PCB board switching vulcanization sealing structure of underwater branch cable

Abstract

The application discloses a kind of underwater branch cable's PCB board switching vulcanization sealing structure, it is related to cable switching technical field, including vulcanization shell, vulcanization shell inside is equipped with electrical conversion component and vulcanization sealing layer;Electrical conversion component includes switching PCB board, switching PCB board is opened with the main fixed hole of matching main cable and a plurality of pass-through fixed holes matching single branch cable;Main cable, branch cable are respectively correspondingly arranged in main fixed hole and pass-through fixed hole inside, by the integrated switching PCB board in vulcanization shell inside, vulcanization sealing layer constitutes integral switching structure, switching PCB board is positioned independently by respectively arranged main fixed hole and pass-through fixed hole to main cable, branch cable one line one hole, the insulating coating of cable and hole wall are engaged to form force fulcrum, realize mechanical stress and welding point position separation, external force generated by water flow impact, cable drag is all received by PCB board material, and welding point is only responsible for signal transmission and does not bear load.

Description

Technical Field

[0001] This invention relates to the field of cable adapter technology, specifically to a PCB board adapter vulcanization sealing structure for underwater branch cables. Background Technology

[0002] Underwater branch cable adapters are widely used in underwater exploration, underwater communication, and marine engineering to distribute signals from the main cable to multiple branch cables. These adapters are subjected to high pressure, high corrosion, and continuous impact from ocean currents in underwater environments. The limiting, fixing, and waterproof sealing structure of the cable transfer area inside the adapter directly determines the long-term stability and service life of the underwater equipment. Therefore, the underwater branch cable adapter sealing structure is a core component in the wiring system of marine underwater equipment.

[0003] Currently, conventional underwater branch cable adapter structures mostly adopt a molding method of direct cable connection and potting, terminal crimping, and then overall potting and sealing. They rarely use standardized PCB adapter carrier structures. When these traditional structures are directly applied to long-term immersion operations in deep sea and nearshore environments, many unavoidable technical defects are exposed. Specific problems are as follows: 1. Traditional adapter structures do not have dedicated physical restraint structures for cables. All the mechanical stress generated by underwater water flow impact, cable dragging, and ocean current vibration is concentrated at the cable welding points or crimp terminals. Under long-term immersion conditions, it is very easy to cause failures such as desoldering, wire breakage, and poor line contact, which directly causes underwater signal interruption, equipment shutdown and failure, resulting in extremely low overall operational reliability.

[0004] 2. In the traditional potting and vulcanization molding process, there is a lack of cable positioning benchmarks. Multiple branch cables are not fixed and are prone to displacement, twisting, and mutual compression, which can easily cause damage to the insulation layer of the cable core and short circuits. At the same time, the lack of a unified positioning carrier leads to large differences in cable layout between batches of products, resulting in poor product consistency and failing to meet the standardized batch assembly and use requirements of marine engineering equipment.

[0005] 3. Traditional discrete terminal adapter structures have low integration and lack a regular line adapter carrier. The potting compound and the cable and metal terminal only have a single bonding interface. Under the high pressure of underwater, the compound is prone to delamination from the components, resulting in water seepage gaps. Seawater intrusion into the adapter will cause oxidation of the metal conductor and corrosion of the circuit, which will significantly shorten the service life of the underwater connector and supporting equipment.

[0006] 4. Traditional solutions lack a dedicated positioning and sealing structure for compatible cables. The outer wall of the branch cable does not fit tightly with the sealing colloid and the adapter substrate. Under long-term underwater pressure differential, tiny water seepage gaps are easily generated. The waterproof, pressure-resistant, and seawater corrosion-resistant performance is weak, making it unsuitable for the harsh underwater operating environment of deep-sea high pressure and long-term immersion.

[0007] Therefore, in view of this, the present invention proposes a PCB board transfer vulcanization sealing structure for underwater branch cables to make up for and improve the deficiencies of the prior art. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a PCB board adapter vulcanization sealing structure for underwater branch cables, thereby resolving the technical issues raised in the background section.

