A cable protection box for passing through a seismic isolation layer

Abstract

This invention belongs to the field of electrical power supply and distribution engineering technology, and relates to a cable protection box for passing through a seismic isolation layer. It includes: a box body, an inlet clamp, an outlet clamp, a top clamp, and side wall clamps. Inside the box, the cable to be protected is coiled into an elliptical cable loop with a vertical major axis and a horizontal minor axis. The bottom of the elliptical cable loop is suspended and not fixed, serving as a pre-reserved tensile redundancy for the cable. The outlet clamp uses a gap fastening, while the inlet clamp uses an interference fit. This ensures that during an earthquake, the tensile displacement of the building above the seismic isolation layer is absorbed by the pre-reserved tensile redundancy at the bottom of the elliptical cable loop and does not continue to propagate along the cable. Therefore, this invention provides safer and more reliable protection for the cable passing through the seismic isolation layer during an earthquake.

Description

Technical Field

[0001] This invention belongs to the field of electrical power supply and distribution engineering technology, and relates to a cable protection box for passing through a seismic isolation layer. Background Technology

[0002] In recent years, an increasing number of new buildings and renovations of existing buildings have adopted seismic isolation technology to improve structural seismic performance, achieving excellent earthquake resistance. Seismically isolated buildings, due to their flexible isolation layers, can isolate seismic forces while separating the foundation or subsurface from the superstructure, isolating seismic energy from the building and ensuring that the building remains largely stationary during an earthquake, thus protecting its safety. This seismic isolation technology is widely used in public buildings such as airports, schools, and hospitals, as well as educational and medical buildings. Its basic structure consists of an isolation layer composed of rubber seismic isolation bearings and dampers. Rubber seismic isolation bearings have high vertical strength, capable of supporting the building's weight, while being flexible horizontally, effectively isolating seismic energy from the upper structure; the dampers effectively suppress resonance under various conditions. Seismic isolation rubber bearings are made by layering steel plates and rubber layers, with the rubber and steel plates firmly bonded together through processing. Therefore, buildings using seismic isolation technology experience near-translational movement of the superstructure during an earthquake and automatically reset afterward.

[0003] In buildings where vibration isolation technology is widely used, cables must pass through the isolation layer to connect the upper and lower floors. One existing method for cables to pass through the isolation layer is to lay the cables together in the open and then directly through the isolation layer. During an earthquake, the upper structure moves almost in translation. During the automatic reset process after the earthquake, the upper end of the cable repeatedly undergoes lateral and vertical displacement. Since the upper and lower ends of the cable are fixed to the building above and below the isolation layer, respectively, the repeated vertical displacement of different amplitudes causes significant damage to the mechanical, waterproof, and fireproof properties of the cable. Over the years, this has a fatal impact on the reliability and safety of the overall power supply system, especially for cables and busbars with large cross-sectional areas. Some buildings use cables that run directly through vertical channels to the ground, with all cables converted at the isolation layer. Flexible cable joints are made at the isolation layer, and the two ends are connected to the cables of the building above and below the isolation layer, respectively. This method is difficult to construct, has high material and labor costs, and cannot avoid mutual interference between cables of different voltage levels and cross-sectional areas.

[0004] Therefore, a safe, reliable, and simple device for cable penetration through the seismic isolation layer is needed to solve this problem. Summary of the Invention

[0005] The technical solution adopted by the present invention to solve the technical problem is: a cable protection box for passing through a seismic isolation layer, comprising: a box body, the box body being rectangular in shape, the box body having a circular inlet hole, the top of the box body having a circular outlet hole, the inner cavity of the box body having an inlet clamp and an outlet clamp, the inlet clamp being fixedly connected to the inner cavity of the box body, the outlet clamp being fixedly connected to the side wall of the box body, the inlet of the inlet clamp facing the inlet hole, the outlet of the outlet clamp facing the outlet hole, the inlet of the inlet clamp facing the inlet hole so that the protected cable enters the inlet hole and passes through the inlet clamp before entering the inner cavity of the box body, the outlet clamp facing the outlet hole so that the protected cable passes through the outlet clamp before leaving the box body through the outlet hole;

[0006] The top of the inner cavity of the enclosure is equipped with a top clamp, and the side walls of the inner cavity of the enclosure are equipped with side wall clamps. The side wall clamps and the outlet clamps are located on two opposite inner side walls of the enclosure, respectively.

