High-safety vacuum circuit breaker for power distribution control equipment

Abstract

The invention relates to the technical field of high-voltage electric appliance switch equipment, and discloses a high-safety vacuum circuit breaker for power distribution control equipment, which comprises a vacuum circuit breaker body and a movable frame for bearing the vacuum circuit breaker body, the vacuum circuit breaker body comprises a solid-sealed polar pole main body, the solid-sealed polar pole main body is provided with an upper transverse outlet and a lower transverse outlet, and plum blossom contacts are arranged at the transverse outlets; a vacuum tank and an inner sealing cylinder positioned below the vacuum tank are packaged in the solid-sealed polar pole main body; an insulating transmission sleeve is arranged in the inner sealing cylinder, and an insulating transmission rod inner core is movably arranged in an inner cavity of the insulating transmission sleeve in a penetrating mode. The wax type temperature sensing bulb is arranged in the conductive arm base, the kick type diaphragm is used as a trigger medium, a direct linkage relation between the contact temperature and mechanical locking is established, contact fusion welding, arcing or explosion accidents caused by forced switching-out are effectively prevented, and the operation and maintenance safety of power distribution equipment is improved.

Description

Technical Field

[0001] This invention relates to the field of high-voltage electrical switchgear technology, specifically a high-safety vacuum circuit breaker for power distribution control equipment. Background Technology

[0002] Vacuum circuit breakers, as core control and protection devices in power distribution systems, are widely used in power grids and industrial and mining enterprises. They are typically installed in switchgear cabinets using a chassis structure, allowing for maintenance or isolation via rocking-in and rocking-out operations. During long-term operation, the connection points of the moving and stationary contacts of the circuit breaker, especially the stud contacts, are highly susceptible to increased contact resistance due to spring fatigue, oxidation corrosion, or loose fasteners, leading to abnormal temperature rises. Forcibly rocking out these connections when they are in a critical state of overheating or even localized welding can easily cause serious electrical accidents such as arcing short circuits, contact damage, or even switchgear explosions.

[0003] Currently, monitoring the temperature of circuit breaker contacts mainly relies on secondary electronic monitoring systems, such as wireless temperature sensors, infrared temperature measurement windows, or fiber optic temperature measurement devices. However, such active monitoring methods have inherent limitations. They are highly dependent on power supply lifespan, signal transmission stability, and the reliability of the backend monitoring system. Once the sensor fails or the signal is interrupted, the monitoring system will be unable to function. More importantly, existing temperature measurement systems can usually only issue audible and visual alarm signals and cannot directly cut off the operation path at the mechanical level. In the event of emergency repairs or human misjudgment, it is difficult to physically prevent operators from inserting the handle and forcibly turning the lead screw mechanism of the chassis, posing a serious safety hazard.

[0004] Furthermore, modern vacuum circuit breakers mostly employ solid-enclosed pole technology, encapsulating the vacuum interrupter and conductive circuit within epoxy resin to improve insulation performance and environmental adaptability. While this fully enclosed structure enhances insulation strength, it also hinders internal heat dissipation, easily leading to internal heat accumulation. Due to the limited internal space of the solid-enclosed pole and the involvement of high-voltage insulation issues, directly arranging mechanical transmission components inside the pole presents significant technical challenges. It is necessary to prevent damage to insulation strength while simultaneously addressing the heat dissipation and assembly issues of the transmission components themselves. Therefore, existing circuit breaker products struggle to achieve a purely mechanical safety linkage that directly drives the low-voltage side locking mechanism using high-voltage side heat energy while maintaining the pole's insulation performance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a high-safety vacuum circuit breaker for power distribution control equipment, solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a high-safety vacuum circuit breaker for power distribution control equipment, comprising: a vacuum circuit breaker body and a movable frame supporting the vacuum circuit breaker body; The vacuum circuit breaker body includes a solid-sealed pole body, which has two horizontal outlets, one above the other, and a quincunx contact at each horizontal outlet. The solid-sealed electrode body is internally encapsulated with a vacuum canister and an inner sealing cylinder located below the vacuum canister; An insulating transmission sleeve is provided inside the inner sealing cylinder. An insulating transmission rod core is movably inserted into the inner cavity of the insulating transmission sleeve. A heat dissipation channel is formed between the inner wall of the insulating transmission sleeve and the outer wall of the insulating transmission rod core. The solid-sealed pole body is provided with a conductive arm base outside the lateral outlet corresponding to the plum blossom contact. The conductive arm base is located outside the plum blossom contact, and a wax-type temperature sensing bulb is embedded in the conductive arm base. The output end of the wax-type temperature sensor is connected to a movable push rod that extends laterally into the solid-sealed electrode body. The solid-sealed electrode body has a snap-type diaphragm located at the end of the stroke of the movable push rod.