[0009] To achieve the above objectives, the technical solution adopted by this invention is as follows: a PCB board adapter vulcanization sealing structure for underwater branch cables, used to adapter a main cable to branch into several branch cables, including a vulcanized outer shell, wherein an electrical conversion component and a vulcanized sealing layer are provided inside the vulcanized outer shell; the electrical conversion component includes an adapter PCB board, wherein the adapter PCB board has a main cable fixing hole matching the main cable and several straight-through fixing holes matching individual branch cables; the main cable and branch cables are respectively inserted into the main cable fixing hole and the straight-through fixing hole, and the cable insulation sheath and... The corresponding main fixing holes and the inner walls of the through fixing holes engage to achieve bidirectional cable positioning; the upper surface of the adapter PCB is provided with main solder pads and branch solder pads, and the conductors of the main cable and branch cable passing through the adapter PCB are respectively soldered to the corresponding solder pad positions. The conductive lines connecting the main solder pads and each branch solder pad inside the adapter PCB split and transfer the signal between the main cable and multiple branch cables; the vulcanized sealing layer covers the adapter PCB, the root of the main cable and the root of the branch cable, and fills the gap between each fixing hole and the outer wall of the cable to form a sealed waterproof structure.

[0010] Furthermore, the main cable extends into the cavity from the front end of the vulcanized shell, and several branch cables extend into the cavity from the rear end of the vulcanized shell. The main cable and branch cables are arranged below the adapter PCB board and pass through the corresponding main fixing hole and straight-through fixing hole from bottom to top.

[0011] Furthermore, the vulcanized sealing layer is formed using a high-pressure integrated vulcanization process, and the vulcanized sealing layer is made of rubber material that is resistant to seawater corrosion and deep-sea high pressure.

[0012] Furthermore, the surface of the adapter PCB is uniformly provided with several heat dissipation holes, and the vulcanized sealing layer covers the surface of the adapter PCB 21 and the outer wall of the heat dissipation hole 26. The interior of the heat dissipation hole 26 is a through hollow channel and is not filled with vulcanized adhesive.

[0013] Furthermore, the outer wall of the vulcanized shell is symmetrically fitted with perforated lugs, which are used for external mounting and fixing of the entire adapter.

[0014] Furthermore, the adapter PCB board has protruding fixing holes at the positions of each branch cable. The protruding fixing holes penetrate the body of the adapter PCB board, and several branch cables pass through the protruding fixing holes.

[0015] Furthermore, a number of limiting protrusions are fixedly mounted circumferentially on the inner side of the protruding fixing hole. The limiting protrusions extend alternately in the vertical direction. Some of the limiting protrusions extend to the upper side of the adapter PCB board with a short length, while the other part of the limiting protrusions extends to the lower side of the adapter PCB board with a short length.

[0016] Furthermore, an interval circuit is formed between adjacent limiting protrusions, and the vulcanized sealing layer can completely fill the gap between the protruding fixing hole and the outer wall of the branch cable along the interval circuit during molding.

[0017] Furthermore, stepped fixing holes are provided on the adapter PCB board at the positions corresponding to each branch cable. The stepped fixing holes penetrate the body of the adapter PCB board, and several branch cables pass through the interior of the stepped fixing holes.

[0018] Furthermore, the stepped fixing hole forms a stepped annular platform along the vertical direction, and the size of the stepped annular platform gradually increases from bottom to top. When the vulcanized sealing layer is formed, it fills the gap between the stepped fixing hole and the mating gap between the branch cable outer wall.

[0019] Compared with the prior art, the beneficial effects of the present invention are: (1) The present invention integrates a transfer PCB board and a vulcanized sealing layer inside the vulcanized shell to form an overall transfer structure. The main cable and branch cable are independently limited by the main fixing hole and the straight-through fixing hole respectively set on the transfer PCB board. The insulation sheath of the cable is engaged with the hole wall to form a force support point, realizing the separation of mechanical stress and welding point. The external force generated by water flow impact and cable dragging is all borne by the PCB board. The solder joint is only responsible for signal transmission and does not bear the load, thus avoiding the failure of desoldering and wire breakage under long-term underwater working conditions from the root. At the same time, the high-pressure integrated vulcanization process makes the rubber completely fill the gap between each fixing hole and the outer wall of the cable, and the overall PCB board and the cable root form a multi-layer sealing barrier. Combined with the inclined heat dissipation hole reserved hollow heat exchange channel to dissipate the accumulated heat during operation, it can not only block the high-pressure penetration of seawater and resist seawater corrosion, but also alleviate the high-temperature aging of the circuit inside the sealed cavity. The standardized hole position constraint ensures that the vulcanization process of multiple cables is free from deviation and torsion, greatly improving the consistency of mass production of products and adapting to the harsh underwater working environment of long-term immersion and continuous vibration impact in the deep sea.

