A cable branch box cable access hole sealing and locking structure

Abstract

The application relates to the technical field of cable branch boxes, and discloses a cable-in and cable-out hole sealing and locking structure of a cable branch box, which comprises a box body, the box body is provided with a cable-in and cable-out hole for allowing a cable to pass through, a rotary sealing structure is rotationally arranged on the box body at the cable-in and cable-out hole, a push gear rod is in transmission connection with the rotary sealing structure, one end of the push gear rod is fixedly connected with a piston, a cylinder body is fixedly arranged on the box body, the piston is slidably arranged in the cylinder body, springs and paraffin are arranged on the two sides of the piston in the cylinder body, and a cooling fan is further connected with the push gear rod in linkage. The passive driving of the expansion of the paraffin and the reset of the spring can make the push gear rod drive the rotary sealing structure to tighten and seal the cable-in and cable-out hole at normal temperature, and to reversely open and start the cooling fan at high temperature, so that the cable branch box can realize self-adaptive switching of sealing and heat dissipation, external electric control is not needed, and the structure is simple and reliable.

Description

Technical Field

[0001] This invention relates to the field of cable branch box technology, specifically to a sealing and locking structure for cable inlet and outlet holes in a cable branch box. Background Technology

[0002] Cable distribution boxes are power distribution equipment used for cable branching and power distribution in power distribution networks. Cables are introduced and led out through inlet and outlet holes opened in the side wall of the box. The sealing and locking structure at the inlet and outlet holes is a key component to ensure the waterproof and dustproof protection level of the box and the safe operation of the internal electrical equipment. Currently, the sealing of the inlet and outlet holes mainly relies on static seals such as fixed sealing rings, cable glands, rubber sheaths, or stuffing boxes. The seal is achieved by manually tightening the pressure nuts or pressure rings to deform the seals and tighten them around the cables. The heat dissipation of the box mostly adopts natural ventilation through louvered vents or forced ventilation by a constantly running cooling fan. The sealing structure and the heat dissipation structure are usually two independent systems.

[0003] The existing technologies have the following shortcomings: there is a contradiction between sealing and heat dissipation. To ensure the protection level, the sealing components need to press and seal the inlet and outlet holes tightly, which makes it difficult for the current inside the box to dissipate. Excessive temperature rise will accelerate insulation aging and affect the life of the equipment. On the other hand, increasing ventilation and heat dissipation will weaken the seal and reduce the protection level. The existing sealing components are static passive seals that require manual pre-tightening. The degree of sealing cannot be adaptively adjusted with changes in the temperature inside the box and the diameter of the cables. Moreover, rubber seals are prone to creep aging under long-term pressure, and the sealing performance deteriorates over time. The constant operation of the fan for heat dissipation is energy-wasting, and the natural ventilation and heat dissipation capacity is limited. Summary of the Invention

[0004] In view of the shortcomings of the existing cable branch box cable inlet and outlet hole sealing and locking structure mentioned in the background art, the present invention provides a cable branch box cable inlet and outlet hole sealing and locking structure with the advantages of adaptive linkage of sealing and heat dissipation and tight and reliable sealing, thus solving the technical problems mentioned in the background art.

[0005] The present invention provides the following technical solution: a sealing and locking structure for cable inlet and outlet holes of a cable branch box, comprising a box body, wherein the box body has inlet and outlet holes for cables to pass through, a rotary sealing structure is rotatably disposed on the box body at the inlet and outlet holes, a push rod is drivenly connected to the rotary sealing structure, a piston is fixedly connected to one end of the push rod, a cylinder is fixedly disposed on the box body, the piston is slidably disposed in the cylinder body, a spring and paraffin wax are respectively disposed on both sides of the piston in the cylinder body, and a cooling fan is also linked to the push rod.

[0006] Preferably, the housing is also provided with a dedicated ventilation opening, and the dedicated ventilation opening is provided with a rainproof louver and a waterproof filter screen. The rainproof louver is linked to the push rod so as to open or close the dedicated ventilation opening as the push rod moves.

[0007] Preferably, the rotary sealing structure includes multiple sealing blades, each sealing blade including a metal frame and an elastic sealing lip disposed in the inner ring of the metal frame, and each sealing blade retracts or opens as the rotary sealing structure rotates.

