A vacuum interrupter shield

Abstract

The utility model discloses a vacuum switch tube shielding case in the technical field of vacuum switch tube, including shell and shielding case, the end of shielding case is formed thin area through mechanical processing, and the thin area passes through the plastic deformation of the process of spinning and pressing, and the inner wall of shell forms mechanical pressure fixed, the shell includes the casing and the recess, the recess is annular and is arranged on the inner cavity circumferential side wall of casing, the recess is distributed on the inner cavity circumferential side wall of casing along the axial direction of casing, this kind of vacuum switch tube shielding case, the end of shielding case is formed thin wall area and is fixed in the casing through the mode of spinning and pressing again, and spinning and pressing is the normal temperature cold working process, thoroughly avoids the residual thermal stress of the high temperature of brazing, eliminates the maximum risk of falling off due to stress from the root, and the mechanical interlocking structure produced by spinning and pressing is stable in performance under the vibration environment, and will not crack like the welding spot due to thermal fatigue, improves the reliability.

Description

Technical Field

[0001] This utility model relates to the field of vacuum switch tube technology, specifically a shielding cover for a vacuum switch tube. Background Technology

[0002] Vacuum switch tubes (also known as vacuum interrupters) are core control and protection components in power systems, widely used in circuit breakers, contactors, and other switching equipment. Their basic structure includes a sealed housing made of ceramic or glass, and moving and stationary contacts encapsulated within this housing in a high-vacuum environment. When current is interrupted, a high-temperature arc is generated between the contacts. Although the vacuum environment can quickly extinguish the arc, the arc still evaporates the contact material, producing metal vapor.

[0003] To prevent metal vapor from condensing on the inner wall of the ceramic insulating shell, which would degrade insulation performance, and to ensure a uniform electric field, a shield made of materials such as electrical pure iron is typically installed inside the vacuum tube. This shield surrounds the contacts and is one of the key components ensuring the long-term stable operation of the vacuum tube. Therefore, a firm and reliable fixation must be achieved between the shield and the ceramic shell.

[0004] Currently, the commonly used fixed process in the industry is brazing. This involves first metallizing the surface of the annular protrusion (called the "central rib") in the middle of the inner wall of the ceramic shell to form a thin metal film that can bond with the solder. Then, the shielding cover is placed on the central rib, and finally, the two are welded together at high temperature using precious metal solders such as silver and copper.

[0005] The brazing process involves high-temperature heating and cooling. Due to the difference in thermal expansion coefficients between ceramics and metals (electrical pure iron), significant residual thermal stress is generated in the weld area after cooling. This stress can cause the shielding cover to crack and detach from the weld point during later use, transportation, or installation when subjected to mechanical vibration or impact. Therefore, overcoming the aforementioned drawbacks of the brazing process and developing a shielding cover fixing method that requires no welding, generates no thermal stress, has higher reliability, and is lower in cost has become an urgent technical challenge in this field. Utility Model Content

[0006] The purpose of this invention is to provide a vacuum switch tube shielding cover to solve the problem mentioned in the background art that the brazing process involves high-temperature heating and cooling. Due to the difference in thermal expansion coefficients between ceramics and metals (electrical pure iron), huge residual thermal stress will be generated in the weld area after cooling. This stress causes the shielding cover to crack and fall off from the weld point when subjected to mechanical vibration or impact during later use, transportation or installation.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a vacuum switch tube shielding cover, comprising an outer shell and a shielding cover;

[0008] The end of the shield is machined to form a thin area, which is then plastically deformed by a turning process to mechanically press and fix it to the inner wall of the outer shell.

[0009] Preferably, the outer casing includes a housing and a recess;

[0010] The groove is formed in a ring shape on the circumferential side wall of the inner cavity of the housing;

[0011] The grooves are distributed along the axial direction of the housing on the circumferential sidewall of the inner cavity of the housing.

[0012] Preferably, the end of the housing is provided with a stationary end, the stationary end including a stationary end cover and a stationary contact;

[0013] The stationary end cap is disposed at the end of the outer shell, with one end of the stationary end cap penetrating through the outer shell and disposed in the inner cavity of the outer shell, and the other end disposed on the outer side of the end of the outer shell;

[0014] The stationary contact is disposed at the end of the stationary end cover, and the stationary contact is disposed in the inner cavity of the housing.

