High-toughness MPP cable protection pipe and preparation method thereof

Abstract

The invention discloses a high-toughness MPP cable protection pipe and a preparation method thereof, and relates to the technical field of cable protection pipes, the high-toughness MPP cable protection pipe comprises a protection pipe main body and an inner pipe layer, a filling core layer is arranged outside the inner pipe layer in an extrusion molding manner, and a plurality of flexible metal wires are spirally wound on the outer surface of the filling core layer. An outer pipe layer is arranged outside the filling core layer in an extrusion molding mode, an inner thread is arranged on the inner wall of one end of the protection pipe body, an outer thread is arranged on the outer wall of the other end of the protection pipe body, the outer thread and the inner thread are correspondingly arranged, and the outer diameter of the outer thread is the same as the inner diameter of the inner thread. The inner wall and the outer wall of the two ends of the MPP cable protection pipe are provided with threads in opposite directions, the head ends and the tail ends of the two cable protection pipes are spliced in a threaded connection mode, auxiliary instruments are not needed for installation, the splicing efficiency of the cable protection pipes is improved, the spliced cable protection pipes can be rapidly disassembled, subsequent maintenance of cables in the cable protection pipes is facilitated, and the maintenance cost is reduced. The use effect of the cable protection pipe is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cable protection tubes, and in particular to a high-toughness MPP cable protection tube and a preparation method thereof. Background Art

[0002] Cable protection conduits are pipes used to protect cables and are widely used in power engineering. MPP cable protection conduits are primarily made of modified polypropylene with additives and are available in both solid-wall and corrugated structures. Solid-wall conduits offer high strength, impact resistance, and chemical corrosion resistance; corrugated conduits are lightweight, can be manufactured to any length, and offer excellent strength, corrosion resistance, and aging resistance.

[0003] The Chinese patent publication number is CN215498079U, and the authorization announcement date is January 11, 2022. A high-toughness power cable protection tube includes a first insulating tube, a soft rubber tube is provided on the outer wall of the first insulating tube, a spring is provided on the outer wall of the soft rubber tube, and a connecting tube is provided on the outer wall of the spring. The inner wall of the connecting tube is fixedly connected with multiple positive connecting buckles, and the inner walls of the multiple positive connecting buckles are in contact with the spring. The positive connecting buckle is engaged with the reverse connecting buckle at one end of the connecting mechanism. The utility model wraps and protects the first insulating tube by inserting the cable into the first insulating tube and the soft rubber tube provided on the outer wall of the first insulating tube. When subjected to external force, the internal spring will undergo elastic deformation. When the external force disappears, the spring will recover under its own elastic action, thereby improving the toughness of the overall device. The annular groove on the outer wall of the elastic tube is bonded with a soft rubber strip. The soft rubber strip can reflect light when exposed to light in a dark environment, which is convenient for staff to find in a dark environment, thereby improving the toughness and convenience of the device.

[0004] The length of the existing MPP cable protection tube is constant, and the cable protection tube is usually connected by hot melt welding. Auxiliary equipment is required for hot melt welding, and the hot melt connection part cannot be disassembled, which is inconvenient for subsequent maintenance of the cables in the cable protection tube, reducing the use effect of the cable protection tube and failing to meet the use requirements. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-toughness MPP cable protection tube and a preparation method thereof, so as to solve the problem proposed in the above background technology that the length of the existing MPP cable protection tube is constant, the cable protection tube is usually connected by hot melt welding, and auxiliary equipment is required for hot melt welding. The hot melt connection part cannot be disassembled, which is inconvenient for subsequent maintenance of the cables in the cable protection tube, reduces the use effect of the cable protection tube, and cannot meet the use requirements.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a high-toughness MPP cable protection tube, comprising a protection tube main body and an inner tube layer, the outer side of the inner tube layer is extruded with a filling core layer, a plurality of flexible metal wires are spirally wound on the outer surface of the filling core layer, and the flexible metal wires are arranged in a circular and equidistant manner along the diameter surface of the inner tube layer, the outer side of the filling core layer is extruded with an outer tube layer, an internal thread is provided on the inner wall of one end of the protection tube main body, and an external thread is provided on the outer wall of the other end of the protection tube main body, and the external thread and the internal thread are arranged correspondingly, and the outer diameter of the external thread is set to be the same as the inner diameter of the internal thread.

[0007] Preferably, an anti-corrosion layer is provided on the outer surface of the outer tube layer, and the anti-corrosion layer and the outer tube layer are coated as one body.