[0007] Preferably, when the temperature of the conductive arm base rises, the wax-type temperature sensing bulb drives the movable top rod to move horizontally, triggering the snap-action diaphragm. The snap-action diaphragm is excited and flips over, striking the inner core of the insulating transmission rod downwards, thereby driving the locking actuator located at the bottom of the solidified pole body to lock the movable frame. The outer wall of the insulating transmission sleeve is provided with annular umbrella skirts distributed axially at intervals, and the outer peripheral surface of the annular umbrella skirts maintains a gap with the inner wall of the inner sealing cylinder. The outer wall of the inner core of the insulating transmission rod is provided with annular reinforcing ribs distributed at intervals along the axial direction, and the annular reinforcing ribs are located in the heat dissipation channel; the annular umbrella skirt is used to enhance the insulation performance between the insulating transmission sleeve and the inner sealing cylinder, and the annular reinforcing ribs are used to enhance the rigidity of the inner core of the insulating transmission rod and change the airflow pattern in the heat dissipation channel.

[0008] Preferably, a limiting protrusion is fixedly connected to the outer edge of the annular umbrella skirt; the inner wall of the inner sealing cylinder is provided with a stepped structure that cooperates with the limiting protrusion, and the axial movement and circumferential rotation of the insulating transmission sleeve in the inner sealing cylinder are restricted by the limiting protrusion.

[0009] Preferably, the inner wall of the insulating transmission sleeve is provided with protruding turbulence ribs, and the turbulence ribs and the annular reinforcing ribs on the outer wall of the inner core of the insulating transmission rod are staggered in the axial position; the cooling airflow in the heat dissipation channel flows through the gap between the turbulence ribs and the annular reinforcing ribs to form turbulence.

[0010] Preferably, the conductive arm base is elastically abutted against the transverse outlet end face of the solid-sealed pole body by a constant-pressure floating disc spring, adapting to thermal expansion and contraction and mechanical vibration; the snap-type diaphragm is disposed above the top of the inner core of the insulating transmission rod and is located in the transition area between the vacuum tank and the inner sealing cylinder.

[0011] Preferably, the locking actuator includes an inclined pressure block fixedly connected to the bottom end of the inner core of the insulating transmission rod, and an inclined movable block that slides with the inclined pressure block; the inclined pressure block has a first inclined surface that is vertically downward, and the inclined movable block has a second inclined surface that receives the first inclined surface, so that the vertical downward movement of the inner core of the insulating transmission rod is converted into the horizontal linear movement of the inclined movable block.

[0012] Preferably, a movable safety shield is mounted on the panel of the movable frame. The movable safety shield is used to cover the operating hole, and a deadlock groove is formed on the surface of the movable safety shield. A locking pin is fixed at one end of the inclined movable block. When the inclined movable block is driven to move horizontally forward, the locking pin is inserted into the deadlock groove to prevent the movable safety shield from moving.

[0013] Preferably, it further includes a bracket fixed to the outside of the movable frame, a cap ring sleeve fixed on the bracket, and a locking pin passing through the cap ring sleeve; the surface of the locking pin is provided with an axially extending strip groove, and the inner wall of the cap ring sleeve is provided with an anti-rotation rib embedded in the strip groove.

[0014] Preferably, a return spring is sleeved on the outside of the locking pin; the return spring is located between the cap ring sleeve and the inclined movable block, and is used to push the inclined movable block and the inclined pressure block to reset after the wax-type temperature sensing bulb cools and shrinks.

[0015] Preferably, the movable safety shield is a sliding plate structure, and the panel of the movable frame is also provided with a limiting buckle plate, which is used to limit the sliding range of the movable safety shield.