[0008] Preferably, the set temperature for the thermal expansion of the paraffin is higher than its cooling and shrinkage temperature, so as to form a hysteresis zone between the start and stop of the cooling fan, thereby avoiding frequent start and stop of the cooling fan at the critical temperature.

[0009] Preferably, the rotary sealing structure has a micro-ventilation position. When the paraffin wax expands due to heat and pushes the piston to move, the push rod drives the rotary sealing structure to rotate to the micro-ventilation position, so that a micro-ventilation gap is formed between the inlet / outlet hole and the cable passing through it.

[0010] Preferably, a linkage switch is fixedly installed on the pusher rod, and the cooling fan is linked to the pusher rod through the linkage switch.

[0011] Preferably, the enclosure has a mounting cavity for installing electrical equipment.

[0012] Preferably, the housing has multiple inlet and outlet holes, and each inlet and outlet hole is provided with a corresponding rotary sealing structure.

[0013] Preferably, the cooling fan is disposed inside the housing and located between the plurality of inlet and outlet holes.

[0014] Preferably, the rotary sealing structure further includes a fixed ring and a rotating ring rotatably sleeved on the fixed ring. The fixed ring is fixed to the housing and surrounds the inlet and outlet holes. The two ends of each sealing blade are slidably engaged with the arcuate grooves on the fixed ring and the rotating ring respectively through pins. The outer periphery of the rotating ring is provided with gear teeth, and the teeth of the push rod mesh with the gear teeth on the rotating ring.

[0015] The present invention has the following beneficial effects: 1. This invention utilizes the passive drive of paraffin wax expanding under heat and spring resetting to enable the pusher rod to drive the rotary sealing structure to tighten and seal the inlet and outlet holes at room temperature, and to open in the opposite direction and start the cooling fan at high temperature. This allows the cable branch box to achieve adaptive switching between sealing and heat dissipation without the need for external electrical control, and the structure is simple and reliable.

[0016] 2. This invention sets the rotary sealing structure as a combination of a metal frame and an elastic sealing lip with multiple sealing blades. When the blades are closed, the elastic sealing lip is compressed and deformed to fit the outer surface of the cable. This allows the inlet and outlet holes to adaptively tighten and seal according to the cable diameter, ensuring a tight seal without damaging the cable.

[0017] 3. By setting the temperature of paraffin wax's thermal expansion above its cooling and contraction temperature, this invention creates a hysteresis zone between the start and stop of the cooling fan, which can prevent the fan from frequently starting and stopping at critical temperatures, reduce energy waste, and extend the service life of the cooling fan and transmission components.

[0018] 4. This invention, by setting rainproof louvers and waterproof filters at the dedicated ventilation openings and having them open and close in conjunction with the push rod, can prevent rainwater and dust from entering the box while providing ventilation and heat dissipation at high temperatures, thus ensuring the protection level and operational safety of the cable branch box. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the external structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is a schematic diagram of the internal structure of the cylinder block of the present invention; Figure 4 This is a schematic diagram of the rotary sealing structure of the present invention.

[0020] In the diagram: 1. Housing; 2. Cable inlet / outlet; 3. Rotary sealing structure; 4. Push rod; 5. Piston; 6. Cylinder; 7. Spring; 8. Paraffin wax; 9. Cooling fan; 10. Dedicated ventilation opening; 11. Rainproof louvers; 12. Waterproof filter; 13. Sealing blades; 131. Metal frame; 132. Elastic sealing lip; 14. Linkage switch; 15. Fixing ring; 16. Rotating ring. Detailed Implementation

[0021] 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.

[0022] Example 1

[0023] like Figures 1 to 3As shown, this embodiment provides a sealing and locking structure for the cable inlet and outlet holes of a cable branch box, including a box body 1, inlet and outlet holes 2, a rotary sealing structure 3, a push rod 4, a piston 5, a cylinder 6, a spring 7, paraffin wax 8, and a cooling fan 9. The box body 1 is the outer shell of the cable branch box, and the interior of the box body 1 forms an installation cavity for installing electrical equipment such as busbars, circuit breakers, and fuses. Inlet and outlet holes 2 for cables to pass through are provided on the side wall of the box body 1, and the inlet and outlet holes 2 penetrate the inner and outer walls of the box body 1 for cable introduction and exit.

