Water-blocking and moisture-proof underground power transmission cable

Abstract

The utility model discloses a waterproof moisture-proof underground power transmission cable, which relates to the technical field of power transmission cables and comprises a polyvinyl chloride outer sheath, a polyvinyl chloride (PVC) inner sheath and a cable core, a cross-linked polyethylene insulating sleeve is arranged on the outer side of the cable core, and woven filler is arranged between the cable core and the PVC inner sheath. A waterproof sleeve, an outer semiconductor shielding sleeve and a water swelling strip are sequentially arranged on the outer side of the PVC inner sheath from inside to outside in a contact mode, annular grooves are formed in the outer side of the water swelling strip in the axis direction of the water swelling strip at intervals, V-shaped dredging grooves are symmetrically formed in the two sides of each annular groove, and the interiors of the annular grooves and the interiors of the V-shaped dredging grooves are communicated. According to the scheme, the water swelling strip is arranged between the polyvinyl chloride outer sheath and the outer semiconductor shielding sleeve, after water seepage occurs in the cable, the water swelling strip can continuously absorb water to swell, then irregular gaps in splicing seams can be formed, and the water stopping and waterproof effects are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of power transmission cables, in particular to an underground power transmission cable for water-blocking and moisture-proofing. Background Art

[0002] There are many types of cables, which can be used in many fields. The usage environments in different fields are different, so there are different requirements for cables. However, due to the unreasonable structural design of existing cables, the cables have poor tear resistance, oxidation resistance, stability and insect resistance, and the functions cannot cooperate with each other, which ultimately makes the cables' water-proof and moisture-proof effects unsatisfactory.

[0003] Underground power transmission cables are particularly vulnerable to moisture concentration due to their underground location. When moisture enters the cable, it can cause oxidation and corrosion of the conductors, impacting the cable's electrical performance and even causing unexpected disconnection. To address this issue, we propose a water- and moisture-resistant underground power transmission cable. Utility Model Content

[0004] The present utility model aims to provide a water-resistant and moisture-proof underground power transmission cable to address the problem in the above-mentioned background art that underground power transmission cables, due to their underground installation, are prone to moisture concentration. When moisture intrudes into the cable, it can cause oxidation and corrosion of the conductor, thereby affecting the electrical performance of the cable and even causing abnormal disconnection accidents.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a water-blocking and moisture-proof underground power transmission cable, comprising a polyvinyl chloride outer sheath, a PVC inner sheath, and a cable core, wherein a cross-linked polyethylene insulating sheath is provided on the outside of the cable core, the cable core is annularly arranged inside the PVC inner sheath, and a braided filler is provided between the cable core and the PVC inner sheath, the outer side of the PVC inner sheath is contacted with a cable water-blocking tape, an outer semiconducting shielding sheath, and a water-swelling waterstop strip in contact therewith from the inside out, and the polyvinyl chloride outer sheath is provided on the outside of the water-swelling waterstop strip;

[0006] Annular grooves are arranged at intervals along the axial direction of the water-swelling waterstop strip on the outside of the water-swelling waterstop strip, and V-shaped drainage grooves are symmetrically arranged on both sides of the annular groove. The annular groove and the V-shaped drainage groove are internally connected.

[0007] Preferably, the V-shaped angle of the V-shaped drainage groove is greater than 90 degrees, and the groove depth of the V-shaped drainage groove is less than the thickness of the water-swelling waterstop strip.

[0008] Preferably, the V-shaped drainage groove is provided between adjacent annular grooves, and the V-shaped drainage groove is distributed in an annular shape with the center of the annular groove.

[0009] Preferably, the width of the V-shaped drainage groove is greater than the width of the annular groove.

[0010] Preferably, the bottom surfaces of the V-shaped drainage groove and the annular groove are flush.

[0011] Preferably, the thickness of the water-swellable waterstop strip is greater than the thickness of the cable water-blocking tape, the outer semiconductor shielding sleeve and the polyvinyl chloride outer sheath.