[0016] This invention provides a high-safety vacuum circuit breaker for power distribution control equipment. It has the following advantages: 1. This invention establishes a direct linkage between contact temperature and mechanical interlocking by setting a wax-type temperature sensing bulb inside the conductive arm base and using a snap-action diaphragm as the trigger medium. When the temperature of the plum blossom contact rises abnormally due to poor contact or overload, the thermal expansion force is converted into mechanical energy to drive the interlocking mechanism to lock the movable safety shield, forcibly blocking the operating hole. This physically prevents personnel from operating the equipment in or out under high-temperature dangerous conditions, effectively preventing contact welding, arcing, or explosion accidents caused by forced shutdown, and improving the operation and maintenance safety of power distribution equipment.

[0017] 2. This invention constructs a heat dissipation channel containing an insulating transmission sleeve and an insulating transmission rod core inside the solid-sealed pole body. Utilizing the staggered distribution structure of the inner wall turbulence ribs and the outer wall annular reinforcing ribs, a turbulent field is formed within the channel, disrupting the airflow boundary layer and improving the heat exchange efficiency inside the pole. Simultaneously, the annular umbrella skirt on the outer side of the insulating transmission sleeve forms an insulating structure with the inner wall of the inner sealing cylinder. Combined with the positioning function of the limiting protrusion, this not only extends the surface creepage distance and ensures the insulation strength under high voltage conditions, but also solves the assembly and heat dissipation problems of transmission components in narrow spaces through integrated design.

[0018] 3. This invention employs a wedge-shaped transmission mechanism that combines a sloping pressure block and a sloping movable block, efficiently converting thermally triggered vertical displacement into horizontal locking force. Compared to traditional lever mechanisms, this mechanism offers higher rigidity and transmission stability. Combined with the strip groove on the locking pin surface and the anti-rotation rib design within the cap ring sleeve, it eliminates the risk of jamming caused by the rotation of the cylindrical pin, ensuring the certainty of the locking action. Furthermore, the conductive arm base is mounted with a constant-pressure floating disc spring, which can adapt to dimensional changes and mechanical vibrations caused by thermal expansion and contraction, ensuring the accuracy of temperature detection and the overall mechanical lifespan of the structure under complex working conditions. Attached Figure Description

[0019] Figure 1 This is a front perspective view of the present invention; Figure 2 This is a bottom-view perspective view of the present invention; Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 This is a schematic diagram of the structure of the cap ring sleeve of the present invention; Figure 5 This is a schematic diagram of the inner sealing cylinder of the present invention; Figure 6 This is a schematic diagram of the structure of the baffle rib of the present invention; Figure 7 This is a schematic diagram of the structure of the movable push rod of the present invention; Figure 8 This is a schematic diagram of the internal structure of the inner sealing tube of the present invention; Figure 9 This is a schematic diagram of the internal structure of the insulating transmission sleeve of the present invention.

[0020] The components include: 1. Vacuum circuit breaker body; 2. Solid-sealed pole body; 3. Conductor arm base; 4. Plum blossom contact; 5. Vacuum tank; 6. Inner sealing cylinder; 7. Wax-type temperature sensing bulb; 8. Constant pressure floating disc spring; 9. Movable top rod; 10. Snap-on diaphragm; 11. Baffle rib; 12. Insulated transmission rod inner core; 13. Annular reinforcing rib; 14. Heat dissipation channel; 15. Insulated transmission sleeve; 16. Annular umbrella skirt; 17. Limiting protrusion; 18. Inclined pressure block; 19. Movable frame; 20. Limiting buckle plate; 21. Movable safety shield; 22. Dead lock groove; 23. Bracket; 24. Cap ring sleeve; 25. Anti-rotation rib; 26. Locking pin; 27. Return spring; 28. Strip groove; 29. ​​Inclined movable block. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see the appendix Figure 1 - Appendix Figure 8 This invention provides a high-safety vacuum circuit breaker for power distribution control equipment, including a vacuum circuit breaker body 1 and a movable frame 19 supporting the vacuum circuit breaker body 1. The vacuum circuit breaker body 1 is fixed to the movable frame 19 by an insulating mounting plate. The bottom of the movable frame 19 is provided with rollers and a push screw mechanism for realizing the rocking-in and rocking-out operation of the circuit breaker in the switch cabinet.