[0024] like Figure 4 As shown, a rotary sealing structure 3 is rotatably mounted on the housing 1 at the inlet / outlet hole 2. The rotary sealing structure 3 adopts a principle similar to the rotation and scaling of a camera aperture, including a fixed ring 15, a rotating ring 16, and multiple sealing blades 13. The fixed ring 15 is fixedly installed on the housing 1 and surrounds the inlet / outlet hole 2; the rotating ring 16 is coaxially arranged with the fixed ring 15 and rotatably sleeved on the fixed ring 15. Multiple sealing blades 13 are arranged in a circumferential overlapping manner to form a central through hole. Each sealing blade 13 includes a metal frame 131 and an elastic sealing lip 132 disposed on the inner ring of the metal frame 131. The metal frame 131 is made of a hard material such as stainless steel or aluminum alloy to ensure the structural rigidity of the sealing blades 13, allowing each sealing blade 13 to rotate smoothly; the elastic sealing lip 132 is made of an elastic material such as silicone rubber, nitrile rubber, or EPDM rubber to adhere to the outer surface of the cable and deform under pressure to achieve a tight seal. The two ends of the sealing blade 13 are slidably engaged with the arc grooves or pin holes on the fixed ring 15 and the rotating ring 16 respectively through pins. When the rotating ring 16 rotates relative to the fixed ring 15, each sealing blade 13 swings and retracts or opens, thereby changing the diameter of the central through hole.

[0025] like Figure 3 As shown, the outer circumferential surface of the rotating ring 16 is provided with gear teeth, and the pusher rod 4 is a vertically arranged rack. The teeth of the pusher rod 4 mesh with the gear teeth on the rotating ring 16 to form a gear and rack transmission. When the pusher rod 4 moves up and down, it drives the rotating ring 16 to rotate, which in turn drives each sealing blade 13 to retract to reduce the diameter of the through hole and tighten the cable, or to open to increase the diameter of the through hole and loosen the cable.

[0026] A piston 5 is fixedly connected to the lower end of the push rod 4, that is, the end away from the rotary sealing structure 3. A cylinder 6 is fixedly installed on the inner wall of the housing 1 or on the support inside the housing. The cylinder 6 is arranged vertically, and the piston 5 is slidably and sealed inside the cylinder 6, dividing the inner cavity of the cylinder 6 into an upper chamber and a lower chamber.

[0027] Springs 7 and paraffin wax 8 are respectively installed on both sides of piston 5 inside cylinder 6. In this embodiment, spring 7 is located in the lower chamber below piston 5, with the upper end of spring 7 abutting the lower end face of piston 5 and the lower end abutting the lower end wall of cylinder 6. Spring 7 is always in a compressed state, applying an upward restoring thrust to piston 5. Paraffin wax 8 is filled in the upper chamber above piston 5. The upper chamber is a sealed chamber, and dynamic sealing between piston 5 and cylinder 6 is achieved by O-ring or lip seal. Paraffin wax 8 is selected from paraffin wax or a mixture of paraffin wax and an expanding agent with a melting point between 40°C and 65°C. Its volume expansion rate when heated and melted is about 10% to 15%, thereby generating an expansion force that pushes piston 5 downward at a set temperature.

[0028] like Figure 2 As shown, a cooling fan 9 is also linked to the push rod 4. Specifically, a linkage switch 14 is fixedly installed on the push rod 4. The cooling fan 9 can be an axial fan or a centrifugal fan, and is installed inside the housing 1. The linkage switch 14 is connected in series in the power circuit of the cooling fan 9. When the push rod 4 moves upward to the first position, the linkage switch 14 is open, and the cooling fan 9 stops; when the push rod 4 moves downward to the second position, the linkage switch 14 is closed, and the cooling fan 9 starts.

[0029] Furthermore, a dedicated ventilation opening 10 is provided on the housing 1, and a rainproof louver 11 and a waterproof filter 12 are installed at the dedicated ventilation opening 10. The multiple blades of the rainproof louver 11 are arranged at a downward angle, and the rainproof louver 11 is linked to the push rod 4 through a connecting rod, opening or closing the dedicated ventilation opening 10 as the push rod 4 moves. The waterproof filter 12 covers the inside of the dedicated ventilation opening 10 and is used to prevent moisture and dust from entering the housing 1 during ventilation.