[0015] Preferably, the end of the housing is provided with a movable end, the movable end including a movable end cover and a movable contact;

[0016] The movable end cap is disposed at the end of the housing, with one end of the movable end cap penetrating the housing and disposed in the inner cavity of the housing, and the other end disposed on the outer side of the end of the housing;

[0017] The moving contact is movably connected to the moving end cover. One end of the moving contact passes through the moving end cover and is disposed in the inner cavity of the housing, while the other end is disposed on the outer side of the end of the housing.

[0018] Preferably, the shielding cover includes a cover body and toothed protrusions;

[0019] The tooth-shaped protrusions are integrally formed at the end edge of the cover;

[0020] The tooth-shaped protrusions are arranged in a ring at the end of the cover.

[0021] Preferably, the ends of the cover are machined to have thin walls;

[0022] The thin wall is located at the end edge of the cover.

[0023] Compared with the prior art, the beneficial effects of this utility model are:

[0024] (1) The end of the shield is machined to form a thin-walled area, and then fixed in the shell by lapping. Lapping is a cold working process at room temperature, which completely avoids the residual thermal stress caused by the high temperature of brazing, and eliminates the greatest risk of falling off due to stress from the root. The mechanical interlocking structure generated by lapping has stable performance under vibration environment and will not crack due to thermal fatigue like the solder joint, thus improving reliability.

[0025] (2) During the lamination process, huge radial pressure is applied to the thin wall with toothed protrusions. After lamination, the deformed metal will tightly wrap around the ceramic rib. At this time, the original toothed structure is pressed together, but it does not completely disappear. These toothed structures pressed into the micro-pores of the ceramic surface form countless tiny hooks or anchors that bite together with the ceramic surface. This makes the connection upgrade from simple surface contact by friction to three-dimensional mechanical interlocking, similar to mortise and tenon structure or gear meshing. After the fixation is completed, these toothed structures themselves have a certain elasticity. When the vacuum tube is running, it will generate electrodynamic force and vibration. These toothed structures can absorb and dissipate vibration energy through their own tiny elastic deformation, just like tiny springs.

[0026] (3) Vacuum circuit breakers will generate severe vibrations when opening and closing. Traditional rigid connections may loosen due to fatigue under long-term vibration. The elastic buffering effect of the toothed structure can effectively absorb vibration energy and greatly reduce the risk of fatigue failure. It is particularly suitable for application scenarios that require long life and high reliability. Even if there are slight dimensional deviations or insufficient roundness on the surface of the ceramic rib or the thin-walled area of ​​the shield, the toothed structure can better adapt to these defects and fill the gaps through deformation to ensure the connection is firm and sealed. This reduces the extreme requirements for the machining accuracy of parts and improves the production yield.

[0027] (4) The metal filler in the groove acts as a positioning pin, which greatly enhances the ability to resist torsional torque. In a vibration environment, the interlocking structure will convert the linear displacement of vibration into compressive stress on the metal filler. The metal can withstand and dissipate this stress well, thus preventing the connection from becoming loose.

[0028] (5) The groove provides a clear end mark and filling target for the turning process. Operators or automated equipment can judge whether the filling is sufficient by monitoring pressure or position changes, thereby ensuring that the connection quality of each product is highly consistent. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of this utility model;

[0030] Figure 2 This is a schematic diagram of the outer shell structure of this utility model;

[0031] Figure 3 This is a schematic diagram of the shielding cover structure of this utility model.

[0032] In the diagram: 100 outer casing, 110 housing, 120 groove, 200 stationary end, 210 stationary end cover, 220 stationary contact, 300 moving end, 310 moving end cover, 320 moving contact, 400 shield, 410 cover body, 411 thin wall, 420 toothed protrusion. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] This invention provides a shielding cover for a vacuum switch tube. The ends of the shielding cover are machined to form a thin-walled area, and then fixed inside the housing by lathe pressing. Lathe pressing is a cold working process at room temperature, completely avoiding the residual thermal stress caused by the high temperature of brazing. This eliminates the greatest risk of stress-induced detachment at the source. The mechanical interlocking structure generated by lathe pressing is stable under vibration conditions and will not crack due to thermal fatigue like solder joints, thus improving reliability. Please refer to [link / reference]. Figure 1 It includes a housing 100, a stationary end 200, a moving end 300, and a shielding cover 400;

[0035] Example 1

[0036] Please see Figure 1 The outer shell 100 is a ceramic shell. The stationary end 200 and the moving end 300 are respectively installed at both ends of the outer shell 100. Part of the structure on the stationary end 200 and the moving end 300 is set in the inner cavity of the outer shell 100, and the remaining part of the structure passes through the end of the outer shell 100 and is set on the outer side of the end of the outer shell 100.

