Waterproof box of metal hard cable and flexible cable connection joint for nuclear power station

Abstract

The invention relates to a nuclear power station metal hard cable and flexible cable connection joint waterproof box, which comprises a metal shell assembly, a sealing unit and a joint fixing module, and is characterized in that the metal shell assembly comprises a shell and a box cover, a pre-tightening bolt is arranged between the shell and the box cover, and a temperature sensing sealing adjusting mechanism is arranged in the shell; the temperature sensing sealing adjusting mechanism comprises a shape memory alloy elastic piece and a sealing pressure adjusting ring, one end of the shape memory alloy elastic piece is fixed to the inner wall of the shell, the other end of the shape memory alloy elastic piece is connected with the sealing pressure adjusting ring, and the sealing pressure adjusting ring is arranged around the sealing contact face of the shell and the box cover in a surrounding mode. The sealing unit comprises a main sealing cavity and an auxiliary sealing cavity, the main sealing cavity is formed in the main contact surface of the shell and the box cover, the auxiliary sealing cavity is formed in the outer side of the main sealing cavity, and the two sealing cavities are connected through a communicating groove; the connector fixing module comprises a magneto-rheological rubber block and a rigidity adjusting controller.

Description

Technical Field

[0001] This invention belongs to the technical field of waterproof box equipment, and particularly relates to a waterproof box for connecting metal rigid and flexible cables in nuclear power plants. Background Technology

[0002] In high-safety environments such as nuclear power plants, waterproof boxes serve as crucial devices for protecting electrical equipment and cable joints. Their sealing performance and environmental adaptability directly impact the reliability and safety of equipment operation. With the increasing complexity of nuclear power plant operating environments, waterproof boxes must maintain stable sealing performance under extreme conditions such as high temperature, high humidity, and frequent vibration, while also placing higher demands on the protection of internal equipment and the isolation from the external environment. However, traditional waterproof boxes often have design shortcomings. For example, when temperatures fluctuate significantly, the sealing structure struggles to adaptively adjust, leading to insufficient or excessive sealing pressure, thus affecting the sealing effect. Furthermore, cable joint fixing modules are prone to loosening or fatigue damage under vibration, hindering effective vibration isolation and increasing the risk of equipment failure. These problems can pose serious safety hazards during nuclear power plant operation. Therefore, there is an urgent need for a waterproof box design that can intelligently sense environmental changes and adaptively adjust sealing performance and vibration isolation to address the challenges posed by temperature fluctuations and vibration interference, thereby enhancing overall protection capabilities. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a waterproof box for connecting rigid and flexible metal cables in nuclear power plants, thereby overcoming the deficiencies in the prior art.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: A waterproof box for connecting metal rigid and flexible cables in a nuclear power plant includes a metal shell assembly, a sealing unit, and a connector fixing module. The metal shell assembly includes a shell and a cover, and a pre-tightening bolt is provided between the shell and the cover. The housing is equipped with a temperature-sensing sealing adjustment mechanism, which includes a shape memory alloy spring and a sealing pressure adjustment ring. One end of the shape memory alloy spring is fixed to the inner wall of the housing, and the other end is connected to the sealing pressure adjustment ring. The sealing pressure adjustment ring is arranged around the sealing contact surface between the housing and the lid. The sealing unit includes a main sealing cavity and an auxiliary sealing cavity. The main sealing cavity is located on the main contact surface between the housing and the lid, and the auxiliary sealing cavity is located outside the main sealing cavity. The two sealing cavities are connected by a connecting groove. The connector fixing module includes a magnetorheological rubber block and a stiffness adjustment controller. The magnetorheological rubber block is set at the fixed position of the cable connector, and the stiffness adjustment controller applies a variable magnetic field to the magnetorheological rubber block through an electromagnetic coil. A micro-pressure differential monitoring channel is provided at the connection between the housing and the cover. A pressure sensing diaphragm is installed in the micro-pressure differential monitoring channel, and the pressure sensing diaphragm is electrically connected to a sealing status indicator.