[0007] The protected cable passes through the enclosure. The protected cable is introduced through the inlet hole, passes through the inlet clamp and the outlet clamp in sequence, and then comes out through the outlet hole. The protected cable is coiled at least once inside the enclosure before coming out through the outlet hole. The inlet clamp and the protected cable are interference-fitted, while the outlet clamp and the protected cable are gap-fitted. The interference fit at the inlet clamp ensures that the protected cable in the section from the enclosure to the building below the seismic isolation layer will not be subjected to axial tensile force due to an earthquake. The gap-fit ​​at the outlet clamp ensures that during an earthquake, the tensile force at the building above the seismic isolation layer is transmitted along the protected cable to the cable inside the enclosure with a pre-existing tensile redundancy. The top clamp and side wall clamp can be selected to use gap-fitted or interference-fitted depending on the actual situation.

[0008] The outlet clamp, top clamp, and side wall clamp form an elliptical cable loop, or an approximately elliptical one, such as a racetrack shape, around the coil of the protected cable closest to the outlet hole. The vertical segment of the cable represents the calculated expansion / contraction redundancy. The radius of curvature of the smallest arc of the elliptical cable loop is greater than the minimum radius of curvature of the protected cable. This elliptical cable loop, with its vertical major axis and horizontal minor axis, is considered the cable's pre-reserved expansion / contraction redundancy. The upper end and one side end of the elliptical cable loop are respectively secured by the top clamp and side wall clamp. The clamp has its lower end suspended and not fixed, while the other side end is interlocked with the clamp at the outlet. Therefore, during an earthquake, the tensile force at the building above the seismic isolation layer is transmitted to the box along the protected cable. The protected cable is pulled out of the box from the outlet. At this time, the cable's pre-reserved tensile redundancy at the lower end of the elliptical cable loop rises under the stress. The tensile force at the side clamp is very small, while the tensile force at the top clamp is almost negligible. At this time, the use of interference fit at the top clamp and side clamp can ensure that the tensile force will not continue to be transmitted along the protected cable to the building below the seismic isolation layer.

[0009] The enclosure is fixedly connected to the building below the seismic isolation layer. The first outer clamp after the protected cable passes through the outlet hole is fixedly connected to the building above the seismic isolation layer. The first outer clamp and the protected cable are interlocked. The rotation axis of the inner cavity of the first outer clamp, the rotation axis of the outlet hole, and the rotation axis of the inner cavity of the outlet clamp are all on the same vertical line. The same vertical line ensures that the gap at the outlet clamp can better meet the free up and down stretching of the protected cable and transfer the stretching to the cable reserved stretching redundancy part of the lower end of the elliptical cable ring.

[0010] Preferably, the enclosure is equipped with a cable catch net with the mesh facing upwards. The periphery of the cable catch net is fixedly connected to the inner wall of the enclosure, and the bottom of the elliptical cable loop rests on the mesh surface of the cable catch net. The cable catch net can provide a tension allowance for the cable that is suspended at the lower end of the elliptical cable loop under normal conditions, and can reduce the downward impact of the tension allowance during earthquake recovery to prevent damage to the cable. The cable catch net is made of non-combustible materials, such as steel or stainless steel, to ensure that it is superior to the cable's combustion performance, smoke toxicity, and combustion drip level. Even if the cable or the enclosure is in a fire, the cable catch net remains safe and reliable.

[0011] Preferably, the inner cavities of the inlet clamp, outlet clamp, top clamp, and side wall clamp are all cylindrical and split along the axial direction. The fixing rods of the inlet clamp, outlet clamp, top clamp, and side wall clamp are all telescopic rods with adjustable length and locking mechanism, and the rotation axis of the fixing rod is perpendicular to the rotation axis of the inner cavity of the clamp. The split clamps and adjustable telescopic rods are used to meet the installation requirements of different sizes of the protected cable and quick and convenient assembly.

[0012] More preferably, the cylindrical inner cavity of the inlet clamp is provided with a rubber tile-shaped gasket; the gasket helps to clamp the protected cable while preventing damage to the cable.

[0013] More preferably, a roller is rotatably connected in the cylindrical inner cavity of the outlet clamp, and the rotation direction of the roller is parallel to the rotation axis of the inner cavity of the outlet clamp. The roller is distributed around the cylindrical cable channel inside the inner cavity of the outlet clamp. Rolling movement has better passability and protection against damage to the protected cable compared with sliding movement.

