A 1960 grade high-strength paint-free suspension bridge sealing sling and a manufacturing method thereof

Abstract

A kind of 1960-grade high-strength coating-free suspension bridge sealing sling, comprising sealing wire rope, sleeve, lower end waterproof cover, anchoring material, anchor cup and fork-shaped lug. The sealing wire rope is composed of single rope, round strand layer and three layers of Z-shaped steel wire, and the structure is 36WS+20+26Z6.6+35Z6.1+42Z6.12. The two ends of the sealing wire rope are evenly separated by separating the wires, and are arranged in the corresponding anchor cups. The anchor cups are cast with anchoring material to fix the separated steel wires in the anchor cups, and the fork-shaped lugs are connected with the anchor cups by screwing. The anchoring material is zinc-copper alloy, and all the steel wires have a zinc-aluminum rare earth alloy coating. The cross section of the sealing wire rope is a circular sealing structure, and no protective layer is needed. The gap and surface of the single rope and the round strand layer are filled with zinc-rich protective ointment. The tensile strength of the sealing wire rope is 1960-grade. It meets the requirements of high strength, corrosion resistance and fatigue resistance of suspension bridge sling.

Description

Technical Field

[0001] This invention relates to suspension bridge cables, and more particularly to a 1960-grade high-strength uncoated sealed suspension bridge cable and its manufacturing method, belonging to the field of metal product processing technology. Background Technology

[0002] As the core load-bearing component connecting the main cable and stiffening girder on a suspension bridge, the suspenders bear the static load of the bridge, the pulsating cyclic load stress caused by road vehicle traffic and wind vibration, as well as the effects of sunlight exposure and rain erosion. Therefore, the suspenders are required to have high strength, good fatigue resistance, and corrosion resistance. The operational status of the suspenders and their components is quite complex, and their proper functioning is crucial to the operational safety and lifespan of the entire bridge.

[0003] Currently, the suspension bridge cable structure in the industry consists of two types: round wire rope cable and parallel wire PE sheath cable. The round wire rope cable has poor structural sealing because it uses round steel wires twisted into round strands before rope twisting. The parallel wire PE sheath cable has poor structural stability because it uses round steel wires combined in parallel to form a regular hexagon. Therefore, it is necessary to use plastic coating to secure the structure and prevent corrosion.

[0004] Sealed steel wire ropes have been successfully applied in large-scale spatial structures and cableway ropes, but due to the technical bottleneck in manufacturing large-specification, high-strength Z-shaped steel wires, the technical level at home and abroad can only reach grade 1570 at most. Summary of the Invention

[0005] The present invention aims to solve the problem of manufacturing a sling with a 1960-grade sealed steel wire rope as the sling body and requiring no coating, to replace existing high-strength parallel steel wire or round strand steel wire rope slings; at the same time, it aims to design a 1960-grade high-strength weather-resistant sealed steel wire rope sling body and a water-proof anchor fixed together, which requires no coating and solves the technical problems of low corrosion resistance of round strand steel wire rope slings and easy aging, cracking and water ingress of PE in parallel steel wire rope slings.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A high-strength, paint-free, grade 1960 suspension bridge sealing cable comprises a sleeve, a sealing steel wire rope, a lower waterproof cover, anchoring material, an anchor cup, and a forked lug plate. One end of the sealing steel wire rope is evenly split and spread out, passing through the lower waterproof cover and placed in the corresponding anchor cup. Anchoring material is cast inside the anchor cup to fix the spread sealing steel wire rope inside. The forked lug plate is connected to the anchor cup by threaded engagement. The other end of the sealing steel wire rope is also evenly split and spread out, then cast with anchoring material and placed inside the sleeve and anchor cup.

[0008] The sealing wire rope is composed of a single strand, a round strand layer, and three layers of Z-shaped wires. The sealing wire rope structure is 36WS+20+26Z6.6+35Z6.1+42Z6.12.

[0009] The surface of the steel wires in the sealed steel wire rope has a zinc-aluminum rare earth alloy coating.

[0010] The cross-section of the sealing steel wire rope is a circular sealing structure, so no protective coating is required.

