A dynamic conductive rod for vacuum interrupter and its casting mold and manufacturing method

Abstract

The present invention relates to a dynamic conductive rod for a vacuum arc extinguishing chamber, and provides a dynamic conductive rod for a vacuum arc extinguishing chamber and a casting mold and a manufacturing method thereof, which solves the problem that the existing dynamic conductive rod for a vacuum arc extinguishing chamber made of pure copper will bend and roughen when impacted during service, resulting in the displacement of the conductive rod, reduced coaxiality, and the problem that the length of the conductive rod is shortened due to roughening, resulting in insufficient contact overtravel. When used at a higher frequency, the dynamic conductive rod will deform, get stuck, bend and other undesirable phenomena. The dynamic conductive rod includes a conductive copper sleeve and a core shaft coaxially embedded in the conductive copper sleeve; the side of the core shaft is provided with threads and grooves, and the grooves include anti-drop grooves and anti-slip grooves, the anti-drop grooves are annular and arranged around the core shaft, and the anti-slip grooves are linear and arranged in a direction parallel to the axis of the core shaft; the inner side wall of the conductive copper sleeve is convex and filled with the above-mentioned threads, anti-drop grooves and anti-slip grooves.

Description

Technical Field

[0001] The invention relates to a movable conductive rod for a vacuum interrupter, and in particular to a movable conductive rod for a vacuum interrupter, a casting mold and a manufacturing method thereof. Background Art

[0002] Vacuum switch is an electrical device used to control and protect the circuit of the power system. The vacuum interrupter is the core component of the medium and high voltage power switch. It uses a pair of electrodes (contacts) and other parts sealed in a vacuum. With the help of the excellent insulation and arc extinguishing performance of the vacuum in the tube, the medium and high voltage circuit can quickly extinguish the arc and suppress the current after the power is cut off, so as to achieve the closing or disconnection of the circuit. It is mainly used in the power transmission and distribution control system, and also used in the power distribution system of metallurgy, mining, petroleum, chemical industry, railway, broadcasting, communication, industrial high-frequency heating, etc. It has the characteristics of energy saving, material saving, fire prevention, explosion prevention, small size, long life, low maintenance cost, reliable operation and no pollution.

[0003] The conductive system of the vacuum interrupter is composed of a moving guide rod and a static guide rod, one end of which extends from the vacuum switch, and the other end connects the moving contact and the static contact. A part of the moving guide rod extending from the vacuum interrupter is connected to the operating mechanism and the external power circuit. When in use, the moving contact assembly moves axially under the drive of the operating mechanism, and is connected or separated from the static contact assembly to achieve the closing or disconnection of the circuit. The vacuum interrupter will bounce at the point of closing during the closing process. If the closing bounce is too large, it will affect the service life of the interrupter. The bounce caused by the closing of the high-speed vacuum circuit breaker will be greater. The continuous impact on the static contact will cause plastic deformation of the moving / static contact, causing mechanical damage to the entire vacuum interrupter, seriously affecting its insulation properties. The quality of the static contact, moving contact, static conductive rod and moving conductive rod is one of the main factors affecting the closing bounce. As a control electrical appliance, the requirements for the vacuum interrupter are that it can be operated frequently and have sufficient mechanical and electrical life.

[0004] At present, the dynamic and static conductive rods are all made of oxygen-free copper. If the part exposed to the atmosphere (dynamic conductive rod) is considered to improve its mechanical strength and reduce costs, this part can also be made of high thermal conductivity materials such as pure copper or copper alloy. Although this material has good electrical properties, oxygen-free copper is soft. Even if the material reaches a high strength through deformation strengthening, the strength will decrease quickly as the welding process of the vacuum interrupter assembly process is performed. The conductive rod of the vacuum interrupter requires that it can make axial movements of several to tens of millimeters to achieve separation and combination. Therefore, during the service process, due to the collision of the dynamic and static contacts, the dynamic and static conductive rods welded to the contacts will bend and bulge due to insufficient strength, resulting in the displacement of the conductive rod, the reduction of coaxiality, and the problem of insufficient contact overtravel caused by the shortening of the conductive rod length due to the bulging. When used at a higher frequency, the dynamic conductive rod will be deformed, stuck, bent, and other undesirable phenomena. In addition, during the installation and use of the vacuum interrupter, the dynamic conductive rod will be subjected to push and pull forces, which greatly reduces the service life of the vacuum interrupter and causes serious failures, resulting in the inability to quickly, reliably, and safely cut off the power supply. In addition, the diameter of the conductive rod also determines its mechanical strength when subjected to mechanical and electrical forces, as well as the heat generated during long-term operation and the heat dissipation conditions through the rated short-time withstand current.

