A load switchgear containing interlocking cam and multi-link closing limiting

Abstract

The application discloses a load switch cabinet containing interlocking cam and multi-link closing limiting, belongs to the technical field of switch cabinets, and comprises a cabinet body, wherein a gas tank is arranged in the cabinet body, a circuit breaker switch is arranged in the gas tank, left and right side test chambers are symmetrically arranged on the left and right sides of the gas tank, each test chamber is provided with an openable and closable test chamber door plate, a three-position load switch is arranged in the right side test chamber, and a three-position mirror image load switch is arranged in the left side test chamber. Compared with the prior art, the application has the beneficial effects that: by adopting a switch dynamic sealing shaft direct drive type multi-link interlocking structure, power is directly transmitted from a three-position switch main shaft to a door lock mechanism, the structure is simple, the transmission path is short, and the risk of transmission jamming and misplacement is avoided; meanwhile, a mechanical forced linkage design is adopted, and no electronic components and control power are needed, so that even if the equipment is completely powered off or the control system is paralyzed, the safety interlocking function can still stably operate.

Description

Technical Field

[0001] This invention relates to the field of switchgear technology, specifically to a load switchgear containing an interlocking cam and a multi-link closing limit switch. Background Technology

[0002] Load switchgear is the core equipment in 12kV distribution networks for power distribution, line control and fault protection. It is widely used in urban underground pipe networks, industrial power distribution systems and residential power supply.

[0003] To meet the needs of routine equipment maintenance and online testing, existing technologies typically include an independent testing chamber connected to the main circuit via a testing sleeve. This allows for main circuit parameter testing without opening the main gas box or leaking sulfur hexafluoride gas. Current testing chamber safety interlock mechanisms generally employ either electronic or mechanical methods. Electronic interlocks rely entirely on the control power supply and electronic components; their safety lock function is completely lost when power is lost or when electronic components age, become damp, or fail. Traditional mechanical interlocks often use multi-stage indirect transmission structures, which, with too many transmission links, are prone to jamming and misalignment, leading to a sharp decline in reliability over long-term use. Most solutions only achieve single-locking at the closing position; even though the main circuit is disconnected in the open state, induced current and residual capacitor voltage still exist, meaning opening the door at this time can still cause electric shock.

[0004] To address the aforementioned issues, this application proposes a load switchgear with interlocking cams and multi-link closing limit switches. Summary of the Invention

[0005] Based on the aforementioned problems in the existing technology, the problem to be solved by the present invention is to provide a load switch cabinet with interlocking cams and multi-link closing limit switches. By adopting a direct-drive multi-link interlocking structure with a dynamic sealing shaft, power is directly transmitted from the main shaft of the three-position switch to the door lock mechanism. The structure is simple and the transmission path is short, avoiding the risk of transmission jamming and misalignment. At the same time, the mechanical forced linkage design is adopted, which does not rely on any electronic components and control power supply. Even if the equipment is completely powered off or the control system is paralyzed, the safety interlocking function can still operate stably, thus solving the problems mentioned in the background technology.

[0006] The technical solution adopted by this invention to solve its technical problem is: A load switch cabinet with interlocking cams and multi-link closing limit switches includes a cabinet body. An air chamber is housed within the cabinet body. The air chamber contains a circuit breaker switch, a circuit breaker operating mechanism, and a three-position disconnect switch. A left-side test chamber and a right-side test chamber are symmetrically arranged on the left and right sides of the air chamber. Each test chamber has an openable test chamber door. A three-position load switch is housed in the right-side test chamber, and a three-position mirror load switch is housed in the left-side test chamber. The mirror load switch and the three-position load switch are installed in a mirror-symmetrical direction. An disconnect load operating mechanism and a mirror load operating mechanism are housed within the cabinet body. The air chamber sidewall is through-mounted... The test chamber has a switch dynamic seal shaft. The output shafts of the isolation load operating mechanism and the mirror load operating mechanism are respectively fixedly connected to the outer end of the corresponding switch dynamic seal shaft, and the inner end of the switch dynamic seal shaft is fixedly connected to the main shaft of the corresponding three-position load switch. Each test chamber is equipped with a multi-link interlocking mechanism, including an interlocking cam fixed to the switch dynamic seal shaft, an interlocking top plate abutting against the interlocking cam, an interlocking connecting rod fixedly connected to the interlocking top plate, a test chamber long swing arm hinged to the cabinet, a limit pin movably connected to the test chamber long swing arm, a door panel lock plate fixed to the inner side of the test chamber door panel, and a reset spring. The two ends of the reset spring are respectively connected to the cabinet and the interlocking top plate or the interlocking connecting rod.