[0005] Preferably, the shape memory alloy spring is made of nickel-titanium alloy material, and its phase transformation temperature is set between 60°C and 80°C. When the ambient temperature exceeds the phase transformation temperature, the shape memory alloy spring deforms and pushes the sealing pressure regulating ring to contract inward, increasing the sealing contact pressure. When the temperature decreases, the shape memory alloy spring returns to its original shape, and the sealing pressure regulating ring returns to its initial position. The inner surface of the sealing pressure regulating ring is provided with multiple radially distributed pressure transmission protrusions. These pressure transmission protrusions are in direct contact with the sealing strip between the housing and the cover, so as to realize the precise transmission and distribution adjustment of pressure.

[0006] Preferably, the cable inlet / outlet hole adopts a spiral progressive sealing structure, including multiple sealing rings. The multiple sealing rings are arranged sequentially along the cable axis, and the inner diameter of each sealing ring gradually decreases to form a stepped sealing channel. Buffer cavities are provided between the multiple sealing rings, and each buffer cavity is connected to the others through micro-connecting holes. When the external pressure increases, each sealing ring bears the pressure in turn to achieve a gradient sealing effect.

[0007] Preferably, the magnetorheological rubber block has ferromagnetic particles uniformly distributed inside, and the magnetic field strength generated by the electromagnetic coil can be adjusted within the range of 1T to 6.8T. When the magnetic field strength increases, the ferromagnetic particles align along the direction of the magnetic field lines, thereby increasing the stiffness of the magnetorheological rubber block. When the magnetic field weakens, the ferromagnetic particles return to a random distribution state, and the stiffness of the rubber block decreases. The stiffness adjustment controller automatically adjusts the current of the electromagnetic coil according to the vibration frequency detected by the vibration sensor, so as to achieve adaptive optimization of the vibration isolation effect. The vibration sensor is installed at the bottom of the joint fixing module and can detect vibration signals in the range of 1Hz to 1000Hz.

[0008] Preferably, the micro-pressure differential monitoring channel is a spiral channel with an inner diameter of 2 mm to 5 mm, and the pressure sensing diaphragm is made of polyimide film with a thickness of 1 mm to 5 mm.

[0009] Preferably, the main sealing cavity is filled with a first sealant, and the auxiliary sealing cavity is filled with a second sealant, wherein the hardness of the first sealant is higher than that of the second sealant.

[0010] Preferably, the sealing status indicator includes an LED indicator and a buzzer. When the pressure sensing diaphragm detects an abnormal pressure, the LED indicator turns red and the buzzer sounds an alarm.

[0011] Preferably, the stiffness adjustment controller further includes a temperature compensation module, which corrects the stiffness adjustment of the magnetorheological rubber block according to the ambient temperature to ensure the consistency of vibration isolation effect under different temperature conditions. The temperature compensation module has a built-in temperature sensor and a compensation algorithm processor. The compensation algorithm processor automatically adjusts the control parameters of the electromagnetic coil according to the preset temperature-stiffness compensation curve. The temperature sensor has a measurement accuracy of ±14.5℃ and a response time of less than 2 seconds.

[0012] The technical effects and advantages of this invention are as follows: 1. This application provides a waterproof box for a metal rigid cable and flexible cable connector for nuclear power plants. Through the coordinated design of a temperature-sensing sealing adjustment mechanism and a double sealing cavity, the shape memory alloy spring can automatically deform according to the ambient temperature change of 60℃-80℃, pushing the sealing pressure adjustment ring to accurately transmit the sealing pressure. Combined with the hardness gradient structure of the main sealing cavity (high hardness sealant) and the auxiliary sealing cavity (low hardness buffer sealant), it effectively compensates for the sealing gap caused by thermal expansion and contraction. At the same time, the spiral progressive multi-stage sealing structure of the cable inlet and outlet holes achieves gradient sealing. With double protection, it can resist the corrosion of the high temperature, high humidity and high radiation environment of nuclear power plants. The sealing performance does not decay after long-term use, avoiding equipment failure caused by moisture intrusion.

