figure 4 for Figure 3 Sectional view along line AA in the middle;
[0027] Figure 5 for Figure 4 Enlarged diagram of point B in the middle.
[0028] Explanation of reference numerals in the attached figures:
[0029] 100 - First metal flange; 110 - Body; 111 - First flange knife edge; 112 - First through hole; 120 - Connecting pipe;
[0030] 200 - Second metal flange; 210 - Second flange knife edge; 220 - Second through hole;
[0031] 300 - Third metal seal ring;
[0032] 400 - Fastening bolt;
[0033] 500 - Fastening nut. Detailed Implementation
[0034] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit it.
[0035] This embodiment provides a vacuum connection structure and a vacuum cavity assembly, wherein, as Figure 2 As shown, the vacuum connection structure includes a first metal flange 100, a second metal flange 200, and a third metal sealing ring 300, with the hardness of the second metal flange 200, the first metal flange 100, and the third metal sealing ring 300 decreasing sequentially; the vacuum chamber assembly includes a vacuum chamber and the vacuum connection structure, and the vacuum chamber and the first metal flange 100 of the vacuum connection structure are made of the same material, and the connecting pipe 120 of the first metal flange 100 is integrally formed with or welded to the vacuum chamber.
[0036] The vacuum connection structure and vacuum chamber assembly provided in this embodiment use a first metal flange 100 and a vacuum chamber made of a first metal with low hardness. Therefore, it has the inherent advantages of the first metal. Moreover, although both have low hardness, the vacuum connection structure provided in this embodiment can still achieve an all-metal sealed connection, meeting the requirements for use in high vacuum environments. It is particularly suitable for connecting a vacuum chamber made of a first metal with low hardness to other components. As a result, the vacuum chamber assembly can achieve a higher level of vacuum than when using O-ring seals.
[0037] The following is a detailed description of the vacuum connection structure provided in this embodiment.
[0038] like Figure 1 as well as Figures 3 to 5 As shown, in the vacuum connection structure provided in this embodiment, the sealing end face of the first metal flange 100 is provided with a first flange knife edge 111, and the surfaces of the sealing end face of the first metal flange 100 and the first flange knife edge 111 are provided with a hardened layer; the sealing end face of the second metal flange 200 is provided with a second flange knife edge 210; the first metal flange 100 and the second metal flange 200 are fixedly connected along the axial direction, and the first flange knife edge 111 and the second flange knife edge 210 respectively cut into the third metal sealing ring 300 from both sides.
[0039] The vacuum connection structure provided in this embodiment has a hardened layer on the sealing end face and the knife edge surface of the first metal flange 100, which increases the hardness of the sealing end face and the knife edge surface of the first metal flange 100. The knife edge 111 of the first flange can cut into one side of the third metal sealing ring 300, so that the first metal flange 100 and the second metal flange 200 can cut into the third metal sealing ring 300 from both sides of the third metal sealing ring 300 respectively. This causes both sides of the third metal sealing ring 300 to deform to fill the gap between it and the corresponding metal flange and the defects of the three. Finally, it can achieve an all-metal sealing connection between the first metal flange 100 with lower hardness and the second metal flange 200 with higher hardness, which meets the usage requirements in a high vacuum environment.
[0040] Specifically, in this embodiment, the first metal flange 100 is an aluminum alloy knife-edge flange. Thus, the first metal flange 100 is suitable for aluminum alloy vacuum chambers, which have advantages such as low price, easy processing, low magnetic permeability, low radioactivity, high thermal conductivity, and low density, making them more suitable for applications such as accelerators, satellite component testing, and ion thruster experiments.
[0041] In this embodiment, the second metal flange 200 is a stainless steel knife-edge flange or a titanium alloy knife-edge flange, and the third metal sealing ring 300 is an oxygen-free copper sealing ring or other soft metal sealing ring.
[0042] In this embodiment, the hardened layer is obtained through surface treatment processes. For example, surface treatment processes such as hard anodizing, ion implantation, surface nitriding, and surface carburizing can significantly improve the surface hardness of aluminum alloys. The aluminum alloy is then machined into a CF flange (knife-edge flange), and the relevant surfaces are subjected to surface hardening treatment. The flange knife edge can then cut into the oxygen-free copper sealing ring to achieve an ultra-high vacuum seal. Of course, it should be noted that in other embodiments of this application, the hardened layer can also be obtained by other means, such as coating, as long as the coating hardness is higher than that of the first metal flange by 100 and the coating is not easily peeled off, meeting the usage requirements.