[0007] Furthermore, the outer peripheral surface of the interlocking cam is provided with three positioning grooves along the circumferential direction, and the three positioning grooves correspond to the closing position, opening position and grounding position of the three-position load switch, respectively.

[0008] Furthermore, the middle part of the test chamber swing arm is hinged to the cabinet body by a pin, the upper end of the test chamber swing arm is hinged to the lower end of the interlocking connecting rod, the lower end of the test chamber swing arm is provided with a guide groove, one end of the limiting pin is slidably embedded in the guide groove, and the other end of the limiting pin can be inserted into the lock hole of the door panel lock plate.

[0009] Furthermore, both the left and right test chambers are equipped with test sleeves, connecting copper busbars, and inlet sleeves.

[0010] Furthermore, the inlet bushing penetrates the side wall of the gas box, the inner end of the inlet bushing is electrically connected to the main circuit of the circuit breaker switch inside the gas box, the outer end of the inlet bushing is electrically connected to the inlet end of the three-position disconnect switch via a connecting copper busbar, the outlet end of the three-position disconnect switch is electrically connected to the inlet end of the corresponding three-position load switch or three-position mirror load switch via a connecting copper busbar, and the outlet ends of the three-position load switch and the three-position mirror load switch are electrically connected to the inner end of the corresponding test bushing via a connecting copper busbar.

[0011] Furthermore, the circuit breaker operating mechanism, the isolated load operating mechanism, and the mirror load operating mechanism are all common manual-electric integrated spring operating mechanisms used in switchgear. They share the same core energy storage and transmission principles and all include an energy storage motor, a reduction gear, a closing spring, a opening spring, a manual energy storage shaft, opening and closing electromagnets, and an output main shaft. The energy storage motor is connected to the manual energy storage shaft via the reduction gear. The opening and closing electromagnets control the release of the corresponding springs. The output main shafts of the isolated load operating mechanism and the mirror load operating mechanism are fixedly connected to the outer end of the corresponding switch dynamic sealing shaft via a flange-type rigid coupling. The output shaft of the circuit breaker operating mechanism is fixedly connected to the main shaft of the circuit breaker switch.

[0012] Furthermore, a grounding bushing is installed through the side wall of the gas box, and an integral copper conductor is embedded inside the grounding bushing.

[0013] Furthermore, the two ends of the integrated copper conductor are respectively connected to the internal switch grounding copper busbar and the external grounding copper busbar of the gas box by bolts to form an all-copper grounding circuit.

[0014] Furthermore, the grounding bushing is integrally cast with epoxy resin, and at least one sealing ring is provided between the mating surface of the grounding bushing and the side wall of the gas box.

[0015] Furthermore, the cabinet contains, from top to bottom, a secondary chamber, a mechanism chamber, and a base pressure relief chamber. The air box is located between the mechanism chamber and the base pressure relief chamber. Below the air box is an outgoing cable chamber, and on both sides of the air box are a right-side incoming cable chamber and a left-side incoming cable chamber, respectively.

[0016] Beneficial effects The beneficial effects of this invention are: 1. This invention adopts a direct-drive multi-link interlocking structure with a dynamic sealing shaft, which completely eliminates all intermediate transmission links in the prior art. Power is directly transmitted from the three-position switch main shaft to the door lock mechanism. The structure is simple and the transmission path is the shortest, eliminating the risk of transmission jamming and misalignment. At the same time, the fully mechanical forced linkage design does not rely on any electronic components and control power supply. Even if the equipment is completely powered off or the control system is paralyzed, the safety interlocking function can still operate stably and reliably, thus improving safety.

[0017] 2. This invention innovatively achieves forced locking in both closing and opening positions. The test chamber door will only unlock automatically after the three-position switch is fully turned to the grounding position and the residual charge in the main circuit is completely released through the all-copper grounding circuit. This solves the long-standing safety hazard of electric shock due to residual voltage in the opening state, and establishes a safety logic of locking the door when there is power and de-energizing the door when it is open from a mechanical structure perspective, which significantly improves the safety protection level.

