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

Abstract

The invention discloses a labor-saving retraction recovery method for a submarine cable flexible joint lead sheath. A special matching device is adopted to carry out lead sheath retraction recovery operation. The special matching device comprises a supporting rack and a retracting die. 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; the pulling-shrinkage inner dies are a pair of semicircular dies, and outer steps of the pulling-shrinkage inner dies abut against the retracting outer dies; the two upper clamping blocks are arranged on the mold closing edge and are provided with mold closing bolts and nuts; the quick clamp is mounted on the mold closing edge; the mold closing edge is matched and fixed with a 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 labor-saving and convenient in installation operation procedure, 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] The present invention relates to the technical field of submarine cables, in particular to a labor-saving retraction and recovery method for a lead sleeve of a submarine cable soft joint. Background Art

[0002] A submarine cable is a cable system used to transmit power, communications, and data signals on the seabed. It is an important infrastructure for modern communications and energy transmission. With the rapid development of economic construction, numerous offshore islands and offshore oil and gas platforms and other marine facilities have a demand for multiple resources such as electricity, communications, fresh water, oil, and gas, which requires the deployment of various submarine cables. Due to the limitations of insulation extrusion technology, submarine cables cannot be produced in unlimited lengths during factory production. There is a maximum production length limit, so multiple sections of submarine cables need to be connected during the production process. Currently, a flexible joint (also known as a factory joint) is often used to connect submarine cables in factories. For submarine cable flexible joints with a lead sheath structure, the lead sheath needs to be restored.

[0003] The production process of a flexible joint for a lead-sheathed submarine cable is generally as follows: grinding the insulation layer to make a pencil tip, welding and restoring the conductor, restoring the conductor shield, restoring the insulation, restoring the insulation shield, wrapping the semi-conductor water hose around it, restoring the lead sheath, and restoring the sheath. There are two common methods for restoring the lead sheath: one is to add a sleeve clamp to the lead sheath and then weld it. This is done by partially wrapping the lead sheath and placing it in a support ring formed by an arc-shaped sleeve. The arc-shaped sleeve is then fixed with a connector, and the weld seam at the overlap of the lead sheath is welded along the opening using a welding device to restore the lead sheath. The other method is to add a lead sheath clamp to the lead sheath die. The lead sheath clamp consists of two half-rings, which are closed and placed outside the lead sheath die. The lead sheath die is locked with the lead sheath clamp, and the die is manually pushed in to restore the lead sheath.

[0004] Among them, the method of adding a sleeve clamp to the lead sheath and then welding it, due to the longitudinal welding process, has a long weld seam, which affects the appearance. Secondly, stress is concentrated on the weld seam, and there is a certain probability of damage, cracking, and deformation during the transportation and construction of the submarine cable. This poses a hidden danger and may affect the normal construction, delivery, and operation of the submarine cable, and increase the risk of emergency repairs. The other method of using a lead sheath drawing die and adding a lead sheath clamp requires a lot of manpower and time to lock the lead sheath clamp and manually push it in. The operation is cumbersome and not convenient. Summary of the Invention

[0005] The purpose of the present invention is to provide a labor-saving retracting and restoring method for a lead sleeve of a submarine cable flexible joint, which has the advantages of convenient operation and reliable operation during the production process of the lead sleeve, convenient installation of supporting devices, and convenient operation.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] A labor-saving method for retracting and restoring a lead sheath of a submarine cable flexible joint comprises: after the lead sheath to be retracted is put on the core structure to be restored, the lead sheath of the core body at one end is staggered and fastened by lap-jointing and welding with the lead sheath to be restored;