[0020] The present invention features a front and rear branch layout that distinguishes between the main input and multiple branch output lines. During assembly, the cables are inserted into the fixing holes of the board from bottom to top, which can avoid the cables from getting tangled and squeezed, causing short circuits. The standardized adapter PCB integrates the main solder pad and multiple branch solder pads. It relies on the pre-embedded conductive lines in the board to complete the distribution and transmission of a single main signal to multiple branches, replacing the traditional processing method of directly connecting and potting the cable cores. This simplifies the assembly process, improves the integration, and the overall structure is compact and can be adapted to the narrow underwater installation space. After the integral vulcanization molding, the colloid is seamlessly attached to the PCB and the cable sheath, eliminating the defects of traditional discrete terminal potting, which are prone to delamination and water seepage at the single interface. This effectively reduces the oxidation and corrosion of metal conductors and extends the overall service life of the underwater adapter.

[0021] (2) This invention replaces the straight-through fixing hole corresponding to the branch cable on the adapter PCB with a protruding fixing hole. The hole wall is integrally formed with a long and short staggered limiting plate. The cable insulation sheath is clamped in all directions by the protruding plate to achieve bidirectional stable limiting. The interval circuit connected between adjacent protruding plates can guide the liquid vulcanized adhesive to flow evenly and completely fill the small gaps in the hole wall and the outer wall of the cable. After curing, the adhesive has a larger bonding area with the cable and PCB, further enhancing the sealing and bonding effect of the wire threading position and the deep-sea pressure resistance.

[0022] (3) This invention replaces the straight-through fixing hole corresponding to the branch cable on the adapter PCB with a stepped fixing hole with the diameter gradually increasing from bottom to top. The cable's insulation sheath abuts against the stepped annular platform to complete the axial anti-retraction limit. The stepped structure forms a multi-layered gap. When the vulcanizing adhesive is molded, each layer of the gap can be filled one by one. The multi-layered stepped bonding structure increases the contact area between the adhesive and the cable and the hole wall, enhances the stability of the cable positioning, effectively suppresses the cable retraction and movement caused by the impact of high-pressure water flow, and the multi-layered sealing interface further blocks the penetration of seawater pressure difference. On the basis of retaining all the advantages of the basic structure, the cable limiting effect and long-term underwater sealing reliability are further optimized. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the axial view three-dimensional structure in Embodiment 1 of the present invention; Figure 2 This is a top view of the planar structure in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the internal structure of the vulcanized shell in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the three-dimensional structure of the main cable assembly in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the three-dimensional structure of the branch cable assembly in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the planar structure of the through-hole fixing hole in Embodiment 1 of the present invention; Figure 7 This is a top view of the adapter PCB board in Embodiment 1 of the present invention; Figure 8 This is a three-dimensional axial view of the branch cable assembly state in Embodiment 1 of the present invention; Figure 9 This is a schematic side view of the inside of the vulcanized shell in Embodiment 1 of the present invention; Figure 10 This is a schematic diagram of the protruding fixing hole in Embodiment 2 of the present invention; Figure 11 This is a three-dimensional schematic diagram of the protruding fixing hole in Embodiment 2 of the present invention; Figure 12 This is a schematic diagram of the positional relationship between the protruding fixing hole and the branch cable in Embodiment 2 of the present invention; Figure 13 This is a schematic diagram of the stepped fixing hole in Embodiment 3 of the present invention; Figure 14 This is a three-dimensional schematic diagram of the stepped fixing hole in Embodiment 3 of the present invention; Figure 15 This is a planar schematic diagram showing the positional relationship between the stepped fixing hole and the branch cable in Embodiment 3 of the present invention.

[0024] The following are the labels in the diagram: 1. Vulcanized shell; 11. Lug with hole; 12. Main cable; 13. Branch cable; 2. Electrical conversion assembly; 21. Adapter PCB board; 22. Main cable mounting hole; 23. Main cable pad; 24. Straight-through mounting hole; 25. Branch cable pad; 26. Heat dissipation hole; 27. Protruding mounting hole; 28. Stepped mounting hole. Detailed Implementation

[0025] 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.