[0011] The gaps and surfaces of the single-strand rope and the round strand layer are filled with zinc-rich protective grease.

[0012] The anchoring material is a zinc-copper alloy.

[0013] A method for manufacturing a 1960-grade high-strength, uncoated, sealed suspension cable for a cable-stayed bridge; comprising the following steps performed sequentially:

[0014] Step 1, Cold Drawing: For Z-shaped steel wire, high-carbon microalloyed wire rod with a diameter of 13mm and a tensile strength ≥1280MPa and a reduction of area ≥30% is used. A gradually changing drawing die is fabricated following a drawing process route from round to elliptical to Z-shaped. Then, continuous cold drawing is performed on a 1270mm diameter drum drawing machine. During each pass of drawing, the wire's infeed and outfeed directions are kept consistent to obtain Z6.1, Z6.6, and Z6.12 diameter steel wires. For round steel wire, high-carbon wire rod with a diameter of 8–11mm is used. This wire is treated with lead bath quenching and has a tensile strength ≥1310MPa. Multiple passes of continuous cold drawing are then performed to obtain round steel wire with a diameter of 2.95–5.5mm.

[0015] Step 2, Coating: After the cold-drawn steel wire is subjected to ultrasonic water washing → pickling → water washing → electrolytic alkaline washing → water washing → drying, it enters a pure zinc plating bath to form a thin transition coating on the surface. Then, a flux is impregnated on the surface of the pure zinc coating. Finally, it enters a zinc-aluminum-rare earth alloy plating bath for alloy plating. The coating thickness and aluminum content meet the Class A requirements of GB / T20492-2006 "Zinc-5% Aluminum-Mixed Rare Earth Alloy Coated Steel Wire and Strand".

[0016] Step 3, core twisting and oiling: Twist qualified zinc-aluminum rare earth alloy coated round steel wire into 1×36WS single strand rope on a tubular stranding machine and use it as the core. Then use a series unit to wrap the round strand layer. At the same time, heat and melt zinc-rich grease and spray it onto the surface and gaps of the single strand rope and the round strand layer. After twisting, wipe the surface.

[0017] Step 4, Sealing Layer Twisting: Using qualified zinc-aluminum rare earth alloy coated Z-shaped steel wire, the outer sealing layer of the round strand is twisted layer by layer on a multi-frame composite rope forming machine. During twisting, the small face of the Z-shaped steel wire is used for positioning to form interlocking rings. The tension of the wire is evenly controlled. After twisting, the vertical and horizontal directions are reinforced by roller pressing to ensure tight interlocking. The twisting directions of adjacent layers of the three sealing layers are opposite. Finally, a 73mm diameter sealed steel wire rope is formed.

[0018] Step 5, Lower waterproof cover and drainage design: Sleeving and fixing the lower waterproof cover can prevent rainwater from flowing directly into the anchor cup and sleeve and causing corrosion; at the same time, a drainage design of 2×φ6mm inclined holes is made at 75° on the lower side of the lower waterproof cover to prevent water seepage and water accumulation in the lower waterproof cover, thereby improving the corrosion resistance of the sling.

[0019] Step 6, Alloy Casting: Distribute the steel wires at both ends of the sealing steel wire rope evenly from the outside to the inside, and place them in the corresponding anchor cups, ensuring that the sealing steel wire rope coincides with the central axis of the anchor cup. Preheat the inner cavity of the anchor cup to 150°C, and cast zinc-copper alloy anchoring material in the anchor cup at a molten state of 450°C~470°C. Finally, allow it to cool and solidify naturally to form a sealing sling.

[0020] The beneficial effects of adopting the above technical solution are:

[0021] Previously, sealed steel wire ropes were mainly used in large spatial structures and cableways, among other load-bearing components. Due to their stable sealing structure, they possess superior corrosion resistance and fatigue resistance. Furthermore, the sealed steel wire rope has a large metal area and a smaller diameter compared to slings of equivalent strength. Its helical surface structure also provides better resistance to wind, rain, and vibration. This invention applies sealed steel wire ropes to the construction of suspension bridge cables, and innovates on the strength grade, corrosion resistance grade of the coating, and protection of the core strands of the zinc-aluminum alloy sealed steel wire rope. It also incorporates a drainage design to address potential water leakage in the lower anchor head waterproof cover of the cable, significantly increasing the cable's corrosion resistance and durability, reducing maintenance costs, and further extending its service life. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the paint-free suspension bridge sealing cable of the present invention.