[0012] Preferably, the thickness of the water-swellable waterstop strip is greater than 1 / 2 of the depth of the V-shaped drainage groove and the annular groove.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] 1. This type of water-blocking and moisture-proof underground power transmission cable has a water-swelling waterstop strip set between the polyvinyl chloride outer sheath and the outer semiconductor shielding sleeve. During use, if water penetrates into the cable, the water-swelling waterstop strip will continue to absorb water and expand through the setting of the annular groove and the V-shaped drainage groove. Then, it can fill the irregular gaps in the structural joints to produce a water-stopping and waterproof effect. The cable water-blocking tape made of polyester non-woven fabric, adhesive, high-speed expansion polymer water-absorbing resin and other materials can further reduce the infiltration of water and moisture in the optical cable, and extend the working life of the optical cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the large structure of the utility model;

[0016] Figure 2 It is a main schematic diagram of the utility model;

[0017] Figure 3 This is a schematic diagram of the local structure of the transmission cable of the present utility model.

[0018] In the figure: 1. PVC outer sheath; 2. Water-swelling waterstop; 21. Annular groove; 22. V-shaped drainage groove; 3. Outer semiconducting shielding sleeve; 4. Cable water-blocking tape; 5. PVC inner sheath; 6. Cross-linked polyethylene insulation sleeve; 7. Cable core; 8. Braided filler. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] Example: See Figure 1-3 The utility model provides a technical solution: a water-proof and moisture-proof underground power transmission cable, which is mainly aimed at underground power transmission cables. Since they are set underground, water vapor is concentrated. When water vapor invades the cable, it will cause oxidation and corrosion of the conductor, thereby affecting the electrical performance of the cable, and even causing abnormal disconnection accidents. The specific solution is as follows: it includes a polyvinyl chloride outer sheath 1, a PVC inner sheath 5 and a cable core 7. Among them, the polyvinyl chloride outer sheath 1 is a particle prepared by mixing, kneading and extrusion with polyvinyl chloride as the base resin, adding stabilizers, plasticizers and inorganic fillers such as calcium carbonate, additives and lubricants. It can be used in various environments and applications. It has low cost, good flexibility, is quite strong, and has fireproof / oil-proof materials. It is set on the outermost layer of the cable as the most important barrier to protect the safety of the internal structure in the cable, protecting the cable from mechanical damage during and after installation.

[0021] See also Figure 1 A cross-linked polyethylene insulation sheath 6 is installed outside the cable core 7. The cable core 7 is annularly positioned inside the PVC inner sheath 5, with a braided filler 8 interposed between the cable core 7 and the PVC inner sheath 5. The outer side of the PVC inner sheath 5 is contacted with, from the inside out, a cable water-blocking tape 4, an outer semiconducting shielding sheath 3, and a water-swelling waterstop strip 2. The cable water-blocking tape 4 is made of polyester non-woven fabric, adhesive, and a high-speed expanding polymer water-absorbing resin. The cable water-blocking tape 4 is non-corrosive and can reduce the infiltration of water and moisture into the optical cable, thereby extending the service life of the optical cable.

[0022] Furthermore, the polyvinyl chloride outer sheath 1 is arranged on the outside of the water-swelling waterstop strip 2; the thickness of the water-swelling waterstop strip 2 is greater than the thickness of the cable water-blocking tape 4, the outer semiconductor shielding sleeve 3 and the polyvinyl chloride outer sheath 1. The water-swelling waterstop strip 2 is made by plasticizing natural rubber (or synthetic rubber) in sections through a rubber mixing equipment (open rubber mixer or internal mixer), and then mixing with more than ten kinds of raw materials such as special antioxidants, vulcanization accelerators, vulcanization aids, reinforcing agents, plasticizers, etc. to obtain a semi-finished rubber mixture, which is then placed in a mold with a certain cavity and subjected to high temperature and high pressure conditions in a vulcanizing press to obtain a waterstop element that meets the comprehensive requirements of waterstopping for hydraulic steel gates. It is not ordinary rubber. The water-swelling waterstop strip 2 will continue to absorb water and expand after encountering water, and then it can fill the irregular gaps in the structural joints to produce a waterstop and waterproof effect.

[0023] See also Figure 1 and Figure 3, wherein, annular grooves 21 are arranged at intervals along the axial direction of the water-swelling waterstop strip 2 on the outside of the water-swelling waterstop strip 2. The annular grooves 21 are evenly arranged on the outside of the water-swelling waterstop strip 2 and can guide the infiltrated water so that it can flow inside the annular grooves 21. V-shaped drainage grooves 22 are symmetrically arranged on both sides of the annular groove 21. The V-shaped drainage grooves 22 are evenly arranged on the outside of the water-swelling waterstop strip 2 and can evenly guide the infiltrated water entering the annular groove 21 to the outside of the water-swelling waterstop strip 2. After encountering water, the water-swelling waterstop strip 2 will continue to absorb water and expand, and then can fill the irregular gaps in the structural joints to produce a water-stopping and waterproofing effect.