[0018] 3. The present invention adopts a symmetrical mirror-type dual test chamber design. The two interlocking mechanisms share the same transmission principle and standardized components, which not only ensures the synchronicity of the door lock action of the left and right test chambers and avoids the risk of unilateral failure, but also greatly reduces the types of parts and inventory pressure, and reduces manufacturing costs and later maintenance difficulty. Attached Figure Description

[0019] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional structural schematic diagram of the present invention; Figure 3 This is a schematic diagram of the internal structure of the rear side of the present invention; Figure 4 This is a schematic diagram of the side cross-sectional structure of the present invention; Figure 5 This is a schematic cross-sectional view of the present invention. Figure 6 This is a view of the interlocking mechanism behind the test chamber and a schematic diagram of the closing and opening of the mechanism in this invention; Figure 7 This is a schematic diagram of the structure of the grounding bushing, the external grounding copper busbar of the gas box, and the internal switch grounding copper busbar of the gas box according to the present invention; Figure 8 This is a schematic diagram of the structure of the external grounding copper busbar of the gas box and the internal switch grounding copper busbar of the gas box according to the present invention; In the diagram: 1. Cabinet; A01. Isolation load operating mechanism; A02. Circuit breaker operating mechanism; A03. Mirror load operating mechanism; A04. Gas box; A05. Outgoing cable compartment; A06. Base pressure relief compartment; A07. Secondary compartment; A08. Mechanism compartment; A09. Three-position isolating switch; A10. Right side test compartment; A11. Three-position load switch; A12. Right side incoming cable compartment; A13. Left side test compartment; A14. Three-position mirror load switch; A15. Circuit breaker switch; A16. Left side incoming cable compartment; B01. Interlocking cam; B02. Interlocking top plate; B03. Interlocking connecting rod; B04. Test compartment long swing arm; B05. Limit pin; B06. Test compartment door lock plate; B07. Reset spring; C01. Grounding bushing; C02. External grounding copper busbar of the gas box; C03. Internal switch grounding copper busbar of the gas box. Detailed Implementation

[0020] The technical solutions of 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.

[0021] like Figures 1-8 As shown, a load switch cabinet with interlocking cams and multi-link closing limit switches includes a cabinet body 1. A gas chamber A04 is located inside the cabinet body 1. The gas chamber A04 contains a circuit breaker switch A15, a circuit breaker operating mechanism A02, and a three-position disconnect switch A09. A left-side test chamber A13 and a right-side test chamber A10 are symmetrically arranged on the left and right sides of the gas chamber A04. Each test chamber has an openable test chamber door. A three-position load switch A11 is located in the right-side test chamber A10, and a three-position mirror load switch A14 is located in the left-side test chamber A13. The three-position mirror load switch A14 and the three-position load switch A11 are installed in mirror symmetrical directions. An isolation load operating mechanism A01 and a mirror load operating mechanism A03 are located inside the cabinet body 1. The gas chamber A04 is perforated by a through-mounted... The test chamber has a switch dynamic seal shaft, and the output shafts of the isolation load operating mechanism A01 and the mirror load operating mechanism A03 are respectively fixedly connected to the outer end of the corresponding switch dynamic seal shaft. The inner end of the switch dynamic seal shaft is fixedly connected to the main shaft of the corresponding three-position load switch. Each test chamber is equipped with a multi-link interlocking mechanism, including an interlocking cam B01 fixed to the switch dynamic seal shaft, an interlocking top plate B02 abutting against the interlocking cam B01, an interlocking connecting rod B03 fixedly connected to the interlocking top plate B02, a test chamber long swing arm B04 hinged to the cabinet 1, a limit pin B05 movably connected to the test chamber long swing arm B04, a door panel lock plate B06 fixed to the inner side of the test chamber door panel, and a return spring B07. The two ends of the return spring B07 are respectively connected to the cabinet 1 and the interlocking top plate B02 or the interlocking connecting rod B03.

[0022] like Figure 6 As shown, the interlocking cam B01 has three positioning grooves along its outer circumferential surface. These three positioning grooves correspond to the closing, opening, and grounding positions of the three-position load switch, respectively. The three positioning grooves precisely correspond to the three positions of the three-position switch. When the interlocking cam B01 rotates with the dynamic sealing shaft of the switch, the lifting and lowering positions of the interlocking top plate B02 are controlled by the changes in the protrusions and grooves on its outer circumferential surface. The outer circumferential surface of the cam corresponding to the closing and opening positions is in a continuous protruding state, which lifts the interlocking top plate B02 and keeps it locked. Only the groove corresponding to the grounding position causes the interlocking top plate B02 to fall down and unlock, thus ensuring the reliability of the dual-position locking structure.