[0008] Preferably, a sealing ring is fixed to one end of the protection tube body, and the sealing ring is arranged on one side of the internal thread.

[0009] Preferably, grooves are provided on the upper surfaces of both ends of the protection tube body, a connecting piece is provided between the two protection tube bodies, and the connecting piece is provided corresponding to the groove, and the connecting piece is snap-connected with the protection tube body.

[0010] Preferably, the inner wall of the inner tube layer is provided with raised strips, there are at least six raised strips, and the raised strips and the inner tube layer are provided as one body, and the raised strips are provided at equal intervals on the inner wall of the inner tube layer.

[0011] Preferably, graphite particles are fixedly provided at the front end of the raised strip, and the front end of the graphite particles is arranged in an arc shape.

[0012] A method for preparing a high-toughness MPP cable protection tube comprises the following steps:

[0013] Step 1: Weigh modified polypropylene - parts, nano calcium carbonate - parts, compatibilizer - parts, flame retardant - parts, toughening agent - parts, dispersant - parts, glass fiber - parts, antioxidant - parts and polyacrylonitrile fiber - parts according to weight parts for later use;

[0014] Step 2: adding the weighed polypropylene resin, nano-calcium carbonate, compatibilizer, flame retardant, toughening agent, dispersant, antioxidant and part of the glass fiber to a high-speed mixer and uniformly mixing them to obtain a mixture A, drying it for later use; then adding the weighed polyacrylonitrile fiber and the remaining glass fiber to a high-speed mixer and uniformly mixing them to obtain a mixture B, drying it for later use;

[0015] Step 3: Adding the mixture A to an extruder for preparing the inner tube layer, extruding the mixture through the extruder, and water-cooling the extruded tube to obtain the inner tube layer;

[0016] Step 4: Adding mixture B to an extruder for preparing a filling core layer, extruding mixture B through the extruder to wrap the inner tube layer, and water-cooling the extruded tube to form a filling core layer outside the inner tube layer;

[0017] Step 5: Wrap the flexible metal wire spirally around the outer surface of the filling core layer and perform preliminary fixation;

[0018] Step 6: Adding mixture A to an extruder for preparing the outer tube layer, extruding mixture A through the extruder to wrap the filling core layer, and water-cooling the extruded tube to form the outer tube layer outside the filling core layer;

[0019] Step 7: Pull the formed cable protection tube by a pulling device, cut the cable protection tube according to the use length of the cable protection tube, set an internal thread on the inner wall of one end of the cable protection tube, set an external thread on the outer wall of the other end of the cable protection tube, and open grooves on the upper surface of both ends of the cable protection tube;

[0020] Step 8: Use polyurethane paint to evenly coat the outer surface of the cable protection tube to form an anti-corrosion layer on the outer surface of the cable protection tube.

[0021] Preferably, the modified polypropylene in step 1 is prepared by first injecting nitrogen into the reactor to empty it, then sequentially adding propylene gas, anhydrous toluene, toughening monomer, anti-corrosion monomer, triisobutylaluminum and triphenylcarbon tetraborate to carry out polymerization reaction, adding anhydrous ethanol to terminate the reaction after polymerization for a period of time, pouring the reaction product into a hydrochloric acid ethanol solution and mixing, and filtering, washing and drying the mixture in sequence to obtain the obtained product.

[0022] Preferably, the compatibilizer in step 1 is maleic anhydride grafted polyolefin, the flame retardant is aluminum hydroxide, the toughening agent is EPDM rubber, the dispersant is calcium stearate, and the antioxidant is a phosphite antioxidant.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The device of the invention is provided with grooves, connecting pieces, sealing rings, internal threads, and external threads. The external threads at one end of the cable protection tube are aligned with the internal threads at one end of the other cable protection tube and inserted, and the two cable protection tubes are threadedly spliced ​​end to end. The sealing ring fills the spliced ​​portion of the two cable protection tubes, improving the sealing of the two spliced ​​cable protection tubes. The two ends of the connecting piece are inserted into the grooves and connected to the cable protection tubes, limiting the position of the spliced ​​cable protection tubes and improving the firmness of the spliced ​​cable protection tubes. The spliced ​​cable protection tubes can be quickly disassembled, facilitating subsequent inspection and maintenance of the cables inside the cable protection tubes.