[0005] At present, the improvement scheme based on the conductive rod used in the traditional vacuum interrupter includes the improvement of the conductive rod structure and the optimization of the conductive rod material. The movable conductive rod of the vacuum interrupter is usually round, but this matching structure is not anti-twisting, and the bellows is a consumable part. The movable conductive rod is easy to twist left and right when the distance is pulled apart, thereby damaging the bellows and causing the product to leak and be scrapped. Therefore, many manufacturers have improved the structure of the conductive rod to increase the service life of the conductive rod, such as designing a movable conductive rod with a multi-section multi-prism structure and a split detachable conductive rod device. However, this method only improves the structure of the conductive rod, and does not involve the improvement of the conductive rod's own material. It still cannot solve the problem of deformation, jamming, bending and other undesirable phenomena of the movable conductive rod when the conductive rod is used at a high frequency.

[0006] With the continuous miniaturization of vacuum interrupters, the size of the conductive rods used in the interrupters is also constantly decreasing. Therefore, more stringent requirements are put forward for the strength, conductivity, and softening temperature of the conductive rod materials. If the materials of the dynamic and static conductive rods are not good, the gas content is large, and there are many impurities, it will significantly affect the performance of the vacuum interrupter. On the one hand, the poor material of the conductive rod will cause the vacuum interrupter to produce more outgassing during storage and use, affecting its vacuum performance, and in severe cases, leading to the loss of its vacuum degree; on the other hand, the poor material of the conductive rod will increase the loop resistance of the vacuum switch and the presence of more impurities. In this way, when the normal current is passed, the switch may burn due to excessive local temperature rise, which may cause accidents in severe cases. The traditional single-component oxygen-free copper conductive rod can no longer meet the use requirements.

[0007] Therefore, in view of the above problems, the present invention provides a moving conductive rod for a vacuum arc chamber with a simple structure, reasonable design, high strength and high conductivity from the perspective of optimizing the structure and materials of the moving conductive rod for the vacuum arc chamber, so as to make up for the shortcomings of the mechanical life and electrical life of the existing moving conductive rod for the vacuum arc chamber, thereby increasing the number of times the moving conductive rod is used to meet the use requirements of the high-voltage vacuum arc chamber. Summary of the invention

[0008] The present invention provides a movable conductive rod for a vacuum interrupter and a casting mold and a manufacturing method thereof to solve the above problems.

[0009] The specific technical solution is:

[0010] A movable conductive rod for a vacuum interrupter, characterized in that it comprises a conductive copper sleeve and a core shaft coaxially embedded in the conductive copper sleeve;

[0011] The side of the mandrel is provided with threads and grooves, the grooves include anti-falling grooves and anti-slip grooves, the anti-falling grooves are annular and arranged around the mandrel, and the anti-slip grooves are linear and arranged in a direction parallel to the axis of the mandrel;

[0012] The inner side wall of the conductive copper sleeve is convex and filled with the above-mentioned threads, anti-falling grooves and anti-slip grooves.

[0013] Furthermore, the anti-falling groove divides the thread into multiple sections, each section of the thread is provided with an anti-skid groove, and the anti-skid grooves on each section of the thread are staggered in the circumferential direction.

[0014] Furthermore, the conductive copper sleeve is made of oxygen-free copper, preferably TU1 oxygen-free copper.

[0015] Furthermore, the core shaft is made of stainless steel or mold steel, preferably 316L stainless steel or 42CrMo mold steel.

[0016] The casting mold for casting the above-mentioned dynamic conductive rod is characterized in that it comprises a mold shell, an upper end cover and a lower end cover, the mold shell is cylindrical and the upper and lower ends are sealed by the upper end cover and the lower end cover, a gate is formed at the lower part of the lower end cover, the gate is circumferentially connected to the mold cavity through a plurality of runners evenly distributed along the circumferential direction, a plurality of exhaust inserts evenly distributed along the circumferential direction are installed on the upper end cover, the exhaust insert is made of molding sand and is provided with a mold cavity penetrating the mold and an external lower exhaust hole;

[0017] The mandrel is installed in the mold shell and its upper and lower ends are respectively positioned and matched with the upper end cover and the lower end cover through positioning inserts;

[0018] The core shaft, mold shell, upper end cover and lower end cover are assembled to form a cavity for forming the conductive copper sleeve. Furthermore, a pressure ring is detachably mounted on the upper end cover, and the pressure ring presses and fixes the exhaust insert to the upper end cover, wherein the pressure ring is provided with an upper exhaust hole corresponding to the lower exhaust hole.

