Labor-saving retraction recovery device for submarine cable flexible joint lead sheath

Abstract

The utility model discloses a submarine cable flexible joint lead sheath labor-saving retraction recovery device. The supporting rack is provided with a cable supporting groove and a pair of first pull rings. The retracting mold is provided with a retracting outer mold, a pulling-retracting inner mold, an upper clamping block and a quick clamp; the retracting outer mold is a pair of semicircular molds and is provided with a pivoting edge and a mold closing edge, and the pivoting edge is provided with a hinge; the pulling-shrinkage inner die is a pair of semicircular dies and is designed in a step shape, and an outer step is propped against the retracting outer die; the two upper clamping blocks are arranged on the mold closing edge and are provided with mold closing bolts and mold closing nuts; the quick clamp is also mounted on the mold closing edge; the mold closing edge is matched and fixed together with a mold closing nut through a quick clamp and a mold closing bolt; a pair of handles and a pair of second pull rings are further mounted on the retracting outer mold; labor-saving equipment is installed between the first pull ring and the second pull ring. The device is simple in structure, small in size, firm and durable, labor-saving and convenient to install and operate, reliable in work, free of damage to the lead sheath, and suitable for recovery operation of submarine cable flexible joint lead sheaths of various specifications and sizes.

Description

Technical Field

[0001] This utility model relates to the technical field of submarine cables, and in particular to the structure of a lead sleeve recovery device for a flexible joint of a submarine cable. Background Technology

[0002] Submarine cables are cable systems used to transmit power, communication, and data signals over the seabed, and are a crucial infrastructure for modern communication and energy transmission. With rapid economic development, numerous near-island islands and offshore oil and gas platforms and other marine facilities have increasing demands for various resources such as electricity, communication, fresh water, oil, and gas, requiring the deployment of various submarine cables. Due to limitations in insulation extrusion technology, submarine cables cannot be produced in unlimited lengths in factories; there is a maximum production length limit. Therefore, multiple sections of submarine cables need to be connected during production. Currently, a flexible joint (also known as a factory joint) is commonly used for splicing submarine cables in factories. For flexible joints with lead-sheathed structures, the lead sheath needs to be restored.

[0003] The general process for manufacturing a lead-sheathed submarine cable expansion joint is as follows: grinding the insulation layer to create a pencil-like shape, conductor welding restoration, conductor shielding restoration, insulation restoration, insulation and shielding restoration, wrapping with semi-conductive resistive water tape, lead sheath restoration, and sheath restoration. Existing lead sheath restoration methods commonly include two approaches: one involves welding a lead sheath with an external sleeve clamp. This is achieved by partially wrapping the lead sheath and placing it within a support ring formed by an arc-shaped sleeve, then fixing the arc-shaped sleeve with connectors, and finally welding the weld seam at the lead sheath overlap using a welding device. The other method uses a lead sheath pull mold with an external lead sheath clamp. The clamp consists of two semi-rings, which are closed outside the lead sheath pull mold. The mold is then locked with the clamp, and the mold is manually pushed forward to restore the lead sheath.

[0004] One method involves welding the lead sheath with an outer sleeve clamp. Because the welding is done longitudinally along the axial direction, it results in a long weld seam, affecting the aesthetics. Furthermore, stress concentrates at the weld seam, increasing the likelihood of damage, cracking, and deformation during cable transportation and construction. This poses a potential hazard, potentially affecting the normal construction, delivery, and operation of the cable, and increasing the risk of emergency repairs. Another method, using a lead sheath pull mold with an outer lead sheath clamp, requires significant manpower and time for locking the clamp and manual advancement, making it cumbersome and inconvenient. Utility Model Content

[0005] The purpose of this utility model is to provide a submarine cable flexible joint lead sleeve labor-saving retraction and restoration device that is simple in structure, convenient in installation and operation procedures, and reliable in operation, for the lead sleeve during the manufacturing process of submarine cable flexible joints.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows:

[0007] A force-saving retraction and recovery device for lead sleeves of submarine cable flexible joints includes a support frame and a retraction mold. The support frame has a cable support groove and a pair of left and right first pull rings. The retraction mold has a retraction outer mold, a retraction inner mold, upper clamping blocks, and a quick clamp. The retraction outer mold is a pair of semi-circular molds, each with a pivot edge and a closing edge, the pivot edges being pivotally connected together by a hinge. The retraction inner mold is also a pair of semi-circular molds, with a stepped design, and the outer step rests on the retraction outer mold. There are two upper clamping blocks, each installed on the closing edge of the retraction outer mold, and each upper clamping block is equipped with a closing bolt and a closing nut. The quick clamp is also installed on the closing edge of the retraction outer mold. The closing edge of the retraction outer mold is fixed together by the quick clamp, the closing bolt, and the closing nut. A pair of handles are also installed on the retraction outer mold, with a pair of left and right second pull rings installed on the handles. A force-saving device is installed between the first pull rings and the second pull rings.

