Optical fiber composite copper alloy contact wire for electrified railway and preparation method thereof

Abstract

The invention relates to an optical fiber composite copper alloy contact wire for electrified railways and a preparation method thereof. The preparation method comprises the following steps: continuously casting, continuously extruding and drawing and grooving a copper alloy billet, and looping and coloring the optical fiber; introducing an optical fiber unit into a copper alloy rod after drawing and grooving and drawing the rod into an optical fiber composite copper alloy contact wire; the invention aims at the technical difficulties in the prior art that the degree of automation of contact network inspection and detection is low and manual inspection and judgment are required, and provides an optical fiber composite copper alloy contact wire for electrified railways and a preparation process thereof. The optical fiber unit can be composited into the copper alloy contact wire to sample, collect, analyze and warn the physical quantity data of the contact wire such as operating temperature, stress, vibration, electromagnetic field and the operating status data such as bow-net detachment, so as to avoid the adverse effects of manual misjudgment on the operation of the contact wire and the contact network, and greatly improve the intelligent safety management level of my country's contact network.

Description

Technical Field

[0001] The invention relates to the field of railway electrification, in particular to an optical fiber composite copper alloy contact wire for electrified railways, and provides a preparation method thereof. Background Art

[0002] As of the end of 2021, my country's total railway operating mileage has reached 150,000 kilometers, the railway electrification rate has reached 73.3%, and the national railway network density is 156.7 kilometers / 10,000 square kilometers; as the railway electrification rate becomes higher and higher, the demand for contact network operation safety is also increasing.

[0003] As a component of the contact network, the contact wire is extremely important for the safe operation of the contact network. Due to the harsh working environment of the contact network and the prone to failure, the current daily operation and maintenance is mostly carried out by regular or irregular manual inspections, vehicle inspections, and inspections by inspection vehicles, which also requires a large number of workers with professional experience in contact network work. On the one hand, it takes a lot of manpower to achieve timely detection and timely troubleshooting. When the contact network fails, it is impossible to completely repair the contact network in time; on the other hand, manual and vehicle inspections cannot achieve continuous monitoring and recording of the operating status and technical parameters of the contact network, and a large number of manual inspections and judgments are also prone to misjudgments.

[0004] The Chinese patent with publication number CN213354232U provides "an embedded optical fiber contact wire". The utility model inserts a cylindrical stainless steel sheath inside the contact wire and embeds the optical fiber through the stainless steel sheath; the existing technology provided by the Chinese patent with publication number CN213354232U has the following problems: the stainless steel material and the copper alloy body of the contact wire are prone to electrochemical corrosion, which is not conducive to the service life and safety of the contact wire. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to overcome the technical difficulties in the prior art that the level of automation of contact network inspection and detection is low and manual inspection and judgment are required, and to provide an optical fiber composite copper alloy contact wire for electrified railways and a preparation process thereof. By compounding the optical fiber unit into the copper alloy contact wire, the contact wire operation data can be automatically sampled, collected, analyzed and warned.

[0006] In order to solve the above technical problems, the present invention provides an optical fiber composite copper alloy contact wire for electrified railway and a preparation method thereof, wherein the preparation method comprises the following steps:

[0007] Step 1: coating the surfaces of single-mode optical fiber and multi-mode optical fiber with different colors respectively to obtain colored optical fiber;

[0008] Step 2:

[0009] Step 2-1: using a copper alloy with a copper mass percentage of 80% as a raw material, and sequentially subjecting it to upward continuous casting, melting, diffusion and homogenization treatment to obtain a billet with a diameter of 20 to 25 mm;

[0010] Step 2-2: forming the blank into a copper alloy rod with a diameter of 28 to 30 mm by continuous extrusion, and cooling the blank in cooling water at a temperature of 20±0.5° C.;

[0011] Step 2-3: drawing the copper alloy rod obtained in step 2-2 to a diameter of 19 to 21 mm;

[0012] Step 2-4: slotting the copper alloy rod processed in step 2-3, using a first die, a second die and a third die in sequence for slotting;