[0024] Specifically, the annular groove 21 and the V-shaped drainage groove 22 are internally connected. The thickness of the water-swelling waterstop strip 2 is greater than 1 / 2 of the groove depth of the V-shaped drainage groove 22 and the annular groove 21. The V-shaped angle of the V-shaped drainage groove 22 is greater than 90 degrees, and the groove depth of the V-shaped drainage groove 22 is less than the thickness of the water-swelling waterstop strip 2. The V-shaped drainage groove 22 is arranged between adjacent annular grooves 21, and the V-shaped drainage groove 22 is distributed in a ring shape with the center of the annular groove 21. The width of the V-shaped drainage groove 22 is greater than the groove width of the annular groove 21. The bottom surfaces of the V-shaped drainage groove 22 and the annular groove 21 are flush.

[0025] When this type of water-blocking and moisture-proof underground power transmission cable is used, since the installation environment of the power transmission cable is relatively humid, during use, if water penetrates into the cable, through the arrangement of the annular groove 21 and the V-shaped drainage groove 22, after water seepage occurs inside the cable, the water-swelling waterstop strip 2 will continue to absorb water and expand, and then it can fill the irregular gaps in the structural joints to produce a water-stopping and waterproof effect; and the cable water-blocking tape 4 made of materials such as polyester non-woven fabric, adhesive, and high-speed expansion polymer water-absorbing resin can further reduce the infiltration of water and moisture in the optical cable, thereby extending the working life of the optical cable.

[0026] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A water-blocking and moisture-proof underground power transmission cable, comprising a polyvinyl chloride outer sheath (1), a PVC inner sheath (5) and a cable core (7), wherein a cross-linked polyethylene insulating sheath (6) is provided on the outer side of the cable core (7), characterized in that: The cable core (7) is annularly arranged inside the PVC inner sheath (5), and a braided filler (8) is arranged between the cable core (7) and the PVC inner sheath (5). The outer side of the PVC inner sheath (5) is contacted with a cable water-blocking tape (4), an outer semiconductor shielding sleeve (3) and a water-swelling waterstop strip (2) in sequence from the inside to the outside, and the polyvinyl chloride outer sheath (1) is arranged on the outer side of the water-swelling waterstop strip (2); Annular grooves (21) are arranged at intervals on the outside of the water-swelling waterstop strip (2) along the axial direction of the water-swelling waterstop strip (2), and V-shaped drainage grooves (22) are symmetrically arranged on both sides of the annular groove (21), and the annular groove (21) and the V-shaped drainage groove (22) are internally communicated.

2. The water-blocking and moisture-proof underground power transmission cable according to claim 1, characterized in that: The V-shaped included angle of the V-shaped drainage groove (22) is greater than 90 degrees, and the groove depth of the V-shaped drainage groove (22) is less than the thickness of the water-expanding waterstop strip (2).

3. The water-blocking and moisture-proof underground power transmission cable according to claim 1, characterized in that: The V-shaped dredging groove (22) is provided between adjacent annular grooves (21), and the V-shaped dredging groove (22) is distributed in an annular shape with the center of the annular groove (21).

4. The water-blocking and moisture-proof underground power transmission cable according to claim 1, characterized in that: The width of the V-shaped drainage groove (22) is greater than the width of the annular groove (21).

5. The water-blocking and moisture-proof underground power transmission cable according to claim 1, characterized in that: The bottom surfaces of the V-shaped drainage groove (22) and the annular groove (21) are flush.

6. The water-blocking and moisture-proof underground power transmission cable according to claim 1, characterized in that: The thickness of the water-swelling waterstop strip (2) is greater than the thickness of the cable water-blocking tape (4), the outer semiconductor shielding sleeve (3) and the polyvinyl chloride outer sheath (1).

7. The water-blocking and moisture-proof underground power transmission cable according to claim 1, characterized in that: The thickness of the water-expanding waterstop strip (2) is greater than 1 / 2 of the depth of the V-shaped drainage groove (22) and the annular groove (21).

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