[0023] like Figure 6As shown, the test chamber long swing arm B04 is hinged to the cabinet 1 in the middle by a pin. The upper end of the test chamber long swing arm B04 is hinged to the lower end of the interlocking connecting rod B03. The lower end of the test chamber long swing arm B04 is provided with a guide groove. One end of the limit pin B05 is slidably embedded in the guide groove, and the other end of the limit pin B05 can be inserted into the lock hole of the door panel lock plate B06. The test chamber long swing arm B04 forms a lever structure through the middle hinge point, which converts the vertical movement of the interlocking connecting rod B03 into the horizontal movement of the limit pin B05. The upper hinge receives the power input, and the lower guide groove provides precise horizontal guidance for the limit pin B05, ensuring that the limit pin can only move in a straight line and avoid jamming. The limit pin B05 realizes the mechanical locking and unlocking of the test chamber door panel by inserting or withdrawing from the lock hole of the door panel lock plate B06. It is the final actuator of the safety interlock.

[0024] like Figure 5 As shown, test sleeves, connecting copper busbars, and inlet sleeves are installed in both the left test chamber A13 and the right test chamber A10. The inlet sleeve D09 penetrates the side wall of the gas box A04. The inner end of the inlet sleeve D09 is electrically connected to the main circuit of the circuit breaker switch A15 in the gas box A04. The outer end of the inlet sleeve D09 is electrically connected to the inlet terminal of the three-position disconnect switch A09 through the connecting copper busbar D08. The outlet terminal of the three-position disconnect switch A09 is connected to the corresponding... The incoming terminals of the three-position load switch A11 or the three-position mirror load switch A14 are electrically connected. The outgoing terminals of the three-position load switch A11 and the three-position mirror load switch A14 are electrically connected to the inner end of the corresponding test sleeve D07 through the connecting copper busbar D08. The incoming sleeve penetrates the side wall of the gas box A04. Under the premise of ensuring the gas box A04 is sealed, the main circuit voltage is led out to the test chamber. The three together form an independent test circuit, realizing the online testing function without disassembling the main gas box A04.

[0025] like Figure 3As shown, the circuit breaker operating mechanism A02, the load isolation operating mechanism A01, and the mirror load operating mechanism A03 are all common manual-electric integrated spring operating mechanisms for 12kV switchgear. They share the same core energy storage and transmission principles, each including an energy storage motor, reduction gears, a closing spring, a opening spring, a manual energy storage shaft, opening and closing electromagnets, and an output main shaft. The energy storage motor is connected to the manual energy storage shaft via the reduction gears. The opening and closing electromagnets control the release of their respective springs. The output main shafts of the load isolation operating mechanism A01 and the mirror load operating mechanism A03 are connected to the corresponding switch dynamic seals via flange-type rigid couplings. The output shaft of the circuit breaker operating mechanism A02 is fixedly connected to the main shaft of the circuit breaker switch A15. The integrated manual and electric design meets the needs of normal electric operation and emergency manual operation during power outages. The energy storage motor and reduction gear provide electric energy storage power, which amplifies the torque through reduction and stretches the closing spring. The opening and closing springs store and release energy, driving the output main shaft to rotate rapidly. The manual energy storage shaft realizes manual emergency energy storage. The opening and closing electromagnet receives electrical signals to control the release of the spring, realizing electric opening and closing. The flange-type rigid coupling ensures that the output main shaft and the switch dynamic sealing shaft rotate synchronously without gaps, ensuring the precise action of the interlocking mechanism.

[0026] like Figures 7-8 As shown, a grounding bushing C01 is installed through the side wall of the gas box A04. An integral copper conductor is embedded inside the grounding bushing C01. The grounding bushing C01 provides insulation support and sealing protection for the grounding circuit. The integral copper conductor is made of whole copper material, which has excellent conductivity and low contact resistance. It can quickly conduct large current and ensure the reliability of the grounding circuit.