[0013] Among them, the drawing compression ratio of the first die is 21%±1%. After drawing, a curved surface is formed on one side of the cross section of the copper alloy rod, and the curved surface and the two sides of the cross section of the copper alloy rod form a first recessed portion. The angle between the two sides of the first recessed portion is 130°±1°, and the angle between the two sides of the curved surface and the horizontal line is 80°; the drawing compression ratio of the second die is 19%±1%. After drawing, a second recessed portion is formed on the curved surface. The use of the second die makes the angle between the two sides of the first recessed portion become 105°±1°, and the angle between the two sides of the curved surface and the horizontal line become 70°; the drawing compression ratio of the third die is 17%±1%. After drawing, the second recessed portion forms a groove. The use of the third die makes the angle between the two sides of the first recessed portion become 90°±1°, and the angle between the two sides of the curved surface and the horizontal line become 60°;

[0014] Step 3: introducing the colored optical fiber obtained in step 1 into the groove obtained in step 2; then closing and welding the edges of both sides of the groove through a closed mold to obtain an optical fiber composite copper alloy contact wire blank; wherein the drawing compression ratio of the closed mold is 16%±1%, and after drawing, the angle between the two sides of the first recessed portion becomes 85°±1°, and the angle between the two sides of the arc surface and the horizontal line becomes 57°;

[0015] Step 4: The optical fiber composite copper alloy contact wire blank obtained in step 3 is drawn into an optical fiber composite copper alloy contact wire finished product through a finished product mold, the drawing compression ratio of the finished product mold is 7%±1%, and the angle between the two sides of the arc surface and the horizontal line becomes 51°.

[0016] In one embodiment of the present invention, the copper alloy includes copper-magnesium alloy, copper-silver alloy or copper-tin alloy.

[0017] In one embodiment of the present invention, the groove is closed to form a mounting hole after being processed by the closing mold.

[0018] In one embodiment of the present invention, the mounting hole has a teardrop shape, and the cross-sectional area of ​​the mounting hole does not exceed 2% of the calculated cross-sectional area of ​​the finished optical fiber composite copper alloy contact wire.

[0019] In one embodiment of the present invention, after being drawn by the third die, the groove has a width of 3 mm and a depth of 4.5 mm.

[0020] In one embodiment of the present invention, after being drawn by the third die, the edges on both sides of the groove are convex.

[0021] In one embodiment of the present invention, the excess length of the colored optical fiber in the copper alloy contact wire is not less than 1‰.

[0022] In one embodiment of the present invention, when welding the edges on both sides of the groove, argon arc welding is used to weld the gap at the outlet of the closed mold.

[0023] In order to solve the above-mentioned technical problems, the present invention provides an optical fiber composite copper alloy contact wire, which is obtained by the above-mentioned preparation method.

[0024] The present invention also provides a cable, comprising the optical fiber composite copper alloy contact wire.

[0025] The above technical solution of the present invention has the following advantages compared with the prior art:

[0026] The present invention discloses an optical fiber composite copper alloy contact wire for electrified railways and a preparation method thereof. In the preparation method, the drawing die of the copper alloy contact wire is improved, and the drawing and grooving process of the copper alloy contact wire is optimized by designing the drawing and grooving angle and the drawing and compression ratio. The sharp angle design facilitates positioning and eliminates the currently used positioning die, thereby avoiding damage to the outer copper alloy by the positioning die.

[0027] In addition, the optical fiber composite copper alloy contact wire prepared by this preparation method has the optical fiber unit compounded inside the copper alloy contact wire, which on the one hand meets the functional requirements of the contact wire and the contact network for carrying and transmitting electric energy, and on this basis realizes the function of optical fiber communication; on the other hand, due to the introduction of the optical fiber unit, it can be used as a sensor to build an intelligent monitoring and perception system for the contact network, and combined with the distributed optical fiber monitoring system to perform real-time monitoring of the operating status of the contact wire and the contact network, and sample, collect, analyze and warn the operating status data of the contact line such as operating temperature, stress, vibration, electromagnetic field and other physical quantities and bow-net detachment, etc., to solve the problems of low automation level of contact network inspection and detection, manual inspection and untimely fault detection in the existing technology, avoid the adverse effects of manual misjudgment on the operation of the contact wire and the contact network, and greatly improve the level of intelligent safety management of my country's contact network. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 It is a schematic flow chart of a method for preparing an optical fiber composite copper alloy contact wire in a preferred embodiment of the present invention;

[0030] Figure 2 It is a cross-sectional schematic diagram of an optical fiber composite copper alloy contact wire in a preferred embodiment of the present invention;

[0031] Figure 3 for Figure 1 A schematic cross-sectional view of the blank after being processed by the first die, the second die and the third die in the copper alloy drawing and grooving step in the preparation method shown;

[0032] Figure 4 for Figure 1 A schematic cross-sectional view of the optical fiber composite copper alloy contact wire obtained after being processed by a closed mold and a finished mold in the preparation method shown.