[0025] 2. The device of the invention is equipped with a filling core layer and flexible metal wire. The filling core layer is made of a mixture of glass fiber and polyacrylonitrile fiber. The filling core layer has excellent toughness, strength, crack resistance and mechanical properties. The flexible metal wire can form a certain degree of protection on the outside of the filling core layer, improving the tensile toughness of the filling core layer and preventing the cable protection tube from bending and breaking. The braided flexible metal wire also has a shielding effect, further improving the use effect of the MPP cable protection tube.

[0026] 3. The device of the invention is provided with an anti-corrosion layer. The anti-corrosion layer adopts polyurethane coating. Polyurethane coating has good acid resistance, alkali resistance, oil resistance, water resistance and wear resistance. It prevents the cable protection tube from being oxidized or aged due to long-term exposure to harsh environments, thereby extending the service life of the MPP cable protection tube.

[0027] 4. The device of the invention is provided with raised strips and graphite particles. The raised strips prevent the cable from directly contacting the inner tube, thereby supporting the cable passing through the cable protection tube. A certain space is left between the cable and the inner tube, thereby improving the heat dissipation effect of the cable. The graphite particles increase the lubrication performance of the front end of the raised strips, reduce the friction between the cable and the raised strips, and facilitate the cable to pass through the cable protection tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 This is a cross-sectional view of the main body of the protection tube of the present invention;

[0030] Figure 3 This is a structural diagram of the outer tube layer of the present invention;

[0031] Figure 4 This is a diagram showing the connection relationship between two protection tubes of the present invention;

[0032] Figure 5 A three-dimensional diagram showing the connection between the flexible metal wire and the filling core layer of the present invention;

[0033] Figure 6 It is a preparation flow chart of the present invention.

[0034] In the figure: 1. Protective tube body; 2. Groove; 3. Connecting piece; 4. Sealing ring; 5. Internal thread; 6. External thread; 7. Raised strip; 8. Inner tube layer; 9. Filling core layer; 10. Flexible metal wire; 11. Outer tube layer; 12. Graphite particles; 13. Anti-corrosion layer. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0036] See also Figure 1-6 , the present invention provides an embodiment: a high-toughness MPP cable protection tube, comprising a protection tube body 1 and an inner tube layer 8, the outer side of the inner tube layer 8 is extruded with a filling core layer 9, and a plurality of flexible metal wires 10 are spirally wound on the outer surface of the filling core layer 9, and the flexible metal wires 10 are arranged in a circular and equidistant manner along the radial surface of the inner tube layer 8, and an outer tube layer 11 is extruded on the outside of the filling core layer 9, an internal thread 5 is provided on the inner wall of one end of the protection tube body 1, and an external thread 6 is provided on the outer wall of the other end of the protection tube body 1, and the external thread 6 is arranged corresponding to the internal thread 5, and the outer diameter of the external thread 6 is set to the same as the inner diameter of the internal thread 5, and an anti-corrosion layer 13 is provided on the outer surface of the outer tube layer 11, and the anti-corrosion layer 13 is coated integrally with the outer tube layer 11.

[0037] When in use: align the external thread 6 at one end of the cable protection tube with the internal thread 5 at one end of the other cable protection tube and insert it, then splice the two cable protection tubes together with their end threads. The spliced ​​cable protection tubes can be quickly disassembled, making it convenient for subsequent inspection and maintenance of the cables inside the cable protection tubes.

[0038] See also Figure 1 and Figure 4 A sealing ring 4 is fixed at one end of the protection tube body 1, and the sealing ring 4 is arranged on one side of the internal thread 5. Grooves 2 are provided on the upper surfaces of both ends of the protection tube body 1. A connecting piece 3 is provided between the two protection tube bodies 1, and the connecting piece 3 is corresponding to the groove 2. The connecting piece 3 is clamped with the protection tube body 1. The sealing ring 4 fills the splicing part of the two cable protection tubes to improve the sealing performance of the two spliced ​​cable protection tubes. The two ends of the connecting piece 3 are inserted into the groove 2 and connected to the cable protection tubes to limit the spliced ​​cable protection tubes and improve the firmness of the spliced ​​cable protection tubes.