[0019] The manufacturing method of the movable conductive rod for the vacuum interrupter is characterized in that the conductive copper sleeve is cast outside the core shaft using vacuum bottom casting technology, and during the casting process, the copper liquid fills the mold cavity from bottom to top.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. The present invention has a built-in reinforcing mandrel on the basis of the original oxygen-free copper rod, which solves the problem that the conductive rod of the existing vacuum interrupter becomes shorter and bent due to high-speed impact when the switch is closed, thereby affecting the performance and life of the vacuum interrupter. While ensuring that the conductive rod has good conductivity, the conductive rod can always maintain good strength and greatly reduce costs. In addition, the conductive rod has a simple structure, reasonable design and easy processing, which can meet the requirements of the vacuum interrupter.

[0022] 2. The conductive copper sleeve is made of TU1 oxygen-free copper, which can provide good conductivity; the mandrel is made of stainless steel or die steel, which can improve the strength and hardness of the conductive rod and greatly reduce the material cost.

[0023] 3. The stainless steel or mold steel mandrel and the conductive copper sleeve are connected by casting pure copper using vacuum bottom casting technology to achieve a tight connection between the conductive copper sleeve and the mandrel without gaps.

[0024] 4. The conductive copper sleeve is cast from bottom to top, which can reduce the accumulation of impurities in the core of the conductive copper sleeve during the casting process and ensure the high density and high strength of the conductive copper sleeve.

[0025] 5. The outer wall surface of the stainless steel or mold steel core shaft is provided with threads to ensure the adhesion effect with the conductive copper sleeve and prevent the axial falling off of the stainless steel or mold steel core shaft and the conductive copper sleeve during operation.

[0026] 6. The outer wall surface of the stainless steel or mold steel mandrel is provided with an anti-slip groove to further increase the adhesion effect with the conductive copper sleeve and prevent the axial shedding of the stainless steel or mold steel mandrel and the conductive copper sleeve during operation.

[0027] 7. The outer wall surface of the stainless steel or mold steel core shaft is provided with anti-slip grooves to prevent the stainless steel or mold steel core shaft and the conductive copper sleeve from rotating during operation, resulting in radial shedding. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a three-dimensional schematic diagram of a movable conductive rod for a vacuum interrupter of the present invention;

[0029] Figure 2 It is a schematic diagram of the explosion of the movable conductive rod for the vacuum interrupter of the present invention;

[0030] Figure 3 It is a top view schematic diagram of a movable conductive rod for a vacuum interrupter of the present invention;

[0031] Figure 4 for Figure 3 A schematic cross-sectional view along the AA direction;

[0032] Figure 5 for Figure 3 A cross-sectional schematic diagram along the BB direction;

[0033] Figure 6 It is a three-dimensional schematic diagram of the casting mold of the present invention;

[0034] Figure 7 It is an exploded schematic diagram of the casting mold of the present invention;

[0035] Figure 8 It is a top view schematic diagram of the casting mold of the present invention;

[0036] Fig. 9 for Figure 8 Schematic cross-sectional view along CC direction.

[0037] In the figure:

[0038] 11. Mandrel; 111. External thread; 112. Anti-drop groove; 113. Anti-slip groove; 114. Mounting hole; 12. Conductive copper sleeve; 121. Internal thread; 122. Anti-drop ridge; 123. Anti-slip ridge; 13. End cap.