[0023] 1-Sleeve, 2-Sealed steel wire rope, 3-Lower end waterproof cover, 4-Anchoring material, 5-Anchor cup, 6-Fork-shaped ear plate.

[0024] Figure 2 for Figure 1 A schematic diagram of the cross-section of the central sealing steel wire rope.

[0025] 21-Z-type steel wire, 22-round strand layer, 23-single strand rope.

[0026] Figure 3 for Figure 1 Schematic diagram of the lower middle waterproof cover structure. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0028] A high-strength, paint-free, grade 1960 suspension bridge sealing cable comprises a sleeve 1, a sealing steel wire rope 2, a lower waterproof cover 3, anchoring material 4, an anchor cup 5, and a forked lug 6. One end of the sealing steel wire rope 2 is evenly split and spread out, passing through the lower waterproof cover 3 and placed in the corresponding anchor cup 5. Anchoring material 4 is cast inside the anchor cup 5 to fix the spread sealing steel wire rope 2 inside the anchor cup 5. The forked lug 6 is connected to the anchor cup 5 by threaded engagement. The other end of the sealing steel wire rope 2 is also evenly split and spread out, and then cast with anchoring material 4 and placed inside the sleeve 1 and the anchor cup 5.

[0029] The sealing wire rope 2 is composed of a single strand rope 23, a round strand layer 22 and three layers of Z-shaped wires 21. The structure of the sealing wire rope 2 is 36WS+20+26Z6.6+35Z6.1+42Z6.12.

[0030] The surface of the steel wire of the sealed steel wire rope 2 is coated with a zinc-aluminum rare earth alloy.

[0031] The cross-section of the sealed steel wire rope 2 is a circular sealing structure, so no further protective coating is required;

[0032] The gaps and surfaces of the single-strand rope 23 and the circular strand layer 22 are filled with zinc-rich protective grease.

[0033] The anchoring material 4 is a zinc-copper alloy.

[0034] A method for manufacturing a 1960-grade high-strength, uncoated, sealed suspension cable for a cable-stayed bridge; comprising the following steps performed sequentially:

[0035] Step 1, Cold Drawing: For Z-shaped steel wire, high-carbon microalloyed wire rod with a diameter of 13mm and a tensile strength ≥1280MPa and a reduction of area ≥30% is used. A gradually changing drawing die is fabricated following a drawing process route from round to elliptical to Z-shaped. Then, continuous cold drawing is performed on a 1270mm diameter drum drawing machine. During each pass of drawing, the wire's infeed and outfeed directions are kept consistent to obtain Z6.1, Z6.6, and Z6.12 diameter steel wires. For round steel wire, high-carbon wire rod with a diameter of 8–11mm is used. This wire is treated with lead bath quenching and has a tensile strength ≥1310MPa. Multiple passes of continuous cold drawing are then performed to obtain round steel wire with a diameter of 2.95–5.5mm.

[0036] Step 2, Coating: After the cold-drawn steel wire is subjected to ultrasonic water washing → pickling → water washing → electrolytic alkaline washing → water washing → drying, it enters a pure zinc plating bath to form a thin transition coating on the surface. Then, a flux is impregnated on the surface of the pure zinc coating. Finally, it enters a zinc-aluminum-rare earth alloy plating bath for alloy plating. The coating thickness and aluminum content meet the Class A requirements of GB / T20492-2006 "Zinc-5% Aluminum-Mixed Rare Earth Alloy Coated Steel Wire and Strand".

[0037] Step 3, core twisting and oiling: Twist qualified zinc-aluminum rare earth alloy coated round steel wire into 1×36WS single strand rope 23 on a tubular stranding machine and use it as the core. Then use a series unit to twist the round strand layer 22. At the same time, heat and melt zinc-rich grease and spray it on the surface and gaps of the single strand rope 23 and the round strand layer 22. After twisting, wipe the surface.