[0014] Preferably, the side wall of the enclosure is provided with an installation opening. The side wall where the installation opening is located is different from the side wall clamp and the cable outlet clamp, which are located on two opposite inner side walls of the enclosure. The installation opening is provided with an enclosure door, and the enclosure door is provided with a transparent observation window. The installation opening is different from the inner side wall where the wall clamp and the cable outlet clamp are fixed, which ensures that the wall clamp and the cable outlet clamp are located on both sides of the installation opening, which facilitates installation and makes it easier to open and close the enclosure door at the installation opening.

[0015] More preferably, the enclosure has a lower elongated groove on the side with the cable inlet, which connects the cable inlet to the installation port. The top surface of the enclosure has an upper elongated groove, which connects the cable outlet to the installation port. A lower cover plate is detachably connected to the lower elongated groove, and an upper cover plate is detachably connected to the upper elongated groove. Since the protected cable enters through the cable inlet and exits through the cable outlet, and needs to be coiled and secured in the slots of the top clamp and side wall clamp, coiling and bending within the limited space of the enclosure is difficult, especially for large cross-section cables. It is almost impossible to do this manually. Therefore, a semi-open type of cable inlet and cable outlet with a slot on the side of the installation port is adopted. The construction operator only needs to coil and bend the protected cable into the required shape outside the enclosure, push it horizontally into the cable inlet and cable outlet from the slot, fix the corresponding clamps, and then install the cover plate to easily complete the installation.

[0016] More preferably, a rubber plug is provided in the inlet hole. The rubber plug is in the shape of a truncated ring that is split along the axial direction. The inner diameter of the rubber plug is equal to the outer diameter of the protected cable. The outer ring of the rubber plug is fitted into the inlet hole. The split rubber plug is used to seal the inlet hole and facilitates quick installation.

[0017] More preferably, the outlet hole is provided with a circular rubber sealing plate, and the rubber sealing plate has a star-shaped deformation joint extending radially from the inside to the outside. The deformation joint connects the upper and lower surfaces of the rubber sealing plate. The rubber sealing plate is fitted onto the outer cylindrical surface of the protected cable. The rubber sealing plate is detachably connected to the top surface of the housing. The rubber sealing plate cooperates with the deformation joint to cover the outlet hole even when the upper end of the protected cable has a large horizontal displacement.

[0018] Preferably, the bottom of the enclosure is provided with feet, which are fixedly connected to the ground of the building below the seismic isolation layer.

[0019] The beneficial effects of this invention are:

[0020] 1. This invention employs an elliptical cable coil inside a housing, with the long axis vertical and the short axis horizontal. The bottom of the elliptical cable coil is suspended and not fixed, serving as a pre-existing tensile redundancy for the cable. The outlet clamp uses a gap fastening, while the inlet clamp uses an interference fit. This ensures that during an earthquake, the tensile displacement of the building above the seismic isolation layer is absorbed by the pre-existing tensile redundancy at the bottom of the elliptical cable coil and does not continue to propagate along the cable. Therefore, this invention provides greater safety and reliability for the protected cable as it passes through the seismic isolation layer during an earthquake.

[0021] 2. The present invention adopts a semi-open type of inlet and outlet hole with a groove on the installation port side. The construction operator only needs to bend the protected cable coil into the required shape outside the box, push it horizontally into the inlet and outlet hole from the groove, fix the corresponding clamps, and then install the cover plate to easily complete the installation. Therefore, the installation operation of the present invention is simpler and easier.

[0022] 3. The present invention provides a cable net inside the box to support the cable's pre-reserved tension redundancy at the lower end of the elliptical cable coil. During earthquake recovery, this reduces the downward impact of the cable's pre-reserved tension redundancy and prevents damage to the cable. In addition, a rubber tile-shaped gasket is provided in the cylindrical cavity of the clamp. The gasket helps to tighten the protected cable while preventing damage to the cable. Therefore, the cable fixing method of the present invention is safer and more reliable. Attached Figure Description

[0023] Figure 1 This is an installation diagram of a cable protection box used for passing through a seismic isolation layer;

[0024] Figure 2 This is a front sectional view of the mounting port side of the enclosure;

[0025] Figure 3 yes Figure 2 A magnified view from direction A;

[0026] Figure 4 yes Figure 3 Explosion breakdown diagram;

[0027] Figure 5 yes Figure 2 A magnified view of BB;

[0028] Figure 6 yes Figure 5 Explosion breakdown diagram;

[0029] Figure 7 This is a front sectional view of the inlet clamp;

[0030] Figure 8 This is a front sectional view of the cable outlet clamp;

[0031] Figure 9 This is a side view of the box door;

[0032] Figure 10 This is a schematic diagram of the installation of the clamp with the inlet located on the side.