[0023] The core component of the vacuum circuit breaker body 1 is the solid-sealed pole body 2. The solid-sealed pole body 2 is formed using an epoxy resin vacuum casting process and has two lateral outlets: an outgoing terminal at the top and an incoming terminal at the bottom. A perforated contact 4 is installed at the top lateral outlet, which is used to connect electrically with the stationary contact inside the switchgear. The solid-sealed pole body 2 internally encapsulates a vacuum chamber 5 (i.e., a vacuum interrupter), located in the upper half of the solid-sealed pole body 2. Below the vacuum chamber 5, the solid-sealed pole body 2 has a reserved space for an inner sealing cylinder 6. The inner sealing cylinder 6 is a cylindrical component made of insulating material, coaxially positioned within the lower half of the solid-sealed pole body 2.

[0024] An insulating transmission sleeve 15 is fixedly installed inside the inner sealing cylinder 6. The insulating transmission sleeve 15 is also made of high-strength insulating material, and its outer wall is fitted and positioned with the inner wall of the inner sealing cylinder 6 through a specific structure. An insulating transmission rod core 12 is movably inserted into the inner cavity of the insulating transmission sleeve 15. The insulating transmission rod core 12 extends vertically and can slide axially within the insulating transmission sleeve 15. The inner diameter of the insulating transmission sleeve 15 is larger than the outer diameter of the insulating transmission rod core 12, and the annular gap formed between them constitutes a heat dissipation channel 14.

[0025] To enhance insulation performance and prevent surface creep, annular skirts 16 are integrally formed on the outer wall of the insulating transmission sleeve 15, spaced axially. The outer circumferential surface of the annular skirts 16 abuts against or approaches the inner wall of the inner sealing cylinder 6, dividing the tiny gap between the insulating transmission sleeve 15 and the inner sealing cylinder 6 into several independent insulation zones. Limiting protrusions 17 are fixedly connected to the outer edge of the annular skirts 16. Correspondingly, a stepped structure or groove matching the shape of the limiting protrusions 17 is formed on the inner wall of the inner sealing cylinder 6. During assembly, the limiting protrusions 17 engage with the stepped structure, thereby restricting axial movement or circumferential rotation of the insulating transmission sleeve 15 within the inner sealing cylinder 6, ensuring the stability of the internal structure.

[0026] To improve the heat exchange efficiency within the heat dissipation channel 14, the inner wall of the insulating transmission sleeve 15 is provided with inwardly protruding turbulence ribs 11, and the outer wall of the inner core 12 of the insulating transmission rod is provided with outwardly protruding annular reinforcing ribs 13. The turbulence ribs 11 and the annular reinforcing ribs 13 are staggered in axial position, that is, one turbulence rib 11 is located in the axial interval between two adjacent annular reinforcing ribs 13. External cold air enters from the opening at the bottom of the inner sealing cylinder 6 and flows through the heat dissipation channel 14. When the airflow passes through the staggered turbulence ribs 11 and the annular reinforcing ribs 13, the flow channel cross-section undergoes periodic contraction and expansion, forcing laminar flow to change into turbulent flow, destroying the boundary layer attached to the wall surface, thereby enhancing the heat dissipation effect on the inner core 12 of the insulating transmission rod and surrounding components. The annular reinforcing ribs 13 also serve to enhance the bending stiffness of the inner core 12 of the insulating transmission rod.

[0027] In terms of thermal detection and triggering, the solid-sealed electrode body 2 has a conductive arm base 3 outside the lateral outlet corresponding to the plum blossom contact 4. The conductive arm base 3 is made of thermally conductive metal and is sleeved on the outside of the plum blossom contact 4 to directly sense the temperature of the main circuit connection point. The conductive arm base 3 is not rigidly fixed to the lateral outlet end face of the solid-sealed electrode body 2, but is elastically abutted by a constant pressure floating disc spring 8. The constant pressure floating disc spring 8 can absorb the deformation displacement of the conductive arm base 3 caused by thermal expansion and contraction, as well as the mechanical vibration during equipment operation, to ensure the stability of the contact pressure.

[0028] A blind-hole-shaped mounting hole is formed along the horizontal axis on the inner side wall of the conductive arm base 3. A wax-type temperature sensing element 7 is press-fitted into the mounting hole with an interference fit. The interference fit ensures that the heat from the conductive arm base 3 can be quickly conducted to the outer shell of the wax-type temperature sensing element 7. The wax-type temperature sensing element 7 (industrially known as a wax-type thermodynamic element) is a general-purpose actuator that converts thermal energy into mechanical displacement. It mainly consists of a high thermal conductivity metal shell, an internally filled high-expansion coefficient paraffin mixture, a rubber sealing sleeve, and an output piston. In this embodiment, the wax-type temperature sensing element 7 is installed horizontally, with its output end facing the central axis of the solidified pole body 2.