[0033] Explanation of the reference numerals in the accompanying drawings in the specification: 1. optical fiber unit; 2. colored optical fiber; 3. fiber paste; 4. copper alloy rod; 5. arc surface; 6. first recessed portion; 7. second recessed portion; 8. mounting hole; 9. groove. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0035] Example

[0036] In order to solve the technical difficulties of low automation level of overhead line inspection and detection in the existing technology and the need for manual inspection and judgment, Figure 1 As shown, the present invention provides an optical fiber composite copper alloy contact wire for electrified railways and provides a preparation method thereof, wherein the preparation method comprises the following steps:

[0037] Step 1: Since the maximum operating temperature of the copper alloy contact wire when carrying current can reach 150°C, the preparation method provided in the embodiment of the present invention preferably uses single-mode and multi-mode optical fibers that are resistant to a temperature of 150°C, and loops and colors the colorless single-mode optical fiber and the colorless multi-mode optical fiber, and coats different colors on their surfaces to obtain colored optical fiber 2. The excess length of the colored optical fiber 2 in the copper alloy contact wire is not less than 1‰ to ensure that the colored optical fiber 2 is not damaged when the optical fiber composite copper alloy contact wire is stretched. The coloring operation facilitates the distinction of the optical fiber in subsequent processes such as installation and use, and the coloring layer has a certain protective effect on the optical fiber.

[0038] Step 2:

[0039] Step 2-1: A copper alloy with a copper mass percentage of 80% is used as a raw material, and the copper alloy includes a copper-magnesium alloy, a copper-silver alloy or a copper-tin alloy. The raw materials are successively subjected to upward continuous casting, melting and diffusion, and the copper alloy components are more evenly diffused in the copper liquid in the melting furnace, and then homogenized in a holding furnace to obtain an oxygen-free homogeneous copper alloy rod blank with a diameter of 20 to 25 mm; it should be noted that the inventor of this case has found through research that when the diameter of the obtained oxygen-free homogeneous copper alloy rod blank is 20 mm, the preparation efficiency is low due to the small diameter; when the diameter of the obtained oxygen-free homogeneous copper alloy rod blank is 25 mm, the cooling effect is not ideal during cooling due to the large diameter, which further affects the mechanical properties of the finished product; therefore, the embodiment of the present invention preferably designs the diameter of the oxygen-free homogeneous copper alloy rod to be 22 mm, which not only meets the efficiency requirements of the preparation process, but also achieves ideal cooling effect and mechanical properties.

[0040] Step 2-2: The oxygen-free homogeneous copper alloy rod blank obtained in the step 2-1 is formed into a copper alloy rod 4 with a diameter of 28 to 30 mm by continuous extrusion, and cooled in cooling water at a temperature of 20±0.5°C; the copper alloy rods 4 with different diameters are respectively drawn into copper alloy contact wires of different specifications. The continuous extrusion process can refine the copper alloy grains and improve the conductivity, greatly enhance the mechanical strength, improve the electrical properties, and increase the diameter of the copper alloy rod 4, thereby increasing the drawing compression ratio of the subsequent drawing section.

[0041] Step 2-3: The copper alloy rod 4 obtained in step 2-2 is drawn through a multi-pass drawing circular die to a diameter of 19 to 21 mm. The drawing operation can improve the tensile strength of the copper alloy rod 4 and obtain a copper alloy rod 4 that meets the grooving requirements. Specifically, the copper alloy rods 4 of different diameters after processing in step 2-3 can be drawn into copper alloy contact wires of different specifications.