[0026] It should be noted that the main cable 12 is responsible for long-distance underwater signal transmission. It achieves stable long-distance transmission of electrical and data signals through the existing underwater communication armored cable structure, adapting to the high-pressure corrosion conditions of seawater. The branch cable 13 is responsible for branch signal output. It achieves signal distribution from a single main cable to multiple terminal devices through the existing underwater branch transmission cable structure. The adapter PCB board 21 provides the function of line transfer carrier. It achieves the layout of conductive lines on the board through the existing standardized signal adapter PCB board 21 structure, connecting the main cable pad 23 and each branch cable pad 25, and completing the signal transfer from the main cable 12 to multiple branch cables 13.

[0027] The working principles of the above components, such as the underwater insulation and shielding transmission principle of the main cable 12 and several branch cables 13, and the signal shunting and conversion principle of the copper foil circuit inside the adapter PCB board 21, as well as the specific structures, such as the core specifications of the main cable 12 and branch cables 13, the material of the insulating and water-pressure resistant outer layer, the arrangement of the shielding layer, the board base material of the adapter PCB board 21, the circuit layout process, the pad forming specifications, and the impedance matching parameters, are all existing mature and common technologies. Given the universality of these structures, their specific principles and forming details will not be elaborated further.

[0028] Example 1: Please refer to Figure 1 - Figure 9 As shown, a PCB board for underwater branch cable conversion vulcanization sealing structure is used to convert a main cable 12 into several branch cables 13. The structure includes a vulcanized outer shell 1, inside which is an electrical conversion component 2 and a vulcanized sealing layer. The electrical conversion component 2 includes a conversion PCB board 21, which has a main cable fixing hole 22 matching the main cable 12 and several through-hole fixing holes 24 matching individual branch cables 13. The main cable 12 and branch cables 13 are respectively inserted into the main cable fixing hole 22 and the through-hole fixing hole 24. The cable's insulating outer sheath is connected to the corresponding main cable fixing hole 22 and through-hole fixing hole 24. The inner walls of the through-type fixing holes 24 engage to achieve bidirectional cable positioning; the upper surface of the adapter PCB board 21 is provided with a main solder pad 23 and a branch solder pad 25. The core conductors of the main cable 12 and the branch cable 13 pass through the adapter PCB board 21 and are respectively soldered to the corresponding solder pad positions. The conductive lines connecting the main solder pad 23 and each branch solder pad 25 inside the adapter PCB board 21 split and transfer the signal between the main cable 12 and multiple branch cables 13; the vulcanized sealing layer covers the adapter PCB board 21, the root of the main cable 12 and the root of the branch cable 13, and fills the gap between each fixing hole and the outer wall of the cable to form a sealed waterproof structure.

[0029] It should be noted that the outer wall of the vulcanized shell 1 is symmetrically fixed with perforated lugs 11, which are used for external mounting and fixing of the entire adapter.

[0030] It should be noted that the main cable 12 extends into the cavity from the front end of the vulcanized shell 1, and several branch cables 13 extend into the cavity from the rear end of the vulcanized shell 1. The main cable 12 and branch cables 13 are arranged below the adapter PCB board 21 and pass through the corresponding main fixing hole 22 and straight-through fixing hole 24 from bottom to top. The vulcanized sealing layer is formed by high-pressure integrated vulcanization process. The vulcanized sealing layer is made of rubber material that is resistant to seawater corrosion and deep-sea high pressure. Several heat dissipation holes 26 are evenly opened on the surface of the adapter PCB board 21.

[0031] It should be added that the vulcanized sealing layer is formed by high-pressure integrated vulcanization of a rubber substrate. The vulcanized material completely fills all assembly gaps between the inner walls of each hole and the outer walls of the cables. At the same time, it comprehensively covers the entire surface of the adapter PCB board 21, the 12 main cables, all 13 branch cables, and the entire adapter area. It is tightly bonded to the inner wall of the vulcanized outer shell 1, forming a continuous and uninterrupted multi-layered sealed protective structure. This can effectively resist the penetration of high-pressure water in the deep sea and the corrosion of seawater salt spray, and prevent the colloid from delaminating and seeping water at the interface between the colloid and the components. The vulcanized layer substrate can be selectively made of water-resistant and corrosion-resistant rubber materials such as silicone rubber, fluororubber, EPDM rubber, and neoprene rubber, depending on the underwater operating depth and seawater corrosion environment. Different rubber substrates can be adapted to different deep-sea pressure resistance and long-term immersion conditions. The high-pressure integrated vulcanization adopts the industry-standard mature vulcanization process to achieve integral molding without limiting specific temperature, pressure, and time parameters.