[0008] Then a special supporting device is used to perform the lead sleeve indentation recovery operation; the special supporting device includes a supporting frame and an indentation mold; the supporting frame has a cable support groove and a pair of left and right first pull rings; the indentation mold has an indentation outer mold, a shrinking inner mold, an upper clamping block, and a quick clamp; the indentation outer mold is a pair of semicircular molds, and the pair of semicircular molds have a pivoting edge and a closing edge, and the pivoting edges are pivoted together by hinges; the shrinking inner mold is also a pair of semicircular molds, and the shrinking inner mold is designed in a stepped shape, and the outer step is on the indentation outer mold; there are two upper clamping blocks and they are respectively installed on the closing edge of the indentation outer mold, and the two upper clamping blocks are respectively equipped with closing bolts and closing nuts; the quick clamp is also installed on the closing edge of the indentation outer mold; the closing edge of the indentation outer mold is fixed together by the quick clamp, closing bolts and closing nuts; a pair of handles are also installed on the indentation outer mold, and a pair of left and right second pull rings are installed on the handles; a labor-saving device is installed between the first pull ring and the second pull ring;

[0009] Indentation recovery operation: first put on a pair of shrinkage inner molds, then put on the shrinkage outer mold, use the mold clamping bolts and mold clamping nuts to perform the mold clamping operation, and after mold clamping, use the quick clamp to fix the shrinkage mold, and operate the labor-saving equipment to perform the shrinkage operation. Replace the next level shrinkage inner mold every time the diameter is retracted by 2mm, until the lead sleeve is retracted to the outer diameter that meets the flexible joint manufacturing process, and remove the shrinkage mold; the main body lead sleeve at the other end and the lead sleeve to be retracted and restored use the same operation to complete the lead sleeve indentation recovery operation.

[0010] The supporting frame is provided with supporting feet with adjustable height.

[0011] The cable supporting groove is in an arc shape.

[0012] The outer step of the shrinking inner mold protrudes from the edge of one side of the shrinking outer mold toward the cable supporting groove.

[0013] The shrinking inner molds are arranged in a group consisting of a plurality of them, and the diameter intervals of the shrinking inner molds in the group are 2 mm.

[0014] The shrinkage inner mold is made of nylon.

[0015] The labor-saving device is a lever hoist or an electric hoist.

[0016] The wire core structure to be restored with lead sheath is composed of a conductor welding section at the innermost part, followed by conductor shielding restoration, insulation restoration, insulation shielding restoration, wrapping with a semi-conductive water-resistant tape, and finally a lead sheath to be restored by indentation.

[0017] After adopting the above scheme, the present invention solves the problem that the existing lead sheathing and sleeve clamping followed by welding lead sheath recovery method has a certain probability of damage, cracking, and deformation during submarine cable transportation and construction, which may affect the normal construction, delivery, and operation of the submarine cable and increase the risk of submarine cable repair, and the other method of using a lead sheath drawing die and a lead sheath clamping method requires a lot of manpower and time when locking the lead sheath clamping and manually pushing, which is cumbersome to operate and not convenient and fast enough. The special supporting device of the present invention has a simple structure, a small size, is sturdy and durable, has a labor-saving and convenient installation procedure, works reliably, does not damage the lead sheath, is suitable for lead sheath recovery operations of submarine cable flexible joints of various specifications and sizes, and has the following characteristics:

[0018] 1. By adding a self-designed hinge-type rotary joint, the accuracy of the mold during mold closing is enhanced.

[0019] 2. Taking advantage of the soft material of the lead sleeve, 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.

[0020] 3. The shrinkage inner mold can be made of nylon material, which will not cause damage to the lead sleeve during the mold closing and indentation process. The shrinkage inner mold can be replaced quickly. Every time the outer diameter of the lead sleeve is indented by 2mm, the next level shrinkage inner mold is replaced and the indentation operation is continued until the outer diameter of the lead sleeve is indented to meet the process size requirements of the flexible joint.

[0021] Fourth, the design adds handles and pull rings that are symmetrical on both sides. The mold can be manually pushed in to retract, or labor-saving equipment such as a lever hoist or an electric hoist can be installed to perform the retraction operation. When installing labor-saving equipment such as a lever hoist or an electric hoist for the retraction operation, one end of the labor-saving equipment hook is hung on the mold handle pull ring, and the other end is hung on the support frame pull ring that supports the overall weight of the submarine cable core. Since the submarine cable core itself is very heavy, the overall force is self-enclosed when the labor-saving equipment is used for retraction, so the operation is very stable, the frame will not shake under the force, and the retraction operation can be carried out stably. In addition, because the labor-saving equipment is used, a lot of effort can be saved, and the function of labor-saving retraction can be achieved.