[0013] 2. This application provides a waterproof box for a metal rigid cable / flexible cable connector for nuclear power plants. The connector fixing module uses a combination of magnetorheological rubber block and stiffness adjustment controller. Based on the vibration signal detected by the vibration sensor from 0.1Hz to 1000Hz, the magnetic field strength (0.1T-0.8T) is dynamically adjusted by the electromagnetic coil to achieve real-time optimization of the rubber block stiffness. At the same time, the temperature compensation module corrects the influence of ambient temperature on the vibration isolation effect through a temperature sensor with an accuracy of ±0.5℃. This significantly improves the vibration resistance of the hybrid rigid and flexible cable connector, reduces contact resistance fluctuations, avoids loosening or fatigue damage of the connector, ensures stable and reliable signal transmission, and extends the service life of the cable connection.

[0014] 3. This application provides a waterproof box for connecting metal rigid cables and flexible cables in nuclear power plants. The spiral micro-differential pressure monitoring channel at the connection between the shell and the box cover has a built-in polyimide pressure sensing diaphragm, which can detect the sealing status in real time. Abnormal alarms are achieved through LED indicator lights and buzzers. Leakage hazards can be detected in time without disassembly, reducing maintenance workload. The shell is made of 316L stainless steel in one piece, with radiation-resistant and high-temperature resistant silicone rubber seals (temperature resistance -60℃ to 200℃), which is suitable for the extreme operating conditions of nuclear power plants. The waterproof box is also compact in size (275mm×90mm×75mm), supporting installation in cable trays or wall-mounted. The irregular clamping and sealing design of the cable inlet and outlet holes is compatible with both metal rigid cables and flexible cables, providing high installation flexibility. It also supports quick disassembly and assembly, facilitating cable maintenance and replacement of sealing components. Attached Figure Description

[0015] Figure 1 Overall structural schematic diagram (front view); Figure 2 Enlarged view of a portion of the temperature-sensing sealing adjustment mechanism; Figure 3 Sectional view of the sealing unit; Figure 4 Enlarged view of a portion of the connector fixing module; Figure 5 Cross-sectional view of the differential pressure monitoring channel; Figure 6 Cross-sectional view of cable inlet / outlet hole.

[0016] In the diagram: 1. Metal housing assembly; 2. Sealing unit; 3. Connector fixing module; 4. Housing; 5. Cover; 6. Pre-tightening bolt; 15. Temperature sensing sealing adjustment mechanism; 16. Shape memory alloy spring; 17. Main sealing cavity; 18. Auxiliary sealing cavity; 19. Magnetorheological rubber block; 20. Micro-pressure differential monitoring channel; 21. Pressure sensing diaphragm; 22. Multi-stage sealing ring; 23. Sealing pressure adjustment ring; 24. Communicating groove; 25. Stiffness adjustment controller; 26. Electromagnetic coil; 27. Sealing status indicator; 28. Pressure transmission protrusion; 29. ​​Sealing strip; 30. Buffer cavity; 31. Micro-connecting hole; 32. Ferromagnetic particles; 33. Vibration sensor; 34. First sealant; 35. Second sealant; 36. LED indicator; 37. Buzzer; 38. Temperature compensation module; 39. Temperature sensor; 40. Compensation algorithm processor. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the embodiments given in the accompanying drawings.

[0018] The technical solutions of the embodiments of the present invention will be described in detail 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.

[0019] For ease of description, the terminology used in this manual is based on the placement of the waterproof box under normal use conditions, such as... Figure 1 As shown, the bottom of the housing 4 is facing down, the cover 5 is on top, and the cable inlet / outlet holes are located on both sides of the housing 4.