[0029] When the temperature of the conductive arm base 3 rises, heat is transferred to the interior of the wax-type temperature sensing bulb 7, causing the paraffin mixture to change from a solid to a liquid state or to expand in volume. Due to the rigid constraint of the metal shell, the pressure generated by the volume expansion can only squeeze the rubber sealing sleeve, thereby forcing the output piston to push outward axially. One end of the movable push rod 9 is coaxially abutted against the output piston of the wax-type temperature sensing bulb 7, or the movable push rod 9 itself serves as an extension output shaft of the wax-type temperature sensing bulb 7; the movable push rod 9 passes through the finger gap of the plum blossom contact 4 or a pre-set guide hole on its base, and the guide hole provides radial constraint to the movable push rod 9, ensuring that it can only move in a horizontal straight line and extend deep into the interior of the solid-sealed pole body 2. Inside the solid-sealed pole body 2, in the transition area between the vacuum tank 5 and the inner sealing cylinder 6, a snap-action diaphragm 10 is provided. The snap-action diaphragm 10 is a bistable metal spring with a pre-fabricated convex curved surface. Its installation position is between the end of the lateral stroke of the movable push rod 9 and the top of the inner core 12 of the insulating transmission rod, waiting to be triggered by the horizontal thrust of the movable push rod 9.

[0030] When the temperature at the conductive arm base 3 rises to a set threshold due to poor contact or overload, the medium inside the wax-type temperature sensing bulb 7 expands, pushing the movable push rod 9 to move horizontally inward. The end of the movable push rod 9 presses against the side edge or arch of the snap-action diaphragm 10. When the accumulated deformation energy exceeds the critical point, the snap-action diaphragm 10 undergoes a transient reverse flip, producing a downward snap-action that strikes the top of the insulating transmission rod inner core 12. This impact force drives the insulating transmission rod inner core 12 to move rapidly downward within the heat dissipation channel 14.

[0031] At the bottom of the solid-sealed pole body 2, a locking actuator is connected. The locking actuator includes an inclined pressure block 18 fixedly connected to the bottom end of the inner core 12 of the insulating transmission rod, and an inclined movable block 29 that slides with the inclined pressure block 18. The inclined pressure block 18 has a first inclined surface that points vertically downward, and the inclined movable block 29 has a second inclined surface that receives the first inclined surface. When the inner core 12 of the insulating transmission rod is subjected to downward force, the first inclined surface of the inclined pressure block 18 presses against the second inclined surface of the inclined movable block 29, converting the vertical displacement into the horizontal linear motion of the inclined movable block 29.

[0032] A locking pin 26 is fixedly connected to the front end of the inclined movable block 29. A movable safety shield 21 is mounted on the front panel of the movable frame 19. The movable safety shield 21 is a plate-like structure that can slide left and right, used to cover or expose the operating hole for inserting the operating handle. A deadlock groove 22 is provided on the side of the movable safety shield 21. A limit plate 20 is also provided on the panel of the movable frame 19 to limit the sliding range of the movable safety shield 21.

[0033] To ensure the guiding accuracy of the locking pin 26's movement, a bracket 23 is fixed externally to the movable frame 19, and a cap ring sleeve 24 is fixed on the bracket 23. The locking pin 26 passes through the cap ring sleeve 24. An axially extending strip groove 28 is formed on the cylindrical surface of the locking pin 26, and an anti-rotation rib 25 protrudes from the inner wall of the cap ring sleeve 24. The anti-rotation rib 25 is slidably engaged within the strip groove 28, restricting the rotation of the locking pin 26 around its own axis and ensuring that the inclined movable block 29 always maintains the correct force-bearing posture.

[0034] A return spring 27 is fitted around the locking pin 26. One end of the return spring 27 abuts against the end face of the cap ring sleeve 24, and the other end abuts against the stepped surface of the inclined movable block 29. When the triggering action occurs, the inclined movable block 29 moves forward against the resistance of the return spring 27, causing the locking pin 26 to insert into the deadlock groove 22 of the movable safety shield 21, physically locking the movable safety shield 21 so that it cannot move to expose the operating hole, thereby prohibiting personnel from shaking the faulty equipment in or out. When the temperature drops, the wax-type temperature sensing bulb 7 contracts, the return spring 27 releases its elastic force, pushing the inclined movable block 29 and the inclined pressure block 18 to reset, and the locking pin 26 exits the deadlock groove 22, releasing the locked state.