[0043] In this embodiment, the third metal sealing ring 300 is a vacuum-annealed sealing ring that has undergone vacuum annealing treatment. Vacuum annealing of the oxygen-free copper sealing ring can reduce its hardness, thereby reducing the stress generated by the oxygen-free copper sealing ring compressing the hardened layer.
[0044] Because the thickness of the hardened layer on the surface of aluminum alloy is typically only a few micrometers to tens of micrometers, although the hardness of the hardened layer is high enough, the low hardness of the base material means that the hardened layer may crack or peel off after repeated disassembly and assembly. This can lead to air leakage channels at the seal, causing the seal to fail. Using a vacuum-annealed sealing ring, however, reduces the hardness of the ring, thus decreasing the compressive stress on the hardened layer and extending its service life, effectively avoiding the aforementioned problems.
[0045] In this embodiment, a fourth metal layer is plated on both sides of the third metal sealing ring 300. The hardness of the fourth metal layer is lower than that of the third metal sealing ring 300. By plating a coating with lower hardness, the surface hardness of the sealing ring can be further reduced, thereby further preventing cracks or peeling of the hardened layer. In addition, since the hardness of the fourth metal layer is lower than that of the third metal sealing ring 300, the fourth metal layer may also be peeled off from the substrate of the third metal sealing ring 300, thereby reducing the possibility of the hardened layer peeling off the flange knife edge during disassembly and assembly.
[0046] Preferably, in this embodiment, the ductility of the fourth metal layer is higher than that of the third metal sealing ring 300. Thus, even if the hardened layer of the flange blade cracks or peels off, the ductility of the fourth metal layer can fill and seal any leaks, ensuring reliable sealing.
[0047] Specifically, in this embodiment, the fourth metal layer is a silver layer. That is, in this embodiment, silver can also be plated on the surface of the oxygen-free copper sealing ring. Silver has lower hardness, so it causes less damage to the cutting edge. The silver layer can also be peeled off from the substrate of the oxygen-free copper sealing ring. At the same time, silver has good ductility and can fill and seal leaking channels.
[0048] In this embodiment, as Figure 1 and Figure 2 As shown, the first metal flange 100 has a plurality of first through holes 112 along its axial direction, and the plurality of first through holes 112 are distributed circumferentially on the outside of the first flange knife edge 111; the second metal flange 200 has a plurality of second through holes 220 along its axial direction, and the plurality of second through holes 220 are distributed circumferentially on the outside of the second flange knife edge 210, and are arranged one-to-one with the plurality of first through holes 112; the vacuum connection structure also includes a plurality of fastening bolts 400 and a plurality of fastening nuts 500, the fastening bolts 400 passing through the corresponding first through holes 112 and second through holes 220, and cooperating with the fastening nuts 500 to provide the first metal flange 100 and the second metal flange 200 with the compressive force to compress the third metal sealing ring 300.
[0049] Specifically, in this embodiment, a plurality of first through holes 112 are evenly distributed along the circumference of the first metal flange 100, and a plurality of second through holes 220 are evenly distributed along the circumference of the second metal flange 200. This arrangement ensures that the tightening force on the first metal flange 100 and the second metal flange 200 is relatively uniform along the circumference, effectively guaranteeing that the deformation of the sealing ring between them is relatively uniform along the circumference, thereby contributing to ensuring the reliability of the seal.
[0050] Specifically, in this embodiment, the first flange blade 111 is coaxially arranged with the first metal flange 100, the second flange blade 210 is coaxially arranged with the second metal flange 200, and the second flange blade 210 is arranged opposite to the first flange blade 111.
[0051] Specifically, in this embodiment, as Figure 1 As shown, the first metal flange 100 includes a body 110 and a connecting pipe 120 integrally connected to the body 110. The connecting pipe 120 is used to connect to the opening of the vacuum chamber. For example, in this embodiment, the connecting pipe 120 is welded to the aluminum alloy vacuum chamber, thereby connecting the aluminum alloy knife-edge flange to the aluminum alloy vacuum chamber. Of course, the aluminum alloy knife-edge flange can also be an integral structure made of the aluminum alloy vacuum chamber.
