Dual self-locking anti-release ocean pipe cable bending limiter

Abstract

The application discloses a double self-locking anti-off ocean pipe cable bending limiter, and relates to the technical field of ocean pipe cable protection equipment. The limiter comprises a plurality of limiting units, each of which is composed of two limiting units. The limiting unit comprises a first connecting section and a second connecting section. The first connecting section is provided with a plurality of connecting heads, and the second connecting section is provided with a plurality of grooves. The connecting heads are matched with the grooves. The first connecting section can be arranged in the second connecting section and can move and rotate relative to the second connecting section. Each limiting unit is divided into a first limiting unit and a second limiting unit. The first limiting unit and the second limiting unit are connected through a mortise and tenon structure and a bolt. In the application, the double limiting protection structure is formed through the cooperation of the first connecting head and the first groove and the cooperation of the second connecting head and the second groove. The double limiting protection structure can simultaneously bear the torque generated by the bending of the ocean pipe cable, effectively relieve the local stress concentration problem, enhance the connecting strength, and effectively improve the stability of long-term service.

Description

Technical Field

[0001] This invention relates to the field of marine cable protection equipment, and in particular to a double self-locking anti-detachment marine cable bending limiter. Background Technology

[0002] Bending limiters, as bending protection devices for flexible pipes and cables, are mainly used to prevent excessive bending and breakage, offering advantages such as small space occupation and simple structure. Current bending limiters generally adopt a half-type structure, where male and female connectors are connected end-to-end to form a locking mechanism when the marine pipeline is subjected to significant bending stress, thereby dispersing the stress to the surrounding structure and protecting the pipeline. However, under the combined effects of waves, ocean currents, and scouring on the seabed, the protective effect of bending limiters gradually weakens, making it difficult to effectively protect marine pipelines in the long term, leading to a high failure rate and significant economic losses.

[0003] Chinese patent document CN110762340A discloses an embedded steel cylinder type marine flexible cable bend limiter, comprising n sections of bend limiter body, each section consisting of two identical units connected together. Each unit is a variable-diameter semi-cylindrical structure, including a male head, a neck section, a female head, and an embedded steel cylinder with an angled bend. The embedded steel cylinder adopts a semi-cylindrical structure in the middle neck section. This patent document adds a steel cylinder to the neck of an existing bend limiter to enhance local stiffness and reduce stress concentration at the transition of the bend limiter cross section, thereby improving overall fatigue resistance. However, the manufacturing process of adding a steel cylinder to the neck is relatively complex, and the long-term stability of the steel cylinder on the seabed cannot be guaranteed after long-term use. In addition, a large number of bolts are installed when connecting the two units to avoid the bolts loosening and separating under the influence of seawater erosion and wave currents. Therefore, the installation and disassembly operations in the marine environment are cumbersome, greatly reducing construction efficiency. Summary of the Invention

[0004] In view of the fact that the existing bending limiters have added components to improve durability, which have complex structures, complicated manufacturing processes, cannot guarantee long-term stability on the seabed, and are cumbersome to install and disassemble, and fail to alleviate the problem of local stress concentration in the structure, the present invention provides a double self-locking anti-derailment marine cable bending limiter.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A double self-locking anti-derailment marine cable bending limiter includes several bending limit units, each bending limit unit is arranged and connected along the axial direction, and has a channel for accommodating marine cables. Each bending limit unit is composed of two bending limit units, each bending limit unit is semi-cylindrical, including a first connecting section and a second connecting section. The outer wall of the first connecting section has several outwardly protruding connectors arranged along the axial direction, and the inner wall of the second connecting section has several recessed grooves arranged along the axial direction. The connectors are adapted to the grooves. Between adjacent bending limit units, the first connecting section located on the rear side is disposed in the second connecting section located on the front side, and can move and rotate relative to the second connecting section. The bending limit unit is divided into a first bending limit unit and a second bending limit unit. The first bending limit unit and the second bending limit unit are fitted together by a tenon and mortise structure and fixedly connected by bolts.

[0006] Furthermore, the outer wall of the first connecting segment is stepped, including a first-level step and a second-level step. The first-level step is located outside the second-level step, and along the radial direction of the first connecting segment, the first-level step is lower than the second-level step.

[0007] Furthermore, the connector includes a first connector and a second connector, the first connector being located outside the first-level step, the second connector being located outside the second-level step, and the second connector being higher than the first connector.