[0037] The shielding cover 400 includes a cover body 410, which is an electrical pure iron shielding cover. The cover body 410 is turned and pressed into the inner cavity of the outer shell 100. The cover body 410 covers the stationary end 200 and the moving end 300 and is located on the outside of a part of the structure of the inner cavity of the outer shell 100. The edge of the cover body 410 facing the stationary end 200 is mechanically ground to form a thin wall 411, forming a pre-deformable area that is easy to deform.

[0038] A huge and uniform radial pressure is applied to the thin wall 411 by a turning device. The pressure exceeds the yield strength of electrical pure iron material but is lower than its tensile strength. The metal of the thin wall 411 will undergo plastic flow without breaking. The lattice between metal atoms will slip. The material will deform continuously and permanently in the direction indicated by the pressure until it tightly wraps the ceramic ribs inside the outer shell 100.

[0039] After lamination, the thin-walled material of the shield will tightly grip all the micro-unevennesses of the ceramic rib. Since the hardness of ceramic is much higher than that of metal and it hardly undergoes plastic deformation, the deformed metal will completely conform to the shape of the ceramic surface, forming an extremely strong interference fit and mechanical interlock.

[0040] Turning is a cold working process at room temperature, which completely avoids the residual thermal stress caused by the high temperature of brazing. It eliminates the biggest risk of detachment caused by stress from the root. The mechanical interlocking structure has stable performance under vibration environment and will not crack due to thermal fatigue like the solder joint. The turning process parameters are easy to control and the product consistency is good, which is far better than the quality fluctuation of manual brazing. The room temperature process avoids the contamination of the inner wall of the vacuum tube by the splashing and volatilization of solder at high temperature, which is conducive to maintaining a higher vacuum degree and insulation strength.

[0041] The working principle of this device is "to achieve an interference fit and mechanical interlock with ceramics by utilizing the plastic deformation of metals". It abandons the traditional molecular-level bonding (brazing) and instead pursues a more reliable and stress-controllable mechanical bonding. Its working principle includes the following two steps:

[0042] (1) A pre-designed weak zone is pre-made at the end of the shielding cover. The outer diameter of the end of the electrical pure iron shielding cover is machined to a thin wall of 0.3-0.5mm, which significantly reduces the cross-sectional area and mechanical strength of this part. This allows the part to undergo plastic deformation without huge pressure during subsequent turning, greatly reducing the risk of the ceramic structure cracking due to excessive pressure. By precisely controlling the length and thickness of the machined thin zone, the deformation is strictly limited to the pre-designed range, like a "pre-defined fold line", ensuring that the deformation process is controllable and consistent, and will not affect other key functional parts of the shielding cover (such as the main shielding surface), thus ensuring that the electrical performance of the product, such as the electric field distribution, is not affected.

[0043] (2) The central rib of the ceramic shell has a raised geometric profile. After the metallization layer is removed, its smooth and hard ceramic surface directly serves as the support surface, applying a uniform and symmetrical radial force to the thinned area, causing it to undergo permanent plastic deformation and tightly wrapping the ceramic central rib. Three precision rollers with 120° angles and consistent inclination angles feed synchronously radially around the shield. These three forces are balanced with each other, avoiding single-point stress or bending moment, ensuring that the shield and the ceramic axis will not shift, and the deformation is uniform and symmetrical. Under constant pressure, the rollers squeeze the thinned area, and the metal material is forced to flow along the slope and root of the ceramic central rib. The inner diameter of the deformed metal is smaller than the outer diameter of the ceramic central rib, generating huge static friction force, achieving preliminary fastening. The flowing metal will fully fill the recessed area at the root of the ceramic central rib, like a "hand" tightly gripping the root of the central rib. This three-dimensional shape fit forms a powerful mechanical self-locking structure, which can effectively resist axial shedding force even under vibration and impact.

[0044] Example 2

[0045] Please see Figure 1 and Figure 3 The shield 400 also includes toothed protrusions 420;

[0046] The toothed protrusion 420 is integrally formed at the edge of the thin wall 411 on the cover 410. The toothed protrusion 420 protrudes outward and is arranged in a ring.