[0032] Specifically, in the assembly stage, such as Figure 3 As shown, the adapter PCB board 21 is first pre-fixed inside the vulcanizing shell 1 cavity; then, the main cable 12 is taken and inserted into the cavity through the front opening of the vulcanizing shell 1. At this time, the main cable 12 is arranged below the adapter PCB board 21. Then, the main cable 12 is inserted upwards from bottom to top, aligned with the corresponding main cable fixing hole 22 on the adapter PCB board 21, and pushed until the outer insulation sheath of the cable is tightly fitted against the inner wall of the main cable fixing hole 22. The axial and radial bidirectional limiting of the main cable 12 is completed by the locking structure between the hole wall and the cable insulation sheath. After the main cable 12 is assembled, the corresponding... Figure 4 As shown, this achieves independent positioning constraints for a single main cable 12, preventing displacement or movement of the main cable 12 during subsequent assembly and vulcanization processes.

[0033] After the main cable 12 is positioned, take one branch cable 13 in sequence and insert it into the cavity from the rear opening of the vulcanized shell 1. At this time, the branch cable 13 is placed below the adapter PCB board 21. Then, insert the branch cable 13 from bottom to top into the matching through-hole 24 on the adapter PCB board 21. Push the cable until the cable's insulation sheath is clamped to the inner wall of the through-hole 24, thus completing the positioning of the single branch cable 13. Repeat the above operation to assemble all the remaining branch cables 13 in sequence, realizing an independent positioning layout of one line and one hole. The front and rear branch layout can clearly distinguish the main input line and the multiple branch output lines. From the assembly method, it can prevent multiple branch cables 13 from being tangled and squeezed together, solving the defects of messy wiring and short circuit after vulcanization in traditional adapter structures.

[0034] After all the main cables 12 and branch cables 13 are threaded and secured, the upper insulation sheaths of the cables are stripped to expose the conductor cores. The conductors of the main cables 12 are soldered to the main cable pads 23 on the upper surface of the adapter PCB 21, and the conductors of each branch cable 13 are correspondingly soldered to their respective branch pads 25. The adapter PCB 21 has conductive lines inside that connect the main cable pads 23 and all the branch pads 25. These built-in conductive lines form an electrical bridge between the main cables 12 and the multiple branch cables 13. After soldering, a complete signal transmission path is formed. The single-channel signal input from the main cable 12 can be distributed to each branch cable 13 via the conductive lines inside the PCB, thus completing the signal transfer and transmission from the main cable to multiple branches. The main cables 12 and several branch cables 13 are all secured to the adapter P by their own outer insulation sheaths. The inner walls of the main fixing holes 22 and straight-through fixing holes 24 corresponding to the CB board 21 are used for limiting and fixing. When the underwater water flow impacts or the cable is dragged, the external force will first act on the insulation sheath of the main cable 12 and the branch cable 13. Then, through the contact position where the insulation sheath and the inner wall of the fixing hole interlock, all the mechanical external force is transmitted and distributed to the entire adapter PCB board 21. The main cable 12 and the branch cable 13 only have the internal core conductors with the insulation removed soldered to the corresponding main solder pads 23 and branch solder pads 25. The tension and impact force of the cable itself will not be transmitted to the soldering point between the core and the corresponding solder pad. The soldering point only undertakes the function of electrical signal transmission and does not bear any mechanical load throughout the process. Relying on this layered force-bearing structure, the problems of solder joint desoldering and internal core breakage can be avoided under long-term underwater working conditions.