[0039] 21. mold shell; 211. step groove; 22. upper end cover; 221. step hole; 23. lower end cover; 231. gate; 232. runner; 233. lower positioning hole; 24. bolt; 25. positioning insert; 26. exhaust insert; 27. pressure ring; 28. cavity. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] See attached Figure 1-5, a dynamic conductive rod for a vacuum interrupter, comprising a conductive copper sleeve 12 and a core shaft 11 coaxially embedded in the conductive copper sleeve 12;

[0042] The side of the core shaft 11 is provided with an external thread 111 and a groove, wherein the groove includes an anti-falling groove 112 and an anti-slip groove 113, wherein the anti-falling groove 112 is annular and arranged around the core shaft 11, and the anti-slip groove 113 is linear and arranged along the axis direction of the core shaft 11;

[0043] The inner side wall of the conductive copper sleeve 12 is convex and filled with the external thread 111 , the anti-falling groove 112 and the anti-slip groove 113 , that is, an internal thread 121 , an anti-falling ridge 122 and an anti-slip ridge 123 that are seamlessly connected with the external thread 111 , the anti-falling groove 112 and the anti-slip groove 113 are formed.

[0044] In this embodiment, the anti-slip groove 112 divides the external thread 111 into multiple sections, and each section of the external thread 111 is provided with an anti-slip groove 113. The upper and lower ends of the anti-slip groove 113 are respectively connected to the adjacent anti-slip groove 112. The anti-slip grooves 113 on each section of the external thread 111 are staggered along the circumferential direction of the core shaft 11. The top anti-slip groove 113 extends upward and passes through the top surface of the core shaft, and the bottom anti-slip groove 113 extends downward to pass through the bottom surface of the core shaft.

[0045] The anti-slip grooves 113 on each section of the external thread 111 are staggered and distributed along the circumferential direction of the core shaft 11, which has the following technical effects:

[0046] 1. Better filling control: Multiple staggered vertical grooves can guide the copper liquid to fill each annular groove more evenly, rather than relying on a single vertical groove to provide the flow of copper liquid. This can reduce the risk of local overcooling and suspended solidification, thereby improving the uniformity of filling;

[0047] 2. More effective gas removal: Each annular groove is connected to its own vertical groove, providing more exhaust paths for gas, which can further reduce pores and bubble defects;

[0048] 3. Reduce thermal stress: Due to the staggered arrangement of vertical grooves, heat distribution may be more uniform, reducing the concentration of thermal stress generated when the metal solidifies, thereby reducing the risk of cracks in the casting during cooling;

[0049] 4. Enhanced structural integrity: The staggered arrangement of vertical grooves avoids the reduction of continuous sections in one direction, which may have less impact on the mechanical properties of the mandrel and has a lower impact on structural strength than a single vertical groove;

[0050] In this embodiment, the conductive copper sleeve 12 is made of oxygen-free copper, preferably TU1 oxygen-free copper; the core shaft 11 is made of stainless steel or mold steel, preferably 316L stainless steel or 42CrMo mold steel.

[0051] See attached Figure 6-9 , a casting mold for casting the above-mentioned dynamic conductive rod, comprising a mold shell 21, an upper end cover 22 and a lower end cover 23, wherein the mold shell 21 is cylindrical and the upper and lower openings are enclosed by the upper end cover 22 and the lower end cover 23 (specifically, the upper end cover 22 and the lower end cover 23 are respectively installed in the step grooves 211 at the openings at both ends of the mold shell 21 and are detachably fixedly connected to the mold shell 21 by bolts 24), a gate 231 is formed at the lower part of the lower end cover 23, and the gate 231 is circumferentially connected to the mold cavity 28 through a plurality of runners 232 uniformly distributed along the circumferential direction, and exhaust inserts 26 are respectively installed in the plurality of step holes 221 of the upper end cover 22, and each exhaust insert 26 is uniformly distributed along the circumferential direction of the upper end cover 22, and the exhaust insert 26 is composed of molding sand and is provided with a mold cavity 28 penetrating the mold and an external lower exhaust hole;

[0052] The mandrel 11 is installed in the mold shell 21, and its upper and lower ends are respectively positioned and matched with the upper end cover 22 and the lower end cover 23 through positioning inserts 25 (specifically, the upper end cover 22 and the lower end cover 23 are respectively provided with positioning holes at the center, and only the lower positioning hole 233 is shown in the figure. The center parts of the two ends of the mandrel 11 are respectively provided with mounting holes 114. The positioning inserts 25 are embedded in the positioning cavity formed by the positioning holes and the mounting holes 114. After the conductive copper sleeve 12 is cast, the mounting hole 114 can be blocked by the head 13);

[0053] The core shaft 11 , the mold shell 21 , the upper end cover 22 and the lower end cover 23 are assembled to form a mold cavity 28 for molding the conductive copper sleeve 12 .