[0047] During the turning process, enormous radial pressure acts on the thin wall with toothed protrusions. After turning, the deformed metal tightly wraps around the ceramic core. At this point, the original toothed structure is pressed together, but it does not completely disappear. These toothed structures pressed into the microscopic pores of the ceramic surface form countless tiny hooks or anchor points that interlock with the ceramic surface. This upgrades the connection from simple surface-to-surface contact based on friction to a three-dimensional mechanical interlock, similar to a mortise and tenon structure or gear meshing. After fixing, these toothed structures themselves have a certain degree of elasticity. When the vacuum tube is running, it generates electrodynamic force and vibration. These toothed structures can absorb and dissipate vibration energy through their own tiny elastic deformation, just like tiny springs.

[0048] Vacuum circuit breakers generate severe vibrations during opening and closing. Traditional rigid connections may loosen due to fatigue under long-term vibration. The elastic buffering effect of the toothed structure can effectively absorb vibration energy and significantly reduce the risk of fatigue failure. It is particularly suitable for applications requiring long life and high reliability. Even if there are slight dimensional deviations or roundness deficiencies on the surface of the ceramic rib or the thin-walled area of ​​the shield, the toothed structure can better adapt to these defects and fill the gaps through deformation, ensuring a firm and sealed connection. This reduces the extreme requirements for the machining precision of parts and improves the production yield.

[0049] Specifically, the working principle of this solution is a dynamic, multi-scale mechanical locking process, which can be explained in detail in two stages: the forming stage and the service stage.

[0050] (1) Formation stage: Constructing micro-interlocking structures

[0051] This stage occurs at the instant when the turning tool rollers apply enormous radial pressure to the thin wall of the shield;

[0052] Stress concentration and plastic flow:

[0053] When the roller presses against the thin wall 411 with toothed protrusions 420, the force will first concentrate at the tip of the toothed protrusion. Due to the small radius of curvature at the tip, a significant stress concentration effect will occur, making these points more likely to break through the material yield strength and undergo plastic deformation first. Under continuous pressure, the entire thin wall area (including the tooth and inter-tooth area) will undergo directional plastic flow towards the surface of the ceramic rib, like clay, with the goal of filling all the microscopic unevenness of the ceramic surface.

[0054] The formation of the micro-anchoring effect:

[0055] The surface of ceramics is not absolutely smooth at the microscopic level, but is composed of countless micrometer-level bumps, pores and grain boundaries. The tooth-like protrusions that are forcibly pressed into these microstructures do not completely disappear in shape, but undergo deformation and adaptation. This process is similar to a climbing claw piercing the ice surface or an anchor being thrown into the seabed. Each tooth pressed into the micropores of the ceramic forms a tiny mechanical anchor point. Countless such anchor points together form a distributed, three-dimensional mechanical locking network, realizing a "mortise and tenon structure" or "gear meshing" at the microscopic level.

[0056] Tolerance compensation and adaptive sealing:

[0057] The toothed structure has a certain compressibility and flow filling ability. If there is a slight deviation in the roundness of the ceramic ribs, or if the thickness of the thin wall itself is uneven, the flexible toothed structure will adapt to these defects through uneven compression deformation, ensuring that the contact pressure is as uniform as possible in the circumferential direction, eliminating possible local gaps. This reduces the stringent requirements for the machining accuracy of the parts and improves the production yield.

[0058] (2) Service phase: dynamic maintenance and failure resistance mechanism

[0059] The superiority of this design is fully demonstrated when the vacuum tube is subjected to vibration and electrodynamic shock during the opening and closing operation of the circuit breaker.

[0060] Elastic buffering and vibration energy dissipation:

[0061] Core mechanism: After the tooth-like structure is flattened, it and its root material are not in a completely rigid state, but retain a small amount of elasticity. It can be regarded as countless miniature springs distributed on the contact surface.

[0062] Working process: When external vibration energy is transmitted to the connection interface, these "micro springs" will undergo slight elastic deformation, absorbing some of the harmful mechanical kinetic energy and converting it into elastic potential energy, which is then dissipated as heat through the internal friction (damping effect) of the material.

[0063] This is equivalent to adding a passive vibration damper to the connection interface, which significantly reduces the peak vibration energy transmitted to the fixed point, thereby effectively suppressing the occurrence of vibration fatigue, which is crucial for vacuum tubes that require long life and high reliability.

[0064] Anti-fretting wear and loosening:

[0065] Under long-term vibration, purely rigid surface contact is prone to "fretting wear", which is wear caused by micron-level relative sliding between the contact surfaces, eventually leading to a decrease in preload and loosening.