[0027] like Figures 7-8 As shown, the two ends of the integrated copper conductor are electrically connected to the internal switch grounding copper busbar C03 and the external grounding copper busbar C02 of the gas box by bolts, forming a full copper grounding circuit. The full copper grounding circuit forms a low-resistance conductive channel. When the three-position switch is turned to the grounding position, it can quickly and completely release the induced current and residual capacitive charge of the main circuit to the ground, ensuring the absolute safety of test personnel when they come into contact with the test components.

[0028] like Figures 7-8 As shown, the grounding bushing C01 is integrally cast with epoxy resin. At least one O-ring is provided between the mating surface of the grounding bushing C01 and the side wall of the gas box A04. The integral casting of epoxy resin provides the grounding bushing C01 with good electrical insulation performance and mechanical strength. The at least one O-ring forms multiple sealing barriers, effectively preventing the leakage of sulfur hexafluoride gas in the gas box A04 through the mating gap between the grounding bushing C01 and the side wall, and ensuring the long-term sealing performance of the gas box A04.

[0029] like Figure 2 Figure 4 and Figure 5As shown, the cabinet 1 contains, from top to bottom, a secondary compartment A07, a mechanism compartment A08, and a base pressure relief compartment A06. An air chamber A04 is located between the mechanism compartment A08 and the base pressure relief compartment A06. Below the air chamber A04 is an outgoing cable compartment A05. On either side of the air chamber A04 are a right-side incoming cable compartment A12 and a left-side incoming cable compartment A16, respectively. This layered layout conforms to switchgear industry design specifications and facilitates installation and maintenance. The secondary compartment A07 houses control, measurement, and protection components. The mechanism compartment A08 accommodates the operating mechanism and provides operating space. The base pressure relief compartment A06 releases high-pressure gas in case of a malfunction inside the air chamber A04, preventing the cabinet from exploding. The air chamber A04 is located in the middle for easy connection to the upper, lower, left, and right compartments. The outgoing cable compartment A05, the right-side incoming cable compartment A12, and the left-side incoming cable compartment A16 are used to connect incoming and outgoing cables, respectively. This symmetrical cable entry layout facilitates flexible wiring on-site.

[0030] Working principle: During normal operation of the equipment, the energy storage motors of the isolating load operating mechanism A01 and the mirror load operating mechanism A03 drive the manual energy storage shaft to rotate via reduction gears, stretching the closing spring to the energy storage position. The opening and closing electromagnets control the closing spring to release energy, driving the output main shaft to rotate. The output main shaft synchronously drives the corresponding switch dynamic seal shaft penetrating the side wall of the gas box A04 to rotate via a flange-type rigid coupling, causing the three-position load switch A11 in the right test chamber A10 and the three-position mirror load switch A14 in the left test chamber A13 to rotate to the closing position. At this time, the three-position isolating switch A09 is closed in advance, relying on the three-position isolating switch A09 to establish a stable electrical isolation path, ensuring stable and reliable power supply to the line. At this time, the main circuit of the circuit breaker switch A15 in the gas box A04 is connected through... The incoming bushing, connecting copper busbar, and test bushing form a conductive circuit. Simultaneously, the interlocking cam B01, fixed on the dynamic seal shaft of the switch, rotates synchronously with the shaft. Its outer circumference pushes the interlocking top plate B02, which abuts against it, to move vertically upward. The interlocking top plate B02 drives the interlocking connecting rod B03, which is fixed to it, to move synchronously upward. The reset spring B07 is stretched and stores energy. The test chamber long swing arm B04, which is hinged to the cabinet 1 in the middle by a pin, swings around the hinge point under the action of the interlocking connecting rod B03. The limit pin B05 in the guide groove at the lower end of the test chamber long swing arm B04 moves horizontally under the guidance of the groove and inserts into the lock hole of the door panel lock plate B06, which is fixed on the inside of the test chamber door panel. This locks the door panels of the left test chamber A13 and the right test chamber A10, preventing them from being opened and eliminating the risk of live testing.

[0031] When tripping is required, first operate the circuit breaker switch A15 to trip and cut off the main circuit current. Then, control the tripping spring to release energy through the tripping electromagnet, which drives the output main shaft to rotate in the opposite direction, so that the three-position load switch A11 and the three-position mirror load switch A14 are rotated to the tripping position. Then, operate the three-position isolating switch A09 to complete the tripping action, forming a clear and visible physical isolation break, completely isolating the upstream live power supply and avoiding the risk of reverse power transmission. At this time, due to the design of the three positioning grooves on the outer circumference of the interlocking cam B01, the interlocking top plate B02 and the interlocking connecting rod B03 are still in the upward position, the reset spring B07 is in the stretched state, and the limit pin B05 is still inserted in the lock hole of the door panel lock plate B06, so the test chamber door panel remains locked.