[0039] See also Figure 1 and Figure 2 , a raised strip 7 is provided on the inner wall of the inner tube layer 8, and there are at least six raised strips 7, and the raised strips 7 and the inner tube layer 8 are integrated. The raised strips 7 are equidistantly arranged on the inner wall of the inner tube layer 8, and the front end of the raised strip 7 is fixedly provided with graphite particles 12, and the front end of the graphite particles 12 is arranged in an arc shape. The raised strip 7 prevents the cable from directly contacting the inner tube and supports the cable passed through the cable protection tube. A certain space is left between the cable and the inner tube. The reserved space facilitates heat flow and improves the heat dissipation effect of the cable. The graphite particles 12 increase the lubrication performance of the front end of the raised strip 7, reduce the friction between the cable and the raised strip 7, and facilitate the cable to pass through the cable protection tube.

[0040] The preparation method of modified polypropylene comprises the following steps: injecting nitrogen into a reaction kettle for evacuation, sequentially adding 1 mol of propylene gas, 1000 mL of anhydrous toluene, 0.5 mol of a toughening monomer, 0.5 mol of an anti-corrosion monomer, 200 g of triisobutylaluminum, and 100 g of triphenylcarbon tetraborate, carrying out a polymerization reaction at a stirring rate of 2000 r / min for 40 min, then adding anhydrous ethanol to terminate the reaction, pouring the reaction product into a 0.5% by mass hydrochloric acid ethanol solution and mixing, filtering the mixture, washing the filtered solid three times with anhydrous ethanol and acetone respectively, and then drying the solid in a vacuum drying oven at 80° C. to obtain modified polypropylene.

[0041] Example 1:

[0042] This embodiment is a method for preparing a high-toughness MPP cable protection tube, comprising the following steps:

[0043] Step 1: Weigh 80 parts of modified polypropylene, 5 parts of nano calcium carbonate, 10 parts of compatibilizer, 30 parts of flame retardant, 10 parts of toughening agent, 1 part of dispersant, 10 parts of glass fiber, 1 part of antioxidant and 30 parts of polyacrylonitrile fiber according to weight parts for later use;

[0044] Step 2: Add the weighed polypropylene resin, nano-calcium carbonate, compatibilizer, flame retardant, toughening agent, dispersant, antioxidant and half of the glass fiber into a high-speed mixer and stir and mix for 20 minutes to obtain a mixture A, and add the weighed polyacrylonitrile fiber and the remaining glass fiber into a high-speed mixer and stir and mix for 20 minutes to obtain a mixture B and dry it for use;

[0045] Step 3: Add the mixture A to an extruder for preparing the inner tube layer 8, extrude the mixture through the extruder, and after water cooling and sizing, obtain the inner tube layer 8;

[0046] Step 4: Add the mixture B to the extruder for preparing the filling core layer 9, extrude the mixture B through the extruder to wrap the inner tube layer 8, and after water cooling and sizing, form the filling core layer 9 on the outside of the inner tube layer 8;

[0047] Step 5: spirally wind the flexible metal wire 10 on the outer surface of the filling core layer 9 and perform preliminary fixation;

[0048] Step 6: Add the mixture A to the extruder for preparing the outer tube layer 11, extrude the mixture A through the extruder to wrap the filling core layer 9, and after water cooling and sizing, form the outer tube layer 11 outside the filling core layer 9;

[0049] Step 7: Pull the formed cable protection tube, cut the cable protection tube according to the use length of the cable protection tube, set an internal thread 5 on the inner wall of one end of the cable protection tube, set an external thread 6 on the outer wall of the other end of the cable protection tube, and open grooves 2 on the upper surface of both ends of the cable protection tube;

[0050] Step 8: Use polyurethane paint to evenly coat the outer surface of the cable protection tube.

[0051] Example 2:

[0052] This embodiment is a method for preparing a high-toughness MPP cable protection tube, comprising the following steps:

[0053] Step 1: Weigh 90 parts of modified polypropylene, 7 parts of nano-calcium carbonate, 15 parts of compatibilizer, 40 parts of flame retardant, 15 parts of toughening agent, 1.5 parts of dispersant, 15 parts of glass fiber, 2 parts of antioxidant and 40 parts of polyacrylonitrile fiber according to weight parts for later use;

[0054] Step 2: Add the weighed polypropylene resin, nano-calcium carbonate, compatibilizer, flame retardant, toughening agent, dispersant, antioxidant and half of the glass fiber into a high-speed mixer and stir and mix for 20 minutes to obtain a mixture A, and add the weighed polyacrylonitrile fiber and the remaining glass fiber into a high-speed mixer and stir and mix for 20 minutes to obtain a mixture B and dry it for use;

[0055] Step 3: Add the mixture A to an extruder for preparing the inner tube layer 8, extrude the mixture through the extruder, and after water cooling and sizing, obtain the inner tube layer 8;