[0042] Step 2-4: slotting the copper alloy rod 4 processed in step 2-3, using a first die, a second die and a third die in sequence to obtain a copper alloy contact wire shape blank;

[0043] Among them, refer to Figure 3As shown, the drawing compression ratio of the first die is 21%±1%. After drawing by the first die, a curved surface 5 is formed on one side of the cross section of the copper alloy rod 4. The curved surface 5 and the two sides of the cross section of the copper alloy rod 4 respectively form a first recessed portion 6. The angle between the two sides of the first recessed portion 6 is 130°±1°, and the angle between the two sides of the curved surface 5 and the horizontal line is 80°, which is convenient for subsequent drawing and positioning. The inventors of this case have found that in the existing copper alloy contact wire preparation process, a positioning die is used for pretreatment before drawing, and the positioning die will cause damage to the outer layer of copper alloy material. In order to solve this technical problem, in an embodiment of the present invention, by designing the drawing compression ratio and the drawing angle of the drawing and slotting die, an 80° acute angle design is used instead of a rounded corner for easy positioning, thereby simplifying the steps for using the positioning die in the existing copper alloy contact wire preparation, and eliminating the wear of the positioning die on the outer layer of copper alloy. The drawing compression ratio of the second die is 19%±1%. After drawing, a second recessed portion 7 is formed on the arc surface 5. The use of the second die makes the angle between the two sides of the first recessed portion 6 become 105°±1°, and the angle between the two sides of the arc surface 5 and the horizontal line become 70°; the drawing compression ratio of the third die is 17%±1%. After drawing, the second recessed portion 7 forms a groove 9, and the width of the groove 9 is 3mm and the depth is 4.5mm; the use of the third die makes the angle between the two sides of the first recessed portion 6 become 90°±1°, and the angle between the two sides of the arc surface 5 and the horizontal line becomes 60°.

[0044] Step 3: Reference Figure 4 As shown, the fiber paste 3 and the colored optical fiber 2 obtained in step 1 are combined into an optical fiber unit 1, which is introduced into the groove 9 obtained in step 2 through a double-layer introduction tube; then the edges on both sides of the groove 9 are closed and welded through a closed mold, and when the edges on both sides of the groove 9 are welded, argon arc welding is used to weld the gaps at the outlet of the closed mold to prevent the fiber paste 3 from leaking out, thereby obtaining an optical fiber composite copper alloy contact wire blank; wherein the drawing compression ratio of the closed mold is 16%±1%, and after drawing, the angle between the two sides of the first recessed portion 6 becomes 85°±1°, and the angle between the two sides of the arc surface 5 and the horizontal line becomes 57°.

[0045] Specifically, the groove 9 is closed after being processed by the closing mold to form a mounting hole 8, the mounting hole 8 has a teardrop shape, and the cross-sectional area of ​​the mounting hole 8 does not exceed 2% of the calculated cross-sectional area of ​​the finished optical fiber composite copper alloy contact wire.

[0046] Furthermore, in an embodiment of the present invention, the groove 9 after being processed by the third mold has its two side edges convex; the convex design makes it easier to weld during subsequent closed mold processing, and the mounting hole 8 has better sealing performance, and no other components such as a sleeve are required to seal the optical fiber unit 1, thereby preventing electrochemical corrosion between other sleeve materials and the contact wire copper alloy body, thereby ensuring the service life and safety of the finished product.

[0047] Step 4: Reference Figure 4 As shown, the optical fiber composite copper alloy contact wire blank obtained in step 3 is drawn into an optical fiber composite copper alloy contact wire finished product through a finished product mold, the drawing compression ratio of the finished product mold is 7%±1%, and the angle between the two sides of the arc surface 5 and the horizontal line becomes 51°.

[0048] In the preparation method described in the embodiment of the present invention, the drawing process of the copper alloy contact wire is divided into two parts. The first part of the drawing process is as follows: Figure 3 As shown, it includes the processing of the first die, the second die and the third die, and the copper alloy contact wire body is grooved and the outer contour is initially formed; the second part of the drawing process refers to Figure 4 As shown, the processing includes the closed mold and the finished mold, the colored optical fiber 2 and the fiber paste 3 are pre-buried in the groove 9 and the groove 9 is closed, and the closed groove 9 is welded by argon arc welding to ensure the sealing and consistency of the outer edge of the groove 9.

[0049] An embodiment of the present invention also provides an optical fiber composite copper alloy contact wire, which is obtained by the above-mentioned preparation method, and its cross-sectional area, specification size, angle and electromechanical properties meet the standard size and performance requirements of TB / T 2809-2017 "Copper and Copper Alloy Contact Wire for Electrified Railway".