[0030] The working principle of the method of using this invention is as follows: When the temperature inside the chamber is lower than the set temperature of paraffin wax 8, paraffin wax 8 does not melt and expand, and its volume is small; the elastic force of spring 7 pushes piston 5 upward, and piston 5 drives push rod 4 upward to the first position. Push rod 4 drives rotating ring 16 to rotate through rack and pinion transmission, causing each sealing blade 13 to close, and each elastic sealing lip 132 to be pressed and adhered to the outer surface of the cable passing through the inlet and outlet hole 2, thereby achieving a sealing and locking of the inlet and outlet hole 2; at the same time, the linkage switch 14 is in the off state, the cooling fan 9 stops, the rainproof louver 11 closes the special ventilation port 10, and the chamber 1 is in a fully sealed state.

[0031] When the temperature inside the chamber rises to the set temperature of paraffin wax 8, the paraffin wax 8 melts and expands due to the heat, increasing its volume and pushing piston 5 downwards against the elastic force of spring 7, further compressing spring 7. Piston 5 drives push rod 4 downwards to the second position, and push rod 4 drives rotating ring 16 in the opposite direction, causing each sealing blade 13 to open to a micro-ventilation position, creating a micro-ventilation gap between the inlet / outlet hole 2 and the cable passing through it; at the same time, linkage switch 14 closes, cooling fan 9 starts, and forced ventilation and cooling are provided inside chamber 1; and push rod 4, through linkage, opens dedicated ventilation port 10 by rainproof louvers 11, realizing air convection and heat dissipation inside and outside chamber 1. During ventilation, rainproof louvers 11 and waterproof filter 12 ensure ventilation and heat dissipation while preventing rainwater and dust from entering chamber 1.

[0032] Once the temperature inside the chamber drops to the required temperature, the paraffin wax 8 shrinks in volume, the spring 7 resets and pushes the piston 5 upward. The piston 5 drives the push rod 4 to move upward again to the first position. The push rod 4 then drives the sealing blades 13 of the rotary sealing structure 3 to tighten and seal the inlet and outlet holes 2. At the same time, the linkage switch 14 is disconnected to stop the cooling fan 9, and the rainproof louver 11 closes the special ventilation port 10 to avoid energy waste caused by the cooling fan 9 working for a long time and to ensure the sealing effect of the inlet and outlet holes 2.

[0033] Because the set temperature for thermal expansion of paraffin 8 is higher than its cooling and shrinkage temperature, meaning that paraffin 8 has thermal hysteresis characteristics, the starting temperature of the cooling fan 9 is higher than its stopping temperature, forming a hysteresis band between its starting and stopping. This avoids the cooling fan 9 from frequently starting and stopping and vibrating near the critical temperature, thereby improving the stability and service life of the system.

[0034] Example 2

[0035] The difference between this embodiment and Embodiment 1 is that the housing 1 has multiple inlet / outlet holes 2, which are arranged vertically along the side wall of the housing 1. Each inlet / outlet hole 2 is equipped with a corresponding rotary sealing structure 3. Each rotary sealing structure 3 is driven by a corresponding push rod 4, piston 5, cylinder 6, spring 7, and paraffin wax 8 to achieve independent sealing and ventilation of each inlet / outlet hole 2. A cooling fan 9 is located inside the housing 1 and between the multiple inlet / outlet holes 2 to simultaneously ventilate and dissipate heat in the area near the multiple inlet / outlet holes 2. The remaining structure and working principle are the same as in Embodiment 1, and will not be described again here.

[0036] In this invention, the set temperature of paraffin wax 8 can be selected according to the working environment of the cable branch box, using paraffin wax with different melting points, such as 45℃, 55℃, or 65℃, to correspond to the switching temperature under different working conditions. The metal frame 131 can be made of stainless steel, aluminum alloy, or hard engineering plastic. The elastic sealing lip 132 can be made of silicone rubber, nitrile rubber, EPDM rubber, or fluororubber. The number of sealing blades 13 can be 5 to 12. The cooling fan 9 can be an axial fan or a centrifugal fan, and can be installed on the top, bottom, or side of the box 1. The rainproof louvers 11 and the push rod 4 can be linked by a connecting rod, lever, wire rope, or cam mechanism. The gear and rack drive of the rotary sealing structure 3 can also be replaced by a worm gear, crank connecting rod, or cam drive, as long as the linear motion of the push rod 4 can be converted into the rotational motion of the rotating ring 16.