[0035] In this embodiment, considering that the surface of the vacuum circuit breaker's plum blossom contact 4 is usually silver-plated, and according to the general technical standards for high-voltage switchgear, its maximum allowable temperature for long-term operation is 105°C. To avoid maloperation under normal rated load operation and to ensure reliable locking in the early stages of overheating faults, the phase change expansion temperature threshold of the temperature-sensing expansion medium inside the wax-type temperature sensing bulb 7 is set to 105°C to 110°C.

[0036] When the temperature conducted by the conductive arm base 3 is below 105°C, the wax-type temperature sensor 7 is in a non-working state or in a low expansion range, and the displacement of the movable push rod 9 is insufficient to trigger the flipping critical point of the snap-action diaphragm 10. When the temperature rises to the range of 105°C to 110°C, the medium inside the wax-type temperature sensor 7 undergoes a violent volume expansion, driving the movable push rod 9 to reach its maximum stroke and triggering the locking mechanism. At the same time, due to the physical hysteresis characteristics of the temperature sensing medium, the medium will only fully contract when the temperature drops below the set range of 85°C to 90°C, causing the locking mechanism to automatically reset under the action of the return spring 27, thereby avoiding frequent repeated actions near the critical temperature.

[0037] Working Principle: When the power distribution control equipment is in normal operation, the plum blossom contact 4 of the vacuum circuit breaker body 1 maintains electrical connection with the stationary contact in the switch cabinet, and the main circuit current flows normally. At this time, the temperature of the conductive arm base 3 is within the allowable normal range, and the temperature sensing medium in the wax-type temperature sensing bulb 7 embedded therein is in a contracted state. The movable push rod 9 does not apply a force sufficient to flip the snap-action diaphragm 10, and the snap-action diaphragm 10 maintains its initial arched state. Under the force of the return spring 27, the inclined movable block 29 is in the retracted position, driving the inclined pressure block 18 and the inner core 12 of the insulating transmission rod to remain in the upper position of the vertical stroke. At this time, the locking pin 26 is housed in the cap ring sleeve 24 and is not inserted into the dead lock groove 22 of the movable safety shield 21, and the movable safety shield 21 can slide freely left and right. The operator can move the movable safety shield 21 normally to expose the operating hole, and then use the crank to crank the movable frame 19 in or out.

[0038] During equipment operation, external air, heated by convection, enters through the air inlet at the bottom of the inner sealing cylinder 6 and flows upward along the heat dissipation channel 14 between the insulating transmission sleeve 15 and the inner core 12 of the insulating transmission rod. As the airflow passes through the turbulence ribs 11 on the inner wall of the insulating transmission sleeve 15 and the annular reinforcing ribs 13 on the outer wall of the inner core 12 of the insulating transmission rod, turbulence is formed due to the alternating changes in the flow channel cross-section. This effectively carries away the heat generated by the inner core 12 of the insulating transmission rod and surrounding components, and finally discharges from the top of the solidified pole body 2, achieving auxiliary heat dissipation inside the pole. Simultaneously, the annular umbrella skirt 16 on the outer wall of the insulating transmission sleeve 15 cooperates with the inner wall of the inner sealing cylinder 6, using the extended creepage distance to block potential transfer, and the limiting protrusion 17 ensures the positional stability of the insulating transmission sleeve 15 during thermal expansion and contraction cycles.

[0039] When poor contact, loose bolts, or prolonged overload cause the temperature at the sprite contact 4 to rise abnormally above the set threshold, the conductive arm base 3, which is in close contact with the outside of the sprite contact 4, rapidly heats up through heat conduction. During this process, the constant-pressure floating disc spring 8 between the conductive arm base 3 and the end face of the solid-sealed pole body 2 maintains a constant contact pressure to prevent displacement or loosening of the base due to thermal expansion. As the temperature rises, the medium inside the wax-type temperature sensing bulb 7 undergoes a phase change expansion, generating a huge thrust that drives the movable push rod 9 to overcome frictional resistance and move horizontally into the solid-sealed pole body 2.