[0033] In the diagram: 1. Enclosure; 2. Cable inlet; 3. Cable outlet; 4. Cable inlet clamp; 5. Cable outlet clamp; 6. Top clamp; 7. Side wall clamp; 8. Protected cable; 9. Building below the seismic isolation layer; 10. First outer clamp; 11. Building above the seismic isolation layer; 12. Cable net; 13. Fixing rod; 14. Gasket; 15. Roller; 16. Mounting port; 17. Enclosure door; 18. Observation window; 19. Lower long slot; 20. Upper long slot; 21. Lower cover plate; 22. Upper cover plate; 23. Rubber plug; 24. Rubber sealing plate; 25. Expansion joint; 26. Foot. Detailed Implementation

[0034] The related technologies of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] refer to Figures 1-10 A cable protection box for passing through a seismic isolation layer includes: a box body 1, which is rectangular in shape, with a circular inlet hole 2 and a circular outlet hole 3 at the top of the box body 1. The inner cavity of the box body 1 is provided with an inlet clamp 4 and an outlet clamp 5. The inlet clamp 4 is fixedly connected to the inner cavity of the box body 1, and the outlet clamp 5 is fixedly connected to the side wall of the box body 1. The inlet of the inlet clamp 4 faces the inlet hole 2, and the outlet of the outlet clamp 5 faces the outlet hole 3. The inlet of the inlet clamp 4 facing the inlet hole 2 allows the protected cable 8 to enter the inner cavity of the box body 1 after entering the inlet hole 2 and passing through the inlet clamp 4. The outlet clamp 5 facing the outlet hole 3 allows the protected cable 8 to leave the box body 1 after passing through the outlet clamp 5 and then through the outlet hole 3.

[0036] The top of the inner cavity of the enclosure 1 is provided with a top clamp 6, and the side wall of the inner cavity of the enclosure 1 is provided with a side wall clamp 7. The side wall clamp 7 and the outlet clamp 5 are respectively located on two opposite inner side walls of the enclosure 1.

[0037] The protected cable 8 passes through the box 1. The protected cable 8 is introduced from the inlet hole 2, passes through the inlet clamp 4 and the outlet clamp 5 in sequence, and is led out from the outlet hole 3. The protected cable 8 is coiled at least once inside the box 1 before being led out from the outlet hole 3. The inlet clamp 4 and the protected cable 8 are interlocked, and the outlet clamp 5 and the protected cable 8 are gapped. The interlock at the inlet clamp 4 ensures that the protected cable 8 in the section from the box 1 to the building 9 below the seismic isolation layer will not be subjected to axial tensile force due to earthquake. The gapped at the outlet clamp 5 ensures that during an earthquake, the tensile force at the building 11 above the seismic isolation layer is transmitted along the protected cable 8 to the cable in the box 1, leaving tensile redundancy. The top clamp 6 and the side wall clamp 7 can be selected to use gapped or interlocked fastening according to the actual situation.

[0038] The outlet clamp 5, top clamp 6, and side wall clamp 7 form an elliptical cable loop, or an approximately elliptical one, such as a racetrack shape, around the coil of the protected cable 8 that is closest to the outlet hole 3. The vertical segment of the cable represents the calculated expansion and contraction allowance. The radius of curvature of the smallest arc of the elliptical cable loop is greater than the radius of curvature of the protected cable 8. The elliptical cable loop with the largest major axis vertical and the smallest minor axis horizontal closest to the outlet hole 3 serves as the cable's pre-reserved expansion and contraction allowance. Since the upper end and one side end of the elliptical cable loop are respectively connected by the top clamp 6 and the side wall clamp 7, and the lower end... The cable is suspended and not fixed, while the other side gap is fastened in the outlet clamp 5. Therefore, during an earthquake, the tensile force at the building 11 above the seismic isolation layer is transmitted to the box 1 along the protected cable 8. The protected cable 8 is pulled out of the box 1 from the outlet hole 3. At this time, the cable's reserved tensile redundancy at the lower end of the elliptical cable ring rises under the stress. The tensile force at the side wall clamp 7 is very small, while the tensile force at the top clamp 6 is almost negligible. If the top clamp 6 and the side wall clamp 7 are used with interference fit, it can be ensured that the tensile force will not continue to be transmitted along the protected cable 8 to the building 9 below the seismic isolation layer.