[0008] Furthermore, the inner wall of the second connecting section is stepped, including three steps and four steps. The three steps are located inside the four steps, and along the radial direction of the second connecting section, the three steps are lower than the four steps.

[0009] Furthermore, the groove includes a first groove and a second groove, the first groove being disposed on the three-step staircase, the second groove being disposed on the four-step staircase, the first connector being disposed in the first groove, and the second connector being disposed in the second groove.

[0010] Furthermore, there is a gap between the first connector and the first groove, and there is also a gap between the second connector and the second groove.

[0011] Furthermore, the first bending limiting unit and the second bending limiting unit have several corresponding fixing holes, and the bolts are adapted to be inserted into the fixing holes and connected with washers and anti-loosening nuts.

[0012] Furthermore, both sides of the contact surface of the first bending limiting unit have tenon structures, and both sides of the contact surface of the second bending limiting unit have mortise structures, with the tenon structures disposed within the mortise structures.

[0013] Furthermore, the tenon structure is formed by a connecting block protruding from the contact surface of the first bending limiting unit, and the mortise structure is formed by a recess in the side wall of the second bending limiting unit.

[0014] Furthermore, all of the aforementioned bending limiting units are made of polyurethane material.

[0015] The beneficial effects of this invention are as follows: This invention forms a double-bend-limiting protective structure by cooperating with the first connector and the first groove, and with the second connector and the second groove. This allows both connectors to simultaneously bear the torque generated by the bending of the marine cable, improving load-bearing capacity and effectively alleviating local stress concentration, thus increasing the strength of the connection between adjacent bend-limiting units. This invention uses a combination of mortise and tenon joints and bolts for fastening, preventing separation between the first and second bend-limiting units. The tenon structure of the first bend-limiting unit is fitted into the mortise structure of the second bend-limiting unit, improving the stability and ease of connection. Furthermore, bolts, washers, and anti-loosening nuts further enhance the stability of the connection between the first and second bend-limiting units. This fastening method not only significantly reduces the number of bolts used and lowers installation difficulty, but also improves the stability of this invention during long-term service on the seabed. Attached Figure Description

[0016] Figure 1 The diagram shown is a schematic representation of the structural principle of one embodiment of the present invention.

[0017] Figure 2 As shown Figure 1 A sectional view.

[0018] Figure 3 As shown Figure 2 A side view.

[0019] Figure 4 As shown Figure 1 A schematic diagram of the structure of the second limiting bending unit.

[0020] Explanation of reference numerals in the attached drawings: 1. First bending limiting unit; 2. Second bending limiting unit; 3. Tenon structure; 4. Mortise structure; 5. First connecting section; 6. Second connecting section; 7. First connector; 8. Second connector; 9. First groove; 10. Second groove; 11. Fixing hole; 12. Bolt. Detailed Implementation

[0021] This invention discloses a dual self-locking anti-detachment marine cable bending limiter. The following describes one embodiment of the invention in detail with reference to the accompanying drawings.

[0022] like Figure 1 As shown, the bending limiter includes several bending limit units, which are arranged and connected sequentially along the axial direction. Each bending limit unit has a channel along the coaxial direction to accommodate the marine cable, and the diameter of the channel is larger than the diameter of the marine cable to ensure that the marine cable can smoothly pass through the channel and has a certain degree of mobility. Each bending limit unit is made of polyurethane material, which has good elasticity and corrosion resistance, can adapt to complex seabed environments, and improves durability. Each bending limit unit is composed of a first bending limit unit 1 and a second bending limit unit 2. The first bending limit unit 1 and the second bending limit unit 2 are approximately semi-cylindrical, and are assembled to form a cylindrical bending limit unit. The first bending limit unit 1 and the second bending limit unit 2 each include a first connecting section 5 and a second connecting section 6. The outer wall of the first connecting section 5 is stepped, including a first step and a second step. The first step is located outside the second step, and along the radial direction of the first connecting section 5, the height of the first step is lower than the height of the second step. Several connectors are arranged axially on the outer wall of the first connecting section 5. The connectors include a first connector 7 and a second connector 8. The first connector 7 is located on the outer edge of the first step, and the second connector 8 is located between the first and second steps, specifically on the outer edge of the second step. In the radial direction of the first connecting section 5, the height of the first connector 7 is lower than the height of the second connector 8.