[0040] The movable push rod 9 moves horizontally and presses against the snap-action diaphragm 10 at the end of its stroke. When the deformation energy accumulated on the snap-action diaphragm 10 crosses the critical point, the snap-action diaphragm 10 undergoes a transient reverse flipping motion, converting the gradual horizontal thrust into a vertically downward instantaneous impact force, striking the top of the inner core 12 of the insulating transmission rod. After being subjected to force, the inner core 12 of the insulating transmission rod rapidly displaces downward within the insulating transmission sleeve 15.

[0041] The downward movement of the inner core 12 of the insulating transmission rod drives the inclined pressure block 18 at the bottom to move downwards synchronously. The first inclined surface of the inclined pressure block 18 presses against the second inclined surface of the inclined movable block 29, converting the vertical downward driving force into a horizontal forward thrust through a wedge-shaped engagement. The inclined movable block 29 then overcomes the resistance of the return spring 27 and moves forward in the horizontal direction, causing the locking pin 26 fixed at its front end to extend outwards. During this process, the strip groove 28 on the surface of the locking pin 26 slides along the anti-rotation rib 25 on the inner wall of the cap ring sleeve 24, restricting the rotation of the locking pin 26 and ensuring the alignment of the inclined engagement. The extended locking pin 26 is radially inserted into the deadlock groove 22 on the side of the movable safety shield 21, physically locking the movable safety shield 21 in the position that blocks the operating hole. At this time, the limit plate 20 restricts the extreme position of the movable safety shield 21. With the locking of the locking pin 26, the operator cannot move the movable safety shield 21, thereby forcibly prohibiting the chassis vehicle from shaking when the contacts are overheated, and avoiding contact welding arcing or explosion accidents caused by forcibly pulling the brake at high temperature.

[0042] When the fault is cleared or the load is reduced, and the temperature of the plum blossom contact 4 and the conductive arm base 3 drops below the reset temperature, the medium inside the wax-type temperature sensing bulb 7 cools and contracts, and the thrust on the movable push rod 9 disappears. At this time, the reset spring 27 releases the accumulated elastic potential energy, pushing the inclined movable block 29 to retract horizontally. The second inclined surface of the inclined movable block 29 reverses and lifts the inclined pressure block 18 and the inner core 12 of the insulating transmission rod back to the initial upper position, and the snap-action diaphragm 10 returns to its original state. The locking pin 26 completely retracts from the dead lock groove 22, the movable safety shield 21 resumes its sliding function, and the operating authority of the vacuum circuit breaker body 1 and the movable frame 19 is automatically restored.

Claims

1. A high-safety vacuum circuit breaker for power distribution control equipment, characterized in that, include: Vacuum circuit breaker body (1) and movable frame (19) supporting the vacuum circuit breaker body (1). The vacuum circuit breaker body (1) includes a solid-sealed pole body (2), which has two horizontal outlets, one above the other, and a plum blossom contact (4) at each horizontal outlet. The solid-sealed pole body (2) is internally encapsulated with a vacuum tank (5) and an inner sealing cylinder (6) located below the vacuum tank (5). An insulating transmission sleeve (15) is provided inside the inner sealing cylinder (6). An insulating transmission rod core (12) is movably inserted in the inner cavity of the insulating transmission sleeve (15). A heat dissipation channel (14) is formed between the inner wall of the insulating transmission sleeve (15) and the outer wall of the insulating transmission rod core (12). The solid-sealed pole body (2) is provided with a conductive arm base (3) outside the transverse outlet corresponding to the plum blossom contact (4). The conductive arm base (3) is located outside the plum blossom contact (4), and a wax-type temperature sensing bulb (7) is embedded in the conductive arm base (3). The output end of the wax-type temperature sensor (7) is connected to a movable top rod (9) that extends laterally into the solid-sealed electrode body (2). The solid-sealed electrode body (2) is provided with a snap-type diaphragm (10) located at the end of the stroke of the movable top rod (9).