[0066] The micro-anchoring effect of the toothed structure greatly suppresses any micro-relative displacement between the shield and the ceramic surface. At the same time, its elastic deformation absorbs vibration energy, reducing the conditions for fretting from the root.

[0067] Example 3

[0068] Please see Figure 1-2 The outer casing 100 includes a housing 110 and a recess 120;

[0069] The housing 110 is a ceramic housing;

[0070] The groove 120 is formed along the axial direction of the housing 110 on the circumferential side wall of the inner cavity of the housing 110 and is connected to the cover 410. The groove 120 is a semi-circular protrusion with a diameter of 0.1mm-0.3mm.

[0071] During the turning process, the huge radial pressure forces the electrical pure iron in the thin-walled area of ​​the shield to undergo plastic deformation. The metal material not only shrinks radially inward, but also fills all the space that can flow under the pressure. At this time, the cavity in the ceramic groove becomes the area where the metal material is most likely to flow. After turning, the deformed metal not only tightly wraps the ceramic rib, but also some of its material is firmly embedded in the annular groove of the ceramic. After cooling, the metal forms all-round contact and interlocking with the side wall and bottom of the groove.

[0072] The metal filler in the groove acts as a positioning pin, greatly enhancing the ability to resist torsional torque. In a vibrating environment, the interlocking structure converts the linear displacement of the vibration into compressive stress on the metal filler, and the metal can withstand and dissipate this stress well, preventing the connection from loosening.

[0073] The groove provides a clear end mark and filling target for the turning process. Operators or automated equipment can judge whether the filling is sufficient by monitoring changes in pressure or position, thereby ensuring that the connection quality of each product is highly consistent.

[0074] The core principle of this technology is to guide the metal to undergo plastic flow through a pre-set geometric cavity to form a "mechanical internal locking structure" to resist loosening forces in all directions. Its working principle can also be analyzed in depth from the two stages of forming and service.

[0075] (1) Forming stage: guiding flow and building internal locks

[0076] This stage is where the groove plays its core role; it is an active "metal flow guide".

[0077] Pre-set deformable cavity and flow guide:

[0078] The annular groove 120 (0.1-0.3mm deep, semi-circular) precisely machined on the inner wall of the ceramic rib is a pre-set cavity before lamination;

[0079] When the roller applies huge radial pressure, the electrical pure iron at the thin wall 411 of the shield is like a squeezed "paste" and will flow in the direction of least path resistance. The cavity of the groove becomes the target area where the metal material can flow most easily and naturally.

[0080] Plastic filling and shape adaptation:

[0081] Under pressure, the metal material flows in continuously and completely fills the entire internal space of the groove. After turning, the inside of the groove is filled with dense electrical pure iron.

[0082] After cooling, the metal filled into the groove forms a tight contact with the sidewalls and bottom of the groove in all directions. At this time, the fixing of the shield no longer depends on the external clamping force, but on the internal mechanical interlocking.

[0083] Provide process termination signal:

[0084] A groove serves as a clear filling target and a physical marker for the end of the process;

[0085] During the automated lamination process, the equipment can monitor multiple parameters. When the metal fills the groove, the required pressure value will rise sharply (because the cavity has been filled), or the spindle torque will change. The operator or the equipment can preset "when the pressure reaches the peak value F and stabilizes for t time" to determine that the filling is complete. This ensures that the connection quality of each product is highly consistent, controllable and detectable, eliminating the quality uncertainty caused by parameter fluctuations in the traditional brazing process.

[0086] (2) Service phase: Multidimensional constraints and failure resistance mechanisms

[0087] Once the vacuum tube is put into operation, the mechanical internal locking structure formed in the groove demonstrates its unparalleled reliability.

[0088] Absolute axial locking (anti-detachment):

[0089] This is the core problem that the groove design solves. Once the groove is filled with metal, any force that attempts to pull the shield out of the ceramic shell axially will act directly on the metal "protrusion" inside the groove.

[0090] For the shielding cover to detach, one of the following two conditions must be met:

[0091] Shear fracture: Shearing off the metal protrusions in the groove (requires extremely high shearing force; the strength of electrical pure iron is much higher than that of solder).

[0092] Ceramic crushing: Crushing the edges of ceramic grooves (ceramics have extremely high compressive strength).

[0093] This structure fundamentally eliminates the possibility of the shield detaching axially under vibration or electrodynamic impact, and its reliability far exceeds that of any planar friction connection.