[0050] Furthermore, an embodiment of the present invention also provides a cable, including the above-mentioned optical fiber composite copper alloy contact wire, and the cable is applied in the field of railway electrification to improve the level of intelligent management of the contact network.

[0051] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for preparing an optical fiber composite copper alloy contact wire, characterized in that: The following steps are involved: Step 1: coating the surfaces of single-mode optical fiber and multi-mode optical fiber with different colors respectively to obtain colored optical fiber; Step 2: Step 2-1: using a copper alloy with a copper mass percentage of 80% as a raw material, and sequentially subjecting it to upward continuous casting, melting, diffusion and homogenization treatment to obtain a billet with a diameter of 20 to 25 mm; Step 2-2: forming the blank into a copper alloy rod with a diameter of 28 to 30 mm by continuous extrusion, and cooling the blank in cooling water at a temperature of 20±0.5° C.; Step 2-3: drawing the copper alloy rod obtained in step 2-2 to a diameter of 19 to 21 mm; Step 2-4: slotting the copper alloy rod processed in step 2-3, using a first die, a second die and a third die in sequence for slotting; Among them, the drawing compression ratio of the first die is 21%±1%. After drawing, a curved surface is formed on one side of the cross section of the copper alloy rod, and the curved surface and the two sides of the cross section of the copper alloy rod form a first recessed portion. The angle between the two sides of the first recessed portion is 130°±1°, and the angle between the two sides of the curved surface and the horizontal line is 80°; the drawing compression ratio of the second die is 19%±1%. After drawing, a second recessed portion is formed on the curved surface. The use of the second die makes the angle between the two sides of the first recessed portion become 105°±1°, and the angle between the two sides of the curved surface and the horizontal line become 70°; the drawing compression ratio of the third die is 17%±1%. After drawing, the second recessed portion forms a groove. The use of the third die makes the angle between the two sides of the first recessed portion become 90°±1°, and the angle between the two sides of the curved surface and the horizontal line become 60°; Step 3: introducing the colored optical fiber obtained in step 1 into the groove obtained in step 2; then closing and welding the edges of both sides of the groove through a closed mold to obtain an optical fiber composite copper alloy contact wire blank; wherein the drawing compression ratio of the closed mold is 16%±1%, and after drawing, the angle between the two sides of the first recessed portion becomes 85°±1°, and the angle between the two sides of the arc surface and the horizontal line becomes 57°; Step 4: The optical fiber composite copper alloy contact wire blank obtained in step 3 is drawn into an optical fiber composite copper alloy contact wire finished product through a finished product mold, the drawing compression ratio of the finished product mold is 7%±1%, and the angle between the two sides of the arc surface and the horizontal line becomes 51°.

2. The method for preparing an optical fiber composite copper alloy contact wire according to claim 1, characterized in that: The copper alloy includes a copper-magnesium alloy, a copper-silver alloy or a copper-tin alloy.

3. The method for preparing an optical fiber composite copper alloy contact wire according to claim 1, characterized in that: The groove is closed after being processed by the closing mold to form a mounting hole.

4. The method for preparing an optical fiber composite copper alloy contact wire according to claim 3, characterized in that: The mounting hole has a teardrop shape, and the cross-sectional area of ​​the mounting hole does not exceed 2% of the calculated cross-sectional area of ​​the finished optical fiber composite copper alloy contact wire.

5. The method for preparing an optical fiber composite copper alloy contact wire according to claim 1, characterized in that: After being drawn by the third die, the groove has a width of 3 mm and a depth of 4.5 mm.

6. The method for preparing an optical fiber composite copper alloy contact wire according to claim 5, characterized in that: After being drawn by the third die, the edges on both sides of the groove are convex.

7. The method for preparing an optical fiber composite copper alloy contact wire according to claim 1, characterized in that: The excess length of the colored optical fiber in the copper alloy contact wire is not less than 1‰.

8. The method for preparing an optical fiber composite copper alloy contact wire according to claim 1, characterized in that: When the edges on both sides of the groove are welded, argon arc welding is used to weld the gap at the outlet of the closed mold.

9. An optical fiber composite copper alloy contact wire, characterized in that: The optical fiber composite copper alloy contact wire is obtained by the preparation method according to any one of claims 1 to 8.

10. A cable, characterized in that: Comprising the optical fiber composite copper alloy contact wire as described in claim 9.

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