[0056] Step 4: Add the mixture B to the extruder for preparing the filling core layer 9, extrude the mixture B through the extruder to wrap the inner tube layer 8, and after water cooling and sizing, form the filling core layer 9 on the outside of the inner tube layer 8;

[0057] Step 5: spirally wind the flexible metal wire 10 on the outer surface of the filling core layer 9 and perform preliminary fixation;

[0058] Step 6: Add the mixture A to the extruder for preparing the outer tube layer 11, extrude the mixture A through the extruder to wrap the filling core layer 9, and after water cooling and sizing, form the outer tube layer 11 outside the filling core layer 9;

[0059] Step 7: Pull the formed cable protection tube, cut the cable protection tube according to the use length of the cable protection tube, set an internal thread 5 on the inner wall of one end of the cable protection tube, set an external thread 6 on the outer wall of the other end of the cable protection tube, and open grooves 2 on the upper surface of both ends of the cable protection tube;

[0060] Step 8: Use polyurethane paint to evenly coat the outer surface of the cable protection tube.

[0061] Example 3:

[0062] This embodiment is a method for preparing a high-toughness MPP cable protection tube, comprising the following steps:

[0063] Step 1: Weigh 100 parts of modified polypropylene, 10 parts of nano-calcium carbonate, 20 parts of compatibilizer, 50 parts of flame retardant, 20 parts of toughening agent, 2 parts of dispersant, 20 parts of glass fiber, 3 parts of antioxidant and 50 parts of polyacrylonitrile fiber according to weight parts for later use;

[0064] Step 2: Add the weighed polypropylene resin, nano-calcium carbonate, compatibilizer, flame retardant, toughening agent, dispersant, antioxidant and half of the glass fiber into a high-speed mixer and stir and mix for 20 minutes to obtain a mixture A, and add the weighed polyacrylonitrile fiber and the remaining glass fiber into a high-speed mixer and stir and mix for 20 minutes to obtain a mixture B and dry it for use;

[0065] Step 3: Add the mixture A to an extruder for preparing the inner tube layer 8, extrude the mixture through the extruder, and after water cooling and sizing, obtain the inner tube layer 8;

[0066] Step 4: Add the mixture B to the extruder for preparing the filling core layer 9, extrude the mixture B through the extruder to wrap the inner tube layer 8, and after water cooling and sizing, form the filling core layer 9 on the outside of the inner tube layer 8;

[0067] Step 5: spirally wind the flexible metal wire 10 on the outer surface of the filling core layer 9 and perform preliminary fixation;

[0068] Step 6: Add the mixture A to the extruder for preparing the outer tube layer 11, extrude the mixture A through the extruder to wrap the filling core layer 9, and after water cooling and sizing, form the outer tube layer 11 outside the filling core layer 9;

[0069] Step 7: Pull the formed cable protection tube, cut the cable protection tube according to the use length of the cable protection tube, set an internal thread 5 on the inner wall of one end of the cable protection tube, set an external thread 6 on the outer wall of the other end of the cable protection tube, and open grooves 2 on the upper surface of both ends of the cable protection tube;

[0070] Step 8: Use polyurethane paint to evenly coat the outer surface of the cable protection tube.

[0071] By comparing Example 1, Example 2 and Example 3, it can be seen that the toughness of the MPP cable protection tube prepared by using the modified polypropylene weighed in parts by weight and adding reagents in Example 2 shows the most excellent performance.

[0072] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0073] While embodiments of the present invention have been shown and described, it will be appreciated 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 invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A high-toughness MPP cable protection tube, comprising a protection tube body (1) and an inner tube layer (8), characterized in that: The outer surface of the inner tube layer (8) is extruded with a filling core layer (9), and a plurality of flexible metal wires (10) are spirally wound on the outer surface of the filling core layer (9), and the flexible metal wires (10) are arranged in a circular and equidistant manner along the diameter surface of the inner tube layer (8). The outer surface of the filling core layer (9) is extruded with an outer tube layer (11), and an internal thread (5) is provided on the inner wall of one end of the protective tube body (1), and an external thread (6) is provided on the outer wall of the other end of the protective tube body (1), and the external thread (6) is arranged corresponding to the internal thread (5), and the outer diameter of the external thread (6) is set to be the same as the inner diameter of the internal thread (5).