[0094] Excellent resistance to torsion and bending moment:

[0095] The metal filled into the groove forms a built-in, annular locating pin or key;

[0096] When the shield is subjected to torsional torque, this "metallic key" will press tightly against the side wall of the ceramic groove, converting the torque into strong compressive stress in the ceramic, thereby preventing the shield from rotating.

[0097] The same applies when subjected to bending moment; the groove structure provides constraints in multiple directions, achieving multi-dimensional self-locking.

[0098] Dissipation and transformation of vibrational energy:

[0099] In a vibration environment, linear displacement is transformed by the interlocking structure into compressive and shear stresses on the metal filler in the groove;

[0100] Metallic materials have good plastic deformation capacity and damping characteristics, which can effectively withstand and dissipate these vibrational energies through minute internal plastic deformation, avoiding energy accumulation that could lead to loosening of the connection.

[0101] Example 4

[0102] The stationary end 200 includes a stationary end cover 210 and a stationary contact 220;

[0103] The stationary end cap 210 is installed at the end of the housing 110. One end of the stationary end cap 210 penetrates the housing 110 and is disposed in the inner cavity of the housing 110, while the other end is disposed on the outer side of the end of the housing 110.

[0104] One end of the stationary contact 220 passes through the stationary end cover 210 and is inserted into the inner cavity of the housing 110, while the other end is located on the outer side of the end of the housing 110. The stationary contact 220 is movably connected to the stationary end cover 210 and can move along the axial direction of the housing 110 on the stationary end cover 210.

[0105] The moving end 300 includes a moving end cover 310 and a moving contact 320;

[0106] The moving end cover 310 is installed on the housing 110 at the end away from the stationary end cover 210. One end of the moving end cover 310 penetrates the housing 110 and is disposed in the inner cavity of the housing 110, while the other end is disposed on the outer side of the end of the housing 110.

[0107] The moving contact 320 is coaxially mounted on the moving end cover 310 at one end facing the inner cavity of the housing 110. The moving contact 320 is located in the inner cavity of the housing 110 and corresponds to the stationary contact 220.

[0108] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the features in the embodiments disclosed in this invention can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A shielding cover for a vacuum switch tube, characterized in that: Includes an outer shell (100) and a shielding cover (400); The end of the shield (400) is machined to form a thin area, which is plastically deformed by a turning process and mechanically pressed and fixed to the inner wall of the outer shell (100).

2. The vacuum switch tube shielding cover according to claim 1, characterized in that: The outer casing (100) includes a housing (110) and a recess (120); The groove (120) is formed in a ring on the circumferential side wall of the inner cavity of the housing (110); The groove (120) is distributed along the axial direction of the housing (110) on the circumferential sidewall of the inner cavity of the housing (110).

3. A vacuum switch tube shielding cover according to claim 2, characterized in that: The end of the housing (100) is provided with a stationary end (200), which includes a stationary end cover (210) and a stationary contact (220). The stationary end cap (210) is disposed at the end of the housing (100). One end of the stationary end cap (210) penetrates the housing (100) and is disposed in the inner cavity of the housing (100), while the other end is disposed on the outer side of the end of the housing (100). The stationary contact (220) is disposed at the end of the stationary end cover (210) and the stationary contact (220) is disposed in the inner cavity of the outer shell (100).

4. A vacuum switch tube shielding cover according to claim 1, characterized in that: The end of the housing (100) is provided with a movable end (300), which includes a movable end cover (310) and a movable contact (320). The movable end cap (310) is disposed at the end of the housing (100). One end of the movable end cap (310) penetrates the housing (100) and is disposed in the inner cavity of the housing (100), while the other end is disposed on the outer side of the end of the housing (100). The moving contact (320) is movably connected to the moving end cover (310). One end of the moving contact (320) passes through the moving end cover (310) and is disposed in the inner cavity of the housing (100), while the other end is disposed on the outer side of the end of the housing (100).

5. A vacuum switch tube shielding cover according to claim 4, characterized in that: The shield (400) includes a cover (410) and toothed protrusions (420). The toothed protrusions (420) are integrally formed at the end edge of the cover (410); The toothed protrusions (420) are arranged in a ring at the end of the cover (410).

6. A vacuum switch tube shielding cover according to claim 5, characterized in that: The end of the cover (410) is machined with a thin wall (411). The thin wall (411) is disposed at the end edge of the cover (410).

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