[0035] After the cable threading and welding processes are completed, seawater-resistant and deep-sea high-pressure resistant rubber vulcanizing adhesive is injected into the cavity of the vulcanized outer shell 1. A high-pressure integrated vulcanization process is used to form a vulcanized sealing layer. Under high pressure, the vulcanized adhesive completely covers the adapter PCB board 21, the 12 main cables, and all 13 branch cables. At the same time, it fully fills the gaps between the main fixing holes 22, the straight-through fixing holes 24 and the outer wall of the cables. After curing, the vulcanized sealing layer is seamlessly bonded to the surface of the adapter PCB board 21 and the cable insulation sheath, forming an integrated, sealed, waterproof and corrosion-resistant structure. During the vulcanization process, the corresponding fixing holes on the adapter PCB board 21 continuously constrain the position of all cables, preventing them from shifting or twisting. This ensures a uniform layout for each batch of products. The multi-layered vulcanized sealing barrier can resist underwater high-pressure penetration and seawater corrosion, eliminating the problems of interface delamination and water seepage, and metal conductor oxidation in traditional potting structures.

[0036] like Figure 5 As shown, the adapter PCB board 21 has several diagonally penetrating heat dissipation holes 26 evenly distributed on its surface. Before vulcanization casting, cylindrical pins with matching diagonal angles are inserted into all the heat dissipation holes 26 to occupy their positions. When the vulcanized adhesive is wrapped around the PCB board, it cannot fill the channels. After curing and demolding, the pins can be pulled out to retain a complete and unobstructed heat dissipation channel. The heat dissipation holes 26 are located on the diagonal side of the PCB, corresponding to a thin vulcanized adhesive layer with no adhesive accumulation or overflow space, further preventing hole blockage. The inner cavity of the vulcanized outer shell 1 is sealed and prone to heat accumulation and moisture buildup. The diagonal heat dissipation holes 26 rely on the hollow channels to form micro-air convection, which diverts the heat accumulated during the operation of the circuit and avoids the high temperature accelerating the aging of the circuit insulation layer. The thin layer of vulcanized coating at the hole opening can prevent seawater from seeping in, simultaneously achieving sealing, waterproofing, and continuous heat dissipation.

[0037] It should be added that the vulcanized sealing layer covering the surface of the adapter PCB 21 and the outer wall of the heat dissipation hole 26 is achieved by a high-pressure integrated molding process using a vulcanizing machine and a closed mold. After the mold is closed, the vulcanizing machine applies standard vulcanizing pressure and injects liquid rubber vulcanizing adhesive into the mold cavity. The closed mold restricts the liquid vulcanizing adhesive to flow only in the mold cavity, the outer surface of the adapter PCB 21, and the outer area of ​​the heat dissipation hole 26. The pre-inserted cylindrical pin fixtures completely occupy the entire space inside the heat dissipation hole 26, physically preventing the liquid vulcanizing adhesive from flowing into the heat dissipation hole 26 channel. After the vulcanizing adhesive is completely cured under high pressure and constant temperature in the mold, the vulcanizing mold is opened for demolding and all cylindrical pin fixtures are pulled out simultaneously. The finished heat dissipation hole 26 retains a complete and unobstructed hollow heat exchange channel. The vulcanized sealing layer is attached to and covers the surface of the adapter PCB 21 and the outer wall of the heat dissipation hole 26, and there will be no situation where the vulcanizing adhesive fills and blocks the inside of the heat dissipation hole 26.

[0038] After the entire set of adapter sealing structure is vulcanized and all processing steps are completed, the perforated lugs 11 symmetrically arranged on the outer wall of the vulcanized shell 1 complete the overall assembly and fixation. The perforated lugs 11 are used to lock the entire adapter device onto the underwater detection, marine engineering equipment cabin or external mounting bracket, providing a stable underwater installation reference for the entire structure. Under underwater operation conditions, the main cable 12 transmits underwater communication and detection electrical signals over long distances. After the signal is shunted by the conductive lines inside the adapter PCB board 21, it is transmitted to the corresponding branch cable 13 through the branch pads 25. The multiple branch cables 13 output branch signals to the underwater terminal equipment respectively. The mechanical stress caused by ocean current impact and cable drag is continuously borne by the adapter PCB board 21. The vulcanized sealing layer prevents seawater from entering the interior. The entire structure can be stably adapted to the harsh underwater operating environment of deep-sea high pressure, seawater corrosion, and continuous vibration impact for a long time.

[0039] Example 2: Based on Example 1, please refer to Figure 10 - Figure 12 As shown, protruding fixing holes 27 are provided on the adapter PCB board 21 at the positions corresponding to each branch cable 13. The protruding fixing holes 27 pass through the board body of the adapter PCB board 21, and several branch cables 13 are all inserted into the protruding fixing holes 27.