[0020] Reference Figure 1 This invention provides a waterproof box for connecting rigid and flexible metal cables in nuclear power plants, comprising a metal outer shell assembly 1, a sealing unit 2, and a connector fixing module 3. The metal outer shell assembly 1 includes a housing 4 and a cover 5, with a pre-tightening bolt 6 between the housing 4 and the cover 5. The housing 4 is integrally formed from 316L stainless steel, exhibiting excellent radiation resistance. Inside the housing 4 is a temperature-sensing sealing adjustment mechanism 15, which includes a shape memory alloy spring 16 and a sealing pressure adjusting ring 23. One end of the shape memory alloy spring 16 is welded to the inner wall of the housing 4, and the other end is connected to the sealing pressure adjusting ring 23 via a snap-fit ​​structure. The sealing pressure adjusting ring 23 is arranged around the sealing contact surface between the housing 4 and the cover 5. This design allows the waterproof box to adapt to the high-temperature environment of nuclear power plants, automatically adjusting the sealing pressure through temperature sensing to improve sealing reliability.

[0021] like Figure 2 As shown, the shape memory alloy spring 16 is made of nickel-titanium alloy, and its phase transition temperature is set between 60°C and 80°C, for example, 70°C. When the ambient temperature exceeds the phase transition temperature, the shape memory alloy spring 16 deforms, pushing the sealing pressure regulating ring 23 to contract inward, increasing the sealing contact pressure; when the temperature decreases, the shape memory alloy spring 16 returns to its original shape, and the sealing pressure regulating ring 23 returns to its initial position. The inner surface of the sealing pressure regulating ring 23 is provided with multiple radially distributed pressure transmission protrusions 28, which directly contact the sealing strip 29 between the housing 4 and the cover 5, realizing precise pressure transmission and distribution adjustment. This structure ensures adaptive adjustment of the sealing pressure when the temperature changes, avoids sealing failure caused by thermal expansion and contraction, and helps maintain the long-term stability of the waterproof box in high temperature and high radiation environments.

[0022] Reference Figure 1The sealing unit 2 includes a main sealing cavity 17 and an auxiliary sealing cavity 18. The main sealing cavity 17 is located at the main contact surface between the housing 4 and the cover 5, and the auxiliary sealing cavity 18 is located outside the main sealing cavity 17. The two sealing cavities are connected by a connecting groove 24. The housing 4 and the cover 5 are sealed with rectangular wide-sided radiation-resistant and high-temperature-resistant silicone rubber. Axial pressure is applied by the pre-tightening bolts 6 to achieve a high level of waterproof and dustproof protection. This sealing unit 2 cooperates with the temperature-sensing sealing adjustment mechanism 15. When the sealing pressure adjustment ring 23 contracts, the pressure can be evenly distributed to the auxiliary sealing cavity 18 through the connecting groove 24, enhancing the redundancy of the overall seal.

[0023] like Figure 3 As shown, the main sealing cavity 17 is filled with a first sealant 34, and the auxiliary sealing cavity 18 is filled with a second sealant 35. The hardness of the first sealant 34 is higher than that of the second sealant 35. For example, the first sealant 34 can be made of silicone rubber with a Shore hardness of 60, and the second sealant 35 can be made of silicone rubber with a Shore hardness of 40. This hardness gradient design allows the main sealing cavity 17 to provide the main waterproof barrier, while the auxiliary sealing cavity 18 acts as a buffer layer to absorb external impacts, which is beneficial to improving the durability of the sealing structure and its moisture barrier effect.