[0022] 5. The outer diameter of the initial lead sheath to be indented is 6-8mm larger than the outer diameter of the submarine cable core sheath, so it can be easily inserted into the section to be indented 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 submarine cable core body before the indentation and restoration operation is performed using a mold. After the indentation and restoration are completed, the other end is also radially overlapped and welded to the lead sheath of the submarine cable core body. Since the restored lead sheath is a complete cylinder, there is no long axial or longitudinal weld seam. The radial overlap welding effect is better and the impact is much smaller than that of the long axial weld seam. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the appearance of the special supporting device of the present invention;

[0024] Figure 2 It is a flexible joint section with a recovery lead sleeve Figure 1 ;

[0025] Figure 3 It is a structural diagram of the supporting frame;

[0026] Figure 4 This is the structural diagram of the indentation mold Figure 1 ;

[0027] Figure 5 This is the structural diagram of the indentation mold Figure 2 ;

[0028] Figure 6 It is a flexible joint section with a recovery lead sleeve Figure 2 ;

[0029] Figure 7 It is a schematic diagram of the indent recovery operation;

[0030] Figure 8 This is the appearance of the wire core after the lead sheath is restored.

[0031] Description of labels

[0032] Submarine cable 1, conductor welding section 101, conductor shield restoration 102, insulation restoration 103, insulation shield restoration 104, insulation cross-linking interface 105, core body insulation 106, semi-conductive water-resistant tape 107, lead sheath to be retracted and restored 108, core body lead sheath 109, core sheath 110, restored lead sheath 111, welding point 112;

[0033] Support frame 2, support foot 201, welding frame 202, first pull ring 203, cable support groove 204;

[0034] Labor-saving equipment 3;

[0035] Retracting mold 4, retracting inner mold 401, retracting outer molds 402 and 403, upper clamping block 404, handle 405, second pull ring 406, outer mold shaft pin 407, shaft pin top screw 408, mold clamping bolt 409, mold clamping nut 410, quick clamp 411, outer step 412. DETAILED DESCRIPTION

[0036] See also Figures 1 to 8 As shown, the present invention discloses a labor-saving retraction and recovery method for a submarine cable flexible joint lead sleeve, and its special supporting device includes a support frame 2, a labor-saving device 3 and a retraction mold 4, which is suitable for the retraction and recovery operation of the lead sleeve of the submarine cable 1 and the lead sleeve 108 to be retracted and recovered.

[0037] Among them, the support frame 2 has an arc-shaped cable support groove 204 and a pair of left and right first pull rings 203. The arc-shaped cable support groove 204 supports the cable and is compatible with the placement of cable cores of various specifications and sizes. The first pull ring 203 is used to connect labor-saving equipment 3 such as a hand hoist or an electric hoist. The main body of the support frame 2 is a painted carbon steel square tube welded frame 202, and the bottom is a support foot 201 with adjustable height.

[0038] The indentation mold 4 comprises an inner shrinkage mold 401, outer shrinkage molds 402 and 403, an upper clamping block 404, and a quick clamp 411. The outer shrinkage molds 402 and 403 are a pair of semicircular molds, each having a pivoting edge and a clamping edge. The pivoting edges are pivotally connected together by a hinge, specifically, by an outer mold axis pin 407. The hinged rotary clamping method can effectively improve the accuracy of the mold clamping. Two axis pin screws 408 tighten the outer mold axis pin 407 to prevent it from falling off. The inner mold 401 is also a pair of semicircular molds made of nylon. It has a stepped design, with an outer step 412 resting on the outer molds 402 and 403. Specifically, the outer step 412 of the inner mold 401 protrudes from the edge of the outer molds 402 and 403 facing the cable support slot 204. The inner mold 401 retracts along with the outer molds 402 and 403, forcing the lead sheath to retract. The outer step 412 protects the lead sheath during this process, preventing damage. Two upper clamps 404 are mounted on the mating edges of the outer molds 402 and 403, respectively. Each upper clamp 404 is equipped with a mating bolt 409 and a mating nut 410. A quick clamp 411 is also mounted on the mating edges of the outer molds 402 and 403. The closing edges of the indentation outer molds 402 and 403 are secured together by a quick-release clamp 411, closing bolts 409, and closing nuts 410. A pair of handles 405 are mounted on the indentation outer molds 402 and 403, each with a pair of left and right second pull rings 406. A labor-saving device 3, such as a lever hoist or electric hoist, is installed between the first pull ring 203 and the second pull ring 406. The indentation outer molds 402 and 403 are connected to the upper clamping block 404 and handles 405 by screwing and then welding, enhancing the overall strength of the mold.