[0040] It should be noted that several limiting protrusions are fixedly mounted circumferentially on the inner side of the protruding fixing hole 27. The limiting protrusions extend alternately in the vertical direction. Some of the limiting protrusions extend a short length towards the upper side of the adapter PCB board 21, while others extend a short length towards the lower side of the adapter PCB board 21. An interval circuit is formed between adjacent limiting protrusions. When the vulcanized sealing layer is formed, it can completely fill the gap between the protruding fixing hole 27 and the outer wall of the branch cable 13 along the interval circuit.

[0041] Specifically, this embodiment improves the fixing hole structure of the matching branch cables 13 on the adapter PCB board 21 by introducing a protruding fixing hole 27 that penetrates the body of the adapter PCB board 21. Each branch cable 13 is correspondingly inserted into the protruding fixing hole 27. Multiple limiting protrusions extending vertically in an interlocking manner are integrally formed on the inner side of the hole wall of the protruding fixing hole 27. The lengths of each limiting protrusion extending to the upper and lower sides of the adapter PCB board 21 are not equal, which can fit and clamp the insulating outer sheath of the branch cable 13 in all directions, and simultaneously complete the radial and axial bidirectional limiting constraint of the branch cable 13.

[0042] Furthermore, a connecting interval circuit is reserved between adjacent limiting protrusions. During the high-pressure vulcanization molding stage, the liquid vulcanizing adhesive can flow evenly along the interval circuit between the limiting protrusions, completely filling all the tiny mating gaps between the inner wall of the protruding fixing hole 27 and the outer wall of the branch cable 13. After curing, it greatly improves the sealing fit and water pressure resistance of the cable insertion position. The workflow of assembling the other main cables 12, conductor welding, heat dissipation structure heat dissipation, overall vulcanization coating, and underwater signal transmission force buffering is exactly the same as in Example 1, and will not be repeated here.

[0043] Example 3: Based on Example 1, please refer to Figure 13 - Figure 15 As shown, stepped fixing holes 28 are provided on the adapter PCB board 21 at the positions corresponding to each branch cable 13. The stepped fixing holes 28 pass through the body of the adapter PCB board 21, and several branch cables 13 pass through the inside of the stepped fixing holes 28.

[0044] It should be noted that the stepped fixing hole 28 forms a stepped annular platform along the vertical direction, and the size of the stepped annular platform gradually increases from bottom to top. When the vulcanized sealing layer is formed, it fills the gap between the stepped fixing hole 28 and the mating gap between the branch cable 13 and the outer wall.

[0045] Specifically, this embodiment improves the fixing hole structure of the matching branch cables 13 on the adapter PCB board 21 by introducing a stepped fixing hole 28 that penetrates the board body of the adapter PCB board 21. Each branch cable 13 is inserted into the stepped fixing hole 28. The stepped fixing hole 28 is formed into a stepped annular platform in the vertical direction. The diameter of the stepped annular platform gradually increases from bottom to top. The insulation sheath of the branch cable 13 is abutted against the stepped annular platform to achieve stable radial and axial bidirectional limiting.

[0046] A stepped gap is formed between the stepped annular platform and the outer wall of the branch cable 13. During the high-pressure vulcanization molding process, the liquid vulcanizing adhesive can penetrate into the interior of the stepped gap layer by layer, completely filling all the mating gaps between the inner wall of the stepped fixing hole 28 and the outer wall of the branch cable 13. After the adhesive is cured, the stability of the cable positioning and the sealing and water-proofing ability are improved by the multi-layer stepped bonding structure. Except for the above-mentioned branch cable 13 positioning hole structure and corresponding vulcanization filling process, the entire process of main cable 12 assembly and positioning, cable core welding and forming, heat dissipation and heat exchange of the oblique heat dissipation hole 26, overall vulcanization sealing and covering, underwater working condition signal transmission and stress bearing is consistent with Example 1, and will not be repeated here.