[0023] Combination Figure 2 and Figure 3 As shown, the inner wall of the second connecting section 6 is stepped, including a three-step and a four-step structure. The three-step structure is located inside the four-step structure, and along the radial direction of the second connecting section 6, the three-step structure is lower than the four-step structure. The inner wall of the second connecting section 6 has several grooves arranged axially, including a first groove 9 and a second groove 10. The first groove 9 is located on the third step, and the second groove 10 is located on the fourth step. Along the radial direction of the second connecting section 6, the top of the first groove 9 is lower than the top of the second groove 10. The first groove 9 is adapted to the first connecting head 7, and there is a gap between the first connecting head 7 and the first groove 9. After the first connecting head 7 is positioned within the first groove 9, it can move and rotate relative to the first groove 9. The second groove 10 is adapted to the second connecting head 8, and there is a gap between the second connecting head 8 and the second groove 10. After the second connecting head 8 is positioned within the second groove 10, it can move and rotate relative to the second groove 10.

[0024] The first bending limiting unit 1 is connected to the second bending limiting unit 2 via a mortise and tenon structure and bolts 12, with the contact surfaces of the first bending limiting unit 1 and the second bending limiting unit 2 in contact. Both sides of the contact surface of the first bending limiting unit 1 have tenon structures 3, formed by connecting blocks protruding from the contact surface of the first bending limiting unit 1. In this embodiment, the connecting blocks are cuboid in shape. Both sides of the contact surface of the second bending limiting unit 2 have mortise structures 4, formed by recessed notches on the sidewalls of the second bending limiting unit 2. The tenon structures 3 are disposed within the mortise structures 4 and are engaged and fixed with them. The first bending limiting unit 1 has several fixing holes 11, and the second bending limiting unit 2 also has several fixing holes 11. The fixing holes 11 of the first bending limiting unit 1 correspond to the fixing holes 11 of the second bending limiting unit 2. The first bending limiting unit 1 and the second bending limiting unit 2 are connected by bolts 12 that are fitted into the fixing holes 11, and the ends of the bolts 12 are tightened using washers and lock nuts.

[0025] When installing the front bend limiting unit and the rear bend limiting unit on the marine cable, the front bend limiting unit includes a first bend limiting unit 1 and a second bend limiting unit 2. For ease of description, the rear bend limiting unit includes a third bend limiting unit and a fourth bend limiting unit. The structure of the first bend limiting unit 1 is the same as that of the third bend limiting unit, and the structure of the second bend limiting unit 2 is the same as that of the fourth bend limiting unit. First, the channel on the first bend limiting unit 1 in the front bend limiting unit is configured on the marine cable. Then, the second bend limiting unit 2 in the front bend limiting unit is fitted and fixed to the first bend limiting unit 1 through a tenon and mortise structure, so that the tenon structure 3 on the first bend limiting unit 1 can be adapted to be inserted into the mortise structure 4 of the second bend limiting unit 2. Finally, the first bend limiting unit 1 and the second bend limiting unit 2 are detachably and fixedly connected by bolts 12, washers, and lock nuts. After the front bend limiting unit is installed, the channel on the third bend limiting unit in the rear bend limiting unit is configured on the marine cable. Simultaneously, the second connecting section 6 on the third bend limiting unit can be fitted onto the first connecting section 5 of the first bend limiting unit 1 or the second bend limiting unit 2, ensuring that the first connector 7 is positioned within the first groove 9 and the second connector 8 is positioned within the second groove 10. Then, the fourth bend limiting unit is fitted and fixed to the third bend limiting unit using a tenon and mortise structure, allowing the tenon structure 3 on the third bend limiting unit to be inserted into the mortise structure 4 of the fourth bend limiting unit. Finally, using bolts 12, washers, and lock nuts, the third and fourth bend limiting units are detachably and securely connected.

[0026] The first connector 7 mates with the first groove 9, and the second connector 8 mates with the second groove 10 to form a double-bend-limiting protection structure. This double-bend-limiting protection structure utilizes the first connector 7 and the second connector 8 to simultaneously bear the torque generated by the bending of the marine cable, improving the load-bearing capacity and alleviating the problem of local stress concentration, thus improving the strength of the connection between the front and rear bend-limiting units. The first bend-limiting unit 1 and the second bend-limiting unit 2 are fastened together by a combination of bolts 12 and tenon joints to prevent separation between them. The tenon joint 3 of the first bend-limiting unit 1 fits into the mortise joint 4 of the second bend-limiting unit 2 to improve the stability of the connection. Furthermore, the first bend-limiting unit 1 and the second bend-limiting unit 2 are further strengthened by bolts 12, washers, and lock nuts. This fastening method not only significantly reduces the number of bolts 12 used and simplifies installation, but also improves stability during long-term service on the seabed.