[0039] Furthermore, the retractable inner mold 401 comprises a set of several pieces. The retractable inner molds 401 can be manufactured in a series of different sizes to accommodate various cable specifications and models, and each series of retractable inner molds 401 can be manufactured with diameters spaced 2mm apart. For example, a cable core sheath 110 has a nominal outer diameter of 120mm, and the core lead sheath 109 has a nominal outer diameter of 114mm. During the flexible joint manufacturing process, the material recovered will be approximately 4mm larger than the outer diameter of the core material. Therefore, the outer diameter of the recovered lead sheath 111 is approximately 118mm. Therefore, the outer diameter of the lead sheath 108 to be recovered during the flexible joint manufacturing process is 128mm (it must be larger than the core to fit). To recover the lead sheath 108 to the nominal outer diameter of 118mm, a pair of retractable inner molds 401 must be manufactured every 2mm (diameter), i.e., 126 / 124 / 122 / 120 / 118, for a total of five sizes of retractable inner molds 401.

[0040] The labor-saving device 3 is a lever hoist or an electric hoist. The two ends of the labor-saving device 3 are hooked and connected to the first pull ring 203 and the second pull ring 406. This method can satisfy the labor-saving retraction operation with the labor-saving device 3 and can also take into account the manual retraction operation by holding the handle 405 with both hands.

[0041] The present invention discloses a labor-saving retraction and recovery method for a lead sleeve of a submarine cable flexible joint, the operating steps of which are:

[0042] First, the lead sheath to be restored (108) is placed over the wire core structure to be restored. The innermost portion of the wire core structure is the conductor welded section (101), followed by conductor shield restoration (102), insulation restoration (103), insulation shield restoration (104), wrapping with semi-conductive water-resistant tape (107), and finally, the lead sheath to be restored (108). Before each restoration operation, the core sheath (110) and core body lead sheath (109) are stripped, the core body insulation (106) is polished, and a pencil tip is formed. An insulation restoration mold is used to create an insulation stress cone. After cross-linking, an insulation cross-linked interface (105) is formed.

[0043] Before performing the retraction recovery operation, the wire core body lead sleeve 109 at one end is staggered and knocked flat and overlapped with the lead sleeve 108 to be retracted and then fully welded (welding point 112) so that the lead sleeve will not slip during the retraction recovery operation.

[0044] Then use the aforementioned special supporting device to perform the lead sleeve indentation recovery operation.

[0045] After the wire core body lead sleeve 109 at one end is staggered and tightened with the lead sleeve 108 to be retracted and restored, a pair of inner shrinkage molds 401 are first put on, and then the retraction outer molds 402 and 403 are put on. The mold bolt 409 is passed through the upper clamp block 404 and connected to the mold nut 410. Use a large wrench to tighten the mold bolt 409 and the mold nut 410 to realize the mold closing operation. After the mold is closed, use the quick clamp 411 to quickly fix the retraction mold.

[0046] When operating the labor-saving device 3 to perform the indentation operation, it is necessary to pay attention to indenting both sides at the same time and maintaining balance. Every time the diameter is indented by 2 mm, the next-level shrinkage inner mold 401 is replaced until the lead sleeve is indented to an outer diameter that meets the flexible joint manufacturing process. The indentation mold (indentation outer molds 402 and 403, shrinkage inner mold 401) is removed, and then the wire core body lead sleeve 109 at the other end and the lead sleeve 108 to be indented and restored are indented and restored by the same operation. The wire core body lead sleeve 109 at the other end and the lead sleeve 108 to be indented and restored should also be staggered, hammered, overlapped, and welded to tighten, and then the lead sleeve indentation recovery operation is completed.