[0008] The support frame has height-adjustable support feet.

[0009] The cable support groove is arc-shaped.

[0010] The outer step of the inner die protrudes from the edge of the outer die facing the cable support groove.

[0011] The tensioning inner mold consists of a group of several molds, and the diameter interval of the group of tensioning inner molds is 2mm.

[0012] The inner mold for stretching is made of nylon.

[0013] The labor-saving device is a lever hoist or an electric hoist.

[0014] By adopting the above solution, this utility model solves the problems of existing lead sheath restoration methods involving welding lead sleeves after adding sleeve clamps, which have a certain probability of damage, cracking, and deformation during submarine cable transportation and construction, potentially affecting normal construction, delivery, and operation of submarine cables and increasing the risk of emergency repairs. It also addresses the issues of another method, using lead sleeve pulling molds and adding lead sleeve clamps, which requires significant manpower and time for locking the clamps and manual advancement, making the operation cumbersome and inconvenient. This utility model features a simple structure, small size, robust durability, labor-saving and convenient installation procedures, reliable operation, and no damage to the lead sleeve. It is suitable for restoration operations of lead sleeves for submarine cable flexible joints of various specifications and sizes, and has the following characteristics:

[0015] 1. By adding a self-designed hinge-type rotary joint, the accuracy of the mold closing is enhanced.

[0016] Second, taking advantage of the relatively soft nature of the lead sleeve material, the mold closing operation adopts a combination of mold closing bolts and mold closing nuts, plus a quick clamp, to achieve labor-saving and fast mold closing operation.

[0017] 3. The inner die for shrinking can be made of nylon, which will not damage the lead sleeve during the mold closing and shrinking process. The inner die for shrinking can be quickly replaced. Replace the next level inner die for every 2mm shrinkage of the lead sleeve outer diameter to continue the shrinking operation until the outer diameter of the lead sleeve shrinks to meet the process size requirements of the flexible joint.

[0018] Fourth, the design incorporates symmetrical handles and pull rings on both sides, allowing for manual retraction of the mold or the installation of labor-saving devices such as lever hoists or electric hoists. When using such devices, one end of the hook is attached to the pull ring on the mold handle, and the other end is attached to the pull ring on the support frame that supports the overall weight of the submarine cable core. Because the submarine cable core is very heavy, the force is self-enclosed during retraction using the labor-saving device, resulting in a stable operation. The frame will not shake under stress, and the retraction operation can be carried out stably. Furthermore, the use of labor-saving devices saves a significant amount of effort, achieving the function of labor-saving retraction.

[0019] 5. The outer diameter of the initial lead sheath to be retracted is 6-8mm larger than the outer diameter of the cable core sheath. Therefore, it can be easily fitted into the section to be retracted and restored. The initial lead sheath is a complete cylindrical lead sheath. One end is first radially overlapped and welded to the lead sheath of the cable core body, and then the retraction and restoration operation is performed using a mold. After the retraction and restoration is completed, the other end is also radially overlapped and welded to the lead sheath of the cable core body. Since the restored lead sheath is a complete cylinder, there is no long axial weld seam, and the radial overlap welding effect is better, with much less impact compared to a long axial weld seam. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the appearance of this utility model;

[0021] Figure 2 It is a cross-section of a flexible joint with a recovery lead sleeve. Figure 1 ;

[0022] Figure 3 This is a structural diagram of the supporting frame;

[0023] Figure 4 This is a schematic diagram of the indentation mold structure. Figure 1 ;

[0024] Figure 5 This is a schematic diagram of the indentation mold structure. Figure 2 ;

[0025] Figure 6 It is a cross-section of a flexible joint with a recovery lead sleeve. Figure 2 ;

[0026] Figure 7 This is a diagram illustrating the indentation recovery operation;

[0027] Figure 8 It is the appearance of the wire core after the lead sheath has been restored.