[0039] The housing 1 is fixedly connected to the building 9 below the vibration isolation layer. The first outer clamp 10 of the protected cable 8 after passing through the outlet hole 3 is fixedly connected to the building 11 above the vibration isolation layer. The first outer clamp 10 and the protected cable 8 are interlocked. The rotation axis of the inner cavity of the first outer clamp 10, the rotation axis of the outlet hole 3, and the rotation axis of the inner cavity of the outlet clamp 5 are located on the same vertical line. The same vertical line ensures that the gap at the outlet clamp 5 can meet the free up and down stretching of the protected cable 8 and transmit the stretching to the cable reserved stretching redundancy part of the lower end of the elliptical cable ring.

[0040] Furthermore, the housing 1 is equipped with a cable catch net 12 with the mesh surface facing upwards. The periphery of the cable catch net 12 is fixedly connected to the inner sidewall of the housing 1, and the bottom of the elliptical cable loop is supported within the mesh surface of the cable catch net 12. The cable catch net 12 can support the cable with a pre-reserved tension redundancy at the lower end of the elliptical cable loop under normal conditions, and can reduce the downward impact of the cable with the pre-reserved tension redundancy during earthquake recovery to prevent damage to the cable. The cable catch net 12 is made of non-combustible materials, such as steel or stainless steel, to ensure that it is superior to the cable's combustion performance, smoke toxicity, and combustion drip level. Even if the cable or the housing is in a fire, the cable catch net 12 remains safe and reliable.

[0041] Furthermore, the inner cavities of the inlet clamp 4, outlet clamp 5, top clamp 6, and side wall clamp 7 are all cylindrical and split along the axial direction. The fixing rods 13 of the inlet clamp 4, outlet clamp 5, top clamp 6, and side wall clamp 7 are all telescopic rods with adjustable length and locking mechanism. The rotation axis of the fixing rod 13 is perpendicular to the rotation axis of the inner cavity of the clamp. The split clamps and adjustable telescopic rods are used to meet the installation requirements of different sizes of the protected cable 8 and quick and convenient assembly.

[0042] Furthermore, the cylindrical inner cavity of the inlet clamp 4 is provided with a rubber tile-shaped gasket 14; the gasket 14 helps to clamp the protected cable 8 while preventing damage to the cable.

[0043] Furthermore, a roller 15 is rotatably connected in the cylindrical inner cavity of the outlet clamp 5. The rotation direction of the roller 15 is parallel to the rotation axis of the inner cavity of the outlet clamp 5. The roller 15 is distributed around the cylindrical cable channel inside the inner cavity of the outlet clamp 5. Rolling movement has better passability and protection against damage to the protected cable 8 compared to sliding movement.

[0044] Furthermore, the side wall of the enclosure 1 is provided with an installation port 16. The side wall where the installation port 16 is located is different from the side wall clamp 7 and the cable outlet clamp 5, which are located on two opposite inner side walls of the enclosure 1. The installation port 16 is provided with a door 17, and the door 17 is provided with a transparent observation window 18. The installation port 16 is different from the inner side wall where the wall clamp 7 and the cable outlet clamp 5 are fixed, which ensures that the wall clamp 7 and the cable outlet clamp 5 are located on both sides of the installation port 16, which facilitates installation and makes it easier to open and close the door 17 at the installation port 16.

[0045] Furthermore, the housing 1 has a lower elongated groove 19 on the side with the inlet hole 2, which connects the inlet hole 2 to the mounting port 16. The top surface of the housing 1 has an upper elongated groove 20, which connects the outlet hole 3 to the mounting port 16. A lower cover plate 21 is detachably connected to the lower elongated groove 19, and an upper cover plate 22 is detachably connected to the upper elongated groove 20. Since the protected cable 8 enters through the inlet hole 2 and exits through the outlet hole 3, it is coiled and secured to the top clamp 6 in between. The side clamp 7 has a slot, which makes it difficult to coil and bend cables in the limited space of the box 1, especially for large cross-section cables. It is almost impossible to do this by manpower alone. Therefore, a semi-open type of inlet hole 2 and outlet hole 3 with a slot on the side of the installation port 16 is adopted. The construction operator only needs to coil and bend the protected cable 8 into the required shape outside the box 1, push it horizontally into the inlet hole 2 and outlet hole 3 from the slot, fix the corresponding clamp, and then install the cover plate to easily complete the installation.