[0047] like Figure 8The figure shows the cable core after the lead sheath is restored. It is normal for the outer diameter of the restored lead sheath 111 to be 4-5 mm larger than the outer diameter of the core lead sheath 109. After the lead sheath is restored, the core sheath 110 can be further restored, completing the submarine cable flexible joint.

[0048] The embodiments described above are merely illustrative of the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. However, they do not limit the patent scope of the present invention. Any equivalent changes or modifications made in accordance with the spirit disclosed in the present invention should still be covered by the patent scope of the present invention.

Claims

1. A labor-saving indentation recovery method for a submarine cable flexible joint lead sleeve, characterized by: After putting the lead sleeve to be indented and restored on the wire core structure to be restored, first stagger the lead sleeve of the wire core body at one end and the lead sleeve to be indented and restored, then tighten them by lap welding; Then a special supporting device is used to perform the lead sleeve indentation recovery operation; the special supporting device includes a supporting frame and an indentation mold; the supporting frame has a cable support groove and a pair of left and right first pull rings; the indentation mold has an indentation outer mold, a shrinking inner mold, an upper clamping block, and a quick clamp; the indentation outer mold is a pair of semicircular molds, and the pair of semicircular molds have a pivoting edge and a closing edge, and the pivoting edges are pivoted together by hinges; the shrinking inner mold is also a pair of semicircular molds, and the shrinking inner mold is designed in a stepped shape, and the outer step is on the indentation outer mold; there are two upper clamping blocks and they are respectively installed on the closing edge of the indentation outer mold, and the two upper clamping blocks are respectively equipped with closing bolts and closing nuts; the quick clamp is also installed on the closing edge of the indentation outer mold; the closing edge of the indentation outer mold is fixed together by the quick clamp, closing bolts and closing nuts; a pair of handles are also installed on the indentation outer mold, and a pair of left and right second pull rings are installed on the handles; a labor-saving device is installed between the first pull ring and the second pull ring; Indentation recovery operation: first put on a pair of shrinkage inner molds, then put on the shrinkage outer mold, use the mold clamping bolts and mold clamping nuts to perform the mold clamping operation, and after mold clamping, use the quick clamp to fix the shrinkage mold, and operate the labor-saving equipment to perform the shrinkage operation. Replace the next level shrinkage inner mold every time the diameter is retracted by 2mm, until the lead sleeve is retracted to the outer diameter that meets the flexible joint manufacturing process, and remove the shrinkage mold; the main body lead sleeve at the other end and the lead sleeve to be retracted and restored use the same operation to complete the lead sleeve indentation recovery operation.

2. The method for labor-saving retraction and recovery of a submarine cable flexible joint lead sleeve according to claim 1, characterized in that: The wire core structure to be restored with lead sheath is composed of a conductor welding section at the innermost part, followed by conductor shielding restoration, insulation restoration, insulation shielding restoration, wrapping with a semi-conductive water tape, and finally a lead sheath to be restored by indentation.

3. The method for labor-saving retraction and recovery of a submarine cable flexible joint lead sleeve according to claim 1, characterized in that: The supporting frame is provided with supporting feet with adjustable height.

4. The method for labor-saving retraction and recovery of a submarine cable flexible joint lead sleeve according to claim 1 is characterized in that: The cable supporting groove is in an arc shape.

5. The method for labor-saving retraction and recovery of a submarine cable flexible joint lead sleeve according to claim 1, characterized in that: The outer step of the shrinking inner mold protrudes from the edge of one side of the shrinking outer mold toward the cable supporting groove.

6. The method for labor-saving retraction and recovery of a submarine cable flexible joint lead sleeve according to claim 1, characterized in that: The shrinking inner molds are arranged in a group consisting of a plurality of shrinking inner molds, and the diameter intervals of the shrinking inner molds in the group are 2 mm.

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

8. The method for labor-saving retraction and recovery of a submarine cable flexible joint lead sleeve according to claim 1, characterized in that: The labor-saving device is a lever hoist or an electric hoist.

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