[0024] Reference Figure 1 The cable inlet / outlet holes employ a spiral progressive sealing structure, including multi-stage sealing rings 22 arranged sequentially along the cable axis. The inner diameter of each sealing ring 22 gradually decreases, forming a stepped sealing channel. Buffer cavities 30 are provided between the multi-stage sealing rings 22, and each buffer cavity 30 is interconnected through micro-connecting holes 31. Metal rigid cable and flexible cable inlet glands are installed on both sides of the waterproof box. The glands are sealed to the housing 4 using large-diameter radiation-resistant and high-temperature-resistant silicone rubber O-rings. The glands contain irregularly shaped clamping and sealing rubber blocks designed according to the cable's outer diameter. The silicone rubber has a temperature resistance range of -60℃ to 200℃. When external pressure increases, each stage of the sealing rings 22 sequentially bears the pressure, achieving a gradient sealing effect. This structure effectively prevents external moisture intrusion and adapts to different cable types, improving installation flexibility.

[0025] like Figure 4As shown, the connector fixing module 3 includes a magnetorheological rubber block 19 and a stiffness adjustment controller 25. The magnetorheological rubber block 19 is fixed at the cable connector position, and the stiffness adjustment controller 25 applies a variable magnetic field to the magnetorheological rubber block 19 through an electromagnetic coil 26. Ferromagnetic particles 32 are uniformly distributed inside the magnetorheological rubber block 19. The magnetic field strength generated by the electromagnetic coil 26 can be adjusted within the range of 0.1T to 0.8T. When the magnetic field strength increases, the ferromagnetic particles 32 align along the magnetic field lines, increasing the stiffness of the magnetorheological rubber block 19; when the magnetic field weakens, the ferromagnetic particles 32 return to a random distribution state, reducing the stiffness of the rubber block. The stiffness adjustment controller 25 automatically adjusts the current of the electromagnetic coil 26 according to the vibration frequency detected by the vibration sensor 33, achieving adaptive optimization of the vibration isolation effect. The vibration sensor 33 is installed at the bottom of the connector fixing module 3 and can detect vibration signals in the range of 0.1Hz to 1000Hz. This adaptive adjustment mechanism significantly improves the vibration resistance of hybrid flexible and rigid cable joints, reduces contact resistance fluctuations, and ensures stable and reliable signal transmission.

[0026] Reference Figure 4 The stiffness adjustment controller 25 also includes a temperature compensation module 38. This module corrects the stiffness adjustment of the magnetorheological rubber block 19 according to the ambient temperature, ensuring consistent vibration isolation performance under different temperature conditions. The temperature compensation module 38 incorporates a temperature sensor 39 and a compensation algorithm processor 40. The processor automatically adjusts the control parameters of the electromagnetic coil 26 according to a preset temperature-stiffness compensation curve. The temperature sensor 39 has a measurement accuracy of ±0.5℃ and a response time of less than 2 seconds. This compensation function enables the waterproof box to maintain stable vibration isolation performance in the high-temperature environment of a nuclear power plant, which is beneficial for extending the service life of cable connections.

[0027] like Figure 5 As shown, a micro-pressure differential monitoring channel 20 is provided at the connection between the housing 4 and the cover 5. This micro-pressure differential monitoring channel 20 is a spiral channel with an inner diameter of 2mm to 5mm, for example, 3mm. A pressure sensing diaphragm 21 is disposed within the channel. The pressure sensing diaphragm 21 is made of polyimide film with a thickness of 0.1mm to 0.5mm, for example, 0.3mm. The pressure sensing diaphragm 21 is electrically connected to a sealing status indicator 27, which includes an LED indicator 36 and a buzzer 37. When the pressure sensing diaphragm 21 detects an abnormal pressure, the LED indicator 36 turns red and the buzzer 37 sounds an alarm. This monitoring mechanism allows for real-time monitoring of the sealing status, timely detection of potential leaks, and improves the ease of maintenance and reliability of the waterproof box.