[0054] In this embodiment, a pressure ring 27 is detachably mounted on the upper end cover 22 , and the pressure ring 27 presses and fixes the exhaust insert 26 to the upper end cover 22 , wherein the pressure ring 27 is provided with an upper exhaust hole corresponding to the lower exhaust hole.

[0055] The manufacturing method of the movable conductive rod for the above-mentioned vacuum arc extinguishing chamber is to form a conductive copper sleeve 12 by casting outside the core shaft 11 through the above-mentioned casting mold and adopting vacuum bottom casting technology. Before casting, the core shaft 11 is preheated to 1100°C. During the casting process, the copper liquid fills the mold cavity 28 from bottom to top. After casting, the mounting holes 114 at both ends of the core shaft 11 are sealed by the head 13.

[0056] Application Example 1

[0057] The conductive copper sleeve of the moving conductive rod for the vacuum interrupter is made of TU1 oxygen-free copper, and the material used for the core shaft is 316L stainless steel.

[0058] The length of the stainless steel core shaft is consistent with that of the conductive copper sleeve, both of which are 51 cm. The outer diameter of the conductive copper sleeve is 58 mm, and the diameter of the stainless steel core shaft is 30 mm.

[0059] The depth of the anti-slip step is 2 mm, the width is 4 cm, and 4 anti-slip steps are evenly spaced along the axial direction of the stainless steel core shaft, with 2.5 mm reserved on each side of the stainless steel core shaft.

[0060] The external thread of the stainless steel core shaft is M30*1.5, and is divided into three sections by anti-slip steps, and the length of each section is 10 cm.

[0061] The depth of the anti-slip groove is 2mm and the width is 6mm.

[0062] The mold and method in the above embodiment are used to manufacture the dynamic conductive rod for the vacuum interrupter. During the manufacturing process, the melting temperature of TU1 oxygen-free copper is 1100°C to 1120°C, and the casting of molten copper is controlled to fill the mold cavity within 30 seconds.

[0063] The dynamic conductive rod alloy for vacuum interrupter prepared by this method has a tensile strength of up to 460MPa (the tensile strength of the currently used oxygen-free copper conductive rod after vacuum brazing is only 240MPa) and a conductivity of 65S / m.

[0064] Application Example 2

[0065] The conductive copper sleeve of the moving conductive rod for the vacuum interrupter is made of TU1 oxygen-free copper, and the material used for the core shaft is 316L stainless steel.

[0066] The length of the stainless steel core shaft is consistent with that of the conductive copper sleeve, both of which are 53 cm. The outer diameter of the conductive copper sleeve is 58 mm, and the diameter of the stainless steel core shaft is 35 mm.

[0067] The depth of the anti-slip step is 3mm and the width is 5cm. Five anti-slip steps are evenly spaced along the axial direction of the stainless steel core shaft, and 1.5mm is reserved on each side of the stainless steel core shaft.

[0068] The external thread of the stainless steel core shaft is M35*1.5, and is divided into 4 sections by anti-slip steps, and the length of each section is 6.25 cm.

[0069] The depth of the anti-slip groove is 3mm and the width is 7mm.

[0070] The mold and method in the above embodiment are used to manufacture the dynamic conductive rod for the vacuum interrupter. During the manufacturing process, the melting temperature of TU1 oxygen-free copper is 1100°C to 1120°C, and the casting of molten copper is controlled to fill the mold cavity within 30 seconds.

[0071] The dynamic conductive rod alloy for vacuum arc chamber prepared by the method has a tensile strength of up to 470 MPa and a conductivity of 62 S / m.

[0072] Application Example 3

[0073] The conductive copper sleeve of the dynamic conductive rod for the vacuum interrupter is made of TU1 oxygen-free copper, and the material used for the core shaft is 42CrMo die steel, which can improve the strength and hardness of the conductive rod.

[0074] The length of the mold steel core shaft is consistent with the length of the conductive copper sleeve, both of which are 55cm. The outer diameter of the conductive copper sleeve is 58mm, and the diameter of the mold steel core shaft is 35mm.

[0075] The depth of the anti-slip step is 4mm and the width is 5cm. Six anti-slip steps are evenly spaced along the axial direction of the mold steel core shaft, and 1mm is reserved on each side of the stainless steel core shaft.

[0076] The external thread of the stainless steel core shaft is M35*1.5, and is divided into 5 sections by anti-slip steps, and the length of each section is 4.6 cm.

[0077] The depth of the anti-slip groove is 4mm and the width is 8mm.