[0028] Label Explanation

[0029] Submarine cable 1, conductor welded section 101, conductor shield restoration 102, insulation restoration 103, insulation shield restoration 104, insulation cross-linking interface 105, core body insulation 106, semiconducting resistance water tape 107, lead sleeve to be retracted and restored 108, core body lead sleeve 109, core sheath 110, restored lead sleeve 111, welded joint 112;

[0030] Support frame 2, support foot 201, welding frame 202, first pull ring 203, cable support groove 204;

[0031] Labor-saving equipment 3;

[0032] Retracting mold 4, retracting inner mold 401, retracting outer mold 402 and 403, upper clamping block 404, handle 405, second pull ring 406, outer mold shaft pin 407, shaft pin set screw 408, mold closing bolt 409, mold closing nut 410, quick clamp 411, outer step 412. Detailed Implementation

[0033] See Figures 1 to 8 As shown, this utility model discloses a labor-saving retraction and restoration device for lead sleeves of submarine cable flexible joints, including a support frame 2, a labor-saving device 3, and a retraction mold 4, which is suitable for the retraction and restoration operation of submarine cable 1 and lead sleeve 108 to be retracted and restored.

[0034] The support frame 2 has an arc-shaped cable support groove 204 and a pair of first pull rings 203 on the left and right. The arc-shaped cable support groove 204 serves to support the cable and is compatible with cable cores of various specifications and sizes. The first pull rings 203 are used to connect labor-saving equipment 3 such as hand lever hoists or electric hoists. The main body of the support frame 2 is a painted carbon steel square tube welded frame 202, and the bottom is an adjustable height support foot 201.

[0035] The retraction mold 4 includes a retraction inner mold 401, retraction outer molds 402 and 403, an upper clamping block 404, and a quick clamping fixture 411. The retraction outer molds 402 and 403 are a pair of semi-circular molds, each with a pivoting edge and a closing edge. The pivoting edges are connected together by a hinge, specifically by an outer mold shaft pin 407. This hinge-type rotary mold closing method effectively improves the accuracy of mold closing. Two shaft pin ejector screws 408 tighten the outer mold shaft pin 407, making it less likely to fall off. The inner drawing die 401 is also a pair of semi-circular dies made of nylon. The inner drawing die 401 has a stepped design, with the outer step 412 resting against the outer drawing dies 402 and 403. Specifically, the outer step 412 of the inner drawing die 401 protrudes beyond the edge of the outer drawing dies 402 and 403 facing the cable support groove 204. The inner drawing die 401 retracts along with the outer drawing dies 402 and 403, forcing the lead sleeve to contract. The outer step 412 protects the lead sleeve and prevents damage during contraction. There are two upper clamping blocks 404, respectively installed on the closing edges of the outer drawing dies 402 and 403. Each upper clamping block 404 is equipped with a closing bolt 409 and a closing nut 410. A quick clamp 411 is also installed on the closing edges of the outer drawing dies 402 and 403. The closing edges of the retractable outer molds 402 and 403 are fixed together by quick clamps 411, closing bolts 409, and closing nuts 410. A pair of handles 405 are also installed on the retractable outer molds 402 and 403, with a pair of second pull rings 406 mounted on each handle 405. A lever hoist or electric hoist, or other labor-saving device 3, is installed between the first pull ring 203 and the second pull ring 406. The retractable outer molds 402 and 403 are connected to the upper clamping block 404 and handles 405 by screw tightening followed by welding, thus strengthening the overall mold strength.

[0036] Furthermore, the shrinkable inner mold 401 is a set consisting of several pieces. The shrinkable inner mold 401 can be made into a series of different sizes to suit various specifications of cables, and each series of shrinkable inner molds 401 can be made with a diameter interval of 2mm. For example, the nominal outer diameter of a cable core sheath 110 is 120mm, and the nominal outer diameter of the core body lead sleeve 109 is 114mm. During the production of the flexible joint, the material to be restored will be about 4mm larger than the outer diameter of the core body material. Therefore, the outer diameter of the restored lead sleeve 111 is about 118mm. Then, the outer diameter of the lead sleeve 108 to be shrunken and restored when making the flexible joint is 128mm (it must be larger than the core to fit). To shrink and restore it to the nominal outer diameter of 118mm, a pair of shrinkable inner molds 401 must be made every 2mm (diameter), that is, 5 specifications of shrinkable inner molds 401: 126 / 124 / 122 / 120 / 118.

[0037] The labor-saving device 3 is a lever hoist or an electric hoist. The hooks at both ends of the labor-saving device 3 are connected and installed on the first pull ring 203 and the second pull ring 406. This method can both meet the needs of labor-saving device 3 for labor-saving retraction operation and also accommodate manual operation of pushing and retracting by holding the handle 405 with both hands.