[0037] 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 alterations 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 sealing and locking structure for cable inlet and outlet holes of a cable branch box, characterized in that: The device includes a housing (1), which has an inlet / outlet hole (2) for cables to pass through. A rotary sealing structure (3) is rotatably installed on the housing (1) at the inlet / outlet hole (2). A push rod (4) is drivenly connected to the rotary sealing structure (3). A piston (5) is fixedly connected to one end of the push rod (4). A cylinder (6) is fixedly installed on the housing (1). The piston (5) is slidably installed in the cylinder (6). A spring (7) and a paraffin wax (8) are respectively installed on both sides of the piston (5) in the cylinder (6). A cooling fan (9) is also linked to the push rod (4).

2. The sealing and locking structure for cable inlet and outlet holes of a cable branch box according to claim 1, characterized in that: The housing (1) is also provided with a dedicated ventilation opening (10). The dedicated ventilation opening (10) is provided with a rainproof louver (11) and a waterproof filter (12). The rainproof louver (11) is linked to the push rod (4) so ​​that the dedicated ventilation opening (10) can be opened or closed as the push rod (4) moves.

3. The sealing and locking structure for cable inlet and outlet holes of a cable branch box according to claim 1, characterized in that: The rotary sealing structure (3) includes multiple sealing blades (13), each sealing blade (13) includes a metal frame (131) and an elastic sealing lip (132) disposed in the inner ring of the metal frame (131). Each sealing blade (13) retracts or opens as the rotary sealing structure (3) rotates.

4. The sealing and locking structure for cable inlet and outlet holes of a cable branch box according to claim 1, characterized in that: The set temperature for the thermal expansion of the paraffin (8) is higher than its cooling and shrinkage temperature, so as to form a hysteresis zone between the start and stop of the cooling fan (9) and avoid the cooling fan (9) from frequently starting and stopping at the critical temperature.

5. The cable branch box cable inlet / outlet sealing and locking structure according to claim 1, characterized in that: The rotary sealing structure (3) has a micro-ventilation position. When the paraffin wax (8) expands due to heat and pushes the piston (5) to move, the push rod (4) drives the rotary sealing structure (3) to rotate to the micro-ventilation position, so that a micro-ventilation gap is formed between the inlet / outlet hole (2) and the cable passing through it.

6. The sealing and locking structure for cable inlet and outlet holes of a cable branch box according to claim 1, characterized in that: A linkage switch (14) is fixedly installed on the pusher rod (4), and the cooling fan (9) is linked to the pusher rod (4) through the linkage switch (14).

7. The sealing and locking structure for cable inlet and outlet holes of a cable branch box according to claim 1, characterized in that: The enclosure (1) has an installation cavity for installing electrical equipment.

8. The sealing and locking structure for cable inlet and outlet holes of a cable branch box according to claim 1, characterized in that: The housing (1) has multiple inlet and outlet holes (2), and each inlet and outlet hole (2) is provided with a corresponding rotary sealing structure (3).

9. The sealing and locking structure for cable inlet and outlet holes of a cable branch box according to claim 1, characterized in that: The cooling fan (9) is disposed inside the housing (1) and located between the plurality of the inlet and outlet holes (2).

10. The cable branch box cable inlet / outlet sealing and locking structure according to claim 3, characterized in that: The rotary sealing structure (3) further includes a fixed ring (15) and a rotating ring (16) rotatably sleeved on the fixed ring (15). The fixed ring (15) is fixed on the housing (1) and arranged around the inlet and outlet holes (2). The two ends of each sealing blade (13) are respectively slidably engaged with the arc grooves on the fixed ring (15) and the rotating ring (16) through pins. The outer periphery of the rotating ring (16) is provided with gear teeth, and the teeth of the push rod (4) mesh with the gear teeth on the rotating ring (16).

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