[0078] The mold and method in the above embodiment are used to manufacture the dynamic conductive rod for the vacuum interrupter. During the manufacturing process, the melting temperature of TU1 oxygen-free copper is 1100°C to 1120°C, and the casting of molten copper is controlled to fill the mold cavity within 30 seconds.

[0079] The dynamic conductive rod alloy for vacuum arc chamber prepared by the method has a tensile strength of up to 480 MPa and a conductivity of 59 S / m.

[0080] Comparative Example 1

[0081] In terms of structure: Comparative Example 1 is based on Application Example 1, but the design of the anti-slip groove is omitted.

[0082] In terms of manufacturing process: Comparative Example 1 is consistent with Application Example 1.

[0083] Comparative Example 2

[0084] In terms of structure: Comparative Example 2 is based on Application Example 1, in which the anti-slip groove is designed to be a structure that runs through the side wall of the core shaft from top to bottom, with unchanged width and depth.

[0085] In terms of manufacturing process: Comparative Example 2 is consistent with Application Example 1.

[0086] Tensile test: Use normal brazing process to braze the conductive copper sleeve and TU1 oxygen-free copper connector, and braze the 316L stainless steel connector and the mandrel. On the tensile testing machine, clamp the stainless steel connector at one end and the oxygen-free copper connector at the other end to test the maximum force required for the oxygen-free copper connector to break.

[0087] The fracture forms of Application Example 1, Comparative Example 1 and Comparative Example 2 were all fractures of the oxygen-free copper connector, and no phenomenon of the steel core being pulled off occurred.

[0088] The maximum force value of application example 1 can reach 320KN, and the maximum force values ​​of comparative examples 1 and 2 can reach 316KN and 298KN;

[0089] The conductivity of application example 1 is 65S / m, 57S / m, and 63S / m.

[0090] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0091] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A movable conductive rod for a vacuum interrupter, characterized in that: It includes a conductive copper sleeve and a core shaft coaxially embedded in the conductive copper sleeve; The side of the mandrel is provided with threads and grooves, the grooves include anti-falling grooves and anti-slip grooves, the anti-falling grooves are annular and arranged around the mandrel, and the anti-slip grooves are linear and arranged in a direction parallel to the axis of the mandrel; The inner side wall of the conductive copper sleeve is convex and filled with the above-mentioned threads, anti-falling grooves and anti-slip grooves; The anti-slip grooves divide the threads into multiple sections, and each section of the threads is provided with anti-slip grooves; The anti-skid grooves on each section of the thread are staggered in the circumferential direction.

2. A movable conductive rod for a vacuum interrupter as claimed in claim 1, characterized in that: The conductive copper sleeve is made of oxygen-free copper.

3. A movable conductive rod for a vacuum interrupter as claimed in claim 2, characterized in that: The conductive copper sleeve is made of TU1 oxygen-free copper.

4. A movable conductive rod for a vacuum interrupter as claimed in claim 1, characterized in that: The core shaft is made of stainless steel or die steel.

5. A movable conductive rod for a vacuum interrupter as claimed in claim 4, characterized in that: The core shaft is made of 316L stainless steel or 42CrMo die steel.

6. A casting mold for casting the movable conductive rod for a vacuum interrupter as claimed in any one of claims 1 to 5, characterized in that: The mold shell comprises a mold shell, an upper end cover and a lower end cover, wherein the mold shell is cylindrical and has upper and lower openings sealed by the upper end cover and the lower end cover, a gate is formed at the lower part of the lower end cover, and the gate is connected to the mold cavity of the mold through a plurality of runners evenly distributed along the circumferential direction in the circumferential direction, and a plurality of exhaust inserts evenly distributed along the circumferential direction are installed on the upper end cover, and the exhaust inserts are made of molding sand and are provided with a mold cavity penetrating the mold and an external lower exhaust hole; The mandrel is installed in the mold shell and its upper and lower ends are respectively positioned and matched with the upper end cover and the lower end cover through positioning inserts; The core shaft, the mold shell, the upper end cover and the lower end cover are assembled to form a mold cavity for forming the conductive copper sleeve.

7. The casting mold according to claim 6, characterized in that: A pressing ring is detachably mounted on the upper end cover, and the pressing ring presses and fixes the exhaust insert to the upper end cover, wherein an upper exhaust hole corresponding to the lower exhaust hole is opened on the pressing ring.

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