2. The high-safety vacuum circuit breaker for power distribution control equipment according to claim 1, characterized in that, When the temperature of the conductive arm base (3) rises, the wax-type temperature sensing bulb (7) drives the movable top rod (9) to move horizontally and trigger the snap-type diaphragm (10). The snap-type diaphragm (10) is excited and flips over and strikes the inner core (12) of the insulating transmission rod downward, thereby driving the locking actuator located at the bottom of the solid-sealing pole body (2) to lock the movable frame (19). The outer wall of the insulating transmission sleeve (15) is provided with annular umbrella skirts (16) distributed axially. The outer circumferential surface of the annular umbrella skirt (16) and the inner wall of the inner sealing cylinder (6) maintain a gap. The outer wall of the inner core (12) of the insulating transmission rod is provided with annular reinforcing ribs (13) spaced along the axial direction. The annular reinforcing ribs (13) are located in the heat dissipation channel (14). The annular umbrella skirt (16) is used to enhance the insulation performance between the insulating transmission sleeve (15) and the inner sealing cylinder (6). The annular reinforcing ribs (13) are used to enhance the rigidity of the inner core (12) of the insulating transmission rod and change the airflow pattern in the heat dissipation channel (14).

3. A high-safety vacuum circuit breaker for power distribution control equipment according to claim 2, characterized in that, The outer edge of the annular umbrella skirt (16) is fixedly connected to a limiting protrusion (17); the inner wall of the inner sealing cylinder (6) is provided with a stepped structure that cooperates with the limiting protrusion (17), and the axial movement and circumferential rotation of the insulating transmission sleeve (15) in the inner sealing cylinder (6) are restricted by the limiting protrusion (17).

4. A high-safety vacuum circuit breaker for power distribution control equipment according to claim 2, characterized in that, The inner wall of the insulating transmission sleeve (15) is provided with an inner protruding turbulence rib (11), and the turbulence rib (11) and the annular reinforcing rib (13) on the outer wall of the inner core (12) of the insulating transmission rod are staggered in the axial position; the cooling airflow in the heat dissipation channel (14) flows through the gap between the turbulence rib (11) and the annular reinforcing rib (13) to form turbulence.

5. A high-safety vacuum circuit breaker for power distribution control equipment according to claim 1, characterized in that, The conductive arm base (3) is elastically contacted with the transverse outlet end face of the solid-sealed pole body (2) by a constant pressure floating disc spring (8) to adapt to thermal expansion and contraction and mechanical vibration; the snap-type diaphragm (10) is set above the top of the inner core (12) of the insulating transmission rod and is located in the transition area between the vacuum tank (5) and the inner sealing cylinder (6).

6. A high-safety vacuum circuit breaker for power distribution control equipment according to claim 2, characterized in that, The locking actuator includes an inclined pressure block (18) fixedly connected to the bottom end of the inner core (12) of the insulating transmission rod, and an inclined movable block (29) that slides with the inclined pressure block (18); the inclined pressure block (18) has a first inclined surface that is vertically downward, and the inclined movable block (29) has a second inclined surface that receives the first inclined surface; the vertical downward movement of the inner core (12) of the insulating transmission rod is converted into the horizontal linear movement of the inclined movable block (29).

7. A high-safety vacuum circuit breaker for power distribution control equipment according to claim 6, characterized in that, The movable frame (19) is equipped with a movable safety shield (21) on its panel. The movable safety shield (21) is used to block the operation hole. The surface of the movable safety shield (21) is provided with a deadlock groove (22). One end of the inclined movable block (29) is fixed with a locking pin (26). When the inclined movable block (29) is driven to move horizontally forward, the locking pin (26) is inserted into the deadlock groove (22) to prevent the movable safety shield (21) from moving.

8. A high-safety vacuum circuit breaker for power distribution control equipment according to claim 7, characterized in that, It also includes a bracket (23) fixed to the outside of the movable frame (19), a cap ring sleeve (24) fixed on the bracket (23), and a locking pin (26) passing through the cap ring sleeve (24); the surface of the locking pin (26) is provided with an axially extending strip groove (28), and the inner wall of the cap ring sleeve (24) is provided with an anti-rotation rib (25) embedded in the strip groove (28).

9. A high-safety vacuum circuit breaker for power distribution control equipment according to claim 8, characterized in that, The locking pin (26) is fitted with a return spring (27); the return spring (27) is located between the cap ring sleeve (24) and the inclined movable block (29), and is used to push the inclined movable block (29) and the inclined pressure block (18) to reset after the wax-type temperature sensing bag (7) cools and shrinks.

10. A high-safety vacuum circuit breaker for power distribution control equipment according to claim 7, characterized in that, The movable safety shield (21) is a sliding plate structure, and the panel of the movable frame (19) is also provided with a limiting buckle (20), which is used to limit the sliding range of the movable safety shield (21).

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