[0028] Reference Figure 1The metal outer casing assembly 1 of this invention forms an electromagnetic shielding cavity with the cable's metal shielding layer, providing excellent shielding performance. The box incorporates vibration-damping and fixing blocks for the connection joints of rigid and flexible metal cables. These fixing blocks are prefabricated using radiation-resistant and high-temperature-resistant silicone rubber, serving to filter and isolate vibrations. Furthermore, the insulating properties of the rubber material isolate the joints from the metal outer casing, preventing interference noise from coupling and transmitting through the joints, thus avoiding interference with signal transmission quality. This overall design is suitable for the high-temperature, high-humidity, and high-radiation environments within nuclear power plant islands, maintaining undiminished sealing performance, supporting rapid assembly and disassembly, and facilitating cable maintenance and replacement of sealing components.

[0029] like Figure 1 As shown, in one embodiment of the present invention, the waterproof box has a shell boundary dimension of 275mm × 90mm × 75mm (length × width × height), which is compact and supports installation in cable trays or wall mounting. During operation, when the ambient temperature rises above the phase transition temperature of the shape memory alloy spring 16, the spring deformation drives the sealing pressure regulating ring 23 to contract, enhancing the sealing pressure of the main sealing cavity 17 and the auxiliary sealing cavity 18; simultaneously, the stiffness adjustment controller 25 adjusts the magnetic field according to the signal from the vibration sensor 33, increasing the stiffness of the magnetorheological rubber block 19 and optimizing vibration isolation; the micro-pressure differential monitoring channel 20 monitors the internal pressure in real time, and if an abnormality is detected, an alarm is triggered through the sealing status indicator 27. This embodiment achieves highly reliable connection and environmental adaptability, meeting the requirements of regular maintenance of nuclear power plants.

[0030] One possible alternative is to add an auxiliary spring to the fixed end of the shape memory alloy spring 16 to provide additional restoring force and ensure stability under extreme temperature fluctuations. This modification does not change the core function but can further improve the precision of adjustment.

[0031] Another possible implementation is to adjust the number of multi-stage sealing rings 22 from three to four to adapt to environments with greater pressure differentials. This variation enhances the effect of gradient sealing, but needs to be optimized according to the specific cable diameter.

[0032] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A waterproof box for connecting metal rigid and flexible cables in nuclear power plants, comprising a metal shell assembly (1), a sealing unit (2), and a connector fixing module (3), wherein the metal shell assembly (1) comprises a housing (4) and a cover (5), and a pre-tightening bolt (6) is provided between the housing (4) and the cover (5), characterized in that: The housing (4) is provided with a temperature sensing sealing adjustment mechanism (15). The temperature sensing sealing adjustment mechanism (15) includes a shape memory alloy spring (16) and a sealing pressure adjustment ring (23). One end of the shape memory alloy spring (16) is fixed to the inner wall of the housing (4), and the other end is connected to the sealing pressure adjustment ring (23). The sealing pressure adjustment ring (23) is arranged around the sealing contact surface between the housing (4) and the cover (5). The sealing unit (2) includes a main sealing cavity (17) and an auxiliary sealing cavity (18). The main sealing cavity (17) is located on the main contact surface between the housing (4) and the cover (5). The auxiliary sealing cavity (18) is located on the outside of the main sealing cavity (17). The two sealing cavities are connected by a connecting groove (24). The connector fixing module (3) includes a magnetorheological rubber block (19) and a stiffness adjustment controller (25). The magnetorheological rubber block (19) is set at the fixed position of the cable connector, and the stiffness adjustment controller (25) applies a variable magnetic field to the magnetorheological rubber block (19) through an electromagnetic coil (26). A micro-pressure differential monitoring channel (20) is provided at the connection between the housing (4) and the cover (5). A pressure sensing diaphragm (21) is provided in the micro-pressure differential monitoring channel (20), and the pressure sensing diaphragm (21) is electrically connected to the sealing status indicator (27).