[0038] Step 4, Sealing Layer Twisting: Using qualified zinc-aluminum rare earth alloy coated Z-shaped steel wire 21, the outer sealing layer of the round strand layer 22 is twisted layer by layer on a multi-frame composite rope forming machine. During twisting, the small face of the Z-shaped steel wire 21 is used for positioning to form interlocking rings. The tension of the wire is evenly controlled. After twisting, the vertical and horizontal directions are reinforced by roller pressing to ensure tight interlocking. The twisting directions of adjacent layers of the three sealing layers are opposite. Finally, a 73mm diameter sealed steel wire rope 2 is formed.

[0039] Step 5, lower waterproof cover and flow guide design: Sleeve and fix the lower waterproof cover 3 to prevent rainwater from flowing directly into the anchor cup 5 and sleeve 1 and causing corrosion; at the same time, 2×φ6mm inclined hole flow guide design is made at 75° on the lower side of the lower waterproof cover 3 to prevent water seepage and water accumulation in the lower waterproof cover (3) and improve the anti-corrosion level of the sling.

[0040] Step 6, Alloy Casting: Distribute the steel wires at both ends of the sealing steel wire rope 2 evenly from the outside to the inside, and place them in the corresponding anchor cup 5, ensuring that the sealing steel wire rope 2 coincides with the central axis of the anchor cup 5. Preheat the inner cavity of the anchor cup 5 to 150°C, and cast zinc-copper alloy anchoring material 4 in the anchor cup 5 in a molten state at a temperature of 450°C to 470°C. Finally, allow it to cool and solidify naturally to form a sealing sling.

[0041] The core technologies of this invention are: First, to manufacture a sling with a 1960-grade sealed steel wire rope as the sling body, which is paint-free, to replace existing high-strength parallel steel wire or round strand steel wire rope slings. Second, to design a paint-free sealed sling that is fixed to a 1960-grade high-strength weather-resistant sealed steel wire rope body and a water-proof anchor, solving the problems of low corrosion resistance of round strand steel wire rope slings and easy aging, cracking, and water ingress of PE in parallel steel wire rope slings. Because the sealed steel wire rope body is designed with interlocking Z-shaped zinc-aluminum rare earth alloy steel wires forming a fully sealed outer layer, the core strands are filled with zinc-rich grease for corrosion protection, and the lower anchor uses a water-proofing and diversion mechanism, it has superior corrosion resistance. At the same time, the sealed steel wire rope body has a large metal area, and compared to slings of equivalent strength, its diameter is the smallest. Furthermore, the spiral structure on the surface gives the sealed sling better resistance to wind, rain, and vibration.

[0042] This invention, through the design of a high-strength sealed steel wire rope sling production process, effectively controls the strength, toughness, and zinc-aluminum-rare-earth alloy coating parameters of the Z-shaped steel wire, as well as the uniformity of the protective grease filling in the core strands of the sealed steel wire rope and the anchorage fixing efficiency during the production process. This ensures the quality of the sling and has successfully developed a paint-free sealed steel wire rope sling for the 1960-class suspension bridge. The sling has been tested by authoritative testing institutions, and all parameters meet relevant standards and design requirements. This lays a solid foundation for the design, construction, and replacement of long-life slings in suspension bridge projects, while simultaneously enhancing the influence and competitiveness of my country's sling products and technologies in the international market.

Claims

1. A high-strength, uncoated, sealed suspension cable for a 1960-grade cable-stayed bridge, characterized in that: It comprises a sleeve (1), a sealing wire rope (2), a lower waterproof cover (3), anchoring material (4), an anchor cup (5), and a fork-shaped ear plate (6); one end of the sealing wire rope (2) is evenly split and spread out, passes through the lower waterproof cover (3) and is placed in the corresponding anchor cup (5), and the anchoring material (4) is poured into the anchor cup (5) to fix the spread sealing wire rope (2) in the anchor cup (5), and the fork-shaped ear plate (6) is connected to the anchor cup (5) by threaded engagement; the other end of the sealing wire rope (2) is also evenly split and spread out, and the anchoring material (4) is poured and placed in the sleeve (1) and the anchor cup (5); The sealing wire rope (2) is composed of a single strand rope (23), a round strand layer (22) and three layers of Z-shaped wires (21). The structure of the sealing wire rope (2) is 36WS+20+26Z6.6+35Z6.1+42Z6.