[0046] Furthermore, a rubber plug 23 is provided inside the inlet hole 2. The rubber plug 23 is in the shape of a truncated ring that is split along the axial direction. The inner diameter of the rubber plug 23 is equal to the outer diameter of the protected cable 8. The outer ring of the rubber plug 23 is fitted into the inlet hole 2. The split rubber plug 23 is used to seal the inlet hole 2 and facilitates quick installation.

[0047] Furthermore, the outlet hole 3 is provided with a circular rubber sealing plate 24, and the rubber sealing plate 24 has a star-shaped deformation joint 25 extending radially from the inside to the outside. The deformation joint 25 connects the upper and lower surfaces of the rubber sealing plate 24. The rubber sealing plate 24 is fitted onto the outer cylindrical surface of the protected cable 8. The rubber sealing plate 24 is detachably connected to the top surface of the housing 1. The rubber sealing plate 24 cooperates with the deformation joint 25 to seal the outlet hole 3 even when the upper end of the protected cable 8 has a large horizontal displacement.

[0048] Furthermore, the bottom of the box body 1 is provided with feet 26, which are fixedly connected to the ground of the building 9 below the seismic isolation layer.

[0049] Example 1

[0050] In this embodiment, in an actual airport power construction project, the largest standard civilian cable WDZ-YJY-4*240+1*120 is used as the protected cable 8 to pass through the seismic isolation layer. Figure 1 As shown. The protected cable 8 is brought in from the cable trench at the bottom of the box 1, bends upward through the inlet hole 2 on the bottom plate of the box 1 and enters the box 1. After entering the box 1, it is clamped by the inlet clamp 4 with the inlet opening facing the inlet hole 2. Then, the protected cable 8 is wound clockwise and passed through the top clamp 6. The clockwise winding of the protected cable 8 is continued and passed through the side wall clamp 7. The protected cable 8 is then wound into an elliptical cable loop with a vertical major axis and a horizontal minor axis. The minimum radius of curvature of the elliptical cable loop is greater than the minimum radius of curvature of the protected cable 8. The lower end of the elliptical cable loop is suspended and not fixed. The bottom of the elliptical cable loop is supported within the upper surface of the cable net 12. The periphery of the cable net 12 is fixedly connected to the inner side wall of the box 1. The lower suspended section serves as a pre-existing tension allowance for the cable. The protected cable 8 continues to bend and coil, then passes through the outlet clamp 5. The outlet clamp 5 uses a gap-locking mechanism, with the clamp's outlet facing the outlet hole 3. Finally, the protected cable 8 exits through the outlet hole 3, completing the installation of the protected cable 8 within the protection cabinet. The protected cable 8 continues upwards, passing through the first outer clamp 10 before connecting to the building above the seismic isolation layer. The first outer clamp 10 is fixedly connected to the building above the seismic isolation layer 11, and the first outer clamp 10 and the protected cable 8 are connected with an interference fit.

[0051] During an earthquake, the tensile force at the building above the seismic isolation layer (11) is transmitted along the protected cable 8 to the enclosure 1. The protected cable 8 is pulled out of the enclosure 1 through the outlet hole (3). At this time, the cable's pre-reserved tensile redundancy at the lower end of the elliptical cable coil rises under the stress. The tensile force at the side wall clamp (7) is very small, while the tensile force at the top clamp (6) is almost negligible. Using interference fits at the top clamp (6) and side wall clamp (7) ensures that the tensile force will not continue to be transmitted along the protected cable 8 to the building below the seismic isolation layer (9). This effectively protects the cable during large displacements during an earthquake.

[0052] After the earthquake, the relative displacement between the building 11 above the seismic isolation layer and the building 9 below the seismic isolation layer recovers. The protected cable 8 falls back into the enclosure 1 from the outlet hole 3. At this time, the cable's reserved tensile redundancy at the lower end of the elliptical cable loop sinks under its own weight. The lower end of the sinking elliptical cable loop falls into the mesh surface of the cable net 12. The cable net 12 slows down the downward impact of the cable's reserved tensile redundancy, preventing damage to the cable. Similarly, the falling force of the protected cable 8 will not continue to be transmitted along the protected cable 8 to the side of the building 9 below the seismic isolation layer. This serves to protect the cable during the recovery after the earthquake.