[0027] Compared with commonly used submarine cable bending limiters on the market, this invention has the following advantages: It has the lowest maximum stress value; the cooperation of the first connector 7 and the second connector 8 enables the invention to have a higher safety margin and resistance to damage under stress; the stress distribution is more uniform; under stress, the invention can disperse stress concentration points, reducing the high stress value borne by a single male / female connector area, improving bending resistance, and avoiding structural fatigue or local damage caused by stress concentration; and it reduces the risk of local failure. Through the dual male / female connector structural design, this invention can effectively improve the overall rigidity and bending resistance of the structure, maintaining structural stability even when the ultimate bending radius is reached. Furthermore, in extreme cases where the first connector 7 fails, the second connector 8 can still limit the bending of the submarine cable, while preventing the overall structure from detaching.

[0028] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A dual self-locking anti-detachment marine cable bending limiter, characterized in that: It includes several bending limiting units, each of which is arranged and connected along the axial direction and has a channel for accommodating marine cables. Each bending limiting unit is composed of two bending limiting units. Each bending limiting unit is semi-cylindrical and includes a first connecting section (5) and a second connecting section (6). The outer wall of the first connecting section (5) has several outwardly protruding connectors arranged along the axial direction, and the inner wall of the second connecting section (6) has several recessed grooves arranged along the axial direction. The connectors are adapted to the grooves. Between adjacent bending limiting units, the first connecting section (5) located on the rear side is disposed in the second connecting section (6) located on the front side and can move and rotate relative to the second connecting section (6). The bending limiting unit is divided into a first bending limiting unit (1) and a second bending limiting unit (2). The first bending limiting unit (1) and the second bending limiting unit (2) are fitted together by a tenon and mortise structure and fixedly connected by bolts (12). The outer wall of the first connecting segment (5) is stepped, including a first step and a second step. The first step is located outside the second step, and along the radial direction of the first connecting segment (5), the first step is lower than the second step. The connector includes a first connector (7) and a second connector (8). The first connector (7) is located on the outside of the first step, and the second connector (8) is located on the outside of the second step. The second connector (8) is higher than the first connector (7). The first bending limiting unit (1) has tenon structure (3) on both sides of the contact surface, and the second bending limiting unit (2) has mortise structure (4) on both sides of the contact surface, and the tenon structure (3) is arranged in the mortise structure (4).

2. The double self-locking anti-detachment marine cable bending limiter according to claim 1, characterized in that: The inner wall of the second connecting section (6) is stepped, including three steps and four steps. The three steps are located inside the four steps, and along the radial direction of the second connecting section (6), the three steps are lower than the four steps.

3. The double self-locking anti-detachment marine cable bending limiter according to claim 2, characterized in that: The groove includes a first groove (9) and a second groove (10). The first groove (9) is disposed on the three-step staircase, and the second groove (10) is disposed on the four-step staircase. The first connector (7) is disposed in the first groove (9), and the second connector (8) is disposed in the second groove (10).

4. The double self-locking anti-detachment marine cable bending limiter according to claim 3, characterized in that: There is a gap between the first connector (7) and the first groove (9), and there is also a gap between the second connector (8) and the second groove (10).

5. The double self-locking anti-detachment marine cable bending limiter according to claim 1, characterized in that: The first bending limiting unit (1) and the second bending limiting unit (2) have several corresponding fixing holes (11), and the bolt (12) is adapted to be inserted into the fixing hole (11) and connected with a washer and a lock nut.

6. The double self-locking anti-detachment marine cable bending limiter according to claim 1, characterized in that: The tenon structure (3) is formed by a connecting block protruding from the contact surface of the first limiting bending unit (1), and the mortise structure (4) is formed by a recess in the side wall of the second limiting bending unit (2).

7. A double self-locking anti-detachment marine cable bending limiter according to claim 1, characterized in that: All of the aforementioned bending limiting units are made of polyurethane material.

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