[0038] The operation steps of the recovery method of this utility model are as follows:

[0039] First, the lead sleeve 108 to be retracted and restored is placed on the core structure to be restored. The innermost part of the core structure to be restored is the conductor welding section 101, followed by conductor shield restoration 102, insulation restoration 103, insulation shield restoration 104, wrapping of semiconducting resistance water tape 107, and finally the lead sleeve 108 to be retracted and restored. Before performing each restoration operation, the core sheath 110 and the core body lead sleeve 109 are stripped, the core body insulation 106 is polished, a pencil tip is made, an insulation stress cone is made using an insulation restoration mold, and an insulation cross-linking interface 105 is formed after cross-linking.

[0040] Before performing the shrinkage restoration operation, first stagger the lead sleeve 109 of the wire core body at one end and tap it tightly and flatten it before fully welding it (welding point 112). This way, the lead sleeve will not slip off during the shrinkage restoration operation.

[0041] Then, the aforementioned submarine cable flexible joint lead sleeve retraction and restoration device is used to perform lead sleeve retraction and restoration operations.

[0042] After the lead sleeve 109 of the wire core body at one end is staggered and tapped and welded to the lead sleeve 108 to be retracted and restored, a pair of inner retraction molds 401 are first put on, and then the outer retraction molds 402 and 403 are put on. The mold closing bolt 409 is passed through the upper clamping block 404 and connected to the mold closing nut 410. The mold closing bolt 409 and the mold closing nut 410 are tightened with a large wrench to realize the mold closing operation. After the mold is closed, the retraction mold is quickly fixed by the quick clamp 411.

[0043] When operating the labor-saving device 3 for the retraction operation, ensure that both sides retract simultaneously and maintain balance. Replace the next level of inner retraction mold 401 every 2mm of diameter retraction until the lead sleeve retracts to the outer diameter that meets the manufacturing process of the flexible joint. Remove the retraction molds (outer retraction molds 402 and 403, inner retraction mold 401). Then, perform the same retraction and restoration operation on the lead sleeve 109 of the wire core body and the lead sleeve 108 to be retracted and restored at the other end. The lead sleeve 109 of the wire core body and the lead sleeve 108 to be retracted and restored at the other end should also be staggered, tapped tightly, and welded securely to complete the lead sleeve retraction and restoration operation.

[0044] like Figure 8The image shows the conductor after the lead sheath has been restored. It is normal for the outer diameter of the restored lead sheath 111 to be 4-5mm larger than the outer diameter of the conductor's lead sheath 109. After the lead sheath is restored, the conductor's protective sheath 110 can be further restored, thus completing the fabrication of the submarine cable flexible joint.

[0045] The embodiments described above are only for illustrating the technical ideas and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly, but they do not limit the patent scope of this utility model. All equivalent changes or modifications made in accordance with the spirit disclosed in this utility model should still be covered within the patent scope of this utility model.

Claims

1. A force-saving retraction and recovery device for lead sleeves of submarine cable flexible joints, characterized in that: The device includes a support frame and a retraction mold. The support frame has a cable support groove and a pair of first pull rings on the left and right. The retraction mold has a retraction outer mold, a retraction inner mold, upper clamping blocks, and a quick clamp. The retraction outer mold is a pair of semi-circular molds, each with a pivot edge and a closing edge, the pivot edges being pivotally connected together by a hinge. The retraction inner mold is also a pair of semi-circular molds, with a stepped design and the outer step resting on the retraction outer mold. There are two upper clamping blocks, each installed on the closing edge of the retraction outer mold, and each upper clamping block is equipped with a closing bolt and a closing nut. The quick clamp is also installed on the closing edge of the retraction outer mold. The closing edge of the retraction outer mold is fixed together by the quick clamp, the closing bolt, and the closing nut. A pair of handles are also installed on the retraction outer mold, with a pair of second pull rings on the left and right. A labor-saving device is installed between the first and second pull rings.

2. A device for force-reducing retraction of a lead sheath of a subsea cable soft joint according to claim 1, characterized in that: The support frame has height-adjustable support feet.

3. A device for force-reducing retraction of a lead sheath of a subsea cable joint according to claim 1, characterized in that: The cable support groove is arc-shaped.

4. A device for force-reducing retraction of a lead sheath of a subsea cable joint according to claim 1, characterized in that: The outer step of the inner die protrudes from the edge of the outer die facing the cable support groove.

5. A device for force-reducing retraction of a lead sheath of a subsea cable joint according to claim 1, characterized in that: The tensioning inner mold consists of a group of several molds, and the diameter interval of the group of tensioning inner molds is 2mm.

6. The submarine cable flexible joint lead sleeve labor-saving retraction and recovery device according to claim 1, characterized in that: The inner mold for stretching is made of nylon.

7. A device for force-reducing retraction of a lead sheath of a subsea cable joint according to claim 1, characterized in that: The labor-saving device is a lever hoist or an electric hoist.

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