[0053] Example 2

[0054] Similarly, in an actual airport power construction project, this embodiment uses two civilian-grade maximum specification cables (WDZ-YJY-4*240+1*120) as the protected cables 8 passing through the seismic isolation layer. Horizontal, side-by-side double-hole cable clamps are used. Figure 10As shown. The protected cable 8 is brought in from the ground cable tray on the side of the box 1, and is horizontally introduced into the box 1 through the inlet hole 2 on the side of the box 1. Due to the small space inside the box 1, which is not suitable for construction, and the fact that the two large cross-section cables cannot be bent and coiled inside the box 1, a semi-open type inlet hole 2 and outlet hole 3 with a slot on the side of the installation port 16 are adopted. After the construction operator coils and bends the protected cable 8 into the required shape outside the box 1, it is horizontally pushed into the inlet hole 2 and outlet hole 3 from the slots of the lower long slot 19 and the upper long slot 20. The protected cable 8 is still bent and coiled into an elliptical cable coil with a vertical major axis and a horizontal minor axis. The minimum arc radius of the elliptical cable coil is greater than the minimum arc radius of the protected cable 8. The clamps are sequentially fastened along the length of the protected cable 8, from one end of the inlet hole 2 to the other end of the outlet hole 3 in the housing 1: First, the inlet clamp 4 is used for interference fit, with the inlet of the inlet clamp 4 facing the inlet hole 2. The protected cable 8 is fastened by the top clamp 6, and then by the side clamp 7. The lower end of the elliptical cable loop is suspended and not fixed. The bottom of the elliptical cable loop is supported within the upper surface of the cable net 12. The periphery of the cable net 12 is fixedly connected to the inner side wall of the housing 1, and the suspended lower end serves as... The cable has a pre-existing tensile strength. The protected cable 8 is finally secured by the outlet clamp 5, which uses a gap-locking mechanism. The outlet of the outlet clamp 5 faces the outlet hole 3. After the protected cable 8 is secured, the lower cover plate 21 and the upper cover plate 22 are installed. A rubber plug 23 is installed on the lower cover plate 21, and a fixed rubber sealing plate 24 is installed on the upper cover plate 22. The laying of the protected cable 8 within the protection cabinet is then complete. The cabinet door 17 is closed, and the condition of the protected cable 8 inside the cabinet 1 can be observed through the observation window 18. The protected cable 8 continues upwards, passing through the first outer clamp 10 and connecting to the building above the seismic isolation layer. The first outer clamp 10 is fixedly connected to the building above the seismic isolation layer 11, and the first outer clamp 10 and the protected cable 8 are interlocked.

[0055] The function of protecting the cable during a large displacement during an earthquake and during recovery after an earthquake is the same as in Embodiment 1. The feature of this embodiment is that the protected cable 8 is horizontally introduced into the box 1 through the inlet hole 2 on the side of the box 1, and the operator bends and rolls the protected cable 8 on a turntable outside the box 1 and pushes it horizontally into the box 1 before fastening and fixing it. The installation operation in this embodiment is simpler and easier.

[0056] In summary, this invention provides a cable protection box for passing through a seismic isolation layer. Inside the box, the cable to be protected is coiled into an elliptical cable coil with a vertical major axis and a horizontal minor axis. The bottom of the elliptical cable coil is suspended and not fixed, serving as a pre-existing tensile redundancy for the cable. The outlet clamp uses a gap fastening, while the inlet clamp uses an interference fit. This ensures that during an earthquake, the tensile displacement from the building above the seismic isolation layer is absorbed by the pre-existing tensile redundancy at the bottom of the elliptical cable coil and does not continue to propagate along the cable. Therefore, this invention provides safer and more reliable protection for the cable passing through the seismic isolation layer during an earthquake, and thus has broad application prospects.