[0032] When testing is required, the operating mechanism continues to drive the switch dynamic seal shaft to rotate, causing the three-position load switch to the grounding position. Simultaneously, the three-position isolating switch A09 is switched to the grounding position, further assisting in releasing residual charge and induced current inside the line, thus doubly improving the grounding leakage effect. At this time, the interlocking cam B01 rotates with the shaft to the positioning groove position corresponding to the grounding position. The reset spring B07 releases its stored energy, pulling the interlocking top plate B02 and the interlocking connecting rod B03 to move vertically downward. The test chamber long swing arm B04 swings in the opposite direction around the hinge point. The limit pin B05 moves horizontally and exits from the lock hole of the door panel lock plate B06, unlocking the test chamber door. The operator can open the door and install the test terminals onto the test sleeve. The main circuit of the circuit breaker switch A15 is tested through the test circuit. At this time, the two ends of the integrated copper conductor inside the grounding bushing C01 on the side wall of the gas box A04 are connected to the grounding copper busbar C03 inside the gas box and the grounding copper busbar C02 outside the gas box by bolt fastening, forming a full copper grounding circuit, which works together with the three-position disconnect switch A09 to ensure test safety. After the test is completed, close the test chamber door. Drive the isolation load operating mechanism A01 and the mirror load operating mechanism A03 to rotate the corresponding switch dynamic seal shaft in the opposite direction. First, make the three-position load switch A11 and the three-position mirror load switch A14 simultaneously disconnect from the grounding position and return to the open position. First, reset the three-position isolation switch A09 to the open standby state. Then, operate the circuit breaker switch A15 to close. Finally, drive the three-position load switch A11 and the three-position mirror load switch A14 to the closed position simultaneously. At the same time, close the three-position isolation switch A09 to restore the normal power supply path, and the equipment returns to normal operation. Throughout the process, the multi-link interlocking mechanism maintains a forced linkage with the position status of the three-position load switch A11 and the three-position mirror load switch A14, and works in conjunction with the three-position disconnect switch A09 to standardize the electrical operation procedures and ensure operational safety. When the equipment is powered off or the electric system fails, the special operating handle can be inserted into the manual energy storage shaft interface of the disconnect load operating mechanism A01 and the mirror load operating mechanism A03 to manually rotate and complete the closing spring energy storage. Then, the opening and closing can be controlled by the manual button. At the same time, the three-position disconnect switch A09 can be manually operated to complete the switching on and off and grounding switching, realizing all-round emergency operation.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A load switch cabinet with interlocking cam and multi-link closing limit switch, comprising the cabinet body (1), wherein the cabinet body (1) is provided with an air box (A04), and the air box (A04) is provided with a circuit breaker switch (A15), a circuit breaker operating mechanism (A02) and a three-position disconnect switch (A09), characterized in that, The gas box (A04) is symmetrically provided with a left test chamber (A13) and a right test chamber (A10) on its left and right sides. Each test chamber is provided with an openable test chamber door. The right test chamber (A10) is provided with a three-position load switch (A11), and the left test chamber (A13) is provided with a three-position mirror load switch (A14). The installation direction of the three-position mirror load switch (A14) is mirror symmetrical to that of the three-position load switch (A11). The cabinet (1) is equipped with an isolation load operating mechanism (A01) and a mirror load operating mechanism (A03). A switch dynamic seal shaft is installed through the side wall of the air box (A04). The output shafts of the isolation load operating mechanism (A01) and the mirror load operating mechanism (A03) are respectively fixedly connected to the outer end of the corresponding switch dynamic seal shaft. The inner end of the switch dynamic seal shaft is fixedly connected to the main shaft of the corresponding three-position load switch. Each test chamber is equipped with a multi-link interlocking mechanism, including an interlocking cam (B01) fixed to the switch dynamic seal shaft, an interlocking top plate (B02) abutting against the interlocking cam (B01), an interlocking connecting rod (B03) fixed to the interlocking top plate (B02), a test chamber long swing arm (B04) hinged to the cabinet (1), a limiting pin (B05) movably connected to the test chamber long swing arm (B04), a door panel lock plate (B06) fixed to the inside of the test chamber door panel, and a reset spring (B07). The two ends of the reset spring (B07) are respectively connected to the cabinet (1) and the interlocking top plate (B02) or the interlocking connecting rod (B03).