[0047] 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 PCB board transfer vulcanization sealing structure for an underwater branch cable, used to transfer a main cable (12) into several branch cables (13), comprising a vulcanized outer shell (1), characterized in that: The vulcanized outer shell (1) is provided with an electrical conversion component (2) and a vulcanized sealing layer inside; The electrical conversion assembly (2) includes an adapter PCB board (21), which has a main fixing hole (22) for matching the main cable (12) and a number of through fixing holes (24) for matching single branch cables (13). The main cable (12) and branch cable (13) are respectively inserted into the main fixing hole (22) and the straight-through fixing hole (24). The insulation sheath of the cable engages with the inner wall of the corresponding main fixing hole (22) and the straight-through fixing hole (24) to achieve bidirectional cable limiting. The upper surface of the adapter PCB (21) is provided with a main pad (23) and a branch pad (25). The core conductors of the main cable (12) and the branch cable (13) pass through the adapter PCB (21) and are respectively soldered to the corresponding pad positions. Through the conductive lines connecting the main pad (23) and each branch pad (25) inside the adapter PCB (21), the signal between the main cable (12) and the multiple branch cables (13) is split and transferred. The vulcanized sealing layer covers the base of the adapter PCB (21), the root of the main cable (12) and the root of the branch cable (13), and fills the gap between each fixing hole and the outer wall of the cable to form a sealed waterproof structure.

2. The PCB board transition vulcanization sealing structure for an underwater branch cable according to claim 1, characterized in that: The main cable (12) extends into the cavity from the front end of the vulcanized shell (1), and several branch cables (13) extend into the cavity from the rear end of the vulcanized shell (1). The main cable (12) and branch cables (13) are arranged below the adapter PCB board (21) and pass through the corresponding main fixing hole (22) and straight-through fixing hole (24) from bottom to top.

3. The PCB board transition vulcanization sealing structure for an underwater branch cable according to claim 2, characterized in that: The vulcanized sealing layer is formed using a high-pressure integrated vulcanization process, and the vulcanized sealing layer is made of rubber material that is resistant to seawater corrosion and deep-sea high pressure.

4. The PCB board transition vulcanization sealing structure for an underwater branch cable according to claim 3, characterized in that: The surface of the adapter PCB (21) is uniformly provided with several heat dissipation holes (26). The vulcanized sealing layer covers the surface of the adapter PCB (21) and the outer wall of the heat dissipation hole (26). The inside of the heat dissipation hole (26) is a through hollow channel and is not filled with vulcanized glue.

5. The PCB board transition vulcanization sealing structure for an underwater branch cable according to claim 4, characterized in that: The outer wall of the vulcanized shell (1) is symmetrically fitted with perforated lugs (11), which are used for external mounting and fixing of the entire adapter.

6. The PCB board transition vulcanization sealing structure for an underwater branch cable according to claim 1, characterized in that: The adapter PCB (21) has protruding fixing holes (27) at the positions corresponding to each branch cable (13). The protruding fixing holes (27) penetrate the body of the adapter PCB (21), and several branch cables (13) pass through the protruding fixing holes (27).

7. The PCB board transition vulcanization sealing structure for an underwater branch cable according to claim 6, characterized in that: The inner side of the protruding fixing hole (27) is fixedly equipped with several limiting protrusions along the circumferential direction. The limiting protrusions extend alternately in the vertical direction. Some of the limiting protrusions extend to the upper side of the adapter PCB board (21) with a short length, and the other part of the limiting protrusions extend to the lower side of the adapter PCB board (21) with a short length.

8. The PCB board transition vulcanization sealing structure for an underwater branch cable according to claim 7, characterized in that: An interval circuit is formed between adjacent limiting protrusions, and the vulcanized sealing layer can completely fill the gap between the protruding fixing hole (27) and the outer wall of the branch cable (13) along the interval circuit when it is formed.

9. The PCB board transition vulcanization sealing structure for an underwater branch cable according to claim 1, characterized in that: The adapter PCB (21) has stepped fixing holes (28) at the positions corresponding to each branch cable (13). The stepped fixing holes (28) penetrate the body of the adapter PCB (21), and several branch cables (13) pass through the stepped fixing holes (28).

10. The PCB board transition vulcanization sealing structure for an underwater branch cable according to claim 9, characterized in that: The stepped fixing hole (28) forms a stepped annular platform in the vertical direction, and the size of the stepped annular platform gradually increases from bottom to top. When the vulcanized sealing layer is formed, it fills the gap between the stepped fixing hole (28) and the mating gap between the branch cable (13) and the outer wall.

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