[0057] It should be emphasized that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A cable protection box for passing through a seismic isolation layer, comprising: The box (1) is rectangular in shape. The box (1) has a circular inlet hole (2) and a circular outlet hole (3) at the top. The box (1) is characterized in that the inner cavity of the box (1) is provided with an inlet clamp (4) and an outlet clamp (5). The inlet clamp (4) is fixedly connected to the inner cavity of the box (1), and the outlet clamp (5) is fixedly connected to the side wall of the box (1). The inlet of the inlet clamp (4) faces the inlet hole (2), and the outlet of the outlet clamp (5) faces the outlet hole (3). The top of the inner cavity of the box (1) is provided with a top clamp (6), and the side wall of the inner cavity of the box (1) is provided with a side wall clamp (7). The side wall clamp (7) and the outlet clamp (5) are respectively located on two opposite inner side walls of the box (1). The protected cable (8) passes through the box (1). After being introduced into the box through the inlet hole (2), the protected cable (8) passes through the inlet clamp (4) and the outlet clamp (5) in sequence and then comes out through the outlet hole (3). The protected cable (8) is coiled at least once inside the box (1) before coming out through the outlet hole (3). The inlet clamp (4) and the protected cable (8) are interlocked, and the outlet clamp (5) and the protected cable (8) are gapped. The outlet clamp (5), top clamp (6), and side wall clamp (7) form an elliptical cable loop with the longest axis vertical and the shortest axis horizontal, around the coil of the protected cable (8) that is closest to the outlet hole (3). The radius of curvature of the minimum arc of the elliptical cable loop is greater than the minimum radius of curvature of the protected cable (8). The box (1) is fixedly connected to the building (9) below the seismic isolation layer. The first outer clamp (10) after the protected cable (8) passes through the outlet hole (3) is fixedly connected to the building (11) above the seismic isolation layer. The first outer clamp (10) and the protected cable (8) are interlocked. The inner rotation axis of the first outer clamp (10), the rotation axis of the outlet hole (3), and the inner rotation axis of the outlet clamp (5) are located on the same vertical line. The box (1) is provided with a cable net (12) with the mesh surface facing upward. The periphery of the cable net (12) is fixedly connected to the inner side wall of the box (1). The bottom of the elliptical cable ring is supported in the mesh surface of the cable net (12). The inner cavities of the inlet clamp (4), outlet clamp (5), top clamp (6), and side wall clamp (7) are all cylindrical and open along the axial direction. The fixing rods (13) of the inlet clamp (4), outlet clamp (5), top clamp (6), and side wall clamp (7) are all telescopic rods with adjustable length and locking. The rotation axis of the fixing rod (13) is perpendicular to the rotation axis of the inner cavity of the clamp.

2. A cable protection box for passing through a vibration isolation layer according to claim 1, characterized in that, The cylindrical inner cavity of the inlet clamp (4) is provided with a rubber tile-shaped gasket (14).

3. A cable protection box for passing through a seismic isolation layer according to claim 1, characterized in that, A roller (15) is rotatably connected in the cylindrical inner cavity of the outlet clamp (5). The rotation direction of the roller (15) is parallel to the rotation axis of the inner cavity of the outlet clamp (5). The roller (15) is distributed around the cylindrical cable channel in the inner cavity of the outlet clamp (5).

4. A cable protection box for passing through a vibration isolation layer according to claim 1, characterized in that, The side wall of the enclosure (1) is provided with an installation port (16). The side wall where the installation port (16) is located is different from the side wall clamp (7) and the cable outlet clamp (5) which are located on two opposing inner side walls of the enclosure (1). The installation port (16) is provided with a door (17), and the door (17) is provided with a transparent observation window (18).

5. A cable protection box for passing through a seismic isolation layer according to claim 4, characterized in that, The box (1) has a lower long groove (19) on one side with a cable inlet hole (2), the lower long groove (19) connects the cable inlet hole (2) and the mounting port (16), the top surface of the box (1) has an upper long groove (20), the upper long groove (20) connects the cable outlet hole (3) and the mounting port (16), a lower cover plate (21) is detachably connected to the lower long groove (19), and an upper cover plate (22) is detachably connected to the upper long groove (20).

6. A cable protection box for passing through a seismic isolation layer according to claim 5, characterized in that, A rubber plug (23) is provided in the inlet hole (2). The rubber plug (23) is a truncated ring shape that is split along the axial direction. The inner diameter of the rubber plug (23) is equal to the outer diameter of the protected cable (8). The outer ring of the rubber plug (23) is fitted into the inlet hole (2).

7. A cable protection box for passing through a seismic isolation layer according to claim 5, characterized in that, The outlet hole (3) is provided with a circular rubber sealing plate (24). The rubber sealing plate (24) has a star-shaped deformation joint (25) extending radially from the inside to the outside. The deformation joint (25) connects the upper and lower surfaces of the rubber sealing plate (24). The rubber sealing plate (24) is sleeved on the outer cylindrical surface of the protected cable (8). The rubber sealing plate (24) is detachably connected to the top surface of the box (1).

8. A cable protection box for passing through a vibration isolation layer according to claim 1, characterized in that, The bottom of the box (1) is provided with feet (26), which are fixedly connected to the ground of the building (9) below the seismic isolation layer.

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