2. A waterproof box for connecting metal rigid and flexible cables in nuclear power plants according to claim 1, characterized in that: The shape memory alloy spring (16) is made of nickel-titanium alloy material, and its phase change temperature is set between 60°C and 80°C. When the ambient temperature exceeds the phase change temperature, the shape memory alloy spring (16) deforms and pushes the sealing pressure regulating ring (23) to contract inward, increasing the sealing contact pressure. When the temperature decreases, the shape memory alloy spring (16) returns to its original shape, and the sealing pressure regulating ring (23) returns to its initial position. The inner surface of the sealing pressure regulating ring (23) is provided with multiple radially distributed pressure transmission protrusions (28). These pressure transmission protrusions (28) are in direct contact with the sealing strip (29) between the housing (4) and the cover (5) to achieve precise pressure transmission and distribution regulation.

3. A waterproof box for connecting rigid and flexible metal cables in nuclear power plants according to claim 1, characterized in that: The cable inlet and outlet holes adopt a spiral progressive sealing structure, including multi-stage sealing rings (22). The multi-stage sealing rings (22) are arranged sequentially along the cable axis, and the inner diameter of each sealing ring (22) gradually decreases to form a stepped sealing channel. A buffer chamber (30) is provided between the multi-level sealing rings (22). Each buffer chamber (30) is connected to the others through a micro-connecting hole (31). When the external pressure increases, each level of sealing ring (22) bears the pressure in turn, thereby achieving a gradient sealing effect.

4. A waterproof box for connecting metal rigid and flexible cables in nuclear power plants according to claim 1, characterized in that: The magnetorheological rubber block (19) has ferromagnetic particles (32) uniformly distributed inside. The magnetic field strength generated by the electromagnetic coil (26) can be adjusted in the range of 1T to 6.8T. When the magnetic field strength increases, the ferromagnetic particles (32) are arranged along the direction of the magnetic field lines, which increases the stiffness of the magnetorheological rubber block (19). When the magnetic field weakens, the ferromagnetic particles (32) return to a random distribution state, and the stiffness of the rubber block decreases. The stiffness adjustment controller (25) automatically adjusts the current of the electromagnetic coil (26) according to the vibration frequency detected by the vibration sensor (33) to achieve adaptive optimization of the vibration isolation effect. The vibration sensor (33) is installed at the bottom of the connector fixing module (3) and can detect vibration signals in the range of 1Hz to 1000Hz.

5. A waterproof box for connecting metal rigid and flexible cables in nuclear power plants according to claim 1, characterized in that: The micro differential pressure monitoring channel (20) is a spiral channel with an inner diameter of 2 mm to 5 mm, and the pressure sensing diaphragm (21) is made of polyimide film with a thickness of 1 mm to 5 mm.

6. A waterproof box for connecting metal rigid and flexible cables in nuclear power plants according to claim 2, characterized in that: The main sealing cavity (17) is filled with a first sealant (34), and the auxiliary sealing cavity (18) is filled with a second sealant (35). The hardness of the first sealant (34) is higher than that of the second sealant (35).

7. A waterproof box for connecting metal rigid and flexible cables in nuclear power plants according to claim 1, characterized in that: The sealing status indicator (27) includes an LED indicator (36) and a buzzer (37). When the pressure sensing diaphragm (21) detects an abnormal pressure, the LED indicator (36) turns red and the buzzer (37) sounds an alarm.

8. A waterproof box for connecting metal rigid and flexible cables in nuclear power plants according to claim 4, characterized in that: The stiffness adjustment controller (25) also includes a temperature compensation module (38), which corrects the stiffness adjustment of the magnetorheological rubber block (19) according to the ambient temperature to ensure the consistency of the vibration isolation effect under different temperature conditions. The temperature compensation module (38) has a built-in temperature sensor (39) and a compensation algorithm processor (40). The compensation algorithm processor (40) automatically adjusts the control parameters of the electromagnetic coil (26) according to the preset temperature-stiffness compensation curve. The temperature sensor (39) has a measurement accuracy of ±14.5℃ and a response time of less than 2 seconds.

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