2. The high-toughness MPP cable protection tube according to claim 1, characterized in that: An anti-corrosion layer (13) is provided on the outer surface of the outer tube layer (11), and the anti-corrosion layer (13) and the outer tube layer (11) are coated as a whole.

3. The high-toughness MPP cable protection tube according to claim 1, characterized in that: A sealing ring (4) is fixed to one end of the protective tube body (1), and the sealing ring (4) is arranged on one side of the internal thread (5).

4. The high-toughness MPP cable protection tube according to claim 1, characterized in that: Grooves (2) are provided on the upper surfaces of both ends of the protection tube main body (1), a connecting piece (3) is provided between the two protection tube main bodies (1), and the connecting piece (3) and the groove (2) are provided correspondingly, and the connecting piece (3) is clamped with the protection tube main body (1).

5. The high-toughness MPP cable protection tube according to claim 1, characterized in that: The inner wall of the inner tube layer (8) is provided with raised strips (7), there are at least six raised strips (7), and the raised strips (7) and the inner tube layer (8) are provided as a whole, and the raised strips (7) are provided at equal intervals on the inner wall of the inner tube layer (8).

6. The high-toughness MPP cable protection tube according to claim 5, characterized in that: Graphite particles (12) are fixedly arranged at the front end of the raised strip (7), and the front end of the graphite particles (12) is arranged in an arc shape.

7. The method for preparing a high-toughness MPP cable protection tube according to claim 2, characterized in that: The following steps are involved: Step 1: Weigh 80-100 parts of modified polypropylene, 5-10 parts of nano-calcium carbonate, 10-20 parts of compatibilizer, 30-50 parts of flame retardant, 10-20 parts of toughening agent, 1-2 parts of dispersant, 10-20 parts of glass fiber, 1-3 parts of antioxidant and 30-50 parts of polyacrylonitrile fiber according to weight parts for later use; Step 2: adding the weighed polypropylene resin, nano-calcium carbonate, compatibilizer, flame retardant, toughening agent, dispersant, antioxidant and part of the glass fiber to a high-speed mixer and uniformly mixing them to obtain a mixture A, drying it for later use; then adding the weighed polyacrylonitrile fiber and the remaining glass fiber to a high-speed mixer and uniformly mixing them to obtain a mixture B, drying it for later use; Step 3: adding the mixture A to an extruder for preparing the inner tube layer (8), extruding the mixture through the extruder, and water-cooling the extruded tube to obtain the inner tube layer (8); Step 4: adding the mixture B to an extruder for preparing the filling core layer (9), extruding the mixture B through the extruder to wrap the inner tube layer (8), water-cooling the extruded tube to form a filling core layer (9) outside the inner tube layer (8); Step 5: spirally wrapping the flexible metal wire (10) around the outer surface of the filling core layer (9) and preliminarily fixing it; Step 6: Adding the mixture A to an extruder for preparing the outer tube layer (11), extruding the mixture A through the extruder to wrap the filling core layer (9), and water-cooling the extruded tube to form the outer tube layer (11) outside the filling core layer (9); Step 7: Pull the formed cable protection tube by a pulling device, cut the cable protection tube according to the use length of the cable protection tube, set an internal thread (5) on the inner wall of one end of the cable protection tube, set an external thread (6) on the outer wall of the other end of the cable protection tube, and open grooves (2) on the upper surfaces of both ends of the cable protection tube; Step 8: Use polyurethane coating to evenly coat the outer surface of the cable protection tube to form an anti-corrosion layer (13) on the outer surface of the cable protection tube.

8. The method for preparing a high-toughness MPP cable protection tube according to claim 7, characterized in that: The modified polypropylene in step 1 is prepared by first injecting nitrogen into the reactor to empty it, and then sequentially adding propylene gas, anhydrous toluene, a toughening monomer, an anti-corrosion monomer, triisobutylaluminum and triphenylcarbon tetraborate to carry out a polymerization reaction. After a period of polymerization, anhydrous ethanol is added to terminate the reaction, and the reaction product is poured into a hydrochloric acid ethanol solution and mixed, and the mixture is filtered, washed and dried in sequence to obtain the obtained product.

9. The method for preparing a high-toughness MPP cable protection tube according to claim 7, characterized in that: The compatibilizer in step 1 is maleic anhydride grafted polyolefin, the flame retardant is aluminum hydroxide, the toughening agent is ethylene propylene diene monomer rubber, the dispersant is calcium stearate, and the antioxidant is a phosphite antioxidant.

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