2. The load switchgear with interlocking cam and multi-link closing limit switch as described in claim 1, characterized in that, The interlocking cam (B01) has three positioning grooves along its outer circumferential surface. The three positioning grooves correspond to the closing position, opening position and grounding position of the three-position load switch, respectively.

3. The load switchgear with interlocking cam and multi-link closing limit switch as described in claim 1, characterized in that, The middle part of the test chamber long swing arm (B04) is hinged to the cabinet (1) by a pin. The upper end of the test chamber long swing arm (B04) is hinged to the lower end of the interlocking connecting rod (B03). The lower end of the test chamber long swing arm (B04) is provided with a guide groove. One end of the limiting pin (B05) is slidably embedded in the guide groove, and the other end of the limiting pin (B05) can be inserted into the lock hole of the door panel lock plate (B06).

4. The load switchgear with interlocking cam and multi-link closing limit switch as described in claim 1, characterized in that, Both the left test chamber (A13) and the right test chamber (A10) are equipped with test sleeves, connecting copper busbars, and incoming line sleeves.

5. The load switchgear with interlocking cam and multi-link closing limit switch as described in claim 4, characterized in that, The incoming bushing (D09) penetrates the side wall of the gas box (A04). The inner end of the incoming bushing (D09) is electrically connected to the main circuit of the circuit breaker switch (A15) inside the gas box (A04). The outer end of the incoming bushing (D09) is electrically connected to the incoming end of the three-position disconnect switch (A09) through the connecting copper busbar (D08). The outgoing end of the three-position disconnect switch (A09) is electrically connected to the incoming end of the corresponding three-position load switch (A11) or three-position mirror load switch (A14) through the connecting copper busbar (D08). The outgoing ends of the three-position load switch (A11) and the three-position mirror load switch (A14) are electrically connected to the inner end of the corresponding test bushing (D07) through the connecting copper busbar (D08).

6. The load switchgear with interlocking cam and multi-link closing limit switch as described in claim 1, characterized in that, The circuit breaker operating mechanism (A02), the load isolation operating mechanism (A01), and the mirror load operating mechanism (A03) are all common manual-electric integrated spring operating mechanisms for 12kV switchgear. They share the same core energy storage and transmission principles and all include an energy storage motor, a reduction gear, a closing spring, a opening spring, a manual energy storage shaft, opening and closing electromagnets, and an output main shaft. The energy storage motor is connected to the manual energy storage shaft via the reduction gear. The opening and closing electromagnets control the release of the corresponding springs. The output main shafts of the load isolation operating mechanism (A01) and the mirror load operating mechanism (A03) are fixedly connected to the outer end of the corresponding switch dynamic sealing shaft via a flange-type rigid coupling. The output shaft of the circuit breaker operating mechanism (A02) is fixedly connected to the main shaft of the circuit breaker switch (A15).

7. The load switchgear with interlocking cam and multi-link closing limit switch as described in claim 1, characterized in that, A grounding bushing (C01) is installed through the side wall of the gas box (A04), and an integral copper conductor is embedded inside the grounding bushing (C01).

8. The load switchgear with interlocking cam and multi-link closing limit switch as described in claim 7, characterized in that, The two ends of the integrated copper conductor are electrically connected to the internal switch grounding copper busbar (C03) and the external grounding copper busbar (C02) of the gas box by bolt fastening, forming an all-copper grounding circuit.

9. The load switchgear with interlocking cam and multi-link closing limit switch as described in claim 7, characterized in that, The grounding bushing (C01) is integrally cast with epoxy resin, and at least one O-ring is provided between the mating surface of the grounding bushing (C01) and the side wall of the gas box (A04).

10. The load switchgear with interlocking cam and multi-link closing limit switch as described in claim 1, characterized in that, The cabinet (1) is provided with a secondary chamber (A07), a mechanism chamber (A08) and a base pressure relief chamber (A06) from top to bottom. The air box (A04) is located between the mechanism chamber (A08) and the base pressure relief chamber (A06). The outlet cable chamber (A05) is provided below the air box (A04). The right inlet cable chamber (A12) and the left inlet cable chamber (A16) are provided on both sides of the air box (A04).

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