[0052] In summary, this embodiment provides a vacuum connection structure and a vacuum chamber assembly. The vacuum connection structure may include an aluminum alloy knife-edge flange with a surface-hardened surface, an oxygen-free copper sealing ring with an annealed and silver-plated surface, and a conventional stainless steel or titanium alloy knife-edge flange. These three components work together to form an ultra-high vacuum connection structure, an all-metal sealing structure for ultra-high vacuum aluminum alloy vacuum chambers, extending the application of aluminum alloy vacuum chambers to 10... -7 Ultra-high vacuum range below Pa.
[0053] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0054] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A vacuum connection structure, characterized in that, It includes a first metal flange (100), a second metal flange (200), and a third metal sealing ring (300), wherein the hardness of the second metal flange (200), the first metal flange (100), and the third metal sealing ring (300) decreases sequentially. The sealing end face of the first metal flange (100) is provided with a first flange knife edge (111), and the sealing end face of the first metal flange (100) and the surface of the first flange knife edge (111) are provided with a hardened layer; the sealing end face of the second metal flange (200) is provided with a second flange knife edge (210); the first metal flange (100) and the second metal flange (200) are fixedly connected along the axial direction, and the first flange knife edge (111) and the second flange knife edge (210) respectively cut into the third metal sealing ring (300) from both sides.
2. The vacuum connection structure according to claim 1, characterized in that, The third metal sealing ring (300) is a vacuum-annealed sealing ring that has undergone vacuum annealing treatment.
3. The vacuum connection structure according to claim 2, characterized in that, The third metal sealing ring (300) is plated with a fourth metal layer on both sides, and the hardness of the fourth metal layer is lower than that of the third metal sealing ring (300).
4. The vacuum connection structure according to claim 3, characterized in that, The fourth metal layer has a higher ductility than the third metal seal (300).
5. The vacuum connection structure according to claim 3, characterized in that, The first metal flange (100) is an aluminum alloy knife-edge flange, the second metal flange (200) is a stainless steel knife-edge flange or a titanium alloy knife-edge flange, and the third metal sealing ring (300) is an oxygen-free copper sealing ring. The fourth metal layer is a silver layer.
6. The vacuum connection structure according to any one of claims 1-5, characterized in that, The first metal flange (100) has a plurality of first through holes (112) along its axial direction, and the plurality of first through holes (112) are distributed circumferentially on the outside of the first flange knife edge (111); the second metal flange (200) has a plurality of second through holes (220) along its axial direction, and the plurality of second through holes (220) are distributed circumferentially on the outside of the second flange knife edge (210), and are respectively corresponding to the plurality of first through holes (112); The vacuum connection structure also includes a plurality of fastening bolts (400) and a plurality of fastening nuts (500), wherein the fastening bolts (400) pass through the corresponding first through hole (112) and second through hole (220), and cooperate with the fastening nuts (500) to provide the first metal flange (100) and the second metal flange (200) with a compressive force to compress the third metal sealing ring (300).
7. The vacuum connection structure according to claim 6, characterized in that, Multiple first through holes (112) are evenly distributed along the circumference of the first metal flange (100), and multiple second through holes (220) are evenly distributed along the circumference of the second metal flange (200).
8. The vacuum connection structure according to any one of claims 1-5, characterized in that, The first flange knife edge (111) is coaxially arranged with the first metal flange (100), the second flange knife edge (210) is coaxially arranged with the second metal flange (200), and the second flange knife edge (210) is arranged opposite to the first flange knife edge (111).
9. The vacuum connection structure according to any one of claims 1-5, characterized in that, The first metal flange (100) includes a body (110) and a connecting pipe (120) integrally connected to the body (110), the connecting pipe (120) being used to connect to the opening of a vacuum chamber.
10. A vacuum cavity assembly, characterized in that, It includes a vacuum chamber and a vacuum connection structure as described in any one of claims 1-9, wherein the vacuum chamber and the first metal flange (100) of the vacuum connection structure are made of the same material, and the connecting pipe (120) of the first metal flange (100) is integrally formed with or welded to the vacuum chamber.