12. The surface of the steel wire of the sealed steel wire rope (2) is coated with a zinc-aluminum rare earth alloy. The cross-section of the sealed steel wire rope (2) is a circular sealing structure, so no protective coating is required; The gaps and surfaces of the single strand rope (23) and the round strand layer (22) are filled with zinc-rich protective grease; The anchoring material (4) is a zinc-copper alloy.

2. The manufacturing method of a 1960-grade high-strength, uncoated, sealed suspension bridge cable as described in claim 1; characterized in that: It involves the following steps implemented sequentially: Step 1, Cold Drawing: For Z-shaped steel wire, high-carbon microalloyed wire rod with a diameter of 13mm and a tensile strength ≥1280MPa and a reduction of area ≥30% is used. A gradually changing drawing die is fabricated following a drawing process route from round to elliptical to Z-shaped. Then, continuous cold drawing is performed on a 1270mm diameter drum drawing machine. During each pass of drawing, the wire's infeed and outfeed directions are kept consistent to obtain Z6.1, Z6.6, and Z6.12 diameter steel wires. For round steel wire, high-carbon wire rod with a diameter of 8–11mm is used. This wire is treated with lead bath quenching and has a tensile strength ≥1310MPa. Multiple passes of continuous cold drawing are then performed to obtain round steel wire with a diameter of 2.95–5.5mm. Step 2, Coating: After the cold-drawn steel wire is subjected to ultrasonic water washing → pickling → water washing → electrolytic alkaline washing → water washing → drying, it enters a pure zinc plating bath to form a thin transition coating on the surface. Then, a flux is impregnated on the surface of the pure zinc coating. Finally, it enters a zinc-aluminum-rare earth alloy plating bath for alloy plating. The coating thickness and aluminum content meet the Class A requirements of GB / T20492-2006 "Zinc-5% Aluminum-Mixed Rare Earth Alloy Coated Steel Wire and Strand". Step 3, core twisting and oiling: Twist a qualified zinc-aluminum rare earth alloy coated round steel wire into a 1×36WS single strand rope (23) on a tubular stranding machine and use it as the core. Then use a series unit to wrap and twist the round strand layer (22). At the same time, heat and melt zinc-rich grease and spray it onto the surface and gaps of the single strand rope (23) and the round strand layer (22). After twisting, wipe the surface. Step 4, sealing layer twisting: Using qualified zinc-aluminum rare earth alloy coated Z-shaped steel wire (21), the outer sealing layer of the round strand layer (22) is twisted layer by layer on a multi-frame composite rope forming machine. During twisting, the small face of the Z-shaped steel wire (21) is used for positioning to form interlocking rings. The tension of the wire is controlled evenly. After twisting, the vertical and horizontal directions are reinforced by roller pressing to ensure tight interlocking. The twisting directions of adjacent layers of the three sealing layers are opposite. Finally, a 73mm diameter sealed steel wire rope (2) is formed. Step 5, lower waterproof cover and flow guide design: The lower waterproof cover (3) is fitted and fixed to prevent rainwater from flowing directly into the anchor cup (5) and sleeve (1) and causing corrosion; at the same time, a 2×φ6mm inclined hole flow guide design is made at 75° on the lower side of the lower waterproof cover (3) to prevent water seepage and water accumulation in the lower waterproof cover (3) and improve the anti-corrosion level of the sling; Step 6, alloy casting: Distribute the steel wires at both ends of the sealing steel wire rope (2) evenly from the outside to the inside and place them in the corresponding anchor cup (5) to ensure that the sealing steel wire rope (2) and the central axis of the anchor cup (5) are coincident. Preheat the inner cavity of the anchor cup (5) to 150°C and cast zinc-copper alloy anchoring material (4) in the anchor cup (5) at a molten state of 450°C~470°C. Finally, let it cool and solidify naturally to make a sealing sling.

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